The Effects of Foam Rolling vs Dynamic Stretching on Anaerobic Performance

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METHODOLOGY FOR AUTOMOTIVE AIR-CONDITIONING CONTROL OPTIMIZATION USING ARTIFICIAL NEURAL NETWORKS

The transient nature of automotive air conditioning systems control is generally achieved through proportional–integral–derivative controllers (PID’s) parameters tunning. Due to the vast database available from decades of automotive manufacturers design and expertise, Artificial Neural Networks (ANN) might be able to identify underlying patterns to predict and properly tune the air-conditioning PID control systems under different thermal requirements. Recently, advances in computational capability have enabled compact embarked systems to rapidly solve complex, multi-variable sets of equations, thus allowing for ANN to promptly calculate tunning parameters and act upon PID controllers. As any new application, technical literature is still scarce. On this research, a coupled PID and 6-layers perceptron ANN system was devised, programmed and used to simulate how an air-conditioning system performance can be optimized through proportional–integral–derivative controllers tuning. This proposed setup response was then compared to a conventional heuristic PID tunning method (Ziegler Nichols) to demonstrate how ANN’s can more rapidly stabilize the system output

EXPERIMENTAL STUDY OF THE PRESSURE DROP OF THE ECOFLUID R1234YF COMPARED TO THE FLUID R134A IN SMOOTH TUBES WITH 4.8MM INTERNAL DIAMMETER

The refrigerant fluid R1234yf is a hydrofluorefine with zero potential for degradation of the ozone layer and low potential for global warming. It is one of the potential substitutes for the currently used R134a in automotive systems. In this work, the pressure drop suffered by the fluids R134a and R1234yf when flowing in a test section through a pipe with a 4.8 mm internal diameter was measured. The pressure drop was plotted as a function of the void fraction at the exit of the test section and the values were compared concerning the change in mass flux, change in saturation temperature, and comparatively between R1234yf and R134a. A significant increase in pressure drop was observed by the increases of the mass flux, showing an increment of 155.46% of the pressure loss from 200 to 300 kg·m-2·s-1 for R1234yf at 35ºC and 161.07% for R134a in the same conditions. Despite being high, those values are expected since increasing mass flux also increases the friction between both phases. On the other hand, by increasing the saturation temperature, the pressure drop is slightly lower once the differences between the densities of the liquid and vapor phases are reduced. Compared with R134a, the R1234yf ecofluid presents less pressure drop, showing a reduction of 24% for 300 kg·m-2·s-1

EXPERIMENTAL STUDY TO DETERMINE THE LOCAL CONDENSATION HEAT TRANSFER COEFFICIENTE FOR R134A FLOWING THROUGH A 4.8 MM INTERNAL DIAMETER SMOOTH HORIZONTAL TUBE

Refrigerant fluid R134a is commonly one of the most utilised invapour compression cycles wordlide, wheter in dommestic HVAC orautomotive regrigeration systems. This paper’s goal is toexperimetnally determine the fluid local condensation Heat TransferCoefficient (HTC), in several flor regimes. In this work, the mass fluxwas equal to 200, 250 and 300 kg/(m2s) and the fluid flowedthrough a smooth, horizontal 4.8 mm internal diameter aluminiumpipe, during which its vapour quality varied along the entire qualityrange. A purpose built test rig was developed, in which fluidconditions were constantly monitored and controlled. Throughmeasurements in temperature and pressure, an energy balance wasused to calculate experimentally the local heat transfer coeeficient.Average results for the unit quality range equalled to 3781 , 3459 and3944 W/m2K for saturation temperature equal to 30 C and theaforementioned mass velocities. Likewise, at 35C the averages HTCfound were 2903, 3141 and 3898 W/m2K at the same mass fluxrates. Later on, the experimental results were compared to tencommonly used HTC correlation found in relevant references,with Chato’s correlation returning the best fitting

Effects of supplemental fish oil on resting metabolic rate, body composition, and salivary cortisol in healthy adults

<p>Abstract</p> <p>Background</p> <p>To determine the effects of supplemental fish oil (FO) on resting metabolic rate (RMR), body composition, and cortisol production in healthy adults.</p> <p>Methods</p> <p>A total of 44 men and women (34 ± 13y, mean+SD) participated in the study. All testing was performed first thing in the morning following an overnight fast. Baseline measurements of RMR were measured using indirect calorimetry using a facemask, and body composition was measured using air displacement plethysmography. Saliva was collected via passive drool and analyzed for cortisol concentration using ELISA. Following baseline testing, subjects were randomly assigned in a double blind manner to one of two groups: 4 g/d of Safflower Oil (SO); or 4 g/d of FO supplying 1,600 mg/d eicosapentaenoic acid (EPA) and 800 mg/d docosahexaenoic acid (DHA). All tests were repeated following 6 wk of treatment. Pre to post differences were analyzed using a treatment X time repeated measures ANOVA, and correlations were analyzed using Pearson's r.</p> <p>Results</p> <p>Compared to the SO group, there was a significant increase in fat free mass following treatment with FO (FO = +0.5 ± 0.5 kg, SO = -0.1 ± 1.2 kg, p = 0.03), a significant reduction in fat mass (FO = -0.5 ± 1.3 kg, SO = +0.2 ± 1.2 kg, p = 0.04), and a tendency for a decrease in body fat percentage (FO = -0.4 ± 1.3% body fat, SO = +0. 3 ± 1.5% body fat, p = 0.08). No significant differences were observed for body mass (FO = 0.0 ± 0.9 kg, SO = +0.2 ± 0.8 kg), RMR (FO = +17 ± 260 kcal, SO = -62 ± 184 kcal) or respiratory exchange ratio (FO = -0.02 ± 0.09, SO = +0.02 ± 0.05). There was a tendency for salivary cortisol to decrease in the FO group (FO = -0.064 ± 0.142 μg/dL, SO = +0.016 ± 0.272 μg/dL, p = 0.11). There was a significant correlation in the FO group between change in cortisol and change in fat free mass (r = -0.504, p = 0.02) and fat mass (r = 0.661, p = 0.001).</p> <p>Conclusion</p> <p>6 wk of supplementation with FO significantly increased lean mass and decreased fat mass. These changes were significantly correlated with a reduction in salivary cortisol following FO treatment.</p

Peripheral injection of human umbilical cord blood stimulates neurogenesis in the aged rat brain

<p>Abstract</p> <p>Background</p> <p>Neurogenesis continues to occur throughout life but dramatically decreases with increasing age. This decrease is mostly related to a decline in proliferative activity as a result of an impoverishment of the microenvironment of the aged brain, including a reduction in trophic factors and increased inflammation.</p> <p>Results</p> <p>We determined that human umbilical cord blood mononuclear cells (UCBMC) given peripherally, by an intravenous injection, could rejuvenate the proliferative activity of the aged neural stem/progenitor cells. This increase in proliferation lasted for at least 15 days after the delivery of the UCBMC. Along with the increase in proliferation following UCBMC treatment, an increase in neurogenesis was also found in the aged animals. The increase in neurogenesis as a result of UCBMC treatment seemed to be due to a decrease in inflammation, as a decrease in the number of activated microglia was found and this decrease correlated with the increase in neurogenesis.</p> <p>Conclusion</p> <p>The results demonstrate that a single intravenous injection of UCBMC in aged rats can significantly improve the microenvironment of the aged hippocampus and rejuvenate the aged neural stem/progenitor cells. Our results raise the possibility of a peripherally administered cell therapy as an effective approach to improve the microenvironment of the aged brain.</p

Transmembrane protein 88: A Wnt regulatory protein that specifies cardiomyocyte development

Genetic regulation of the cell fate transition from lateral plate mesoderm to the specification of cardiomyocytes requires suppression of Wnt/β-catenin signaling, but the mechanism for this is not well understood. By analyzing gene expression and chromatin dynamics during directed differentiation of human embryonic stem cells (hESCs), we identified a suppressor of Wnt/β-catenin signaling, transmembrane protein 88 (TMEM88), as a potential regulator of cardiovascular progenitor cell (CVP) specification. During the transition from mesoderm to the CVP, TMEM88 has a chromatin signature of genes that mediate cell fate decisions, and its expression is highly upregulated in advance of key cardiac transcription factors in vitro and in vivo. In early zebrafish embryos, tmem88a is expressed broadly in the lateral plate mesoderm, including the bilateral heart fields. Short hairpin RNA targeting of TMEM88 during hESC cardiac differentiation increases Wnt/β-catenin signaling, confirming its role as a suppressor of this pathway. TMEM88 knockdown has no effect on NKX2.5 or GATA4 expression, but 80% of genes most highly induced during CVP development have reduced expression, suggesting adoption of a new cell fate. In support of this, analysis of later stage cell differentiation showed that TMEM88 knockdown inhibits cardiomyocyte differentiation and promotes endothelial differentiation. Taken together, TMEM88 is crucial for heart development and acts downstream of GATA factors in the pre-cardiac mesoderm to specify lineage commitment of cardiomyocyte development through inhibition of Wnt/β-catenin signaling