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Topic Review
Mechanochemical Machines for Biorefining
Grinding and mechanical pretreatment are very popular methods utilized to enhance the reactivity of polymers and plant raw materials; however, the choice of devices and their modes of action is often performed through trial and error. An inadequate choice of equipment often results in inefficient grinding, low reactivity of the product, excess energy expenditure, and significant wear of the equipment.
  • 1.8K
  • 03 Dec 2020
Topic Review
Modified Frequency Modulation
Modified Frequency Modulation, commonly MFM, is a run-length limited (RLL) coding scheme used to encode the actual data-bits on most floppy disks. It was first introduced in disk drives with the IBM 3330 hard disk drive in 1970. Floppy disk drive hardware examples include Amiga, most CP/M machines as well as IBM PC compatibles. MFM is a modification to the original digital FM (digital frequency modulation also known as delay coding) scheme for encoding data on single-density floppy disks and some early hard disk drives. Due to the minimum spacing between flux transitions that is a property of the disk, head and channel design, MFM, which guarantees at most one flux transition per data bit, can be written at higher density than FM, which can require two transitions per data bit. It is used with a data rate of 250–500 kbit/s (500–1000 kbit/s encoded) on industry standard 5¼-inch and 3½-inch ordinary and high density diskettes. MFM was also used in early hard disk designs, before the advent of more efficient types of run-length limited codes. Except for the steadily disappearing 360 KiB/1.2 MiB (5.25-inch) and 720~880 KiB/1.4~1.6 MiB (3.5-inch) floppy disk formats, MFM encoding is obsolete in magnetic recording.
  • 1.8K
  • 22 Nov 2022
Topic Review
List of AMD Athlon Microprocessors
Athlon is the name of a family of CPUs designed by AMD, targeted mostly at the desktop market. It has been largely unused as just "Athlon" since 2001 when AMD started naming its processors Athlon XP, but in 2008 began referring to single core 64-bit processors from the AMD Athlon X2 and AMD Phenom product lines. Later the name began being used for some APUs.
  • 1.8K
  • 26 Oct 2022
Topic Review
Dynamic Positioning
Dynamic positioning (DP) is a computer-controlled system to automatically maintain a vessel's position and heading by using its own propellers and thrusters. Position reference sensors, combined with wind sensors, motion sensors and gyrocompasses, provide information to the computer pertaining to the vessel's position and the magnitude and direction of environmental forces affecting its position. Examples of vessel types that employ DP include, but are not limited to, ships and semi-submersible mobile offshore drilling units (MODU), oceanographic research vessels, cable layer ships and cruise ships. The computer program contains a mathematical model of the vessel that includes information pertaining to the wind and current drag of the vessel and the location of the thrusters. This knowledge, combined with the sensor information, allows the computer to calculate the required steering angle and thruster output for each thruster. This allows operations at sea where mooring or anchoring is not feasible due to deep water, congestion on the sea bottom (pipelines, templates) or other problems. Dynamic positioning may either be absolute in that the position is locked to a fixed point over the bottom, or relative to a moving object like another ship or an underwater vehicle. One may also position the ship at a favorable angle towards wind, waves and current, called weathervaning. Dynamic positioning is used by much of the offshore oil industry, for example in the North Sea, Persian Gulf, Gulf of Mexico, West Africa, and off the coast of Brazil . There are currently more than 1800 DP ships.
  • 1.8K
  • 04 Nov 2022
Topic Review
Assisted GPS
Assisted GPS or Augmented GPS (abbreviated generally as A-GPS and less commonly as aGPS) is a system that often significantly improves the startup performance—i.e., time-to-first-fix (TTFF)—of a GPS satellite-based positioning system. A-GPS is extensively used with GPS-capable cellular phones, as its development was accelerated by the U.S. FCC's 911 requirement to make cell phone location data available to emergency call dispatchers.
  • 1.8K
  • 25 Nov 2022
Topic Review
Bioglass
Bioglass 45S5, commonly referred to by its commercial name Bioglass, is a glass specifically composed of 45 wt% SiO2, 24.5 wt% CaO, 24.5 wt% Na2O, and 6.0 wt% P2O5.  Glasses are non-crystalline amorphous solids that are commonly composed of silica-based materials with other minor additives.  Compared to soda-lime glass (commonly used, as in windows or bottles), Bioglass 45S5 contains less silica and higher amounts of calcium and phosphorus.  The 45S5 name signifies glass with 45 weight % of SiO2 and 5:1 molar ratio of calcium to phosphorus.  This high ratio of calcium to phosphorus promotes formation of apatite crystals; calcium and silica ions can act as crystallization nuclei.  Lower Ca:P ratios do not bond to bone.  Bioglass 45S5's specific composition is optimal in biomedical applications because of its similar composition to that of hydroxyapatite, the mineral component of bone. This similarity provides Bioglass' ability to be integrated with living bone. This composition of bioactive glass is comparatively soft in comparison to other glasses. It can be machined, preferably with diamond tools, or ground to powder. Bioglass has to be stored in a dry environment, as it readily absorbs moisture and reacts with it. Bioglass 45S5 is the first formulation of an artificial material that was found to chemically bond with bone. One of its main medical advantages is its biocompatibility, seen in its ability to avoid an immune reaction and fibrous encapsulation. Its primary application is the repair of bone injuries or defects too large to be regenerated by the natural process. The first successful surgical use of Bioglass 45S5 was in replacement of ossicles in the middle ear, as a treatment of conductive hearing loss. Other uses include cones for implantation into the jaw following a tooth extraction. Composite materials made of Bioglass 45S5 and patient's own bone can be used for bone reconstruction. Further research is being conducted for the development of new processing techniques to allow for more applications of Bioglass.
  • 1.8K
  • 01 Nov 2022
Topic Review
Blancpain
Blancpain SA (French pronunciation: ​[blɑ̃pɛ̃]) is a Swiss luxury watch manufacturer, headquartered in Paudex/Le Brassus, Switzerland . It designs, manufactures, distributes, and sells prestige and luxury mechanical watches. Founded by Jehan-Jacques Blancpain in Villeret, Switzerland in 1735, Blancpain is the oldest surviving watchmaking brand in the world. Blancpain has been a subsidiary of the Swiss Swatch Group since 1992, and is regarded as a top-tier Swatch brand. It is best known for its Fifty Fathoms diving watch introduced in 1953 and its 1735 Grande Complication wristwatch introduced in 1991.
  • 1.8K
  • 16 Nov 2022
Topic Review
Drone Architecture for Crowd Monitoring and Analysis
Crowd monitoring and analysis is an important evolving applications of unmanned aerial vehicle or drones. From preventing stampede in high concentration crowds to estimating crowd density and to surveilling crowd movements, crowd monitoring and analysis have long been employed in the past by authorities and regulatory bodies to tackle challenges posed by large crowds.
  • 1.8K
  • 03 Mar 2022
Topic Review
Texture (Crystalline)
In materials science, texture is the distribution of crystallographic orientations of a polycrystalline sample (it is also part of the geological fabric). A sample in which these orientations are fully random is said to have no distinct texture. If the crystallographic orientations are not random, but have some preferred orientation, then the sample has a weak, moderate or strong texture. The degree is dependent on the percentage of crystals having the preferred orientation. Texture is seen in almost all engineered materials, and can have a great influence on materials properties. Also, geologic rocks show texture due to their thermo-mechanic history of formation processes. One extreme case is a complete lack of texture: a solid with perfectly random crystallite orientation will have isotropic properties at length scales sufficiently larger than the size of the crystallites. The opposite extreme is a perfect single crystal, which likely has anisotropic properties by geometric necessity.
  • 1.7K
  • 04 Nov 2022
Topic Review
Acer Predator
Predator Gaming is a gamer-focused brand and line of computer hardware owned by Acer. In 2008, Acer introduced itself in the gaming computer market with a line of desktop computers: the Acer Aspire Predator series, later renamed as Acer Predator. The series is characterized by the futuristic computer chassis and high performance. In 2016, a complete range of Predator desktops, gaming laptops, tablets and accessories exists. The range competes with Lenovo's Legion, Dell's G series and Alienware subsidiary, HP's Omen and Asus ROG series.
  • 1.7K
  • 20 Oct 2022
Topic Review
Electricity Tariffs and Solutions for Optimal Energy Management
Today, electricity tariffs play an essential role in the electricity retail market as they are the key factor for the decision-making of end-users. Additionally, tariffs are necessary for increasing competition in the electricity market. They have a great impact on load energy management. Moreover, tariffs are not taken as a fixed approach to expense calculations only but are influenced by many other factors, such as electricity generation, transmission, distribution costs, and governmental taxation. Thus, electricity pricing differs significantly between countries or between regions within a country. Improper tariff calculation methodologies in some areas have led to high-power losses, unnecessary investments, increased operational expenses, and environmental pollution due to the non-use of available sustainable energy resources.
  • 1.7K
  • 25 Nov 2022
Biography
James Heppelmann
James E. Heppelmann (born September 4, 1964) [1] is an American engineer and businessman. He is the chief executive officer (CEO) of PTC (software company) (formerly Parametric Technology) a multinational software company he joined in January of 1998 as Senior Vice President Windchill, Parametric Technology Corp. Heppelmann grew up in rural Minnesota on a small dairy farm with his seven sibli
  • 1.7K
  • 29 Dec 2022
Topic Review
Wastewater
Wastewater is any water that has been contaminated by human use. Wastewater is "used water from any combination of domestic, industrial, commercial or agricultural activities, surface runoff or stormwater, and any sewer inflow or sewer infiltration". Therefore, wastewater is a byproduct of domestic, industrial, commercial or agricultural activities. The characteristics of wastewater vary depending on the source. Types of wastewater include: domestic wastewater from households, municipal wastewater from communities (also called sewage) and industrial wastewater. Wastewater can contain physical, chemical and biological pollutants. Households may produce wastewater from flush toilets, sinks, dishwashers, washing machines, bath tubs, and showers. Households that use dry toilets produce less wastewater than those that use flush toilets. Wastewater may be conveyed in a sanitary sewer that conveys only sewage. Alternatively, wastewater can be transported in a combined sewer that conveys both stormwater runoff and sewage, and possibly also industrial wastewater. After treatment at a wastewater treatment plant, treated wastewater (also called effluent) is discharged to a receiving water body. The terms "wastewater reuse" and "water reclamation" apply if the treated waste is used for another purpose. Wastewater that is discharged to the environment without suitable treatment can cause water pollution. In developing countries and in rural areas with low population densities, wastewater is often treated by various on-site sanitation systems and not conveyed in sewers. These systems include septic tanks connected to drain fields, on-site sewage systems (OSS), vermifilter systems and many more.
  • 1.7K
  • 19 Oct 2022
Topic Review
Biorefinery of agroindustrial banana waste
Life cycle system of second-generation ethanol production from rachis of banana.
  • 1.7K
  • 27 Aug 2020
Topic Review
Dialysis
In medicine, dialysis (from Greek διάλυσις, dialysis, "dissolution"; from διά, dia, "through", and λύσις, lysis, "loosening or splitting") is the process of removing excess water, solutes, and toxins from the blood in people whose kidneys can no longer perform these functions naturally. This is referred to as renal replacement therapy. The first successful dialysis was performed in 1943. Dialysis may need to be initiated when there is a sudden rapid loss of kidney function, known as acute kidney injury (previously called acute renal failure), or when a gradual decline in kidney function, chronic kidney disease, reaches stage 5. Stage 5 chronic renal failure is reached when the glomerular filtration rate is 10–15% of normal, creatinine clearance is less than 10 mL per minute and uremia is present. Dialysis is used as a temporary measure in either acute kidney injury or in those awaiting kidney transplant and as a permanent measure in those for whom a transplant is not indicated or not possible. In Australia, Canada, the United Kingdom, and the United States, dialysis is paid for by the government for those who are eligible. In research laboratories, dialysis technique can also be used to separate molecules based on their size. Additionally, it can be used to balance buffer between a sample and the solution "dialysis bath" or "dialysate" that the sample is in. For dialysis in a laboratory, a tubular semipermeable membrane made of cellulose acetate or nitrocellulose is used. Pore size is varied according to the size separation required with larger pore sizes allowing larger molecules to pass through the membrane. Solvents, ions and buffer can diffuse easily across the semipermeable membrane, but larger molecules are unable to pass through the pores. This can be used to purify proteins of interest from a complex mixture by removing smaller proteins and molecules.
  • 1.7K
  • 07 Nov 2022
Topic Review
SCMaglev
The SCMaglev (superconducting maglev, formerly called the MLU) is a magnetic levitation (maglev) railway system developed by Central Japan Railway Company (JR Central) and the Railway Technical Research Institute. On 21 April 2015, a manned seven-car L0 Series SCMaglev train reached a speed of 603 km/h (375 mph), less than a week after the same train clocked 590 km/h (370 mph), breaking the previous land speed record for rail vehicles of 581 km/h (361 mph) set by a JR Central MLX01 maglev train in December 2003.
  • 1.7K
  • 20 Oct 2022
Topic Review
Sakia
A saqia, alternative spelling sakieh, saqia or saqiya (from Arabic: ساقية, sāqiyah), also called Persian wheel, tablia, rehat, and in Latin tympanum is a mechanical water lifting device, similar in function to a scoop wheel, which uses buckets, jars, or scoops fastened either directly to a vertical wheel, or to an endless belt activated by such a wheel. The vertical wheel is itself attached by a drive shaft to a horizontal wheel, which is traditionally set in motion by animal power (oxen, donkeys, etc.) Because it is not using the power of flowing water, the sakia is different from a noria and any other type of water-wheel. It is still used in India , Egypt and other parts of the Middle East, and in the Iberian Peninsula and the Balearic Islands. It may have been invented in Hellenistic Egypt, Persia or India . The sakia was mainly used for irrigation, but not exclusively, as the example of Qusayr Amra shows, where it was used at least in part to provide water for a royal bathhouse.
  • 1.7K
  • 23 Nov 2022
Topic Review
Cutting Forces
Monitoring tool-behavior is of utmost importance regarding the machining process’s productivity and costs. The machining tool performance can be assessed in several different ways, such as evaluating the machined material’s surface roughness, or by analyzing the cutting forces that are developed during the process. The force assessment is achieved by employing cutting force prediction methods or by measuring the cutting forces by using dynamometers or other sensor systems. Thus, it is crucial to know the various advantages and drawbacks of each of the different techniques for this matter.
  • 1.7K
  • 21 Oct 2020
Topic Review
Meat Analogue
A meat analogue is a food industry term for a meat-like substance made from vegetarian ingredients. More common terms are plant-based meat, vegan meat, meat substitute, mock meat, meat alternative, imitation meat, or vegetarian meat, or, sometimes more pejoratively, fake meat or faux meat. Meat analogues typically approximate certain aesthetic qualities (such as texture, flavor, appearance) or chemical characteristics of specific types of meat. Many analogues are soy-based (e.g., tofu, tempeh) or gluten-based but now may also be made from pea protein. Other less common analogues include cottage cheese and mycoprotein. Because of their similarity to meats, they are frequently used in dishes and food practices similar to meat. The target market for meat analogues includes vegetarians, vegans, non-vegetarians seeking to reduce their meat consumption, and people following religious dietary laws in Hinduism, Judaism, Islam, Christian vegetarianism, and Buddhism. Increasingly, the global demand for sustainable diets in response to the outsized role animal products play in global warming and other environmental impacts has seen an increase in industries focused on finding substitutes similar to meat. However, the motivation for seeking out mock meats tends to vary depending on consumer group. The market for meat alternatives is highly dependent on "meat-reducers" — a consumer group who is primarily motivated by health consciousness and weight management. Consumers who identify as vegan, vegetarian or pescetarian are more likely to endorse concerns regarding animal welfare and/or environmentalism as primary motivators. Meat substitution has a long history. Tofu, a popular meat analogue made from soybeans, was known in China during the period of the Western Han dynasty (206 BCE – 9 CE). A document written by Tao Gu (903–970) describes how tofu was called "small mutton" and valued as an imitation meat. Meat analogues such as tofu and wheat gluten are associated with Buddhist cuisine in China and other parts of East Asia. In Medieval Europe, meat analogues were popular during the Christian observance of Lent, when the consumption of meat from warm-blooded animals is forbidden. In the 2010s, owing to concern over global warming, demand for meat from a growing middle class, and major investments by companies such as Beyond Meat and Impossible Foods, there was an increase in awareness and the market size for meat analogues in Western and Westernized markets.
  • 1.7K
  • 24 Oct 2022
Topic Review
Plastic Waste Disposal in South African Townships
Twenty-first century human behaviour continues to escalate activities that result in environmental damage. This calls for environmentally friendly solutions, such as waste recycling and handling, to deal with the increased amount of waste, especially plastics. The plastic materials manufacturing sector is booming, particularly packaging; while only a fraction of its waste is recycled, another fraction is destroyed, and the larger part continues to pollute the environment. In addition to other waste disposal activities, destroying plastic or incineration (which could be for energy recovery) is usually subjected to strict legal requirements because of its effect on the environment. However plastic is destroyed or disposed of, it poses a serious challenge in both the short term and the long term to humans and their natural environment if the process is not efficiently managed.
  • 1.7K
  • 30 Jan 2022
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