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Topic Review
Al-Abid
The Al-Abid(Arabic: العابد) LV was an Iraqi three-stage "Satellite launch system", a civilian project that was commenced in 1988. The Iraqis intended to launch an Al-Ta'ir satellite with the help of such a launch vehicle. The Iraqis therefore pursued a LV with stages based on Scud missiles and the S-75 Dvina. However only the first stage could be tested on December 1989 and according to General Ra'ad the next stages could not be developed. General Ra'ad says that not even the drawings of the second and third stage vehicles are available and that no final report could be produced. UN inspectors and U.S intelligence did not offer many details regarding the Al-Abid launch vehicle as they were not interested in it.
  • 607
  • 29 Nov 2022
Topic Review
Co-Torrefaction Progress of Biomass
The co-torrefaction of several biomasses may be a viable solution in the study area, as it produces biofuels and addresses waste-treatment concerns. Furthermore, the parameters of co-torrefaction, including temperature, reaction time, mass yield, energy yield, and the composition of the H/C and O/C ratio of the co-torrefied materials, are similar to those for coal composition. Different reactor types, such as fixed-bed, fluidized-bed, microwave, and batch reactors, are used for co-torrefaction, in which biomass blends with optimized blend ratios.
  • 641
  • 29 Nov 2022
Topic Review
Construction of Arch Structure Model
The application of the arch structure model focuses on the prediction and prevention of mining pressure and surface subsidence, and there are relatively few means to actively regulate overburden arch.
  • 709
  • 29 Nov 2022
Topic Review
Strengths and Weaknesses of Transmission Conductors
Electricity transmission is the necessary intermediary linking electricity generation and its distribution to the consumers. It is only efficient and effective electricity transmission that ensures high power delivery to target areas.
  • 787
  • 29 Nov 2022
Topic Review
Particulate Matter Generation and Mitigation in Poultry Houses
Poultry farming plays a key role in agricultural air emissions. Particulate matter (PM) level tends to be high in broiler and cage-free layer houses, that may impair health and welfare of animals and their caretakers. To protect public health and welfare, the occupational exposure limit for PM10 and PM2.5 (i.e., PM diameters that are generally ≤10 and 2.5 μm, respectively) are suggested not to exceed 150 µg m−3 and 35 µg m−3, respectively, based on 24-h concentrations thresholds as suggested by US. EPA. However, the levels of PM10 and PM2.5 in poultry houses could be 100 times higher than that limit. Generally, PM emissions are affected by various factors, including housing types, seasonal and diurnal variation, manure management, bedding materials, ventilation rates, and birds’ activities. High PM concentrations in poultry houses impair birds’ and caretakers’ liver, kidneys, and respiratory systems. Effective mitigation strategies include frequent house cleaning, optimum light intensity, liquid spraying, bedding management, and air filtration systems. However, mitigation strategies can be cost-prohibitive and have side effects. Therefore, poultry farms should select mitigation strategies based on farm location, climate conditions, environmental policies, and available resources (government assistance programs). 
  • 940
  • 29 Nov 2022
Topic Review
Emission Standard
Emission standards are the legal requirements governing air pollutants released into the atmosphere. Emission standards set quantitative limits on the permissible amount of specific air pollutants that may be released from specific sources over specific timeframes. They are generally designed to achieve air quality standards and to protect human life.
  • 1.3K
  • 29 Nov 2022
Topic Review
Damen Stan Patrol Vessel
The Dutch shipbuilding firm The Damen Group, designs and manufactures a wide variety of vessels, including a range of related patrol vessels known generally as the Damen Stan Patrol Vessels. The Damen Stan patrol vessel designs' names include a four digit code, where the first two digits are the vessel's length, in metres, and the second two digits are its width. Over a dozen nations have classes of vessels based on the Damen Stan 4207 patrol vessel design, which are 42 metres (138 ft) long and 7 metres (23 ft) wide. The United States Coast Guard's Sentinel class cutters, based on the Damen Stan 4708 patrol vessel design, are 47 metres (154 ft) long and 8 metres (26 ft) wide. In the late 1990s three 41 patrol vessels were built for service in the Dutch Antilles, and experience with those vessels informed the later designs of the 4207 and 4708. Rather than design vessels that were strictly for naval use, the underlying Damen Stan patrol vessel designs do not include weapons, or a sensor suite. The designs have been adapted for constabulary duties, and for fishery and environmental patrols. According to Sanjay Badri-Maharaj, of the -Institute for Defence Studies and Analyses, described how adding an autocannon and military class sensor suite to the USCG's Sentinel class boosted its cost per vessel from $20 million United States dollar to $65 million. In recent years Damen has developed Damen Stan patrol vessels based on their Sea Axe bow design. The Stan 4207 design are 42.8-metre (140 ft) patrol vessels. They are 7.1 metres (23 ft) wide, and can travel at 22 knots (41 km/h; 25 mph). They are designed to carry a complement of approximately a dozen. The Stan 4708 are 46.8 metres (154 ft) long, 8.11 metres (26.6 ft) wide, have a maximum speed of 23.8 knots (44.1 km/h; 27.4 mph), and carry a complement of 16-24.
  • 735
  • 29 Nov 2022
Topic Review
Liver Support Systems
Liver support systems are therapeutic devices to assist in performing the functions of the liver in persons with liver damage. The primary functions of the liver include removing toxic substances from the blood, manufacturing blood proteins, storing energy in the form of glycogen, and secreting bile. The hepatocytes that perform these tasks can be killed or impaired by disease, resulting in hepatic insufficiency. A sudden onset of life-threatening hepatic insufficiency is known as acute liver failure (ALF). In hyperacute and acute liver failure the clinical picture develops rapidly with progressive encephalopathy and multiorgan dysfunction such as hyperdynamic circulation, coagulopathy, acute kidney injury and respiratory insufficiency, severe metabolic alterations and cerebral edema that can lead to brain death. In these cases the mortality without liver transplantation (LTx) ranges between 40-80%. LTx is the only effective treatment for these patients although it requires a precise indication and timing to achieve good results. Nevertheless, due to the scarcity of organs to carry out liver transplantations, it is estimated that one third of patients with ALF die while waiting to be transplanted. On the other hand, a patient with a chronic hepatic disease can suffer an acute decompensation of liver function following a precipitating event such as variceal bleeding, sepsis and excessive alcohol intake among others that can lead to a condition referred to as acute-on-chronic liver failure (ACLF). Both types of hepatic insufficiency, ALF and ACLF, can potentially be reversible and liver functionality can return to a level similar to that prior to the insult or precipitating event. LTx is the only treatment that has shown an improvement in the prognosis and survival with most severe cases of ALF. Nevertheless, cost and donor scarcity have prompted researchers to look for new supportive treatments that can act as “bridge” to the transplant procedure. By stabilizing the patient's clinical state, or by creating the right conditions that could allow the recovery of native liver functions, both detoxification and synthesis can improve, after an episode of ALF or ACLF. Basically, three different types of supportive therapies have been developed: bio-artificial, artificial and hybrid liver support systems (Table 2). Bio-artificial liver support systems are experimental extracorporeal devices that use living cell lines to provide detoxification and synthesis support to the failing liver. Bio-artificial liver (BAL) Hepatassist 2000 uses porcine hepatocytes11 whereas ELAD system employs hepatocytes derived from human hepatoblastoma C3A cell lines.9, Both techniques can produce, in fulminant hepatic failure (FHF), an improvement of hepatic encephalopathy grade and biochemical parameters. Nevertheless, they are therapies with high complexity that require a complex logistic approach for implementation; a very high cost and possible inducement of important side effects such as immunological issues (porcine endogenous retrovirus transmission), infectious complications and tumor transmigration have been documented. Other biological hepatic systems are Bioartificial Liver Support (BLSS)12 and Radial Flow Bioreactor (RFB).15 Detoxification capacity of these systems is poor and therefore they must be used combined with other systems to mitigate this deficiency. Today its use is limited to centers with high experience in their application. Artificial liver support systems are aimed to temporally replace native liver detoxification functions and they use albumin as scavenger molecule to clear the toxins involved in the physiopathology of the failing liver. Most of the toxins that accumulate in the plasma of patients with liver insufficiency are protein bound, and therefore conventional renal dialysis techniques, such as hemofiltration, hemodialysis or hemodiafiltration are not able to adequately eliminate them. Between the different albumin dialysis modalities, single pass albumin dialysis (SPAD) has shown some positive results at a very high cost; it has been proposed that lowering the concentration of albumin in the dialysate does not seem to affect the detoxification capability of the procedure. Nevertheless, the most widely used systems today are based on hemodialysis and adsorption. These systems use conventional dialysis methods with an albumin containing dialysate that is later regenerated by means of adsorption columns, filled with activated charcoal and ion exchange resins. At present, there are two artificial extracorporeal liver support systems: the Molecular Adsorbents Recirculating System (MARS)10 from Gambro and Fractionated Plasma Separation and Adsorption (FPSA), commercialised as Prometheus (PROM) from Fresenius Medical Care.13 Of the two therapies, MARS is the most frequently studied, and clinically used system to date.
  • 456
  • 29 Nov 2022
Topic Review
Artificial Pancreas
The artificial pancreas is a technology in development to help people with diabetes, primarily type 1, automatically and continuously control their blood glucose level by providing the substitute endocrine functionality of a healthy pancreas. The endocrine functionality of the pancreas is provided by islet cells which produce the hormones insulin and glucagon. Artificial pancreatic technology mimics the secretion of these hormones into the bloodstream in response to the body's changing blood glucose levels. Maintaining balanced blood sugar levels is crucial to the function of the brain, liver, and kidneys. Therefore, for type 1 patients, it is necessary that the levels be kept balanced when the body cannot produce insulin itself. The artificial pancreas is a broad term for different bio-engineering strategies currently in development to achieve these requirements. Different bio-engineering approaches under consideration include:
  • 722
  • 29 Nov 2022
Topic Review
Redoutable-Class Submarine (1931)
The Redoutable-class submarines were a group of 31 submarines built between 1924 and 1937 for the French Navy. Most of the class saw service during the Second World War. The class is also known in French as the Classe 1 500 tonnes, and they were designated as "First Class submarines", or "large submarine cruisers". They are known as the Redoutable class in reference to the lead boat Redoutable, in service from 1931 to 1942. The class is divided into two sub-class series, Type I, known as Le Redoutable and Type II, Pascal. Modern submarines when they were designed, they quickly became outdated, and were approaching obsolescence by the beginning of the Second World War. The conditions of the Armistice of 22 June 1940 prevented the Vichy government from carrying out a modernization programme. 24 out of the 29 units that served in the war were lost. Used in the defence of the Second French colonial empire under the Vichy regime, submarines of the class saw action against Allied offensives at the Battles of Dakar, Libreville and Madagascar. Many of the submarines of the class came under Allied control after the Allied landings in North Africa. Few however saw much further active service after this due to a period of refitting and alterations done in the United States between February 1943 and March 1945. One exception was Casabianca, which took part in the liberation of Corsica. The surviving submarines were largely used for training purposes after the war, with the last of them being disarmed in 1952.
  • 758
  • 29 Nov 2022
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