The heat capacity of liquid carbon disulfide + acetonitrile, especially near the upper critical solution temperature

The heat capacity Cp of the binary liquid system CS2 + CH3CN has been studied. This system has an upper critical solution temperature To ≈ 323.4 K and a critical mole fraction of CS2xo ≈ 0.5920. Measurements were made both for mixtures close to and far away from the critical region. The heat capacity of the mixture with x = xo exhibits a symmetric logarithmic anomaly around Tc, which is apparently preserved even for compositions in the immediate vicinity of xc. For compositions far away from xc, only a normal rise in Cp over the covered temperature range is observed.

Integration and optimization of pressure retarded osmosis with reverse osmosis for power generation and high efficiency desalination

Salinity gradient power is proposed as a source of renewable energy when two solutions of different salinity are mixed. In particular, Pressure Retarded Osmosis (PRO) coupled with a Reverse Osmosis process (RO) has been previously suggested for power generation, using RO brine as the draw solution. However, integration of PRO with RO may have further value for increasing the extent of water recovery in a desalination process. Consequently, this study was designed to model the impact of various system parameters to better understand how to design and operate practical PRO-RO units. The impact of feed salinity and recovery rate for the RO process on the concentration of draw solution, feed pressure, and membrane area of the PRO process was evaluated. The PRO system was designed to operate at maximum power density of . Model results showed that the PRO power density generated intensified with increasing seawater salinity and RO recovery rate. For an RO process operating at 52% recovery rate and 35 g/L feed salinity, a maximum power density of 24 W/m2 was achieved using 4.5 M NaCl draw solution. When seawater salinity increased to 45 g/L and the RO recovery rate was 46%, the PRO power density increased to 28 W/m2 using 5 M NaCl draw solution. The PRO system was able to increase the recovery rate of the RO by up to 18% depending on seawater salinity and RO recovery rate. This result suggested a potential advantage of coupling PRO process with RO system to increase the recovery rate of the desalination process and reduce brine discharge.

Sleep quantity and quality during heat-based training and the effects of cold-water immersion recovery

- Introduction Heat-based training (HT) is becoming increasingly popular as a means of inducing acclimation before athletic competition in hot conditions and/or to augment the training impulse beyond that achieved in thermo-neutral conditions. Importantly, current understanding of the effects of HT on regenerative processes such as sleep and the interactions with common recovery interventions remain unknown. This study aimed to examine sleep characteristics during five consecutive days of training in the heat with the inclusion of cold-water immersion (CWI) compared to baseline sleep patterns. - Methods Thirty recreationally-trained males completed HT in 32 ± 1 °C and 60% rh for five consecutive days. Conditions included: 1) 90 min cycling at 40 % power at VO2max (Pmax) (90CONT; n = 10); 90 min cycling at 40 % Pmax with a 20 min CWI (14 ± 1 °C; 90CWI; n = 10); and 30 min cycling alternating between 40 and 70 % Pmax every 3 min, with no recovery intervention (30HIT; n = 10). Sleep quality and quantity was assessed during HT and four nights of 'baseline' sleep (BASE). Actigraphy provided measures of time in and out of bed, sleep latency, efficiency, total time in bed and total time asleep, wake after sleep onset, number of awakenings, and wakening duration. Subjective ratings of sleep were also recorded using a 1-5 Likert scale. Repeated measures analysis of variance (ANOVA) was completed to determine effect of time and condition on sleep quality and quantity. Cohen's d effect sizes were also applied to determine magnitude and trends in the data. - Results Sleep latency, efficiency, total time in bed and number of awakenings were not significantly different between BASE and HT (P > 0.05). However, total time asleep was significantly reduced (P = 0.01; d = 1.46) and the duration periods of wakefulness after sleep onset was significantly greater during HT compared with BASE (P = 0.001; d = 1.14). Comparison between training groups showed latency was significantly higher for the 30HIT group compared to 90CONT (P = 0.02; d = 1.33). Nevertheless, there were no differences between training groups for sleep efficiency, total time in bed or asleep, wake after sleep onset, number of awakenings or awake duration (P > 0.05). Further, cold-water immersion recovery had no significant effect on sleep characteristics (P > 0.05). - Discussion Sleep plays an important role in athletic recovery and has previously been demonstrated to be influenced by both exercise training and thermal strain. Present data highlight the effect of HT on reduced sleep quality, specifically reducing total time asleep due to longer duration awake during awakenings after sleep onset. Importantly, although cold water recovery accelerates the removal of thermal load, this intervention did not blunt the negative effects of HT on sleep characteristics. - Conclusion Training in hot conditions may reduce both sleep quantity and quality and should be taken into consideration when administering this training intervention in the field.

Numerical study of heat transfer in laminar film boiling by the finite-difference method

The finite-difference form of the basic conservation equations in laminar film boiling have been solved by the false-transient method. By a judicious choice of the coordinate system the vapour-liquid interface is fitted to the grid system. Central differencing is used for diffusion terms, upwind differencing for convection terms, and explicit differencing for transient terms. Since an explicit method is used the time step used in the false-transient method is constrained by numerical instability. In the present problem the limits on the time step are imposed by conditions in the vapour region. On the other hand the rate of convergence of finite-difference equations is dependent on the conditions in the liquid region. The rate of convergence was accelerated by using the over-relaxation technique in the liquid region. The results obtained compare well with previous work and experimental data available in the literature.

Heat transfer to power-law fluids in thermal entrance region with viscous dissipation for constant heat flux conditions

An analytical solution of the heat transfer problem with viscous dissipation for non-Newtonian fluids with power-law model in the thermal entrance region of a circular pipe and two parallel plates under constant heat flux conditions is obtained using eigenvalue approach by suitably replacing one of the boundary conditions by total energy balance equation. Analytical expressions for the wall and the bulk temperatures and the local Nusselt number are presented. The results are in close agreement with those obtained by implicit finite-difference scheme. It is found that the role of viscous dissipation on heat transfer is completely different for heating and cooling conditions at the wall. The results for the case of cooling at the wall are of interest in the design of the oil pipe line.

Response of a turbulent boundary layer to a step change in surface heat flux

Measurements of both the velocity and the temperature field have been made in the thermal layer that grows inside a turbulent boundary layer which is subjected to a small step change in surface heat flux. Upstream of the step, the wall heat flux is zero and the velocity boundary layer is nearly self-preserving. The thermal-layer measurements are discussed in the context of a self-preserving analysis for the temperature disturbance which grows underneath a thick external turbulent boundary layer. A logarithmic mean temperature profile is established downstream of the step but the budget for the mean-square temperature fluctuations shows that, in the inner region of the thermal layer, the production and dissipation of temperature fluctuations are not quite equal at the furthest downstream measurement station. The measurements for both the mean and the fluctuating temperature field indicate that the relaxation distance for the thermal layer is quite large, of the order of 1000θ0, where θ0 is the momentum thickness of the boundary layer at the step. Statistics of the thermal-layer interface and conditionally sampled measurements with respect to this interface are presented. Measurements of the temperature intermittency factor indicate that the interface is normally distributed with respect to its mean position. Near the step, the passive heat contaminant acts as an effective marker of the organized turbulence structure that has been observed in the wall region of a boundary layer. Accordingly, conditional averages of Reynolds stresses and heat fluxes measured in the heated part of the flow are considerably larger than the conventional averages when the temperature intermittency factor is small.

Lidar heat map based channel sounding for complex wireless environments

This thesis is a development of a methodology to predict the radio transmitter signal attenuation, via vertical density profiling of digitised objects, through the use of Light Detection and Ranging (LiDaR) measurements. The resulting map of indexed signal attenuation is useful for dynamic radio transmitter placement within the geospatial data set without expensive and tedious radio measurements.

Light and heat induced interdiffusion in Sb/As2S3 nano-multilayered film

The light and heat induced changes in the optical band gap of Sb/As2S3 nanomultilayered chalcogenide film has been studied. Even though the changes in optical bandgap are attributed to the light and heat induced interdiffusion, the diffusional intermixing between the layers is rather different with light and heat. The observed difference in the light and heat induced interdiffusion is due to unequal diffusion coefficients of light and heat predicted by thermal spike model.

Arabidopsis thaliana J-class heat shock proteins: cellular stress sensors

Plants are sessile organisms that have evolved a variety of mechanisms to maintain their cellular homeostasis under stressful environmental conditions. Survival of plants under abiotic stress conditions requires specialized group of heat shock protein machinery, belonging to Hsp70:J-protein family. These heat shock proteins are most ubiquitous types of chaperone machineries involved in diverse cellular processes including protein folding, translocation across cell membranes, and protein degradation. They play a crucial role in maintaining the protein homeostasis by reestablishing functional native conformations under environmental stress conditions, thus providing protection to the cell. J-proteins are co-chaperones of Hsp70 machine, which play a critical role by stimulating Hsp70s ATPase activity, thereby stabilizing its interaction with client proteins. Using genome-wide analysis of Arabidopsis thaliana, here we have outlined identification and systematic classification of J-protein co-chaperones which are key regulators of Hsp70s function. In comparison with Saccharomyces cerevisiae model system, a comprehensive domain structural organization, cellular localization, and functional diversity of A. thaliana J-proteins have also been summarized. Electronic supplementary material The online version of this article (doi:10.1007/s10142-009-0132-0) contains supplementary material, which is available to authorized users.

A Control Strategy for Reference Wave Adaptive Current Generation

Speed control of ac motors requires variable frequency, variable current, or variable voltage supply. Variable frequency supply can be obtained directly from a fixed frequency supply by using a frequency converter or from a dc source using inverters. In this paper a control technique for reference wave adaptive-current generation by modulating the inverter voltage is explained. Extension of this technique for three-phase induction-motor speed control is briefly explained. The oscillograms of the current waveforms obtained from the experimental setup are also shown.

Generation and Characterization of the Cation-Chloride Cotransporter KCC2 Hypomorphic Mouse

The cation-Cl- cotransporter (CCC) family comprises of Na+-Cl- cotransporter (NCC), Na+-K+-2Cl- cotransporters (NKCC1-2), and four K+-Cl- cotransporters (KCC1-4). These proteins are involved in several physiological activities, such as cell volume regulation. In neuronal tissues, NKCC1 and KCC2 are important in determining the intracellular Cl- levels and hence the neuronal responses to inhibitory neurotransmitters GABA and glycine. One aim of the work was to elucidate the roles for CCC isoforms in the control of nervous system development. KCC2 mRNA was shown to be developmentally up-regulated and follow neuronal maturation, whereas NKCC1 and KCC4 transcripts were highly expressed in the proliferative zones of subcortical regions. KCC1 and KCC3 mRNA displayed low expression throughout the embryogenesis. These expression profiles suggest a role for CCC isoforms in maturation of synaptic responses and in the regulation of neuronal proliferation during embryogenesis. The major aim of this work was to study the biological consequences of KCC2-deficiency in the adult CNS, by generating transgenic mice retaining 15-20% of normal KCC2 levels. In addition, by using these mice as a tool for in vivo pharmacological analysis, we investigated the requirements for KCC2 in tonic versus phasic GABAA receptor-mediated inhibition. KCC2-deficient mice displayed normal reproduction and life span, but showed several behavioral abnormalities, including increased anxiety-like behavior, impaired performance in water maze, alterations in nociceptive processing, and increased seizure susceptibility. In contrast, the mice displayed apparently normal spontaneous locomotor activity and motor coordination. Pharmacological analysis of KCC2-deficient mice revealed reduced sensititivity to diazepam, but normal gaboxadol-induced sedation, neurosteroid hypnosis and alcohol-induced motor impairment. Electrophysiological recordings from CA1-CA3 subregions of the hippocampus showed that KCC2 deficiency affected the reversal potentials of both the phasic and tonic GABA currents, and that the tonic conductance was not affected. The results suggest that requirement for KCC2 in GABAergic neurotransmission may differ among several functional systems in the CNS, which is possibly due to the more critical role of KCC2 activity in phasic compared to tonic GABAergic inhibition.

Negative sequence compensation within fundamental positive sequence reference frame for a stiff micro-grid generation in a wind power system using slip ring induction machine

An isolated wind power generation scheme using slip ring induction machine (SRIM) is proposed. The proposed scheme maintains constant load voltage and frequency irrespective of the wind speed or load variation. The power circuit consists of two back-to-back connected inverters with a common dc link, where one inverter is directly connected to the rotor side of SRIM and the other inverter is connected to the stator side of the SRIM through LC filter. Developing a negative sequence compensation method to ensure that, even under the presence of unbalanced load, the generator experiences almost balanced three-phase current and most of the unbalanced current is directed through the stator side converter is the focus here. The SRIM controller varies the speed of the generator with variation in the wind speed to extract maximum power. The difference of the generated power and the load power is either stored in or extracted from a battery bank, which is interfaced to the common dc link through a multiphase bidirectional fly-back dc-dc converter. The SRIM control scheme, maximum power point extraction algorithm and the fly-back converter topology are incorporated from available literature. The proposed scheme is both simulated and experimentally verified.

Next-generation sequencing: A frameshift in skeletal dysplasia gene discovery

In the last decade, huge breakthroughs in genetics - driven by new technology and different statistical approaches - have resulted in a plethora of new disease genes identified for both common and rare diseases. Massive parallel sequencing, commonly known as next-generation sequencing, is the latest advance in genetics, and has already facilitated the discovery of the molecular cause of many monogenic disorders. This article describes this new technology and reviews how this approach has been used successfully in patients with skeletal dysplasias. Moreover, this article illustrates how the study of rare diseases can inform understanding and therapeutic developments for common diseases such as osteoporosis. © International Osteoporosis Foundation and National Osteoporosis Foundation 2013.

It's not the heat, it's the humidity

The performance aspect of a PhD thesis. In 1976, The Saints released “I’m Stranded” and Brisbane was suddenly on the map. People starting talking about Brisbane bands in the same way they had talked about Liverpool bands or would talk about Seattle bands. The history of the Brisbane music scene has been constructed and interpreted by both journalists (at the time and since) and academics (in retrospect). These histories and analyses have come some way to painting a picture of a time and place that is somewhat mythic. As a significant member of this scene, my memory stores a different picture, different shadings: a vibrant social scene with cultural by-products (music, art, film, fashion). By gathering the ephemera of the time and embellishing with a series of interviews with some Brisbane musicians, I will be growing new, untold stories, grounded in shared experience and understanding. The interview footage, and the bounty of ephemera that continues to be unearthed, will be thrown together in the style of the times and presented in public as a live documentary filled with the faces, voices and music on which these times were built. The performances are the Creative Practice component of the PhD, and are the result of a curatorial process which will be examined in the exegetic component of the thesis due for delivery in mid 2016.