Experimental study of the hydraulic jump in a hydraulic jump in a sloped rectangular channel

The hydraulic jump in a sloped rectangular channel is theoretically and experimentally examined. The study aims to determine the effect of the channel’s slope on the sequent depth ratio of the jump. A theoretical relation is proposed for the inflow Froude number as function of the sequent depth ratio and the channel slope. An experimental analysis is also proposed to find a better  formulation of the obtained relation. For this motive, five positive slopes are tested. The relations obtained are recommended for designing irrigation ditches.Keywords: Hydraulic jump; rectangular channel; positive slope; open channels;  irrigation ditches

Comparison of resting and total energy expenditure in peritoneal dialysis patients and body composition measured by dual-energy X-ray absorptiometry

Under basal resting conditions muscle metabolism is reduced, whereas metabolism increases with physical activity. We wished to determine whether there was an association between resting energy expenditure (REE) and total energy expenditure (TEE) in peritoneal dialysis (PD) patients and lean body mass (LBM). We determined REE and TEE by recently validated equations, using doubly labelled isotopic water, and LBM by dual-energy X-ray absorptiometry (DXA) scanning. We studied 87 patients, 50 male (57.4%), 25 diabetic (28.7%), mean age 60.3±17.6 years, with a median PD treatment of 11.4 (4.7-29.5) months. The mean weight was 70.1±17.7 kg with a REE of 1509±245 kcal/day and TEE 1947±378 kcal/day. REE was associated with body size (weight r=0.78 and body mass index (BMI) r=0.72) and body composition (LBM r=0.77, lean body mass index (LBMI) r=0.76, r=0.62), all P<0.001). For TEE, there was an association with weight r=0.58, BMI r=0.49 and body composition (LBM r=0.64, LBMI (r=0.54), all P<0.001). We compared LBMI measured by DXA and that estimated by the Boer equation using anthropomorphic measurements, which overestimated and underestimated LBM for smaller patients and heavier patients, respectively. Muscle metabolism is reduced at rest and increases with physical activity. Whereas previous reports based on REE did not show any association with LBM, we found an association between both REE and TEE, using a recently validated equation derived from dialysis patients, and LBM measured by DXA scanning. Estimation of muscle mass from anthropomorphic measurements systematically overestimated LBM for small patients and conversely underestimated for heavier patients

Deconfinement and freezeout boundaries in equilibrium thermal models

In different approaches, the temperature-baryon density plane of QCD matter is studied for deconfinement and chemical freezeout boundaries. Results from various heavy-ion experiments are compared with the recent lattice simulations, the effective QCD-like Polyakov linear-sigma model, and the equilibrium thermal models. Along the entire freezeout boundary, there is an excellent agreement between the thermal model calculations and the experiments. Also, the thermal model calculations agree well with the estimations deduced from the Polyakov linear-sigma model (PLSM). At low baryonic density or high energies, both deconfinement and chemical freezeout boundaries are likely coincident and therefore the agreement with the lattice simulations becomes excellent as well, while at large baryonic density, the two boundaries become distinguishable forming a phase where hadrons and quark-gluon plasma likely coexist.Comment: 8 pages, 2 figures, accepted for publication in AHE

Palaeoenvironmental analysis of the Miocene barnacle facies: case studies from Europe and South America

Acorn barnacles are sessile crustaceans common in shallow-water settings, both in modern oceans and in the Miocene geological record. Barnacle-rich facies occur from polar to equatorial latitudes, generally associated with shallow-water, high-energy, hard substrates. The aim of this work is to investigate this type of facies by analysing, from the palaeontological, sedimentological and petrographical points of view, early Miocene examples from Northern Italy, Southern France and South-western Peru. Our results are then compared with the existing information on both modern and fossil barnacle-rich deposits. The studied facies can be divided into two groups. The first one consists of very shallow, nearshore assemblages where barnacles are associated with an abundant hard-substrate biota (e.g., barnamol). The second one includes a barnacle-coralline algae association, here named “barnalgal” (= barnacle / red algal dominated), related to a deeper setting. The same pattern occurs in the distribution of both fossil and recent barnacle facies. The majority of them are related to very shallow, high-energy, hard-substrate, a setting that represents the environmental optimum for the development of barnacle facies, but exceptions do occur. These atypical facies can be identified through a complete analysis of both the skeletal assemblage and the barnacle association, showing that barnacle palaeontology can be a powerful tool for palaeoenvironmental reconstruction

Functional MRI using robotic MRI compatible devices for monitoring rehabilitation from chronic stroke in the molecular medicine era (Review)

The number of individuals suffering from stroke is increasing daily, and its consequences are a major contributor to invalidity in today’s society. Stroke rehabilitation is relatively new, having been hampered from the longstanding view that lost functions were not recoverable. Nowadays, robotic devices, which aid by stimulating brain plasticity, can assist in restoring movement compromised by stroke-induced pathological changes in the brain which can be monitored by MRI. Multiparametric magnetic resonance imaging (MRI) of stroke patients participating in a training program with a novel Magnetic Resonance Compatible Hand-Induced Robotic Device (MR_CHIROD) could yield a promising biomarker that, ultimately, will enhance our ability to advance hand motor recovery following chronic stroke. Using state-of-the art MRI in conjunction with MR_CHIROD-assisted therapy can provide novel biomarkers for stroke patient rehabilitation extracted by a meta-analysis of data. Successful completion of such studies may provide a ground breaking method for the future evaluation of stroke rehabilitation therapies. Their results will attest to the effectiveness of using MR-compatible hand devices with MRI to provide accurate monitoring during rehabilitative therapy. Furthermore, such results may identify biomarkers of brain plasticity that can be monitored during stroke patient rehabilitation. The potential benefit for chronic stroke patients is that rehabilitation may become possible for a longer period of time after stroke than previously thought, unveiling motor skill improvements possible even after six months due to retained brain plasticity

SEMI-THEORETICAL APPROACH TO THE EFFECT OF ROUGHNESS ON THE RELATIVE HEIGHT OF THE HYDRAULIC RESSAGE EVOLVING IN A TRIANGULAR CHANNEL

The study aims to analyze the theoretical and experimental jump evolving in a triangular channel with a rough bottom. The principal goal of the study is to find a general relationship connecting the relative downstream height and the channel bottom roughness. This study will show also that the channel roughness contributes in the decrease of the downstream height of the jump

Gamow-Teller strength in 54Fe and 56Fe

Through a sequence of large scale shell model calculations, total Gamow-Teller strengths ($S_+$ and $S_-$) in $^{54}$Fe and $^{56}$Fe are obtained. They reproduce the experimental values once the $\sigma\tau$ operator is quenched by the standard factor of $0.77$. Comparisons are made with recent Shell Model Monte Carlo calculations. Results are shown to depend critically on the interaction. From an analysis of the GT+ and GT$-$ strength functions it is concluded that experimental evidence is consistent with the $3(N-Z)$ sum rule.Comment: 6 pages, RevTeX 3.0 using psfig, 7 Postscript figures included using uufile

Comparison of equations of resting and total energy expenditure in peritoneal dialysis patients using body composition measurements determined by multi-frequency bioimpedance

Background & aims: Waste products of metabolism accumulate in patients with kidney failure and it has been proposed that the amount of dialysis treatment patients require be adjusted for energy expenditure. This requires validation of methods to estimate energy expenditure in dialysis patients. Methods: We compared values of resting energy expenditure (REE) estimated in peritoneal dialysis (PD) patients using a selection of available equations with estimates derived using a novel equation recently validated in chronic kidney disease patients (CKD equation). We also determined the relationship of these estimates of REE and of total energy expenditure (TEE – which is REE plus physical activity associated energy expenditure (PAEE) estimated using the Recent Physical Activity Questionnaire) – to bioimpedance-derived parameters of body composition. Results: We studied 118 adult PD patients; 75 male (63.6%), 33 diabetic (28.5%), Caucasoid (42.4%), mean age 59.3 ± 18.2 years and weight 73.1 ± 16.6 kg. REE with the CKD equation was 1532 ± 237 kcal/day, which was more than that for Mifflin–St. Joer 1425 ± 254, Harris–Benedict 1489 ± 267, Katch–McArdle 1492 ± 243, but less than Cunningham 1648 ± 248 kcal/day. Bland Altman mean bias ranged from −107 to 111 kcal/day. TEE was 1924 (1700–2262) kcal/day, and on multi-variate analysis was associated with appendicular muscle mass and nitrogen appearance rate (β 34.3, p < 0.001 and β 5.6, p = 0.002, respectively). Conclusion: With reference to the CKD equation, the majority of standard equations underestimate REE in PD patients. Whereas the Cunningham equation overestimates REE. TEE was associated with appendicular muscle mass and estimated dietary protein intake