Sample records for experimental study comparing

  1. It Pays to Compare: An Experimental Study on Computational Estimation (United States)

    Star, Jon R.; Rittle-Johnson, Bethany


    Comparing and contrasting examples is a core cognitive process that supports learning in children and adults across a variety of topics. In this experimental study, we evaluated the benefits of supporting comparison in a classroom context for children learning about computational estimation. Fifth- and sixth-grade students (N = 157) learned about…

  2. Comparative study of experimental signals for multipactor and breakdown.

    CERN Document Server

    Dehler, Micha; Wuensch, Walter; Faus-Golfe, Angeles; Gimeno Martinez, Benito; Kovermann, Jan; Boria, Vicente; Raboso, David


    Performance limiting high-power rf phenomenon occur in both transmitter systems in satellites and high-gradient accelerating structures in particle accelerators. In satellites the predominant effect is multipactor while in accelerators it is breakdown. Both communities have studied their respective phenomena extensively and developed particular simulation tools and experimental techniques. A series of experiments to directly compare measurements made under multipactor and breakdown conditions has been initiated with the objective to crosscheck and compare the physics, simulation tools and measurement techniques.

  3. Tax evasion and income source: A comparative experimental study

    NARCIS (Netherlands)

    Gërxhani, K.; Schram, A.J.H.C.


    We compare tax evasive behavior in a country in transition from communism to that in a developed economy by running an experiment across distinct social groups in Albania and the Netherlands. Aside from the tax compliance decision, subjects choose a source of income, where one type enables

  4. Impairment due to alcohol, tetrahydrocannabinol, and benzodiazepines in impaired drivers compared to experimental studies. (United States)

    Høiseth, Gudrun; Berg-Hansen, Grim Otto; Øiestad, Åse Marit L; Bachs, Liliana; Mørland, Jørg


    In some countries, per se laws for other drugs than alcohol are used to judge drunk and drugged drivers. These blood concentration limits are often derived from experimental studies on traffic relevant behavior of healthy volunteers. Knowledge about how results from experimental studies could be transferred to a real-life setting is missing. The aim of this study was to compare impairment seen in experimental studies to the impairment seen at equivalent concentrations in apprehended drunk and drugged drivers. Results from previously performed meta-analyses of experimental studies regarding impairment from alcohol, tetrahydrocannabinol (THC), and benzodiazepines were compared to impairment in apprehended drunk and drugged drivers as judged by a clinical test of impairment. Both experimental studies and real-life cases were divided into 4 groups according to increasing blood drug concentration intervals. The percentage of impaired test results in experimental studies was compared to the percentage of impaired subjects among drivers within the same blood drug concentration window. For ethanol, the percentage of impaired drivers (n = 1,223) increased from 59% in the lowest drug concentration group to 95% in the highest drug concentration group, compared to 7 and 72% in the respective groups in experimental studies. For THC, the percentage of impaired drivers (n = 950) increased from 42 to 58%, the corresponding numbers being 11 and 42% for experimental studies. For benzodiazepines, the percentage of impaired drivers (n = 245) increased from 46 to 76%, the corresponding numbers being 16 and 60% for experimental studies. The increased odds ratio for impairment between 2 concentration groups was comparable for experimental studies and impaired drivers. Fewer test results indicated impairment in experimental studies compared to impaired drivers in real life when influenced by similar blood concentrations of either ethanol, THC, or benzodiazepines. In addition, a comparable

  5. Comparative study of sound absorption coefficient determination using FEM method and experimental tests on Kundt's tube (United States)

    Deaconu, Marius; Toma, Adina Cristina; Dragasanu, Luminita Ioana; Mihai, Dragos


    Sound absorption coefficient is a commonly used parameter to characterize the acoustic properties of sound absorbing materials that plays an important role in noise attenuation. For this study a specific material has been chosen in order to be evaluated experimentally and compared with the simulated results. Both simulation and experimental assessments used to estimate the sound absorption coefficient are based on transfer function method in accordance with standard SR EN JSO 10354-2. Results are obtained for 15, 30, 45 mm material sample thickness in order to assess the relationship between absorption coefficient, thickness and frequency response. Comparative analysis is performed to determine differences given by the two approaches.

  6. Crystalline and Spectroscopic Experimental Study of the Dinitromesithylen (DNM) Compared with the Theoretical Results (United States)

    Brihi, O.; Medjroubi, M. L.; Hamdouni, N.; Meinnel, J.; Boucekkine, A.; Boudjada, A.

    The aim by our group is to understand the behaviour of the grouping methyl starting from the study of molecules having a great symmetry. In this part of work, it is had the crystalline structure of the dinitromesitylen (DNM) who is solved starting from the diffraction of x-rays starting from a monocrystal at the ambient temperature. Parallel to the experimental study, we undertook theoretical calculations conformation of the insulated molecule of DNM by using the methods of the DFT (Density Functional Theory).Calculations of optimization of the molecular conformation of the DNM by using the chain of program GAUSSIAN03 and functional MPW1PW91, B3LYP level with the 6-311G and LANL2DZ bases gave a conformation Cs with results very close to the experiment for the lengths and the angles of bond. The computation results obtained starting from the base set (6-311G) and functional MPW1PW91 give for the conformation of Dinitromesitylen (DNM) a good agreement of about a 1.9% for the lengths of bond and 1.2% for the angles of bond compared with the results of the diffraction of x-rays. Calculations of Raman and infra-red spectroscopy undertaken starting from the results of optimization by using same functional MPW1PW91 and B3LYP and the sets of bases 6-311G LanL2DZ led to the values of frequencies very close to the experimental results.

  7. Dynamics tromal hydration during phacoemulsification: a comparative study with experimental data

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    Erhan Özyol


    Full Text Available AIM: To present a different approach called dynamic stromal hydration. Though common, conventional hydration technique should be standardized to ascertain wound integrity at the time of stromal hydration during cataract surgery. No explicit criteria exist to suggest that hydration of wound edges is adequate. METHODS: This study was designed as prospective, randomized, comparative study. Leakage sites were detected by continuous irrigation. At that point, stromal hydration was performed in consideration of the leakage points. The wound edges were hydrated until no further leakage could be visually detected. Trypan blue 0.0125% was applied over the wound sites, and each wound was individually observed for leakage. On the day after surgery, Seidel's test was performed to assess wound integrity.RESULTS: All 120 eyes in the experimental group were evaluated, including all 360 wound sites-120 left side ports, 120 right side ports, and 120 main incisions-as were all 120 eyes in the control group. Though the dye test revealed leakage of aqueous humour from only 29 wound sites of 22 eyes(8.0% of 360 woundsin the experimental group, leakage appeared in 41 wound sites of 30 eyes(11.3% of 360 woundsin the control group. When groups were compared in terms of leakage, the difference was statistically different(P=0.042.CONCLUSION: Dynamic stromal hydration-meaning standardized conventional stromal hydration-is a direct observational technique that allows the easy evaluation of wound integrity at the time of stromal hydration by way of observing wound dynamics.

  8. Comparative numerical and experimental study of two combined wind and wave energy concepts

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    Zhen Gao


    Full Text Available With a successful and rapid development of offshore wind industry and increased research activities on wave energy conversion in recent years, there is an interest in investigating the technological and economic feasibility of combining offshore wind turbines (WTs with wave energy converters (WECs. In the EU FP7 MARINA Platform project, three floating combined concepts, namely the spar torus combination (STC, the semi-submersible flap combination (SFC and the oscillating water column (OWC array with a wind turbine, were selected and studied in detail by numerical and experimental methods. This paper summarizes the numerical modeling and analysis of the two concepts: STC and SFC, the model tests at a 1:50 scale under simultaneous wave and wind excitation, as well as the comparison between the numerical and experimental results. Both operational and survival wind and wave conditions were considered. The numerical analysis was based on a time-domain global model using potential flow theory for hydrodynamics and blade element momentum theory (for SFC or simplified thrust force model (for STC for aerodynamics. Different techniques for model testing of combined wind and wave concepts were discussed with focus on modeling of wind turbines by disk or redesigned small-scale rotor and modeling of power take-off (PTO system for wave energy conversion by pneumatic damper or hydraulic rotary damper. In order to reduce the uncertainty due to scaling, the numerical analysis was performed at model scale and both the numerical and experimental results were then up-scaled to full scale for comparison. The comparison shows that the current numerical model can well predict the responses (motions, PTO forces, power production of the combined concepts for most of the cases. However, the linear hydrodynamic model is not adequate for the STC concept in extreme wave conditions with the torus fixed to the spar at the mean water level for which the wave slamming on the

  9. Benchmarking in a rotating annulus: a comparative experimental and numerical study of baroclinic wave dynamics

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    Miklos Vincze


    Full Text Available The differentially heated rotating annulus is a widely studied tabletop-size laboratory model of the general mid-latitude atmospheric circulation. The two most relevant factors of cyclogenesis, namely rotation and meridional temperature gradient are quite well captured in this simple arrangement. The radial temperature difference in the cylindrical tank and its rotation rate can be set so that the isothermal surfaces in the bulk tilt, leading to the formation of baroclinic waves. The signatures of these waves at the free water surface have been analyzed via infrared thermography in a wide range of rotation rates (keeping the radial temperature difference constant and under different initial conditions. In parallel to the laboratory experiments, five groups of the MetStröm collaboration have conducted numerical simulations in the same parameter regime using different approaches and solvers, and applying different initial conditions and perturbations. The experimentally and numerically obtained baroclinic wave patterns have been evaluated and compared in terms of their dominant wave modes, spatio-temporal variance properties and drift rates. Thus certain “benchmarks” have been created that can later be used as test cases for atmospheric numerical model validation.

  10. Sacroiliac joint pain: Prospective, randomised, experimental and comparative study of thermal radiofrequency with sacroiliac joint block. (United States)

    Cánovas Martínez, L; Orduña Valls, J; Paramés Mosquera, E; Lamelas Rodríguez, L; Rojas Gil, S; Domínguez García, M


    To compare the analgesic effects between the blockade and bipolar thermal radiofrequency in the treatment of sacroiliac joint pain. Prospective, randomised and experimental study conducted on 60 patients selected in the two hospitals over a period of nine months, who had intense sacroiliac joint pain (Visual Analogue Scale [VAS]>6) that lasted more than 3 months. Patients were randomised into three groups (n=20): Group A (two intra-articular sacroiliac injections of local anaesthetic/corticosteroid guided by ultrasound in 7 days). Group B: conventional bipolar radiofrequency "palisade". Target points were the lateral branch nerves of S1, S2, and S3, distance needles 1cm. Group C: modified bipolar radiofrequency "palisade" (needle distance >1cm). Patients were evaluated at one month, three months, and one year. Demographic data, VAS reduction, and side effects of the techniques were assessed. One month after the treatment, pain reduction was >50% in the three groups PDolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  11. Cerebral biochemical pathways in experimental autoimmune encephalomyelitis and adjuvant arthritis: a comparative metabolomic study.

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    Norbert W Lutz

    Full Text Available Many diseases, including brain disorders, are associated with perturbations of tissue metabolism. However, an often overlooked issue is the impact that inflammations outside the brain may have on brain metabolism. Our main goal was to study similarities and differences between brain metabolite profiles of animals suffering from experimental autoimmune encephalomyelitis (EAE and adjuvant arthritis (AA in Lewis rat models. Our principal objective was the determination of molecular protagonists involved in the metabolism underlying these diseases. EAE was induced by intraplantar injection of complete Freund's adjuvant (CFA and spinal-cord homogenate (SC-H, whereas AA was induced by CFA only. Naive rats served as controls (n = 9 for each group. Two weeks after inoculation, animals were sacrificed, and brains were removed and processed for metabolomic analysis by NMR spectroscopy or for immunohistochemistry. Interestingly, both inflammatory diseases caused similar, though not identical, changes in metabolites involved in regulation of brain cell size and membrane production: among the osmolytes, taurine and the neuronal marker, N-acetylaspartate, were decreased, and the astrocyte marker, myo-inositol, slightly increased in both inoculated groups compared with controls. Also ethanolamine-containing phospholipids, sources of inflammatory agents, and several glycolytic metabolites were increased in both inoculated groups. By contrast, the amino acids, aspartate and isoleucine, were less concentrated in CFA/SC-H and control vs. CFA rats. Our results suggest that inflammatory brain metabolite profiles may indicate the existence of either cerebral (EAE or extra-cerebral (AA inflammation. These inflammatory processes may act through distinct pathways that converge toward similar brain metabolic profiles. Our findings open new avenues for future studies aimed at demonstrating whether brain metabolic effects provoked by AA are pain/stress-mediated and

  12. A comparative study of processing simulated and experimental data in elastic laser light scattering. (United States)

    Popovici, M A; Mincu, N; Popovici, A


    The intensity of the laser light scattered by a suspension of biological particles undergoing Brownian motion contains information about their size distribution function and optical properties. We used several methods (implemented in MathCAD programs), including a new one, to invert the Fredholm integral equation of the first kind, which represents the angular dependence of the elastic scattering of light. The algorithms were first tested on different sets of simulated data. Experimental data were obtained using biological samples and an experimental arrangement which are briefly described. We study the stability of the inversion procedures relative to the noise levels, and compute the first two moments of the retrieved size distribution function. A comparison of the results corresponding to simulated and experimental data is done, to select the best processing algorithm.

  13. Comparing the effect of breastfeeding promotion interventions on exclusive breastfeeding: an experimental study

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    Asieh Moudi


    Full Text Available Introduction: Despite the proven risks associated with not breastfeeding, few mothers exclusively breastfeed their babies for six months as recommended by the World Health Organization. This study was conducted to compare the effect of breastfeeding promotion interventions on exclusive BMF among primiparous women. Methods: This quasi-experimental study was conducted on a sample of 93 primiparous women who were referred to health care centres, Mashhad, Iran, in 2010. Health care centres were selected by multistage sampling method, and then randomly allocated into two intervention groups (peer support group and health care provider’s education group and one control group. Primigravidae aged 18-35 years old, with singleton pregnancy, with gestational age of 35-36 weeks, and intending to breastfeed their children were randomly selected out of health care centres. The peer support group participants received supports from their peers four times and education group’s participants received 4 training sessions by health care providers. The control group received only routine cares. Exclusive BMF duration and rate assessed at 4 and 8 weeks postpartum and collected data were analysed using SPSS (ver.11.5 software. Results: There were no significant differences in exclusive BMF duration at 4 and 8 weeks among the 3 groups (P=0.993, P=0.904. Exclusive BMF rate at 4 and 8 weeks after birth was significantly different among the 3 groups (P=0.043, P=0.023. No significant difference was found between peer support and healthcare provider’s education groups with respect to BMF rate at 4 weeks (P=0.111, but the difference was significant at 8 weeks (P=0.027. Conclusion: All women should be offered education and peer support to breastfeed their babies to increase the exclusive breastfeeding rate. But to continue exclusive breastfeeding, and increase its duration, help of family is more important than education and peer support. Support that is only offered

  14. Usefulness comparative experimental study of the CT and MR imaging in the dog clonorchiasis

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    Goo, Eun Hoe; Kweon, Dae Cheol; Kim, Dong Sung; Choi, Chun Kyu [Seoul National University Hospital, Seoul (Korea, Republic of)


    Be aware of clinical possibilities on image quality by comparison of contrast-enhanced dynamic CT and MR imaging applied of MIP technique after the experimentally induced clonorchasis infection in dogs. Twenty mongrel dogs prepared in zoo-laboratory were followed up with serial CT scans and MR imaging for 13 weeks after the experimental infection in liver. Two-phase helical CT was acquired in the supine position with the following scanning parameters. After the injection of contrast material, the arterial phase was initiated using a bolus-tracking method. The portal phase scan was started 15 seconds after the arterial phase scan. CT protocol was determined after single level dynamic scans. MR imaging used the CP body coil and images get a 2D image using HASTE, FLASH, TSE pulse sequence. Bile duct MR imaging were obtained in three plans. Then each image was post processed by using target MIP algorithm. Two experimentation above, as a method of evaluation, one pathologist, three radiologist and five radiological technologist were analyzed visually for evaluation of following findings, enhancement of the bile duct wall, dilatation of bile duct tip, liver parenchyma, background suppression. Five dogs was died of a disease after the infection, the rest one else shows the chronic dilatation of the intrahepatic bile duct with CT and MR imaging. Contrast administration of CT shows the contrast-enhanced of the bile duct walls with live parenchyma. MR Imaging calculated of CNR and CR from pulse sequence for comparative evaluation and shows the pattern of the intrahepatic bile duct, dilatation of bile duct tip using MIP technique. CNR of the clonorchiasis, HASTE was 16 {+-} 0.83, TSE 7.06 {+-} 3.0, FLASH 1.19 {+-} 0.2 and CR, HASTE was 73.3%, TSE 62.3%, FLASH 6.4%. CT and MR imaging is very usefulness in diagnosis of dog clonorchiasis.


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    Alexander Doroshenko


    Full Text Available Full-scale metal solar collectors and solar collectors fabricated from polymeric materials are studied in present research. Honeycomb multichannel plates made from polycarbonate were chosen to create a polymeric solar collector. Polymeric collector is 67.8% lighter than metal solar collector. It was experimentally shown that the efficiency of a polymeric collector is 7–14% lower than a traditional collector. An ecologically based Life Cycle Assessment showed the advantages of the application of polymeric materials in the construction of solar collectors.

  16. Benchmarking in a rotating annulus: a comparative experimental and numerical study of baroclinic wave dynamics

    CERN Document Server

    Vincze, Miklos; Achatz, Ulrich; von Larcher, Thomas; Baumann, Martin; Hertel, Claudia; Remmler, Sebastian; Beck, Teresa; Alexandrov, Kiril; Egbers, Christoph; Froehlich, Jochen; Heuveline, Vincent; Hickel, Stefan; Harlander, Uwe


    The differentially heated rotating annulus is a widely studied tabletop-size laboratory model of the general mid-latitude atmospheric circulation. The two most relevant factors of cyclogenesis, namely rotation and meridional temperature gradient are quite well captured in this simple arrangement. The radial temperature difference in the cylindrical tank and its rotation rate can be set so that the isothermal surfaces in the bulk tilt, leading to the formation of baroclinic waves. The signatures of these waves at the free water surface have been analyzed via infrared thermography in a wide range of rotation rates (keeping the radial temperature difference constant) and under different initial conditions. In parallel to the laboratory experiments, five groups of the MetStr\\"om collaboration have conducted numerical simulations in the same parameter regime using different approaches and solvers, and applying different initial conditions and perturbations. The experimentally and numerically obtained baroclinic wa...

  17. A comparative study on intra-articular versus systemic gene electrotransfer in experimental arthritis. (United States)

    Khoury, M; Bigey, P; Louis-Plence, P; Noel, D; Rhinn, H; Scherman, D; Jorgensen, C; Apparailly, F


    Electric pulse mediated gene transfer has been applied successfully in vivo for increasing naked DNA administration in various tissues. To achieve non-viral gene transfer into arthritic joint tissue, we investigated the use of electrotransfer (ET). Because anti-inflammatory cytokine strategies have proven efficient in experimental models of arthritis, we compared the therapeutic efficiency of local versus systemic delivery of the interleukin-10 (IL-10) using in vivo ET. A plasmid vector expressing IL-10 was transferred into DBA/1 mouse knee joints by ET with 12 pulses of variable duration and voltage. The kinetics of transgene expression were analyzed by specific enzyme-linked immunosorbent assay (ELISA) in sera and knees. Optimal conditions were then used to deliver increasing amounts of IL-10 plasmid intra-articularly (i.a.) in the collagen-induced arthritis (CIA) mouse model. The therapeutic efficiency was compared with the potency of intra-muscular (i.m.) ET. Following i.a. ET, local IL-10 secretion peaked on day 7 and dropped 2 weeks after. A second ET produced the same kinetics without enhancing gene transfer efficiency, while transgene was still detected in injected muscles 4 weeks after ET. Only the i.m. ET of 25 microg of IL-10 significantly inhibited all the clinical and biological features of arthritis. The i.a. ET only showed mild improvement of arthritis when 100 microg of IL-10 plasmid were electrotransfered weekly from day 18 following arthritis induction. The present results suggest that gene transfer into arthritic joints by ET is an effective means to deliver anti-inflammatory cytokines. However, short duration of transgene expression impedes a significant effect for the treatment of arthritis, making i.m. ET more potent than i.a. ET for clinical benefit in CIA. 2006 John Wiley & Sons, Ltd.

  18. Modified method for bronchial suture by Ramirez Gama compared to separate stitches suture: experimental study

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    Vitor Mayer de Moura

    Full Text Available OBJECTIVE: To experimentally compare two classic techniques described for manual suture of the bronchial stump. METHODS: We used organs of pigs, with isolated trachea and lungs, preserved by refrigeration. We dissected 30 bronchi, which were divided into three groups of ten bronchi each, of 3mm, 5mm, and 7mm, respectively. In each, we performed the suture with simple, separated, extramucosal stitches in five other bronchi, and the technique proposed by Ramirez and modified by Santos et al in the other five. Once the sutures were finished, the anastomoses were tested using compressed air ventilation, applying an endotracheal pressure of 20mmHg. RESULTS: the Ramirez Gama suture was more effective in the bronchi of 3, 5 and 7 mm, and there was no air leak even after subjecting them to a tracheal pressure of 20mmHg. The simple interrupted sutures were less effective, with extravasation in six of the 15 tested bronchi, especially in the angles of the sutures. These figures were not significant (p = 0.08. CONCLUSION: manual sutures of the bronchial stumps were more effective when the modified Ramirez Gama suture was used in the caliber bronchi arms when tested with increased endotracheal pressure.

  19. Experimentally induced pyogenic arthritis of rabbit knees: comparative study of MR imaging and pathology

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    Hong, Sung Hwan; Koh, Sung Hye; Chung, Hye Won; Lee, Kyung Won; Kim, Chong Jai; Kang, Heung Sik [Seoul National University College of Medicine, Seoul (Korea, Republic of)


    To compare the MR imaging findings of experimentally induced pyogenic arthritis of rabbit knees with the corresponding histopathologic findings. Infection was induced in 20 rabbit knees by direct intra-articular injection of staphylococcus aureus. The animals were divided into four groups of five rabbits each, and spin-echo sagittal T1- and T2-weighted images were obtained 3 days, 1 week, 2 weeks, and 4 weeks, respectively, after staphylococcal inoculation. MR-pathologic correlation was performed, with emphasis on intra-and extra-articular soft tissue lesion characteristics. Soft tissue lesion signal intensity (SI) was classified as low, iso, or high on the basis of that of muscle, and high SI was further subdivided into three categories. At T2-weighted imaging, all soft tissue lesion showed high SI. Pathologic examination revealed the presence of inflammatory cell infiltration (n=2), abscess (n=1), granulation tissue (n=3), fibrosis (n=11), edema (n=4), congestion (n=9), and joint fluid (n=11). Except for the abscess, these lesions were irregular in shape and had variable SI (grade 1-3) and at T2WI could not, therefore, be differentiated. In nine knees, extra-articular soft-tissue lesions were demonstrated at T2WI and correlated with infectious soft tissue lesions such as inflammatory cell infiltration, abscess, granulation tissues and fibrosis; and non-infectious reactive soft tissue changes such as edema and congestion. In pyogenic arthritis, the MR imaging features of soft tissue lesions varied and were nonspecific, depending on the histopathologic abnormalities observed. Our results indicate that in assessing the extent of pyogenic arthritis with MR imaging, caution is required.

  20. Pain in experimental autoimmune encephalitis: a comparative study between different mouse models

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    Lu Jianning


    Full Text Available Abstract Background Pain can be one of the most severe symptoms associated with multiple sclerosis (MS and develops with varying levels and time courses. MS-related pain is difficult to treat, since very little is known about the mechanisms underlying its development. Animal models of experimental autoimmune encephalomyelitis (EAE mimic many aspects of MS and are well-suited to study underlying pathophysiological mechanisms. Yet, to date very little is known about the sensory abnormalities in different EAE models. We therefore aimed to thoroughly characterize pain behavior of the hindpaw in SJL and C57BL/6 mice immunized with PLP139-151 peptide or MOG35-55 peptide respectively. Moreover, we studied the activity of pain-related molecules and plasticity-related genes in the spinal cord and investigated functional changes in the peripheral nerves using electrophysiology. Methods We analyzed thermal and mechanical sensitivity of the hindpaw in both EAE models during the whole disease course. Qualitative and quantitative immunohistochemical analysis of pain-related molecules and plasticity-related genes was performed on spinal cord sections at different timepoints during the disease course. Moreover, we investigated functional changes in the peripheral nerves using electrophysiology. Results Mice in both EAE models developed thermal hyperalgesia during the chronic phase of the disease. However, whereas SJL mice developed marked mechanical allodynia over the chronic phase of the disease, C57BL/6 mice developed only minor mechanical allodynia over the onset and peak phase of the disease. Interestingly, the magnitude of glial changes in the spinal cord was stronger in SJL mice than in C57BL/6 mice and their time course matched the temporal profile of mechanical hypersensitivity. Conclusions Diverse EAE models bearing genetic, clinical and histopathological heterogeneity, show different profiles of sensory and pathological changes and thereby enable

  1. Prevention of cyclophosphamide-induced hemorrhagic cystitis by resveratrol: a comparative experimental study with mesna. (United States)

    Keles, Ibrahim; Bozkurt, Mehmet Fatih; Cemek, Mustafa; Karalar, Mustafa; Hazini, Ahmet; Alpdagtas, Saadet; Keles, Hikmet; Yildiz, Turan; Ceylan, Cavit; Buyukokuroglu, Mehmet Emin


    Hemorrhagic cystitis (HC) is the most common urotoxic side effect of cyclophosphamide (CP). The aim of this study was to compare the classical efficacy of mesna (2-mercaptoethane sulfonate sodium) with three different doses of resveratrol (RES) on cyclophosphamide-induced HC in rats. Forty-six male Sprague-Dawley rats were divided into six groups. Group 1 served as a negative control (sham). Five groups received a single dose of cyclophosphamide (150 mg/kg) intraperitoneally at the same time. Groups 2, 3, 4, 5, and 6 received only CP, CP + 20 mg/kg RES, CP + 40 mg/kg RES, CP + 80 mg/kg RES, and CP + classical protocol of three doses of mesna (30 mg/kg three times), respectively. Antioxidants, cytokines, and malondialdehyde levels were measured in all groups. In addition, histopathological alterations in tissues were examined. CP administration induced severe HC with marked edema, hemorrhage, and inflammation in group 2. RES 20 mg/kg showed meaningful protection against bladder damage compared to the control group. It was seen that RES 40 mg/kg gave weaker protection but RES 80 mg/kg was not found to be effective. In conclusion, marked bladder protection was found in 20 and 40 mg/kg RES applications compared to the control group, but this protection was weaker than with mesna.

  2. Comparative and Experimental Studies on the Genes Altered by Chronic Hypoxia in Human Brain Microendothelial Cells

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    Eugenia Mata-Greenwood


    Full Text Available Background : Hypoxia inducible factor 1 alpha (HIF1A is a master regulator of acute hypoxia; however, with chronic hypoxia, HIF1A levels return to the normoxic levels. Importantly, the genes that are involved in the cell survival and viability under chronic hypoxia are not known. Therefore, we tested the hypothesis that chronic hypoxia leads to the upregulation of a core group of genes with associated changes in the promoter DNA methylation that mediates the cell survival under hypoxia.Results : We examined the effect of chronic hypoxia (3 days; 0.5% oxygen on human brain micro endothelial cells (HBMEC viability and apoptosis. Hypoxia caused a significant reduction in cell viability and an increase in apoptosis. Next, we examined chronic hypoxia associated changes in transcriptome and genome-wide promoter methylation. The data obtained was compared with 16 other microarray studies on chronic hypoxia. Nine genes were altered in response to chronic hypoxia in all 17 studies. Interestingly, HIF1A was not altered with chronic hypoxia in any of the studies. Furthermore, we compared our data to three other studies that identified HIF-responsive genes by various approaches. Only two genes were found to be HIF dependent. We silenced each of these 9 genes using CRISPR/Cas9 system. Downregulation of EGLN3 significantly increased the cell death under chronic hypoxia, whereas downregulation of ERO1L, ENO2, adrenomedullin, and spag4 reduced the cell death under hypoxia.Conclusions : We provide a core group of genes that regulates cellular acclimatization under chronic hypoxic stress, and most of them are HIF independent.

  3. Autologous serum eye drops diluted with sodium hyaluronate: clinical and experimental comparative study. (United States)

    López-García, José S; García-Lozano, Isabel; Rivas, Luis; Ramírez, Nuria; Raposo, Rafaela; Méndez, Maria T


    To assess the efficacy of sodium hyaluronate as vehicle for diluting autologous serum. The concentration and temporal stability of EGF, TGF-β, PDGF-AB and albumin in fresh and frozen samples of autologous serum diluted with sodium hyaluronate and saline solution, as well as the pH, osmolarity and density was studied. In parallel, the clinic effects of autologous serum diluted to 20% with sodium hyaluronate were compared with another solution of autologous serum diluted to 20% with saline in a prospective, comparative, randomized and double-blind study in 26 patients (52 eyes) with Sjögren syndrome. Patients underwent a complete ophthalmic assessment including tear film evaluation and corneal and conjunctival impression cytology at the beginning of the study and 2 months later. The growth factor (GF) concentration remained stable during 1 month at 4°C both in fresh and defrosted samples without any differences being found between both preparations. No differences were found related to osmolarity, pH and density between these preparations before and after frosting. Autologous serum diluted with sodium hyaluronate caused a significant improvement of the tear film stability, fluorescein and rose Bengal stain, break-up time, corneal and conjunctival squamous metaplasia as well as in the patient subjective perception. Sodium hyaluronate is an excellent vehicle for diluting autologous serum due to the gradual release of GF and increasing their duration and effect on the ocular surface. Preparations diluted with sodium hyaluronate are better tolerated by patients and require a lower number of drops administrations. © 2013 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  4. An experimental study comparing the respiratory effects of tapentadol and oxycodone in healthy volunteers. (United States)

    van der Schrier, R; Jonkman, K; van Velzen, M; Olofsen, E; Drewes, A M; Dahan, A; Niesters, M


    There is a clinical need for potent opioids that produce little or no respiratory depression. In the current study we compared the respiratory effects of tapentadol, a mu-opioid receptor agonist and noradrenaline reuptake inhibitor, and oxycodone, a selective mu-opioid receptor agonist. We hypothesize that tapentadol 100 mg has a lesser effect on the control of breathing than oxycodone 20 mg. Fifteen healthy volunteers were randomized to receive oral tapentadol (100 and 150 mg), oxycodone 20 mg or placebo immediate release tablets in a crossover double-blind randomized design. The main end-point of the study was the effect of treatment on the ventilatory response to hypercapnia and ventilation at an extrapolated end-tidal PCO2 of 7.3 kPa (55 mmHg, VE55); VE55 was assessed prior and for 6-h following drug intake. All three treatments had typical opioid effects on the hypercapnic ventilatory response: a shift to the right coupled to a decrease of the response slope. Oxycodone 20 mg had a significantly larger respiratory depressant effect than tapentadol 100 mg (mean difference -5.0 L min-1, 95% confidence interval: -7.1 to -2.9 L min-1, Ptapentadol 150 mg (oxycodone vs. tapentadol 150 mg: P>0.05). In this exploratory study we observed that both tapentadol and oxycodone produce respiratory depression. Tapentadol 100 mg but not 150 mg had a modest respiratory advantage over oxycodone 20 mg. Further studies are needed to explore how these results translate to the clinical setting.

  5. Adhesion-preventing properties of 4% icodextrin and canola oil: a comparative experimental study

    Directory of Open Access Journals (Sweden)

    Cengizhan Yigitler

    Full Text Available OBJECTIVE: Postsurgical abdominal adhesions are common, serious postoperative complications. The present study compared the usefulness of 4% icodextrin and canola oil in preventing postoperative peritoneal adhesions. METHODS: Twenty-four Wistar albino rats were divided into three groups. Following a laparotomy, a serosal abrasion was made by brushing the cecum, and 3 mL of 0.9% NaCl, 4% icodextrin, or 3 mL of canola oil were intraperitoneally administered for the control, icodextrin, and canola oil groups, respectively. The abdomen was then closed. All of the rats were sacrificed at day 10. Macroscopic, histopathological, and biochemical evaluations were performed. The results were statistically analyzed using Kruskal-Wallis and ANOVA tests. RESULTS: Macroscopic analyses revealed that both canola oil and 4% icodextrin reduced adhesion formation, but the difference was not statistically significant (p = 0.17. The histopathological examinations revealed no significant differences in terms of giant cell, lymphocyte/plasmocyte, neutrophil, ICAM1, or PECAM1 scores. However, both canola oil and 4% icodextrin significantly reduced fibrosis (p = 0.025. In the canola oil group, the histiocytic reactions were significantly increased (p = 0.001, and the hydroxyproline levels were significantly lower than those in the other groups (p = 0.034. CONCLUSIONS: In the present study, canola oil was determined to be superior to 4% icodextrin in lowering hydroxyproline levels and increasing histiocytic reactions. Considering these results, we believe that canola oil is a promising agent for preventing adhesion formation.

  6. UV-Vis optoelectronic properties of α-SnWO4: A comparative experimental and density functional theory based study

    KAUST Repository

    Ziani, Ahmed


    We report a combined experimental and theoretical study on the optoelectronic properties of α-SnWO4 for UV-Vis excitation. The experimentally measured values for thin films were systematically compared with high-accuracy density functional theory and density functional perturbation theory using the HSE06 functional. The α-SnWO4 material shows an indirect bandgap of 1.52 eV with high absorption coefficient in the visible-light range (>2 × 105 cm−1). The results show relatively high dielectric constant (>30) and weak diffusion properties (large effective masses) of excited carriers.

  7. Comparative Experimental and Modeling Study of Fluid Velocities in Heterogeneous Rocks (United States)

    Hingerl, F.; Romanenko, K.; Pini, R.; Balcom, B.; Benson, S. M.


    Understanding the spatial distribution of fluid velocities and effective porosities in rocks is crucial for predicting kinetic reaction rates and fluid-rock interactions in a plethora of geo-engineering applications, ranging from geothermal systems, Enhanced Oil Recovery to Carbon Capture and Storage. Magnetic Resonance Imaging can be used to measure spatially resolved porosities and fluid velocities in porous media. Large internal field gradients and short spin relaxation times, however, constrain the usability of the conventional MRI technique in natural rock samples. The combination of three-dimensional Single Point Ramped Imaging with T1 Enhancement (SPRITE) and the 13-interval Alternating-Pulsed-Gradient Stimulated-Echo (APGSTE) scheme - a method developed at the UNB MRI Center - is able to compensate for those challenges and quantitative 3 dimensional maps of porosities and fluid velocities can be obtained. In this study we measured velocities and porosities using MRI in a sandstone rock sample showing meso-scale heterogeneities. Then we generated permeabilities using three independent approaches, employed them to model single-phase fluid flow in the measured rock sample and compared the generated velocity maps with the respective MRI measurements. For the first modeling approach, we applied the Kozeny-Carman relationship to create a permeability map based on porosities measured using MRI. For the second approach we used permeabilities derived from CO2-H2O multi-phase experiments performed in the same rock sample assuming the validity of the J-Leverett function. The permeabilities in the third approach were generated by applying a new inverse iterative-updating technique. The resulting three permeability maps were then used as input for a CFD simulation - using the Stanford CFD code AD-GPRS - to create a respective velocity map, which in turn was then compared to the measured velocity map. The results of the different independent methods for generating

  8. The tragedy of the commons in microbial populations: insights from theoretical, comparative and experimental studies. (United States)

    MacLean, R C


    First principles of thermodynamics imply that metabolic pathways are faced with a trade-off between the rate and yield of ATP production. Simple evolutionary models argue that this trade-off generates a fundamental social conflict in microbial populations: average fitness in a population is highest if all individuals exploit common resources efficiently, but individual reproductive rate is maximized by consuming common resources at the highest possible rate, a scenario known as the tragedy of the commons. In this paper, I review studies that have addressed two key questions: What is the evidence that the rate-yield trade-off is an evolutionary constraint on metabolic pathways? And, if so, what determines evolutionary outcome of the conflicts generated by this trade-off? Comparative studies and microbial experiments provide evidence that the rate-yield trade-off is an evolutionary constraint that is driven by thermodynamic constraints that are common to all metabolic pathways and pathway-specific constraints that reflect the evolutionary history of populations. Microbial selection experiments show that the evolutionary consequences of this trade-off depend on both kin selection and biochemical constraints. In well-mixed populations with low relatedness, genotypes with rapid and efficient metabolism can coexist as a result of negative frequency-dependent selection generated by density-dependent biochemical costs of rapid metabolism. Kin selection can promote the maintenance of efficient metabolism in structured populations with high relatedness by ensuring that genotypes with efficient metabolic pathways gain an indirect fitness benefit from their competitive restraint. I conclude by suggesting avenues for future research and by discussing the broader implications of this work for microbial social evolution.

  9. "In vitro" comparative experimental study of antimicrobial action of mouth washing products


    Ruiz Martínez, Lidia; Escribano Patón, César; Veiga Crespo, Patricia; Tomás G. Villa; Vinuesa Aumedes, Teresa


    Regular use of mouth rinses modifies the oral habitat, since bacterial populations are submitted to a high selective pressure during the treatment exercised by the active presence of the disinfectant. Mostly mouth rinses are based on the antibacterial effect of Chlorhexidine, Triclosan, essential oils and other antibacterials although other pharmaceutical characteristics can also affect their effectiveness. In this paper we compare"in vitro" the antibacterial effect of different oral rinsing ...

  10. Comparative analysis of results from experimental and numerical studies on concrete strength

    Directory of Open Access Journals (Sweden)

    Mkrtychev Oleg


    Full Text Available Some results of numerical experiments of testing concrete cubes and prisms on unconfined compression, and the comparison of results obtained with experimental and specified data, are presented in the article. When performing calculations of structures in a nonlinear setting, it is very important to choose adequate deformation diagrams or material models. Because of the fact that there are no instructions how to use the diagrams of concrete and armature deformation in collaboration of steel and concrete, the simulation of reinforced concrete structures by finite elements of the same type without any assumptions is impossible. Numerical experiments have been performed in the LS-DYNA software package. This software package allows simulating the collaboration of concrete and steeling with the help of three-dimensional (for concrete and rod (for the reinforcement finite elements. As samples, a cube and a prism with dimensions of 150×150×150 mm and 150×150×600 mm, respectively, have been taken. The samples are simulated by solid finite elements. For the simulation of concrete, the non-linear CSCM (Continuous Surface Cap Model material is used. The tests were carried out with samples of the following classes of concrete as for cylinder compressive strength: C12, C16, C20, C25, C30, C35. This corresponds to the following classes of cube compression strength: B15, B20, B25, B30, B37, B45. The tests have been carried out considering the friction coefficients between the plates of a testing machine, and a sample. The performed researches have shown that the destruction nature of the samples in a numerical experiment corresponds to the failure nature in real tests. The investigated model of CSCM concrete can be used in the calculation of concrete and reinforced concrete structures with acceptable accuracy for main classes of concrete.

  11. A comparative experimental study of steel fibre-additive reinforced concrete beams

    Directory of Open Access Journals (Sweden)

    Altun, F.


    Full Text Available Five different batches of class C20 concrete, containing Dramix-RC-80/60-BN steel fibers (SFs as additives at doses of 0, 30, 40, 50 and 60 kg/m3, and six Ø 15x30 cm prisms were poured from each batch. Standard crushing tests were run on all the specimens and the respective load-displacement and stress-strain curves were plotted. Toughness, ultimate compressive strength and the modulus of elasticity were determined for all specimens. The compressive strength and modulus of elasticity declined in 30 kg/m3 steel-fiber-additive concrete (SFAC by 9% and 7% compared to the reference C20 concrete without SFs, and the area under the load-deflection curve grew more than twofold. In concrete with a higher SF dosage, the differences in strength and elasticity were around I0% whilst toughness was about the same. Because toughness values were similar in 30, 40, 50 and 60 kg/m3 plain SF-additive concrete and the strength and modulus of elasticity were slightly better in the mixes with the smallest proportion of SF for reasons of economy, 30 kg/m3 was taken as the optimum dose of steel fiber to be added to the reinforced concrete used in a second phase of the study. Hence, of the six reinforced concrete (RC beams made, all of equal size and with the same under-reinforced tensile reinforcement design, three were made with concrete containing the above-mentioned dose of SF. In addition to compressive strength, these beams were tested for flexural strength, which was found to be 18% greater for the SFARC beams than the ordinary RC beams, and the upper arms of the load versus mid-span deflection curves prior to ultimate failure of the SFARC beams were considerably longer than the same arms on the curves for ordinary RC beams.

    Se han utilizado cinco lotes diferentes de hormigón clase C20 cuatro de ellos con fibras de acero (FA, identificadas como Dramix-CR-80/60-BN, en cuatro proporciones diferentes: 30, 40, 50 y 60 kg/m3 y el quinto exento de

  12. Comparing Different Approaches to Visualizing Light Waves: An Experimental Study on Teaching Wave Optics (United States)

    Mešic, Vanes; Hajder, Erna; Neumann, Knut; Erceg, Nataša


    Research has shown that students have tremendous difficulties developing a qualitative understanding of wave optics, at all educational levels. In this study, we investigate how three different approaches to visualizing light waves affect students' understanding of wave optics. In the first, the conventional, approach light waves are represented…

  13. Carbon fiber based composites stress analysis. Experimental and computer comparative studies (United States)

    Sobek, M.; Baier, A.; Buchacz, A.; Grabowski, Ł.; Majzner, M.


    Composite materials used nowadays for the production of composites are the result of advanced research. This allows assuming that they are among the most elaborate tech products of our century. That fact is evidenced by the widespread use of them in the most demanding industries like aerospace and space industry. But the heterogeneous materials and their advantages have been known to mankind in ancient times and they have been used by nature for millions of years. Among the fibers used in the industry most commonly used are nylon, polyester, polypropylene, boron, metal, glass, carbon and aramid. Thanks to their physical properties last three fiber types deserve special attention. High strength to weight ratio allow the use of many industrial solutions. Composites based on carbon and glass fibers are widely used in the automotive. Aramid fibers ideal for the fashion industry where the fabric made from the fibers used to produce the protective clothing. In the paper presented issues of stress analysis of composite materials have been presented. The components of composite materials and principles of composition have been discussed. Particular attention was paid to the epoxy resins and the fabrics made from carbon fibers. The article also includes basic information about strain measurements performed on with a resistance strain gauge method. For the purpose of the laboratory tests a series of carbon - epoxy composite samples were made. For this purpose plain carbon textile was used with a weight of 200 g/mm2 and epoxy resin LG730. During laboratory strain tests described in the paper Tenmex's delta type strain gauge rosettes were used. They were arranged in specific locations on the surface of the samples. Data acquisition preceded using HBM measurement equipment, which included measuring amplifier and measuring head. Data acquisition was performed using the Easy Catman. In order to verify the results of laboratory tests numerical studies were carried out in a

  14. A Comparative Study of Collagen Matrix Density Effect on Endothelial Sprout Formation Using Experimental and Computational Approaches. (United States)

    Shamloo, Amir; Mohammadaliha, Negar; Heilshorn, Sarah C; Bauer, Amy L


    A thorough understanding of determining factors in angiogenesis is a necessary step to control the development of new blood vessels. Extracellular matrix density is known to have a significant influence on cellular behaviors and consequently can regulate vessel formation. The utilization of experimental platforms in combination with numerical models can be a powerful method to explore the mechanisms of new capillary sprout formation. In this study, using an integrative method, the interplay between the matrix density and angiogenesis was investigated. Owing the fact that the extracellular matrix density is a global parameter that can affect other parameters such as pore size, stiffness, cell-matrix adhesion and cross-linking, deeper understanding of the most important biomechanical or biochemical properties of the ECM causing changes in sprout morphogenesis is crucial. Here, we implemented both computational and experimental methods to analyze the mechanisms responsible for the influence of ECM density on the sprout formation that is difficult to be investigated comprehensively using each of these single methods. For this purpose, we first utilized an innovative approach to quantify the correspondence of the simulated collagen fibril density to the collagen density in the experimental part. Comparing the results of the experimental study and computational model led to some considerable achievements. First, we verified the results of the computational model using the experimental results. Then, we reported parameters such as the ratio of proliferating cells to migrating cells that was difficult to obtain from experimental study. Finally, this integrative system led to gain an understanding of the possible mechanisms responsible for the effect of ECM density on angiogenesis. The results showed that stable and long sprouts were observed at an intermediate collagen matrix density of 1.2 and 1.9 mg/ml due to a balance between the number of migrating and proliferating

  15. Comparative haematological changes in experimentally infected ...

    African Journals Online (AJOL)

    A comparative study of haematological changes in Savannah brown goats experimentally infected with Trypanosoma brucei and Trypanosoma vivax was carried out using thirty (30) goats aged between 20 and 48 months and average weight of 13.00 kg. The parameters determined before and after infection included ...

  16. Comparative study of experimental and numerical behaviors of microwave absorbers based on ultrathin Al and Cu films

    Energy Technology Data Exchange (ETDEWEB)

    Costa, D.S., E-mail: [Instituto de Ciência e Tecnologia/UNIFESP, Rua Talim, 330, CEP 12.231-280, São José dos Campos, SP (Brazil); Nohara, E.L. [Universidade de Taubaté, Rua Daniel Danelli, s/n, CEP 12060-440, Taubaté, SP (Brazil); Rezende, M.C. [Instituto de Ciência e Tecnologia/UNIFESP, Rua Talim, 330, CEP 12.231-280, São José dos Campos, SP (Brazil)


    The study of radar absorbing materials increasingly thin, lightweight and flexible has gained growing importance in recent years. In military area these characteristics allow the reduction of weight and volume of platforms, and in civilian sector these materials stimulate innovative projects of electronic and microwave devices. The present work was devoted to studying ultrathin films of Al (20–80 nm) and Cu (10–100 nm) deposited on poly(ethylene terephthalate) (PET) substrate by magnetron sputtering technique. The electrical conductivity values of the films were determined by 4 probes method, the S parameters (S{sub 11} and S{sub 12}) were obtained by transmission line using a X-band waveguide and the skin depth calculated. The results show the dependence of the electrical conductivity with the thickness for both films. The experimental values of microwave attenuation were compared with calculated values based on the equivalent electric circuit theory. This comparison shows a good adjustment and confirms the use of electrical conductivity measurements to predict the microwave absorption behavior of ultrathin films. - Highlights: • This article focuses on recent progresses in ultrathin films aiming microwave absorption. • Nanometric films of Al and Cu deposited on poly(ethylene terephthalate) substrate were produced. • Electrical conductivity (4-probes) and S-parameters (S{sub 11} and S{sub 12}) of nanofilms were measured. • Calculated microwave attenuations were obtained based on the equivalent electric circuit theory. • A good fit between experimental and predictions data of microwave absorption was observed.

  17. Cowhage-induced itch as an experimental model for pruritus. A comparative study with histamine-induced itch.

    Directory of Open Access Journals (Sweden)

    Alexandru D P Papoiu

    Full Text Available BACKGROUND: Histamine is the prototypical pruritogen used in experimental itch induction. However, in most chronic pruritic diseases, itch is not predominantly mediated by histamine. Cowhage-induced itch, on the other hand, seems more characteristic of itch occurring in chronic pruritic diseases. OBJECTIVES: We tested the validity of cowhage as an itch-inducing agent by contrasting it with the classical itch inducer, histamine, in healthy subjects and atopic dermatitis (AD patients. We also investigated whether there was a cumulative effect when both agents were combined. METHODS: Fifteen healthy individuals and fifteen AD patients were recruited. Experimental itch induction was performed in eczema-free areas on the volar aspects of the forearm, using different itch inducers: histamine, cowhage and their combination thereof. Itch intensity was assessed continuously for 5.5 minutes after stimulus application using a computer-assisted visual analogue scale (COVAS. RESULTS: In both healthy and AD subjects, the mean and peak intensity of itch were higher after the application of cowhage compared to histamine, and were higher after the combined application of cowhage and histamine, compared to histamine alone (p<0.0001 in all cases. Itch intensity ratings were not significantly different between healthy and AD subjects for the same itch inducer used; however AD subjects exhibited a prolonged itch response in comparison to healthy subjects (p<0.001. CONCLUSIONS: Cowhage induced a more intense itch sensation compared to histamine. Cowhage was the dominant factor in itch perception when both pathways were stimulated in the same time. Cowhage-induced itch is a suitable model for the study of itch in AD and other chronic pruritic diseases, and it can serve as a new model for testing antipruritic drugs in humans.

  18. Comparative study of antifibrotic activity of some magnesium-containing supplements on experimental liver toxicity. Molecular study. (United States)

    El-Tantawy, Walid Hamdy; Sabry, Dina; Abd Al Haleem, Ekram Nemr


    Liver fibrosis is the excessive accumulation of extracellular matrix (ECM) proteins including collagen that occurs in most types of chronic liver diseases. This study aimed to investigate and compare the therapeutic efficacy of different magnesium (Mg)-containing supplements (formulations A, B, and C) on carbon tetrachloride (CCl4)-induced liver fibrosis in rats. Liver fibrosis was induced by intraperitoneal injection of rats with CCl4 (1:1 in olive oil, 2 mL/kg, three times/week) for 4 weeks, and then rats were orally treated with different Mg-containing supplements (formulations A, B, and C) once daily for another one month. Liver fibrosis was quantified by evaluation of expressions of Collagen I, transforming growth factor β-1 (TGFβ1), platelet-derived growth factor-C (PDGF-C), nuclear factor kappa-β (NF-κβ), and measurement of hepatic collagen (hydroxyproline) level. Also, malondialdehyde (MDA), nitric oxide (NO), glutathione (GSH) level, superoxide dismutase (SOD), and glutathione-S-transferase (GST) activities were estimated. CCl4 administration significantly elevated expressions of the studied genes, hepatic hydroxyproline, MDA, and NO levels and caused depletion of GSH level, decreased SOD, and GST activities when compared with those of their corresponding control, p magnesium supplements significantly inhibited expressions of the studied genes and attenuated the hepatic hydroxyproline level as compared with those of CCl4-treated group; p magnesium supplements revealed normalization of oxidant and antioxidants parameters. Histopathological examination supports the biochemical and molecular findings. Mg supplements were effective in the treatment of hepatic CCl4-induced fibrosis-rat model.

  19. Comparative Packaging Study (United States)

    Perchonok, Michele; Antonini, David


    This viewgraph presentation describes a comparative packaging study for use on long duration space missions. The topics include: 1) Purpose; 2) Deliverables; 3) Food Sample Selection; 4) Experimental Design Matrix; 5) Permeation Rate Comparison; and 6) Packaging Material Information.

  20. A Comparative Experimental Study on Head-Disk Touch-Down Detectability Based on Off-Track Vibration

    Directory of Open Access Journals (Sweden)

    Sheng-Xiang Chen


    Full Text Available To further increase the hard-disk drive’s areal density, the head-disk spacing needs to be reduced to sub 1 nm and it requires accurately detect the head-disk touch down (TD. The off-track-vibration-based TD detection methods are widely applied in current hard-disk drive (HDD for head-disk TD detection. However, few studies perform on how to improve the off-track-vibration-based TD detection sensitivity. In this paper, a comparative experimental study was conducted between comparative two off-track-vibration-based TD detection methods: one is based on the low-frequency-forced vibration; the other is based on the off-track-structure vibration. Besides, the skew angle, touch down area (TDA, and the head-stack assembly (HSA rotation inertia effects on TD detectability were discussed. Bigger skew angle and bigger TDA are helpful for good TD sensitivity for these two methods. To the method based on low frequency forced vibration, the smaller HSA rotation inertia design is also helpful.

  1. Cardiac "fitness" training: an experimental comparative study of three methods of pulmonary artery banding for ventricular training. (United States)

    Le Bret, Emmanuel; Lupoglazoff, Jean Marc; Borenstein, Nicolas; Fromont, Gaelle; Laborde, François; Bachet, Jean; Vouhé, Pascal


    When the left ventricle is unable to sustain a systemic pressure in transposition of the great arteries (TGA), left ventricular retraining is mandatory before the morphologic left ventricle under the aorta is switched. This is currently achieved by creating a ventricular overload through pulmonary artery banding, usually associated with an aortopulmonary shunt in case of a TGA with an intact ventricular septum. Our experimental study compared three different modes of increased ventricular afterload to obtain ventricular hypertrophy. Fifteen lambs (mean weight 48 kg) underwent pulmonary artery banding. Five animals (group I) received a classic band; 5 (group II) received a classic band which was adjusted at week 1 and 3; and 4 (group III) received a band which was tightened for 1 hour, twice a day (early morning and late afternoon). After 5 weeks, the lambs were evaluated hemodynamically before they were sacrificed and their hearts harvested for histologic examination. No difference was noted in the hemodynamic data between groups 1 and II. Group III showed a greater ability to increase ventricular pressure in this model. No significant difference was noted between the three groups in terms of macroscopic alterations, but all animals demonstrated an increase in right ventricular wall thickness compared with control animals. Several fibrosis areas were evident in group I and II but none in group III. Intermittent pulmonary artery banding is able to induce hemodynamically sufficient ventricular hypertrophy without fibrosis.

  2. Accuracy and Precision of Three-Dimensional Low Dose CT Compared to Standard RSA in Acetabular Cups: An Experimental Study. (United States)

    Brodén, Cyrus; Olivecrona, Henrik; Maguire, Gerald Q; Noz, Marilyn E; Zeleznik, Michael P; Sköldenberg, Olof


    Background and Purpose. The gold standard for detection of implant wear and migration is currently radiostereometry (RSA). The purpose of this study is to compare a three-dimensional computed tomography technique (3D CT) to standard RSA as an alternative technique for measuring migration of acetabular cups in total hip arthroplasty. Materials and Methods. With tantalum beads, we marked one cemented and one uncemented cup and mounted these on a similarly marked pelvic model. A comparison was made between 3D CT and standard RSA for measuring migration. Twelve repeated stereoradiographs and CT scans with double examinations in each position and gradual migration of the implants were made. Precision and accuracy of the 3D CT were calculated. Results. The accuracy of the 3D CT ranged between 0.07 and 0.32 mm for translations and 0.21 and 0.82° for rotation. The precision ranged between 0.01 and 0.09 mm for translations and 0.06 and 0.29° for rotations, respectively. For standard RSA, the precision ranged between 0.04 and 0.09 mm for translations and 0.08 and 0.32° for rotations, respectively. There was no significant difference in precision between 3D CT and standard RSA. The effective radiation dose of the 3D CT method, comparable to RSA, was estimated to be 0.33 mSv. Interpretation. Low dose 3D CT is a comparable method to standard RSA in an experimental setting.

  3. MR-Imaging of teeth and periodontal apparatus: an experimental study comparing high-resolution MRI with MDCT and CBCT

    Energy Technology Data Exchange (ETDEWEB)

    Gaudino, Chiara; Csernus, Reka; Pham, Mirko; Bendszus, Martin; Rohde, Stefan [University Hospital Heidelberg, Department of Neuroradiology, Heidelberg (Germany); Cosgarea, Raluca; Kim, Ti-Sun [University Hospital Heidelberg, Department of Periodontology, Heidelberg (Germany); Heiland, Sabine [University Hospital Heidelberg, Section of Experimental Radiology, Heidelberg (Germany); Beomonte Zobel, Bruno [University Campus Bio-Medico of Rome, Department of Radiology, Interdisciplinary Center for Biomedical Research, Rome (Italy)


    The aim of this study was (1) to assess the ability of magnetic resonance imaging (MRI) to visualize dental and periodontal structures and (2) to compare findings with multidetector computed tomography (MDCT) and cone beam CT (CBCT). Four porcine mandibles were examined with (1) 3T-MRI, (2) MDCT and (3) CBCT. Two observers independently reviewed MR, MDCT and CBCT images and assessed image quality of different dental and periodontal structures. To assess quantitatively the accuracy of the different imaging technique, both observers measured burr holes, previously drilled in the mandibles. Dental structures, e.g. teeth roots, pulpa chamber and dentin, were imaged accurately with all imaging sources. Periodontal space and cortical/trabecular bone were better visualized by MRI (p < 0.001). MRI could excellently display the lamina dura, not detectable with MDCT and only inconstant visible with CBCT (p < 0.001). Burr hole measurements were highly precise with all imaging techniques. This experimental study shows the diagnostic feasibility of MRI in visualization of teeth and periodontal anatomy. Detection of periodontal structures was significantly better with MRI than with MDCT or CBCT. Prospective trials have to evaluate further the potential benefit of MRI in a clinical setting. (orig.)

  4. MR-Imaging of teeth and periodontal apparatus: an experimental study comparing high-resolution MRI with MDCT and CBCT. (United States)

    Gaudino, Chiara; Cosgarea, Raluca; Heiland, Sabine; Csernus, Réka; Beomonte Zobel, Bruno; Pham, Mirko; Kim, Ti-Sun; Bendszus, Martin; Rohde, Stefan


    The aim of this study was (1) to assess the ability of magnetic resonance imaging (MRI) to visualize dental and periodontal structures and (2) to compare findings with multidetector computed tomography (MDCT) and cone beam CT (CBCT). Four porcine mandibles were examined with (1) 3T-MRI, (2) MDCT and (3) CBCT. Two observers independently reviewed MR, MDCT and CBCT images and assessed image quality of different dental and periodontal structures. To assess quantitatively the accuracy of the different imaging technique, both observers measured burr holes, previously drilled in the mandibles. Dental structures, e.g. teeth roots, pulpa chamber and dentin, were imaged accurately with all imaging sources. Periodontal space and cortical/trabecular bone were better visualized by MRI (p < 0.001). MRI could excellently display the lamina dura, not detectable with MDCT and only inconstant visible with CBCT (p < 0.001). Burr hole measurements were highly precise with all imaging techniques. This experimental study shows the diagnostic feasibility of MRI in visualization of teeth and periodontal anatomy. Detection of periodontal structures was significantly better with MRI than with MDCT or CBCT. Prospective trials have to evaluate further the potential benefit of MRI in a clinical setting.

  5. Comparative experimental study on fouling mechanisms in nano-porous membrane: cheese whey ultrafiltration as a case study. (United States)

    Torkamanzadeh, Mohammad; Jahanshahi, Mohsen; Peyravi, Majid; Shokuhi Rad, Ali


    Determination of fouling mechanisms and accurate quantitative prediction of nano-porous membrane behavior are of great interest in membrane processes. This work has focused on a comprehensive comparison of two classical and new fouling models. Different operational conditions were tested to analyze the level of agreement of these models with experimental observation. Whey solutions of 8, 0.8 and 0.5 g/L were ultrafiltered in transmembrane pressures (TMPs) of 300 and 500 KPa through a synthesized polyethersulfone/copolymer blend membrane. Fouling mechanisms and the effect of different combinations of TMPs and protein concentrations were determined and analyzed by fitting the experimental data to different models. Based on the results obtained from classical models, it was found that the predictions of the cake layer formation model were quite acceptable, followed by the intermediate blocking model. The new combined pore blockage-cake filtration model, however, was found to be very successful in predicting the flux decline over time for every operational condition tested, with all relative errors of prediction less than 5%. The latter also showed a good performance in the transition from the pore blockage mechanism to cake layer formation.

  6. A Comparative Experimental Study of Wave Forces on a Vertical Cylinder in Long-Crested and Short-Crested Seas

    DEFF Research Database (Denmark)

    Frigaard, Peter; Burcharth, Hans F.


    An experimental study is carried out to investigate the wave forces on a slender cylinder. Special attention is given to the wave forces in the surface zone and correlation of forces along the cylinder. The experiments consider the effects of both long and short-crested irregular waves.......An experimental study is carried out to investigate the wave forces on a slender cylinder. Special attention is given to the wave forces in the surface zone and correlation of forces along the cylinder. The experiments consider the effects of both long and short-crested irregular waves....

  7. Leadership Styles: An Experimental Study to Determine the Comparative Effectiveness of Democratic and Autocratic Leadership in Adult, "Real World" Groups. (United States)

    Fadely, L. Dean; Fadely, Patricia R.

    To study the effect of democratic and autocratic leadership styles upon the commitment and productivity of voluntary adult groups, eight tenant councils, composed of approximately six persons each, were selected to serve as experimental groups. Trained researchers acting as discussion leaders for each council functioned as either democratic or…

  8. Physiotherapists use a small number of behaviour change techniques when promoting physical activity: A systematic review comparing experimental and observational studies. (United States)

    Kunstler, Breanne E; Cook, Jill L; Freene, Nicole; Finch, Caroline F; Kemp, Joanne L; O'Halloran, Paul D; Gaida, James E


    Physiotherapists promote physical activity as part of their practice. This study reviewed the behaviour change techniques physiotherapists use when promoting physical activity in experimental and observational studies. Systematic review of experimental and observational studies. Twelve databases were searched using terms related to physiotherapy and physical activity. We included experimental studies evaluating the efficacy of physiotherapist-led physical activity interventions delivered to adults in clinic-based private practice and outpatient settings to individuals with, or at risk of, non-communicable diseases. Observational studies reporting the techniques physiotherapists use when promoting physical activity were also included. The behaviour change techniques used in all studies were identified using the Behaviour Change Technique Taxonomy. The behaviour change techniques appearing in efficacious and inefficacious experimental interventions were compared using a narrative approach. Twelve studies (nine experimental and three observational) were retained from the initial search yield of 4141. Risk of bias ranged from low to high. Physiotherapists used seven behaviour change techniques in the observational studies, compared to 30 behaviour change techniques in the experimental studies. Social support (unspecified) was the most frequently identified behaviour change technique across both settings. Efficacious experimental interventions used more behaviour change techniques (n=29) and functioned in more ways (n=6) than did inefficacious experimental interventions (behaviour change techniques=10 and functions=1). Physiotherapists use a small number of behaviour change techniques. Less behaviour change techniques were identified in observational studies compared to experimental studies, suggesting physiotherapists use less BCTs clinically than experimentally. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  9. An experimental comparative study on classic tube thoracostomy and thoracostomy with a newly designed thorax drainage catheter. (United States)

    Tokur, Mahmut; Ergin, Mehmet; Okumuş, Mehmet; Dündar, Zerrin Defne


    The collection of fluids, blood, pus, or air in the pleural cavity is a pathological condition requiring pleural drainage. A newly designed thorax drainage catheter in the prototype phase was used in this experimental study to test its efficacy. A hemopneumothorax was first caused by a penetrating injury on the frontal axis of the sixth intercostal space on the right hemithorax with a scalpel on 6 female Sus domesticus swine subjects. After resting for 5 min, a tube or catheter was inserted. The same procedure with a tube thoracostomy or thorax drainage catheter was repeated on the left hemithorax. The time periods were recorded. After all procedures were completed, the thoracic organs were assessed for iatrogenic injuries. In terms of time elapsed for procedure, statistically significant differences between the tube thoracostomy and thorax drainage catheter applications were identified (P < 0.05). Additional iatrogenic injuries were nonexistent for both groups. During the thorax drainage catheter application, a surgical set or the use of sutures was not required. This study showed promising results regarding the efficacy of the thorax drainage catheter for convenient use in prehospital and hospital settings by physicians with little experience with tube thoracostomy.

  10. Comparative Study of the Use of Intra-articular and Systemic Meloxicam to Control Experimentally Induced Osteoarthritis in Rabbit Knees

    Directory of Open Access Journals (Sweden)

    Valeria Trombini Vidotto


    Full Text Available Objective: This study aimed to evaluate morphologic changes, as well as chondroprotective and intra-articular effects of meloxicam on joint repair in rabbits induced by experimental trochleoplasty, minimizing possible adverse side effects. Methods: Thirty-five rabbits were divided into four groups: the control group, which did not undergo surgery, and operated groups, which used different ways of administering the anti-inflammatory agent: systemic, 0.2 mg/kg; intra-articular, 0.5 mg/kg; positive group control, without meloxicam. Each operated group was divided according to the periods of 7 or 30 days evaluation after surgery. Results: Regarding macroscopic and histological evaluation of cartilage, after 30 days, most animals showed almost complete joint repair, the presence of few or no inflammatory cells; whereas part of the animals treated with meloxicam presented necrosis in the trochlear ridge and absence of inflammatory cells after 7 days. In positive control group, it was observed moderate inflammation and connective tissue proliferation. None of the animals in the operated groups showed irregularities 30 days after surgery. Conclusion: Either intra-articular or systemic, meloxicam revealed to be favorable to be used for joint repair and control of inflammatory reaction.

  11. Comparative evaluation of HMG CoA reductase inhibitors in experimentally-induced myocardial necrosis: Biochemical, morphological and histological studies. (United States)

    Variya, Bhavesh C; Patel, Snehal S; Trivedi, Jinal I; Gandhi, Hardik P; Rathod, S P


    The present study was carried out to evaluate the protective effect of different statins on isoproterenol (ISO) induced myocardial necrosis. Atorvastatin, rosuvastatin, fluvastatin, simvastatin and pravastatin (10 mg/kg/day) were administered for 12 weeks. After pretreatment of 12 weeks myocardial necrosis was induced by subsequent injection of ISO (85 mg/kg/day, s.c.) to wistar rats. Serum biochemical parameters like glucose, lipid profile, cardiac markers and transaminases were evaluated. Animals were killed and heart was excised for histopathology and antioxidant study. Statins pretreated rats showed significant protection against ISO induced elevation in serum biochemical parameters and serum level of cardiac marker enzymes and transaminase level as compared to ISO control group. Mild to moderate protection was observed in different statins treated heart in histopathology and TTC stained sections. Result from our study also revealed that statins could efficiently protect against ISO intoxicated myocardial necrosis by impairing membrane bound enzyme integrity and endogenous antioxidant enzyme levels. Amongst all statins used, rosuvastatin and pravastatin were found to have maximum cardio-protective activity against ISO induced myocardial necrosis as compared to other statins. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Experimental study comparing the behaviour of steel truss plates and birch plywood inserts in ridge joints on glued laminated rafters

    Directory of Open Access Journals (Sweden)

    López Gayarre, F.


    Full Text Available The present paper reports on an analysis of the mechanical performance of two flat joining systems used in roof members made of glued laminated timber.Six pairs of laminated timber rafters for a double-pitched roof with a 100x180-mm cross-section, a 6.00-m span and a height of 1.00 m were subjected to full-scale four-point bending. In three of the specimens the rafters were joined at the ridge with a birch plywood insert, while in the other three the connection was secured with a fitting consisting in a standard flat steel truss plate. The objective pursued was to evaluate the possibility of replacing the steel fittings with birch plywood inserts. The approach adopted to reach this objective was to compare the strength of the two joint pieces and the deformation generated in the overall structure during strength tests.The results proved to be highly satisfactory in terms of both the bearing capacity and the stiffness of the structures tested.El presente trabajo tiene por objeto llevar a cabo un análisis experimental del comportamiento mecánico de ciertos sistemas planos de unión para elementos estructurales de madera laminada empleados en la construcción de cubiertas.El estudio incluye los ensayos a escala real de seis din-teles a dos aguas de madera laminada, de 6 m de luz, 1 m de altura y una sección de 100 mm x 180 mm, sometidos a flexión en cuatro puntos. En tres dinteles el elemento de unión es una pieza de tablero contra-chapado de abedul, mientras que en los otros tres se ha utilizado un herraje de acero. La finalidad es valorar la posibilidad de sustituir los elementos de unión, realizados mediante herrajes, por otros constituidos por piezas de tablero contrachapado de abedul. Este objetivo se logra comparando el comportamiento resistente mostrado por ambos dispositivos de unión, y las deformaciones en cada caso de las estructuras completas.Los resultados resultaron muy satisfactorios tanto en la capacidad portante como en la

  13. Comparative study of the effect of PTH (1-84) and strontium ranelate in an experimental model of atrophic nonunion. (United States)

    Pérez Núñez, M I; Ferreño Blanco, D; Alfonso Fernández, A; Casado de Prado, J A; Sánchez Crespo, M; De la Red Gallego, M; Pascual Carra, A; Rodriguez López, T; Diego Cavia, S; Garcés Zarzalejo, C; Mayorga Fernández, M; Ruiz Martínez, E; Carrascal Vaquero, I; Riancho Moral, J A


    This study aimed to set up an experimental model of long bone atrophic nonunion and to explore the potential role of PTH-1-84 (PTH 1-84) and strontium ranelate (SrR). A model of atrophic nonunion was created in Sprague-Dawley rats at the femoral midshaft level. The animals were randomised into four groups. Group A1: control rodents, fracture without bone gap; Group A2: rodents with subtraction osteotomy (non-union model control) treated with saline; Group B: rodents with subtraction osteotomy treated with human-PTH (PTH 1-84); and Group C: rodents with subtraction osteotomy treated with strontium ranelate (SrR). The groups were followed for 12 weeks. X-rays were be obtained at weeks 1, 6 and 12. After sacrificing the animals, we proceeded to the biomechanical study and four point bending tests to evaluate the resistance of the callus and histological study. In second phase, the expression of genes related to osteoblast function was analysed by reverse transcription-quantitative PCR in rats subjected to substraction osteotomy and treated for 2 weeks. The animals were randomised into three groups: Group A2: rodents treated with saline; Group B: rodents treated with PTH 1-84 and Group C: rodents treated with SrR. No significant histological differences were found between animals subjected to subtraction osteotomy and treated with either saline or PTH (p=0.628), but significant difference existed between animals receiving saline or SrR (p=0.005). There were no significant differences in X-ray score between the saline and PTH groups at either 6 or 12 weeks (p=0.33 and 0.36, respectively). On the other hand, better X-ray scores were found in the SrR group (p=0.047 and 0.006 in comparison with saline, at 6 and 12 weeks, respectively). In line with this, biomechanical tests revealed improved results in the SrR group. Gene expression analysis revealed a slightly decreased levels of DKK1, a Wnt pathway inhibitor, in rats treated with SrR. SrR increases has a beneficial

  14. Is the "Heart Age" Concept Helpful or Harmful Compared to Absolute Cardiovascular Disease Risk? An Experimental Study. (United States)

    Bonner, Carissa; Jansen, Jesse; Newell, Ben R; Irwig, Les; Teixeira-Pinto, Armando; Glasziou, Paul; Doust, Jenny; McKinn, Shannon; McCaffery, Kirsten


    Cardiovascular disease (CVD) prevention guidelines are generally based on the absolute risk of a CVD event, but there is increasing interest in using 'heart age' to motivate lifestyle change when absolute risk is low. Previous studies have not compared heart age to 5-year absolute risk, or investigated the impact of younger heart age, graphical format, and numeracy. Compare heart age versus 5-year absolute risk on psychological and behavioral outcomes. 2 (heart age, absolute risk) × 3 (text only, bar graph, line graph) experiment. Online. 570 Australians aged 45-64 years, not taking CVD-related medication. CVD risk assessment. Intention to change lifestyle, recall, risk perception, emotional response, perceived credibility, and lifestyle behaviors after 2 weeks. Most participants had lifestyle risk factors (95%) but low 5-year absolute risk (94%). Heart age did not improve lifestyle intentions and behaviors compared to absolute risk, was more often interpreted as a higher-risk category by low-risk participants (47% vs 23%), and decreased perceived credibility and positive emotional response. Overall, correct recall dropped from 65% to 24% after 2 weeks, with heart age recalled better than absolute risk at 2 weeks (32% vs 16%). These results were found across younger and older heart age results, graphical format, and numeracy. Communicating CVD risk in a consultation rather than online may produce different results. There is no evidence that heart age motivates lifestyle change more than 5-year absolute risk in individuals with low CVD risk. Five-year absolute risk may be a better way to explain CVD risk, because it is more credible, does not inflate risk perception, and is consistent with clinical guidelines that base lifestyle and medication recommendations on absolute risk. © The Author(s) 2015.

  15. Physiologic Responses to Infrarenal Aortic Cross-Clamping during Laparoscopic or Conventional Vascular Surgery in Experimental Animal Model: Comparative Study

    Directory of Open Access Journals (Sweden)

    María F. Martín-Cancho


    Full Text Available The aim of this study was to compare the hemodynamic and ventilatory effects of prolonged infrarenal aortic cross-clamping in pigs undergoing either laparotomy or laparoscopy. 18 pigs were used for this study. Infrarenal aortic crossclamping was performed for 60 minutes in groups I (laparotomy, n=6 and II (laparoscopy, n=6. Group III (laparoscopy, n=6 underwent a 120-minute long pneumoperitoneum in absence of aortic clamping (sham group. Ventilatory and hemodynamic parameters and renal function were serially determined in all groups. A significant decrease in pH and significant increase in PaCO2 were observed in group II, whereas no changes in these parameters were seen in group I and III. All variables returned to values similar to baseline in groups I and II 60 minutes after declamping. A significant increase in renal resistive index was evidenced during laparoscopy, with significantly higher values seen in Group II. Thus a synergic effect of pneumoperitoneum and aortic cross-clamping was seen in this study. These two factors together cause decreased renal perfusion and acidosis, thus negatively affecting the patient's general state during this type of surgery.

  16. Comparative experimental and modeling studies of the viscosity behavior of ethanol+C7 hydrocarbon mixtures versus pressure and temperature

    DEFF Research Database (Denmark)

    Zeberg-Mikkelsen, Claus Kjær; Watson, G.; Baylaucq, A.


    The viscosity of the binary system ethanol+n-heptane has been measured with a falling-body viscometer for seven compositions as well as for the pure compounds in the temperature range 293.15-353.15 K and up to 100 MPa with an experimental uncertainty of +/- 2%. At 0.1 MPa, the viscosity has been...... measured with a classical capillary viscometer (Ubbelohde) with an uncertainty of +/- 1%. A total of 208 experimental datapoints are reported. The viscosity behavior of this binary system is interpreted as the results of changes in the free volume, and the breaking or weakening of hydrogen bonds...... viscosity models with a physical and theoretical background. The evaluated models are based on the hard-sphere scheme, the concepts of the free-volume and the friction theory, and a model derived from molecular dynamics. In addition to these models, the simple compositional models by Grunberg...

  17. Modelling of organic Rankine cycle power systems in off-design conditions: an experimentally-validated comparative study


    Dickes, Rémi; Dumont, Olivier; Daccord, Rémi; Quoilin, Sylvain; Lemort, Vincent


    Because of environmental issues and the depletion of fossil fuels, the world energy sector is undergoing many changes toward increased sustainability. Among the many fields of research and development, power generation from low-grade heat sources is gaining interest and the organic Rankine cycle (ORC) is seen as one of the most promising technologies for such applications. In this paper, it is proposed to perform an experimentally-validated comparison of different modelling methods for the of...

  18. A Comparative Study of the Analysis, Numerical Modelling and Experimental Test on a Sandwich Panel with Plane and Profiled Facings

    Directory of Open Access Journals (Sweden)

    Raluca Hohan


    Full Text Available Sandwich panels are remarkable products because they can be as strong as a solid material but with less weight. The analysis that is required to predict the stresses and deflections in panels with flat or lightly profiled facings is that of conventional beam theory but with the addition of shear deformation. Knowing that the profiled sheets bring an increase of the flexural stiffness, formulas showing the calculus of a panel with flat and profiled facings are established. A comparison between the results of a mathematical calculus, an experimental test and a numerical modelling is provided.

  19. A comparative study of the experimental and the theoretical elastic data of Tm{sup 3+} doped zinc borotellurite glass

    Energy Technology Data Exchange (ETDEWEB)

    Hasnimulyati, L. [Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400, UPM, Serdang, Selangor (Malaysia); Halimah, M.K., E-mail: [Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400, UPM, Serdang, Selangor (Malaysia); Zakaria, A.; Halim, S.A. [Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400, UPM, Serdang, Selangor (Malaysia); Ishak, M. [Technical Support Division, Malaysian Institute for Nuclear Technology Research (MINT), Bangi, 43000 Kajang (Malaysia)


    A series of glass samples with composition {[(TeO_2)_0_._7(B_2O_3)_0_._3]_0_._7[ZnO]_0_._3}{sub 1-x}{Tm_2O_3}{sub x} was prepared by using the melt-quenching technique. Then, the samples were characterized by using the densimeter, FTIR and ultrasound technique. The variations of density, molar volume, ultrasonic velocity, elastic moduli, and Poisson’s ratio were discussed and correlated with the composition of the glass samples and the FTIR spectra. It was found that the addition of thulium caused bridging and non-bridging oxygen to be formed at the same time due to the different effect that occur to tellurite and borate network as thulium is added. As thulium is varied from 1 until 3 mol%, bridging oxygens had been found to occur at a high rate and caused the ultrasonic velocity to increase. Nonetheless, when thulium oxide exceeded 3 mol%, non-bridging oxygens formed at a high rate. As a result, ultrasonic velocity was reduced. Furthermore, the values of elastic moduli (including bulk, shear, Young’s modulus, and Poisson’s ratio) were compared with the data that were calculated theoretically by using bulk compression, Makishima-Mackenzie, and Rocherulle models. - Highlights: • Bridging and non-bridging oxygen produced concurrently with the addition of Tm{sub 2}O{sub 3}. • All elastic moduli are increase with the increment of thulium oxide. • The three theoretical models are found invalid to be used in this study.

  20. Comparative study of OMA applied to experimental and simulated data from an operating Vestas V27 wind turbine

    DEFF Research Database (Denmark)

    Requeson, Oscar Ramirez; Tcherniak, Dmitri; Larsen, Gunner Chr.


    is the Coleman transformation, which transforms the vibrations expressed in the blade rotating coordinates to the fixed-ground frame of reference. The application of this transformation, originally from helicopter theory, allows for the conversion of a LPTV system to a LTI system under certain assumptions, among......), and modal analysis requirements are thus fulfilled for the dynamic characterization. Under operation, the system cannot be considered as LTI and must be modelled as a linear periodic time-variant (LPTV) system, which allows for the application of the related theory for such systems. One of these methods...... which is the assumption of isotropic rotors. Since rotors are never completely isotropic in real life, this paper presents the application of operational modal analysis together with the Coleman transformation on both experimental data from a full-scale Vestas wind turbine with instrumented blades...

  1. A comparative evaluation of efficacy of chemotherapy, immunotherapy and immunochemotherapy in visceral leishmaniasis-an experimental study. (United States)

    Joshi, Jyoti; Malla, Nancy; Kaur, Sukhbir


    Visceral leishmaniasis (VL) represents the second most challenging infectious disease worldwide, leading to nearly 500,000 new cases and 60,000 deaths annually. Ninety per cent of VL cases occur in five countries namely Bangladesh, India, Nepal, Sudan and Brazil. No licensed vaccine is available till date against any form of leishmaniasis. High toxicity and increasing resistance to the current chemotherapeutic regimens have further complicated the situation in VL endemic regions of the world. To combat this situation, immunochemotherapy can provide a solution. In the present study, an attempt has been made to assess the in vivo antileishmanial efficacy of chemotherapy, immunotherapy and immunochemotherapy with the use of a first generation antigen Killed Leishmania donovani (KLD) along with a standard drug sodium stibogluconate (SSG) and a newly tested antileishmanial cisplatin. Inbred BALB/c mice were infected with 10(7) promastigotes/0.1 ml of Leishmania donovani. A month after infection, these animals were given specific immunotherapy (KLD/KLD+MPL-A) or chemotherapy (SSG/cisplatin) or immunochemotherapy (SSG+KLD/SSG+KLD+MPL-A/cisplatin+KLD/cisplatin+KLD+MPL-A). Animals were sacrificed on 1, 15 and 30(th) day post treatment. The efficacy of these combinations was assessed in terms of parasite load and by immunological investigations. Infected mice and normal mice served as controls. Results showed that combination of drug and KLD significantly reduced the parasite burden, enhanced the DTH (Delayed Type Hypersensitivity) responses, showed increased levels of IgG2a and decreased levels of IgG1 as compared to mice given chemotherapy or immunotherapy alone. Further maximum protection was provided by SSG+KLD+MPL-A and it was most effective as depicted by 98.5% reduction in parasite load, a potent increase in IFN-γ levels and a significant decrease in IL-10 and IL-4 levels thus skewing the immune response towards Th1 type. Hence, immunochemotherapy is more effective

  2. Comparing the effects of community service and imprisonment on reconviction: results from a quasi-experimental Danish study

    DEFF Research Database (Denmark)

    Klement, Christian


    . Results Imprisonment is associated with a higher rate of recidivism and the result is statistically significant at conventional statistical levels. Conclusions Community service (CS) compared to imprisonment appears to cause a lower reconviction rate in general. Additional research is needed to shed light...

  3. Experimental study comparing the tensile strength of different surgical meshes following aponeurotic-muscle deformity synthesis on Wistar rats. (United States)

    d'Acampora, Armando José; Kestering, Darlan de Medeiros; Soldi, Marly da Silveira; Rossi, Lucas Félix


    To assess the tensile strength of polypropylene and polypropylene associated with polyglactin meshes (Vypro II--Ethicon, Somerville, NJ, USA) in a situation of partial separation of abdominal muscle aponeurosis on rats. Thirty rats were used of the Wistar strain, which were randomized into two groups of 15 specimens each. In both groups an aponeurotic-muscle deformity was created on the abdominal wall measuring 3.0 x 1.0 cm, which was closed with polypropylene mesh (polypropylene group) or Vypro mesh (vypro group). After 28 days the rats underwent euthanasia and an area was removed from the abdominal wall with which a strip was made measuring 2.0 cm in length and 6.0 cm in width comprising the abdominal muscles with the implanted mesh. This sample was placed in a mechanical test machine in which a constant force was applied contrary to the tissue strips. Maximum force expressed in Newton was considered until full rupture of the sample occurred. The non-parametric Kruskal-Wallis test was used for statistical analysis admitting pabdominal wall. All animals in both groups developed epiplon adherence to the mesh. The average force was 48.08 N for the polypropylene group and 45.32 for the vypro group. In these experimental conditions it could be observed that there is no statistically significant difference in the rupture force of the polypropylene and Vypro meshes (p=0.54).

  4. Proteomics investigation of human platelets by shotgun nUPLC-MSE and 2DE experimental strategies: a comparative study. (United States)

    Finamore, Francesco; Pieroni, Luisa; Ronci, Maurizio; Marzano, Valeria; Mortera, Stefano Levi; Romano, Mario; Cortese, Claudio; Federici, Giorgio; Urbani, Andrea


    Platelets, the smallest human blood cells component, have a key role in the control of haemostasis and thrombosis but they have also been shown to be implicated in a number of different pathological states because of their involvement also in the process of inflammation end its resolution. Their peculiar anucleated morphology render the proteomics an intriguing approach to understand their biology. Given the high impact of platelet in different diseases we have started a systematic investigation of protein repertoire in controlled platelet preparation. Platelets have been extracted from blood of healthy donors (n=6) collected by venipuncture in Vacutainer. The quality of the preparation was assessed by observation and enumeration in a Bürker chamber with a conventional tissue culture microscope. To characterize human platelets proteome we analysed the pool of purified platelets combining two proteomic approaches: 2-DE separation combined with Mass Spectrometry and nanoscale ultra performances LC-MS(E) shotgun proteomics experiments. The 2D gel analysis leads an average of 1900 protein spots, after the filtering of "noise" and "false positive" spots, over 500 were selected to be eligible for further analysis given their optimal spot quality value. To perform the analysis by ion accounting shotgun proteomic approach, based on nano ultra performance liquid chromatography (nUPLC) coupled to MS(E) processing of continuum LC-MS data, the same pool of samples was subject to liquid phase tryptic digestion and the peptide obtained used for the experiments. All the data obtained were analysed using ProteinLynx GlobalServer v2.3 (PLGS, Waters). Three analytical replicates run were acquire in high/low energy modes and associated to a human protein database returning the identification of 100 distinct genes. Comparative analysis of the Gene Ontology has been performed to evaluate the differential functional representation of the molecular repertoire investigated with these two

  5. Experimental Study on Welded Headed Studs Used In Steel Plate-Concrete Composite Structures Compared with Contactless Method of Measuring Displacement (United States)

    Kisała, Dawid; Tekieli, Marcin


    Steel plate-concrete composite structures are a new innovative design concept in which a thin steel plate is attached to the reinforced concrete beam by means of welded headed studs. The comparison between experimental studies and theoretical analysis of this type of structures shows that their behaviour is dependent on the load-slip relationship of the shear connectors used to ensure sufficient bond between the concrete and steel parts of the structure. The aim of this paper is to describe an experimental study on headed studs used in steel plate-concrete composite structures. Push-out tests were carried out to investigate the behaviour of shear connectors. The test specimens were prepared according to standard push-out tests, however, instead of I-beam, a steel plate 16 mm thick was used to better reflect the conditions in the real structure. The test specimens were produced in two batches using concrete with significantly different compressive strength. The experimental study was carried out on twelve specimens. Besides the traditional measurements based on LVDT sensors, optical measurements based on the digital image correlation method (DIC) and pattern tracking methods were used. DIC is a full-field contactless optical method for measuring displacements in experimental testing, based on the correlation of the digital images taken during test execution. With respect to conventional methods, optical measurements offer a wider scope of results and can give more information about the material or construction behaviour during the test. The ultimate load capacity and load-slip curves obtained from the experiments were compared with the values calculated based on Eurocodes, American and Chinese design specifications. It was observed that the use of the relationships developed for the traditional steel-concrete composite structures is justified in the case of ultimate load capacity of shear connectors in steel plate-concrete composite structures.

  6. Comparative antioxidant status in freshwater fish Carassius auratus exposed to six current-use brominated flame retardants: A combined experimental and theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Mingbao; Qu, Ruijuan; Wang, Chao; Wang, Liansheng; Wang, Zunyao, E-mail:


    Highlights: •A combined experimental and theoretical approach was used for risk assessments of six BFRs in fish. •Oxidative stress biomarkers were measured for toxicity identification. •Toxicity order was proposed via the integrated biomarker response. •Theoretical calculations were performed to analyze the BFRs toxicity. -- Abstract: Decabromodiphenyl ether (BDE-209) and several non-polybrominated diphenyl ether (PBDE) brominated flame retardants (BFRs), such as tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD), decabromodiphenyl ethane (DBDPE), hexabromobenzene (HBB) and pentabromotoluene (PBT), are persistent halogenated contaminants ubiquitously detected in aquatic systems. However, data on comparative toxicological effects of these BFRs are lacking for fish. In this study, a combined experimental and theoretical approach was used to compare and analyze the effects of these BFRs on biochemical biomarkers in liver of Carassius auratus injected intraperitoneally with different doses (10 and 100 mg/kg) for 7, 14 and 30 days. Oxidative stress was evoked evidently for the prolonged exposure, represented by the significantly altered indices (superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione, and malondialdehyde). The integrated biomarker response (IBR) index ranked biotoxicity as: PBT > HBB > HBCD > TBBPA > BDE-209 > DBDPE. Quantum chemical calculations (electronic parameters, frontier molecular orbitals, and Wiberg bond order) were performed for theoretical analysis. Notably, some descriptors were correlated with the toxicity order, probably implying the existence of a potential structure–activity relationship when more BFRs were included. Besides, theoretical calculations also provided some valuable information regarding the molecular characteristics and metabolic pathways of these current-use BFRs, which may facilitate the understanding on their environmental behavior and fate. Overall, this study adopted a combined

  7. Setup of a bone aging experimental model in the rabbit comparing changes in cortical and trabecular bone: Morphological and morphometric study in the femur. (United States)

    Pazzaglia, Ugo E; Sibilia, Valeria; Congiu, Terenzio; Pagani, Francesca; Ravanelli, Marco; Zarattini, Guido


    Bone aging was studied in an experimental model (rabbit femur) in three populations aged 0.5, 1.5, and 7.5 years. Cortical bone histology was compared with a data set from a 1.5-month-old population of an earlier published paper. From 0.5-year-old onward, the mean femur length did not increase further. Thereafter, the mean marrow area increased and the cortical area decreased significantly with aging. This was associated with a structural pattern transformation from plexiform to laminar and then Haversian-like type. The distal meta-epiphysis bone trabecular density of the oldest populations also was significantly lower in specific regions of interest (ROI). Percentage sealed primary vascular canals in laminar bone significantly increased with aging without variation of percentage sealed secondary osteons. Remodeling rate reflected by the density of cutting cones did not significantly change among the age populations. These data suggest that laminar bone vascular pattern is more functional in the fast diaphyseal expansion but not much streamlined with the renewal of blood flow during secondary remodeling. Bone aging was characterized by: 1) secondary remodeling subendosteally; 2) increment of sealed primary vascular canals number; 3) increased calcium content of the cortex; 4) cortical and trabecular bone mass loss in specific ROIs. Taken together, the present data may give a morphological and morphometric basis to perform comparative studies on experimental models of osteoporosis in the rabbit. © 2015 Wiley Periodicals, Inc.

  8. A comparative study on the hepatoprotective action of bear bile and coptidis rhizoma aqueous extract on experimental liver fibrosis in rats

    Directory of Open Access Journals (Sweden)

    Wang Ning


    Full Text Available Abstract Aim of the study Bear bile and Coptidis Rhizoma have been used in Chinese medicine with a long tradition in treating heat-diseases. Both bear bile and Coptidis Rhizoma are used to treat liver diseases in clinical practice of Chinese Medicine. Since bears are currently endangered, it raises the question whether the use of bear bile is ethical. To look for substitute for bear bile, the aim of this study is to compare the anti-fibrotic effects of Coptidis Rhizoma and its major component berberine with the actions of bear bile and its major compound tauroursodeoxycholic acid on experimental liver fibrosis in rats. Method Quality assessment was conducted with high performance liquid chromatography. The experimental liver fibrosis in rats was induced by carbon tetrachloride, alcohol, and bile duct ligation respectively. The biochemical criteria in the blood and tissue samples were measured to evaluate the anti-fibrotic properties and underlying mechanisms of the drugs. Results Coptidis Rhizoma Aqueous Extract (CRAE, berberine, and bear bile exerted anti-fibrotic properties on various liver fibrosis models in rats. CRAE and berberine significantly reduced the peroxidative stress in liver through increasing the superoxide dismutase enzyme activity. CRAE and berberine were able to excrete bilirubin products from the liver and protect hepatocytes from cholestatic damage. The effect of CRAE and berberine are comparable to that of bear bile. Conclusion Instead of using bear bile, CRAE and berberine can be potential substitutes in treating liver fibrosis.

  9. A comparative study on the hepatoprotective action of bear bile and Coptidis Rhizoma aqueous extract on experimental liver fibrosis in rats. (United States)

    Wang, Ning; Feng, Yibin; Cheung, Fan; Chow, Oi-Yee; Wang, Xuanbin; Su, Weiwei; Tong, Yao


    Bear bile and Coptidis Rhizoma have been used in Chinese medicine with a long tradition in treating heat-diseases. Both bear bile and Coptidis Rhizoma are used to treat liver diseases in clinical practice of Chinese Medicine. Since bears are currently endangered, it raises the question whether the use of bear bile is ethical. To look for substitute for bear bile, the aim of this study is to compare the anti-fibrotic effects of Coptidis Rhizoma and its major component berberine with the actions of bear bile and its major compound tauroursodeoxycholic acid on experimental liver fibrosis in rats. Quality assessment was conducted with high performance liquid chromatography. The experimental liver fibrosis in rats was induced by carbon tetrachloride, alcohol, and bile duct ligation respectively. The biochemical criteria in the blood and tissue samples were measured to evaluate the anti-fibrotic properties and underlying mechanisms of the drugs. Coptidis Rhizoma Aqueous Extract (CRAE), berberine, and bear bile exerted anti-fibrotic properties on various liver fibrosis models in rats. CRAE and berberine significantly reduced the peroxidative stress in liver through increasing the superoxide dismutase enzyme activity. CRAE and berberine were able to excrete bilirubin products from the liver and protect hepatocytes from cholestatic damage. The effect of CRAE and berberine are comparable to that of bear bile. Instead of using bear bile, CRAE and berberine can be potential substitutes in treating liver fibrosis.

  10. Does smoking abstinence influence distress tolerance? An experimental study comparing the response to a breath-holding test of smokers under tobacco withdrawal and under nicotine replacement therapy. (United States)

    Cosci, Fiammetta; Anna Aldi, Giulia; Nardi, Antonio Egidio


    Distress tolerance has been operationalized as task persistence in stressful behavioral laboratory tasks. According to the distress tolerance perspective, how an individual responds to discomfort/distress predicts early smoking lapses. This theory seems weakly supported by experimental studies since they are limited in number, show inconsistent results, do not include control conditions. We tested the response to a stressful task in smokers under abstinence and under no abstinence to verify if tobacco abstinence reduces task persistence, thus distress tolerance. A placebo-controlled, double-blind, randomized, cross-over design was used. Twenty smokers underwent a breath holding test after the administration of nicotine on one test day and a placebo on another test day. Physiological and psychological variables were assessed at baseline and directly before and after each challenge. Abstinence induced a statistically significant shorter breath holding duration relative to the nicotine condition. No different response to the breath holding test was observed when nicotine and placebo conditions were compared. No response to the breath holding test was found when pre- and post-test values of heart rate, blood pressure, Visual Analogue Scale for fear or discomfort were compared. In brief, tobacco abstinence reduces breath holding duration but breath holding test does not influence discomfort. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. Histopathological comparative analysis of peri-implant soft tissue response after dental implant placement with flap and flapless surgical technique. Experimental study in pigs. (United States)

    Vlahovic, Zoran; Markovic, Aleksa; Golubovic, Mileta; Scepanovic, Miodrag; Kalanovic, Milena; Djinic, Ana


    The aim of this study was comparing the effect of flapless vs. flap technique of implant placement on inflammation degree of peri-implant soft tissue, through histopathological analysis. The experiment was conducted on five domestic pigs. Nine weeks after tooth extraction, implants were installed. Each animal received six implants in mandible. According to split-mouth design, randomly one side was used for flapless technique using mini-incision, while on the other side, flap was raised. After 7, 14, 21, 28, and 90 days, the experimental animals were sacrificed. Samples for histopathological analyzes were taken from the buccal side of peri-implant mucosa next to the neck of implants, from three levels. The degree of inflammatory response in the peri-implant soft tissue was estimated through ordinal scores from 0 to 3. In the flap group Score 3 indicating high degree of inflammation was present from day 7 to day 21, in contrast to flapless group where Score 3 was not recorded during the entire follow-up. Three months after implantation, there were no signs of inflammation neither around flap nor around flapless implants. Flapless surgical implantation technique using mini-incision decreases peri-implant soft tissue inflammatory reaction compared with flap surgery. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Comparative experimental and modeling study of the low- to moderate-temperature oxidation chemistry of 2,5-dimethylfuran, 2-methylfuran, and furan

    KAUST Repository

    Tran, Luc-Sy


    The reaction chemistry of furanic fuels, proposed as next-generation bio-derived fuels, has been a target of recent studies. However, quantitative intermediate species profiles at low- to moderate-temperature (LMT) conditions remain scarce. The present paper reports the first systematic full speciation dataset in the temperature range 730–1170 K for three furanic fuels, 2,5-dimethylfuran (DMF), 2-methylfuran (MF), and furan, measured for different equivalence ratios under near-identical LMT conditions in a flow reactor at 1 bar. More than 35 species including reactants, intermediate species, and products were analyzed using electron ionization (EI) molecular-beam mass spectrometry (MBMS). These experimental results provided motivation to extend a previous single joint mechanism for the three furanic fuels, developed for the high-temperature regime in low-pressure premixed flames, to include the LMT oxidation chemistry. A decisive difference of the present mechanism versus all previously reported models is a more complete description of fuel radical reactions for LMT oxidation, obtained from theoretical calculations of thermodynamic properties and rate constants. The experimentally observed differences in fuel conversion behavior and species distribution between the three fuels have been compared to model predictions using the newly extended mechanism. The dependence of fuel conversion on equivalence ratio decreases significantly from DMF to furan, a behavior consistent with the different number of lateral methyl groups in the fuel structure. All three furanic fuels, especially DMF, produce several highly toxic oxygenated species including acrolein, methyl vinyl ketone, furfural, and phenol. These toxic species were found to be products of the primary reactions of these fuels, and these undesirable trends could be explained satisfactorily by the present model, pointing to some caution with regard to the potential emission spectra under LMT conditions.

  13. Comparing four service delivery models for adolescent girls and young women through the 'Girl Power' study: protocol for a multisite quasi-experimental cohort study. (United States)

    Rosenberg, Nora E; Pettifor, Audrey E; Myers, Laura; Phanga, Twambilile; Marcus, Rebecca; Bhushan, Nivedita Latha; Madlingozi, Nomtha; Vansia, Dhrutika; Masters, Avril; Maseko, Bertha; Mtwisha, Lulu; Kachigamba, Annie; Tang, Jennifer; Hosseinipour, Mina C; Bekker, Linda-Gail


    In sub-Saharan Africa, adolescent girls and young women (AGYW) face a range of sexual and reproductive health (SRH) challenges. Clinical, behavioural and structural interventions have each reduced these risks and improved health outcomes. However, combinations of these interventions have not been compared with each other or with no intervention at all. The 'Girl Power' study is designed to systematically make these comparisons. Four comparable health facilities in Malawi and South Africa (n=8) were selected and assigned to one of the following models of care: (1) Standard of care : AGYW can receive family planning, HIV testing and counselling (HTC), and sexually transmitted infection (STI) syndromic management in three separate locations with three separate queues with the general population. No youth-friendly spaces, clinical modifications or trainings are offered, (2) Youth-Friendly Health Services (YFHS) : AGYW are meant to receive integrated family planning, HTC and STI services in dedicated youth spaces with youth-friendly modifications and providers trained in YFHS, (3) YFHS+behavioural intervention (BI) : In addition to YFHS, AGYW can attend 12 monthly theory-driven, facilitator-led, interactive sessions on health, finance and relationships, (4) YFHS+BI+conditional cash transfer (CCT) : in addition to YFHS and BI, AGYW receive up to 12 CCTs conditional on monthly BI session attendance.At each clinic, 250 AGYW 15-24 years old (n=2000 total) will be consented, enrolled and followed for 1 year. Each participant will complete a behavioural survey at enrolment, 6 months and 12 months . All clinical, behavioural and CCT services will be captured. Outcomes of interest include uptake of each package element and reduction in HIV risk behaviours. A qualitative substudy will be conducted. This study has received ethical approval from the University of North Carolina Institutional Review Board, the University of Cape Town Human Research Ethics Committee and Malawi

  14. Experimental study of vortex diffusers

    Energy Technology Data Exchange (ETDEWEB)

    Shakerin, S.; Miller, P.L. [National Renewable Energy Lab., Golden, CO (United States)


    This report documents experimental research performed on vortex diffusers used in ventilation and air-conditioning systems. The main objectives of the research were (1) to study the flow characteristics of isothermal jets issuing from vortex diffusers, (2) to compare the vortex diffuser`s performance with that of a conventional diffuser, and (3) to prepare a report that disseminates the results to the designers of ventilation and air-conditioning systems. The researchers considered three diffusers: a conventional round ceiling diffuser and two different styles of vortex diffusers. Overall, the vortex diffusers create slightly more induction of ambient air in comparison to the conventional diffuser.

  15. Comparative radiographic and resonance frequency analyses of the peri-implant tissue after dental implants placement using flap and flapless techniques: an experimental study on domestic pigs. (United States)

    Vlahović, Zoran; Mihailović, Branko; Lazić, Zoran; Golubović, Mileta


    Flapless implant surgery has become very important issue during recent years, mostly thanks to computerization of dentistry and software planning of dental implants placements. The aim of this study was to compare flap and flapless surgical techniques for implant placement through radiographic and radiofrequency analyses. The experiment was made in five domestic pigs. Nine weeks following domestic pigs teeth extraction, implants were placed, on the right side using surgical technique flap, and flapless on the left side. Digital dental Xrays were applied to determine primary dental implant stability quality (ISQ). At certain intervals, not later than three months, the experimental animals were sacrificed, and just before it, control X-rays were applied to measure dental implants stability. Radiographic analysis showed that peri-implant bone resorption in the first 4 weeks following placement implants with flap and flapless surgical techniques was negligible. After the 3 months, mean value of peri-implant bone resorption of the implants placed using flap tehnique was 1.86 mm, and of those placed using flapless tehnique was 1.13 mm. In relation to the primary dental implant stability in the first and second week there was an expected decrease in ISQ values, but it was less expressed in the dental implants placed using the flapless technique. In the third week the ISQ values were increased in the dental implants placed by using both techniques, but the increase in flapless implant placement was higher (7.4 ISQ) than in flap implant placement (1.5 ISQ). The upward trend continued in a 4-week period, and after 3 months the dental implant stability values in the implants placed using flap technique were higher than the primary stability for 7.1 ISQ, and in the implants placed using flapless technique were higher comparing to the primary stability for 10.1 ISQ units. Based on the results of radiographic and resonance frequency analyses it can be concluded that the flapless

  16. Comparative radiographic and resonance frequency analyses of the peri-implant tissue after dental implants placement using flap and flapless techniques: An experimental study on domestic pigs

    Directory of Open Access Journals (Sweden)

    Vlahović Zoran


    Full Text Available Background/Aim. Flapless implant surgery has become very important issue during recent years, mostly thanks to computerization of dentistry and software planning of dental implants placements. The aim of this study was to compare flap and flapless surgical techniques for implant placement through radiographic and radiofrequency analyses. Methods. The experiment was made in five domestic pigs. Nine weeks following domestic pigs teeth extraction, implants were placed, on the right side using surgical technique flap, and flapless on the left side. Digital dental Xrays were applied to determine primary dental implant stability quality (ISQ. At certain intervals, not later than three months, the experimental animals were sacrificed, and just before it, control X-rays were applied to measure dental implants stability. Results. Radiographic analysis showed that peri-implant bone resorption in the first 4 weeks following placement implants with flap and flapless surgical techniques was negligible. After the 3 months, mean value of peri-implant bone resorption of the implants placed using flap technique was 1.86 mm, and of those placed using flapless technique was 1.13 mm. In relation to the primary dental implant stability in the first and second week there was an expected decrease in ISQ values, but it was less expressed in the dental implants placed using the flapless technique. In the third week the ISQ values were increased in the dental implants placed by using both techniques, but the increase in flapless implant placement was higher (7.4 ISQ than in flap implant placement (1.5 ISQ. The upward trend continued in a 4- week period, and after 3 months the dental implant stability values in the implants placed using flap technique were higher than the primary stability for 7.1 ISQ, and in the implants placed using flapless technique were higher comparing to the primary stability for 10.1 ISQ units. Conclusion. Based on the results of radiographic and


    Directory of Open Access Journals (Sweden)

    Guangming Chen


    Full Text Available Full-scale traditional metal solar collectors and solar collector specimens fabricated from polymeric materials were investigated in the present study. A polymeric collector is 67.8% lighter than a traditional metal solar collector, and a metal solar collector with transparent plastic covering is 40.3% lighter than a traditional metal solar collector. Honeycomb multichannel plates made from polycarbonate were chosen to create a polymeric solar collector. A test rig for the natural circulation of the working fluid in a solar collector was built for a comparative experimental investigation of various solar collectors operating at ambient conditions. It was shown experimentally that the efficiency of a polymeric collector is 8–15% lower than the efficiency of a traditional collector.

  18. Comparative study of the corrosion behavior of peripheral stents in an accelerated corrosion model: experimental in vitro study of 28 metallic vascular endoprostheses (United States)

    Paprottka, Karolin J.; Paprottka, Philipp M.; Reiser, Maximilian F.; Waggershauser, Tobias


    PURPOSE Clinical cases of stent-fractures show that corrosion behavior might play a role in these fractures. Implanted in vivo, especially in combination with other implanted foreign materials, these metallic products are exposed to special conditions, which can cause a process of corrosion. Here, we aimed to test the corrosion potential of stents made of different materials in an in vitro setting. METHODS A total of 28 peripheral stents of different materials (nitinol, cobalt-chromium-nickel, tantalum, V4A) and surface treatments (electropolish, mechanical polish, no polish) were tested in vitro. Corrosion was accelerated by applying a constant voltage of 3.5 V and amperage of 1.16 mA in 0.9% NaCl. RESULTS Nitinol stents showed the lowest susceptibility to corrosion and the longest period without damage. The Memotherm II® (BARD Angiomed®) was the only stent that showed neither macroscopic nor microscopic damages. The worst performing material was cobalt-chromium-nickel, which showed corrosion damages about ten times earlier compared to nitinol. Considering the reasons for termination of the test, nitinol stents primarily showed length deficits, while V4A and tantalum stents showed fractures. Cobalt-chromium-nickel stents had multiple fractures or a complete lysis in equal proportions. When placed in direct contact, nitinol stents showed best corrosion resistance, regardless of what material they were combined with. In terms of polishing treatments, electropolished stents performed the best, mechanical-polished stents and those without polishing treatment followed. CONCLUSION The analysis of corrosion behavior may be useful to select the right stent fulfilling the individual needs of the patient within a large number of different stents. PMID:26268301

  19. A Comparative Study of Densitometric Parameters of the Bone Tissue Under Transosseous Osteosynthesis by Using Experimental Implants Coated with Superhard Compounds

    Directory of Open Access Journals (Sweden)

    Galimzyan KABIROV


    Full Text Available By X-ray computed tomography (CT, density characteristics of the tibiae bones in 25 experimental adult male rats were studied after their tibiae bones have experimentally fractured and then repaired by osteosynthesis using different implants. According to the data that was obtained by computed tomography, it has been defined that bone densities depend on the type of the implant and the chemical composition of the coating which is applied on the surface of the implant. Thus, average values of the density of the tibiae bones in the experimental rats with implants coated with a combination of titanium and hafnium nitrides were not different from the density values of the intact bones. At the same time, the densities of the tibiae in rats with implants made of copper and implants coated with a combination of titanium and zirconium nitrides were 1.5-2 times lower than those of the intact bones. This leads us to conclude that implants coated with titanium and hafnium nitrides are biologically and chemically inert because less pathologic changes in the bone tissue were observed, in contrast to the copper-based implants and those where the coating contains zirconium.

  20. Experimental study of potential neutron moderator materials (United States)

    Mocko, M.; Daemen, L. L.; Hartl, M. A.; Huegle, Th.; Muhrer, G.


    We present an experimental investigation of thermal neutron energy spectra produced by lead and bismuth hydroxides (Pb(OH) 2, and Bi(OH) 3). The experimental energy spectra are compared with a thermal neutron energy spectrum produced by water measured in the same geometry. We developed an MCNPX geometry model designed to help with the interpretation of the experimental data. We demonstrate a very good reproduction of the experimental thermal neutron energy spectrum produced by the water moderator in our tightly coupled geometry. We study our experimental results for Pb(OH) 2 and Bi(OH) 3 using thermal neutron scattering kernels for hydrogen, bismuth, and lead.

  1. Experimental comparative study and fracture resistance simulation with irrigation solution of 0.2% chitosan, 2.5% NaOCl and 17% EDTA

    Directory of Open Access Journals (Sweden)

    Ernani Ernani


    Full Text Available Background: Preparation in endodontic need irrigation materials as root canal debridement and disinfectant. However, irrigation materials is one of the factors that influence the tendency of fracture. Purpose: This study was aimed to see the resistance and fracture distribution if teeth irrigated with high molecular horseshoe crab chitosan at 0.2% concentration, 2.5% NaOCl solution and 17% EDTA solution in endodontic treatment with finite element method (FEM simulation study and experimental studies. Method: Endodontic treatment performed on 28 maxillary premolars with group A: irrigation solution of 17% EDTA and 2.5% NaOCl solution; group B: 2.5% NaOCl irrigation solution; group C: 2.5% NaOCl irrigation solution and 0.2% chitosan solution; group D: 0.2% chitosan solution irrigation. Final restoration was done using prefabricated glass fiber post. Cementation of post using resin cement then restored with direct composite resin restorations. Pressure test was performed with a Universal Testing Machine with a speed of 0.5 mm/min until fracture occurred. A three dimensional finite element analysis was performed for total deformation, equivalent (von-mises stress, and equivalent elastic strains. Result: Anova test showed significant differences in fracture resistance (p0.05. Statistical analysis showed no significant difference (p>0.05 between the results of experiment and FEM analysis results using the t-test. Conclusion: The results of this study demonstrated that there was effect of the use of high molecular 0.2% chitosan as a combined irrigation with NaOCl, but did not affect the fracture pattern distribution of endodontically treated teeth both experimentally and FEM analysis test.

  2. Comparative Studies for What?

    Directory of Open Access Journals (Sweden)

    Pedro Guedes de Carvalho


    Full Text Available ISCPES stands for International Society for Comparative Physical Education and Sports and it is going to celebrate its 40th anniversary in 2018. Since the beginning (Israel 1978 the main goals of the Society were established under a worldwide mind set considering five continents and no discrimination of any kind. The founders wanted to compare Physical Education and Sports across the world, searching for the best practices deserving consideration and applied on the purpose of improving citizen quality of life. The mission still stands for “Compare to learn and improve”. As all the organizations lasting for 39 years, ISCPES experienced several vicissitudes, usually correlated with world economic cycles, social and sports changes, which are in ISS journal articles - International Sport Studies. ISS journal is Scopus indexed, aiming to improve its quality (under evaluation to reach more qualified students, experts, professionals and researchers; doing so it will raise its indexation, which we know it is nowadays a more difficult task. First, because there are more journals trying to compete on this academic fierce competitive market; secondly, because the basic requirements are getting more and more hard to gather in the publishing environment around Physical Education and Sports issues. However, we can promise this will be one of our main strategic goals. Another goal I would like to address on this Editorial is the language issue. We have this second strategic goal, which is to reach most of languages spoken in different continents; besides the English language, we will reach Chinese, Spanish and Portuguese speaking countries. For that reason, we already defined that all the abstracts in English will be translated into Chinese, Spanish and Portuguese words so people can find them on any search browser. That will expand the demand for our journal and articles, increasing the number of potential readers. Of course this opportunity, given by

  3. Operations dashboard: comparative study (United States)

    Ramly, Noor Nashriq; Ismail, Ahmad Zuhairi; Aziz, Mohd Haris; Ahmad, Nurul Haszeli


    In this present days and age, there are increasing needs for companies to monitor application and infrastructure health. Apart from having proactive measures to secure their application and infrastructure, many see monitoring dashboards as crucial investment in disaster preparedness. As companies struggle to find the best solution to cater for their needs and interest for monitoring their application and infrastructure's health, this paper summarizes the studies made on several known off-the-shelf operations dashboard and in-house developed dashboard. A few criteria of good dashboard are collected from previous studies carried out by several researchers and rank them according to importance and business needs. The finalized criteria that will be discussed in later sections are data visualization, performance indicator, dashboard personalization, audit capability and alert/ notification. Comparative studies between several popular dashboards were then carried out to determine whether they met these criteria that we derived from the first exercise. The findings hopefully can be used to educate and provide an overview of selecting the best IT application and infrastructure operations dashboard that suit business needs, thus become the main contribution of this paper.

  4. Comparative radiographic and resonance frequency analyses of the peri-implant tissue after dental implants placement using flap and flapless techniques: An experimental study on domestic pigs


    Vlahović Zoran; Mihailović Branko; Lazić Zoran; Golubović Mileta


    Background/Aim. Flapless implant surgery has become very important issue during recent years, mostly thanks to computerization of dentistry and software planning of dental implants placements. The aim of this study was to compare flap and flapless surgical techniques for implant placement through radiographic and radiofrequency analyses. Methods. The experiment was made in five domestic pigs. Nine weeks following domestic pigs teeth extraction, implants were placed, on the right side us...

  5. Comparative study on ultrasonic assisted adsorption of dyes from single system onto Fe3O4 magnetite nanoparticles loaded on activated carbon: Experimental design methodology. (United States)

    Bagheri, Ahmad Reza; Ghaedi, Mehrorang; Asfaram, Arash; Bazrafshan, Ali Akbar; Jannesar, Ramin


    The present study the ultrasound assisted adsorption of dyes in single system onto Fe3O4 magnetite nanoparticles loaded on activated carbon (Fe3O4-MNPs-AC) was described following characterization and identification of this adsorbent by conventional techniques likes field emission scanning electron microscopy, transmission electron microscopy, particle-size distribution, X-ray diffraction and Fourier transform infrared spectroscopy. A central composite design in conjunction with a response surface methodology according to f-test and t-test for recognition and judgment about significant term led to construction of quadratic model which represent relation among responses and effective terms. This model has unique ability to predict adsorption data behavior over a large space around central and optimum point. Accordingly Optimum conditions for well and quantitative removal of present dyes was obtained best operation and conditions: initial SY, MB and EB dyes concentration of 15, 15 and 25mgL(-1), 4.0, 6.0 and 5.0 of pH, 360, 360 and 240s sonication time and 0.04, 0.03 and 0.032g of Fe3O4-MNPs-AC. Replication of similar experiment (N=5) guide that average removal percentage of SY, MB and EB were found to be 96.63±2.86%, 98.12±1.67% and 99.65±1.21% respectively. Good agreement and closeness of Predicted and experimental result and high adsorption capacity of dyes in short time strongly confirm high suitability of present method for waste water treatment, while easy separation of present nanoparticle and its good regeneration all support good applicability of Fe3O4-MNPs-AC for waste water treatment. The kinetic study can be represented by combination of pseudo second-order and intraparticle diffusion. The obtained maximum adsorption capacities correspond to Langmuir as best model for representation of experimental data correspond to dyes adsorption onto Fe3O4-MNPs-AC were 76.37, 78.76 and 102.00mgg(-1) for SY, MB and EB, respectively. In addition, the performance

  6. Nutrition attitudes and knowledge in medical students after completion of an integrated nutrition curriculum compared to a dedicated nutrition curriculum: a quasi-experimental study. (United States)

    Walsh, Carolyn O; Ziniel, Sonja I; Delichatsios, Helen K; Ludwig, David S


    Nutrition education has presented an ongoing challenge to medical educators. In the 2007-2008 academic year, Harvard Medical School replaced its dedicated Preventive Medicine and Nutrition course with an integrated curriculum. The objective of the current study was to assess the effect of the curriculum change on medical student attitudes and knowledge about nutrition. A survey was administered in a quasi-experimental design to students in the last class of the dedicated curriculum (n = 131) and the first class of the integrated curriculum (n = 135) two years after each class completed the required nutrition course. Main measures were attitude scores based on modified Nutrition in Patient care Survey and satisfaction ratings, performance on a nutrition knowledge test, and demographic variables. Two-tailed t-tests were performed. Response rates were 50.4% and 42.2%. There were no differences between the groups in attitude scores from the Nutrition in Patient care Survey (p = 0.43) or knowledge scores (p = 0.63). Students with the integrated curriculum were less satisfied with both the quantity (p student attitudes and knowledge about nutrition were not affected by the model of nutrition education they receive, though students in an integrated curriculum may feel their education is inadequate and seek additional training.

  7. Comparative Studies for What?


    Pedro Guedes de Carvalho


    ISCPES stands for International Society for Comparative Physical Education and Sports and it is going to celebrate its 40th anniversary in 2018. Since the beginning (Israel 1978) the main goals of the Society were established under a worldwide mind set considering five continents and no discrimination of any kind. The founders wanted to compare Physical Education and Sports across the world, searching for the best practices deserving consideration and applied on the purpose of improving citiz...

  8. Experimental model for endometriosis. Comparative histological study between the ectopic and eutopic endometrium Modelo experimental de endometriose: estudo histológico comparativo entre o endométrio estópico e o eutópico

    Directory of Open Access Journals (Sweden)

    Cézar Alencar de Lima Rezende


    Full Text Available Thyrty-six rats werw implanted with endometrial squares (2 X 2mm to the left parietal peritoneum and the right uterine horn was tied. The rats were mated for 20 days and then sacrificed. Topic and ectopic endometrial histological pattern were compared. There was a correlation between the histological pattern of the autografted endometrium and the eutopic endometrium im most rats, pregnant or not. This suggests that both responded in a similar way to the same endocrine stimuli. The experimental model for endometriosis admiting the histological correlation between the uterine endometrium and the ectopic is factible and it is easy to be repetead.Trinta e seis ratas foram submetidas a implante cirúrgico de retalho endometrial quadrangular (2 x 2mm no peritônio parietal esquerdo e ligadura do corno uterino direito. As ratas foram acasaladas por 20 dias e logo após sacrificadas. Foram comparados o padrão histológico do endométrio eutópico e do ectópico.Houve correspondência entre o padrão histológico do endométrio auto-transplantado e o endométrio eutópico na maioria das ratas, prenhes ou não, sugerindo que ambos responderam de forma semelhante aos mesmo estímulos endócrinos. O modelo experimental de endometriose na rata, permitindo a correlação histológica entre o endométrio uterino e o ectópico, é viável e de fácil repetição.

  9. Neural responses to a modified Stroop paradigm in patients with complex chronic musculoskeletal pain compared to matched controls: an experimental functional magnetic resonance imaging study. (United States)

    Taylor, Ann M; Harris, Ashley D; Varnava, Alice; Phillips, Rhiannon; Hughes, Owen; Wilkes, Antony R; Hall, Judith E; Wise, Richard G


    Chronic musculoskeletal pain (CMSKP) is attentionally demanding, complex and multi-factorial; neuroimaging research in the population seen in pain clinics is sparse. A better understanding of the neural activity underlying attentional processes to pain related information compared to healthy controls may help inform diagnosis and management in the future. Blood oxygenation level dependent functional magnetic resonance imaging (BOLD fMRI) compared brain responses in patients with CMSKP (n = 15) and healthy controls (n = 14) while completing a modified Stroop task using pain-related, positive-emotional, and neutral control words. Response times in the Stroop task were no different for CMSKP patients compared with controls, but patients were less accurate in their responses to all word types. BOLD fMRI responses during presentation of pain-related words suggested increases in neural activation in patients compared to controls in regions previously reported as being involved in pain perception and emotion: the anterior cingulate cortex, insula and primary and secondary somatosensory cortex. No fMRI differences were seen between groups in response to positive or control words. Using this modified Stroop tasks, specific differences were identified in brain activity between CMSKP patients and controls in response to pain-related information using fMRI. This provided evidence of differences in the way that pain-related information is processed in those with chronic complex musculoskeletal pain that were not detectable using the behavioural measures of speed and accuracy. The study may be helpful in gaining new insights into the impact of attention in those living with chronic pain.

  10. Dental students\\' satisfaction of applying a combination of lecture and work in small groups compared to applying only lecture: a quasi-experimental study

    Directory of Open Access Journals (Sweden)

    Pouyan Amini Shakib


    Full Text Available Background and Aims: Choosing an appropriate style of teaching-learning by educators is a way to reach high quality education. The objective of this study conducted in Babol Dental School was to compare dental students, satisfaction of teaching theoretical general pathology course by means of a combination of lecture and work in small groups with their satisfaction of teaching the course by means of only lecture. Materials and Methods: This study was performed in the second semester of school year 2011-12 and 2012-13. In 2012 (intervention group, response rate=92%, the teaching of theoretical general pathology course was implemented by means of a combination of lecture and work in small groups, but in 2013 (control group, response rate=81% by means of only lecture. An anonymous self-administered questionnaire was used to assess students, satisfaction of the teaching methods. To compare the mean total score of satisfaction (ranging from 18 through 90 between the two groups, T-test was used. Results: Comparing the mean total scores between the two groups revealed that students, satisfaction of the combined teaching method was significantly higher (P<0.001. The difference of satisfaction between genders (separately for each group was not significant in combination group and lecture group (P=0.63 and P=0.87,   respectively. Conclusion: Regarding learning, combining lecture with other teaching methods such as work in small groups may increase health sciences students' satisfaction. In regard to teaching theoretical general pathology course, our findings could confirm this hypothesis.

  11. Performance Evaluation of Photovoltaic Solar System with Different Cooling Methods and a Bi-Reflector PV System (BRPVS: An Experimental Study and Comparative Analysis

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    Muhammad Adil Khan


    Full Text Available Reducing the price of solar photovoltaic (PV systems has been a constant challenge. Despite recent advances, solar PV systems are still more costly than conventional energy resources. For the first time, this study examines the effectiveness of three different structures/materials: (i silvered glass plane mirror; (ii convex spherical mirrors; and (iii aluminum (Al foil as reflector. Comparative analysis of four different cooling techniques, i.e., water sprinkling system, passive heat sink method, active air fan method, and closed loop method, for enhancement of output power was performed. A novel Bi reflector solar PV system (BRPVS was suggested to control the working of the reflectors. The Al foil enhanced the power output compared to the others. In addition, the effect of using a reflector on the temperature of a solar PV system was studied. High operating temperatures resulted in a decrease in the maximum output power under the same solar radiation conditions. The combined enhancement of the output power by both Al foil BRPVS system and cooling system was almost 22.75–38.55%. An optimal control algorithm to use cooling and BRPVS in an efficient manner is described.


    African Journals Online (AJOL)


    The study of thermal and ventilation parameters, obtained in a transient, laminar solar chimney of reduced dimensions, (1 < m <3) m with a square collector (side = 2m) is presented. Experimental measurements has been made to determine the temperature of the absorber and the fluid in the collector, it is shown that at the ...

  13. A comparative study on the efficacy of 10% hypertonic saline and equal volume of 20% mannitol in the treatment of experimentally induced cerebral edema in adult rats

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    Fang Ming


    Full Text Available Abstract Background Hypertonic saline and mannitol are commonly used in the treatment of cerebral edema and elevated intracranial pressure (ICP at present. In this connection, 10% hypertonic saline (HS alleviates cerebral edema more effectively than the equal volume of 20% mannitol. However, the exact underlying mechanism for this remains obscure. This study aimed to explore the possible mechanism whereby 10% hypertonic saline can ameliorate cerebral edema more effectively than mannitol. Results Adult male Sprague-Dawley (SD rats were subjected to permanent right-sided middle cerebral artery occlusion (MCAO and treated with a continuous intravenous infusion of 10% HS, 20% mannitol or D-[1-3H(N]-mannitol. Brain water content (BWC as analyzed by wet-to-dry ratios in the ischemic hemisphere of SD rats decreased more significantly after 10% HS treatment compared with 20% mannitol. Concentration of serum Na+ and plasma crystal osmotic pressure of the 10% HS group at 2, 6, 12 and 18 h following permanent MCAO increased significantly when compared with 20% mannitol treated group. Moreover, there was negative correlation between the BWC of the ipsilateral ischemic hemisphere and concentration of serum Na+, plasma crystal osmotic pressure and difference value of concentration of serum Na+ and concentration of brain Na+ in ipsilateral ischemic hemisphere in the 10% HS group at the various time points after MCAO. A remarkable finding was the progressive accumulation of mannitol in the ischemic brain tissue. Conclusions We conclude that 10% HS is more effective in alleviating cerebral edema than the equal volume of 20% mannitol. This is because 10% HS contributes to establish a higher osmotic gradient across BBB and, furthermore, the progressive accumulation of mannitol in the ischemic brain tissue counteracts its therapeutic efficacy on cerebral edema.

  14. Higher bioavailability of iron from whole wheat bread compared with iron-fortified white breads in caco-2 cell model: an experimental study. (United States)

    Nikooyeh, Bahareh; Neyestani, Tirang R


    Bread, as the staple food of Iranians, with average per capita consumption of 300 g d -1 , could potentially be a good vehicle for many fortificants, including iron. In this study, iron bioavailability from flat breads (three fortified and one whole wheat unfortified) was investigated using in vitro simulation of gastrointestinal digestion and absorption in a caco-2 cell model. Despite having a lower ferritin/protein ratio in comparison with fortified breads, whole wheat bread showed higher iron bioavailability than the other three types of bread. Assuming iron bioavailability from the ferrous sulfate supplement used as standard was about 10%, the estimated bioavailability of iron from the test breads was calculated as 5.0-8.0%. Whole wheat bread (∼8%), as compared with the fortified breads (∼5-6.5%), had higher iron bioavailability. Iron from unfortified whole wheat bread is more bioavailable than from three types of iron-fortified breads. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  15. Experimental comparative study of the histotoxicity of poly(lactic-co-glycolic acid copolymer and poly(lactic-co-glycolic acid-poly(isoprene blend

    Directory of Open Access Journals (Sweden)

    Jung Ho Kim


    Full Text Available Current treatments of craniosynostosis rely on the application of metal springs for cranial bone deviation. However, those metal springs demand a second surgical procedure for their removal. An attractive alternative would be the substitution of metal for bioresorbable polymers in the composition of the springs. The addition of poly(isoprene, PI, to poly(lactic-co-glycolic acid, PLGA, produces a polymeric blend with partial miscibility and distinct mechanical behavior that may benefit the patient recover. It is necessary to compare the histotoxicity of PLGA/PI to that presented by PLGA. In order to verify the histological behavior of the blend, 46 male Wistar rats (Rattus norvegicus, albino strain underwent implantation of PLGA or PLGA/PI in the skull and were allocated into subgroups by timing of euthanasia (15, 30, 60, or 90 days. After euthanasia, the skull was removed and the histotoxicity was assessed histopathologically. The PLGA/PI blend showed greater histotoxicity in animals euthanized at 60 days, although in this period the histotoxicity of the PLGA/PI blend was similar to that of the PLGA copolymer at 15 days. Despite the instability of histological response, presented in different periods of observation, the results obtained in long-term show that the material has high potential for studies in craniosynostosis treatment.

  16. Traditional and virtual microscopy compared experimentally in a classroom setting. (United States)

    Scoville, Sheila A; Buskirk, Trent D


    The technology known as virtual microscopy is now widely available to medical students. A number of medical school histology and pathology course directors, including those at the Eastern Virginia Medical School, are exploring the question of how best to make use of this new tool. The current study compared the efficacy of teaching and testing one unit of histology, bone and cartilage, using two technologies, namely, virtual microscopy and traditional microscopy. Additionally, the study examined whether low, moderate, high moderate, or high achieving students perform more effectively in any of the learning/testing formats. In a completely randomized block design, 96 first semester, first-year medical students were grouped by previous exam quartiles then subsequently randomly assigned to one of four groups. Using identical laboratory exercises with highly comparable slides for each experimental group, half of the subjects learned the exercise with traditional microscopy and half learned with virtual microscopy. Subjects were further randomly subdivided into virtual or actual testing groups. The authors found no significant differences in test scores when they examined effects by learning group or by testing group, nor were there significant interaction effects. Student performance evaluated by previous exam quartile was significant (P < 0.001). That is, students who had scored in a particular quartile on a previous test tended to score in the same quartile on the bone and cartilage test regardless of learning or testing method. In a short opinion survey, students were polled to evaluate their experience. Student preferences for both learning and testing method varied widely. Copyright 2006 Wiley-Liss, Inc.

  17. Yellow fever virus isolated from a fatal post vaccination event: an experimental comparative study with the 17DD vaccine strain in the Syrian hamster (Mesocricetus auratus

    Directory of Open Access Journals (Sweden)

    Sueli Guerreiro Rodrigues


    Full Text Available In order to investigate the pathogenicity of the virus strain GOI 4191 that was isolated from a fatal adverse event after yellow fever virus (YFV vaccination, an experimental assay using hamsters (Mesocricetus auratus as animal model and YFV 17DD vaccine strain as virus reference was accomplished. The two virus strains were inoculated by intracerebral, intrahepatic and subcutaneous routes. The levels of viremia, antibody response, and aminotransferases were determined in sera; while virus, antigen and histopathological changes were determined in the viscera. No viremia was detected for either strain following infection; the immune response was demonstrated to be more effective to strain GOI 4191; and no significant aminotransferase levels alterations were detected. Strain GOI 4191 was recovered only from the brain of animals inoculated by the IC route. Viral antigens were detected in liver and brain by immunohistochemical assay. Histothological changes in the viscera were characterized by inflammatory infiltrate, hepatocellular necrosis, and viral encephalitis. Histological alterations and detection of viral antigen were observed in the liver of animals inoculated by the intrahepatic route. These findings were similar for both strains used in the experiment; however, significant differences were observed from those results previously reported for wild type YFV strains.

  18. Comparative experimental and theoretical study of the rotational excitation of CO by collision with ortho- and para-D2 molecules. (United States)

    Stoecklin, T; Faure, A; Jankowski, P; Chefdeville, S; Bergeat, A; Naulin, C; Morales, S B; Costes, M


    A joint crossed beam and quantum mechanical investigation of the rotationally inelastic collisions of CO with ortho- and para-D2 molecules is reported. A new 4D potential energy surface (PES) averaged over the ground vibrational states of D2 and CO is used to calculate the rovibrational bound states of the ortho-D2-CO complexes. Close coupling calculations are then performed in the rigid rotor approximation for ortho- and para-D2 colliding with CO for the experimentally investigated transition of CO (j = 0 → 1) and for collision energies ranging from 0.1 to 25 cm-1. The agreement between theory and experiment is found to be very good for both the bound state energies of the ortho-D2-CO complexes and for the inelastic scattering cross-sections showing that the free rotation of two rigid rotors is a very good model of the D2-CO system in this low collision energy domain.

  19. [Comparative analysis between sclera treated with glycerin and sclera treated with gamma irradiation, alkali and glycerin in the reconstruction of anophthalmic socket: experimental study in rabbits]. (United States)

    Fernandes, José Byron Vicente Dias; Matayoshi, Suzana; Osaka, Junko Takano; Tolosa, Erasmo Castro Magalhães; Nunes, Tânia Pereira; Moura, Eurípedes da Mota


    To compare two sclera decontamination methods: treatment with glycerin versus treatment with gamma irradiation, alkali and glycerin, aiming to detect the clinical and histological alterations in rabbit anophthalmic sockets reconstructed with sclera-involved polymethylmethacrylate spheres. Thirty-nine New Zealand-breed rabbits were divided into two groups: group I, whose animals were submitted to enucleation of one eye and reconstruction with a polymethylmethacrylate sphere involved in glycerin-treated sclera; group II, where there was enucleation, and reconstruction performed with a polymethylmethacrylate sphere involved in sclera treated with gamma irradiation, alkali and glycerin. The two groups were observed at four moments, at 7, 21, 42 and 84 days after surgery. Preset times elapsed, the rabbits were euthanized, sockets were exenterated, the material was processed for embedment in paraffin, cut into 5 microm sections thick and stained with hematoxylin-eosin and Masson's trichrome techniques. The scleras were submitted to morphometric and semiquantitative analysis. Results were compared by Mann-Whitney's non-parametric test. Comparative analysis of vascularization of the surgical interface pointed out a significative difference in the evaluation done 21 days after the implant (Pglycerin reacted similarly to the traditionally used glycerin-treated sclera. The two treatments induced a similar inflammatory response. The formation of neovessels, thickness of fibrous capsule and of sclera developed differently in the two groups. Nevertheless, they presented similar results at the end of the 84-day observation period. There was no significant difference between the two groups, with regard to sclera preservation.

  20. Experimental Study Comparing a Traditional Approach to Performance Appraisal Training to a Whole-Brain Training Method at C.B. Fleet Laboratories (United States)

    Selden, Sally; Sherrier, Tom; Wooters, Robert


    The purpose of this study is to examine the effects of a new approach to performance appraisal training. Motivated by split-brain theory and existing studies of cognitive information processing and performance appraisals, this exploratory study examined the effects of a whole-brain approach to training managers for implementing performance…

  1. Comparative in vitro and experimental in vivo studies of the anti-epidermal growth factor receptor antibody nimotuzumab and its aglycosylated form produced in transgenic tobacco plants. (United States)

    Rodríguez, Meilyn; Pérez, Lincidio; Gavilondo, Jorge V; Garrido, Greta; Bequet-Romero, Mónica; Hernández, Ignacio; Huerta, Vivian; Cabrera, Gleysin; Pérez, Marlene; Ramos, Osmani; Leyva, René; León, Mariela; Ramos, Pedro Luis; Triguero, Ada; Hernández, Abel; Sánchez, Belinda; Ayala, Marta; Soto, Jeny; González, Ernesto; Mendoza, Osmani; Tiel, Kenia; Pujol, Merardo


    A broad variety of foreign genes can be expressed in transgenic plants, which offer the opportunity for large-scale production of pharmaceutical proteins, such as therapeutic antibodies. Nimotuzumab is a humanized anti-epidermal growth factor receptor (EGFR) recombinant IgG1 antibody approved in different countries for the treatment of head and neck squamous cell carcinoma, paediatric and adult glioma, and nasopharyngeal and oesophageal cancers. Because the antitumour mechanism of nimotuzumab is mainly attributed to its ability to interrupt the signal transduction cascade triggered by EGF/EGFR interaction, we have hypothesized that an aglycosylated form of this antibody, produced by mutating the N(297) position in the IgG(1) Fc region gene, would have similar biochemical and biological properties as the mammalian-cell-produced glycosylated counterpart. In this paper, we report the production and characterization of an aglycosylated form of nimotuzumab in transgenic tobacco plants. The comparison of the plantibody and nimotuzumab in terms of recognition of human EGFR, effect on tyrosine phosphorylation and proliferation in cells in response to EGF, competition with radiolabelled EGF for EGFR, affinity measurements of Fab fragments, pharmacokinetic and biodistribution behaviours in rats and antitumour effects in nude mice bearing human A431 tumours showed that both antibody forms have very similar in vitro and in vivo properties. Our results support the idea that the production of aglycosylated forms of some therapeutic antibodies in transgenic plants is a feasible approach when facing scaling strategies for anticancer immunoglobulins. © 2012 The Authors Plant Biotechnology Journal © 2012 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.

  2. Histopathological comparative analysis of periimplant bone inflammatory response after dental implant insertion using flap and flapless surgical technique. An experimental study in pigs. (United States)

    Vlahović, Zoran; Marković, Aleksa; Lazić, Zoran; Šćepanović, Miodrag; Đinić, Ana; Kalanović, Milena


    To evaluate by histopathological analysis the peri-implant bone inflammation degree, in certain time intervals (7, 14, 21 and 28 days), following mini-incision flapless and flap implant placement. The experiment was conducted on four domestic pigs. Nine weeks prior to implant insertion, second and third mandibular premolars were extracted. Each animal received six implants in lower jaw. On one randomly chosen side of jaw flapless technique using mini-incision was performed, while on the other side implants were inserted after flap raising. After 7, 14, 21, and 28 days, the experimental animals were sacrificed. Following mandibular resection and decalcification, the samples for histopathological analysis of the peri-implant bone were obtained in the empty implant bed area, from the buccal side of the mandible, adjacent to implant neck region and parallel to crestal edge of implant bed. The degree of inflammatory response of the peri-implant bone was estimated through ordinal scores from 0 to 2. Seven days after the surgery all samples in the flap group had score 2 indicating high inflammation degree, in contrast to lower inflammatory reaction in flapless group. On the 14th and 21st postoperative day decreasing of inflammation degree was noted in all samples of the flapless group (score 1), while in flap group samples presented scores 1 and 2. Twenty-eight days after the implant placement, further reduction of inflammation in the flapless group (33% of samples had score 0) was observed. Flapless technique in comparison to conventional flap procedure minimizes postoperative bone inflammatory reactions. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. compared performances of the experimental digesters of the animal

    African Journals Online (AJOL)


    Jun 30, 2014 ... 80% of the consumption of primary energy is based on fossile fuels and the share is likely to remain high in ... renewable energy producer process, the biomethanisation takes part in the reduction of the ... and energy valorization, this study proposes the evaluation on an experimental scale, on the one hand ...

  4. compared performances of the experimental digesters of the animal

    African Journals Online (AJOL)


    Jun 30, 2014 ... ABSRACT. This study proposes to look further into experimentally of the effect of the variation of certain physicochemical parameters of anaerobic digestion on the quantitative gas productivity of four digesters of treating bovine dejections. Moreover, four digesters supplied with the avicolous droppings, in ...

  5. Ionospheric topside models compared with experimental electron density profiles

    Directory of Open Access Journals (Sweden)

    S. M. Radicella


    Full Text Available Recently an increasing number of topside electron density profiles has been made available to the scientific community on the Internet. These data are important for ionospheric modeling purposes, since the experimental information on the electron density above the ionosphere maximum of ionization is very scarce. The present work compares NeQuick and IRI models with the topside electron density profiles available in the databases of the ISIS2, IK19 and Cosmos 1809 satellites. Experimental electron content from the F2 peak up to satellite height and electron densities at fixed heights above the peak have been compared under a wide range of different conditions. The analysis performed points out the behavior of the models and the improvements needed to be assessed to have a better reproduction of the experimental results. NeQuick topside is a modified Epstein layer, with thickness parameter determined by an empirical relation. It appears that its performance is strongly affected by this parameter, indicating the need for improvements of its formulation. IRI topside is based on Booker's approach to consider two parts with constant height gradients. It appears that this formulation leads to an overestimation of the electron density in the upper part of the profiles, and overestimation of TEC.

  6. Lecture Based Versus peer Assisted Learning: Quasi-Experimental Study to Compare Knowledge Gain of Forth Year Medical Students in Community Health and Nutrition Course

    Directory of Open Access Journals (Sweden)

    Seema Daud


    Conclusion: The present study concludes that in terms of academic achievements, PAL was equally effective to lectures. Therefore, PAL can be incorporated as a supplement to lectures in medical school curricula.

  7. Comparative study on deformation and mechanical behavior of corroded pipe: Part I–Numerical simulation and experimental investigation under impact load

    Directory of Open Access Journals (Sweden)

    Dong-Man Ryu


    Full Text Available Experiments and a numerical simulation were conducted to investigate the deformation and impact behavior of a corroded pipe, as corrosion, fatigue, and collision phenomena frequently occur in subsea pipelines. This study focuses on the deformation of the corrosion region and the variation of the geometry of the pipe under impact loading. The experiments for the impact behavior of the corroded pipe were performed using an impact test apparatus to validate the results of the simulation. In addition, during the simulation, material tests were performed, and the results were applied to the simulation. The ABAQUS explicit finite element analysis program was used to perform numerical simulations for the parametric study, as well as experiment scenarios, to investigate the effects of defects under impact loading. In addition, the modified ASME B31.8 code formula was proposed to define the damage range for the dented pipe.

  8. [Comparative experimental study of the influence of drugs that improve brain metabolism (angiogen, cytoflavin) on neuronal apoptosis and function of cerebral cortex during aging]. (United States)

    Bazhanova, E D; Anisimov, V N; Sukhanov, D S; Teplyĭ, D L


    The safety of cortical neurons and their functional activity is essential for organism at all stages of ontogenesis. However, aging changes leading to an increase in apoptosis level may cause considerable damage to cerebral cortex function, including sensorimotor. We have studied the role of exogenous neurometabolites (angiogen, cytoflavin) in apoptosis regulation and correction of age-related motor and behavioral disturbances. To study the regulation of neuronal morphofunctional activity, we used accelerate-senescent transgenic HER2 mice in comparison to wild type FBV mice. Functional changes in cerebral cortex were studied by the Suok test and open field test, the level of neuronal apoptosis was assessed by TUNEL method, the expression of apoptosis-modulating proteins was detected by immunohistochemistry and Western blotting. We have revealed differences in psycho-emotional and locomotor activity of these strains of mice. In addition, results of our study showed morphological differences: increase in the apoptosis level of cortical neurons in aged FBV type mice, but no changes in aged HER2 mice. The investigated drugs induce cell death of cortical neurons in transgenic mice of both ages and in young wild-type mice by p53-dependent pathway. Increased apoptosis in the cortex of old transgenic mice has important clinical implications, because reduced apoptosis during aging is one of the causes of cancer. The treatment of old wild-type animals reduces elevated neuronal apoptosis, which decreases risk of age neurodegeneration. Thus, revealed morphological changes in the cerebral cortex are the basis for involutional disabilities (including reduced locomotor activity and increased anxiety level). The use of angiogen and cytoflavin treatment improves functional activity of the cortex and protects normal structure of nervous tissue.

  9. Comparative value of clinical, cytological, and histopathological features in feline mammary gland tumors; an experimental model for the study of human breast cancer


    Shafiee, Radmehr; Javanbakht, Javad; Atyabi, Nahid; Bahrami, Alimohammad; Kheradmand, Danial; Safaei, Reyhaneh; Khadivar, Farshid; Hosseini, Ehsan


    Background The diagnosis of breast lesions is usually confirmed by fine-needle aspiration cytology (FNAC) or histological biopsy. Although there is increasing literature regarding the advantages and limitations of both modalities, there is no literature regarding the accuracy of these modalities for diagnosing breast lesions in high-risk patients, who usually have lesions detected by screening. Moreover, few studies have been published regarding the cytopathology of mammary tumors in cats des...

  10. A comparative evaluation of different teaching aids among fourth term medical students to improve the knowledge, attitude and perceptions about pharmacovigilance: An experimental study

    Directory of Open Access Journals (Sweden)

    Harish G. Bagewadi


    Full Text Available Objectives: The Study was designed to assess the awareness of Pharmacovigilance and Adverse Drug Reactions (ADR’s and to evaluate the effectiveness of different teaching aids.Materials and Methods: This was a questionnaire-based pre- and post-test on (KAP Knowledge, Attitude, Perception about pharmacovigilance. Students were given handouts regarding pharmacovigilance and ADR reporting one week before the educational interventions. Fourth term medical students (n=72 participated in the study. They were randomly allocated into group A (n=24, group B (n=24 and group C (n=24. A pre-validated 20-point questionnaire on Pharmacovigilance and Adverse Drug Reactions (ADR’s reporting was distributed to each group of students before the educational intervention to know their awareness. The interactive educational interventions on Pharmacovigilance were given using Overhead projector (OHP and transparencies to group A students, Black board (BB method to group B students, Power point presentation (PPT method to group C students respectively. Theoretical content was the same in all the educational interventions. The chi-square test and one way ANOVA was used for statistical calculation.Results: The overall response rates were expressed as percentages, Mean±SD. The Mean Pre-KAP scores on knowledge was (7.7±0.48 but the total post- KAP scores after (OHP, (BB, and (PPT were (12.1±0.39, (17.4±0.3, (19.4±0.21 respectively. The correct response rates were found to be statistically significant (P<0.001.The feedback from the students was encouraging; handouts before the class were greatly welcomed.Conclusion: The study greatly imparted knowledge about pharmacovigilance and ADR’s reporting and students preferred power point presentations the most.

  11. Comparative value of clinical, cytological, and histopathological features in feline mammary gland tumors; an experimental model for the study of human breast cancer. (United States)

    Shafiee, Radmehr; Javanbakht, Javad; Atyabi, Nahid; Bahrami, Alimohammad; Kheradmand, Danial; Safaei, Reyhaneh; Khadivar, Farshid; Hosseini, Ehsan


    The diagnosis of breast lesions is usually confirmed by fine-needle aspiration cytology (FNAC) or histological biopsy. Although there is increasing literature regarding the advantages and limitations of both modalities, there is no literature regarding the accuracy of these modalities for diagnosing breast lesions in high-risk patients, who usually have lesions detected by screening. Moreover, few studies have been published regarding the cytopathology of mammary tumors in cats despite widespread use of the animal model for breast cancer formation and inhibition. The objective of the present study was to evaluate the diagnostic interest of cytological and histopathological analysis in feline mammary tumours (FMTs), in order to evaluate its possible value as an animal model. The study was performed in 3 female cats submitted to surgical resections of mammary tumours. The mammary tumours were excised by simple mastectomy or regional mastectomy, with or without the superficial inguinal lymph nodes. Female cats were of different breeds (1 siamese and 2 persians). Before surgical excision of the tumour, FNA cytology was performed using a 0.4 mm diameter needle attached to a 8 ml syringe held in a standard metal syringe holder. The cytological sample was smeared onto a glass slide and either air-dried for May-Grünwald-stain and masses were surgically removed, the tumours were grossly examined and tissue samples were fixed in 10%-buffered-formalin and embedded in paraffin. Sections 4 μm thick were obtained from each sample and H&E stained. Cytologically, atypical epithelial cells coupled to giant nucleus, chromatin anomalies, mitotic figures, spindle shape cells, anisocytosis with anisokaryosis and hyperchromasia were found. Histologically, these tumors are characterized by pleomorphic and polygonal cell population together with mitotic figures, necrotic foci and various numbers inflammatory foci. Also, spindle shaped cells, haemorrhage localized in the different

  12. Comparing rainfall features in two experimental basins in brazil (United States)

    das Neves Almeida, Cristiano; Romero Barbosa, Luis; da Silva Freitas, Emerson; Rabelo Coelho, Victor Hugo; de Araújo, José Carlos


    This paper presents a comparison between rainfall data of two experimental basins in Brazil, both located in the Northeast, but in different climate regimes. The first experimental basin is the Guaraíra river, which is in the Paraíba State, in the coastal region, where the average rainfall is about 1.700 mm/year. According to Köpper the climate is tropical with dry summer. The second experimental basin used was the Aiuaba basin, located in the Ceará State, in the semiarid region, where the average rainfall is about 580 mm/year. Both experimental basins belong to the network for hydrology of the semiarid region (REHISA in Portuguese), that was created in Brazil in 2003. The aim of this paper was to analyze only rainfall events named as non-characterized, once the hyetograph does not have a recognizable shape (triangular or rectangular). In order to define the rainfall event the Minimum Intra-event Time (MIT) criteria was used, in this case equal to thirty minutes and six hours, furthermore, the rainfall events with depths less than 1,016 mm were discarded. The studied period for the Guaraíra experimental basin from 2003 to 2014, while to the Aiuaba EB was from 2004 to 2011. The results showed a good relationship between total rainfall data analysed and the yearly rainfall, but Guaraíra EB presented a better agreement, with determination coefficient equal to 0.95, while Aiuaba EB was 0.78 to MIT= 6 hours. Considering the MIT= 30 minutes, the determination coefficient was equal to 0.83 in Guaraíra EB, while Aiuaba EB was 0.89. Differently the relation above, the intensity in Aiuaba EB always is greater than Guaraíra EB, where to MIT=6 hours, the average intensity was 9.6 mm.h-1 and 7.4 mm.h-1, while to MIT=30 min, the average intensity was 4.5 mm.h-1 and 2.3 mm.h-1, respectively. The rainfall intensities were then classified into five different categories (ranging from very light to extreme). Guaraíra EB presented 90% of the rainfall events classified either

  13. Experimental study of snow friction (United States)

    Cohen, Caroline; Canale, Luca; Siria, Alessandro; Quere, David; Bocquet, Lyderic; Clanet, Christophe


    Snow friction results from the interplay of different physical processes: solid friction of granular material, phase change and lubrication, heat transport, capillarity, elasticity and plasticity. The multiple conditions of temperature, humidity and density of the snow result in different regimes of friction. In particular, there is an optimal amount of melted water to lubricate the contact between the ski sole and the snow grains. The thickness of the water layer depends on temperature, speed... A huge variety of waxes have been empirically developed to adapt the amount of water to the conditions of skiing, but remain mysterious. In these study, we investigate experimentally the mechanisms of snow friction at different scales: first, the friction of a ski on snow is measured on a test bench, depending on the snow characteristics and for different waxes. Then microscopic experiments are led in order to understand the friction at the ice crystals scale.

  14. Comparative evaluation of the efficacy of the cyclooxygenase pathway inhibitor and nitric oxide synthase inhibitor in the reduction of alveolar bone loss in ligature induced periodontitis in rats: An experimental study. (United States)

    Jagadish, Rekha; Mehta, Dhoom Singh


    Alveolar bone loss is the most striking feature of periodontal disease. The aim of this study was to investigate the effect of a cyclooxygenase (COX) pathway inhibitor and nitric oxide synthase (NOS) inhibitor in the reduction of alveolar bone loss in an experimental periodontal disease (EPD) model. The study was conducted on 60 Wistar rats divided into three groups of 20 rats each and then subjected to a ligature placement around the left maxillary second molars. Group 1 rats were treated with COX inhibitor (diclofenac sodium 10 mg/kg/d), group 2 with NOS inhibitor (aminoguanidine hydrochloride 10 mg/kg/d) and group 3 served as controls, receiving only saline, intraperitoneally 1h before EPD induction and daily until the sacrifice on the 11(th) day. Leukogram was performed before ligation, at 6 h and at the first, seventh and 11(th) days after EPD induction. After sacrifice, all the excised maxillae were subjected to morphometric and histometric analysis to measure the alveolar bone loss. Histopathological analysis was carried out to estimate cell influx, alveolar bone and cementum integrity. Induction of experimental periodontitis in the rat model produced pronounced leucocytosis, which was significantly reduced by the administration of diclofenac sodium and aminoguanidine on the 11(th) day. In morphometric and histometric examinations, both the test drugs significantly (P < 0.05) inhibited the alveolar bone loss as compared with the control group. Both COX inhibitor and NOS inhibitor are equally effective in inhibiting the inflammatory bone resorption in an experimental periodontitis model.

  15. Therapeutic trial in experimental tegumentary leishmaniasis caused by Leishmania (Leishmania amazonensis. A comparative study between mefloquine and aminosidine Ensaio terapêutico na leishmaniose tegumentar experimental causada por Leishmania (Leishmania amazonensis. Um estudo comparativo entre mefloquina e aminosidine

    Directory of Open Access Journals (Sweden)

    Letícia Oba Galvão


    Full Text Available One hundred and eighty-two male inbred C57/BL/6 mice were infected with 3 x 106 Leishmania (Leishmania amazonensis promastigotes of the MHOM/BR/PH8 strain by means of a subcutaneous injection in the right ear. The animals were separated in three groups: 1 oral mefloquine hydrochloride treatment (16mg/kg/day/10 days, 2 intramuscular aminosidine (Paromomycin® treatment (20mg/kg/20 days and 3 control. Twenty six mice of each treated group were sacrificed, one at the end of treatment (nine weeks after inoculation, and one six weeks later (fifteen weeks after inoculation. Control Group animals were sacrificed at weeks six, nine and fifteen after inoculation. There was no significant difference between Group 1 (mefloquine and Group 3 (control subjects. Group 2 animals (aminosidine presented the smallest differences of all, both at the end of the treatment and six weeks later. The histopato-logical parameters have shown the following findings: a there was no significant difference between the mefloquine treated group and the control group; the group treated with aminosidine showed fewer of vacuolated macrophages than the control group, at week 9 (end of treatment. b both at the end of treatment and six weeks later, evaluation of tissue necrosis and tissue fibrosis revealed no differences between the treated groups. It was found that six weeks after the end of treatment, mice in the control group presented significantly more severe degrees of fibrosis than mice in the other groups. It can be concluded that mefloquine showed limited therapeutic effect in this experimental model, whereas aminosidine had a significant effect. Nevertheless, neither of them resulted in cure of the lesions.Foram utilizados 182 camundongos machos, isogênicos, da linhagem C57BL/6 inoculados na orelha direita com 3,0 x 10(6 formas promastigotas da cepa MHOM/BR/PH8 de Leishmania (Leishmania amazonensis. Os animais foram separados em três grupos: 1 52 animais tratados com

  16. Experimental Infrasound Studies in Nevada (United States)

    Herrin, E. T.; Negraru, P. T.; Golden, P.; Williams, A.


    An experimental propagation study was carried out in Nevada in June 2009 on Julian days 173-177. During this field experiment we deployed 16 single channel digital infrasound recorders to monitor the munitions disposal activities near Hawthorne, NV. The sensors were deployed in a single line and placed approximately 12 km apart at distances ranging from 2 to 177 km. A four element semi-permanent infrasound array named FNIAR was installed approximately 154 km north of the detonation site in line with the individual temporary recorders. Tropospheric arrivals were observed during all days of the experiment, but during day 176 the observed arrivals had very large amplitudes. A large signal was observed at 58 km from the detonation site with amplitude as large as 4 Pascals, while at 94 km no signal was observed. At FNIAR the amplitude of the tropospheric arrival was 1 Pascal. During this day meteorological data acquired in the propagation path showed a strong jet stream to the north. On day 177 we were not able to identify tropospheric arrivals beyond 34 km, but at stations beyond 152 km we observed stratospheric arrivals. Continuous monitoring of these signals at FNIAR shows that stratospheric arrivals are the most numerous. In a two month period, from 06/15/2009 to 08/15/2009 there were 35 operational days at the Hawthorne disposal facility resulting in 212 explosions with known origin times. Based on the celerity values there were 115 explosions that have only stratospheric arrivals (celerities of 300-275 m/s), 72 explosions with both tropospheric (celerities above 330 m/s) and stratospheric arrivals, 20 explosions that were not detected and five explosions that have only tropospheric arrivals.

  17. Experimental Study on Permeability of Concrete (United States)

    Yang, Honglu; Liu, Rentai; Zheng, Zhuo; Liu, Haojie; Gao, Yan; Liu, Yankai


    To study the influencing factors on permeability of pervious concrete, by adding inorganic organic composite materials obtained experimental results show that different aggregate size, aggregate cement ratio of different, different water cement ratio on the permeability performance. The permeability of the concrete was tested by using the self - made permeable device. The experimental results showed that the permeation coefficient of the experiment was obtained and the factors influencing the permeability of the concrete were compared and analyzed. At the same time, the porosity of pervious concrete was measured, the influence of various variables on porosity was studied, and the influence of various factors on the permeability of voids was found. Finally, through comprehensive analysis of a variety of factors, the optimal water cement ratio is 0.28. At this time, the pervious performance of concrete is optimal.


    Directory of Open Access Journals (Sweden)

    Y. M’Sadak


    Full Text Available This study proposes to look further into experimentally of the effect of the variation of certain physicochemical parameters of anaerobic digestion on the quantitative gas productivity of four digesters of treating bovine dejections. Moreover, four digesters supplied with the avicolous droppings, in different concentrations of Dry Matter (DM, were followed. The assessments of depollution (Suspended Matter and Biological Demand for Oxygen together with qualitative energy (gas composition and calorific value were also appreciated. We can release particularly that: the quantity of bovine biogas produced is variable according to the parameters of digestion. It is maximum in the presence of high temperature and under mechanical agitation of the substrate introduced; the quantitative productivity is more interesting in the case of the digesters avicolous. It is more important with the increase of the concentration of solids; the digester with 8% DM presents attractive valuations of depollution and energy efficiency.


    Directory of Open Access Journals (Sweden)

    Y. M’Sadak


    Full Text Available This study proposes to look further into experimentally of the effect of the variation of certain physicochemical parameters of anaerobic digestion on the quantitative gas productivity of four digesters of treating bovine dejections. Moreover, four digesters supplied with the avicolous droppings, in different concentrations of Dry Matter (DM, were followed. The assessments of depollution (Suspended Matter and Biological Demand for Oxygen together with qualitative energy (gas composition and calorific value were also appreciated. We can release particularly that: the quantity of bovine biogas produced is variable according to the parameters of digestion. It is maximum in the presence of high temperature and under mechanical agitation of the substrate introduced; the quantitative productivity is more interesting in the case of the digesters avicolous. It is more important with the increase of the concentration of solids; the digester with 8% DM presents attractive valuations of depollution and energy efficiency.


    African Journals Online (AJOL)


    climatic conditions are favorable for the development of solar chimneys for the production of electrical energy or the drying of agro-food products. 1.1 Experimental models. The first prototype tower was built in Manzanares in. 1981, thanks to the team of Professor Schlaich, Haaf et al., (1983); Haaf et al., (1984), in Spain.

  1. Comparative evaluation of the efficacy of the cyclooxygenase pathway inhibitor and nitric oxide synthase inhibitor in the reduction of alveolar bone loss in ligature induced periodontitis in rats: An experimental study

    Directory of Open Access Journals (Sweden)

    Rekha Jagadish


    Full Text Available Background: Alveolar bone loss is the most striking feature of periodontal disease. The aim of this study was to investigate the effect of a cyclooxygenase (COX pathway inhibitor and nitric oxide synthase (NOS inhibitor in the reduction of alveolar bone loss in an experimental periodontal disease (EPD model. Materials and Methods: The study was conducted on 60 Wistar rats divided into three groups of 20 rats each and then subjected to a ligature placement around the left maxillary second molars. Group 1 rats were treated with COX inhibitor (diclofenac sodium 10 mg/kg/d, group 2 with NOS inhibitor (aminoguanidine hydrochloride 10 mg/kg/d and group 3 served as controls, receiving only saline, intraperitoneally 1h before EPD induction and daily until the sacrifice on the 11 th day. Leukogram was performed before ligation, at 6 h and at the first, seventh and 11 th days after EPD induction. After sacrifice, all the excised maxillae were subjected to morphometric and histometric analysis to measure the alveolar bone loss. Histopathological analysis was carried out to estimate cell influx, alveolar bone and cementum integrity. Results: Induction of experimental periodontitis in the rat model produced pronounced leucocytosis, which was significantly reduced by the administration of diclofenac sodium and aminoguanidine on the 11 th day. In morphometric and histometric examinations, both the test drugs significantly (P < 0.05 inhibited the alveolar bone loss as compared with the control group. Conclusion: Both COX inhibitor and NOS inhibitor are equally effective in inhibiting the inflammatory bone resorption in an experimental periodontitis model.

  2. Comparing TCV experimental VDE responses with DINA code simulations

    Energy Technology Data Exchange (ETDEWEB)

    Favez, J.Y.; Khayrutdinov, J.B.; Lister, J.B.; Lukash, V.E


    The DINA free-boundary equilibrium simulation code has been implemented for TCV, including the full TCV feedback and diagnostic systems. First results showed good agreement with control coil perturbations and correctly reproduced certain non-linear features in the experimental measurements. The latest DINA code simulations, presented in this paper, exploit discharges with different cross- sectional shapes and different vertical instability growth rates which were subjected to controlled Vertical Displacement Events, extending previous work with the DINA code on the DIII-D tokamak. The height of the TCV vessel allows observation of the non- linear evolution of the VDE growth rate as regions of different vertical field decay index are crossed. The vertical movement of the plasma is found to be well modelled. For most experiments, DINA reproduces the S-shape of the vertical displacement in TCV with excellent precision. This behaviour cannot be modelled using linear time-independent models because of the predominant exponential shape due to the unstable pole of any linear time-independent model. The other most common equilibrium parameters like the plasma current Ip, the elongation K, the triangularity d, the safety factor q, the ratio between the averaged plasma kinetic pressure and the pressure of the poloidal magnetic field at the edge of the plasma bp and the internal self inductance l also show acceptable agreement. The evolution of the growth rate g is estimated and compared with the evolution of the closed loop growth rate calculated with the RZIP linear model, confirming the origin of the observed behaviour. (author)


    Directory of Open Access Journals (Sweden)

    Cuzdriorean Dan Dacian


    Full Text Available This empirical study extends the study conducted by Vladu, Grosanu and Cuzdriorean (2012 and reached similar conclusions. This particular research was conducted with the scope of assessing the impact of: positive bias, persuasive language, creative visual manipulation and performance comparisons over the unsophisticated users of accounting opinion. We have chosen this particular category since retail investors have been identified as relying on the information provided in corporate annual reports for decision making (Wills, 2008. Based on their relative inexperience and limited knowledge of these investors it is plausible that they can be mislead easily comparing to more sophisticated users of accounting information, as financial analysts. The main argument for conducting such a research is the fact that little research was conducted so far and the effects of creative disclosure on investment decision cannot be assessed so far. Based on this, we conducted a laboratory experiment where participants where provided with an informational set of financial data and required to make an investment decision. Our results document that the users perceptions is strongly affected by creative disclosure, contradictory with previous results documented in the literature, that their opinion cannot be influenced since they relay mostly on numerical information and less on the narrative segments of the financial statements. Even if our sample compressed few participants, we consider the results conclusive. A further research can extend the sample and test if our research hypothesis can be validated. Another possible spring of research can deal with the assessing of the opinion of the users of accounting information that are not considered unsophisticated, as financial analysts.

  4. Comparative bone marrow responses of albino rats experimentally ...

    African Journals Online (AJOL)

    It involved laboratory based experimental infection of albino rats as research models. A total of 32 adult albino rats of mixed sexes were used for this investigation. The rats were randomly grouped into three groups, A, B, C made up of 8 rats each, and infected with T. congolense, T brucei and mixed infection of these species ...


    Directory of Open Access Journals (Sweden)

    O. M. Ustarkhanov


    Full Text Available The paper deals a new structural solution of reinforced glued wooden beam and results ofexperimental studies of the bearing capacity of reinforced beams in a special way. We presentthedesign parameters ofprototypebeams, description ofthe experimental setup, results of experimental studies and comparative analysis ofthe stresses anddeflectionsdepending on how the pinching inclined armature.

  6. Comparing Brief Experimental Analysis and Teacher Judgment for Selecting Early Reading Interventions (United States)

    Wagner, Dana L.; Coolong-Chaffin, Melissa; Deris, Aaron R.


    The purpose of this study was to examine the use of brief experimental analysis (BEA) to identify early reading interventions for students in the primary grades and to compare teachers' judgments about their students' early reading intervention needs to BEA results. In addition, the research was conducted to explore how teachers make decisions…

  7. Organ models in wound ballistics: experimental study. (United States)

    Ozer, Mustafa Tahir; Oğünç, Gökhan; Eryilmaz, Mehmet; Yiğit, Taner; Menteş, Mustafa Oner; Dakak, Mehmet; Uzar, Ali Ihsan; Oner, Köksal


    Effects of various types and diameters of guns and related treatment principles are different. Our study was performed to experimentally demonstrate the effects of different gunshots in body tissues. 9x19 mm hand-gun and 7.62x51 mm G-3 infantry rifle were used in the study. Injury models were created through hand-gun and rifle shootings at isolated soft tissue, lower extremity, liver and intestine tissue simulants made of ballistic candle. High-speed cameras were used to capture 1000 frames per second. Images were examined and wound mechanisms were evaluated. It was observed that the colon content distributed more within the surrounding tissues by the rifle shootings comparing with hand-gun shootings and could be an infection source due to the large size of the cavity in the colon. Especially when the bullets hitting the bone were investigated, it was seen that much more tissue injury occurs with high speed bullets due to bullet deformation and fragmentation. However, no significant difference was found between the effect of hand-gun and rifle bullets passing through the extremity without hitting the bone. To know the type of the gun that caused the injury and its characteristics will allow to estimate severity and size of the injury before the treatment and to focus on different alternatives of treatment. Therefore, use of appropriate models is required in experimental studies.

  8. Sodium lactate improves renal microvascular thrombosis compared to sodium bicarbonate and 0.9% NaCl in a porcine model of endotoxic shock: an experimental randomized open label controlled study. (United States)

    Duburcq, Thibault; Durand, Arthur; Tournoys, Antoine; Gnemmi, Viviane; Gmyr, Valery; Pattou, François; Jourdain, Mercedes; Tamion, Fabienne; Besnier, Emmanuel; Préau, Sebastien; Parmentier-Decrucq, Erika; Mathieu, Daniel; Poissy, Julien; Favory, Raphaël


    Sodium lactate seemed to improve fluid balance and avoid fluid overload. The objective of this study was to determine if these beneficial effects can be at least partly explained by an improvement in disseminated intravascular coagulation (DIC)-associated renal microvascular thrombosis. Ancillary work of an interventional randomized open label controlled experimental study. Fifteen female "Large White" pigs (2 months old) were challenged with intravenous infusion of E. coli endotoxin. Three groups of five animals were randomly assigned to receive different fluids: a treatment group received sodium lactate 11.2% (SL group); an isotonic control group received 0.9% NaCl (NC group); a hypertonic control group, with the same amount of osmoles and sodium than SL group, received sodium bicarbonate 8.4% (SB group). Glomerular filtration rate (GFR) markers, coagulation and inflammation parameters were measured over a 5-h period. Immediately after euthanasia, kidneys were withdrawn for histological study. Statistical analysis was performed with nonparametric tests and the Dunn correction for multiple comparisons. A p < 0.05 was considered significant. The direct immunofluorescence study revealed that the percentage of capillary sections thrombosed in glomerulus were significantly lesser in SL group [5 (0-28) %] compared to NC [64 (43-79) %, p = 0.01] and SB [64 (43-79), p = 0.03] groups. Alterations in platelet count and fibrinogen level occurred earlier and were significantly more pronounced in both control groups compared to SL group (p < 0.05 at 210 and 300 min). The increase in thrombin-antithrombin complexes was significantly higher in NC [754 (367-945) μg/mL; p = 0.03] and SB [463 (249-592) μg/mL; p = 0.03] groups than in SL group [176 (37-265) μg/mL]. At the end of the experiment, creatinine clearance was significantly higher in SL group [55.46 (30.07-67.85) mL/min] compared to NC group [1.52 (0.17-27.67) mL/min, p = 0.03]. In this study, we

  9. Experimental studies of neutrino oscillations

    CERN Document Server

    Kajita, Takaaki


    The 2015 Nobel Prize in physics has been awarded to Takaaki Kajita and Arthur McDonald "for the discovery of neutrino oscillations, which shows that neutrinos have mass". Takaaki Kajita of Tokyo University is a Japanese physicist, known for neutrino experiments at the Kamiokande and its successor, Super-Kamiokande. This volume of collected works of Kajita on neutrino oscillations provides a good glimpse into as well as a record of the rise and the role of Asian research in the frontiers of neutrino physics. Japan is now a major force in the study of the 3 families of neutrinos. Much remains to be done to clarify the Dirac vs. Majorana nature of the neutrino, and the cosmological implications of the neutrino. The collected works of Kajita and his Super-Kamiokande group will leave an indelible foot-print in the history of big and better science.

  10. An experimental double-blind irradiation study of a novel topical product (TPF 50) compared to other topical products with DNA repair enzymes, antioxidants, and growth factors with sunscreens: implications for preventing skin aging and cancer. (United States)

    Emanuele, Enzo; Spencer, James M; Braun, Martin


    The exposure to ultraviolet radiation (UVR) is a major risk factor for skin aging and the development of non-melanoma skin cancer (NMSC). Although traditional sunscreens remain the mainstay for the prevention of UVR-induced skin damage, they cannot ensure a complete protection against the whole spectrum of molecular lesions associated with UVR exposure. The formation of helix-distorting photoproducts such as cyclobutane pyrimidine dimers (CPD), as well as oxidative damage to DNA bases, including the formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8OHdG) are among the key DNA lesions associated with photoaging and tumorigenesis. Besides DNA lesions, UVR-induced formation of free radicals can result in protein carbonylation (PC), a major form of irreversible protein damage that inactivates their biological function. This study compares a complex novel topical product (TPF50) consisting of three actives, ie, 1) traditional physical sunscreens (SPF 50), 2) a liposome-encapsulated DNA repair enzymes complex (photolyase, endonuclease, and 8-oxoguanine glycosylase [OGG1]), and 3) a potent antioxidant complex (carnosine, arazine, ergothionine) to existing products. Specifically, we assessed the ability of TFP50 vs those of DNA repair and antioxidant and growth factor topical products used with SPF 50 sunscreens in preventing CPD, 8OHdG, and PC formation in human skin biopsies after experimental irradiations. In head-to-head comparison studies, TPF50 showed the best efficacy in reducing all of the three molecular markers. The results indicated that the three TPF50 components had a synergistic effect in reducing CPD and PC, but not 8OHdG. Taken together, our results indicate that TPF50 improves the genomic and proteomic integrity of skin cells after repeated exposure to UVR, ultimately reducing the risk of skin aging and NMSC.

  11. Strategies for comparing LES and experimental data of urban turbulence (United States)

    Hertwig, D.; Nguyen van yen, R.; Patnaik, G.; Leitl, B.


    Unsteady flow within and above built environments is an important example of the complex nature of near-surface atmospheric turbulence. Typically, obstacle-resolving micro-scale meteorological models based on the Reynolds-averaged conservation equations are adopted to investigate and predict the mean-states of urban flow phenomena. The rapid advancements in computer capacities, however, fostered the use of time-resolved approaches like large-eddy simulation (LES) for applications on the urban micro-scale. LES has the potential to provide a realistic picture of the spatio-temporal behavior of turbulent flows within and above the urban canopy layer, which cannot be easily achieved with classic in-situ micro-meteorological measurements. The further success of eddy-resolving techniques, however, is coupled to the critical assessment of the model performance in terms of a rigorous validation against suitable reference data. This task is particularly challenging with regard to the time-dependent nature of the problem and the need to verify whether the model predicts turbulence structures in a realistic way. In this study, a hierarchy of validation strategies for urban LES flow fields is formulated and systematically applied. The test case is neutrally stratified turbulent flow in the inner city of Hamburg, Germany. The LES computations were conducted by the U.S. Naval Research Laboratory on the basis of a monotone integrated LES methodology. Reference experiments in terms of single-point, high resolution time-series measurements were carried out in the boundary-layer wind-tunnel facility at the University of Hamburg. The wind-tunnel model was built on a scale of 1:350 and included building structures with a full-scale spatial resolution of 0.5 m. Benchmark parameters for the congruent representation of atmospheric inflow conditions in the physical and the numerical model were obtained from long-term sonic anemometer measurements at a suburban meteorological field site

  12. Comments on SEE: Comparative Advantages and and Experimental Consequences (United States)

    Smalley, Larry L.


    The Satellite Energy Exchange experiment measures the periodic, near-miss encounters between a sheppard satellite and a small test body (satellite) in approximately the same orbit about a primary. Several important experimental requirements have been chosen to enhance capabilities: (a) The satellite be flown in a sun-synchronous orbit at an altitude of about 1350 Km, (b) Passive temperature system stabilized by spacecraft axial rotation with sunshade baffles at the end of the spacecraft, (c) Test bodies with different material composition be available for experiments, (d) The containment spacecraft fly about the sheppard mass in a zero-g environment whereas the test bodies, experience average zero-g environment over an orbital period, (e) Primary attitude and station-keeping uses magnetic field alignment plus micro-Newton thrusters such as Field Emission Electric Propulsion, and (f) Very low power (nW) laser tracking systems minimize impulse delivered to test bodies. With the above conditions, SEE has the capabilities: (1) Long duration (several years life-time) flight experiment (2) Long-term, active (with historical time record), self-calibration of satellite mass distribution (capsule geodesy) over lifetime of the spacecraft. (3) Novel passive thermal stabilization systems designed to attain cryogenic temperatures around 78K. (4) Novel spacecraft stabilization systems. (5) Ability to measure G to 1 part in 10(exp 6-7) depending on ultimate duration of experiment. (6) Ability to place limits on both temporal and spacial variations on G. (7) Ability to set experimental limits on the Post Newtonian parameters (PPN) alpha(2) and zeta(2). (8) Ability to measure (or place limits on) the non Einsteinian eccentricity of the Earth-Sun system (and the parameter alpha(1)) for long duration flight. (9) Ability to measure Delta((dot)-G)/G to 1 part in 10(exp 12-13). The MiniSTEP, competes in a limited way with Project SEE. It is designed to improve the measurement of the

  13. Sex work: a comparative study. (United States)

    McCarthy, Bill; Benoit, Cecilia; Jansson, Mikael


    Explanations of adult involvement in sex work typically adopt one of two approaches. One perspective highlights a variety of negative experiences in childhood and adolescence, including physical and sexual abuse, family instability, poverty, associations with "pimps" and other exploiters, homelessness, and drug use. An alternative account recognizes that some of these factors may be involved, but underscores the contribution of more immediate circumstances, such as current economic needs, human capital, and employment opportunities. Prior research offers a limited assessment of these contrasting claims: most studies have focused exclusively on people working in the sex industry and they have not assessed the independent effects of life course variables central to these two perspectives. We add to this literature with an analysis that drew on insights from life course and life-span development theories and considered the contributions of factors from childhood, adolescence, and adulthood. Our comparative approach examined predictors of employment in sex work relative to two other low-income service or care work occupations: food and beverage serving and barbering and hairstyling. Using data from a study of almost 600 workers from two cities, one in Canada and the other in the United States, we found that both immediate circumstances and negative experiences from early life are related to current sex work involvement: childhood poverty, abuse, and family instability were independently associated with adult sex work, as were limited education and employment experience, adult drug use, and marital status.

  14. Experimental Studies on the Hypolipidemic and Haematological ...

    African Journals Online (AJOL)



    Jan 14, 2011 ... Experimental Studies on the Hypolipidemic and. Haematological Properties of Aqueous ... lipid and haematological profile of serum and blood samples collected were determined respectively. Results: Treatment with simvastatin (10 ..... pathway for cholesterol homeostasis. Science. (Washington, DC) 1986 ...

  15. The Mechanisms of Pharmacological Preconditioning of the Brain and the Comparative Efficacy of the Drugs — Direct- and Indirect-Acting Glycogen Synthase Kinase-3β Inhibitors: Experimental Study

    Directory of Open Access Journals (Sweden)

    V. V. Likhvantsev


    Full Text Available Objective: to investigate the activity of sevoflurane, dalargin, and lithium chloride in protecting the rat brain from total ischemia/reperfusion and to define whether the GSK=3^ deposphorylation contributes to the mechanism of pharmacological preconditioning. Materials and methods. Experiments were carried out on 80 male albino rats in which temporary circulatory arrest (CA was simulated by ligating the cardiovascular fascicle for 10 and 20 minutes. The animals were revived by mechanical ventilation external cardiac massage, and the intratracheal injection of adrenaline (epinephrine, Moscow Endocrinology Plant at a dose of 0.1 mg/kg. Animals were divided into 9 groups and sevorane (sevoflurane, Abbott Laboratories, dalargin (Microgen Research-and-Production Association, or lithium chloride (Sigma Chemical Co. were separately given with and without CA. Brain tissue homogenate specimens were obtained from euthanized animals. The concentration of total glycogen synthase kinase-3^ (GSK-3^ was colorimetrically determined using a Hitachi-557 spectrophotometer (Hitachi Ltd., Japan. The content of phosphorylated GSK-3/3 (pGSK-3^ in brain homogenate was estimated by Western blotting. Results. The total level of GSK-3^ in each group was similar (80—90 relative units and remained unchanged throughout each experiment. Twenty-minute ischemia maximally activated GSK-30 through dephosphorylation. Ten-minute ischemia elevated pGSK-3^ levels by more than 5 times as compared to the baseline value revealing the «training» effect. The quantity of pGSK-3^ was unchanged in the ischemia/perfusion group during sevoflurane insufflation and was decreased by 27% during dalargin administration. Conclusion. The experimental model of total ischemia provided evidence that the test drugs had a pharmacological preconditioning effect on brain neurons. According to their increasing effect, the drugs were arranged in the following order: dalargin < sevoflurane < lithium

  16. An experimental study of passive regenerator geometries

    DEFF Research Database (Denmark)

    Engelbrecht, Kurt; Nielsen, Kaspar Kirstein; Pryds, Nini


    experimental uncertainty associated with magnetocaloric material properties, all regenerators are made of aluminum. The performance of corrugated plates and dimpled plates are compared to traditional flat plate regenerators for a range of cycle times and utilizations. Each regenerator is built using 18...

  17. Experimental models of congenital hydrocephalus and comparable clinical problems in the fetal and neonatal periods. (United States)

    Oi, S; Yamada, H; Sato, O; Matsumoto, S


    Morphological and developmental changes of the ventricular system are analyzed in three major experimental models of congenital hydrocephalus in the rat: 6-aminonicotinamide (6-AN)-induced and LEW/Jms and HTX mutant hydrocephalus. The clinically comparable forms of hydrocephalus and problems occurring during each period of intrauterine hydrocephalus are then discussed. Comparative morphological study revealed that 6-AN-induced hydrocephalus was comparable to the Dandy-Walker syndrome and that the critical period regarding this syndrome in fetal life was at the time of "legal termination". The LEW/Jms and HTX mutant models were identical with regard to the form of progressive hydrocephalus in the postnatal period, but the condition underlying the hydrocephalus during the fetal period differed. The LEW/Jms model was comparable to primary congenital aqueductal stenosis (aqueductal agenesis), and the hydrocephalic state appeared in the period of "intrauterine preservation" before pulmonary maturation was completed. On the other hand, the HTX fetuses demonstrated secondary change of the aqueduct in the perinatal period, although the model was considered to be of congenital communicating hydrocephalus. Cerebrospinal fluid (CSF) dynamics studied in the fetuses with 6-AN-induced hydrocephalus disclosed considerable pathophysiology comparable to "hydromyelic hydrocephalus." The historical trends of animal experimental models of congenital hydrocephalus are reviewed and comparable clinical problems suggested by those models discussed further.

  18. Experimental Study of Alluvial Fan Formation (United States)

    Delorme, P.; Devauchelle, O.; Barrier, L.; Métivier, F.


    At the outlet of mountain ranges, rivers flow onto flatter lowlands. The associated change of slope causes sediment deposition. As the river is free to move laterally, it builds conical sedimentary structures called alluvial fans. Their location at the interface between erosional and depositional areas makes them valuable sedimentary archives. To decipher these sedimentary records, we need to understand the dynamics of their growth. Most natural fans are built by braided streams. However, to avoid the complexity of braided rivers, we develop a small-scale experiment in which an alluvial fan is formed by a single channel. We use a mixture of water and glycerol to produce a laminar river. The fluid is mixed with corindon sand (~ 300 μm) in a tilted channel and left free to form a fan around its outlet. The sediment and water discharges are constant during an experimental run. We record the fan progradation and the channel morphology with top-view pictures. We also generate an elevation map with an optical method based on the deformation of a moiré pattern. We observe that, to leading order, the fan remains self-affine as it grows, with a constant slope. We compare two recent studies about the formation of one-dimensionnal fan [Guerit et al. 2014] and threshold rivers [Seizilles et al. 2013] to our experimental findings. In particular, we propose a theory witch relates the fan morphology to the control parameters ( fluid and sediment discharges, grain size). Our observation accord with the predictions, suggesting that the fan is built near the threshold of sediment motion. Finally, we intend to expand our interpretation to alluvial fans build by single-thread channels ( Okavango, Bostwana; Taquari and Paraguay, Brasil; Pastaza, Peru).

  19. Experimental studies of herbicide drift characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Renne, D.S.; Wolf, M.A.


    A knowledge of the drift characteristics of herbicides and pesticides released from ground and aerial rigs is important in forestry and agricultural applications so that methods for minimizing damage to downwind systems sensitive to these chamicals can be developed. A field experiment was undertaken on the Hanford Reservation in eastern Washington State during 1975 to study techniques for maximizing herbicide applications from a spray airplane on the intended area and minimizing drift. Several early morning experiments comparing drift characteristics of a fixed with a test application for various nozzle systems and herbicide concentrations were made. The results of these experiments have shown that the initial drift and drift deposit components varied by only a factor of two or so, depending on the production of smaller droplets, as various techniques were used to put the herbicides down from the aircraft. Meteorological conditions become increasingly important at greater downwind distances from the source. Furthermore, drift reduction was most effective under conditions of high relative humidities and cool temperatures. At large distances from the source, ground level drift was higher on stable than on unstable days. Comments on methods for improving the experimental design, and applications of studies such as these to forestry will be made.


    African Journals Online (AJOL)


    Jun 30, 2010 ... could supply enough hydrogen to operate a fuel cell vehicle. In our study [23] an experimental study is done in the Center of Development of the Renewable Energy,. Algiers, Algeria; hydrogen is produced using a Proton Exchange Membrane (PEM) electrolyser supplied by PV panel; when an electric ...

  1. Comparative Study of Prestress Losses

    Directory of Open Access Journals (Sweden)

    M. Boukendakdji


    Full Text Available This paper compares the prestress losses as calculated by four different design codes; British standard CP110, Comite Europeen du Beton 70 and 78, American Concrete Institute 77 and the Prestressed Concrete Institute method (PCI. The comparison is done by determining the total losses which take place in a rectangular prestressed concrete beam for both pre-tensioning and post-tensioning systems. The results show that total losses calculated for the post-tensioning method are higher than those calculated for the pre-tensioning method, which is not the usual case. It seems that the PCI method may be required for special structures or for simply supported slender members which may be sensitive to small changes in deflections. However, for non-special structures, or where actual losses have little effect on the design, it is better to compute losses by the ACI method because it is simple and does take into considerations interactions between the various sources of losses. However, it is not possible to conclude which method gives the more accurate prediction of shrinkage and creep without direct co-relation to realistic insitu data.

  2. Benchmarked Library Websites Comparative Study

    KAUST Repository

    Ramli, Rindra M.


    This presentation provides an analysis of services provided by the benchmarked library websites. The exploratory study includes comparison of these websites against a list of criterion and presents a list of services that are most commonly deployed by the selected websites. In addition to that, the investigators proposed a list of services that could be provided via the KAUST library website.


    Directory of Open Access Journals (Sweden)

    Gavrea Corina


    Full Text Available Corporate governance is a key element of today’s economic reality being more and more present in many countries around the world. This paper has two main objectives. The first one is to offer more insight into the concept of corporate governance by a thorough literature review and by presenting and analyzing a framework of corporate governance. The second objective of this paper is to investigate the corporate governance situation in three developing economies (Romania, Bulgaria and Hungary. The World Bank and the European Bank for Reconstruction and Development published a series of reports on corporate governance. The present study uses data from these reports in order to illustrate how these developing economies are dealing with corporate governance. Based on ROSC Reports a corporate governance score was calculated. As this score shows, there is room for improvement for all three developing economies. This study is important because it shows the differences in corporate governance among developing economies and the need to study these nations at the individual country level. Corporate governance has many benefits for developing economies. It helps developing economies to register sustainable growth rates, to increases investors’ confidence in the national economy, and to increase the ability of capital markets to mobilize savings.

  4. Biodiversity and Complexity Influence Seagrass Functioning: A Comparative-Experimental Approach Across the Northern Hemisphere (United States)

    Reynolds, P. L.


    Coastal ecosystems are mediated by interactions between resource supply, consumer pressure, and community composition, with the balance shifting along environmental gradients. Comparative-experimental approaches, including observational and experimental networks, are a promising way forward to organizing this complexity into predictive models and to quantify the role of biodiversity on ocean processes. Through the Zostera Experimental Network we utilize this approach to study the community ecology of eelgrass (Zostera marina), the most widespread marine plant and foundation of important but threatened coastal ecosystems throughout the northern hemisphere. In 2014, parallel field surveys and experiments were conducted at 50 field sites to measure correlations between mesograzer species diversity, eelgrass genetic diversity, predation pressure, and seagrass dynamics. Biodiversity was positively correlated with plant and grazer biomass across sites. Predation pressure in these systems decreased with grazer biomass and latitude. In subsequent experiments in 2015, habitat complexity influenced the grazer community. These results suggest that the impacts of biodiversity loss on ecosystems will be of comparable magnitude to those of other global change factors and should be accounted for in relevant monitoring and restoration activities.

  5. Laparoscopic ureterocalicostomy in pigs - experimental study


    Caldas, Paulo Fernando de Oliveira; Rocha, Luiz Carlos de Almeida; Oliveira, Marília Teresa de; Ataíde, Michelli Westphal de; Spagnolo, Julio David; Feranti, João Pedro Scussel; Souza, Fernando Wiecheteck de; Silva, Marco Augusto Machado; Brun, Maurício Veloso


    This study aimed to evaluated laparoscopic ureterocalicostomy as treatment of experimental ureteropelvic junction (UPJ) obstruction in pigs. Ten male Large White pigs weighting approximately 28.4 (±1.43) kg were used in the current study. The UPJ obstruction was created laparoscopically by double-clipping of the left ureter. After 14 days the animals underwent laparoscopic ureterocalicostomy f The animals were sacrificed for subsequent retrograde pyelography in order to assess the anastomotic...

  6. Experimental and computational study of thaumasite structure

    Energy Technology Data Exchange (ETDEWEB)

    Scholtzová, Eva, E-mail: [Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 36 Bratislava (Slovakia); Kucková, Lenka; Kožíšek, Jozef [Department of Physical Chemistry, Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 812 37 Bratislava (Slovakia); Pálková, Helena [Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 36 Bratislava (Slovakia); Tunega, Daniel [Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 36 Bratislava (Slovakia); Institute for Soil Science, University of Natural Resources and Life Sciences, Peter-Jordanstrasse 82, A-1190 Wien (Austria)


    The structure of thaumasite has been studied experimentally by means of a single crystal X-ray diffraction and FTIR methods, and theoretically using density functional theory (DFT) method. Very good agreement was achieved between calculated and experimental structural parameters. In addition, calculations offered the refinement of the positions of the hydrogen atoms. The detailed analysis of the hydrogen bonds existing in the thaumasite structure has been performed. Several types of hydrogen bonds have been classified. The water molecules coordinating Ca{sup 2+} cation act as proton donors in moderate O-H···O hydrogen bonds formed with CO₃⁻²and SO₄⁻² anions. The multiple O-H···O hydrogen bonds exist among water molecules themselves. Finally, relatively weak hydrogen bonds form water molecules with the OH groups from the coordination sphere of the Si(OH)₆⁻² anion. Further, calculated vibrational spectrum allowed complete assignment of all vibrational modes which are not available from the experimental spectrum that has a complex structure with overlapped bands, especially below 1500 cm⁻¹. Highlights: • The thaumasite structure was studied experimentally and using DFT method. • We used DFT method for the refinement of the positions of hydrogen atoms. • A detailed analysis of the hydrogen bonds was done. • A complete assignment of all bands to particular types of vibrations was done.

  7. Comparative efficacy of tulathromycin and tildipirosin for the treatment of experimental Mycoplasma bovis infection in calves


    Bartram, David J.; Moyaert, Hilde; Vanimisetti, Bindu H.; Ramage, Clifford P.; Reddick, David; Stegemann, Michael R


    Abstract The objective of this negative controlled, blinded, randomised, parallel group study was to compare the efficacy of two injectable macrolide antimicrobials, tulathromycin and tildipirosin, administered by single subcutaneous injection at dose rates of 2.5 and 4.0 mg kg−1 bodyweight, respectively, in the treatment of an experimentally induced Mycoplasma bovis infection in calves. A total of 238 M. bovis‐negative calves were challenged on three consecutive days with M. bovis by endobro...

  8. Experimental studies on transitional separated boundary layers


    Serna Serrano, José


    Separated transitional boundary layers appear on key aeronautical processes such as the flow around wings or turbomachinery blades. The aim of this thesis is the study of these flows in representative scenarios of technological applications, gaining knowledge about phenomenology and physical processes that occur there and, developing a simple model for scaling them. To achieve this goal, experimental measurements have been carried out in a low speed facility, ensuring the flow homogeneity and...

  9. Comparative evaluation of fracture resistance under static and fatigue loading of endodontically treated teeth restored with carbon fiber posts, glass fiber posts, and an experimental dentin post system: an in vitro study. (United States)

    Ambica, Khetarpal; Mahendran, Kavitha; Talwar, Sangeeta; Verma, Mahesh; Padmini, Govindaswamy; Periasamy, Ravishankar


    This investigation sought to compare the fracture resistance under static and fatigue loading of endodontically treated teeth restored with fiber-reinforced composite posts and experimental dentin posts milled from human root dentin by using computer-aided design/computer-aided manufacturing. Seventy maxillary central incisors were obturated and divided into 4 groups: control group without any post (n = 10), carbon fiber post group (n = 20), glass fiber post group (n = 20), and dentin post group (n = 20). Control group teeth were prepared to a height of 5 mm. In all other teeth, post space was prepared; a post was cemented, and a core build-up was provided. Half the samples from each group were statistically loaded until failure, and the remaining half were subjected to cyclic loading, followed by monostatic load until fracture. One-way analysis of variance and Bonferroni multiple comparisons revealed a significant difference among test groups. The control group demonstrated highest fracture resistance (935.03 ± 33.53 N), followed by the dentin post group (793.12 ± 33.69 N), glass fiber post group (603.44 ± 46.67 N), and carbon fiber post group (497.19 ± 19.27 N) under static loading. These values reduced to 786.69 ± 29.64 N, 646.34 ± 26.56 N, 470 ± 36.34 N, and 379.71 ± 13.95 N, respectively, after cyclic loading. Results suggest that human dentin can serve as post material under static and fatigue loading. Although at an early stage in research, the use of dentin posts in root-filled teeth looks promising. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  10. Fully Bayesian Experimental Design for Pharmacokinetic Studies

    Directory of Open Access Journals (Sweden)

    Elizabeth G. Ryan


    Full Text Available Utility functions in Bayesian experimental design are usually based on the posterior distribution. When the posterior is found by simulation, it must be sampled from for each future dataset drawn from the prior predictive distribution. Many thousands of posterior distributions are often required. A popular technique in the Bayesian experimental design literature, which rapidly obtains samples from the posterior, is importance sampling, using the prior as the importance distribution. However, importance sampling from the prior will tend to break down if there is a reasonable number of experimental observations. In this paper, we explore the use of Laplace approximations in the design setting to overcome this drawback. Furthermore, we consider using the Laplace approximation to form the importance distribution to obtain a more efficient importance distribution than the prior. The methodology is motivated by a pharmacokinetic study, which investigates the effect of extracorporeal membrane oxygenation on the pharmacokinetics of antibiotics in sheep. The design problem is to find 10 near optimal plasma sampling times that produce precise estimates of pharmacokinetic model parameters/measures of interest. We consider several different utility functions of interest in these studies, which involve the posterior distribution of parameter functions.

  11. Experimental study of natural circulation circuit

    Energy Technology Data Exchange (ETDEWEB)

    Lemos, Wanderley F.; Su, Jian, E-mail:, E-mail: [Coordenacao dos Programas de Pos-Graduacao de Engenharia (LASME/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Simulacao e Metodos Numericos; Faccini, Jose L.H., E-mail: [Instituto de Engenharia Nuclear (LTE/IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. de Termo-Hidraulica Experimental


    This work presents an experimental study about fluid flows behavior in natural circulation, under conditions of single-phase flow. The experiment was performed through experimental thermal-hydraulic circuit built at IEN. This test equipment has performance similar to passive system of residual heat removal present in Advanced Pressurized Water Reactors (APWR). This experimental study aims to observing and analyzing the natural circulation phenomenon, using this experimental circuit that was dimensioned and built based on concepts of similarity and scale. This philosophy allows the analysis of natural circulation behavior in single-phase flow conditions proportionally to the functioning real conditions of a nuclear reactor. The experiment was performed through procedures to initialization of hydraulic feeding of primary and secondary circuits and electrical energizing of resistors installed inside heater. Power controller has availability to adjust values of electrical power to feeding resistors, in order to portray several conditions of energy decay of nuclear reactor in a steady state. Data acquisition system allows the measurement and monitoring of the evolution of the temperature in various points through thermocouples installed in strategic points along hydraulic circuit. The behavior of the natural circulation phenomenon was monitored by graphical interface on computer screen, showing the temperature evolutions of measuring points and results stored in digital spreadsheets. The results stored in digital spreadsheets allowed the getting of data to graphic construction and discussion about natural circulation phenomenon. Finally, the calculus of Reynolds number allowed the establishment for a correlation of friction in function of geometric scales of length, heights and cross section of tubing, considering a natural circulation flow throughout in the region of hot leg. (author)

  12. Experimental study on partial coherence source

    CERN Document Server

    Zhao Xue Qing; Yuan Xiao; LiuJingRu; Wang Long Hua; Tang Ying; Huang, Kerson


    Partial coherence source is a key part in the laser system using echelon-free introduced spatial incoherence beam smoothing technique. Different kinds of partial coherence sources have been studied experimentally for improving the uniformity of laser intensity distribution. It is found that the source produced by excimer laser scattering on the surface of a teflon plate is ideal. The properties of this kind of source are studied. As a result, the uniformity of source beam intensity distribution, the beam spatial coherence and energy transfer efficiency of the source are obtained



    Shrama, Gopal Dutt; Tripathi, S. N.


    SUMMARY Water soluble fraction of total alcoholic in the treatment of bronchial asthma 1.2. The same fraction is studied here on frog heart and on blood pressure and respiration of dog, to screen its action on cardio vascular and respiratory systems experimentally. The paper deals with the above experiments with their observations and results. In nut shell the drug is found to have cardiac depresent action an isolated frog heart as well as on frog heart in situ. The drug also possesses potent...

  14. Experimental study of rf pulsed heating

    CERN Document Server

    Laurent, L; Nantista, C; Dolgashev, V; Higashi, Y; Aicheler, M; Tantawi, S; Wuensch, W


    Cyclic thermal stresses produced by rf pulsed heating can be the limiting factor on the attainable reliable gradients for room temperature linear accelerators. This is especially true for structures that have complicated features for wakefield damping. These limits could be pushed higher by using special types of copper, copper alloys, or other conducting metals in constructing partial or complete accelerator structures. Here we present an experimental study aimed at determining the potential of these materials for tolerating cyclic thermal fatigue due to rf magnetic fields. A special cavity that has no electric field on the surface was employed in these studies. The cavity shape concentrates the magnetic field on one flat surface where the test material is placed. The materials tested in this study have included oxygen free electronic grade copper, copper zirconium, copper chromium, hot isostatically pressed copper, single crystal copper, electroplated copper, Glidcop (R), copper silver, and silver plated co...

  15. Physics studies in Europe; a comparative study

    NARCIS (Netherlands)

    Steenstrup, S; dalle Rose, LFD; Jones, WG; Tugulea, L; van Steenwijk, FJ

    What are the differences and similarities between physics studies at different universities across Europe (here the definition of Europe is broad)? How much does a student have to work to obtain a degree in physics? Questions like those prompted EUPEN (European Physics Education Network) to make a

  16. Experimental study on HVAC sound parameters (United States)

    Bujoreanu, C.; Benchea, M.


    HVAC system represent major source of buildings internal noise and therefore they are designed to provide a human acoustic comfort besides the thermal and air quality requirements. The paper experimentally investigates three types of commercial air handler units (AHU) with different ducts cross-section sizes and inlet-outlet configuration. The measurements are performed in an anechoic room. The measurements are carried out at different fan's speeds, ranging the power-charge from 30-100% while the duct air flow is slowly adjusted from full open to full closed, between 0-500 Pa. The sound pressure levels of the radiant units are rated using NR curves. Also, the supply and the outdoor ducts sound levels are compared in order to point the frequencies where the noise must be reduced. Third-octave band analysis of random noise of an air handling unit from a HVAC system is realized, using measurement procedures that agrees the requirements of the ISO 3744:2011 and ISO 5136:2010 standards. The comparatively results highlight the effects of the geometry, air flow pressure and power-charging dependencies upon the sound level. This is the start for a noise reduction strategy.

  17. Computational and experimental study of laminar flames

    Energy Technology Data Exchange (ETDEWEB)

    Smooke, Mitchell [Yale Univ., New Haven, CT (United States)


    During the past three years, our research has centered on an investigation of the effects of complex chemistry and detailed transport on the structure and extinction of hydrocarbon flames in coflowing axisymmetric configurations. We have pursued both computational and experimental aspects of the research in parallel on both steady-state and time-dependent systems. The computational work has focused on the application of accurate and efficient numerical methods for the solution of the steady-state and time-dependent boundary value problems describing the various reacting systems. Detailed experimental measurements were performed on axisymmetric coflow flames using two-dimensional imaging techniques. Previously, spontaneous Raman scattering, chemiluminescence, and laser-induced fluorescence were used to measure the temperature, major and minor species profiles. Particle image velocimetry (PIV) has been used to investigate velocity distributions and for calibration of time-varying flames. Laser-induced incandescence (LII) with an extinction calibration was used to determine soot volume fractions, while soot surface temperatures were measured with three-color optical pyrometry using a color digital camera. A blackbody calibration of the camera allows for determination of soot volume fraction as well, which can be compared with the LII measurements. More recently, we have concentrated on a detailed characterization of soot using a variety of techniques including time-resolved LII (TiRe-LII) for soot primary particles sizes, multi-angle light scattering (MALS) for soot radius of gyration, and spectrally-resolved line of sight attenuation (spec-LOSA). Combining the information from all of these soot measurements can be used to determine the soot optical properties, which are observed to vary significantly depending on spatial location and fuel dilution. Our goal has been to obtain a more fundamental understanding of the important fluid dynamic and chemical interactions in

  18. Comparative study on direct burning of oil shale and coal (United States)

    Hammad, Ahmad; Al Asfar, Jamil


    A comparative study of the direct burning processes of oil shale and coal in a circulating fluidized bed (CFB) was done in this study using ANSYS Fluent software to solve numerically the governing equations of continuity, momentum, energy and mass diffusion using finite volume method. The model was built based on an existing experimental combustion burner unit. The model was validated by comparing the theoretical results of oil shale with proved experimental results from the combustion unit. It was found that the temperature contours of the combustion process showed that the adiabatic flame temperature was 1080 K for oil shale compared with 2260 K for coal, while the obtained experimental results of temperatures at various locations of burner during the direct burning of oil shale showed that the maximum temperature reached 962 K for oil shale. These results were used in economic and environmental analysis which show that oil shale may be used as alternative fuel for coal in cement industry in Jordan.

  19. An Experimental Study of Soft Lubrication (United States)

    Wu, Qianhong; Gacka, Thomas; Nathan, Rungun; Wu, Li-Zhu; Cbmss Team


    Lift generation in soft porous media, as a planing surface glides over it, is a new topic in porous media flow with superior potential for lubrication and squeeze damping. This paper presents the first experimental study of this phenomenon. The experimental setup consists of a running conveyer belt covered with a soft porous sheet, and a stationary instrumented inclined planar upper board. Twelve pressure transducers mounted on the upper board captured the pore pressure generation, while a load cell was used to capture the total lifting force, arising from both the pore pressure and the compression of the solid fibers. One finds that the pore pressure distribution is consistent with theoretical predictions (Feng and Weinbaum, JFM, 2000; Wu et al., MSSE, 2006, 2011), and depends on the running belt velocity, U, the mechanical properties of the porous material, and the compression ratios of the porous layer. For a typical trial (h2/h1=5,h2/h0=1, U=3.8 m/s, where h2, h1, and h0 are the leading edge, trailing edge, and undeformed porous layer thicknesses, respectively), 68% of the lifting force was generated by the pore pressure. It conclusively demonstrates the validity of using soft porous materials for super lubrication. applications. Villanova Cellular Biomechanics and Sports Science Laboratory.

  20. Experimental Study of Separate Type Thermosyphon (United States)

    Hirashima, Masao; Kawahata, Kenya; Negishi, Kanji

    The passages of vapor flow and the returning liquid flow are perfectly partitioned in a separate type thermosyphon. Therefore the flooding limit can be eliminated and practicability based on its construction is highly evaluated. The carry-over of the liquid into the condensing section accompanied with the rising vapor flow should be avoided in the separate type thermosyphon, since it causes to decrease the heat transfer coefficient on the heat transfer surface in the condenser. In the present work, the effect of liquid level, the heat input into the evaporating section, the charging rate of the liquid, and the dimension of the adiabatic section supposed on the generation of carry-over were studied experimentally. The frequency of the bumping and the velocity of the vapor in the adiabatic section were examined as the function of the termination of the carry-over. The experimental correlation representing the relation among the elapsed time, the liquid temperature and the charging rate of the liquid were also derived.

  1. Experimental Verification of Comparability between Spin-Orbit and Spin-Diffusion Lengths


    Niimi, Yasuhiro; Wei, Dahai; Idzuchi, Hiroshi; Wakamura, Taro; Kato, Takeo; Otani, YoshiChika


    We experimentally confirmed that the spin-orbit lengths of noble metals obtained from weak anti-localization measurements are comparable to the spin diffusion lengths determined from lateral spin valve ones. Even for metals with strong spin-orbit interactions such as Pt, we verified that the two methods gave comparable values which were much larger than those obtained from recent spin torque ferromagnetic resonance measurements. To give a further evidence for the comparability between the two...

  2. Sinus Floor Augmentation Comparing an In Situ Hardening Biphasic Calcium Phosphate (Hydroxyapatite/β-Tricalcium Phosphate) Bone Graft Substitute with a Particulate Biphasic Calcium Phosphate (Hydroxyapatite/β-Tricalcium Phosphate) Bone Graft Substitute: An Experimental Study in Sheep. (United States)

    Wildburger, Angelika; Bubalo, Vladimir; Magyar, Marton; Nagursky, Heiner; Jakse, Norbert; Schmelzeisen, Rainer; Sauerbier, Sebastian


    The aim of the present split-mouth study in sheep was to assess the influence of in situ hardening properties of a biphasic calcium phosphate (BCP) bone graft substitute (BGS) (ratio hydroxyapatite/β-tricalcium phosphate = 60/40) compared with a particulate BGS with the same biphasic core-granule composition without in situ hardening properties on sinus floor augmentation. Therefore, bilateral sinus floor augmentation was performed in eight sheep. Poly(lactide-co-glycolide) (PLGA)-coated, in situ hardening biphasic BGS (PLGA-NMP [N-Methyl-2-pyrrolidone]-BCP) was placed at the test site, and a particulate biphasic BGS without PLGA coating (BCP) was used for the contralateral site as a control. Animals were sacrificed after 21 weeks. Sinus augmentation sites were analyzed histologically. The volume was analyzed by computed tomography. Histomorphometric parameters were assessed for the 12 and 21 weeks' time points. Slopes of new bone formation over time were compared with a linear growth regression model. Bone formation after 12 and 21 weeks of healing was 8.94% (±3.74) and 19.82% (±6.29) for PLGA-NMP-BCP and 7.00% (±2.58) and 14.38% (±4.51) for BCP, respectively. The bone growth rate for PLGA-NMP-BCP was higher than the growth rate for BCP (probability 97.5%). The total fraction of calcified hard tissue (% bone fraction + % biomaterial) was around 46% for both tested biomaterials, 21 weeks after sinus floor augmentation. The in situ hardening BGS (PLGA-NMP-BCP) performed better than the particulate material (BCP) in terms of bone formation rate. The in situ hardening properties of the PLGA-NMP-BCP material mediated by the PLGA coating and NMP solution as plasticizer had no negative influence on the bone formation.

  3. [Experimental infection of goats with Schistosoma bovis and S. curassoni: comparative pathogenic effects]. (United States)

    Labbo, R; Boulanger, D; Brémond, P; Chippaux, J P


    Specific mortality and morbidity have been quantified in goats experimentally infected with Schistosoma bovis or S. curassoni strains from Niger. The study involved nine animals followed during 380 days after infection with, respectively, 1,800 or 2,400 cercariae. S. bovis was significatively more pathogenic than S. curossoni in terms of mortality, weight loss and packed cell volume decrease. In addition, the intensity of clinical symptoms was significatively and positively correlated to the levels of fecal egg excretion. Compared to non-infected controls, a growth differential of, respectively, 1,600 and 880 grams per month should incite to consider S. bovis and S. curassoni as parasites of serious economical impact in sahelian countries.

  4. Metabolic Desynchronization in Critical Conditions: Experimental Study

    Directory of Open Access Journals (Sweden)

    G. V. Livanov


    Full Text Available Objective. To conduct an experimental study of the impact of the time of administration of succinic acid preparations on central nervous system (CNS function and gas exchange while simulating metabolic therapy for severe poisoning by ethyl alcohol. The study was performed on 74 male albino rats weighing 140—180 g. Acute severe and very severe intoxication was simulated, by intraabdominally administering 30% ethanol to the rats. Cytoflavin was used to simulate experimental therapy. The rate of gas exchange was estimated by the oxygen uptake determined by the closed chamber method in a Regnault apparatus (Germany. Spontaneous bioelectrical activity was recorded in the frontooccipital lead by the routine procedure. External pain stimulation and rhythmical photostimulation were employed to evaluate cerebral responsiveness. Heterodirectional EEG changes in the «early» and «late» administration of succinate were not followed by the similar alterations of gas exchange: oxygen consumption in both the «early» and «late» administration of succinate remained significantly lower than in the control animals. With the late administration of succinate to the animals with mixed (toxic and hypoxic coma, the so-called discrepancy between the noticeably increased energy production and brutally diminished metabolism occurred. It may be just the pathological mechanism that was the basis for higher mortality in the late succinate administration group. The findings and their analysis make it possible to advance a hypothesis that succinate may cause metabolic desynchronization if activation of metabolic processes takes place under severe tissue respiratory tissue depression. In these cases, there is a severe damage to tissue and chiefly the brain. This manifests itself as EEG epileptiform activity splashes preceding the animals’ death. Therefore, resuscitation aimed at restoring the transport of oxygen and its involvement in tissue energy processes should

  5. Contribution to the experimental study of the hydraulic jump in ...

    African Journals Online (AJOL)

    The purpose of this study is to study experimentally the hydraulic jump evolving in a symmetric trapezoidal channel with a positive slope, requires the use of an experimental protocol, and to find experimental relations linking the characteristics of the formed projection. The experimental study investigated the variation of the ...

  6. [Endodontics in horses. An experimental study]. (United States)

    Garcia, F; Sanromán, F; Llorens, M P


    A total of 44 experimental endodontic treatments were performed in incisors of eight horses of different ages. Four different endodontic pastes were used: Cloropercha, AH26 De Trey, Eugenol-Endometasone, and Universal N2. Gutta-percha points were also included in the last two treatments. Access to the pulp cavity of incisors was gained through their vestibular and occlusal faces. Holes drilled in vestibular faces were sealed with composite and those drilled in occlusal faces were sealed with Amalgama. Animals were observed during eighteen months at least after endodontics. Radiographic controls were done just after surgery and before slaughtering. Treated incisors and alveoli were studied histopathologically. During the experiment all animals were in good condition. They ate apparently without trouble, and neither clinical nor radiological signs were present.

  7. An experimental study of reactive turbulent mixing (United States)

    Cooper, L. P.; Marek, C. J.; Strehlow, R. A.


    An experimental study of the turbulent mixing of two coaxial gas streams, which react very rapidly (pseudo-hypergolic chemical kinetics), was performed to investigate the mixing characteristics of turbulent flow fields. The center stream consisted of a CO-N2 mixture and the outer annular stream consisted of air vitiated by H2 combustion. The streams were at equal velocity (50 m/sec) and temperature (1280 K). Turbulence measurements were obtained using hot film anemometry. A sampling probe was used to obtain time averaged gas compositions. Six different turbulence generators were placed in the annular passage to alter the flow field mixing characteristics. The turbulence generators affected the bulk mixing of the streams and the extent of CO conversion to different degrees. The effects can be related to the average eddy size and the bulk mixing. Higher extents of conversion of CO to CO2 were found by increasing the bulk mixing and decreasing the average eddy size.

  8. Experimental and theoretical study of reflux condensation

    Energy Technology Data Exchange (ETDEWEB)

    Bakke, Knut


    This thesis studies the separation of gas mixtures in a reflux condenser. also called a dephlegmator. Reflux condensation is separation of a gas mixture, in reflux flow with condensing liquid, under continuous heat removal. A numerical model of a dephlegmator for binary mixtures was developed. The model may readily be extended to multi-component mixtures, as the solution method is based on a matrix solver. Separation of a binary mixture in a reflux condenser test rig is demonstrated. The test facility contains a single-tube test section that was designed and built as part of the project. Test mixtures of propane and n-butane were used, and a total of 15 experiments are reported. Limited degree of separation was achieved due to limited heat transfer area and narrow boiling point range of the test mixture. The numerical model reproduces the experimental data within reasonable accuracy. Deviation between calculated and measured properties is less than 6% of the measured temperature and less than 5% of the measured flow rate. The model is based on mechanistic models of physical processes and is not calibrated or tuned to fit the experimental data. The numerical model is applied to a number of separation processes. These case studies show that the required heat transfer area increases rapidly with increments in top product composition (light component). Flooding limits the amount of reflux liquid. The dephlegmator is suitable for separation of feed mixtures that are rich in light components. The gliding temperature in the dephlegmation process enables utilization of top product as refrigerant, with subsequent energy saving as a result. 61 refs., 50 figs., 34 tabs.

  9. Randomized, interventional, prospective, comparative study to ...

    African Journals Online (AJOL)

    Randomized, interventional, prospective, comparative study to evaluate the antihypertensive efficacy and tolerability of ramipril versus telmisartan in stage 1 hypertensive patients with diabetes mellitus.

  10. Comparative studies on pectinases obtained from Aspergillus ...

    African Journals Online (AJOL)

    Comparative studies on pectinases obtained from Aspergillus fumigatus and Aspergillus niger in submerged fermentation system using pectin extracted from mango, orange and pineapple peels as carbon sources.

  11. Experimental study of asymmetric heart valve prototype (United States)

    Vukicevic, M.; Fortini, S.; Querzoli, G.; Cenedese, A.; Pedrizzetti, G.


    The mechanical heart valves (MHVs) are extremely important medical devices, commonly used for diseased heart valves replacement. Despite the long term of use and constant design refinement, the MHVs are very far from ideal and their performance is very diverse from that of the native ones. It has been approved that small variations in geometry of valvular leaflets influence the significant change in the intraventricular vortical flow, known as one of the most important factors for the overall functionality of the heart. We have experimentally examined the home-made heart valve prototypes, exclusively modeled for the mitral valve replacement. The performance and energetic properties of the prototypes have been compared with those in the presence of standard MHVs. The analysis was based on the testing of intraventricular fluid dynamics, usually missing criteria for the quality of the valve performance. It has been shown that the asymmetric prototype, with unequal leaflets and D-shaped orifice produces flow patterns and energetic properties close to those found in the healthy subjects. Thus, the break of symmetry in the standard bi-leaflet MHV prosthesis, at least from the fluid dynamics point of view, is worthwhile to be considered for the design of MHVs for the mitral valve replacement.

  12. Experimental studies of ongoing conscious experience. (United States)

    Singer, J L


    A research programme designed to find ways of applying a variety of methods in psychological science to studying the seemingly ephemeral phenomena of the human stream of consciousness and its manifestations in daydreams, interior monologues, imagery and related private experiences is described. Approaches include psychometric studies to establish normative information on daydreaming and experimental studies using signal-detection paradigms to capture the ongoing stream of thought. Recent experiments involve thought-sampling methods for identifying the determinants of the content of the stream of thought in adolescents or the ways in which self-beliefs and emotions are manifested in a group of cocaine and heroin abusers. Children's pretend play is studied as a possible forerunner of adult consciousness. It is proposed that the human condition involves a continuing tension between processing information generated from the physical and social milieu and the continuous operation of centrally generated material from long-term memory in the form of reminiscences, wishes, current concerns, expectancies and fantasies. This concept has implications for personality variation, affective arousal and adaptive behaviour.

  13. Experimental and numerical study on condensation in transonic steam flow

    Directory of Open Access Journals (Sweden)

    Majkut Mirosław


    Full Text Available The present paper describes an experimental and numerical study of steam condensing flow in a linear cascade of turbine stator blades. The experimental research was performed on the facility of a small scale steam power plant located at Silesian University of Technology in Gliwice, Poland. The test rig of the facility allows us to perform the tests of steam transonic flows for the conditions corresponding to these which prevail in the low-pressure (LP condensing steam turbine stages. The experimental data of steam condensing flow through the blade-to- blade stator channel were compared with numerical results obtained using the in-house CFD numerical code TraCoFlow. Obtained results confirmed a good quality of the performed experiment and numerical calculations.

  14. Mechanical properties of jennite: A theoretical and experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Juhyuk, E-mail: [Civil Engineering Program, Department of Mechanical Engineering, Stony Brook University, NY 11794 (United States); Yoon, Seyoon [School of Engineering, Kings College, University of Aberdeen, Aberdeen AB24 3UE (United Kingdom); Monteiro, Paulo J.M. [Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720 (United States)


    The objective of this study is to determine the mechanical properties of jennite. To date, several hypotheses have been proposed to predict the structural properties of jennite. For the first time as reported herein, the isothermal bulk modulus of jennite was measured experimentally. Synchrotron-based high-pressure x-ray diffraction experiments were performed to observe the variation of lattice parameters under pressure. First-principles calculations were applied to compare with the experimental results and predict additional structural properties. Accurately measured isothermal bulk modulus herein (K{sub 0} = 64(2) GPa) and the statistical assessment on experimental and theoretical results suggest reliable mechanical properties of shear and Young's modulus, Poisson's ratio, and elastic tensor coefficients. Determination of these fundamental structural properties is the first step toward greater understanding of calcium–silicate–hydrate, as well as provides a sound foundation for forthcoming atomic level simulations.

  15. Estudio comparativo entre valores característicos experimentales y normativos de madera aserrada de pino silvestre = Comparative study between experimental and normative values of sawnwood of wild pine

    Directory of Open Access Journals (Sweden)

    Enrique Gómez de la Peña


    Full Text Available Este trabajo realiza un estudio comparativo de caracterización de vigas de madera aserradas y su comparación con la normativa. Para ello se ha utilizado dos tipos de madera muy diferentes, una muy heterogenea, con gran número de defectos, y otra muy homogénea, para comprobar la influencia de los nudos en el comportamiento mecánico de la madera. Para ello se han ensayado un total de 18 vigas de madera y 5 probetas a compresión. Posteriormente se ha realizado una comparativa con la normativa de caracterización, para comprobar su grado de definición. Se ha podido comprobar que dicha norma, se encuentra en el lado de la seguridad en el ámbito de las resistencias, pero que su definición es escasa en cuanto al módulo de elasticidad de la madera. Abstract This work makes a comparative study of the characterization of sawn timber and its comparison with the standard. For this purpose, two very different types of wood have been used, one very heterogeneous, with a large number of defects, and a very homogeneous one, to verify the influence of the knots on the mechanical behavior of the wood. To this end, a total of 18 wooden beams and 5 test specimens have been tested. Subsequently a comparison has been made with the standardization of characterization, to verify its degree of definition. It has been possible to verify that this norm, is in the side of the security in the field of the resistances, but that its definition is scarce as far as the modulus of elasticity of the wood.

  16. Tissue concentration of transforming growth factor beta1 and basic fibroblast growth factor in skin wounds created with a CO2 laser and scalpel: a comparative experimental study, using an animal model of skin resurfacing. (United States)

    Manolis, Evangelos N; Kaklamanos, Ioannis G; Spanakis, Nicholas; Filippou, Dimitrios K; Panagiotaropoulos, Theophanis; Tsakris, Athanassios; Siomos, Konstadinos


    Although a number of ablative-laser techniques based on CO(2) and Er: YAG laser devices have been successfully developed and used in the clinical setting, the bio-molecular processes influencing wound healing after exposure to laser energy are not well elucidated. In this study, we aim to assess the impact of the mechanism of injury on the secretion of transforming growth factor beta1 (TGF-beta1) and basic fibroblast growth factor (bFGF) in various stages of wound healing, in wounds created with a CO(2) laser and scalpel. Ten Wistar rats were used to determine the levels of growth factor proteins TGF-beta1 and bFGF after CO(2) laser- and scalpel-induced skin injury. Tissue was excised on day 0 for untreated skin (control sites), and on days 1, 10, 30, and 90 following laser and scalpel surgery. Specimens were processed for histopathological analysis and for determining the concentration of growth factors by a Western blot technique. The concentration of TGF-beta1 increased markedly, at day 1 postinjury, from a baseline of 130+/-16 mm(2) (mean surface area of blotted-protein lanes) to 261+/-23 mm(2) and 394+/-22 mm(2) for laser-inflicted injury and scalpel wounds, respectively; the latter values were found to differ significantly (plaser sites (553+/-45 mm(2)) and the corresponding scalpel sites (418+/-41 mm(2)). Laser energy alters local tissue secretion of TGF-beta1 and bFGF of skin injuries created with the CO(2) laser compared with wounds created with a scalpel. These differences might have an impact on various aspects of wound healing of skin injuries created by a laser.

  17. Hot forming of composite prepreg : Experimental study (United States)

    Tardif, Xavier; Duthille, Bertrand; Bechtel, Stephane; le Pinru, Louis; Campagne, Benjamin; Destombes, Gautier; Deshors, Antoine; Marchand, Christophe; Azzouzi, Khalid El; Moro, Tanguy


    The hot forming of thermoset prepreg consists in bending an uncured composite part by applying a mechanical constrain on the hot laminate. Most of the time, the mold is inserted in a vacuum box and the mechanical constrain is applied on the composite laminate by a single membrane or a double-membrane. But the performance improvement products resulted in forming increasingly complex parts with advanced materials having a less formability. These new complex parts require a finer comprehension of the process and an optimization of the key parameters to get acceptable quality. In this work, an experimental study has been carried out to identify the process conditions that do not lead to unacceptable defaults: undulations of fibers. In the present study, downward-bending has been evaluated with an original light mechanical forming concept, for a given stacking sequence. The influence of the part's temperature and the part's bending speed are investigated. To carry this study out, a hot forming test bench has been designed and manufactured to have a precise supervision of the process conditions. It is able to bend parts of 1500 mm length x 600 mm width x 20 mm thick.

  18. Experimental study of rf pulsed heating

    Directory of Open Access Journals (Sweden)

    Lisa Laurent


    Full Text Available Cyclic thermal stresses produced by rf pulsed heating can be the limiting factor on the attainable reliable gradients for room temperature linear accelerators. This is especially true for structures that have complicated features for wakefield damping. These limits could be pushed higher by using special types of copper, copper alloys, or other conducting metals in constructing partial or complete accelerator structures. Here we present an experimental study aimed at determining the potential of these materials for tolerating cyclic thermal fatigue due to rf magnetic fields. A special cavity that has no electric field on the surface was employed in these studies. The cavity shape concentrates the magnetic field on one flat surface where the test material is placed. The materials tested in this study have included oxygen free electronic grade copper, copper zirconium, copper chromium, hot isostatically pressed copper, single crystal copper, electroplated copper, Glidcop®, copper silver, and silver plated copper. The samples were exposed to different machining and heat treatment processes prior to rf processing. Each sample was tested to a peak pulsed heating temperature of approximately 110°C and remained at this temperature for approximately 10×10^{6} rf pulses. In general, the results showed the possibility of pushing the gradient limits due to pulsed heating fatigue by the use of copper zirconium and copper chromium alloys.

  19. A comparative study on zero tillage with bulldozing as land ...

    African Journals Online (AJOL)

    A comparative study on zero tillage and bulldozing, as land preparations for oil palm seedling transplanted into the field was conducted at Ayip Eku Oil Palm Estate between 1993 and 1997. The experimental site was a five-year fallow land in which Panicum maximum (Guinea grass) and Centresoma pubescence were ...

  20. Comparative study of the thermal performance and emission levels ...

    African Journals Online (AJOL)

    Comparative study of the thermal performance and emission levels of an existing and modified coal/biomass burning stove. ... The stove was charged with jive (5) selected wood species and a number of parameters, such as temperature projile amI flue gas composition were measured. Experimental evidence points to an ...

  1. Comparative Study of the Compressive Strength of Cement Laterite ...

    African Journals Online (AJOL)

    The paper presents an outcome of experimental comparative study on the compressive strength of laterite brick made with rice husk ash and wood ash as partial replacement of cement. First, Rice Husk Ash (RHA) and Wood Ash (WA) were prepared and subjected to the following tests: specific gravity, density and bulk ...

  2. Phytochemical screening and study of comparative antibacterial ...

    African Journals Online (AJOL)



    Jun 30, 2013 ... Comparative study on antibacterial activity of Terminalia- catappa on Multiresistant strains. 5040. Phytochemical screening and study of comparative antibacterial activity of aqueous and alcoholic extracts of the leaves and barks of Terminalia catappa on multiresistant strains. Rubens Dinzedi Mbengui1, 2, ...

  3. Theoretical and experimental studies on the foundation theoretical and experimental studies on the foundation of mesomechanics (United States)

    Chudnovsky, A.; Wu, S.


    The report summarizes a closely coupled experimental and theoretical investigation of various stages of Fracture Process: (1) accumulation of 'damage' on submicroscopical and microscopical scales leading to crack initiation; (2) slow (subcritical) crack growth and an evolution of the damage zone; (3) transition to dynamic crack growth and the catastrophic failure. The experimental part of the program is focused on the observation and quantitative characterization of damage preceding and accompanying crack initiation and growth. A special experimental setup for studying the fracture process under variable stress field is reported in Chapter 2. A leading role of crack-damage interaction in fracture process is well documented. A new formalism for solution of crack-microcrack array interaction problem and its successful implementation in the evaluation of crack layer driving forces is presented in Chapter 3. A new model of the process zone, which generalizes the well-known Dagdale-Barenblatt model is presented in Chapter 4. A new measure for material toughness and the prediction of R-curve behavior illustrate the practical application of our model. Experimental examinations of our model under various test conditions are reported in Chapters 4, 5 and 6. The development of the constitutive equations for Crack Layer evolution and their experimental examinations under stress relaxation, fatigue and creep conditions are reported in Chapters 5 and 6. An accelerated test procedure and the formulation of crack layer instability criteria as a substitution for the conventional fracture toughness parameters are also discussed in Chapter 6.

  4. Cartilage integrity and proteoglycan turnover are comparable in canine experimentally induced and human joint degeneration

    Directory of Open Access Journals (Sweden)

    Femke Intema


    Full Text Available The value of experimental models of osteoarthritis (OA largely depends on the ability to translate observations to human OA. Surprisingly, direct comparison of characteristics of human and experimental OA is scarce. In the present study, cartilage integrity and matrix turnover in a canine model of joint degeneration were compared to human clinical OA. In 23 Beagle dogs, joint degeneration was induced in one knee, the contra-lateral knee served as a control. For comparison, human osteoarthritic and healthy knee cartilage were obtained at arthroplasty (n=14 and post-mortem (n=13. Cartilage was analyzed by histology and biochemistry. Values for cartilage integrity and proteoglycan (PG synthesis showed species specific differences; GAG content of healthy cartilage was 2-fold higher in canine cartilage and PG synthesis even 8-fold. However, the relative decrease in PG content between healthy and OA cartilage was similar for humans and canines (-17% vs. -15%, respectively, as was the histological damage (+7.0 vs. +6.1, respectively and the increase of PG synthesis (+100% vs. +70%, respectively. Remarkably, the percentage release of total and of newly formed PGs in human and canine controls was similar, as was the increase due to degeneration (+65% vs. +81% and +91% vs. +52%, respectively. Despite differences in control conditions, the observed changes in characteristics of cartilage integrity and matrix turnover are similar in a canine model of joint degeneration and human clinical OA. The canine Groove model shows that its characteristics reflect those of human OA which makes the model appropriate for studying human OA.

  5. Estudo Comparativo de Polimerização de Propileno com Diferentes Catalisadores Metalocênicos Através de um Planejamento de Experimentos Comparative Study of Propylene Polymerization with Different Metallocene Catalysts Using a Statistic Experimental Planning Model

    Directory of Open Access Journals (Sweden)

    Maria de Fátima V. Marques


    Full Text Available Neste trabalho, o desempenho dos catalisadores SiMe2(Ind2ZrCl2, Et(Ind2ZrCl2, SiMe2(Ind2HfCl2 e Et(Ind2HfCl2 na polimerização de propileno usando MAO como cocatalisador empregando-se um Planejamento estatístico de experimentos foi avaliado. As polimerizações foram realizadas em diferentes temperaturas e razões molares alumínio/metal de transição. O efeito destas variáveis na atividade de cada catalisador e nas características do polipropileno obtido foi melhor investigado utilizando-se os modelos propostos para cada variável. Foram observadas influências significativas das condições experimentais principalmente na atividade catalítica, bem como no peso molecular ponderal médio, temperatura de fusão e percentagem de isotaticidade dos polímeros obtidos. A partir dos modelos propostos através do tratamento estatístico realizado pode-se observar que os catalisadores a base de zircônio são os de maior atividade catalítica, enquanto que os hafnocenos produzem polipropileno com peso molecular mais elevado. Os complexos com ponte dimetil-silânica produziram polipropileno com maior peso molecular, estereorregularidade e maior temperatura de fusão do que os similares com ponte etilidênica.In this work, the performance of the catalysts SiMe2(Ind2ZrCl2, Et(Ind2ZrCl2, SiMe2(Ind2HfCl2 e Et(Ind2HfCl2 on propylene polymerization using MAO as cocatalyst and employing a Statistic Experimental Planning Model was evaluated. The polymerizations were carried out at different temperatures and aluminum/transition metal molar ratios. The effect of these variables on the catalyst activity and on the polymer characteristics was investigated using the proposed models for each variable. A significant influence was observed of the experimental conditions on the catalyst activity in particular, but also on the weight-average molecular weight, melting point and isotacticity of the polypropylenes produced; the statistical analysis with the proposed

  6. A Comparative Study on Error Analysis

    DEFF Research Database (Denmark)

    Wu, Xiaoli; Zhang, Chun


    students (N= 54 students from LU; and N= 33 students from AU) participating in the studies, among them 44 are 2nd-year students (n=28 from LU and n=16 from AU) and 43 3rd-year students (n=26 from LU and n=17 from AU). Students’ writing samples were first collected and the errors on the use of comparative...... of the grammatical errors with using comparative sentences is developed, which include comparative item-related errors, comparative result-related errors and blend errors. The results further indicate that these errors could attribute to negative L1 transfer and overgeneralization of grammatical rule and structures......Title: A Comparative Study on Error Analysis Subtitle: - Belgian (L1) and Danish (L1) learners’ use of Chinese (L2) comparative sentences in written production Xiaoli Wu, Chun Zhang Abstract: Making errors is an inevitable and necessary part of learning. The collection, classification and analysis...

  7. Experimental studies of fiber concrete creep

    Directory of Open Access Journals (Sweden)

    Korneeva Irina


    Full Text Available The results of two-stage experimental studies of the strength and deformation characteristics of fibrous concrete reinforced with steel fiber. In the experiments we used steel fiber with bent ends, which practically does not form "hedgehogs", which allows to achieve an even distribution of the fiber by volume. At the first stage, the cube and prismatic strength, deformability at central compression, a number of special characteristics are determined: water absorption, frost resistance, abrasion; the optimal percentage of fiber reinforcement and the maximum size of the coarse aggregate fraction were selected. Fiber reinforcement led to an increase in the strength of concrete at compression by 1,35 times and an increase in the tensile strength at bending by 3,4 times. At the second stage, the creep of fibrous concrete and plain concrete of similar composition at different stress levels was researched. Creep curves are plotted. It is shown that the use of fiber reinforcement leads to a decrease in creep strain by 21 to 30 percent, depending on the stress level.

  8. Experimental study of finite Larmor radius effects

    Energy Technology Data Exchange (ETDEWEB)

    Struve, K.W.


    Linear Z-pinches in Ar, Kr, Xe, N/sub 2/, and He are experimentally studied in regimes where strong finite Larmor radius effects could provide a significant stabilizing effect. Scaling arguments show that for deuterium such a pinch has an electron line density of order 2 x 10/sup 15//cm. For higher Z plasmas a higher line density is allowed, the exact value of which depends on the average ion charge. The pinch is formed by puffing gas axially through the cathode towards the anode of an evacuated pinch chamber. When the gas reaches the anode, the pinch bank is fired. The pinch current rises in 2 to 3 to a maximum of 100 to 200 kA. The pinch bank capacitance is 900, and the external inductance is 100 nH. Additionally, the bank is fused to increase dI/dt. The primary diagnostics are a framing camera, a spatially resolved Mach-Zehnder interferometer, and X-ray absorption.

  9. The experimental studies of thermoacoustic cooler. (United States)

    Sakamoto, Shin-ichi; Watanabe, Yoshiaki


    The experimental studies of thermoacoustic cooler consisting of acoustic loop-tube were carried out. The loop-tube was filled with the mixture of air and helium gas or air at atmospheric pressure. The dimensions of the loop-tube were 3.3 m of length, 44 mm of inner diameter and 4 mm of thickness. A pair of stacks (stack 1 and stack 2) which were sandwiched between two heat exchangers was placed symmetrically in the loop-tube. Stack 1 was employed as a prime mover and stack 2 as a heat pump. The self-sustained sound generated by the thermoacoustic effect and the cooling phenomena at the stack 2 were observed. The distribution of the sound pressures and the waveforms in the loop-tube were measured, and the frequency component of the self-sustained sound was investigated at the starting phase. The fundamental frequency component was confirmed and it was developing as the sound pressure increasing. The higher harmonics frequency components were generated and they were also developing.

  10. Experimental study of trimethyl aluminum decomposition (United States)

    Zhang, Zhi; Pan, Yang; Yang, Jiuzhong; Jiang, Zhiming; Fang, Haisheng


    Trimethyl aluminum (TMA) is an important precursor used for metal-organic chemical vapor deposition (MOCVD) of most Al-containing structures, in particular of nitride structures. The reaction mechanism of TMA with ammonia is neither clear nor certain due to its complexity. Pyrolysis of trimethyl metal is the start of series of reactions, thus significantly affecting the growth. Experimental study of TMA pyrolysis, however, has not yet been conducted in detail. In this paper, a reflectron time-of-flight mass spectrometer is adopted to measure the TMA decomposition from room temperature to 800 °C in a special pyrolysis furnace, activated by soft X-ray from the synchrotron radiation. The results show that generation of methyl, ethane and monomethyl aluminum (MMA) indicates the start of the pyrolysis process. In the low temperature range from 25 °C to 700 °C, the main product is dimethyl aluminum (DMA) from decomposition of TMA. For temperatures larger than 700 °C, the main products are MMA, DMA, methyl and ethane.

  11. Learning, forecasting and optimizing : An experimental study

    NARCIS (Netherlands)

    Bao, Te; Duffy, John; Hommes, Cars

    Rational Expectations (RE) models have two crucial dimensions: (i) agents on average correctly forecast future prices given all available information, and (ii) given expectations, agents solve optimization problems and these solutions in turn determine actual price realizations. Experimental tests

  12. Evapotranspiration studies for protective barriers: Experimental plans

    Energy Technology Data Exchange (ETDEWEB)

    Link, S.O.; Waugh, W.J.


    This document describes a general theory and experimental plans for predicting evapotranspiration in support of the Protective Barrier Program. Evapotranspiration is the combined loss of water from plants and soil surfaces to the atmosphere. 45 refs., 1 fig., 4 tabs.

  13. An experimental-numerical method for comparative analysis of joint prosthesis; Un metodo numerico-experimental para el analisis comparativo de protesis articulares

    Energy Technology Data Exchange (ETDEWEB)

    Claramunt, R.; Rincon, E.; Zubizarreta, V.; Ros, A.


    The difficulty that exists in the analysis of mechanical stresses in bones is high due to its complex mechanical and morphological characteristics. This complexity makes generalists modelling and conclusions derived from prototype tests very questionable. In this article a relatively simple comparative analysis systematic method that allow us to establish some behaviour differences in different kind of prosthesis is presented. The method, applicable in principle to any joint problem, is based on analysing perturbations produced in natural stress states of a bone after insertion of a joint prosthesis and combines numerical analysis using a 3-D finite element model and experimental studies based on photoelastic coating and electric extensometry. The experimental method is applied to compare two total hip prosthesis cement-free femoral stems of different philosophy. One anatomic of new generation, being of oblique setting over cancellous bone and the other madreporique of trochantero-diaphyseal support over cortical bone. (Author) 4 refs.

  14. Experimental and computational studies of nanofluids (United States)

    Vajjha, Ravikanth S.

    The goals of this dissertation were (i) to experimentally investigate the fluid dynamic and heat transfer performance of nanofluids in a circular tube, (ii) to study the influence of temperature and particle volumetric concentration of nanofluids on thermophysical properties, heat transfer and pumping power, (iii) to measure the rheological properties of various nanofluids and (iv) to investigate using a computational fluid dynamic (CFD) technique the performance of nanofluids in the flat tube of a radiator. Nanofluids are a new class of fluids prepared by dispersing nanoparticles with average sizes of less than 100 nm in traditional heat transfer fluids such as water, oil, ethylene glycol and propylene glycol. In cold regions of the world, the choice of base fluid for heat transfer applications is an ethylene glycol or propylene glycol mixed with water in different proportions. In the present research, a 60% ethylene glycol (EG) or propylene glycol (PG) and 40% water (W) by mass fluid mixture (60:40 EG/W or 60:40 PG/W) was used as a base fluid, which provides freeze protection to a very low level of temperature. Experiments were conducted to measure the convective heat transfer coefficient and pressure loss of nanofluids flowing in a circular tube in the fully developed turbulent regime. The experimental measurements were carried out for aluminum oxide (Al2O3), copper oxide (CuO) and silicon dioxide (SiO2) nanoparticles dispersed in 60:40 EG/W base fluid. Experiments revealed that the heat transfer coefficient of nanofluids showed an increase with the particle volumetric concentration. Pressure loss was also observed to increase with the nanoparticle volumetric concentration. New correlations for the Nusselt number and the friction factor were developed. The effects of temperature and particle volumetric concentration on different thermophysical properties (e.g. viscosity, thermal conductivity, specific heat and density) and subsequently on the Prandtl number

  15. Comparing the invasibility of experimental "reefs" with field observations of natural reefs and artificial structures.

    Directory of Open Access Journals (Sweden)

    Katherine A Dafforn

    Full Text Available Natural systems are increasingly being modified by the addition of artificial habitats which may facilitate invasion. Where invaders are able to disperse from artificial habitats, their impact may spread to surrounding natural communities and therefore it is important to investigate potential factors that reduce or enhance invasibility. We surveyed the distribution of non-indigenous and native invertebrates and algae between artificial habitats and natural reefs in a marine subtidal system. We also deployed sandstone plates as experimental 'reefs' and manipulated the orientation, starting assemblage and degree of shading. Invertebrates (non-indigenous and native appeared to be responding to similar environmental factors (e.g. orientation and occupied most space on artificial structures and to a lesser extent reef walls. Non-indigenous invertebrates are less successful than native invertebrates on horizontal reefs despite functional similarities. Manipulative experiments revealed that even when non-indigenous invertebrates invade vertical "reefs", they are unlikely to gain a foothold and never exceed covers of native invertebrates (regardless of space availability. Community ecology suggests that invertebrates will dominate reef walls and algae horizontal reefs due to functional differences, however our surveys revealed that native algae dominate both vertical and horizontal reefs in shallow estuarine systems. Few non-indigenous algae were sampled in the study, however where invasive algal species are present in a system, they may present a threat to reef communities. Our findings suggest that non-indigenous species are less successful at occupying space on reef compared to artificial structures, and manipulations of biotic and abiotic conditions (primarily orientation and to a lesser extent biotic resistance on experimental "reefs" explained a large portion of this variation, however they could not fully explain the magnitude of differences.

  16. Ovine and Caprine Toxoplasmosis: Experimental Study

    Directory of Open Access Journals (Sweden)

    Shawkat Q. Lafi


    Full Text Available Eighteen mature ewes of the Mytilene breed and 18 mature Local- Damascus crossbred goats, seronegative for Toxoplasma gondii (T. gondii by ELISA were used. All animals were mated after synchronization of estrus. On day 90 of pregnancy, animals were randomly assigned to 3 experimental groups; 6 ewes (S1 and 6 goats (G1 were orally inoculated by stomach tube with 1000 oocysts; 6 ewes (S2 and 6 goats (G2 were orally inoculated with a non-infected control inoculum. On day 140+2 of pregnancy, the remaining 6 ewes (S3 and 6 goats (G3 were inoculated by stomach tube with 3000 oocysts. Positive T. godii DNA was detected in 94% of fetal and maternal blood, 95% fetal tissue, 89% pre-colostral udder secretions and 12.5% milk samples using Polymerase Chain Reaction (PCR. Infected animals and their live newborns was seropositive (ELISA until the end of the study. PCR was able to detect T. gondii DNA in maternal blood of infected animals 3-5 days before abortion occurred. This time period may be used to implement preventive and therapeutic measure to reduce abortion rate and associated economic losses. Since milk and milk products are important food sources in rural areas and in many cases it is used unpasteurized before consumption. The T. gondii DNA, detected by PCR in milk samples of infected animals, increases the possibility that the parasite is transmitted through consumption of unpasteurized milk which is a highly relevant result for public health considerations and providing valuable information for future research.

  17. Numerical and Experimental Case Study of Blasting Works Effect (United States)

    Papán, Daniel; Valašková, Veronika; Drusa, Marian


    This article introduces the theoretical and experimental case study of dynamic monitoring of the geological environment above constructed highway tunnel. The monitored structure is in this case a very important water supply pipeline, which crosses the tunnel and was made from steel tubes with a diameter of 800 mm. The basic dynamic parameters had been monitored during blasting works, and were compared with the FEM (Finite Element Method) calculations and checked by the Slovak standard limits. A calibrated FEM model based on the experimental measurement data results was created and used in order to receive more realistic results in further predictions, time and space extrapolations. This case study was required and demanded by the general contractor company and also by the owner of water pipeline, and it was an answer of public safety evaluation of risks during tunnel construction.

  18. Clinical methods of goniometry: a comparative study. (United States)

    Goodwin, J; Clark, C; Deakes, J; Burdon, D; Lawrence, C


    This investigation compared the reliability and interchangeable use of three currently available goniometers--a universal goniometer, a fluid goniometer, and an electrogoniometer. Three consecutive readings of the active range of movement of the right elbow joint were taken from each of 23 healthy female volunteers; three experienced observers each used each type of goniometer on two occasions. A balanced experimental design was used to eliminate order effects with respect to subject, tester, or goniometer, and a rigid protocol was employed to reduce error due to diurnal or methodological variations. The results show that there are significant differences between the goniometers used, the testers, and the replications. Significant interaction effects also exist between the goniometers and the occasion, the goniometers and the testers, and the testers and replications. The data suggest that the interchangeable use of different types of goniometer in a clinical setting is inadvisable.

  19. Computatonal and experimental study of laminar flames

    Energy Technology Data Exchange (ETDEWEB)

    Smooke, M.D.; Long, M.B. [Yale Univ., New Haven, CT (United States)


    This research has centered on an investigation of the effects of complex chemistry and detailed transport on the structure and extinction of hydrocarbon flames in counterflow, cylindrical and coflowing axisymmetric configurations. The authors have pursued both computational and experimental aspects of the research in parallel. The computational work has focused on the application of accurate and efficient numerical methods for the solution of the one and two-dimensional nonlinear boundary value problems describing the various reacting systems. Detailed experimental measurements were performed on axisymmetric coflow flames using two-dimensional imaging techniques. In particular, spontaneous Raman scattering and laser induced fluorescence were used to measure the temperature, major and minor species profiles.

  20. Biomass thermochemical gasification: Experimental studies and modeling (United States)

    Kumar, Ajay

    The overall goals of this research were to study the biomass thermochemical gasification using experimental and modeling techniques, and to evaluate the cost of industrial gas production and combined heat and power generation. This dissertation includes an extensive review of progresses in biomass thermochemical gasification. Product gases from biomass gasification can be converted to biopower, biofuels and chemicals. However, for its viable commercial applications, the study summarizes the technical challenges in the gasification and downstream processing of product gas. Corn stover and dried distillers grains with solubles (DDGS), a non-fermentable byproduct of ethanol production, were used as the biomass feedstocks. One of the objectives was to determine selected physical and chemical properties of corn stover related to thermochemical conversion. The parameters of the reaction kinetics for weight loss were obtained. The next objective was to investigate the effects of temperature, steam to biomass ratio and equivalence ratio on gas composition and efficiencies. DDGS gasification was performed on a lab-scale fluidized-bed gasifier with steam and air as fluidizing and oxidizing agents. Increasing the temperature resulted in increases in hydrogen and methane contents and efficiencies. A model was developed to simulate the performance of a lab-scale gasifier using Aspen Plus(TM) software. Mass balance, energy balance and minimization of Gibbs free energy were applied for the gasification to determine the product gas composition. The final objective was to optimize the process by maximizing the net energy efficiency, and to estimate the cost of industrial gas, and combined heat and power (CHP) at a biomass feedrate of 2000 kg/h. The selling price of gas was estimated to be 11.49/GJ for corn stover, and 13.08/GJ for DDGS. For CHP generation, the electrical and net efficiencies were 37 and 86%, respectively for corn stover, and 34 and 78%, respectively for DDGS. For

  1. Experimental techniques for cement hydration studies

    Directory of Open Access Journals (Sweden)

    Andreas Luttge


    Full Text Available Cement hydration kinetics is a complex problem of dissolution, nucleation and growth that is still not well understood, particularly in a quantitative way. While cement systems are unique in certain aspects they are also comparable to natural mineral systems. Therefore, geochemistry and particularly the study of mineral dissolution and growth may be able to provide insight and methods that can be utilized in cement hydration research. Here, we review mainly what is not known or what is currently used and applied in a problematic way. Examples are the typical Avrami approach, the application of Transition State Theory (TST to overall reaction kinetics and the problem of reactive surface area. Finally, we suggest an integrated approach that combines vertical scanning interferometry (VSI with other sophisticated analytical techniques such as atomic force microscopy (AFM and theoretical model calculations based on a stochastic treatment.

  2. Experimental Study of a Thermoelectric Generation System

    DEFF Research Database (Denmark)

    Zhu, Junpeng; Gao, Junling; Chen, Min


    A flat wall-like thermoelectric generation system is developed for applications in exhaust heat of kilns. The design of the whole experimental setup is presented. The essential performance of the thermoelectric generation system is tested, including open-circuit voltage, output power, and system ...

  3. Economic principles in communication: An experimental study

    NARCIS (Netherlands)

    De Jaegher, K.; Rosenkranz, S.; Weitzel, G.U.


    This paper experimentally investigates how economic principles affect communication. In a simple sender–receiver game with common interests over payoffs, the sender can send a signal without a pre-given meaning in an infrequent or frequent state of the world. When the signal is costly, several

  4. Blast mitigation experimental and numerical studies

    CERN Document Server


    Presents experimental methods of material and structural response to dynamic blast loads Includes computational analysis of material and structural response to dynamic blast loads Offers mitigation measures for structures in various environments Relates lab experiments to larger field tests Features more than 150 illustrations

  5. Comparative efficacy of tulathromycin and tildipirosin for the treatment of experimental Mycoplasma bovis infection in calves. (United States)

    Bartram, David J; Moyaert, Hilde; Vanimisetti, Bindu H; Ramage, Clifford P; Reddick, David; Stegemann, Michael R


    The objective of this negative controlled, blinded, randomised, parallel group study was to compare the efficacy of two injectable macrolide antimicrobials, tulathromycin and tildipirosin, administered by single subcutaneous injection at dose rates of 2.5 and 4.0 mg kg-1 bodyweight, respectively, in the treatment of an experimentally induced Mycoplasma bovis infection in calves. A total of 238 M. bovis-negative calves were challenged on three consecutive days with M. bovis by endobronchial deposition. Post-challenge, a total of 126 animals fulfilled the inclusion criteria and were randomly allocated to three treatment groups: tulathromycin, tildipirosin and saline. Clinical observations for signs of respiratory disease and injection site assessments were conducted daily for 14 days post-treatment. The animals were then killed, the lungs were examined for evidence of lesions, and samples collected for bacterial isolation. Calves treated with tulathromycin had a lower percentage of lung with lesions (P = 0.0079), lower mortality (P = 0.0477), fewer days with depressed demeanour (P = 0.0486) and higher body weight (P = 0.0112) than calves administered tildipirosin.

  6. Comparative activity of cloxacillin and vancomycin against methicillin-susceptible Staphylococcus aureus experimental endocarditis. (United States)

    Fernández Guerrero, Manuel L; de Górgolas, Miguel


    To compare the activity of cloxacillin and vancomycin against methicillin-susceptible Staphylococcus aureus and to determine how rapidly their bactericidal activity occurs in cardiac vegetations. In vitro and in vivo studies using an experimental model of endocarditis in rabbits. Animals were treated for 1, 2 or 3 days with cloxacillin 200 mg/kg intramuscularly three times a day or vancomycin 25 mg/kg intravenously twice a day. Cloxacillin and vancomycin at concentrations 4- and 16-fold the MIC produced a modest decrease in the number of microorganisms at 4 h. After 24 h, cloxacillin produced a decrease in the counts of staphylococci from 2.19 to 4.84 log10 cfu/mL of inoculum. Only concentrations of vancomycin from 16- to 32-fold the MIC resulted in equivalent decreases. After 24 h of treatment, both antibiotics were equally effective in preventing mortality of rabbits. Cloxacillin produced a greater decrease in the number of staphylococci than vancomycin (3.50+/-2.18 log10 cfu/g vegetation and 6.25+/-1.28 log10 cfu/g vegetation, respectively; Pcloxacillin in vivo.

  7. Mathematics education and comparative historical studies

    Directory of Open Access Journals (Sweden)



    Full Text Available This paper has as its aims: to characterize the area of research «history of mathematics education» and to defend the idea that mathematics education has constituted a privileged research theme within the field of comparative historical studies. To achieve these aims, the text includes references to a review of the literature concerning comparative studies, the analysis of two fundamental moments focused on attempts to internationalize the mathematics curriculum, both of which occurred during the 20th century, and, to end, a case study emanating from an international cooperation between researchers in Brazil and Portugal.

  8. World Studies through a Comparative Constitutional Prism. (United States)

    Robinson, Donald


    Emphasizes the importance of understanding the development of democracy around the world by comparative study of constitutions. Uses the development of the Japanese constitution after World War II as a case study. Describes the work of the team appointed by General Douglas MacArthur and the significance of the clause guaranteeing equal rights for…

  9. Comparative study of bioethanol production from sugarcane ...

    African Journals Online (AJOL)

    The study was designed to compare the bioethanol production from Zymomonas mobilis and Saccharomyces cerevisiae using molasses as production medium. The focus was on the retention time at lab scale. Bioethanol and petroleum blend can be used in existing gasoline engines. Present study showed a more ...


    African Journals Online (AJOL)

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    experimental and theoretical data have showed that the molecular geometry and the ... 1D and 2D hetero- and homonuclear NMR methods enable to ... The essence of this study is briefly to report experimental and theoretical NMR features of.

  11. Model refinement for offshore platforms: Experimental study (United States)

    Zhang, Min; Chen, Zongli; Wu, Yanjian


    Offshore jacket platforms are widely used in offshore oil and gas exploitation. Finite element models of such structures need to have many degrees of freedom (DOFs) to represent the geometrical detail of complex structures, thereby leading to incompatibility in the number of DOFs of experimental models. To bring them both to the same order while ensuring that the essential eigen- properties of the refined model match those of experimental models, an extended model refinement procedure is presented in this paper. Vibration testing of an offshore jacket platform model is performed to validate the applicability of the proposed approach. A full-order finite element model of the platform is established and then tuned to meet the measured modal properties identified from the acceleration signals. Both model reduction and modal expansion methods are investigated, as well as various scenarios of sensor arrangements. Upon completion of the refinement, the updated jacket platform model matches the natural frequencies of the measured model well.

  12. Comparative Studies: historical, epistemological and methodological notes

    Directory of Open Access Journals (Sweden)

    Juan Ignacio Piovani


    Full Text Available In this article some historical, epistemological and methodological issues related to comparative studies in the social sciences are addressed, with specific reference to the field of education. The starting point is a discussion of the meaning of comparison, its logical structure and its presence in science and in everyday life. It follows the presentation and critical appraisal of the perspectives regarding comparison as a scientific method. It is argued that, even rejecting this restrictive meaning of comparison as a method, there is some consensus on the specificity of comparative studies within the social sciences. And in relation to them, the article address in more detail those studies that can be defined as trans-contextual (cross-national and cross-cultural, with emphasis on the main methodological and technical challenges they face. The socio-historical comparative perspective, which has gained importance in recent years in the field of education, is also discussed.

  13. Experimental studies of Steel Corrugated Constructions

    Directory of Open Access Journals (Sweden)

    Lazarev Yuriy


    Full Text Available The purpose of this particular article is to assess existing calculations of steel corrugated constructions. Steel Corrugated Construction is a perspective type of constructions, which is exhibiting numerous advantages in comparison with one that currently applied in automobile and railroad networks (reinforced concrete water-throughput pipes, reinforced concrete frame bridges. The evaluation of experimental data on models of constructions of this particular type has been carried out in order to improve calculations of Steel Corrugated Constructions.

  14. Experimental study of the nucleon spin structure

    Energy Technology Data Exchange (ETDEWEB)

    Litmaath, M.F.


    After introducing the theoretical framework, which includes DIS, the Quark Parton Model (QPM) and QCD, we describe the implementation of the experiment. The SMC uses a beam of 190 GeV naturally polarized muons, scattering off nucleons in a large cryogenic target containing protons or deuterons that are polarized through Dynamic Nuclear Polarization (DNP). The target material is located in two cells in a row, with opposite polarizations. Every 5 hours the polarizations of both cells are reversed. The target polarization is measured by an NMR system. The polarization of the beam is measured in a polarimeter, located downstream of the main experimental setup. (orig.).

  15. Experimental Studies of Coaxial Plasma Gun Current (United States)


    insertion into experimental systems (117-133), fueling for proposed thermonuclear reactors (134-138], breeding fissionable material [139, 140] and...Center Top Level Linear Exponential Yield Current Current Extrap . Extrap . (MA) (MA) Current Current (MA) (MA) 02901 2.8106 0.18 0.05 D3001 1.2x107...Exponential Yield Current Current Extrap . Extrap . (MA) (MA) Current Current (MA) (MA) 30703 1.610 8 1.57 0.64 0.54 0.59 J0706 4.040O 1.46 0.85 0.80 0.82 J

  16. A comparative study of microbiological and physicochemical ...

    African Journals Online (AJOL)

    A comparative study of microbiological and physicochemical characteristics of water distributed from two water treatment plants in Rwanda. ... Following their physicochemical records, their pH values (at 25°C) ranged from 6.61 to 7.01, temperatures ranging from 28 to 30°C, while their turbidity ranged from 1.34 to 4.9 NTU.

  17. Comparative studies of intestinal parasitic infections between ...

    African Journals Online (AJOL)

    The study compared the prevalence of intestinal parasitic infections among some Riverine communities with Upland communities in Rivers state, Nigeria. Three local government areas (LGAs) were randomly selected from both riverine and upland communities respectively and three communities were further selected from ...

  18. Comparative study of quantum anharmonic potentials

    Energy Technology Data Exchange (ETDEWEB)

    Amore, Paolo [Facultad de Ciencias, Universidad de Colima, Bernal Diaz del Castillo 340, Colima (Mexico)]. E-mail:; Aranda, Alfredo [Facultad de Ciencias, Universidad de Colima, Bernal Diaz del Castillo 340, Colima (Mexico); De Pace, Arturo [Istituto Nazionale di Fisica Nucleare, Sezione di Torino, via P. Giuria 1, I-10125 Torino (Italy); Lopez, Jorge A. [Physics Department, University of Texas at El Paso, El Paso, TX (United States)


    We perform a study of various anharmonic potentials using a recently developed method. We calculate both the wave functions and the energy eigenvalues for the ground and first excited states of the quartic, sextic and octic potentials with high precision, comparing the results with other techniques available in the literature.

  19. A comparative study of map use

    DEFF Research Database (Denmark)

    Bouvin, Niels Olof; Brodersen, Ann Christina; Bødker, Susanne


    We present a study comparing the handling of three kinds of maps, each on a physical device: a paper map, a tablet-PC based map, and a cellular phone based one. Six groups of users were asked to locate eight landmarks, looking out a window, and using a particular map. We have begun analyzing video...

  20. Experimental hydrophilic vinyl polysiloxane (VPS) impression materials incorporating a novel surfactant compared with commercial VPS. (United States)

    Ud Din, Shahab; Parker, Sandra; Braden, Michael; Tomlins, Pete; Patel, Mangala


    To formulate experimental hydrophilic (Exp) VPS impression materials incorporating a novel surfactant (Rhodasurf CET-2), and to compare their contact angles (CAs) with commercial materials, before/after disinfection. CAs were measured immediately after setting and after disinfection (1% NaOCl; 30min and 24h), together with their change whilst a droplet remained on the materials surface (over 10, 20, 30 60 and 120s), on three commercial (Aquasil Ultra-Monophase [Aq M], Elite HD-Monophase [Elt M], Extrude Medium-bodied [Extr M]) and four experimental (Exp I-IV) materials, using the Drop Shape Analysis 100 technique. The results were compared statistically. CAs of all experimental materials were within the range of those obtained for the commercial materials, with the exception of Exp-IV, which presented with the lowest CAs at the three time points. The control Exp-I was hydrophobic at all three time points (CAs ∼100+), as was Elite. Immediately after setting, Aq M had low CAs but these increased significantly after 30min of disinfection. After twenty four hours' disinfection CAs of all Exp/commercial VPS increased significantly compared to immediately after setting. The CAs of droplets left on the material (120s) decreased with time, even after disinfection, except for Exp-I. The novel surfactant Rhodasurf CET-2 in Exp-III and IV, is an effective surfactant, retaining a low CA after disinfection, compared with Igepal CO-530 in Aq M. Disinfecting VPS impression materials for more than 30min increases their surface CAs, and therefore prolonged disinfection periods should be avoided. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.



    BAS, Gökhan


    The purpose of this study was to introduce the Education System of the United States of America (USA) and to compare it with the Turkish Education System. The Education System of the United States of America was held from different factors (e.g., education structure, curriculum and instruction, principal selection, educational supervision, special education ,teacher education, finance for education, international examinations, vs.) and these factors were explained under headlines in the study...

  2. Comparing Conventional Bank Credit Vis A Vis Shariah Bank Musharakah: Experimental Economic Approach

    Directory of Open Access Journals (Sweden)

    Muhamad Abduh


    Full Text Available Central Bank of Indonesia with dual banking system – i.e Shariah and Conventional Bank – keep on developing system that considered as an answer to generate the national economic growth. One of the banking activities that emphasized by the Central Bank of Indonesia is fund distribution through either conventional bank credit or shariah bank fi nancing. Having the Experimental Economic Approach based on Induced Value Theory and employing ANOVA, this paper found that shariah bank musharakah fi nancing system would come up with higher profi t opportunity compare to conventional credit system. One main reason is that musharakah fi nancing in shariah bank applies profi t and lost sharing (PLS scheme so that will not be a burden to the customer when he fi nd low profi t.Keywords: Credit Loan, Musharakah Financing, Induced Value Theory, Experimental Economic Approach, Analysis of Variance (ANOVA.

  3. Feasibility study of the AOSTA experimental campaign

    Directory of Open Access Journals (Sweden)

    Carta M.


    Full Text Available The reduction of the nuclear waste is one of the most important nuclear issues. The high radiotoxicity of the spent fuel is due to plutonium and some minor actinides (MAs such as neptunium, americium and curium, above all. One way to reduce their hazard is to destroy by fission MAs in appropriate nuclear reactors. To allow the MAs destruction an important effort have been done on the nuclear data due to the poor knowledge in this field. In the framework of one of the NEA Expert Group on Integral Experiments for Minor Actinide Management an analysis of the feasibility of MAs irradiation campaign in the TAPIRO fast research reactor is carried out. This paper provides preliminary results obtained by calculations modelling the irradiation, in different TAPIRO irradiation channels, of some CEA samples coming from the French experimental campaign OSMOSE, loaded with different contents of MAs, in order to access, through particular peak spectrometry, to their capture cross section. On the basis of neutron transport calculation results, obtained by both deterministic and Monte Carlo methods, an estimate of the irradiated samples counting levels from the AOSTA (Activation of OSMOSE Samples in TAPIRO experimental campaign is provided.

  4. Design of an experimental set up for convective drying: experimental studies at different drying temperature (United States)

    Mohan, V. P. Chandra; Talukdar, Prabal


    An experimental setup is designed to investigate the convective drying of moist object experimentally. All the design data, components of setup, materials and specifications are presented. Transient moisture content of a rectangular shaped potato slice (4 × 2 × 2 cm) is measured at different air temperatures of 40, 50, 60 and 70 °C with an air velocity of 2 m/s. Two different drying rate periods are observed. Results are compared with available results from literature.

  5. The Experimental Study Of Effects Of Irradiation On Osseointegration

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kwan Soo; Lee, Sang Rae; Hwang, Eui Hwan [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Kyunghee University, Seoul (Korea, Republic of)


    The purpose of this study was to investigate the effects of the Co-60 gamma irradiation on the osseointegration. 2.0 mm titanium alloy screw implants were placed in the tibial metaphysics of the rabbits, bilaterally. The mean length of the implants was 6.0 mm. The right tibia was irradiated with a single dose of 15 Gy from 6{sup 0C}o teletherapic machine at 5th postoperative day. The experimental group was irradiated tibia. The control group was non-irradiated tibia. To observe the phase of bone formation, the bone labeling by intramuscular injection of 20 mg/Kg of Tetracycline, Calcein, Alizarin red S, was performed. The rabbits were sacrificed on the 1st, 2nd, 4th, 6th, 8th week and the tibia including implants were taken, and then the specimens were examined by the microradiography, light microscopy, and fluorescent microscopy.The obtained results were as follows; 1. There were connective tissue between bone and titanium at 1st week, in both group. Especially, the many empty lacunae without nucleus and obscure cytoplasm in experimental group, were observed. 2. The osteons were observed at 4th week in control group, and at 6th week in experimental group. The bone formation in experimental group was retarded as compared to the control group. 3. In fluorescent microscopy, bone labelling band was observed as linear, arc or concentric shape. Occasionary interrupted labelling band was observed, which is demonstrated bone remodeling. 4. In microradiographic examination, the radiolucent image was found between bone and implant with widening of bone marrow spaces as compared to the control group.

  6. Study on analyses of experimental data at DCA

    Energy Technology Data Exchange (ETDEWEB)

    Min, Byung Joo; Suk, Ho Chun; Hazama, T. [Korea Atomic Energy Research Institute, Taejon (Korea)


    In this report, the lattice characteristics of DCA are calculated to validate WIMS-AECL code for the lattice analysis of CANDU core by using experimental data of DCA and JNC. These results are compared with those of WIMS-ATR code. Analytical studies of some critical experiments had been performed to analyze the effects of fuel composition and lattice pitch. Different items of reactor physics such as local power peaking factor (LPF), effective multiplication factor (Keff) and coolant void reactivity were calculated for two coolant void fractions (0% and 100%). LPFs calculated by WIMS-ATR code are in close agreement with the experimental results. LPFs calculated by WIMS-AECL code with WINFRITH and ENDF/B-V libraries have similar values for both libraries but the differences between experimental data and results of WIMS-AECL code are larger than those of WIMS-ATR code. The maximum difference between the values calculated by WIMS-ATR and experimental values of LPFs are within 1.3%. LPF of Pu fuel cluster is found to be higher than that of the uranium fuel cluster. The coupled code systems WIMS-ATR and CITATION used in this analysis predict Keff within 1% {delta}K and coolant void reactivity within 4%{delta}K/K in all cases. The coolant void reactivity of uranium fuel is found to be positive for two lattice pitches (25.0 and 28.3 cm). Presence of plutonium fuel makes it more negative compare to uranium fuel. To validate WIMS-AECL code, the core characteristics of DCA shall be calculated by WIMS-AECL and CITATION codes in the future. 8 refs., 8 figs., 12 tabs. (Author)

  7. A Comparative Study of Business Ethics


    KOSAKA, Katsuaki


     In this brief paper, we shall try to analyse the concept of Business Ethics. For this purpose, we want to adopt the Comparative studies of Business Ethics. The main points of this argument are as follows.  At first, we want to make clear the relation of Modern Capitalism and the Ethics of Calvinism proposed by Max Weber. And next, we want to inquire into the spirit of merchants in the Edo period (1600-1864). We must compare the business spirit of the modern age in Japan and that of the Edo p...

  8. Mechanical comparative analysis of three different types of sutures in different dimensions tendons: experimental study Análise mecânica comparativa de três tipos de sutura entre tendões de dimensões diferentes: estudo experimental

    Directory of Open Access Journals (Sweden)

    Trajano Sardenberg


    Full Text Available The aim of this experimental investigation was study of mechanical profile of three kinds of suture, between tendons with different dimensions. Were utilized 21 mongrel dogs ( 11males, 10 females of wich were obtained the tendon comum flexor and tendon tibial cranial of both pelvic limbs. After the dissection of the tendons, suture was done, seven animal per group. The tendons utilized allways were from the right limb and from the left limb side utilized as control. After the suture, we performed axial traction tests, rate level of 30mm /min, using special jaws. After the test the machine's program informed the values of ultimate load, elongation and strain, and load elongation diagram. The results were submite to statistical study, that showed no difference between the technics utilized. The values of suture groups were smaller than the control, for ultimate load, and higher for elongation and strain.O objetivo da presente investigação experimental foi avaliar o perfil mecânico de três tipos de técnicas de sutura entre tendões de dimensões diferentes. Foram utilizados 21 cães sem raça definida (11machos/10 fêmeas, dos quais foram obtidos os tendões flexor comum dos dedos - t.c. (maior dimensão e tibial cranial - (menor dimensão, de ambos os membros pélvicos. Logo após a obtenção das peças foi realizada sutura, segundo cada tipo de técnica, porém sempre com o mesmo número de pontos. Os tendões utilizados para sutura foram sempre do lado direito e o controle do lado esquerdo ( Após a sutura, os corpos de prova foram fixados em garras especialmente desenvolvidas e submetidos a ensaio de tração axial à velocidade de 30mm/minuto. Após o ensaio o programa da máquina forneceu os valores da carga máxima ( na ruptura e deformação absoluta (mm e relativa (%, além do diagrama carga-deformação. Os resultados foram submetidos a estudo estatístico pela análise de medidas repetidas no nível de 5% de signific

  9. Experimental Study of Rectangular Labyrinth Weir

    Directory of Open Access Journals (Sweden)

    M. Rezaee


    Full Text Available Introduction: Labyrinth weirs compare with straight weirs had required less freeboard in upstream so they are more appropriate for the irrigation networks. So they could maked more space to sotrage water and restrained foold with higher discharge. Labyrinths weirs have three generally form triangles, trapezoidal and rectangular that Tullis et al. (15 presented formula (3 for discharge coefficient of labyrinth weirs (triangles and rectangular and a few studiescarried out on rectangular shape and its hydraulic characteristics are not specified.Therefore main aim of this paper study and characterized hydraulic characteristics of rectangular labyrinth weirs by using laboratory data. Materials and Methods: In this study rectangular labyrinth weir discharge and coefficient discharge relationships used dimensional analysis and experiment on hydraulic modeling, constant coefficient was defined. Laboratory flume is shown in Figure 2 (0.5 m wide x 12 m long x 0.8 m deep. Models was made from clear plexiglass plate with 10 cm thickness thatcuted using leaserdevice and the crest manualy shaped quadrant with radius 10 cm, all models using silicon glue install in the flume. The upstream depth readership by point gauge that installed in upstream of models. Discharge calcutaed byupsterm depth of triangular weir that installed in down stream of flume.Data were analyzed by SPSS software and to compare relationships with each other used two parameter root mean square error and correlation coefficient and charts darw in Excel Results and Discussion: discharge coefficient formula (11 carried out by using SPSS software that compared with formula (3. Results showed (Tables 2 and 3 that the correlation coefficient of formula (11 was more than a formula (3 and formula (11 RSME was less than formula (3 RSME except in first and fifth hydraulic model (rectengular1 and 5 that they were almost equal. So the formula (11 was more accurate than a formula (3 to peredict

  10. A comparative study of Averrhoabilimbi extraction method (United States)

    Zulhaimi, H. I.; Rosli, I. R.; Kasim, K. F.; Akmal, H. Muhammad; Nuradibah, M. A.; Sam, S. T.


    In recent year, bioactive compound in plant has become a limelight in the food and pharmaceutical market, leading to research interest to implement effective technologies for extracting bioactive substance. Therefore, this study is focusing on extraction of Averrhoabilimbi by different extraction technique namely, maceration and ultrasound-assisted extraction. Fewplant partsof Averrhoabilimbiweretaken as extraction samples which are fruits, leaves and twig. Different solvents such as methanol, ethanol and distilled water were utilized in the process. Fruit extractsresult in highest extraction yield compared to other plant parts. Ethanol and distilled water have significant role compared to methanol in all parts and both extraction technique. The result also shows that ultrasound-assisted extraction gave comparable result with maceration. Besides, the shorter period on extraction process gives useful in term of implementation to industries.

  11. Comparative study of background subtraction algorithms (United States)

    Benezeth, Yannick; Jodoin, Pierre-Marc; Emile, Bruno; Laurent, Hélène; Rosenberger, Christophe


    We present a comparative study of several state-of-the-art background subtraction methods. Approaches ranging from simple background subtraction with global thresholding to more sophisticated statistical methods have been implemented and tested on different videos with ground truth. The goal is to provide a solid analytic ground to underscore the strengths and weaknesses of the most widely implemented motion detection methods. The methods are compared based on their robustness to different types of video, their memory requirements, and the computational effort they require. The impact of a Markovian prior as well as some postprocessing operators are also evaluated. Most of the videos used come from state-of-the-art benchmark databases and represent different challenges such as poor SNR, multimodal background motion, and camera jitter. Overall, we not only help to better understand for which type of videos each method best suits but also estimate how, sophisticated methods are better compared to basic background subtraction methods.

  12. An Experimental Study on Wall Thickness Distribution in Thermoforming

    Directory of Open Access Journals (Sweden)

    Sencer Süreyya Karabeyoglu


    Full Text Available In this work, Polystyrene (PS sheets were thermoformed in predetermined conditions. Wall thickness distributions obtained by experimental method in PS thermoformed products. Then same thickness distributions were predicted by using Geometric Element Analysis (GEA. The thickness results which obtained experimentally, compared to thickness distributions which were predicted by GEA. It has been found that GEA does not reveal thickness distributions precisely.

  13. Experimental Study of Axially Tension Cold Formed Steel Channel Members (United States)

    Apriani, Widya; Lubis, Fadrizal; Angraini, Muthia


    Experimental testing is commonly used as one of the steps to determine the cause of the collapse of a building structure. The collapse of structures can be due to low quality materials. Although material samples have passed laboratory tests and the existing technical specifications have been met but there may be undetected defects and known material after failure. In this paper will be presented Experimental Testing of Axially Tension Cold Formed Steel Channel Members to determine the cause of the collapse of a building roof truss x in Pekanbaru. Test of tensile strength material cold formed channel sections was performed to obtain the main characteristics of Cold Formed steel material, namely ultimate tensile strength loads that can be held by members and the yield stress possessed by channel sections used in construction. Analysis of axially tension cold formed steel channel section presents in this paper was conducted through experimental study based on specificationsAnnualBook of ASTM Standards: Metal Test methods and Analitical Procedures, Section 3 (1991). The result of capacity loads experimental test was compared with design based on SNI 03-7971-2013standard of Indonesia for the design of cold formed steel structural members. The results of the yield stress of the material will be seen against the minimum allowable allowable stress range. After the test, the percentace of ultimate axial tension capacity theory has a result that is 16.46% larger than the ultimate axial tension capacity experimental. When compared with the load that must be borne 5.673 kN/m it can be concluded that 2 specimens do not meet. Yield stress of member has fulfilled requirement that wass bigger than 550 MPa. Based on the curve obtained ultimate axial tension capacity theory, results greater than experimental. The greatest voltage value (fu) is achieved under the same conditions as its yield stress. For this specimen with a melting voltage value fy = 571.5068 MPa has fulfilled the

  14. Experimental study of external fuel vaporization (United States)

    Szetela, E. J.; Tevelde, J. A.


    The fuel properties used in the design of a flash vaporization system for aircraft gas turbine engines were evaluated in experiments using a flowing system to determine critical temperature and pressure, boiling points, dew points, heat transfer coefficients, deposit formation rates, and deposit removal. Three fuels were included in the experiments: Jet-A, an experimental referree broad specification fuel, and a premium No. 2 diesel fuel. Engine conditions representing a NASA Energy Efficient Engine at sea-level take-off, cruise, and idle were simulated in the vaporization system and it was found that single phase flow was maintained in the heat exchanger and downstream of the throttle. Deposits encountered in the heat exchanger represented a thermal resistance as high as 1300 sq M K/watt and a deposit formation rate over 1000 gC/sq cm hr.

  15. Experimental Study of the Sampled Labyrinth Chaos

    Directory of Open Access Journals (Sweden)

    J. Petrzela


    Full Text Available In this paper, some new numerical as well as experimental results connected with the so-called labyrinth chaos are presented. This very unusual chaotic motion can be generated by mathematical model involving the scalar goniometrical functions which makes a three-dimensional autonomous dynamical system strongly nonlinear. Final circuitry implementation with analog core and digital parts can be used for modeling Brownian motion. From the viewpoint of generating chaotic motion by some electronic circuit, first step is to solve problems associated with the two-port nonlinear transfer functions synthesis. In the case of labyrinth chaos the finite dynamical range of the input variables introduced by the used active elements usually limits the performance greatly, similarly as it holds for the multi-grid spiral attractors. This paper shows an elegant way how to remove these obstacles by using uni-versal multiple-port with internal digital signal processing.

  16. Experimental Study of Pollutant Transfer within Dwellings

    CERN Document Server

    Koffi, Juslin; Allard, Francis; Husaunndee, Ahmad


    A mechanical ventilation principle used in French residential buildings was tested in the experimental house of the CSTB research centre. The experiments dealt with pollutant removal efficiency of this ventilation principle, mainly with air tightness and the influence of internal doors. Tracer gas constant injection method was used to simulate the pollution source in the living room. SF6 concentrations were measured in several rooms. The results showed that the air flow routes were in agreement with the theory as long as internal doors were closed. When doors were open, the air pattern was disturbed a lot; a great quantity of the emitted pollutant was measured in the bedrooms. Besides, stack effect promotes the pollutant moving towards the bedrooms under higher indoor-outdoor air temperature differences. In addition, the results showed that if the opening of the bedroom window increases the air change rate, it does not guarantee a good indoor air quality.

  17. An experimental study on pump clogging (United States)

    Isono, M.; Nohmi, M.; Uchida, H.; Kawai, M.; Kudo, H.; Kawahara, T.; Miyagawa, K.; Saito, S.


    For sewage pump that various foreign substance is flowed into, anti-clogging performance is a factor as important as pump efficiency in order to avoid clogging trouble by foreign substance. Many investigations about pump inner flow and pump efficiency estimation have been carried out conventionally in order to realize coexistence with anti-clogging performance and pump performance. And these results have been reflected in construction of the running water section design method. As a index of anti-clogging performance, "impeller passage diameter" which is diameter of spherical solid that can pass through the pump is used widely. And there are various type of the sewage pump which have large impeller passage diameter. However real cause of clog is not a solid, and it is fibrous material such as towel and clothes, vinyl and paper diaper. In most case these material accumulate in the pump, so that clog is occurred. In this study, for the purpose of quantification of anti-clogging performance against fibrous materials, the factor that affect to clogging of pump was investigated by pump model test using a string. The test is done based on Taguchi method. In this test, type of the pump model, diameter of the string, material of the string, length of the string and flow rate are selected for the factor, and the effect that they have on the clogging of the pump was investigated. As a result of this test, it was made clear that length of the string has a strong influence on the clogging of the pump. And from the result of this test, evaluation method of anti-clogging performance of the pump against fibrous material by using string was considered. According to the result of above test based on Taguchi method, it was assumed that quantification of anti-clogging performance against fibrous materials is possible by flowing plural strings into the pump and calculating the probability of passing. Plurality sewage pumps of different types were evaluated based on this assumption

  18. Comparative study of convective heat transfer characteristics of nanofluids (United States)

    Muryam, Hina; Ramzan, Naveed; Umer, Asim; Awan, Gul Hameed; Hassan, Ali


    The present research is about to draw a comparison between heat transfer characteristics of gold/deionized water (DIW) and silver/DIW based nanofluid under same heat flux for laminar flow. Experiments are performed on both nanofluid by using different concentrations (0.015, 0.045, 0.0667%) of nano-particles (NPs) in DIW as a base fluid. The experimental study concludes that an appreciable intensification in heat transfer coefficient (HTC) of both nanofluid has been attained as compare to base fluid. However, gold/DIW based nanofluid exhibit better convective heat transfer intensification compared with silver/DIW based nanofluid but Shah correlation cannot predict as much augmentation as in experimental work for both nanofluid. It is also noticed that the anomalous enhancement in Nusselt number and HTC is not only due to the accession in thermal properties but also by the formation of thinner thermal boundary layer at the entrance of the tube due to NPs.

  19. Um estudo comparativo das cepas Feira de Santana (Bahia e Porto Rico do Schistosoma Mansoni na infecção experimental do camundongo A comparative study of the Feira de Santana (Bahia and Porto Rico strains of Schistosoma mansoni in the experimental infection of mice

    Directory of Open Access Journals (Sweden)

    Zilton A. Andrade


    Full Text Available Dois grupos de camundongos, infectados com cem cercárias do S. mansoni, um com a cepa Porto Rico e outro com a cepa Feira de Santana mostraram resultados semelhantes quanto à recuperação de esquistossômulos pulmonares, recuperação de vermes do sistema porta, número de ovos por grama de tecido no figado e intestinos, lesões histopatológicas e mortalidade. Na realidade as diferenças entre animais infectados pela mesma cepa foram maiores que quando os dados conjuntos das duas cepas foram considerados.A comparative study of mice infected either with the Porto Rican or a Brazilian (Feira de Santana strain of Schistosoma mansoni failed to show any difference regarding recovery of five day lung worms, recovery of adult worms from the portal system, number of eggs per gram of tissue in liver and intestines, histopathology or mortality rate. In fact, the differences, although small, were greater among animals infected with the same strain, that when the total results from both strains were compared.

  20. Comparative Study of Bancruptcy Prediction Models

    Directory of Open Access Journals (Sweden)

    Isye Arieshanti


    Full Text Available Early indication of bancruptcy is important for a company. If companies aware of  potency of their bancruptcy, they can take a preventive action to anticipate the bancruptcy. In order to detect the potency of a bancruptcy, a company can utilize a a model of bancruptcy prediction. The prediction model can be built using a machine learning methods. However, the choice of machine learning methods should be performed carefully. Because the suitability of a model depends on the problem specifically. Therefore, in this paper we perform a comparative study of several machine leaning methods for bancruptcy prediction. According to the comparative study, the performance of several models that based on machine learning methods (k-NN, fuzzy k-NN, SVM, Bagging Nearest Neighbour SVM, Multilayer Perceptron(MLP, Hybrid of MLP + Multiple Linear Regression, it can be showed that fuzzy k-NN method achieve the best performance with accuracy 77.5%

  1. Experimental and numerical studies of rotating drum grate furnace

    Directory of Open Access Journals (Sweden)

    Basista Grzegorz


    Full Text Available Waste material from the meat industry can be taken into account as a biofuel. Studies confirm, that calorific value is higher and ash content is lower comparing to some conventional fuels. EU directives regulate details of thermal disposal of the waste material from the meat industry - especially in range of the process temperature and time of the particle presence in area of the combustion zone. The paper describes design of the rotating drum grate stove, dedicated to thermal disposal of the meat wastes as well as solid biomass (pellet, small bricket, wood chips combustion. Device has been developed in frames of cooperation between AGH University of Science and Technology (Krakow, Poland and producer focused on technologies of energy utilization of biomass in distributed generation. Results of measurements of selected operational parameters performed during startup of the furnace have been presented and discussed. Furthermore, numerical model of the combustion process has been developed to complement experimental results in range of the temperature and oxygen distribution in the area of the combustion chamber. ANSYS CFX solver has been applied to perform simulations including rotational domain related with specifics of operation of the device. Results of numerical modelling and experimental studies have been summarized and compared.


    Directory of Open Access Journals (Sweden)

    Mădălina Marian


    Full Text Available This paper presents a comparative study between the coordinates that result by measuring with a Total Station, precision 5cc, and the coordinates obtained by using classical calculation. Measurements were made in the compilation of cadastral documentation necessary for obtaining provisional registration of a number of land ownership in the Land Registry. The results of measurements and errors were within the tolerances allowed by regulation.

  3. Friendship in Latin American Social Comparative Studies

    Directory of Open Access Journals (Sweden)

    Agnaldo Garcia


    Full Text Available Friendship has been traditionally investigated in the field of interpersonal relationships using different theoretical frameworks and approaches. This paper discusses the possibility of investigating friendship from a comparative Latin American perspective, based on a wide literature review on the subject. Based on the theoretical proposals of Hinde (1997 for the investigation of interpersonal relationships, the paper considers that friendship involves several levels of complexity and affects and is affected by distinct dimensions of Latin American society. The paper recognizes that comparative studies have placed the importance of friends and friendship in areas such as economy, health, education, and migration, among others. As expected, Latin American comparative studies are more frequent in some disciplines, mainly those based on censuses data, and theoretically related to social-economic and demographic concepts, including social networks and social capital. The possibility of developing a Latin American perspective for the study of friendship requires not only the need of empirical but also theoretical advances, as well as scientific cooperation and innovation. Friendship is seen as relevant for the constitution of the social tissue of Latin American society, being affected and affecting different areas and levels. In the social economic dimension, friends are relevant, specifically in Latin America, to themes such as poverty and social vulnerability. Some future possibilities for investigation are discussed.

  4. An experimental study to compare inflammatory response due to liquid or gas joint distension in horses submitted to arthroscopy Estudo experimental para comparar a resposta inflamatória decorrente da distensão líquida ou gasosa em cavalos submetidos à artroscopia

    Directory of Open Access Journals (Sweden)

    Renata Bello Rossetti


    Full Text Available PURPOSE: To assess comparatively the inflammatory response that follows CO2 or Ringer's lactate joint capsular distension of horses submitted to experimental arthroscopy METHODS: Each animal was submitted to a bilateral tarsocrural arthroscopy employing gas distention in one joint and fluid distention in the contralateral joint. Synovial fluid was evaluated at 0, six, 12, 24 and 48 hours post-operative. RESULTS: The use of CO2 for arthroscopy causes an acute and mild synovitis alike to the liquid capsular distension, showing similar synovial fluid increase of leukocytes, TP, and TNF-α. Although synovial fluid PGE2 content was higher in joints submitted to CO2 distension, lower levels of hemoglobin and leukocytes oxidative burst after surgery indicates that CO2 arthroscopy decreased intra-articular bleeding and activation of infiltrating leukocytes. CONCLUSIONS: The use of CO2 for arthroscopic examination causes acute and mild synovitis that is similar to the effects caused by the liquid capsular distension. CO2 also seems to decrease intra-articular bleeding and activation of leukocytes.OBJETIVO: Avaliar comparativamente a resposta inflamatória decorrente da distensão líquida ou gasosa em cavalos submetidos ao exame artroscópico. MÉTODOS: Cada animal foi submetido a uma artroscopia bilateral tarsocrural empregando uma distensão com gás em uma articulação e líquido na articulação contralateral. O líquido sinovial foi avaliado as zero, seis, 12, 24 e 48 horas do pós-operatório. RESULTADOS: A utilização de CO2 para a artroscopia provoca uma sinovite aguda e leve tal como a distensão capsular por líquido, mostrando um aumento similar de leucócitos, TP (proteína total e TNF-a. Embora no líquido sinovial a quantidade de PGE2 tenha sido maior nas articulações submetidas à distensão por CO2, níveis mais baixos de hemoglobina e explosão oxidativa de leucócitos após a cirurgia indica que a artroscopia com CO2 diminuiu o

  5. Economic principles in communication: an experimental study. (United States)

    De Jaegher, Kris; Rosenkranz, Stephanie; Weitzel, Utz


    This paper experimentally investigates how economic principles affect communication. In a simple sender-receiver game with common interests over payoffs, the sender can send a signal without a pre-given meaning in an infrequent or frequent state of the world. When the signal is costly, several theories (focal point theory, the intuitive criterion, evolutionary game theory) predict an efficient separating equilibrium, where the signal is sent in the infrequent state of the world (also referred to as Horn׳s rule). To analyze whether Horn׳s rule applies, and if so, which theory best explains it, we develop and test variants of the sender-receiver game where the theories generate discriminatory hypotheses. In costly signaling variants, our participants follow Horn׳s rule most of the time, in a manner that is best explained by focal point theory. In costless signaling variants, evolutionary game theory best explains our results. Here participants coordinate significantly more (less) often on a separating equilibrium where the signal is sent in the frequent state if they are primed to associate the absence of a signal with the infrequent (frequent) state of the world. We also find indications that a similar priming effect applies to costly signals. Thus, while the frequency with which participants follow Horn׳s rule in costly signaling variants is best explained by Horn׳s rule, the priming effect shows that some of our participants׳ behavior is best explained by evolutionary game theory even when signals are costly. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Study of comparative bioavailability of omeprazole pellets. (United States)

    Karim, Sabiha; Hay, Yuen Kah; Baie, Saringat H; Bukhari, Nadeem Irfan; Murtaza, Ghulam


    The objective of this study was to assess the bioequivalence between the omeprazole laboratory based formulation and the commercial formulation, Zimor Rubio, Spain, considered as reference formulation. The experiment was carried out according to a 2-period, 2-sequence crossover design with a two week washout period. A validated high performance liquid chromatographic method was applied for in vivo experiments. It was observed that omeprazole contents were comparable in all formulations. To establish bioequivalence, 90% confidence intervals (CI) for the differences of total AUCs of the test and reference formulations were calculated. The 95% CI ratio of the AUC within 0.80 to 1.25 was considered as bioequivalent. The carryout effect was investigated prior to assessing the bioequivalence of the two formulations. The test formulation of omeprazole was found to be comparable with the reference formulation (Zimor) with regard to bioavailability.

  7. A Comparative Analysis of Ultrasound Velocity in Binary Liquid Systems of PPG by Mathematical and Experimental Methods (United States)

    Gayathri, A.; Venugopal, T.; Venkatramanan, K.

    The estimation of the speed of ultrasound is the fundamental requirement for investigating the transport properties of liquid and solid systems. Ultrasonic velocities of liquid mixtures containing polar and non-polar groups are of considerable importance in understanding inter-molecular interaction between component molecules and they find applications in several industrial and technological processes. There are many standard mathematical methods available to measure the ultrasonic velocity. In the present study, interferometric technique is planned for experimental measurement of ultrasound velocity. In this paper, the speed of ultrasound waves in Polypropylene Glycol (PPG 400, PPG 4000) in toluene has been estimated for different concentrations (2%, 4%, 6%, 8% & 10%) at 303K and these experimental values compared with theoretical values obtained by using various mathematical methods like Nomotto's Relation, Vandeal Vangeal Relation, Impedance Relation, and Rao's specific sound velocity. The most reliable method that matches with experimental method is identified using Average Percentage Error (APE) and analysed in the light of molecular interactions occurring in the binary liquid systems. Comparison of evaluated theoretical velocities with experimental values will reveal the nature of interaction between component molecules in the mixtures. Such theoretical study is useful in defining a comprehensive theoretical model for a specific liquid mixture. Also, various molecular interaction parameters like free volume, internal pressure, viscous relaxation time, inter atomic free length, etc are calculated and discussed in terms of polymer-solvent interactions.

  8. Rapidly resorbable vs. non-resorbable suture for experimental colonic anastomoses in rats--a randomized experimental study

    DEFF Research Database (Denmark)

    Klein, Mads; Pommergaard, Hans-Christian; Gögenur, Ismail


    Anastomotic dehiscence remains an important challenge for colorectal surgeons worldwide. Extensive research focused on performing a safe anastomosis is conducted with rats being the most used model when examining colorectal anastomoses. In daily clinical practice resorbable sutures are used when...... hand-sewn anastomoses are performed. However, in the experimental studies examining colorectal anastomoses, non-resorbable sutures have predominantly been used. The aim of this study was to compare a rapidly resorbable suture with a non-resorbable suture in experimental colorectal anastomoses....

  9. Comparative Study of Daylighting Calculation Methods

    Directory of Open Access Journals (Sweden)

    Mandala Ariani


    Full Text Available The aim of this study is to assess five daylighting calculation method commonly used in architectural study. The methods used include hand calculation methods (SNI/DPMB method and BRE Daylighting Protractors, scale models studied in an artificial sky simulator and computer programs using Dialux and Velux lighting software. The test room is conditioned by the uniform sky conditions, simple room geometry with variations of the room reflectance (black, grey, and white color. The analyses compared the result (including daylight factor, illumination, and coefficient of uniformity value and examines the similarity and contrast the result different. The color variations trial is used to analyses the internally reflection factor contribution to the result.

  10. Theoretical & Experimental Studies of Elementary Particles

    Energy Technology Data Exchange (ETDEWEB)

    McFarland, Kevin [Univ. of Rochester, NY (United States)


    Abstract High energy physics has been one of the signature research programs at the University of Rochester for over 60 years. The group has made leading contributions to experimental discoveries at accelerators and in cosmic rays and has played major roles in developing the theoretical framework that gives us our ``standard model'' of fundamental interactions today. This award from the Department of Energy funded a major portion of that research for more than 20 years. During this time, highlights of the supported work included the discovery of the top quark at the Fermilab Tevatron, the completion of a broad program of physics measurements that verified the electroweak unified theory, the measurement of three generations of neutrino flavor oscillations, and the first observation of a ``Higgs like'' boson at the Large Hadron Collider. The work has resulted in more than 2000 publications over the period of the grant. The principal investigators supported on this grant have been recognized as leaders in the field of elementary particle physics by their peers through numerous awards and leadership positions. Most notable among them is the APS W.K.H. Panofsky Prize awarded to Arie Bodek in 2004, the J.J. Sakurai Prizes awarded to Susumu Okubo and C. Richard Hagen in 2005 and 2010, respectively, the Wigner medal awarded to Susumu Okubo in 2006, and five principal investigators (Das, Demina, McFarland, Orr, Tipton) who received Department of Energy Outstanding Junior Investigator awards during the period of this grant. The University of Rochester Department of Physics and Astronomy, which houses the research group, provides primary salary support for the faculty and has waived most tuition costs for graduate students during the period of this grant. The group also benefits significantly from technical support and infrastructure available at the University which supports the work. The research work of the group has provided educational opportunities

  11. Comparative study of INPIStron and spark gap (United States)

    Han, Kwang S.; Lee, Ja H.


    An inverse pinch plasma switch, INPIStron, was studied in comparison to a conventional spark gap. The INPIStron is under development for high power switching applications. The INPIStron has an inverse pinch dynamics, opposed to Z-pinch dynamics in the spark gap. The electrical, plasma dynamics and radiative properties of the closing plasmas have been studied. Recently the high-voltage pulse transfer capabilities or both the INPIStron and the spark gap were also compared. The INPIStron with a low impedance Z = 9 ohms transfers 87 percent of an input pulse with a halfwidth of 2 mu s. For the same input pulse the spark gap of Z = 100 ohms transfers 68 percent. Fast framing and streak photography, taken with an TRW image converter camera, was used to observe the discharge uniformity and closing plasma speed in both switches. In order to assess the effects of closing plasmas on erosion of electrode material, emission spectra of two switches were studied with a spectrometer-optical multi channel analyzer (OMA) system. The typical emission spectra of the closing plasmas in the INPIStron and the spark gap showed that there were comparatively weak carbon line emission in 658.7 nm and copper (electrode material) line emissions in the INPIStron, indicating low erosion of materials in the INPIStron.

  12. Comparative efficacy of oral meloxicam and phenylbutazone in 2 experimental pain models in the horse. (United States)

    Banse, Heidi; Cribb, Alastair E


    The efficacy of oral phenylbutazone [PBZ; 4.4 mg/kg body weight (BW), q12h], a non-selective non-steroidal anti-inflammatory drug (NSAID), and oral meloxicam (MXM; 0.6 mg/kg BW, q24h), a COX-2 selective NSAID, were evaluated in 2 experimental pain models in horses: the adjustable heart bar shoe (HBS) model, primarily representative of mechanical pain, and the lipopolysaccharide-induced synovitis (SYN) model, primarily representative of inflammatory pain. In the HBS model, PBZ reduced multiple indicators of pain compared with the placebo and MXM. Meloxicam did not reduce indicators of pain relative to the placebo. In the SYN model, MXM and PBZ reduced increases in carpal skin temperature compared to the placebo. Meloxicam reduced lameness scores and lameness-induced changes in head movement compared to the placebo and PBZ. Phenylbutazone reduced lameness-induced change in head movement compared to the placebo. Overall, PBZ was more effective than MXM at reducing pain in the HBS model, while MXM was more effective at reducing pain in the SYN model at the oral doses used.

  13. Comparative Study of Vented vs. Unvented Crawlspaces

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Kaushik [ORNL; Christian, Jeffrey E [ORNL; Gehl, Anthony C [ORNL


    There has been a significant amount of research in the area of building energy efficiency and durability. However, well-documented quantitative information on the impact of crawlspaces on the performance of residential structures is lacking. The objective of this study was to evaluate and compare the effects of two crawlspace strategies on the whole-house performance of a pair of houses in a mixed humid climate. These houses were built with advanced envelope systems to provide energy savings of 50% or more compared to traditional 2010 new construction. One crawlspace contains insulated walls and is sealed and semi-conditioned. The other is a traditional vented crawlspace with insulation in the crawlspace ceiling. The vented (traditional) crawlspace contains fiberglass batts installed in the floor chase cavities above the crawl, while the sealed and insulated crawlspace contains foil-faced polyisocyanurate foam insulation on the interior side of the masonry walls. Various sensors to measure temperatures, heat flux through crawlspace walls and ceiling, and relative humidity were installed in the two crawlspaces. Data from these sensors have been analyzed to compare the performance of the two crawlspace designs. The analysis results indicated that the sealed and insulated crawlspace design is better than the traditional vented crawlspace in the mixed humid climate.


    Directory of Open Access Journals (Sweden)

    W. Bendaikha


    Full Text Available Hydrogen is a sustainable fuel option and one of the potential solutions for the current energy and environmental problems. In this study hydrogen is produced using a hydrogen generator with a Proton Exchange Membrane (PEM electrolyser. An experimental study is done in the Center of Development of the Renewable Energy, Algiers, Algeria.The experimental device contains essentially a photovoltaic module, a PEM electrolyser, a gasometer and the devices of measures of characteristics of the PEM electrolyser as well as two pyranometers for the horizontal and diffuse global radiance registration. This system in pilots scale is permitted on the one hand, to measured and analyzed the characteristics: of the PEM electrolyser for two different pressures of working (Patm and P=3 bar, on the other hand, to study the volume of hydrogen produces in the time with different sources of electrical power (generator, photovoltaic module, fluorescent lamp, the efficiency for every case is calculated and compared. We present in this paper the variation of the solar hydrogen flow rate produced according to the global radiance and according to the time for a typical day’s of August.

  15. Experimental studies of electron-phonon interactions in gallium nitride

    CERN Document Server

    Stanton, N M


    This thesis presents an experimental investigation of the electron-phonon interaction in GaN. Bulk epilayers, grown by MBE, and AIGaN/GaN heterostructure grown by MOCVD, have been studied. The energy relaxation rate for hot electrons has been measured over a wide range of temperatures, allowing both acoustic and optic phonon emission to be studied in GaN epilayers. Direct phonon measurements, both studying the emission and absorption processes, have been performed. Detection of phonons emitted when hot electrons relax their excess energy complements the measurements of relaxation rates. Absorption of acoustic phonons by the epilayers, using both fixed and extended metal film phonon sources, allowed investigation into the effectiveness of the 2k sub F cutoff in the low mobility layers. The experimental findings are compared with the predictions of theory. AIGaN/GaN heterostructures were characterised and measurements of the energy relaxation rate in the temperature range 4K-40K obtained. Excellent agreement wi...


    Directory of Open Access Journals (Sweden)



    Full Text Available The main objective of the study is the determination of students’ satisfaction regarding curricular activities. The study has been accomplished using the qualitative and quantitative research, using the bibliographic study, various secondary sources and different primary sources. The study is developed with a marketing research and accomplished using the survey method. 699 students from four universities have been questioned. Due to a comparative study the University of Applied Sciences Worms, University of Applied Sciences Wiesbaden Rüsselsheim, University of Applied Sciences Frankfurt am Main and Nürtingen-Geislingen University have been analysed and their similarities and differences have been identified. The collected data, based on the established sample, is evaluated through univariate and bivariate analysis. In accordance with the evaluated sample, specific gaps from each region are identified regarding the curricular offer of the analysed universities. As a result to the conducted study, recommendations for the University of Applied Sciences Worms regarding the student’s satisfaction concerning the curricular offer are presented.

  17. Tensile strength of biological fibrin sealants: a comparative study. (United States)

    Lacaze, Laurence; Le Dem, Nicolas; Bubenheim, Michael; Tsilividis, Basile; Mezghani, Julien; Schwartz, Lilian; Francois, Arnaud; Ertaud, Jean Yves; Bagot d'Arc, Maurice; Scotté, Michel


    Fibrin sealants are commonly used in liver surgery, although their effectiveness in routine clinical practice remains controversial. Individual sealant characteristics are based on hemostatic effects and adhesion properties that can be experimentally measured using the 'rat skin test' or the 'pig skin test'. This study used a more relevant and realistic experimental canine model to compare the differences in the adhesive properties of four fibrin sealants in hepatectomy: Tisseel/Tissucol, Tachosil, Quixil, and Beriplast. A partial hepatectomy was performed in beagle dogs under general anesthesia to obtain liver cross-sections. Fibrin sealants were allocated to dog livers using a Youden square design. The tensile strength measurement was performed using a traction system to measure the rupture stress point of a small wooden cylinder bonded to the liver cross-section. Significantly greater adhesion properties were observed with Tisseel/Tissucol compared with Quixil or Beriplast (P = 0.002 and 0.001, respectively). Similarly, Tachosil demonstrated significantly greater adhesive properties compared with Beriplast (P = 0.009) or Quixil (P = 0.014). No significant differences were observed between Tisseel/Tissucol and Tachosil or between Beriplast and Quixil. The results of this comparative study demonstrate that different fibrin sealants exhibit different adhesive properties. Tisseel/Tissucol and Tachosil provided greatest adhesion to liver cross-section in our canine model of hepatectomy. These results may enable the optimal choice of fibrin sealants for this procedure in clinical practice. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Experimental studies with low transition energy optics in the SPS

    CERN Document Server

    Bartosik, H; Bohl, T; Cettour Cave, S; Esteban Muller, J; Cornelis, K; Papaphilippou, Y; Rumolo, G; Salvant, B; Shaposhnikova, E; Wenninger, J


    The optics of the SPS can be tuned to lower transition energy such that the slippage factor at injection is raised by a factor of almost 3. From theory, an increase of the intensity thresholds for transverse mode coupling, longitudinal coupled bunch and longitudinal instabilities due to the loss of Landau damping can be expected. In this paper, experimental studies in the SPS with single bunches of protons with intensities of up to 3.5e11 p/b on the flat bottom and at 450 GeV/c are presented. Longitudinal instabilities were studied with LHC-type beams with 50 ns spacing and injected intensities up to 1.8e11 p/b. The measurements address the increase of intensity thresholds and the achievable transverse emittances in the new low gamma transition optics with respect to the nominal SPS optics. The obtained results are compared with numerical simulations.

  19. Experimental studies of auroral arc generators

    Energy Technology Data Exchange (ETDEWEB)

    Suszcynsky, D.M.; Borovsky, J.E.; Thomsen, M.F. [and others


    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). An all-sky video camera system was deployed in Eagle, Alaska at the foot of the magnetic field line that threads geosynchronous satellite 1989-046 as part of a campaign to study correlations of ground-based auroral activity with satellite-based plasma and energetic particle measurements. The overall intent of the project was to study magnetosphere-ionosphere coupling as it relates to the aurora, and, in particular, to look for signatures that may help to identify various auroral generator mechanism(s). During this study, our efforts were primarily directed towards identifying the generator mechanism(s) for pulsating aurora. Our data, though not conclusive, are found to support theories that propose a cyclotron resonance mechanism for the generation of auroral pulsations.

  20. Experimental studies of actinides in molten salts

    Energy Technology Data Exchange (ETDEWEB)

    Reavis, J.G.


    This review stresses techniques used in studies of molten salts containing multigram amounts of actinides exhibiting intense alpha activity but little or no penetrating gamma radiation. The preponderance of studies have used halides because oxygen-containing actinide compounds (other than oxides) are generally unstable at high temperatures. Topics discussed here include special enclosures, materials problems, preparation and purification of actinide elements and compounds, and measurements of various properties of the molten volts. Property measurements discussed are phase relationships, vapor pressure, density, viscosity, absorption spectra, electromotive force, and conductance. 188 refs., 17 figs., 6 tabs.

  1. Experimental Study on Gastric Juice Secretion by ...

    African Journals Online (AJOL)



    May 29, 2012 ... reduced (P < 0.05) when acupuncture at zusanli was applied after treatment with cimetidine. Therefore, our study shows that when electroacupuncture at zusanli is applied, the gastric electrical frequency increased and gastric electrical amplitude reduced, while the flux of gastric juice secretion increased.

  2. Experimental and computational studies of polar solvation

    Energy Technology Data Exchange (ETDEWEB)


    Many articles and papers were published; a few are still in preparation or will be published. The solvation dynamics studies will be extended to ionic solutions. Computer simulations were also performed. A new line of research was begun on excited-state proton-transfer reactions catalyzed by alcohol solvents. (DLC)

  3. Comparative evaluation of two vaccine candidates against experimental leishmaniasis due to Leishmania major infection in four inbred mouse strains. (United States)

    Benhnini, Fouad; Chenik, Mehdi; Laouini, Dhafer; Louzir, Hechmi; Cazenave, Pierre André; Dellagi, Koussay


    Experimental leishmaniasis in BALB/c and C57BL/6 mice are the most investigated murine models that were used for the preclinical evaluation of Leishmania vaccine candidates. We have previously described two new inbred mouse strains named PWK and MAI issued from feral founders that also support the development of experimental leishmaniasis due to L. major. In this study, we sought to determine whether different mouse inbred strains generate concordant or discordant results when used to evaluate the potential of Leishmania proteins to protect against experimental leishmaniasis. To this end, two Leishmania proteins, namely, LACK (for Leishmania homolog of receptor for activated C kinase) and LmPDI (for L. major protein disulfide isomerase) were compared for their capacity to protect against experimental leishmaniasis in PWK, MAI, BALB/c, and C57BL/6 inbred mouse strains. Our data show that the capacity of Leishmania proteins to confer protection depends on the mouse strain used, stressing the important role played by the genetic background in shaping the immune response against the pathogen. These results may have important implications for the preclinical evaluation of candidate Leishmania vaccines: rather than using a single mouse strain, a panel of different inbred strains of various genetic backgrounds should be tested in parallel. The antigen that confers protection in the larger range of inbred strains may have better chances to be also protective in outbred human populations and should be selected for clinical trials.

  4. Comparative Evaluation of Two Vaccine Candidates against Experimental Leishmaniasis Due to Leishmania major Infection in Four Inbred Mouse Strains▿ (United States)

    Benhnini, Fouad; Chenik, Mehdi; Laouini, Dhafer; Louzir, Hechmi; Cazenave, Pierre André; Dellagi, Koussay


    Experimental leishmaniasis in BALB/c and C57BL/6 mice are the most investigated murine models that were used for the preclinical evaluation of Leishmania vaccine candidates. We have previously described two new inbred mouse strains named PWK and MAI issued from feral founders that also support the development of experimental leishmaniasis due to L. major. In this study, we sought to determine whether different mouse inbred strains generate concordant or discordant results when used to evaluate the potential of Leishmania proteins to protect against experimental leishmaniasis. To this end, two Leishmania proteins, namely, LACK (for Leishmania homolog of receptor for activated C kinase) and LmPDI (for L. major protein disulfide isomerase) were compared for their capacity to protect against experimental leishmaniasis in PWK, MAI, BALB/c, and C57BL/6 inbred mouse strains. Our data show that the capacity of Leishmania proteins to confer protection depends on the mouse strain used, stressing the important role played by the genetic background in shaping the immune response against the pathogen. These results may have important implications for the preclinical evaluation of candidate Leishmania vaccines: rather than using a single mouse strain, a panel of different inbred strains of various genetic backgrounds should be tested in parallel. The antigen that confers protection in the larger range of inbred strains may have better chances to be also protective in outbred human populations and should be selected for clinical trials. PMID:19726616

  5. Experimental study of highly viscous impinging jets

    Energy Technology Data Exchange (ETDEWEB)

    Gomon, M. [Univ. of Texas, Austin, TX (United States). Dept. of Mechanical Engineering


    The objective of this research is to study the behavior of highly viscous gravity-driven jets filling a container. Matters of interest are the formation of voids in the fluid pool during the filling process and the unstable behavior of the fluid in the landing region which manifests itself as an oscillating motion. The working fluids used in this research are intended to simulate the flow behavior of molten glass. Qualitative and quantitative results are obtained in a parametric study. The fraction of voids present in the fluid pool after the filling of the container is measured for different parameter values of viscosity and mass flow rate. Likewise, frequencies of the oscillating jet are measured. Results are inconclusive with regard to a correlation between parameter settings and void fractions. As for frequencies, power law correlations are established.

  6. Experimental Study of Flow in a Bifurcation (United States)

    Fresconi, Frank; Prasad, Ajay


    An instability known as the Dean vortex occurs in curved pipes with a longitudinal pressure gradient. A similar effect is manifest in the flow in a converging or diverging bifurcation, such as those found in the human respiratory airways. The goal of this study is to characterize secondary flows in a bifurcation. Particle image velocimetry (PIV) and laser-induced fluorescence (LIF) experiments were performed in a clear, plastic model. Results show the strength and migration of secondary vortices. Primary velocity features are also presented along with dispersion patterns from dye visualization. Unsteadiness, associated with a hairpin vortex, was also found at higher Re. This work can be used to assess the dispersion of particles in the lung. Medical delivery systems and pollution effect studies would profit from such an understanding.

  7. Fasciola hepatica: comparative metacercarial productions in experimentally-infected Galba truncatula and Pseudosuccinea columella

    Directory of Open Access Journals (Sweden)

    Vignoles Philippe


    Full Text Available As large numbers of metacercariae of Fasciola hepatica are necessary for research, experimental infections of Galba truncatula and Pseudosuccinea columella with this digenean were carried out to determine the better intermediate host for metacercarial production and, consequently, the most profitable snail for decreasing the cost price of these larvae. Pre-adult snails (4 mm in shell height originating from two populations per lymnaeid species were individually exposed to two or five miracidia, raised at 23 °C and followed for cercarial shedding up to their death. Compared to values noted in G. truncatula, the survival of P. columella on day 30 post-exposure was significantly greater, while the prevalence of F. hepatica infection was significantly lower. In the four P. columella groups, metacercarial production was significantly greater than that noted in the four groups of G. truncatula (347–453 per cercariae-shedding snail versus 163–275, respectively. Apart from one population of G. truncatula, the use of five miracidia per snail at exposure significantly increased the prevalence of F. hepatica in P. columella and the other population of G. truncatula, whereas it did not have any clear effect on the mean number of metacercariae. The use of P. columella for experimental infections with F. hepatica resulted in significantly higher metacercarial production than that noted with G. truncatula, in spite of a lower prevalence for the former lymnaeid. This finding allows for a significant decrease in the cost price of these larvae for commercial production.

  8. Numerical Modeling of Local Scouring Around Group Bridge Piers and Compared with Experimental Results

    Directory of Open Access Journals (Sweden)

    B. Mahjoob


    Full Text Available Bridges are the most important structures in river engineering. One of the most causes in bridges destruction is local scouring around the bridge piers. Many bridges failed in the world because of the extreme scour around piers, which have caused to disappear a lot of investments. Then, it is essential to predict the scour depth around bridge piers. In this research, the Fluent three-dimensional numerical model was used to investigate the scouring around the group cylindrical pier in clear water and uniform sand bed conditions. In this model, sedimentary flow was considered as two-phase flow (water - sand and Eulerian two-phase model was used. To estimate the parameters of flow turbulence in the water phase, the RNG K-ε model was used. To evaluate and verify the numerical model, the computational results were compared with experimental data. The maximum scour depth in front of the first pier on a numerical model equal to 12.5 cm and in experimental model equal to 12 cm have been measured. Also scour depth at the second pier less than that at the first pier and scour depth at the third pier has been less than the values of the first and second pier .The results showed that the two phase model can simulate the scour phenomena around the pier.

  9. A comparative study of teenage pregnancy. (United States)

    Mahavarkar, S H; Madhu, C K; Mule, V D


    Teenage pregnancy is a global problem and is considered a high-risk group, in spite of conflicting evidence. Our objective was to compare obstetric outcomes of pregnancy in teenagers and older women. This was a retrospective study of case records of pregnancies from August 2000 to July 2001. Girls aged pregnancy outcomes in older women (19-35 years) in the same hospital. The study took place in the Government General Hospital, Sangli, India, a teaching hospital in rural India, with an annual delivery rate of over 3,500. A total of 386 teenage pregnancies were compared with pregnancies in 3,326 older women. Socioeconomic data, age, number of pregnancies, antenatal care and complications, mode of delivery, and neonatal outcomes were considered. The incidence of teenage pregnancy in the study was 10%. A significant proportion of teenage pregnant mothers were in their first pregnancies. The teenage mothers were nearly three times more at risk of developing anaemia (OR = 2.83, 95% CI = 2.2-3.7, p Teenage mothers were twice as likely to develop hypertensive problems in pregnancy (OR = 2.2, 95% CI = 1.5-3.2, p teenage pregnancies are still a common occurrence in rural India in spite of various legislations and government programmes and teenage pregnancy is a risk factor for poor obstetric outcome in rural India. Cultural practices, poor socioeconomic conditions, low literacy rate and lack of awareness of the risks are some of the main contributory factors. Early booking, good care during pregnancy and delivery and proper utilisation of contraceptive services can prevent the incidence and complications in this high-risk group.

  10. The pelvic ileal reservoir: an experimental assessment of its function compared with that of normal rectum. (United States)

    Cranley, B; McKelvey, S T


    The function of the 3-loop pelvic ileal reservoir as an alternative to total proctocolectomy and ileostomy is assessed experimentally in dogs and compared with normal rectum under identical conditions. No difference was found between the pelvic ileal reservoir and normal rectum in their ability to maintain continence. The efficiency of evacuation, however, is significantly better in normal rectum (P less than 0.01). Observations made over a prolonged period of time suggest that frequency of defecation, tenesmus and incomplete evacuation are persistent problems with an ileal reservoir. The results of the experiments concur with clinical findings that satisfactory continence may be achieved by using the ileal reservoir but that it does not possess the ability of normal rectum to evacuate completely. Hence the frequent need for self-catheterization.

  11. Method matters: Experimental evidence for shorter avian sperm in faecal compared to abdominal massage samples.

    Directory of Open Access Journals (Sweden)

    Antje Girndt

    Full Text Available Birds are model organisms in sperm biology. Previous work in zebra finches, suggested that sperm sampled from males' faeces and ejaculates do not differ in size. Here, we tested this assumption in a captive population of house sparrows, Passer domesticus. We compared sperm length in samples from three collection techniques: female dummy, faecal and abdominal massage samples. We found that sperm were significantly shorter in faecal than abdominal massage samples, which was explained by shorter heads and midpieces, but not flagella. This result might indicate that faecal sampled sperm could be less mature than sperm collected by abdominal massage. The female dummy method resulted in an insufficient number of experimental ejaculates because most males ignored it. In light of these results, we recommend using abdominal massage as a preferred method for avian sperm sampling. Where avian sperm cannot be collected by abdominal massage alone, we advise controlling for sperm sampling protocol statistically.

  12. Experimental studies in non-equilibrium physics (United States)

    Cressman, John Robert, Jr.

    This work is a collection of three experiments aimed at studying different facets of non-equilibrium dynamics. Chapter I concerns strongly compressible turbulence, which turns out to be very different from incompressible turbulence. The focus is on the dispersion of contaminants in such a flow. This type of turbulence can be studied, at very low mach number, by measuring the velocity fields of particles that float on a turbulently stirred body of water. It turns out that in the absence of incompressibility, the turbulence causes particles to cluster rather than to disperse. The implications of the observations are far reaching and include the transport of pollutants on the oceans surface, phytoplankton growth, as well as industrial applications. Chapter II deals with the effects of polymer additives on drag reduction and turbulent suppression, a well-known phenomenon that is not yet understood. In an attempt to simplify the problem, the effects of a polymer additive were investigated in a vortex street formed in a flowing soap film. Measurements suggest that an increase in elongational viscosity is responsible for a substantial reduction in periodic velocity fluctuations. This study also helps to illuminate the mechanism responsible for vortex separation in the wake of a bluff body. Chapter III describes an experiment designed to test a theoretical approach aimed at generalizing the classical fluctuation dissipation theorem (FDT). This theorem applies to systems driven only slightly away from thermal equilibrium, whereas ours, a liquid crystal under-going electroconvection, is so strongly driven, that the FDT does not apply. Both theory and experiment focus on the flux in global power fluctuations. Physical limitations did not permit a direct test of the theory, however it was possible to establish several interesting characteristics of the system: the source of the fluctuations is the transient defect structures that are generated when the system is driven hard

  13. An experimental study of rip channel flow

    DEFF Research Database (Denmark)

    Drønen, Nils Kjetil; Karunarathna, H.; Fredsøe, Jørgen


    A laboratory study of the flow over a bar with a single rip channel has been performed. First, the well-known pattern of a bar circulation cell with a strong offshore-directed current out through the rip channel and a weaker onshore-directed return flow over the bar is documented. Then measurements...... of the three-dimensional structure of the flow in the area where the rip channel, the bar and the trough meet and well inside the rip channel are presented. These measurements reveal that 3D effects play an important role, and that a depth-integrated viewpoint may not always be sufficient for predicting...

  14. Estudo experimental comparativo no uso de enxerto ósseo orgânico e inorgânico no reparo de fraturas cirúrgicas em rádio de coelhos Organic and inorganic bone graft use in rabbits' radius surgical fractures rapair: an experimental and comparative study

    Directory of Open Access Journals (Sweden)

    Elson Souza Miranda


    group II (G2, an Osteosynt inorganic bone graft, composed by synthetic hydroxyapatite and calcium phosphate was placed. The groups were subdivided into 5 periods (P15 = 15 days, P30 = 30 days, P45 = 45 days, P60 = 60 days, P75 = 75 days for evaluating x-ray and histological aspects of the osteotomy site (surgical fracture aiming to check local bone union process. X-ray studies showed that G2 developed a faster repair process in all observation periods when compared to G1. This fact was confirmed by histological evaluation. We conclude that the inorganic bone graft may be routinely used in orthopaedic surgery, providing an early bone healing.

  15. Buried Target Imaging: A Comparative Study (United States)

    Ghaderi Aram, Morteza; Dehmollaian, Mojtaba; Khaleghi, Ali


    A wide variety of qualitative methods have been proposed for microwave imaging. It is difficult to select only one of these methods based on a priori information and measurement equipment to achieve a reliable reconstruction. Various arrangements for antennas to be used in, for instance, have been proposed which have direct impacts on the complexity of inverse methods as well as the quality of output images. In this study, four qualitative methods of the linear sampling method (LSM), time reversal (TR), diffraction tomography (DT), and back-projection (BP) have been reviewed in a 2D scenario; the performance of the methods is compared within the same framework of a multi-static configuration. The goal is to compare their resolutions and determine their advantages and drawbacks. It is shown that LSM provides the best azimuth resolution but the worst range resolution. It is almost invariant to dielectric contrast and is appropriate for a wide range of dielectric contrasts and relatively large objects. It is also shown that at relatively low dielectric contrasts, TR images are most similar to the true object, show fewer artifacts, and offer high immunity to noise. While suffering from more artifacts due to the presence of some ghost images, DT offers the best range resolution. The results also show that BP has the worst azimuth resolution when reconstructing deeply-buried targets, although its implementation is straightforward and not computationally complex.

  16. A Comparative Characteristic Study of Jatropha and Cardanol Biodiesel Blends (United States)

    Pugazhenthi, R.; Chandrasekaran, M.; Muthuraman, R. K.; Vivek, P.; Parthiban, A.


    The demand in fuel needs and the depleting fossil fuels raised the need towards bio-fuels. The emerging trend in research field is highly focused on biodiesel production and their characteristic analysis. Since pollution is a major threat to the environment, emission parameter analyses are much important to be concentrated. As the entire world contains plenty of biofuels, it is necessary to explore them for its efficiency and analyze their parameters. In this experimental work jatropha and cashew nut shell biodiesel (Cardanol) was extracted and they were blended with diesel. The characteristics of jatropha and cardanol biodiesel were studied in the DI diesel engine by varying the load at the same speed. In brief, this experimental analysis is carried out to compare the emission characteristics between Jatropha biodiesel at 20% (B20) and 40% (B40) and Cardanol biodiesel blends at 20% (C20) and 40% (C40).

  17. Experimental Study of Methane Hydrates in Coal

    Directory of Open Access Journals (Sweden)

    Smirnov Vyacheslav


    Full Text Available The possibility of gas hydrate formation in porous space of coal has been studied. The experiments conducted have proven the possibility of methane gas hydrate formation in moist coal. It has been demonstrated that the decomposition points of methane gas hydrates in coal are near to the phase equilibrium curve for bulk methane hydrate. Only part of water absorbed by coal can be involved in the methane gas hydrate formation. With the increase in gas pressure increases the amount of gas hydrate formed in natural coal. For formation of hydrates at a positive temperature, the pressure in the system has to be at least 2 MPa. At the same time the speed of formation and decomposition of gas hydrates in coal is big enough.

  18. ESP Teaching for Tourism. An Experimental Study

    Directory of Open Access Journals (Sweden)

    Buzarna-Tihenea (Gălbează Alina


    Full Text Available This paper is focused on those teaching and learning methods and techniques which can improve the practical use of English for work-related purposes, this giving the students the opportunity to develop their language skills by means of attractive, motivating and useful learning activities. The paper aims at providing an in-depth knowledge about ways of studying and applying English for Specific Purposes in the Tourism field, as well as types of activities to be used in the classroom in order to assist learners overcome language difficulties. It is of great importance to emphasize the specific tasks and strategies used while teaching ESP for Tourism classes, strategies that differ from the ones used in a traditional English language classroom. The main purpose of all these ESP methods and approaches is to prepare students for their future jobs so that they can perform effectively in their area of work.

  19. Experimental Study of Liquid Fuel Spray Combustion

    DEFF Research Database (Denmark)

    Westlye, Fredrik Ree

    by the Danish Council for Strategic Research. Other supporters of the project have been MAN Diesel & Turbo A/S, DTU Mechanical Engineering, DTU Chemical Engineering, Sandia National Laboratories USA, Norwegian University of Science & Technology (NTNU) and University of Nottingham, Malaysia Campus....... The continuing stringency of emission regulations for marine diesel engines forces a deeper understanding of the complex physical processes occurring inside the engine cylinder. A deeper understanding can lead to higher accuracy of predictive numerical models, thereby enabling evaluation of multiple engine...... the specific physical quantities needed in CFD validation of these types of flames. This work is a testament to that fact. The first part of this thesis is an extensive study of optical combustion diagnostics applied to complex transient sprayflames in a high temperature and pressure environment...

  20. Flapless implant surgery: an experimental study. (United States)

    Jeong, Seung-Mi; Choi, Byung-Ho; Li, Jingxu; Kim, Han-Sung; Ko, Chang-Yong; Jung, Jae-Hyung; Lee, Hyeon-Jung; Lee, Seoung-Ho; Engelke, Wilfried


    The purpose of this study was to examine the effect of flapless implant surgery on crestal bone loss and osseointegration in a canine mandible model. In 6 mongrel dogs, bilateral, edentulated, flat alveolar ridges were created in the mandible. After 3 months of healing, 2 implants in each side were placed by either flap or flapless procedures. After a healing period of 8 weeks, microcomputerized tomography at the implantation site was performed. Osseointegration was calculated as percentage of implant surface in contact with bone. Additionally, bone height was measured in the peri-implant bone. The mean osseointegration was greater at flapless sites (70.4%) than at sites with flaps (59.5%) (P flapless sites (10.1 mm) than at sites with flaps (9.0 mm) (P Flapless surgery can achieve results superior to surgery with reflected flaps. The specific improvements of this technique include enhanced osseointegration of dental implants and increased bone height.

  1. Preliminary experimental studies of waste coal gasification

    Energy Technology Data Exchange (ETDEWEB)

    Su, S.; Jin, Y.G.; Yu, X.X.; Worrall, R. [CSIRO, Brisbane, QLD (Australia). Advanced Coal Technology


    Coal mining is one of Australia's most important industries. It was estimated that coal washery rejects from black coal mining was approximately 1.82 billion tonnes from 1960 to 2009 in Australia, and is projected to produce another one billion tonnes by 2018 at the current production rate. To ensure sustainability of the Australian coal industry, we have explored a new potential pathway to create value from the coal waste through production of liquid fuels or power generation using produced syngas from waste coal gasification. Consequently, environmental and community impacts of the solid waste could be minimized. However, the development of an effective waste coal gasification process is a key to the new pathway. An Australian mine site with a large reserve of waste coal was selected for the study, where raw waste coal samples including coarse rejects and tailings were collected. After investigating the initial raw waste coal samples, float/sink testing was conducted to achieve a desired ash target for laboratory-scale steam gasification testing and performance evaluation. The preliminary gasification test results show that carbon conversions of waste coal gradually increase as the reaction proceeds, which indicates that waste coal can be gasified by a steam gasification process. However, the carbon conversion rates are relatively low, only reaching to 20-30%. Furthermore, the reactivity of waste coal samples with a variety of ash contents under N{sub 2}/air atmosphere have been studied by a home-made thermogravimetric analysis (TGA) apparatus that can make the sample reach the reaction temperature instantly.

  2. Experimental and clinical studies with intraoperative radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Sindelar, W.F.; Kinsella, T.; Tepper, J.; Travis, E.L.; Rosenberg, S.A.; Glatstein, E.


    Studies of normal tissue tolerance to intraoperative radiotherapy were done upon 65 dogs subjected to laparotomy and 11 million electron volt electron irradiation in doses ranging from zero to 5,000 rads. Results of studies indicated that intact aorta and vena cava tolerate up to 5,000 rads without loss of structural integrity. Ureteral fibrosis and stenosis develop at doses of 3,000 rads or more. Arterial anastomoses heal after doses of 4,500 rads, but fibrosis can lead to occlusion. Intestinal suture lines heal after doses of 4,500 rads. Bile duct fibrosis and stenosis develop at doses of 2,000 rads or more. Biliary-enteric anastomoses fail to heal at any dose level. A clinical trial of intraoperative radiotherapy combined with radical surgery was performed upon 20 patients with advanced malignant tumors which were considered unlikely to be cured by conventional therapies and which included carcinomas of the stomach, carcinomas of the pancreas, carcinomas involving the hilus of the liver, retroperitoneal sarcomas and osteosarcomas of the pelvis. All patients underwent resection of gross tumor, followed by intraoperative irradiation of the tumor bed and regional nodal basins. Some patients received additional postoperative external beam radiotherapy. Treatment mortality for combined operation and radiotherapy occurred in four of 20 patients. Postoperative complications occurred in four of the 16 surviving patients. Local tumor control was achieved in 11 of the 16 surviving patients, with an over-all median follow-up period of 18 months. The clinical trial suggested that intraoperative radiotherapy is a feasible adjunct to resection in locally advanced tumors, that the resulting mortality and morbidity is similar to that expected from operation alone and that local tumor control may be improved.

  3. Experimental study of forearm compartmental pressures. (United States)

    Ardolino, Antonella; Zeineh, Nedal; O'Connor, David


    Chronic compartment syndrome is well recognized, although it is rare in the forearm. Diagnosis is based on history, clinical examination, and compartment pressure readings. Existing normal pressure ranges for the forearm are based on lower limb measurements. This study aimed to establish normal pre- and post-exercise forearm compartment pressures. Using a Stryker intracompartmental pressure monitor (Stryker, Kalamazoo, MI), 41 volunteers had pressure measurements of the extensor and flexor forearm compartments before and after exercise. Normal ranges were established for pre-exercise extensor compartment (2-27 mm Hg; upper confidence interval [CI] 18.8-25.2 mm Hg), post-exercise extensor compartment (2-24 mm Hg; upper CI 16.8-22.8 mm Hg), pre-exercise flexor compartment (1-19 mm Hg; upper CI 13.3-17.4 mm Hg), and post-exercise flexor compartment (0-19 mm Hg; upper CI 16-21.4 mm Hg) pressures. No significant difference was found between pressures before and after exercise. There was no correlation between whether pressures increased or decreased following exercise. There was a significant gender difference. Normal ranges were 0 to 25.2 mm Hg for the extensor compartment and 0 to 21.4 mm Hg for the flexor compartment. This study has shown a significant difference in normal forearm compartment pressures between genders. A normal reference range of flexor and extensor forearm compartment pressures to aid diagnosis of chronic compartment syndrome has been determined. This might also prove useful in aiding the diagnosis of acute forearm compartment syndrome. Copyright © 2010 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  4. A comparative study of bike lane injuries. (United States)

    Wee, Jung Hee; Park, Jeong Ho; Park, Kyu Nam; Choi, Seung Pill


    Because of the increased number of bicycle riders and governmental promotions, a recent increase in the construction of bicycle lanes has occurred. We aimed to characterize injuries specific to bicycle lane accidents by comparing them with injuries that occurred on regular roadways. On the basis of our findings, we provide suggestions on proper preventive strategies. We performed a retrospective study on 408 cases obtained between January 1, 2009, and December 31, 2010. Of these cases, 387 met the criterion that the location of the injury could be confirmed by telephone or via review of the patient's chart. Data regarding age, gender, Injury Severity Score, time of the accident, location of the accident, and other characteristics were collected. Data were analyzed using SPSS 12.0K. Of the 387 cases, 204 (52.7%) patients were injured in bicycle lanes and 183 (47.3%) were injured on regular roadways. Comparing cases of bicycle lane injuries and non-bicycle lane injuries, there were no differences in age, day of the week, season, or the time at which the accident occurred. Bicycle helmets were used more frequently in bicycle lane injuries (33.2% vs. 13.7%; p lane incidences were falls (59.3%) and collisions with other bicycles (23.5%), whereas in non-bicycle lane cases, falls (42.6%) and collisions with other vehicles (39.3%) were the most common causes of injury. Although the severity of injuries was slightly lower in bicycle lane cases, it was not significantly lower than non-bicycle lane cases. Although people are increasingly using bicycle lanes for safety, this study shows that they are not definitively safer. Therefore, improvements in the policies related to implementing bicycle lane safety are needed, for example, by enforcing the use of protective gear or preventing the use of bicycle lanes by pedestrians. More safety education programs are also needed. III.

  5. Experimental study of flow through compressor Cascade

    Directory of Open Access Journals (Sweden)

    Satyam Panchal


    Full Text Available The objective of this research work is to study the behaviour of flow at the inlet, within the blade passage and at the exit of a compressor cascade. For this purpose, a cascade with six numbers of aerofoil blades was designed and constructed. The cascade was fitted on the cascade test tunnel. Out of six blades two were instrumented for measuring the pressure distribution on the pressure and suction surface. The blades had a parabolic camber line, with a maximum camber position at 40% of the chord from the leading edge of the blade. The profile of the blade was C4, height of the blade was 160 mm, chord length was 80 mm, camber angle was 45° and stagger angle was 30°. Similarly, the length of the cascade was 300 mm, span was 160 mm, pitch was 60 mm, the actual chord of the cascade was 80 mm, the axial chord of the cascade was 70 mm, the stagger angle of the cascade was 30° and the pitch-chord ratio was 0.75. The data was taken and analyzed at −500% of the axial chord before the cascade, −25% of the axial chord before the leading edge, 25%, 50%, 75% and 150% of the axial chord from the leading edge of the blade. The readings were taken from the cascade wall to the mid span position along the pitch wise direction. The angle of incidence was also changed during the experiment and varied from i=−50°, −30°, −10° to 5°.

  6. Medical waste to energy: experimental study. (United States)

    Arcuri, C; Luciani, F; Piva, P; Bartuli, F N; Ottria, L; Mecheri, B; Licoccia, S


    Although waste is traditionally assessed as a pollutant which needs to be reduced or lessened, its management is certainly necessary. Nowadays, biological fuel cells, through the direct conversion of organic matter to electricity using biocatalysts, represent a technology able to produce sustainable energy by means of waste treatment. This study aims to propose a mean to generate energy from blood and saliva, that are common risk-infectious medical waste. Material employed (purchased by Sigma-Aldrich) were: Glucose oxidase (GOx), Nafion perfluorinated resin solution at 5% in a mixture of lower aliphatic alcohols and water, Polyethylene oxide. Stock solutions of D (+) glucose were prepared in a 0.1 M phosphate buffer solution and stored at 4 °C for at least 24 h before use. Carbon cloth electrode ELAT HT 140 E-W with a platinum loading of 5 gm-2 was purchased by E-Tek. Electrospun Nafion fibers were obtained as follows. Scanning electron microscopy was used to characterize the electrode morphologies. In order to develop an effective immobilization strategy of GOx on the electrode surface, Nafion fibers (a fully fluorinated ion conducting polymer used as a membrane material in enzymatic fuel cells - EFC) were selected as immobilizing polymer matrix. In this work, exploiting the nafion fibers capability of being able to cathalize Gox activity, we have tried to produce an enzymatic fuel cell which could produce energy from the blood and the saliva within medical-dental waste. Medical waste refers to all those materials produced by the interaction among doctor and patient, such as blood and saliva. During our research we will try to complete an EFC prototype able to produce energy from blood and saliva inside the risk-infectious medical waste in order to contribute to the energy requirements of a consulting room.


    Rhoads, C P


    Through the kindness of Dr. W. H. Park we have been enabled to study a horse antipoliomyelitic serum. This preparation has been supplied us in three forms: citrated blood plasma, serum, and globulin concentrate. We have tested these preparations in vitro and in vivo for inactivating or neutralizing or, to use perhaps a better term, antiviral effects against a constant, potent, filtrate virus of poliomyelitis. The preparations exhibited these effects when combined in vitro. Their action in this respect appears to be greater and more constant than that found by Stewart and Haselbauer for the Pettit antipoliomyelitic horse serum. On the other hand, in vivo tests carried out by us were less successful. In comparison with the constancy of action, under given conditions, of convalescent monkey and human sera, the antipoliomyelitic horse serum displayed striking irregularity, and certain preparations were devoid of protective power. The precise nature of the inactivating substances in the horse antiserum and their relation to the corresponding substances in convalescent sera have still, to be determined. As far as one absorption test carried out by us indicates, precipitin does not play a major rôle in the inactivating process. When an active globulin concentrate was filtered through Berkefeld candles, it lost its in vitro inactivating power. This is not true of convalescent sera in the native state. No tests have, however, been made with globulin concentrates from such sera. The experiments described in this paper raise the question whether, therapeutically considered, the antipoliomyelitic horse serum should be regarded as an exact equivalent of, and hence employed as a perfect substitute for, convalescent serum. This question can only be answered by further experiment and observation.

  8. Markets and morals: an experimental survey study.

    Directory of Open Access Journals (Sweden)

    Julio J Elias

    Full Text Available Most societies prohibit some market transactions based on moral concerns, even when the exchanges would benefit the parties involved and would not create negative externalities. A prominent example is given by payments for human organs for transplantation, banned virtually everywhere despite long waiting lists and many deaths of patients who cannot find a donor. Recent research, however, has shown that individuals significantly increase their stated support for a regulated market for human organs when provided with information about the organ shortage and the potential beneficial effects a price mechanism. In this study we focused on payments for human organs and on another "repugnant" transaction, indoor prostitution, to address two questions: (A Does providing general information on the welfare properties of prices and markets modify attitudes toward repugnant trades? (B Does additional knowledge on the benefits of a price mechanism in a specific context affect attitudes toward price-based transactions in another context? By answering these questions, we can assess whether eliciting a market-oriented approach may lead to a relaxation of moral opposition to markets, and whether there is a cross-effect of information, in particular for morally controversial activities that, although different, share a reference to the "commercialization" of the human body. Relying on an online survey experiment with 5,324 U.S. residents, we found no effect of general information about market efficiency, consistent with morally controversial markets being accepted only when they are seen as a solution to a specific problem. We also found some cross-effects of information about a transaction on the acceptance of the other; however, the responses were mediated by the gender and (to a lesser extent religiosity of the respondent--in particular, women exposed to information about legalizing prostitution reduced their stated support for regulated organ payments. We

  9. Injury Based on Its Study in Experimental Models

    Directory of Open Access Journals (Sweden)

    M. Mendes-Braz


    Full Text Available The present review focuses on the numerous experimental models used to study the complexity of hepatic ischemia/reperfusion (I/R injury. Although experimental models of hepatic I/R injury represent a compromise between the clinical reality and experimental simplification, the clinical transfer of experimental results is problematic because of anatomical and physiological differences and the inevitable simplification of experimental work. In this review, the strengths and limitations of the various models of hepatic I/R are discussed. Several strategies to protect the liver from I/R injury have been developed in animal models and, some of these, might find their way into clinical practice. We also attempt to highlight the fact that the mechanisms responsible for hepatic I/R injury depend on the experimental model used, and therefore the therapeutic strategies also differ according to the model used. Thus, the choice of model must therefore be adapted to the clinical question being answered.

  10. An experimental and modeling study of n-octanol combustion

    KAUST Repository

    Cai, Liming


    This study presents the first investigation on the combustion chemistry of n-octanol, a long chain alcohol. Ignition delay times were determined experimentally in a high-pressure shock tube, and stable species concentration profiles were obtained in a jet stirred reactor for a range of initial conditions. A detailed kinetic model was developed to describe the oxidation of n-octanol at both low and high temperatures, and the model shows good agreement with the present dataset. The fuel\\'s combustion characteristics are compared to those of n-alkanes and to short chain alcohols to illustrate the effects of the hydroxyl moiety and the carbon chain length on important combustion properties. Finally, the results are discussed in detail. © 2014 The Combustion Institute.

  11. An experimental study on improvement of Savonius rotor performance

    Directory of Open Access Journals (Sweden)

    N.H. Mahmoud


    In this work different geometries of Savonius wind turbine are experimentally studied in order to determine the most effective operation parameters. It was found that, the two blades rotor is more efficient than three and four ones. The rotor with end plates gives higher efficiency than those of without end plates. Double stage rotors have higher performance compared to single stage rotors. The rotors without overlap ratio (β are better in operation than those with overlap. The results show also that the power coefficient increases with rising the aspect ratio (α. The conclusions from the measurements of the static torque for each rotor at different wind speeds verify the above summarized results of this work.

  12. An experimental study on particle effects in liquid sheets

    Directory of Open Access Journals (Sweden)

    Sauret Alban


    Full Text Available Many industrial processes, such as surface coating or liquid transport in tubes, involve liquid sheets or thin films of suspensions. In these situations, the thickness of the liquid film becomes comparable to the particle size, which leads to unexpected dynamics. In addition, the classical constitutive rheological law for suspensions cannot be applied as the continuum approximation is no longer valid. Here, we consider experimentally a transient particle-laden liquid sheet that expands radially. We characterize the influence of the particles on the shape of the liquid film and the atomization process. We highlight that the presence of particles modifies the thickness and stability of the liquid sheet. Our study suggests that the influence of particles through capillary effects can modify significantly the dynamics of processes that involve suspensions and particles confined in liquid films.

  13. Experimental study on silicon micro-heat pipe arrays

    Energy Technology Data Exchange (ETDEWEB)

    Launay, S.; Sartre, V.; Lallemand, M. [Institut National des Sciences Appliquees, Villeurbanne (France). Centre de Thermique


    In this study, micro-heat pipe arrays etched into silicon wafers have been investigated for electronic cooling purposes. Micro-heat pipes of triangular cross-section and with liquid arteries were fabricated by wet anisotropic etching with a KOH solution. The microchannels (230 {mu}m wide) are closed by molecular bonding of a plain wafer with the grooved one. A test bench was developed for the micro-heat pipe filling and the thermal characterisation. The temperature profile on the silicon surface is deduced from experimental measurements. The results show that with the artery micro-heat pipe array, filled with methanol, the effective thermal conductivity of the silicon wafer is significantly improved compared to massive silicon. (author)

  14. Statistical Power in Experimental Audit Studies: Cautions and Calculations for Matched Tests With Nominal Outcomes (United States)

    Vuolo, Mike; Uggen, Christopher; Lageson, Sarah


    Given their capacity to identify causal relationships, experimental audit studies have grown increasingly popular in the social sciences. Typically, investigators send fictitious auditors who differ by a key factor (e.g., race) to particular experimental units (e.g., employers) and then compare treatment and control groups on a dichotomous outcome…

  15. Theoretical and Experimental Studies in Accelerator Physics

    Energy Technology Data Exchange (ETDEWEB)

    Rosenzweig, James [Univ. of California, Los Angeles, CA (United States). Dept. of Physics and Astronomy


    . We note also that PBPL graduates remain as close elaborators for the program after leaving UCLA. The UCLA PBPL program is a foremost developer of on-campus facilities, such as the Neptune and Pegasus Laboratories, providing a uniquely strong environment for student-based research. In addition, the PBPL is a strong user of off-campus national lab facilities, such as SLAC FACET and NLCTA, and the BNL ATF. UCLA has also vigorously participated in the development of these facilities. The dual emphases on off- and on-campus opportunities permit the PBPL to address in an agile way a wide selection of cutting-edge research topics. The topics embraced by this proposal illustrate this program aspect well. These include: GV/m dielectric wakefield acceleration/coherent Cerenkov radiation experiments at FACET (E-201) and the ATF; synergistic laser-excited dielectric accelerator and light source development; plasma wakefield (PWFA) experiments on “Trojan horse” ionization injection (FACET E-210), quasi-nonlinear PWFA at BNL and the production at Neptune high transformer ratio plasma wakes; the inauguration of a new type of RF photoinjector termed “hybrid” at UCLA, and application to PWFA; space-charge dominated beam and cathode/near cathode physics; the study of advanced IFEL systems, for very high energy gain and utilization of novel OAM modes; the physcis of inverse Compton scattering (ICS), with applications to e+ production and γγ colliders; electron diffraction; and advanced beam diagnostics using coherent imaging techniques. These subjects are addressed under the leadership of PBPL director Prof. James Rosenzweig in Task A, and Prof. Pietro Musumeci in Task J, which was initiated following his OHEP Outstanding Junior Investigator award.

  16. The experimental study of seed dispersal by fish (ichthyochory)

    NARCIS (Netherlands)

    Pollux, B.J.A.


    1.The last few years have seen an increased interest in the experimental study of seed dispersal by fish (ichthyochory). This paper reviews such experiments, aiming to determine what functional aspects of ichthyochory have been investigated, what experimental designs have been used and what the

  17. Comparative studies of groundwater vulnerability assessment (United States)

    Maria, Rizka


    Pollution of groundwater is a primary issue because aquifers are susceptible to contamination from land use and anthropogenic impacts. Groundwater susceptibility is intrinsic and specific. Intrinsic vulnerability refers to an aquifer that is susceptible to pollution and to the geological and hydrogeological features. Vulnerability assessment is an essential step in assessing groundwater contamination. This approach provides a visual analysis for helping planners and decision makers to achieve the sustainable management of water resources. Comparative studies are applying different methodologies to result in the basic evaluation of the groundwater vulnerability. Based on the comparison of methods, there are several advantages and disadvantages. SI can be overlaid on DRASTIC and Pesticide DRASTIC to extract the divergence in sensitivity. DRASTIC identifies low susceptibility and underestimates the pollution risk while Pesticide DRASTIC and SI represents better risk and is recommended for the future. SINTACS method generates very high vulnerability zones with surface waters and aquifer interactions. GOD method could be adequate for vulnerability mapping in karstified carbonate aquifers at small–moderate scales, and EPIK method can be used for large scale. GOD method is suitable for designing large area such as land management while DRASTIC has good accuracy and more real use in geoenvironmental detailed studies.

  18. Scintigraphic and Radiographic Study of the Experimental Periapical Lesions

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Youn Sik; Park, Tae Won [Dept. of Oral Radiology, College of Dentistry, Seoul National University, Seoul (Korea, Republic of)


    The purpose of this study was to clarify that scintigram was a more effective method than radiogram in the early detection of periapical lesion. Periapical lesions were produced artificially by the opening of the pulp chambers of the lower right 3rd and 4th premolars in 6 dogs. The serial bone scintigrams using 99m-Tc-MDP and periapical radiograms were taken weekly. The uptake counts of the 99-Tc-MDP in the experimental side were compared with those in the control side. The periapical radiograms were interpreted with the joint evaluation by three dental radiologists. The following results were obtained.; 1. The radioactivity in the experimental side was increased at the 1st week except one animal in which the radioactivity was increased at the 2nd week. 2. It was observed that increasing amount of radioactivity per week was prominent from the 1st day of experiment to the 1st week, and the 3rd week to the 4th week. 3. The radiographic evidence of the periapical lesions was observed at the 3rd week and became more apparent at the 4th week. 4. Histologically, proliferation of blood vessels and infiltration of chronic inflammatory cells were observed at the 1st week and osteoblasts were found after the 3rd week.

  19. Intentional burns in Nepal: a comparative study. (United States)

    Lama, Bir Bahadur; Duke, Janine M; Sharma, Narayan Prasad; Thapa, Buland; Dahal, Peeyush; Bariya, Nara Devi; Marston, Wendy; Wallace, Hilary J


    Intentional burns injuries are associated with high mortality rates, and for survivors, high levels of physical and psychological morbidity. This study provides a comprehensive assessment of intentional burn admissions to the adult Burns Unit at Bir Hospital, Kathmandu, Nepal, during the period 2002-2013. A secondary data analysis of de-identified data of patients hospitalized at Bir Hospital, Kathmandu, with a burn during the period of 1 January 2002 to 31 August 2013. Socio-demographic, injury and psychosocial factors of patients with intentional and unintentional burns are described and compared. Chi-square tests, Fisher's exact test and Wilcoxon rank sum tests were used to determine statistical significance. There were a total of 1148 burn admissions of which 329 (29%) were for intentional burn, 293 (26%) were self-inflicted and 36 (3%) were due to assault. Mortality rates for intentional burns were approximately three times those for unintentional burns (60 vs. 22%). When compared to unintentional burns, patients with intentional burns were more likely to be female (79 vs. 48%), married (84 vs. 67%), younger (25 vs. 30 years), have more extensive burns (total body surface area, %: 55 vs. 25) and higher mortality (60 vs. 22%). Intentional burns were more likely to occur at home (95 vs. 67%), be caused by fire (96 vs. 77%), and kerosene was the most common accelerant (91 vs. 31%). A primary psychosocial risk factor was identified in the majority of intentional burn cases, with 60% experiencing adjustment problems/interpersonal conflict and 32% with evidence of a pre-existing psychological condition. A record of alcohol/substance abuse related to the patient or other was associated with a greater proportion of intentional burns when compared with unintentional burns (17 vs. 4%). The majority of intentional burn patients were female. Almost all intentional burns occurred in the home and were caused by fire, with kerosene the most common accelerant used. Underlying

  20. Bipolar mood disorder, creativity and schizotypy: an experimental study. (United States)

    Rybakowski, Janusz K; Klonowska, Paulina


    Our purpose was to make an experimental assessment of the elements of creativity and the features of schizotypy in patients with bipolar disorder, compared with healthy control subjects and to investigate the effect of an acute affective episode (depressed or manic) and the features of schizotypy on the measurements of creativity. Forty patients with bipolar disorder, and 48 age- and gender-matched control subjects were studied. For the assessment of creativity the Revised Art Scale and the 'inventiveness' part of the Berlin Intelligence Structure Test (BIS) were used. The Oxford-Liverpool Inventory of Feelings and Experiences was applied for estimation of schizotypy. The bipolar patients did not differ on the RAS scale from the control subjects but obtained significantly higher scores on the BIS-total as well as on the verbal part of the test. Their scores on the BIS scale during depression were significantly lower than in remission. The bipolar patients obtained significantly higher scores on all dimensions of schizotypy compared with the controls. These results confirm previous data showing higher scores on some creativity scales in bipolar patients compared with healthy subjects. They also corroborate a relationship between the features of schizotypy and creativity scores in bipolar patients. Copyright © 2011 S. Karger AG, Basel.

  1. Inner detached frequency response curves: an experimental study (United States)

    Gatti, Gianluca; Brennan, Michael J.


    Certain nonlinear vibrating systems have frequency response curves (FRCs), in which isolated detached curves exist inside the main continuous FRC. The behavior of these systems has hitherto been studied analytically and numerically, but to the authors' knowledge, there is no record of an inner detached FRC being detected experimentally. These curves may be hidden by numerical or experimental analysis, particularly when a system is subject to swept or stepped-sine excitation. Their existence may thus lead to unexpected dramatic changes in the amplitude of the system response. This paper presents an experimental study that involves the design, construction and testing of a specific system that has an isolated detached FRC inside the main continuous FRC. The experimental design of the test rig is supported by multibody dynamic simulations, and in the experimental tests the existence of a detached FRC was verified.


    Directory of Open Access Journals (Sweden)

    Dogaru Gabriela


    Full Text Available Pulsed short waves are short electromagnetic waves emitted as intermittent trains with a fixed duration, separated by free intervals of variable duration. The biological effects of pulsed short waves could be explained according to most of the authors by an activation of cellular enzymatic reactions, a stimulation of energy metabolism, a stimulation of liver function, of adrenal gland function and of the reticulocyte system, changes in cell permeability, by an increase of peripheral blood flow through the enhancement of local vascularization. This research aimed to investigate the biological effects of exposure to pulsed short waves at different doses on the adrenal glands of experimental animals, by structural and ultrastructural studies. The study included 35 animals assigned to 4 groups. Group I included 10 experimental animals exposed to radiation at a dose of 1/80 impulses/sec, group II, 10 animals exposed to a dose of 4/400 impulses/sec, group III, 10 animals exposed to a dose of 6/600 impulses/sec, for 10 min/day, and the control group consisted of 5 unexposed animals. Structural and ultrastructural changes of adrenal glands induced by the dose of 4/400 impulses/sec, compared to the unexposed control group and the dose of 1/80 impulses/sec, include an intensification of protein synthesis processes, an enhancement of energy metabolism in providing the energy required for an increased production of hormones, an intensification of collagen fiber synthesis processes in the capsule, necessary for healing. It was demonstrated that this dose induced an intensification of hormone synthesis and secretion, a stimulation of adrenal function. At the dose of 6/600 cycles/sec, a slight diminution of hormone synthesis and secretion activity was found, which was not below the limits existing in the unexposed control group, but was comparable to group II. This dose is probably too strong for experimental animals, inducing them a state of stress. The


    Directory of Open Access Journals (Sweden)



    Full Text Available Placed in the international trend, Romanian accounting had experienced various changes, especially as regards of progress on disconnection between accounting and fiscality. In the present, fiscal rules should not have any role in accounting decisions, because accounting rules are applied to produce accounting information that is useful in making decisions and to provide a "true and fair view" upon financial reality of the entity. However, the barrier in the habit of accounting to thinking for fiscal point of view all economic transactions remains insurmountable, yet. Starting from this perspective on disconnection between accounting and fiscality would mean that amortization recorded in the accounting, as a result of management policy, to be different from fiscality amortization, to calculate income tax. Although formally accepted, disconnect between accounting and fiscality continues to meet many difficulties. In this sense, it is usual in practice to use the same method of amortization for accounting purposes and for fiscal purposes to prevent complications of double track amortization and prevent wandering in the rules in this field. Accounting rule is deliberately eluded in favor of the fiscal rules. This is the reason we proposed to make in this paper a comparative study between norms and rules on accounting and fiscal amortization, paper in which we intend to show the benefits of applying accounting and fiscal rules separately.

  4. Indução anestésica após o tratamento do choque hemorrágico: estudo experimental comparando a cetamina e o etomidato Inducción anestésica después del tratamiento del choque hemorrágico: estudio experimental eomparando la cetamina y el etomidato Anesthetic induction after treated hemorrhagic shock: experimental study comparing ketamine and etomidate

    Directory of Open Access Journals (Sweden)

    Adilson O. Fraga


    ón venosa central, frecuencia cardiaca, presión capilar pulmonar y el índice de resistencia pulmonar vascular aumentaron significativamente después de la administración de cetamina. El índice cardíaco, el índice de resistencia vascular sistémica y el transporte de oxígeno permanecieron estables en todos los grupos. CONCLUSIONES: El etomidato o la cetamina fueron capaces de mantener la estabilidad hemodinámica en los perros que sufrieron choque hemorrágico severo y que fueron tratados con NaCl a 0,9% o NaCl a 7,5%.BACKGROUND AND OBJECTIVES: Bleeding causing hemorrhagic shock usually requires surgical treatment under general anesthesia. Anesthetic drugs may further compromise hemodynamics. The objective was to compare the hemodynamic effects of ketamine and etomidate during anesthetic induction in dogs submitted to an experimental model of hemorrhagic shock and resuscitation. METHODS: Thirty-two mongrel dogs were submitted to a pressure-controlled hemorrhagic shock, resuscitation and anesthetic induction model. After achieving the target pressure of 40 mmHg, they were randomly assigned in two groups according to the resuscitation fluid to be used: NaCl 0.9% (32 and NaCl 7.5% (4 After volume infusion, these groups were reassigned according to anesthetic drug used: GI NaCl 0.9% and ketamine; GII NaCl 7.5% and ketamine; GIII NaCl 0.9% and etomidate; and GIV NaCl 7.5% and etomidate. Hemodynamic measurements were obtained at five moments: (M0 baseline; (M1 after bleeding to shock; (M2 after volume expansion; (M3 5 minutes after anesthetic induction; (M4 15 minutes after anesthetic induction. Statistical analysis was performed using Student t test and two way ANOVA. Value of p lower than 0.05, was considered significant. RESULTS: After shock, both solutions restored hemodynamics to baseline values. Independently of anesthetic agent or expansion solution used, mean arterial pressure remained unaltered for all groups after induction. Central venous

  5. Studies on pathogenesis and treatment of experimental immune complex glomerulonephrtis.

    NARCIS (Netherlands)

    Fleuren, Gerard Johannes Maria


    Chapter 1. In this thesis an investigation into pathogenetic mechanisms of epimembranous immune complex depostion in the glomeruli was described. For this study we used two related models of experimental immune complex glemerulonephritis: the heterologous and the autologous immune complex

  6. Experimental study of convective flows in the freezer

    Directory of Open Access Journals (Sweden)

    Krasnoshlykov Alexander


    Full Text Available The article discusses an experimental study of convective heat transfer in the amount of air and water in the freezer, under various operating conditions of the refrigeration unit.

  7. Experimental geothermal research facilities study (Phase 0). Volume 1

    Energy Technology Data Exchange (ETDEWEB)


    The study comprises Phase 0 of a project for Experimental Geothermal Research Facilities. The study focuses on identification of a representative liquid-dominated geothermal reservoir of moderate temperature and salinity, preliminary engineering design of an appropriate energy conversion system, identification of critical technology, and planning for implementation of experimental facilities. The objectives included development of liaison with the industrial sector, to ensure responsiveness to their views in facility requirements and planning, and incorporation of environmental and socioeconomic factors. This Phase 0 report covers problem definition and systems requirements. Facilities will incorporate capability for research in component, system, and materials technology and a nominal 10 MWe experimental, binary cycle, power generating plant.

  8. Comparative effect of carperitide and furosemide on left atrial pressure in dogs with experimentally induced mitral valve regurgitation. (United States)

    Suzuki, S; Fukushima, R; Yamamoto, Y; Ishikawa, T; Hamabe, L; Kim, S; Yoshiyuki, R; Fukayama, T; Machida, N; Tanaka, R


    The effects of carperitide on left atrial pressure (LAP) in dogs with mitral valve disease (mitral regurgitation, MR) have not been documented. The objective was to compare the short-term effects of carperitide versus furosemide on LAP and neurohumoral factors in MR dogs. Six healthy Beagle dogs weighing 9.8-12.6 kg (2 males and 4 females; aged 3 years) were used. Experimental, randomized, cross-over, and interventional study. Carperitide 0.1 μg/kg/min or furosemide 0.17 mg/kg/h (1 mg/kg/6 h) was administered to dogs with surgically induced MR for 6 hours, and after a 14 day wash-out period, the other drug was administered. LAP, plasma renin activity, plasma aldosterone, and echocardiographic variables were measured. Left atrial pressure was decreased similarly after the administration of carperitide 0.1 μg/kg/min and furosemide 0.17 mg/kg/h (1 mg/kg/6 h) compared with baseline in dogs with MR (Baseline 14.75 ± 3.74 mmHg, carperitide 10.24 ± 4.97 mmHg, P dogs with acute MR caused by experimental chordal rupture. Carperitide can have additional benefits from the viewpoint of minimal activation of neurohumoral factors in the treatment of dogs with MR. Additional studies in dogs with spontaneous disease are warranted. Copyright © 2013 by the American College of Veterinary Internal Medicine.

  9. Are larger effect sizes in experimental studies good predictors of higher citation rates?

    DEFF Research Database (Denmark)

    Schneider, Jesper Wiborg; Henriksen, Dorte


    areas and with a more credible model selection procedure. Using meta-analyses, we identify comparable individual experimental studies (n=259) from five different research specialties. Effect sizes are compared to the citation rates of the individual studies and impact factors for the journals where...

  10. Comparative experimental and theoretical investigations of the DM neutron moisture probe

    DEFF Research Database (Denmark)

    Ølgaard, Povl Lebeck; Haahr, Vagner


    Theoretical and experimental investigations of the Danish produced DM subsurface moisture probe have been carried out at the Research Establishment Risö, and the results obtained are presented in this paper. The DM probe contains an Am-Be fast neutron source and has a glass scintillator containing...... 6Li as neutron detector. Through modification of the probe it was possible to vary the source-detector distance in steps. By the use of a three-group diffusion model and a semi-empirical calibration procedure good agreement between measured and calculated calibration curves was obtained. Further...... the model has been used to study the effect of variations in the dry soil density and in the boron content of soil. Finally the applicability of the model in connection with probe design has been considered....

  11. Experimental Study on the Langlee Wave Energy Converter

    DEFF Research Database (Denmark)

    Lavelle, John; Kofoed, Jens Peter

    This report concerns the experimental study of the 1:20 scale model of the Langlee Wave Energy Converter (WEC) carried out at Aalborg University’s wave basin during the summer of 2010.......This report concerns the experimental study of the 1:20 scale model of the Langlee Wave Energy Converter (WEC) carried out at Aalborg University’s wave basin during the summer of 2010....

  12. Cellular Mechanisms and Behavioral Outcomes in Blast-Induced Neurotrauma: Comparing Experimental Setups. (United States)

    Bailey, Zachary S; Hubbard, W Brad; VandeVord, Pamela J


    Blast-induced neurotrauma (BINT) has increased in incidence over the past decades and can result in cognitive issues that have debilitating consequences. The exact primary and secondary mechanisms of injury have not been elucidated and appearance of cellular injury can vary based on many factors, such as blast overpressure magnitude and duration. Many methodologies to study blast neurotrauma have been employed, ranging from open-field explosives to experimental shock tubes for producing free-field blast waves. While there are benefits to the various methods, certain specifications need to be accounted for in order to properly examine BINT. Primary cell injury mechanisms, occurring as a direct result of the blast wave, have been identified in several studies and include cerebral vascular damage, blood-brain barrier disruption, axonal injury, and cytoskeletal damage. Secondary cell injury mechanisms, triggered subsequent to the initial insult, result in the activation of several molecular cascades and can include, but are not limited to, neuroinflammation and oxidative stress. The collective result of these secondary injuries can lead to functional deficits. Behavioral measures examining motor function, anxiety traits, and cognition/memory problems have been utilized to determine the level of injury severity. While cellular injury mechanisms have been identified following blast exposure, the various experimental models present both concurrent and conflicting results. Furthermore, the temporal response and progression of pathology after blast exposure have yet to be detailed and remain unclear due to limited resemblance of methodologies. This chapter summarizes the current state of blast neuropathology and emphasizes the need for a standardized preclinical model of blast neurotrauma.

  13. South-East Asia and Comparative Studies

    Directory of Open Access Journals (Sweden)

    Keith Watson


    Full Text Available This paper shows how important is context in undertaking comparative and international educational research. It begins by showing how early UNESCO Plans for Asia largely ignored this crucial aspect. It then goes on to trace the development of the twin fields of comparative and international education, their purposes and different approaches and areas of inquiry before turning to South-'‐East Asia. By looking at the context of South-'‐east Asia as a region in its own right, with its diversity and complexities, and by highlighting the region's uniqueness, the paper suggests that there has been too little comparative research across the region as a whole. Too much has been concentrated on individual countries or on a couple of countries at a time. The paper ends by making some recommendations for future comparative educational research.

  14. Hyperspectral image classification based on filtering: a comparative study (United States)

    Cao, Xianghai; Ji, Beibei; Ji, Yamei; Wang, Lin; Jiao, Licheng


    The classification of hyperspectral images benefits greatly from integration of spectral information and spatial context. There have been many means to incorporate spatial information into the classification, such as the Markov random field, extended morphological profiles, and segmentation-based methods. Recently, spatial filtering was introduced to improve the classification accuracy of hyperspectral images. Compared with other spectral-spatial algorithms, spatial filtering is simple and easy to implement. This advantage makes it suitable for practical applications. However, spatial filtering has not been given enough attention. A comprehensive comparative study of spatial filtering is conducted. Specifically, 10 kinds of filters are used to smooth the hyperspectral images and the classified maps, respectively. The experimental results show that most filtering-based classification methods perform well with high efficiency.

  15. CFD analysis of pressure drop across grid spacers in rod bundles compared to correlations and heavy liquid metal experimental data

    Energy Technology Data Exchange (ETDEWEB)

    Batta, A., E-mail:; Class, A.G., E-mail:


    Early studies of the flow in rod bundles with spacer grids suggest that the pressure drop can be decomposed in contributions due to flow area variations by spacer grids and frictional losses along the rods. For these shape and frictional losses simple correlations based on theoretical and experimental data have been proposed. In the OECD benchmark study LACANES it was observed that correlations could well describe the flow behavior of the heavy liquid metal loop including a rod bundle with the exception of the core region, where different experts chose different pressure-loss correlations for the losses due to spacer grids. Here, RANS–CFD simulations provided very good data compared to the experimental data. It was observed that the most commonly applied Rehme correlation underestimated the shape losses. The available correlations relate the pressure drop across a grid spacer to the relative plugging of the spacer i.e. solidity e{sub max}. More sophisticated correlations distinct between spacer grids with round or sharp leading edge shape. The purpose of this study is to (i) show that CFD is suitable to predict pressure drop across spacer grids and (ii) to access the generality of pressure drop correlations. By verification and validation of CFD results against experimental data obtained in KALLA we show (i). The generality (ii) is challenged by considering three cases which yield identical pressure drop in the correlations. First we test the effect of surface roughness, a parameter not present in the correlations. Here we compare a simulation assuming a typical surface roughness representing the experimental situation to a perfectly smooth spacer surface. Second we reverse the flow direction for the spacer grid employed in the experiments which is asymmetric. The flow direction reversal is chosen for convenience, since an asymmetric spacer grid with given blockage ratio, may result in different flow situations depending on flow direction. Obviously blockage

  16. Experimental study on mechanical properties of aircraft honeycomb sandwich structures

    Directory of Open Access Journals (Sweden)

    Talebi Mazraehshahi H.


    Full Text Available Mechanical behaviour of sandwich panels under different conditions have been exprimentally studied in this research to increase the knowledge of aircraft sandwich panel structures and facilitate design criteria for aircraft structures. Tests were concentrated on the honeycomb sandwich structures under different loads including flexural, insert shear, flat wise tension and compression loads. Furthermore, effect of core density and face material on mechanical behavior of different samples were investigated and compared with analytical and FEM method. Effects of skin thickness on strength of honycomb sandwhich panels under shear pull out and moments have also been considerd in this study. According to this investigation, insert strength and flexural test under different load conditions is strongly affected by face thickness, but compression and tearoff (falt wise tensile properties of a sandwich panel depends on core material. The study concludes that the correlation between experimental results and the analytical predictions will enable the designer to predict the mechanical behaviour and strength of a sandwich beam; however, applied formula may lead engineers to unreliable results for shear modulus.

  17. Designing Awe in Virtual Reality: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Alice Chirico


    Full Text Available Awe is a little-studied emotion with a great transformative potential. Therefore, the interest toward the study of awe’s underlying mechanisms has been increased. Specifically, researchers have been interested in how to reproduce intense feelings of awe within laboratory conditions. It has been proposed that the use of virtual reality (VR could be an effective way to induce awe in controlled experimental settings, thanks to its ability of providing participants with a sense of “presence,” that is, the subjective feeling of being displaced in another physical or imaginary place. However, the potential of VR as awe-inducing medium has not been fully tested yet. In the present study, we provided an evidence-based design and a validation of four immersive virtual environments (VEs involving 36 participants in a within-subject design. Of these, three VEs were designed to induce awe, whereas the fourth VE was targeted as an emotionally neutral stimulus. Participants self-reported the extent to which they felt awe, general affect and sense of presence related to each environment. As expected, results showed that awe-VEs could induce significantly higher levels of awe and presence as compared to the neutral VE. Furthermore, these VEs induced significantly more positive than negative affect. These findings supported the potential of immersive VR for inducing awe and provide useful indications for the design of awe-inspiring virtual environments.

  18. A theoretical and experimental study of coplanar waveguide shunt stubs (United States)

    Dib, Nihad I.; Ponchak, George E.; Katehi, Linda P. B.


    A comprehensive theoretical and experimental study of straight and bent coplanar waveguide (CPW) shunt stubs is presented. In the theoretical analysis, the CPW is assumed to be inside a cavity while, the experiments are performed on open structures. For the analysis of CPW discontinuities with air-bridges, a hybrid technique was developed which was validated through extensive theoretical and experimental comparisons. The effect of the cavity resonances on the behavior of the stubs with and without air-bridges is investigated. In addition, the encountered radiation loss due to the discontinuities is evaluated experimentally.

  19. Experimental study of the robust global synchronization of Brockett oscillators (United States)

    Ahmed, Hafiz; Ushirobira, Rosane; Efimov, Denis


    This article studies the experimental synchronization of a family of a recently proposed oscillator model, i.e. the Brockett oscillator [R. Brockett, Synchronization without periodicity, in Mathematical Systems Theory, A Volume in Honor of U. Helmke, edited by K. Huper, J. Trumpf (CreateSpace, Seattle, USA, 2013), pp. 65-74]. Due to its structural property, Brockett oscillator can be considered as a promising benchmark nonlinear model for investigating synchronization and the consensus phenomena. Our experimental setup consists of analog circuit realizations of a network of Brockett oscillators. Experimental results obtained in this work correspond to the prior theoretical findings.

  20. Experimental study of integrated a solar collector in the shading device; Estudio experimental de un colector solar termico integrado en un sombreador

    Energy Technology Data Exchange (ETDEWEB)

    Palmero, M. A.; Oliveira, A. C.; Garcia, R. L.


    The integration of solar collectors into louvres has been studied. An existing louvre design was modified to integrate a solar collector in the shading device. This solar louvre collector has been experimentally tested under real outside conditions, during Summer and Winter seasons. Experimental results were compared to numerical ones, and a good agreement was obtained. (Author)

  1. Comparative analysis of experimental methods for quantification of small amounts of oil in water

    DEFF Research Database (Denmark)

    Katika, Konstantina; Ahkami, Mehrdad; Fosbøl, Philip Loldrup


    ) and the quantification of oil is then difficult. In this study, we compare four approaches to determine the volume of the collected oil fraction in core flooding effluents. The four methods are: Image analysis, UV/visible spectroscopy, liquid scintillation counting, and low-field nuclear magnetic resonance (NMR...... comparison to a pre-made standard curve. Image analysis, UV/visible spectroscopy, and liquid scintillation counting quantify only the oil fraction by comparing with a pre-made standard curve. The image analysis technique is reliable when more than 0.1 ml oil is present, whereas liquid scintillation counting...... performs well when less than 0.6 ml oil is present. Both UV/visible spectroscopy and NMR spectrometry produced high accuracy results in the entire studied range (0.006-1.1 ml). In terms of laboratory time, the liquid scintillation counting is the fastest and least user dependent, whereas the NMR...

  2. Comparative study of motion detection methods for video surveillance systems (United States)

    Sehairi, Kamal; Chouireb, Fatima; Meunier, Jean


    The objective of this study is to compare several change detection methods for a monostatic camera and identify the best method for different complex environments and backgrounds in indoor and outdoor scenes. To this end, we used the CDnet video dataset as a benchmark that consists of many challenging problems, ranging from basic simple scenes to complex scenes affected by bad weather and dynamic backgrounds. Twelve change detection methods, ranging from simple temporal differencing to more sophisticated methods, were tested and several performance metrics were used to precisely evaluate the results. Because most of the considered methods have not previously been evaluated on this recent large scale dataset, this work compares these methods to fill a lack in the literature, and thus this evaluation joins as complementary compared with the previous comparative evaluations. Our experimental results show that there is no perfect method for all challenging cases; each method performs well in certain cases and fails in others. However, this study enables the user to identify the most suitable method for his or her needs.

  3. The importance of being systematically surprisable : Comparative social simulation as experimental technique

    NARCIS (Netherlands)

    Achterkamp, M.C.; Imhof, P.


    We argue that computer simulation can serve as a functional equivalent for the experimental method in sociology, with respect to theory development. To this end Eve present accounts of experimentation and simulation by experimenting/simulating scientists and sociologists of science. From these

  4. Real-World Experimentation Comparing Time-Sharing and Batch Processing in Teaching Computer Science, (United States)

    effectiveness of time-sharing and batch processing in teaching computer science . The experimental design was centered on direct, ’real world’ comparison...ALGOL). The experimental sample involved all introductory computer science courses with a total population of 415 cadets. The results generally

  5. Using an experimental model for the study of therapeutic touch. (United States)

    dos Santos, Daniella Soares; Marta, Ilda Estéfani Ribeiro; Cárnio, Evelin Capellari; de Quadros, Andreza Urba; Cunha, Thiago Mattar; de Carvalho, Emilia Campos


    to verify whether the Paw Edema Model can be used in investigations about the effects of Therapeutic Touch on inflammation by measuring the variables pain, edema and neutrophil migration. this is a pilot and experimental study, involving ten male mice of the same genetic strain and divided into experimental and control group, submitted to the chemical induction of local inflammation in the right back paw. The experimental group received a daily administration of Therapeutic Touch for 15 minutes during three days. the data showed statistically significant differences in the nociceptive threshold and in the paw circumference of the animals from the experimental group on the second day of the experiment. the experiment model involving animals can contribute to study the effects of Therapeutic Touch on inflammation, and adjustments are suggested in the treatment duration, number of sessions and experiment duration.

  6. A comparative study of fingerprint thinning algorithms

    CSIR Research Space (South Africa)

    Khanyile, NP


    Full Text Available are compared in terms of the quality of the skeletons they produce (i.e. connectivity and spurious branches) as well as the time complexity associated with each algorithm. Results show that faster algorithms have difficulty preserving connectivity. Zhang...

  7. Comparative study of different Schlieren diffracting elements

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 70; Issue 1. Comparative ... A K Aggarwal1. Coherent Optics Division, Central Scientific Instruments Organisation, Sector 30, Chandigarh 160 030, India; Department of Applied Physics, Guru Jambheshwar University of Science and Technology, Hisar 125 001, India ...

  8. Counseling in Costa Rica: A Comparative Study (United States)

    Collier, Crystal


    With one of the world's most comprehensive universal healthcare systems, medical tourism in Costa Rica has increased significantly over the past few decades. American tourists save up to 80% of comparative costs for procedures, from heart surgery to root canal treatment. Although many Costa Rican healthcare professionals receive training in North…

  9. Comparative study of extralevator vs. conventional ...

    African Journals Online (AJOL)

    Abstract: Abdominoperineal excision (APE) is used to resect cancers in the distal rectum and anus where sphincterpreserving surgery is not possible. It is associated with increased local recurrence rates compared to anterior resection. The extralevator abdominoperineal excision (ELAPE) was developed to reduce local ...

  10. Hans Strahl's pioneering studies in comparative placentation

    DEFF Research Database (Denmark)

    Carter, Anthony Michael; Mess, A


    Hans Strahl, a contemporary of Duval and Hubrecht, made many important contributions to comparative placentation. Despite this he is not well known and some of his original observations tend to be attributed to later authors. Strahl published a classification of placental types based on their sha...

  11. Comparative Studies on Some Physicochemical Properties of ...

    African Journals Online (AJOL)

    Industrial and nutritional processes have increased the demands for oil and this in turn has led to the search for oils from different types of seeds. It is in this vein that baobab seed oil was extracted, analyzed and some of it physicochemical properties compared with those of vegetable, peanut and palm oils. The percentage ...


    Directory of Open Access Journals (Sweden)

    S. Senthil


    Full Text Available Data Compression may be defined as the science and art of the representation of information in a crisply condensed form. For decades, Data compression has been one of the critical enabling technologies for the ongoing digital multimedia revolution. There are a lot of data compression algorithms which are available to compress files of different formats. This paper provides a survey of different basic lossless data compression algorithms. Experimental results and comparisons of the lossless compression algorithms using Statistical compression techniques and Dictionary based compression techniques were performed on text data. Among the Statistical coding techniques, the algorithms such as Shannon-Fano Coding, Huffman coding, Adaptive Huffman coding, Run Length Encoding and Arithmetic coding are considered. Lempel Ziv scheme which is a dictionary based technique is divided into two families: one derived from LZ77 (LZ77, LZSS, LZH, LZB and LZR and the other derived from LZ78 (LZ78, LZW, LZFG, LZC and LZT. A set of interesting conclusions are derived on this basis.

  13. Experimental study of a single channel alluvial fan (United States)

    Delorme, Pauline; Devauchelle, Olivier; Barrier, Laurie; Métivier, François


    At the outlet of mountain ranges, rivers reach a flat plain and start to depose their sediment load into a conical sedimentary structure called alluvial fan. To decipher these sedimentary records, we need to understand the dynamics of their growth. Most natural fans are built by braided streams. However, to avoid the complexity of braided rivers, we develop a small-scale experiment in which an alluvial fan is formed by a single channel. We use a mixture of water and glycerol to produce a laminar river. The fluid is mixed with corindon sand (~ 300 μm) in a tilted channel and left free to form a fan around its outlet. The sediment and water discharges are constant during an experimental run. We record the fan progradation and the channel morphology with top-view pictures. We also generate an elevation map with an optical method based on the deformation of a moiré pattern. We observe that, to leading order, the fan remains self-affine as it grows, with a constant slope. We compare two recent studies about the formation of one-dimensionnal fan [Guerit et al. 2014] and threshold rivers [Seizilles et al. 2013] to our experimental findings. In particular, we propose a theory witch relates the fan morphology to the control parameters (fluid and sediment discharges, grain size). Our observations accord with the predictions, suggesting that the fan is built near the threshold of sediment motion. At the first order, the fan profile is linear and control by the water discharge. The downstream decrease in sediment discharge add a curvature to this profile. Finally, we intend to expand our interpretation to alluvial fans build by single-thread channels ( Okavango, Bostwana; Taquari and Paraguay, Brasil).

  14. A. Hepatica in European ground squirrel (Citellus Citellus compared to other experimental animals

    Directory of Open Access Journals (Sweden)

    Blagojević Miloš


    Full Text Available European ground squirrel is the only representative of its genus in Serbia. It is used as experimental animal in microbioogy, parasitology, pharmacology and immunology. The objective of this work was to investigate a part of cardiovascular system of ground squirrel so in that way to contribute to a better knowledge of this animal body structure and accordingly to comparative anatomy in general. The investigation included 6 ground squirrels, of both gender, body weight 200-300 grams. For obtaining the liver arterial vascularization, after exsanguination of the animal, contrast mass of gelatin coloured with tempera was injected into abdominal aorta (Aorta abdominalis. After injecting, the blood vessels were prepared and photographed. In ground squirrel A. celiaca is odd, larger vessel that exits the abdominal aorta. It is divided into three branches: A. lienalis, A. gastrica sinistra and A. hepatica. A. hepatica is divided into A. hepatica propria and A. gastroduodenalis. A. hepatica propria further gives A. cystica, Rami cardiaci and small branches for Lnn. portales. A. gastroduodenalis is divided into A. pancreaticoduodenalis and A. gastroepiploica dextra. A. celiaca in nutria and rat is an odd artery, divided into A. lienalis, A. gastrica sinistra and A. hepatica. In rabbits, celiac artery (A. celiaca is divided into A. lienalis and short trunk from which A. gastrica sinistra and A. Hepatica emerge. A. celiaca in golden hamster does not exist in the form of tripus coeliacus (A. lienalis, A. gastrica sinistra and A. hepatica, but from A. celiaca it is firstly separated A. hepatica, and then short trunk from which A. gastrica sinistra and A. Lienalis emerge. In guinea-pig, from abdominal aorta a joint tree branches off into A. celiaca and A. mesenterica cranialis (Truncus celiacomesentericus. Based on the above mentioned results, it can be concluded that A. celiaca in European ground squirrel, nutria and rat branches from abdominal aorta as a

  15. CFD Simulations of Supersonic Highly Swirling Flow Exiting a Turbine Vane Row Compared with Experimental Observations (United States)

    West, Jeff S.; Richardson, Brian R.; Schmauch, Preston; Kenny, Robert J.


    Marshall Space Flight Center (MSFC) has been heavily involved in developing the J2-X engine. The Center has been testing a Work Horse Gas Generator (WHGG) to supply gas products to J2-X turbine components at realistic flight-like operating conditions. Three-dimensional time accurate CFD simulations and analytical fluid analysis have been performed to support WHGG tests at MSFC. The general purpose CFD program LOCI/Chem was utilized to simulate flow of products from the WHGG through a turbine manifold, a stationary row of turbine vanes, into a Can and orifice assembly used to control the back pressure at the turbine vane row and finally through an aspirator plate and flame bucket. Simulations showed that supersonic swirling flow downstream of the turbine imparted a much higher pressure on the Can wall than expected for a non-swirling flow. This result was verified by developing an analytical model that predicts wall pressure due to swirling flow. The CFD simulations predicted that the higher downstream pressure would cause the pressure drop across the nozzle row to be approximately half the value of the test objective. With CFD support, a redesign of the Can orifice and aspirator plate was performed. WHGG experimental results and observations compared well with pre-test and post-test CFD simulations. CFD simulations for both quasi-static and transient test conditions correctly predicted the pressure environment downstream of the turbine row and the behavior of the gas generator product plume as it exited the WHGG test article, impacted the flame bucket and interacted with the external environment.

  16. Comparative Transport Studies of '1212' Superconductors

    Directory of Open Access Journals (Sweden)

    Albert Gapud


    Full Text Available HgBa2CaCu2O6+δ (Hg -1212 thin films were fabricated by exchanging the T1 cations in TlBa2CaCu2O7-δ (Tl-1212 thin films with Hg cations, causing a 30-K increase in Tc. To determine how this exchange effects such a Tc increase, the irreversibility lines, temperature dependence of critical current density, and temperature dependence of Hall angle ofHg-1212 and TI-1212 thin films were measured and then compared. The results strongly suggest that the Tc shift is caused by a doubling of charge carrier density.


    Noguchi, Hideyo; Tilden, Evelyn B.


    obtained in culture, all the strains grow well on leptospira medium, as well as on blood slants. Growth takes place both at 26°C. and at 37°. The morphology of the organisms is considerably modified by cultivation. This is especially true of the plant flagellates. In the latex they have ribbon-like bodies, often twisted, and comparatively short flagella; the protoplasm is clear, almost hyaline. The flagellates seen in the gut and feces of insects are usually large, slender organisms, with flagella as long as or even longer than the body, which contains numerous volutin granules in the cytoplasm. In cultures under parallel conditions the flagellates from both these sources become shorter and thicker, the plant forms no longer appear flat and ribbon-like, and in general the organisms approach one another in morphological features. Even in the case of the least modified insect flagellates, i.e. those from flies, there is never exact correspondence between the natural and the cultivated forms. The morphological features of the cultivated flagellates vary according to the medium on which the organisms are grown and the age of the culture. The flagellates grown on the surface of blood slants are pyriform, with truncated anterior portion, and short flagellum; in the condensation water, however, the individuals are elongated and have long active flagella. On the leptospira medium the slender active forms with long flagella predominate. In the presence of fermentable carbohydrate, or in medium containing considerable acid, peculiar bifurcated or multifurcated individuals are seen. Similar forms have been seen under natural conditions. Cultures of Leishmania behave in the same way under the conditions described. There is a striking difference in rapidity of growth between the organisms isolated by us and the leishmanias, H. ctenocephali, and T. rotatorium. While the stock cultures of the group first mentioned multiply rapidly at 37°C., growth becoming visible within 24 hours, the

  18. Comparative experimental investigation and gap flow simulation in electrical discharge drilling using new electrode geometry

    Directory of Open Access Journals (Sweden)

    A. T. Bozdana


    Full Text Available This study presents experimental and numerical investigation on the effectiveness of electrode geometry on flushing and debris removal in Electrical Discharge Drilling (EDD process. A new electrode geometry, namely side-cut electrode, was designed and manufactured based on circular electrode geometry. Several drilling operations were performed on stainless steel 304 using rotary tubular electrodes with circular and side-cut geometries. Drilling performance was characterized by Material Removal Rate (MRR, Electrode Wear Rate (EWR, and Tool Wear Ratio (TWR. Dimensional features and surface quality of drilled holes were evaluated based on Overcut (OC, Hole Depth (HD, and Surface Roughness (SR. Three-dimensional three-phase CFD models were built using ANSYS FLUENT software to simulate the flow field at interelectrode gap. Results revealed that the overall performance of side-cut electrode was superior due to improved erosion rates and flushing capabilities, resulting in production of deep holes with good dimensional accuracy and surface quality.

  19. Comparative study of bridge plate associated to the intramedullary pin and the dynamic compression plate on the experimental osteotomy fixation of femoral in rabbits (Oryctolagus cuniculus). Clinical, radiographic, histological and scintigraphy analyses; Estudo comparativo da placa em ponte associada ao pino intramedular e da placa de compressao dinamica na fixacao de osteotomia experimental em femur de coelhos (Oryctolagus cuniculus). Analises clinica, radiografica, histologica e cintilografica

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Natalie Ferreira


    The objectives were to benchmark and monitor the fracture healing of femoral osteotomy in rabbits after fixation with dynamic compression plate and bridge plate associated with intramedullary pin. Were used 14 New Zealand rabbits, four months old with mean weight of 3.5 pounds, from the Experimental Farm Professor Helio Barbosa of the Veterinary School of Minas Gerais Federal Univ. (UFMG). The animals were randomly divided into two groups (I and II). All rabbits underwent osteotomy across the middle third of right femur. In the group I was made to fix the osteotomy with the bridge plate (BP) associated with intramedullary pin, introduced the technique of minimal invasion. In group II, we used dynamic compression plate (DCP) via the conventional approach. Both groups were evaluated clinical, radiographic, histologic and scintigraphic findings. Clinical assessments were performed weekly until the 12{sup th} postoperative week and radiographic examinations were performed before, immediately after, at 15, 30, 45, 60 and 90 days. The bone scintigraphy were performed before and at 20, 50 and 90 days after surgery to monitor the bone metabolism qualitatively and quantitatively. Observed perfusion and bone healing process. After 90 days of study, there was histopathologic evaluation of the osteotomized area and the insertion of screws. In the region of the osteotomy was observed predominance of trabecular bone in group I and group II, the predominance of bone osteons, compatible with the original bone. On insertion of the screws did not differ between groups and there was cortical discontinuity, little necrosis and local hemorrhage. The two types of fixation have led to consolidation within the scheduled period, maturing in early fixation with DCP fixation compared with BP. Scintigraphy demonstrated by the indices of activity and image characteristics, the process of bone healing was significantly greater in animals undergoing early fixation with DCP. (author)

  20. Bioaccumulation of Lead In Body Tissues of Atlantic Salmon (Salmo Salar L: Experimental Investigation and Comparative Analysis

    Directory of Open Access Journals (Sweden)

    Raimondas Leopoldas Idzelis


    Full Text Available The article presents tests on one-year artificially bred Atlantic salmon. For 14 days, fish were exposed to lead nitrate Pb (NO32 under concentration corresponding to the highest allowable standard of inland water making 0.005 mg Pb/l. Lead (Pb in fish tissues (muscle and gills was determined applying atomic absorption spectrophotometry (AAS. The obtained results have showed that the maximum-permissible-amount of lead in fish (MPA = 0.2 mg Pb/kg (Lithuanian Hygiene Standard HN 54:2003 slightly exceeds in salmon gills (0.237 mg/kg, whereas in muscles, it exceeds more than twice (0.4 mg/kg. The received data have been compared with the results of the previous studies, where under the same experimental conditions, the bioaccumulation of lead in five types of fish, including roach, perch, rainbow trout, stone loach and gibel carp has been investigated. The conducted research has also revealed that different fish species quite differently accumulate lead while MPA has exceeded in the body tissues of a number of fish, i.e., in the majority of cases, it can be attributed to salmon and stone loach muscles and gills. When observing water bodies, the collected experimental data completely coincide with the results of studies on lead bioaccumulation in fish.Article in Lithuanian

  1. Proteomic Studies on Human and Experimental Cerebral Malaria

    KAUST Repository

    Moussa, Ehab


    Cerebral malaria (CM) is a severe neurological complication of malaria infection that results from interrelated pathologies. Despite extensive research efforts, the mechanism of the disease is not completely understood. Clinical studies, postmortem analysis, and animal models have been the main research arenas in CM. In this thesis, shotgun proteomics approach was used to further understand the pathology of human and experimental CM. The mechanism by which CM turns fatal is yet to be identified. A clinical proteomics study was conducted on pooled plasma samples from children with reversible or fatal CM from the Gambia. The results show that depletion of coagulation factors and increased levels of circulating proteasomes are associated with fatal pediatric CM. This data suggests that the ongoing coagulation during CM might be a disseminated intravascular coagulation state that eventually causes depletion of the coagulation factors leading to petechial hemorrhages. In addition, the mechanism(s) by which blood transfusion benefits CM in children was investigated. To that end, the concentration and multimerization pattern of von-willebrand factor, and the concentration of haptoglobin in the plasma of children with CM who received blood transfusions were measured. In addition to clinical studies, experimental cerebral malaria (ECM) in mice has been long used as a model for the disease. A shotgun proteomics workflow was optimized to identify the proteomic signature of the brain tissue of mice with ECM.Because of the utmost importance of membrane proteins in the pathology of the disease, sample fractionation and filter aided sample preparation were used to recover them. The proteomic signature of the brains of mice infected with P. berghei ANKA that developed neurological syndrome, mice infected with P. berghei NK56 that developed severe malaria but without neurological signs, and non-infected mice, were compared to identify CM specific proteins. Among the differentially

  2. Advertisement Analysis: A Comparative Critical Study (United States)

    Abdelaal, Noureldin Mohamed; Sase, Amal Saleh


    This study aimed at analyzing two advertisements, and investigating how advertisers use discourse and semiotics to make people and customers buy into their ideas, beliefs, or simply their products. The two advertisements analyzed are beauty products which have been selected from internet magazines. The methodology adopted in this study is…

  3. A Comparative Comment on the Case Studies

    DEFF Research Database (Denmark)

    Kjeldsen, Christian Christrup; Ley, Thomas; Jensen, Niels Rosendal


    Denne konklusion sammenfatter hovedtrækkene af de gennemførte case studies i WorkAble-projektet. Vigtige pointer er, at unge på tværs af de forskellige case studies har vanskeligt ved at blive hørt og taget alvorligt. I stedet spises de af med "realistisk vejledning" eller dårlige uddannelses- og...

  4. Comparative studies on different molecular methods for ...

    African Journals Online (AJOL)

    The present study aims to evaluate two molecular methods for epidemiological typing of multi drug resistant Klebsiella pneumoniae isolated from Mansoura Hospitals. In this study, a total of 300 clinical isolates were collected from different patients distributed among Mansoura Hospitals, Dakahlia governorate, Egypt.

  5. A comparative study of staff removal algorithms. (United States)

    Dalitz, Christoph; Droettboom, Michael; Pranzas, Bastian; Fujinaga, Ichiro


    This paper presents a quantitative comparison of different algorithms for the removal of stafflines from music images. It contains a survey of previously proposed algorithms and suggests a new skeletonization based approach. We define three different error metrics, compare the algorithms with respect to these metrics and measure their robustness with respect to certain image defects. Our test images are computer-generated scores on which we apply various image deformations typically found in real-world data. In addition to modern western music notation our test set also includes historic music notation such as mensural notation and lute tablature. Our general approach and evaluation methodology is not specific to staff removal, but applicable to other segmentation problems as well.

  6. Comparative Study of Light Sources for Household (United States)

    Pawlak, Andrzej; Zalesińska, Małgorzata


    The article describes test results that provided the ground to define and evaluate basic photometric, colorimetric and electric parameters of selected, widely available light sources, which are equivalent to a traditional incandescent 60-Watt light bulb. Overall, one halogen light bulb, three compact fluorescent lamps and eleven LED light sources were tested. In general, it was concluded that in most cases (branded products, in particular) the measured and calculated parameters differ from the values declared by manufacturers only to a small degree. LED sources prove to be the most beneficial substitute for traditional light bulbs, considering both their operational parameters and their price, which is comparable with the price of compact fluorescent lamps or, in some instances, even lower.

  7. Comparative studies on Egyptian elapid venoms. (United States)

    Hassan, F; Seddik, S


    The immunological properties of Naja haje from Western Desert, Naja haje of the Nile Delta, Naja nigricollis from Upper Egypt and Walternnesia aegyptia from Sinai Desert were compared using horse serum antivenin prepared from the Delta Naja haje venom. All elapid venoms showed very similar precipitin lines with immunodiffusion or immunoelectrophoresis on agar gel. Results of cellulose-acetate electrophoresis showed either different concentration of certain similar protein components or the absence of some major protein fractions. However, different migration and localization of protein components were observed. LD50 of the 4 elapids and their degree of lethality was determined. Naja haje (Delta) antivenin had different degree of neutralization capacity on the investigated elapid venoms. No correlation between immunodiffusion similarities and the degree of neutralization could be deducted.


    Directory of Open Access Journals (Sweden)

    Andrzej PAWLAK


    Full Text Available The article describes test results that provided the ground to define and evaluate basic photometric, colorimetric and electric parameters of selected, widely available light sources, which are equivalent to a traditional incandescent 60-Watt light bulb. Overall, one halogen light bulb, three compact fluorescent lamps and eleven LED light sources were tested. In general, it was concluded that in most cases (branded products, in particular the measured and calculated parameters differ from the values declared by manufacturers only to a small degree. LED sources prove to be the most beneficial substitute for traditional light bulbs, considering both their operational parameters and their price, which is comparable with the price of compact fluorescent lamps or, in some instances, even lower.

  9. Vessels under Body Accelerations: A Comparative Study

    Directory of Open Access Journals (Sweden)

    D. S. Sankar


    Full Text Available Pulsatile flow of blood in constricted narrow arteries under periodic body acceleration is analyzed, modeling blood as non-Newtonian fluid models with yield stress such as (i Herschel-Bulkley fluid model and (ii Casson fluid model. The expressions for various flow quantities obtained by Sankar and Ismail (2010 for Herschel-Bulkley fluid model and Nagarani and Sarojamma (2008, in an improved form, for Casson fluid model are used to compute the data for comparing these fluid models. It is found that the plug core radius and wall shear stress are lower for H-B fluid model than those of the Casson fluid model. It is also noted that the plug flow velocity and flow rate are considerably higher for H-B fluid than those of the Casson fluid model. The estimates of the mean velocity and mean flow rate are considerably higher for H-B fluid model than those of the Casson fluid model.

  10. Experimental Investigation of Comparative Process Capabilities of Metal and Ceramic Injection Molding for Precision Applications

    DEFF Research Database (Denmark)

    Islam, Aminul; Giannekas, Nikolaos; Marhöfer, David Maximilian


    The purpose of this paper is to make a comparative study on the process capabilities of the two branches of the powder injection molding (PIM) process—metal injection molding (MIM) and ceramic injection molding (CIM), for high-end precision applications. The state-of-the-art literature does...... and discussion presented in the paper will be useful for thorough understanding of the MIM and CIM processes and to select the right material and process for the right application or even to combine metal and ceramic materials by molding to produce metal–ceramic hybrid components....

  11. Comparative study on diagonal equivalent methods of masonry infill panel (United States)

    Amalia, Aniendhita Rizki; Iranata, Data


    ratio of height to width of 1 to 1.5. Load used in the experiment was based on Uniform Building Code (UBC) 1991. Every method compared was calculated first to get equivalent diagonal strut width. The second step was modelling method using structure analysis software as a frame with a diagonal in a linear mode. The linear mode was chosen based on structure analysis commonly used by structure designers. The frame was loaded and for every model, its load and deformation values were identified. The values of load - deformation of every method were compared to those of experimental test specimen by Mehrabi and open frame. From comparative study performed, Holmes' and Bazan-Meli's equations gave results the closest to the experimental test specimen by Mehrabi. Other equations that gave close values within the limit (by comparing it to the open frame) are Saneinejad-Hobbs, Stafford-Smith, Bazan-Meli, Liauw Kwan, Paulay and Priestley, FEMA 356, Durani Luo, Hendry, Papia and Chen-Iranata.

  12. XY sex chromosome complement, compared with XX, in the CNS confers greater neurodegeneration during experimental autoimmune encephalomyelitis. (United States)

    Du, Sienmi; Itoh, Noriko; Askarinam, Sahar; Hill, Haley; Arnold, Arthur P; Voskuhl, Rhonda R


    Women are more susceptible to multiple sclerosis (MS) and have more robust immune responses than men. However, men with MS tend to demonstrate a more progressive disease course than women, suggesting a disconnect between the severity of an immune attack and the CNS response to a given immune attack. We have previously shown in an MS model, experimental autoimmune encephalomyelitis, that autoantigen-sensitized XX lymph node cells, compared with XY, are more encephalitogenic. These studies demonstrated an effect of sex chromosomes in the induction of immune responses, but did not address a potential role of sex chromosomes in the CNS response to immune-mediated injury. Here, we examined this possibility using XX versus XY bone marrow chimeras reconstituted with a common immune system of one sex chromosomal type. We found that experimental autoimmune encephalomyelitis mice with an XY sex chromosome complement in the CNS, compared with XX, demonstrated greater clinical disease severity with more neuropathology in the spinal cord, cerebellum, and cerebral cortex. A candidate gene on the X chromosome, toll-like receptor 7, was then examined. Toll-like receptor 7 expression in cortical neurons was higher in mice with XY compared with mice with XX CNS, consistent with the known neurodegenerative role for toll-like receptor 7 in neurons. These results suggest that sex chromosome effects on neurodegeneration in the CNS run counter to effects on immune responses, and may bear relevance to the clinical enigma of greater MS susceptibility in women but faster disability progression in men. This is a demonstration of a direct effect of sex chromosome complement on neurodegeneration in a neurological disease.

  13. Experimental study of mechanical properties of friction welded AISI ...

    Indian Academy of Sciences (India)

    Friction welding is widely used as a mass production method in various industries. In the present study, an experimental set-up was designed in order to achieve friction welding of plastically deformed AISI 1021 steels. In this study, low alloy steel (AISI 1021) was welded under different welding parameters and afterwards ...

  14. Experimental study of mechanical properties of friction welded AISI ...

    Indian Academy of Sciences (India)

    Abstract. Friction welding is widely used as a mass production method in vari- ous industries. In the present study, an experimental set-up was designed in order to achieve friction welding of plastically deformed AISI 1021 steels. In this study, low alloy steel (AISI 1021) was welded under different welding parameters and ...

  15. Infections in orthopaedic surgery : clinical and experimental studies

    NARCIS (Netherlands)

    Vogely, Henri Charles


    The diagnostic difficulties, variability in outcome and the heterogeinity of the problem of orthopaedic infections stimulated the author to a study of the literature, and several clinical and experimental studies. The diagnosis prosthesis-related infection can only be reached with an acceptable

  16. Systematic review of experimental studies on intestinal anastomosis

    NARCIS (Netherlands)

    Yauw, S.T.K.; Wever, K.E.; Hoesseini, A.; Ritskes-Hoitinga, M.; Goor, H. van


    BACKGROUND: The contribution of animal research to a reduction in clinical intestinal anastomotic leakage is unknown, despite numerous experimental studies. In view of the current societal call to replace, reduce and refine animal experiments, this study examined the quality of animal research

  17. What Shapes the Intention to Study Abroad? An Experimental Approach (United States)

    Petzold, Knut; Moog, Petra


    In contrast to previous studies, this investigation aims to get deeper insights into the causes of the intention to study abroad by using an experimental approach. Although international experience is often considered as important, many students at German universities do not even consider abroad. Referring to the Theory of Rational Choice (RCT)…

  18. Experimental Study of the Production of Solar Hydrogen in Algeria ...

    African Journals Online (AJOL)

    Hydrogen is a sustainable fuel option and one of the potential solutions for the current energy and environmental problems. In this study hydrogen is produced using a hydrogen generator with a Proton Exchange Membrane (PEM) electrolyser. An experimental study is done in the Center of Development of the Renewable ...

  19. Experimental Studies on Electronic Portfolios in Turkey: A Literature Review (United States)

    Alan, Selahattin; Sünbül, Ali Murat


    In this study, a literature review was conducted about an individual's selected efforts, products stored in electronic format, and electronic portfolios that reflect the development and capacity of multimedia systems. In this context, relevant experimental studies performed in Turkey are collected to show e-portfolio application forms, their…

  20. Experimental measurements of diffraction for periodic patterns by 193-nm polarized radiation compared to rigorous EMF simulations (United States)

    Bennett, Marylyn H.; Grenville, Andrew; Hector, Scott D.; Palmer, Shane R.; Leunissen, Leonardus H. A.; Philipsen, Vicky; Bloomstein, Theodore M.; Hardy, Dennis E.; Rothschild, Mordechai; Hilfiker, James N.


    Polarization dependent diffraction efficiencies in transmission through gratings on specially designed masks with pitch comparable to the wavelength were measured using an angle-resolved scatterometry apparatus with a 193 nm excimer source. Four masks - two binary, one alternating and one attenuated phase shift mask - were included in the experimental measurements. The validity of models used in present commercially available simulation packages and additional polarization effects were evaluated against the experimental scattering efficiencies.

  1. A "self adhering" prosthesis for hernia repair: experimental study. (United States)

    Champault, G; Polliand, C; Dufour, F; Ziol, M; Behr, L


    Prosthetic reinforcement is now routine in the management of inguinal and incisional hernia, and it significantly reduces the risk of recurrence. After surgery, chronic pain is often attributed to the characteristics of the mesh and to the method of fixation in the wound, with a potential risk of nerve or muscle injuries. To evaluate the properties of a new "self adhering" prosthesis in an experimental animal study. The self adhering prosthesis, a lightweight (40 mg/m(2)) polypropylene mesh coated with a synthetic glue on one side, was implanted laparoscopically in pigs. Removal of the prosthesis was performed at one day, one week and one month post operatively. A macroscopic and microscopic evaluation was performed. The results, using a quantitative score, were compared to those of a control group using the same polypropylene mesh without glue, but fixed by staples. The operative time was significantly lower in the self adhering group: 23 min (15-32) versus 31 min (21-40) (P = 0.01). The average time interval from the introduction of the mesh into the preperitoneal space until the appearance of the first tough adhesion was 3 min (2-4). In the control group, the mesh handling time was 8.3 min (5-14) (P = 0.01). At the time of implantation, the score was at a maximum value in all cases for the self adhering prostheses, especially concerning handling and adhesiveness. Upon removal, this score was noted to be good or very good in 90-100% of the cases. There was a good integration in the muscle confirmed histologically, and there was no shrinkage, no mobilisation and no migration. At one month, the thickness of the fibrosis at the limits of the meshes was significantly higher for the self adhering prostheses (P = 0.02). In this experimental study, the self adhering prosthesis demonstrated its adhesive properties and its ability to be well tolerated, with a good macroscopic and microscopic integration into the abdominal wound. This should allow us to perform a clinical

  2. [Descriptive, experimental and comparative investigations on the ecology of diplopoda of the Rhein-Main-region]. (United States)

    Haacker, Ulrich


    1. The ecology of 14 millipede-species of the Rhein-Main-region was analysed by descriptive, experimental and comparative methods. 2. Quantitative field-investigations showed that 6 species are stenoecic in woodlands, 3 species stenoecic in open country, and 4 species euryoecic; one further species, Cylindroiulus truncorum, has been introduced from North-Africa and is synanthropic, near Wiesbaden it has spread out from a cemetery into the surrounding beech-wood. 3. In 4 typical habitats (leaf-wood, pine-wood, potatoefield on loam, grassland on sand) the microclimate at the surface and in the soil was registred over 24 hours as well as over the year. 4. Sexual activity and behaviour in the habitat were observed. Some species show a marked activity at the surface including herbs and trees. 6 species have a diurnal rhythmic behaviour: they are migrating vertically in soil and litter. 5. A number of factors with possible influence on distribution were analysed by experiments. Locomotion-speed and scototactic orientation are of no influence, food-preference plays a part in 3 species. As shown by preference-experiments, fir litter is not accepted as food; this helps to understand the rareness of millipedes in fir-monocultures. Distribution is mainly determined by abiotic factors. Resistance against desiccation and preference towards a humidity-gradient - both closely correlated by transpiration - agree with distribution in 10 species. Low temperature-resistance is a limiting factor in 4 cases; 1 species living but under barks, Nemasoma varicorne, can be euryoecic only by its high resistance against frost and heat. Preference reactions towards temperature agree with distribution in 11 species, being the only distributional factor to be found in 4 cases. 6. Distribution is determined by specific factorial patterns, which even in related species are rarely the same. 7. In cases of diverging microclimatic claims, unfavourable humidity conditions are tolerated if by this

  3. Attentional bias in snus users: an experimental study.

    Directory of Open Access Journals (Sweden)

    Rune Aune Mentzoni

    Full Text Available The use of nicotine in the form of "snus" is substantial and increasing in some geographic areas, in particular among young people. It has previously been suggested that addictions may operate through a mechanism of attentional bias, in which stimuli representative of the dependent substance increase in salience, thus increasing the addictive behavior. However, this hypothesis has not been tested for the case of snus. The current experiment used a modified Stroop task and a dot-probe task to investigate whether 40 snus users show an attentional bias towards snus-relevant stimuli, compared to 40 non-snus users. There were no significant differences between the two groups on reaction times or accuracy on either Stroop or dot-probe task, thus failing to show an attentional bias towards snus-relevant stimuli for snus users. This could imply that other mechanisms may contribute to maintenance of snus use than for other addictions. However, this is the first experimental study investigating attentional bias in snus users, and more research is warranted.

  4. Experimental study on titanium wire drawing with ultrasonic vibration. (United States)

    Liu, Shen; Shan, Xiaobiao; Guo, Kai; Yang, Yuancai; Xie, Tao


    Titanium and its alloys have been widely used in aerospace and biomedical industries, however, they are classified as difficult-to-machine materials. In this paper, ultrasonic vibration is imposed on the die to overcome the difficulties during conventional titanium wire drawing processes at the room temperature. Numerical simulations were performed to investigate the variation of axial stress within the contacting region and study the change of the drawing stress with several factors in terms of the longitudinal amplitude and frequency of the applied ultrasonic vibration, the diameter reduction ratio, and the drawing force. An experimental testing equipment was established to measure the drawing torque and rotational velocity of the coiler drum during the wire drawing process. The result indicates the drawing force increases with the growth of the drawing velocity and the reduction ratio, whether with or without vibrations. Application of either form of ultrasonic vibrations contributes to the further decrease of the drawing force, especially the longitudinal vibration with larger amplitude. SEM was employed to detect the surface morphology of the processed wires drawn under the three circumstances. The surface quality of the drawn wires with ultrasonic vibrations was apparently improved compared with those using conventional method. In addition, the longitudinal and torsional composite vibration was more effective for surface quality improvement than pure longitudinal vibration, however, at the cost of weakened drawing force reduction effect. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Experimental studies of the snowflake divertor in TCV

    Directory of Open Access Journals (Sweden)

    B. Labit


    Full Text Available To address the risk that, in a fusion reactor, the conventional single-null divertor (SND configuration may not be able to handle the power exhaust, alternative divertor configurations, such as the Snowflake divertor (SFD, are investigated in TCV. The expected benefits of the SFD-minus in terms of power load and peak heat flux are discussed and compared to experimental measurements. In addition, key results obtained during the last years are summarized.

  6. Annual Journal citation indices: a comparative study

    CERN Document Server

    Khaleque, Abdul; Sen, Parongama


    We study the statistics of citations made to the indexed Science journals in the Journal Citation Reports during the period 2004-2013 using different measures. We consider different measures which quantify the impact of the journals. To our surprise, we find that the apparently uncorrelated measures, even when defined in an arbitrary manner, show strong correlations. This is checked over all the years considered. Impact factor being one of these measures, the present work raises the question whether it is actually a nearly perfect index as claimed often. In addition we study the distributions of the different indices which also behave similarly.

  7. Child Labor in Africa: A Comparative Study

    DEFF Research Database (Denmark)

    Nielsen, Helena Skyt; Canagarajah, Sudharshan


    This paper analyzes the determinants of child labor in Africa as inferred from recent empirical studies. The empirical analysis is based upon five country studies undertaken in three different African countries, namely Côte d'Ivoire, Ghana, and Zambia. Some support is found for the popular belief...... of poverty as a determinant of child labor, however other determinants are of similar importance. Among school costs, transportation costs have the greatest effect on child labor and school attendance, whereas the hypothesis of imperfect capital markets and that of household composition generally find some...

  8. Child Labor in Africa: A Comparative Study

    DEFF Research Database (Denmark)

    Canagarajah, Sudharshan; Nielsen, Helena Skyt


    This paper analyzes the determinants of child labor in Africa as inferred from recent empirical studies. The empirical analysis is based upon five country studies undertaken in three different African countries, namely Côte d'Ivoire, Ghana, and Zambia. Some support is found for the popular belief...... of poverty as a determinant of child labor, however other determinants are of similar importance. Among school costs, transportation costs have the greatest effect on child labor and school attendance, whereas the hypothesis of imperfect capital markets and that of household composition generally find some...


    African Journals Online (AJOL)



    Aug 16, 2012 ... The division bryophyta also consists of liverworts and hornworts. Bryophyta have been long considered to be insignificant in the economy of man except for those used in packing, plugging and decoration. Recent progress in environmental pollution studies has changed our understanding of bryophytes as ...


    African Journals Online (AJOL)


    hole water samples. `coliform bacteria but coliform bacteria but coliform bacteria but after treatment by boiling an after treatment by boiling an was reduced to was reduced to zero with .... Sanitation and Hygiene) ... STUDY OF HOUSEHOLD WATER TREATMENT IN A RURAL COMMUNITY IN KWARA STATE NIGERIA.

  11. Comparative Efficacy Study of Chloroquine Dihydroartemisinin and ...

    African Journals Online (AJOL)

    This study evaluated the efficacy of chloroquine (CQ), dihyroartemisinin (DHA) and the combination of dihyroartemisinin plus mefloquine (MQ) in Nigerian children with acute uncomplicated falciparum malaria. Method: Seventy-five subjects aged 2-13 years attending the outpatient clinic of Ijede health center, Ikorodu and ...

  12. Metacognition and Group Differences: A Comparative Study (United States)

    Al-Hilawani, Yasser A.


    In this study, metacognition refers to performing visual analysis and discrimination of real life events and situations in naïve psychology, naïve physics, and naïve biology domains. It is used, along with measuring reaction time, to examine differences in the ability of four groups of students to select appropriate pictures that correspond with…

  13. Bilingual Language Proficiency : A comparative study

    NARCIS (Netherlands)

    Duarte, Joana


    his book investigates the role native language plays in the process of acquiring a second language within a bilingual educational model. The research presented is based on a 2 year longitudinal study of students in a bilingual school. Particular attention is paid to the development of academic

  14. Children's Friendship Development: A Comparative Study (United States)

    Yu, SeonYeong; Ostrosky, Michaelene M.; Fowler, Susan A.


    Establishing friendships is an important developmental goal of early childhood, but little research has addressed ways in which parents support the friendship development of their young children with disabilities. The purpose of this survey study was to explore the support strategies that parents use to facilitate their children's friendships.…

  15. Comparative study of environmental impact assessment methods ...

    African Journals Online (AJOL)

    Environmental Impacts Assessment has been developed as a critically substantial approach to determine, predict and interpret the ecological impact on the environment, public hygiene and healthy ecosystems. This study aims to introduce and systematically investigate the environmental issues during important ...


    African Journals Online (AJOL)



    Jun 30, 2014 ... ABSTRACT. The aim of the present study was to evaluate the physical and chemical properties of five. Algerian unifloral types of honey. Several physical parameters of honey, such as pH, moisture content, electrical conductivity, total dissolved solids, color intensity and total sugar content, were measured.

  17. Implicature, Pragmatics, and Documentation: A Comparative Study (United States)

    Wright, David


    This study investigates the link between the linguistic principles of implicature and pragmatics and software documentation. When implicatures are created in conversation or text, the listener or reader is required to fill in missing information not overtly stated. This information is usually filled in on the basis of previous knowledge or…

  18. Diffusion in liquids a theoretical and experimental study

    CERN Document Server

    Tyrrell, H J V


    Diffusion in Liquids: A Theoretical and Experimental Study aims to discuss the principles, applications, and advances in the field of diffusion, thermal diffusion, and thermal conduction in liquid systems. The book covers topics such as the principles of non-equilibrium thermodynamics; diffusion in binary and multicompetent systems; and experimental methods of studying diffusion processes in liquids. Also covered in the book are topics such as the theoretical interpretations of diffusion coefficients; hydrodynamic and kinetic theories; and diffusion in electrolyte systems. The text is recommen

  19. Analytical and Experimental Study of Residual Stresses in CFRP

    Directory of Open Access Journals (Sweden)

    Chia-Chin Chiang


    Full Text Available Fiber Bragg Grating sensors (FBGs have been utilized in various engineering and photoelectric fields because of their good environment tolerance. In this research, residual stresses of carbon fiber reinforced polymer composites (CFRP were studied using both experimental and analytical approach. The FBGs were embedded inside middle layers of CFRP to study the formation of residual stress during curing process. Finite element analysis was performed using ABAQUS software to simulate the CFRP curing process. Both experimental and simulation results showed that the residual stress appeared during cooling process and the residual stresses could be released when the CFRP was machined to a different shape.

  20. Restoration of a 17th-century harpsichord to playable condition: a numerical and experimental study. (United States)

    Le Moyne, Sylvie; Le Conte, Sandie; Ollivier, François; Frelat, Joël; Battault, Jean-Claude; Vaiedelich, Stéphane


    The Music Museum in Paris recently acquired a harpsichord made by Ioannes Couchet in Antwerp in 1652. This instrument is considered to be a masterpiece and is protected as a "National Treasure." It was restored with the aim to be played again in concert. An experimental and numerical study of the vibraoacoustic behavior of this harpsichord is presented. A numerical modal analysis was performed with a finite element model. For the experimental part, impact nearfield acoustical holography was used. Experimental eigenmodes are compared to literature and to the finite element results. An application of the model for restoration studies is also proposed. © 2012 Acoustical Society of America.

  1. Gas Absorption by Alkaline Solution in a Cyclone Scrubber: Experimental and Modeling Study

    Directory of Open Access Journals (Sweden)

    Mariana Mariana


    Full Text Available Experimental and modeling studies have been conducted on a CO2 absorption in a cyclone scrubber operated at room temperature. The effects of parameters such as the initial concentration of alkali in the solution and the liquid – gas ratio on the CO2 absorbed flux were experimentally and theoretically investigated. A theoretical study has been performed using a mathematical model based on the absorption in the liquid droplet with instantaneous reaction, in the inlet duct of the cyclone and in the cyclone itself. The results from the model were compared with experimental data and showed satisfactory agreement.   Keywords: CO2 removal, mathematical model, wet cyclone scrubber

  2. A comparative study of machine learning models for ethnicity classification (United States)

    Trivedi, Advait; Bessie Amali, D. Geraldine


    This paper endeavours to adopt a machine learning approach to solve the problem of ethnicity recognition. Ethnicity identification is an important vision problem with its use cases being extended to various domains. Despite the multitude of complexity involved, ethnicity identification comes naturally to humans. This meta information can be leveraged to make several decisions, be it in target marketing or security. With the recent development of intelligent systems a sub module to efficiently capture ethnicity would be useful in several use cases. Several attempts to identify an ideal learning model to represent a multi-ethnic dataset have been recorded. A comparative study of classifiers such as support vector machines, logistic regression has been documented. Experimental results indicate that the logical classifier provides a much accurate classification than the support vector machine.

  3. A comparative study of cognitive radio platforms

    CSIR Research Space (South Africa)

    Masonta, MT


    Full Text Available of their results to ensure accurate deployments of new network protocols, applications and services. The three commonly used evaluation techniques in the study of communications systems are simulations, emulations, and testbeds or plat- forms. Simulation...- uated in CR platforms include dynamic spectrum manage- ment, spectrum sensing, TV white space exploitation (such as in IEEE 802.22), energy e ciency, MAC protocols, wire- less distributed computing and green radios [17]. CR plat- forms have evolved...

  4. Conjunctivitis in the newborn- a comparative study. (United States)

    Wadhwani, Meenakshi; D'souza, Pamela; Jain, Rajesh; Dutta, Renu; Saili, Arvind; Singh, Abha


    Conjunctivitis of the newborn is defined as hyperemia and eye discharge in the neonates and is a common infection occurring in the neonates in the first month of life. In the United States, the incidence of neonatal conjunctivitis ranges from 1-2%, in India, the prevalence is 0.5-33% and varies in the world from 0.9-21% depending on the socioeconomic status. To study the organisms causing conjunctivitis of the newborn and to correlate the etiology with the mode of delivery. Single center, prospective, observational study. A total of 300 mothers and their newborns, born over a period of one year, were included in the study. Of these 200 newborns were delivered through vaginal route (Group A) and 100 (Group B) delivered by lower segment caesarean section (LSCS). At the time of labour, high vaginal swabs were taken from the mothers. Two conjunctival swabs each from both eyes of the newborn were collected at birth and transported to Microbiology department in a candle jar immediately. Eight babies in Group A, developed conjunctivitis at birth. None of the babies in Group B developed conjunctivitis, this difference was statistically highly significant (Pconjunctivitis in the newborn in this study was Coagulase negative Staphylococcus. It was observed that the mothers of 5 out of 8 babies (60%) developing conjunctivitis gave history of midwife interference and premature rupture of membranes so the presence of risk factors contribute to the occurrence of conjunctivitis in the newborn. It is inferred that the mode of delivery and the presence of risk factors is responsible for conjunctivitis in the newborn.

  5. A comparative study of various decalcification techniques

    Directory of Open Access Journals (Sweden)

    Prathibha Prasad


    Full Text Available Background : Study of fibrilar, cellular and sub cellular structures of mineralized tissues is only possible after the removal of the calcium apatite of these tissues by the process of demineralization. Aims: The present study aims to evaluate six commonly used demineralizing agents to identify the best decalcifying agent. Materials and Methods: The present study included six different decalcifying solutions: 10% formal nitric acid, 8% formal nitric acid, 10% formic acid, 8% formic acid, Perenyi′s fluid and Ethylene Di-Amine Tetra Acetic Acid. eight samples of posterior mandible of rat were decalcified in each of the decalcifying solutions and subjected to chemical end-point test. Ehrlich′s Hematoxylin stain was used. Statistical Analysis Used: One way ANOVA was used for multiple group comparisons and Chi-square test was used for analyzing categorical data. P value of 0.05/less was set for statistical significance. Results: Samples treated with EDTA showed the best overall histological impression and the tissue integrity were well preserved. Formal nitric of both the percentages 10 and 8% gave fairly good cellular detail and were rapid in their action. Conclusion: The final impression led to the proposition that EDTA was indeed the best decalcifying agent available. However, with time constraint, the use of formal nitric acid is advocated.

  6. Agoraphobia and Panic Disorder: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Ayse Kart


    Full Text Available Aim: In this study we aim to get more information about agoraphobia (AG which is an independent diagnosis in Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5 and to evaluate overlaps or differences between agoraphobia and panic disorder (PD upon sociodemographic features and comorbidity with considering relation of these two disorders. Material and Method: Sociodemographic Data Form was given and Structural Clinical Interview for DSM Axis I Disorders (SCID-I was applied to 33 patients diagnosed as AG and 34 patients diagnosed as PD with AG (PDA.Results: AG group consisted of 21 females (63.1%, 12 males (36%, totally 33 patients and PDA group consisted of 23 females (67.6%, 11 males (32.4%, totally 34 patients. Mean age of onset was 32.4±10.2 in PDA group and 31.1±12.1 in AG group. According to sociodemographic features, violence in family and smoking rates were significantly higher in PDA group than AG group. Major Depressive Disorder (MDD as a comorbidity was higher in PDA group. Discussion: In this study, we tried to identify the overlaps and differences of PDA and AG. For a better recognition of AG, further studies are needed.

  7. Automated Versus Conventional Systematic Desensitization: A Study of Comparative Effectiveness. (United States)

    De Csipkes, Robert A.; Rowe, Wayne

    This study investigates whether variations in method of presentation of anxiety items (experimenter's voice, experimenter's taped voice, subject's taped voice) will result in differences in autonomic arousal (as measured by self-report, galvanic skin response, cardiac rate, blood pressure). Ss were 24 Naval Academy midshipmen. The procedure…

  8. Experimental study of lithium target under high power load

    Energy Technology Data Exchange (ETDEWEB)

    Khripunov, B.I. E-mail:; Petrov, V.B.; Shapkin, V.V.; Pleshakov, A.S.; Rupyshev, A.S.; Antonov, N.V.; Litnovsky, A.M.; Romanov, P.V.; Shpansky, Yu.S.; Evtikhin, V.A.; Lyublinsky, I.E.; Vertkov, A.V


    This paper presents experimental research on simulation of a free liquid lithium surface under high heat flux impact for divertor application. Capillary porous structure (CPS) was taken to form the free liquid metal surface imitating divertor target plate. Experiments were performed in the SPRUT-4 linear plasma device with electron beam as power source. Lithium-filled targets were investigated at 1-50 MW/m{sup 2} heat loads in steady state. Lithium evaporation, energy and mass balance, surface temperature, vapor ionization, lithium plasma parameters and radiation were studied. Detailed thermal analysis was made to study heat flows in the target and their correspondence with experimental observations. Durable operation of the setup was possible in the range 1-20 MW/m{sup 2} without damage of the structure. The relevance of the experimental performance to divertor condition is analyzed.

  9. Conversion of eugenol to methyleugenol: Computational study and experimental (United States)

    Kurniawan, Muhammad Arsyik; Matsjeh, Sabirin; Triono, Sugeng


    This study provides comprehensive benchmark calculations for the computational study and experimental research on conversion of eugenol to methyleugenol with different pathway of the transition state compounds. First-principle calculation (DFT) were used to generate the structure optimization, energies of species. The calculation parameter are used to predict reactant, product and transition state species as guide to predict the experimental development of chemical characterization method including NMR and IR. The calculation showed significant effect of NaOH in formation of transition state in reaction. Experimentally, the step was nucleophilic substitution reaction of eugenolate ion to dimethylsulfate compound, it was obtained methyleugenol compound with purity of 90.73 %, which analyzed by Infrared and H-NMR spectrometer.

  10. Experimental and numeric study of aluminum wire explosion in vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Tkachenko, S.I.; Khattatov, T.A.; Tilikin, I.N. [MIPT, Dolgoprudny, Moscow Region (Russian Federation); Romanova, V.M.; Mingaleev, A.R.; Ter-Oganesyan, A.E.; Shelkovenko, T.A.; Pikuz, S.A. [P.N. Lebedev Physical Institute RAS, Moscow (Russian Federation); Olhovskaya, O.G.; Krukovskij, A.Y.; Gasilov, V.A.; Novikov, V.G. [IMM RAS, Moscow (Russian Federation)


    Full text of publication follows: Distribution of matter in the discharge channel formed upon a nanosecond electrical explosion of Al wire in vacuum was studied experimentally and theoretically. Several series of experiments with 25 {mu}m diameter 12 mm long wires were performed; the charging voltage, the current amplitude and current rise rate were U{sub 0} = 20 kV, Imax {approx} 10 kA and dI/dt = 50 A/ns, respectively [1]. 'Shadow and Schlieren' images of the discharge channel were obtained using optical probing at the second harmonic of a YAG: Nd{sup +3} laser ({lambda} = 0.532 {mu}m, {tau} {approx} 70 ps). Simultaneous use of optical and UV diagnostics made it possible to distinguish qualitatively different regions of the discharge channel, such as the current-carrying plasma layers and the region occupied by a weakly conducting cold matter. The simulations were performed using a program containing the Braginsky two temperature magnetic gas-dynamic model: Lagrange-Euler code RAZRYAD-2.5 [2] on the basis of homogeneous, conservative and implicit differences of MHD schemes. Radiation energy exchange is accounted for in a multi-group (from the spectrum) approximation, using a radiation diffusion model. Heat- and electro- conductivity anisotropy in magnetic field is taken into account. Tables of thermal-physical and optical properties of aluminum were used in calculations in the present work [3]. The influence of radiation on the distribution of the parameters of matter (temperature, density) and current density in the discharge channel was studied. Several variants with differing amounts of radiation of spectral groups were evaluated. The obtained results are compared with experimental data. This work was supported in part by the RFBR 08-08-00688, 09-02-01532, and the ESC FIAN.; [1]. S.I. Tkachenko et. al., Plasma Physics Reports, 2009, Vol. 35, No. 9, pp. 734-753; [2]. V.A. Gasilov et. al., Mathematical Modelling, 2003, v. 15, No 9, pp. 107-124; [3]. A

  11. Comparative toxicity of oxygenated monoterpenoids in experimental hydroalcoholic lotions to permethrin-resistant adult head lice. (United States)

    Gonzalez-Audino, Paola; Picollo, María Inés; Gallardo, Anabella; Toloza, Ariel; Vassena, Claudia; Mougabure-Cueto, Gastón


    The use of botanical compounds such as essential oils has recently become the subject of great interest as a natural means of pest control because of their ovicidal, larvicidal, or adulticidal activity against various insect species including head lice. We tested and compared the efficacy of pure oxygenated monoterpenoids that are main ingredients of essential oils of good biological activity. We used pulegone and citral, components of Aloysia citrodora, and geraniol, citronellol, and linalool, components of Geranium sp. oil. We found that citronellol and geraniol showed the highest knockdown and mortality effect (>60%) on adults of both sexes (50:50%) and third-stage nymphs. Pulegone, linalool, and citral showed knockdown percentages between 42 and 55%, and mortality percentages between 47 and 53%. A simple linear regression analysis showed statistically significant relationships between the studied toxic effects and viscosity of the monoterpenoids (p < 0.05), but not with their partition coefficient (log P).

  12. Comparative Cognitive Task Analyses of Experimental Science and Instructional Laboratory Courses (United States)

    Wieman, Carl


    Undergraduate instructional labs in physics generate intense opinions. Their advocates are passionate as to their importance for teaching physics as an experimental activity and providing "hands-on" learning experiences, while their detractors (often but not entirely students) offer harsh criticisms that they are pointless, confusing and…

  13. Comparative evaluation of photodynamic therapy induced by two different photosensitizers in rat experimental candidiasis

    Directory of Open Access Journals (Sweden)

    Heidar Khademi


    Full Text Available Background: Antimicrobial efficacy of photodynamic therapy (PDT depends on both the photosensitizer (PS and laser parameters. In the present study, antimicrobial effectiveness of PDT with different concentrations of two PSs was compared. Materials and Methods: In this study, we employed fifty-nine 6-week-old male Wistar rats. All except the negative and overall control groups were immunosuppressed and then orally inoculated with a suspension of Candida albicans (9 × 10 8 CFU/ml. At 4 days after oral inoculation, swabbing of tongue dorsum was performed to recover yeast from the tongue before treatment; on the next day, PDT was carried out on tongue dorsums by use of different concentrations of methylene blue (MB or poly-L-lysine-chlorine (e6 conjugate (pL-ce6 as PS; followed by a 10 min diode laser illumination at 660 nm (n = 6 each. Then, sampling was again performed. The difference between yeast recovery before and after treatment was compared between the groups by one-way analysis of variance test (α = 0.05. After sacrificing the animals, their tongues were surgically removed and processed for histological evaluation of the presence of yeast and tissue reaction. Results: PDT mediated by both PSs, regardless of the type and their concentration, resulted in a significant microbiological and histological reduction in C. albicans counts in comparison with positive control group (P < 0.001. There was no difference in epithelial lesions and inflammatory responses between groups. Conclusion: PDT mediated MB or pL-ce6 is a promising approach for treatment of oral candidiasis.

  14. Experimental study of hole cleaning performance in underbalanced

    African Journals Online (AJOL)


    factors affecting cost, time and drilling quality can be significantly hindered due to poor hole cleaning performance. Experimental study of hole cleaning performance in underbalanced drilling at downhole temperatures260C, 400C and 600C and water influx of 0.25m3/s in a simulated vertical well using gasified mud was ...

  15. An experimental study on effect of process parameters in deep ...

    African Journals Online (AJOL)

    DR OKE

    The effects of various deep drawing process parameters were determined by experimental study with the use of Taguchi fractional factorial .... have used Taguchi method to optimize the turning operation of S45C steel bars using tungsten carbide cutting tools and reported .... The Nd:YAG laser with oxygen cutting gas were.

  16. Experimental studies of the transient fluctuation theorem using liquid ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 72; Issue 5. Experimental studies of the transient ... Recently a fluctuation theorem, known as the transient fluctuation theorem (TFT), which generalizes the second law of thermodynamics to small systems has been proposed. This theorem has been tested in small ...

  17. Premium auctions and risk preferences: an experimental study

    NARCIS (Netherlands)

    Brunner, C.; Hu, A.; Oechssler, J.


    In premium auctions, the highest losing bidder receives a reward from the seller. This paper studies the private value English premium auction (EPA) for different risk attitudes of bidders. We explicitly derive the symmetric equilibrium for bidders with CARA utilities and conduct an experimental

  18. Sciara as an experimental model for studies on the evolutionary ...

    Indian Academy of Sciences (India)

    Sciara as an experimental model for studies on the evolutionary relationships between the zygotic, maternal and environmental primary signals for sexual development. Lucas Sánchez. Review Article Volume ... Lucas Sánchez1. Centro de Investigaciones Biol´ogicas (C. S. I. C.), Ramiro de Maeztu 9, 28040 Madrid, Spain ...

  19. Experimental Study of Cloud Formation from Rapidly Opened Containers

    Energy Technology Data Exchange (ETDEWEB)

    Wooldridge, C.E. [Stanford Research Institute; Amaro, A.J. [Stanford Research Institute; Kier, R.J. [Stanford Research Institute


    This report presents the results of an experimental study of droplet size emanating from a rapidly-opened container of volatile liquid, of the internal dynamics of the cavitation process inside such a container, & of the evaporation time of propane drops.

  20. Experimental study in natural convection | Ousmane | Global Journal ...

    African Journals Online (AJOL)

    The study of thermal and ventilation parameters, obtained in a transient, laminar solar chimney of reduced dimensions, (1 < m <3) m with a square collector (side = 2m) is presented. Experimental measurements has been made to determine the temperature of the absorber and the fluid in the collector, it is shown that at the ...

  1. Synthesis, experimental and theoretical studies of two cocrystals in 1 ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 127; Issue 11. Synthesis, experimental and theoretical studies of two cocrystals in 1:1 stoichiometric ratio from 4,4'-bithiazole-2,2'-diamine with two hydrogen acceptor molecules. Zohreh Rashidi Ranjbar Ali Morsali. Articles Volume 127 Issue 11 November 2015 pp ...

  2. Experimental studies on an indigenous coconut shell based ...

    Indian Academy of Sciences (India)

    Satyabrata Sahoo

    Abstract. Experimental studies are carried out to characterize an indigenous, coconut shell based, activated carbon suitable for storage of natural gas. Properties such as BET surface area, micropore volume, average pore diameter and pore size distribution are obtained by using suitable instruments and techniques.

  3. Experimental Study on a Rotor for WEPTOS Wave Energy Converter

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter; Marchalot, Tanguy

    This report presents the results of an experimental study of the power conversion capabilities of one single rotor of the WEPTOS wave energy converter. The investigation focuses mainly on defining the optimal weight distribution in the rotor in order to improve the hydraulic performance through...

  4. Real versus Simulated Mobile Phone Exposures in Experimental Studies

    Directory of Open Access Journals (Sweden)

    Dimitris J. Panagopoulos


    Full Text Available We examined whether exposures to mobile phone radiation in biological/clinical experiments should be performed with real-life Electromagnetic Fields (EMFs emitted by commercially available mobile phone handsets, instead of simulated EMFs emitted by generators or test phones. Real mobile phone emissions are constantly and unpredictably varying and thus are very different from simulated emissions which employ fixed parameters and no variability. This variability is an important parameter that makes real emissions more bioactive. Living organisms seem to have decreased defense against environmental stressors of high variability. While experimental studies employing simulated EMF-emissions present a strong inconsistency among their results with less than 50% of them reporting effects, studies employing real mobile phone exposures demonstrate an almost 100% consistency in showing adverse effects. This consistency is in agreement with studies showing association with brain tumors, symptoms of unwellness, and declines in animal populations. Average dosimetry in studies with real emissions can be reliable with increased number of field measurements, and variation in experimental outcomes due to exposure variability becomes less significant with increased number of experimental replications. We conclude that, in order for experimental findings to reflect reality, it is crucially important that exposures be performed by commercially available mobile phone handsets.

  5. Chemometric Optimization Studies in Catalysis Employing High-Throughput Experimentation

    NARCIS (Netherlands)

    Pereira, S.R.M.


    The main topic of this thesis is the investigation of the synergies between High-Throughput Experimentation (HTE) and Chemometric Optimization methodologies in Catalysis research and of the use of such methodologies to maximize the advantages of using HTE methods. Several case studies were analysed

  6. Experimental and modeling studies of mass transfer in ...

    African Journals Online (AJOL)

    Gaining a better understanding of mass transfer problems in encapsulated cell systems and in tissue engineering requires both experimental investigations and mathematical modelling. Specific mass transfer studies are reviewed including oxygen transfer in immobilised animal cell culture systems, modelling of ...

  7. Experimental study of buoyancy driven natural ventilation through horizontal openings

    DEFF Research Database (Denmark)

    Heiselberg, Per; Li, Zhigang


    An experimental study of buoyancy driven natural ventilation through single-sided horizontal openings was performed in a full-scale laboratory test rig. Measurements were made for opening ratios L/D range from 0.027 to 4.455, where L and D are the length and the diameter of the opening, respectiv...

  8. An experimental study on effect of process parameters in deep ...

    African Journals Online (AJOL)

    The effects of various deep drawing process parameters were determined by experimental study with the use of Taguchi fractional factorial design and analysis of variance for AA6111 Aluminum alloy. The optimum process parameters were determined based on their influence on the thickness variation at different regions ...

  9. Experimental study on imaging spectrometer focusing formula in orbit (United States)

    Ma, Hong-tao; Jin, Hui


    Experimental verification for a focusing mechanism of imaging spectrometer is studied. The mechanism uses stepper motor driven precision harmonic drive. Wave generator is composed of elliptical cam and a flexible bearing. The output end is connected with the ball screw rotary motion into linear motion, which drives the focusing lens linear guide reciprocating motion. In view of the practical application of the mechanism in the imaging spectrometer, the thermal optical experimental imaging spectrometer has been focusing the formula. Data show that the focus formula ensures linear relationship between the focal plane position and temperature. The linear relationship shows that the imaging spectrometer onboard the variation with temperature and automatic focusing is very important.

  10. Holding Strength of Suture: An Experimental Study Using Porcine Kidney (United States)

    Akpinar, Haluk; Karadag, Mert Ali; Dönmez, Muhammet İrfan; Altunrende, Fatih


    Background and Objectives: The search for the perfect suture is going on and has resulted in the introduction of many different suture types into the market. The purpose of this study is to investigate the holding strength (HS) of different sutures in the renal parenchyma in an experimental study on pig kidneys. Methods: The HS that caused sliding of the suture was investigated in 5 adult porcine kidneys with 7 suture variants. HS-caused tearing of the kidney was investigated with 3 suture types on 5 kidneys. The third investigation, performed on 5 porcine kidneys, was a comparison between 2-0 Vicryl sutures with a Hem-o-lok clip and 2-0 V-Loc sutures with 1 knot. The Friedman test was used to compare the groups. Post hoc analysis was performed with the Wilcoxon signed ranks test (Bonferroni corrected). Results: For HS causing sliding of the suture, the mean HSs of the tested sutures were as follows: 2-0 Vicryl with 1 Hem-o-lok clip, 3.26 ± 0.55 N; 2-0 Vicryl with 2 Hem-o-lok clips, 4.1 ± 0.46 N; 2-0 V-Loc, 2.52 ± 0.63 N; 4-0 V-Loc, 1.62 ± 0.17 N; 0 Quill, 0.48 ± 0.16 N; 2-0 Vicryl with 1 Hem-o-lok clip (halfway), 3.62 ± 0.66 N; and 2-0 V-Loc (halfway), 1.02 ± 0.40 N. For HS causing tearing of the kidney, the mean value of 2-way 2-0 Vicryl (Hem-o-lok in the middle) was 13.28 ± 1.38 N, 2-0 2-way Vicryl (Hem-o-lok at the end) was 5.86 ± 0.75 N, and 2-way 2-0 V-Loc was 3.98 ± 1.60 N. For the third group, the difference between the 2 suture variants was not statistically significant. Conclusion: Our study revealed that 2-0 Vicryl (polyglactin 910) sutures with 2 Hem-o-lok clips had the maximum HS in renal parenchyma when compared with other sutures. PMID:28729782

  11. Holding Strength of Suture: An Experimental Study Using Porcine Kidney. (United States)

    Özkuvanci, Ünsal; Akpinar, Haluk; Karadag, Mert Ali; Dönmez, Muhammet İrfan; Altunrende, Fatih


    The search for the perfect suture is going on and has resulted in the introduction of many different suture types into the market. The purpose of this study is to investigate the holding strength (HS) of different sutures in the renal parenchyma in an experimental study on pig kidneys. The HS that caused sliding of the suture was investigated in 5 adult porcine kidneys with 7 suture variants. HS-caused tearing of the kidney was investigated with 3 suture types on 5 kidneys. The third investigation, performed on 5 porcine kidneys, was a comparison between 2-0 Vicryl sutures with a Hem-o-lok clip and 2-0 V-Loc sutures with 1 knot. The Friedman test was used to compare the groups. Post hoc analysis was performed with the Wilcoxon signed ranks test (Bonferroni corrected). For HS causing sliding of the suture, the mean HSs of the tested sutures were as follows: 2-0 Vicryl with 1 Hem-o-lok clip, 3.26 ± 0.55 N; 2-0 Vicryl with 2 Hem-o-lok clips, 4.1 ± 0.46 N; 2-0 V-Loc, 2.52 ± 0.63 N; 4-0 V-Loc, 1.62 ± 0.17 N; 0 Quill, 0.48 ± 0.16 N; 2-0 Vicryl with 1 Hem-o-lok clip (halfway), 3.62 ± 0.66 N; and 2-0 V-Loc (halfway), 1.02 ± 0.40 N. For HS causing tearing of the kidney, the mean value of 2-way 2-0 Vicryl (Hem-o-lok in the middle) was 13.28 ± 1.38 N, 2-0 2-way Vicryl (Hem-o-lok at the end) was 5.86 ± 0.75 N, and 2-way 2-0 V-Loc was 3.98 ± 1.60 N. For the third group, the difference between the 2 suture variants was not statistically significant. Our study revealed that 2-0 Vicryl (polyglactin 910) sutures with 2 Hem-o-lok clips had the maximum HS in renal parenchyma when compared with other sutures.

  12. Experimental study on beam for composite CES structural system (United States)

    Matsui, Tomoya


    Development study on Concrete Encase Steel (CES) composite structure system has been continuously conducted toward the practical use. CES structure is composed of steel and fiber reinforced concrete. In previous study, it was found that CES structure has good seismic performance from experimental study of columns, beam - column joints, shear walls and a two story two span frame. However, as fundamental study on CES beam could be lacking, it is necessary to understand the structural performance of CES beam. In this study, static loading tests of CES beams were conducted with experimental valuable of steel size, the presence or absence of slab and thickness of slab. And restoring characteristics, failure behavior, deformation behavior, and strength evaluation method of CES beam were investigated. As the results, it was found that CES beam showed stable hysteresis behavior. Furthermore it was found that the flexural strength of the CES beam could be evaluated by superposition strength theory.

  13. Numerical and experimental studies of droplet-gas flow

    Energy Technology Data Exchange (ETDEWEB)

    Joesang, Aage Ingebret


    This thesis considers droplet-gas flow by the use of numerical methods and experimental verification. A commercial vane separator was studied both numerical and by experiment. In addition some efforts are put into the numerical analysis of cyclones. The experimental part contains detailed measurements of the flow field between a pair of vanes in a vane separator and droplet size measurements. LDA (Laser Doppler Anemometry) was used to measure the velocity in two dimensions and corresponding turbulence quantities. The results from the LDA measurements are considered to be of high quality and are compared to numerical results obtained from a CFD (Computational Fluid Dynamics) analysis. The simulation showed good agreement between the numerical and experimental results. Combinations of different turbulence models; the standard k-epsilon model and the Reynold Stress Mode, different schemes; first order and higher order scheme and different near wall treatment of the turbulence; the Law of the wall and the Two-Layer Zonal model were used in the simulations. The Reynold Stress Model together with a higher order scheme performed rather poorly. The recirculation in parts of the separator was overpredicted in this case. For the other cases the overall predictions are satisfactory. PDA (Phase Doppler Anemometry) measurements were used to study the changes in the droplet size distribution through the vane separator. The PDA measurements show that smaller droplets are found at the outlet than present at the inlet. In the literature there exists different mechanisms for explaining the re-entrainment and generation of new droplets. The re-entrainments mechanisms are divided into four groups where droplet-droplet interaction, droplet break-up, splashing of impinging droplet and re-entrainment from the film are defined as the groups of re-entrainment mechanisms. Models for these groups are found in the literature and these models are tested for re-entrainment using the operational

  14. In silico and in vitro comparative activity of novel experimental derivatives against Leishmania major and Leishmania infantum promastigotes. (United States)

    Khademvatan, Shahram; Adibpour, Neda; Eskandari, Alborz; Rezaee, Saeed; Hashemitabar, Mahmoud; Rahim, Fakher


    This in silico and in vitro comparative study was designed to evaluate the effectiveness of some biurets (K1 to K8) and glucantime against Leishmania major and Leishmania infantum promastigotes. Overall, eight experimental ligands and glucantime were docked using AutoDock 4.3 program into the active sites of Leishmania major and Leishmania infantum pteridine reductase 1, which were modeled using homology modeling programs. The colorimetric MTT assay was used to find L. major and L. infantum promastigotes viability at different concentrations of biuret derivatives in a concentration and time-dependent manner and the obtained results were expressed as 50% and 90% of inhibitory concentration (IC₅₀ and IC₉₀). In silico method showed that out of eight experimental ligands, four compounds were more active on pteridine reductase 1. K3 was the most active against L. major promastigotes with an IC₅₀ of 6.8 μM and an IC₉₀ of 40.2 μM, whereas for L. infantum promastigotes was K8 with IC₅₀ of 7.8 μM. The phenylethyl derivative (K7) showed less toxicity (IC₅₀s>60 μM) in both Leishmania strains. Glucantime displayed less growth inhibition in concentration of about 20 μM. In silico and especially docking results in a recent study were in accordance with the in vitro activity of these compounds in presented study and compound K3, K2 and K8 showed reasonable levels of selectivity for the Leishmania pteridine reductase 1. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. [Comparative estimation of antilithogenic activity of porcine kidney derived biomedical substance and sodium citrate in experimental urolithiasis]. (United States)

    Pavlyashik, G V; Zharikov, A Yu; Kiselev, V I


    to compare the anti-lithogenic activity of biomedical substance derived from freeze-dried porcine kidney and sodium citrate. The experiments were conducted on Wistar rats divided into three groups of 15 animals each: control group (disease control), comparison group (sodium citrate treatment) and experimental group (treatment with biomedical substance from porcine kidneys). Experimental urolithiasis was modeled using the ethylene glycol model. On every 7th day of the 6 week experiment testing was done calcium and oxalate urine concentration and the activity of marker enzymes of renal epithelial damage: lactate dehydrogenase (LDH), -glutamyl transferase (GGT), and N-acetyl--D-glucosaminidase (NAG). At the end of the experiment, a part of the rats were decapitated and the renal tissue was tested for the oxidant status indicators of (renal thiobarbiturate reactive product content, TBRP, and total prooxidant activity, TPA) and antioxidant enzyme activities: glutathione peroxidase (GPO), superoxide dismutase (SOD) and catalase (CAT). To measure the number and size of calcium deposits formed in the renal papillary area, the Koss histochemical method was used. The experimental findings showed developing oxalate nephrolithiasis in the control group, as indicated by urinary supersaturation of oxalate ion, increased activity of marker enzymes, oxidative stress and the formation of numerous calcium deposits in the renal papillary area. In the comparison group, the 3-week use of sodium citrate contributed to a significant decrease in nephrolithiasis: a 3 to 4-fold decrease in the activity of marker enzymes in the urine, a 3.8-fold increase in the concentration of TBRP, normalization of GPO activity; the number and size of urinary calcium deposits decreased by 3.4 and 1.9 times, respectively. In the experimental group, using biomedical substance led to an even greater therapeutic effect. LDH activity and concentration of TPRP showed 1.9 times and by 26.2% greater decrease than

  16. Spatial Visualization Ability and Impact of Drafting Models: A Quasi Experimental Study (United States)

    Katsioloudis, Petros J.; Jovanovic, Vukica


    A quasi experimental study was done to determine significant positive effects among three different types of visual models and to identify whether any individual type or combination contributed towards a positive increase of spatial visualization ability for students in engineering technology courses. In particular, the study compared the use of…

  17. Pseudoepitheliomatous hyperplasia after diode laser oral surgery. An experimental study (United States)

    Seoane, Juan; González-Mosquera, Antonio; García-Martín, José-Manuel; García-Caballero, Lucía; Varela-Centelles, Pablo


    Background To examine the process of epithelial reparation in a surgical wound caused by diode laser. Material and Methods An experimental study with 27 Sprage-Dawley rats was undertaken. The animals were randomly allocated to two experimental groups, whose individuals underwent glossectomy by means of a diode laser at different wattages, and a control group treated using a number 15 scalpel blade. The animals were slaughtered at the 2nd, 7th, and 14th day after glossectomy. The specimens were independently studied by two pathologists (blinded for the specimens’ group). Results At the 7th day, re-epithelisation was slightly faster for the control group (conventional scalpel) (p=0.011). At the 14th day, complete re-epithelization was observed for all groups. The experimental groups displayed a pseudoepitheliomatous hyperplasia. Conclusions It is concluded that, considering the limitations of this kind of experimental studies, early re-epithelisation occurs slightly faster when a conventional scalpel is used for incision, although re-epithelisation is completed in two weeks no matter the instrument used. In addition, pseudoepitheliomatous hyperplasia is a potential event after oral mucosa surgery with diode laser. Knowledge about this phenomenon (not previously described) may prevent diagnostic mistakes and inadequate treatment approaches, particularly when dealing with potentially malignant oral lesions. Key words:Diode laser, animal model, oral biopsy, oral cancer, oral precancer, pseudoepitheliomatous hyperplasia. PMID:26116841

  18. Early differentiation of the Moon: Experimental and modeling studies and experimental and modeling studies of massif anorthosites (United States)

    Longhi, John


    NASA grant NAG9-329 was in effect from 3/1/89 to 8/31/94, the last 18 months being a no-cost extension. While the grant was in effect, the P.I., coworkers, and students gave 22 talks and poster sessions at professional meetings, published 12 articles in referred journals (one more is in press, and another is in review), and edited 2 workshop reports relevant to this project. Copies of all the publications are appended to this report. The major accomplishments during the grant period have derived from three quarters: 1) the application of quantitative models of fractional crystallization and partial melting to various problems in planetary science, such as the petrogenesis of picritic glasses and mare basalts and the implications of the SNC meteorites for martian evolution; 2) an experimental study of silicate liquid immiscibility relevant to early lunar differentiation and the petrogenesis of evolved highlands rocks; and 3) experimental studies of massif anorthosites and related rocks that provide terrestrial analogs for the proposed origin of lunar anorthosites by multistage processes. The low-pressure aspects of the quantitative models were developed by the P.I. in the 1980s with NASA support and culminated with a paper comparing the crystallization of terrestrial and lunar lavas. The basis for the high-pressure modifications to the quantitative models is a data set gleaned from high pressure melting experiments done at Lamont and is supplemented by published data from other labs that constrain the baric and compositional dependences of various liquidus phase boundaries such as olivine/orthopyroxene, relevant to the melting of the mantles of the terrestrial planets. With these models it is possible to predict not only the thermal and compositional evolution of magmatic liquids ranging in composition from lumar mare basalt to terrestrial calc-alkaline basalts, but also the small increments of fractional melting that are produced when mantle rises adiabatically

  19. Experimental data comparing two coral grow-out methods in nursery-raised Acropora cervicornis (United States)

    Kuffner, Ilsa B.; Bartels, Erich; Stathakopoulos, Anastasios; Enochs, Ian C.; Kolodziej, Graham; Toth, Lauren; Manzello, Derek P.


    Staghorn coral, Acropora cervicornis, is a threatened species and the primary focus of western Atlantic reef-restoration efforts to date. As part of the USGS Coral Reef Ecosystems Studies project (, we investigated skeletal characteristics of nursery-grown staghorn coral reared using two commonly used grow-out methods at Mote Tropical Research Laboratory’s offshore nursery. We compared linear extension, calcification rate, and skeletal density of nursery-raised A. cervicornis branches reared for six months either on blocks attached to substratum or hanging from monofilament line (on PVC “trees”) in the water column. We demonstrate that branches grown on the substratum had significantly higher skeletal density, measured using computerized tomography (CT), and lower linear extension rates compared to water-column fragments. Calcification rates determined with buoyant weighing were not statistically different between the two grow-out methods, but did vary among coral genotypes. Whereas skeletal density and extension rates were plastic traits that depended on environment, calcification rate was conserved. Our results show that the two rearing methods generate the same amount of calcium-carbonate skeleton but produce colonies with different skeletal characteristics, and suggest that genetically based variability in coral-calcification performance exists. The data resulting from this experiment are provided in this data release and are interpreted in Kuffner et al. (2017).Kuffner, I.B., E. Bartels, A. Stathakopoulos, I.C. Enochs, G. Kolodziej, L.T. Toth, and D.P. Manzello, 2017, Plasticity in skeletal characteristics of nursery-raised staghorn coral, Acropora cervicornis: Coral Reefs, in press.

  20. Construction of an experimental plot seeder of wheat planting and compare it by imported one

    Directory of Open Access Journals (Sweden)

    I Eskandari


    Full Text Available Introduction Researchers frequently include multiple cultivars and fertility levels in field experiments. Therefore, the experiments sowing operation must represent a considerable saving in time and labor, compared to hand sowing. Greater flexibility in experimental design and setup could be achieved by equipment that enables quick changes in the cultivar and fertilizer rates from one plot to the next. A satisfactory seed drill must distribute a given quantity of seed evenly over a predetermined length of coulter row, the coulters must be spaced at exact intervals and depth of sowing must be uniform. In a self-propelled type of plot seeder, no coulter should run in a wheel track as the compaction of the soil can cause observable differences in vigor between plants in such a row and those in un-compacted rows. The machine should sow in succession from a try in which a series of seed pocket separated clearly and must be put into distributer funnel by an assistant operator. The length of gap being varied according to the nature and purpose of the plot. The objectives of this experiment were 1- to design and construct a local self-propelled plot seeder and 2- To compare it with the imported (Wintersteiger plot seeder in cereal breeding programs. Materials and Methods A small-plot seeder was designed and constructed to meet this objective. The unit consists of the following basic components: a toolbar for pulling a set of six blade coulter, an air compressor for lifting and putting down the openers and metering transmission drive wheel, an operators chair and work rack, one belt seed distribution. A cone-celled and rotor seed distributor is used for seed distribution to the openers. The cone system is connected to the gearbox and allows for great flexibility in changing cultivars, crop species, and plot length. This is driven by the separate drive wheel. The cone-celled distributor sows all the seed of the sample in making one complete turn. The

  1. Experimental Study on Volume for Fly Ash of Building Block


    Ling Wang; He Sun; Zhihui Sun; Enqing Ma


    Fly ash is a waste substance from thermal power plants, steel mills, etc. That is found in abundance in the world. It has polluted the environment, wasting the cultivated land. This study introduces an experimental research on fly ash being reused effectively, the study introduces raw materials of fly ash brick, production process and product inspection, fly ash content could be amounted to 40%~75%. High doping fly ash bricks are manufactured, which selects wet fly ash from the power plants, ...

  2. Experimental and Analytical Studies of Solar System Chemistry (United States)

    Burnett, Donald S.


    The cosmochemistry research funded by this grant resulted in the publications given in the attached Publication List. The research focused in three areas: (1) Experimental studies of trace element partitioning. (2) Studies of the minor element chemistry and O isotopic compositions of MgAlO4 spinels from Ca-Al-Rich Inclusions in carbonaceous chondrite meteorites, and (3) The abundances and chemical fractionations of Th and U in chondritic meteorites.

  3. A comprehensive experimental and modeling study of isobutene oxidation

    KAUST Repository

    Zhou, Chong-Wen


    Isobutene is an important intermediate in the pyrolysis and oxidation of higher-order branched alkanes, and it is also a component of commercial gasolines. To better understand its combustion characteristics, a series of ignition delay time (IDT) and laminar flame speed (LFS) measurements have been performed. In addition, flow reactor speciation data recorded for the pyrolysis and oxidation of isobutene is also reported. Predictions of an updated kinetic model described herein are compared with each of these data sets, as well as with existing jet-stirred reactor (JSR) species measurements. IDTs of isobutene oxidation were measured in four different shock tubes and in two rapid compression machines (RCMs) under conditions of relevance to practical combustors. The combination of shock tube and RCM data greatly expands the range of available validation data for isobutene oxidation models to pressures of 50 atm and temperatures in the range 666–1715 K. Isobutene flame speeds were measured experimentally at 1 atm and at unburned gas temperatures of 298–398 K over a wide range of equivalence ratios. For the flame speed results, there was good agreement between different facilities and the current model in the fuel-rich region. Ab initio chemical kinetics calculations were carried out to calculate rate constants for important reactions such as H-atom abstraction by hydroxyl and hydroperoxyl radicals and the decomposition of 2-methylallyl radicals. A comprehensive chemical kinetic mechanism has been developed to describe the combustion of isobutene and is validated by comparison to the presently considered experimental measurements. Important reactions, highlighted via flux and sensitivity analyses, include: (a) hydrogen atom abstraction from isobutene by hydroxyl and hydroperoxyl radicals, and molecular oxygen; (b) radical–radical recombination reactions, including 2-methylallyl radical self-recombination, the recombination of 2-methylallyl radicals with

  4. A comparative study of explicit and implicit modelling of ...

    Indian Academy of Sciences (India)

    Abstract. In this paper, the explicit and implicit modelling of the subsegmental excitation information are experimentally compared. For explicit modelling, the static and dynamic values of the standard Liljencrants–Fant (LF) parameters that model the glottal flow derivative (GFD) are used. A simplified approximation method is.

  5. Experimental Studies of the Transport Parameters of Warm Dense Matter

    Energy Technology Data Exchange (ETDEWEB)

    Chouffani, Khalid [Idaho State Univ., Pocatello, ID (United States)


    There is a need to establish fundamental properties of matter and energy under extreme physical conditions. Although high energy density physics (HEDP) research spans a wide range of plasma conditions, there is one unifying regime that is of particular importance and complexity: that of warm dense matter, the transitional state between solid state condensed matter and energetic plasmas. Most laboratory experimental conditions, including inertial confinement implosion, fall into this regime. Because all aspects of laboratory-created high-energy-density plasmas transition through the warm dense matter regime, understanding the fundamental properties to determine how matter and energy interact in this regime is an important aspect of major research efforts in HEDP. Improved understanding of warm dense matter would have significant and wide-ranging impact on HEDP science, from helping to explain wire initiation studies on the Sandia Z machine to increasing the predictive power of inertial confinement fusion modeling. The central goal or objective of our proposed research is to experimentally determine the electrical resistivity, temperature, density, and average ionization state of a variety of materials in the warm dense matter regime, without the use of theoretical calculations. Since the lack of an accurate energy of state (EOS) model is primarily due to the lack of experimental data, we propose an experimental study of the transport coefficients of warm dense matter.

  6. Experimental study on viscosity reduction for residual oil by ultrasonic. (United States)

    Huang, Xintong; Zhou, Cuihong; Suo, Quanyu; Zhang, Lanting; Wang, Shihan


    Because of characteristics of large density, high viscosity and poor mobility, the processing and transportation of residual oil are difficult and challenging, viscosity reduction of residual oil is of great significance. In this paper, the effects of different placement forms of ultrasonic transducers on the sound pressure distribution of ultrasonic inside a cubic container have been simulated, the characteristics of oil bath heating and ultrasonic viscosity reduction were compared, viscosity reduction rule of residual oil was experimentally analyzed by utilizing Response Surface Method under conditions of changing ultrasonic exposure time, power and action mode, the mechanism of viscosity reduction was studied by applying Fourier transform infrared spectrometer, the viscosity retentivity experiment was carried out at last. Experiments were conducted using two kinds of residual oil, and results show that ultrasonic effect on the viscosity reduction of residual oil is significant, the higher viscosity of residual oil, the better effect of ultrasonic, ultrasonic power and exposure time are the significant factors affecting the viscosity reduction rate of residual oil. The maximum viscosity reduction rate is obtained under condition of ultrasonic power is 900W, exposure time is 14min and action mode of exposure time is 2s and interrupting time is 2s, viscosity reduction rate reaching up to 63.95%. The infrared spectroscopy results show that light component in residual oil increased. The viscosity retentivity experiment results show that the viscosity reduction effect remains very well. This paper can provide data reference for the application of ultrasonic in the field of viscosity reduction for residual oil. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Composition of intraocular foreign bodies: experimental study of ultrasonographic presentation. (United States)

    Costa, Márcio Augusto Nogueira; Garcia, Patrícia Novita; Barroso, Letícia Fernandes; Ferreira, Marco Antonio; Okuda, Érika Araki; Allemann, Norma


    To investigate the reliability of ultrasound in determining the size and identify the sonographic features and artifacts generated by intraocular foreign bodies of different materials. Experimental study using 36 enucleated porcine eyes. Fragments of nine different compositions (wood, glass, plastic, cardboard, iron, aluminum, lead, powder and concrete) and similar dimensions (4 mm) were implanted via scleral incision into the vitreous cavity of 36 porcine eyes, four eyes were used for each material. Ultrasound examination was performed in all eyes using the contact technique, conductive gel and 10-MHz transducer (EZScan, Sonomed). Considering the material fragments of gunpowder, lead, concrete, aluminum, wood and glass, the size determined by ultrasound was considered statistically similar to the actual size. The material iron presented ultrasound-determined dimension statistically smaller than its actual size. Cardboard and plastic materials showed ultrasound-determined measurements far greater than the actual. All fragments of intraocular foreign bodies demonstrated hyper-reflective interfaces, irrespective of their composition. Whereas the artifacts generated by different materials, it was found that the materials iron, aluminum and lead showed reverberation of great extent. The material wood showed no reverberation. The length of the reverberation artifact for the materials iron, glass, aluminum and cardboard was lower when compared to other materials. All materials presented posterior shadowing artifact, with the exception of aluminum. Ultrasonography was considered a reliable technique to determine the size of intraocular foreign bodies in pigs, with little influence caused by its composition. Ultrasound artifacts generated were considered material-dependent and can assist the examiner to identify the nature of a foreign body of unknown etiology. Ultrasonography aided the surgeon to identify, locate and measure the intraocular foreign body, directing

  8. Composition of intraocular foreign bodies: experimental study of ultrasonographic presentation

    Directory of Open Access Journals (Sweden)

    Márcio Augusto Nogueira Costa


    Full Text Available PURPOSE: To investigate the reliability of ultrasound in determining the size and identify the sonographic features and artifacts generated by intraocular foreign bodies of different materials. METHODS: Experimental study using 36 enucleated porcine eyes. Fragments of nine different compositions (wood, glass, plastic, cardboard, iron, aluminum, lead, powder and concrete and similar dimensions (4 mm were implanted via scleral incision into the vitreous cavity of 36 porcine eyes, four eyes were used for each material. Ultrasound examination was performed in all eyes using the contact technique, conductive gel and 10-MHz transducer (EZScan, Sonomed. RESULTS: Considering the material fragments of gunpowder, lead, concrete, aluminum, wood and glass, the size determined by ultrasound was considered statistically similar to the actual size. The material iron presented ultrasound-determined dimension statistically smaller than its actual size. Cardboard and plastic materials showed ultrasound-determined measurements far greater than the actual. All fragments of intraocular foreign bodies demonstrated hyper-reflective interfaces, irrespective of their composition. Whereas the artifacts generated by different materials, it was found that the materials iron, aluminum and lead showed reverberation of great extent. The material wood showed no reverberation. The length of the reverberation artifact for the materials iron, glass, aluminum and cardboard was lower when compared to other materials. All materials presented posterior shadowing artifact, with the exception of aluminum. CONCLUSION: Ultrasonography was considered a reliable technique to determine the size of intraocular foreign bodies in pigs, with little influence caused by its composition. Ultrasound artifacts generated were considered material-dependent and can assist the examiner to identify the nature of a foreign body of unknown etiology. Ultrasonography aided the surgeon to identify, locate and

  9. Transarterial nephrectomy: the current status of experimental and clinical studies. (United States)

    Rassweiler, Jens; Prager, Peter; Haferkamp, Axel; Alken, Peter; Kauffmann, Günther W; Richter, Götz


    Open nephrectomy is associated with significant morbidity. For several years, minimally invasive alternatives have been developed such as laparoscopic nephrectomy or transarterial renal ablation. This paper focuses on the different principles of vaso-occlusion and further improvements of the technique such as capillary chemoembolization in experimental as well as clinical studies. Based on own in vitro studies, the principle of capillary embolization with occlusion of the entire arterial system up to the capillaries by a precipitating corn protein (Ethibloc) has been developed in animal studies (i.e., rat and canine kidney model). The precipitation speed of Ethibloc can be prolonged by 40% glucose per injection. The organ-ablative efficacy was evaluated in models of unilateral hypertension and chemically induced renal tumors (i.e., dimethyl-nitrosamine). Further studies using the model of unilateral transarterial implantation of Yoshida-sarcoma cells compared capillary chemoembolization using Ethibloc/mitomycin C (MMC) versus chemoperfusion and capillary embolization. Before starting clinical trials, the optimal mixture of Ethibloc and MMC was determined in vitro and in vivo. Prior to the vaso-occlusion, the volume of the arterial system of the kidney is determined by perfusion of the kidney with contrast-dye via a blocked balloon-catheter. Then 25% of the determined volume of 40% glucose is pre-injected followed by Ethibloc/MMC being injected with 1-cm(3) syringes. Once the capillary bed and tumor sinusoids are reached, the balloon catheter is emptied by postinjection of 40% glucose. Capillary embolization proved to be significantly superior to a central (i.e., ligation of renal artery) or peripheral type of occlusion resulting in complete coagulation necrosis of the normal rat and canine kidney with reduction of the elevated blood pressure, similar to nephrectomy in the model of renal hypertension. In the model of chemically induced renal tumors, complete

  10. Comparative Effects of Two Gingerol-Containing Zingiber officinale Extracts on Experimental Rheumatoid Arthritis1 (United States)

    Funk, Janet L.; Frye, Jennifer B.; Oyarzo, Janice N.; Timmermann, Barbara N.


    Ginger (Zingiber officinale) supplements are being promoted for arthritis treatment in western societies based on ginger’s traditional use as an anti-inflammatory in Chinese and Ayurvedic medicine. However, scientific evidence of ginger’s antiarthritic effects is sparse, and its bioactive joint-protective components have not been identified. Therefore, the ability of a well-characterized crude ginger extract to inhibit joint swelling in an animal model of rheumatoid arthritis, streptococcal cell wall (SCW)-induced arthritis, was compared to that of a fraction containing only gingerols and their derivatives. Both extracts were efficacious in preventing joint inflammation. However, the crude dichloromethane extract, which also contained essential oils and more polar compounds, was more efficacious (when normalized to gingerol content) in preventing both joint inflammation and destruction. In conclusion, these data document a very significant joint-protective effect of these ginger samples, and suggest that non-gingerol components are bioactive and can enhance the antiarthritic effects of the more widely studied gingerols. PMID:19216559


    Directory of Open Access Journals (Sweden)



    Full Text Available This study was contemplated to determine the comparative beneficial effects of hypertonic saline solution and sterile saline solution in induced endotoxic shock in dogs. For this purpose, 12 healthy Mongrel dogs were randomly divided into two equal groups (A and B. All the animals were induced endotoxaemia by slow intravenous administration of Escherichia coli endotoxins 0111:B4. Group A was treated with normal saline solution @ 90 ml/kg BW, while group B was given hypertonic saline solution @ 4 ml/kg BW, followed by normal saline solution @ 10 ml/kg BW. Different parameters were observed for evaluation of these fluids including clinical and haematological parameters, serum electrolytes, mean arterial pressure, and blood gases at different time intervals up to 24 hours post treatments. After infusion of respective fluids, all parameters returned to baseline values in both the groups but group B showed better results than group A except bicarbonates, which better recovered in group A. Thus, it was concluded that a small-volume of hypertonic saline solution could be effectively used in reversing the endotoxaemia. Moreover, it provides a rapid and inexpensive resuscitation from endotoxic shock.

  12. Experimental and Theoretical Studies in Hydrogen-Bonding Organocatalysis

    Directory of Open Access Journals (Sweden)

    Matej Žabka


    Full Text Available Chiral thioureas and squaramides are among the most prominent hydrogen-bond bifunctional organocatalysts now extensively used for various transformations, including aldol, Michael, Mannich and Diels-Alder reactions. More importantly, the experimental and computational study of the mode of activation has begun to attract considerable attention. Various experimental, spectroscopic and calculation methods are now frequently used, often as an integrated approach, to establish the reaction mechanism, the mode of activation or explain the stereochemical outcome of the reaction. This article comprises several case studies, sorted according to the method used in their study. The aim of this review is to give the investigators an overview of the methods currently utilized for mechanistic investigations in hydrogen-bonding organocatalysis.

  13. A comparative kinetic study of SNCR process using ammonia

    Directory of Open Access Journals (Sweden)

    M. Tayyeb Javed


    Full Text Available The paper presents comparative kinetic modelling of nitrogen oxides (NOx removal from flue gases by selective non-catalytic reduction process using ammonia as reducing agent. The computer code SENKIN is used in this study with the three published chemical kinetic mechanisms; Zanoelo, Kilpinen and Skreiberg. Kinetic modeling was performed for an isothermal plug flow reactor at atmospheric pressure so as to compare it with the experimental results. A 500 ppm NOx background in the flue gas is considered and kept constant throughout the investigation. The ammonia performance was modeled in the range of 750 to 1250 ºC using the molar ratios NH3/NOx from 0.25 to 3.0 and residence times up to 1.5 seconds. The modeling using all the mechanisms exhibits and confirms a temperature window of NOx reduction with ammonia. It was observed that 80% of NOx reduction efficiency could be achieved if the flue gas is given 300 msec to react with ammonia, while it is passing through a section within a temperature range of 910 to 1060 ºC (Kilpinen mechanism or within a temperature range of 925 to 1030 ºC (Zanoelo mechanism or within a temperature range of 890 to 1090 ºC (Skreiberg mechanism.

  14. Comparative Evaluation of Enalapril and Losartan in Pharmacological Correction of Experimental Osteoporosis and Fractures of Its Background (United States)

    Rajkumar, D. S. R.; Faitelson, A. V.; Gudyrev, O. S.; Dubrovin, G. M.; Pokrovski, M. V.; Ivanov, A. V.


    In the experiment on the white Wistar female rats (222 animals), the osteoprotective effect of enalapril and losartan was studied on experimental models of osteoporosis and osteoporotic fractures. It was revealed that in rats after ovariectomy, the endothelial dysfunction of microcirculation vessels of osteal tissue develops, resulting in occurrence of osteoporosis and delay of consolidation of experimental fractures. Enalapril and losartan prevented the reduction of microcirculation in bone, which was reflected in slowing the thinning of bone trabeculae and in preventing the occurrence of these microfractures, as well as increasing quality of experimental fractures healing. PMID:23401845

  15. Comparative Evaluation of Enalapril and Losartan in Pharmacological Correction of Experimental Osteoporosis and Fractures of Its Background

    Directory of Open Access Journals (Sweden)

    D. S. R. Rajkumar


    Full Text Available In the experiment on the white Wistar female rats (222 animals, the osteoprotective effect of enalapril and losartan was studied on experimental models of osteoporosis and osteoporotic fractures. It was revealed that in rats after ovariectomy, the endothelial dysfunction of microcirculation vessels of osteal tissue develops, resulting in occurrence of osteoporosis and delay of consolidation of experimental fractures. Enalapril and losartan prevented the reduction of microcirculation in bone, which was reflected in slowing the thinning of bone trabeculae and in preventing the occurrence of these microfractures, as well as increasing quality of experimental fractures healing.

  16. Comparative study of hygrothermal properties of five thermal insulation materials

    Directory of Open Access Journals (Sweden)

    Laure Ducoulombier


    Full Text Available The objective of this article is to carry out a comparative study of the main hygrothermal properties of five thermal insulation materials for buildings. These properties are necessary for a correct prediction of heat and moisture transfers through the walls and the selection of the most appropriate materials according to the specific buildings. The studied materials were glass wool, rock wool, expanded polystyrene, wood fiberboard and polyester fiberfill. The article is divided into three parts. The first part presents the phenomena of hygrothermal transfers in walls in order to understand the need for determining specific properties of the insulating materials. The second part describes in details the five studied insulating materials and the methods used for the characterization and identification of their main properties. Finally, the last part presents the experimental results and makes comparisons between materials. The differences between the insulating materials are brought out, such as the strong dependence of the thermal conductivity of polystyrene on temperature, or the good permeability of fibrous insulating materials to water vapor. A detailed analysis of the obtained results is presented.

  17. Experimental study on anelasticty of polycrystalline material for seismological application (United States)

    Takei, Y.; Karasawa, F.


    . Experimental data for these quantities are few (Jackson & Faul, 2010) and more data are needed. In this study, anelasticity of polycrystalline material at higher normalized frequencies (f/fM) was measured by using a rock analogue (organic polycrystal). Compared to the previous study by using the same analogue material (McCarthy et al 2012, homorogous temperature T/Tm = 0.67 - 0.61, f = 0.0001 - 2 Hz, f/fM = 0.1 - 5×104), anelasticity data were obtained at lower temperatures (T/Tm = 0.61 - 0.57), higher frequencies (f = 0.0001 - 50 Hz), and hence at higher normalized frequencies (f/fM = 0.1 - 5×107). We improved the accuracy of the modulus (Young's modulus) and Q-1 measurements by improving the stiffness of the apparatus and by correcting the data for a small time delay caused by measuring instruments. Based on the obtained data, we would like to discuss the mechanism and scaling law active in the seismic waves.

  18. An experimental and modeling study of diethyl carbonate oxidation

    KAUST Repository

    Nakamura, Hisashi


    Diethyl carbonate (DEC) is an attractive biofuel that can be used to displace petroleum-derived diesel fuel, thereby reducing CO2 and particulate emissions from diesel engines. A better understanding of DEC combustion characteristics is needed to facilitate its use in internal combustion engines. Toward this goal, ignition delay times for DEC were measured at conditions relevant to internal combustion engines using a rapid compression machine (RCM) and a shock tube. The experimental conditions investigated covered a wide range of temperatures (660-1300K), a pressure of 30bar, and equivalence ratios of 0.5, 1.0 and 2.0 in air. To provide further understanding of the intermediates formed in DEC oxidation, species concentrations were measured in a jet-stirred reactor at 10atm over a temperature range of 500-1200K and at equivalence ratios of 0.5, 1.0 and 2.0. These experimental measurements were used to aid the development and validation of a chemical kinetic model for DEC.The experimental results for ignition in the RCM showed near negative temperature coefficient (NTC) behavior. Six-membered alkylperoxy radical (RO˙2) isomerizations are conventionally thought to initiate low-temperature branching reactions responsible for NTC behavior, but DEC has no such possible 6- and 7-membered ring isomerizations. However, its molecular structure allows for 5-, 8- and 9-membered ring RO˙2 isomerizations. To provide accurate rate constants for these ring structures, ab initio computations for RO˙2⇌Q˙OOH isomerization reactions were performed. These new RO˙2 isomerization rate constants have been implemented in a chemical kinetic model for DEC oxidation. The model simulations have been compared with ignition delay times measured in the RCM near the NTC region. Results of the simulation were also compared with experimental results for ignition in the high-temperature region and for species concentrations in the jet-stirred reactor. Chemical kinetic insights into the

  19. Lung Morphological Changes in Closed Chest Injury (an experimental study

    Directory of Open Access Journals (Sweden)

    A. M. Golubev


    Full Text Available Objective: to study lung morphological changes in a closed chest injury model in laboratory animals. Material and methods. Experiments were carried out in 30 male albino nonbred rats weighing 350—380 g. Closed chest injury was simulated, by exposing the chest of anesthetized rats to a 300-g metal cylinder falling from a height of 30 cm. The observation periods were 1, 3, 6, and 24 hours. Results. The signs of evident perivenular edema that was uncharas-teristic to acute respiratory distress syndrome induced by other causes are an important peculiarity of lung morphological changes in this experimental model of closed chest injury. Conclusion. The experimental studies clarified the pattern of lung morphological changes in the early period after closed chest injury. Key words: closed chest injury, pulmonary edema.

  20. [Experimental study of anatomo-pathological and physiopathological manifestations of acute cholecystitis]. (United States)

    Vayre, P; Delavierre, P; Duran, M


    From their experimental findings in 120 rabbits, the authors conclude that, at first, cholecystitis is usually an aseptic lesion and infection occurs only secondarily. In a large number of cases the initial physiopathological mechanism is that of inflammation which may be due to mechanical causes such as obstruction of the gall bladder siphon and vasomotor phenomena under autonomic control. The histological lesions and course are comparable to those observed in clinical medicine. The interest of this experimental study is to compare the pathology of acute cholecystitis with pancreatitis and Reilly's syndrome and Gregoire and Couvelaire's theory of visceral apoplexy.

  1. Experimental study on energy performance of clean air heat pump

    DEFF Research Database (Denmark)

    Fang, Lei; Nie, Jinzhe; Olesen, Bjarne W.


    to investigate its energy performance. Energy consumption of the prototype of CAHP was measured in laboratory at different climate conditions including mild-cold, mildhot and extremely hot and humid climates. The energy saving potential of the clean air heat pump compared to a conventional ventilation and air......-conditioning system was calculated. The experimental results showed that the clean air heat pump saved substantial amount of energy compared to the conventional system. For example, the CAHP can save up to 59% of electricity in Copenhagen, up to 40% of electricity in Milan and up to 30% of electricity in Colombo......An innovative clean air heat pump (CAHP) was designed and developed based on the air purification capacity of regenerative silica gel rotor. The clean air heat pump integrated air purification, dehumidification and cooling in one unit. A prototype of the clean air heat pump was developed...

  2. Experimental and theoretical study of horizontal-axis wind turbines


    Anderson, Michael Broughton


    An experimental and theoretical study of horizontal-axis wind turbines is undertaken. The theoretical analyses cover the four major areas of aerodynamics, turbulence. aeroelasticity and blade optimisation. EXisting aerodynamic theories based on blade-element theory for predicting the loads on a wind turbine blade are reviewed and extended to include non-uniform flow, tip losses and the 'turbulent wake' state. A theoretical model based on a free vortex representation of a ...

  3. Composition of intraocular foreign bodies: experimental study of ultrasonographic presentation


    Márcio Augusto Nogueira Costa; Patrícia Novita Garcia; Letícia Fernandes Barroso; Marco Antonio Ferreira; Érika Araki Okuda; Norma Allemann


    PURPOSE: To investigate the reliability of ultrasound in determining the size and identify the sonographic features and artifacts generated by intraocular foreign bodies of different materials. METHODS: Experimental study using 36 enucleated porcine eyes. Fragments of nine different compositions (wood, glass, plastic, cardboard, iron, aluminum, lead, powder and concrete) and similar dimensions (4 mm) were implanted via scleral incision into the vitreous cavity of 36 porcine eyes, four eyes we...

  4. Respecifying lab ethnography an ethnomethodological study of experimental physics

    CERN Document Server

    Sormani, Philippe


    Respecifying Lab Ethnography delivers the first ethnomethodological study of current experimental physics in action, describing the disciplinary orientation of lab work and exploring the discipline in its social order, formal stringency and skilful performance - in situ and in vivo. In bringing together two major strands of ethnomethodological inquiry, reflexive ethnography and video analysis, which have hitherto existed in parallel, Respecifying Lab Ethnography introduces a practice-based video analysis. In doing so, the book recasts conventional distinctions to shed fresh light on methodolog

  5. Experimental study on durability of small wind turbine (United States)

    Bao, Daorina; Shang, Wei; Wang, Huan


    Through the basic theory of durability test technology for small and medium sized wind power generation units, and the durability of 3KW wind turbine, this paper analyzed the test method of time available rate of unit and studied the power generation capability of the wind turbine. No power attenuation trend has been found, and a lot of experimental data and rich experience in engineering practice has been obtained with the success of experiments.

  6. Experimental studies toward the characterization of Inmetro's circulating water channel (United States)

    Santos, A. M.; Alho, A. T. P.; Garcia, D. A.; Farias, M. H.; Massari, P. L.; Silva, V. V. S.


    Circulating water channels are facilities which can be used for conducting environmental, metrological and engineering studies. The Brazilian National Institute of Metrology-INMETRO has a water channel of innovative design, and the present work deals with the prior experimental investigation of its hydrodynamics performance. By using the optical technique PIV - Particle Image Velocimetry, under certain conditions, the velocity profile behavior in a region inside the channel was analyzed in order to evaluate the scope of applicability of such bench.

  7. Fuel model Validation in the TASS/SMR-S code by Comparing with Experimental Results

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Sang Jun; Yang, Soo Hyung; Chung, Young Jong; Lee, Won Jae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)


    An advanced integral pressurized water reactor, SMART (System-Integrated Modular Advanced ReacTor) has been developed by KAERI (Korea Atomic Energy Research and Institute). For the purpose of an electric power generation and seawater desalination by using nuclear energy, SMART has been developed by KAERI (KAERI, 2010). For the safety evaluation and performance analysis of the SMART, TASS/SMR-S (Transient And Setpoint Simulation/System- integrated Modular Reactor) code, has been developed. In this paper, the gap conductance model for the calculation of gap conductance has been validated by using experimental results. In the validation, the behaviors of fuel temperature and off-center temperature are selected as the major parameters

  8. Experimental tests on winter cereal: Sod seeding compared to minimum tillage and traditional plowing

    Directory of Open Access Journals (Sweden)

    Antoniotto Guidobono Cavalchini


    Full Text Available Compared to traditional plowing and minimum tillage, the sod seeding technique has been tested in order to evaluate the differences in energy consumption, labor and machinery requirement and CO2 emission reduction. The experiments were conducted on winter cereal seeding in a Po valley farm in October 2011. The tests were carried out as follows: wheat variety seeding, over corn and alfalfa crops, in large plots with three repetitions for each thesis. They included: sod seeding anticipated by round up weeding in the case of the plots over alfalfa; traditional plowing at 35 cm followed by rotary tillage and combined seeding (seeder plus rotary tiller; minimum tillage based on ripping at the same depth (35 cm and combined seeder ( seeder plus rotary tiller. The following farm operations - fertilizer, and other agrochemical distributionshave been the same in all the considered theses. The results, statistically significant (P<0.001 in terms of yields, highlighted slight differences: the best data in the case of the traditional plowing both in the case of wheat crop over corn and alfalfa (84.43 and 6.75 t/ha; slightly lower yields for the sod seeding (6.23 and 79.9 t/ha for corn and alfalfa respectively; lower in the case of minimum tillage (5.87; 79.77 t/ha in the two situations. Huge differences in energy and oil consumption have been recorded: in the case of succession to corn 61.47; 35.31; 4.27 kg oil/ha respectively for, traditional plowing, minimum tillage and sod seeding; in the case of alfalfa 61.2; 50.96; 5.14 kg oil/ha respectively for traditional plowing, minimum tillage and sod seeding. The innovative technique, highlighted huge energy saving with an oil consumption equal to 92% and 89% (P<0.001 of what happens in traditional plowing and minimum tillage. Large differences concern labor and machine productivity. These parameters together with oil consumption and machine size [power (kW and weight (t] lead to even greater differences in

  9. Comparative study of biogenic and abiotic iron-containing materials

    Energy Technology Data Exchange (ETDEWEB)

    Cherkezova-Zheleva, Z., E-mail:; Shopska, M., E-mail:; Paneva, D. [Bulgarian Academy of Sciences, Institute of Catalysis (Bulgaria); Kovacheva, D. [Bulgarian Academy of Sciences, Institute of General and Inorganic Chemistry (Bulgaria); Kadinov, G.; Mitov, I. [Bulgarian Academy of Sciences, Institute of Catalysis (Bulgaria)


    Series of iron-based biogenic materials prepared by cultivation of Leptothrix group of bacteria in different feeding media (Sphaerotilus-Leptothrix group of bacteria isolation medium, Adler, Lieske and silicon-iron-glucose-peptone) were studied. Control samples were obtained in the same conditions and procedures but the nutrition media were not infected with bacteria, i.e. they were sterile. Room and low temperature Mössbauer spectroscopy, powder X-ray diffraction (XRD), and infrared spectroscopy (IRS) were used to reveal the composition and physicochemical properties of biomass and respective control samples. Comparative analysis showed differences in their composition and dispersity of present phases. Sample composition included different ratio of nanodimensional iron oxyhydroxide and oxide phases. Relaxation phenomena such as superparamagnetism or collective magnetic excitation behaviour were registered for some of them. The experimental data showed that the biogenic materials were enriched in oxyhydroxides of high dispersion. Catalytic behaviour of a selected biomass and abiotic material were studied in the reaction of CO oxidation. In situ diffuse-reflectance (DR) IRS was used to monitor the phase transformations in the biomass and CO conversion.

  10. Comparative study of biogenic and abiotic iron-containing materials (United States)

    Cherkezova-Zheleva, Z.; Shopska, M.; Paneva, D.; Kovacheva, D.; Kadinov, G.; Mitov, I.


    Series of iron-based biogenic materials prepared by cultivation of Leptothrix group of bacteria in different feeding media ( Sphaerotilus-Leptothrix group of bacteria isolation medium, Adler, Lieske and silicon-iron-glucose-peptone) were studied. Control samples were obtained in the same conditions and procedures but the nutrition media were not infected with bacteria, i.e. they were sterile. Room and low temperature Mössbauer spectroscopy, powder X-ray diffraction (XRD), and infrared spectroscopy (IRS) were used to reveal the composition and physicochemical properties of biomass and respective control samples. Comparative analysis showed differences in their composition and dispersity of present phases. Sample composition included different ratio of nanodimensional iron oxyhydroxide and oxide phases. Relaxation phenomena such as superparamagnetism or collective magnetic excitation behaviour were registered for some of them. The experimental data showed that the biogenic materials were enriched in oxyhydroxides of high dispersion. Catalytic behaviour of a selected biomass and abiotic material were studied in the reaction of CO oxidation. In situ diffuse-reflectance (DR) IRS was used to monitor the phase transformations in the biomass and CO conversion.

  11. Current transport modeling and experimental study of THz room temperature ballistic deflection transistors (United States)

    Kaushal, Vikas; Margala, Martin; Yu, Qiaoyan; Ampadu, Paul; Guarino, Gregg; Sobolewski, Roman


    In this paper, two different theoretical models, Comsol Multiphysics™ (a Finite Element Analysis tool), and a field solver Atlas/Blaze from Silvaco, are compared qualitatively to study the effect of the deflector position, its size and electric field on the charge transport and its distribution along the channel, resulting in current outputs and leakages in ballistic deflection transistors (BDT). Silvaco simulations and experimental results were then used to study the lateral charge transport as a result of variation in electric field distribution, which controls the charge current along the channel in BDT. The electric field dependence of gain is also studied with experimental and theoretical results.

  12. Current transport modeling and experimental study of THz room temperature ballistic deflection transistors

    Energy Technology Data Exchange (ETDEWEB)

    Kaushal, Vikas; Margala, Martin [Department of Electrical and Computer Engineering, University of Massachusetts Lowell, MA, 01854 (United States); Yu Qiaoyan; Ampadu, Paul; Guarino, Gregg; Sobolewski, Roman, E-mail: vikas_kaushal@student.uml.ed [Department of Electrical and Computer Engineering, University of Rochester, NY, 14627 (United States)


    In this paper, two different theoretical models, Comsol Multiphysics{sup TM} (a Finite Element Analysis tool), and a field solver Atlas/Blaze from Silvaco, are compared qualitatively to study the effect of the deflector position, its size and electric field on the charge transport and its distribution along the channel, resulting in current outputs and leakages in ballistic deflection transistors (BDT). Silvaco simulations and experimental results were then used to study the lateral charge transport as a result of variation in electric field distribution, which controls the charge current along the channel in BDT. The electric field dependence of gain is also studied with experimental and theoretical results.

  13. Effects of Writing Instruction on Kindergarten Students' Writing Achievement: An Experimental Study (United States)

    Jones, Cindy D'On


    This full-year experimental study examined how methods of writing instruction contribute to kindergarten students' acquisition of foundational and compositional early writing skills. Multiple regression with cluster analysis was used to compare 3 writing instructional groups: an interactive writing group, a writing workshop group, and a…

  14. Electronic structure of copper phthalocyanine : An experimental and theoretical study of occupied and unoccupied levels

    NARCIS (Netherlands)

    Evangelista, Fabrizio; Carravetta, Vincenzo; Stefani, Giovanni; Jansik, Branislav; Alagia, Michele; Stranges, Stefano; Ruocco, Alessandro


    An experimental and theoretical study of the electronic structure of copper phthalocyanine (CuPc) molecule is presented. We performed x-ray photoemission spectroscopy (XPS) and photoabsorption [x-ray absorption near-edge structure (XANES)] gas phase experiments and we compared the results with

  15. Experimental and numerical studies of two arterial wall delamination modes. (United States)

    Leng, Xiaochang; Zhou, Boran; Deng, Xiaomin; Davis, Lindsey; Lessner, Susan M; Sutton, Michael A; Shazly, Tarek


    Arterial wall dissection, which results from various pathophysiological processes, can lead to the occurrence of large area delamination in the aortic wall that can potentially block blood flow and lead to deleterious clinical conditions. Despite its critical clinical relevance, few studies have focused on investigating the failure mode of delamination in the arterial wall. In this study, we quantify the energy release rate of the medial layer of a porcine abdominal aorta via two delamination experiments: the mixed-mode delamination experiment and the "T"-shaped delamination experiment. A cohesive zone model (CZM) is applied to simulate the arterial wall delamination and Holzapfel-Gasser-Ogden (HGO) material model is used to capture the bulk arterial material behavior. A set of parameter values for the HGO and CZM models are identified through matching simulation predictions of the load vs. load-point displacement curve with experimental measurements. Then the parameter values and critical energy release rates obtained from experiments are used as input data for simulation predictions for two arterial wall delamination experiments. The simulation predictions show that the delamination front matches well with experimental measurements. Moreover, the mixed-mode delamination experiment reveals a shear mode-dominated failure event, whereas the "T"-shaped delamination experiment is an opening failure process. The integration of experimental data and numerical predictions of arterial delamination events provides a comprehensive description of distinct failure modes and aids in the prediction of aortic dissection. Copyright © 2017. Published by Elsevier Ltd.

  16. Analytical and experimental studies of wakes behind circularly capped bubbles (United States)

    Bessler, W. F.

    The wakes behind circularly capped bubbles are examined by means of an experimental and analytical study. A single two-inch diameter bubble is injected into a six by three foot fluid column, one half inch thick, producing an essentially two-dimensional flow. Aspirin powder placed in the fluid column just prior to bubble release highlights the structure of the flow field before dissolving. High speed film and sequenced photographs are taken to document the observed results. Pressure-time measurements are made with sensitive capacitive transducers mounted in the rear column wall and are synchronized with photographs using a high speed clock. Experimental fluids, prepared by mixing water and glycerine in varying proportions, are used to study the effects of viscosity on bubble shape and wake structure. Testing is performed over a range of Reynolds numbers from 14 to 29,655 which includes the transition from circularly capped to ellipsoidal bubble shape. Experimental data is reduced and summarized in convenient dimensionless form to permit comparison with analytical predictions.

  17. An experimental study on recovering heat from domestic drain water (United States)

    Ramadan, Mohamad; Al Shaer, Ali; Haddad, Ahmad; Khaled, Mahmoud


    This paper concerns an experimental study on a system of heat recovery applied to domestic drain water pipes. The concept suggested consists of using the heat still present in the drain water as a preheating/heating source to the cold water supply of the building. To proceed, an appropriate experimental setup is developed and a coil heat exchanger is used as heat transfer device in the recovery system. Several scenarios are simulated and corresponding parameters are recorded and analyzed. It was shown that the suggested recovery concept can considerably preheat the cold water supply and then decrease the energy consumption. Particularly, up to 8.6 kW of heat were recovered when the cold water supply is initially at 3 °C.

  18. Experimental and theoretical study of metal combustion in oxygen flows

    CERN Document Server

    El-Rabii, Hazem; Muller, Maryse


    The effects of oxygen flow speed and pressure on the iron and mild steel combustion are investigated experimentally and theoretically. The studied specimens are vertical cylindrical rods subjected to an axial oxygen flow and ignited at the upper end by laser irradiation. Three main stages of the combustion process have been identified experimentally: (1) Induction period, during which the rod is heated until an intensive metal oxidation begins at its upper end; (2) Static combustion, during which a laminar liquid "cap" slowly grows on the upper rod end; and, after the liquid cap detachment from the sample, (3) Dynamic combustion, which is characterized by a rapid metal consumption and turbulent liquid motions. An analytical description of these stages is given. In particular, a model of the dynamic combustion is constructed based on the turbulent oxygen transport through the liquid metal-oxide flow. This model yields a simple expression for the fraction of metal burned in the process, and allows one to calcul...

  19. Experimental study of effect of stenosis geometry on flow parameters

    Directory of Open Access Journals (Sweden)

    Veselý Ondřej


    Full Text Available A stenosis is a narrowing in a tubular organ or structure. In medicine, vessel stenosis poses health risks for people. In this work, experimental investigations of pressure loss coefficient for varying stenosis eccentricity and shape were performed. Five models of different geometry were studied; all models were stenosis of 75 % area reduction. The flow conditions approximate physiological flow. The measuring range of Reynolds number was from 130 to 2730, measured values of pressure loss coefficient were from 12 to 20. The steady experimental results indicated that static pressure loss coefficient is affected by the shape of stenosis, but it was affected more significantly by the eccentricity. Visualization experiments have been performed in Polycarbonate models.

  20. Experimental study of hydronic panels system and its environment

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, Nestor Fonseca [University of Liege Belgium, Thermodynamics Laboratory, Campus du Sart Tilman, Bat: B49 - P33, B-4000 Liege (Belgium); Universidad Tecnologica de Pereira, Facultad de Ingenieria Mecanica (Colombia)


    An experimental analysis of hydronic cooling or heating ceiling panels coupled to the building is present in this investigation as a part of the commissioning study of this system. Two test chambers are adapted in a way to reproduce the interaction of the system to the building (windows, internal thermal loads distribution, building structure and ventilation). A series of experimental tests were performed in which the main objective is to observe the influence of parameters such as the water mass flow rate, supply water temperature, thermal load distribution, window and ventilation system effects on the hydronic ceiling capacity and comfort conditions. Test results show that the influence of asymmetric surfaces temperatures inside the room, especially the window effect is not negligible. Then, it is clear that the cooling hydronic ceiling must be evaluated coupled to the building systems and structure. (author)

  1. Experimental study of hydronic panels system and its environment

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca Diaz, Nestor, E-mail: [University of Liege Belgium, Thermodynamics Laboratory, Campus du Sart Tilman, Bat: B49 - P33, B-4000 Liege (Belgium); Universidad Tecnologica de Pereira, Facultad de Ingenieria Mecanica (Colombia)


    An experimental analysis of hydronic cooling or heating ceiling panels coupled to the building is present in this investigation as a part of the commissioning study of this system. Two test chambers are adapted in a way to reproduce the interaction of the system to the building (windows, internal thermal loads distribution, building structure and ventilation). A series of experimental tests were performed in which the main objective is to observe the influence of parameters such as the water mass flow rate, supply water temperature, thermal load distribution, window and ventilation system effects on the hydronic ceiling capacity and comfort conditions. Test results show that the influence of asymmetric surfaces temperatures inside the room, especially the window effect is not negligible. Then, it is clear that the cooling hydronic ceiling must be evaluated coupled to the building systems and structure.

  2. Experimental study of heat transfer to falling liquid films (United States)

    Fagerholm, N. E.; Kivioja, K.; Ghazanfari, A. R.; Jaervinen, E.


    This project was initiated in order to obtain more knowledge about thermal design of falling film heat exchangers and to find methods to improve heat transfer in film flow. A short literature survey of film flow characteristics and heat transfer is presented. An experimental apparatus designed and built for studying falling film evaporation is described. The first experiments were made with smooth Cu tube 25/22 mm and refrigerant R114 as evaporating liquid. A significant amount of droplet entrainment was observed during the tests. The measured average heat transfer coefficient varied from 1000 to 1800 W/m K when Re=1300 to 11000 respectively and when the transfer mode is surface evaporation. This could be predicted accurately with the experimental correlation of Chun and Seban. When nucleate boiling is dominant the heat transfer could be predicted well with pool boiling correlation of VDI-84.

  3. Experimental Study on the WavePiston Wave Energy Converter

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter; Angelelli, E.

    This report presents the results of an experimental study of the power performance of the WavePiston wave energy converter. It focuses mainly on evaluating the power generating capabilities of the device and the effect of the following issues: Scaling ratios PTO loading Wave height and wave period...... dependency Oblique incoming waves Distance between plates During the study, the model supplied by the client, WavePiston, has been rigorously tested as all the anticipated tests have been done thoroughly and during all tests, good quality data has been obtained from all the sensors....

  4. Game theory and experimental games the study of strategic interaction

    CERN Document Server

    Colman, Andrew M


    Game Theory and Experimental Games: The Study of Strategic Interaction is a critical survey of the essential ideas of game theory and the findings of empirical research on strategic interaction. Some experiments using lifelike simulations of familiar kinds of strategic interactions are presented, and applications of game theory to the study of voting, the theory of evolution, and moral philosophy are discussed.Comprised of 13 chapters, this volume begins with an informal definition of game theory and an outline of the types of social situations to which it applies. Games of skill, games of cha

  5. Manipulation of pain catastrophizing: An experimental study of healthy participants

    Directory of Open Access Journals (Sweden)

    Joel E Bialosky


    Full Text Available Joel E Bialosky1*, Adam T Hirsh2,3, Michael E Robinson2,3, Steven Z George1,3*1Department of Physical Therapy; 2Department of Clinical and Health Psychology; 3Center for Pain Research and Behavioral Health, University of Florida, Gainesville, Florida, USAAbstract: Pain catastrophizing is associated with the pain experience; however, causation has not been established. Studies which specifically manipulate catastrophizing are necessary to establish causation. The present study enrolled 100 healthy individuals. Participants were randomly assigned to repeat a positive, neutral, or one of three catastrophizing statements during a cold pressor task (CPT. Outcome measures of pain tolerance and pain intensity were recorded. No change was noted in catastrophizing immediately following the CPT (F(1,84 = 0.10, p = 0.75, partial η2 < 0.01 independent of group assignment (F(4,84 = 0.78, p = 0.54, partial η2 = 0.04. Pain tolerance (F(4 = 0.67, p = 0.62, partial η2 = 0.03 and pain intensity (F(4 = 0.73, p = 0.58, partial η2 = 0.03 did not differ by group. This study suggests catastrophizing may be difficult to manipulate through experimental pain procedures and repetition of specific catastrophizing statements was not sufficient to change levels of catastrophizing. Additionally, pain tolerance and pain intensity did not differ by group assignment. This study has implications for future studies attempting to experimentally manipulate pain catastrophizing.Keywords: pain, catastrophizing, experimental, cold pressor task, pain catastrophizing scale

  6. An Experimental Approach to Comparing Trust in Pastoral and Non-Pastoral Australia


    Ryan R. J. McAllister; Andrew F. Reeson


    It is generally held that rural Australians are more cooperative in character than their urban counterparts. To explore one aspect of this notion, we conducted an experiment which compared trust and trustworthiness among a sample of Australian senior high school students which included students with both pastoral and non-pastoral backgrounds. While student behaviour is unlikely to mimic adult behaviour, any significant differences between pastoral and non-pastoral students would suggest diffe...

  7. Testing the role of genetic background in parallel evolution using the comparative experimental evolution of antibiotic resistance. (United States)

    Vogwill, Tom; Kojadinovic, Mila; Furió, Victoria; MacLean, R Craig


    Parallel evolution is the independent evolution of the same phenotype or genotype in response to the same selection pressure. There are examples of parallel molecular evolution across divergent genetic backgrounds, suggesting that genetic background may not play an important role in determining the outcome of adaptation. Here, we measure the influence of genetic background on phenotypic and molecular adaptation by combining experimental evolution with comparative analysis. We selected for resistance to the antibiotic rifampicin in eight strains of bacteria from the genus Pseudomonas using a short term selection experiment. Adaptation occurred by 47 mutations at conserved sites in rpoB, the target of rifampicin, and due to the high diversity of possible mutations the probability of within-strain parallel evolution was low. The probability of between-strain parallel evolution was only marginally lower, because different strains substituted similar rpoB mutations. In contrast, we found that more than 30% of the phenotypic variation in the growth rate of evolved clones was attributable to among-strain differences. Parallel molecular evolution across strains resulted in divergent phenotypic evolution because rpoB mutations had different effects on growth rate in different strains. This study shows that genetic divergence between strains constrains parallel phenotypic evolution, but had little detectable impact on the molecular basis of adaptation in this system. © The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  8. Numerical and experimental study in piping system dead legs

    Energy Technology Data Exchange (ETDEWEB)

    Deutsch, E.; Barcouda, M.; Rousset, J.L. [Electricite de France (EDF), 78 - Chatou (France). Lab. National d`Hydraulique; Mallez, C.


    This paper deals with an experimental and numerical study of the isothermal flow at the junction of a zero flow-rate pipe connected to high Reynolds number piping system. The motivation is to understand and model the hydraulic behaviour of various auxiliary lines connected to the primary circuit of Pressurised Water Reactors. Experimental data have been obtained on a hydraulic mock-up using flow visualisation method and particle image velocimetry (PIV). These qualitative results show an helicoidal flow extending along the auxiliary pipe. Numerical calculations performed with the 3D ESTET code are presented and contrast the performance of the k-epsilon eddy viscosity model and a second moment closure turbulence model. Fine (1 500 000) mesh were used. The numerical results obtained using the second moment closure turbulence model confirm the swirl flow structure into the dead leg observed on the mock-up. On the other hand the k-epsilon eddy viscosity model is not able to predict the vortex penetration along the auxiliary pipe. These results illustrate the necessity to use second moment closure turbulence model to simulate flows in piping system dead legs. Unfortunately the powerful of the vortex is very sensitive to geometric details of the junction and gives difficulties for quantitative comparisons of the numerical results with experimental data. (author)

  9. Nonlocal Regularized Algebraic Reconstruction Techniques for MRI: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Xin Li


    Full Text Available We attempt to revitalize researchers' interest in algebraic reconstruction techniques (ART by expanding their capabilities and demonstrating their potential in speeding up the process of MRI acquisition. Using a continuous-to-discrete model, we experimentally study the application of ART into MRI reconstruction which unifies previous nonuniform-fast-Fourier-transform- (NUFFT- based and gridding-based approaches. Under the framework of ART, we advocate the use of nonlocal regularization techniques which are leveraged from our previous research on modeling photographic images. It is experimentally shown that nonlocal regularization ART (NR-ART can often outperform their local counterparts in terms of both subjective and objective qualities of reconstructed images. On one real-world k-space data set, we find that nonlocal regularization can achieve satisfactory reconstruction from as few as one-third of samples. We also address an issue related to image reconstruction from real-world k-space data but overlooked in the open literature: the consistency of reconstructed images across different resolutions. A resolution-consistent extension of NR-ART is developed and shown to effectively suppress the artifacts arising from frequency extrapolation. Both source codes and experimental results of this work are made fully reproducible.

  10. Experimental Method For Studying Habitual Behavior In Food Consumption

    Directory of Open Access Journals (Sweden)

    Naziha Kasraoui


    Full Text Available Abstract To investigate the process of habit formation in everyday life a sample of 126 participants students chooses an eating and drinking for three periods weeks. They completed the self-report habit each period and we have recorded their choices. All participants provided sufficient data for analysis and collected experimental data were examined over the study periods 3 weeks. Experimental analysis was used to examine the persistence of habit formation process in the behavior of participants. The game is carried out with 126 students and repeated for three periods. Using experimental laboratory data approach and economic analysis elasticity results show that into the presence of labor income and for 126 students of whom approximately 70 showed that habit formation process is persist in their behaviors along the three periods. The rest 30 of them who dont present habit formation in their behavior for the three periods did not materially affect our conclusion about the assumption of habit formation process. Participants to the game persistently spend too much in early periods they learn rapidly from their own experience to consume the same choice of meals and drinks. Their spending is closely linked to optimal consumption non conditional on earlier spending and they choose the same basket of goods in the future horizon which shows that theres a habit formation in the behaviors of participants.

  11. Static response of deformable microchannels: a comparative modelling study (United States)

    Shidhore, Tanmay C.; Christov, Ivan C.


    We present a comparative modelling study of fluid–structure interactions in microchannels. Through a mathematical analysis based on plate theory and the lubrication approximation for low-Reynolds-number flow, we derive models for the flow rate-pressure drop relation for long shallow microchannels with both thin and thick deformable top walls. These relations are tested against full three-dimensional two-way-coupled fluid–structure interaction simulations. Three types of microchannels, representing different elasticity regimes and having been experimentally characterized previously, are chosen as benchmarks for our theory and simulations. Good agreement is found in most cases for the predicted, simulated and measured flow rate-pressure drop relationships. The numerical simulations performed allow us to also carefully examine the deformation profile of the top wall of the microchannel in any cross section, showing good agreement with the theory. Specifically, the prediction that span-wise displacement in a long shallow microchannel decouples from the flow-wise deformation is confirmed, and the predicted scaling of the maximum displacement with the hydrodynamic pressure and the various material and geometric parameters is validated.

  12. A comparative and experimental evaluation of performance of stocked diploid and triploid brook trout (United States)

    Budy, Phaedra E.; Thiede, G.P.; Dean, A.; Olsen, D.; Rowley, G.


    Despite numerous negative impacts, nonnative trout are still being stocked to provide economically and socially valuable sport fisheries in western mountain lakes. We evaluated relative performance and potential differences in feeding strategy and competitive ability of triploid versus diploid brook trout Salvelinus fontinalis in alpine lakes, as well as behavioral and performance differences of diploid and triploid brook trout in two controlled experimental settings: behavioral experiments in the laboratory and performance evaluations in ponds. Across lakes, catch per unit effort (CPUE) and relative weight (Wr ) were not significantly different between ploidy levels. Mean sizes were also similar between ploidy levels except in two of the larger lakes where diploids attained slightly larger sizes (approximately 20 mm longer). We observed no significant differences between diploids and triploids in diet, diet preference, or trophic structure. Similarly, growth and condition did not differ between ploidy levels in smaller-scale pond experiments, and aggressive behavior did not differ between ploidy levels (fed or unfed fish trials) in the laboratory. Independent of ploidy level, the relative performance of brook trout varied widely among lakes, a pattern that appeared to be a function of lake size or a factor that covaries with lake size such as temperature regime or carrying capacity. In summary, we observed no significant differences in the relative performance of brook trout from either ploidy level across a number of indices, systems, and environmental conditions, nor any indication that one group is more aggressive or a superior competitor than the other. Collectively, these results suggest that triploid brook trout will offer a more risk-averse and promising management opportunity when they are stocked to these lakes and elsewhere to simultaneously meet the needs for the sport fishery and conservation objectives.

  13. Ultra-Wideband Coplanar-Fed Monopoles: A Comparative Study

    Directory of Open Access Journals (Sweden)

    J. Jilkova


    Full Text Available The paper provides an experimental comparison of four types of ultra-wideband coplanar-fed planar monopole antennas. Parameters of the open stub completed by an L-shaped monopole and the cross monopole were adopted from the literature. The forked monopole and the coplanar monopole were fabricated and measured. Monopoles were compared from the viewpoint of the impedance bandwidth, gain, directivity patterns and dimensions.

  14. Planar Millimeter-Wave Antennas: A Comparative Study

    Directory of Open Access Journals (Sweden)

    K. Pitra


    Full Text Available The paper describes the design and the experimental verification of three types of wideband antennas. Attention is turned to the bow-tie antenna, the Vivaldi antenna and the spiral antenna designed for the operation at millimeter waves. Bandwidth, input impedance, gain, and directivity pattern are the investigated parameters. Antennas are compared considering computer simulations in CST Microwave Studio and measured data.

  15. Experimental and theoretical studies on concrete structures with special-shaped shear walls

    Directory of Open Access Journals (Sweden)

    LIU Jianxin


    Full Text Available On the basis of concept design and staggered shear panels structure,this paper puts forward a new reinforced concrete high rise biuding structure with special-shaped shear walls and presents an experimental study of the seismic performance of the new special-shaped shear walls structure under low reversed cyclic loading using MTS electro hydraulic servo system.Compared with experimental results,a finite element analysis on this special-shaped shear wall structure,which considers the nonlinearity of concrete structure,is found suitable.It shows that the experimental results fairly confirms to the calculated values,which indicates that this new structure has advantages as good architecture function,big effective space,high overall lateral stiffness,fine ductility,advanced seismic behavior,etc..That is,the close r agreement between the theoretical and experimental results indicates the proposed shear wall structure has wide applications.

  16. Experimental Study and Numerical Modeling of Wave Induced Pore Pressure Attenuation Inside a Rubble Mound Breakwater

    DEFF Research Database (Denmark)

    Troch, Peter; Rouck, Julien De; Burcharth, Hans Falk


    attenuation is studied using experimental data (in Section 2) and using a numerical wave flume (in Section 3). The experimental study includes the analysis of large scale data from a physical breakwater model and prototype data from the Zeebrugge breakwater. The large scale data are taken from literature...... and have been re-analysed in detail with respect to the attenuation characteristics. The analysis follows the method by Burcharth et al. (1999) and confirms the practical calculation method for the attenuation of the pore pressure in the core given in this reference. The attenuation of pore pressures...... in a breakwater core is also studied in the numerical wave flume VOFbreak. The numerical results are compared to the results from the experimental study....

  17. Experimental studies of tuned particle damper: Design and characterization (United States)

    Zhang, Kai; Xi, Yanhui; Chen, Tianning; Ma, Zhihao


    To better suppress the structural vibration in the micro vibration and harsh environment, a new type of damper, tuned particle damper (TPD), was designed by combining the advantage of classical dynamic vibration absorber (DVA) and particle damper (PD). An equivalent theoretical model was established to describe the dynamic behavior of a cantilever system treated with TPD. By means of a series of sine sweep tests, the dynamic characteristic of TPD under different excitation intensity was explored and the damping performance of TPD was investigated by comparing with classical DVA and PD with the same mass ratio. Experimental results show that with the increasing of excitation intensity TPD shows two different dynamic characteristics successively, i.e., PD-like and DVA-like. TPD shows a wider suppression frequency band than classical DVA and better practicability than PD in the micro vibration environment. Moreover, to characterize the dynamic characteristic of TPD, a simple evaluation of the equivalent dynamic mass and equivalent dynamic damping of the cantilever system treated with TPD was performed by fitting the experimental data to the presented theoretical model. Finally, based on the rheology behaviors of damping particles reported by the previous research results, an approximate phase diagram which shows the motion states of damping particles in TPD was employed to analyze the dynamic characteristic of TPD and several motion states of damping particles in TPD were presented via a high-speed camera.

  18. Experimental study of soliton interaction with a vertical wall (United States)

    Shurgalina, Ekaterina; Kimmoun, Olivier; Kharif, Christian; Pelinovsky, Efim


    The occurrence of a residual jet in the case of interaction of two large counter propagating solitons was found numerically in the paper [J .Chambarel, C.Kharif , and J.Touboul, Head-on collision of two solitary waves and residual falling jet formation, Nonlin. Processes Geophys., 16, 111-122, 2009] using a Boundary Integral Equation Method (BIEM). This phenomenon occurs for amplitudes of soliton larger than a threshold value (the normalized amplitude of soliton has to be larger than 0.60). We check this effect experimentally and consider soliton interaction with a vertical wall that corresponds to the case of collision of two identical counter propagating solitons. The impact on the wall is compared with the jet found in numerical simulations. The experimental canal is located in Ecole Central de Marseille (France) and has the following dimensions (220*20*40cm). Solitons are generated by a piston wavemaker. Results could be applied to the problem of big wave formation on the coast and on the coastal structures.

  19. Experimental studies of pion-nucleus interactions at intermediate energies

    Energy Technology Data Exchange (ETDEWEB)


    This report summarizes the work on experimental research in intermediate energy nuclear physics carried out at New Mexico State University in 1991 under a great from the US Department of Energy. Most of these studies have involved investigations of various pion-nucleus interactions. The work has been carried out both with the LAMPF accelerator at the Los Alamos National Laboratory and with the cyclotron at the Paul Scherrer Institute (PSI) near Zurich, Switzerland. Part of the experimental work involves measurements of new data on double-charge-exchange scattering, using facilities at LAMPF which we helped modify, and on pion absorption, using a new detector system at PSI that covers nearly the full solid-angle region which we helped construct. Other work involved preparation for future experiments using polarized nuclear targets and a new high-resolution spectrometer system for detecting {pi}{sup 0} mesons. We also presented several proposals for works to be done in future years, involving studies related to pi-mesonic atoms, fundamental pion-nucleon interactions, studies of the difference between charged and neutral pion interactions with the nucleon, studies of the isospin structure of pion-nucleus interactions, and pion scattering from polarized {sup 3}He targets. This work is aimed at improving our understanding of the pion-nucleon interaction, of the pion-nucleus interaction mechanism, and of nuclear structure.

  20. Experimental Study on Thrust Characteristics of Airspace Laser Propulsion Engine (United States)

    Ageichik, A. A.; Egorov, M. S.; Rezunkov, Y. A.; Safronov, A. L.; Stepanov, V. V.


    In the paper a specially designed airspace laser propulsion engine is examined at the non-conventional laser beam input into the engine nozzle. The experiments are carried out by using of the laboratory stand and pulsed CO2 laser. In the experiments, geometrical parameters of the engine and laser pulse characteristics are varied. The technique of the experiments allowed measuring of momentum coupling coefficient Cm with accuracy of +/-10%. The coupling coefficient Cm was experimentally measured and compared with Cm determined theoretically. The dependences of the coupling coefficient on the laser pulse characteristics and geometrical parameters of the engine are also obtained. In the paper the analysis of the flight model of the airspace laser propulsion engine is considered too.

  1. Experimental and numerical study of micro deep drawing

    Directory of Open Access Journals (Sweden)

    Luo Liang


    Full Text Available Micro forming is a key technology for an industrial miniaturisation trend, and micro deep drawing (MDD is a typical micro forming method. It has great advantages comparing to other micro manufacturing methods, such as net forming ability, mass production potential, high product quality and complex 3D metal products fabrication capacity. Meanwhile, it is facing difficulties, for example the so-called size effects, once scaled down to micro scale. To investigate and to solve the problems in MDD, a combined micro blanking-drawing machine is employed and an explicit-implicit micro deep drawing model with a voronoi blank model is developed. Through heat treatment different grain sizes can be obtained, which affect material's properties and, consequently, the drawing process parameters, as well as produced cups' quality. Further, a voronoi model can provide detailed material information in simulation, and numerical simulation results are in accordance with experimental results.

  2. Electroacupuncture-Induced Attenuation of Experimental Epilepsy: A Comparative Evaluation of Acupoints and Stimulation Parameters

    Directory of Open Access Journals (Sweden)

    Xuezhi Kang


    Full Text Available The efficacy of electroacupuncture (EA on epilepsy remains to be verified because of previous controversies that might be due to the complexity of the effects induced by different acupoints and stimulation approaches adopted. Therefore, we investigated the effects of EA on epilepsy to determine the specific acupoints and optimal stimulation parameters in this work. Experimental epilepsy was induced by injecting kainic acid to the lateral cerebral ventricle of adult male SD rats. EA with a low-frequency (10 Hz/1 mA or high-frequency (100 Hz/1 mA current was applied to the epileptic model for 30 minutes starting at 0.5 hour after the injection. Four pairs of acupoints were tested, that is, Shuigou (DU26 + Dazhui (DU14, Jinsuo (DU8 + Yaoqi (EXB9, Neiguan (PC6 + Quchi (LI11, and Fenglong (ST40 + Yongquan (KI1. We found that (1 low- or high-frequency EA at different acupoints reduced epileptic seizures (P<0.05 versus the control with an exception of low-frequency EA at Neiguan (PC6 and Quchi (LI11; (2 low-frequency EA induced a better effect at Fenglong (ST40 plus Yongquan (KI1 than that of the other acupoints (P<0.05; (3 there is no significant difference in the effects of high-frequency EA at these acupoints; and (4 the high-frequency EA elicited a greater effect than that of low-frequency EA in all groups (P<0.05, with an exception at Jinsuo (DU8 + Yaoqi (EXB9. The EA-induced attenuation appeared 1–1.5 hours after EA with no appreciable effect in the first hour after EA in either the EEG or the behavioral tests. We conclude that EA attenuation of epileptic seizures is dependent on the stimulation parameters and acupoints and that the delay in appearance of the EA effect could be a reflection of the time required by the EA signal to regulate neural function in the central nervous system.

  3. Experimental study of microtabs in smart blades for wind turbines


    Senosiain Suescun, David; Morales Goicoechea, Joseba


    The goal of this thesis is to carry out an experimental study of the performance of smart blades reducing extreme and/or cyclic loads for their use in wind turbines. First of all, theoretical research about wind turbines and smart blades was done. Some of this information is explained in the thesis in order to set the background and make it more readable and understandable (Chapters 1 to 3). The next step was to choose a blade profile that would fit well the requirements of ...

  4. Experimental study of temperature effects on air gun signatures

    Energy Technology Data Exchange (ETDEWEB)

    Langhammer, J.; Landroe, M.


    The effect of varying the water temperature between 5[sup o]C and 46[sup o]C upon seismic air gun signatures has been studied experimentally. The experiments were carried out in a 850 litres water tank. Increasing the water temperature from 5[sup o]C to 29[sup o]C leads to 10% increase in the primary to bubble ratio, given that the signatures are filtered with a 0-128 Hz high cut filter. The bubble time period increases with 1 ms, or 4 % within the same temperature range. 7 refs., 28 figs., 3 tabs.

  5. A numerical and experimental study of confined swirling jets (United States)

    Nikjooy, M.; Mongia, H. C.; Samuelsen, G. S.; Mcdonell, V. G.


    A numerical and experimental study of a confined strong swirling flow is presented. Detailed velocity measurements are made using a two-component laser Doppler velocimeter (LDV) technique. Computations are performed using a differential second-moment (DSM) closure. The effect of inlet dissipation rate on calculated mean and turbulence fields is investigated. Various model constants are employed in the pressure-strain model to demonstrate their influences on the predicted results. Finally, comparison of the DSM calculations with the algebraic second-monent (ASM) closure results shows that the DSM is better suited for complex swirling flow analysis.

  6. Experimental studies of ionospheric irregularities and related plasma processes (United States)

    Baker, Kay D.


    Utah State University (USU) continued its program of measuring and interpreting electron density and its variations in a variety of ionospheric conditions with the Experimental Studies of Ionospheric Irregularities and Related Plasma Processes program. The program represented a nearly ten year effort to provide key measurements of electron density and its fluctuations using sounding rockets. The program also involved the joint interpretation of the results in terms of ionospheric processes. A complete campaign summary and a brief description of the major rocket campaigns are also included.

  7. Experimental study of flapping jets in a soap film (United States)

    Lee, Julia; Kim, Ildoo; Mandre, Shreyas


    Plateau and Rayleigh's observation and explanation on jet instability have inspired us over the years and there has been a significant advance in understanding the jet dynamics. Here, we present a quasi-two-dimensional experimental study of flapping jets in a soap film. Newtonian and non-Newtonian solutions are injected in a flowing soap film. Thinning, break-ups, and beads-on-a-string of the jets, and axisymmetric vortices shredded from the flapping jets are visualized. We employ PIV of the flow motion around the jets to gain an understanding of the roles of instabilities in the flow.

  8. Experimental study of dynamic stall on Darrieus wind turbine blades (United States)

    Brochier, G.; Fraunie, P.; Beguier, C.; Paraschivoiu, I.


    An experimental study of periodic vortex phenomena was performed on a model of a two straight-bladed Darrieus wind turbine under controlled-rotation conditions in the IMST water tunnel. The main focus of interest was the tip-speed ratios at which dynamic stall appears. Observations of this phenomenon from dye emission and the formation of hydrogen bubbles were made in the form of photographs, film and video recordings. Velocity measurements were obtained using the Laser-Doppler Velocimeter and components of velocity fluctuations could be determined quantitatively.

  9. Interaction of ordinary Portland cement and Opalinus Clay: Dual porosity modelling compared to experimental data (United States)

    Jenni, A.; Gimmi, T.; Alt-Epping, P.; Mäder, U.; Cloet, V.


    Interactions between concrete and clays are driven by the strong chemical gradients in pore water and involve mineral reactions in both materials. In the context of a radioactive waste repository, these reactions may influence safety-relevant clay properties such as swelling pressure, permeability or radionuclide retention. Interfaces between ordinary Portland cement and Opalinus Clay show weaker, but more extensive chemical disturbance compared to a contact between low-pH cement and Opalinus Clay. As a consequence of chemical reactions porosity changes occur at cement-clay interfaces. These changes are stronger and may lead to complete pore clogging in the case of low-pH cements. The prediction of pore clogging by reactive transport simulations is very sensitive to the magnitude of diffusive solute fluxes, cement clinker chemistry, and phase reaction kinetics. For instance, the consideration of anion-depleted porosity in clays substantially influences overall diffusion and pore clogging at interfaces. A new concept of dual porosity modelling approximating Donnan equilibrium is developed and applied to an ordinary Portland cement - Opalinus Clay interface. The model predictions are compared with data from the cement-clay interaction (CI) field experiment in the Mt Terri underground rock laboratory (Switzerland), which represent 5 y of interaction. The main observations such as the decalcification of the cement at the interface, the Mg enrichment in the clay detached from the interface, and the S enrichment in the cement detached from the interface, are qualitatively predicted by the new model approach. The model results reveal multiple coupled processes that create the observed features. The quantitative agreement of modelled and measured data can be improved if uncertainties of key input parameters (tortuosities, reaction kinetics, especially of clay minerals) can be reduced.

  10. Experimental study of masonry wall exposed to blast loading

    Directory of Open Access Journals (Sweden)

    Ahmad, S.


    Full Text Available The challenge of protecting the nation against the attack of terrorism has raised the importance to explore the understanding of building materials against the explosion. Unlike most of the building materials, brick masonry materials offer relatively small resistance against blast loading. In this research, a brick masonry wall was exposed to varying blast load at different scaled distances. Six tests with different amounts of explosives at various distances were carried out. Pressure time history, acceleration time history and strain at specific location were measured. The parameters measured from experimental pressure time history and acceleration time history is compared with those determined by ConWep to establish the correlations between experimental determined records and ConWep values. The experimental results were also compared with some researchers. These correlations may assist in understanding the behaviour of masonry structures subjected to explosive loading.Con el reto que supone proteger a la nación contra atentados terroristas se ha visto acrecentada la importancia de conocer el comportamiento de materiales de construcción cuando se someten a una carga explosiva. Al contrario de la mayoría de los materiales, las fábricas de ladrillo ofrecen poca resistencia a dichas cargas. En el presente trabajo, se estudió el comportamiento de una fábrica de ladrillo ante cargas explosivas colocadas a diferentes distancias del muro. Se realizaron seis pruebas con explosivos de potencias distintas y a diferentes distancias. Se trazaron las curvas presión-tiempo y aceleración-tiempo, midiéndose asimismo la deformación en un punto concreto. Los valores experimentales de las curvas presión-tiempo y aceleración-tiempo se compararon con los que se calcularon con la ayuda de la aplicación informática ConWep a fin de establecer las correlaciones entre ambos conjuntos de resultados. También se compararon los resultados experimentales

  11. Experimental Study into the Stability of Whitlockite in Basaltic Magmas (United States)

    McCubbin, F. M.; Barnes, J. J.; Srinivasan, P.; Whitson, E. S.; Vander Kaaden, K. E.; Boyce, J. W.


    Apatite Ca5(PO4)3(F,Cl,OH), merrillite Ca18Na2Mg2(PO4)14, and whitlockite Ca9(Mg,Fe2+)(PO4)6[PO3(OH)] are the primary phosphate minerals found in most planetary materials including rocks from Earth, Moon, Mars, and asteroids [1-2]. For many years, the terms merrillite and whitlockite have been used interchangeably in the meteorite literature. Much of the confusion regarding the relationship between terrestrial and extraterrestrial "whitlockite" is based on the presence or absence of hydrogen in the mineral structure. Whitlockite has approximately 8500 ppm H2O, and the term "merrillite" has been adopted to identify the hydrogen-free form of whitlockite [2]. The atomic structures of merrillite and whitlockite were examined in detail by Hughes et al. [3-4]. On Earth, whitlockite has been found in rocks from evolved pegmatitic systems [2-4] and in some mantle rocks [e.g., 5]. Furthermore, terrestrial whitlockite has been shown to have some merrillite component [4]. For the meteoritic and lunar materials that have been investigated, merrillite appears to be far more common than whitlockite, and it has been proposed that the whitlockite component is unique to terrestrial samples [4]. There are some reports of "whitlockite" in the meteorite literature; however, these likely represent misidentifications of merrillite because there have been no reports of extraterrestrial whitlockite that have been verified through crystal structural studies or analyzed for their H contents. Hughes et al. [3] reported the atomic arrangement of lunar merrillite and demonstrated that the phase is similar to meteoritic merrillite and, predictably, devoid of hydrogen. In a follow-up study, Hughes et al. [4] reported the atomic arrangements of two natural samples of whitlockite, one synthetic whitlockite, and samples of synthetic whitlockite that were heated at 500degC and 1050degC for 24 h. The crystal chemistry and crystal structures of the phases were compared, and it was discovered that the

  12. Experimental and theoretical study on the electrospinning nanoporous fibers process

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jianghui; Si, Na [National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou (China); Xu, Lan, E-mail: [National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou (China); Nantong Textile Institute of Soochow University, Nantong (China); Tang, Xiaopeng; Song, Yanhua; Sun, Zhaoyang [National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou (China)


    Porous materials can be prepared by sol–gel method, hydrothermal synthesis method, electrospinning and other methods. In this paper, electrospun porous nanofibers were prepared by adjusting electrospinning parameters. And the properties of obtained porous nanofiber mats were investigated. Theoretical analysis and experiment research were carried out to research mechanical mechanism of electrospun porous nanofibers, and could be used to optimize and control the porous structure. The theoretical analysis results were further verified according to the experimental data. In addition, Bernoulli equation was used to study the electrospinning “splaying” process. We found the ratio of pore width to pore length was varied along with the variation of the internal pressure of the jet, and the internal pressure of the jet increases with the velocity of the charged jet decreases. - Highlights: • Mechanical mechanism of electrospun porous nanofibers process was studied. • A simplifying gas–liquid two-phase flow model was established. • Bernoulli equation was used to study the electrospinning “splaying” process. • The theoretical results were in good agreement with the experimental data. • The electrospinning parameters affected the surface morphology of charged jet.


    Directory of Open Access Journals (Sweden)

    Yulia Alexandrowna Griber


    Full Text Available The objective of the study was informal social norms of urban culture. The paper contains the detailed description of the experimental situation and the main steps of the field research, focused on the observance of informal social norms in the sphere of urban coloristics. The experiment was conducted in three districts of Smolensk (Russia – Leninskiy, Zadneprovskiy and Promyshlennyy. Particular attention was paid to the analysis of the results of the field research, including evaluation of reaction of participants (residents of multi-storied houses, breakers of informal norms of urban coloristics (experimenters and casual experiment witnesses (neighbors and passersby. In addition, the accuracy of results “forecasting”, done before the beginning of the experiment, is analyzed. The research was conducted using the methodology of breaking experiment that is one of the most provocative ways of studying informal norms in sociology and social psychology. The experiment allowed to draw a number of important conclusions. It showed that urban coloristics is regulated by strict informal norms, that are not noticed by citizens until a violation occurs. The power of informal norms is significantly underestimated by citizens, and their break causes a negative reaction and protest. The most important contribution to the study of informal norms of urban culture was the comparison of the reaction degree by men and women, by the residents of different districts (central, residential or blue-collar neighborhoods, by different age groups.

  14. Experimental study of friction in aluminium bolted joints

    Directory of Open Access Journals (Sweden)

    Vincenzi N.


    Full Text Available This study aims at developing an experimental tool useful to define accurately the friction coefficients in bolted joints and, therefore, at relating precisely the tightening torque to the bolt preloading force in some special components used in front motorbike suspensions. The components under investigation are some clamped joints made of aluminium alloy. The preloading force is achieved by applying a torque wrench to the bolt head. Some specific specimens have been appropriately designed and realized in order to study the tribological aspects of the tightening phase. Experimental tests have been performed by applying the Design of Experiment (DOE method in order to obtain a mathematical model for the friction coefficients. Three replicas of a full factorial DOE at two levels for each variable have been carried out. The levels include cast versus forged aluminium alloy, anodized versus spray-painted surface, lubricated versus unlubricated screw, and first tightening (fresh unspoiled surfaces versus sixth tightening (spoiled surfaces. The study considers M8x1.25 8.8 galvanized screws.

  15. Experimental Studies of Phase Equilibria of Meteorites and Planetary Bodies (United States)

    Stolper, Edward M.


    The primary theme of this project was the application of experimental petrology and geochemistry to a variety of problems in meteoritics and planetary geology. The studies were designed to help develop constraints on the histories of primitive meteorites and their components, the environments in which they formed and evolved, and to understand quantitatively the processes involved in the evolution of igneous rocks on the earth and other planetary bodies. We undertook several projects relating to the origin of CAIs and chondrules. Systematics in the thermodynamic properties of CAI-like liquids were investigated and used to elucidate speciation of multi-valent cations and sulfide capacity of silicate melts and to constrain redox conditions and the vapor pressures of volatile species over molten chondrules. We experimentally determined vanadium speciation in meteoritic pyroxenes and in pyroxenes crystallized from CAI-like melts under very reducing conditions. We also found that bulk oxygen isotope compositions of chondrules in the moderately unequilibrated LL chondrites are related to the relative timing of plagioclase crystallization. We completed an experimental study on the vaporization of beta-SiC and SiO2 (glass or cristobalite) in reducing gases and established the conditions under which these presolar grains could have survived in the solar nebula. We expanded our technique for determining the thermodynamic properties of minerals and liquids to iron-bearing systems. We determined activity-composition relationships in Pt-Fe, Pt-Cr and Pt-Fe-Cr alloys. Results were used to determine the thermodynamic properties of chromite-picrochromite spinels including the free energy of formation of end-member FeCr2O4. We also established a new approach for evaluating Pt-Fe saturation experiments. We calculated the T-fO2 relationships in equilibrated ordinary chondrites and thereby constrained the conditions of metamorphism in their parent bodies.

  16. Biodiversity mediates top-down control in eelgrass ecosystems: a global comparative-experimental approach. (United States)

    Duffy, J Emmett; Reynolds, Pamela L; Boström, Christoffer; Coyer, James A; Cusson, Mathieu; Donadi, Serena; Douglass, James G; Eklöf, Johan S; Engelen, Aschwin H; Eriksson, Britas Klemens; Fredriksen, Stein; Gamfeldt, Lars; Gustafsson, Camilla; Hoarau, Galice; Hori, Masakazu; Hovel, Kevin; Iken, Katrin; Lefcheck, Jonathan S; Moksnes, Per-Olav; Nakaoka, Masahiro; O'Connor, Mary I; Olsen, Jeanine L; Richardson, J Paul; Ruesink, Jennifer L; Sotka, Erik E; Thormar, Jonas; Whalen, Matthew A; Stachowicz, John J


    Nutrient pollution and reduced grazing each can stimulate algal blooms as shown by numerous experiments. But because experiments rarely incorporate natural variation in environmental factors and biodiversity, conditions determining the relative strength of bottom-up and top-down forcing remain unresolved. We factorially added nutrients and reduced grazing at 15 sites across the range of the marine foundation species eelgrass (Zostera marina) to quantify how top-down and bottom-up control interact with natural gradients in biodiversity and environmental forcing. Experiments confirmed modest top-down control of algae, whereas fertilisation had no general effect. Unexpectedly, grazer and algal biomass were better predicted by cross-site variation in grazer and eelgrass diversity than by global environmental gradients. Moreover, these large-scale patterns corresponded strikingly with prior small-scale experiments. Our results link global and local evidence that biodiversity and top-down control strongly influence functioning of threatened seagrass ecosystems, and suggest that biodiversity is comparably important to global change stressors. © 2015 John Wiley & Sons Ltd/CNRS.

  17. Estudo comparativo da eficácia do etanol e do ácido L-glutâmico na prevenção da calcificação das cúspides e parede aórtica porcina: estudo experimental em ratos Comparative study on the efficacy of ethanol and of l-glutamic acid for preventing calcification of pig cusps and aortic wall: experimental study in rats

    Directory of Open Access Journals (Sweden)

    George Ronald Soncini da ROSA


    álcio/ mg tecido, E80% 30 dias (9,47 ± 2,59mg cálcio/mg tecido e E80% 60 dias (23,56±7,75 mg cálcio/mg tecido no grupo de AG 0,8% 15 dias (4,31±0,85 mg cálcio/mg tecido, AG 0,8% 30 dias (7,69±1,48 mg cálcio/mg tecido e AG 0,8% 60 dias (20,50± 1,22 mg cálcio/mg tecido com o grupo controle GDA 15 dias (7,34±1,32 mg cálcio/mg tecido, GDA 30 dias (9,28±0,76 mg cálcio/mg tecido e GDA 60 dias (27,60±1,08 mg cálcio/mg tecido. Na avaliação microscópica da cúspide aórtica houve uma progressiva calcificação naquelas submetidas à fixação com GDA. Este processo foi parcialmente encontrado com o AG 0,8% e totalmente ausente com o E80%. Quanto à avaliação referente aos segmentos da parede aórtica, também evidenciou-se progressiva calcificação, não sendo inibida pelos tratamentos com AG 0,8% e E80%. CONCLUSÕES: O pré-tratamento com etanol a 80% inibiu a calcificação nas cúspides aórticas porcinas, entretanto, não teve a mesma eficácia na parede aórtica. Contudo, o ácido L-glutâmico a 0,8% demonstrou minimizar a calcificação na parede aórtica. Estudos devem ser feitos para evidenciar se a ação anticalcificante do etanol a 80% mantém-se nas biopróteses aórticas porcinas se estas forem implantadas no sistema circulatório.INTRODUCTION: The glutataldehyde (GDA treated pigs cusps are one of most employed tissues in bioprosthesis, but is late post-implant calcification is main cause of its failure. BACKGROUND: This study aims at comparing and analyzing two methods (ethanol 80% and l-glutamic acid 0.8% to prevent calcification in pig cusps and aortic wall implanted subcutaneously in rats, the cusps and aortic wall segments of the control were in glutaraldehyde (GDA, during a 15, 30 and 60 days period after the implant. MATERIAL AND METHODS: We used 45 young rats, distributed in 3 groups of 15 rats each, which in turn were subdivided in 3 subgroups of 5 rats each, in which we implanted one cusp and one aortic wall segment in 2 subcutaneous

  18. Immunotoxicology of arc welding fume: worker and experimental animal studies. (United States)

    Zeidler-Erdely, Patti C; Erdely, Aaron; Antonini, James M


    Arc welding processes generate complex aerosols composed of potentially hazardous metal fumes and gases. Millions of workers worldwide are exposed to welding aerosols daily. A health effect of welding that is of concern to the occupational health community is the development of immune system dysfunction. Increased severity, frequency, and duration of upper and lower respiratory tract infections have been reported among welders. Specifically, multiple studies have observed an excess mortality from pneumonia in welders and workers exposed to metal fumes. Although several welder cohort and experimental animal studies investigating the adverse effects of welding fume exposure on immune function have been performed, the potential mechanisms responsible for these effects are limited. The objective of this report was to review both human and animal studies that have examined the effect of welding fume pulmonary exposure on local and systemic immune responses.

  19. Experimental and trial-based study of Resilient Packet Ring (United States)

    Ramnath, Vasudha; Cheng, Heng Seng; Ngoh, Lek Heng


    An experimental study of the Resilient Packet Ring (RPR) media access control (MAC) technology that is optimized for IP traffic in the metropolitan-area-network (MAN) environment is described. The study involved the deployment and trials of a RPR testbed encompassing a public optical fiber infrastructure in which Cisco Systems' Dynamic Packet Transport (DPT) Ring Technology - a prestandard RPR implementation - was used. We focus on a number of important RPR protocol features that are vital to the future success of RPR as a MAN/wide-area-network (WAN) network technology. Related research on RPR/DPT has been done so far through simulation studies only. Standardization of RPR is currently being performed by the Institute of Electrical and Electronics Engineers (IEEE) 802.17 working group and is expected to be completed in 2003. Also, we present and discuss the experiments and tests performed to investigate the key features of RPR, along with the results obtained.

  20. Immunotoxicology of arc welding fume: Worker and experimental animal studies (United States)

    Zeidler-Erdely, Patti C.; Erdely, Aaron; Antonini, James M.


    Arc welding processes generate complex aerosols composed of potentially hazardous metal fumes and gases. Millions of workers worldwide are exposed to welding aerosols daily. A health effect of welding that is of concern to the occupational health community is the development of immune system dysfunction. Increased severity, frequency, and duration of upper and lower respiratory tract infections have been reported among welders. Specifically, multiple studies have observed an excess mortality from pneumonia in welders and workers exposed to metal fumes. Although several welder cohort and experimental animal studies investigating the adverse effects of welding fume exposure on immune function have been performed, the potential mechanisms responsible for these effects are limited. The objective of this report was to review both human and animal studies that have examined the effect of welding fume pulmonary exposure on local and systemic immune responses. PMID:22734811