Search

Diet maintains health by regulating host metabolism and immunity. The results revealed the consequence of starch-, unsaturated fat-, and saturated fat-rich diets on differentially immune-biased mice C57BL/6 and BALB/c. Time-course of various diets on differentially immune-biased mice revealed that starch-rich and unsaturated fat-rich diets reduced insulin resistance (IR) and visceral adiposity in BALB/c mice while a saturated fat-rich diet enhanced both parameters. In C57BL/6 mice, a fat-rich diet enhanced IR with time while visceral adiposity remained unchanged. Eight weeks' consumption of saturated fat-rich diet induced highest visceral adiposity in C57BL/6 mice, while the same diet resulted in the maximum IR in BALB/c mice. The current report presented a detailed metabolomic analysis of diets and evaluated differential index of each treatment for each mouse strain using a vector analysis of the multivariate linear discriminant data. The outcome identified metabolites that affected lipid and glucose metabolism to establish the inter-strain physiological differences.

We present a theoretical study on probe field propagation through a three-level Ξ type system formed in an atomic vapour medium in presence of a strong control field. The model is based on density matrix method and is solved analytically, without neglecting any term in any power of probe and control Rabi frequencies, to find out the probe response under Doppler free condition as well as at room temperature. The probe response for a four-level Ξ type system is also determined analytically. Electromagnetically induced transparency is formed in the simulated probe response for both the level schemes. We also present the switching of probe field propagation from subluminal to superluminal as a function of probe detuning for different control transitions, one of which is to a Rydberg state. The switching window becomes asymmetric under detuned control field with the asymmetry depending on the wavelength mismatching factor between the control field and the probe field. Under strong probe regime probe propagation switches from superluminal to subluminal on resonance when the wavelength mismatch between the probe and the control field is increased, an effect which can be explained with the help of the analytical model that is free from any perturbative treatment.

The study of walking pattern also known as gait is affected by several underlying musculoskeletal and neurological factors. All humans have contrasting gait pattern however the pattern lies within a predictable range for all human with no underlying health disorders affecting gait. However, deviation from a regular distribution range can indicate underlying health conditions. The gait could be regularly and inexpensively monitored in real-time with help of smartphones embedded sensors such as tri-axial accelerometers and tri-axial gyroscopes as smartphones are widely available. The advancements in computational power and artificial intelligence led to the development of several supervised machine learning algorithms which could be used to detect certain patterns associated with different gait conditions. However, the machine learning has widely been used to study different gait diseases, with this paper we have proposed a more efficient motion tracking approach and a new algorithm utilizing Dynamic Time Warping for an optimized locomotor disorder detection with affordable, practically applicable and globally deployable setup to monitor gait. In this experiment, we have tracked motion of 30 healthy and gait deformed human subjects with the proposed motion tracking approach and utilizing the proposed algorithm, we have achieved 35.95 times faster classification with up to 95.20% detection accuracy.

This paper proposes a peer-to-peer energy trading system based on multi-objective game-theoretic optimisation for a clustered microgrid to find suitable sizes of distributed generations, including energy storage systems. The chosen architecture includes three different microgrids, and each microgrid can be a combination of solar panels, wind turbines and batteries, to meet the requirements of their residential loads. In the clustered microgrid, all microgrids are connected with one another, and also with the main grid, and they have the ability to perform both peer-to-peer and peer-to-grid energy trading based on load requirements and to reach the optimum value of the outlined objective function. To formulate a multi-objective function, two different criteria’ the annual profit and the loss of power supply probability are considered, and the Nash equilibrium-based game theory technique is modelled for clustered microgrids using a particle swarm optimisation algorithm to obtain suitable sizes of the players and payoff values. In the end, for each microgrid, suitable sizes of solar panels, wind turbines and batteries are proposed to meet the residential load requirements in the grid-connected mode. The outcomes of the multi-objective function are analysed and compared for two energy trading schemes, including peer-to-grid and peer-to-peer. The trends of objective functions and sizes of the players are analysed to verify the design of the proposed architecture.

This paper endeavors to provide the reader with an overview of the various tools needed to forecast photovoltaic (PV) power within a very short-term horizon. The study focuses on the specific application of a large scale grid-connected PV farm. Solar resource is largely underexploited worldwide whereas it exceeds by far humans’ energy needs. In the current context of global warming, PV energy could potentially play a major role to substitute fossil fuels within the main grid in the future. Indeed, the number of utility-scale PV farms is currently fast increasing globally, with planned capacities in excess of several hundred megawatts. This makes the cost of PV-generated electricity quickly plummet and reach parity with non-renewable resources. However, like many other renewable energy sources, PV power depends highly on weather conditions. This particularity makes PV energy difficult to dispatch unless a properly sized and controlled energy storage system (ESU) is used. An accurate power forecasting method is then required to ensure power continuity but also to manage the ramp rates of the overall power system. In order to perform these actions, the forecasting timeframe also called horizon must be first defined according to the grid operation that is considered. This leads to define both spatial and temporal resolutions. As a second step, an adequate source of input data must be selected. As a third step, the input data must be processed with statistical methods. Finally, the processed data are fed to a precise PV model. It is found that forecasting the irradiance and the cell temperature are the best approaches to forecast precisely swift PV power fluctuations due to the cloud cover. A combination of several sources of input data like satellite and land-based sky imaging also lead to the best results for very-short term forecasting.

Ethnopharmacological relevance Ginkgo biloba L. (Ginkgoaceae) has been widely used in traditional medicine for variety of neurological conditions particularly behavioral and memory impairments. Aim of the study The present study was envisaged to explore the effect of a standardized fraction of Ginkgo biloba leaves (GBbf) in rat model of lithium-pilocarpine induced spontaneous recurrent seizures, and associated behavioral impairments and cognitive deficit. Materials and methods Rats showing appearance of spontaneous recurrent seizures following lithium pilocarpine (LiPc)-induced status epilepticus (SE) were treated with different doses of GBbf or vehicle for subsequent 4 weeks. The severity of seizures and aggression in rats were scored following treatment with GBbf. Further, open field, forced swim, novel object recognition and Morris water maze tests were conducted. Histopathological, protein levels and gene expression studies were performed in the isolated brains. Results Treatment with GBbf reduced seizure severity score and aggression in epileptic animals. Improved spatial cognitive functions and recognition memory, along with reduction in anxiety-like behavior were also observed in the treated animals. Histopathological examination by Nissl staining showed reduction in neuronal damage in the hippocampal pyramidal layer. The dentate gyrus and Cornu Ammonis 3 regions of the hippocampus showed reduction in mossy fiber sprouting. GBbf treatment attenuated ribosomal S6 and pS6 proteins, and hippocampal mTOR, Rps6 and Rps6kb1 mRNA levels. Conclusions The results of present study concluded that GBbf treatment suppressed lithium-pilocarpine induced spontaneous recurrent seizures severity and incidence with improved cognitive functions, reduced anxiety-like behavior and aggression. The effect was found to be due to inhibition of mTOR pathway hyperactivation linked with recurrent seizures.

This paper proposes a cooperative control of battery energy storage (BES) units within a microgrid (MG) which includes two control subsystems for charge and discharge operation mode of the BES. In addition, the proposed cooperative control strategy provides accurate reactive power sharing among the BES units. During discharge operation, the proposed strategy utilizes a SoC-based droop control in order to avoid promptly depleting of the BES units, by dedicating the highest priority to their SoC level and respecting their power rating. This is achieved without any disturbance in the power balance of the MG. In addition, during charge operation of the BES units, the proposed control method uses a proportional-integral (PI) controller to limit the BES absorbing power and match it with the available surplus power from the renewable energy sources (RESs). This in turn avoids any power imbalance within the system. Finally, to utilize the extra capacity of the BES converters and also to avoid overloading of RESs, a new adaptive virtual impedance (AVI) strategy is proposed here which provides accurate reactive power sharing by imposing a virtual impedance in series with the coupling impedance of each BES and RES unit. The system performance is validated through extensive simulations carried out in PSCAD/EMTDC software.

Due to stringent laws and increasing awareness of customers, organizations are becoming environmental conscious and looking beyond conventional cost minimization/profit maximization approach and striving to curb carbon emission. In this article, we have considered strict carbon cap policy to determine the optimal order quantity, reorder point and number of shipments in a two-echelon supply chain under stochastic demand considering partial backorders. All the major sources of emission such as production, inventory, and transportation have been considered. The objective is to minimize the total expected supply chain cost while satisfying the carbon emission constraint. A numerical example is given to illustrate the solution procedure. Further, sensitivity analyses have been carried out to get insight that how with operational adjustments both cost and emission can be controlled.

Several factors can affect performance of an ultrasound system such as quality of excitation signal and ultrasound transducer behaviour. Nonlinearity of piezoelectric ultrasound transducers is a key determinant in designing a proper driving power supply. Although, the nonlinearity of piezoelectric transducer impedance has been discussed in different literatures, the trend of the nonlinearity at different frequencies with respect to excitation voltage variations has not been clearly investigated in practice. In this paper, to demonstrate how the nonlinearity behaves, a sandwich piezoceramic transducer was excited at different frequencies. Different excitation signals were generated using a linear power amplifier and a multilevel converter within a range of 30–200 V. Empirical relation was developed to express the resistance of the piezoelectric transducer as a nonlinear function of both excitation voltage and resonance frequency. The impedance measurements revealed that at higher voltage ranges, the piezoelectric transducer can be easily saturated. Also, it was shown that for the developed ultrasound system composed of two transducers (one transmitter and one receiver), the output voltage measured across receiver is a function of a voltage across the resistor in the RLC branches and is related to the resonance frequencies of the ultrasound transducer.

The present study has been carried out to determine the sources and distribution of fluoride (F−) contamination in the water of district Bijapur, Chhattisgarh, central India. For this study, 45 water samples were collected from surface and groundwater from shallow and deeper aquifers. It was observed that 50% of groundwater samples have elevated F− level and varies from 0.1 to 7.1 mg/L, though, F− level in water bodies was below the WHO maximum permissible limit (1.5 mg/L). The major ions of water samples reveal the dominance of Ca–Mg–HCO3 hydrochemical facies. This study suggests F− contaminated water shows a significant correlation with Cl− which further supported by statistical correlation. Analysis of rocks and sediments from the study area suggests leaching of minerals like biotite, hornblende, and richterite which are likely sources for elevated F− level in groundwater. Gibbs diagram reveals the dominance of the evaporative process for contaminated water by F− in the study area. Due to improper awareness, the local tribal population (≈2, 55,000) of the area is consuming F− enriched groundwater and vulnerable to dental and skeletal fluorosis. Thus, surface and uncontaminated water w.r.t F− should be developed for providing safe water to the inhabitants.

Keeping in mind the potential usefulness of mixed ionic liquid (IL)-cosolvents systems in several industrial applications, intermolecular interactions between a borate-based IL, bis(1-methyl-1H-imidazol-3-ium-3-yl)dihydroborate bis(trifluoromethylsulfonyl)amide ([BIMIMDBA][TF 2 N]), and its binary mixtures with several molecular solvents has been investigated through NMR and fluorescence spectroscopy. Analysis of the 1 H chemical shifts ( δ /ppm) and translational diffusion coefficients ( D ) of the IL in different solvent mixtures demonstrate interplay of nonspecific (ion-dipole) and specific (hydrogen bonding) interactions in governing the properties of these mixtures. Fluorescence correlation spectroscopy (FCS) and time-resolved fluorescence anisotropy data provide evidence in favour of different IL-solvent interaction for different IL-cosolvent systems.

This paper discusses how two islanded microgrids, when connected together, can support each other during contingencies. Nominally, each microgrid supplies local loads connected to it. However, during any overloading in one of the microgrids, the other supplies power to support it, if possible. The microgrids are interconnected through a back to back converter so that each of them can operate independently. The power exchange through these converters takes place only when there is a shortfall in one of the microgrids. In this paper, it is shown how such a collaborative scheme can work satisfactorily. Some important strategies, such as overload detection and excess power calculation are required for this type of interconnection and are proposed in this paper. The proposals are validated through extensive PSCAD/EMTDC simulation studies.

Presence of large number of single-phase, customer-owned, distributed energy resources that are installed randomly in any phase of Low Voltage (LV) distribution feeders, may lead the generation, in a particular phase, to exceed its load demand. This may result in reverse power flow in that phase towards the upstream network while in the other phases, power flows from the upstream network to the LV feeder. To avoid such problems, this paper proposes the use of Distribution Static Compensators (DSTATCOM) to circulate the reverse flowing power from one phase to the other phases. In this paper, the installation of DSTATCOMs is considered in the medium voltage feeders. The DSTATCOM can be connected in either wye or delta, both of these connections are explored here. Different control strategies are developed for each connection. The main objective of the DSTATCOM is to provide a path for the power, to circulate among the phases, through its DC link. The DSTATCOM controller is further developed to balance its upstream powers and to supply the load reactive power demand. The proposed configurations and the developed control methods for the DSTATCOM are numerically validated through extensive computer simulation studies in PSCAD/EMTDC.

Manufacturers face challenges while collecting used products in their reverse supply chain from several scattered geographic regions. These regions are different in terms of quality of used products returned, quantity returned, the timing of the returns, and regions’ distance from the central remanufacturing facility. The paper proposes a mixed-integer linear programming model for such manufacturer to decide on an optimal combination of channels for collecting used products from these regions in a finite multi-period situation. In each region the manufacturer has two potential sources of collection activity for the manufacturer are −1) through a regional independent collection firm, and 2) direct collection from regional customers. The decision problem is considered under constrains of the quantity and quality of returned products, carbon emission cap-and-trade regulation. A numerical analysis using parameter value estimated using field studies in India for steel drums is presented. The results of the analysis suggest that manufacturers and carbon policymakers should consider the quantity of returned product over the product life cycle. Further, the target for long term carbon emission reduction has implication to a manufacturer’s channels selection for collection activity from multiple regions. Results of analysis also indicate the effect of timing for carbon-cap-and-trade policy implementation on the selection of channels for collection activity in a multi-region problem.

In this paper a cooperative type of game theoretical technique is proposed at the planning stage to model a grid-connected clustered microgrid. In order to make it more applicable, the selected microgrid consists of different combinations of generation resources like wind turbines, solar cells, and batteries. In the game model, generation resources are considered as players and their profit as the payoff. The technique of the Nash bargaining solution is adopted in this study for capacity allocation of generation resources and batteries, and also to maximize the annual profit of individual microgrids and its cluster. As a cooperative game model, all possible coalitions are discussed between the players to find their optimum sizes, and most the suitable one is selected based upon the game theory technique and maximum payoff value. For this purpose, a particle swarm optimization (PSO) algorithm is developed to find the most feasible Nash bargaining solution using MATLAB software. In the simulations and for the system analysis, the realistic electrical load data and weather forecast is taken for a remote town Mount Magnet in Western Australia. Finally, a sensitivity analysis is performed to validate and show the reasonability of the optimized results concerning the proposed clustered system.

We describe a rare haematological complication of pulmonary thromboembolism in a scrub typhus infection. There are very few case reports on scrub typhus infection causing deep venous thrombosis. Vasculitis and perivasculitis with endothelial dysfunction could be considered as the main pathologic mechanism causing this complication.

The role of PI3K/AKT/mTOR signalling pathway has been widely deciphered in pathogenesis of epilepsy. LY294002 is a selective inhibitor of phosphatidylinositol-3-kinase (PI3K). The present study was designed to explore the anticonvulsant potential of LY294002 in a zebrafish model of pentylenetetrazole (PTZ)-mediated convulsions. Zebrafish larvae at 7dpf (days post fertilization) were pre-incubated with varying concentrations of LY294002, prior to PTZ exposure. The adult zebrafish were also exposed to PTZ after intraperitoneal injection with different concentrations of LY294002, followed by gene expression studies in the brain. The hyperactive responses indicated by total distance travelled and the mean speed of larva was drastically decreased, whereas latency to first clonic-like seizure was increased following LY294002 pre-treatment. Additionally, a marked decrease in c-fos expression was also observed in the larvae group exposed to LY294002 in comparison to control. Furthermore, PTZ evoked seizure severity was considerably decreased, while latency to clonic-like seizure was increased in adult zebrafish group treated with 100 nM of LY294002. Furthermore, the occurrence of tonic-like seizures was also reduced in the adult zebrafish treated with LY294002. The mRNA levels of PIK3CA, PIK3R1, AKT1, mTOR, Rps6 and Rps6kb1 in adult zebrafish brain was significantly reduced as compared to vehicle control group. Our results provided conclusive support for the anticonvulsant potential of LY294002.

Doped and undoped specimens of nano-particulate ZnO with 0.5 wt% and 1 wt% ruthenium were prepared through a chemical route. Structural characterization of the samples performed with XRD established that all the nanoparticles are of zinc oxide having polycrystalline nature. Morphological studies were conducted using FESEM to confirm the grain size and texture. Electrical measurements showed that the ac conductivity increases with frequency but decreases with increasing ruthenium concentration, making it a potential option for device applications. It is found that the absorbance does not significantly change with doping. The above fact is further confirmed from the bandgap calculations using the reflectance graphs. A decrease of bandgap from 3.42 to 3.19 eV with increasing Ru concentration is observed making it an important and advantageous material for potential visible light photocatalytic applications involving metal oxide nanostructures.

Single phase nanocrystalline Zn0.8−xNixMg0.1Cu0.1Fe2O4 (x = 0.0−0.8), were synthesized by sol–gel auto-combustion method without post-preparation treatment and, effect of Ni content on structural and magnetic properties is studied by X-ray diffraction (XRD), magnetic measurements and cation distribution. Scherrer’s grain diameter range between 23.5 and 35.1 nm. Experimental and theoretical lattice parameter values suggest that the estimated cation distribution is close to the real distribution. Change in Ni-content leads to variation in cation distribution at site A and B. Ni2+ ions occupy both A and B site, but when Zn2+ is fully replaced by Ni2+, it totally goes to A site. Both coercivity measured at 50 Hz and quasi static coercivity value is found to increase with nickel content. Same trend is observed for anisotropy constant values. Best magnetization value of 25.04 emu/g was obtained for the specimen with x = 0.60. Variation of magnetic properties and other parameters (obtained via cation distribution) can be understood in terms of observed changes in distribution of cation(s) on A and B site.

Electron-irradiation induced changes in structural and, magnetic properties of Co 57.6 Fe 14.4 Si 4.8 B 19.2 Nb 4 , Fe 72 Si 4.8 B 19.2 Nb 4 and, Co 72 Si 4.8 B 19.2 Nb 4 metallic glasses were studied using magnetic hysteresis and, synchrotron X-ray diffraction measurements. Results reveal composition dependent changes of magnetic properties in electron irradiated metallic glasses. A low electron irradiation dose (15 kGy) enhances saturation magnetization (up to 62%) in Fe-based alloy (Fe 72 Si 4.8 B 19.2 Nb 4 ). Synchrotron XRD measurements reveal that electron irradiation transforms the amorphous matrix to a more ordered phase, accountable for changes in magnetic properties.

The aim of this work is to develop a demand-side-response model, which assists electricity consumers exposed to the market price to independently and proactively manage air-conditioning peak electricity demand. The main contribution of this research is to show how consumers can optimize the energy cost caused by the air conditioning load considering to several cases e.g. normal price, spike price, and the probability of a price spike case. This model also investigated how air-conditioning applies a pre-cooling method when there is a substantial risk of a price spike. The results indicate the potential of the scheme to achieve financial benefits for consumers and target the best economic performance for electrical generation distribution and transmission. The model was tested with Queensland electricity market data from the Australian Energy Market Operator and Brisbane temperature data from the Bureau of Statistics regarding hot days from 2011 to 2012.

This paper proposes the use of a common DC link in residential buildings to allow customers to inject their surplus power that otherwise would be limited due to AC power quality violation. The surplus power can easily be transferred to other phases and feeders through common DC link in order to maintain the balance between generated power and load. PSCAD-EMTDC platform is used to simulate and study the proposed approach. This paper suggests that this structure can be a pathway to the future DC power systems.

Nanocrystalline SnO 2 was prepared by the co-precipitation method and doped with CuO. Crystallite sizes were estimated by Scherrer formula to be of the order of 90 nm and lesser. A.C. conduction behaviour of the samples has been described by the different hopping processes. From impedance analysis multi-relaxation processes in the samples are evident. Shrinkage of Cole–Cole plots with increase in temperature is also observed in our case which shows role of grain and grain boundary effects in the conduction mechanism with rise in temperature. Dielectric constant decreases with frequency but increases with rise in temperature which is governed by different components of polarizability (deformational and relaxational polarization). Dielectric constant increases with rise in temperature but at higher frequency range it takes constant value. Impedance analysis is used to explain the effects of grain and grain boundary on transport mechanism of undoped and CuO modified SnO 2 nanoparticles.

A wide variety of unsymmetrical sulfides can be synthesized by trapping 2-naphthoquinone-1-methide intermediates, which are generated in situ from 2-naphthol and aromatic aldehydes, with thiols in presence of catalytic amount of n-tetrabutylammonium tribromide (TBATB). Mild reaction conditions, good yields and no dithioacetal formation as well as formation of brominated product are some of the salient features of the present protocol. Interestingly, the synthesized unsymmetrical sulfide 4aa can be used as selective fluorescence probe for mercury(II) ion.

The synthesis of dihydrochromeno[4,3-b]pyrazolo[4,3-e]pyridin-6(7H)-ones was achieved through one-pot three-component reaction from 4-hydroxycoumarin, aldehydes, and 3-amino-5-methyl-pyrazole in acetonitrile using 5 mol % TBATB as the catalyst under reflux condition. The product formation is through tandem Knoevenagel–Michael reaction followed by concomitant cyclization. Simple reaction procedure, shorter reaction time, good yields, avoidance of aqueous work-up, and column chromatographic separation are some of the salient features of the present protocol.

Voltage unbalance is a major power quality problem in low voltage residential feeders due to the random location and rating of single-phase rooftop photovoltaic cells (PV). In this paper, two different improvement methods based on the application of series (DVR) and parallel (DSTATCOM) custom power devices are investigated to improve the voltage unbalance problem in these feeders. First, based on the load flow analysis carried out in MATLAB, the effectiveness of these two custom power devices is studied vis-a-vis the voltage unbalance reduction in urban and semi-urban/rural feeders containing rooftop PVs. Their effectiveness is studied from the installation location and rating points of view. Later, a Monte Carlo based stochastic analysis is carried out to investigate their efficacy for different uncertainties of load and PV rating and location in the network. After the numerical analyses, a converter topology and control algorithm is proposed for the DSTATCOM and DVR for balancing the network voltage at their point of common coupling. A state feedback control, based on pole-shift technique, is developed to regulate the voltage in the output of the DSTATCOM and DVR converters such that the voltage balancing is achieved in the network. The dynamic feasibility of voltage unbalance and profile improvement in LV feeders, by the proposed structure and control algorithm for the DSTATCOM and DVR, is verified through detailed PSCAD/EMTDC simulations.

We exhibit a technique to detect and estimate precipitation over the global oceans using the radar back scattering coefficient and brightness temperature measurements from Oceansat-II scatterometer along with numerical weather prediction model derived rain sensitive parameters via a neural network (NN) based setup. Rain/no-rain labels are generated by analyzing rainfall observations from Tropical Rainfall Measuring Mission (TRMM) and Advanced Microwave Scanning Radiometer for Earth Observation Satellite (EOS) (AMSR-E) which are concurrent (within a spatiotemporal bin 0.25° × 0.25° latitude–longitude and 900 s) to Oceansat-II overpasses. The rain sensitivity of all the parameters is examined. NN is applied in two stages: (1) rain identification and (2) rain quantification with training samples from five different overlapping geographical regions [I(25°N–25°S), II(15°N–45°N), III(35°N–70°N), IV(15°S–45°S) and V(35°S–70°S)]. Rain identification accuracy is about 93%, 87%, 90%, 79%, and 85%, and no-rain detection accuracy of about 97%, 87%, 86%, 84% and 86% for these regions. The missing rain cases are few compared to the size of no-rain samples and are largely from the low rain regime. The RMS error of instantaneous rain estimation for regions I to V (rain rates varying from > 0 to approximately 45, 25, 25, 45, and 20 mm h− 1) is found to be 1.86, 0.69, 0.47, 0.56, and 0.46 mm h− 1, respectively. The qualitative comparisons of instantaneous, 3-days, monthly and seasonal rain rates from scatterometer and AMSR-E demonstrate a good agreement between them. Probability distribution of monthly rain rates from scatterometer and AMSR-E is also compared, indicating the consistency of scatterometer derived rain with AMSR-E rain in a climatic scale.

Here we present the fabrication and characterization of a new class of hybrid devices where the constituents are graphene and ultrathin molybdenum di-sulphide (MoS2). This device is one of the simplest member of a family of hybrids where the desirable electrical characteristics of graphene such as high mobility are combined with optical activity of semiconductors. We find that in the presence of an optically active substrate, considerable photoconductivity is induced in graphene which is persistent up to a time scale of at least several hours. This photo induced memory can be erased by the application of a suitable gate voltage pulse. This memory operation is stable for many cycles. We present a theoretical model based on localized states in MoS2 which explains the data. (C) 2013 Elsevier Ltd. All rights reserved.

• Consequence of abusive handling of bearing during assembly and maintenance are discussed (two case studies are presented).

Tin dioxide (SnO2) powder was prepared by the co-precipitation method using SnCl2 solution as a precursor. The powder was then pelletized and sintered. Structural characterization of the samples with XRD confirmed that all the pellets were of SnO2 having polycrystalline nature with the crystallite size of the order of 90 nm. SEM-EDAX was used to confirm the morphology and composition of the samples. The measurements of electrical properties were carried out in the frequency range of 100 Hz to 100 kHz at various fixed temperatures from 40 °C to 160 °C. The a.c. conductivity and the dielectric constant were found to be dependent on both frequency and temperature. The frequency and temperature dependent conduction properties of SnO2 are found to be in accordance with correlated barrier hoping model. Infrared and visible spectroscopic studies show that a strong vibration band characteristic of the SnO2 stretching mode was present at around 620 cm−1 and the samples exhibited optical transmittance in the visible range.

• Investigation on premature failure of tapered roller bearing to identify the root cause.

An iterative based strategy is proposed for finding the optimal rating and location of fixed and switched capacitors in distribution networks. The substation Load Tap Changer tap is also set during this procedure. A Modified Discrete Particle Swarm Optimization is employed in the proposed strategy. The objective function is composed of the distribution line loss cost and the capacitors investment cost. The line loss is calculated using estimation of the load duration curve to multiple levels. The constraints are the bus voltage and the feeder current which should be maintained within their standard range. For validation of the proposed method, two case studies are tested. The first case study is the semi-urban 37-bus distribution system which is connected at bus 2 of the Roy Billinton Test System which is located in the secondary side of a 33/11 kV distribution substation. The second case is a 33 kV distribution network based on the modification of the 18-bus IEEE distribution system. The results are compared with prior publications to illustrate the accuracy of the proposed strategy.

CdS quantum dots thin-films have been deposited onto the glass substrate at room temperature using modified chemical bath deposition technique. The prepared thin films were further annealed in air atmosphere at 150, 250 and 350 °C for 1 h and subsequently characterized by scanning electron microscopy, ultraviolet–visible spectroscopy, electrical resistivity and I – V system. The modifications observed in morphology and opto-electrical properties of the thin films are presented.

The synthesis of multi-functionalized dihydro-2-oxypyrrole can be achieved using one-pot four-component domino reaction from dialkylacetylene dicarboxylate, amines, and formaldehyde by employing molecular iodine as catalyst at room temperature. The salient features of the present method are: simple, straightforward, cost-effective, environmentally benign, and no column chromatographic separation is applicable on a broad range of substrates.

CdS, Bi2S3 and CdS–Bi2S3 nanocomposite thin films were grown by successive ionic layer adsorption and reaction method (SILAR) onto the glass substrates at room temperature. These films were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and electrical measurement systems. A comparative study was made between CdS, Bi2S3 and CdS–Bi2S3 nanocomposite thin films. The XRD patterns reveal that CdS, Bi2S3 and CdS–Bi2S3 nanocomposite thin film have hexagonal, orthorhombic and mixed phase of hexagonal CdS and orthorhombic Bi2S3 crystal structure, respectively. SEM images showed uniform deposition of the material over the entire glass substrate. The energy band gap for CdS, Bi2S3 and CdS–Bi2S3 thin films were revealed from the optical studies and were found to be 2.4, 1.6 and 1.69 eV, respectively. The thermoemf measurements of CdS–Bi2S3 nanocomposite thin film revealed n-type electrical conductivity, while the I–V measurement of CdS, Bi2S3 and CdS–Bi2S3 nanocomposite thin film under dark and illumination condition (100 mW/cm2) exhibited photoconductivity phenomena suggesting its applicability in photosensors devices.

A generalized theory is presented for novel mirrored hypercomplex time domain sampling (MHS) of NMR spectra. It is the salient new feature of MHS that two interferograms are acquired with different directionality of time evolution, that is, one is sampled forward from time t=0 to the maximal evolution time tmax, while the second is sampled backward from t=0 to -tmax. The sampling can be accomplished in a (semi) constant time or non constant-time manner. Subsequently, the two interferograms are linearly combined to yield a complex time domain signal. The manifold of MHS schemes considered here is defined by arbitrary settings of sampling phases ('primary phase shifts') and amplitudes of the two interferograms. It is shown that, for any two given primary phase shifts, the addition theorems of trigonometric functions yield the unique linear combination required to form the complex signal. In the framework of clean absorption mode (CAM) acquisition of NMR spectra being devoid of residual dispersive signal components, 'secondary phase shifts' represent time domain phase errors which are to be eliminated. In contrast, such secondary phase shifts may be introduced by experimental design in order to encode additional NMR parameters, a new class of NMR experiments proposed here. For generalization, it is further considered that secondary phase shifts may depend on primary phase shifts and/or sampling directionality. In order to compare with MHS theory, a correspondingly generalized theory is derived for widely used hypercomplex ('States') sampling (HS). With generalized theory it is shown, first, that previously introduced 'canonical' schemes, characterized by primary phases being multiples of π/4, afford maximal intensity of the desired absorptive signals in the absence of secondary phase shifts, and second, how primary phases can be adjusted to maximize the signal intensity provided that the secondary phase shifts are known. Third, it is demonstrated that theory enables one to accurately measure secondary phase shifts and amplitude imbalances. Application to constant time 2D [13C, 1H]-HSQC spectra recorded for a protein sample with canonical MHS/HS schemes showed that accurate CAM data acquisition can be readily implemented on modern spectrometers for experiments based on through-bond polarization transfer. Fourth, when moderate variations of secondary phase shifts with primary phase shift and/or sampling directionality are encountered, generalized theory allowed comparison of the robustness of different MHS/HS schemes for CAM data acquisition, and thus to identify the scheme best suited to suppress dispersive peak components and quadrature image peaks. Moreover, it is shown that for spectra acquired with several indirect evolution periods, the best suited scheme can be identified independently for each of the periods.

We present an efficient detection of liquefied petroleum gas (LPG) using zinc oxide (ZnO) thin films irradiated with swift heavy ions (SHI) of 120 MeV Au9+ ions. The nanostructured ZnO thin films on ITO glass substrates were synthesized using a simple, low cost, and efficient successive ionic layer adsorption and reaction (SILAR) technique. The as-synthesized thin films were annealed at 250 °C (pristine) in vacuum atmosphere (10−2 Torr) for 1 h and these films were further irradiated using SHI of 120 MeV Au9+ ions with different fluence 3 × 1012 and 5 × 1012 ions/cm2, respectively. SHI induced modification in structural, morphological, optical and electrical properties of ZnO thin films were studied. We observed significant enhancement in LPG gas sensing properties in the ZnO thin films on irradiation with fluence 5 × 1012 ions/cm2, especially showing maximum sensitivity to LPG at (200 °C) with LPG concentration of 200 ppm. In addition, irradiated ZnO thin film sensors displayed fast response and recovery time. The observed improvement in gas sensing properties is mainly attributed to the formation of cabbage leaf-like porous ZnO nanostructures throughout the film surface after irradiation. These results along with a simple fabrication process demonstrate that the ZnO thin films irradiated using 120 MeV Au9+ ions with fluence 5 × 1012 ions/cm2 is promising for developing low cost and high performance LPG sensors.

A new technique for optimal planning of MV and LV segments of a distribution system is presented in this paper. The main goal is to find optimally distribution transformer and substation locations and ratings, as well as, the route and type of Medium Voltage (MV) and Low Voltage (LV) feeders. The proposed technique is applicable to both uniform and non-uniform load densities areas. In this method, the planning area is divided into regions with relatively uniform load density such as urban, semi-urban, sub-urban. Each of regions is divided into zones, called LV zone. Each LV zone is supplied by an MV/LV transformer. The dimensions of LV zones are found based on the average load of each region. The placement and rating of MV/LV transformers, the type and route of LV conductors in an LV zone all depend on its loads’ location and power. Regarding the placement and rating of MV/LV transformers in planning area and the space of regions, the dimensions of a zone which is supplied by a HV/MV transformer, called MV zone, is determined. Additionally, the location and rating of HV/MV transformers as well as the feeder's routes and types are calculated. Since the dimensions of an LV zone influence the associated length of MV feeder, the MV feeder cost needs to be included in the total cost associated with the LV zone. This requires the MV feeder type to be known to calculate the corresponding cost. However, the MV feeder type is determined as an output from MV zone planning. As a result, an iterative based method is proposed to consider this common element in computations to develop integrated planning of both LV and MV zones. It is observed that the iterative technique quickly converges to the same results as the exhaustive search method. Discrete particle swarm optimization (DPSO) method is employed for solving the planning problem. The results are compared with nonlinear programming, genetic algorithm and exhaustive search methods. It is observed that DPSO is as accurate as the exhaustive search method for integrated planning of MV–LV distribution systems while its computation time is significantly lower.

The installation of domestic rooftop photovoltaic cells (PVs) are on the rise due to feed-in tariff and changes driven by environmental concerns. Even though the increase in the PV installation is gradual, their locations and ratings are often random. Therefore, such single-phase bi-directional power flow can have adverse effect on the voltage imbalance of a three-phase distribution network. In this paper, a voltage imbalance sensitivity analysis and stochastic evaluation based on the ratings and locations of single-phase grid-connected rooftop PVs in a residential low voltage distribution network are presented. The stochastic evaluation, based on Monte Carlo method, predicts a failure index of non-standard voltage imbalance in the network in presence of PVs. Some improvement methods are discussed and a new improvement method based on PV converter control is proposed.

Herein, we report engineering of nanostructured p -CuIn 3 Se 5 / n -CdS heterojunction thin film on a glass substrate, which is prepared at room temperature using simple wet chemical approach involving ion exchange reactions between CdS and Cu + , In 3+ and Se 2− ions in alkaline medium. The uniform deposition of heterojunction thin films is achieved by optimizing the pH, temperature and molarity of the reactant bath. The as-deposited thin-films were annealed at 200 °C in air for 1 h and further characterized for structural, optical and electrical properties using UV–Vis spectrophotometer, X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), Hall effect for type of conductivity, and I – V measurement to investigate the charge conduction phenomenon. The characteristic (1 1 2) and (1 1 0) planes in XRD and the electron diffraction pattern could confirm the formation of CuIn 3 Se 5 . The chemical composition and the band gap energy E g = 1.4 eV of the nanostructured p -CuIn 3 Se 5 / n -CdS heterojunction thin-films were confirmed using XPS and the absorbance spectra, respectively. Based on the data and energy band gap calculations of CuIn 3 Se 5 and CdS thin films, the probable band alignment between the nanostructured p -CuIn 3 Se 5 / n -CdS heterojunction is proposed.

This paper discusses the use of trajectory sensitivity analysis (TSA) in determining the transient stability margin of a power system compensated by a shunt FACTS device. The shunt device used is static synchronous compensator (STATCOM). It is shown that TSA can be used for the design of controller for the STATCOM. The preferable locations for the placement of the STATCOM for different fault conditions are also identified. The effects of STATCOM in maintaining different bus voltages in the post-fault condition are studied. The STATCOM is modeled by a voltage source connected to the system through a transformer. The systems used for the study are the WSCC 3-machine 9-bus system and the IEEE 16-machine 68-bus system.