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Dust vortices with a void at the centre are reported in this paper. The role of the spatial variation of the plasma potential in the rotation of dust particles is studied in a parallel plate glow discharge plasma. Probe measurements reveal the existence of a local potential minimum in the region of formation of the dust vortex. The minimum in the potential well attracts positively charged ions, while it repels the negatively charged dust particles. Dust rotation is caused by the interplay of the two oppositely directed ion drag and Coulomb forces. The balance between these two forces is found to play a major role in the radial confinement of the dust particles above the cathode surface. Evolution of the dust vortex is studied by increasing the discharge current from 15 to 20 mA. The local minimum of the potential profile is found to coincide with the location of the dust vortex for both values of discharge currents. Additionally, it is found that the size of the dust vortex as well as the void at the centre increases with the discharge current.
We have studied, the relationship between monthly variations of average counting rates of cosmic ray intensity (CRI) at Moscow super neutron monitoring station with mid cut-off rigidities (~2.42 GV), and the solar radio flux at 10.7cm (F10.7) and sunspot number (SSN) during the solar cycles 22 − 24. The F10.7cm (2800 MHz) and SSN is an excellent indicator of solar activity for the study period. We have investigated the patterns of long-term and mid-term periodicities of SSN and F10.7, using Fast Fourier Transform (FFT) technique. We have observed the time-lag between ascending phase of CRI with F10.7cm and SSN during solar cycles 22 − 24.
A polarimeter for the measurement of Stokes' parameters for stellar and quasi stellar objects in specific wavelength regions has been reported. The variable retardation and dispersive property of a small angle Babinet Compensator has been exploited for such measurement. The theoretical basis of the method is given in detail.
Measurements of local plasma parameters in dusty plasma are crucial for understanding
the physics issues related to such systems. The Langmuir probe, a small electrode
immersed in the plasma, provides such measurements. However, designing of a Langmuir
probe system in a dusty plasma environment demands special consideration. First, the
probe has to be miniaturized enough so that its perturbation on the ambient dust
structure is minimal. At the same time, the probe dimensions must be such that a
well-defined theory exists for interpretation of its characteristics. The associated
instrumentation must also support the measurement of current collected by the probe
with high signal to noise ratio. The most important consideration, of course, comes
from the fact that the probes are prone to dust contamination, as the dust particles
tend to stick to the probe surface and alter the current collecting area in
unpredictable ways. This article describes the design and operation of a Langmuir
probe system that resolves these challenging issues in dusty plasma. In doing so,
first, different theories that are used to interpret the probe characteristics in
collisionless as well as in collisional regimes are discussed, with special emphasis
on application. The critical issues associated with the current–voltage
characteristics of Langmuir probe obtained in different operating regimes are
discussed. Then, an algorithm for processing these characteristics efficiently in
presence of ion-neutral collisions in the probe sheath is presented.
On June 22, 1982, the main power transformer at a local high school (St. Paul, Minnesota) overheated, causing the pressure relief valve to operate and release smoke and mist throughout the building. The transformer contained thermal-dielectric fluid with the tradename “Pyranol,” consisting of polychlorinated biphenyls (PCB's) in the form of “Aroclor” and chlorinated benzenes. The transformer did not explode or flame. The emmission characterized by a “white mist” occurred over an approximately 4-hour period with resultant contamination of basement and first floor areas. The temperature of the emission was estimated to be approximately 250-300°F.
“Pyranol” contains PCB aroclor 1260 (45%) and chlorinated benzenes (40% trichloro and 15% tetrachlorobenzenes). Commercial PCB preparations manufactured in the United States have been marketed under the trade name “Aroclor.” Several grades of Aroclor have been designated by numbers such as 1260. The first two digits represent the type of molecule (12 = chlorinated biphenyl). The last wo digits give the weight percent of chlorine.
The fire was discovered by the school janitor and the firefighters arrived at 5:40 a.m. As the firefighters walked near the transformer, several men began complaining of nausea, sore throat and burning of exposed skin. Firefighters having symptoms were asked to go out in the open and were immediately hosed down with water. Initially, 14 firefighters were taken to the emergency room of St. Paul-Ramsey Medical Center, where they were evaluated, treated and released. When inquiry was begun to find out what kind of substance was burning, it was discovered that the transformer which contained “Pyranol” (installed in the school in 1958) had overheated.
In recent years a number of intergovernmental initiatives have been activated in order to enhance the capacity of countries to improve access to essential medicines, particularly for mental disorders. In May 2013 the 66th World Health Assembly adopted the World Health Organization (WHO) Comprehensive Mental Health Action Plan 2013–2020, which builds upon the work of WHO's Mental Health Gap Action Programme. Within this programme, evidence-based guidelines for mental disorders were developed, including recommendations on appropriate use of medicines. Subsequently, the 67th World Health Assembly adopted a resolution on access to essential medicines, which urged Member States to improve national policies for the selection of essential medicines and to promote their availability, affordability and appropriate use.
Following the precedent set by these important initiatives, this article presents eleven actions for improving access and appropriate use of psychotropic medicines.
A 4 × 4 framework mapping actions as a function of the four components of access – selection, availability, affordability and appropriate use – and across four different health care levels, three of which belong to the supply side and one to the demand side, was developed. The actions are: developing a medicine selection process; promoting information and education activities for staff and end-users; developing a medicine regulation process; implementing a reliable supply system; implementing a reliable quality-control system; developing a community-based system of mental health care and promoting help-seeking behaviours; developing international agreements on medicine affordability; developing pricing policies and a sustainable financing system; developing or adopting evidence-based guidelines; monitoring the use of psychotropic medicines; promoting training initiatives for staff and end-users on critical appraisal of scientific evidence and appropriate use of psychotropic medicines.
Activating these actions offers an unique opportunity to address the broader issue of increasing access to treatments and care for mental disorders, as current lack of attention to mental disorders is a central barrier across all domains of the 4 × 4 access framework.
The discovery of graphene based materials has led to significant advancement in several different areas. The large surface area, nanoporous structure and availability of delocalized electron network provide a unique opportunity for purification of solvents via adsorption, absorption or simple trapping. This makes graphene based materials as potential candidates for purification and desalination of water. Here we report synthesis of 3D porous network of oxidized graphene for purification of sea water. The membranes fabricated using these frameworks are hierarchically linked intrinsically defected oxidised graphene sheets by long micro-channels and capable of filtering small ions such as Na+ and Cl-. These are easy to fabricate, reusable and economically viable especially for point of use application. We finally show a fabricated device using membrane made from these 3D networks of oxidized graphene.
Various promising applications such as acoustic cloaking, sub-wavelength imaging, acoustic wave manipulation, transmission or reflection control etc. are feasible because of the ability of manipulating sounds and vibrations using artificially engineered “Acoustics meta-materials”. Recent works on space-coiling acoustic metamaterials show their extreme constitutive parameters like large refractive index, double negativity and zero mass density. Three dimensional structures have a wide application in sub-wavelength broadband acoustic wave suppression due to huge attenuation. Here we report the study of propagated and transmitted wave through 3D acoustic metamaterials structure using finite element method. Our simulations on 3D structure show a huge absorption/damping over few hundreds kilohertz frequency range.
In a quasineutral plasma, electrons undergo collective oscillations, known as plasma oscillations, when perturbed locally. The oscillations propagate due to finite temperature effects. However, the wave can lose the phase coherence between constituting oscillators in an inhomogeneous plasma (phase mixing) because of the dependence of plasma oscillation frequency on plasma density. The longitudinal electric field associated with the wave may be used to accelerate electrons to high energies by exciting large amplitude wave. However when the maximum amplitude of the wave is reached that plasma can sustain, the wave breaks. The phenomena of wave breaking and phase mixing have applications in plasma heating and particle acceleration. For detailed experimental investigation of these phenomena a new device, inverse mirror plasma experimental device (IMPED), has been designed and fabricated. The detailed considerations taken before designing the device, so that different aspects of these phenomena can be studied in a controlled manner, are described. Specifications of different components of the IMPED machine and their flexibility aspects in upgrading, if necessary, are discussed. Initial results meeting the prerequisite condition of the plasma for such study, such as a quiescent, collisionless and uniform plasma, are presented. The machine produces δnnoise/n ⩽ 1%, Luniform ~ 120 cm at argon filling pressure of ~10−4 mbar and axial magnetic field of B = 1090 G.
Guanylate kinase, a nucleoside monophosphate kinase of Brugia malayi which is involved in reversible transfer of phosphate groups from ATP to GMP, was cloned, expressed and characterized. The native molecular mass of BmGK was found to be 45 kDa as determined by size exclusion chromatography and glutaraldehyde cross-linking which revealed that the protein is homodimer in nature. This is a unique characteristic among known eukaryotic GKs. GMP and ATP served as the most effective phosphate acceptor and donor, respectively. Recombinant BmGK utilized both GMP and dGMP, as substrates showing Km values of 30 and 38 μm, respectively. Free Mg+2 (un-complexed to ATP) and GTP play a regulatory role in catalysis of BmGK. The enzyme showed higher catalytic efficiency as compared with human GK and showed ternary complex (BmGK-GMP-ATP) formation with sequential substrate binding. The secondary structure of BmGK consisted of 45% α-helices, 18% β-sheets as revealed by CD analysis. Homology modelling and docking with GMP revealed conserved substrate binding residues with slight differences. Differences in kinetic properties and oligomerization of BmGK compared with human GK can provide the way for design of parasite-specific inhibitors.
Glucose-6-phosphate dehydrogenase (G6PD), a regulatory enzyme of the pentose phosphate pathway from Brugia malayi, was cloned, expressed and biochemically characterized. The Km values for glucose-6-phosphate and nicotinamide adenine dinucleotide phosphate (NADP) were 0·25 and 0·014 mm respectively. The rBmG6PD exhibited an optimum pH of 8·5 and temperature, 40 °C. Adenosine 5′ [γ-thio] triphosphate (ATP-γ-S), adenosine 5′ [β,γ-imido] triphosphate (ATP-β,γ-NH), adenosine 5′ [β-thio] diphosphate (ADP-β-S), Na+, K+, Li+ and Cu++ ions were found to be strong inhibitors of rBmG6PD. The rBmG6PD, a tetramer with subunit molecular weight of 75 kDa contains 0·02 mol of SH group per mol of monomer. Blocking the SH group with SH-inhibitors, led to activation of rBmG6PD activity by N-ethylmaleimide. CD analysis indicated that rBmG6PD is composed of 37% α-helices and 26% β-sheets. The unfolding equilibrium of rBmG6PD with GdmCl/urea showed the triphasic unfolding pattern along with the highly stable intermediate obtained by GdmCl.
Pigeonpea is an important legume crop of the semi-arid tropics. In India, pigeonpea is mostly grown in areas prone to waterlogging, resulting in major production losses. It is imperative to identify genotypes that show tolerance at critical crop growth stages to prevent these losses. A selection of 272 diverse pigeonpea accessions was evaluated for seed submergence tolerance for different durations (0, 120, 144, 168 and 192 h) under in vitro conditions in the laboratory. All genotypes exhibited high (0·79–0·98) survival rates for up to 120 h of submergence. After 192 h of submergence, the hybrids as a group exhibited significantly higher survival rates (0·79) than the germplasm (0·71), elite breeding lines (0·68) and commercial varieties (0·58). Ninety-six genotypes representing the phenotypic variation observed during laboratory screening were further evaluated for waterlogging tolerance at the early seedling stage using pots, and survival rates were recorded for 8 days after completion of the stress treatment. Forty-nine of these 96 genotypes, representing the phenotypic variation for waterlogging tolerance, were chosen in order to evaluate their performance under natural field conditions. The following cultivated varieties and hybrids were identified as tolerant after three levels of testing (in vitro, in pots and in the field): ICPH 2431, ICPH 2740, ICPH 2671, ICPH 4187, MAL 9, LRG 30, Maruti, ICPL 20128, ICPL 332, ICPL 20237, ICPL 20238, Asha and MAL 15. These materials can be used as sources of waterlogging tolerance in breeding programmes.
Phosphoenolpyruvate carboxykinase (PEPCK, EC 18.104.22.168) is an essential regulatory enzyme of glycolysis in helminths in contrast to its role in gluconeogenesis in their host. Previously we have reported that phytochemicals from Flemingia vestita (Family: Fabaceae), genistein in particular, have vermifugal action and are known to affect carbohydrate metabolism in the cestode, Raillietina echinobothrida. In order to determine the functional differences of PEPCK from the parasite and its avian host (Gallus domesticus), we purified the parasite enzyme apparently to homogeneity, and characterized it. The native PEPCK is a monomer with a subunit molecular weight of 65 kDa. The purified enzyme displayed standard Michaelis-Menten kinetics with Km value of 42·52 μM for its substrate PEP. The Ki for the competitive inhibitors GTP, GMP, ITP and IMP for the carboxylation reaction were determined and discussed. In order to identify putative modulators from plant sources, phytochemicals from F. vestita and Stephania glabra were tested on the purified PEPCK, which resulted in alteration of its activity. From our results, we hypothesize that PEPCK may be a potential target site for anthelmintic action.
Pigeonpea is an important rainfed pulse crop grown in the rainy season that is subject to waterlogging. There are not many sources of waterlogging tolerance available; therefore the mini core pigeonpea germplasm (n=146) were screened, along with a few genotypes already reported to exhibit tolerance. Five trials were conducted starting at 40 and 50 days after sowing (DAS) in 2008, and at 40, 62 and 76 DAS in 2009. The mortality rate in any trial depended on the vapour pressure deficits (VPD) that prevailed during waterlogging and the recovery periods. There were large and highly significant variations due to genotype and to genotype×trial interactions. The heritability of individual trials ranged from 0·27 to 0·75, while it was 0·40 when all the trials were considered together. The survival counts were grouped into representative groups using a hierarchical cluster analysis, which yielded five distinctive groups. The highly tolerant group, with above-average survival means in all five trials, comprised 24 accessions. None of the previously tested or control entries appeared in this group. The sensitive entries comprised 37 accessions including ICP 7035, ICP 8338 and ICP 13562, which were known to be sensitive from previous reports. The tolerant group comprised 39 accessions, moderately tolerant 42 and moderately sensitive 18. Survival during waterlogging and a rapid recovery are considered equally important for categorizing the genotypes and their further use.
Abstract We compare for multiblock copolymers the results of mean field calculations with those from Monte Carlo simulations based on the bond uctuation method and experimental results from scattering data. The application of Leibler's  theory for copolymers and the results of Monte Carlo simulations indicate that the microphase separation transition occurs at larger xN as the number of blocks is increased beyond two (i.e., beyond diblock), and that the characteristic length scale of the emerging morphology decreases as the number of blocks increases. The latter is in qualitative agreement with published experimental results  for model multiblock poly(styrene-isoprene) systems and recent results  for a segmented poly(ester-urethane).
The step-coverage and gap-filling characteristics of SiO2 films deposited by TEOS based plasma CVD and Thermal CVD processes on AlX and Cu/X metallizations were studied. It was found that the conformality of the films, in the case of plasma CVD, is influenced by the relative flow rates of TEOS to oxygen. The suitability of the two types of SiO2 films for filling gaps of different aspect ratios on AlX and Cu/X metallizations with different aspect ratios was examined. The results are discussed and correlated with the other important characteristics of these SiO2 films.
The effects of TEOS (Tetra-ethyl-ortho-silicate) concentration on the physical, chemical and electrical characteristics of undoped SiO2 films deposited by plasma (PECVD) and thermal CVD (ThCVD) processes, are described. It is shown that the (TEOS/O3) or (TEOS/O) ratio strongly influences the various film properties. The uniformity of film thickness is better at higher (TEOS/O3) or (TEOS/O2) ratios in both processes. In ThCVD the SiO2 films are denser (low etch rate) when deposited at low (TEOS/O3 ) ratio. This study has shown that the TEOS concentration can be used to tailor film properties.
Nanocrystalline tin oxide powder was prepared using a solution precipitation technique after adding the surfactant sodium bis (2-ethylhexyl) sulfosuccinate (AOT). Powders were characterized using X-ray diffraction (XRD), surface area (BET) and transmission electron microscopy (TEM). The gas sensitivity for surfactant added powders increased for liquid petroleum gas (LPG) as well as compressed natural gas (CNG), due to the decreased particle size and the increased surface area. The LPG gas sensitivity increased several times using phosphorus treated surfactant AOT.
The optical degradation of polysilane copolymer has been studied in spin cast thin films and solutions using light source of 325 nm wavelength. The room temperature photoluminescence (PL) spectrum of these films show a sharp emission at 368 nm when excited with a source of 325 nm. However, the PL intensity deteriorates with time upon light exposure. Further the causes of this degradation have been examined by characterizing the material for its transmission behaviour and changes occurring in molecular weight as analysed by GPC data.