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Topic Review
Chlamydomonas Reinhardtii
Chlamydomonas reinhardtii is a single-cell green alga about 10 micrometres in diameter that swims with two flagella. It has a cell wall made of hydroxyproline-rich glycoproteins, a large cup-shaped chloroplast, a large pyrenoid, and an eyespot that senses light. Chlamydomonas species are widely distributed worldwide in soil and fresh water. Chlamydomonas reinhardtii is an especially well studied biological model organism, partly due to its ease of culturing and the ability to manipulate its genetics. When illuminated, C. reinhardtii can grow photoautotrophically, but it can also grow in the dark if supplied with organic carbon. Commercially, C. reinhardtii is of interest for producing biopharmaceuticals and biofuel, as well being a valuable research tool in making hydrogen.
  • 4.5K
  • 02 Nov 2022
Topic Review
Renewable Energy Status in Azerbaijan
Azerbaijan has a well-developed hydrocarbon industry backed with abundant domestic resources. Oil and gas have played a crucial role in the economic revival of the country since independence was regained back in 1991. The legal foundation of the transition to carbon-zero energy generation was laid in the 1990s with a number of acts mentioning the importance of the shift. The government has an ambitious plan to improve the situation, though an action plan with targeted renewables share in production and consumption is still to be prepared.
  • 4.5K
  • 24 Jan 2022
Topic Review
Sociology of Space
The sociology of space is a sub-discipline of sociology that mostly borrows from theories developed within the discipline of geography, including the sub fields of human geography, economic geography, and feminist geography. The "sociology" of space examines the social and material constitution of spaces. It is concerned with understanding the social practices, institutional forces, and material complexity of how humans and spaces interact. The sociology of space is an inter-disciplinary area of study, drawing on various theoretical traditions including Marxism, postcolonialism, and Science and Technology Studies, and overlaps and encompasses theorists with various academic disciplines such as geography and architecture. Edward T. Hall developed the study of Proxemics which concentrates on the empirical analysis of space in psychology.
  • 4.5K
  • 03 Nov 2022
Topic Review
CO2 Activation on Catalyst Surfaces
Utilizing CO2 as a sustainable carbon source to form valuable products requires activating it by active sites on catalyst surfaces. These active sites are usually in or below the nanometer scale. Some metals and metal oxides in this scale dimension can catalyze the CO2 transformation reactions. Herein, CO2 activation on metal-based catalyst surfaces and how their structures impact the activation process are highlighted.
  • 4.5K
  • 13 Dec 2021
Topic Review
Fungicides
Fungicides are considered a vital tool for agriculture, protecting crops against fungal diseases and therefore securing high agricultural productivity. The evolution of technology can provide novel chemical fungicides, such as nanofungicides and chiral fungicides, to address plant resistance development. The extensive use of chemical fungicides leads to a risk for public health, natural waters, and non-target organisms.
  • 4.5K
  • 08 Apr 2022
Topic Review
Vitamin D in Dairy Products
The term Vitamin D was created in 1922, describing a vitamin able to promote calcium deposition. Vitamin D in nature is available as ergocalciferol (vitamin D2) or cholecalciferol (vitamin D3).
  • 4.5K
  • 05 Nov 2020
Topic Review
Applications of Tannins
The origin of tannins, their historical evolution, their different types, and their applications are described. Old and established applications are described, as well as the future applications which are being developed at present and that promise to have an industrial impact in the future. The chemistry of some of these applications is discussed where it is essential to understand the tannins and their derivates role. The essential points of each application, their drawbacks, and their chance of industrial application are briefly discussed.
  • 4.5K
  • 29 Jul 2021
Topic Review
Nematode Identification
Nematodes are non-segmented roundworms evenly distributed with various habitats ranging to approximately every ecological extremity. These are the least studied organisms despite being the most diversified group. Nematodes are the most critical equilibrium-maintaining factors, having implications on the yield and health of plants as well as well-being of animals. As a result of the lack of precise taxonomic features, nematode taxonomy remains uncertain. Morphology-based identification has proved inefficacious in identifying and exploring the diversity of nematodes, as there are insufficient morphological variations. Different molecular and new evolving methodologies have been employed to augment morphology-based approaches and bypass these difficulties with varying effectiveness. These identification techniques vary from molecular-based targeting DNA or protein-based targeting amino acid sequences to methods for image processing. High-throughput approaches such as next-generation sequencing have also been added to this league. These alternative approaches have helped to classify nematodes and enhanced the base for increased diversity and phylogeny of nematodes, thus helping to formulate increasingly more nematode bases for use as model organisms to study different hot topics about human well-being.
  • 4.5K
  • 12 Jul 2022
Topic Review
Combat History of the T-26
Though nearly obsolete by the beginning of World War II, the T-26 was the most important tank of the Spanish Civil War and played a significant role during the Battle of Lake Khasan in 1938 as well as in the Winter War. The T-26 was the most numerous tank in the Red Army's armoured force during the German invasion of the Soviet Union in June 1941. The Soviet T-26 light tanks last saw combat in August 1945, in Manchuria. The T-26 was used extensively in the armies of Spain, China and Turkey. In addition, captured T-26 light tanks were used by the Finnish, German, Romanian and Hungarian armies.
  • 4.5K
  • 29 Sep 2022
Topic Review
Insect Pests of Brassica oleracea
The propagation and regeneration of Brassica species has been successful using seeds and different explants like petioles, cotyledons, stems and shoot tips. Shoot regeneration and rooting of Brassica species are successfully obtained from cotyledons and hypocotyl explants. The biological cycle length of Brassica species may either differ slightly or may not differ from one species to another. For instance, the seeds of Brassica oleracea take five days to germinate after sowing at 20–25 °C while the seeds of Brassica campestries take about three to five days to germinate after sowing at 20–25 °C. The most common insect pests of economic importance to Brassica oleracea in African smallholder farmers include Plutella xylostella, Helula undalis, Pieris brassicae, Brevycoryne brassicae, Trichoplusia ni and Myzus persicae. Those insect pests infest cabbages at different stages of growth, causing huge damage and resulting into huge yield losses. The African smallholder farmers use cultural and synthetic pesticides to control those insect pests and minimize infestations. The cultural practices are environmental friendly but are ineffective to control the insect pests. Due to ineffectiveness of cultural practices, African smallholder famers use broad-spectrum synthetic pesticides to effectively control the Brassica species insect pests. The improper and misuse of synthetic pesticides result into insect pests resistance towards the insecticides applied, environmental pollution and human health threats. Insect pests such as Plutella xylostella, Hellula undalis, Brevicoryne brassicae and Myzus persicae have developed resistance to a wide range of pesticides used such as cypermethrin, parathion, decamethrin, quinalphos and lamda-cyhalothrin. Therefore, that calls for search of the alternative products which can effectively be used to control those insect pests in the field.
  • 4.5K
  • 28 Oct 2020
Topic Review Video
Direct Carbon Fuel Cells
Most fuel cells invariably use gaseous or liquid fuels. A fuel cell technology that has attracted attention only recently, the direct carbon fuel cell (DCFC) uses solid fuel (carbon) and converts the chemical energy in the carbon to electricity through its direct participation in the fuel cell reactions and electrochemical oxidation. The fuel use can be almost 100% compared with about 85% for most other fuel cells. The electrical efficiency is expected to be above 70% - almost twice those of current generation coal-fired plants leading to 50% reduction in greenhouse gas emissions. The amount of CO2 for storage/sequestration is also halved. Moreover, the exit gas is almost pure carbon dioxide stream, requiring no or minimal gas separation and processing for sequestration. Therefore, the energy and cost penalties to capture the CO2 will be significantly less than for other technologies. However, the technology is at an early stage of development requiring many complex challenges to be overcome, related to materials and corrosion, fuel delivery mechanism, and system development, before it can be commercialized. Section 19.4 of a recent book by the author gives an overview of this technology focusing on its main issues (Sequeira, 2019.). Two of the main DCFCs, the direct carbon molten carbonate fuel cell (DC-MCFC) and the direct carbon solid oxide fuel cell (DC-SOFC) are described in this topic review. 
  • 4.5K
  • 04 Aug 2021
Topic Review
C3 to CAM Photosynthesis Transition
Global climate change and population growth are persistently posing threats to natural resources (e.g., freshwater) and agricultural production. Crassulacean acid metabolism (CAM) evolved from C3 photosynthesis as an adaptive form of photosynthesis in hot and arid regions. It features the nocturnal opening of stomata for CO2 assimilation, diurnal closure of stomata for water conservation, and high water-use efficiency.
  • 4.5K
  • 08 Sep 2023
Topic Review
Power Electronics for Distributed Generation
Power electronics is formed by technologies that, through advanced controls of semiconductor devices, efficiently convert electrical energy for appropriate use in many areas. Distributed generation (DG), mainly renewable energy, is a group of power sources that can be installed in distinct points of the power system or be isolated, such as: wind power, photovoltaic systems, fuel cells, small hydro, and microturbines. Power converters are a crucial technology for the integration of DG into the modern sustainable power system, including microgrids and smart grids structures. They allow correct adaptation, but also enable DG units to fully realize their potential benefits in their wide variety of configurations.
  • 4.5K
  • 23 Mar 2022
Topic Review
Widow
A widow is a woman whose spouse has died and a widower is a man whose spouse has died. The treatment of widows and widowers around the world varies.
  • 4.5K
  • 25 Oct 2022
Topic Review
Papaverine and Its Mechanism of Action
Papaverine has been proven to be a high-value opioid alkaloid in the field of therapeutics either in solitude or in combination with other metabolites/molecules. Pharmacological research has revealed that papaverine demonstrates a variety of biological activities, including activity against erectile dysfunction, postoperative vasospasms, and pulmonary vasoconstriction, as well as antiviral, cardioprotective, anti-inflammatory, anticancer, neuroprotective, and gestational actions.
  • 4.5K
  • 07 Apr 2023
Topic Review
Bitumen Aging and Rejuvenation Chemistry
Bitumen aging and rejuvenation include a series of chemical transformations that the material undergoes and that results in the variation of its physical characteristics.
  • 4.5K
  • 30 Jun 2021
Topic Review
MINIX
Minix (from "mini-Unix") is a POSIX-compliant (since version 2.0), Unix-like operating system based on a microkernel architecture. Early versions of MINIX were created by Andrew S. Tanenbaum for educational purposes. Starting with MINIX 3, the primary aim of development shifted from education to the creation of a highly reliable and self-healing microkernel OS. MINIX is now developed as open-source software. MINIX was first released in 1987, with its complete source code made available to universities for study in courses and research. It has been free and open-source software since it was re-licensed under the BSD license in April 2000.
  • 4.5K
  • 28 Sep 2022
Topic Review
Waveguide (Electromagnetism)
In electromagnetics and communications engineering, the term waveguide may refer to any linear structure that conveys electromagnetic waves between its endpoints. However, the original and most common meaning is a hollow metal pipe used to carry radio waves. This type of waveguide is used as a transmission line mostly at microwave frequencies, for such purposes as connecting microwave transmitters and receivers to their antennas, in equipment such as microwave ovens, radar sets, satellite communications, and microwave radio links. A dielectric waveguide employs a solid dielectric rod rather than a hollow pipe. An optical fibre is a dielectric guide designed to work at optical frequencies. Transmission lines such as microstrip, coplanar waveguide, stripline or coaxial cable may also be considered to be waveguides. The electromagnetic waves in a (metal-pipe) waveguide may be imagined as travelling down the guide in a zig-zag path, being repeatedly reflected between opposite walls of the guide. For the particular case of rectangular waveguide, it is possible to base an exact analysis on this view. Propagation in a dielectric waveguide may be viewed in the same way, with the waves confined to the dielectric by total internal reflection at its surface. Some structures, such as non-radiative dielectric waveguides and the Goubau line, use both metal walls and dielectric surfaces to confine the wave.
  • 4.5K
  • 07 Oct 2022
Topic Review
IMAGE
IMAGE (Imager for Magnetopause-to-Aurora Global Exploration) is a NASA Medium Explorers mission that studied the global response of the Earth's magnetosphere to changes in the solar wind. It was believed lost but as of August 2018 might be recoverable. It was launched 25 March 2000 by a Delta II rocket from Vandenberg Air Force Base on a two-year mission. Almost six years later, it unexpectedly ceased operations in December 2005 during its extended mission and was declared lost. The spacecraft was part of NASA's Sun-Earth Connections Program, and during its run had over 400 research articles published in peer-reviewed journals using its data. It had special cameras that provided various breakthroughs in understanding the dynamics of plasma around the Earth. The Principal Investigator was Jim Burch of the Southwest Research Institute. In January 2018, an amateur satellite tracker found it to be transmitting some signals back to Earth. NASA made attempts to communicate with the spacecraft and determine its payload status, but has had to track down and adapt old hardware and software to the current systems. On 25 February, contact with IMAGE was again lost, but if reestablished, NASA may decide to fund a restarted mission.
  • 4.5K
  • 13 Oct 2022
Topic Review
Reusable Launch System
A reusable launch system is a launch system that allows for the reuse of some or all of the component stages. To date, several fully reusable suborbital systems and partially reusable orbital systems have been flown. The first reusable spacecraft to reach orbit was the Space Shuttle (in 1981), which failed to accomplish the intended goal of reducing launch costs to below those of expendable launch systems. During the 21st century, commercial interest in reusable launch systems has grown considerably, with several active launchers. SpaceX CEO Elon Musk has said that if one can figure out how to reuse rockets like airplanes then the cost of access to space will be reduced by as much as a factor of a hundred. SpaceX's Falcon 9 rocket has a reusable first stage and capsule (for Dragon flights) with an expendable second stage. SpaceX has been developing a reusable second stage since the late 2010s which, if successful, could make possible the first fully-reusable orbital launch vehicle during the 2020s. Virgin Galactic has flown reusable suborbital spaceplanes, and the suborbital Blue Origin New Shepard rocket has a recoverable boost stage and passenger capsule.
  • 4.5K
  • 12 Dec 2022
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