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The deposition of reduced graphene oxide over layer on the SnS thin films had been shown to be an effective tool to improve its photoelectrochemical response. Pure phase SnS thin films were prepared using simple and inexpensive thermal evaporation method on ITO glass substrate followed by the deposition of reduced graphene oxide (rGO) layer by drop cast method. Samples were characterized using X-ray diffraction, Raman, scanning electron microscopy, UV–Visible absorption spectroscopy and their photoelectrochemical activity has been investigated. The results show the formation of pure phase SnS having orthorhombic crystal structure with optical band gap of 2.0 eV, rGO layer enhances the absorption in visible region. Maximum photocurrent density exhibited by SnS/0.1 wt% rGO was observed to be 1.1 mA/cm2 as compared to pristine SnS (0.3 mA/cm2) at 0.95V Ag/AgCl with enhanced photostability up to 1 h. Graphene oxide over layer acts as protecting layer for SnS in the electrolyte and plays a promising role in enhancing the charge carriers separation at the interface on account of being an electron reservoir to accept the photoexcited electrons. This work highlights the role of rGO and SnS interface on the photoelectrochemical water splitting.

Hot energy carrier filtering as a means to improve the thermoelectric (TE) property in Sb2Te3 thin film samples having size-selected Au nanoparticles (NPs) is investigated in the present study. Nonagglomerated Au NPs with a very narrow size distribution grown by an integrated gas-phase synthesis setup are incorporated into the Sb2Te3 thin film synthesized by RF magnetron sputtering. TE properties have been investigated as a function of size-selected Au NP concentrations and compared with that of a nanocomposite sample having non-size-selected Au NPs. An increase in the Seebeck coefficient and power factor, along with a slight decrease in electrical conductivity, is observed for samples with a NP size of minimum variance. Further, the Kelvin probe force microscopy and conducting atomic force microscopy techniques were employed to understand the nature of the interface and charge transport across the Sb2Te3 matrix and Au NPs. The study provides an opportunity to modulate the TE properties in Sb2Te3 thin films by constructing a metal-semiconductor heterostructure through controlling the concentration and randomness to achieve a high TE performance.

The photoelectrochemical performance of a BiVO4 photoanode is limited by its poor charge transport properties, despite other useful optical absorption properties. Modifying the surface charge transport properties by forming heterojunction of BiVO4 with other metal oxides layers having ultralow thickness is a promising route, as it may facilitate charge separation/transport without affecting other properties of BiVO4. In this study, the structural, optical and PEC properties of heterojunction of BiVO4 having ultrathin overlayers of Fe2O3, MoO3 and ZnO has been investigated. The electrochemical impedance (via electrochemical impedance spectra in PEC cell) and surface photovoltage (using KPFM) measurements indicates improved charge transport owing to staggered band alignment and favourable band bending in case of BiVO4/MoO3 heterojunction as compared to pristine BiVO4, BiVO4/Fe2O3 and BiVO4/ZnO heterojunctions. Enhanced photocurrent density in BiVO4/MoO3 of ~0.22 mA/cm2 at 1.23 VRHE which is 6 times as compared to pristine BiVO4 layers has been observed. The results of the present study show that by forming heterojunction with a suitable semiconductor material can be used to enhance the PEC response by modifying the surface charge transfer characteristics and there is a large possibility of using other semiconductor materials for further investigations and improvement.

Many cancers are termed immunoevasive due to expression of immunomodulatory ligands. Programmed death ligand-1 (PD-L1) and cluster of differentiation 80/86 (CD80/86) interact with their receptors, programmed death receptor-1 (PD-1) and cytotoxic T-lymphocyte antigen-4 (CTLA-4), respectively, on tumor-infiltrating leukocytes eliciting immunosuppression. Immunotherapies aimed at blocking these interactions are revolutionizing cancer treatments, albeit in an inadequately described patient subset. To address the issue of patient stratification for immune checkpoint intervention, we quantitatively imaged PD-1/PD-L1 interactions in tumor samples from patients, employing an assay that readily detects these intercellular protein–protein interactions in the less than or equal to 10 nm range. These analyses across multiple patient cohorts demonstrated the intercancer, interpatient, and intratumoral heterogeneity of interacting immune checkpoints. The PD-1/PD-L1 interaction was not correlated with clinical PD-L1 expression scores in malignant melanoma. Crucially, among anti-PD-1–treated patients with metastatic non–small cell lung cancer, those with lower PD-1/PD-L1 interaction had significantly worsened survival. It is surmised that within tumors selecting for an elevated level of PD-1/PD-L1 interaction, there is a greater dependence on this pathway for immune evasion and hence, they exhibit more impressive patient response to intervention. Significance: Quantitation of immune checkpoint interaction by direct imaging demonstrates that immunotherapy-treated patients with metastatic NSCLC with a low extent of PD-1/PD-L1 interaction show significantly worse outcome.

Modern electronic devices increasingly rely on efficient antenna integration strategies for supporting high-speed wireless connectivity. Especially for bezel-less displays, these antennas are generally placed underneath the touch sensor panel (TSP) where they interact strongly with the sensing electrodes. To overcome this problem, we engineer the shapes of these electrodes to facilitate the transmission of electromagnetic waves having frequency identical to the operating frequency of the integrated antenna. We thereby propose a new design methodology for TSP electrodes and demonstrate its advantages with respect to antenna integration. As an example, we present the design of a TSP that has a pass-band at 2.51GHz and 5.66GHz for TE polarization and 3.01GHz for TM polarization. We integrate a printed dipole antenna with the proposed as well as a standard TSP geometry, placing it right underneath rather than beside the panel. Comparing the radiation patterns at 2.5GHz, we show that the pattern is significantly different than its free-space one, when a standard TSP geometry is used. Yet, the proposed one leads to a pattern that is almost identical (improved by 3.93dB as compared to standard TSP) to that in free-space.

The considerable decline of conventional oil and gas reserves and respectively their production introduces new challenges to the energy industry. It resulted in the involvement of hard-to-recover reserves using advanced enhanced oil recovery (EOR) techniques. Thermal methods of EOR are recognized as most technically and commercially developed methods for the highly viscous crude oil. High-Pressure Air Injection (HPAI) is one of the thermal production methods that reduce oil viscosity and increases recovery. HPAI has already been effectively applied for different types of reservoirs development and proven to be economically feasible. The application performance of the HPAI technology strongly depends on the quality of experimental and numerical modeling conducted on the target object basis. Before the field tests, physicochemical and thermodynamic characteristics of the process were studied. Further consequent numerical modeling of laboratory-scale oxidation experiments and field-scale simulation was conducted to estimate HPAI method feasibility based on the results of oxidation studies. A medium pressure combustion tube (MPCT) oxidation experiment was carried out to provide stoichiometry of the reactions and field design parameters. A 3D numerical model of the MPCT experiment was constructed taking into account the multilayer design, thermal properties, heating regimes, and reaction model. The “history” matched parameters such as fluid production masses and volumes, temperature profiles along the tubes at different times and produced gas composition demonstrated good correspondence with experimental results. The results obtained during the experiment and modeling of MPCT (fluid properties, relative phase permeability, kinetic model, technological parameters) were used in field-scale modeling using various thermal EOR scenarios. Air breakthrough into production wells was observed, thus a 2 % oxygen concentration limit where implied. The overall performance of four different scenarios was compared within 30 years timeframe. The development system was also examined to achieve the maximum economic indicators with the identifications of risks and main uncertainties.

Author(s): Turgeon, Ricky D; Althouse, Andrew D; Cohen, Jordana B; Enache, Bogdan; Hogenesch, John B; Johansen, Michael E; Mehta, Raj; Meyerowitz-Katz, Gideon; Ziaeian, Boback; Hiremath, Swapnil

In individuals with type 2 diabetes, glycaemic control and cardiovascular risk factor management reduces the likelihood of late-stage diabetic complications. Guidelines recommend treatment goals targeting HbA1c, body weight, blood pressure, and low-density lipoprotein cholesterol. Development of new treatments for type 2 diabetes requires an understanding of their mechanism and efficacy, as well as their relative effects compared to other treatment choices, plus demonstration of cardiovascular safety. Subcutaneous semaglutide is a glucagon-like peptide-1 receptor agonist currently approved in several countries for once-weekly treatment of type 2 diabetes. Semaglutide works via the incretin pathway, stimulating insulin and inhibiting glucagon secretion from the pancreatic islets, leading to lower blood glucose levels. Semaglutide also decreases energy intake by reducing appetite and food cravings, and lowering relative preference for fatty, energy-dense foods. Semaglutide was evaluated in the SUSTAIN clinical trial programme in over 8000 patients across the spectrum of type 2 diabetes. This review details the efficacy and safety profile of semaglutide in the SUSTAIN 1–5 and 7 trials, and its cardiovascular safety profile in the SUSTAIN 6 trial. Semaglutide consistently demonstrated superior and sustained glycemic control and weight loss vs. all comparators evaluated. In SUSTAIN 6, involving patients at high risk of cardiovascular disease, semaglutide significantly decreased the occurrence of cardiovascular events compared with placebo/standard of care (hazard ratio 0.74, P

Pulsed laser deposited thin films of Cu2SnS3 (CTS) are characterized for the structural, electronic and optical properties using X-ray diffraction, Raman, UV–Vis-NIR spectroscopy, scanning electron microscopic techniques, and density functional theory. It is observed that thin-film samples annealed at low temperature have a metastable tetragonal structure, whereas the films annealed at 450 °C have a predominant stable monoclinic phase. A direct band gap of 1.1 eV, measured from the transmittance spectra, in close agreement with the theoretical band gap value of 0.89 eV obtained from density functional theory calculations. Optical properties reveal that CTS has a large absorption coefficient ~0.5 × 104 cm−1 at 1.5 eV which is comparable to other Cu S based materials like CuInS2 and Cu2ZnSnS4. The direct band gap and large absorption coefficient make CTS as one of the potential alternative absorber materials for thin-film solar cell applications.

Location and time-based taxi demand prediction is an essential aspect for e-hailing taxi service providers to monitor the distribution of taxis around the city, which helps in maximizing utilization, minimizing average passenger waiting time, and average cab idle time and efficient fuel usage. Two critical challenges faced to achieve the above goal are an accurate and quick prediction of the demand and organizing the driver fleet according to the prediction. Hence, we propose a system that can be center indirectly managing the dispatch of taxis according to future demand. The system deploys a sequence learning model LSTM (time) and clustering algorithms (location) for predicting taxi demands in different areas (clusters) of a city. For organizing driver distribution, the system implements a rank-based mapping algorithm that minimizes the average vacant taxi travel of the drivers and maintains demand-supply balance.

Atomically thin transition-metal dichalcogenides (MoS2, WSe2, etc.) have long been touted as promising materials for gas detection because of their tunable band gaps; however, the sensing mechanism, based on a charge-transfer process, has not been fully explored. Here, we directly observe the effect of this charge transfer on the doping levels in MoS2 upon exposure to NOx by performing scanning photoelectron microscopy (SPEM) on a monolayer MoS2 transistor under bias conditions in a gas environment. By a comparison of the operando SPEM maps of the transistor with and without exposure to NOx gas, a downward shift in the Fermi level position could be detected, consistent with NOx gas making the MoS2 channel less n-type.

In this environment of accelerated development around the world, more and more waste is generated by direct or indirect means. A daily generation of waste in tons requires an effective management technique. If not done suitably, virtually unlimited amounts of open spaces will be required to dump the waste. The system proposed in this research will lend a hand to solve these waste management problems. The main constituent of this system is a waste bin which will automatically segregate the waste by employing technologies such as Internet of Things and Machine Learning. The bin is connected to the cloud to assist in systematic waste collection by tracking and uploading various data points for a particular bin. A group of these bins will help in efficient garbage collection and management starting from the origin of the waste itself. An Android application which is also a part of this system will assist the relevant authorities to manage the bins as per real time requirements. Two versions of the system are elaborated in this paper with the first version achieving an accuracy of 75% in classifying the waste as wet or dry whereas the second version achieves an accuracy of 90% when segregating the waste into six distinct categories.

Minimally invasive alternatives to traditional prostate surgery are increasingly utilized to treat benign prostatic hyperplasia and localized prostate cancer in select patients. Advantages of these treatments over prostatectomy include lower risk of complication, shorter length of hospital stay, and a more favorable safety profile. Multiparametric magnetic resonance imaging (mpMRI) has become a widely accepted imaging modality for evaluation of the prostate gland and provides both anatomical and functional information. As prostate mpMRI and minimally invasive prostate procedure volumes increase, it is important for radiologists to be familiar with normal post-procedure imaging findings and potential complications. This paper reviews the indications, procedural concepts, common post-procedure imaging findings, and potential complications of prostatic artery embolization, prostatic urethral lift, irreversible electroporation, photodynamic therapy, high-intensity focused ultrasound, focal cryotherapy, and focal laser ablation.

Delivery of subsidies to deserving beneficiaries forms an essential part of government expenditure. In 2018-19 alone, the Government of India spent $60 Bn on welfare subsidies, majorly through the Public Distribution System(PDS). Of this amount, it is estimated that 40% was lost in the form of misuse, corruption and related inefficiencies in the system. Recognising this problem, the government began Direct Benefit Transfers in 2013 for a select few schemes, for instance, LPG subsidy. Using Aadhaar and biometric tokens for validation, the beneficiaries would receive the subsidy as direct cash transfers to their bank accounts. However, in reality, the DBT program has had the same efficiency as the PDS. According to the analysis of the DBT policy, the key drawbacks of this system are lack of auditability, inability to control the use of funds for intended purposes, and over-reliance on the banking infrastructure, which is underdeveloped in the rural areas. In order to plug loopholes in the DBT system, we propose a blockchain-based system. Blockchain consists of cryptographic hash secured distributed ledgers which maintain an immutable log of transactions between all participants of a blockchain network. They have the ability to execute Smart Contracts, which allow for automation of execution of real-world contracts given that certain specified conditions are met. Appropriating the Governments Aadhaar UID, we aim to develop a smart blockchain which automates the disbursement of subsidy which bypasses the need for banks in rural nodes while creating an auditable and transparent ecosystem to curb corruption and financial mismanagement.

To improve the photoelectrochemical (PEC) performance of hematite thin-film photoanode, we report a novel heterostructure based on Fe2O3/TiO2 and hydrogenated Fe2O3/TiO2 (Fe2O3/H:TiO2) for faster c...

A direct mapping of photovoltage in a complete Mo/CZTSSe/CdS/ZnO/Al:ZnO solar cell device is carried out using Kelvin probe force microscopic (KPFM) measurements in surface and junction modes. Four cells having different values of open circuit voltage (VOC) have been studied, and nanoscale variation of photovoltage have been obtained from the difference of surface potential (SP) images in the two modes. The maps exhibit a higher photovoltage at grain boundaries in general. Observed SP image of pristine CZTSe layer reveals downward band bending resulting in reduction of carrier recombination, and thus, lower Jdark at grain boundaries (GB). The observed downward band bending resulting in low Jdark at GB in CZTSe layer is used to explain the increase in photovoltage (VOC) at the GB. KPFM measurements of CZTSe and CZTSe/CdS layers show that the surface potential of CZTSe layer and its variation can be affected by CdS deposition and further device processing, in addition to surface adsorption and contamination effects. The photovoltage mapping obtained from Kelvin probe force microscopic measurements on the final device without any interfering effects, is an important advantage of the present method.

Nanostructured CeO2/TiO2 bilayer thin films were fabricated by sequential deposition of CeO2 on TiO2 with varying the thickness of CeO2 using sol–gel spin-coating method. All samples were characterized by XRD, SEM, and UV–Visible absorption spectroscopy with an inspiration to use them as photoanode in photoelectrochemical splitting of water. The CeO2/TiO2 bilayer with the optimized thickness of CeO2 and TiO2 showed enhanced photoelectrochemical response of 2.1 mA cm-2 at 0.95 V/Ag/AgCl as compared to pristine CeO2 and TiO2. The improved photocurrent density of CeO2/TiO2 bilayer probably due to rapid transfer of charge carriers or electrical gradient at CeO2/TiO2 interface. This scalable and cost effective work with stable PEC performance of CeO2/TiO2 also shows the potential for realistic PEC applications.

The growth of MoS2 layers of desired dimensions at predefined locations is essential for fabricating opto-electronic devices based solely on MoS2 or on hetero-structures based on MoS2. Here we present a new route for patterned growth of MoS2 by combining radio frequency (RF) magnetron sputtering, stencil mask lithography and vapour phase sulfurization. The present method does not involve chemical etchants and organic photoresist and hence provides a simplified process of achieving MoS2 patterns. Here, the control over the number of layers (mono, few and bulk) of MoS2 is achieved by varying the thickness of Mo films. The statistical variation in thickness i.e., number of MoS2 layers within the individual patterns is investigated from Raman mappings which revealed the uniform growth of 3-4 MoS2 layers. From Kelvin probe force microscopy, the surface potential values of MoS2 patterns lie in the range -350 to -370 mV, which is consistent with 2D MoS2 layer with thickness of 3-4 layers. The surface potential analysis across individual patterns indicates weakly n-type doping of few layers MoS2 with Fermi level located ~0.83-0.85 eV below the conduction band edge.

Vertical heterojunctions formed by layer-by-layer stacking of two-dimensional (2D) transition metal dichalcogenides (TMDs) are believed to be the key element of next-generation optoelectronic devices. For developing devices based on such heterostructures, their patterned arrays at pre-defined locations are needed. Here, we present a novel route for achieving MoS 2 (2D)/WS 2 heterojunctions arrays by combining radio frequency (RF) magnetron sputtering, stencil mask lithography and vapour phase sulfurization. Kelvin probe force microscopy (KPFM) based surface potential measurements have been carried out to locate the Fermi level position in an individual MoS 2 pattern and uncovered WS 2 portion. For MoS 2 , Fermi level is found to be located at 4.6 eV which suggests its n-type nature while WS 2 shows p-type nature with Fermi level lying just below the middle of the energy band gap. MoS 2 /WS 2 heterojunctions are electrically characterized using conducting atomic force microscopy (CAFM) where localized I-V curves are obtained from a few random locations of these patterned heterojunctions. Rectifying I-V behaviour from each location confirms formation of the junctions with good point-to-point uniformity. Present study is an effort towards the fabrication of patterned arrays of vertical MoS 2 /WS 2 heterojunctions and understanding the junction formation using KPFM and CAFM techniques.

In this present work, one dimensional (1D) ZnO nanostructures were synthesized by mechanical assisted thermal decomposition process. The samples were characterized by transmission electron microscopy (TEM) for morphology, high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) for structural characterization. Photoluminescence (PL) and Photoluminescence spectra evolution was studied as a function of (i) excitation wavelength (λEx: 310–370 nm) and (ii) morphology (nanoneedles and nanorods). PL spectra were observed to be highly asymmetric with strong dependence on excitation wavelength (λEx). PL spectra categorized into two types as a function of excitation wavelength (λEx): I. λEx≤345 nm and II. λEx≥350 nm. The PL spectra were deconvoluted into multiple Gaussian components for each excitation wavelength. The position of each component is a signature of its origin and corresponds to specific visible transition. The transition involving origin from conduction band (CB) are absent for excitation wavelength λEx≥350 nm. The tunable photoresponse is achieved in 1D ZnO nanostructures by varying (i) excitation wavelength and (ii) morphology: nanoneedles to nanorods. PL intensity increases as aspect ratio decrease from nanoneedles to nanorods morphology. This is attributed to non-radiative quenching by near surface defects.

Hydrogen (H2) gas is rising as a promising fuel source to replace available fossil fuels. It is well known that H2 based fuel finds numerous applications in transportation, industries and in rockets for space vehicles, therefore, the fabrication of H2 sensor is important for its safe and controlled use. But, detection of H2 gas at room temperature with fast response and recovery time is still a challenge. In last few years, carbon materials are widely investigated because it is enormously sensitive to H2 at room temperature conditions. In this work, the inexpensive candle carbon soot (CCS) is used to detect H2 gas at room temperature conditions. A simple flame of candle is used to synthesize the multilayers of carbon soot at room temperature conditions. It is observed that the functionalized of CCS in inert atmosphere plays an important role in the enhancement of structural and sensing properties as compared to as-synthesized CCS. The structural properties were investigated by X-ray diffraction(XRD), Raman spectroscopy and scanning electron microscopy (SEM). We further reported that CCS proved prominent sensing materials for the 2% detection of H2 at room temperature.

In the present work, kelvin probe force microscopy (KPFM) technique has been used to study the CZTSe/CuxSe bilayer interface prepared by multi-step deposition and selenization process of metal precursors. Transmission electron microscopy (TEM) confirmed the bilayer configuration of the CZTSe/CuxSe sample. Two configuration modes (surface mode and junction mode) in KPFM have been employed in order to measure the junction voltage under illumination conditions. The results show that CZTSe/CuxSe has small junction voltage of ∼21 mV and the presence of CuxSe secondary phase in the CZTSe grain boundaries changes the workfunction of the local grain boundaries region. The negligible photovoltage difference between grain and grain boundaries in photovoltage image indicates that CuxSe phase deteriorates the higher photovoltage at grain boundaries normally observed in CZTSe based device. These results can be important for understanding the role of secondary phases in CZTSe based junction devices.

Background Conventionally, focus groups are facilitated by academic researchers who mediate discussions with public participants. The researchers consider in advance group composition, topic guides and within-group dynamics. As part of a mixed methods evaluation of a health care improvement programme, we co-produced a series of focus groups with a patient representative. Aim To critically reflect on the process of developing and undertaking focus groups in partnership with patient representatives, and make recommendations for others considering using a similar approach in health research. Methods Focus group materials were co-designed with a patient representative and piloted with a patient and public advisory panel. We conducted three focus groups with individuals who had undergone surgery in the last two years (surgical groups) and individuals who had not (non-surgical group). Each group was co-facilitated with the patient representative who later contributed to discussions to interpret the findings. Results Co-production during planning stages provided a unique patient perspective about how to communicate information to the public and emphasise the patient perspective. We re-framed the topic guide to acknowledge that the patient journey is experienced along a continuum, not bounded by time or contact points with care providers. Co-facilitation of the groups enabled transparency, legitimacy and balance of contribution across academic and lay representatives. Rather than following convention and leading a focus group, researchers’ roles shifted and they became co-facilitators. Focus groups benefitted from instances where the patient representative usefully sought to extend discussions and pursue emergent topics, where academic members might have tacitly sought to stick to the topic guide and keep discussions within the remit of the study objectives. Conclusion We suggest that this process of co-production, when instituted as part of a critically reflective team approach, democratised the research process and supported stronger engagement within the groups themselves.

In this work, the effects of Si-doping in Cu2ZnSnS4 are examined computationally and experimentally. The density functional theory calculations show that an increasing concentration of Si (from x = 0 to x = 1) yields a band gap rise due to shifting of the conduction band minimum towards higher energy states in the Cu2Zn(Sn1-xSix)S-4. CZTSiS thin film prepared by co-sputtering process shows Cu2Zn(Sn1-xSix)S-4 (Si-rich) and Cu2ZnSnS4 (S-rich) kesterite phases on the surface and in the bulk of the sample, respectively. A significant change in surface electronic properties is observed in CZTSiS thin film. Si-doping in CZTS inverts the band bending at grain-boundaries from downward to upward and the Fermi level of CZTSiS shifts upward. Further, the coating of the CdS and ZnO layer improves the photocurrent to approximate to 5.57 mA cm(-2) at -0.41 V-RHE in the CZTSiS/CdS/ZnO sample, which is 2.39 times higher than that of pure CZTS. The flat band potential increases from CZTS approximate to 0.43 V-RHE to CZTSiS/CdS/ZnO approximate to 1.31 V-RHE indicating the faster carrier separation process at the electrode-electrolyte interface in the latter sample. CdS/ZnO layers over CZTSiS significantly reduce the charge transfer resistance at the semiconductor-electrolyte interface.

In the present work, catalyst free GaN nanowires were grown on Si (111) substrates by plasma assisted molecular beam epitaxy followed by chemical vapour deposited few layers MoS2. The morphology of the GaN nanowires and MoS2/GaN were studied using scanning electron microscopy. The vibrational properties of MoS2/GaN nanowires/Si (111) substrates were analysed using Raman spectroscopy. The difference of 24.8 cm−1 between E2g and A1g Raman peaks confirmed few layers of MoS2. High Resolution X-ray diffraction results in accordance with Raman results also indicated the growth of few layers of MoS2 on GaN nanowires grown on Si (111) substrates. As a result MoS2/GaN nanowires heterojunction with their exceptional structural and vibrational properties as studied in the present work can have great potential for future optoelectronic devices.

In the present work, photoanodic response of ZnTe thin films is enhanced by incorporating oxygen, which is explained by analyzing oxygen-induced modifications in structural, optical, and electronic behavior of ZnTe thin films, using detailed experimental characterizations and density functional theory (DFT) based calculations. On incorporating oxygen, the nanocrystalline character of ZnTe is increased with a change in optical properties due to absorption through sub band states and an increase in fundamental absorption edge. From DFT analysis, origin of these sub band gap states is attributed to oxygen incorporation induced electronic states and Te vacancies. Photoelectrochemical (PEC) performances of ZnTe with and without oxygen have been investigated where a change over from photocathodic response for ZnTe to enhanced photoanodic response for ZnTe:O thin films along with increased response for low energy photons is observed. These findings are explained in terms of oxygen induced modification in visible...

In the present study, the effect of the presence of monolayer graphene (G) on the nanoscale electrical and thermal conductivities of Bi 2 Te 3 has been investigated. Atomic force and conducting atomic force microscopic studies show that G incorporation results in lower electrical conductivity at Bi 2 Te 3 :Graphene (Bi 2 Te 3 :G) interfaces. The Kelvin probe and scanning thermal images show that Bi 2 Te 3 composites have different work function and thermal conductivity values compared to Bi 2 Te 3 sample. The decrease in the value of thermal conductivity was further confirmed by measuring the thermoelectric properties of Bi 2 Te 3 and its composites in the temperature range 300–480 K. The simultaneous increase in the value of power factor and decrease in the value of thermal conductivity of the Bi 2 Te 3 /G composite sample led to enhanced value of ZT = 0.92. This increase in the value of ZT is attributed to increased phonon scattering, and limited effect on the electron transport due to large interface area and 2D nature of G. The present study provides an insight into a new path for direct nanoscale measurements of topographical, electrical and thermally conducting characteristics of nanocomposite samples which is important for establishing the role of 2D materials for improving thermoelectric properties.

Wide optical absorption window, long lived and high charge carrier transfer efficiency are the prime characteristics towards the accomplishment of remarkably efficient photocatalysts. In this context, we have synthesized TiO2/CdS/Ag2S core/shell/shell (CSS) heterostructures by using ion-exchange method. The photoelectrochemical (PEC) measurements unveiled appreciably increased PEC water splitting performance of the CSS heterostructure (used as photoanodes), as indicated by high photocurrent density of ∼ 7.6 mA/cm2 at 1.0 V versus Ag/AgCl and low photocurrent onset potential of ∼ 0.1 V as compared to pristine TiO2 nanorods. Mott-Schottky analysis evident the p-n junction features of heterostructures that strengthen the separation of electron and holes. We have investigated the exciton dynamics with photoluminescence (PL) and time correlated single photon counting (TCSPC) studies. The diminished PL intensity and shorten average lifetime (τavg) in CSS heterostructures is a clear manifestation of suppression of charge carrier recombination as well as efficient charge carrier transfer from CdS (shell) to TiO2 (core). Thus, both factors prolonged and efficient transfer of visible light driven charge carriers led to phenomenal photoactivity of TiO2/CdS/Ag2S based CSS heterostructures towards the degradation of toxic organic pollutants and PEC water oxidation. We anticipate that the architecture of CSS hetrostructures will provide a new paradigm in the realm of photocatalysis.

The electronic and optical properties of Cu2ZnGeS4 are calculated by means of the full potential linearized augmented plane wave method (FP-LAPW) using the generalized gradient approximation (GGA) and the modified Becke–Johnson (mBJ) as exchange correlation functionals. The band structures, total and partial densities of states as well as optical properties are presented and discussed in the context of the available experimental data and theoretical calculations. Our calculations show that the conduction bands minima (CBM) is composed of contributions mainly from Ge–p states while the valence bands maxima (VBM) is dominated by Cu–d states. We find that Cu2ZnGeS4 possesses a direct energy band gap situated at the center (Γ point) of the Brillouin Zone (BZ). The calculated energy gaps of 0.50 eV (GGA) and 1.21 eV (mBJ) are much smaller than the experimental value of around 2.2 eV. We have shown anisotropic behavior of the compound using optical constants and birefringence plots and found that the Δn(0) in GGA and mBJ is about 0.06 and 0.08, respectively when applied scissors correction. We find that applying the scissors correction leads to better agreement with the experiment.

The efficient separation of photogenerated electron–hole pairs and stability against corrosion are critical preconditions for a photoelectrode to achieve a high photoelectrochemical performance. In this work it is shown how both criteria can be met by employing a heterostructure of bismuth vanadate (BiVO4) and titanium dioxide (TiO2) as the photocatalyst. Using electronic structure calculations, an alteration of the band alignment is predicted at the heterojunction from type I to type II by hydrogen treatment of the top TiO2 layer. Guided by this idea, we have fabricated heterostructures of BiVO4 and TiO2 and studied the effect of hydrogen treatment. The achieved band engineering results in a significant improvement in photocurrent density, up to 4.44 mA cm–2 at 1.23 V vs RHE, and a low onset potential, −0.14 V vs RHE, under visible light illumination. The enhanced photoelectrochemical performance originates in facilitated hole transport to the electrode surface and enhanced photoabsorption in the TiO2 la...

The phenomenon of resistive switching is based on nanoscale changes in the electrical properties of the interface. In the present study, conductive atomic force microscope based nanoscale measurements of copper oxide (CuO)-multilayer graphene (MLG) hybrid interface based devices have been carried out to understand changes in the electrical properties during resistive switching of the Ti–CuO/MLG-Cu memory cells having different dimensions fabricated on the same substrate using stencil lithography technique. The dependence of resistive switching characteristics in LRS and HRS and current level of the conductive filaments (CF) on the electrode area have been studied. As the device dimension is reduced, the filamentary contribution is enhanced in comparison to the background contribution, resulting in an increase in the current density ratio between LRS and HRS. It is also observed that as the device dimension is decreased from 150 to 25 μm, the filament size decreases from 95 nm to 20 nm, respectively, which causes a decrease in the reset current and reset voltage. The results of the nanoscale CAFM measurements have shown a good correlation with the switching parameters obtained by the macroscale pad I–V measurements, thereby, suggesting the origin of resistive switching is due to the formation and rupture of an entity called filament, whose dimension is in nanorange. It is observed that changes in the electrical properties of the overall interface layer along with changes in the electrical conductivity of these filaments contribute towards resistive switching phenomenon. This study suggests that a significant reduction of reset current can be achieved by decreasing the memory device dimensions.

In this study, nanoscale interface formation and photogenerated carrier transfer in Schottky-junction between CVD graphene and n-Si wafer have been investigated using CAFM and KPFM techniques. The difference in the surface potential images of graphene observed on applying voltage between tip-graphene and tip-Si under light conditions has been understood in terms of holes transfer to graphene resulting in the shift of Fermi level and the open circuit voltage variations at the junction. A decrease in surface potential due to PMMA residues and an increase in surface potential near wrapping boundaries are the main reasons for the variation in photovoltaic parameters.

2D materials offer excellent possibilities for high performance gas detection due to their high surface-to-volume ratio, high surface activities, tunable electronic properties and dramatic change in resistivity upon molecular adsorption. This paper demonstrates a simple field effect transistor (FET) of molybdenum disulphide (MoS2) fabricated on a hexagonal boron nitride (hBN) substrate that can detect NOx down to concentrations of 6 ppb and possibly far below at room temperature (RT) with a systematic optimization of the device design and fabrication parameters as well as the device operating conditions. The effects of the substrate, number of MoS2 layers, channel layout and biasing conditions on the response of MoS2 FETs to NOx were investigated, providing directions for maximizing the sensitivity. This work also sheds light the issues of recovery and stability and present a methodology for calibration of the sensors which is critical for repeatable and reliable measurements.

Two-dimensional (2D) layered semiconducting materials, such as MoS2, SnS2 and SnS, have received remarkable consideration due to their thickness dependent properties and potential applications. In this study, SnS and SnS2 thin films were grown using a simple method of thermal evaporation and their possible application in photoelectrochemical splitting of water reaction have been investigated. X-ray diffraction, Scanning electron microscopy, Raman spectroscopy, and UV–Vis spectroscopy techniques results show the presence of SnS and SnS2 pure phases with orthorhombic and hexagonal crystal structure, having band gap values of 1.8 eV and 2.75 eV, respectively. The photoelectrochemical response of as grown SnS and SnS2 thin films was investigated and the results showed the photoanodic behaviour for SnS2 films with photocurrent density of 1 mA cm−2 and photocathodic nature for SnS with photocurrent density of 0.4 mA cm−2 at 0.95 V vs. Ag/AgCl. The above obtained properties of SnS and SnS2 opens a pathway for using these films for SnS–SnS2 heterojunctions for further improving the photoelectrochemical response.

In this study the effect of hot phosphoric acid treatment on the evolution of microstructures in plasma assisted molecular beam epitaxy grown GaN thin films and GaN/AlGaN/GaN heterostructures is investigated. The surface morphology of the as grown samples and chemically treated samples is studied using field emission scanning electron microscopy which reveal the formation of different geometrical microstructures namely dodecagonal pyramids in one sample and hexagonal pits in the other after chemical treatment due to the different polar nature of GaN in both the samples.

In this work, we have investigated the effect of light on the single walled carbon nanotubes (SWCNTs) and silicon (Si) interface. It is observed that, chemical stimulated SWCNTs/Si interface shows better rectifying behavior as compared to pristine SWCNTs/Si interface. Moreover, the power conversion efficiency for functionalized SWCNTs/Si interface is 1.4% which is mainly due acid doping in CNTs. The outcome of the present work might provide a new avenue for designing optoelectronic and light-energy conversion devices.

In the present investigation TiO2, CdS and TiO2/CdS heterostructure thin films have been deposited on the indium doped tin oxide substrates (In: SnO2; ITO) by rf magnetron sputtering technique. A further study has been made for structural, optical and photoelectrochemical (PEC) properties of TiO2, CdS and TiO2/CdS heterostructure system. PEC behaviour of TiO2/CdS heterostructure thin film was studied and compared with TiO2 and CdS pristine thin film photoelectrodes. Enhanced photocurrent density of 0.36 mA/cm2 was observed in TiO2/CdS heterostructure thin films as compared to pristine TiO2(0.18 mA/cm2) and CdS (35 μA/cm2) at an applied bias of 0.23 V versus Ag/AgCl in 0.5 M Na2SO4 (pH = 7) electrolyte. This work provides promising methods to enhance the PEC water oxidation performance of the TiO2-based heterostructure photoanodes.

In the present study, chemical vapor deposited two-dimensional (2D) heterostructures are studied for their interesting electrical, and mechanical properties. The two-dimensional materials, molybdenum disulfide (MoS2) and Graphene are characterized based on the nanoscale variations in the work function of the heterostructure using kelvin probe force microscopy (KPFM) and electrical properties using conductive atomic force microscopy (CAFM) techniques. Raman spectroscopy has been employed to identify MoS2, Graphene and study their layer dependence. The surface potential value of the heterostructure exhibits a value of 527 mV, necessary to identify the nature of metal tip contact to be used for its loading force dependence. The I–V characteristics are studied with two different AFM metal tips in contact mode, namely, Cobalt (Co) and Silver (Ag) coated tips, forming an Ohmic contact with MoS2-Graphene heterostructure, theoretically, to probe the junction characteristics. The study emphasizes the critical influence of two-dimensional nature of MoS2 with metal contacts in novel 2D materials based devices.

The water oxidation capability of the promising photoanode bismuth vanadate (BiVO4) is hampered by poor bulk electron transport and by high rates of charge recombination at the semiconductor/electrolyte interface. Here, we demonstrate that a dual modification of BiVO4 by: (i) annealing in a hydrogen-containing environment and (ii) coating with FeOOH overlayer substantially enhances the water oxidation ability of BiVO4 photoanodes. Hydrogen treated, FeOOH coated BiVO4 photoanodes exhibit a water oxidation photocurrent density of 2.16 mA cm−2 at 1.23 VRHE, which is 5 times higher than for untreated BiVO4 films. Moreover, they showed an impressive low photocurrent onset potential of −0.11 VRHE. A stable photocurrent was observed for 1 h of water oxidation measurement at 1.23 VRHE under 1 Sun illumination. The enhanced photocurrent of FeOOH/H:BiVO4 photoanode is ascribed to an improved bulk charge transport, as confirmed by impedance spectroscopy measurements and Mott-Schottky analysis. The cathodic shift of the onset potential originates from a lowering of the flat band potential and from an improvement of the charge transport at the semiconductor/electrolyte interface. The dual modification strategy used here offers a simple but effective approach of improving the water oxidation performance of BiVO4.

With the rapid expansion of novel technologies in the automobile industry, there has been an increase in the number of interaction hardware inside various types of automobiles. This has led to drivers taking their eyes off the road to control the various systems in the automobiles. According to a study, done by the AAA Foundation for Traffic Safety, an average driver is distracted visually and mentally from the road while using an infotainment system for a dangerous span of 40 seconds. We have come up with a review of various proposed gesture recognition systems to solve the problem of driver interacting with the in-car system. Gesture recognition thus opens up the possibility of implementing a Human Vehicle Interaction System for controlling however complex, an infotainment system.

Here, we report the emergence of superhydrophobic wetting behavior and enhanced UV stability of indium oxide (IO) nanorods due to their vertical alignment. Both randomly distributed and vertically aligned IO nanorods were synthesized via chemical vapor deposition (CVD) method. Our results reveal that the static water contact angle ( θ ) shows a significant dependence on the alignment of the nanorods. The randomly distributed IO nanorods shows θ value of 133.7° ± 6.8° whereas for vertically aligned IO nanorods θ was found to be 159.3° ± 4.8°. Interestingly, continuous UV light illumination for 30 min exhibited the change in contact angle (Δ θ ) of about 41° for vertically aligned IO nanorods whereas randomly distributed IO nanorods become hydrophilic with a dramatic change in θ value of 108°. The superhydrophobicity of vertically aligned IO nanorods and their enhanced UV stability were discussed by comparing the effective solid fraction at solid-liquid interface and the reactivity of surface crystallographic planes. The superhydrophobic surface of aligned vertically standing IO nanorods along with its resistance against photoinduced wetting transition make them suitable for electronic devices with reduced surface discharge even at relatively high humidity level.

A decision support system (DSS) was developed in Visual Basic 6.0 programming language to design transmission system of low horsepower agricultural tractors, which involved the design of clutch and gearbox. The DSS provided graphical user interface by linking databases to support decision on design of transmission system for low horsepower tractors on the basis of modified ASABE draft model. The developed program for design of tractor transmission system calculated clutch size, gear ratios, number of teeth on each gear, and various gear design parameters. Related deviation was computed for design of transmission system of tractors based on measured and predicted values (simulated). The related deviation was less than 7% for design of clutch plate outer diameter and less than 3% for inner diameter. There was less than 1% variation between the predicted results by the developed DSS and those obtained from actual measurement for design of gear ratio. The DSS program was user friendly and efficient for predicting the design of transmission system for different tractor models to meet requirements of research institutions and industry. © 2015 Wiley Periodicals, Inc. Comput. Appl. Eng. Educ. Comput Appl Eng Educ 23:760–770, 2015; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21648

In the present study, Kelvin probe force microscopy (KPFM) has been used to study a prototype CdS–CZTS lengthwise single nanorod heterojunction. A shift in surface potential (SP) of the entire sample is observed as the device is taken from dark into light. It has been demonstrated that plots showing the number of pixels with different values of surface potential as a function of the SP itself, can be effectively used to topographically segregate regions composed of different semiconductors. On illumination, a new SP peak emerges and based on its topographical position and SP value, both of which lie in between that of CZTS and CdS, it has been assigned to the heterojunction interfacial layer. These observations have been discussed in terms of junction quality and charge generation and separation to gain a better understanding of the operation of nanorod based solar cell devices.

A new anti-reflection coating based on amorphous barium titanate (a-BTO) was developed using RF magnetron sputtering technique. Systematic studies on the structural and optical properties were carried on a-BTO thin films deposited on polished Si and textured Si substrates. In the visible range of the solar spectrum, the refractive index was found to be 2.02-1.91 with high transmittance of greater than 85%. Maximum reduction in the reflectance for a-BTO on polished Si and textured Si substrates was found to be 100% (at 550 nm) and 85% (at 400 nm), respectively. Further, improvement in cell efficiency of a Si solar cell with a-BTO anti-reflection coating was found with an increase from 9.3% to 10% accompanied by improvements in overall performance parameters such as short circuit density (J(sc)), open circuit voltage (V-oc) and fill factor (FF). These results indicate that an a-BTO thin film deposited using RF magnetron sputtering can be used as an alternative anti-reflection coating for Si based photovoltaic cells.

Business-to-business electronic markets have emerged as robust, legitimate channels for conducting transactions, where firms participate in these markets according to their investments in the channel, such that they might participate as an expert, explorer, or passive firm. Over time, repeated interactions with the same trading partners can result in virtual interorganizational relationships even in an environment predicated to promote transactional exchange. We suggest that the nature of firm participation should moderate the influence of organizational interdependence—which comprises both total interdependence and interdependent asymmetry—on relational outcomes such as trust and satisfaction for virtual interorganizational relationships that arise in the electronic market. Results from analysis of data collected from a survey of participant firms in an electronic market confirm the moderating role of the nature of participation. Across the three participation states, total interdependence enhances relational outcomes at a diminishing rate. In contrast, interdependence asymmetry does not influence relational outcomes for expert firms, diminishes them at an increasing rate for explorer firms, and increases trust at a decreasing rate for passive firms. The interaction between total interdependence and interdependence asymmetry increased satisfaction for expert firms and decreased trust and satisfaction for explorer firms.

The current-voltage and resistive switching properties of Cu2O and CuO based resistive random access memories in metal-oxide-metal structure with Cu as bottom electrode and different metals (Ti, Ag, Au and Pd) as top electrodes have been investigated. The observation of resistive switching in Cu2O and its absence in CuO based devices indicates that Ohmic nature of top and bottom metal–oxide contacts is favourable for resistive switching behaviour. The rectifying metal-oxide contact results in the applied voltage drop at the rectifying contact, resulting in the absence of electric field induced structural changes which are crucial for occurrence of resistive switching. The values of switching parameters, such as, electroforming, reset, set voltages and also the resistance ratio are also observed to depend upon the work function of the electrode materials and nature of metal-oxide interface.