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Topic Review
Innovative Uses of Polyhydroxyalkanoates
Polyhydroxyalkanoate (PHA), a biodegradable polymer obtained from microorganisms and plants, have been widely used in biomedical applications and devices, such as sutures, cardiac valves, bone scaffold, and drug delivery of compounds with pharmaceutical interests, as well as in food packaging. The novel applications are based on the production and composition of the polymer, which can be modified by genetic engineering, a semi-synthetic approach, by changing feeding carbon sources and/or supplement addition, among others. The future of PHA is promising, and despite its production costs being higher than petroleum-based plastics, tools given by synthetic biology, bioinformatics, and machine learning, among others, have allowed for great production yields, monomer and polymer functionalization, stability, and versatility, a key feature to increase the uses of this interesting family of polymers.
  • 2.1K
  • 13 Dec 2022
Topic Review
Biomass-Based Chemical Looping Gasification
Chemical Looping Gasification is a process allowing for the conversion of solid feedstock (e.g. biomass) into N2-free, high-calorific syngas or producer gas. The process utilizes the ability of so-called oxygen carriers (e.g. ilmenite, iron ore) to take up and release oxygen in oxidizing and reducing atmospheres, respectively. Employing this characteristic, the oxygen carrier is cycled between two or more reactors to transport oxygen into the so-called fuel reactor, where the inlet feedstock is firstly gasified using steam or CO2, before intermediate gaseous products (e.g. H2, CH4) are further oxidized by the oxygen carrier, providing additional process heat to drive the endothermic gasification reactions. The loop is then closed as the reduced oxygen carrier is re-oxidized in a so-called air reactor, using the oxygen contained in ambient air, resulting in a stream of pure nitrogen at the air reactor outlet.
  • 2.1K
  • 03 Nov 2021
Topic Review
Calcium Carbonate
Technologies for the management of various types of waste and the production of useful products from them are currently widely studied. Both carbon dioxide and calcium-rich waste from various production processes are problematic wastes that can be used to produce calcium carbonate. Therefore, the purpose of this paper is to provide an overview about the state of the development of processes that use these two wastes to obtain a valuable CaCO3 powder.
  • 2.1K
  • 15 Dec 2020
Topic Review
Gut Lymphatic Vessels
Lymphatic vessels play a distinctive role in draining fluid, molecules and even cells from interstitial and serosal spaces back to the blood circulation. Lymph vessels of the gut, and especially those located in the villi (called lacteals), not only serve this primary function, but are also responsible for the transport of lipid moieties absorbed by the intestinal mucosa and serve as a second line of defence against possible bacterial infections.
  • 2.1K
  • 15 Oct 2021
Topic Review
Prussian Blue and Its Analogues
Prussian blue analogues (PBAs)-based anode materials (oxides, sulfides, selenides, phosphides, borides, and carbides) have been extensively investigated in the field of energy conversion and storage. This is due to PBAs’ unique properties, including high theoretical specific capacity, environmental friendly, and low cost.
  • 2.1K
  • 02 Mar 2023
Topic Review
Paint Atomization and Paint Film Formation
The special surface appearance of complex surfaces restricts the coating film quality of spraying. The study of the atomization and film formation characteristics of typical complex surfaces, as well as the spraying mechanism, is essential for planning the spraying robotic trajectory and improving the spraying efficiency. Modeling and characteristics of the atomization and film formation process, based on CFD numerical simulations in previous studies, are systematically reviewed, focusing especially on airless spraying. In addition, the advantages and disadvantages of the existing research from the perspective of numerical models and methods are discussed. Finally, a further research direction for spraying on complex surface is prospected. Overall, a comprehensive and up-to-date review of spray atomization and film formation characteristics is considered valuable to practitioners and researchers in these fields, and will facilitate the further application of robotic spraying in the mechanical, automotive, marine, aerospace, petrochemical and other industries.
  • 2.1K
  • 22 Dec 2023
Topic Review
Health Benefits of Phenolic Compounds from Pigmented Corn
Pigmented corn is a gramineae food of great biological, cultural and nutritional importance for many Latin American countries, with more than 250 breeds on the American continent. It confers a large number of health benefits due to its diverse and abundant bioactive compounds. Phenolic compounds, among which are anthocyanins are some of the most studied and representative compounds in these grasses, with a wide range of health properties, mainly the reduction of pro-oxidant molecules.
  • 2.1K
  • 13 Mar 2024
Topic Review
Maximum Power Point Techniques for Solar Photovoltaic Systems
The characteristics of a PV (photovoltaic) module is non-linear and vary with nature. The tracking of maximum power point (MPP) at various atmospheric conditions is essential for the reliable operation of solar-integrated power generation units. Researchers compare the most widely used maximum power point tracking (MPPT) techniques such as the perturb and observe method (P&O), incremental conductance method (INC), fuzzy logic controller method (FLC), neural network (NN) model, and adaptive neuro-fuzzy inference system method (ANFIS) with the modern approach of the hybrid method (neural network + P&O) for PV systems. The hybrid method combines the strength of the neural network and P&O in a single framework. The PV system is composed of a PV panel, converter, MPPT unit, and load modelled using MATLAB/Simulink. These methods differ in their characteristics such as convergence speed, ease of implementation, sensors used, cost, and range of efficiencies. Based on all these, performances are evaluated. In this analysis, the drawbacks of the methods are studied, and wastage of the panel’s available output energy is observed. The hybrid technique concedes a spontaneous recovery during dynamic changes in environmental conditions. The simulation results illustrate the improvements obtained by the hybrid method in comparison to other techniques.
  • 2.1K
  • 01 Dec 2022
Topic Review
Laser Dynamic Compression in Diamond Anvil Cells
The field of high-pressure materials research has grown steadily, with many remarkable discoveries having been made. Recent progress in laser material processing within diamond anvil cells (L-DACs); researchers focus on the practice of laser-driven dynamic compression within diamond anvil cells (i.e., LDC–DAC experimentation).
  • 2.1K
  • 28 Nov 2022
Topic Review
Graphene
Graphene is the new generation material, which finds potential and practical applications in a vast range of research areas. It has unrivalled characteristics, chiefly in terms of electronic conductivity, mechanical robustness and large surface area, which allow the attainment of outstanding performances in many fields of materials science.
  • 2.1K
  • 09 Oct 2020
Topic Review
Sensing Tyrosinase Activity
Tyrosinase (TYR, E.C. 1.14.18.1), a critical enzyme participating in melanogenesis, catalyzes the first two steps in melanin biosynthesis including the ortho-hydroxylation of L-tyrosine and the oxidation of L-DOPA. Previous pharmacological investigations have revealed that an abnormal level of TYR is tightly associated with various dermatoses, including albinism, age spots, and malignant melanoma.
  • 2.1K
  • 08 Sep 2021
Topic Review
Large Synoptic Survey Telescope
The Large Synoptic Survey Telescope (LSST) is a wide-field survey reflecting telescope with an 8.4-meter primary mirror, currently under construction, that will photograph the entire available sky every few nights. The word synoptic is derived from the Greek words σύν (syn "together") and ὄψις (opsis "view"), and describes observations that give a broad view of a subject at a particular time. The telescope uses a novel 3-mirror design, a variant of three-mirror anastigmat, which allows a compact telescope to deliver sharp images over a very wide 3.5-degree diameter field of view. Images will be recorded by a 3.2-gigapixel CCD imaging camera, the largest digital camera ever constructed. The telescope is located on the El Peñón peak of Cerro Pachón, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile , alongside the existing Gemini South and Southern Astrophysical Research Telescopes. The LSST Base Facility is located about 100 kilometres (62 mi) away by road, in the town of La Serena. The LSST was proposed in 2001, and construction of the mirror began (with private funds) in 2007. LSST then became the top-ranked large ground-based project in the 2010 Astrophysics Decadal Survey, and the project officially began construction 1 August 2014 when the National Science Foundation (NSF) authorized the FY2014 portion ($27.5 million) of its construction budget. The ceremonial laying of the first stone was performed on 14 April 2015. Site construction began on April 14, 2015, with engineering first light anticipated in 2019, science first light in 2021, and full operations for a ten-year survey commencing in January 2022. LSST, unlike almost all previous large astronomical observatories, has committed to making all data public as soon as it is taken. In their words "By providing immediate public access to all the data it obtains, it will provide everyone, the professional and the “just curious” alike, a deep and frequent window on the entire sky."
  • 2.1K
  • 10 Nov 2022
Topic Review
Wearable Sensors and Computer-Vision-Based Methods
Real-time sensing and modeling of the human body, especially the hands, is an important research endeavor for various applicative purposes such as in natural human computer interactions. Hand pose estimation is a big academic and technical challenge due to the complex structure and dexterous movement of human hands. Boosted by advancements from both hardware and artificial intelligence, various prototypes of data gloves and computer-vision-based methods have been proposed for accurate and rapid hand pose estimation in recent years. However, existing reviews either focused on data gloves or on vision methods or were even based on a particular type of camera, such as the depth camera. The purpose of this survey is to conduct a comprehensive and timely review of recent research advances in sensor-based hand pose estimation, including wearable and vision-based solutions. Hand kinematic models are firstly discussed. An in-depth review is conducted on data gloves and vision-based sensor systems with corresponding modeling methods. Particularly, this review also discusses deep-learning-based methods, which are very promising in hand pose estimation. Moreover, the advantages and drawbacks of the current hand gesture estimation methods, the applicative scope, and related challenges are also discussed.
  • 2.1K
  • 22 Feb 2021
Topic Review
N-Type Organic Semiconductors
This work was intended to enlarge the gates toward green organic technologies at room temperature, searching for new types of semiconductors with low toxicity and simple molecular organization. In our previous studies, para-aminobenzoic acid was used to construct a p-type green semiconductor. A non-toxic organic compound, acting as an electron donor, is sulpho-salicylic acid. SSA can be efficiently attached to the external shell of a ferrite (Fe3O4) nanocore, providing Fe3O4–SSA nanoparticles. This is a N-Type Organic Semiconductor - made by green technologies and used to construct a simple thin film transistor. 
  • 2.1K
  • 22 Oct 2020
Topic Review
Pre-clinical Cerebral Perfusion MRI Techniques
Alterations to the cerebral microcirculation have been recognized to play a crucial role in the development of neurodegenerative disorders. However, the exact role of the microvascular alterations in the pathophysiological mechanisms often remains poorly understood. The early detection of changes in microcirculation and cerebral blood flow (CBF) can be used to get a better understanding of underlying disease mechanisms. This could be an important step towards the development of new treatment approaches. Animal models allow for the study of the disease mechanism at several stages of development, before the onset of clinical symptoms, and the verification with invasive imaging techniques. Specifically, pre-clinical magnetic resonance imaging (MRI) is an important tool for the development and validation of MRI sequences under clinically relevant conditions. This article reviews MRI strategies providing indirect non-invasive measurements of microvascular changes in the rodent brain that can be used for early detection and characterization of neurodegenerative disorders. The perfusion MRI techniques: Dynamic Contrast Enhanced (DCE), Dynamic Susceptibility Contrast Enhanced (DSC) and Arterial Spin Labeling (ASL), will be discussed, followed by less established imaging strategies used to analyze the cerebral microcirculation: Intravoxel Incoherent Motion (IVIM), Vascular Space Occupancy (VASO), Steady-State Susceptibility Contrast (SSC), Vessel size imaging, SAGE-based DSC, Phase Contrast Flow (PC) Quantitative Susceptibility Mapping (QSM) and quantitative Blood-Oxygenation-Level-Dependent (qBOLD). We will emphasize the advantages and limitations of each strategy, in particular on applications for high-field MRI in the rodent’s brain. 
  • 2.1K
  • 02 Jun 2021
Topic Review
Product Attributes, Evaluability, and Consumer Satisfaction
Consumer satisfaction is considered essential to long-term business success. Organizations have a need to produce products and services that yield highly satisfied and loyal consumers. Having loyal consumers reduces the costs for firms, since the expenses for acquiring new consumers are much higher than those for keeping existing ones. Studying the factors that determine consumer satisfaction is of vital importance for a company, as consumer satisfaction has been described as the best indicator of a company’s future profits. In addition, several studies have indicated that there are positive effects of consumer satisfaction on overall brand equity and its different aspects, i.e., retailer awareness, retailer associations, the retailers’ perceived quality, and retailer loyalty. Most studies of consumer satisfaction have been based on the overall satisfaction with a product as a whole, while only a few have related consumer satisfaction to the performance of product attributes. We aimed to study which type of product attribute leads to the most satisfaction, thus providing clues for providers to improve their products. We focused on attribute evaluability and analyzed the ease or difficulty in evaluating a product’s attribute. This was assumed to be related to consumer satisfaction Although evaluability has usually been manipulated experimentally, we studied evaluability as a consumer’s perceptions of product attributes. We aimed to show the effects of attribute evaluability on consumer satisfaction outside of the laboratory context, in a real consumer setting. This aim matched the endeavor in research to study the scaling-up of small-scale laboratory findings to larger markets and settings, as advocated by List.  Another basic process in the formation of consumer satisfaction is a judgment of product performance that is relative to the reference point of the product’s performance expectations. In general, the positive disconfirmation of expectations (the perceived realizations of performance exceeding expectations) will lead to consumer satisfaction, whereas negative disconfirmation (the perceived realizations of performance falling short of expectations) induces dissatisfaction. From prospect theory, it is known that negative deviations from a reference point are judged more negatively than their commensurate positive deviations are judged positively, thus indicating asymmetric effects of product evaluations.  A hitherto under-researched topic is whether consumer satisfaction differs when it is due to an attribute expectation disconfirmation of easy-to-evaluate versus difficult-to-evaluate attributes. This topic is theoretically interesting, because such differences may be driven by different psychological processes. Also, it is of practical significance, because it provides a clue to providers in regard to the type of product attributes for which negative expectation disconfirmation needs to be avoided. We consider attribute evaluability as a factor that moderates the effects of attribute disconfirmation on consumer satisfaction.
  • 2.1K
  • 15 Nov 2021
Topic Review
Photoautotrophic Euendoliths
Photoautotrophic euendoliths, including cyanobacteria, and red and green microalgae, are part of the endolithic community. The term ‘endolith’ refers to a morphologically and physiologically heterogenous group of microorganisms living within a rock or other stony matter, such as coral skeletons or animal shells, and more specifically, to organisms that actively bore into relatively soluble substrates, such as phosphate and carbonate substrates. Euendoliths are ubiquitous, as they can be found in almost every environment, geographical location, or depth, where the appropriate substratum (e.g., relatively soluble carbonate and phosphate substrates) is available and the requirements for photosynthesis are met. The most diverse and abundant modern euendolithic communities can be found in the marine environment. Euendoliths, as microorganisms infesting inanimate substrates, were first thought to be ecologically irrelevant. Numerous studies have subsequently shown that euendoliths can colonize living marine calcifying organisms, such as coral skeletons and bivalve shells, causing both sub-lethal and lethal damage. Moreover, under suitable environmental conditions, their presence can have surprising benefits for the host. Thus, infestation by photoautotrophic euendoliths has significant consequences for calcifying organisms that are of particular importance in the case of ecosystems underpinned by calcifying ecosystem engineers.
  • 2.1K
  • 17 Oct 2022
Topic Review
Felicia (Genus)
Felicia is a genus of small shrubs, perennial or annual herbaceous plants, with 85 known species, that is assigned to the daisy family (Compositae or Asteraceae). Like in almost all Asteraceae, the individual flowers are 5-merous, small and clustered in typical heads, and which are surrounded by an involucre of, in this case between two and four whorls of, bracts. In Felicia, the centre of the head is taken by yellow, seldomly whitish or blackish blue disc florets, and is almost always surrounded by one single whorl of mostly purple, sometimes blue, pink, white or yellow ligulate florets and rarely ligulate florets are absent. These florets sit on a common base (or receptacle) and are not individually subtended by a bract (or palea). Most species occur in the Cape Floristic Region, which is most probably the area where the genus originates and had most of its development. Some species can be found in the eastern half of Africa up to Sudan and the south-western Arabian peninsula, while on the west coast species can be found from the Cape to Angola and one species having outposts on the Cameroon-Nigeria border and central Nigeria. Some species of Felicia are cultivated as ornamentals and several hybrids have been developed for that purpose.
  • 2.1K
  • 21 Oct 2022
Topic Review
Reformed Fundamentalism
Reformed fundamentalism arose in some conservative Presbyterian, Reformed Baptist, and other Reformed churches, which agreed with the motives and aims of broader evangelical Protestant fundamentalism. The fundamentalism of the movement is defined by a rejection of liberal and modernist theology, and the legacy of The Fundamentals, published at the start of the twentieth century. The Fundamentalist–Modernist controversy, and the Downgrade Controversy in the United Kingdom, shaped reformed fundamentalism in the United States and United Kingdom. Some of the better known leaders who have described themselves as both Calvinist and fundamentalist have been Carl McIntire of the American Bible Presbyterian Church, D. James Kennedy of Coral Ridge Presbyterian Church, Ian Paisley of the Northern Irish Free Presbyterian Church of Ulster and J. Oliver Buswell of Wheaton College. J. Gresham Machen, Cornelius Van Til, Martyn Lloyd-Jones, J. I. Packer and John Stott were Protestant theologians with moderate associations to the movement. Those in the reformed fundamentalist tradition draw upon the lives and works of Protestant ministers, particularly from the Anglosphere, of sundry centuries. John Calvin, Martin Luther, John Gill, Matthew Henry, Charles Spurgeon, J. C. Ryle, John Wesley, George Whitefield, John Knox, Jonathan Edwards, John Bunyan, G. Campbell Morgan, were evangelical inspirations for McIntire, Paisley and others.
  • 2.1K
  • 04 Nov 2022
Topic Review
Green Building Standards and Sustainability in Iran
The concept of green buildings (GBs) is a recent response to addressing the problems that stem from the building sector. The World Green Building Council (WGBC) defines a green building as “a building that reduces or eliminates negative impacts, in its design, construction or operation and can have positive impacts on the climate and natural environment”. Green buildings use environmentally friendly materials and ensure the optimal use of natural resources, such as water and energy, and minimum waste production. Researchers have analyzed various aspects of GBs, such as technological innovation, energy savings, risk management, influencing factors for development, policy incentives and regulations, and economic benefits.
  • 2.1K
  • 22 Dec 2023
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