99 research outputs found
Meloidogyne graminicola (Golden and Birchfield): Threat to Rice Production
Abstract Meloidogyne graminicola (Golden and Birchfield
Influence of Grain Size on the Band-gap of Annealed SnS Thin Films
The manuscript reports the variation in optical band-gap of vacuum annealed
SnS thin films. The samples were characterized by using X-Ray Diffraction,
UV-visible Spectroscopy and Raman Analysis. Results show that while annealing
does not effect the nano-crystalline sample's lattice structure or unit cell
size it does control the grain size. The band-gap (Eg) decreases with increase
in grain size. Eg values were found to be very high (1.8-2.5 eV) for samples
studied
Advanced Technologies for Oral Controlled Release: Cyclodextrins for oral controlled release
Cyclodextrins (CDs) are used in oral pharmaceutical formulations, by means of inclusion complexes formation, with the following advantages for the drugs: (1) solubility, dissolution rate, stability and bioavailability enhancement; (2) to modify the drug release site and/or time profile; and (3) to reduce or prevent gastrointestinal side effects and unpleasant smell or taste, to prevent drug-drug or drug-additive interactions, or even to convert oil and liquid drugs into microcrystalline or amorphous powders. A more recent trend focuses on the use of CDs as nanocarriers, a strategy that aims to design versatile delivery systems that can encapsulate drugs with better physicochemical properties for oral delivery. Thus, the aim of this work was to review the applications of the CDs and their hydrophilic derivatives on the solubility enhancement of poorly water soluble drugs in order to increase their dissolution rate and get immediate release, as well as their ability to control (to prolong or to delay) the release of drugs from solid dosage forms, either as complexes with the hydrophilic (e.g. as osmotic pumps) and/ or hydrophobic CDs. New controlled delivery systems based on nanotechonology carriers (nanoparticles and conjugates) have also been reviewed
Antimony-Doped Tin(II) Sulfide Thin Films
Thin-film solar cells made from earth-abundant, inexpensive, and nontoxic materials are needed to replace the current technologies whose widespread use is limited by their use of scarce, costly, and toxic elements. Tin monosulfide (SnS) is a promising candidate for making absorber layers in scalable, inexpensive, and nontoxic solar cells. SnS has always been observed to be a p-type semiconductor. Doping SnS to form an n-type semiconductor would permit the construction of solar cells with p-n homojunctions. This paper reports doping SnS films with antimony, a potential n-type dopant. Small amounts of antimony (1%) were found to greatly increase the electrical resistance of the SnS. The resulting intrinsic SnS(Sb) films could be used for the insulating layer in a p-i-n design for solar cells. Higher concentrations (5%) of antimony did not convert the SnS(Sb) to low-resistivity n-type conductivity, but instead the films retain such a high resistance that the conductivity type could not be determined. Extended X-ray absorption fine structure analysis reveals that the highly doped films contain precipitates of a secondary phase that has chemical bonds characteristic of metallic antimony, rather than the antimony–sulfur bonds found in films with lower concentrations of antimony.United States. Dept. of Energy. Sunshot Initiative (Contract DE-EE0005329)National Science Foundation (U.S.) (Grant CBET-1032955
Technical standards for digital electroencephalogram recording in epilepsy practice
With the advent of digital technology in the recording of the electroencephalogram (EEG) in the last decade, analogue paper-EEG machines have all but disappeared. While there are several advantages of digital EEG over its analog counterpart, like being paperless and therefore easy to store and the ability to change montages and filter settings during review, there is wide disparity in the standards of EEG recording, display and reporting in laboratories across the country. Colorful brain maps conveying little meaning are usually appended to reports. This article reviews the minimum standards that must be observed for recording digital EEG as recommended by the International Federation of Clinical Neurophysiology (IFCN) and illustrates the importance of use of appropriate derivations, montages, filters and gains during recording and review of digital EEG in the context of evaluation of patients with suspected epilepsy
Whitelisting versus advertising-recovery: Strategies to overcome advertising blocking by consumers
The significance of online advertising as a primary revenue stream for digital media cannot be understated. However, the rising adoption of ad-blocking software by users has adversely affected these revenues. In response to this challenge, digital publishers are exploring various strategies not only to maintain their revenues, but also to enhance them through online advertising, in addition to paid subscriptions. We discuss three potential strategies to overcome ad-blocking. The first is the subscription fee strategy, termed the benchmark strategy in the paper, wherein users pay a subscription fee to access content without encountering any ads. The second strategy is whitelisting, which involves publishers seeking users’ consent to display acceptable ads that support the website. The third approach is ad-recovery, which employs a third-party service to continue displaying ads even to users employing ad-blocking software. We utilize a duopolistic game-theoretical framework and identify conditions under which digital publishers might adopt either symmetric or asymmetric strategies to counter ad-blocking usage. We find that both firms tend to opt for whitelisting when the advertising revenue parameter is relatively low, and the proportion of consenting ad-block users is relatively high. On the other hand, when the advertising revenue parameter is high, and the proportion of consenting ad-block users is low, both firms benefit from an ad-recovery strategy. Further, under some conditions, firms utilize asymmetric strategies. The analysis suggests that a number of consumer- and firm-level factors represent important determinants of the digital marketing strategies of media firms
Spray Pyrolysed Tin Chalcogenide Thin Films: Optimization of optoelectronic properties of SnS for possible photovoltaic application as an absorber layer
In the early 19th century, industrial revolution was fuelled mainly by
the development of machine based manufacturing and the increased use of
coal. Later on, the focal point shifted to oil, thanks to the mass-production
technology, ease of transport/storage and also the (less) environmental
issues in comparison with the coal!! By the dawn of 21st century, due to the depletion of oil reserves and pollution resulting from heavy usage of oil the demand for clean energy was
on the rising edge. This ever growing demand has propelled research on photovoltaics which has emerged successful and is currently being looked up to as the only solace for meeting our present day energy requirements. The proven PV technology on commercial scale is based on silicon but the recent boom in the demand for photovoltaic modules has in turn created a shortage in supply of silicon. Also the technology is still not accessible to common man. This has onset the research and development work on moderately efficient, eco-friendly and low cost photovoltaic devices (solar cells). Thin film photovoltaic modules have made a breakthrough entry in the PV market on these grounds. Thin films have the potential to revolutionize the present cost structure of solar cells by eliminating the use of the expensive silicon wafers that alone accounts for above 50% of total module manufacturing cost.Well developed thin film photovoltaic technologies are based on amorphous silicon, CdTe and CuInSe2. However the cell fabrication process using amorphous silicon requires handling of very toxic gases (like phosphene, silane and borane) and costly technologies for cell fabrication. In the case of other materials too, there are difficulties like maintaining stoichiometry (especially in large area films), alleged environmental hazards and high cost of indium. Hence there is an urgent need for the development of materials that are easy to prepare, eco-friendly and available in abundance. The work presented in this thesis is an attempt towards the development of a cost-effective, eco-friendly material for thin film solar cells using simple economically viable technique. Sn-based window and absorber layers deposited using Chemical Spray Pyrolysis (CSP) technique have been chosen for the purposeCochin University of Science and TechnologyDepartment of Physics
Cochin University of Science and Technolog
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