Electronic and Optical Modeling of Solar Cell Compounds CuGaSe<Subscript>2</Subscript> and CuInSe<Subscript>2</Subscript>

We present dielectric-function-related optical properties such as absorption coefficient, refractive index, and reflectivity of the semiconducting chalcopyrites CuGaSe₂ and CuInSe₂. The optical properties were calculated in the framework of density functional theory (DFT) using linear combination of atomic orbitals (LCAO) and full-potential linearized augmented plane wave (FP-LAPW) methods. The calculated spectral dependence of complex dielectric functions is interpreted in terms of interband transitions within energy bands of both chalcopyrites; for example, the lowest energy peak in the e₂ (w) \varepsilon_{2} (\omega ) spectra for CuGaSe₂ corresponds to interband transitions from Ga/Se-4p → Ga-4s while that for CuInSe₂ emerges as due to transition between Se-4p → In-5s bands. The calculated dielectric constant, e₁ (0) \varepsilon_{1} (0) , for CuInSe₂ is higher than that of CuGaSe₂. The electronic structure of both compounds is reasonably interpreted by the LCAO (DFT) method. The optical properties computed using the FP-LAPW model (with scissor correction) are close to the spectroscopic ellipsometry data available in the literature.     

A study on drying of textile substrates and a new concept for the enhancement of drying rate

Gravimetric absorption test system (GATS) is used to measure the absorption capacity, absorption rate and drying rate of knit hoses, prepared from different fibres. The fibres studied are cotton, polyester and variety of modified polyesters. The study has shown that desorption or drying rate is at least two orders of magnitude lower than absorption rate. This finding implies that drying is the limiting process in moisture management. Further experiments on knit fabrics made from polyester and cotton, show that the drying rates are independent of fibre type in the constant-rate period, while the drying rates in the falling-rate period are dependent on fibre type. Subsequently, it is shown on the polyester fabric that drying rate in the falling-rate period depends on water concentration. Based on this understanding, an approach for enhancing drying rate in the falling-rate period is defined. The approach is demonstrated on knit hoses prepared from cotton and polyester yarns in alternating stripe form. The drying rate in the falling-rate period is found to be higher in the polyester-cotton stripe knit hose. A hypothesis for the observed enhancement in drying rate by wicking is put forth in terms of the internal movement of water from polyester to cotton portion. Experimentally, it is shown that 16% improvement in drying time is achieved in the case of the polyester–cotton stripe samples. Further, indications of internal water movement from polyester to cotton portion have been obtained by tracking the surface temperatures of the knit hoses during drying by infrared (IR) thermography.     

Parallel support vector architectures for taxonomy of radial pulse morphology

Application of impedance plethysmography (IP) for impedance measurement is the paradigm in assessment of central and peripheral blood flow. We propose the expediency of IP to unearth hidden patterns from Plethysmographic observations on a radial pulse. The variability analysis in one thousand control and disease subjects evolves an archetype of eight different morphological patterns. The peripheral pulse waveforms not only characterize the physiology of control subjects, but also define the morphology of patients suffering from Myocardial Infarction, cirrhosis of liver, and disorder of lungs. Diverse parallel support vector machine (pSVM) topologies are designed as an aid to the physician for multiclass pattern recognition problem. Besides a lowest confusion coefficient (0.133), the PCA-based pSVM classifier offers a comparatively higher generalized correlation coefficient and κ value of 0.6586 and 0.8407, respectively. However, the ROC characteristics and the benchmark parameters suggest that wavelet-based pSVM is the optimum classifier with a sensitivity of 85.33 %, an elevated MCC (0.69), and a least upper bound on the expected error. pSVM stands out as a model classifier as compared with identified indices such as, Fishers Ratio, Morphology Index, and Heart rate variability.     

Emulation of multipath effects on a wireless testbed and its impact on MAC layer performance

Field experiments are an important part of research in wireless networks. Since the wireless channel varies with location and time, the results vary for the same field experiment at a different place and time. Assumptions about the wireless environment can lead to biased results. It is necessary to shield wireless transmission from uncontrolled interference in order to make the experiment repeatable. This paper describes A\underline{A}dvanced wireleSS\underline{SS} E\underline{E}nvironment R\underline{R}esearch T\underline{T}estbed (ASSERT) which uses shielded co-axial cables as the communication media for radio signals to conduct reliable, scalable and accurate wireless experiments. Shielding the transmission also protects the signal from random burst of noise introduced by the environment. The paper describes how the combination of programmable attenuators and RF splitters/combiners, which are part of ASSERT, helps in emulating complex and varying environments including those in which multipath interference plays a significant role. Our experimental results indicate that (1) tweaking the MAC layer and retransmissions at the application layer neutralize, to an extent, the impact of multipath effects when the received signal strength is extremely good, and (2) when the received signal strength falls below a certain threshold multipath interference plays a significant role.     

Anticancer activity of essential oils: a review

Natural essential oil constituents play an important role in cancer prevention and treatment. Essential oil constituents from aromatic herbs and dietary plants include monoterpenes, sesquiterpenes, oxygenated monoterpenes, oxygenated sesquiterpenes and phenolics among others. Various mechanisms such antioxidant, antimutagenic and antiproliferative, enhancement of immune function and surveillance, enzyme induction and enhancing detoxification, modulation of multidrug resistance and synergistic mechanism of volatile constituents are responsible for their chemopreventive properties. This review covers the most recent literature to summarize structural categories and molecular anticancer mechanisms of constituents from aromatic herbs and dietary plants. © 2013 Society of Chemical Industry     

Optimisation of spray drying process parameters for low‐fat honey‐based milk powder with antioxidant activity

The purpose of this study was to optimise process parameters to prepare spray‐dried honey‐based milk powder containing functional properties of honey. Experimental design with temperature (180 to 200 °C), honey concentration (5–15%) and feed flow rate (8–10 rpm) as independent variables was studied to investigate the effect on product responses. Results showed that increasing the temperature resulted in powder with lower moisture, bulk density, antioxidant activity, total phenolic contents, total flavonoid contents and higher water solubility index. Increasing feed flow rate resulted in higher moisture, bulk density, antioxidant activity, reduced water solubility index, total phenolic content and total flavonoid content, whereas increasing honey concentration resulted in increase in antioxidant activity, total phenolic content and total flavonoid content. The moisture content, bulk density, water solubility index, DPPH scavenging activity, total phenolic content and total flavonoid content were 3.27%, 0.44 g cc^?1, 96.67 g g^?1, 17.45%, 2.54 GAE g^?1 powder and 1.40 RE g^?1 powder, respectively.     

Phase Selection in a Laser Surface Melted Zr-Cu-Ni-Al-Nb Alloy

The present work explores the use of the LENS? (laser engineered net shaping) powder deposition technique in combination with laser surface melting to evaluate the formation–properties–production of bulk metallic glass-forming systems. A model Zr-Cu-Ni-Al-Nb alloy was subjected to a number of laser surface melting experiments to remelt and rapidly solidify a thin surface layer (the laser power varied from 150 W to 450 W and the travel speed of the substrate surface relative to the laser beam varied from 8 mm/s to 170 mm/s). Detailed SEM/TEM evaluation of the microstructure formed under selected laser surface melting conditions was conducted. A marked transition in the microstructure was observed as a result of phase selection, driven by the undercooling manifest under the different imposed solidification conditions. It is considered that such a technique provides valuable insight into the scope for microstructure manipulation through the precise control of the processing variables. The control of the microstructural length scale and the tuning of the intrinsic elastic constants of the constituent phases have been identified as being paramount, for example, in the alloy design of amorphous matrix composites.     

Sulfonated poly(arylene ether sulfone) nanocomposite electrolyte membrane for fuel cell applications: A review

Polymer electrolyte membrane (PEM) fuel cells are considered a promising technology for generating power with water as a byproduct. Recently, sulfonated poly(arylene ether sulfone) (SPAES) has emerged as a most suitable alternative for PEM applications because of its high proton conductivity, high CO tolerance, and low fuel crossover. However, the existing SPAES polymeric membrane materials have poor chemical reactivity, mechanical processability, and thermal usability. Thus, the effects of mixing inorganic nanomaterials with SPAES polymers on proton conductivity, power density, fuel crossover, thermal and chemical stability, and durability are discussed in this review. Further, the progress in preparation methods and fuel cell characteristics by the addition of silica, clay, heteropolyacids (HPA), and carbon nanotubes (CNTs) in polymer membrane materials for PEM applications is also discussed.     

Thromboinflammation in Myeloproliferative Neoplasms (MPN)—A Puzzle Still to Be Solved

Myeloproliferative neoplasms (MPNs), a group of malignant hematological disorders, occur as a consequence of somatic mutations in the hematopoietic stem cell compartment and show excessive accumulation of mature myeloid cells in the blood. A major cause of morbidity and mortality in these patients is the marked prothrombotic state leading to venous and arterial thrombosis, including myocardial infarction (MI), deep vein thrombosis (DVT), and strokes. Additionally, many MPN patients suffer from inflammation-mediated constitutional symptoms, such as fever, night sweats, fatigue, and cachexia. The chronic inflammatory syndrome in MPNs is associated with the up-regulation of various inflammatory cytokines in patients and is involved in the formation of the so-called MPN thromboinflammation. JAK2-V617F, the most prevalent mutation in MPNs, has been shown to activate a number of integrins on mature myeloid cells, including granulocytes and erythrocytes, which increase adhesion and drive venous thrombosis in murine knock-in/out models. This review aims to shed light on the current understanding of thromboinflammation, involvement of neutrophils in the prothrombotic state, plausible molecular mechanisms triggering the process of thrombosis, and potential novel therapeutic targets for developing effective strategies to reduce the MPN disease burden.     

Evaluation of flocculation characteristics and biodegradation studies of reduced gum rosin and psyllium-based hydrogel

Present study explored the swelling behavior, biodegradability and flocculation efficiency of hydrogel polymer based on renewable backbones-psyllium and gum rosin. Swelling studies revealed that the polymer sample exhibit pH and temperature-dependent swelling behavior. The polymer sample was assessed for its flocculation efficiency by optimizing the process parameters such as polymer dose, pH, and temperature. The polymer sample illustrated the maximum flocculation efficiency of 96% in 500 mg/L kaolin suspension under optimized experimental conditions. Investigation of biodegradation behavior was carried out using the soil burial and composting method. The percentage degradation of the polymer sample was observed to be 86.8% and 90.4% in 63 days using soil burial and composting method, respectively. The progress of biodegradation was analyzed through Fourier transform infrared and scanning electron microscopy techniques. Thus, the polymer sample was found to be cost effective, eco-friendly, biodegradable material that has significant flocculation characteristics, and hence can be utilized for treatment of kaolinated wastewater.