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Search Results: 1 - 10 of 9110 matches for " Experimental study "
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Study on the Wireless Heat Meters  [PDF]
Rujian Ma, Xueyan Yang, Xiao Wang, Enping Zhang
Wireless Sensor Network (WSN) , 2010, DOI: 10.4236/wsn.2010.23034
Abstract: The design of a new type heat meters based on RFID technology are presented in this paper. By use of RFID technology in heat meters, the data can be exchanged between heat meters and heat supplying department by RF cards. The information can be transmitted in a non-contact way. In this way, the purpose of automatic identification can be achieved. The experimental study of the heat meters is also performed in the paper. The results show that the new type of heat meters can meet the demands of users. Compared with the ordinary heat meters, the new type of heat meters have the advantages of small in meter volume, high accuracy, no impact of water quality and good reliability.
Effects of High Dose and Long Term Montelukast Treatment on Skin:An Experimental Rat Study
Kaan Gidero?lu,Mualla Polat,Tülin F?rat,Aysel Kükner
Turkderm , 2008,
Abstract: Background and Design: The aim of this study was to assess the effects of long term, high dose montelukast administration on normal rat skin by histological examination.Material and Method: Sixteen rats were randomly divided into 2 groups-the control and the montelukast treated (study) group (n=8). In the control group 0.2ml of 0.9% NaCl was administered intraperitonealy (i.p.) daily for 6 weeks. In the study group the same amount of solution containing 1 mg/kg montelukast was administered i.p. daily for six weeks. At the end of the 6 weeks skin biopsies were taken and histologically examined.Results: There was no significant difference between two groups regarding the dermal and epidermal thickness. Histologic examination of collagen fiber structure did not show difference between two groups. Toluidin blue stained specimens showed that the number of mast cells in dermis significantly decreased in montelukast treated group (p=0.001). Conclusion: Montelukast treatment has significantly decreased the number of mast cells in dermis without any effect on the dermal or epidermal thickness and collagen fiber structure. We think that with the support of further studies, high dose montelukast may have an effective role on the treatment of inflammatory skin disease. (Turkderm 2008; 42: 118-21)
Experimental and numerical study of buoyancy driven flow within a bottom heated vertical concentric cylindrical enclosure  [PDF]
Asif Hussain Malik, Shahab Khushnood, Ajmal Shah
Natural Science (NS) , 2013, DOI: 10.4236/ns.2013.57093

The study of buoyancy driven flow within bottom-heated vertical concentric cylindrical enclosure was important with respect to the processes in chemical and nuclear industries. In this research paper, experimental and numerical study of the axial temperature gradient and the heat transfer mechanism within the enclosure were performed. The numerical simulations were validated by comparing the numerical results with experimentally measured axial temperature. The numerical results of the streamlines within the enclosure depicted the real picture of the buoyancy effects. Eighteen different experiments were performed by using inner cylinder of different materials and outer cylinder of different diameters within the bottom disc temperature range of 353 - 433 K. The CFD simulations were performed to study the buoyancy effects within the enclosure. At the bottom disc with temperature up to 393 K, the streamlines within the inner cylinder were almost the same for both con- figurations being independent of outer cylinder diameter, while at 433 K streamlines within the inner cylinders varied. With larger diameter outer cylinder configuration, the buoyancy effects in the outer annulus were stronger as compared to smaller one.

Characterization of Hydraulic Behaviours of Coarse Rock Materials in a Large Permeameter  [PDF]
Farzad Ferdos, James Yang, Anders W?rman
Journal of Geoscience and Environment Protection (GEP) , 2013, DOI: 10.4236/gep.2013.13001

The hydraulic behaviour of a rock material structure is a major feature for its design and safety assess- ment. Similar to all other physical problems, in order to enclose the governing equations systems and achieve a solution, the hydraulic characteristics of these materials need to be determined experimentally and implemented then into adopted thermo-dynamical models. This paper covers the process of the design, construction and operation of an experimental rig built for this specific purpose. Using the constructed large-scale permeameter, tests have been conducted. The non-linear hydraulic behaviour of various mate- rials under extreme turbulent conditions, where Reynolds number reaches unprecedented values, has not been studied before. Preliminary results are presented and discussed.

Effects of Rigid Vegetation on the Turbulence Characteristics in Sediment-Laden Flows  [PDF]
Shengqi Lu, Jieren Chen
Journal of Applied Mathematics and Physics (JAMP) , 2014, DOI: 10.4236/jamp.2014.212126

The effects of rigid vegetation on the turbulence characteristics were experimentally studied in the interior water flume. An ADV was used to determine the three dimensional turbulent velocities in clear water flow without vegetation, sediment-laden flow without vegetation, sediment-laden flow with submerged vegetation and sediment-laden flow with non-submerged vegetation. By experimental and theoretical analysis, the effects of rigid vegetation on the distribution of averaged velocities, turbulence intensities and Reynolds stress were summarized. In sediment-laden flow with submerged vegetation, the averaged stream wise velocities above the top of vegetation fit well with the log distribution low. The three-dimensional turbulence intensities increase from the bottom until they reach the maximum at the top of the vegetation. The method to calculate the shear velocity with the maximum of the Reynolds stress is recommended. In sediment-laden flow with non-submerged vegetation, the turbulence problems cannot be explained by theory of bed shear flow. The average velocities, turbulence intensities and Reynolds stress approximate uniformly distributed along vertical direction.

Passive Study of Energy Efficiency of a Building with PCM on the Roof during Summer in Casablanca  [PDF]
Amina Mourid, Mustapha El Alami, Mostafa Najam
Journal of Power and Energy Engineering (JPEE) , 2016, DOI: 10.4236/jpee.2016.48003
Abstract: Energy efficiency in buildings is today a prime objective for energy policy at national and international levels. Because the residential and commercial energy consumption has steadily increased reaching figures between 20% and 40%. The use of thermal insulation of the building envelope is one of the most currently requested solutions to reduce this energy consumption. Phase Change Materials (PCM) have received increased attention due to their ability to store large amounts of thermal energy within narrow temperature ranges. This property makes them ideal for storage of passive heat in the building envelopes. An experimental study was conducted to analyze the influence of PCM in the construction of exterior walls. Two test cells are constructed in the Faculty of Science Ain Chock, Casablanca. One is equipped with a 0.56 cm layer of PCM on its roof while the second is a reference cell without PCM. The results presented for the period from 8th to 10th July 2014 show that the integration of PCM layer reduces the amplitude of instantaneous heat flux through the horizontal wall. The indoor and the internal vertical wall temperatures, in the case of the cell with PCM, are relatively decreased compared to those of the reference one. For example, the maximum deviation between the indoor temperatures of the cubicles is not more than 1.5 while the one on the west faces reaches 3 by mid day. Also the inclusion of a layer of PCM shifts the time of peak load and discharge.
Experimental Study on Improved Engineered Cementitious Composite Using Local Material  [PDF]
Fariborz Nateghi-A, Mohammad Hossein Ahmadi, Ayoub Dehghani
Materials Sciences and Applications (MSA) , 2018, DOI: 10.4236/msa.2018.93021
Abstract: Engineered Cementitious Composite (ECC) is a cement based material with ultra-high ductility and strength in tension. This material is a kind of highperformance fiber-reinforced cementitious composite materials (HPFRCCs) reinforced with short fibers and characterized by tight multiple cracking. These characteristics of ECC make it applicable to increase the capacity and the ductility of structural elements so that structural design is economic and sustainable. This paper presents an extended evaluation of Improved Engineered Cementitious Composites (IECC) for the use in the strengthening of masonry in filled reinforced concrete frames. IECC is a mixture of cement, fly ash, water, sand, quartz powder and poly-vinyl alcohol fibers with a better quality of tensile strain rather than common ECC. Two types of fine sand and quartz powder used in this study as filler to improve ECC behavior. Also, to show the effect of fly ash on IECC properties, five different mixtures were considered with various fly ash ratios. Different mixtures of IECC using fine aggregates produced in Iran were selected to find out how the aggregates and fly ash would affect IECC performance. The results show that the optimized mixture has the best characteristics including tensile strength and strain. Also, three-dimensional diagrams were used to compare the properties of different mixtures of IECC more effectively and to represent the influence of the range of fly ash ratios so that it can be opted based on design objectives such as ECC properties, costs and structural parameters and demands. These diagrams show the behavior of IECC which its fly ash content ratio in the binder is 50% to 67%.
Excre??o de gordura fecal de ratos (Rattus norvegicus, Wistar), submetidos a dietas hiperlipídicas e hipercolesterolêmicas suplementadas com quitosana
Cherem, Adriana da Rosa;Bramosrki, Adriana;
Revista Brasileira de Ciências Farmacêuticas , 2008, DOI: 10.1590/S1516-93322008000400017
Abstract: the effect of two comercial brands of chitosan in the faecal fat excretion was investigated in mice submitted to hypercholesterolemic and hyperlipidic diets. 32 rats wistar, recently weaned, distributed randomly in four groups (n=8): control group (cg), received diet of ain93g; hyperlipidic group (hg): diet of ain-93g modified in the lipids content (12%) and supplemented with cholesterol (1%); and the chitosan hyperlipidic groups 1 (qhg1) and chitosan hyperlipidic 2 (qhg2), that received the same diet of the hg, supplemented with their respective chitosan (5%). the faecal collection was conducted on the days 0, 14th and 28th of the experiment. the faecal fat determination (g) was conducted through the soxhlet method. no significant statistical differences (p>0.05) were observed among the 4 groups as to the fat content in the beginning of the experiment. on the 14th day, the ghq1 group had a significant increase of faecal fat when compared to the other three groups (p<0.05). on the 28th day, in the ghq1 group, the faecal fat excretion was larger than in the other groups (p<0.05), while the group ghq2 had not statistically differed from the group gh. the results suggest that the differences between these two groups can be caused by the purity degree, viscosity and deacetylation degree of the chitosans.
Novel study designs to investigate the placebo response
Paul Enck, Sibylle Klosterhalfen, Stephan Zipfel
BMC Medical Research Methodology , 2011, DOI: 10.1186/1471-2288-11-90
Abstract: We reviewed the respective literature for trials designs that may be used to elucidate the size of the placebo response and the mechanisms associated with it.In general, this can be done by either manipulation the information provided to the subjects, or by manipulation the timing of the drug applied. Two examples of each strategy are discussed: the "balanced placebo design" (BDP) and the "balanced cross-over design" (BCD) and their variants are based on false information, while the "hidden treatment" (HT) and the ""delayed response test" (DRT) are based on manipulating the time of drug action. Since most such approaches include deception or incomplete information of the subjects they are suitable for patient only with authorized deception.Both manipulating the information provided to subjects (BDP, DCD) or manipulating the timing of drug application (HT, DRT) allows overcoming some of the restrictions of conventional drug trials in the assessment of the placebo response, but they are feasible mostly in healthy subjects for ethical reasons.Ever since the dawn of the first randomized placebo-controlled trials testing new drugs and treatments in the middle of the last century, and even before [1], placebo responses in clinical trials have given rise to discussion and concern regarding their mechanisms, and have usually been regarded as a nuisance or a barrier to a rational approach in modern drug development. High placebo responses have induced false expectations regarding drug efficacy and resulted in the refusal or withdrawal of drugs in some cases, e.g. neurokinins in the treatment of depression.Not only do placebo responses in clinical trials impose significant limits to the testing of new compounds, but they are also linked to the drug adherence and compliance of patients in such trials in a paradoxical way. Patients that adhered to medication instructions by more than 80% showed better survival in a coronary disease study, and poor drug adherence in a myocardial
Investigación de seromas postliposucción y dermolipectomía abdominal
Moretti,E.; Gómez García,F.; Monti,J.; Vázquez,G.;
Cirugía Plástica Ibero-Latinoamericana , 2006, DOI: 10.4321/S0376-78922006000300001
Abstract: seroma is one of the complications of the aesthetic procedures in the abdominal wall. this fluid collected in the subcutaneous cellular tissue and in the supraaponeurotic space is a frequent subject of discussion since there are many divergent and contradictory opinions with regard to the etiologic factors and the elements that contribute in its formation and or its treatment. a two-year study was conducted to investigate incidence of seromas in liposuction and abdominal dermolipectomy and when both procedures was performed in the abdominal flap. we studied this complication from different aspects: experimental (15 new zealand albino rabbits), histopathology examinations, as well as retrospective clinical analysis (60 cases). it is concluded, from the laboratorial point of view, that seromas are exudates. their lymphatic origin was assessed by the presence of lymphagiectasia in the biopsies in animals. the retrospective clinical analysis and the laboratory results determined that when dermolipectomy and liposuctions are performed in isolation, the risk of developing seromas is less (13,04%) than in the cases where both techniques are associated in the abdominal flap (50%). the presence of polymorphonuclear cells in the fluid indicates the contamination of the seroma.
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