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Flow field around a typical reentry capsule has been investigated adopting experiments and computations. The reentry capsule has the flap which could be useful to obtain control force. All the studies have been made at a free stream Mach number of 2 and Reynolds number of 30 X 106. Experiments consisted of schlieren flow visualization and measurement of axial force only. Three dimensional computation has been made using FLUENT and adopting k-ω turbulence model. Effect of angle of attack and flap angle has been obtained. Based on present study, it is observed the flap increases the axial force.
Gas evaporation was employed to prepare nitrogen-doped ZnO nanoparticles, which showed in- tense UV/blue emission (380 nm) at room temperature. The thin lms were deposited by dip coating with nanoparticles dispersed in isopropanol and water. The PL spectrum showed dominant acceptor bound excitons around 371 nm at low temperatures, which was due to the substitution of nitrogen acceptors in oxygen sites. Nitrogen doping was also conrmed from Raman spectroscopy, which showed a nitrogen-related local vibrational mode (LVMN) at 583 cm-1. Gas evaporation was employed to prepare nitrogen-doped ZnO nanoparticles, which showed in- tense UV/blue emission (380 nm) at room temperature. The thin lms were deposited by dip coating with nanoparticles dispersed in isopropanol and water. The PL spectrum showed dominant acceptor bound excitons around 371 nm at low temperatures, which was due to the substitution of nitrogen acceptors in oxygen sites. Nitrogen doping was also conrmed from Raman spectroscopy, which showed a nitrogen-related local vibrational mode (LVMN) at 583 cm-1.
We have reported about bipolar resistive switching effect on Poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene]:Graphene oxide composite films, which are sandwiched between aluminum and indium tin oxide electrodes. In this case, I-V sweep curve showed a hysteretic behavior, which varied according to the polarity of the applied voltage bias. The device exhibited excellent switching characteristics, with the ON/OFF ratio being approximately two orders in magnitude. The device had good endurance (10<sup>5</sup> cycles without degradation) and long retention time (5 × 10<sup>3</sup> s) at room temperature. The bistable switching behavior varied according to the trapping and de-trapping of charges on GO sites; the carrier transport was described using the space-charge-limited current (SCLC) model.
<P><B>Abstract</B></P> <P>Sustainable, safe, and low-cost energy storage systems are essential for large-scale electrical energy storage. Herein, we report a sodium (Na)-ion hybrid electrolyte battery with a replaceable cathode system, which is separated from the Na metal anode by a Na superionic conducting ceramic. By using a fast Na-ion-intercalating nickel hexacyanoferrate (NiHCF) cathode along with an eco-friendly seawater catholyte, we demonstrate good cycling performance with an average discharge voltage of 3.4 V and capacity retention >80% over 100 cycles and >60% over 200 cycle. Remarkably, such high capacity retention is observed for both the initial as well as replaced cathodes. Moreover, a Na-metal-free hybrid electrolyte battery containing hard carbon as the anode exhibits an energy density of ∼146 Wh kg<SUP>−1</SUP> at a current density of 10 mA g<SUP>−1</SUP>, which is comparable to that of lead-acid batteries and much higher than that of conventional aqueous Na-ion batteries. These results pave the way for further advances in sustainable energy storage technology.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A novel sodium-ion hybrid electrolyte battery is fabricated. </LI> <LI> Nickel hexacyanoferrate is prepared via a precipitation method for the cathode. </LI> <LI> Cathode part is an open system which enables a cathode replaceable. </LI> <LI> Seawater used as a low cost and eco-friendly catholyte. </LI> <LI> Both fresh and replaced cathode exhibit excellent electrochemical performances. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Light weight and high strength materials like carbon fiber reinforce plastics (CFRP), Titanium alloys (Ti) and stacks (CFRP/Ti, CFRP/Al, CFRP/Al/Ti) are being extensively used in commercial aircraft. Drilling process on the aircraft components was carried out to facilitate the assembly process. Drilling operations are made under dry condition which leads to tool wear and poor hole quality. In this paper study on drilling of CFRP/Ti6Al4V stacks under minimum quantity lubrication (MQL) using LRT 30 oil with varying flow rate, spindle speed and feed rate have been carried out using three modified drill tool made of solid carbide (K 20) coated with TiAlN. The recital of the tools were evaluated based on hole quality, burr height, thrust force, chip formation and tool wear. It was found that TG1 tool performance was better by producing minimum burr height while drilling Ti. TG2 recital was better by producing minimum force and better hole quality.
<P>In this work, we report the fabrication of a new high voltage hybrid fiber supercapacitor (HFSC) with porous carbon coated carbon fibers (PC@CFs) as the negative electrode and copper hexacyanoferrate coated carbon fibers (CuHCF@CFs) as the positive electrode. Carbon fibers (CFs) were used as both the substrate and the current collector due to their good conductivity, high flexibility, good mechanical strength, and light weight. The as-fabricated HFSC can be cycled reversibly in the range of 0-2 V and exhibits excellent electrochemical performance with a specific capacitance of 19.2 F g(-1) (68.2 mF cm(-2) or 3.1 F cm(-3)) and an energy density of 10.6 W h kg(-1) (180.85 mu Wh cm(-2) or 8.11 mW h cm(-3)), better than those reported in the previous literature. Additionally, the HFSCs have retained their original electrochemical performance even after bending, suggesting good flexibility of the device. The promising results show great potential in developing HFSCs with CuHCF@CFs and PC@CFs electrodes for practical wearable devices.</P>
Crohn disease has a wide spectrum of clinical presentations and rarely can present with complications such as a bowel stricture or fistula. In this case report, we describe a 17-year-old male who presented with a history of recurrent anterior abdominal wall abscesses and dysuria. He was diagnosed with Crohn disease and also found to have a fistulous communication between the terminal ileum and a patent urachus. An ileocecectomy with primary anastomosis and complete resection of the abscess cavity was performed. He is on azathioprine for maintenance therapy and currently in remission. Clinicians should have a high index of suspicion for this complication in Crohn disease patients presenting with symptoms suggestive of urachal anomalies such as suprapubic abdominal pain, dysuria, umbilical discharge, and periumbilical mass.
Methyl isocyanate may have a role in cancer etiology, although the link is unclear. There is evidence in the literature that it can induce cancer in animals but the carcinogenic potency is weak. Pheochromocytoma of adrenal medulla and acinar cell tumors of pancreas have been observed in methyl isocyanate exposed animals. Conversely, emerging data from population-based epidemiological studies are contradictory since there is no evidence of such cancers in methyl isocyanate exposed humans. Recently, we reported a high prevalence of breast and lung cancers in such a population in Bhopal. In vitro findings appearing in the latest scientific literature suggest that genomic instability is caused by methyl isocyanate analogs in lung, colon, kidney, ovary epithelial cells, and that hepatocytes may undergo oncogenic transformation, have obvious implications. The conflicting information prompted us to present this update over the last three decades on methyl isocyanate-induced cancers after an extensive literature search using PubMed. While the pertinent literature remains limited, with a scarcity of strong laboratory analyses and field-epidemiological investigations, our succinct review of animal and human epidemiological data including in vitro evidences, should hopefully provide more insight to researchers, toxicologists, and public health professionals concerned with validation of the carcinogenicity of methyl isocyanate in humans.
<▼1><P>Control of the microstructures of graphene oxide is realized by introducing a cationic fullerene, resulting in a high-performance pseudo-capacitor.</P></▼1><▼2><P>Control of the microstructures of graphene oxide (GO) is realized by introducing a cationic fullerene (CFU), resulting in a high-performance pseudo-capacitor. The strong electrostatic interaction between anionic GO and the CFU produces a self-assembled composite (GO/CFU), in which the CFU units intervene to form randomly stacked GO layers. The CFU acts as a spacer between GO layers, allowing a significant fraction of the oxygen-functional groups of GO to be redox-active. When tested as a pseudo-capacitor in 1.0 M H2SO4, the optimized GO/CFU composite delivers a capacitance of 357 F g<SUP>−1</SUP> at 0.4 A g<SUP>−1</SUP>, in contrast to 160 F g<SUP>−1</SUP> for GO alone, which is one of the greatest values reported for graphene composites with electro-inactive carbonaceous entities. The improvement in the capacitance by CFU incorporation is also evidenced at a high charge/discharge rate (285 and 137 F g<SUP>−1</SUP> at 5 A g<SUP>−1</SUP> for GO/CFU and GO, respectively). As a result, the GO/CFU composite delivers an energy density of 40 W h kg<SUP>−1</SUP> and a power density of 2793 W kg<SUP>−1</SUP> at 5 A g<SUP>−1</SUP>, in contrast to 19 W h kg<SUP>−1</SUP> and 2748 W kg<SUP>−1</SUP> for GO alone. During 5000 charge/discharge cycles at 5 A g<SUP>−1</SUP>, the capacitance of the GO/CFU composite increases slightly (4% increase in GO/CFU <I>vs.</I> 4% decrease in GO), which validates the effectiveness of a self-assembly strategy for high performance supercapacitor applications.</P></▼2>