- Creado: 25-08-21
- Última sesión: 25-08-21
Descripción: Valves 101: Two Types of Ball Valves Small-size valve balls are a type of piping equipment that shuts off or controls the flow in a pipeline by using a hollow sphere and round seats held in a valve body. There are two basic technologies for the design of ball valves, floating ball design and trunnion mounted ball design. The major components of a ball valve include: Valve body – A pressure vessel that contains the components needed to control or shut off the flow through a pipe. It is designed to connect two or more sections of pipe or tubing to each other. Ball – A sphere with a flow path (hole or tunnel) through the center of it and a connection point for a shaft to rotate it. Seats – Round donut-shaped discs that form a seal between the body and ball. Stem – A shaft that connects the internal ball to the outside of the valve to facilitate rotation of the ball. Packing – Flexible seals that fit around the shaft and prevent the media traveling through the valve from escaping externally. Bonnet – The part of the valve body that houses the stem and packing. Operator or Actuator – An external device designed to rotate the stem of the valve. This can be a lever, a gear, a motor-operated gear (electric actuator), or a pneumatic/hydraulic actuator. Floating Ball Design A floating design ball valve sandwiches the hollow ball between two or more cupped seats that form a tight seal between the body and the ball at the inlet and outlet ports of the valve body. The floating valve balls are rotated (usually 90 degrees) by a shaft that protrudes outside of the valve body and is connected to some form of operator. For this reason, most ball valves are referred to as quarter-turn valves. This shaft is not rigidly attached to the ball in order for the ball to pivot on the end of the shaft as it rotates on the axis of the ball. This is usually accomplished with a slot on top of the ball, perpendicular to the ball’s flow path. The cupped portion of the seats cradle the ball prevents it from moving down in the valve body. The valve packing prevents the media from escaping the valve body through the stem opening in the bonnet. The most common type of packing today is chevron v-ring type packing. If you look at the cross section profile of this packing, it resembles the letter “V”. The outer diameter of the packing matches the bore of the bonnet. The inside diameter matches the outer diameter of the stem. Multiple rings of this packing are stacked on top of each other and the stem is inserted through the packing. A packing gland on top of the bonnet pushes down on the top of the “V” and causes the packing to expand and seals agains the stem and bonnet. When the ball is in the closed position, the flow path in the ball is perpendicular to the flow path in the valve body. The solid parts of the ball covers both upstream and downstream cupped seat openings. The pressure in the upstream pipe pushes against the solid part of the ball which moves on its pivot point and is forced tightly against the downstream seat. This shuts off flow. As the operator rotates the ball from the closed position, the ports in the body in relation to the ports in the ball create a variable size orifice which, as it gets larger, will increase the flow through the pipe. When moving from open to close, this orifice gets smaller and decreases flow. Floating ball design valves are the most economical valves, but are limited by the amount of pressure the seats can handle. Trunnion Mounted Ball Design The Trunnion Valve Balls work nearly the same way as the floating ball except the seats are spring loaded against the ball and the ball does not pivot. The ball only rotates on its axis in this design. In the trunnion mounted ball valve, the ball utilizes a second shaft and bearing on the bottom of the ball. This stem or “post” holds the bottom of the valve in place. The top of the ball is not slotted and the upper stem is rigidly attached to the ball. This prevents the ball from moving into the downstream seat. Since the ball does not move into the seats, the seats must move towards the ball. Springs behind the seat push them tightly into the ball in order to make the seal. Trunnion valves are very effective at sealing off very low pressures that would not be strong enough to move a floating ball into the downstream seat. They are also required on large diameter valves and high-pressure valves. The reason for this is the contact area of the seats in a floating ball is relatively small. From physics, we know force = Pressure x Area. The force on the downstream seat in a floating ball is derived from the process pressure in the upstream pipe pushing on the solid area of the ball in the closed position. If the pressure is high or the area is large, the downstream seat will be destroyed. The tradeoff is that trunnion valves are much more expensive than floating ball designs. Both floating ball and trunnion designs are available as multi-port valves by using elaborate flow paths in the ball and additional ports in the body. Are you looking for ball valves for your facility? Our team has years of experience in selecting the perfect valve for any application. Contact us today to discuss your specific valve needs! HOLLOW VS. SOLID BALL VALVE The ball valve is available with many different options, and one of the most important distinctions is in how the ball is made. Manufacturers either join two hollow hemispheres or machine a hole through a solid ball. Machining takes more work, but it produces a valve with better flow characteristics. Here’s why. Ball construction In a solid ball valve, the hole is the same diameter all the way through. That helps the fluid flow smoothly at a constant velocity. Hollow valve balls are, as the name implies, hollow inside. That creates a bigger space for the fluid to fill, which changes its velocity and creates turbulence. Turbulence is almost always undesirable. It creates noise and it’s inefficient. The Cv drops, and it takes more energy to pump fluid through the system. In a few applications, valve weight is an issue. In such cases, the hollow ball may have an appreciable advantage, especially in larger valves. Solid ball, better flow When evaluating ball valves, check the Cv values and be sure to compare identical port formats. In most cases, the solid ball will give a higher Cv than the hollow ball. Advantages of V-Ball Valves Ball valves are designed to be used in a variety of applications and markets, but V opening valve balls offer the added ability to be used as a control valve where necessary. The main differentiator is a contoured V-port in the ball, most commonly available with a 15°, 30°, 45°, 60°, or 90° angle, which produces an equal percentage flow characteristic for better control. V-ball valves are known to offer a variety of advantages in flow control applications, especially when compared to larger and more expensive control valves. Low Pressure Drop The V-port design allows material to flow straight through the valve, minimizing pressure drop across the valve. V-ball valves also have higher flow coefficients (Cv) compared to other control valve types of a similar size; this means that a smaller V-ball valve can be used to achieve the same flow rates as a comparable control valve of a larger size. Bubble Tight Shut-Off V-port ball valves use the “floating ball principle, which will provide a bubble tight shut-off in addition to the modulating flow control. When the valve is closed, upstream pressure pushes the ball against the downstream seat, thus enhancing the seal. These can control or shut off bi-directional flow, which proves to be especially beneficial in gas applications. Comparable control valves often require additional shut-off valves; V-ball valves eliminate the need for these additional valves, saving the user cost and reducing the number of overall components in the system. Precise Flow Control Precision machined V-ball valves are available with 60° and 90° V openings and offer equal percentage flow characteristics. As the ball rotates, desired flow rates can be achieved by positioning the ball anywhere between 0° and 90°. Response time is also increased due to the ability to use smaller actuators with these valves. High Shut-Off Pressure V-ball valves feature a quarter turn (90°) ball rotation, allowing them to operate and shut off at much higher working pressures. Because of this, smaller lower torque actuators can be used, which results in cost savings and higher efficiency in the user’s application. Ball Valves Defined Ball valves use a handle to turn a ball in the valve, with a hole or port through it. The ball is used to allow or prevent flow through the valve depending on its position. If the hole is aligned with the pipe, flow continues through the valve; if the hole is perpendicular to the pipe, flow will stop at the valve. It’s really that simple! Not all ball valves look the same and some have special uses, but they all have the same concept. Did you know? Ball valves are considered ? turn valves because of the quarter turn that is required to close the valve. The Benefits of Ball Valves Easy to see if it is open or closed. When the handle is in line with the pipe you can easily tell that the valve is open; and when the handle is perpendicular to the pipe the valve is closed. This is a great visual indication of whether there is flow through the valve or not. Operation after years of disuse is easy. The durability of ball valves allows them to work and completely shut off flow after years of disuse. This provides extra peace of mind. Quick shut off. The motion that is required to operate a ? turn the valve is quick and minimal compared to gate valves. Water hammer is a possibility if the flow through the valve is strong enough to vibrate the line when it comes to an abrupt stop as the valve is quickly shut off. A more compact and economical valve. Thanks to the design of ball valves they are more compact than gate valves. Gate valves are taller and require more space, as the gate needs a place to go to allow the flow to travel through the valve. By using a rotating ball, ball valves are smaller and require less material. Different Types of Balls There are three different types of balls that can be found in ball valves. For each of these three types, the outside of the ball needs to be smooth and the surface gets ground down to remove any dips or imperfections on the surface. As the material cools, the shape may change, resulting in more or less grinding. The three types are hollow, solid, and cored, so let's take a closer look at each of them. Hollow Ball The hollow ball has a cavity that goes from an open hole in the bottom of the ball to the top where the valve stem is inserted. Hollow balls require less material to construct, making them more economical, but may require more grinding to get the dips out. Solid Ball The solid ball is molded as one solid ball, larger than required, to account for any shrinkage and grinding. Solid balls are usually more expensive to manufacture as they require more raw material and grinding to get them to the perfect round shape. Cored Ball The cored ball is cored through the center, leaving a consistent wall thickness around the whole ball. This ensures that the ball cools more evenly, again decreasing the amount of grinding required once it has fully cooled. These types of balls are becoming more popular due to the cost savings compared to solid balls.
Fecha de Publicación: 26-08-21
Descripción: Oxygen Absorbers: Their Function and Use Oxygen absorbers are little packets of iron powder packaged in a material that keeps the iron in, but allows oxygen and moisture to enter and be absorbed. The iron absorbs the oxygen causing the iron to rust. As it rusts, or oxidizes, it absorbs any oxygen that may be present. Why do I need Oxygen Absorbers? Oxygen and moisture are two factors that destroy the value of dehydrated and freeze-dried foods. Theses elements have a detrimental effect on color, flavor, vitamin content, and fats of stored foods. Oxygen will enhance the growth of insects, bacteria, mold, and yeast in your food, accelerating spoilage. Oxygen absorber help to remove the oxygen in your container, leaving nitrogen. Dry foods are protected against spoilage and bacteria growth in a nitrogen environment. A “nitrogen flush” is often used to force the oxygen out of a product before it is sealed for storage. But even when a nitrogen flush has been done, it's still wise to include an oxygen absorber inside the container to help eliminate any remaining moisture. During the freeze-drying or dehydrating process, much of the moisture causing molding or spoilage is eliminated. An oxygen absorber will help to mitigate any moisture that remains once the food is packaged. Foods with a high moisture or oil content should not be stored in reduced oxygen packaging because it can cause botulism poisoning. Only store foods with in low moisture (10% or less) with oxygen absorbers. Oxygen absorbers actually remove oxygen more effectively than vacuum packaging because they only remove the oxygen rather than all the air. What Type of Containers do I Need? with seamed lids, , PETE plastic bottles with airtight, screw-on lids, and glass canning jars with metal lids and gaskets all do well with oxygen absorbers. Do not use plastic containers that are not identified as PETE or PET under the recycling triangle on the bottom of the container. Metallized cans and bags prevent light, another source of spoilage, from reaching your food with the added help of your oxygen absorbers. Oxygen absorber packets come in different sizes, two of the most common are 500cc and 2000cc. To decide which size is right for you, consider the size of the container you'll store your food in and the amount of empty space between the food particles and between the top of the food and the lid of the container. Some companies that manufacture absorber packets rate them according to their oxygen absorption capacity in milliliters, while others do so by the equivalent air volume (the actual total amount of air between the product pieces). How do I Preserve the Life of my Absorbers? Store unused absorbers in small glass jars that have a lid and ring seal. A one-pint jar will hold 25 absorbers. You can also heat-seal them back into the bag they came in. Or you can store them in plastic freezer bags, but you must use them within the next few months because the plastic will slowly admit oxygen and shorten the lifespan of your absorbers. When using a combo like the Do-it-Yourself Superpail Kit, do not plan to package more food than you can in 20 minutes. Prolonged exposure to air in the room will speed up the demise of your absorbers. Instead, place the number of absorbers you expect to need for one batch of packaging on a tray . Use one absorber per package of food, and work as quickly as possible to preserve the life of the absorbers. When you are ready to do another batch, remove enough absorbers from their bag or jar for that batch. You'll know the lifespan of your oxygen absorber by its color. Some absorber packages turn pink when they're working properly and are still absorbing the oxygen in your can. Some turn purple or blue when they're used up. COMMON DESICCANTS AND THEIR PROPERTIES A desiccant is a substance that promotes drying by absorbing moisture or water vapor from the air. Consumers are probably most familiar with small paper packets of desiccants that are often packed with items so that they will not rust or mold during shipment, especially for imported items that will spend time in the hold of a ship between the time they leave the factory and arrive at the store. In industrial settings, desiccants are used for the same reason in compressed air systems: to dry the air. The changes in pressure when air is compressed will cause water to condense, and this moisture must be removed. To do this, compressed air is passed over desiccant material to dry it out. There are several types of desiccants: Silica Gel Silica occurs in nature as Silica dioxide, SiO2. It is processed into gel-like beads for use as a desiccant dryer. Silica gel was first used in World War I to absorb vapor in gas mask canisters. Pure silica gel is one of the few desiccants that is safe for use around food. Indicating Silica Gel Indicating silica gel is silica gel that is processed with cobalt chloride. The cobalt chloride will change color from blue to pink as the silica gel absorbs moisture. This ‘indicates ’ when the silica gel is becoming saturated. Because cobalt chloride is a heavy metal salt, it cannot be safely used around food. Clay Clay that is high in magnesium aluminum silicate, a naturally occurring mineral, is processed into Montmorillonite clay for use in drying. It works best at room temperature or below. Clay is one of the most inexpensive desiccants, which makes it popular for industrial use Quicklime and Gypsum Quicklime is a common term for Calcium Oxide. It is alkaline and highly caustic, so special care in handling is necessary. Its chief benefit is that it can be used to gradually drop the humidity to a very low state. Gypsum is Calcium Sulfate. Molecular Sieve Molecular Sieve is a synthetic desiccant manufactured from alumino silicates. Like the name sounds, it has many tiny holes or pores the absorb liquid and gas. It is a highly effective desiccant that can absorb water up to 22% of its own weight. Most of these various types of desiccant dehumidifiers can be recharged and recycled by using a heating process to dry them for reuse. Ethylene Absorber Through extensive research, ethylene absorber has been able to provide innovative technologies that extend the freshness and quality of fresh food and flowers. Such thorough research has enabled us to launch our first commercialised product, a discreet but high-tech filter that removes the ripening hormone from around fresh produce.This is helping the global supply chain maximise value from growing, transporting and retailing top-quality produce for consumers, by extending quality, prolonging freshness and enhancing flavour in a secure and sustainable way. It's Fresh! helps to address the key industry challenges of food security, profitability and global food waste. It's Fresh! is a division of Food Freshness Technology Holdings a world class business that has invested over $20min areas such as the research and development of unique technologies and delivery systems, to bring to market a range of ground-breaking products that help leading retail groups and their supply chains to make a positive change to the fresh produce industry and to people around the world. These unique technologies are delivered via state-of-the-art materials science developed in partnership with world leading research & technology organisations. To learn more about our research and what it means for the future of the 'fruit industry', check out our research page here Our filter absorbs the ethylene gas given off normally as fruit ripens. By capturing this gas (before the fruit does) research has shown that your fruit will be kept in peak condition for longer, naturally. Proven across five continents to reduce waste and costs within the supply chain network It's Fresh! can deliver enhanced yields and returns; For Growers and suppliers, by helping them to benefit from consistency and management of maturity, reducing grade-outs and rejections to deliver superior quality and extended product life. For Retailers, by providing extended quality freshness and shelf-life, delivering reduced in-store waste, greater availability on-shelf and increased sales as satisfied consumers return to buy more fruit more often. CO2 absorber has been used in anesthesiology for many years. However, this process is not limited to this field of medicine. Removing carbon dioxide from human environment is used in other areas as well: mining industry, submarines, scuba diving, space travel and many others. The rationale to remove carbon dioxide from confined spaces is that cannot be eliminated otherwise. Anesthesia practitioners are well aware of this component of the circle system, the carbon dioxide absorber. In daily practice the clinician is less concerned with what kind of substance fills the dedicated canister, as this is usually in the care of the maintenance personnel. The appearance of Sevoflurane and Desflurane, with their own chemical characteristics, prompted the clinician to dedicate new attention to these absorbents. The classical substances used for this purpose are different combinations of limes. The practical concern of the anesthesiologist is to notice when the absorbent is consumed and call for its replacement. Still, many other aspects remain: compound A formation with Sevoflurane, carbon monoxide formation with Desflurane and dry absorbent for instance. The latest member of these products in the medical field is the LiOH carbon dioxide absorbent. Although used for many years in the space exploration, its way into the operating room is a rather recent achievement. Special chemical properties and high absorptive capacity make this new type of absorbent an attractive option for modern anesthesia practice.
Fecha de Publicación: 25-08-21
Descripción: How Leak Testing Works Leak testing is a broad term that includes a multitude of technologies. For the purposes of this article, different leak test methods will be referenced but not described in full detail. This article defines the broad term leak test and takes a closer look at the pressure decay leak test method. Furthermore, this article will describe how a pressure decay test works, considerations for the pressure decay method, and how recent technological advancements have impacted manufacturing environments. What is Leak Testing? A fixed head leak tester is a procedure used to determine if an object, product, or system functions within a specified leak limit. A leak occurs when a gas or liquid flows through an object via an imperfection or manufacturing defect such as a hole, crack or weak seal. These imperfections create high- and low-pressure zones within a product, forcing the gas or liquid to flow from the high-pressure area to the low-pressure area. The primary leak test method discussed in this article uses pressurized air to identify leaks. Leak Testing Methods There are many different types of leak test methods, which have different detectable leak rate limits. This article will primarily discuss the pressure decay leak test method. A pressure decay test identifies if a part is leaking or not within a predetermined leak rate limit. The smallest detectable leak rate for the pressure decay method is 10-4 mbar*l/s or 0.0059 SCCM. The benefits of pressure decay leak testing include: Economical Fast (depending on the internal test volume of a part) Easy to set up Only requires compressed clean, dry air Quantitative Nondestructive No pre or post processing required Determining a leak rate is vital to selecting the best leak test method. Typical industries for pressure decay leak test methods include: Automotive Sealed Electronics Medical Devices Packaging Consumer Goods How a pressure decay test works During a pressure decay test, a product is attached to a leak test system and filled with air. Once pressurized, the air source is closed off and the pressure is allowed to settle. During the test any decrease in air pressure over time signifies a leak. Variations of pressure decay methods Pressure Decay – Measures the pressure change of an object under positive pressure Vacuum Decay – Measures the pressure change of an object under negative pressure Occlusion – Checks for a blockage in the gas flow path of an object Burst – A destructive or nondestructive ramping pressure test that measures the point at which the device opens or has a catastrophic event (rupture). Crack – Typically performed on check valves to detect weeping prior to reaching the opening pressure. A downstream sensor monitors for weeping. Chamber – Finds leaks in sealed packaging or devices that do not include an opening for filling. Depending on the functional use of an object or part, any of the above tests may be required. Considerations for leak testing: What is the intended use of the part? What medium is being constrained inside or outside of a part? A medical device manufacturer designing an IV set may try to keep saline inside the IV set. An automotive manufacturer may have designed their manifold to prevent exhaust gases from escaping the exhaust manifold. An acceptable hole or porosity in these parts is contingent upon the application by which a leak limit will be determined. Medium An oil molecule is larger than a water molecule and a water molecule is larger than an air molecule. If an eight micron hole is subjected to 45 psi of pressure, air will create a noticeable leak, whereas water will only create a droplet and oil may not leak at all. What pressure range is a part subjected to during use? What safety factor is required? Finding the appropriate pressure range for an application is vital. If the test pressure is too low, quality may be affected, and faulty parts may pass the leak test and go on to fail during use. Conversely, selecting a pressure range that is too high will extend the time it takes to complete the test and possibly damage the part. Internal Volume The test volume plays a significant role in creating a repeatable and sensitive test. Reducing the overall volume enables shorter test times with greater sensitivity. Parts that cannot have a volume reduction will benefit from pneumatic and sensor assemblies appropriately sized to meet test cycle expectations. Acceptable Leak Rate Everything leaks but what leak rate is acceptable for an application? Leak rates are most often specified by regulatory requirements specific to an industry. Often when testing a new product some trial and error is involved in finding what leak rate is acceptable for the product’s application. Material The material of the part under test affects test time. Compliance influences both the fill and settle steps in a leak test. If a malleable object is subjected to pressure and is not given enough time to settle before a test begins, the part may be expanding or contracting during the leak test, yielding inconsistent results. Design During the design and development of a product it is important to consider the test criteria to ensure a part has been manufactured correctly. Design criteria such as test pressures, access ports, shared walls or vessels, internal test volumes, and leak rate specifications all have an impact on the complexity and time required for a leak test. How the object connects to a leak test system helps to determine what kind of leak test will be run on the object. A fully enclosed object with no port to fill the item, such as a waterproof enclosed electronic device, requires a chamber test which includes a sealing fixture. An object with one port or opening, such as a catheter, can be directly connected to the front port of a leak tester without a fixture. Conveyor has been a staple in the materials handling industry for decades. As the demand for reduced cost, increased throughput and integrated automation grows, so does the need for conveyor systems of all types. Conveyor is available in many styles and is used in countless applications. In this Equipment 101 article, Modern spotlights the basics of some of the most common conveyor types: ? Non-powered skatewheel and roller conveyor ? Powered, or live, belt and roller conveyor used in handling packages and other small products ? Powered chain and roller conveyor used in handling pallet loads of goods NON-POWERED CONVEYOR Non-powered conveyor, the simplest form of conveyor, uses the natural forces of inertia and/or gravity to keep products moving. Portable sections of non-powered conveyor are often used for loading packages onto the back of an over-the-road truck. Non-powered conveyor can also serve as takeaway conveyor for cartons coming out of an automated sorter, and it’s often used in workstations and pick modules where employees complete their tasks and then push their work along to the next zone or station. The two most common types of non-powered conveyor are skatewheel and roller. Skatewheel conveyor Only a little energy is needed to turn the small wheels of a skatewheel conveyor, and that makes skatewheel good at maintaining the speed of a product. Because each wheel turns independently, skatewheel conveyor is also a good choice for the curved sections of a conveyor line. Roller conveyor Non-powered roller conveyor is commonly used for workstations and pick modules because it provides a better working surface and is often less expensive than skatewheel conveyor. It’s also good at slowing the inertia of products coming out of a high-speed sorter. Whether it’s skatewheel or roller, non-powered conveyor that relies on gravity to move product is still used a lot in the market, says Russ Devilbiss, sales manager for Carter Controls and chair of the Material Handling Industry of America’s (MHIA) Conveyor & Sortation Systems industry group. The limitation with non-powered conveyor, however, is control. “With gravity, you can’t control the force, and you always want to be in control of your product,” says Devilbiss. POWERED PACKAGE-HANDLING CONVEYOR When it comes to moving packages and other relatively small items, two styles of conveyor dominate the market: belt conveyor and powered roller conveyor. Traditionally, belt conveyor has been used for transporting products, while roller conveyor has been used for accumulating products. Another factor taken into consideration when choosing between belt or roller conveyor depends on the size of the product being moved. Belt conveyor In traditional belt conveyor, an AC motor drives a pulley that then turns a long, looped belt. Underneath the belt sits either a bed of non-powered rollers or a sheet of metal known as a slider bed. The belt can be made of a variety of materials with a variety of surfaces, depending on the items it is intended to convey. For example, according to Ken Ruehrdanz, warehousing and distribution market manager for Dematic, a belt surface can be smooth where you need to slide an item off a conveyor easily or ribbed to give it more gripping power, like on inclines and declines. And, belted incline or decline conveyor can be used to move product from one level of a facility to another. Spiral conveyor is another way to move product from one level to another. If floor space is limited, spiral conveyors are often a good solution. Regardless, traditional belt conveyor is a simple, time-tested technology. It’s less expensive than powered buffer conveyor, it provides a more stable surface, and it can convey a variety of products. Poly bags, envelopes and electronics are examples of products handled easily by belt conveyor that are often too small or too light to be conveyed directly on rollers. Roller conveyor Despite the advantages of belt conveyor, many of today’s distribution centers are filled with roller conveyor because it allows accumulation of products. Accumulation is a way to make the conveyor store product for a determined amount of time then released into an automated sorter or palletizer, for example. Zero pressure accumulation means products on the conveyor do not touch each other. Minimum pressure accumulation, however, allows the products to make contact, but with a determined degree of impact that will not cause damage. Powered roller conveyor falls into a number of different categories, depending on the way the rollers are driven. Three common categories are line-shaft, belt-driven and motorized roller. Line-shaft conveyor: In a section of line-shaft conveyor, a long metal shaft runs below the bed of rollers. Rubber o-rings connect the rollers to the shaft so that when the motor turns the shaft, the shaft turns the rollers. Line-shaft conveyor is the least expensive type of roller conveyor. It has been in the market for a long time, but it has limitations. Even though line-shaft flexible conveyor costs less, explains Don Erickson, director engineering for Automotion, it is parts-intensive, which leads to high maintenance requirements.
Fecha de Publicación: 25-08-21
Descripción: Monitor Display Panel BOE monitor display panels cover a full range of products from 18.5 inches to 43 inches, with high image quality, wide viewing angles, high refresh rate, low power consumption, a borderless design, and other features. Resolution of up to 8K can be achieved. The products are widely used in entertainment, office, professional design, and other fields. BOE LCD panel offers super sharp pictures and great color. But do the pros outweigh the cons when it comes to LCD TV displays? Before deciding on a thumbs up or thumbs down, you should understand how an LCD display works. Liquid crystal display (LCD), electronic display device that operates by applying a varying electric voltage to a layer of liquid crystal, thereby inducing changes in its optical properties. LCDs are commonly used for portable electronic games, as viewfinders for digital cameras and camcorders, in video projection systems, for electronic billboards, as monitors for computers, and in flat-panel televisions. Electro-optical effects in liquid crystals Liquid crystals are materials with a structure that is intermediate between that of liquids and crystalline solids. As in liquids, the molecules of a liquid crystal can flow past one another. As in solid crystals, however, they arrange themselves in recognizably ordered patterns. In common with solid crystals, liquid crystals can exhibit polymorphism; i.e., they can take on different structural patterns, each with unique properties. LCDs utilize either nematic or smectic liquid crystals. The molecules of nematic liquid crystals align themselves with their axes in parallel, as shown in the figure. Smectic liquid crystals, on the other hand, arrange themselves in layered sheets; within different smectic phases, as shown in the figure, the molecules may take on different alignments relative to the plane of the sheets. (For further details on the physics of liquid crystalline matter, see the article liquid crystal.) The optical properties of liquid crystals depend on the direction light travels through a layer of the material. An electric field (induced by a small electric voltage) can change the orientation of molecules in a layer of liquid crystal and thus affect its optical properties. Such a process is termed an electro-optical effect, and it forms the basis for LCDs. For nematic LCDs, the change in optical properties results from orienting the molecular axes either along or perpendicular to the applied electric field, the preferred direction being determined by the details of the molecule’s chemical structure. Liquid crystal materials that align either parallel or perpendicular to an applied field can be selected to suit particular applications. The small electric voltages necessary to orient liquid crystal molecules have been a key feature of the commercial success of LCDs; other display technologies have rarely matched their low power consumption. Mechanics of an LCD display The LCD consists of a large number of pixels, or picture elements, consisting of liquid crystal molecules held between two sets of transparent electrodes. The liquid crystals react in predictable ways when the electrical charge running between those electrodes is changed — meaning they twist and move in ways that let different amounts (and colors) of light through the crystals. The LCD has a control system that translates your video signals into the proper charges for each electrode. A light source shines through the TV LCD panel and creates your picture. When compared to the other type of flat-panel display (plasma), LCDs tend to be found on the smaller size of the spectrum. You’ll rarely find a plasma TV smaller than 42 inches, but you can find LCDs at sizes as small as 13 inches. Benefits of LCD displays LCD displays have some strong points when it comes to playing video: · Extremely high resolutions: LCDs can easily reach HDTV resolutions (in fact, most LCD displays do). You can find a 1080p-capable LCD display in all but the smallest sizes — while many plasma displays are still 720p. · Excellent color: LCDs offer exceptional reproduction of colors, with the potential for beautifully re-created colors across the spectrum. This differs from other flat-panel displays (such as plasma systems), which often tend to display certain colors inaccurately. · Great picture: The newest and most expensive LCDs use an LED (light emitting diode) instead of a traditional bulb for their light source. These LEDs produce a higher-quality picture because the LED itself emits a more natural (closer to daylight) light than a bulb (which tends to be yellowish, not true white). · Energy efficiency: LCD HDTVs are perhaps the greenest HDTVs. Compared to plasmas, LCD HDTVs use less electricity to run. You can probably expect to use about 30 percent less power for an LCD than for a similar-sized plasma. · PC monitor-capable: Most LCD television displays can also do double-duty as a PC monitor, plugging directly into any PC with a standard PC video cable. · No burn-in: If you play a lot of video games, watch the stock ticker on MSNBC, or do other things with your display that involve a lot of static content (images that don’t change or move around) on a CRT display, you can end up with those images permanently burned into the phosphors on your screen. Because LCDs use a separate backlight instead of creating their own light with phosphors, they are immune to this problem (plasmas are not, by the way). · Inherently progressive: Unlike direct-view systems, LCDs don’t display their picture using electron guns scanning lines across a screen. Instead, LCDs use millions of tiny transistors that can be individually controlled by the “brains” inside the display. This means that LCDs can easily handle progressive-scan sources, such as progressive-scan DVD and HDTV. We learned in school that there are three common states of matter: solid, liquid or gaseous. Solids act the way they do because their molecules always maintain their orientation and stay in the same position with respect to one another. The molecules in liquids are just the opposite: They can change their orientation and move anywhere in the liquid. But there are some substances that can exist in an odd state that is sort of like a liquid and sort of like a solid. When they are in this state, their molecules tend to maintain their orientation, like the molecules in a solid, but also move around to different positions, like the molecules in a liquid. This means that liquid crystals are neither a solid nor a liquid. That's how they ended up with their seemingly contradictory name. So, do liquid crystals act like solids or liquids or something else? It turns out that liquid crystals are closer to a liquid state than a solid. It takes a fair amount of heat to change a suitable substance from a solid into a liquid crystal, and it only takes a little more heat to turn that same liquid crystal into a real liquid. This explains why liquid crystals are very sensitive to temperature and why they are used to make thermometers and mood rings. It also explains why a laptop computer display may act funny in cold weather or during a hot day at the beach. Drawbacks of LCD displays Consider the following problem areas before you buy an LCD system as your primary display in a home theater: Slightly more expensive for their size: Inch for viewing inch, LCDs tend to be a bit more expensive than plasma flat-panels. Poor reproduction of blacks: Compared with direct-view tube displays, LCDs do a poor job of reproducing black images. Darker screen images never show up as true black, but rather as various shades of gray, and actions happening in these darker areas are difficult to discern. Limited viewing angle: Although they are getting better due to some intensive efforts by manufacturers, LCDs typically have a poor viewing angle. If you are not sitting almost directly in front of the screen, you don’t get a good picture. Limited brightness: Because LCDs use a backlight shining through the liquid crystal, most of the light is absorbed. As a result, the LCD displays have lower contrast and are harder to view in a brightly lit room (the picture appears washed out), compared with plasma TVs. LCD TVs with LED backlights do better in this regard. SEOUL (Reuters) - Samsung Electronics’ display unit said on Tuesday it will extend production of liquid crystal display (LCD) panels for TVs and monitors, as more people sought home entertainment during the coronavirus pandemic. Samsung Display’s decision to extend LCD production in South Korea for an unspecified period of time overrides its announcement in March that it would end all production by the end of the year to focus on more advanced technology. Samsung Display said the length of the extension would depend on profitability considerations and market conditions. It had said in late October that it was considering a “short-term” extension. Local media outlet IT Chosun reported earlier on Tuesday that production would be extended by a year at the request of Samsung Electronics’ set manufacturing division, citing unnamed tech industry sources. A spokeswoman for Samsung Display declined to comment on the IT Chosun report. The stay-at-home trend sparked by the coronavirus pandemic led to a 30% quarter-on-quarter spike in global panel demand in the third quarter of the year amid more TV and notebook demand, according to technology research firm TrendForce. However, the firm added that the influx of more production capacities from Chinese LCD makers was likely to worsen a supply glut next year. SAMSUNG LCD panel is in both South Korea and China, but it earlier this year sold a majority stake in its Suzhou LCD production unit to TCL Technology Group Corp’s China Star Optoelectronics Technology unit. LG Display has changed its CEO in its bid to reorganise its businesses amid declining LCD profits and lackluster OLED display panel sales. The company, which is the display panel-making affiliate of LG Group, approved the motion to name LG Chem President Jeong Ho-young as its new CEO in an emergency board meeting on Monday, LG Display said in a statement. Current CEO and Vice Chairman Han Sang-beom had expressed his desire to resign in order to take responsibility for the company's recent profits decline, LG said. Jeong is expected to officially take over the CEO position in the shareholders meeting in March next year but will become the acting CEO on Tuesday. The move is highly unusual as it normally makes leadership changes during its group-wide year-end reshuffle. LG Display had once been a profit darling for the group, but its fortunes have drastically changed since 2018 from intensifying competition in both its traditional LCD business as well as the newer OLED one. It is losing out to Chinese rival BOE in the LCD market, while its large-sized OLED display panel business has suffered from slower than expected sales from increased competition by Samsung's QLED counterpart. LG Electronics' TV business saw its operating profit halved in the second quarter from slower than expected OLED TV sales. In regards to the small-sized LCD and OLED display panels used in smartphones and tablets, Chinese clients are increasingly relying on local suppliers over LG. At the same time, the South Korean tech giant cannot match Samsung's volume and yield rate when it comes to providing display panels for the more profitable mobile OLEDs. LG Display posted operating losses of 369 billion won in the second quarter of 2019 with revenues of 5.35 trillion won, which was much lower than analysts' expectations. But the company has increased the production capacity of its OLED factories in China and South Korea, with the goal of moving 10 million large-sized panels by 2022 to decrease unit cost and increase sales. LG Display has also commenced the restructuring of its LCD business, halting some of its factory lines and lowering production output, and will likely now make even tougher measures under new leadership. RELATED COVERAGE LG's Q2 profit drops due to low OLED and mobile sales LG's second quarter profit saw a 15.4% decline from lower TV profits and sales and losses from mobile, but overall sales increased 4.1% thanks to record sales from its home appliances business. LG's OLED TV strategy needs to change or face mobile's plight LG's second quarter profit has been hit hard by declines in OLED TV sales and rival Samsung's QLED onslaught. It's time for LG LCD panel to drop its over-confidence and pursue a more aggressive pricing model and better warranties for its OLED TVs. Fear and Trembling: LG Display faces the axe for OLED burn-in and market squeeze After seven years of ignoring the warning signs, LG Display's OLED TV panel business is facing a reckoning by LG Group's leadership and the market as rival Samsung jumps to MicroLED and QD-OLED panels. LG to unveil V60 ThinQ smartphone at IFA 2019 LG has sent out an invitation for the unveiling of its yet unnamed next flagship smartphone to take place at IFA on September 6 that hints at strong gaming feature and dual-screen support. Samsung, Huawei, LG, and Sony phones vulnerable to rogue 'provisioning' messages Fake phone provisioning messages can allow hackers to hijack email or web traffic from legitimate devices. Nearly half of all Android smartphones impacted.
Fecha de Publicación: 25-08-21
Descripción: Taking an Inside Look at TDMoIP: A Tutorial Service providers are presently seeking to increase their profits through low cost deployment of voice and leased line services over more efficient Ethernet and IP infrastructures. At the same time enterprises are looking for ways to take advantage of the promise of convergence by integrating their voice and data networks while preserving their investment in traditional PBX and TDM equipment. The voice-over-IP (VoIP) approach is maturing, but its deployment requires a certain level of investment in new network infrastructure and/or customer premises equipment (CPE). TDM-over-IP (TDMoIP) is a technology that enables voice and leased-line services such as video and data to be offered inexpensively over service provider IP networks while retaining the reliability and quality of the public switched telephone network (PSTN). In this article, we'll discuss the technical challenges inherent in transporting TDM circuits over IP networks, how TDMoIP technology meets those challenges, and the standards shaping TDMoIP and related technologies. Challenges of Transporting TDM Conventional TDM networks are highly deterministic. A source device transmits one or more octets to a destination device via a dedicated-bandwidth channel every 125 μs. The circuit delay through a TDM network is predictably low and constant throughout the life of a connection. Timing is delivered along with the data, and the permitted variability (jitter and wander) of TDM clocks is tightly defined. In addition, the infrastructure supports a rich set of user features via a vast set of signaling protocols. Packet-switched networks (PSNs), such as IP/multi-protocol label switching (MPLS) systems, are more efficient than TDM networks due to bandwidth sharing. However, this sharing leads to PSNs being inherently non-deterministic. Packets entering and transiting the network must compete for bandwidth and switch/router ports, leading to packet delay variation (PDV) and lost packets. A source device may inject packets into the network at regular intervals, but the network offers no guarantee that these packets will arrive at the destination edge device spaced at the same intervals, in the same order, or even that they will arrive at all. In addition, IP networks were designed for transport of arbitrary data. Thus, TDM-related signaling is not supported. There are two main ways that designers are trying to integrate TDM services into IP-based networks. On one hand, designers can completely replace the TDM network and end-user equipment with a new infrastructure that provides innovative mechanisms for voice transport and signaling. The other approach leaves the end-user equipment and protocols intact, tunneling TDM data through the packet network. In the end, this second approach could provide an easier and most cost-effective migration path for carriers and equipment vendors. With that in mind, let's dive into how TDMoIP works. Diving into TDMoIP TDMoIP emulates T1, E1, T3, E3, and N*64K links by adapting and encapsulating the TDM traffic at the network ingress. Adaptation denotes mechanisms that modify the payload to enable its proper restoration at the PSN egress. By using proper adaptation, the TDM signaling and timing can be recovered, and a certain amount of packet loss can be accommodated. Encapsulation signifies placing the adapted payload into packets of the format required by the underlying PSN technology. TDMoIP encapsulations are presently defined for user datagram protocol (UDP)/IP, MPLS, and Layer 2 tunneling protocol (L2TP)/IP networks, and even pure Ethernet can be utilized with minimal adjustments. Let's take a closer look at adaptation and encapsulation. How Adaptation Works TDMoIP can utilize several different adaptation techniques, depending on the TDM traffic characteristics. Whenever possible, TDMoIP draws on proven adaptation mechanisms originally developed for ATM. A side benefit of this choice of payload types is simplified interworking with circuit emulation services carried over ATM networks. For statically allocated, constant bit-rate (CBR) TDM links, TDMoIP employs ATM adaptation layer 1 (AAL1). This mechanism, defined in ITU-T standard I.363.1 and ATM Forum specification atm-vtoa-0078, was developed for carrying CBR services over ATM. AAL1 operates by segmenting the continuous stream of TDM data into small 48-byte cells and inserting sequencing, timing, error recovery, and synchronization information into them. For example, if the original TDM stream consisted of a DS1 with channel associated signaling (CAS), the AAL1 adaptation inserts a pointer to the beginning of the next superframe. Thus, even if cells are lost, the pointer will enable recovery from the next superframe. TDMoIP allows concatenation of any number of AAL1 cells into a packet (note that these are AAL1 cells and not ATM cells, i.e. they do not include the five-byte “cell tax”). By allowing multiple cells per packet, TDMoIP facilitates flexible tradeoffs of buffering delay (which decreases with fewer cells per packet) for bandwidth efficiency (which increases with more cells per packet, due to the per packet overhead). For dynamically allocated TDM links, whether the information rate varies due to activation of time slots or due to voice activity detection, TDMoIP employs ATM adaptation layer 2 (AAL2). This mechanism, defined in ITU-T standard I.366.2, was developed for carrying variable bit rate (VBR) services over ATM. AAL2 operates by buffering each TDM time slot into short minicells, inserting the time slot identifier and length indication, sequencing, and then sending this minicell only if it carries valid information. TDMoIP concatenates the minicells from all active time slots into a single packet. For time slots carrying high-level data link control (HDLC) data, such as data for common channel signaling (CCS), a special adaptation is provided that spots areas of non-idle data, which can then be directly encapsulated. Encapsulating TDM Data In TDMoIP packets, payload information is immediately preceded by a control word. This 32-bit control word, shown in Figure 1 , contains the packet sequence number (needed to detect packet re-ordering and packet loss), the payload type, payload length, and alarm indications. PCM (1) See phase change memory. (2) See also PMC ( programmable metallization cell). (3) (Plug Compatible Manufacturer) An organization that makes a computer or electronic device that is compatible with an existing machine. (4) (Pulse Code Modulation) The primary way analog audio signals are converted into digital form by taking samples of the waveforms from 8 to 192 thousand times per second (8 to 192 kHz) and recording each sample as a digital number from 8 to 24 bits long (see sampling). PCM data are pure digital audio samples, and they are the underlying data in several music and surround sound formats (see WAV, FLAC, AIFF and surround sound). Sound Cards Support PCM For output, a sound card's audio-out port provides an analog signal to the speakers. Compressed formats such as MP3 and AAC are first converted to PCM, and the PCM data are then converted to analog (see D/A converter). Sound cards may also output PCM and other digital signals such as Dolby Digital (see S/PDIF). For input, an analog microphone is plugged into the audio-in port, and the sound card converts the analog signals to PCM. PCM Ports on A/V Equipment When ports on set-top boxes and Blu-ray/DVD players are labeled PCM or linear PCM (LPCM), they refer to uncompressed audio channels rather than encoded formats such as Dolby Digital, TrueHD, DTS and DTS-HD. PCM can be mono, stereo or have multiple channels for surround sound. See Bitstream mode and linear PCM. It Started With the Telcos PCM was introduced in the U.S. in the early 1960s when the telephone companies began converting voice to digital for transport over intercity trunks. See mu-Law. Strong Third-Quarter Results DXC posted earnings of 84 cents a share as revenue fell 14.5% year-on-year to $4.29 billion. Both figures beat consensus estimates. Investors who bought the stock after the report did well so far. The stock is up by around 30% in the quarter. Still, the stock is undervalued, trading at a forward price-to-earnings ratio of 9.79 times. DXC attributed its stronger adjusted EBIT margin to cost optimization efforts. Book-to-bill of 1.13 times could rise from here. The "new DXC" is gaining momentum and brand recognition: Source: DXC Q3 Earnings Presentation Oftentimes, companies in a turnaround spend too much effort on cost-cutting instead of service quality. DXC focused on its customers in the quarter. This led to a stabilization in revenues, earning DXC more work from its existing customer base. Outlook DXC will deliver around ~$550 million in cost savings for the fiscal year. In the current period (Q4), expect margins to expand. EBIT margin of 7% posted last quarter should rise from here. Chief Financial Officer Ken Sharp pointed to the new management team led by its Chief Executive Officer, Mike Salvino, in leading DXC's transformation. The enterprise technology stack performance is at the core of DXC's turnaround: Source: DXC Q3 Earnings Presentation Quarterly sequential growth will reverse from negative to positive going into Q3/FY2021. DXC's customer relationship building is paying off. Instead of losing customers and watching businesses shrink, the opposite is now happening. For example, DXC's work is from 55% new work and 45% from renewals. And since the renewals are sole-sourced, profit margins improve. Opportunity DXC's growth will come primarily from expanding work from existing customers. Around 20% of the customer base needs to move to the cloud over the next two years. Of the 80% remaining, 60% want to see their technology stock modernized. E1 protection switch allows the user to connect a single E1 line from the telephone company to an "active", as well as to a "standby" E1 terminal, such as data server / router etc. at the customer premises. In the event of the failure of the data server(s) / equipment connected to the "A / active" ports, the T1 Protection (Fail-Over) Switch shall automatically switch and connect the T1 line(s) from the telephone company to the data server(s) / equipment connected to "B / standby" ports. This ensures minimum downtime -that would have otherwise occurred due to equipment failure. Enhances the efficiency of that network. Features and Highlights Allows the user to connect an E1 line from the Telephone Company and to switch it automatically between an "active" and a "standby" E1 terminal at the customer premises. The user programmable switching criterion may be Loss Of E1 Signal, AIS and Loss Of E1 Frame. Can accommodate upto four E1 lines - may be used switch between "active" and "standby" E1 terminals connected to upto four (or fewer) E1 lines. Independent switching for each of the four E1 lines. User programmable switching criterion - independent for each E1 line. Built-in real-time clock / real-time logging maintains a history of all events. Remotely accessible over a TCP-IP networks. Allows the user to access and carry out maintenance, or / and switch the E1 line(s) between the "active" and "standby" E1 terminals, remotely, if required. Allows the users to install and maintain active/standby/duplicate customer premises data networks/data servers, without bearing the recurring $$ expense of leasing additional expensive E1 lines from the telephone company. Automatically switches the E1 line from the Telephone Company between the "active" and "standby" E1 equipment at the customer premises, according to the customer-programmed criterion. Improves equipment and data security. Allows the user to co-locate the "backup / standby" equipment in a different room/building and prevent any data loss arising out of conditions of natural calamity such as fire, flooding etc. Increases the reliability of the customer's data/IT networks without having to bear the recurring and additional cost of leasing additional E1 lines from the telephone company. The equipment may be used to create secondary/backup systems at the customer premises to provide virtually uninterrupted service.
Fecha de Publicación: 25-08-21
Descripción: How to Choose a Backpack Planning to buy a new backpack for backpacking? There are three main areas where you’ll need to make choices. Backpack capacity: The size of the pack you’ll need is tied to the length of your trip and how much weight and bulk you want to carry. Backpack features: These are the refinements that affect how the pack works for you. Backpack fit: Torso length—not your height—matters most. Frame Type Internal-frame backpacks: The majority of packs sold at REI today are body-hugging, internal-frame packs where the structure is hidden inside the back panel. They are designed to keep a hiker stable on uneven, off-kilter terrain and may incorporate a variety of load-support technologies that all function to transfer the load to the wearer’s hips. External-frame backpacks: With an external-frame pack, you can see the structure that supports the load: aluminum (usually) hardware on the outside. Because the frame extends beyond the packbag, a backpack like this may be an appropriate choice if you’re carrying a heavy, irregular load (like an oversize tent or inflatable kayak). External-frame packs also offer good ventilation and lots of gear organization options. Frameless backpacks: Ultralight devotees who like to hike fast and light might choose a frameless pack or a climbing pack where the frame is removable for weight savings. But packs without a frame are much more uncomfortable under heavy loads. Ventilation Some packs feature a suspended mesh back panel to combat the sweaty-back syndrome you tend to get with internal-frame packs that ride against your body. Also called a “tension- mesh suspension,” this is a trampoline-like design where the frame-supported packbag rides a few inches away from your back, which instead rests against the highly breathable mesh. Other packs will have ventilation channels (sometimes called “chimneys”) in the back panel to solve the same issue. Why the Shoulder Bag Is Perfect for Post-Pandemic Life The shoulder bag is back. As we reemerge —whether that entails a return to office life, resuming dinner dates with old friends, or planning travels for the summer—there’s an appetite for the best slouchy handbags that are soft yet comfortable to carry. Recently during the resort 2022 collections, Louis Vuitton made a case for the silhouette, as did Khaite and Balmain, which showcased their own iterations on the catwalk: Louis Vuitton presented its signature monogrammed versions, Khaite displayed its classic minimalist take, and over at Balmain, slouchy bags were oversized and front and center. And just last week Altuzarra released its new Duo bag collection, which features its own unstructured shoulder bag. Altuzarra’s version, however, takes it a step further by offering it in a reversible option—why choose just one color when you can have two?This accessories trend seems to wink at the comfort we’ve all been seeking as of late. We need practicality in our handbags, but that doesn’t mean they can’t be cushy and soft. Just as our wardrobes are shifting from cozy pajamas to double-duty dresses and our winter slippers to summer shoes, we’re all looking to ease back rather than rush. Ahead, shop 24 of the best slouchy handbags for post-pandemic life, perfect for all occasions—work, play, travel, and beyond. What is a hobo bag? While hobo bag is characterized by its crescent shape, slouchy posture and a long strap designed to be worn over the shoulder. This type of bag is typically large-size and are made from soft, flexible material that tends to slump or slouch when it is set down. This bag is called hobo bag since it looks the same shape with the bindle on a stick that hobos are portrayed as carrying over their shoulder in cartoons and drawings. But if you are getting bored with your regular totes, satchels and other purses, a Hobo bag can be an exciting addition to your collection. Legend has it that a late fashionista took note from the cartoon characters, the hobos, and tied her belongings in a stylish handkerchief, giving birth the hobo bag. WHY IS IT CALLED A BUCKET BAG? Wondering why is it called a bucket bag? Simple! The bag literally resembles a bucket with its roughly cylindrical shape, deep interior and tall sturdy sides. Typically, the bucket bag’s wide brim is closed by a convenient drawstring that makes it easy to use. WHAT IS A BUCKET BAG? The bucket bag might look as striking as any totally modern and fresh style, but actually, it’s been around for quite a while. Major names in fashion have been playing around with versions of the bucket bag since the 1940s. One of the first bucket bags to popularize the style, from Hermès, took the name quite literally. They removed the bag’s typical drawstring and used stiff material to design a look essentially indistinguishable from a bucket tooled out of leather. With contemporary brands always looking to re-image dazzling silhouettes, the bucket bag has undergone many transformations. It came back onto the radar of fashionistas in a big way when Mansur Gavriel, a New York City brand founded in 2012, introduced their own take on the bucket bag. Their take on the bag was refined, but still glittering with personality—a perfect companion to anyone who dresses with intention. HOW TO WEAR A BUCKET BAG? This quirky but somehow still oh-so elegant bag has quickly made its name as a cult favorite. Since the fashion world fell back in love with bucket bags, designers have been putting their own twist on the look, softening the shape to create a more elegant look or applying minimalism to create a more stripped-down statement piece. There is really no wrong way to wear a bucket bag. You have to love its versatility. Because it is the bag’s shape, not material or print that defines what is a bucket bag, there is endless room for brands to bring their own take to the design. Some bucket bags, like Hozen’s mini bucket bag come with two straps so that the silhouette can be adjusted to different lengths to make it a perfect partner for a variety of styles. Whether you want to wear it as a chic shoulder bag, or as a longer across the body bag, the bucket shape can fill out any outfit perfectly. Plus, the utility of the design has been modernized with super user-friendly features like drawstrings and weather- proof materials. Bucket bags are a great choice for a weekend get-away because their functional size can easily fit everything you need in the interior’s ample storage space. The wide and round top also makes it a great beach-side companion because it’s easy to access your phone or lipstick without having to dig around and risk dragging in dreaded sand. ARE BUCKET BAGS IN STYLE? Even though the design-new PU bucket bag has a rather minimal shape, it can be endlessly customized to suit any style. From bright and bold patterns to vegan eco-friendly leathers, to canvas and woven raffias, there ’s a bucket bag out there for every look. The bucket bag is the perfect solution for girls who prefer bold individual looks but cannot afford the high price tags of adventurous bags that might quickly go out of style. The timeless quality is essential to what is a bucket bag. Because the bucket bag can so easily be re-imagined by fashion brands, it’s an amazing opportunity for eco-conscious designers to introduce looks that are just as ethical as they are cute. At Hozen, their delightful stripe bucket bags are made of pi?atex, a leather look-a-like that’s made from recycled pineapple crop. As times change, innovative future- thinking designers will keep bucket bags in style. ARE BUCKET BAGS MORE OF A SPRING OR A WINTER ACCESSORY? The minimal look can be dressed down or dressed up—and shines in every season. In dark winter colors or light flirty spring patterns, this classic look seems to radiate style. Something to love about bucket bags is that most have minimal logos and do without signature patterns that would detract from the individuality of the person who is wearing it. Just another reason the bucket bag is oh so desirable. So rain or shine, snow or sun, these sleek, utilitarian bags won’t be going out of style anytime soon. They may have been a hit on spring runways last year, but their timeless shape can be worn effortlessly even in the dead of winter. CONVINCED YET Bucket bags aren’t exactly new, despite what trend-setters might have you think. They are one of those classic shapes that will always appeal to lovers of beauty. So, when the twenty-first century fell back in love with the bucket bag, we fell hard. These days, it’s almost impossible to walk into a top fashion brand’s store without seeing one. The classic drawstring PU bucket bag is undeniably a solid choice investment for the new decade, as one of spring’s most coveted trends. Whether you like to keep things classic, experiment with bold prints and patterns, or if you are the kind of person who goes for an elegant formal look, then our vegan leather bucket bags are an excellent choice. From high couture to lifestyle wear: the bucket bag has a place in every closet! Curious about vegan leather? Then head this way to learn more about vegan leather and the benefits.
Fecha de Publicación: 25-08-21
Descripción: Indoor And Outdoor LED Display(s): How Are They Different? LED displays are versatile communication tools. Businesses speak to their clients via these amazing LED billboards and screens. These displays also serve educational and awareness-building objectives. The outdoor screen displays are often used as highway billboards, in stadiums and during outdoor celebrations, while indoor LED screens are widely used inside places of worship, offices, conference halls, restaurants, malls and retail outlets. Other applications of LED displays are in retail, transportation, sports arenas, corporate campuses, institutions of higher education, at gaming hubs and casinos. Indoor LED display screens also provide seamless displays that are ideal for ambient lighting and shorter viewing distances. LED video walls make the indoor environment more interesting by delivering a spectacular viewing experience—in retail stores, corporate lobbies, etc. Besides typical indoor and outdoor LED display screens, there are also semi-outdoor screens. These are seen in open halls, under eaves, sometimes beneath sun roofs or even under an outdoor canopy. However, despite giving the same ultra-high brightness as outdoor LED displays, these semi-outdoor screens are not resistant to adverse weather conditions. Differences between indoor and outdoor LEDs Outdoor LED screens are mostly used at venues where a mega show is on—for brand advertisements, for instance, as they can offer full colour and very high brightness. Indoor LED screens, on the other hand, cannot address the needs of mega outdoor display projects but are ideal for indoor applications. They offer better spectrophotometric colour. Besides this, they also provide high colour saturation. The factors that differentiate outdoor and indoor LED displays are explored in this article. Brightness This is undoubtedly one of the striking differences between indoor and outdoor LED display screens. Bright sunlight can make it difficult to read dull or less bright LED signs. Thus, to provide ultra-high brightness, outdoor LED display screens are power-packed with many bright LEDs in one pixel. Since indoor signs are not viewed under the harsh glare of the sun, they need to be less bright, by default. Outdoor displays offer several times more brightness than indoor LED screens. Brightness is measured by units called nits or candelas per square metre. The higher the luminosity level, the higher the level of brightness. Resilience to external weather conditions Outdoor LED display screens should be highly leak-proof, waterproof, dust-proof, readable in sunlight, anti-lightning and resistant to high temperatures. Indoor LED display screens do not need to offer the same resistance to the outside environment and hence do not come with such features. The outdoor LED screens normally have IP65 water-proof levels while indoor screens have IP20 waterproof levels. Display resolution Outdoor LED screen displays will be typically viewed from further distances as compared to their indoor counterparts, thus they have a lower resolution. Since the distance between the viewer and an indoor LED screen is shorter, typically, the resolution for indoor LED displays needs to be high. The greater the resolution the better the picture quality. The pixel pitch, which describes the density of the pixels on an LED display, is another differentiating factor between indoor and outdoor display screens. Outdoor displays have a larger pixel pitch and a lower resolution, whereas indoor displays that need a high resolution for close viewing have a smaller pixel pitch. Points to remember while choosing LED moving displays Indoor LED screen displays can be designed in several ways, depending upon the configuration and architectural needs. This is because they don’t require a cabinet for installation. On the other hand, outdoor LED signs cannot be assembled panel by panel on the site. The entire installation is based on the design (as a sign or billboard) or is placed on a building. The type of LED display chosen should depend on whether it will be positioned indoors or outdoors. Then factor in the size of the placement area or installation site, check if there is a remote control requirement via a PC, and find out the minimum or least viewing distance. The default design of indoor LED display screens is for easy and rapid integration with several input resources and third-party players. However, outdoor LED screen displays need a rugged regulator or controller for playback purposes. They are normally regulated via a copyrighted software suite, which also provides remote access along with sign diagnostics. Screens with higher brightness are costly and consume more electrical power. Hence, it is important to choose a screen with the right brightness for your needs, so that you don’t pay more for something that is not necessary. Non-weatherproof small pitch LED screen uses LEDs with lower light output, but water-resistant outdoor LED screens need to use brighter LEDs. Growth in the outdoor LED display market The outdoor LED display market is expected to boom by 2021. All outdoor LED displays offer the primary features of energy efficiency and durability. Governments across the globe, like in India, China, Malaysia and the GCC (Gulf Cooperation Council) countries, are encouraging energy conservation measures. LED displays to reduce power consumption considerably. These countries are also formulating regulatory policies for a flourishing LED industry. Modern multiplexes and shopping malls incorporate LED displays as an integral part of their overall design. Outdoor LED displays that deliver dynamic and audio-backed content are more attention-grabbing. Businesses invest heavily in LED displays to grab the maximum attention of their customers. The huge screens that show flashy images along with thunderous sounds never fail to catch the attention of visitors in a mall. Real-time advertising has further increased the demand for outdoor LED screens. The advertisers carefully monitor their clients’ choices, the market trends as well as consumer responses to the messages displayed and can alter the content accordingly. Indoor applications of video walls are diverse, as can be seen in transportation (airports, bus terminals, subways, etc), which was an early adopter. However, there’s been increased adoption of these walls at shopping malls and other retailers, hotels, casinos, museums and galleries. Robust high brightness outdoor LED walls are designed to convey information in a visually appealing manner even in tough outdoor conditions like extreme heat, rain and dust. Unlike other conventional displays, these video walls are highly customisable in shape and size and provide daytime visibility even under direct sunlight. Indoor And Outdoor LED Display(s): How Are They Different? Outdoor LED billboard, screens and other products are getting more popular by the day. LED displays have become an important part of the way modern businesses communicate with their customers. Their high brightness, low power consumption, and longer shelf life are just some of the characteristics that give them an edge over the earlier LCD screens. Indoor LED displays, however, are different from outdoor displays in a number of ways. What are the main 3D technologies for 3D LED displays? The 3D LED display can express the details of dark and light parts incisively and vividly. It is characterized by high refresh, high gray scale and high contrast, so that the audience can enjoy the content with the immersive experience effect of scenery but no screen in their eyes. 3D LED display is a kind of 3D effect on the screen that can be viewed with naked eyes without wearing professional glasses. The effect presented by the naked eye 3D LED display is very realistic, which can perfectly display the broadcast content and attract the eyes of pedestrians. As a brilliant LED display in the display market in recent years, with its more and more into the indoor high-definition display field, how to achieve the 3D display technology suitable for LED display has also begun to attract much attention. So, do you know what are the main 3D technologies for 3D LED displays? 1. 3D display technology of glasses:Glass 3D technology, we can subdivide into three main types: chromatic aberration, polarized light and active shutter, which is commonly known as color division, light division and time division method. 2. Color difference 3D technology: Passive red-blue filter 3D glasses are used together. The technology is the oldest, the imaging principle is simple, and the cost of implementation is relatively low -- the glasses cost only a few dollars -- but the 3D results are also among the worst. 3. Polarized 3D technology: Also called Polarized 3D technology, it uses passive polarized glasses. Polarized light type 3 d is the use of light have "vibration" principle to decompose the original image, first through the level of the image is divided into vertical polarized light and polarized light images in both groups, and then about 3 d glasses with different polarization direction of the polarized lenses, so that people around the eyes can receive two sets of pictures, after brain synthetic stereo images. 4. Shutter-type 3D technology: This 3D technology is most widely used in TV and projector, with relatively more resources and excellent image effect. It is highly praised and adopted by many manufacturers, but its matching 3D glasses are relatively expensive. At present, including LG, Samsung, Panasonic, Skyworth and other brands launched 3D TV, using active shutter 3D technology. The unique 3D LED display mode creates a sense of spatial dimension. Combined with the stage lighting, it creates an immersive lighting and movie feast, which brings a strong visual impact to the audience. In addition, in recent years, the demand for artistic performance has been on the rise, and the future prospects of the immersive visual performance stage are very bright. 1. What is LED module? LED module is a basic unit of led display, which has complete drive circuit and certain appearance. Outdoor LED module 2. LED module classification. a.Classifying from the application environment, there are two types led modules. One is indoor LED module and another one is outdoor LED module. The latter module must be water-proof. b.LED module can also be classified from its color, such as single color led module, tricolor LED module and full color led module. c.According to the type of LED, the LED module can be classified into DIP LED module and SMD LED module. 3. The composition of LED module. The LED module is consisted of the following parts & components: a.LED b.IC. Generally the driving IC model we used include, ⅰ.Macroblock MBI5020, Macroblock MBI5024; ⅱ.Macroblock high refresh rate MBI5042, MBI5050; ⅲ.Macroblock energy saving MBI5035; ⅳ.Macroblock error detection MBI5036; ⅴ.Toshiba TB62726; ⅵ.Philip 74HCXXX; ⅶ.ANPEC4953. c.PCB. There are so many kinds of PCB in the market, such as single layer board, double layers board and four layers board etc. And the PCB we adopt to our led display modules: FR-4; 1.6mm thickness; Copper foil thickness 35(1oz), SMOBC&HAL, black or green surface painting. d.Signal connector. There are three types as following, ⅰ. Contact pin. It has price advantage, low cost. We use only the best type connector to ensure the stability of our led displays. And if there's no special requirement, the power connector we use is VH4 to give the great convenience of the maintenance to the led displays. e.Module kit. ⅰ. Bottom case. It is just like a carrier of the LED screen module, the whole LED PCB will be put in it. It seems like a container when the LED module is used to outdoor environment, since the waterproof silicon glue will be poured into it and seal around the LED to realize waterproof. It is LED's basic structure and whether there is cabinet or not the LED module will be installed on the cabinet or frame through it. The bottom case also can protect the LED from damage when under the working state. ⅱ. Mask. There are three kinds of mask in the market. 1）Conventional hard plastic cement mask. 2）Soft mask. It is usually for sport perimeter led display usage. Considering the athletes' safety and the intactness of the LED display, at the first layer of the LED display the PC mask will be used and then the soft mask will be attached on the surface. 3) Silica gel mask. It is mainly used to the smaller pixel pitch LED display and can be pasted on the LED PCB with 3M glue. f. Resistor and capacitor. ⅰ. Resistor model: 0603, 0805, 1206 etc. ⅱ.Capacitor types: electrolytic capacitor, SMD ceramic capacitor. We use high precision resistor to ensure the color of LED display to be disposable, and to make our products more reliable.
Fecha de Publicación: 25-08-21
Descripción: Extrusion and Thermoplastics In a thermoplastic extrusion, the material is first softened by heating so that it can be shaped. This process is performed by the extruder, or extrusion machine. This heat softening is referred to by different names, such as ‘thermal softening’, ‘plasticization’, or ‘plastication’. Most extruders are single screw machines. The screw is what forces the material towards, and then through, the die. Shape is imparted by the die, and/or by post-extrusion forming, and the product is then set to shape by cooling while maintaining its shape. The equipment used to perform this process is known as the post extrusion equipment, while the entire system is known as an extrusion line. In addition, there are food extruder machine and feed extruder machine. Extruder Classification Extruders may be categorized by three figures, for instance, 1-60-24. The first number specifies the amount of screws the machine has, the second number indicates the screw diameter in millimeters (mm), and the third number indicates the effective screw length as a multiple of the screw diameter. Therefore, in the given example, a single screw machine is being described that has a screw diameter of 60 mm and a length of 24 (i.e., a L/D ratio of 24/1). Machine Construction Figure 1 shows a cut-away diagram of a simple single screw machine. This diagram shows the arrangement the different parts of the machine. The two units - screw and barrel - interact together to convey the plastic material, melt the material, and then push it through the die. The screw is rotated at a predetermined speed with the electric motor drive unit and gearbox. Temperature controllers are connected to heating/cooling elements on the barrel to maintain the temperature at the set-point temperatures. The capability of the screw and barrel assembly to extrude a given material is based on the characteristics or construction of the barrel and screw, the characteristics of the plastics material, and the circumstances under which the system is operated. Post Extrusion Equipment When the extrudate leaves the die, it can either be set to the desired shape or its shape can be altered and then set to shape. The equipment that performs this process is known as the ‘post extrusion equipment’ or the ‘haul off’, and in terms of size, it is generally much larger than that of the extruder. This is because plastics take a considerable amount of time to cool, and this cooling process determines the speed the line will operate. Pet Feed Machinery The growing demands of today’s pet food market require increasingly specialized knowledge combined with advanced processing technologies. As a longtime partner to hundreds of premium pet food producers worldwide, we provides comprehensive processing solutions and aftermarket services to keep your operations ahead of the curve. All to guarantee easy, safe, and efficient operations that can quickly adapt to the next market trend. We offers a full range of pet feed machinery – from raw material intake to finished feed bagging – as single unit or complete plant solution. The individual process machines offered are selected from the standardized and proven range of product families. A wide variety of food products is produced worldwide on our complete twin screw extrusion processing lines to answer increasing consumers demands : cereals, snacks, crispy breads and crackers, baby food, textured proteins and food ingredients. At the same time, we also offer pasta machinery and couscous turn-key processing lines integrating our specific design Rotante hot air drying technology. To enable our partners in the Food industry to gain market shares and leveradge their brands, our expert teams are continuously innovating to develop and produce high-quality food products with new flavors and taste combinations. Pasta Production Line Over 50 years, pasta production line has offered complete production solutions for a wide range of typical short-cut pasta shapes. Over the years, Clextral experts have continuously refined every component in the production process, building high-performance lines to customer specifications, including its exclusive VHT (Very High Temperature) drying system. Clextral short pasta extruders are particularly adapted to the modern requirements of production in terms of cost-effectiveness, flexibility, ease of use, hygiene and maintenance. HOW IS PASTA MADE ? The raw materials are mixed with a precise dosing mechanism to maintain constant flow and obtain homogenous dough in the pasta extruder. The pressing phase is carried out with a single screw system specially designed to ensure optimal semolina hydration, mixing, compression and extrusion. Once the dough is kneaded to the required consistency it is put through fitted dies to produce the required shapes and cut to length. Drying is achieved in two phases : first, the pre-drying Trabatto is used to crust the dough surface in order to avoid sticking. The second phase is done on Rotante drying units which include a VHT (Very High Temperature) drying system, which offers several advantages, including faster pasta producton, heightened quality of the final product (especially for pasta made with soft wheat), reduced product loss, short changeover times and very hygienic processing. After drying, the pasta is cooled and stabilized in the industrial pasta machine and then transported to storage or packaged directly. STATE-OF-THE-ART PRODUCTION OF PASTA Clextral pasta extruders are designed and manufactured to strict production standards ensuring: Quality construction and superior hygienic standards – stainless steel parts, easy cleaning, low loss of raw materials, etc. Quick and easy on-site assembly – modular pre-mounted parts End-to-end process control – full automation to guarantee product consistency Flexibility – quick changeover, easy shape changes and adjustment of production parameters, capacity varies from 1,500kg to 6,000kg/h Efficient maintenance – standardized extrusion and drying parts, easy access for servicing Follow-up services –training, support, new product design expertise Sustainability – intensified processing to generate energy and water savings, as well as cost-effectiveness High-Quality Modified Starch Products Microtec Engineering Group is an eminent name in the modified starch industry. With a vision to be one of the world-leading Provider of premium modified starch technology, our focus is to increase our penetration in global markets by helping clients to manufacture quality modified starch products using the latest technology and strictly adhering to the Industrial Standards. Using our advanced equipment and processing technology ,you’ll obtain starch products that are distinguished from the rest. Our starch modifying equipment is designed to produce top-of-the-line products that cater to the requirements of a widening customer base. Industrial Application of Our Modified Starch Technology Our modified starch machinery serves a wide range of industrial applications. These include: 1. Food Modified starches are excellent thickening agents. Our advanced starch modifying technology will enable you to provide the required thickness, stretch ability, crispness, stabilizing and binding properties as well as texture to numerous food products related to: Bakery Coating Confectionary Soups, sauces & gravies Pasta & noodles Snacks 2. Textile Textile industry relies on the use of modified starch products as they reduce the breakage of fibre and wastage. Especially when used on fabrics like polyester, cotton and acrylic, they yield satisfying results. Advanced starch enhancing technology like ours can also help you to manufacture a wide number of products like: Thin boiled starch Binder Softener Lubricants 3. Paper & Packaging Paper – The demand for modified starch in the paper making industry is never less. The reason? Because modified starch increases the bonding strength of paperboard and plain white paper. Our top-of-the-line technology is instrumental in enhancing the strength, quality and brightness of the paper. Packaging – The adhesive property of modified starch is remarkable. Modified starch is an essential component in packaging glue which, in turn, is used for making boxes and cartons. Our unique starch modifying equipment enables you to impart excellent adhesive property to your packaging glue.
Fecha de Publicación: 25-08-21