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Zeolites as Catalyst Supports for Hydrocarbon Oxidation Reactions
Catalytic oxidation is a key technology for the conversion of petroleum-based feedstocks into useful chemicals (e.g., adipic acid, caprolactam, glycols, acrylates, and vinyl acetate) since this chemical transformation is always involved in synthesis processes. Zeolites are microporous, crystalline aluminosilicate materials known since 1756 when the stilbite structure was identified by the Swedish mineralogist Crönstedt. Zeolites and other related porous materials can be supports for organometallic or metallic active species. These materials are the most studied supports due to their combined properties of mechanical and thermal stability that allows it an easy regeneration and recycling.
25 Mar 2022
Zeolites as Carriers of Nano-Fertilizers
The world is facing immense challenges in terms of food security, due to the combined impacts of the ever-increasing population and the adversity of climate change. In an attempt to counteract these factors, smart nutrient delivery systems, including nano-fertilizers, additives, and material coatings, have been introduced to increase food productivity to meet the growing food demand. Use of nanocarriers in agro-practices for sustainable farming contributes to achieving up to 75% nutrient delivery for a prolonged period to maintain nutrient availability in soil for plants in adverse soil conditions.
29 Sep 2022
Zen is the codename for a computer processor microarchitecture from AMD, and was first used with their Ryzen series of CPUs in February 2017. The first Zen-based preview system was demonstrated at E3 2016, and first substantially detailed at an event hosted a block away from the Intel Developer Forum 2016. The first Zen-based CPUs codenamed "Summit Ridge" reached the market in early March 2017, Zen-derived Epyc server processors launched in June 2017 and Zen-based APUs arrived in November 2017. Zen is a clean sheet design that differs from the long-standing Bulldozer architecture. Zen-based processors use a 14 nm FinFET process, are reportedly more energy efficient, and can execute significantly more instructions per cycle. SMT has been introduced, allowing each core to run two threads. The cache system has also been redesigned, making the L1 cache write-back. Zen processors use three different sockets: desktop and mobile Ryzen chips use the AM4 socket, bringing DDR4 support; the high-end desktop Zen-based Threadripper chips support quad-channel DDR4 RAM and offer 64 PCIe 3.0 lanes (vs 24 lanes), using the TR4 socket; and Epyc server processors offer 128 PCI 3.0 lanes and octal-channel DDR4 using the SP3 socket. But not all Socket AM4 CPUs are based on Zen microarchitecture (the 7th gen APUs and Athlon X4s are based on Excavator microarchitecture). Zen is based on a SoC design. The memory, PCIe, SATA, and USB controllers are incorporated into the same chip as the processor cores. This has advantages in bandwidth and power, at the expense of chip complexity and die area. This SoC design allows the Zen microarchitecture to scale from laptops and small-form factor mini PCs to high-end desktops and servers.
11 Nov 2022
Zellige (Arabic: [zˈliʑ]; Arabic: الزليج; also zelige or zellij) is mosaic tilework made from individually chiseled geometric tiles set into a plaster base. This form of Islamic art is one of the main characteristics of Moroccan architecture. It consists of geometrically patterned mosaics, used to ornament walls, ceilings, fountains, floors, pools and tables.
06 Oct 2022
Zeiss Inner Rail
Zeiss Inner Rail, often simply called Zeiss rail, is a ringless telescopic sight mounting system introduced by Zeiss in 1990 as an alternative to traditional ring mounts. A patent was granted in 1992, and the patent expired in 2008. The mounting system is now also offered on sights sold by other major manufacturers, such as Blaser, Leica, Minox, Meopta, Nikon, Noblex (formerly Docter), Schmidt & Bender and Steiner. It has therefore, in some sense, become the industry standard for scope mounting rails. The system has so far seen most use on the European high end market.
30 Nov 2022
ZED Depth Sensors
The ZED depth sensor is considered as one of the world's fastest depth camera. It is composed of stereo cameras with dual 4 mega-pixel RGB sensors.
09 Mar 2022
YSD-11 Class Seaplane Wrecking Derrick
YSD-11 Class Seaplane Wrecking Derrick is a class of US Navy derrick crane ship. While listed to service seaplanes the crane was able to lift small boats and large engines also. Hull classification symbol YSD is for Yard Seaplane Dirrick, Yard as in ship repair yard. YSD-11s were used to remove broken seaplanes from the water for repair or regular maintenance. The US had 2,661 Consolidated PBY Catalina built for the war, Canada built 620. Other seaplanes built in mass production were the 1,366 Martin PBM Mariner, 749 Short Sunderland and 345 Grumman G-21 Goose. The YSD-11 Class Derrick was built to support World War 2, having a displacement of 220 tons no load and 270 tons loaded. The YSD-11 Class had a length 104 feet; a beam of 31 feet and 2 inches; a draft of 4 feet. They had a top speed 10 knots, built with a steel hull. The ship had one American Hoist & Derrick model 685 rotating crane. The crane had a boom of 54 feet with a lifting capacity of 10 tons. The crane was powered by a 6-cylinder Cummins Diesel engine. The ship housed a crew of one Officer and 15 Enlisted men. The ships had a diving gear locker for the crew salvage work. For service power, the ship had two generators: one 30Kw Diesel engine to electric generator and one 20Kw Diesel Generator. Ship power was from two Superior model MRDB-8 200 HP Diesel engines with two propellers, 640shp. The YSD-11 Class Derricks were built by a number of United States shipyards, including Moore Equipment Company, Puget Sound Navy Yard, Charleston Navy Yard, Mare Island Naval Shipyard, Soule Steel Company, Pearl Harbor Navy Yard and Boston Navy Yard.
24 Oct 2022
Youth Road Safety Behavior in Serbia
Road traffic crashes are a leading cause of death for young people. Aberrant driver behaviors, such as drink driving, speeding, not wearing seatbelts, non-compliance with traffic rules and aggressive driving, are key contributors to these crashes. Gender and urban/rural differences are also risk factors. Younger people have the highest road crash and fatality risk.
07 Nov 2022
In chemistry, yield, also referred to as reaction yield, is a measure of the quantity of moles of a product formed in relation to the reactant consumed, obtained in a chemical reaction, usually expressed as a percentage. Yield is one of the primary factors that scientists must consider in organic and inorganic chemical synthesis processes. In chemical reaction engineering, "yield", "conversion" and "selectivity" are terms used to describe ratios of how much of a reactant was consumed (conversion), how much desired product was formed (yield) in relation to the undesired product (selectivity), represented as X, Y, and S.
18 Oct 2022
A yard ramp, sometimes called mobile yard ramp or container ramp, is a movable metal ramp for loading and unloading of shipping containers and vehicle trailers, without the need for permanent docking bays. A yard ramp is placed at the back of a vehicle to provide access for forklifts to ascend the ramp, quickly and safely into the container or truck body. Using a yard ramp for container loading or unloading allows the work to be carried out by a single forklift operator. Businesses handling only one or two loads per day normally find that a yard ramp is more cost effective than a permanent loading dock.
23 Nov 2022
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Encyclopedia of Social Sciences
Encyclopedia of ZEMCH Research and Development
Encyclopedia of Engineering
Encyclopedia of COVID-19
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