A monolithically integrated high‐efficiency Cu(In,Ga)Se2 mini‐module structured solely by laser

Monolithically integrated Cu(In,Ga)Se₂ mini‐modules were fabricated in order to reduce the width of patterning related dead area. The Cu(In,Ga)Se₂ layers were prepared on soda‐lime glasses using the multistage process at low substrate temperature below 500 °C. A picosecond laser with a wavelength of 532 nm was used for all of the structuring processes (P1, P2, and P3) for the monolithic integration. A “lift‐off” type structuring was applied for P1 and P3, and an “ablation” type was for P2. The laser structuring was optimized to be minimizing the dead area width, and the width of about 70 µm was successfully achieved. A mini‐module, in which the optimized structuring processes were applied for the integration, demonstrated a certified efficiency of 16.6%. Copyright © 2015 John Wiley & Sons, Ltd.     

Development of 99Mo-alfa-benzoin oxime complex as industrial radiotracer for identification of leaky heat exchanger and its validation with 99mTc

Journal of Radioanalytical and Nuclear Chemistry - In the traditional medicine of Iran, some herbal medicines are used for treating of high blood sugar. In this study, the concentration of Ca, Cr,...     

A quick and regioselective access of spirooxindole-oxazoline by reaction of isatin and isocyanoacetate “on water”

A greener, rapid and regioselective “on water” synthesis of spirooxindole-oxazoline by the reaction of isatin and isocyanoacetate at room temperature is described. The developed protocol has the advantage of being atom-economical, eco-friendly, and benign reaction conditions. Broader substrate scope, experimentally simple procedures, and easy purification of products with high yield further make this method attractive. The synthesized compounds have been fully characterized with spectral analysis.     

Flowerlike hybrid horseradish peroxidase nanobiocatalyst for the polymerization of guaiacol

In this study, the catalytic activity and stability of flowerlike hybrid horseradish peroxidase (HRP) nanobiocatalyst (HRP-Cu ²⁺ ) obtained from Cu ²⁺ ions and HRP enzyme in the polymerization reaction of guaiacol were analyzed. We demonstrated that HRP-Cu ²⁺ and hydrogen peroxide (H ₂ O ₂ ) initiator showed significantly increased catalytic activity and stability on the polymerization of guaiacol compared to that of free HRP enzyme. Poly(guaiacol) was observed with quite high yields (88%) and molecular weights (38,000 g/mol) under pH 7.4 phosphate-buffered saline (PBS) conditions at 60 °C with 5 weight% of HRP-Cu ²⁺ loading. HRP-Cu ²⁺ also shows very high thermal stability and works even at 70 °C reaction temperature; free HRP enzyme denatures at that temperature. Furthermore, HRP-Cu ²⁺ provided considerable repeated use and showed some degree of catalytic activity, even after the fourth recycle, in the polymerization of guaiacol.     

Chemical composition,antimicrobial, and lipase enzyme activity of essential oil and solvent extracts from Serapias orientalis subsp. orientalis

The volatile components of essential oil (EO), SPME, and SPME of solvent extracts ( n -hexane, methanol, and water) obtained from fresh Serapias orientalis subsp. orientalis ( Soo ) were analyzed by GC-FID/MS. EO of Soo gave 11 compounds in the percentage of 99.97%; capronaldehyde (37.01%), 2-( E )-hexenal (23.19%), and n -nonanal (19.05%) were found to be major constituents. SPME GC-FID/MS analyses of fresh plant and solvent extracts of Soo revealed 7, 12, 7, and 4 compounds within the range of 99.7% to 99.9%. Limonene (76.5%, 41.7%, and 61.3%) was the major compound in SPMEs of the n -hexane and methanol extracts. α -Methoxy- p -cresol (52.9%) was the main component in its water extract. The antimicrobial activity of EO and the solvent extracts of Soo were screened against 9microorganisms. EO showed the best activity against Mycobacterium smegmatis , with 79.5 µg/mL MIC value. The n -hexane, methanol, and water extracts were the most active against the Staphylococcus aureus within the range of 81.25–125.0 µg/mL (MIC). IC ₅₀ values for the lipase enzyme inhibitory activity of EO and solvent extracts ( n -hexane, methanol, and water) were determined to be 59.87 µg/mL, 64.03 µg/mL, 101.91 µg/mL, and 121.24 µg/mL, respectively.     

Formation and Structure of Fluorescent Silver Nanoclusters at Interfacial Binding Sites Facilitating Oligomerization of DNA Hairpins

Fluorescent, DNA‐stabilized silver nanoclusters (DNA‐AgNCs) are applied in a range of applications within nanoscience and nanotechnology. However, their diverse optical properties, mechanism of formation, and aspects of their composition remain unexplored, making the rational design of nanocluster probes challenging. Herein, a synthetic procedure is described for obtaining a high yield of emissive DNA‐AgNCs with a C‐loop hairpin DNA sequence, with subsequent purification by size‐exclusion chromatography (SEC). Through a combination of optical spectroscopy, gel electrophoresis, inductively coupled plasma mass spectrometry (ICP‐MS), and small‐angle X‐ray scattering (SAXS) in conjunction with the systematic study of various DNA sequences, the low‐resolution structure and mechanism of the formation of AgNCs were investigated. Data indicate that fluorescent DNA‐AgNCs self‐assemble by a head‐to‐head binding of two DNA hairpins, bridged by a silver nanocluster, resulting in the modelling of a dimeric structure harboring an Ag₁₂ cluster.     

Intraspecific competition of predator for prey with variable rates in protected areas

Nonlinear Dynamics - In this present study, we systematically explore the periodicity (almost periodic nature) of a dynamical system in time-varying environment, which portrays a special case of...     

Nighttime enhancements in TEC near the crest of northern equatorial ionization anomaly during low solar activity period

Enhancement in nighttime total electron content (TEC) near the crest of equatorial ionization anomaly at Bhopal (Geog. 23.2°N, 77.4°E, and MLAT 14.2°N) has been studied for the solar minimum period March 2005- November 2006. TEC data recorded by GPS Ionospheric Scintillation and TEC Monitor (GISTM) GSV4004A receiver is used for the study and results are presented in the paper. More than 10% increase in TEC with respect to background content is considered for analysis. Out of total 138 enhancements, 65 observed during pre midnight hours and 73 during post midnight hours. It is observed that nighttime enhancement in TEC at Bhopal occurs in all seasons; it is more frequent during summer, less during equinox and least during winter months. The enhancement in nighttime TEC can be observed both in geomagnetic disturbed time and in quiet time. We found that mean peak amplitude for pre-midnight TEC enhancement are more in equinox and less in winter, while in post-midnight TEC enhancement it is highest in summer and less in winter. Post-midnight enhancements have smaller peak amplitude as compared to pre-midnight. Also the most probable values for pre- and post-midnights are 4.4 TECU and 2.17 TECU respectively. The percentage occurrence of nighttime TEC enhancement does not show any dependence on solar activity whereas the peak amplitude depends on solar activity. The percentage occurrence of nighttime TEC enhancement decreases as the magnetic activity increases whereas there is no such dependency found with peak amplitude. It is also observed that majority of nighttime TEC enhancements are occurred without scintillation. The localised nighttime TEC enhancements near the crest of equatorial ionization anomaly region have been observed most of the nights during the period of study.     

A ghost fluid Lattice Boltzmann method for complex geometries

A ghost fluid Lattice Boltzmann method (GF‐LBM) is developed in this study to represent complex boundaries in Lattice Boltzmann simulations of fluid flows. Velocity and density values at the ghost points are extrapolated from the fluid interior and domain boundary via obtaining image points along the boundary normal inside the fluid domain. A general bilinear interpolation algorithm is used to obtain values at image points which are then extrapolated to ghost nodes thus satisfying hydrodynamic boundary conditions. The method ensures no‐penetration and no‐slip conditions at the boundaries. Equilibrium distribution functions at the ghost points are computed using the extrapolated values of the hydrodynamic variables, while non‐equilibrium distribution functions are extrapolated from the interior nodes. The method developed is general, and is capable of prescribing Dirichlet as well as Neumann boundary conditions for pressure and velocity. Consistency and second‐order accuracy of the method are established by running three test problems including cylindrical Couette flow, flow between eccentric rotating cylinders and flow over a cylinder in a confined channel. Copyright © 2011 John Wiley & Sons, Ltd.