451 research outputs found
Semiclassical Hartree-Fock theory of a rotating Bose-Einstein condensation
In this paper, we investigate the thermodynamic behavior of a rotating
Bose-Einstein condensation with non-zero interatomic interactions
theoretically. The analysis relies on a semiclassical Hartree-Fock
approximation where an integral is performed over the phase space and function
of the grand canonical ensemble is derived. Subsequently, we use this result to
derive several thermodynamic quantities including the condensate fraction,
critical temperature, entropy and heat capacity. Thereby, we investigate the
effect of the rotation rate and interactions parameter on the thermodynamic
behavior. The role of finite size is discussed. Our approach can be extended to
consider the rotating condensate in optical potential
VISUALIZATION-BASED DECISION SUPPORT FOR OPTIMIZING SITE SELECTION:QUARRIES IN LEBANON; WHERE TO?
Traditionally the term visualization has been used to describe the process of graphically conveying or presenting end results. This paper argues that the utility of visualization approaches extends beyond these limits as it plays key role in fields of exploration, analysis and presentation, which enhances planner\u27s capabilities to solve complex planning problems. It proposes a transdisciplinary method that combines visualization approaches to site selection, integrated with spatial scenario planning, and stakeholder participation. However, it focuses on visualization as it relates to spatial data, to be applied to all the stages of problem-solving in geographical analysis, from development of initial hypotheses, through knowledge discovery, analysis, presentation and evaluation. It uses three different spatial scenarios – nature conservation, residential expansion, and sustainable development- to investigate the potentials of GIS based visualization to develop maps of a range of plausible future for possible quarrying locations in Lebano
Multiwall carbon nanotube reinforced HA/HDPE biocomposite for bone reconstruction
The healing of bone fractures naturally occurs without surgical intervention. Some damage and fractures in bone tissue are complex and leave remnant deformation, and this requires the use of bone replacement material. Hydroxyapatite (HA) is the main element of the bone mineral form and consider as a bioactive material which supports bone growth. Nevertheless, the HA has poor mechanical properties, such as low tensile strength. Thus the applications in bone replacement have been limited, especially in high load-bearing applications. A Carbone nanotube has newly obtained considerable concern because of their mechanical properties, potentially enhancing the bone implant's clinical efficiency. This study attempted to explain the effect of adding Multi-walled carbon nanotubes MWCNT Nanoparticles to the HDPE/HA bio-composites. Two groups of the composites samples were produced 20HA/80 HDPE and 40 HA/ 60 HDPE with adding (0.6, 1, 1.4, 2) % weights of (MWCNT) to each group. The composites were fabricated using a hot pressing technique with various pressing pressures (29, 57, 86, and 114 Mpa) at a compounding temperature of 150 C° and a holding time of 15 minutes. To evaluate samples' characteristics and performance, X-ray powder diffraction (XRD), surface topography by Field Emission Scanning Electron Microscopy (FE-SEM), tensile strength and, microhardness test were investigated. The results showed that the hybrid bio-composites demonstrated excellent structural integrity, homogeneous with the fibrous structure, and improved mechanical properties. When increasing in MWNT additions and increasing hot-press pressure, enhancing the composites' fracture strength and microhardness is beneficial. The excellent properties of hybrids bio-composite (HA/HDPE/MWCNT) samples for homogeneous fibrous structure and high mechanical properties could be applied in bone tissue engineering for bone reconstruction
The chemopreventive effect of Ginkgo biloba and Silybum marianum extracts on hepatocarcinogenesis in rats
<p>Abstract</p> <p>Background/objective</p> <p>This study was designed to evaluate the potential chemopreventive activities of <it>Ginkgo biloba </it>extract (EGb) and <it>Silybum marianum </it>extract (silymarin) against hepatocarcinogenesis induced by N-nitrosodiethylamine (NDEA) in rats.</p> <p>Methods</p> <p>Rats were divided into 6 groups. Group 1 served as normal control rats. Group 2 animals were intragastrically administrated NDEA at a dose of 10 mg/kg five times a week for 12 weeks to induce hepatocellular carcinoma (HCC). Groups 3 and 4 animals were pretreated with silymarin and EGb respectively. Groups 5 and 6 animals were posttreated with silymarin and EGb respectively. The investigated parameters in serum are alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma glutamyltransferase (GGT) and vascular endothelial growth factor (VEGF). The investigated parameters in liver tissue are malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR) and comet assay parameters.</p> <p>Results</p> <p>In NDEA group, MDA level was elevated with subsequent decrease in GSH level and SOD, GPx and GR activities. In addition, NDEA group revealed a significant increase in serum ALT, AST and GGT activities and VEGF level. Furthermore, NDEA administrated animals showed a marked increase in comet assay parameters. These biochemical alterations induced by NDEA were confirmed by the histopathological examination of rat livers intoxicated with NDEA that showed an obvious cellular damage and well differentiated HCC.</p> <p>In contrast, silymarin+NDEA treated groups (3&5) and EGb+NDEA treated groups (4&6) showed a significant decrease in MDA level and a significant increase in GSH content and SOD, GPx and GR activities compared to NDEA group. Silymarin and EGb also beneficially down-regulated the increase in serum ALT, AST, GGT activities and VEGF level induced by NDEA. In addition, silymarin and EGb significantly decreased comet assay parameters. Histopathological examination of rat livers treated with either silymarin or EGb exhibited an improvement in the liver architecture compared to NDEA group.</p> <p>Conclusions</p> <p>The obtained findings suggested that silymarin and EGb may have beneficial chemopreventive roles against hepatocarcinogenesis through their antioxidant, antiangiogenic and antigenotoxic activities.</p
Effect of Wiper Edge Geometry on Machining Performance While Turning AISI 1045 Steel in Dry Conditions Using the VIKOR-ML Approach
AISI 1045 can be machined well in all machining operations, namely drilling, milling, turning, broaching and grinding. It has many applications, such as crankshafts, rollers, spindles, shafts, and gears. Wiper geometry has a great influence on cutting forces (Fr, Ff, Fc and R), temperature, material removal rate (MRR) and surface roughness (Ra). Wiper inserts are used to achieve good surface quality and avoid the need to buy a grinding machine. In this paper, an optimization-based investigation into previously reported results for Taguchi’s based L27 orthogonal array experimentations was conducted to further examine effect of the edge geometry on the turning performance of AISI 1045 steel in dry conditions. Three input parameters used in current research include the cutting speed (Vc), feed (f) and depth of cut (ap), while performance measures in this research were Ra, Fr, Ff, Fc, R, temperature (temp) and MRR. The Vise Kriterijumska Optimizacija Kompromisno Resenje (VIKOR) method was used to normalize and convert all the performance measures to a single response known as the VIKOR-based performance index (Vi). The machine learning (ML) approach was used for the prediction and optimization of the input variables. A correlation plot is developed between the input variable and Vi using the ML approach. The optimized setting suggested by Vi-ML is Vc: 160 m/min; ap: 1 mm and f: 0.135 mm/rev, and the corresponding value of Vi was 0.2883, while the predicted values of Ra, Fr, Ff, Fc, R, temp and MRR were 2.111 µm, 43.85 N, 159.33 N, 288.13 N, 332,16 N, 554.4 °C and 21,600 mm3/min, respectively
New Scores for the Assessment of Mitral Stenosis Using Real-Time Three-Dimensional Echocardiography
Nonsurgical management of patients with symptomatic mitral valve stenosis has been established as the therapeutic modality of choice for two decades. Catheter-based balloon dilation of the stenotic valvular area has been shown, at least, as effective as surgical interventions. Unfavorable results of catheter-based interventions are largely due to unfavorable morphology of the valve apparatus, particularly leaflets calcification and subvalvular apparatus involvement. A mitral valve score has been proposed in Boston, MA, about two decades ago, based on morphologic assessment of mitral valve apparatus by two-dimensional (2D) echocardiography to predict successful balloon dilation of the mitral valve. Several other scores have been developed in the following years in order to more successfully predict balloon dilatation outcome. However, all those scores were based on 2D echocardiography, which is limited by ability to distinguish calcification and subvalvular involvement. The introduction of new matrix-based ultrasound probe has allowed 3D echocardiography (3DE) to provide more detailed morphologic analysis of mitral valve apparatus including calcification and subvalvular involvement. Recently, a new 3DE scoring system has been proposed by our group, which represents an important leap into refinement of the use of echocardiography guiding mitral valve interventions
Exercise capacity and muscle fatiguability alterations following a progressive maximal exercise of lower extremities in children with cystic fibrosis
Background: Impairment of peripheral skeletal muscle function is a
common phenomenon in patients with cystic fibrosis (CF) in addition to
great clinical connotations, such as lack of exercise tolerance and
decrease of health-related quality of life. There is very limited data
on the effects of maximal exercise on muscle fatiguability and exercise
capacity in children with cystic fibrosis. Objectives: The aim of this
study was to evaluate the effect of progressive maximal exercise
training of the lower extremities on exercise capacity and muscle
fatiguability in children with cystic fibrosis. Study design: Between
June and September 2017, eighteen children aged 8-12 years were
recruited in this study. This study had two groups of children; the CF
group consisted of nine children (6 males and 3 females) with cystic
fibrosis and the control group consisted of nine healthy age matched
children (6 males and 3 females). The children underwent a progressive
maximal cardiopulmonary exercise cycling test (CPET), muscle fatigue
test, and magnetic resonance imaging (MRI) to measure a muscle
cross-section area (CSA). Also, pulmonary functions were assessed.
Results: The findings of this study showed that the CF children had
less pulmonary functions, had a less exercise capacity, and had a
higher breathing reserve index and oxygen desaturation when compared
with healthy children (p<0.05). On the other hand, there was a
non-significant difference in muscle fatiguability, muscle
cross-section area, and maximal voluntary contraction between the CF
and healthy children (p>0.05). Conclusion: This study indicates that
progressive maximal exercise doesn\u2019t affect muscle fatiguability,
muscle cross-section area, and maximal voluntary contraction in CF
children with moderate respiratory diseases but includes lower exercise
capacity. CF children and healthy age matched children have similar
responses to maximal exercise in muscle fatiguability, muscle
cross-section area, and maximal voluntary contractions but lower
exercise capacity in the CF group
Pomegranate peel as a natural antioxidant boosts bucks' fertility under Egyptian summer conditions
[EN] Exposure of male rabbits to heat stress during summer adversely affects their fertility, leading to major production losses. A total of 16 male rabbits were randomly divided into 4 experimental groups exposed to temperatures ranging from a high of 30.3 to a low of 27.3 °C. Animals from first to fourth groups were fed diets containing 0, 1.5, 3.0, or 4.5% pomegranate peel (PP) to evaluate the ability of PP feeding to enhance bucks¿ reproductive status. Pomegranate peel treatments significantly increased ejaculate volume by 19, 18 and 12%, increased seminal plasma fructose by 7, 18, and 24%, improved sperm motility by 28, 34 and 49%, increased sperm total output by 37, 69 and 102% and reduced dead sperm by 24, 32 and 64% with diets containing 1.5, 3.0 and 4.5% of PP compared to the heat stressed control animals. Seminal plasma total lipids, cholesterol and triglycerides increased while alkaline phosphatase decreased with PP treatments. Seminal plasma total antioxidant capacity increased to reach 126, 143 and 191% with diets containing 1.5, 3.0 and 4.5% of PP, while lipid peroxide (malondialdehyde) levels decreased significantly to reach around 54% of the heat stressed bucks¿ value with the three PP dietary doses used. It was concluded that supplementations of PP in the diet of bucks during summer season in Egypt can improve their semen characteristics, probably due to their antioxidant actions.Zeweil, HS.; Elnagar, S.; Zahran, SM.; Ahmed, MH.; El-gindy, Y. (2013). Pomegranate peel as a natural antioxidant boosts bucks' fertility under Egyptian summer conditions. World Rabbit Science. 21(1):33-39. doi:10.4995/wrs.2013.1209.SWORD333921
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