Plasmonic Copper-activated ZnO Microarrays for Efficient Photoelectrocatalytic Applications.

In the present work, green synthesized plasmonic copper nanostructures derived from carbon quantum dots (PCQDs) activated ZnO microarrays (MAs) based catalyst system is developed and studied for photocatalytic activity and photoelectrocatalytic water splitting. CQDs are synthesized from pharmaceutical waste and used as a reducing agent to synthesize PCQDs of an average size of 10±2 nm. PCQDs decorated ZnO (PCQDs/ZnO) MAs exhibited enhanced photocurrent density of ∼7.1 mA/cm2 at 1.23 V (vs. RHE), which is ∼11 fold to ZnO MAs alone (0.65 mA/cm2 ). The catalyst exhibits an ABPE of 1.07% at 0.7 V (vs. RHE), IPEC of 8.8% for 450 nm, and hydrogen production rate of 435 µmol/h. The enhanced PEC characteristics are assigned to the improved photons collection and better charge transfer for their participation in oxidation/reduction reaction. The same is well supported with DFT studies for the PCQDs/ZnO MAs catalyst for the first time.

Effect of core hydrophobicity on the electrophoresis of pH-regulated soft particles.

We propose a theoretical study on the electrophoresis of core-shell composite soft particles considering the effect of hydrodynamic slip length of the hydrophobic inner core. The surface of the inner core as well as the soft polymeric shell bear zwitterionic functional groups and the charged conditions depend on the nearby micro-environment. Within a low potential and weak electric field framework, the mathematical equations of the generalized electrokinetic theory for soft surfaces are solved analytically subject to appropriate boundary conditions, and a general electrophoretic mobility expression in an integral form involving the pH-dependent electrostatic potential is derived. With the help of suitable numerical schemes, electrophoretic mobility can easily be obtained. The effect of hydrophobicity of the inner core on the electrophoretic mobility of pH-regulated soft particles is illustrated for a wide range of pertinent parameters.

Electrophoresis of dielectric and immiscible-liquid-layer-encapsulated colloids in aqueous media.

In this paper we consider the electrophoresis of a functionalized nanoparticle in electrolyte solution. The undertaken particle is comprised of a rigid inner core encapsulated with a layer of dielectric liquid (e.g., oil or lipid layer), which is immiscible to the bulk aqueous medium. The peripheral liquid layer of the undertaken nanoparticle contains mobile charges due to presence of solubilized surfactants. The mobile electrolyte ions can penetrate across the peripheral layer depending on the difference in the Born energy of the both phases. Such types of nanoparticles have received substantial attention due to their widespread applications in biomedical research. The electric double layer (EDL) is governed by the linearized Poisson-Boltzmann equation under a low potential limit and the electroosmotic flow field is governed by modified Stokes equation. We adopt the flat-plate formalism to obtain the closed analytical expression for the electrophoretic mobility of the undertaken particle under a thin EDL approximation. The dependence of electrophoretic mobility on the pertinent parameters is also illustrated.

TiO2 nanofibres decorated with green-synthesized PAu/Ag@CQDs for the efficient photocatalytic degradation of organic dyes and pharmaceutical drugs.

Organic pollutants such as dyes and pharmaceutical drugs have become an environmental menace, particularly in water bodies owing to their unregulated discharge. It is thus required to develop an economically viable and environment-friendly approach for their degradation in water bodies. In this study, for the first time, we report green route-synthesized plasmonic nanostructures (PM-CQDs (where M: Au and Ag)) decorated onto TiO2 nanofibers for the treatment of toxic dye- and pharmaceutical drug-based wastewater. PM-CQDs are efficaciously synthesized using carbon quantum dots (CQDs) as the sole reducing and capping agent, wherein CQDs are derived via a green synthesis approach from Citrus limetta waste. The characteristic electron-donating property of CQDs played a key role in the reduction of Au3+ to Au0 and Ag+ to Ag0 under visible light irradiation to obtain PAu-CQDs and PAg-CQDs, respectively. Thus, the obtained CQDs, PAu-CQDs, and PAg-CQDs are loaded onto TiO2 nanofibers to obtain a PM-CQD/TiO2 nanocomposite (NC), and are further probed via transmission electron microscopy, scanning electron microscopy and UV-visible spectrophotometry. The degradation of organic pollutants and pharmaceutical drugs using methylene blue and erythromycin as model pollutants is mapped with UV-vis and NMR spectroscopy. The results demonstrate the complete MB dye degradation in 20 minutes with 1 mg mL-1 of PAu-CQD/TiO2 NC, which otherwise is 30 minutes for PAg@CQD/TiO2 dose under visible light irradiation. Similarly, the pharmaceutical drug was found to degrade in 150 minutes with PAu-CQD/TiO2 photocatalysts. These findings reveal the enhanced photocatalytic performance of the green-synthesized Au decorated with TiO2 nanofibers and are attributed to the boosted SPR effect and aqueous-phase stability of Au nanostructures. This study opens a new domain of utilizing waste-derived and green-synthesized plasmonic nanostructures for the degradation of toxic/hazardous dyes and pharmaceutical pollutants in water.

Electrophoresis of hydrophilic/hydrophobic rigid colloid with effects of relaxation and ion size.

This article deals with a semi-analytical study on the electrophoresis of charged spherical rigid colloid by considering the effects of relaxation and ion size. The particle surface is taken to be either hydrophilic or hydrophobic in nature. In order to consider the ion size effect we have invoked the Carnahan and Starling model (J. Chem. Phys. 1969, 51, 635-636). The mathematical model is based on Stokes equation for fluid flow, modified Boltzmann equation for spatial distribution of ionic species and Poisson equation for electric potential. We adopt a linear perturbation technique under a weak electric field assumption. An iterative numerical technique in employed to solve the coupled set of perturbed equations. We have validated the numerically obtained electrophoretic mobility with the corresponding analytical solution derived under low potential limit. Going beyond the widely employed Debye-Hückel linearization, we have presented the results for a wide range of surface charge density, electrolyte concentration, and slip length to Debye length ratio. We have also identified several interesting features including occurrence of local maxima and minima in the mobility for critical choice of pertinent parameters.

New directions in the science and technology of advanced sheet explosive formulations and the key energetic materials used in the processing of sheet explosives: Emerging trends.

This review presents the work carried out by the international community in the area of sheet explosive formulations and its applications in various systems. The sheet explosive is also named as PBXs and is a composite material in which solid explosive particles like RDX, HMX or PETN are dispersed in a polymeric matrix, forms a flexible material that can be rolled/cut into sheet form which can be applied to any complex contour. The designed sheet explosive must possess characteristic properties such as flexible, cuttable, water proof, easily initiable, and safe handling. The sheet explosives are being used for protecting tanks (ERA), light combat vehicle and futuristic infantry carrier vehicle from different attacking war heads etc. Besides, sheet explosives find wide applications in demolition of bridges, ships, cutting and metal cladding. This review also covers the aspects such as risks and hazard analysis during the processing of sheet explosive formulations, effect of ageing on sheet explosives, detection and analysis of sheet explosive ingredients and the R&D efforts of Indian researchers in the development of sheet explosive formulations. To the best of our knowledge, there has been no review article published in the literature in the area of sheet explosives.

Enhanced field emission properties from CNT arrays synthesized on Inconel superalloy.

One of the most promising materials for fabricating cold cathodes for next generation high-performance flat panel devices is carbon nanotubes (CNTs). For this purpose, CNTs grown on metallic substrates are used to minimize contact resistance. In this report, we compare properties and field emission performance of CNTs grown via water assisted chemical vapor deposition using Inconel vs silicon (Si) substrates. Carbon nanotube forests grown on Inconel substrates are superior to the ones grown on silicon; low turn-on fields (∼1.5 V/µm), high current operation (∼100 mA/cm(2)) and very high local field amplification factors (up to ∼7300) were demonstrated, and these parameters are most beneficial for use in vacuum microelectronic applications.

Analysis and design of hybrid ARROW-B plasmonic waveguides.

A hybrid antiresonant reflecting waveguide, type B (ARROW-B) plasmonic waveguide based on the resonant coupling between a guided dielectric mode and surface plasmon polariton wave is proposed. Employing the finite element method, hybrid modes including two bound supermodes are obtained at visible frequencies by varying the environmental refractive index. We investigate the propagation characteristics of hybrid modes, where the significant change of modal power by the symmetric bound mode is observed in plasmonic waveguide coupling suitable for highly sensitive detection of bulk refractive index change. Further, anomalous dispersion is shown by the antisymmetric bound mode which leads to large group velocity dispersion of -3.165×10(4) ps/km nm and, thus, makes this hybrid plasmonic waveguide ideal for observation of soliton generation.

Phase control of nanostructured iron oxide for application to biosensor.

We report results of the studies relating to the phase transformation of bare Fe3O4 nanoparticles (NPs) to α-Fe2O3 NPs obtained during electrophoretic film deposition onto indium-tin oxide coated glass plates. The in situ oxidation of NPs during electrophoretic deposition can be circumvented using surface passivation of the Fe3O4 NPs with an organic shell (carbon) as well as an inorganic shell (silica), while retaining the biocompatibility of the Fe3O4 NPs. XRD and XPS studies reveal the transformation of Fe3O4 NPs to α-Fe2O3 NPs upon electrophoretic deposition, and the retention of the phase of the Fe3O4 NPs upon encapsulation with carbon and silica, respectively. The results of SEM studies indicate decreased agglomeration of the Fe3O4 NPs upon encapsulation during film deposition. Attempts have been made to compare the characteristics of cholesterol biosensors fabricated using Fe3O4@C and α-Fe2O3 NPs, respectively. The Fe3O4@C NPs based cholesterol biosensor shows response time of 60 s, a linearity range of 25-500 mg dl-1, a sensitivity of 193 nA mg-1 dl cm-2 and a Michaelis-Menten constant of 1.44 mg dl-1.

Nonlinear pulse propagation in chalcogenide As2Se3 glass photonic crystal fiber using RK4IP method.

Pulse propagation through chalcogenide As(2)Se(3) glass photonic crystal fiber (PCF) is numerically investigated using fourth-order Runge-Kutta in the interaction picture (RK4IP) method. The fully vectorial effective index method (FVEIM) is used to calculate the variation of effective refractive index, effective area, dispersion, and nonlinear coefficient (γ) in As(2)Se(3) PCF with wavelength for different values of pitch and air hole size. The RK4IP method is used to demonstrate the soliton propagation, self-phase modulation (SPM), soliton collision and cross phase modulation (XPM) in the designed As(2)Se(3) PCF. The numerically obtained value of soliton collision length (L(col)=51.3L(D)) using the RK4IP method is found to be in good agreement with the theoretical value of soliton collision length (L(col)=51.408L(D)) obtained from inverse scattering transform method, thus providing a verification of the RK4IP accuracy in solving generalized nonlinear schrödinger equation (GLNSE). We also evaluate and apply the value of wavelength for distortionless (L(NL)=L(D)) propagation of the soliton pulse.

Quality differentials and reproductive health service utilisation determinants in India.

PURPOSE: This paper seeks to establish relationships between women's reproductive health service use, assessed longitudinally and by facility type, with service quality perceptions related to public or private health facilities. DESIGN/METHODOLOGY/APPROACH: The study was mainly secondary and quantitative in nature. It included analysing data collected by the International Institute for Population Sciences (IIPS) and The Johns Hopkins University (JHU) as a follow-up study to the 1998-1999 National Family Health Survey (NFHS-2). The follow-up survey was carried out in Tamil Nadu, Maharashtra, Bihar and Jharkhand. In 2002-2003, these four states were selected to capture socio-economic and demographic variations. Analysis includes composite indices and logistic regression analysis. A scale was constructed to measure utilisation levels. Dimensions include: service proximity, doctor availability, waiting time, medicines, facility cleanliness, dignified treatment, privacy, service affordability and treatment effectiveness. FINDINGS: Findings indicate that doctor availability, waiting time, cleanliness, privacy and affordability at private health facilities enhance the probability that a health facility will be used for any reproductive health purpose. At the combined states level, medicine availability and treatment effectiveness at public health facilities enhances service use. RESEARCH LIMITATIONS/IMPLICATIONS: The major limitation is that the study includes only selected Indian states. PRACTICAL IMPLICATIONS: The findings may enhance Indian service-quality policy. ORIGINALITY/VALUE: The paper's main contribution is that seemingly for the first time in India, healthcare service use has been measured longitudinally and then explained through service quality variables by comparing public and private health facilities.

Cognition related to domestic violence in India: implications for reproductive health programme.

In India, the nature of interdependency between wife and husband is regarded as different from what it is in the west. It is observed that in Indian state of Bihar, there is co-existence of memory of domestic violence and attitudinal justification of domestic violence on all the dimensions of domestic violence. However, In Tamil Nadu, demographic transition is likely to create the differentiation and therefore significant co-existence of certain forms of attitude (attitudinal justification of beating for household chores, contraceptives, and sex refusal) and 'memories related to domestic violence' are not present there. Attitudinal assertion against domestic violence in the name of 'unfaithfulness' seems to be helping women both in Bihar & Tamil Nadu. However, in Tamil Nadu, if women raise her voice against beating by husband for sex refusal; her chance of facing domestic violence gets increased here. These kind of connect between violence and attitude is not present in Bihar. In Bihar, attitudinally if women assert their voice against violence for contraceptive decision making; it makes them to feel lesser amount of constant strain. The study shows the implications for reproductive health programme in India.

Raman amplification characteristics of As2Se3 photonic crystal fibers.

We present the dispersion and Raman amplification characteristics of As2Se3 photonic crystal fibers (PCFs). We compare the gain characteristics with conventional As2Se3 fibers and find that the Raman gain efficiency in PCFs can be improved by a factor of more than 4. This allows us to either use a small length of the fiber or to use the low pump power to attain similar gain characteristics. Numerical simulations reveal that a peak gain of 10 dB can be achieved in a 1.1 m long PCF when it is pumped at 1.5 microm in wavelength with an input power of 500 mW.

Consistency and predictive ability of fertility preference indicators: longitudinal evidence from rural India.

CONTEXT: Ideal family size and desire for an additional child are the two most commonly used fertility preference indicators. However, little is known about the consistency over time of responses to each measure, the consistency between the two indicators or the predictive value of these indicators in India. METHOD: Longitudinal data from the 1998-1999 National Family Health Survey and a follow-up survey conducted four years later were analyzed to determine the consistency of responses to the two fertility preference indicators (both over time and between indicators) and to determine whether baseline responses were associated with subsequent fertility, unwanted births and contraceptive use. RESULTS: Responses on the measure of ideal family size were consistent at the two time points for 53% of nonsterilized women. Eighty-two percent of women who explicitly said in 1998 that they did not desire more children responded identically in 2002, although about half of these women had given birth in the intervening period. The indicators were associated with each other: Among women with at least one son, 79% of those who had attained or surpassed their ideal family size said they wanted to stop childbearing, compared with 18% of those who had not. Both indicators predicted future fertility, unwanted births and contraceptive use, particularly among women who had a son. CONCLUSION: Both indicators are useful in understanding future fertility behavior. As the prevalence of son preference declines in India, the predictive ability of the indicators is likely to improve.

Strategies for realizing photonic crystal fiber bandpass filters.

Numerical design strategies are presented to achieve efficient broad or narrow band-pass filters based on index-guiding, solid-core, and single-mode photonic crystal fibers (PCFs). The filtering characteristics have been verified through BPM solver. By scaling the pitch constant, the bandpass window can be shifted accordingly. The fiber design constitutes a fluorine-doped central core, enlarged air-holes surrounding the down-doped core, and small air-holes in the cladding. The proposed bandpass filter is based on controlling the leakage losses, so one can tune filter characteristics simply by changing its length. From numerical simulations we show that for large values of air-hole diameter in the first ring, the bandpass window is narrow, while for low doping concentration and small sized air-holes in the first ring, bandpass window is very broad. We also simulate how the hole-size and number of rings in the PCF cladding affects the device characteristics. We find that a 5-cm long PCF with down-doped core and eleven rings of air-holes can result in approximately 440 nm 3-dB bandwidth with more than 90% of transmission. The longer device has reduced transmission and smaller 3-dB bandwidth. Tolerance analysis has also been performed to check the impact of fiber tolerances on the performance of the PCF bandpass filter. It has been observed that the decrement in cladding hole-diameter by 1% reduces the transmission to 21% from its peak value of 93%, however +/-1% tolerance in the inner hole-diameter degrades the transmission to 75% from its peak.

Consent and coercion: examining unwanted sex among married young women in India.

CONTEXT: Although there is a growing body of research examining the issue of nonconsensual sex among adolescents, few studies have looked at coerced sex within marriage in settings where early marriage is common, or at sex that may not be perceived as forced, but that is unwanted. METHODS: A cross-sectional study, using both survey research and in-depth interviews, was conducted among 1,664 married young women in Gujarat and West Bengal, India. Descriptive data and multinomial logistic regression were used to identify the prevalence and risk factors for occasional and frequent unwanted sex. Qualitative data were analyzed to examine the context in which unwanted sex takes place. RESULTS: Twelve percent of married young women experienced unwanted sex frequently; 32% experienced it occasionally. The risk of experiencing unwanted sex was lower among women who knew their husband fairly well at the time of marriage, regularly received support from their husband in conflicts with other family members or lived in economically better-off households. Frequent unwanted sex was associated with not yet having had a child or having become pregnant, with lower education and with agreeing with norms that justify wife beating. CONCLUSION: For married young women, sex is not always consensual or wanted. Further research is required to determine the effects of unwanted sex on sexual and reproductive health outcomes and to help programs develop the best strategies for dealing with coerced sex within marriage.

Study of birefringence of elliptical core photonic crystal fiber using Mathieu function.

The birefringence of the elliptical core photonic crystal fiber with circular pores in the cladding has been studied by using higher order Mathieu functions. It is observed that the birefringence decreases with decreasing wavelength. Calculated results also indicate the sensitivity to the radius of the pores in the cladding. High birefringence up to 0.0079 is obtained. The efficacy of this proposed method is proved by comparing the results.

Ultraviolet-visible-near infrared and mid-Fourier transform infrared spectroscopic studies of intermolecular interaction in cholesteryl oleyl carbonate in mesophases.

Ultraviolet-visible-near infrared (UV-Vis-NIR) and Fourier transform infrared (FTIR) spectroscopic studies are presented of molecular association between like molecules of cholesteryl oleyl carbonate, each containing suitable pi-donor (steroid ring C=C) and pi-acceptor (C-O single bonds united with a C=O bond to give a carbonate group) moieties. Frequency shifts and intensity enhancements of donor and acceptor oscillators appear to be governed by reduced mass, vibronic coupling constants, and a few other parameters such as relative change in force constants, etc. Donor-acceptor complex formation is characterized not only by the appearance of new bands in the mid-FTIR spectrum but also by the emergence of a new, intense electronic band centered at approximately 3700 cm(-1), the so-called charge-transfer band, in the UV-Vis-NIR spectrum. This band is strong in the smectic-A and solid phases, but progressively diminishes when temperature is raised to realize the upper end of the cholesteric phase and eventually the isotropic phase. Also, a new, small electronic band at approximately 360 nm, only seen in the entire thermal range of the cholesteric phase, is attributed to the Lifshitz-van der Waals interaction between pretransitional smectic-A domains existing in the cholesteric phase. It is argued that mesophases may owe their thermodynamic stability to both Lifshitz-van der Waals and vibronic coupling (or electron-phonon coupling in extended systems such as smectics and solids) interactions.

Organochlorine pesticides, polychlorinated biphenyls, and polybrominated diphenyl ethers in Irrawaddy dolphins from India.

The Irrawaddy dolphin (Orcaella brevirostris) is at risk of extinction throughout its range as a result of incidental catches, habitat degradation, and pollution. Populations of Irrawaddy dolphins are constrained by the species' narrow habitat requirement-lagoons, estuaries, rivers, and lakes-and are therefore particularly vulnerable to the effects of human activities. In this study, for the first time, concentrations of organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were determined in tissues of Irrawaddy dolphins collected from Chilika Lake, India, to understand the status of contamination. Dichlorodiphenyltrichloroethane and its metabolites (DDTs) were the predominant contaminants found in Irrawaddy dolphins; the highest concentration found was 10,000 ng/g lipid weight in blubber. Hexachlorocyclohexanes (HCHs) were the second most prevalent contaminants in dolphin tissues. Concentrations of PCBs, chlordanes, hexachlorobenzene, tris(4-chlorophenyl)methane, and tris(4-chlorophenyl)methanol were in the ranges of few ng/g to few hundreds of ng/g on a lipid-weight basis. In general, concentrations of OC pesticides and PCBs in Irrawaddy dolphins were lower than the concentrations reported for coastal and riverine dolphins collected in Asia. PBDEs were detected in the blubber of Irrawaddy dolphins at concentrations ranging from 0.98 to 18 ng/g lipid weight. BDE congener 47 accounted for 60% to 75% of the total PBDE concentrations. Although these results establish the baseline levels of persistent organic pollutants in Irrawaddy dolphins, efforts should be made to decrease the sources of contamination by DDTs and HCHs in Chilika Lake.