Large area Cl irradiated PET membranes for hydrogen separation

In the present case, Polyethylene terephthalate (PET) membranes of thickness 25 μm were irradiated by 100 MeV Cl⁹⁺ ion beam with ion fluence of 10⁷ ions/cm². These membranes were etched in 6N NaOH at 60 °C at different etching times to generate pores. The permeabilities of nitrogen, oxygen, methane, carbon dioxide as well as hydrogen were measured for etched membranes at various etching times. The permeability of gases was found to increase with etching time and a rapid increase was noticed after a critical etching time when the etched tracks meet at their vertexes. The selectivity of hydrogen gas over other gases was also observed.     

Oxidative stress following traumatic brain injury in rats

BACKGROUND: Free radicals may be involved in the pathophysiology of traumatic brain injury (TBI) through oxidative damage of neurovascular structures. Endogenous antioxidants, such as ascorbate and alpha-tocopherol, may play a critical role in combating these oxidative reactions and their oxidized products can serve as an important index of oxidative stress. METHODS: We used electron spin resonance (ESR) spectroscopy and in vivo spin trapping (reaction of an organic compound with free radical species) to detect the possible generation of free radicals after TBI. Injury was inflicted by a weight drop technique over the head (5.7 kg-cm). Rats were intravenously infused with either 1 mL, 0.1 M of the spin trap, alpha-phenyl-N-tert-butyl nitrone (PBN), or an equivalent volume of saline immediately before TBI or sham-injury. Animals were divided into four groups: (1) Group I: PBN-infused sham-injured, (2) Group II: PBN-infused injured, (3) Group III: saline-infused sham-injured, and (4) Group IV: saline-infused injured. Additional groups of saline-infused uninjured, saline-infused, and PBN-infused injured animals were used for histopathology. Sixty minutes after TBI or sham-injury, rats were again anesthetized and decapitated. The brains were removed within 1 minute, homogenized, and extracted for lipids. The extracts were analyzed by ESR spectroscopy. Brain ascorbic acid (AA) concentration was determined spectrophotometrically, using the ascorbate oxidase assay. RESULTS: No PBN spin adduct signals (indicating trapped free radical species) were visible 60 minutes after TBI. All groups of rats showed an ascorbyl free radical signal. The ascorbyl signal intensity (AI) was, however, significantly higher in the injured rats, while the brain (AA) was significantly reduced. In addition, the ratio of AI/AA, which eliminates the effect of variable ascorbate concentrations in the brain, was also significantly higher in the injured animals. CONCLUSIONS: We conclude that 60 minutes following TBI there was a significantly increased level of oxidative stress in the brain. This may reflect formation of free radical species with subsequent interaction with ascorbate (antioxidant) during the 60 minute period. The lack of PBN spin adduct signals 1 hour after TBI may indicate that free radical generation is time dependent and might be detectable earlier or later than the 60 minute period.     

Growth and characterizations of dual ion beam sputtered CIGS thin films for photovoltaic applications

The growth of CIGS thin films on soda-lime glass substrates at different substrate temperatures by dual ion beam sputtering system in a single-step route from a single quaternary sputtering target with the composition of Cu (In_0.70 Ga_0.30) Se₂ was reported. The effects of the substrate temperature on structural, optical, morphological and electrical properties of CIGS films were investigated. Stoichiometry of one such film was investigated by X-ray photoelectron spectroscopy. All CIGS films had demonstrated a strong (112) orientation located at 2θ ~26.70^o, which indicated the chalcopyrite structure of films. The value of full-width at half-maximum of (112) peak was reduced from 0.58° to 0.19° and crystallite size was enlarged from 14.98 to 43.05 nm as growth temperature was increased from 100 to 400 °C. However, atomic force microscope results showed a smooth and uniform surface at lower growth temperature and the surface roughness was observed to increase with increasing growth temperature. Hall measurements exhibited the minimum film resistivity of 0.09 Ω cm with a hole concentration of 2.42 × 10¹⁸ cm^?3 and mobility of 28.60 cm² V^?1 s^?1 for CIGS film grown at 100 °C. Film absorption coefficient was found to enhance nominally from 1 × 10⁵ to 2.3 × 10⁵ cm^?1 with increasing growth temperature from 100 to 400 °C.     

ATP-Dependent human erythrocyte glutathione-conjugate transporter. I. Purification, photoaffinity labeling, and kinetic characteristics of ATPase activity

Dinitrophenyl S-glutathione (DNP-SG) ATPase is a 38 kDa membrane protein expressed in erythrocytes and other tissues. Although stimulation of ATP hydrolysis catalyzed by DNP-SG ATPase has been demonstrated in the presence of several structurally unrelated amphiphilic ions, structural and functional properties of this protein have not been well-defined. In the present study, we have developed an improved protocol for the purification of DNP-SG ATPase and investigated its kinetic and substrate-binding properties. The purification procedure was based on highly specific elution of the 38 kDa protein from DNP-SG affinity resin in the presence of ATP. The protein could not be eluted using either ADP or adenosine-5'-[beta,gamma-methylene]triphosphate (methylene-ATP), a nonhydrolyzable analogue of ATP. Doxorubicin (DOX), a weakly basic anthracycline chemotherapy agent, was found to be the preferred activator for stimulation of ATP hydrolysis by the enzyme. ATP binding to the enzyme was demonstrated using 8-azido-ATP photoaffinity labeling and binding of trinitrophenyl (TNP)-ATP, a fluorescent analogue of ATP. The photoaffinity labeling of DNP-SG ATPase (38 kDa) was saturable with respect to 8-azido ATP (Kd = 2 microM), indicating that the enzyme was capable of specific and saturable binding to ATP. DNP-SG binding was evident from the purification procedure itself and was also demonstrable by quenching of tryptophan fluorescence. Results of quenching of tryptophan fluorescence as well as radioactive isotope-binding studies indicated that DOX was bound to the purified protein as well.     

Anthocyanin-rich fruit vinegar from Grewia and Cantaloupe fruit blends

Grewia is a tropical berry rich in anthocyanins and antioxidants but highly perishable in nature. In this study, desirable composite blend of overripe Grewia (Phalsa) berries and cantaloupe was sought for conversion to acetic acid. Composition of raw macerate, and the alcoholic and acetic ferments was analysed for sugars, alcohol and acetic acid. The primary alcohol yield varied significantly (5.75–99.44%) with blend composition. Vinegar from select blend attained 4.98% acidity with 138.57 mg mL⁻¹ of phenols and high anthocyanins retention (74.77%). Gompertz model was used to fit the growth curves of S. cerevisiae and A. aceti (R²> 0.92) during fermentation. Presence of ethyl acetate, iso-pentyl alcohols explained pleasant sweet fruity aroma of resulting vinegar. Thus, high quality functional red fruit vinegar can be obtained to prevent spoilage and utilise the functional potential of this delicate and nutritious berry.     

Compact multiband planar monopole antenna for Bluetooth,LTE, and reconfigurable UWB applications including X‐band and Ku‐band wireless communications

In this article, a small‐printed Bluetooth/LTE/UWB/X‐band/Ku‐band monopole antenna with high rejection triple band‐notch is presented. Notched bands include WiMAX (IEEE802.16 3.30‐3.80 GHz), WLAN IEEE802.11a/h/j/n (5.15‐5.35 GHz, 5.25‐5.35 GHz, 5.47‐5.725 GHz, and 5.725‐5.825 GHz), and downlink satellite system (7.1‐7.9 GHz). By including inverted T‐shaped stub and etching two C‐shaped slots on the radiating patch, triple band‐notch function is obtained with measured high band rejection (VSWR = 14.59 at 3.69 GHz, VSWR = 39.40 at 5.42 GHz, and VSWR = 6.43 at 7.57 GHz) and covers a UWB useable fractional bandwidth of 157.75% (2.285‐19.35 GHz = 17.065 GHz). Reconfigurable characteristics are obtained using PIN diodes, which control the individual notched bands. Proposed antenna is printed on Rogers RT/duroid5880 substrate with compact dimensions of 20 × 22 mm². Proposed antenna finds its applications for Bluetooth, LTE, UWB, other multiple wireless applications for close range radar (8‐12 GHz) in X‐band, and satellite communication in Ku‐Band with omnidirectional pattern in H‐plane.     

Hybrid Metamodel—NSGA-III—EDAS Based Optimal Design of Thin Film Coatings

In this work, diamond-like carbon (DLC) thin film coatings are deposited on silicon substrates by using plasma-enhanced chemical vapour deposition (PECVD) technique. By varying the hydrogen (H₂) flow rate, CH₄−Argon (Ar) flow rate and deposition temperature (T_d) as per a Box-Behnken experimental design (BBD), 15 DLC deposition experiments are carried out. The Young’s modulus (E) and the coefficient of friction (COF) for the DLCs are measured. By using a second-order polynomial regression approach, two metamodels are built for E and COF, that establish them as functions of H₂ flow rate, CH₄-Ar flow rate and T_d. A non-dominated sorting genetic algorithm (NSGA-III) is used to obtain a set of Pareto solutions for the multi-objective optimization of E maximization and COF minimization. According to various practical scenarios, evaluation based on distance from average solution (EDAS) approach is used to identify the most feasible solutions out of the Pareto solution set. Confirmation experiments are conducted which shows the efficacy of the polynomial regression—NSGA-III—EDAS hybrid approach. The surface morphology of the DLCs deposited as per the optimal predictions is also studied by using atomic force microscopy.     

High Diversity Gain MIMO-Antenna for UWB Application with WLAN Notch Band Characteristic Including Human Interface Devices

Wireless Personal Communications - In this paper, a UWB–MIMO antenna with the WLAN band-notch (5.1–5.85 GHz) characteristic is offered. This antenna consists of two radiated...