Carbothermal synthesis of Sn-based composites as negative electrode for lithium-ion batteries

The composite [Sn-BPO₄/xC] to be used as negative electrode material for the storage of electrochemical energy was obtained by dispersing electroactive tin species onto a BPO₄ buffer matrix by carbothermal reduction of a mixture of SnO₂ and nanosized BPO₄. This composite material was thoroughly characterized by X-ray diffraction, Scanning Electron Microscopy, ¹¹⁹Sn Mössbauer spectroscopy and Raman spectroscopy. The electrochemical tests of this new material highlight its very interesting electrochemical properties, i.e., a discharge capacity of 850 mAh g⁻¹ for the first cycle and reversible capacity around 585 mAh g⁻¹ at C/5 rate. These electrochemical performances are attributed to the very high dispersion and stabilisation of tin metal particles onto the BPO₄ matrix. The irreversible capacity observed for the first charge/discharge cycle is due the reduction of interfacial Sn^II species and to the passivation of the anode surface by liquid electrolyte decomposition (formation of the SEI layer).     

Craving and physiological reactivity to trauma and alcohol cues in posttraumatic stress disorder and alcohol dependence.

The high comorbidity of posttraumatic stress disorder (PTSD) and alcohol dependence (AD) has been firmly established. Although laboratory studies have examined self-reported craving in response to trauma and alcohol cues, no studies have reported on alcohol-related physiological responding in response to trauma cues in PTSD-AD individuals. Using a cue reactivity paradigm, this study examined the impact of personalized trauma-image cues and in vivo alcohol cues on alcohol-related responding (e.g., salivation, craving) in individuals with PTSD and AD (n = 40). Participants displayed reactivity to both trauma and alcohol cues when compared to neutral cues, including increased self-reported craving and distress, as well as greater salivation. These findings suggest that through repeated pairings of trauma memories and alcohol consumption, salivation may become classically conditioned to trauma cues. Moreover, the fact that the trauma-alcohol cue combination elicited greater alcohol craving, salivary responding, distress, and arousal than either the trauma-neutral or neutral-alcohol cue combinations suggests that effects of the trauma and alcohol cues were additive in nature. Evidence that AD individuals with PTSD report increased alcohol craving and display greater salivation in response to trauma memories, supplements prior research indicating that PTSD-related negative emotion and trauma-related alcohol craving may play an important role in the maintenance of AD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chemical Crystallography: when are ‘ bad data’ ‘good data’?

There is an increasing trend to reduce diffraction data collection to a set of numbers and the crystallography to a set of criteria. Many of these criteria have been passed on through generations of crystallographers. In Chemical Crystallography, the majority of small-molecule singe crystal diffraction data are still collected using laboratory equipment. Herein we review the methods for analysing data, discuss some of the influences on data quality and try to determine whether some of the validation tropes widely used are sound advice, or ‘Chinese Whispers’.     

Energy-related environmental and economic performance analysis of two different types of electrically heated student residence halls

Student residence halls occupy 26% of the total area of a typical university campus in the UK and are directly responsible for 24% of university’s annual CO₂ emissions. Based on five years measured data, this paper aims to investigate the energy-related environmental and economic performance of electrically heated residence halls in which space heating is provided by two different types of electric heaters, that is, panel heater (PHT) and storage heater (SHT). Secondly, using statistical and machine learning methods, the paper attempts to investigate the relationship between daily electricity consumption and five factors (ambient temperature, solar radiation, relative humidity, wind speed and type of day). Data analysis revealed that electricity consumption of both halls is mainly driven by ambient temperature only, whereas SHT residence has 39% higher annual electricity bill and emits 70% higher CO₂ emissions on a per square metre basis compared to the PHT residence hall.     

Simultaneous Determination of Quercetin,Rutin, Naringin,and Naringenin in Different Fruits by Capillary Zone Electrophoresis

A fast and reliable capillary zone electrophoretic (CZE) method has been developed for the simultaneous determination of four fruit flavonoids using photodiode array (PDA) detector. The effects of CE parameters including concentration and pH of the running buffer, voltage, and injection time were optimized. Under the optimized conditions, all flavonoids were well determined in a 10 mM borate buffer of pH 8.5 within 10 min at an applied voltage of 25 kV. Naringin, naringenin, and quercetin were found to have linear response in the range of 3.12–200 μg/mL whereas rutin’s response was linear from 6.25 to 200 μg/mL. LOD was found to be 0.406, 0.314, 0.582, and 0.333 μg/mL and LOQ 1.355, 1.046, 1.941, and 1.11, respectively. Relative standard deviations (RSD) were found to be less than 3 % for both migration time and peak height which shows long-term stability and good reproducibility of the developed method. The method was successfully applied for the simultaneous determination of flavonoids from various fruit juice samples.     

Colorimetric bio-barcode amplification assay for cytokines

The bio-barcode amplification assay has become a powerful tool in detecting tens to hundreds of biological targets such as proteins and nucleic acids in the entire sample. However, current bio-barcode detection schemes still require many experimental steps including microarrayer-based immobilization of oligonucleotides on a glass chip, silver enhancement of immobilized gold nanoparticles on a chip, and light-scattering measurement. Here, we report a colorimetric bio-barcode method that minimizes the above requirements while detecting 30 aM concentrations of cytokines (approximately 3 orders of magnitude more sensitive than conventional nonenzymatic cytokine detection assays). The assay is based on porous microparticles, which enable loading of a large number of barcode DNA per particle, and gold nanoparticle-based colorimetric barcode detection method.     

Thermo-environmental investigation of solar parabolic dish-assisted multi-generation plant using different working fluids

The present study investigates the performance of a multi-generation plant by integrating a parabolic dish solar collector to a steam turbine and absorption chiller producing electricity and process heat and cooling. Thermodynamic modeling of the proposed solar dish integrated multi-generation plant is conducted using engineering equation solver to investigate the effect of certain operating parameters on the performance of the integrated system. The performance of the solar integrated plant is evaluated and compared using three different heat transfer fluids, namely, supercritical carbon dioxide, pressurized water, and Therminol-VPI. The useful heat gain by collector is utilized to drive a Rankine cycle to evaluate the network output, rate of process heat, cooling capacity, overall energetic, and exergetic efficiencies as well as coefficient of performance. The results show that water is an efficient working fluid up to a temperature of 550 K, while Therminol-VPI performs better at elevated temperatures (630 K and above). Higher integrated efficiencies are linked with the lower inlet temperature and higher mass flow rates. The integrated system using pressurized water as a heat transfer fluid is capable of producing 1278 and 832 kW of power output and process heat, respectively, from input source of almost 6121 kW indicating overall energy and exergy efficiencies of 34.5% and 37.10%, respectively. Furthermore, multi-generation plant is evaluated to assess the exergy destruction rate and steam boiler is witnessed to have the major contribution of this loss followed by the turbine. The exergo-environmental analysis is carried out to evaluate the impact of the system on its surroundings. Exergo-environmental impact index, impact factor, impact coefficient, and impact improvement are evaluated against increase in the inlet temperature of the collector. The single-effect absorption cycle is observed to have the energetic and exergetic coefficient of performances of 0.86 and 0.422, for sCO₂ operating system, respectively, with a cooling load of 228 kW.     

Deformation rate-, hold time-, and cycle-dependent shape-memory performance of Veriflex-E resin

Shape-memory polymers have attracted great interest in recent years for application in reconfigurable structures (for instance morphing aircraft, micro air vehicles, and deployable space structures). However, before such applications can be attempted, the mechanical behavior of the shape-memory polymers must be thoroughly understood. The present study represents an assessment of viscous effects during multiple shape-memory cycles of Veriflex-E, an epoxy-based, thermally triggered shape-memory polymer resin. The experimental program is designed to explore the influence of multiple thermomechanical cycles on the shape-memory performance of Veriflex-E. The effects of the deformation rate and hold times at elevated temperature on the shape-memory behavior are also investigated.     

Modal frequency degeneracy in thermally loaded optical resonators

We observe power coupling from the fundamental mode to frequency-degenerate higher-order spatial modes in optical resonators illuminated with a 30 W laser. Thermally-induced modal frequency degeneracy facilitates power transfer from the fundamental mode to higher-order modes, reduces power coupling into the cavity, and triggers power fluctuations. Modeling thermoelastic deformation of a mirror's surface shows predicted modal frequency degeneracy to be in reasonable agreement with experimental observations. Predictions for the Laser Interferometer Gravitational-wave Observatory (LIGO) show that the circulating fundamental-mode power necessary for gravitational-wave detection is compromised at coating absorptions of 3.8 and 0.44 ppm for Enhanced and Advanced LIGO Fabry-Pérot cavities, respectively.