• A team of scientists at Cornell University and the University of Chicago have imaged this behavior and have explained the forces causing it for the first time. Its findings appear in the Dec. 19-23 early edition of the Proceedings of the National Academy of Sciences.

    “The experimental breakthrough revealed that these string structures were perpendicular to the shear instead of parallel to it, contrary to what many in the field were expecting,” said Aaron Dinner, associate professor in chemistry at UChicago and a study co-author.

    The experiment was led by Itai Cohen, associate professor of physics at Cornell, who custom-built a device that would enable him simultaneously to exert shearing forces on suspended colloids (the spheres) and image the resulting motion at 100 frames per second with a confocal microscope. Imaging speed was critical to the experiment because the string-like structures appear only at certain shear rates.

    “This issue of strings has been pretty controversial. I’m not sure that we’ve solved all the controversies associated with them, but at least we’ve made a step forward,” Cohen said.

    Shearing forces affect the dynamic behavior of paint, shampoo and other viscous household products, but an understanding of these and related phenomena at the microscopic level has largely eluded a detailed scientific understanding until the last decade, Dinner noted.

    Futuristically speaking, these forces potentially could be harnessed to produce microscopic patterns on computer chips or biosensors via special paints that flow easily when layered in one direction, but becomes hard when layered in another direction.

    Cohen’s objective was more scientifically immediate: to devise an experiment that would overcome the technical difficulties associated with measuring the mechanical properties of the colloidal strings while also imaging their formation. “The holy grail is to be able to understand how the structure leads to the mechanical properties and then to be able to control the mechanical properties by influencing the structure,” Cohen explained.

    Cohen, PhD’01, received his doctorate in physics at UChicago, as did lead author Xiang Cheng, PhD’09, a postdoctoral associate at Cornell who assembled the team; and co-author Xinliang Xu, PhD’07, a postdoctoral scholar at UChicago. The study co-authors also included Stuart Rice, the Frank P. Hixon Distinguished Service Professor Emeritus in Chemistry at UChicago and a 1999 recipient of the National Medal of Science.

    As members of UChicago’s Materials Research Science and Engineering Center, Rice and Dinner are part of a larger effort to determine how materials behave under the influence of various dynamic forces. Some of their physics colleagues analyze forces operating on macroscopic scales, while chemists such as Rice and Dinner attempt to assess how those findings might apply to microscopic phenomena.

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  • It is not unusual that more companies are choosing balers today. Horizontal or even vertical balers are used today for their own waste control advantages. Many more companies are seeing the advantages of baling devices and I’m one of the company owners that have realized the value of balers in today’s world. The increasing amount of garbage made by the ever growing industrial world is an issue, indeed.

    We often need to allow our waste problems overpower us or develop ways to cut down our waste generation. I believe that this is why balers and compactors came to be. These equipment were created to help industrial sectors deal with their waste. Waste we deal with in our business is not the kind of trash you handle in your own home. We work with loads of waste. A great deal of it may still be put into use and must therefore be transferred for recycling. The remainder should have a trip to the garbage dump.

    Many companies around the globe work with baling equipments. Industries and manufacturers deal with the bulk of their recycleable waste by placing them inside balers. Horizontal balers are generally common for large industrial sectors because they may take in more garbage. All right, a few individuals were asking me the real difference among balers and compactors. Balers are really for recyclable products whilst compactors are often for complete garbage. Normally, paper, cardboard, as well as plastics are put in balers. Items that can no longer be used and therefore are regarded as waste are tossed away into compactors.

    Both balers and compactors are helpful to the company due to their key work of compressing waste materials. Compressed waste materials occupies smaller space than loose garbage. A compactor gets filled in a longer time than a waste container of similar size. Starting from twice each week, our waste hauling has been done less frequent, about 3 times every month.

    Vertical baling machines are good for small companies with small sized organizations and fewer garbage. They can be installed indoors to steer clear of the weather conditions. Vertical baling equipments are operated by hand. I once had vertical baling equipments however I sold them to a company owner. Today, I use the bigger horizontal baling equipments which work by means of fully automated mechanism. Nonetheless, I have assigned someone to monitor the operations of the balers.

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  • Two-ram balers provide the most efficient and versatile means for high-volume processing of multiple materials.  Dozens of models offer the capability to process a wide range of cardboard, paper, plastics, cans, non-ferrous, solid waste and other materials.

    Small footprint

    Looking for the versatility and automation of a two-ram baler at an affordable price?  Smaller models are available for operations that don’t require high processing rates, but still need to automatically process multiple products into dense, stackable, high quality bales.

    Narrow Box

    Narrow box balers are multi-purpose automated two-ram balers with all the features of larger machines.  Narrow box models offer charge openings up to 85″x42″ and processing rates over 30 tons per hour.  High-quality components and advanced design are packaged with user-friendly features such as the Combo-door, Smart-knife shear blades, abrasion resistant wear surfaces and state-of-the-art OIT controls.

    Wide Box

    Wide box balers are designed for high-volume material processing with easy operation and simple maintenance.  Models with large feed openings have been the workhorse of two-ram baler design for decades.  The latest technologies have been incorporated into improvements in structural design, hydraulics, controls and features.  Maximum compaction densities provide ultra-dense bales for maximized payload.

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  • If those billions of individual pieces have an electric charge, let’s say a positive charge, you’ve got problems because the particles now have enough charge and small enough mass that they all repel each other- Voila! suspended and unwanted particles in water. They may settle- in days, weeks, months, years… virtually never. You just may want to return the water a little cleaner than you just made it processing food or textiles, so what now?

    Dissolved air, as mentioned, won’t help you alone- but you can give it its own charge too. Trace chemicals, usually based on aluminum, usually in parts per million, can be introduced to your water. Seems like more of a mess, doesn’t it?

    The chemicals create their own charge and the particles now have something to which they can bond or attach electrically speaking. If you’ve got positive charges on each waste particle, you introduce negative charges on the newly introduced aluminum. A particle of aluminum may attract many waste particles and form a clump. Now we’ve got suspended clumps.

    One more introduction of something in very tiny particles with a lot of surface area- and an opposite charge. Air. Not just air bubbles, but microscopic ones with an attitude (a charge) Now we’ve got action. The water is white with these very microscopic bubbles. They have little mass and buoyancy, so they’re not in a dead run for the surface. They collect plenty of your particle/aluminum clusters on their way to the top with millions of units of opposite charged surfaces. All the clusters- original waste solids, clumped in microscopic size bits around flocculant aluminum or other introduced medium, and billions of tiny air bubbles that collect around these larger particles (the air bubbles are extremely small). All rises to the top in a nice sludge the consistency of cooked oatmeal. Skim it off and you have clear water that is clean enough to send back to town without the taxi fare of pollution credits.

    keystec air-whip DAF pumpThis operation is known as dissolved air flotation and it’s relatively cheap compared to systems that use membranes to squeeze water through under high pressure. The equipment that does this is called a DAF so that the acronym becomes a noun. A DAF uses varied techniques and DAF pumps to achieve the right balance of chemicals, charges and volume to clean the water for each application. Formulas are generally used and adjusted while the waste water flow is analyzed and the balance of flocculant and air are tweaked. The biggest expense of the operation tends to be the DAF pumps, followed by chemicals to use as flocculant. The cost of chemicals is ongoing, but when a DAF pump must be replaced, it can far outweigh what was spent on chemicals. The Keystec Air-Whip DAF pump reduces this replacement cost to a fraction because it’s both cheaper to manufacture and buy and lasts far longer than the 6 or 12 month life expectancy of most competitors.

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  • It is characterized by a buckle instead of hand-tied with iron strapping strapping, to prevent the use or transportation staff is metallic iron buckle scratches. It also saves packaging costs. Now become a widely used carton packaging equipment. Degree of automation of the equipment into semi-automatic and fully automatic, semi-automatic strapping need to manually insert, automatic does not. Binder called packer, is the use of banding winding the product or packaging, and then tighten both ends by melting or thermal effects and other materials connected with covered buttons of the machine. The function is to make the plastic strapping band can be bundled in the package close to the surface, to ensure that packages in transport, storage is not due to binding is not strong and scattered, while also bundling tidy. Dongtai quick packer with positioning accuracy, thermal bonding solid, long service life characteristics of the machine. Automatic strapping machine strapping products have reached a continuous, reliable, snapping the plastic bag with the surface, the joint firm, the machine electrical safety, noise, smoke and other work does not affect the health of operators.

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  • Ostatní 02.12.2011 1 Comment

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