WorldWideScience

Sample records for experimental studies part

  1. Creep investigation of GFRP RC Beams - Part A : Literature review and experimental Study

    Directory of Open Access Journals (Sweden)

    masmoudi abdelmonem

    2014-11-01

    This paper (Part A presents a literature review and the loading history of six experimental beams reinforced with GFRP and steel bars. The results of this study revealed that Beams reinforced with GFRP are less marked with creep phenomenon.  This investigation should guide the civil engineer/designer for a better understanding creep phenomenon in GFRP reinforced concrete members.

  2. Combustion Behaviour of Pulverised Wood - Numerical and Experimental Studies. Part 1 Numerical Study

    Energy Technology Data Exchange (ETDEWEB)

    Elfasakhany, A.; Xue-Song Bai [Lund Inst. of Tech. (Sweden). Dept. of Heat and Power Engineering

    2002-12-01

    This report describes a theoretical/numerical investigation of the particle motion and the particle drying, pyrolysis, oxidation of volatile and char in a pulverised biofuel (wood) flame. This work, along with the experimental measurement of a pulverised wood flame in a vertical furnace at TPS, is supported by the Swedish Energy Agency, STEM. The fundamental combustion process of a pulverised wood flame with determined size distribution and anisotropy character is studied. Comprehensive submodels are studied and some models not available in the literature are developed. The submodels are integrated to a CFD code, previously developed at LTH. The numerical code is used to simulate the experimental flame carried out at TPS (as sub-task 2 within the project). The sub-models describe the drying, devolatilization, char formation of wood particles, and the oxidation reaction of char and the gas phase volatile. At the present stage, the attention is focused on the understanding and modelling of non-spherical particle dynamics and the drying, pyrolysis, and oxidation of volatile and char. Validation of the sub-models against the experimental data is presented and discussed in this study. The influence of different factors on the pulverised wood flame in the TPS vertical furnace is investigated. This includes shape of the particles, the effect of volatile release, as well as the orientation of the particles on the motion of the particles. The effect of particle size on the flame structure (distribution of species and temperature along the axis of the furnace) is also studied. The numerical simulation is in close agreement with the TPS experimental data in the concentrations of species O{sub 2}, CO{sub 2} as well as temperature. Some discrepancy between the model simulations and measurements is observed, which suggests that further improvement in our understanding and modeling the pulverised wood flame is needed.

  3. Advanced computational tools for PEM fuel cell design. Part 2. Detailed experimental validation and parametric study

    Science.gov (United States)

    Sui, P. C.; Kumar, S.; Djilali, N.

    This paper reports on the systematic experimental validation of a comprehensive 3D CFD-based computational model presented and documented in Part 1. Simulations for unit cells with straight channels, similar to the Ballard Mk902 hardware, are performed and analyzed in conjunction with detailed current mapping measurements and water mass distributions in the membrane-electrode assembly. The experiments were designed to display sensitivity of the cell over a range of operating parameters including current density, humidification, and coolant temperature, making the data particularly well suited for systematic validation. Based on the validation and analysis of the predictions, values of model parameters, including the electro-osmotic drag coefficient, capillary diffusion coefficient, and catalyst specific surface area are determined adjusted to fit experimental data of current density and MEA water content. The predicted net water flux out of the anode (normalized by the total water generated) increases as anode humidification water flow rate is increased, in agreement with experimental results. A modification of the constitutive equation for the capillary diffusivity of water in the porous electrodes that attempts to incorporate the experimentally observed immobile (or irreducible) saturation yields a better fit of the predicted MEA water mass with experimental data. The specific surface area parameter used in the catalyst layer model is found to be effective in tuning the simulations to predict the correct cell voltage over a range of stoichiometries.

  4. The Mallory body: morphological, clinical and experimental studies (Part 1 of a literature survey)

    DEFF Research Database (Denmark)

    Jensen, K; Gluud, C

    1994-01-01

    suggest a hit-and-run effect of alcohol, whereas other chronic liver diseases show evidence of gradual increase in prevalence of Mallory bodies with severity of hepatic pathology. Mallory bodies in cirrhosis do not imply alcoholic pathogenesis. Obesity, however, is associated with alcoholism and diabetes......, and Mallory bodies are only present in diabetic patients if alcoholism or obesity complicates the condition. In addition, case studies on diseases in which Mallory bodies have been identified, along with pharmacological side effects and experimental induction of Mallory bodies by various antimitotic......To aid understanding of markers of disease and predictors of outcome in alcohol-exposed systems, we undertook a literature survey of more than 700 articles to view the morphological characteristics and the clinical and experimental epidemiology of the Mallory body. Mallory bodies are filaments...

  5. Experimental Studies on Assemblies 1 and 2 of the Fast Reactor FR-0. Part 2

    Energy Technology Data Exchange (ETDEWEB)

    Hellstrand, E.; Andersson, T.L.; Brunfelter, B.; Kockum, J.; Londen, S.O.; Tiren, L.I.

    1965-12-15

    In a first part of this report, published as AE-195, an account was given of critical mass determinations and measurements of flux distribution and reaction ratios in the first assemblies of the fast zero power reactor FR0. This second part of the report deals with various investigations involving the measurement of reactivity. Control rod calibrations have been made using the positive period, the inverse multiplication, the rod drop and the pulsed source techniques, and show satisfactory agreement between the various methods. The reactivity worths of samples of different materials and different sizes have been measured at the core centre. Comparisons with perturbation calculations show that the regular and adjoint fluxes are well predicted in the central region of the core. The variation in the prompt neutron life-time with reactivity has been studied by means of the pulsed source and the Rossi-{alpha} techniques. Comparison with one region calculations reveals large discrepancies, indicating that this simple model is inadequate. Some investigations of streaming effects in an empty channel in the reactor and of interaction effects between channels have been made and are compared with theoretical estimates. Measurements of the reactivity worth of an air gap between the reactor halves and of the temperature coefficient are also described in the report. The work has been performed as a joint effort by AB Atomenergi and the Research Institute of National Defence.

  6. Feasibility Study of a Novel Membrane Reactor for Syngas Production. Part 1: Experimental Study of O2 Permeation through Perovskite Membranes under Reducing and Non-Reducing Atmospheres

    NARCIS (Netherlands)

    Zhang Wenxing, Z.W.; Zhang, Wenxing; Smit, J.; van Sint Annaland, M.; Kuipers, J.A.M.

    2007-01-01

    In this contribution, the feasibility of a novel membrane reactor for energy efficient syngas production is investigated by means of an experimental and a simulation study. In Part 1, a detailed experimental study is performed on the O2 permeation through a perovskite membrane with composition

  7. Sensory perception in cetaceans: Part II – Promising experimental approaches to study chemoreception in dolphins

    Directory of Open Access Journals (Sweden)

    Dorothee eKremers

    2016-05-01

    Full Text Available Chemosensory perception in cetaceans remains an intriguing issue as morphological, neuroanatomical and genetic studies draw unclear conclusions, while behavioral data suggest that dolphins may use it for food selection or socio-sexual interactions. Experimental approaches have been scarce due to the practical difficulties of testing chemoreception in wild dolphins. Go/no-go tasks are one elegant way to investigate discrimination abilities; however, they require to train the animals, thus preventing spontaneous responses and hence the expression of preferences. Here, we aimed at testing potential spontaneous responses to chemical stimuli and developed novel procedures. First, we conducted a study to test whether captive dolphins respond to a biologically relevant smell. Therefore, we placed dead fish within an opaque barrel at the border of the pool and counted the number of respirations at proximity as an indicator of investigation. The same dead fishes were presented several times during experiments lasting three consecutive days. From the second day on (i.e. when the odor composition changed, dolphins breathed more often close to the fish-smelling barrel than close to the visually identical but empty control barrel. Second, we conducted a study to test whether dolphins are able to discriminate food flavors. Captive dolphins are commonly provided with ice cubes as a source of enrichment. We took this opportunity to provide ice cubes with different flavors and to compare the reaction to these different flavors as a measure of discrimination. Hence, we used the latency of return to the ice cube begging spot as a measure of discrimination from the previous ice cube flavor. Thus, our method used a non-invasive and easily replicable technique based on the spontaneous begging responses of dolphins toward more or less attractive items bearing biological relevance. The procedures used enabled us to show that dolphins may discriminate odors and flavors

  8. Variable Modal Parameter Identification for Non-Linear Mdof Systems. Part II: Experimental Validation and Advanced Case Study

    Directory of Open Access Journals (Sweden)

    Y.H. Chong

    2000-01-01

    Full Text Available The purpose of Part II is to provide an experimental validation of the methodology presented in Part I and to consider a representative engineering case, the study of which requires a relatively large numerical model. A beam system with cubic stiffness type non-linearity was used in the experimental study. The non-linear response was measured at three locations and the underlying linear system was obtained via linear modal analysis of low-excitation response data. The non-linear parameter variations were obtained as a function of the modal amplitude and the response of the system was generated for other force levels. The results were found to agree very well with the corresponding measurements, indicating the success of the non-linear modal analysis methodology, even in the presence of true experimental noise. An advanced numerical case study that included both inherent structural damping and non-linear friction damping, was considered next. The linear finite element model of a high-pressure turbine blade was used in conjunction with three local non-linear friction damper elements. It was shown that the response of the system could be predicted at any force level, provided that that non-linear modal parameters were available at some reference force level. The predicted response levels were compared against those obtained from reference simulations and very good agreement was achieved in all cases.

  9. Experimental Study of Residual Stresses in Metal Parts Obtained by Selective Laser Melting

    Science.gov (United States)

    Protasov, C. E.; Safronov, V. A.; Kotoban, D. V.; Gusarov, A. V.

    High local temperature gradients occur at additive manufacturing by selective laser melting of powder. This gives rise to undesirable residual stresses, deformations, and cracks. To understand how to control the formation of the residual stresses, a reliable method is necessary for measuring their distribution in the fabricated part. It is proposed to cut the part into thin plates and to reconstruct the residual stresses from the measured deformation of the plates. This method is tested on beams with square cross-section built from stainless steel. The beams were cut by electrical discharge machining and chemically etched. The obtained stress profile in vertical transversal direction slightly increases from the top to the bottom of the beam. This dependency is confirmed by numerical modeling. The measured stress profile agrees with the known results by other authors.

  10. An experimental and modeling study of propene oxidation. Part 2: Ignition delay time and flame speed measurements

    KAUST Repository

    Burke, Sinéad M.

    2015-02-01

    Experimental data obtained in this study (Part II) complement the speciation data presented in Part I, but also offer a basis for extensive facility cross-comparisons for both experimental ignition delay time (IDT) and laminar flame speed (LFS) observables. To improve our understanding of the ignition characteristics of propene, a series of IDT experiments were performed in six different shock tubes and two rapid compression machines (RCMs) under conditions not previously studied. This work is the first of its kind to directly compare ignition in several different shock tubes over a wide range of conditions. For common nominal reaction conditions among these facilities, cross-comparison of shock tube IDTs suggests 20-30% reproducibility (2σ) for the IDT observable. The combination of shock tube and RCM data greatly expands the data available for validation of propene oxidation models to higher pressures (2-40. atm) and lower temperatures (750-1750. K).Propene flames were studied at pressures from 1 to 20. atm and unburned gas temperatures of 295-398. K for a range of equivalence ratios and dilutions in different facilities. The present propene-air LFS results at 1. atm were also compared to LFS measurements from the literature. With respect to initial reaction conditions, the present experimental LFS cross-comparison is not as comprehensive as the IDT comparison; however, it still suggests reproducibility limits for the LFS observable. For the LFS results, there was agreement between certain data sets and for certain equivalence ratios (mostly in the lean region), but the remaining discrepancies highlight the need to reduce uncertainties in laminar flame speed experiments amongst different groups and different methods. Moreover, this is the first study to investigate the burning rate characteristics of propene at elevated pressures (>5. atm).IDT and LFS measurements are compared to predictions of the chemical kinetic mechanism presented in Part I and good

  11. Thermal conductivity of catalyst layer of polymer electrolyte membrane fuel cells: Part 1 - Experimental study

    Science.gov (United States)

    Ahadi, Mohammad; Tam, Mickey; Saha, Madhu S.; Stumper, Jürgen; Bahrami, Majid

    2017-06-01

    In this work, a new methodology is proposed for measuring the through-plane thermal conductivity of catalyst layers (CLs) in polymer electrolyte membrane fuel cells. The proposed methodology is based on deconvolution of bulk thermal conductivity of a CL from measurements of two thicknesses of the CL, where the CLs are sandwiched in a stack made of two catalyst-coated substrates. Effects of hot-pressing, compression, measurement method, and substrate on the through-plane thermal conductivity of the CL are studied. For this purpose, different thicknesses of catalyst are coated on ethylene tetrafluoroethylene (ETFE) and aluminum (Al) substrates by a conventional Mayer bar coater and measured by scanning electron microscopy (SEM). The through-plane thermal conductivity of the CLs is measured by the well-known guarded heat flow (GHF) method as well as a recently developed transient plane source (TPS) method for thin films which modifies the original TPS thin film method. Measurements show that none of the studied factors has any effect on the through-plane thermal conductivity of the CL. GHF measurements of a non-hot-pressed CL on Al yield thermal conductivity of 0.214 ± 0.005 Wṡm-1ṡK-1, and TPS measurements of a hot-pressed CL on ETFE yield thermal conductivity of 0.218 ± 0.005 Wṡm-1ṡK-1.

  12. Experimental Studies for Determining Gas Flow Rate Accidental Release on Linear Part of Pipeline

    Science.gov (United States)

    Fetisov, V. G.; Nikolaev, A. K.; Lykov, Y. V.

    2017-10-01

    The method of determining the flow rate of gas in the gas-dynamic resistance of a medium gas stream with high linear speed was studied. The reduction of the density of the gas is a result of its expansion. Multiple calculations of gas losses were evaluated. Calculation is set by loss of gas depending on the area of the pipeline damage. A comparative analysis was done. In order to establish a functional empirical dependence of the flow rate on the whole on the parameters of the leakage process, a series of experiments was conducted on a test bench and their processing was carried out. In experiments conducted, the effect of pressure and temperature in the receiver was evaluated, the physical properties of the gas and the diameter of the hole were predetermined by the limits of the amount of the whole flow rate in critical conditions, as well as the critical regime of gas leakage.

  13. Temporomandibular joint reconstruction with a 2-part chrome-cobalt prosthesis, chondro-osseous graft, and silastic: clinical and experimental studies.

    Science.gov (United States)

    Kummoona, Raja

    2009-11-01

    Seventy-six patients including 27 females and 49 males, with ages ranging between 4 and 35 years (mean, 19.5 y), all experienced loss of weight, stiff temporomandibular joints and inability to chew food, and facial deformities. These patients were treated in the Maxillofacial Unit, Surgical Specialties Hospital, Medical City, Baghdad, Iraq, using 4 different techniques according to the requirement of each case and the facilities available. These patients were divided into 4 groups: the first group consists of 16 children (21.06%) treated with a chondro-osseous graft; the second group, 10 children (13.16%) treated with a 2-part chrome-cobalt prosthesis; the third group, 32 children (42.11%) treated with a Sialastic rubber silicone implant (Koken Co, Tokyo, Japan); and the fourth group, 18 children (23.69%) treated with interposition arthroplasty with a temporalis muscle flap. The follow-up period of the cases ranged between 3 and 15 years. Experimental studies were done on using rabbits to assess the viability of the chondro-osseous graft and on monkeys to demonstrate the biological acceptability of the 2-part chrome-cobalt prosthesis. The aim of this clinical and experimental study was to show our experience in managing difficult tasks that craniofacial or maxillofacial surgeons may face and to share these experiences with other colleagues all over the world.

  14. Effect of systemic administration of nicotine on healing in osseous defects. An experimental study in rabbits. Part II

    DEFF Research Database (Denmark)

    Balatsouka, Dimitra; Gotfredsen, Klaus; Sørensen, Lars

    2006-01-01

    group lost weight, while the control group gained weight during the experiment. The prostaglandin E(2) levels in plasma increased significantly following nicotine exposure in the test group. No significant differences in the percentage of vessels and bone density in the osseous defects were found...... between the test and the control groups after 2 and 4 weeks of healing. CONCLUSIONS: In this experiment, systemic administration of nicotine over 4 or 6 weeks, respectively, influenced body weight and systemic prostaglandin E(2) levels but not the amount of blood vessels and the bone mineral density......OBJECTIVES: The aim of the present study was to analyze the effect of systemic administration of nicotine on bone healing in osseous defects in the tibia of rabbits. MATERIAL AND METHODS: Sixteen female rabbits received nicotine (n=8; test group) or saline (n=8; control group) via subcutaneously...

  15. Biomass-Ash-Induced Agglomeration in a Fluidized Bed. Part 1: Experimental Study on the Effects of a Gas Atmosphere

    DEFF Research Database (Denmark)

    Ma, Teng; Fan, Chuigang; Hao, Lifang

    2016-01-01

    with quartz sand and fluidized by the gas mixtures of N2/CO2, N2/H2, and N2/steam or by air. At 550 °C, the bed temperature is increased at the rate of 3 °C/min until defluidization occurs. In this way, the defluidization temperature can be determined, which represents the agglomeration tendency....... Understanding of the agglomeration in various atmospheres is crucial to optimize the design and operation conditions. This study focuses on the effects of gases on agglomeration tendency with different types of biomass, including corn straw, rice straw, and wheat straw. The biomass ash samples are mixed....... The agglomerates are analyzed by scanning electron microscopy–energy-dispersive X-ray spectrometry (SEM–EDS) for morphology and elemental composition. Significant differences are observed on the defluidization temperature (Td) and agglomeration mechanisms in different gas atmospheres. Td in H2 and steam...

  16. Experimental study of physical and rheological properties of grape juice using different temperatures and concentrations. Part I: Cabernet Sauvignon.

    Science.gov (United States)

    de Castilhos, Maurício Bonatto Machado; Betiol, Lilian Fachin Leonardo; de Carvalho, Gisandro Reis; Telis-Romero, Javier

    2017-10-01

    The effect of the temperature and concentration on rheological behavior of Cabernet Sauvignon juice concentrates was assessed using a rheometer over a wide range of temperature (1-66°C) and concentrations (13.6-45.0Brix) at shear rates of 0.84-212.1 1/s. The Ostwald-De Waele was the best rheological model fitted the data (R 2 =0.99957 and relative error=7.77%). The Cabernet Sauvignon juice concentrates presented a non-Newtonian pseudoplastic behavior (n<1). The consistency levels were significantly reduced with the increase of temperature and increased with the increase of the concentrations. The flow activation energy ranged from 28.87 (45.0Brix) to 38.05KJ/mol (37.0Brix) with a R 2 =0.9798 for both cases. Density and specific heat were influenced by both temperature and concentration; however, thermal conductivity was only influenced by concentration. The Cabernet Sauvignon juice concentrates will be useful as wine chaptalization agent in future studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Indicative properties on snow cover based on the results of experimental studies in the winter 2011/12 in the central part of the East European Plain

    Directory of Open Access Journals (Sweden)

    L. M. Kitaev

    2013-01-01

    Full Text Available Local and regional differences in the snow formation were studied in different landscapes of the central part of the East European Plain – within reserves in the Moscow and Tver’ regions (south-north direction; the study period is the winter 2011/12. The observed increase of snow storage in 1.3–1.5 times in the direction south-north is connected, apparently. The difference in the five-day appearance of snow cover maximum is related to differences in regional winter air temperature. Throughout the snow depth and snow storage in spruce are smaller than in deciduous forest – in the ratio of 0.81 in south area and 0.93 in north area; in spruce the large part of solid precipitation is intercepted by the crowns pine trees. Snow stratigraphy at south areas has four layers, six layers at the north area are more variable in snow density and snow storage. Perhaps, gravitational conversion is more noticeable due to larger snow depth. Snow density and snow storage at the open areas are more heterogeneous than in the forest. This is due to sharp fluctuations in air temperature, wind transport and compaction of snow, evaporation from the snow surface. The stratigraphy of snow also reflects the history of winter changes of air temperature and snow accumulation. Common feature for reserves at south and north is the availability of layers with maximum snow storage in the middle of the snow thickness, which were formed during the air temperature drops to the lowest seasonal values in period with increase of snow depth to maximum. Formation of depth hoar in snow thickness are touched everywhere the bottom and middle layers, respectively, it was formed both before and during the period with minimal air temperature. Thus, the results of experimental studies confirm the significance of the differences of individual components of the landscape setting. Analytical conclusions are largely qualitative in nature due to the lack to date of initial information, and

  18. The Imperial College Cambridge Manchester (ICCAM) platform study: An experimental medicine platform for evaluating new drugs for relapse prevention in addiction. Part A: Study description.

    Science.gov (United States)

    Paterson, Louise M; Flechais, Remy S A; Murphy, Anna; Reed, Laurence J; Abbott, Sanja; Boyapati, Venkataramana; Elliott, Rebecca; Erritzoe, David; Ersche, Karen D; Faluyi, Yetunde; Faravelli, Luca; Fernandez-Egea, Emilio; Kalk, Nicola J; Kuchibatla, Shankar S; McGonigle, John; Metastasio, Antonio; Mick, Inge; Nestor, Liam; Orban, Csaba; Passetti, Filippo; Rabiner, Eugenii A; Smith, Dana G; Suckling, John; Tait, Roger; Taylor, Eleanor M; Waldman, Adam D; Robbins, Trevor W; Deakin, J F William; Nutt, David J; Lingford-Hughes, Anne R

    2015-09-01

    Drug and alcohol dependence are global problems with substantial societal costs. There are few treatments for relapse prevention and therefore a pressing need for further study of brain mechanisms underpinning relapse circuitry. The Imperial College Cambridge Manchester (ICCAM) platform study is an experimental medicine approach to this problem: using functional magnetic resonance imaging (fMRI) techniques and selective pharmacological tools, it aims to explore the neuropharmacology of putative relapse pathways in cocaine, alcohol, opiate dependent, and healthy individuals to inform future drug development. Addiction studies typically involve small samples because of recruitment difficulties and attrition. We established the platform in three centres to assess the feasibility of a multisite approach to address these issues. Pharmacological modulation of reward, impulsivity and emotional reactivity were investigated in a monetary incentive delay task, an inhibitory control task, and an evocative images task, using selective antagonists for µ-opioid, dopamine D3 receptor (DRD3) and neurokinin 1 (NK1) receptors (naltrexone, GSK598809, vofopitant/aprepitant), in a placebo-controlled, randomised, crossover design. In two years, 609 scans were performed, with 155 individuals scanned at baseline. Attrition was low and the majority of individuals were sufficiently motivated to complete all five sessions (n=87). We describe herein the study design, main aims, recruitment numbers, sample characteristics, and explain the test hypotheses and anticipated study outputs. © The Author(s) 2015.

  19. EXPERIMENTAL INVESTIGATIONS FOR MODELLING THE THERMAL FATIGUE PHENOMENON IN MACHINES PARTS OF AUTOMOTIVE ENGINES

    National Research Council Canada - National Science Library

    Camelia Pinca-Bretotean; Lucia Vîlceanu

    2013-01-01

      The purpose of this paper is to present some experimental investigations for validate an experimental plant designed and built for study the thermal fatigue phenomenon that occurs in machines parts...

  20. A micromachined capacitive incremental position sensor: part 2. experimental assessment

    NARCIS (Netherlands)

    Kuijpers, A.A.; Krijnen, Gijsbertus J.M.; Wiegerink, Remco J.; Lammerink, Theodorus S.J.; Elwenspoek, Michael Curt

    2006-01-01

    Part 2 of this two-part paper presents the experimental assessment of a micromachined capacitive incremental position sensor for nanopositioning of microactuator systems with a displacement range of 100 μm or more. Incremental sensing in combination with quadrature detection reduces the requirements

  1. Experimental Study of Wave Field Around the Outer Part of a Rubble Mound Roundhead Solution for the new Port of La Coruña at Punto Langosteira

    DEFF Research Database (Denmark)

    Burcharth, Hans F.; Pedersen, Thomas Schmidt

    The wave agitation in the port and at the entrance to the port depends on the length of the outer part of the breakwater (west of the spur breakwater) and on the type of structure, e.g. caissons or rubble mound. In the present study is investigated the wave field around a rubble mound head armoured...

  2. EXPERIMENTAL STUDIES ON INFLAMMATION

    Science.gov (United States)

    Wolf, Elizabeth Pauline

    1923-01-01

    1. None of the salts tested produce a marked inflammation in vivo in concentrations under 10 per cent. Potassium salts and the different citrates produced atypical inflammatory reactions in mice, but not in frogs. There was no true inflammation, however, characterized by blood vessel changes, migration of polymorphonuclear leucocytes and erythrocytes, and fluid exudation. 2. Synergistic action occurs when equal parts of strontium and magnesium salts are employed. There is a change in the appearance of the mesentery without a true inflammation, and this change does not occur with either salt alone. 3. Amino-acids and amines as a class do not produce inflammation, but histamine produces a marked inflammatory reaction in frogs and mice. 4. Tyramine does not cause an inflammatory reaction but has other marked effects; agglutination thrombi occur within the smaller blood vessels, both veins and arteries; in frogs there is a rapid clumping of the white blood cells followed by a true coagulation with strands of fibrin and entanglement of erythrocytes. This is very widespread and often kills the animal within an hour after injection. In mice it is the erythrocytes that clump and coagulation occurs very much later, usually at the end of 24 hours; still later there is complete absorption of the coagulated masses and the mesenteric circulation returns to normal. None of the mice died during the stage of clumping, and the clots never extended up the larger vessels as they did in the frogs. These effects are similar to the phenomena observed in the in vitro work, in which clumping of the cells appeared constantly. 5. Cantharidinum, histamine, and turpentine produced the most rapid and marked inflammation of any substances tried. These substances are all strongly positively chemotactic in vitro. The differences occurring when these substances are used in different species is a quantitative rather than a qualitative one, the body temperature being of some importance. Papain acted

  3. Animal experimentation-Part II: In periodontal research

    Directory of Open Access Journals (Sweden)

    T K Pal

    2015-01-01

    Full Text Available Animals contribute to the development of medical and dental sciences by being sacrificed in the hands of scientists. The experimental design demands a specific type of animal to be used for experimentation. Each animal needs proper handling, care, and diet. Alongside specific advantages and disadvantages pertaining to each type of animal need to be understood well depending on the type of study/experiment. It is important for the researcher to know the disease susceptibility of each animal. The purpose of this paper is to highlight the salient factors that need to be considered for animal experimentations.

  4. Effects of stimulant drugs on actual and simulated driving: perspectives from four experimental studies conducted as part of the DRUID research consortium

    NARCIS (Netherlands)

    Ramaekers, J.G.; Kuypers, K.P.C.; Bosker, W.M.; Brookhuis, K.A.; Veldstra, J.A.; Simons, R.; Martens, Marieke Hendrikje

    2012-01-01

    The Integrated Project DRUID (Driving under the Influence of Drugs, Alcohol and Medicines) involved researchers from more than 20 European countries. It aimed to gain new insights to the degree of impairment caused by psychoactive drugs and their actual impact on road safety. Part of this large

  5. Aspidosperma (Apocynaceae plant cytotoxicity and activity towards malaria parasites. Part II: experimental studies withAspidosperma ramiflorum in vivo and in vitro

    Directory of Open Access Journals (Sweden)

    Anna CC Aguiar

    2015-11-01

    Full Text Available Several species of Aspidospermaplants are used to treat diseases in the tropics, including Aspidosperma ramiflorum, which acts against leishmaniasis, an activity that is experimentally confirmed. The species, known as guatambu-yellow, yellowperoba, coffee-peroba andmatiambu, grows in the Atlantic Forest of Brazil in the South to the Southeast regions. Through a guided biofractionation of A. ramiflorumextracts, the plant activity against Plasmodium falciparumwas evaluated in vitro for toxicity towards human hepatoma G2 cells, normal monkey kidney cells and nonimmortalised human monocytes isolated from peripheral blood. Six of the seven extracts tested were active at low doses (half-maximal drug inhibitory concentration < 3.8 µg/mL; the aqueous extract was inactive. Overall, the plant extracts and the purified compounds displayed low toxicity in vitro. A nonsoluble extract fraction and one purified alkaloid isositsirikine (compound 5 displayed high selectivity indexes (SI (= 56 and 113, respectively, whereas compounds 2 and 3 were toxic (SI < 10. The structure, activity and low toxicity of isositsirikine in vitro are described here for the first time in A. ramiflorum, but only the neutral and precipitate plant fractions were tested for activity, which caused up to 53% parasitaemia inhibition of Plasmodium bergheiin mice with blood-induced malaria. This plant species is likely to be useful in the further development of an antimalarial drug, but its pharmacological evaluation is still required.

  6. Aspidosperma (Apocynaceae) plant cytotoxicity and activity towards malaria parasites. Part II: experimental studies withAspidosperma ramiflorum in vivo and in vitro.

    Science.gov (United States)

    Aguiar, Anna C C; Cunha, Ananda C; Ceravolo, Isabela Penna; Gonçalves, Regina A Correia; Oliveira, Arildo J B; Krettli, Antoniana Ursine

    2015-11-01

    Several species of Aspidosperma plants are used to treat diseases in the tropics, including Aspidosperma ramiflorum, which acts against leishmaniasis, an activity that is experimentally confirmed. The species, known as guatambu-yellow, yellow peroba, coffee-peroba and matiambu, grows in the Atlantic Forest of Brazil in the South to the Southeast regions. Through a guided biofractionation of A. ramiflorum extracts, the plant activity against Plasmodium falciparum was evaluated in vitro for toxicity towards human hepatoma G2 cells, normal monkey kidney cells and nonimmortalised human monocytes isolated from peripheral blood. Six of the seven extracts tested were active at low doses (half-maximal drug inhibitory concentration < 3.8 µg/mL); the aqueous extract was inactive. Overall, the plant extracts and the purified compounds displayed low toxicity in vitro. A nonsoluble extract fraction and one purified alkaloid isositsirikine (compound 5) displayed high selectivity indexes (SI) (= 56 and 113, respectively), whereas compounds 2 and 3 were toxic (SI < 10). The structure, activity and low toxicity of isositsirikine in vitro are described here for the first time in A. ramiflorum, but only the neutral and precipitate plant fractions were tested for activity, which caused up to 53% parasitaemia inhibition of Plasmodium berghei in mice with blood-induced malaria. This plant species is likely to be useful in the further development of an antimalarial drug, but its pharmacological evaluation is still required.

  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

    2017-09-01

    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. An outline of the 1994-1998 European inspection and maintenance study: part i-design, tests, and results of experimental methods

    OpenAIRE

    SAMARAS, Z; ZACHARIADIS, T; JOUMARD, R; HASSEL, D; WEBER, FJ; RIJKEBOER, R

    2001-01-01

    This paper provides an overview and the main results of a study aiming to evaluate current and alternative inspection and maintenance (I/M) programs to control emissions from in-use cars in Europe. For this purpose, a large number of passenger cars from five countries (France, Germany, Greece, the Netherlands, and the United Kingdom) were tested according to a common test protocol that included a variety of driving cycles and short tests, both legislative and specifically developed for this e...

  9. An experimental study on particular physical properties of several interocclusal recording media. Part II: Linear dimensional change and accompanying weight change.

    Science.gov (United States)

    Michalakis, Konstantinos X; Pissiotis, Argiris; Anastasiadou, Vassiliki; Kapari, Danai

    2004-09-01

    The purpose of this study was to evaluate the linear dimensional change and accompanying weight change of several elastomeric interocclusal recording media. Ten 50 mm long, 8 mm wide, 3 mm deep Teflon molds and a stainless steel die were constructed for the purposes of this study. The die was made in order to produce standardized reference lines, which were used for the measurement of the linear change. After homogeneous mixing, each material was carried from the mixing pad or directly from the mixing tip to the Teflon mold. The mold was inverted onto the stainless steel die. The materials were allowed to set for the manufacturers' suggested setting time plus an additional 3 minutes to ensure polymerization of the material. An electronic scale (Galaxy 110, Ohaus, Pine Brook, NJ) was used for the measurement of the weight change of the specimens and a traveling micrometer microscope (Griffin Ltd., London, England) was used to measure the linear changes at 5 time intervals: 0, 1 hour, 24, 48, and 72 hours. Analysis of variance for a significance level of 5% revealed that there was a statistically significant effect of the "material" factor on the weight changes (F= 2,229.98, p Ramitec). Analysis of variance for a significance level of 5% revealed that there is a statistically significant effect of the "material" factor on the linear changes (F= 215.54, p Ramitec). Of all materials tested, Ramitec (polyether) presented the smallest linear change at all time intervals. Addition reaction silicones presented statistically significant differences in recordings of linear changes among them only at the 1st and the 24th hour. Linear changes did not seem to be associated with weight changes.

  10. The ICCAM platform study: An experimental medicine platform for evaluating new drugs for relapse prevention in addiction. Part B: fMRI description.

    Science.gov (United States)

    McGonigle, John; Murphy, Anna; Paterson, Louise M; Reed, Laurence J; Nestor, Liam; Nash, Jonathan; Elliott, Rebecca; Ersche, Karen D; Flechais, Remy Sa; Newbould, Rexford; Orban, Csaba; Smith, Dana G; Taylor, Eleanor M; Waldman, Adam D; Robbins, Trevor W; Deakin, Jf William; Nutt, David J; Lingford-Hughes, Anne R; Suckling, John

    2017-01-01

    We aimed to set up a robust multi-centre clinical fMRI and neuropsychological platform to investigate the neuropharmacology of brain processes relevant to addiction - reward, impulsivity and emotional reactivity. Here we provide an overview of the fMRI battery, carried out across three centres, characterizing neuronal response to the tasks, along with exploring inter-centre differences in healthy participants. Three fMRI tasks were used: monetary incentive delay to probe reward sensitivity, go/no-go to probe impulsivity and an evocative images task to probe emotional reactivity. A coordinate-based activation likelihood estimation (ALE) meta-analysis was carried out for the reward and impulsivity tasks to help establish region of interest (ROI) placement. A group of healthy participants was recruited from across three centres (total n=43) to investigate inter-centre differences. Principle observations: The pattern of response observed for each of the three tasks was consistent with previous studies using similar paradigms. At the whole brain level, significant differences were not observed between centres for any task. In developing this platform we successfully integrated neuroimaging data from three centres, adapted validated tasks and applied whole brain and ROI approaches to explore and demonstrate their consistency across centres.

  11. A vapourized Δ(9)-tetrahydrocannabinol (Δ(9)-THC) delivery system part I: development and validation of a pulmonary cannabinoid route of exposure for experimental pharmacology studies in rodents.

    Science.gov (United States)

    Manwell, Laurie A; Charchoglyan, Armen; Brewer, Dyanne; Matthews, Brittany A; Heipel, Heather; Mallet, Paul E

    2014-01-01

    Most studies evaluating the effects of Δ(9)-tetrahydrocannabinol (Δ(9)-THC) in animal models administer it via a parenteral route (e.g., intraperitoneal (IP) or intravenous injection (IV)), however, the common route of administration for human users is pulmonary (e.g., smoking or vapourizing marijuana). A vapourized Δ(9)-THC delivery system for rodents was developed and used to compare the effects of pulmonary and parenteral Δ(9)-THC administration on blood cannabinoid levels and behaviour. Sprague-Dawley rats were exposed to pulmonary Δ(9)-THC (1, 5, and 10mg of inhaled vapour) delivered via a Volcano® vapourizing device (Storz and Bickel, Germany) or to parenteral Δ(9)-THC (0.25, 0.5, 1.0, and 1.5mg/kg injected IP). Quantification of Δ(9)-THC and its psychoactive metabolite, 11-hydroxy-Δ(9)-THC (11-OH-Δ(9)-THC), in blood was determined by liquid chromatography/mass spectrometry (LC/MS). In order to verify the potential for the vapourization procedure to produce a robust conditioned place preference (CPP) or conditioned place avoidance CPA, classical conditioning procedures were systematically varied by altering the exposure time (10 or 20min) and number of exposed rats (1 or 2) while maintaining the same vapourization dose (10mg). Blood collected at 20min intervals showed similar dose-dependent and time-dependent changes in Δ(9)-THC and 11-OH-Δ(9)-THC for both pulmonary and parenteral administration of Δ(9)-THC. However, vapourized Δ(9)-THC induced CPP under certain conditions whereas IP-administered Δ(9)-THC induced CPA. These results support and extend the limited evidence (e.g., in humans, Naef et al., 2004; in rodents, Niyuhire et al., 2007) that Δ(9)-THC produces qualitatively different effects on behaviour depending upon the route of administration. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. EXPERIMENTAL STUDY IN NATURAL CONVECTION

    African Journals Online (AJOL)

    PROF. BARTH EKWEME

    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. Experimental design strategy a part of an innovative construction industry

    NARCIS (Netherlands)

    Maarten Gjaltema; Rogier Laterveer; Dr Ruben Vrijhoef

    2013-01-01

    From the article: Abstract. This exploratory and conceptual article sets out to research what arguments and possibilities for experimentation in construction exists and if experimentation can contribute towards more innovative construction as a whole. Traditional, -western- construction is very

  14. Experimental Design Strategy As Part of an Innovative Construction Industry

    NARCIS (Netherlands)

    Rogier Laterveer

    2013-01-01

    This exploratory and conceptual article sets out to research what arguments and possibilities for experimentation in construction exists and if experimentation can contribute towards more innovative construction as a whole. Traditional, -western- construction is very conservative and regional, often

  15. Hot forming of composite prepreg : Experimental study

    Science.gov (United States)

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

    2017-10-01

    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.

  16. Experimental study of vortex diffusers

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-11-01

    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.

  17. Experimental Investigation of Charpy Impact Tests on Metallic SLM parts

    OpenAIRE

    Yasa, Evren; Deckers, Jan; Kruth, Jean-Pierre; Rombouts, Marleen; Luyten, Jan

    2009-01-01

    Selective laser melting (SLM) is a layer-additive manufacturing technology making it possible to create fully functional parts directly from standard metal powders without using any intermediate binders or any additional post-processing steps. During the process, a laser source selectively scans a powder bed according to the CAD data of the part to be produced and powder particles are completely molten by a high intensity laser beam. SLM is capable of producing near full density metallic part...

  18. Experimental study on partial coherence source

    CERN Document Server

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

    2002-01-01

    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

  19. Experimental study of snow friction

    Science.gov (United States)

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

    2017-11-01

    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.

  20. Utilização do planejamento experimental no estudo do efeito da composição de misturas de bentonitas na reologia de fluidos de perfuração. Parte II: composições ternárias Experimental design applied to the study of composition effect of bentonite on the rheology of drilling fluids. Part II: ternary compositions

    Directory of Open Access Journals (Sweden)

    L. F. A. Campos

    2007-03-01

    Full Text Available O objetivo deste trabalho foi utilizar o planejamento experimental para avaliar o efeito da composição de misturas ternárias de bentonitas na reologia de fluidos de perfuração de poços de petróleo. Por meio do planejamento foram determinadas as proporções dos componentes nas misturas ternárias das argilas e então ajustados modelos de regressão relacionando viscosidade aparente, viscosidade plástica e volume de filtrado com a proporção de cada argila. A aplicação da modelagem de misturas, incluindo composições ternárias, aliada a metodologia de superfícies de resposta e otimização matemática e gráfica permitiu delimitar uma gama de composições de argilas que favorece a melhoria das propriedades reológicas e de filtração dos fluidos estudados.The purpose of this work was to study of composition effect of ternary bentonite mixtures on the rheology of drilling fluids. Through the experimental design were defined the components proportions in the ternary clays mixtures and then adjusted regression models relating apparent and plastic viscosities and water loss, with the proportion of each clay. The application of mixture experimental design, include ternary composition, response surface methodology, graphic and mathematical optimization allowed to delimit a strip of compositions that favors the improvement of the rheological properties of the drilling fluids.

  1. Contact Modelling in Resistance Welding, Part II: Experimental Validation

    DEFF Research Database (Denmark)

    Song, Quanfeng; Zhang, Wenqi; Bay, Niels

    2006-01-01

    Contact algorithms in resistance welding presented in the previous paper are experimentally validated in the present paper. In order to verify the mechanical contact algorithm, two types of experiments, i.e. sandwich upsetting of circular, cylindrical specimens and compression tests of discs...... with a solid ring projection towards a flat ring, are carried out at room temperature. The complete algorithm, involving not only the mechanical model but also the thermal and electrical models, is validated by projection welding experiments. The experimental results are in satisfactory agreement...... with the simulation prediction, showing the validity of the algorithm....

  2. Experimental design in analytical chemistry--part I: theory.

    Science.gov (United States)

    Ebrahimi-Najafabadi, Heshmatollah; Leardi, Riccardo; Jalali-Heravi, Mehdi

    2014-01-01

    This paper reviews the main concepts of experimental design applicable to the optimization of analytical chemistry techniques. The critical steps and tools for screening, including Plackett-Burman, factorial and fractional factorial designs, and response surface methodology such as central composite, Box-Behnken, and Doehlert designs, are discussed. Some useful routines are also presented for performing the procedures.

  3. Advances in Unsteady Boundary Layer Transition Research, Part II: Experimental Verification

    Directory of Open Access Journals (Sweden)

    M. T. Schobeiri

    2003-01-01

    Full Text Available This two-part article presents recent advances in boundary layer research into the unsteady boundary layer transition modeling and its validation. This, Part II, deals with the results of an inductive approach based on comprehensive experimental and theoretical studies of unsteady wake flow and unsteady boundary layer flow. The experiments were performed on a curved plate at a zero streamwise pressure gradient under periodic unsteady wake flow, in which the frequency of the periodic unsteady flow was varied. To validate the model, systematic experimental investigations were performed on the suction and pressure surfaces of turbine blades integrated into a high-subsonic cascade test facility, which was designed for unsteady boundary layer investigations. The analysis of the experiment's results and comparison with the model's prediction confirm the validity of the model and its ability to predict accurately the unsteady boundary layer transition.

  4. Experimental Infrasound Studies in Nevada

    Science.gov (United States)

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

    2009-12-01

    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.

  5. Nuestra Comunidad: Primaria para Adultos. Segunda Parte. Edicion Experimental (Our Community: Primer for Adults. Part Two. Experimental Edition).

    Science.gov (United States)

    Instituto Nacional para la Educacion de los Adultos, Mexico City (Mexico).

    This textbook is part of a Mexican series of instructional materials designed for Spanish speaking adults who are in the process of becoming literate or have recently become literate in their native language. It is designed to teach people with developing literacy skills to participate in a meaningful way in the life of their community. Topics…

  6. Nuestra Familia: Primaria para Adultos. Segunda Parte. Edicion Experimental (Our Family: Primer for Adults. Part Two. Experimental Edition).

    Science.gov (United States)

    Instituto Nacional para la Educacion de los Adultos, Mexico City (Mexico).

    This textbook is part of a Mexican series of instructional materials designed for Spanish speaking adults who are in the process of becoming literate or have recently become literate in their native language. It is designed to orient people with little education or developing literacy skills to a sense of responsibility toward their families.…

  7. Nuestro Trabajo: Primaria para Adultos. Segunda Parte. Edicion Experimental (Our Work: Primer for Adults. Part Two. Experimental Edition).

    Science.gov (United States)

    Instituto Nacional para la Educacion de los Adultos, Mexico City (Mexico).

    This workbook is part of a Mexican series of instructional materials designed for Spanish speaking adults who are in the process of becoming literate or have recently become literate in their native language. This workbook is designed to orient people who are only recently literate to the world of work and business. Topics covered include worker…

  8. EXPERIMENTAL STUDY IN NATURAL CONVECTION

    African Journals Online (AJOL)

    PROF. BARTH EKWEME

    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.

  9. Experimental and Numerical Investigations in Single Point Incremental Sheet Forming For Micro parts

    Science.gov (United States)

    Dejardin, S.; Thibaud, S.; Gelin, J. C.

    2007-04-01

    Incremental Sheet Forming processes have been demonstrated in recent studies as a very promising technology to manufacture sheet metal parts by the CNC controlled movement of a simple generative tool. In glance with its various advantages, such process has been introduced as an alternative to reduce costs resulting from stamping technology when small batches or prototypes have to be manufactured. In this paper, an application is carried out accounting flexibility of the process linked to the fact that the punches or dies are avoided. Although the process still needs a further optimization, preliminary results have been obtained through experimental tests to manufacture micro parts. At the same time, a FEM analysis has been carried out in order to get the characteristics of the formed parts.

  10. An experimental data set for benchmarking 1-D, transient heat and moisture transfer models of hygroscopic building materials. Part II: Experimental, numerical and analytical data

    Energy Technology Data Exchange (ETDEWEB)

    Talukdar, Prabal [Department of Mechanical Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016 (India); Osanyintola, Olalekan F. [XXL Engineering Ltd., 101-807 Manning Road NE, Calgary, AB (Canada); Olutimayin, Stephen O.; Simonson, Carey J. [Department of Mechanical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK (Canada)

    2007-12-15

    This paper presents the experimental results on spruce plywood and cellulose insulation using the transient moisture transfer (TMT) facility presented in Part I [P. Talukdar, S.O. Olutmayin, O.F. Osanyintola, C.J. Simonson, An experimental data set for benchmarking 1-D, transient heat and moisture transfer models of hygroscopic building materials-Part-I: experimental facility and property data, Int. J. Heat Mass Transfer, in press, doi:10.1016/j.ijheatmasstransfer.2007.03.026] of this paper. The temperature, relative humidity and moisture accumulation distributions within both materials are presented following different and repeated step changes in air humidity and different airflow Reynolds numbers above the materials. The experimental data are compared with numerical data, numerical sensitivity studies and analytical solutions to increase the confidence in the experimental data set. (author)

  11. Charge Transport in LDPE Nanocomposites Part I—Experimental Approach

    Directory of Open Access Journals (Sweden)

    Anh T. Hoang

    2016-03-01

    Full Text Available This work presents results of bulk conductivity and surface potential decay measurements on low-density polyethylene and its nanocomposites filled with uncoated MgO and Al2O3, with the aim to highlight the effect of the nanofillers on charge transport processes. Material samples at various filler contents, up to 9 wt %, were prepared in the form of thin films. The performed measurements show a significant impact of the nanofillers on reduction of material’s direct current (dc conductivity. The investigations thus focused on the nanocomposites having the lowest dc conductivity. Various mechanisms of charge generation and transport in solids, including space charge limited current, Poole-Frenkel effect and Schottky injection, were utilized for examining the experimental results. The mobilities of charge carriers were deduced from the measured surface potential decay characteristics and were found to be at least two times lower for the nanocomposites. The temperature dependencies of the mobilities were compared for different materials.

  12. Dynamic spreading of nanofluids on solids. Part I: experimental.

    Science.gov (United States)

    Kondiparty, Kirtiprakash; Nikolov, Alex D; Wasan, Darsh; Liu, Kuan-Liang

    2012-10-16

    Nanofluids have enhanced thermophysical properties compared to fluids without nanoparticles. Recent experiments have clearly shown that the presence of nanoparticles enhances the spreading of nanofluids. We report here the results of our experiments on the spreading of nanofluids comprising 5, 10, and 20 vol % silica suspensions of 19 nm particles displacing a sessile drop placed on a glass surface. The contact line position is observed from both the top and side views simultaneously using an advanced optical technique. It is found that the nanofluid spreads, forming a thin nanofluid film between the oil drop and the solid surface, which is seen as a bright inner contact line distinct from the conventional three-phase outer contact line. For the first time, the rate of the nanofluidic film spreading is experimentally observed as a function of the nanoparticle concentration and the oil drop volume. The speed of the inner contact line is seen to increase with an increase in the nanoparticle concentration and decrease with a decrease in the drop volume, that is, with an increase in the capillary pressure. Interestingly, the formation of the inner contact line is not seen in fluids without nanoparticles.

  13. Size effects in ductile cellular solids. Part II : experimental results

    NARCIS (Netherlands)

    Andrews, E.W.; Gioux, G.; Onck, P.; Gibson, L.J.

    2001-01-01

    There is increasing interest in the use of metallic foams in a variety of applications, including lightweight structural sandwich panels and energy absorption devices. In such applications, the mechanical response of the foams is of critical importance. In this study, we have investigated the effect

  14. Theoretical and experimental studies on the foundation theoretical and experimental studies on the foundation of mesomechanics

    Science.gov (United States)

    Chudnovsky, A.; Wu, S.

    1992-06-01

    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.

  15. Experimental study of potential neutron moderator materials

    Science.gov (United States)

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

    2010-12-01

    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.

  16. Experimental and theoretical study of reflux condensation

    Energy Technology Data Exchange (ETDEWEB)

    Bakke, Knut

    1997-12-31

    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.

  17. Experimental studies of neutrino oscillations

    CERN Document Server

    Kajita, Takaaki

    2016-01-01

    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.

  18. CREATIVE DISCLOSURE: AN EXPERIMENTAL STUDY

    Directory of Open Access Journals (Sweden)

    Cuzdriorean Dan Dacian

    2012-07-01

    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.

  19. Experimental and computational investigation of an electromagnetic pump used for manufacturing aluminium parts

    Science.gov (United States)

    Morinigo, D.; Rodrigues, M. A.; Rivas, A.; Duque, O.; Vazquez, V.; Maroto, J. A.; Cuesta, R.

    2007-03-01

    An experimental and computational investigation was carried out on an electromagnetic pump for molten aluminum. The electromagnetic pump is a MHD device to drive molten metals by means of electromagnetic fields and without mechanical parts in contact with the metal at high temperature. An exact computer simulation of the electromagnetic pump would require the simultaneous solution of electromagnetic and fluid dynamics problems. However, in this study we divide the simulation into two independent stages. First, the electromagnetic system is simulated by ANSYS considering the secondary of the pump as a solid. This simulation is experimentally validated in a test bed with a solid secondary replacing the molten metal. Secondly, a 3D field of electromagnetic forces provided by the ANSYS simulation is imported into the FLUENT CFD code to simulate the fluid dynamic problem, considering now the secondary of the pump as a liquid. This second simulation is also experimentally validated by measuring the static head provided by the pump. This simulation process is valid only if the electromagnetic system and the fluid dynamic problem are uncoupled, which has been verified by calculating the magnetic Reynolds number and the interaction parameter. Tables 4, Figs 14, Refs 15.

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

    African Journals Online (AJOL)

    Uche

    2011-01-14

    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 ...

  1. A novel embeddable spherical smart aggregate for structural health monitoring: part II. Numerical and experimental verifications

    Science.gov (United States)

    Kong, Qingzhao; Fan, Shuli; Mo, Y. L.; Song, Gangbing

    2017-09-01

    The newly developed spherical smart aggregate (SSA) based on a radially polarized spherical piezoceramic shell element has unique omnidirectional actuating and sensing capabilities that can greatly improve the detection aperture and provide additional functionalities in health monitoring applications in concrete structures. Detailed fabrication procedures and electrical characterization of the SSA have been previously studied (Part I). In this second paper (Part II), the functionalities of the SSA used in both active sensing and passive sensing approaches were investigated in experiments and numerical simulations. One SSA sample was embedded in a 1 ft3 concrete specimen. In the active sensing approach, the SSA was first utilized as an actuator to generate stress waves and six conventional smart aggregates (SA) mounted on the six faces of the concrete cube were utilized as sensors to detect the wave response. Conversely, the embedded SSA was then utilized as a sensor to successively detect the wave response from each SA. The experimentally obtained behavior of the SSA was then compared with the numerical simulation results. Further, a series of impact tests were conducted to verify the performance of the SSA in the detection of the impact events from different directions. Comparison with the wave response associated with different faces of the cube verified the omnidirectional actuating and sensing capabilities of the SSA.

  2. EXPERIMENTAL STUDY OF THE PRODUCTION OF SOLAR ...

    African Journals Online (AJOL)

    2010-06-30

    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 ...

  3. Utilization and processing of forest energy. Part 4. Experimental study of wood pelletization. [Other reports of the project are VTT-POV--36, VTT-POV--37 and VTT-POV--38

    Energy Technology Data Exchange (ETDEWEB)

    Kytoe, M.; Aeijaelae, M.

    1981-11-01

    The aim of this experimental study was to complete and check information material on requirements set on the raw material and the test equipment for pelletizing wood. The tests were carried out mainly on a plane matrice machine, the capacity of which was about 100 kg/h for wood. The preliminary experiments were carried out by briquetting different kinds of raw material in a hydraulic press and by pelletizing sawdust on a small ring matrice machine (capacity about 10 kg/h). A test run was also carried out on a fairly large pelletizing line. Different kinds of sawdust and dusts ground from forest waste chips and willow chips were used as test materials. The pellets produced from energy willow containing bark and from forest waste were harder than those made from saw dust. The pelletization result improved when bark was added to the saw dust. The best results were achieved by adding 15-40% bark. The pelletization of wood dusts succeeded best at 15-20% moisture content of the raw material. The moisture content of peat may vary in considerably wider limits. A matrice with straight holes was most applicable to wood pelletizing; the ratio of hole diameter and length was 0.20-0.25. The minimum consumption of energy was about 60 kWh/t in wood pelletization. This is about 1-2% of the calorific value of wood pellets. The bulk density of the pellets varied from 600 to 700 kg/m/sup 3/ and the solid volume from 110 to 1500 kg/m/sup 3/. The moisture content of wood pellets is usually 8-15%, when the calorific value is about 17 MJ/kg. The weather resistance of wood pellets is rather poor.

  4. The Aalborg Survey / Part 4 - Literature Study

    DEFF Research Database (Denmark)

    Harder, Henrik; Christensen, Cecilie Breinholm

    ) and the research focus within the cluster of Mobility and Tracking Technologies (MoTT), AAU. Summary / Part 4 - Literature Study The 4th part of the DUS research project has been carried out during the spring 2012 and consists primarily of a literature search and bibliographical listings of literature by the three...... specific authors: William Hollingsworth Whyte (1917-1999), Jan Gehl (b. 1936) and Erving Goffman (1922-1982), as well as literature on the topics of ‘plazas’, ‘squares’, ‘parks’, ‘young people’s use of urban space’ and ’GPS’. Secondarily, there has been made a bibliographical listing of publications...

  5. Laparoscopic ureterocalicostomy in pigs - experimental study

    OpenAIRE

    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

    2015-01-01

    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: Eva.Scholtzova@savba.sk [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)

    2014-05-01

    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. Experimental Study of the Sampled Labyrinth Chaos

    Directory of Open Access Journals (Sweden)

    J. Petrzela

    2011-12-01

    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.

  8. Chemometrics in analytical chemistry-part I: history, experimental design and data analysis tools.

    Science.gov (United States)

    Brereton, Richard G; Jansen, Jeroen; Lopes, João; Marini, Federico; Pomerantsev, Alexey; Rodionova, Oxana; Roger, Jean Michel; Walczak, Beata; Tauler, Romà

    2017-10-01

    Chemometrics has achieved major recognition and progress in the analytical chemistry field. In the first part of this tutorial, major achievements and contributions of chemometrics to some of the more important stages of the analytical process, like experimental design, sampling, and data analysis (including data pretreatment and fusion), are summarised. The tutorial is intended to give a general updated overview of the chemometrics field to further contribute to its dissemination and promotion in analytical chemistry.

  9. Experimental Study on Permeability of Concrete

    Science.gov (United States)

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

    2018-01-01

    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.

  10. Experimental studies on transitional separated boundary layers

    OpenAIRE

    Serna Serrano, José

    2013-01-01

    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...

  11. Fully Bayesian Experimental Design for Pharmacokinetic Studies

    Directory of Open Access Journals (Sweden)

    Elizabeth G. Ryan

    2015-03-01

    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.

  12. Experimental study of natural circulation circuit

    Energy Technology Data Exchange (ETDEWEB)

    Lemos, Wanderley F.; Su, Jian, E-mail: wlemos@lasme.coppe.ufrj.br, E-mail: sujian@lasme.coppe.ufrj.br [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: faccini@ien.gov.br [Instituto de Engenharia Nuclear (LTE/IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. de Termo-Hidraulica Experimental

    2011-07-01

    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)

  13. EXPERIMENTAL STUDIES ON EUPHORBIA PROSTATA W. AIT

    OpenAIRE

    Shrama, Gopal Dutt; Tripathi, S. N.

    1983-01-01

    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. Organ models in wound ballistics: experimental study.

    Science.gov (United States)

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

    2007-01-01

    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.

  15. Experimental Study of Hysteretic Steel Damper for Energy Dissipation Capacity

    Directory of Open Access Journals (Sweden)

    Daniel R. Teruna

    2015-01-01

    Full Text Available This study aims to evaluate energy absorption capacity of hysteretic steel damper for earthquake protection of structures. These types of steel dampers are fabricated from mild steel plate with different geometrical shapes on the side part, namely, straight, concave, and convex shapes. The performance of the proposed device was verified experimentally by a series of tests under increasing in-plane cyclic load. The overall test results indicated that the proposed steel dampers have similar hysteretic curves, but the specimen with convex-shaped side not only showed stable hysteretic behavior but also showed excellent energy dissipation capabilities and ductility factor. Furthermore, the load-deformation relation of these steel dampers can be decomposed into three parts, namely, skeleton curve, Bauschinger part, and elastic unloading part. The skeleton curve is commonly used to obtain the main parameters, which describe the behavior of steel damper, namely, yield strength, elastic stiffness, and postyield stiffness ratio. Moreover, the effective stiffness, effective damping ratio, cumulative plastic strain energy, and cumulative ductility factor were also derived from the results. Finally, an approximation trilinear hysteretic model was developed based on skeleton curve obtained from experimental results.

  16. Experimental study of rf pulsed heating

    CERN Document Server

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

    2011-01-01

    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...

  17. EXPERIMENTAL STUDIES ON INFLAMMATION : II. EXPERIMENTAL CHEMICAL INFLAMMATION IN VIVO.

    Science.gov (United States)

    Wolf, E P

    1923-03-31

    1. None of the salts tested produce a marked inflammation in vivo in concentrations under 10 per cent. Potassium salts and the different citrates produced atypical inflammatory reactions in mice, but not in frogs. There was no true inflammation, however, characterized by blood vessel changes, migration of polymorphonuclear leucocytes and erythrocytes, and fluid exudation. 2. Synergistic action occurs when equal parts of strontium and magnesium salts are employed. There is a change in the appearance of the mesentery without a true inflammation, and this change does not occur with either salt alone. 3. Amino-acids and amines as a class do not produce inflammation, but histamine produces a marked inflammatory reaction in frogs and mice. 4. Tyramine does not cause an inflammatory reaction but has other marked effects; agglutination thrombi occur within the smaller blood vessels, both veins and arteries; in frogs there is a rapid clumping of the white blood cells followed by a true coagulation with strands of fibrin and entanglement of erythrocytes. This is very widespread and often kills the animal within an hour after injection. In mice it is the erythrocytes that clump and coagulation occurs very much later, usually at the end of 24 hours; still later there is complete absorption of the coagulated masses and the mesenteric circulation returns to normal. None of the mice died during the stage of clumping, and the clots never extended up the larger vessels as they did in the frogs. These effects are similar to the phenomena observed in the in vitro work, in which clumping of the cells appeared constantly. 5. Cantharidinum, histamine, and turpentine produced the most rapid and marked inflammation of any substances tried. These substances are all strongly positively chemotactic in vitro. The differences occurring when these substances are used in different species is a quantitative rather than a qualitative one, the body temperature being of some importance. Papain acted

  18. An Experimental Study of Soft Lubrication

    Science.gov (United States)

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

    2012-11-01

    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.

  19. Experimental Study of Separate Type Thermosyphon

    Science.gov (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.

  20. Experimental studies of auroral arc generators

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-08-01

    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.

  1. Metabolic Desynchronization in Critical Conditions: Experimental Study

    Directory of Open Access Journals (Sweden)

    G. V. Livanov

    2006-01-01

    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

  2. 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 ...

  3. Iron(III) solubility and speciation in aqueous solutions. experimental study and modelling: part 1. hematite solubility from 60 to 300°C in NaOH-NaCl solutions and thermodynamic properties of Fe(OH) 4 -(aq)

    Science.gov (United States)

    Diakonov, Igor I.; Schott, Jacques; Martin, Francois; Harrichourry, Jean-Claude; Escalier, Jocelyne

    1999-08-01

    The solubility of natural and synthetic hematite (α-Fe 2O 3) was measured in NaOH-NaCl solutions (0.007 ≤ m(NaOH) ≤ 2.0) between 60 and 300°C at saturated water vapour pressure and under excess oxygen. Solubility constants determined in the present study and by Yishan et al. (1986) at 300°C were combined with the thermodynamic properties of hematite (Hemingway, 1990) and water (SUPCRT92, Johnson et al., 1992) to generate within the framework of the revised Helgeson-Kirkham-Flowers (HKF) model the standard partial molal thermodynamic properties at 25°C and 1 bar, and the revised HKF equations of state parameters of Fe(OH) 4 -. The extrapolated value for the Gibbs energy of formation for Fe(OH) 4 - at 25°C is -201.97 kcal/mol. Thermodynamic calculations show that Fe(OH) 4 - exhibits a chemical behaviour different from that of Ga(OH) 4 - and Al(OH) 4 -.

  4. [Endodontics in horses. An experimental study].

    Science.gov (United States)

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

    1990-04-01

    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.

  5. An experimental study of reactive turbulent mixing

    Science.gov (United States)

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

    1977-01-01

    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.

  6. Experimental studies of ongoing conscious experience.

    Science.gov (United States)

    Singer, J L

    1993-01-01

    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.

  7. 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)

    2011-01-15

    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)

  8. Experimental study of hydronic panels system and its environment

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca Diaz, Nestor, E-mail: nestorfonseca5@hotmail.co [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)

    2011-01-15

    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.

  9. Experimental Study of Alluvial Fan Formation

    Science.gov (United States)

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

    2015-12-01

    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).

  10. Experimental study of rf pulsed heating

    Directory of Open Access Journals (Sweden)

    Lisa Laurent

    2011-04-01

    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.

  11. Experimental Study of Methane Hydrates in Coal

    Directory of Open Access Journals (Sweden)

    Smirnov Vyacheslav

    2017-01-01

    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.

  12. 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...

  13. Simulation and experimental study of resin flow in fibre fabrics

    Science.gov (United States)

    Yan, Fei; Yan, Shilin; Li, Yongjing

    2017-06-01

    Liquid Composite Moulding (LCM) is gradually becoming the most competitive manufacturing technology for producing large composite parts with complex geometry with high quality and low cost. These parts include those for airplanes, wind turbine blades and automobile components. Fibre fabrics in liquid composite moulding can be considered as dual-scale porous media. In different gap scales, an unsaturated flow is produced during the mould filling process. This particular flow behaviour deviates from the traditional Darcy’s law, which is used to calculate the filling pressure and will cause errors. According to sink theory, the unsaturated flow characteristics of this dual-scale porous media were studied in this paper, and a FEM solution program was developed. The results showed that the pressure curves against the position which simulated by sink functions were departure from the position of traditional theory. In addition, the simulation results of partially-saturated region were consistent with the experimental data.

  14. Numerical-experimental investigation of PE/EVA foam injection molded parts

    Science.gov (United States)

    Spina, Roberto

    The main objective of the presented work is to propose a robust framework to test foaming injection molded parts, with the aim of establishing a standard testing cycle for the evaluation of a new foam material based on numerical and experimental results. The research purpose is to assess parameters influencing several aspects, such as foam morphology and compression behavior, using useful suggestions from finite element analysis. The investigated polymeric blend consisted of a mixture of low density polyethylenes (LDPEs), a high-density polyethylene (HDPE), an ethylene-vinyl acetate (EVA) and an azodicarbonamide (ADC). The thermal, rheological and compression properties of the blend are fully described, as well as the numerical models and the parameters of the injection molding process.

  15. Thermomechanical Effects during Direct Chill and Electromagnetic Casting of Aluminum Alloys Part I : Experimental Investigation

    Science.gov (United States)

    Drezet, J.-M.; Plata, M.

    The deformation and the temperature field evolution within direct chill (DC) and electromagnetic (EM) cast aluminum ingots have been measured in-situ using a simple experimental set-up. The deformation of the cross section of the cold ingots has also been characterized as a function of the casting speed, alloy composition and inoculation condition. The pull-in of the lateral rolling faces has been found to occur in two sequences for DC cast ingots whereas that associated with EMC was continuous. The pull-in was maximum at the center of these faces (about 7-9 %) and strongly depended upon the casting speed. The present results constitute a basis for the validation of the model presented in part II.

  16. EXPERIMENTAL INVESTIGATION AND DYNAMIC SIMULATION FOR SINGULARIZING UNIT IN PART FEEDERS

    Directory of Open Access Journals (Sweden)

    M. SURESH

    2015-06-01

    Full Text Available In the automotive sector, the act of feeding and orienting the asymmetric components in desired orientation was considered as major problem. Brake pad was considered in this work and a singularizing unit (hopper was developed for separating them. The objective of this work was to identify the suitable parameters for feeding the irregular part one by one in the specified orientations. Experiments were conducted for various frequency levels at various levels of inclination of the hopper using base plates. The experimental outcome provides the suitable parameters of base plate thickness and frequency of vibration. The hopper model was developed and the vibration analysis was carried out using dynamic simulation software. The results of the physical experiments and simulated design experiment were compared. The comparison shows an appreciable relationship to each other.

  17. Experimental studies of herbicide drift characteristics

    Energy Technology Data Exchange (ETDEWEB)

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

    1976-05-20

    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.

  18. A Stability Formula for Plastic-Tipped Bullets Part 2: Experimental Testing

    CERN Document Server

    Courtney, Michael W

    2014-01-01

    Part 1 of this paper describes a modification of the original Miller twist rule for computing gyroscopic bullet stability that is better suited to plastic-tipped bullets. The original Miller twist rule assumes a bullet of constant density, but it also works well for conventional copper (or gilding metal) jacketed lead bullets because the density of copper and lead are sufficiently close. However, the original Miller twist rule significantly underestimates the gyroscopic stability of plastic-tipped bullets, because the density of plastic is much lower than the density of copper and lead. Here, a new amended formula is developed for the gyroscopic stability of plastic-tipped bullets by substituting the length of just the metal portion for the total length in the (1 + L2) term of the original Miller twist rule. Part 2 describes experimental testing of this new formula on three plastic-tipped bullets. The new formula is relatively accurate for plastic-tipped bullets whose metal portion has nearly uniform density,...

  19. Experimental studies of fiber concrete creep

    Directory of Open Access Journals (Sweden)

    Korneeva Irina

    2017-01-01

    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.

  20. Experimental study of finite Larmor radius effects

    Energy Technology Data Exchange (ETDEWEB)

    Struve, K.W.

    1980-08-01

    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 ..mu..sec to a maximum of 100 to 200 kA. The pinch bank capacitance is 900 ..mu..F, 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.

  1. The experimental studies of thermoacoustic cooler.

    Science.gov (United States)

    Sakamoto, Shin-ichi; Watanabe, Yoshiaki

    2004-04-01

    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.

  2. Experimental study of trimethyl aluminum decomposition

    Science.gov (United States)

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

    2017-09-01

    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.

  3. 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

  4. Evapotranspiration studies for protective barriers: Experimental plans

    Energy Technology Data Exchange (ETDEWEB)

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

    1989-11-01

    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.

  5. Experimental and computational studies of nanofluids

    Science.gov (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

  6. A four-part working bibliography of neuroethics: part 2--Neuroscientific studies of morality and ethics.

    Science.gov (United States)

    Darragh, Martina; Buniak, Liana; Giordano, James

    2015-02-15

    Moral philosophy and psychology have sought to define the nature of right and wrong, and good and evil. The industrial turn of the twentieth century fostered increasingly technological approaches that conjoined philosophy to psychology, and psychology to the natural sciences. Thus, moral philosophy and psychology became ever more vested to investigations of the anatomic structures and physiologic processes involved in cognition, emotion and behavior--ultimately falling under the rubric of the neurosciences. Since 2002, neuroscientific studies of moral thought, emotions and behaviors have become known as--and a part of--the relatively new discipline of neuroethics. Herein we present Part 2 of a bibliography of neuroethics from 2002-2013 addressing the "neuroscience of ethics"--studies of putative neural substrates and mechanisms involved in cognitive, emotional and behavioral processes of morality and ethics. A systematic survey of the neuroethics literature was undertaken. Bibliographic searches were performed by accessing 11 databases, 8 literature depositories, and 4 individual journal searches, and employed indexing language for National Library of Medicine (NLM) Medical Subject Heading databases. All bibliographic searches were conducted using the RefWorks citation management program. This bibliography lists 397 articles, 65 books, and 52 book chapters that present (1) empirical/experimental studies, overviews, and reviews of neural substrates and mechanisms involved in morality and ethics, and/or (2) reflections upon such studies and their implications. These works present resources offering iterative descriptions, definitions and criticisms of neural processes involved in moral cognition and behaviors, and also provide a historical view of this field, and insights to its developing canon.

  7. Structure Property Studies for Additively Manufactured Parts

    Energy Technology Data Exchange (ETDEWEB)

    Milenski, Helen M [Univ. of Mexico, Los Alamos, NM (United States); Schmalzer, Andrew Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kelly, Daniel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-17

    Since the invention of modern Additive Manufacturing (AM) processes engineers and designers have worked hard to capitalize on the unique building capabilities that AM allows. By being able to customize the interior fill of parts it is now possible to design components with a controlled density and customized internal structure. The creation of new polymers and polymer composites allow for even greater control over the mechanical properties of AM parts. One of the key reasons to explore AM, is to bring about a new paradigm in part design, where materials can be strategically optimized in a way that conventional subtractive methods cannot achieve. The two processes investigated in my research were the Fused Deposition Modeling (FDM) process and the Direct Ink Write (DIW) process. The objectives of the research were to determine the impact of in-fill density and morphology on the mechanical properties of FDM parts, and to determine if DIW printed samples could be produced where the filament diameter was varied while the overall density remained constant.

  8. Experimental Investigation into Suitable Process Conditions for Plastic Injection Molding of Thin-Sheet Parts

    Directory of Open Access Journals (Sweden)

    Dyi-Cheng Chen

    2014-04-01

    Full Text Available This study performs an experimental investigation into the effects of the process parameters on the surface quality of injection molded thin-sheet thermoplastic components. The investigations focus specifically on the shape, number and position of the mold gates, the injection pressure and the injection rate. It can be seen that the gravity force entering point improved filling of the cavity for the same forming time and injection pressure. Moreover, it shows the same injection pressure and packing time, the taper-shape gate yields a better surface appearance than the sheet-shape gate. The experimental results provide a useful source of reference in suitable the process conditions for the injection molding of thin-sheet plastic components.

  9. Ovine and Caprine Toxoplasmosis: Experimental Study

    Directory of Open Access Journals (Sweden)

    Shawkat Q. Lafi

    2014-01-01

    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.

  10. 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)

    1993-12-01

    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.

  11. Stress state dependence of in-reactor creep and swelling. Part 2: Experimental results

    Science.gov (United States)

    Hall, M. M., Jr.; Flinn, J. E.

    2010-01-01

    Irradiation creep constitutive equations, which were developed in Part I, are used here to analyze in-reactor creep and swelling data obtained ca. 1977-1979 as part of the US breeder reactor program. The equations were developed according to the principles of incremental continuum plasticity for the purpose of analyzing data obtained from a novel irradiation experiment that was conducted, in part, using Type 304 stainless steel that had been previously irradiated to significant levels of void swelling. Analyses of these data support an earlier observation that all stress states, whether tensile, compressive, shear or mixed, can affect both void swelling and interactions between irradiation creep and swelling. The data were obtained using a set of five unique multiaxial creep-test specimens that were designed and used for the first time in this study. The data analyses demonstrate that the constitutive equations derived in Part I provide an excellent phenomenological representation of the interactive creep and swelling phenomena. These equations provide nuclear power reactor designers and analysts with a first-of-its-kind structural analysis tool for evaluating irradiation damage-dependent distortion of complex structural components having gradients in neutron damage rate, temperature and stress state.

  12. Biomass thermochemical gasification: Experimental studies and modeling

    Science.gov (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

  13. Experimental Study of a Thermoelectric Generation System

    DEFF Research Database (Denmark)

    Zhu, Junpeng; Gao, Junling; Chen, Min

    2011-01-01

    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 ...

  14. Economic principles in communication: An experimental study

    NARCIS (Netherlands)

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

    2014-01-01

    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

  15. Blast mitigation experimental and numerical studies

    CERN Document Server

    2013-01-01

    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

  16. An experimental study of passive regenerator geometries

    DEFF Research Database (Denmark)

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

    2011-01-01

    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. Exit blade geometry and part-load performance of small axial flow propeller turbines: An experimental investigation

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Punit; Nestmann, Franz [Institute for Water and River Basin Management (IWG), University of Karlsruhe, Kaiser Str. 12, D 76128 Karlsruhe (Germany)

    2010-09-15

    A detailed experimental investigation of the effects of exit blade geometry on the part-load performance of low-head, axial flow propeller turbines is presented. Even as these turbines find important applications in small-scale energy generation using micro-hydro, the relationship between the layout of blade profile, geometry and turbine performance continues to be poorly characterized. The experimental results presented here help understand the relationship between exit tip angle, discharge through the turbine, shaft power, and efficiency. The modification was implemented on two different propeller runners and it was found that the power and efficiency gains from decreasing the exit tip angle could be explained by a theoretical model presented here based on classical theory of turbomachines. In particular, the focus is on the behaviour of internal parameters like the runner loss coefficient, relative flow angle at exit, mean axial flow velocity and net tangential flow velocity. The study concluded that the effects of exit tip modification were significant. The introspective discussion on the theoretical model's limitation and test facility suggests wider and continued experimentation pertaining to the internal parameters like inlet vortex profile and exit swirl profile. It also recommends thorough validation of the model and its improvement so that it can be made capable for accurate characterization of blade geometric effects. (author)

  18. Texture evolution of experimental silicon steel grades. Part I: Hot rolling

    OpenAIRE

    Sandoval Robles, J. A.; Salas Zamarripa, A.; Martha P. Guerrero Mata; Cabrera Marrero, José M.

    2017-01-01

    The metallurgical understanding of the deformation processes during the fabrication of non-oriented electrical steels plays a key role in improving their final properties. Texture control and optimization is critical in these steels for the enhancement of their magnetic properties. The aim of the present work is to study the texture evolution of six non-oriented experimental silicon steel grades during hot rolling. These steels were low carbon steel with a silicon content from 0.5 to 3.0 wt%....

  19. Experimental studies of pion-nucleus interactions at intermediate energies

    Energy Technology Data Exchange (ETDEWEB)

    1991-12-31

    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 AND THEORETICAL NMR STUDY OF 4-(1 ...

    African Journals Online (AJOL)

    Preferred Customer

    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.

  1. Model refinement for offshore platforms: Experimental study

    Science.gov (United States)

    Zhang, Min; Chen, Zongli; Wu, Yanjian

    2017-08-01

    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.

  2. Experimental studies of Steel Corrugated Constructions

    Directory of Open Access Journals (Sweden)

    Lazarev Yuriy

    2016-01-01

    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.

  3. Probabilistic evidential assessment of gunshot residue particle evidence (Part II): Bayesian parameter estimation for experimental count data.

    Science.gov (United States)

    Biedermann, A; Bozza, S; Taroni, F

    2011-03-20

    Part I of this series of articles focused on the construction of graphical probabilistic inference procedures, at various levels of detail, for assessing the evidential value of gunshot residue (GSR) particle evidence. The proposed models--in the form of Bayesian networks--address the issues of background presence of GSR particles, analytical performance (i.e., the efficiency of evidence searching and analysis procedures) and contamination. The use and practical implementation of Bayesian networks for case pre-assessment is also discussed. This paper, Part II, concentrates on Bayesian parameter estimation. This topic complements Part I in that it offers means for producing estimates usable for the numerical specification of the proposed probabilistic graphical models. Bayesian estimation procedures are given a primary focus of attention because they allow the scientist to combine (his/her) prior knowledge about the problem of interest with newly acquired experimental data. The present paper also considers further topics such as the sensitivity of the likelihood ratio due to uncertainty in parameters and the study of likelihood ratio values obtained for members of particular populations (e.g., individuals with or without exposure to GSR). Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  4. Scaling Factor Estimation Using Optimized Mass Change Strategy, Part 2: Experimental Results

    DEFF Research Database (Denmark)

    Fernández, Pelayo Fernández; Aenlle, Manuel López; Garcia, Luis M. Villa

    2007-01-01

    of the structure. On the other hand, the aforementioned objectives are difficult to achieve for all modes simultaneously. Thus, a study of the number, magnitude and location of the masses must be performed previously to the modal tests. In this paper, the mass change method was applied to estimate the scaling......The mass change method is used to estimate the scaling factors, the uncertainty is reduced when, for each mode, the frequency shift is maximized and the changes in the mode shapes are minimized, which in turn, depends on the mass change strategy chosen to modify the dynamic behavior...... factors of a steel cantilever beam. The effect of the mass change strategy was experimentally studied by performing several modal tests in which the magnitude, the location and the number of the attached masses were changed....

  5. Experimental study of the nucleon spin structure

    Energy Technology Data Exchange (ETDEWEB)

    Litmaath, M.F.

    1996-05-07

    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.).

  6. Experimental Studies of Coaxial Plasma Gun Current

    Science.gov (United States)

    1988-09-01

    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

  7. An experimental study of rotor-filter pump performance

    Energy Technology Data Exchange (ETDEWEB)

    Marshek, K.M.; Naja, M.R.

    1982-09-01

    The performance of a rotor-filter pump has been studied experimentally. To develop an understanding of pump performance, and in particular to discern the mechanism of hydraulic pulsing, flow visualization in the rotor, vibration analyses of the pump, frequency analysis of the pump hydraulic pressure pulsation, and analyses of flow characteristics for different pick-up tubes in combination with different impellers and cover plates were conducted. The frequencies of the pump's hydraulic pulsation is shown to be a function of the number of pick-up arms and the motor speed. The pump vibration and its pulsation amplitude were reduced by increasing the number of pick-up arms or by adding a radial impeller. These actions increased the lowest frequency of pulsation and decreased the chance of excitation of the pump system parts.

  8. Feasibility study of the AOSTA experimental campaign

    Directory of Open Access Journals (Sweden)

    Carta M.

    2016-01-01

    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.

  9. Experimental design from user studies to psychophysics

    CERN Document Server

    Cunningham, Douglas

    2011-01-01

    This book explains the basic terminology used to discuss experiments and takes a brief look at the more than 150 year history has in psychology. It covers how to generalize from a few people to the whole population. The largest part of the book is dedicated to the most flexible, and arguably the most central, aspect of an experiment: What do the participants do? Each chapter follows the same structure and includes two examples, one from traditional psychophysics and on using computer animated facial expressions as stimuli.

  10. Experimental study of external fuel vaporization

    Science.gov (United States)

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

    1982-01-01

    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.

  11. Experimental Study of Pollutant Transfer within Dwellings

    CERN Document Server

    Koffi, Juslin; Allard, Francis; Husaunndee, Ahmad

    2010-01-01

    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.

  12. Computational and experimental study of laminar flames

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-05-29

    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

  13. Mineral scale management. Part 1, Case studies

    Science.gov (United States)

    Peter W. Hart; Alan W. Rudie

    2006-01-01

    Mineral scale increases operating costs, extends downtime, and increases maintenance requirements. This paper presents several successful case studies detailing how mills have eliminated scale. Cases presented include calcium carbonate scale in a white liquor strainer, calcium oxalate scale in the D0 stage of the bleach plant, enzymatic treatment of brown stock to...

  14. Age 60 Study. Part 1. Bibliographic Database

    Science.gov (United States)

    1994-10-01

    decisional errors made by newly certified private pilots during in-flight tests. However, the subjects in these studies were all college-age students... TOMA , J. Several aspects of laboratory psychophysiological activity in the flying personnel of various age. (Laboratory psychophysiological efficiency in

  15. Interdisciplinary Study: Research as Part of Artmaking

    Science.gov (United States)

    Eubanks, Paula

    2012-01-01

    As education budgets shrink, art teachers need to find ways to position the study of art closer to mainstream academics by exploring concepts that cut across disciplinary boundaries. Art teachers can challenge students to do serious and thorough research about subject matter partnering with teachers in other areas to select subject matter that is…

  16. Parts of Plants. Hawaii Nature Study Project.

    Science.gov (United States)

    Hawaii Univ., Honolulu. Curriculum Research and Development Group.

    This teaching guide is one of a series developed by the Curriculum Research and Development Group at the University of Hawaii. The program is laboratory and field oriented for elementary students. The focus of study for the project is the plant and animal life and the physical components of the Hawaiian environment, and their ecological…

  17. Crater studies: Part A: lunar crater morphometry

    Science.gov (United States)

    Pike, Richard J.

    1973-01-01

    Morphometry, the quantitative study of shape, complements the visual observation and photointerpretation in analyzing the most outstanding landforms of the Moon, its craters (refs. 32-1 and 32-2). All three of these interpretative tools, which were developed throughout the long history of telescopic lunar study preceding the Apollo Program, will continue to be applicable to crater analysis until detailed field work becomes possible. Although no large (>17.5 km diameter) craters were examined in situ on any of the Apollo landings, the photographs acquired from the command modules will markedly strengthen results of less direct investigations of the craters. For morphometry, the most useful materials are the orbital metric and panoramic photographs from the final three Apollo missions. These photographs permit preparation of contour maps, topographic profiles, and other numerical data that accurately portray for the first time the surface geometry of lunar craters of all sizes. Interpretations of craters no longer need be compromised by inadequate topographic data. In the pre-Apollo era, hypotheses for the genesis of lunar craters usually were constructed without any numerical descriptive data. Such speculations will have little credibility unless supported by accurate, quantitative data, especially those generated from Apollo orbital photographs. This paper presents a general study of the surface geometry of 25 far-side craters and a more detailed study of rim-crest evenness for 15 near-side and far-side craters. Analysis of this preliminary sample of Apollo 15 and 17 data, which includes craters between 1.5 and 275 km in diameter, suggests that most genetic interpretations of craters made from pre-Apollo topographic measurements may require no drastic revision. All measurements were made from topographic profiles generated on a stereoplotter at the Photogrammetric Unit of the U.S. Geological Survey, Center of Astrogeology, Flagstaff, Arizona.

  18. Experimental study on HVAC sound parameters

    Science.gov (United States)

    Bujoreanu, C.; Benchea, M.

    2016-08-01

    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.

  19. Experimental study of asymmetric heart valve prototype

    Science.gov (United States)

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

    2011-11-01

    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.

  20. Experimental Studies with an Active Magnetic Regenerating Refrigerator

    DEFF Research Database (Denmark)

    Eriksen, Dan; Engelbrecht, Kurt; Bahl, Christian

    2015-01-01

    Experimental results for an active magnetic regenerator (AMR) are presented. The focus is on whether or not it pays off to partly substitute soft magnetic material with non-magnetic insulation in a flux-conducting core in the magnet system. Such a substitution reduces losses due to heat conductio...

  1. Oxidation of hazardous waste in supercritical water: Part 1, A comparison of modeling and experimental results for methanol destruction

    Energy Technology Data Exchange (ETDEWEB)

    Butler, P.B. [Iowa Univ., Iowa City, IA (United States); Bergan, N.E.; Bramlette, T.T. [Sandia National Labs., Livermore, CA (United States); Westbrook, C.K.; Pitz, W.J. [Lawrence Livermore National Lab., CA (United States)

    1991-12-31

    Recent experiments at Sandia National Laboratories conducted in conjunction with MODEC Corporation have demonstrated successful clean-up of contaminated water in a supercritical water reactor. These experiments targeted wastes of interest to Department of Energy (DOE) production facilities. In this paper we present modeling and experimental results for a surrogate waste containing 98% water, 2% methanol, and parts per million of chlorinated hydrocarbons and laser dyes. Our initial modeling results consider only methanol and water. Experimental data are available for inlet and outlet conditions (composition, flow rate, and temperature), and axial temperature profiles along the outside reactor wall. The purpose of our model is to study the chemical and physical processes inside the reactor. We are particularly interested in the parameters that control the location of the reaction zone. The laboratory-scale reactor operates at 25 MPa., between 300 K and 900 K; it is modeled as a plug-flow reactor with a specified temperature profile. We use Chemkin Real-Gas to calculate mixture density, with the Peng-Robinson equation of state. The elementary reaction set for methanol oxidation and reactions of other C{sub 1} and C{sub 2} hydrocarbons is based on previous models for gas-phase kinetics. Results from our calculations show that the methanol is 99.99% destroyed at 1/3 the total reactor length. Although we were not able to measure composition of the fluid inside the experimental reactor, this prediction occurs near the location of the high reactor temperature. This indicates that the chemical reaction is triggered by thermal effects, not kinetic rates. Results from ideal-gas calculations show nearly identical chemical profiles inside the reactor in dimensionless distance. However, reactor residence times are overpredicted by nearly 150% using an ideal-gas assumption.

  2. Bipolar mood disorder, creativity and schizotypy: an experimental study.

    Science.gov (United States)

    Rybakowski, Janusz K; Klonowska, Paulina

    2011-01-01

    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.

  3. Volatile particles formation during PartEmis: a modelling study

    Directory of Open Access Journals (Sweden)

    X. Vancassel

    2004-01-01

    Full Text Available A modelling study of the formation of volatile particles in a combustor exhaust has been carried out in the frame of the PartEmis European project. A kinetic model has been used in order to investigate nucleation efficiency of the H2O-H2SO4 binary mixture in the sampling system. A value for the fraction of the fuel sulphur S(IV converted into S(VI has been indirectly deduced from comparisons between model results and measurements. In the present study, ranges between roughly 2.5% and 6%, depending on the combustor settings and on the value assumed for the parameter describing sulphuric acid wall losses. Soot particles hygroscopicity has also been investigated as their activation is a key parameter for contrail formation. Growth factors of monodisperse particles exposed to high relative humidity (95% have been calculated and compared with experimental results. The modelling study confirms that the growth factor increases as the soot particle size decreases.

  4. Economic principles in communication: an experimental study.

    Science.gov (United States)

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

    2014-12-21

    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.

  5. Theoretical & Experimental Studies of Elementary Particles

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-10-04

    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

  6. Experimental Ejection Forces of Thermoplastic Parts From Rapid Tooled Injection Mold Inserts (Preprint)

    National Research Council Canada - National Science Library

    Kinsella, Mary E; Lilly, Blaine

    2007-01-01

    .... Ejection forces for cylindrical parts molded with high density polyethylene and high impact polystyrene were measured directly and compared with values calculated from an ejection force differently...

  7. Texture evolution of experimental silicon steel grades. Part I: Hot rolling

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval Robles, J.A., E-mail: jsandoval.uanl@yahoo.com [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, Ave. Universidad S/N, Cd. Universitaria, San Nicolás de los Garza, Nuevo León C.P. 66450 (Mexico); Salas Zamarripa, A.; Guerrero Mata, M.P. [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, Ave. Universidad S/N, Cd. Universitaria, San Nicolás de los Garza, Nuevo León C.P. 66450 (Mexico); Cabrera, J. [Universitat Politècnica de Catalunya, Departament de Ciència dels Materials I Enginyeria Metal-lúrgica, Av. Diagonal 647, Barcelona 08028 (Spain)

    2017-05-01

    The metallurgical understanding of the deformation processes during the fabrication of non-oriented electrical steels plays a key role in improving their final properties. Texture control and optimization is critical in these steels for the enhancement of their magnetic properties. The aim of the present work is to study the texture evolution of six non-oriented experimental silicon steel grades during hot rolling. These steels were low carbon steel with a silicon content from 0.5 to 3.0 wt%. The first rolling schedule was performed in the austenitic (γ-Fe) region for the steel with a 0.5 wt% of silicon content, while the 1.0 wt% silicon steel was rolled in the two-phase (α+γ) region. Steels with higher silicon content were rolled in the ferritic (α-Fe) region. The second rolling schedule was performed in the α-Fe region. Samples of each stage were analyzed by means of Electron Backscatter Diffraction (EBSD). Findings showed that the texture was random and heterogeneous in all samples after 60% of rolling reduction, which is due to the low deformation applied during rolling. After the second rolling program, localized deformation and substructured grains near to surface were observed in all samples. The Goss {110}<001>texture-component was found in the 0.5 and 1.0 wt.-%silicon steels. This is due to the thermomechanical conditions and the corresponding hot band microstructure obtained after the first program. Moreover, the α<110>//RD and the γ <111>//ND fiber components of the texture presented a considerable increment as the silicon content increases. Future research to be published soon will be related to the texture evolution during the cold-work rolling process. - Highlights: • We analyze six silicon steel experimental grades alloys trough the rolling process. • Material was subjected to a hot deformation process in the α-γ region. • No recrystalization was observed during-after the rolling schedules. • Rise of the magnetic texture components

  8. EXPERIMENTAL STUDY OF CARRYING CAPACITY GLULAM BEAMS, REINFORCED SPECIAL WAY

    Directory of Open Access Journals (Sweden)

    O. M. Ustarkhanov

    2013-01-01

    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.

  9. Experimental studies of actinides in molten salts

    Energy Technology Data Exchange (ETDEWEB)

    Reavis, J.G.

    1985-06-01

    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.

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

    African Journals Online (AJOL)

    管理平台

    2012-05-29

    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.

  11. Experimental and computational studies of polar solvation

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    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)

  12. 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

    1998-12-01

    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.

  13. Experimental Study of Flow in a Bifurcation

    Science.gov (United States)

    Fresconi, Frank; Prasad, Ajay

    2003-11-01

    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.

  14. Investigation of sol-gel transition by rheological methods. Part I. Experimental methods.

    Directory of Open Access Journals (Sweden)

    KUDRYAVTSEV Pavel Gennadievich

    2017-08-01

    Full Text Available In this work rheological studies of the gelling process were carried out. We have developed a measuring system for studying the rheology of the gelation process. It consisted of several measuring cells of the Weiler-Rebinder type, system for automatic regulation of the composition of the medium and hermostabilization system. This complex is designed to measure the dependence of the value of the ultimate shear stress as a function of time, from the start of the sol-gel transition to the complete conversion of the sol to the gel. The developed device has a wide range of measured values of critical shear stresses τ0 = (0,05÷50000 Dyne/cm2. Using the developed instrument, it was possible to establish the shape of the initial section of the curve τ0 = f(t and develop a methodology for more accurate determination of gelation time. The developed method proved that the classical method for determining the start time of the sol-gel transition using the point of intersection of the tangent to the linear part of the rheological curve τ0 = f(t,gives significantly distorted results. A new phenomenon has been discovered: the kinetic curves in the coordinates of the Avrami-Erofeev-Bogolyubov equation have an inflection point which separates the kinetic curve into two parts, the initial and the final. It was found that the constant k in the Avrami–Erofeev–Bogolyubov quation does not depend on the temperature and is the same for both the initial and final parts of the kinetic curve. It depends only on the chemical nature of the reacting system. It was found that for the initial section of the kinetic curves, the value of the parameter n in the Avrami-Erofeev-Bogolyubov equation was n = 23,4±2,8 and, unlike the final section of the rheological curve, does not depend on temperature. A large value of this parameter can be interpreted as the average number of directions of growth of a fractal aggregate during its growth. The value of this parameter depends

  15. Experimental studies in non-equilibrium physics

    Science.gov (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

  16. An experimental study of rip channel flow

    DEFF Research Database (Denmark)

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

    2002-01-01

    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...

  17. Experimental techniques for cement hydration studies

    Directory of Open Access Journals (Sweden)

    Andreas Luttge

    2011-10-01

    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.

  18. ESP Teaching for Tourism. An Experimental Study

    Directory of Open Access Journals (Sweden)

    Buzarna-Tihenea (Gălbează Alina

    2017-01-01

    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. Flapless implant surgery: an experimental study.

    Science.gov (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

    2007-07-01

    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.

  20. 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

    2013-07-01

    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.

  1. 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.

    1983-09-01

    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.

  2. Experimental study of forearm compartmental pressures.

    Science.gov (United States)

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

    2010-10-01

    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.

  3. Restoration of a 17th-century harpsichord to playable condition: a numerical and experimental study.

    Science.gov (United States)

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

    2012-01-01

    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.

  4. Experimental study of flow through compressor Cascade

    Directory of Open Access Journals (Sweden)

    Satyam Panchal

    2017-09-01

    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°.

  5. Medical waste to energy: experimental study.

    Science.gov (United States)

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

    2013-04-01

    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.

  6. EXPERIMENTAL STUDY OF A HORSE ANTIPOLIOMYELITIC SERUM.

    Science.gov (United States)

    Rhoads, C P

    1931-01-01

    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.

  7. 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

  8. Injury Based on Its Study in Experimental Models

    Directory of Open Access Journals (Sweden)

    M. Mendes-Braz

    2012-01-01

    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.

  9. An experimental study on pump clogging

    Science.gov (United States)

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

    2014-03-01

    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

  10. Experimental Study of Rectangular Labyrinth Weir

    Directory of Open Access Journals (Sweden)

    M. Rezaee

    2016-09-01

    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

  11. 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

    2017-03-08

    . 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.

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

    NARCIS (Netherlands)

    Pollux, B.J.A.

    2011-01-01

    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

  13. BIOLOGICAL EFFECTS OF PULSED SHORT WAVE TREATMENT. AN EXPERIMENTAL STUDY

    Directory of Open Access Journals (Sweden)

    Dogaru Gabriela

    2015-02-01

    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

  14. Overview: Experimental studies of crystal nucleation: Metals and colloids

    Science.gov (United States)

    Herlach, Dieter M.; Palberg, Thomas; Klassen, Ina; Klein, Stefan; Kobold, Raphael

    2016-12-01

    Crystallization is one of the most important phase transformations of first order. In the case of metals and alloys, the liquid phase is the parent phase of materials production. The conditions of the crystallization process control the as-solidified material in its chemical and physical properties. Nucleation initiates the crystallization of a liquid. It selects the crystallographic phase, stable or meta-stable. Its detailed knowledge is therefore mandatory for the design of materials. We present techniques of containerless processing for nucleation studies of metals and alloys. Experimental results demonstrate the power of these methods not only for crystal nucleation of stable solids but in particular also for investigations of crystal nucleation of metastable solids at extreme undercooling. This concerns the physical nature of heterogeneous versus homogeneous nucleation and nucleation of phases nucleated under non-equilibrium conditions. The results are analyzed within classical nucleation theory that defines the activation energy of homogeneous nucleation in terms of the interfacial energy and the difference of Gibbs free energies of solid and liquid. The interfacial energy acts as barrier for the nucleation process. Its experimental determination is difficult in the case of metals. In the second part of this work we therefore explore the potential of colloidal suspensions as model systems for the crystallization process. The nucleation process of colloids is observed in situ by optical observation and ultra-small angle X-ray diffraction using high intensity synchrotron radiation. It allows an unambiguous discrimination of homogeneous and heterogeneous nucleation as well as the determination of the interfacial free energy of the solid-liquid interface. Our results are used to construct Turnbull plots of colloids, which are discussed in relation to Turnbull plots of metals and support the hypothesis that colloids are useful model systems to investigate crystal

  15. Analysis of the ecotoxicity data submitted within the framework of the REACH Regulation. Part 3. Experimental sediment toxicity assays.

    Science.gov (United States)

    Cesnaitis, Romanas; Sobanska, Marta A; Versonnen, Bram; Sobanski, Tomasz; Bonnomet, Vincent; Tarazona, Jose V; De Coen, Wim

    2014-03-15

    For the first REACH registration deadline, companies have submitted registrations with relevant hazard and exposure information for substances at the highest tonnage level (above 1000 tonnes per year). At this tonnage level, information on the long-term toxicity of a substance to sediment organisms is required. There are a number of available test guidelines developed and accepted by various national/international organisations, which can be used to investigate long-term toxicity to sediment organisms. However instead of testing, registrants may also use other options to address toxicity to sediment organisms, e.g. weight of evidence approach, grouping of substances and read-across approaches, as well as substance-tailored exposure-driven testing. The current analysis of the data provided in ECHA database focuses on the test methods applied and the test organisms used in the experimental studies to assess long-term toxicity to sediment organisms. The main guidelines used for the testing of substances registered under REACH are the OECD guidelines and OSPAR Protocols on Methods for the Testing of Chemicals used in the Offshore Oil Industry: "Part A: A Sediment Bioassay using an Amphipod Corophium sp." explaining why one of the mostly used test organisms is the marine amphipod Corophium sp. In total, testing results with at least 40 species from seven phyla are provided in the database. However, it can be concluded that the ECHA database does not contain a high enough number of available experimental data on toxicity to sediment organisms for it to be used extensively by the scientific community (e.g. for development of non-testing methods to predict hazards to sediment organisms). © 2013.

  16. A thermoelectric power generating heat exchanger: Part I – Experimental realization

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Sarhadi, Ali; Pryds, Nini

    2016-01-01

    An experimental realization of a heat exchanger with commercial thermoelectric generators (TEGs) is presented. The power producing capabilities as a function of flow rate and temperature span are characterized for two different commercial heat transfer fluids and for three different thermal...

  17. A Transverse Oscillation Approach for Estimation of Three-Dimensional Velocity Vectors, Part II: Experimental Validation

    DEFF Research Database (Denmark)

    Pihl, Michael Johannes; Stuart, Matthias Bo; Tomov, Borislav Gueorguiev

    2014-01-01

    The 3-D transverse oscillation method is investigated by estimating 3-D velocities in an experimental flowrigsystem. Measurements of the synthesized transverse oscillatingfields are presented as well. The method employs a 2-D transducer; decouples the velocity estimation; and estimates the axial,...

  18. E-learning for Part-Time Medical Studies

    Directory of Open Access Journals (Sweden)

    Półjanowicz Wiesław

    2016-12-01

    Full Text Available Distance education undoubtedly has many advantages, such as individualization of the learning process, unified transmission of teaching materials, the opportunity to study at any place and any time, reduction of financial costs for commuting to classes or accommodation of participants, etc. Adequate working conditions on the e-learning portal must also be present, eg. well-prepared, substantive courses and good communication between the participants. Therefore, an important element in the process of conducting e-learning courses is to measure the increase of knowledge and satisfaction of participants with distance learning. It allows for fine-tuning the content of the course and for classes to be properly organized. This paper presents the results of teaching and assessment of satisfaction with e-learning courses in “Problems of multiculturalism in medicine”, “Selected issues of visual rehabilitation” and “Ophthalmology and Ophthalmic Nursing”, which were carried out experimentally at the Faculty of Health Sciences at the Medical University of Bialystok for nursing students for the 2010/2011 academic year. The study group consisted of 72 part-time students who learnt in e-learning mode and the control group of 87 students who learnt in the traditional way. The students’ opinions about the teaching process and final exam scores were analyzed based on a specially prepared survey questionnaire. Organization of e-learning classes was rated positively by 90% of students. The average result on the final exams for all distance learning subjects was at the level of 82%, while for classes taught in the traditional form it was 81%. Based on these results, we conclude that distance learning is as effective as learning according to the traditional form in medical education studies.

  19. Inner detached frequency response curves: an experimental study

    Science.gov (United States)

    Gatti, Gianluca; Brennan, Michael J.

    2017-05-01

    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.

  20. A theoretical and experimental study of the thermal degradation of biomass

    Energy Technology Data Exchange (ETDEWEB)

    Groenli, Morten G.

    1996-12-31

    This thesis relates to the thermal degradation of biomass covering a theoretical and experimental study in two parts. In the first part, there is presented an experimental and modeling work on the pyrolysis of biomass under regimes controlled by chemical kinetics, and the second part presents an experimental and modeling work on the pyrolysis of biomass under regimes controlled by heat and mass transfer. Five different celluloses, and hemicellulose and lignin isolated from birch and spruce have been studied by thermogravimetry. The thermo grams of wood species revealed different weight loss characteristics which can be attributed to their different chemical composition. The kinetic analysis gave activation energies between 210 and 280 kJ/mole for all the celluloses, and a model of independent parallel reactions was successfully used to describe the thermal degradation. In the second part of the thesis there is presented experimental and modeling work on the pyrolysis of biomass under regimes controlled by heat and mass transfer. The effect of heating conditions on the product yields distribution and reacted fraction was investigated. The experiments show that heat flux alters the pyrolysis products as well as the intra particle temperatures to the greatest extent. A comprehensive mathematical model which can simulate drying and pyrolysis of moist wood is presented. The simulation of thermal degradation and heat transport processes agreed well with experimental results. 198 refs., 139 figs., 68 abs.

  1. Experimenter's Pantomimes Influence Children's Use of Body Part as Object and Imaginary Object Pantomimes: A Replication

    Science.gov (United States)

    Mitchell, Robert W.; Clark, Heather

    2015-01-01

    Young children asked to pretend to use a series of absent objects typically pantomime by using a body part as the object (BPO) rather than by acting as if using an imaginary object (IO). This replication of Lyons's work (1983, 1986) examines whether different pretend contexts when requesting pantomimes influence children's use of IO and BPO…

  2. MATLAB-based Applications for Image Processing and Image Quality Assessment – Part II: Experimental Results

    Directory of Open Access Journals (Sweden)

    L. Krasula

    2012-04-01

    Full Text Available The paper provides an overview of some possible usage of the software described in the Part I. It contains the real examples of image quality improvement, distortion simulations, objective and subjective quality assessment and other ways of image processing that can be obtained by the individual applications.

  3. Amniotic membrane as part of a skin substitute for full-thickness wounds: an experimental evaluation in a porcine model.

    Science.gov (United States)

    Loeffelbein, Denys J; Baumann, Claudia; Stoeckelhuber, Mechthild; Hasler, Rafael; Mücke, Thomas; Steinsträßer, Lars; Drecoll, Enken; Wolff, Klaus-Dietrich; Kesting, Marco R

    2012-07-01

    We evaluated the use of human amniotic membrane (HAM) as a graft material for the treatment of iatrogenic full-thickness (FT) skin wounds in a porcine model with a view to reducing donor site morbidity in free flap transfer. Forty experimental FT-wounds were covered with an autologous split-thickness skin graft (STSG) alone or in combination with a mono- or multilayer HAM or Integra(®). Untreated wounds served as controls. Clinical evaluation and biopsy-sampling for histological and immunohistochemical staining with von-Willebrand-factor (vWF) antibody, laminin antibody, Ki-67 antibody, and smooth muscle actin (αSMA) antibody were performed on days 5, 7, 10, 20, 40, and 60 after surgical intervention. Considerable disparities in the estimated criteria were observed between the various treatment groups of the FT-wounds. The use of HAM was found to have an accelerating impact on re-epithelialization. The multilayered amnion membrane showed better results than the Integra(®) and monolayer technique in terms of contraction rate, inflammation, and scarring and seemed useful as a dermal substitute in FT-wounds giving comparable results to STSG coverage alone. This study demonstrates the successful application of HAM as part of a skin substitute in FT-wounds in minipigs. The results offer promise as a simple and effective technique for the application of multilayer HAM in iatrogenic human skin defects and the acceleration of wound healing. Copyright © 2012 Wiley Periodicals, Inc.

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

    NARCIS (Netherlands)

    Fleuren, Gerard Johannes Maria

    1976-01-01

    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

  5. Experimental study of convective flows in the freezer

    Directory of Open Access Journals (Sweden)

    Krasnoshlykov Alexander

    2014-01-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    1974-01-01

    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.

  7. Numerical and experimental studies of droplet-gas flow

    Energy Technology Data Exchange (ETDEWEB)

    Joesang, Aage Ingebret

    2002-07-01

    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

  8. 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....

  9. Experimental and numerical study of globe valve housing

    Directory of Open Access Journals (Sweden)

    Mitrovic Nenad R.

    2017-01-01

    Full Text Available Complex structure experimental analysis has always been a huge challenge for researchers. Conventional experimental methods (e.g., strain gauges give only limited data sets regarding measurement on critical areas with high geometrical discontinuities. A 3D Digital Image Correlation method is an optical method that overcomes the limitations of conventional methods and enables full-field displacement and strain measurement of geometrically complex structures. System Aramis, based on Digital Image Correlation method, is used for experimental analysis and numerical model verification in this paper. Investigated complex structure is sphere/cylinder junction on globe valve housing subjected to axial loading. The highest experimentally measured von Mises strain values around 0.15% are recorded on cylinder/sphere intersection. Von Mises strain values on cylindrical and spherical part are several times smaller than on intersection itself. It is important to emphasize that, to the authors’ best knowledge, this is the first paper showing experimental results of 3D full and strain field of geometrically complex structure (sphere/cylinder intersection on the intersection itself on pressure equipment. It is proven that 3D Digital Image Correlation method is fast and versatile method for recording strain during loading of complex structures. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR35031 and Grant no. TR35040

  10. Biological characteristics as a part of pollution monitoring studies

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, V.R.; Govindan, K.

    Ecosystem modifications can be considered as an integral part of any pollution monitoring studies and in such cases community structure/diversity is of prime importance. Considering this advantage of aquatic life, pelagic and benthic communities...

  11. The two-stroke poppet valve engine. Part 1: Intake and exhaust ports flow experimental assessments

    Science.gov (United States)

    Kamili Zahidi, M.; Razali Hanipah, M.; Ramasamy, D.; Noor, M. M.; Kadirgama, K.; Rahman, M. M.

    2017-10-01

    A two-stroke poppet valve engine is developed to overcome the common problems in conventional two-stroke engine designs. However, replacing piston control port with poppet valve will resulted different flow behaviour. This paper is looking at experimental assessment on a two-stroke poppet valve engine configuration to investigate the port flow performance. The aims are to evaluate the intake and exhaust coefficient of discharge and assess the twostroke capability of the cylinder head. The results has shown comparable coefficient of discharge values as production engine for the intake while the exhaust has higher values which is favourable for the two-stroke cycle operation.

  12. A theoretical and experimental study of coplanar waveguide shunt stubs

    Science.gov (United States)

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

    1993-01-01

    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.

  13. Experimental study of the robust global synchronization of Brockett oscillators

    Science.gov (United States)

    Ahmed, Hafiz; Ushirobira, Rosane; Efimov, Denis

    2017-12-01

    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.

  14. 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)

    2011-07-01

    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

  15. Studies on the Process Parameters of Rapid Prototyping Technique (Stereolithography for the Betterment of Part Quality

    Directory of Open Access Journals (Sweden)

    Raju Bangalore Singe Gowda

    2014-01-01

    Full Text Available Rapid prototyping (RP has evolved as frontier technology in the recent times, which allows direct transformation of CAD files into functional prototypes where it tremendously reduces the lead time to produce physical prototypes necessary for design verification, fit, and functional analysis by generating the prototypes directly from the CAD data. Part quality in the rapid prototyping process is a function of build parameters such as hatch cure depth, layer thickness, orientation, and hatch spacing. Thus an attempt was made to identify, study, and optimize the process parameters governing the system which are related to part characteristics using Taguchi experimental design techniques quality. The part characteristics can be divided into physical part and mechanical part characteristics. The physical characteristics are surface finish, dimensional accuracy, distortion, layer thickness, hatch cure, and hatch file, whereas mechanical characteristics are flexural strength, ultimate tensile strength, and impact strength. Thus, this paper proposes to characterize the influence of the physical build parameters over the part quality. An L9 orthogonal array was designed with the minimum number of experimental runs with desired parameter settings and also by analysis tools such as ANOVA (analysis of variance. Establishment of experimentally verified correlations between the physical part characteristics and mechanical part characteristics to obtain an optimal process parameter level for betterment of part quality is obtained. The process model obtained by the empirical relation can be used to determine the strength of the prototype for the given set of parameters that shows the dependency of strength, which are essential for designers and RP machine users.

  16. Using an experimental model for the study of therapeutic touch.

    Science.gov (United States)

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

    2013-02-01

    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.

  17. Professional Learning in Part-time University Study

    DEFF Research Database (Denmark)

    Rasmussen, Palle

    2007-01-01

    The theme of this article is adult students' learning in part-time studies at university level in Denmark. One issue discussed is the interplay of research and teaching in this kind of study programme. Examples are presented from the Master of Learning Processes study programme at Aalborg University...

  18. More accurate macro-models of solid oxide fuel cells through electrochemical and microstructural parameter estimation - Part I: Experimentation

    Science.gov (United States)

    Boigues Muñoz, Carlos; Pumiglia, Davide; McPhail, Stephen J.; Montinaro, Dario; Comodi, Gabriele; Santori, Giulio; Carlini, Maurizio; Polonara, Fabio

    2015-10-01

    The distributed relaxation times (DRT) method has been employed in order to deconvolute the electrochemical impedance spectroscopy (EIS) measurements carried out on a Ni-YSZ|YSZ|Pr2NiO4+δ - GDC solid oxide fuel cell (SOFC). This has enabled to shed light on the diverse physicochemical processes occurring within the aforementioned cell by individuating the characteristic relaxation times of these by means of a specifically designed experimental campaign where temperature and gas compositions in anode and cathode were varied one at a time. A comprehensive equivalent circuit model (ECM) has thus been generated based on the processes observed in the DRT spectra. This ECM has proved to be instrumental for the obtainment of parameters which describe the microstructural and electrochemical properties of the SOFC when used contemporaneously with experimental results and modelling theory (described in Part II of this work).

  19. Frequency-Dependent Streaming Potential of Porous Media—Part 1: Experimental Approaches and Apparatus Design

    Directory of Open Access Journals (Sweden)

    P. W. J. Glover

    2012-01-01

    Full Text Available Electrokinetic phenomena link fluid flow and electrical flow in porous and fractured media such that a hydraulic flow will generate an electrical current and vice versa. Such a link is likely to be extremely useful, especially in the development of the electroseismic method. However, surprisingly few experimental measurements have been carried out, particularly as a function of frequency because of their difficulty. Here we have considered six different approaches to make laboratory determinations of the frequency-dependent streaming potential coefficient. In each case, we have analyzed the mechanical, electrical, and other technical difficulties involved in each method. We conclude that the electromagnetic drive is currently the only approach that is practicable, while the piezoelectric drive may be useful for low permeability samples and at specified high frequencies. We have used the electro-magnetic drive approach to design, build, and test an apparatus for measuring the streaming potential coefficient of unconsolidated and disaggregated samples such as sands, gravels, and soils with a diameter of 25.4 mm and lengths between 50 mm and 300 mm.

  20. Experimental Study of Supercooled Large Droplet Impingement Effects

    Science.gov (United States)

    Papadakis, M.; Rachman, A.; Wong, S. C.; Hung, K. E.; Vu, G. T.

    2003-01-01

    Typically, ice accretion results from small supercooled droplets (droplets cooled below freezing), usually 5 to 50 microns in diameter, which can freeze upon impact with an aircraft surface. Recently, ice accretions resulting from supercooled large droplet (SLD) conditions have become a safety concern. Current ice accretion codes have been extensively tested for Title 14 Code of Federal Regulations Part 25, Appendix C icing conditions but have not been validated for SLD icing conditions. This report presents experimental methods for investigating large droplet impingement dynamics and for obtaining small and large water droplet impingement data.

  1. A transverse oscillation approach for estimation of three-dimensional velocity vectors, part II: experimental validation.

    Science.gov (United States)

    Pihl, Michael Johannes; Stuart, Matthias Bo; Tomov, Borislav Gueorguiev; Rasmussen, Morten Fischer; Jensen, Jørgen Arendt

    2014-10-01

    The 3-D transverse oscillation method is investigated by estimating 3-D velocities in an experimental flow-rig system. Measurements of the synthesized transverse oscillating fields are presented as well. The method employs a 2-D transducer; decouples the velocity estimation; and estimates the axial, transverse, and elevation velocity components simultaneously. Data are acquired using a research ultrasound scanner. The velocity measurements are conducted with steady flow in sixteen different directions. For a specific flow direction with [α, ß] = [45, 15]°, the mean estimated velocity vector at the center of the vessel is (v(x), v(y), v(z)) = (33.8, 34.5, 15.2) ± (4.6, 5.0, 0.6) cm/s where the expected velocity is (34.2, 34.2, 13.0) cm/s. The velocity magnitude is 50.6 ± 5.2 cm/s with a bias of 0.7 cm/s. The flow angles α and ß are estimated as 45.6 ± 4.9° and 17.6 ± 1.0°. Subsequently, the precision and accuracy are calculated over the entire velocity profiles. On average for all direction, the relative mean bias of the velocity magnitude is -0.08%. For α and ß, the mean bias is -0.2° and -1.5°. The relative standard deviations of the velocity magnitude ranges from 8 to 16%. For the flow angles, the ranges of the mean angular deviations are 5° to 16° and 0.7° and 8°.

  2. Olfactory ensheathing cells: part I—current concepts and experimental laboratory models.

    Science.gov (United States)

    Gladwin, Karen; Choi, David

    2015-01-01

    This study sought to assess the results of current laboratory studies of olfactory ensheathing cell (OEC) transplantation for the treatment of central nervous system repair. This study used a literature search and topic review. There are numerous successful reports of regeneration and functional improvements in animals after OEC transplantation, but a few negative studies raise questions. Although the exact mechanisms of action of OECs are not fully understood, it is clear that OECs have beneficial regenerative properties in laboratory studies, and the ease with which OECs can be harvested and cultured in animal models make clinical application a very reasonable prospect. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. A Novel Camera Calibration Algorithm as Part of an HCI System: Experimental Procedure and Results

    Directory of Open Access Journals (Sweden)

    Sauer Kristal

    2006-02-01

    Full Text Available Camera calibration is an initial step employed in many computer vision applications for the estimation of camera parameters. Along with images of an arbitrary scene, these parameters allow for inference of the scene's metric information. This is a primary reason for camera calibration's significance to computer vision. In this paper, we present a novel approach to solving the camera calibration problem. The method was developed as part of a Human Computer Interaction (HCI System for the NASA Virtual GloveBox (VGX Project. Our algorithm is based on the geometric properties of perspective projections and provides a closed form solution for the camera parameters. Its accuracy is evaluated in the context of the NASA VGX, and the results indicate that our algorithm achieves accuracy similar to other calibration methods which are characterized by greater complexity and computational cost. Because of its reliability and wide variety of potential applications, we are confident that our calibration algorithm will be of interest to many.

  4. Curation of Laboratory Experimental Data as Part of the Overall Data Lifecycle

    Directory of Open Access Journals (Sweden)

    Jeremy Frey

    2008-08-01

    Full Text Available The explosion in the production of scientific data in recent years is placing strains upon conventional systems supporting integration, analysis, interpretation and dissemination of data and thus constraining the whole scientific process. Support for handling large quantities of diverse information can be provided by e-Science methodologies and the cyber-infrastructure that enables collaborative handling of such data. Regard needs to be taken of the whole process involved in scientific discovery. This includes the consideration of the requirements of the users and consumers further down the information chain and what they might ideally prefer to impose on the generators of those data. As the degree of digital capture in the laboratory increases, it is possible to improve the automatic acquisition of the ‘context of the data’ as well as the data themselves. This process provides an opportunity for the data creators to ensure that many of the problems they often encounter in later stages are avoided. We wish to elevate curation to an operation to be considered by the laboratory scientist as part of good laboratory practice, not a procedure of concern merely to the few specialising in archival processes. Designing curation into experiments is an effective solution to the provision of high-quality metadata that leads to better, more re-usable data and to better science.

  5. 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 ...

  6. 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 ...

  7. Infections in orthopaedic surgery : clinical and experimental studies

    NARCIS (Netherlands)

    Vogely, Henri Charles

    2000-01-01

    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

  8. 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

    2015-01-01

    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

  9. What Shapes the Intention to Study Abroad? An Experimental Approach

    Science.gov (United States)

    Petzold, Knut; Moog, Petra

    2018-01-01

    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)…

  10. 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 ...

  11. Experimental Studies on Electronic Portfolios in Turkey: A Literature Review

    Science.gov (United States)

    Alan, Selahattin; Sünbül, Ali Murat

    2015-01-01

    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…

  12. Hydrogeophysical study of parts of charnockite terrain of Akure ...

    African Journals Online (AJOL)

    Hydrogeophysical study of parts of Charnockite terrain of Akure, southwestern Nigeria was carried out using the electrical resistivity method. The study involved one hundred and fifty two (152) Schlumberger geoelectric soundings (with seven (7) of them parametric)) alongside static water level measurements in 102 ...

  13. An Experimental Study of Drag Reduction in a Pipe with Superhydrophobic Coating at Moderate Reynolds Numbers

    Directory of Open Access Journals (Sweden)

    Kuo L.

    2010-06-01

    Full Text Available This paper experimentally investigates drag reduction, durability for operations and effects for preventing microorganism from adhering to the surface when the superhydrophobic coating is applied on a solid surface. The experiments are divided into two parts. In the first part, a pipe flow system was established to measure the drag and to test the durability of the micro-structure of superhydrophobic coating at average speeds varying from 1m/sec to 6m/sec. In the second part, we tested the effect for preventing microorganism from adhering to the surface by putting the coated steel plates into sea water. There are four different superhydrophobic coatings in the present study. The experimental results were compared to those applied by ship paint usually used at CSBC.

  14. Diffusion in liquids a theoretical and experimental study

    CERN Document Server

    Tyrrell, H J V

    1984-01-01

    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

  15. Analytical and Experimental Study of Residual Stresses in CFRP

    Directory of Open Access Journals (Sweden)

    Chia-Chin Chiang

    2013-01-01

    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.

  16. Experimental study of lithium target under high power load

    Energy Technology Data Exchange (ETDEWEB)

    Khripunov, B.I. E-mail: boris@nfi.kiae.ru; 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

    2001-03-01

    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.

  17. Conversion of eugenol to methyleugenol: Computational study and experimental

    Science.gov (United States)

    Kurniawan, Muhammad Arsyik; Matsjeh, Sabirin; Triono, Sugeng

    2017-03-01

    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.

  18. Experimental study of hole cleaning performance in underbalanced

    African Journals Online (AJOL)

    ADEBOYE

    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 ...

  19. 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.

  20. It Pays to Compare: An Experimental Study on Computational Estimation

    Science.gov (United States)

    Star, Jon R.; Rittle-Johnson, Bethany

    2009-01-01

    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…

  1. 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 ...

  2. Premium auctions and risk preferences: an experimental study

    NARCIS (Netherlands)

    Brunner, C.; Hu, A.; Oechssler, J.

    2014-01-01

    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

  3. 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 ...

  4. 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

    1969-08-01

    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.

  5. 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 ...

  6. 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 ...

  7. 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.

  8. 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...

  9. Real versus Simulated Mobile Phone Exposures in Experimental Studies

    Directory of Open Access Journals (Sweden)

    Dimitris J. Panagopoulos

    2015-01-01

    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.

  10. Chemometric Optimization Studies in Catalysis Employing High-Throughput Experimentation

    NARCIS (Netherlands)

    Pereira, S.R.M.

    2008-01-01

    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

  11. 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 ...

  12. Experimental study of buoyancy driven natural ventilation through horizontal openings

    DEFF Research Database (Denmark)

    Heiselberg, Per; Li, Zhigang

    2007-01-01

    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...

  13. 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 ...

  14. Forward tracking at the next $e^{+}e^{-}$ collider part II: experimental challenges and detector design

    CERN Document Server

    Aplin, S.; Dannheim, D.; Duarte, J.; Gaede, F.; Ruiz-Jimeno, A.; Sailer, A.; Valentan, M.; Vila, I.; Vos, M.

    2013-06-01

    We present the second in a series of studies into the forward tracking system for a future linear e+e− collider with a center-of-mass energy in the range from 250 GeV to 3 TeV. In this note a number of specific challenges are investigated, which have caused a degradation of the tracking and vertexing performance in the forward region in previous experiments. We perform a quantitative analysis of the dependence of the tracking performance on detector design parameters and identify several ways to mitigate the performance loss for charged particles emitted at shallow angle.

  15. Experimental study on imaging spectrometer focusing formula in orbit

    Science.gov (United States)

    Ma, Hong-tao; Jin, Hui

    2015-02-01

    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.

  16. Morphometric studies on a part of Central Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Kodagali, V.N.

    Morphometric and slope angle studies carried out on a part of Indian Ocean Basin have shown that gentle slope angle ranges dominate, 92% of the area represented by 0-3 degrees slopes. Young's hypothesis of log-normal distribution of slope angle...

  17. Experimental study on beam for composite CES structural system

    Science.gov (United States)

    Matsui, Tomoya

    2017-10-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Majkut Mirosław

    2015-09-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Juhyuk, E-mail: juhyuk.moon@stonybrook.edu [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)

    2015-05-15

    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.

  20. The role of chemometrics in single and sequential extraction assays: a review. Part II. Cluster analysis, multiple linear regression, mixture resolution, experimental design and other techniques.

    Science.gov (United States)

    Giacomino, Agnese; Abollino, Ornella; Malandrino, Mery; Mentasti, Edoardo

    2011-03-04

    Single and sequential extraction procedures are used for studying element mobility and availability in solid matrices, like soils, sediments, sludge, and airborne particulate matter. In the first part of this review we reported an overview on these procedures and described the applications of chemometric uni- and bivariate techniques and of multivariate pattern recognition techniques based on variable reduction to the experimental results obtained. The second part of the review deals with the use of chemometrics not only for the visualization and interpretation of data, but also for the investigation of the effects of experimental conditions on the response, the optimization of their values and the calculation of element fractionation. We will describe the principles of the multivariate chemometric techniques considered, the aims for which they were applied and the key findings obtained. The following topics will be critically addressed: pattern recognition by cluster analysis (CA), linear discriminant analysis (LDA) and other less common techniques; modelling by multiple linear regression (MLR); investigation of spatial distribution of variables by geostatistics; calculation of fractionation patterns by a mixture resolution method (Chemometric Identification of Substrates and Element Distributions, CISED); optimization and characterization of extraction procedures by experimental design; other multivariate techniques less commonly applied. Copyright © 2010 Elsevier B.V. All rights reserved.

  1. A novel cadaveric study of the morphometry of the serratus anterior muscle: one part, two parts, three parts, four?

    Science.gov (United States)

    Webb, Alexandra Louise; O'Sullivan, Elizabeth; Stokes, Maria; Mottram, Sarah

    2018-01-01

    The serratus anterior is portrayed as a homogeneous muscle in textbooks and during functional activities and rehabilitation exercises. It is unclear whether the serratus anterior is composed of subdivisions with distinctive morphology and functions. The purpose of this study was to determine whether the serratus anterior could be subdivided into different structural parts on the basis of its segmental architectural parameters. Eight formalin-embalmed serratus anterior muscles were dissected and the attachments of each fascicle documented. Orientation and size of each fascicle were measured and the physiological cross-sectional area (PCSA) calculated. Three subdivisions of the serratus anterior were identified. A new finding was the discovery of two distinctive fascicles attached to the superior and inferior aspects of rib 2. The rib 2 inferior fascicle had the largest PCSA (mean 1.6 cm 2 ) and attached, with the rib 3 fascicle, along the medial border of the scapula to form the middle division. The rib 2 superior and rib 1 fascicles attached to the superior angle of the scapula (upper division). Fascicles from ribs 4-8/9 attached to the inferior angle of the scapula (lower division). Mean fascicle angle relative to a vertical midline reference and PCSA for each division were 29° and 1.3 cm 2 (upper), 90° and 2.2 cm 2 (middle) and 59° and 3.0 cm 2 (lower). This novel study demonstrated the presence of morphologically distinct serratus anterior subdivisions. The results of this study will inform the development of optimal techniques for the assessment, treatment and rehabilitation of this architecturally complex muscle in shoulder and neck pain.

  2. Pseudoepitheliomatous hyperplasia after diode laser oral surgery. An experimental study

    Science.gov (United States)

    Seoane, Juan; González-Mosquera, Antonio; García-Martín, José-Manuel; García-Caballero, Lucía; Varela-Centelles, Pablo

    2015-01-01

    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

  3. Solar-Powered Desalination: A Modelling and Experimental Study

    Science.gov (United States)

    Leblanc, Jimmy; Andrews, John

    2007-10-01

    Water shortage is becoming one of the major problems worldwide. As such, desalination technologies have been implemented to meet growing demands for fresh water. Among the desalination technologies, thermal desalination, including multi stage flash (MSF) and multi effect evaporation (MEE), is the current leading desalination process. Reverse osmosis (RO) is also being increasingly used. Despite technological improvements, thermal desalination and reverse osmosis continue to be intensive fossil-fuel consumers and contribute to increased levels of greenhouse gases. As energy costs rise, thermal desalination by solar energy and/or low cost waste heat is likely to become increasingly attractive. As part of a project investigating the productive use of saline land and the development of sustainable desalination systems, the feasibility of producing potable water from seawater or brackish water using desalination systems powered by renewable energy in the form of low-temperature solar-thermal sources has been studied. A salinity-gradient solar pond and an evacuated tube solar collector system have been used as heat sources. Solar ponds combine solar energy collection with long-term storage and can provide reliable thermal energy at temperature ranges from 50 to 90 °C. A visual basic computer model of the different multi-stage flash desalination processes coupled with a salinity-gradient solar pond was developed to determine which process is preferable in regards to performance and greenhouse impact. The governing mathematical equations are derived from mass balances, heat energy balances, and heat transfer characteristics. Using the results from the modelling, a small-scale solar-powered desalination system, capable of producing up to 500 litres of fresh water per day, was designed and manufactured. This single-stage flash system consists of two main units: the heat supply and storage system and the flash desalination unit. Two different condenser heat exchanger

  4. Experimental Study on Volume for Fly Ash of Building Block

    OpenAIRE

    Ling Wang; He Sun; Zhihui Sun; Enqing Ma

    2013-01-01

    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, ...

  5. Experimental and Analytical Studies of Solar System Chemistry

    Science.gov (United States)

    Burnett, Donald S.

    2003-01-01

    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.

  6. Experimental Studies of the Transport Parameters of Warm Dense Matter

    Energy Technology Data Exchange (ETDEWEB)

    Chouffani, Khalid [Idaho State Univ., Pocatello, ID (United States)

    2014-12-01

    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.

  7. Experimental and Theoretical Studies in Hydrogen-Bonding Organocatalysis

    Directory of Open Access Journals (Sweden)

    Matej Žabka

    2015-08-01

    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.

  8. Experimental study of prequalified status of flush end plate connections

    Directory of Open Access Journals (Sweden)

    Sherif H.M. Hassanien

    2016-04-01

    Full Text Available Seismic design of steel structures is an essential part of the design process. Egyptian loading code development process continues in a high rate to catch up with emerging new concepts and standards. Steel design codes (ASD and LRFD are not developing in the same speed, which prevents the full utilization and application of loading code. The above reason leads to the need for evaluating flush end plate connections from prequalification point of view according to international standards. Due to the lack of sufficient experimental data on flush end-plate connections, an experimental program was conducted to investigate this topic. Six flush end-plate samples were designed according to the Egyptian code for steel construction (ECP205 ASD using different beam and column sections, bolt diameters and grades. A cyclic loading pattern defined by international standards was used in the testing process, and the performance was evaluated accordingly. Evaluation of M–Φ curves showed that in some cases flush end plate connections satisfy the strict requirements for prequalification. However, beam sections having limited depth fail to achieve prequalification criteria for the connections. Reduced web may be used to enhance the connection status and is investigated in one of the samples to evaluate its impact on connection performance and the failure mode. The proposed staggered hole configuration showed a promising performance.

  9. Ethnic Heritage Studies: Northern European Foods. Experimental Unit.

    Science.gov (United States)

    Freepartner, Susan

    This teaching guide focuses on the Northern European food heritage. It is part of the Louisville Area Ethnic Heritage Studies Project described in ED 150 043. The materials are designed to foster communication across intercultural/ethnic lines. The objective of this unit is to gain familiarity with and appreciate foods from Scandinavia, the Soviet…

  10. Ethnic Heritage Studies: Southern European Foods. Experimental Unit.

    Science.gov (United States)

    Freepartner, Susan

    This teaching guide focuses on the Southern European food heritage. It is part of the Louisville Area Ethnic Heritage Studies Project described in ED 150 043. The project materials are designed to foster communication across intercultural/ethnic lines. The objective of this unit is to gain familiarity with and appreciate foods from Spain, France,…

  11. An experimental and theoretical study of oligo- and polyelectrolyte adsorption

    NARCIS (Netherlands)

    Schee, van der H.A.

    1984-01-01

    The purpose of this study is the description of the behaviour of a model polyelectrolyte near a model interface.

    Chapter 1 gives a general background and the outline of the investigations.

    The chapters 2 and 3 comprise the theoretical parts. Chapter 2 considers the applicability of

  12. Lunar evolution: a combined numerical modelling and HPT experimental study

    NARCIS (Netherlands)

    de Vries, J.

    2012-01-01

    Recent studies, some of them using data from the Apollo seismic network from the 1960's and 1970's, others using newer data, have shown that part of the lunar core may still be fluid today. Furthermore, a possible partial melt zone has been detected in the deep mantle, just above the core-mantle

  13. Experimental study on iodine chemistry (EXSI) - Containment experiments with elemental iodine

    Energy Technology Data Exchange (ETDEWEB)

    Kaerkelae, T.; Auvinen, A. (VTT Technical Research Centre of Finland (Finland)); Holm, J.; Ekberg, C. (Chalmers Univ. of Technology (Sweden)); Glaenneskog, H. (Vattenfall Power Consultant (Sweden))

    2009-10-15

    The behaviour of iodine during a severe accident has been studied in several experimental programs, ranging from the large-scale PHEBUS FP tests and intermediate-scale ThAI tests to numerous separate effect studies. Oxidation of iodine in gas phase has been one of the greatest remaining uncertainties in iodine behaviour during a severe accident. In this study the possible formation of iodine oxide aerosol due to radiolytic oxidation of gaseous iodine is experimentally tested and the reaction products are analysed. The experimental facility applied in this study is based on the sampling system built at VTT for ISTP program project CHIP conducted IRSN. The experimental facility and the measuring technology are sophisticated and unique in the area of nuclear research as well as in the field of aerosol science. The results from the experiments show an extensive particle formation when ozone and gaseous iodine react with each other. The formed particles were collected on filters, while gaseous iodine was trapped into bubbles. The particles were iodine oxides and the size of particles was approximately 100 nm. The transport of gaseous iodine through the facility decreased when both gaseous iodine and ozone were fed together into facility. Experimental study on radiolytic oxidation of iodine was conducted in co-operation between VTT and Chalmers University of Technology as a part of the NKS-R programs. (author)

  14. Study of the twinned dendrite tip shape II: Experimental assessment

    Energy Technology Data Exchange (ETDEWEB)

    Salgado-Ordorica, M.A., E-mail: mario.salgado@novelis.com [Laboratoire de Simulation des Materiaux LSMX, Ecole Polytechnique Federale de Lausanne, Station 12, 1015 Lausanne (Switzerland); Burdet, P.; Cantoni, M. [Centre Interdisciplinaire de Microscopie Electronique CIME, Ecole Polytechnique Federale de Lausanne, Station 12, 1015 Lausanne (Switzerland); Rappaz, M. [Laboratoire de Simulation des Materiaux LSMX, Ecole Polytechnique Federale de Lausanne, Station 12, 1015 Lausanne (Switzerland)

    2011-08-15

    The favorable growth kinetics of twinned dendrites can be explained by their complex morphology, multiple side branching mechanisms, growth undercooling and tip morphology. Three models were proposed for the twinned dendrite tip shape: (i) a grooved tip satisfying the Smith condition at the triple line; (ii) a doublon , i.e. a double-tip dendrite that grows with a narrow and deep liquid channel in its center; and (iii) a pointed (or edgy) tip, with consideration of the solid-liquid interfacial energy anisotropy. In the first part of this work, phase field simulations of half a twinned dendrite with an appropriate boundary condition to reproduce the Smith condition supported the doublon conjecture, with a narrow liquid channel ending its solidification with the formation of small liquid droplets. In this part, experimental observations of twinned dendrite tips reveal the presence of a small, but well-defined, groove, thus definitely eliminating the edged tip hypothesis. Focused ion beam nanotomography and energy-dispersive spectroscopy chemical analysis in a transmission electron microscope reveal the existence of a positive solute gradient in a region localized within 2 {mu}m around the twin plane. In Al-Zn specimens, small particles aligned within the twin plane further support the doublon conjecture and the predicted formation of small liquid droplets below the doublon root.

  15. Numerical and Experimental Case Study of Blasting Works Effect

    Science.gov (United States)

    Papán, Daniel; Valašková, Veronika; Drusa, Marian

    2016-10-01

    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.

  16. Lung Morphological Changes in Closed Chest Injury (an experimental study

    Directory of Open Access Journals (Sweden)

    A. M. Golubev

    2012-01-01

    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.

  17. 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

    2012-01-01

    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.

  18. Experimental and theoretical study of horizontal-axis wind turbines

    OpenAIRE

    Anderson, Michael Broughton

    1981-01-01

    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 ...

  19. Composition of intraocular foreign bodies: experimental study of ultrasonographic presentation

    OpenAIRE

    Márcio Augusto Nogueira Costa; Patrícia Novita Garcia; Letícia Fernandes Barroso; Marco Antonio Ferreira; Érika Araki Okuda; Norma Allemann

    2013-01-01

    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...

  20. Respecifying lab ethnography an ethnomethodological study of experimental physics

    CERN Document Server

    Sormani, Philippe

    2014-01-01

    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

  1. Experimental study on durability of small wind turbine

    Science.gov (United States)

    Bao, Daorina; Shang, Wei; Wang, Huan

    2017-06-01

    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.

  2. Experimental studies toward the characterization of Inmetro's circulating water channel

    Science.gov (United States)

    Santos, A. M.; Alho, A. T. P.; Garcia, D. A.; Farias, M. H.; Massari, P. L.; Silva, V. V. S.

    2016-07-01

    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.

  3. Experimental and numerical studies of two arterial wall delamination modes.

    Science.gov (United States)

    Leng, Xiaochang; Zhou, Boran; Deng, Xiaomin; Davis, Lindsey; Lessner, Susan M; Sutton, Michael A; Shazly, Tarek

    2017-09-19

    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.

  4. Analytical and experimental studies of wakes behind circularly capped bubbles

    Science.gov (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.

  5. Experimental studies of the stress state of the surface layer of detailat treatment with submerged jets

    Directory of Open Access Journals (Sweden)

    Олександр Олександрович Анділахай

    2015-03-01

    Full Text Available In the instrument and electrical industry was the use of the method of abrasive machining submerged jet, which is the most promising method for abrasive blasting of small parts of low stiffness. This method eliminates the main drawback сhip plants - abrasion channel nozzles or injection nozzles, but the state of the surface layer of machined parts are poorly understood and to make maximum use of the potential to provide the required quality parameters. The study of the state of the surfaces of parts resulting from abrasive blasting traditional methods, dedicated work, which define quality indicators: microhardness depth residual stress, as well as their nature (compressive, tensile. However, known from the literature values correspond to the conditions of surface treatment of parts in a fixed state with an abrasive material through the feed nozzle, and therefore the dynamics of the interaction of a single abrasive grain and significantly different parts. The process in question, and different modes of processing characteristics of the abrasive grains. In the paper, a series of experimental studies designed to assess the state of machined surfaces of parts as a result of abrasion submerged jets. It is established that during the treatment the non-oriented disorderly traces overlay the abrasive grains on the treated surface, thereby forming a tight skin layer thickness of 4 - 5 micrometers. Processed surface gets cold working, as evidenced by the study of microhardness before and after abrasive machining in a free state submerged jets

  6. An experimental study on recovering heat from domestic drain water

    Science.gov (United States)

    Ramadan, Mohamad; Al Shaer, Ali; Haddad, Ahmad; Khaled, Mahmoud

    2016-07-01

    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.

  7. Experimental and theoretical study of metal combustion in oxygen flows

    CERN Document Server

    El-Rabii, Hazem; Muller, Maryse

    2016-01-01

    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...

  8. Experimental study of effect of stenosis geometry on flow parameters

    Directory of Open Access Journals (Sweden)

    Veselý Ondřej

    2015-01-01

    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.

  9. Experimental study of heat transfer to falling liquid films

    Science.gov (United States)

    Fagerholm, N. E.; Kivioja, K.; Ghazanfari, A. R.; Jaervinen, E.

    1985-12-01

    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.

  10. Assessing the Penetrating Abilities of Experimental Preparation with Dental Infiltrant Features Using Optical Microscope: Preliminary Study.

    Science.gov (United States)

    Skucha-Nowak, Małgorzata; Machorowska-Pieniążek, Agnieszka; Tanasiewicz, Marta

    2016-01-01

    The aim of the infiltration technique is to penetrate demineralized enamel with a low viscosity resin. Icon® (DMG) is the first ever and so far the only dental infiltrant. Bacteriostaticity is one of the properties that should be inherent in dental infiltrants, but Icon lacks this feature. The aim of the preliminary study was to properly choose a dye which would allow us to assess the penetrating abilities of our own, experimental preparation with features of a dental infiltrant with bacteriostatic properties and to compare using an optical microscope the depth of infiltration of the designed experimental preparation with the infiltrant available on the market. The preparation is supposed to infiltrate decalcified human enamel and be assessed with an optical microscope. Eosin, neutral fuchsine and methylene blue were added to experimental preparation with dental infiltrant features and to Icon® (DMG) in order to assess the depth of penetration of the experimental solution into the decalcified layers of enamel. The experimental solution mixes well with eosin, neutral fuchsine, and methylene blue. During the preliminary study, the authors concluded that the experimental solution mixes well with methylene blue, neutral fuchsine, and eosin. An addition of eosin to a preparation which infiltrates inner, demineralized enamel layers, facilitates the assessment of such a preparation with an optical microscope. A designed experimental solution with the main ingredients, i.e., 2-hydroxyethyl methacrylate (HEMA) and tetraethylene glycol dimethacrylate (TEGDMA) with a ratio of 75% to 25% penetrates the demineralized (decalcified) inner parts of the enamel and polymerizes when exposed to light. In order to assess the infiltration of the experimental solution into the demineralized enamel layers, it is required to improve the measurement techniques that utilize optical microscopy.

  11. 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....

  12. Game theory and experimental games the study of strategic interaction

    CERN Document Server

    Colman, Andrew M

    1982-01-01

    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

  13. Experimental Study of Axially Tension Cold Formed Steel Channel Members

    Science.gov (United States)

    Apriani, Widya; Lubis, Fadrizal; Angraini, Muthia

    2017-12-01

    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. Manipulation of pain catastrophizing: An experimental study of healthy participants

    Directory of Open Access Journals (Sweden)

    Joel E Bialosky

    2008-11-01

    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

  15. A Study of Active Rotor-Blade Vibration Control using Electro-Magnetic Actuation - Part II: Experiment

    DEFF Research Database (Denmark)

    Christensen, Rene Hardam; Santos, Ilmar

    2004-01-01

    mistuning, can easily be generated by substitution or rearranging the blades. Six sets of electro-magnetic actuators are applied to the system in order to control the blades as well as the rotor vibrations. Four sets of actuators are mounted in the rotating disc acting directly onto each one of the blades......This is the second paper in a two-part study on active rotor-blade vibration control. This part presents an experimental contribution into the work of active controller design for rotor-blade systems. The primary aim is to give an experimental validation and show the applicability...... of the theoretical results presented in part 1 of the study. A test rig of a coupled rotor-blade system, where blades flexible motion is coupled to rotor lateral motion, is build for the experimental research. The rig is build by four flexible blades radially attached onto a rotating rigid disc and shaft. The rigid...

  16. Solid oxide fuel cell short stack performance testing - Part A: Experimental analysis and μ-combined heat and power unit comparison

    Science.gov (United States)

    Mastropasqua, L.; Campanari, S.; Brouwer, J.

    2017-12-01

    The need to experimentally understand the detailed performance of SOFC stacks under operating conditions typical of commercial SOFC systems has prompted this two-part study. The steady state performance of a 6-cell short stack of yttria (Y2O3) stabilised zirconia (YSZ) with Ni/YSZ anodes and composite Sr-doped lanthanum manganite (LaMnO3, LSM)/YSZ cathodes is experimentally evaluated. In Part A, the stack characterisation is carried out by means of sensitivity analyses on the fuel utilisation factor and the steam-to-carbon ratio. Electrical and environmental performances are assessed and the results are compared with a commercial full-scale micro-CHP system, which comprises the same cells. The results show that the measured temperature dynamics of the short stack in a test stand environment are on the order of many minutes; therefore, one cannot neglect temperature dynamics for a precise measurement of the steady state polarisation behaviour. The overall polarisation performance is comparable to that of the full stack employed in the micro-CHP system, confirming the good representation that short-stack analyses can give of the entire SOFC module. The environmental performance is measured verifying the negligible values of NO emissions (<10 ppb) across the whole polarisation curve.

  17. 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.

    1997-12-31

    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)

  18. Nonlocal Regularized Algebraic Reconstruction Techniques for MRI: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Xin Li

    2013-01-01

    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.

  19. Experimental Method For Studying Habitual Behavior In Food Consumption

    Directory of Open Access Journals (Sweden)

    Naziha Kasraoui

    2015-03-01

    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.

  20. 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)

    1999-02-15

    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.

  1. 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)

    1999-11-01

    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)

  2. Experimental study of flight effects on underexpanded supersonic jet noise

    OpenAIRE

    André, Benoît; Castelain, Thomas; Bailly, Christophe

    2012-01-01

    International audience; Broadband shock-associated noise is a component of jet noise encountered in imperfectly expanded supersonic jets. It is going to be responsible for a dominant part of cabin noise levels at cruise condition for the next-generation commercial aircraft including composite fuselage. A flight simulating facility has been built in the anechoic room of the Centre Acoustique at Ecole Centrale de Lyon and extensive aero-acoustical measurements have been performed to study fligh...

  3. Trends and missing parts in the study of movement ecology

    Science.gov (United States)

    Holyoak, Marcel; Casagrandi, Renato; Nathan, Ran; Revilla, Eloy; Spiegel, Orr

    2008-01-01

    Movement is important to all organisms, and accordingly it is addressed in a huge number of papers in the literature. Of nearly 26,000 papers referring to movement, an estimated 34% focused on movement by measuring it or testing hypotheses about it. This enormous amount of information is difficult to review and highlights the need to assess the collective completeness of movement studies and identify gaps. We surveyed 1,000 randomly selected papers from 496 journals and compared the facets of movement studied with a suggested framework for movement ecology, consisting of internal state (motivation, physiology), motion and navigation capacities, and external factors (both the physical environment and living organisms), and links among these components. Most studies simply measured and described the movement of organisms without reference to ecological or internal factors, and the most frequently studied part of the framework was the link between external factors and motion capacity. Few studies looked at the effects on movement of navigation capacity, or internal state, and those were mainly from vertebrates. For invertebrates and plants most studies were at the population level, whereas more vertebrate studies were conducted at the individual level. Consideration of only population-level averages promulgates neglect of between-individual variation in movement, potentially hindering the study of factors controlling movement. Terminology was found to be inconsistent among taxa and subdisciplines. The gaps identified in coverage of movement studies highlight research areas that should be addressed to fully understand the ecology of movement. PMID:19060194

  4. Experimental study of microtabs in smart blades for wind turbines

    OpenAIRE

    Senosiain Suescun, David; Morales Goicoechea, Joseba

    2013-01-01

    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 ...

  5. Experimental study of temperature effects on air gun signatures

    Energy Technology Data Exchange (ETDEWEB)

    Langhammer, J.; Landroe, M.

    1992-01-01

    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.

  6. A numerical and experimental study of confined swirling jets

    Science.gov (United States)

    Nikjooy, M.; Mongia, H. C.; Samuelsen, G. S.; Mcdonell, V. G.

    1989-01-01

    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.

  7. Experimental studies of ionospheric irregularities and related plasma processes

    Science.gov (United States)

    Baker, Kay D.

    1992-01-01

    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.

  8. Experimental study of flapping jets in a soap film

    Science.gov (United States)

    Lee, Julia; Kim, Ildoo; Mandre, Shreyas

    2015-11-01

    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.

  9. Experimental study of dynamic stall on Darrieus wind turbine blades

    Science.gov (United States)

    Brochier, G.; Fraunie, P.; Beguier, C.; Paraschivoiu, I.

    1985-12-01

    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.

  10. Theoretical and Experimental Studies of Elementary Particle Physics

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Harold G [Indiana University; Kostelecky, V Alan [Indiana University; Musser, James A [Indiana University

    2013-07-29

    The elementary particle physics research program at Indiana University spans a broad range of the most interesting topics in this fundamental field, including important contributions to each of the frontiers identified in the recent report of HEPAP's Particle Physics Prioritization Panel: the Energy Frontier, the Intensity Frontier, and the Cosmic Frontier. Experimentally, we contribute to knowledge at the Energy Frontier through our work on the D0 and ATLAS collaborations. We work at the Intensity Frontier on the MINOS and NOvA experiments and participate in R&D for LBNE. We are also very active on the theoretical side of each of these areas with internationally recognized efforts in phenomenology both in and beyond the Standard Model and in lattice QCD. Finally, although not part of this grant, members of the Indiana University particle physics group have strong involvement in several astrophysics projects at the Cosmic Frontier. Our research efforts are divided into three task areas. The Task A group works on D0 and ATLAS; Task B is our theory group; and Task C contains our MINOS, NOvA, and LBNE (LArTPC) research. Each task includes contributions from faculty, senior scientists, postdocs, graduate and undergraduate students, engineers, technicians, and administrative personnel. This work was supported by DOE Grant DE-FG02-91ER40661. In the following, we describe progress made in the research of each task during the final period of the grant, from November 1, 2009 to April 30, 2013.

  11. Experimental study of physical parameters significant in fullerene synthesis

    Directory of Open Access Journals (Sweden)

    T. NENADOVIC

    2003-07-01

    Full Text Available In this work, the effect of physical parameters on the yield of fullerene, synthesized in a hollow cathode plasma reactor is investigated. The experimental investigations done previously have shown that the fullerene yield depended on tehcnical parameters - the current intensity, inert gas pressure, type of gas and interelectrode gap. The aim of this work was to show that the fullerene yield depends on physical parameters - carbon concentration, carbon flow rate from the interelectrode gap, axial temperature and temperature gradient between the arc channel and the chamber walls as well. It was found that fullerene synthesis occurs in an inert heat bath with dimensions determined by the temperature gradient. The lower temperature limit is around 2000 K and the value of the upper limit is the value of the axis temperature which depends on the discharge conditions. The synthesis of fullerenes is more effective if the carbon concentration in the heat bath is large and the carbon flow rate from that zone to colder parts of chamber is small.

  12. Field, experimental, and numerical studies of deformation localization bands

    Science.gov (United States)

    Petit, J.-P.; Chemenda, A.

    2011-10-01

    Characterization and Formation Mechanisms of Deformation Localization Bands(Shear, Compaction, and Dilatancy): Field and Experimental Data,Theoretical Analysis and Numerical Models;Montpellier, France, 9-10 May 2011. The origin of fractures and discontinuities in rocks has been for decades a subject of common interest in both the academic world and industry, as these features influence hydrocarbon reservoir production. Fractures (notably joints) and deformation bands are usually analyzed on a separate basis. Joints have commonly been interpreted as mode I fractures susing fracture mechanics, whereas the bifurcation theory has been used for deformation bands. This diversity was called into question by the research carried on by the Geo-FracNet consortium sponsored by Total and Shell International. New findings (A. I. Chemenda et al., J. Geophys. Res., 116, B04401, doi:10.1029/2010JB008104, 2011, and references therein) suggest that at least a part of joints could have been formed as dilatancy (dilation) bands, i.e., due not to the strong effective tensile stress concentration at the opening fracture tip but to the porosity increase and decohesion (perigranular and/ or intragranular grain breakage) of the material within a band several grains thick. The band (material damage and dilatancy within it) can propagate along the strike without opening and can eventually be opened.

  13. 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: lanxu@suda.edu.cn [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)

    2016-02-15

    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.

  14. EXPERIMENTAL STUDY OF THE PRODUCTION OF SOLAR HYDROGEN IN ALGERIA

    Directory of Open Access Journals (Sweden)

    W. Bendaikha

    2015-08-01

    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 STUDY OF INFORMAL NORMS OF URBAN COLORISTICS

    Directory of Open Access Journals (Sweden)

    Yulia Alexandrowna Griber

    2017-02-01

    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.

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

    CERN Document Server

    Stanton, N M

    2001-01-01

    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...

  17. Experimental study of friction in aluminium bolted joints

    Directory of Open Access Journals (Sweden)

    Vincenzi N.

    2010-06-01

    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.

  18. PIO I-II tendencies case study. Part 1. Mathematical modeling

    Directory of Open Access Journals (Sweden)

    Adrian TOADER

    2010-03-01

    Full Text Available In the paper, a study is performed from the perspective of giving a method to reduce the conservatism of the well known PIO (Pilot-Induced Oscillation criteria in predicting the susceptibility of an aircraft to this very harmful phenomenon. There are three interacting components of a PIO – the pilot, the vehicle, and the trigger (in fact, the hazard. The study, conceived in two parts, aims to underline the importance of human pilot model involved in analysis. In this first part, it is shown, following classical sources, how the LQG theory of control and estimation is used to obtain a complex model of human pilot. The approach is based on the argument, experimentally proved, that the human behaves “optimally” in some sense, subject to his inherent psychophysical limitations. The validation of such model is accomplished based on the experimental model of a VTOL-type aircraft. Then, the procedure of inserting typical saturation nonlinearities in the open loop transfer function is presented. A second part of the paper will illustrate PIO tendencies evaluation by means of a grapho-analytic method.

  19. Thermal-Hydraulic Analysis of an Experimental Reactor Cavity Cooling System with Air. Part I: Experiments; Part II: Separate Effects Tests and Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Corradin, Michael [Univ. of Wisconsin, Madison, WI (United States). Dept. of Engineering Physics; Anderson, M. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Engineering Physics; Muci, M. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Engineering Physics; Hassan, Yassin [Texas A & M Univ., College Station, TX (United States); Dominguez, A. [Texas A & M Univ., College Station, TX (United States); Tokuhiro, Akira [Univ. of Idaho, Moscow, ID (United States); Hamman, K. [Univ. of Idaho, Moscow, ID (United States)

    2014-10-15

    This experimental study investigates the thermal hydraulic behavior and the heat removal performance for a scaled Reactor Cavity Cooling System (RCCS) with air. A quarter-scale RCCS facility was designed and built based on a full-scale General Atomics (GA) RCCS design concept for the Modular High Temperature Gas Reactor (MHTGR). The GA RCCS is a passive cooling system that draws in air to use as the cooling fluid to remove heat radiated from the reactor pressure vessel to the air-cooled riser tubes and discharged the heated air into the atmosphere. Scaling laws were used to preserve key aspects and to maintain similarity. The scaled air RCCS facility at UW-Madison is a quarter-scale reduced length experiment housing six riser ducts that represent a 9.5° sector slice of the full-scale GA air RCCS concept. Radiant heaters were used to simulate the heat radiation from the reactor pressure vessel. The maximum power that can be achieved with the radiant heaters is 40 kW with a peak heat flux of 25 kW per meter squared. The quarter-scale RCCS was run under different heat loading cases and operated successfully. Instabilities were observed in some experiments in which one of the two exhaust ducts experienced a flow reversal for a period of time. The data and analysis presented show that the RCCS has promising potential to be a decay heat removal system during an accident scenario.

  20. Experimental Studies of Phase Equilibria of Meteorites and Planetary Bodies

    Science.gov (United States)

    Stolper, Edward M.

    2005-01-01

    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.

  1. THE COMBINED PROCESSES STUDY FOR MANUFACTURING AIRCRAFT PARTS

    Directory of Open Access Journals (Sweden)

    Mr. Boris N. Maryin

    2016-06-01

    Full Text Available The article is devoted to research of the combined processes of forming tubular billets with various media in the process of bending-expanding, breaking-down -expanding while using thermal effects. The paper discusses the processes of forming tubular billets of hard punches, using elastic-granular materials, the peculiarities of forming tubular billets, while the breaking-down -expanding of crimp in a hard punch using elastic-granular bodies. The article presents experimental studies of the bending-expanding of tubular billets in horn-shaped blanks. The authors established the main features of billet distorting in the combined process. The article shows a diagram of the true distorting distribution in the process of stretching and compression in the horn-shaped blanks. The recommendations allow increasing the bending moment and realizing better shaping. The authors make conclusions about the prospects of the application of combined processes in air and rocket.

  2. Immunotoxicology of arc welding fume: worker and experimental animal studies.

    Science.gov (United States)

    Zeidler-Erdely, Patti C; Erdely, Aaron; Antonini, James M

    2012-01-01

    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.

  3. Experimental and trial-based study of Resilient Packet Ring

    Science.gov (United States)

    Ramnath, Vasudha; Cheng, Heng Seng; Ngoh, Lek Heng

    2002-08-01

    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.

  4. Immunotoxicology of arc welding fume: Worker and experimental animal studies

    Science.gov (United States)

    Zeidler-Erdely, Patti C.; Erdely, Aaron; Antonini, James M.

    2015-01-01

    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

  5. Design of an experimental set up for convective drying: experimental studies at different drying temperature

    Science.gov (United States)

    Mohan, V. P. Chandra; Talukdar, Prabal

    2013-01-01

    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.

  6. Biofouling in forward osmosis systems: An experimental and numerical study

    KAUST Repository

    Bucs, Szilard

    2016-09-20

    This study evaluates with numerical simulations supported by experimental data the impact of biofouling on membrane performance in a cross-flow forward osmosis (FO) system. The two-dimensional numerical model couples liquid flow with solute transport in the FO feed and draw channels, in the FO membrane support layer and in the biofilm developed on one or both sides of the membrane. The developed model was tested against experimental measurements at various osmotic pressure differences and in batch operation without and with the presence of biofilm on the membrane active layer. Numerical studies explored the effect of biofilm properties (thickness, hydraulic permeability and porosity), biofilm membrane surface coverage, and biofilm location on salt external concentration polarization and on the permeation flux. The numerical simulations revealed that (i) when biofouling occurs, external concentration polarization became important, (ii) the biofilm hydraulic permeability and membrane surface coverage have the highest impact on water flux, and (iii) the biofilm formed in the draw channel impacts the process performance more than when formed in the feed channel. The proposed mathematical model helps to understand the impact of biofouling in FO membrane systems and to develop possible strategies to reduce and control biofouling. © 2016 Elsevier Ltd

  7. Experimental and numerical studies of rotating drum grate furnace

    Directory of Open Access Journals (Sweden)

    Basista Grzegorz

    2017-01-01

    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.

  8. Experimental studies of irradiated and hydrogen implantation damaged reactor steels

    Energy Technology Data Exchange (ETDEWEB)

    Slugeň, Vladimír, E-mail: vladimir.slugen@stuba.sk; Pecko, Stanislav; Sojak, Stanislav

    2016-01-15

    Radiation degradation of nuclear materials can be experimentally simulated via ion implantation. In our case, German reactor pressure vessel (RPV) steels were studied by positron annihilation lifetime spectroscopy (PALS). This unique non-destructive method can be effectively applied for the evaluation of microstructural changes and for the analysis of degradation of reactor steels due to neutron irradiation and proton implantation. Studied specimens of German reactor pressure vessel steels are originally from CARINA/CARISMA program. Eight specimens were measured in as-received state and two specimens were irradiated by neutrons in German experimental reactor VAK (Versuchsatomkraftwerk Kahl) in the 1980s. One of the specimens which was in as-received and neutron irradiated condition was also used for simulation of neutron damage by hydrogen nuclei implantation. Defects with the size of about 1–2 vacancies with relatively small contribution (with intensity on the level of 20–40 %) were observed in “as-received” steels. A significant increase in the size of the induced defects due to neutron damage was observed in the irradiated specimens resulting in 2–3 vacancies. The size and intensity of defects reached a similar level as in the specimens irradiated in the nuclear reactor due to the implantation of hydrogen ions with energies of 100 keV (up to the depth <500 nm).

  9. Experimental Study of a Pulse Detonation Engine Driven Ejector

    Science.gov (United States)

    Santoro, Robert J.; Pal, Sibtosh; Shehadeh, R.; Saretto, S.; Lee, S.-Y.

    2005-01-01

    Results of an experimental effort on pulse detonation driven ejectors are presented and discussed. The experiments were conducted using a pulse detonation engine (PDE)/ejector setup that was specifically designed for the study. The results of various experiments designed to probe different aspects of the PDE/ejector setup are reported. The baseline PDE was operated using ethylene (C2H4) as the fuel and an oxygen/nitrogen (O2 + N2) mixture at an equivalence ratio of one. The PDE only experiments included propellant mixture characterization using a laser absorption technique, high fidelity thrust measurements using an integrated spring-damper system, and shadowgraph imaging of the detonation/shock wave structure emanating from the tube. The baseline PDE thrust measurement results are in excellent agreement with experimental and modeling results reported in the literature. These PDE setup results were then used as a basis for quantifying thrust augmentation for various PDE/ejector setups with constant diameter ejector tubes and various detonation tube/ejector tube overlap distances. The results show that for the geometries studied here, a maximum thrust augmentation of 24% is achieved. Further increases are possible by tailoring the ejector geometry based on CFD predictions conducted elsewhere. The thrust augmentation results are complemented by shadowgraph imaging of the flowfield in the ejector tube inlet area and high frequency pressure transducer measurements along the length of the ejector tube.

  10. Experimental and analytical studies on pedestrian induced footbridge vibrations

    DEFF Research Database (Denmark)

    Gudmundsson, Gudmundur Valur; Ingólfsson, Einar Thór; Einarsson, Baldvin

    2007-01-01

    This paper presents results from experimental study on human-induced vibrations of three lively footbridges in Reykjavik. The project was funded by the Icelandic Public Roads Administration with two main focus areas; validating the FE-models used at the design stage in terms of dynamic characteri......This paper presents results from experimental study on human-induced vibrations of three lively footbridges in Reykjavik. The project was funded by the Icelandic Public Roads Administration with two main focus areas; validating the FE-models used at the design stage in terms of dynamic...... with two equal spans crossing the same highway and was built in 2000. A commercially available finite element program (SAP2000) was used in the design phase to model the bridges. The FE-models were updated after the initial tests in order to have the frequencies and damping of the fundamental vibration...... modes corresponding to the measured values. The models were subsequently used to calculate the predicted acceleration according to the preliminary version of the Eurocode (ENV 1992-2: Concrete bridges) using time-history analysis with a moving load as representative for a single pedestrian. The load...

  11. Biofouling in forward osmosis systems: An experimental and numerical study.

    Science.gov (United States)

    Bucs, Szilárd S; Valladares Linares, Rodrigo; Vrouwenvelder, Johannes S; Picioreanu, Cristian

    2016-12-01

    This study evaluates with numerical simulations supported by experimental data the impact of biofouling on membrane performance in a cross-flow forward osmosis (FO) system. The two-dimensional numerical model couples liquid flow with solute transport in the FO feed and draw channels, in the FO membrane support layer and in the biofilm developed on one or both sides of the membrane. The developed model was tested against experimental measurements at various osmotic pressure differences and in batch operation without and with the presence of biofilm on the membrane active layer. Numerical studies explored the effect of biofilm properties (thickness, hydraulic permeability and porosity), biofilm membrane surface coverage, and biofilm location on salt external concentration polarization and on the permeation flux. The numerical simulations revealed that (i) when biofouling occurs, external concentration polarization became important, (ii) the biofilm hydraulic permeability and membrane surface coverage have the highest impact on water flux, and (iii) the biofilm formed in the draw channel impacts the process performance more than when formed in the feed channel. The proposed mathematical model helps to understand the impact of biofouling in FO membrane systems and to develop possible strategies to reduce and control biofouling. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Thermodynamic and experimental study of UC powders ignition

    Energy Technology Data Exchange (ETDEWEB)

    Le Guyadec, F., E-mail: fabienne.leguyadec@cea.f [Commissariat a l' Energie Atomique CEA-MARCOULE, DEN/DTEC/SDTC/Laboratoire d' Etude des Materiaux en Environnement, BP 17171, 30207 Bagnols sur Ceze (France); Rado, C.; Joffre, S.; Coullomb, S. [Commissariat a l' Energie Atomique CEA-MARCOULE, DEN/DTEC/SDTC/Laboratoire d' Etude des Materiaux en Environnement, BP 17171, 30207 Bagnols sur Ceze (France); Chatillon, C.; Blanquet, E. [SIMAP, Sciences et Ingenierie des Materiaux et Procedes, INPG-CNRS-UJF ENSEEG, BP 75, 38402 St Martin-d' Heres (France)

    2009-09-01

    Mixed plutonium and uranium carbide (UPuC) is considered as a possible fuel material for future nuclear reactors. However, UPuC is pyrophoric and fine powders of UPuC are subject to temperature increase due to oxidation with air and possible ignition during conditioning and handling. In a first approach and to allow easier experimental conditions, this study was undertaken on uranium monocarbide (UC) with the aim to determine safe handling conditions for the production and reprocessing of uranium carbide fuels. The reactivity of uranium monocarbide in oxidizing atmosphere was studied in order to analyze the ignition process. Experimental thermogravimetric analysis (TGA) and differential thermal analysis (DTA) revealed that UC powder obtained by arc melting and milling is highly reactive in air at about 200 deg. C. The phases formed at the various observed stages of the oxidation process were analyzed by X-ray diffraction. At the same time, ignition was analyzed thermodynamically along isothermal sections of the U-C-O ternary diagram and the pressure of the gas produced by the UC + O{sub 2} reaction was calculated. Two possible oxidation schemes were identified on the U-C-O phase diagram and assumptions are proposed concerning the overall oxidation and ignition paths. It is particularly important to understand the mechanisms involved since temperatures as high as 2500 deg. C could be reached, leading to CO(g) production and possibly to a blast effect.

  13. Thermodynamic and experimental study of UC powders ignition

    Science.gov (United States)

    Le Guyadec, F.; Rado, C.; Joffre, S.; Coullomb, S.; Chatillon, C.; Blanquet, E.

    2009-09-01

    Mixed plutonium and uranium carbide (UPuC) is considered as a possible fuel material for future nuclear reactors. However, UPuC is pyrophoric and fine powders of UPuC are subject to temperature increase due to oxidation with air and possible ignition during conditioning and handling. In a first approach and to allow easier experimental conditions, this study was undertaken on uranium monocarbide (UC) with the aim to determine safe handling conditions for the production and reprocessing of uranium carbide fuels. The reactivity of uranium monocarbide in oxidizing atmosphere was studied in order to analyze the ignition process. Experimental thermogravimetric analysis (TGA) and differential thermal analysis (DTA) revealed that UC powder obtained by arc melting and milling is highly reactive in air at about 200 °C. The phases formed at the various observed stages of the oxidation process were analyzed by X-ray diffraction. At the same time, ignition was analyzed thermodynamically along isothermal sections of the U-C-O ternary diagram and the pressure of the gas produced by the UC + O 2 reaction was calculated. Two possible oxidation schemes were identified on the U-C-O phase diagram and assumptions are proposed concerning the overall oxidation and ignition paths. It is particularly important to understand the mechanisms involved since temperatures as high as 2500 °C could be reached, leading to CO(g) production and possibly to a blast effect.

  14. Experimental studies of irradiated and hydrogen implantation damaged reactor steels

    Science.gov (United States)

    Slugeň, Vladimír; Pecko, Stanislav; Sojak, Stanislav

    2016-01-01

    Radiation degradation of nuclear materials can be experimentally simulated via ion implantation. In our case, German reactor pressure vessel (RPV) steels were studied by positron annihilation lifetime spectroscopy (PALS). This unique non-destructive method can be effectively applied for the evaluation of microstructural changes and for the analysis of degradation of reactor steels due to neutron irradiation and proton implantation. Studied specimens of German reactor pressure vessel steels are originally from CARINA/CARISMA program. Eight specimens were measured in as-received state and two specimens were irradiated by neutrons in German experimental reactor VAK (Versuchsatomkraftwerk Kahl) in the 1980s. One of the specimens which was in as-received and neutron irradiated condition was also used for simulation of neutron damage by hydrogen nuclei implantation. Defects with the size of about 1-2 vacancies with relatively small contribution (with intensity on the level of 20-40 %) were observed in "as-received" steels. A significant increase in the size of the induced defects due to neutron damage was observed in the irradiated specimens resulting in 2-3 vacancies. The size and intensity of defects reached a similar level as in the specimens irradiated in the nuclear reactor due to the implantation of hydrogen ions with energies of 100 keV (up to the depth <500 nm).

  15. Experimental and numerical investigations of internal heat transfer in an innovative trailing edge blade cooling system: stationary and rotation effects, part 1—experimental results

    Science.gov (United States)

    Beniaiche, Ahmed; Ghenaiet, Adel; Facchini, Bruno

    2017-02-01

    The aero-thermal behavior of the flow field inside 30:1 scaled model reproducing an innovative smooth trailing edge of shaped wedge discharge duct with one row of enlarged pedestals have been investigated in order to determine the effect of rotation, inlet velocity and blowing conditions effects, for Re = 20,000 and 40,000 and Ro = 0-0.23. Two configurations are presented: with and without open tip configurations. Thermo-chromic liquid crystals technique is used to ensure a local measurement of the heat transfer coefficient on the blade suction side under stationary and rotation conditions. Results are reported in terms of detailed 2D HTC maps on the suction side surface as well as the averaged Nusselt number inside the pedestal ducts. Two correlations are proposed, for both closed and open tip configurations, based on the Re, Pr, Ro and a new non-dimensional parameter based on the position along the radial distance, to assess a reliable estimation of the averaged Nusselt number at the inter-pedestal region. A good agreement is found between prediction and experimental data with about ±10 to ±12 % of uncertainty, for the simple form correlation, and about ±16 % using a complex form. The obtained results help to predict the flow field visualization and the evaluation of the aero-thermal performance of the studied blade cooling system during the design step.

  16. Towards the synthesis of an experimental bioactive dental ceramic. Part I: Crystallinity characterization and bioactive behavior evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Goudouri, O.-M. [Physics Department, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Kontonasaki, E. [School of Dentistry, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Papadopoulou, L.; Kantiranis, N. [Department of Geology, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Lazaridis, N.K. [Chemistry Department, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Chrissafis, K.; Chatzistavrou, X. [Physics Department, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Koidis, P. [School of Dentistry, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Paraskevopoulos, K.M., E-mail: kpar@auth.gr [Physics Department, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

    2014-05-01

    An attachment between the dental ceramic and the surrounding marginal tissues in fixed prosthetic restorations could eliminate secondary carries prevalence. The development of dental ceramics with apatite forming ability could provide the biological surface required for selective spread and attachment of specific cell types able to promote tissue attachment. Dental ceramics/bioactive glass composites synthesized by the sol gel method have been previously reported to develop carbonated hydroxyapatite (HCAp) in biomimetic solutions, requiring though a high amount of bioactive glass, which resulted in the compromise of their mechanical integrity. Thus, the aim of the present work was the synthesis and characterization of an experimental sol–gel derived dental ceramic with low amount of bioactive glass and the evaluation of its in vitro bioactivity. Differential thermal and thermogravimetric analysis (TG–DTA), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffractometry (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) were used to evaluate the crystal structure and the in vitro apatite forming ability of the synthesized material. The results of this study indicated the successful sol–gel synthesis of an experimental dental ceramic containing low amount of bioactive glass that presented similar structural and morphological characteristics with a commercial feldspathic dental ceramic, while exhibiting in vitro bioactivity. The apatite forming ability of the experimental sol–gel derived feldspathic dental ceramic may trigger the appropriate cellular mechanisms towards the establishment of attachment with the surrounding connective tissue. This attachment could provide a barrier to oral bacteria penetration, prolonging the life expectation of the restorations. - Highlights: • Synthesis of a bioactive sol–gel dental ceramic for fixed prosthetic restorations. • The sol–gel technique promoted the crystallization of

  17. Blade System Design Study. Part II, final project report (GEC).

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, Dayton A. (DNV Global Energy Concepts Inc., Seattle, WA)

    2009-05-01

    As part of the U.S. Department of Energy's Low Wind Speed Turbine program, Global Energy Concepts LLC (GEC)1 has studied alternative composite materials for wind turbine blades in the multi-megawatt size range. This work in one of the Blade System Design Studies (BSDS) funded through Sandia National Laboratories. The BSDS program was conducted in two phases. In the Part I BSDS, GEC assessed candidate innovations in composite materials, manufacturing processes, and structural configurations. GEC also made recommendations for testing composite coupons, details, assemblies, and blade substructures to be carried out in the Part II study (BSDS-II). The BSDS-II contract period began in May 2003, and testing was initiated in June 2004. The current report summarizes the results from the BSDS-II test program. Composite materials evaluated include carbon fiber in both pre-impregnated and vacuum-assisted resin transfer molding (VARTM) forms. Initial thin-coupon static testing included a wide range of parameters, including variation in manufacturer, fiber tow size, fabric architecture, and resin type. A smaller set of these materials and process types was also evaluated in thin-coupon fatigue testing, and in ply-drop and ply-transition panels. The majority of materials used epoxy resin, with vinyl ester (VE) resin also used for selected cases. Late in the project, testing of unidirectional fiberglass was added to provide an updated baseline against which to evaluate the carbon material performance. Numerous unidirectional carbon fabrics were considered for evaluation with VARTM infusion. All but one fabric style considered suffered either from poor infusibility or waviness of fibers combined with poor compaction. The exception was a triaxial carbon-fiberglass fabric produced by SAERTEX. This fabric became the primary choice for infused articles throughout the test program. The generally positive results obtained in this program for the SAERTEX material have led to its

  18. Desorption of plutonium from montmorillonite: An experimental and modeling study

    Science.gov (United States)

    Begg, James D.; Zavarin, Mavrik; Kersting, Annie B.

    2017-01-01

    Desorption of plutonium (Pu) will likely control the extent to which it is transported by mineral colloids. We evaluated the adsorption/desorption behavior of Pu on SWy-1 montmorillonite colloids at pH 4, pH 6, and pH 8 using batch adsorption and flow cell desorption experiments. After 21 days adsorption, Pu(IV) affinity for montmorillonite displayed a pH dependency, with Kd values highest at pH 4 and lowest at pH 8. The pH 8 experiment was further allowed to equilibrate for 6 months and showed an increase in Kd, indicating that true sorption equilibrium was not achieved within the first 21 days. For the desorption experiments, aliquots of the sorption suspensions were placed in a flow cell, and Pu-free solutions were then pumped through the cell for a period of 12 days. Changes in influent solution flow rate were used to investigate the kinetics of Pu desorption and demonstrated that it was rate-limited over the experimental timescales. At the end of the 12-day flow cell experiments, the extent of desorption was again pH dependent, with pH 8 > pH 6 > pH 4. Further, at pH 8, less Pu was desorbed after an adsorption contact time of 6 months than after a contact time of 21 days, consistent with an aging of Pu on the clay surface. A conceptual model for Pu adsorption/desorption that incorporated known surface-mediated Pu redox reactions was used to fit the experimental data. The resulting rate constants indicated processes occurring on timescales of months and even years which may, in part, explain observations of clay colloid-facilitated Pu transport on decadal timescales. Importantly, however, our results also imply that migration of Pu adsorbed to montmorillonite colloids at long (50-100 year) timescales under oxic conditions may not be possible without considering additional phenomena, such as co-precipitation.

  19. Experimental study on neon refrigeration system using commercial helium compressor

    Science.gov (United States)

    Ko, Junseok; Kim, Hyobong; Hong, Yong-Ju; Yeom, Hankil; Koh, Deuk-Yong; Park, Seong-Je

    2012-06-01

    In this study, we developed neon refrigeration system using commercial helium compressor which was originally designed for GM cryocooler. We performed this research as precedent study before developing neon refrigeration system for small-scale hydrogen liquefaction system. The developed system is based on precooled Linde-Hampson system with liquid nitrogen as precoolant. Design parameters of heat exchangers are determined from thermodynamic cycle analysis with operating pressure of 2 MPa and 0.4 MPa. Heat exchangers have concentric-tube heat exchanger configuration and orifice is used as Joule- Thomson expansion device. In experiments, pressure, temperature, mass flow rate and compressor input power are measured as charging pressure. With experimental results, the characteristics of heat exchanger, Joule-Thomson expansion and refrigeration effect are discussed. The developed neon refrigeration system shows the lowest temperature of 43.9 K.

  20. Experimental study on a natural circulation driven HPLWR

    Energy Technology Data Exchange (ETDEWEB)

    T' Joen, C.; Rohde, M. [Delft Univ. of Tech., Delft (Netherlands)

    2011-07-01

    The large density change through the core of a supercritical water reactor could be used as the driving force for circulating the coolant. To study such a natural circulation system, a scaled experimental setup was developed using Freon R23. This paper presents the first power-flow measurements for single core heating as well as 3 core heating (HPLWR power distribution) indicating that natural circulation occurs. A numerical model was developed to further study the impact of geometric and system parameters. This model shows good qualitative agreement with the experiment. By further refining the proposed model to include the pressure drop over the heat exchanger, a better quantitative agreement could be obtained. (author)

  1. Reverse running pumps analytical, experimental and computational study: A review

    Energy Technology Data Exchange (ETDEWEB)

    Nautiyal, Himanshu; Varun; Kumar, Anoop [Department of Mechanical Engineering, National Institute of Technology, Hamirpur (India)

    2010-09-15

    A pump can be used as turbine and has good application in micro-hydropower schemes. Pump as turbine (PAT) is one of the best alternatives for fulfilling the energy demands and providing the electricity in remote and rural areas. In this study a review on the work done in the area of pump working as turbine has been explained. Based upon the literature survey, analytical, experimental and computational works on pump as turbine have been discussed. Several methods for predicting the behaviour of pumps in turbine mode have been developed but no method is appropriate for the entire range of specific speeds. Computational fluid dynamics (CFD) is also used to study the reverse operation of centrifugal pumps, but still results are not yet acceptable. (author)

  2. 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

    2011-01-01

    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.

  3. Experimental study of rectenna coupling at low power level

    Science.gov (United States)

    Douyère, A.; Alicalapa, F.; Rivière, S.; Luk, J.-D. Lan Sun

    2013-04-01

    The experimental results presented in this paper focus on the performance of a rectenna array by studying the effect of mutual coupling between two rectennas. The measurements in several planes of the space are investigated and used to help us to define the minimum distance for future rectenna arrays that can be used at a low power density level. The single element chosen for the array is composed of a rectifier circuit and a CSPA (Circular Slot Patch Antenna). This study shows that at a distance greater than 6cm (λ/2) between two rectennas in reception, we observe that the DC received voltage is constant in the Y plane, while in the X plane, the DC received voltage remains constant whatever the distance. We deduce that these rectennas are uncoupled in this case. We can consider each rectenna like an independent system.

  4. An experimental study of laser supported hydrogen plasmas

    Science.gov (United States)

    Vanzandt, D. M.; Mccay, T. D.; Eskridge, R. H.

    1984-01-01

    The rudiments of a rocket thruster which receives its enthalpy from an energy source which is remotely beamed from a laser is described. An experimental study now partially complete is discussed which will eventually provide a detailed understanding of the physics for assessing the feasibility of using hydrogen plasmas for accepting and converting this energy to enthalpy. A plasma ignition scheme which uses a pulsed CO2 laser has been developed and the properties of the ignition spark documented, including breakdown intensities in hydrogen. A complete diagnostic system capable of determining plasma temperature and the plasma absorptivity for subsequent steady state absorption of a high power CO2 laser beam are developed and demonstrative use is discussed for the preliminary case study, a two atmosphere laser supported argon plasma.

  5. Experimental Study of the WEPTOS Wave Energy Converter

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter; Marchalot, Tanguy

    This report presents the results of an experimental study on the power conversion capabilities and structural loads of the WEPTOS wave energy converter. The investigation focuses mainly at identifying the performance of the WEPTOS prototype in a wide range of production wave states...... and at the mooring forces and structural bending moments in extreme wave conditions, in order to estimate the performance and structural loads of larger WEPTOS machines being located at various offshore locations of interest. The following aspects were the main subjects of investigation: Performance of the prototype...... under a constant and linear PTO loading, the opening angle of the device, the effect of alterations to the wave conditions, and mooring forces and structural bending moments in production and extreme wave states. During the study, a highly realistic scale model was supplied by the client, WEPTOS, which...

  6. Experimental Study on the Langlee Wave Energy Converter

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter; Weisz, A.

    This report presents the results of an experimental study of the wave energy converting abilities of the Langlee wave energy converter (WEC). It focused mainly on evaluating the power generating capabilities of the device, including investigations of the following issues: Scaling ratiosPTO loadingWave...... height and wave period dependencyOblique incoming waves and directional spreading of waves (3D waves)Damping platesMooring forces and fixed structure setupPitch, surge and heave motion During the study the model supplied by the client (Langlee Wave Power AS) has been heavily instrumented - up to 23...... different instruments was deployed to measure and record data. Tests were performed at scales of 1:30 and 1:20 based on the realized reference wave states....

  7. Experimental Study of the Weptos Wave Energy Converter

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter; Larsen, Tommy

    2012-01-01

    This paper presents the power performance results of the experimental study of the WEPTOS wave energy converter (WEC). This novel device combines an established and efficient wave energy absorbing mechanism with an adjustable structure that can regulate the amount of incoming wave energy and reduce...... loads in extreme wave conditions. This A-shaped floating structure absorbs the energy in the waves through a multitude of rotors, the shape of which is based on the renowned Salter’s Duck. These rotors pivot around a common axle, one for each leg of the structure, to which the rotors transfer...... the absorbed wave energy and which is connected to a common power take off system (one for each leg). The study investigates the performance of the device in a large range of wave states and estimates the performance in terms of mechanical power available to the power take off system of the WEPTOS WEC for two...

  8. An experimental study of tether reel system: A laboratory model

    OpenAIRE

    Yoshimura, Shoichi; Okamoto, Osamu; 吉村 庄市; 岡本 修

    1992-01-01

    A laboratory prototype model of a reel system has been made as the first step of an in-house hardware study of the tether system in space. The model is consisted of two main parts, i. e., a Reel Drum Driving (RDD) unit (25 kg weight) and a Power Supply/Signal Processing (PSSP) unit (32 kg weight). The tether (0.8 mm in diameter and 300 m long) consists of a Kevlar fiber core and a nylon fiber jacket. Following the preliminary functional test, a computer-controlled functional test has been car...

  9. Dynamic transport of suspended sediment by solitary wave: Experimental study

    Science.gov (United States)

    cho, JaeNam; Kim, DongHyun; Hwang, KyuNam; Lee, SeungOh

    2016-04-01

    Solitary waves are able to transport a large amount of suspended sediment when approaching on the beach, which sometimes causes - serious beach erosion, especially in the east and south coastal lines in Korea. But it has rarely been known about the method how to evaluate or estimate the amount of beach erosion caused by solitary waves. Experimental assessment is necessary to comprehend the process of sediment transport on a slope. The prismatic rectangular channel is 12 m long, 0.8 m wide, and 0.75 m high. A sluice gate is applied at prismatic channel in order to produce the solitary waves. Upstream water depth is more than channel water depth and the sluice gate is suddenly opened to simulate conditions of solitary waves. A sand slope with a 1/6 and a sediment thickness is 0.03 m. The experimental sediments are used anthracite (d_50=1.547 mm ,C_u=1.38) and Jumoonjin sand (d_50=0.627 mm ,C_u=1.68). Specific laboratory equipment are designed to collect suspended sediment samples at the same time along the wave propagation at 5 points with evenly space. Each amount of sampling is approximately 25 ml and they are completely dried in oven over 24 hours according to the USGS (Guideline and standard techniques and method 3-C4). Two video cameras (Model No. : Sony, HDR-XR550) are mounted for capturing images at top and side-view when the processes of solitary wave and run up/down on slope. Also, this study are analyzed the correlation between Suspended sediment concentration and turbidity. Also, this study are analyzed the correlation between suspended sediment concentration and turbidity. Turbidity is used to verify suspended sediment concentration. Dimensionless analyses of experimental results carried out in this study. One dimensionless parameter is expressed with pressure of solitary wave on a slope to suspended sediment concentration, which is concerned about lifting force. The other is relate to drag force presenting with run up/down velocity on a slope and

  10. Experimental Study of Current-Driven Turbulence During Magnetic Reconnection

    Energy Technology Data Exchange (ETDEWEB)

    Porkolab, Miklos; Egedal-Pedersen, Jan; Fox, William

    2010-08-31

    CMPD Final Report Experimental Study of Current-Driven Turbulence During Magnetic Reconnection Miklos Porkolab, PI, Jan Egedal, co-PI, William Fox, graduate student. This is the final report for Grant DE-FC02-04ER54786, MIT Participation in the Center for Multiscale Plasma Dynamics, which was active from 8/1/2004 to 7/31/2010. This Grant supported the thesis work of one MIT graduate student, William Fox, The thesis research consisted of an experimental study of the fluctuations arising during magnetic reconnection in plasmas on the Versatile Toroidal Facility (VTF) at MIT Plasma Science and Fusion Center (PSFC). The thesis was submitted and accepted by the MIT physics Department,. Fox, Experimental Study of Current-Driven Turbulence During Magnetic Reconnection, Ph.D. Thesis, MIT (2009). In the VTF experiment reconnection and current-sheet formation is driven by quickly changing currents in a specially arranged set of internal conductors. Previous work on this device [Egedal, et al, PRL 98, 015003, (2007)] identified a spontaneous reconnection regime. In this work fluctuations were studied using impedance-matched, high-bandwidth Langmuir probes. Strong, broadband fluctuations, with frequencies extending from near the lower-hybrid frequency [fLH = (fcefci)1/2] to the electron cyclotron frequency fce were found to arise during the reconnection events. Based on frequency and wavelength measurements, lower-hybrid waves and Trivelpiece-Gould waves were identified. The lower-hybrid waves are easiest to drive with strong perpendicular drifts or gradients which arise due to the reconnection events; an appealing possibility is strong temperature gradients. The Trivelpiece-Gould modes can result from kinetic, bump-on-tail instability of a runaway electron population energized by the reconnection events. We also observed that the turbulence is often spiky, consisting of discrete positive-potential spikes, which were identified as electron phase-space holes, a class of

  11. Experimental study of visual training effects in shooting initiation.

    Science.gov (United States)

    Quevedo, Lluïsa; Solé, Joan; Palmi, Joan; Planas, Antoni; Soana, Carlos

    1999-01-01

    INTRODUCTION: The present study was conducted to investigate the influence of specific visual training in shooting initiation performance. METHODS: Seventy-one first-year university students were divided randomly into two groups. The experimental group followed a nine-session shooting training program that included technical, physical and psychological components, along with specific visual exercises. The control group followed the same program with one difference: this group received theoretical lectures on psychological training techniques instead of doing visual exercises. Pre- and post-test results were obtained for shooting, concentration, saccades and visual acuity. RESULTS: Statistical analysis indicated significant gains in the four mentioned variables for the experimental group. The control group also showed significant differences in the three first variables but no significant improvement in visual acuity. No significant differences in shooting performance were observed between groups. CONCLUSIONS: The effect of vision training on sports initiation performance is still not clear. It cannot be assumed that the improvement is transferable to the performance of precision shooting at the stage of sports initiation.

  12. Experimental Vertical Stability Studies for ITER Performance and Design Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Humphreys, D A; Casper, T A; Eidietis, N; Ferrera, M; Gates, D A; Hutchinson, I H; Jackson, G L; Kolemen, E; Leuer, J A; Lister, J; LoDestro, L L; Meyer, W H; Pearlstein, L D; Sartori, F; Walker, M L; Welander, A S; Wolfe, S M

    2008-10-13

    Operating experimental devices have provided key inputs to the design process for ITER axisymmetric control. In particular, experiments have quantified controllability and robustness requirements in the presence of realistic noise and disturbance environments, which are difficult or impossible to characterize with modeling and simulation alone. This kind of information is particularly critical for ITER vertical control, which poses some of the highest demands on poloidal field system performance, since the consequences of loss of vertical control can be very severe. The present work describes results of multi-machine studies performed under a joint ITPA experiment on fundamental vertical control performance and controllability limits. We present experimental results from Alcator C-Mod, DIII-D, NSTX, TCV, and JET, along with analysis of these data to provide vertical control performance guidance to ITER. Useful metrics to quantify this control performance include the stability margin and maximum controllable vertical displacement. Theoretical analysis of the maximum controllable vertical displacement suggests effective approaches to improving performance in terms of this metric, with implications for ITER design modifications. Typical levels of noise in the vertical position measurement which can challenge the vertical control loop are assessed and analyzed.

  13. SOLAR VACUUM TUBE INTEGRATED SEAWATER DISTILLATION - AN EXPERIMENTAL STUDY

    Directory of Open Access Journals (Sweden)

    Selcuk Selimli

    2016-04-01

    Full Text Available The subject of this study is the seawater distillation process enhancement through integration of the solar vacuum tube into the system. Positive effects on the rate of distillated freshwater achieved by means of the enhanced system have been investigated experimentally. Experiments were done in the Turkish city of Samsun in the Black Sea region. A distillation pond setup having the volume of 0.015m3 and a water surface area of 0.24m2 was constructed. The distillation pond is covered with a condensation glass and also equipped with a 0.15m solar vacuum tube that is inclined at an angle of 30o to the ground, a feed water tank connected with a ball cock, and distillated fresh water tank. Experimental results have shown that the rate of distilled fresh water was enhanced for about 62.5% by integrating the solar vacuum tube and the natural distillation pond. Isolation of the condensation glass not only prevents the light transmission to the pond but also heat loss from the pond; hence the rate of the distillated fresh water is increased for about 137.5% due to the natural distillation.

  14. 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)

    1989-11-15

    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.

  15. A comprehensive experimental and modeling study of 2-methylbutanol combustion

    KAUST Repository

    Park, Sungwoo

    2015-05-01

    2-Methylbutanol (2-methyl-1-butanol) is one of several next-generation biofuels that can be used as an alternative fuel or blending component for combustion engines. This paper presents new experimental data for 2-methylbutanol, including ignition delay times in a high-pressure shock tube and premixed laminar flame speeds in a constant volume combustion vessel. Shock tube ignition delay times were measured for 2-methylbutanol/air mixtures at three equivalence ratios, temperatures ranging from 750 to 1250. K, and at nominal pressures near 20 and 40. bar. Laminar flame speed data were obtained using the spherically propagating premixed flame configuration at pressures of 1, 2, and 5. bar. A detailed chemical kinetic model for 2-methylbutanol oxidation was developed including high- and low-temperature chemistry based on previous modeling studies on butanol and pentanol isomers. The proposed model was tested against new and existing experimental data at pressures of 1-40. atm, temperatures of 740-1636. K, equivalence ratios of 0.25-2.0. Reaction path and sensitivity analyses were conducted for identifying key reactions at various combustion conditions, and to obtain better understanding of the combustion characteristics of larger alcohols.

  16. Experimental study of moving throat plug in a shock tunnel

    Science.gov (United States)

    Lee, J. K.; Park, C.; Kwon, O. J.

    2015-07-01

    An experimental study has been carried out to investigate the flow in the KAIST shock tunnel with two moving throat plugs at a primary shock velocity of 1.19 km/s. The nozzle reservoir pressure and the Pitot pressure at the exit of the nozzle were measured to examine the influence of the moving throat plugs on the shock tunnel flow. To assess the present experimental results, comparisons with previous work using a stationary throat plug were made. The mechanism for closing the moving throat plug was developed and verified. The source of the force to move the plug was the pressure generated when the primary shock was reflected at the bottom of the plug. It was observed that the two plugs terminated the shock tunnel flow after the steady flow. .The time for the plugs to terminate the flow showed good agreement with the calculation of the proposed simple analytic solution. There was a negligible difference in flow values such as the reflected pressure and the Pitot pressure between the moving and the stationary plugs.

  17. Small Crack Growth and Fatigue Life Predictions for High-Strength Aluminium Alloys. Part 1; Experimental and Fracture Mechanics Analysis

    Science.gov (United States)

    Wu, X. R.; Newman, J. C.; Zhao, W.; Swain, M. H.; Ding, C. F.; Phillips, E. P.

    1998-01-01

    The small crack effect was investigated in two high-strength aluminium alloys: 7075-T6 bare and LC9cs clad alloy. Both experimental and analytical investigations were conducted to study crack initiation and growth of small cracks. In the experimental program, fatigue tests, small crack and large crack tests A,ere conducted under constant amplitude and Mini-TWIST spectrum loading conditions. A pronounced small crack effect was observed in both materials, especially for the negative stress ratios. For all loading conditions, most of the fatigue life of the SENT specimens was shown to be crack propagation from initial material defects or from the cladding layer. In the analysis program, three-dimensional finite element and A weight function methods were used to determine stress intensity factors and to develop SIF equations for surface and corner cracks at the notch in the SENT specimens. A plastisity-induced crack-closure model was used to correlate small and large crack data, and to make fatigue life predictions, Predicted crack-growth rates and fatigue lives agreed well with experiments. A total fatigue life prediction method for the aluminum alloys was developed and demonstrated using the crack-closure model.

  18. Experimental human-like model to assess the part of viable Legionella reaching the thoracic region after nebulization.

    Directory of Open Access Journals (Sweden)

    Jérémie Pourchez

    Full Text Available The incidence of Legionnaires' disease (LD in European countries and the USA has been constantly increasing since 1998. Infection of humans occurs through aerosol inhalation. To bridge the existing gap between the concentration of Legionella in a water network and the deposition of bacteria within the thoracic region (assessment of the number of viable Legionella, we validated a model mimicking realistic exposure through the use of (i recent technology for aerosol generation and (ii a 3D replicate of the human upper respiratory tract. The model's sensitivity was determined by monitoring the deposition of (i aerosolized water and Tc99m radio-aerosol as controls, and (ii bioaerosols generated from both Escherichia coli and Legionella pneumophila sg 1 suspensions. The numbers of viable Legionella prior to and after nebulization were provided by culture, flow cytometry and qPCR. This study was designed to obtain more realistic data on aerosol inhalation (vs. animal experimentation and deposition at the thoracic region in the context of LD. Upon nebulization, 40% and 48% of the initial Legionella inoculum was made of cultivable and non-cultivable cells, respectively; 0.7% of both populations reached the filter holder mimicking the thoracic region in this setup. These results are in agreement with experimental data based on quantitative microbial risk assessment methods and bring new methods that may be useful for preventing LD.

  19. An Experimental Study to Control Scour at River Confluence

    Science.gov (United States)

    Wuppukondur, A.; Chandra, V.

    2015-12-01

    The aim of present study is finding a method to control sediment erosion at river confluence. The confluences are mixture of two different flows and are common occurrences along the river. River confluences are sites of natural scour phenomenon and also influence reservoir sedimentation. The river confluence is associated with a separation zone, stagnation zone and a mixing layer along which the scour hole is observed. The eroded sediment creates potential problems by depositing at unwanted downstream locations such as barrages, weirs, check dams, reservoirs etc. As per the literature, the storage capacity of major reservoirs in India is going to be reduced nearly half of the storage capacity by 2020. Hence, an experimental study has been conducted on mobile bed (d50=0.28 mm) with a confluence angle of 90o for a discharge ratio (Qr) of 0.5, where, Qr is defined as the ratio between lateral flow discharge (Ql) and main flow discharge (Qm). Circular shape pile models of same diameter are arranged in a systematic manner with constant spacing (5 cm, 10 cm and 15 cm) to change the flow pattern for reducing scour at the confluence. Two types of pile models (8 mm ϕ and 12 mm ϕ) are used to conduct the experiments. The experimental results show that maximum scour depth at confluence is reduced by 60%. In addition, the bed profile modifications are also reported. Keywords: Reservoir sedimentation, River confluence, Mobile bed, Scour, Vanes. References:1. Borghei, S. M., and Sahebari, A. J. (2010). "Local Scour at Open-Channel Junctions", Journal of Hydraulic Research, 48(4), 37 - 41. 2. Kothyari, U. C. (1996). "Methods for Estimation Sediment Yield from Catchments", Proc., Int. Sem. On Civil Engg. Practices in Twenty First Century, Roorkee, India, 1071-1086. 3. Mosley, M. P. (1976) "An Experimental Study of Channel Confluences". The Journal of Geology, 84(55), 532-562. 4. Ouyang, H. T. (2009). "Investigation on the dimensions and shape of a submerged vane for sediment

  20. Experimental process development and aerospace alloy formability studies for hydroforming

    Science.gov (United States)

    Mojarad Farimani, Saeed

    In tube hydroforming process, a pressurized liquid is used to expand a thin walled tube inside a closed die in order to fill the die cavity. Tube hydroforming has many advantages that make it interesting for different industries such as automotive and aerospace, but due to the effects of different factors, such as formability of the material, load path (end feeding force and internal pressure during the process), tool geometry and friction, it is a quite complex manufacturing process. Therefore, finite element simulation along with optimization methods can significantly reduce the cost of trial and error approach used in conventional manufacturing methods. In this work, to investigate the effects of different process parameters such as friction condition, tube thickness and end feeding on the final product, tube hydroforming experiments were performed using a round to square-shape die. Experiments were performed on stainless steel 321 tubes with 50.8 mm (2 in) diameter and two different thicknesses; 0.9 mm and 1.2 mm. Experimental load paths were obtained via the data acquisition system of the hydroforming press, which is fully instrumented. An automated deformation measurement system, Argus, was used to measure the strains on the hydroformed tubes. Data collected from the initial experiments were used to simulate and then optimize the process. The process was simulated and optimized using Ls-Dyna and Ls-Opt software, respectively. Strains and thickness variations measured from experiments were compared to FE simulation results at critical sections. The comparison of the results from FE simulations and experiments were in good agreement, indicating that the approach can be used for predicting the final shape and thickness variations of the hydroformed parts for aerospace applications.

  1. New approach for the determination of aerosol refractive indices - Part II: Experimental set-up and application to amorphous silica particles

    Science.gov (United States)

    Hubert, P.; Herbin, H.; Visez, N.; Pujol, O.; Petitprez, D.

    2017-10-01

    This article is the Part II of a work aimed at proposing a new method for determining the optical constants of aerosols. The Part I detailed the theoretical and numerical basis of an algorithm devoted to retrieve the imaginary and the real part of complex refractive indices from extinction spectra of aerosols. This algorithm associates the Mie theory, the single subtractive Kramers-Kronig relation, and an optimal estimation method in an iterative process. This Part II presents the experimental set-up developed to record simultaneously high spectral resolution extinction spectra and size distributions of airborne silica particles. Extinction spectra are measured with a high spectral resolution on a broad spectral range, including both infrared (650 - 2 , 500cm-1) and UV-visible (9 , 000 - 32 , 500cm-1) spectral regions. Experimental data were used to retrieve the complex refractive indices of aerosol particles. By associating the numerical procedure presented in the first paper and this experimental set-up, complex refractive indices of silica spherical aerosol particles have been determined under controlled experimental conditions. Additional comparison between experimental and simulated extinction spectra from retrieved complex refractive indices shows that this new methodology provides optical properties representative of the material.

  2. Experimental and theoretical study of friction torque from radial ball bearings

    Science.gov (United States)

    Geonea, Ionut; Dumitru, Nicolae; Dumitru, Ilie

    2017-10-01

    In this paper it is presented a numerical simulation and an experimental study of total friction torque from radial ball bearings. For this purpose it is conceived a virtual CAD model of the experimental test bench for bearing friction torque measurement. The virtual model it is used for numerical simulation in Adams software, that allows dynamic study of multi-body systems and in particularly with facility Adams Machinery of dynamic behavior of machine parts. It is manufactured an experimental prototype of the test bench for radial ball bearings friction torque measurement. In order to measure the friction torque of the tested bearings it is used an equal resistance elastic beam element, with strain gauge transducer to measure bending deformations. The actuation electric motor of the bench has the shaft mounted on two bearings and the motor housing is fixed to the free side of the elastic beam, which is bended by a force proportional with the total friction torque. The beam elastic element with strain gauge transducer is calibrated in order to measure the force occurred. Experimental determination of the friction torque is made for several progressive radial loads. It is established the correlation from the friction torque and bearing radial load. The bench allows testing of several types and dimensions of radial bearings, in order to establish the bearing durability and of total friction torque.

  3. Experimental techniques for deflection and radiation studies with bent crystals

    CERN Document Server

    Hasan, Said

    2011-01-01

    What happens when a high energy charged particle crosses an amorphous material? It loses energy by ionization and its trajectory is affected by the multiple Coulomb scattering, being these phenomena originated by uncorrelated collisions with the atoms. If the atoms of the target were distributed according to an ordered scheme, the uncorrelated collisions would turn into a coherent interaction with the whole atomic structure. This is the case of an aligned crystal that, depending on the orientation, is seen as a set of atomic planes or strings by the impinging particles. Planes and strings produce potential wells able to confine the charged particles in a transversal region of the crystal, in the so called channeling condition, so that, bending the crystal, particles are forced to follow the curvature, being deflected. This simple and powerful idea, dating 1979, is at the basis of many theoretical and experimental studies that have proven bent crystals effectiveness, described their possible applications and ...

  4. A Transmission Electron Microscope Study of Experimentally Shocked Pregraphitic Carbon

    Science.gov (United States)

    Rietmeijer, Frans J. M.

    1995-01-01

    A transmission electron microscope study of experimental shock metamorphism in natural pre-graphitic carbon simulates the response of the most common natural carbons to increased shock pressure. The d-spacings of this carbon are insensitive to the shock pressure and have no apparent diagnostic value, but progressive comminution occurs in response to increased shock pressure up to 59.6 GPa. The function, P = 869.1 x (size(sub minimum )(exp -0.83), describes the relationship between the minimum root-mean-square subgrain size (nm) and shock pressure (GPa). While a subgrain texture of natural pregraphitic carbons carries little information when pre-shock textures are unknown, this texture may go unnoticed as a shock metamorphic feature.

  5. Experimental study of coherent betatron resonances with a Paul trap

    Directory of Open Access Journals (Sweden)

    S. Ohtsubo

    2010-04-01

    Full Text Available Linear and nonlinear resonant instabilities of charged-particle beams traveling in periodic quadrupole focusing channels are studied experimentally with a compact non-neutral plasma trap. The present experiments are based on the idea that the collective motion of a beam in an accelerator is physically similar to that of a one-component plasma in a trap. A linear Paul trap system named “S-POD” (simulator for particle orbit dynamics was developed to explore a variety of space-charge-induced phenomena. To emulate lattice-dependent effects, periodic perturbations are applied to quadrupole electrodes, which gives rise to additional resonance stop bands that shift depending on the plasma density. It is confirmed that an mth-order resonance takes place when the corresponding tune of an mth-order collective mode Ω_{m} is close to a half integer.

  6. Modular hybrid total hip arthroplasty. Experimental study in dogs

    Directory of Open Access Journals (Sweden)

    Ranzani José JT

    2011-07-01

    Full Text Available Abstract Background This prospective experimental study evaluated the surgical procedure and results of modular hybrid total hip arthroplasty in dogs. Methods Ten skeletally mature healthy mongrel dogs with weights varying between 19 and 27 kg were used. Cemented modular femoral stems and uncemented porous-coated acetabular cups were employed. Clinical and radiographic evaluations were performed before surgery and at 30, 60, 90, 120, 180 and 360 days post-operation. Results Excellent weight bearing was noticed in the operated limb in seven dogs. Dislocation followed by loosening of the prosthesis was noticed in two dogs, which were therefore properly treated with a femoral head osteotomy. Femoral fracture occurred in one dog, which was promptly treated with full implant removal and femoral osteosynthesis. Conclusions The canine modular hybrid total hip arthroplasty provided excellent functionality of the operated limb.

  7. Numerical and Experimental Study of Friction Loss in Hydrostatic Motor

    DEFF Research Database (Denmark)

    Sørensen, Rasmus Mørk; Hansen, Michael R.; Mouritsen, Ole Ø.

    2012-01-01

    This paper presents a numerical and experimental study of the losses in a hydrostatic motor principle. The motor is designed so that the structural de ections and lubricating regimes between moving surfaces and, subsequently, the leakage and friction losses, can be controlled during operation....... This is done by means of additional pressure volumes that in uence the stator de ection. These pressures are referred to as compensation pressures and the main emphasis is on friction or torque loss modeling of the motor as a function of the compensation pressures and the high and low pressures related...... to the load torque. The torque loss modeling is identied as a Stribeck curve which depends on gap height. The asperity friction is decreasing exponentially with an increase in gap height. The parameters of the torque loss model are based on prototype measurements that include the structural de ections...

  8. Experimental study of equilibrium in a bumpy torus

    Energy Technology Data Exchange (ETDEWEB)

    Hiroe, S.; Cobble, J.A.; Colchin, R.J.; Chen, G.L.; Connor, K.A.; Goyer, J.R.; Solensten, L.

    1986-06-01

    Plasma equilibrium in the ELMO Bumpy Torus (EBT) was studied experimentally by measurements of the electrostatic potential structure. Before an electron tail population is formed, the electric field is found, roughly speaking, to be in the vertical direction. The appearance of a high-energy electron tail signals the formation of a negative potential well, and the potential contours start to nest. The potential contours are shifted inward with respect to the center of the conducting wall. The electric field between the plasma and the conducting wall forces the plasma inward, balancing the outward expansion force. This force balance provides a horizontal electric field that cancels the concentric radial electric field locally at the separatrix of the potential contour and leads to convective energy loss.

  9. Experimental study of a rotating packed bed distillation column

    Directory of Open Access Journals (Sweden)

    J. V. S. Nascimento

    2009-03-01

    Full Text Available The purpose of this work was to study the mass transfer performance of rotating packed beds applying the "Higee" process. The operations were carried out with the n-hexane/n-heptane distilling system at atmospheric pressure and under total reflux conditions. The rotating speed could be varied between 300 and 2500 rpm, which provided centrifugal forces from 5 to 316 times the Earth's gravity. The effects of concentration, vapor velocity, rotating speed and packing type (two different Raschig ring sizes and structured wire mesh packing on mass transfer behavior were analyzed. Experimental results showed that the mass transfer coefficient depends on the liquid flow rates and rotating speed. The equipment had high separation efficiency in a reduced bed volume.

  10. Numerical and Experimental Study of Pump Sump Flows

    Directory of Open Access Journals (Sweden)

    Wei-Liang Chuang

    2014-01-01

    Full Text Available The present study analyzes pump sump flows with various discharges and gate submergence. Investigations using a three-dimensional large eddy simulation model and an acoustic Doppler velocimeter are performed. Flow patterns and velocity profiles in the approaching flow are shown to describe the flow features caused by various discharges and gate submergence. The variation of a large-scale spanwise vortex behind a sluice gate is examined and discussed. The suction effect on approaching flow near the pipe column is examined using numerical modeling. To gain more understanding of the vortices variation, a comparison between time-averaged and instantaneous flow patterns is numerically conducted. Additionally, swirl angle, a widely used index for evaluating pump efficiency, is experimentally and numerically examined under various flow conditions. The results indicate that the pump becomes less efficient with increasing discharge and gate submergence. The fluctuation of the free surface over the pump sump is also discussed.

  11. Experimental Study of a 45-MHz Array for Radio Astronomy

    Science.gov (United States)

    Alvarez, H.; Aparici, J.; May, J.; Olmos, F.

    1994-09-01

    The University of Chile transit radiotelescope is a 528-dipole array operating at 45 MHz. We present a comparison of an experimental study of the antenna radiation pattern with the basic theoretical pattern in three dimensions. We concentrate in the meridian plane diagram since this is particularly difficult to measure for an array like ours. The comparison shows excellent agreement. We have measured several important antenna parameters like the effective area as a function of zenith distance, the orientation of the plane of the array and the pointing accuracy. We include a detailed treatment of these subjects since not much information related to low frequency arrays for radio astronomy can be found in the literature. We discuss the importance of knowing these parameters in the preparation of the 45-MHz Sky Survey under way at the University of Chile Radio Observatory.

  12. Numerical simulation and experimental study of explosive projectile devices

    Science.gov (United States)

    Selivanov, V. V.; Gryaznov, E. F.; Goldenko, N. A.; Sudomoev, A. D.; Feldstein, V. A.

    2017-06-01

    A study of explosive-throwing device (ETD) was undertaken to simulate the hypervelocity impact of space debris fragments (SDF) and meteoroids with spacecrafts. The principle of operation of an ETD is based on the cumulative effect in combination with the cut-off head of the cumulative jet, which enables one to simulate a compact particle, such as a meteoroid or a fragment of space debris. Different design schemes of ETD with different composition explosive charge initiation schemes with notably low speeds of the jet cut-off are explored, and a method to control the particle velocity is proposed. Numerical simulation of device modes and basic technical characteristics of experimental testing are investigated.

  13. Experimental and simulated study of a composite structure metamaterial absorber

    Science.gov (United States)

    Li, Shengyong; Ai, Xiaochuan; Wu, Ronghua; Chen, Jiajun

    2017-11-01

    In this paper, a high performance metamaterial absorber is designed and experimental studied. Measured results indicate that a perfect absorption band and a short-wavelength absorption peak are achieved in the near-infrared spectrum. Current strength distributions reveal that the absorption band is excited by the cavity resonance. And electric field distributions show that the short-wavelength absorption peak is excited by the horizontal coupled of localized surface plasmon (LSP) modes near hole edges. On the one hand, the absorption property of the measured metamaterial absorber can be enhanced through optimizing the structural parameters (a, w, and H). On the other hand, the absorption property is sensitive to the change of refractive index of environmental medias. A sensing scheme is proposed for refractive index detecting based on the figure of merit (FOM) value. Measured results indicate that the proposed sensing scheme can achieve high FOM value with different environmental medias (water, glucose solution).

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

    KAUST Repository

    Cai, Liming

    2015-01-01

    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.

  15. Experimental study of infrared filaments under different initial conditions

    Science.gov (United States)

    Mirell, Daniel Joseph

    In 1964, four years after the first working laser was constructed, long skinny damage tracks and fluorescence trails were seen inside of certain transparent media that were excited by intense light pulses [1]. What was so remarkable about these features was the narrowness of the spatial profile and their long propagation length in the beam in concert with the very high intensity of the light that would be necessary to produce them. A purely linear model of light propagation through such media was insufficient to explain the results of these experiments and hence a new area of nonlinear optics, latex coined filamentation (to describe the length, slimness, and intensity of the light field), was born. Filament studies begin with a medium that has a nonlinear index of refraction, n¯2, that interacts with an intense beam of light so as to cause it to self-focus. The n¯2 of liquid and solid transparent media is much higher than the n¯ 2 of gases and therefore a much higher intensity of laser source would need to be invented to begin the study of filaments in air. With the advent of the Ti-Sapphire Kerr-lens modelocked laser [2], working in combination with the development of the chirped pulse amplifier system in the mid-1990's, light intensities sufficient to produce filaments in air was realized. Since that time much experimental and theoretical work has been done to better understand some of the additional complexities that arise specifically in the filamentation of light in air using several different wavelengths (UV to IR) and pulsewidths (femto- to pico-seconds). Many theoretical models exist each with a different emphasis on the various physical mechanisms that may produce the features experimentally observed in filaments. The experimental work has sought to give the theoretician better data on some of the properties of filaments such as the: (a) spatial and temporal structure of the beam and of the produced plasma (that arises due to the high intensity light

  16. Experimental study of drag reduction in flumes and spillway tunnels

    Directory of Open Access Journals (Sweden)

    Ying-kui Wang

    2010-06-01

    Full Text Available Experiments in an open flume model and spillway tunnel model were carried out using drag reduction techniques. Two drag reduction techniques were adopted in the experiments: polymer addition and coating. The drag reduction effect of a polyacrylamide (PAM solution and dimethyl silicone oil coating were studied in the flume model experiments, and the results were analyzed. Experiments were then carried out with a model of the Xiluodu Hydropower Station, the second largest dam in China. In order to reduce the resistance, the spillway tunnels were internally coated with dimethyl silicone oil. This is the first time that these drag reduction techniques have been applied to so large a hydraulic model. The experimental results show that the coating technique can effectively increase flood discharge. The outlet velocity and the jet trajectory distance are also increased, which enhances the energy dissipation of the spillway tunnel.

  17. An experimental study on improvement of Savonius rotor performance

    Directory of Open Access Journals (Sweden)

    N.H. Mahmoud

    2012-03-01

    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.

  18. Perceptions of unfairness in price increases: an experimental study

    Directory of Open Access Journals (Sweden)

    Verônica Feder Mayer

    2014-09-01

    Full Text Available This experimental study investigates antecedents and consequences of perceptions of price unfairness in a price increase situation. The proposed theoretical model states that consumer dependence on the service provider as well as the relevance the consumer attributes to the service (for the consumer's life will affect his/her degree of (a unfairness price perception, (b anger, and (c intention to complain and retaliate. The results support all the hypotheses specified in the model. The findings not only indicate that some situations of unfairness price perception lead to stronger emotions and more dramatic reactions from consumers, but also allow us to predict which situations of perceived unfairness offer greater risks and have greater potential for conflict.

  19. The role of bibliotherapy in health anxiety: an experimental study.

    Science.gov (United States)

    Jones, Freda A

    2002-10-01

    Despite its high prevalence and implications for health care resources, health anxiety is generally considered difficult and expensive to manage. Structured self-help materials (bibliotherapy) using a cognitive behaviour therapy (CBT) treatment approach have been shown to be clinically effective. This experimental study investigated the effects of bibliotherapy on patients who had been identified as demonstrating health concerns. The 40 participants (patients drawn from GP surgeries) were randomly allocated to two groups, one receiving bibliotherapy and the other not. Half the patients had a medically diagnosed problem. Anxiety was assessed before and after the bibliotherapy intervention, which took the form of a cognitive-behavioural self-help booklet for health anxiety sufferers. Patients in the bibliotherapy group showed reduced levels of anxiety at post-test, even when they also had an identifiable physical problem. These results are consistent with the idea that self-help materials can be an effective and accessible intervention in CBT, although further research is recommended.

  20. An experimental study on particle effects in liquid sheets

    Directory of Open Access Journals (Sweden)

    Sauret Alban

    2017-01-01

    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.

  1. Theoretical and experimental study of 15N NMR protonation shifts.

    Science.gov (United States)

    Semenov, Valentin A; Samultsev, Dmitry O; Krivdin, Leonid B

    2015-06-01

    A combined theoretical and experimental study revealed that the nature of the upfield (shielding) protonation effect in 15N NMR originates in the change of the contribution of the sp(2)-hybridized nitrogen lone pair on protonation resulting in a marked shielding of nitrogen of about 100 ppm. On the contrary, for amine-type nitrogen, protonation of the nitrogen lone pair results in the deshielding protonation effect of about 25 ppm, so that the total deshielding protonation effect of about 10 ppm is due to the interplay of the contributions of adjacent natural bond orbitals. A versatile computational scheme for the calculation of 15N NMR chemical shifts of protonated nitrogen species and their neutral precursors is proposed at the density functional theory level taking into account solvent effects within the supermolecule solvation model. Copyright © 2015 John Wiley & Sons, Ltd.

  2. 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

    2004-02-01

    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)

  3. [Pathomorphological studies of experimental thiazole-80 poisoning in sheep].

    Science.gov (United States)

    Petkov, P

    1979-01-01

    Investigations on the pathomorphological changes occurring in the organisms of 4 sheep poisoned experimentally by varying Thiazole-80 doses applied orally were made. It was established macroscopically that after opening the rumen a smell of sulfuric hydrogen is felt. The abomasum was with rusty brown haemorrhages and liver distrophy as well as enlarged gall bladder were observed. The histological studies of parenchymal organs revealed vascular disturbances, hyperemia, oedema and intervascular haemolysis. A heavy diffuse nephrosis, hyaline and protein cylinders were found in the kidney cortex, while in the ganglial cells of medula oblongata were evident degenerative changes. Histochemically, in sheep poisoned by thiazole-80, a well expressed reaction to iron in the lungs, leptomeniges and distrophic hepatocytes were established. Glycogen quantity in the liver was considerably reduced.

  4. Experimental measurements of the thermal conductivity of ash deposits: Part 2. Effects of sintering and deposit microstructure

    Energy Technology Data Exchange (ETDEWEB)

    A. L. Robinson; S. G. Buckley; N. Yang; L. L. Baxter

    2000-04-01

    The authors report results from an experimental study that examines the influence of sintering and microstructure on ash deposit thermal conductivity. The measurements are made using a technique developed to make in situ, time-resolved measurements of the effective thermal conductivity of ash deposits formed under conditions that closely replicate those found in the convective pass of a commercial boiler. The technique is designed to minimize the disturbance of the natural deposit microstructure. The initial stages of sintering and densification are accompanied by an increase in deposit thermal conductivity. Subsequent sintering continues to densify the deposit, but has little effect on deposit thermal conductivity. SEM analyses indicates that sintering creates a layered deposit structure with a relatively unsintered innermost layer. They hypothesize that this unsintered layer largely determines the overall deposit thermal conductivity. A theoretical model that treats a deposit as a two-layered material predicts the observed trends in thermal conductivity.

  5. Experimental plan for the Single-Family Study

    Energy Technology Data Exchange (ETDEWEB)

    Berry, L.G.; Brown, M.A.; Wright, T.; White, D.L.

    1991-09-01

    The national evaluation of the Weatherization Assistance Program (WAP) consists of five separate studies. The Single-Family Study is one of three studies that will estimate program energy savings and cost effectiveness in principal WAP submarkets. This report presents the experimental plan for the Single-Family Study, which will be implemented over the next three years (1991--1993). The Single-Family Study will directly estimate energy savings for a nationally representative sample of single-family and small multifamily homes weatherized in the 1989 program year. Savings will be estimated from gas and electric utility billing records using the Princeton Scorekeeping Method (PRISM). The study will also assess nonenergy impacts (e.g., health, comfort, safety, and housing affordability), estimate cost effectiveness, and analyze factors influencing these outcomes. For homes using fuels such as wood, coal, fuel oil, kerosene, and propane as the primary source of space conditioning, energy savings will be studied indirectly. The study will assemble a large nationally representative data base. A cluster sampling approach will be used, in which about 400 subgrantees are selected in a first stage and weatherized homes are selected in a second range. To ensure that the Single-Family Study is able to identify promising opportunities for future program development, two purposively selected groups of subgrantees will be included: (1) subgrantees that install cooling measures (such as more efficient air conditioning equipment or radiant barriers), and (2) exemplary subgrantees that use state-of-the-art technologies and service delivery procedures (such as advanced audit techniques, blower door tests, infrared scanners, extensive client education, etc.). These two groups of subgrantees will be analyzed to identify the most effective program elements in specific circumstances. 14 refs., 4 figs., 3 tabs.

  6. Computational and experimental studies of hydrodynamic instabilities and turbulent mixing: Review of VNIIEF efforts

    Science.gov (United States)

    Andronov, V. A.; Zhidov, I. G.; Meskov, E. E.; Nevmerzhitskii, N. V.; Nikiforov, V. V.; Razin, A. N.; Rogatchev, V. G.; Tolshmyakov, A. I.; Yanilkin, Y. V.

    The report presents the basic results of some calculations, theoretical and experimental efforts in the study of Rayleigh-Taylor, Kelvin-Helmholtz, Richtmyer-Meshkov instabilities and the turbulent mixing which is caused by their evolution. Since the late forties the VNIIEF has been conducting these investigations. This report is based on the data which were published in different times in Russian and foreign journals. The first part of the report deals with calculations on theoretical techniques for the description of hydrodynamic instabilities applied currently, as well as with the results of several individual problems and their comparison with the experiment. These methods can be divided into two types: direct numerical simulation methods and phenomenological methods. The first type includes the regular 2D and 3D gasdynamical techniques as well as the techniques based on small perturbation approximation and on incompressible liquid approximation. The second type comprises the techniques based on various phenomenological turbulence models. The second part of the report describes the experimental methods and cites the experimental results of Rayleigh-Taylor and Richtmyer-Meskov instability studies as well as of turbulent mixing. The applied methods were based on thin-film gaseous models, on jelly models and liquid layer models. The research was done for plane and cylindrical geometries. As drivers, the shock tubes of different designs were used as well as gaseous explosive mixtures, compressed air and electric wire explosions. The experimental results were applied in calculational-theoretical technique calibrations. The authors did not aim at covering all VNIIEF research done in this field of science. To a great extent the choice of the material depended on the personal contribution of the author in these studies.

  7. Experimental studies and modeling on concentration polarization in forward osmosis.

    Science.gov (United States)

    Qin, Jian-Jun; Chen, Sijie; Oo, Maung Htun; Kekre, Kiran A; Cornelissen, Emile R; Ruiken, Chris J

    2010-01-01

    Concentration polarization (CP) is an important issue in forward osmosis (FO) processes and it is believed that the coupled effect of dilutive internal CP (DICP) and concentrative external CP (CECP) limits FO flux. The objective of this study was to distinguish individual contribution of different types of DICP and CECP via modeling and to validate it by pilot studies. The influence of DICP/CECP on FO flux has been investigated in this study. The CP model presented in this work was derived from a previous study and evaluated by bench-scale FO experiments. Experiments were conducted with drinking water as the feed and NaCl/MgSO(4) as draw solutions at different concentrations and velocities. Modeling results indicated that DICP contributed to a flux reduction by 99.9% for 0.5 M NaCl as a draw solution although the flow pattern of both feed and draw solutions was turbulent. DICP could be improved via selection of the draw solution. The modeling results were well fit with the experimental data. It was concluded that the model could be used for selection of the draw solution and prediction of water flux under similar situation. A draw solution with greater diffusion coefficient or a thinner substrate of an asymmetric FO membrane resulted in a higher flux.

  8. Mayak film dosimeter response studies, part I: measurements.

    Science.gov (United States)

    Vasilenko, E K; Knyazev, V; Gorelov, M; Smetanin, M; Scherpelz, R I; Fix, J J

    2007-09-01

    The Mayak Worker Dosimetry study is a joint Russian/U.S. project to evaluate doses received by workers at the Mayak Production Association facilities from 1948-1972. A key investigation in this project is the characterization of responses of the three types of film dosimeters used to monitor workers during this time period. Experimental irradiations of the dosimeters were performed in the radiation calibration laboratories at the National Research Center for Environment and Health (GSF) in Munich, Germany. The irradiations used photon sources from x-ray beams with ten different energy distributions and with Co and Cs isotopic gamma sources. Irradiations were performed with the dosimeters on phantoms and free-in-air. The dosimeters and phantoms were also positioned at varying angles to the radiation beam. The result of the experiments was a thorough characterization of the dosimeter response as a function of photon energy and as a function of angle for energy and angular ranges that cover the conditions encountered in the Mayak workplaces. The characterization data were then available for use in developing correction factors, which could be applied to worker dosimeter readings to provide a more accurate assessment of worker dose and estimates of doses to organs.

  9. Equilibrium p-T phase diagram of boron: experimental study and thermodynamic analysis.

    Science.gov (United States)

    Solozhenko, Vladimir L; Kurakevych, Oleksandr O

    2013-01-01

    Solid-state phase transformations and melting of high-purity crystalline boron have been in situ and ex situ studied at pressures to 20 GPa in the 1500-2500 K temperature range where diffusion processes become fast and lead to formation of thermodynamically stable phases. The equilibrium phase diagram of boron has been constructed based on thermodynamic analysis of experimental and literature data. The high-temperature part of the diagram contains p-T domains of thermodynamic stability of rhombohedral β-B106, orthorhombic γ-B28, pseudo-cubic (tetragonal) t'-B52, and liquid boron (L). The positions of two triple points have been experimentally estimated, i.e. β-t'-L at ~ 8.0 GPa and ~ 2490 K; and β-γ-t' at ~ 9.6 GPa and ~ 2230 K. Finally, the proposed phase diagram explains all thermodynamic aspects of boron allotropy and significantly improves our understanding of the fifth element.

  10. A Novel Approach to Experimental Studies of Mineral Dissolution Kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Chen Zhu; William E. Seyfried

    2005-01-01

    Currently, DOE is conducting pilot CO{sub 2} injection tests to evaluate the concept of geological sequestration. One strategy that potentially enhances CO{sub 2} solubility and reduces the risk of CO{sub 2} leak back to the surface is dissolution of indigenous minerals in the geological formation and precipitation of secondary carbonate phases, which increases the brine pH and immobilizes CO{sub 2}. Clearly, the rates at which these dissolution and precipitation reactions occur directly determine the efficiency of this strategy. However, one of the fundamental problems in modern geochemistry is the persistent two to five orders of magnitude discrepancy between laboratory-measured and field derived feldspar dissolution rates. To date, there is no real guidance as to how to predict silicate reaction rates for use in quantitative models. Current models for assessment of geological carbon sequestration have generally opted to use laboratory rates, in spite of the dearth of such data for compositionally complex systems, and the persistent disconnect between lab and field applications. Therefore, a firm scientific basis for predicting silicate reaction kinetics in CO{sub 2} injected geological formations is urgently needed to assure the reliability of the geochemical models used for the assessments of carbon sequestration strategies. The funded experimental and theoretical study attempts to resolve this outstanding scientific issue by novel experimental design and theoretical interpretation to measure silicate dissolution rates and iron carbonate precipitation rates at conditions pertinent to geological carbon sequestration. In the first year of the project, we have successfully developed a sample preparation method and completed three batch feldspar dissolution experiments at 200 C and 300 bars. The changes of solution chemistry as dissolution experiments progressed were monitored with on-line sampling of the aqueous phase at the constant temperature and pressure

  11. An Experimental Study of Oil / Water Flow in Horizontal Pipes

    Energy Technology Data Exchange (ETDEWEB)

    Elseth, Geir

    2001-07-01

    The purpose of this thesis is to study the behaviour of the simultaneous flow of oil and water in horizontal pipes. In this connection, two test facilities are used. Both facilities have horizontal test sections with inner pipe diameters equal to 2 inches. The largest facility, called the model oil facility, has reservoirs of 1 m{sub 3} of each medium enabling flow rates as high as 30 m{sub 3}/h, which corresponds to mixture velocities as high as 3.35 m/s. The flow rates of oil and water can be varied individually producing different flow patterns according to variations in mixture velocity and input water cut. Two main classes of flows are seen, stratified and dispersed. In this facility, the main focus has been on stratified flows. Pressure drops and local phase fractions are measured for a large number of flow conditions. Among the instruments used are differential pressure transmitters and a traversing gamma densitometer, respectively. The flow patterns that appear are classified in flow pattern maps as functions of either mixture velocity and water cut or superficial velocities. From these experiments a smaller number of stratified flows are selected for studies of velocity and turbulence. A laser Doppler anemometer (LDA) is applied for these measurements in a transparent part of the test section. To be able to produce accurate measurements a partial refractive index matching procedure is used. The other facility, called the matched refractive index facility, has a 0.2 m{sub 3} reservoir enabling mainly dispersed flows. Mixture velocities range from 0.75 m/s to 3 m/s. The fluids in this facility are carefully selected to match the refractive index of the transparent part of the test section. A full refractive index matching procedure is carried out producing excellent optical conditions for velocity and turbulence studies by LDA. In addition, pressure drops and local phase fractions are measured. (author)

  12. Experimental studies of light emission phenomena in superconducting RF cavities

    Energy Technology Data Exchange (ETDEWEB)

    Anthony, P.L. [SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Delayen, J.R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport, News, VA 23606 (United States); Center for Accelerator Science, Old Dominion University, Norfolk, VA, 23529 (United States); Fryberger, D., E-mail: fryberger@slac.stanford.ed [SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Goree, W.S. [2G Enterprises, Pacific Grove, CA 93950 (United States); Mammosser, J. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport, News, VA 23606 (United States); Szalata, Z.M.; Weisend, J.G. [SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States)

    2009-12-21

    Experimental studies of light emission phenomena in superconducting RF cavities, which we categorize under the general heading of cavity lights, are described. The cavity lights data, which were obtained using a small CCD video camera, were collected in a series of nine experimental runs ranging from approx1/2 to approx2 h in duration. The video data were recorded on a standard VHS tape. As the runs progressed, additional instrumentation was added. For the last three runs a LabVIEW-controlled data acquisition system was included. These runs furnish evidence for several, possibly related, light emission phenomena. The most intriguing of these is what appear to be small luminous objects <=1.5 mm in size, freely moving about in the vacuum space, generally without wall contact, as verified by reflections of the tracks in the cavity walls. In addition, on a number of occasions, these objects were observed to bounce off of the cavity walls. The wall-bounce aspect of most of these events was clearly confirmed by pre-bounce and post-bounce reflections concurrent with the tracks. In one of the later runs, a mode of behavior was observed that was qualitatively different from anything observed in the earlier runs. Perhaps the most perplexing aspect of this new mode was the observation of as many as seven luminous objects arrayed in what might be described as a macromolecular formation, coherently moving about in the interior of the cavity for extended periods of time, evidently without any wall contact. It is suggested that these mobile luminous objects are without explanation within the realm of established physics. Some remarks about more exotic theoretical possibilities are made, and future plans are discussed.

  13. Experimental Studies of Light Emission Phenomena in Superconducting RF Cavitites

    Energy Technology Data Exchange (ETDEWEB)

    Anthony, P.L.; /SLAC; Delayen, J.R.; /Jefferson Lab; Fryberger, D.; /SLAC; Goree, W.S.; Mammosser, J.; /Jefferson Lab /SNS Project, Oak Ridge; Szalata, Z.M.; II, J.G.Weisend /SLAC

    2009-08-04

    Experimental studies of light emission phenomena in superconducting RF cavities, which we categorize under the general heading of cavity lights, are described. The cavity lights data, which were obtained using a small CCD video camera, were collected in a series of nine experimental runs ranging from {approx} 1/2 to {approx} 2 h in duration. The video data were recorded on a standard VHS tape. As the runs progressed, additional instrumentation was added. For the last three runs a LabVIEW controlled data acquisition system was included. These runs furnish evidence for several, possibly related, light emission phenomena. The most intriguing of these is what appear to be small luminous objects {le} 1.5 mm in size, freely moving about in the vacuum space, generally without wall contact, as verified by reflections of the tracks in the cavity walls. In addition, on a number of occasions, these objects were observed to bounce off of the cavity walls. The wall-bounce aspect of most of these events was clearly confirmed by pre-bounce and post-bounce reflections concurrent with the tracks. In one of the later runs, a mode of behavior was observed that was qualitatively different from anything observed in the earlier runs. Perhaps the most perplexing aspect of this new mode was the observation of as many as seven luminous objects arrayed in what might be described as a macromolecular formation, coherently moving about in the interior of the cavity for extended periods of time, evidently without any wall contact. It is suggested that these mobile luminous objects are without explanation within the realm of established physics. Some remarks about more exotic theoretical possibilities are made, and future plans are discussed.

  14. Experimental study of vortex breakdown in a cylindrical, swirling flow

    Science.gov (United States)

    Stevens, J. L.; Celik, Z. Z.; Cantwell, B. J.; Lopez, J. M.

    1996-01-01

    The stability of a steady, vortical flow in a cylindrical container with one rotating endwall has been experimentally examined to gain insight into the process of vortex breakdowwn. The dynamics of the flow are governed by the Reynolds number (Re) and the aspect ratio of the cylinder. Re is given by Omega R(sup 2)/nu, where Omega is the speed of rotation of the endwall, R is the cylinder radius, and nu is the kinematic viscosity of the fluid filling the cylinder. The aspect ratio is H/R, where H is the height of the cylinder. Numerical simulation studies disagree whether or not the steady breakdown is stable beyond a critical Reynolds number, Re(sub c). Previous experimental researches have considered the steady and unsteady flows near Re(sub c), but have not explored the stability of the steady breakdown structures beyond this value. In this investigation, laser induced fluorescence was utilized to observe both steady and unsteady vortex breakdown at a fixed H/R of 2.5 with Re varying around Re(sub c). When the Re of a steady flow was slowly increased beyond Re(sub c), the breakdown structure remained steady even though unsteadiness was possible. In addition, a number of hysteresis events involving the oscillation periods of the unsteady flow were noted. The results show that both steady and unsteady vortex breakdown occur for a limited range of Re above Re(sub c). Also, with increasing Re, complex flow transformations take place that alter the period at which the unsteady flow oscillates.

  15. Epidural blood patch: A study on an experimental model

    Directory of Open Access Journals (Sweden)

    S K Sengupta

    2013-01-01

    Full Text Available Aim: Epidural blood patch has been used to treat spinal headache with varying success. An experimental model was designed to ascertain whether an epidural blood patch can be used to seal the needle puncture sites in dural repair. Materials and Methods: Bovine dura was secured to the lower end of an open-ended calibrated plastic cylinder. Multiple interrupted stitches were applied over a 02 cm length of the dura without any incision. The cylinder was filled with colored saline gradually with the dura placed in a dependent position. Height of the water column at which sutured dura leaked was recorded. A layer of fresh blood was laid over the dura and allowed to clot. The test was repeated and the hydrostatic pressure at which leak took place was noted again. The test was repeated three times. Similar studies were done with two specimens with 02-cm dural incisions repaired with interrupted stitches of 4-0 silk in one specimen and 4-0 prolene in another, and three specimens with 3-mm unsutured dural rent in one and dural punctures made with 23-G and 26-G spinal needles in the other two. Results: All the dural preparations leaked, at a very low hydrostatic pressure (<30 mm of H 2 O. By covering the needle puncture sites with clotted blood, a watertight closure could be achieved, that can withstand a much higher hydrostatic pressure (mean of 180 mm of H 2 O. Conclusion : The experimental findings indicate that an epidural blood patch does enhance the ability of a dural closure to prevent a leak; however, its utility in clinical setting is questionable.

  16. Experimental study of a single channel alluvial fan

    Science.gov (United States)

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

    2016-04-01

    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).

  17. Axisymmetric flow in a cylindrical tank over a rotating bottom. Part II. Deformation of the water surface and experimental verification of the theory

    Science.gov (United States)

    Iga, Keita; Yokota, Sho; Watanabe, Shunichi; Ikeda, Takashi; Niino, Hiroshi; Misawa, Nobuhiko

    2017-12-01

    The theory of axisymmetric flow in a cylindrical container with a rotating bottom, as described in Part I, is validated against the results of previous and our own laboratory experiments. First, deformation of the water surface is derived using the velocity distribution of the axisymmetric flow obtained by the theory. The form of the water surface is classified into three regimes, and the rotation rates of the transitions between these regimes are determined. The parameters predicted from this theory are compared with the results measured in laboratory experiments and also with data from previous experimental studies. The theory predicts the experimental data well, but a slight difference was found in the narrow region close to the side wall. Corrections estimated by considering the fluid behavior around the side wall boundary layer successfully explain most of the discrepancies. This theory appears to predict the results of the laboratory experiments very well, much better than a theory using an assumption of quadratic drag as a model of turbulent boundary layers.

  18. Determination of the Clean Air Delivery Rate (CADR) of Photocatalytic Oxidation (PCO) Purifiers for Indoor Air Pollutants Using a Closed-Loop Reactor. Part II: Experimental Results.

    Science.gov (United States)

    Héquet, Valérie; Batault, Frédéric; Raillard, Cécile; Thévenet, Frédéric; Le Coq, Laurence; Dumont, Éric

    2017-03-06

    The performances of a laboratory PhotoCatalytic Oxidation (PCO) device were determined using a recirculation closed-loop pilot reactor. The closed-loop system was modeled by associating equations related to two ideal reactors: a perfectly mixed reservoir with a volume of VR = 0.42 m³ and a plug flow system corresponding to the PCO device with a volume of VP = 5.6 × 10-3 m³. The PCO device was composed of a pleated photocatalytic filter (1100 cm²) and two 18-W UVA fluorescent tubes. The Clean Air Delivery Rate (CADR) of the apparatus was measured under different operating conditions. The influence of three operating parameters was investigated: (i) light irradiance I from 0.10 to 2.0 mW·cm-2; (ii) air velocity v from 0.2 to 1.9 m·s-1; and (iii) initial toluene concentration C₀ (200, 600, 1000 and 4700 ppbv). The results showed that the conditions needed to apply a first-order decay model to the experimental data (described in Part I) were fulfilled. The CADR values, ranging from 0.35 to 3.95 m³·h-1, were mainly dependent on the light irradiance intensity. A square root influence of the light irradiance was observed. Although the CADR of the PCO device inserted in the closed-loop reactor did not theoretically depend on the flow rate (see Part I), the experimental results did not enable the confirmation of this prediction. The initial concentration was also a parameter influencing the CADR, as well as the toluene degradation rate. The maximum degradation rate rmax ranged from 342 to 4894 ppbv/h. Finally, this study evidenced that a recirculation closed-loop pilot could be used to develop a reliable standard test method to assess the effectiveness of PCO devices.

  19. Determination of the Clean Air Delivery Rate (CADR of Photocatalytic Oxidation (PCO Purifiers for Indoor Air Pollutants Using a Closed-Loop Reactor. Part II: Experimental Results

    Directory of Open Access Journals (Sweden)

    Valérie Héquet

    2017-03-01

    Full Text Available The performances of a laboratory PhotoCatalytic Oxidation (PCO device were determined using a recirculation closed-loop pilot reactor. The closed-loop system was modeled by associating equations related to two ideal reactors: a perfectly mixed reservoir with a volume of VR = 0.42 m3 and a plug flow system corresponding to the PCO device with a volume of VP = 5.6 × 10−3 m3. The PCO device was composed of a pleated photocatalytic filter (1100 cm2 and two 18-W UVA fluorescent tubes. The Clean Air Delivery Rate (CADR of the apparatus was measured under different operating conditions. The influence of three operating parameters was investigated: (i light irradiance I from 0.10 to 2.0 mW·cm−2; (ii air velocity v from 0.2 to 1.9 m·s−1; and (iii initial toluene concentration C0 (200, 600, 1000 and 4700 ppbv. The results showed that the conditions needed to apply a first-order decay model to the experimental data (described in Part I were fulfilled. The CADR values, ranging from 0.35 to 3.95 m3·h−1, were mainly dependent on the light irradiance intensity. A square root influence of the light irradiance was observed. Although the CADR of the PCO device inserted in the closed-loop reactor did not theoretically depend on the flow rate (see Part I, the experimental results did not enable the confirmation of this prediction. The initial concentration was also a parameter influencing the CADR, as well as the toluene degradation rate. The maximum degradation rate rmax ranged from 342 to 4894 ppbv/h. Finally, this study evidenced that a recirculation closed-loop pilot could be used to develop a reliable standard test method to assess the effectiveness of PCO devices.

  20. Proteomic Studies on Human and Experimental Cerebral Malaria

    KAUST Repository

    Moussa, Ehab

    2012-07-01

    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

  1. [Crystalline lens photodisruption using femtosecond laser: experimental study].

    Science.gov (United States)

    Chatoux, O; Touboul, D; Buestel, C; Balcou, P; Colin, J

    2010-09-01

    The aim of this study was to analyze the interactions during femtosecond (fs) laser photodisruption in ex vivo porcine crystalline lenses and to study the parameters for laser interaction optimization. An experimental femtosecond laser was used. The laser characteristics were: 1030 nm wavelength; pulse duration, 400 fs; and numerical aperture, 0.13. Specific software was created to custom and monitor any type of photoablation pattern for treatment purposes. Porcine crystalline lenses were placed in an open sky holder filled with physiological liquid (BSS) covered by a glass plate. A numerical camera was associated with metrological software in order to magnify and quantify the results. Transmission electron microscopy (TEM) was performed on some samples to identify the microscopic plasma interactions with the lens. The optimization of parameters was investigated in terms of the optical breakdown threshold, the sizing of interactions, and the best pattern for alignments. More than 150 crystalline lenses of freshly enucleated pigs were treated. The optical breakdown threshold (OBT) was defined as the minimal energy level per pulse necessary to observe a physical interaction. In our study, the OBT varied according to the following parameters: the crystalline lens itself, varying from 4.2 to 7.6 μJ (mean, 5.1 μJ), and the depth of laser focus, varying up to 1 μJ, increasing in the depth of the tissue. Analyzing the distance between impacts, we observed that the closer the impacts were the less power was needed to create a clear well-drawn defect pattern (lines), i.e., with a 4-μJ optimized OBT, when the impacts were placed every 2 μm for the x,y directions and 60 μm for the z direction. Coalescent bubbles created by plasma formation always disappeared in less than 24h. The nonthermal effect of plasma and the innocuousness on surrounding tissues were proven by the TEM results. The crystalline lens photodisruption by the femtosecond laser seems an innovative

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

    Directory of Open Access Journals (Sweden)

    Talebi Mazraehshahi H.

    2010-06-01

    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.

  3. Designing Awe in Virtual Reality: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Alice Chirico

    2018-01-01

    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.

  4. Theoretical and experimental study of fiber-optic fluorescence immunosensors

    Science.gov (United States)

    Cao, He

    This dissertation investigates the optical detection of antigens (in this case, food pathogens such as Salmonella) with fiber-optic immunosensors. The major techniques used for this optical detection include: (1)Linking the antigens to some physical tracers that can be optically detected; (2)Collecting and transmitting the optical signal to an optical detector. From an optical point of view, the problem is a nonimaging-optics problem to collect a fluorescent signal from an extended Lambertian source and deliver it to an optical detection system with maximum energy transfer and distinct wavelength separation. A raytrace model of the optical detection system was used for numerical simulations to analyze and optimize the optical design. The result leads to an improvement of the optical detection. Related physical problems such as magnetic focusing effect, fluorescence detection, and wavelength separation have also been studied in detail. With the adoption of a single-step immunomagnetic assay, experimental studies have been conducted for the detection of Salmonella, with a dual- fiber optical probe and tapered tubular waveguide probes. The test results have shown that the detection system gives detection limit of approximately 106 CFU/ml with dual-fiber optical probes, and 105 CFU/ml with improved tubular waveguide probes. The system developed for this research project is designed as a cost-effective portable instrument that may be used for field-testing. Rapid and on-site detection, low cost instrumentation and a reusable optical probe have been emphasized throughout the study.

  5. The Benefits of Part-Time Undergraduate Study and UK Higher Education Policy: A Literature Review

    Science.gov (United States)

    Bennion, Alice; Scesa, Anna; Williams, Ruth

    2011-01-01

    Part-time study in the UK is significant: nearly 40 per cent of higher education students study part-time. This article reports on a literature review that sought to understand the economic and social benefits of part-time study in the UK. It concludes that there are substantial and wide-ranging benefits from studying part-time. The article also…

  6. Studies on experimental models used for nutritional and biological ...

    African Journals Online (AJOL)

    The anatomical location for a successful implantation in order to reduce complications to the hearest minimum has been suggested . The maintenance of the implanted cannulae for the purpose of keeping the modified experimental model in perfect health is discussed. Key Words: Experimental Models, Nutritional Biological ...

  7. An Experimental Study on Wall Thickness Distribution in Thermoforming

    Directory of Open Access Journals (Sweden)

    Sencer Süreyya Karabeyoglu

    2017-09-01

    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.

  8. A "self adhering" prosthesis for hernia repair: experimental study.

    Science.gov (United States)

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

    2009-02-01

    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

  9. Experimental and theoretical study of delayed ettringite damage in concrete

    Science.gov (United States)

    Ramadan, Elsaid Osman

    2000-12-01

    An experimental study is conducted to investigate the effect of a range of parameters on concrete expansion and premature deterioration associated with delayed ettringite formation (DEF). These parameters were identified from a comprehensive literature review; they include concrete curing conditions and cement chemistry. Specifically, the study investigated the effect of potassium and magnesium contents as well as the effect of water and steam curing conditions on concrete damage associated with DEF. An accelerated test method for DEF was evaluated and modifications are suggested. Concrete specimens were prepared with varying amounts of potassium and magnesium and subjected to different curing conditions. To accelerate any potential expansion, a beat cycle was employed. The change in length of the specimens was monitored for the duration of the study. Specimens were analyzed using the scanning electron microscope, x-ray dispersive analysis, and x-ray diffraction to determine the mechanism responsible for deterioration. Computed tomography x-ray was also employed as a non-destructive method for examining the internal crack patterns associated with expansion. The expansion data is fitted using the Kohnogorov-Avrami-Johenson-Mehl (KAJM) equation. This theory makes it possible to identify individual expansion processes and to identify the contribution of different expansion mechanisms. All concretes showed expansion following the beat cycle. Subjecting concrete to the heat cycle has a primary role in accelerating expansion. The age at which concrete is subjected to the beat cycle as well as the sample dimensions have a profound effect on the resulting expansion. The use of the concrete prisms as suggested in the modified test method offers a better alternative to cores suggested by Duggan. Increasing the potassium content has a deleterious effect on concrete expansion and premature deterioration and is also associated with dramatic reduction in compressive strength

  10. Service-Learning and Leadership Life Skills: An Experimental Study

    Directory of Open Access Journals (Sweden)

    B. Darlene Locke

    2007-06-01

    Full Text Available This study examined the effect of service activities on the development of leadership life skills in youth and (queried if having a reflection component as part of the activity makes a difference. Additionally, the study examined the impact of selected demographics including age, gender, type of service completed monthly and 4-H membership on the development of leadership life skills. Participants in the study were from two samples. One group represented the El Paso National Youth Service Day, the other represented the District 11 4-H Leadership Lab in Branham, Texas. Participants were randomly assigned to a control (no reflection or treatment (with reflection group. Youth participants self rated their leadership life skills using a 33-question post-test only questionnaire. Demographics were reported in nine additional questions. The major findings of the study are as follows: 1 Overall, the participants reported their perceived leadership life skills to be high in four of the five subscales; 2 The inclusion of a reflection component did not significantly affect perceived leadership life skills; 3 Type of service, whether direct or indirect, had a significant impact on perceived leadership life skills; 4 4-H membership had a significant impact on the Personal Leadership Development subscale.

  11. Theoretical and Experimental Study of Bimetal-Pipe Hydroforming.

    Science.gov (United States)

    Dezhi, Zeng; Kuanhai, Deng; Taihe, Shi; Yuanhua, Lin; Hongjun, Zhu; Tianlei, Li; Yongxing, Sun

    2014-12-01

    The corrosion of oil country tubular goods (OCTG) gets more and more serious especially in the acidic environment. So, it is very important to develop a perfect anticorrosion technology for exploring sour oil and gas fields economically and safely. Analysis indicates that the bimetal-pipe (BP) which consists of the base layer of low carbon steel and a corrosion resistant alloy (CRA) cladding layer is an economic and reliable anticorrosion technology and has broad application prospects in the transportation of acid medium. However, theoretical study of hydraulic expansion mechanism for BP is not enough. In this paper, the deformation compatibility condition of BP was obtained by studying the deformation rule of the (CRA) liner and the outer pipe of carbon steel in the forming process; the mechanical model which can compute the hydroforming pressure of BP has been established based on the nonlinear kinematic hardening characteristics of material; furthermore, based on the stress strain curve of inner pipe simultaneously, the calculation method of the plastic hardening stress has been proposed. Thus, the accurate method for computing the forming pressure was obtained. The experimental data show that results are consistent with results of the proposed model. It indicates that the model can be used to provide theoretical guidance for the design and production as well as use of BP.

  12. Laser Experimental Study of the Surface Vibrations of EMUS Sensor

    Science.gov (United States)

    Wilkie-Chancellier, N.; Wang, Y.; Martinez, L.; Roucaries, B.; Serfaty, S.

    In order to ensure a comprehensive monitoring of the material structuration in liquid phase, the traditional ultrasonic techniques require excitation in contact which is often inadequate for online tracking. To monitor the material evolution remotely, a new electromagnetic ultrasonic sensor (EMUS) was successfully developed in our laboratory. The EMUS transducer is based on a resonant thickness shear mode sensor (TSM) magnetically coupled to a high frequency antenna. The TSM resonator consists in a piezoelectric AT-cut quartz plate with metal electrodes on opposite sides. The application of a radio frequency electrical signal gives rise to the excitation of a shear mechanical resonance. The work presented here allows characterizing the acoustic behavior of the EMUS. A laser vibrometer is used to scan the surface of the TSM resonator and visualize the propagation of the generated surface waves. This study shows a good agreement between experimental and theoretical results which encourages the study of acoustic interaction between the TSM resonator and a material in contact with the quartz surface. They therefore suggest that this non-destructive technique can be used to extract the viscoelastic properties of materials.

  13. A Perspective on the Experimental Techniques for Studying Lamins

    Directory of Open Access Journals (Sweden)

    Ilaria Pecorari

    2017-10-01

    Full Text Available Lamins are type V intermediate filaments that collectively form a meshwork underneath the inner nuclear membrane, called nuclear lamina. Furthermore, they are also present in the nucleoplasm. Lamins are experiencing a growing interest, since a wide range of diseases are induced by mutations in the gene coding for A-type lamins, globally known as laminopathies. Moreover, it has been demonstrated that lamins are involved in other pathological conditions, like cancer. The role of lamins has been studied from several perspectives, exploiting different techniques and procedures. This multidisciplinary approach has contributed to resolving the unique features of lamins and has provided a thorough insight in their role in living organisms. Yet, there are still many unanswered questions, which constantly generate research in the field. The present work is aimed to review some interesting experimental techniques performed so far to study lamins. Scientists can take advantage of this collection for their novel investigations, being aware of the already pursued and consolidated methodologies. Hopefully, advances in these research directions will provide insights to achieve better diagnostic procedures and effective therapeutic options.

  14. [Muscular control of scapholunate instability. An experimental study].

    Science.gov (United States)

    León-López, M M; García-Elías, M; Salvà-Coll, G; Llusá-Perez, M; Lluch-Bergadà, A

    2014-01-01

    As long as the neuromuscular stabilizers are intact, a lesion of the scapholunate ligament may or may not progress to a carpal instability. The mechanisms by which the muscles compensate this defect are not very well known. We designed an experimental study with the aim of clarifying these mechanisms. Using 10 fresh wrists, with no pre-existing lesions, we studied the movements of the scaphoid, triquetrum and capitate produced by the isometrical loading of the muscles which move the wrist, each of them isolated or combined, before and after cutting off the scapholunate ligaments. To do this, we placed sensors in each of these bones and used the Fastrack system to record these movements. The simultaneous loading of the muscles of the wrist produce rotational movements in flexion and supination of the proximal carpal row. After cutting off the scapholunate ligaments, the scaphoid rotates in pronation and flexion, while the triquetrum rotates in pronation and extension. In this situation of a scapholunate lesion, the muscles that worsen the carpal dexasation are the extensor carpi ulnaris and flexor carpi ulnaris. On the other hand, the isolated loading of the radial muscles reduce the scapholunate diastasis, thus improving the carpal alignment. In dynamic scapholunate instabilities, isometric contraction of the ulnar carpal muscles must be avoided, as it promotes the scapholunate diastasis. The rest of the muscles have the opposite effect, stabilizing the carpus when primary stabilizers have failed. Copyright © 2013 SECOT. Published by Elsevier Espana. All rights reserved.

  15. A retrievable nitinol endobronchial stent : an experimental study in dog

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Sang Jin; Park, Sang Soo; Yoon, Hyun Ki; Sung, Kyu Bo; Song, Ho Young [Asan Medical Center, Ulsan Univ. College of Medicine, Seoul (Korea, Republic of); Kang, Sung Gwon [Inha Univ. College of Medicine, Inchon (Korea, Republic of)

    1999-06-01

    The purpose of this study was to evaluate the safety and the retrievability of a new covered retrievable nitinol tracheobronchial stent. Stents were knitted from 0.2mm nitinol wire, covered with polyurethane, and were 20-22mm in diameter and 2cm in length. Under fluoroscopic guidance, a stent was placed in the normal right bronchus intermedius of ten dogs. Using a retrieval hook, stent retrieval was attempted after 1 month(N=5) or 2 months(N=5). After removal, the dogs were sacrificed and their their tracheobronchial trees were examined grossly and histologically. Eleven stents were successfully placed in ten dogs. Migration and expectoration occurred in four of ten stents in nine dogs(40%). Five stents were successfully removed from six dogs(83%). Without significant difference between the two groups, mild to moderate mucosal hyperplasia was noted at the sites of stents as well as above and below them. On microscopy, three of five dogs showed pneumonia in the right middle lobes, but none of the stents was covered with epithelium. Temporary placement of a covered expandable nitinol stent in the tracheobronchial tree is feasible, but to establish its efficacy, further experimental studies are needed.

  16. Cold-formed steel pallet rack connection: an experimental study

    Science.gov (United States)

    Mohan, Vimal; Prabha, P.; Rajasankar, J.; Iyer, Nagesh R.; Raviswaran, N.; Nagendiran, V.; Kamalakannan, S. S.

    2015-03-01

    Industrial pallet rack systems are made up of three-dimensional structural arrangement using cold-formed steel members. The rack columns (upright) have perforations at prescribed intervals to facilitate the assemblage of beams with end connections. The tabs are used as connections which are engaged into the perforations and are in particular, highly semi-rigid in nature. Due to the diversity of rack systems, connecting member's stiffness and strength, it is almost impossible to develop a generalised model for analytical predication of the connection stiffness. This paper describes the beam-column connection tests carried out on a commercially available pallet rack system by adopting single cantilever test set-up. Thirty-five sets of combinations are identified based on the variation in upright profile and thickness, depth of beam and the connector to study the connection stiffness. Three tests were performed for each set to bring in uniformity in the result taking the total number of tests to 105. A full range parametric study is carried out to understand the influence of above said parameters on moment-rotation behaviour and the joint stiffness. The experimental results showed that an improved performance of the joint connection is achieved using connectors with more number of tabs, greater thickness and improved profile of the upright and larger depth of the beam.

  17. Modelling transient pipe flow with cavitation and frequency dependent friction. Part II. Friction and numerical-experimental validation

    Directory of Open Access Journals (Sweden)

    Kamil Urbanowicz

    2015-09-01

    Full Text Available Modelling of time-depended hydraulic friction is not an easy issue. As numerous studies have shown, wall shear stress in the pipe can be determined as a sum of the quasi-steady and time-dependent expressions. Time-depended expression is an convolution integral of the local acceleration of the liquid and a weighting function. The weighting function, in general, makes allowance for relation of historic velocity changes and unsteady component of wall shear stress. The original weighting function has usually a very complicated structure, and what is more it makes impossible to do an efficient simulation of dynamical runs. In this paper, in order to enable efficient calculation of unsteady component wall shear stress, new weighting functions are presented as a sum of exponential components. To aim this goal in case of turbulent flow, the scaling procedure proposed by Vitkovsky et al. is used. This method makes very easy the estimation of any new turbulent weighting function. Presented approximated weighting functions are compared with the original counterparts, known from literature in case of laminar and turbulent flows. Using the previously discussed models of cavitation flow CSM, CSMG, CSMA, and the BCM with implemented effective weighting function a series of simulation studies has been made, which showed that the introduced changes in models of unsteady flow with cavitation greatly improve the degree of simulation fit in comparison with experimental results.[b]Keywords[/b]: numerical fluid mechanics, transient flow, cavitation, frequency-dependent friction losses, pipeline, waterhammer

  18. A Study of Speech Parts in Joneyd-nameh

    National Research Council Canada - National Science Library

    Y Talebian; M Puyan Mehr

    2011-01-01

    .... This method has been used for analyzing mythical narratives. Todorov considered different aspects of these stories and in doing so he divided their various speech parts into the categories of noun, adjective and verb...

  19. Nab: precise experimental study of unpolarized neutron beta decay

    Science.gov (United States)

    Pocanic, Dinko; Nab Collaboration

    2014-09-01

    Nab, a program of experimental study of unpolarized neutron decays at the Spallation Neutron Source, Oak Ridge, TN, aims to determine a, the electron-neutrino correlation with precision of δa / a =10-3 , and b, the Fierz interference term, with uncertainty δb ~= 3 ×10-3 . Neutron beta decay's simple theoretical description in the Standard Model (SM) is overconstrained by the set of available observables, providing opportunities to search for evidence of SM extensions. Planned Nab results will lead to a new precise determination of the ratio λ =GA /GV , and to significant reductions in the allowed limits for both right- and left-handed scalar and tensor currents. Alternatively, the experiment may detect a discrepancy from SM predictions consistent with certain realizations of supersymmetry. An optimized, asymmetric spectrometer has been designed to achieve the narrow proton momentum response function required to meet the physics goals of the experiment. The apparatus is to be used in a follow-up measurement (ABba) of asymmetry observables A and B in polarized neutron decay. Nab is funded, now in the construction stage, with planned beam readiness in 2016. We discuss the experiment's motivation, expected reach, design and method. Nab, a program of experimental study of unpolarized neutron decays at the Spallation Neutron Source, Oak Ridge, TN, aims to determine a, the electron-neutrino correlation with precision of δa / a =10-3 , and b, the Fierz interference term, with uncertainty δb ~= 3 ×10-3 . Neutron beta decay's simple theoretical description in the Standard Model (SM) is overconstrained by the set of available observables, providing opportunities to search for evidence of SM extensions. Planned Nab results will lead to a new precise determination of the ratio λ =GA /GV , and to significant reductions in the allowed limits for both right- and left-handed scalar and tensor currents. Alternatively, the experiment may detect a discrepancy from SM

  20. Spine alignment in men during lateral sleep position: experimental study and modeling

    Directory of Open Access Journals (Sweden)

    Leilnahari Karim

    2011-11-01

    Full Text Available Abstract Background A proper sleep system can affect the spine support in neutral position. Most of the previous studies in scientific literature have focused on the effects of customary mattresses on the spinal alignment. To keep the spine in optimal alignment, one can use sleep surfaces with different zonal elasticity, the so called custom-made arrangements. The required stiffness of a sleep surface for each individual can be obtained by changing this arrangement applying the experimental method and modeling. Methods In experimental part, the coordinate positions of the markers mounted on the spinous processes of the vertebrae of 25 male volunteers were registered in frontal plane through the optical tracking method and so the spinal alignment was obtained in lateral sleep position on soft and firm surfaces and on the best custom-made arrangement. Thereupon the π-P8 angles were extracted from these alignments and then were compared with each other. In modeling part the anthropometric data of four different types of volunteers were used. And then the models built in BRG.LifeMOD (ver. 2007, Biomechanics Research Group, Inc., USA based on these data and in accordance with the experimental tests, were analyzed. Results The one way ANOVA statistical model and the post hoc tests showed a significant difference in the π-P8 angles between soft & custom-made and soft & firm mattresses at the p = 0.001 level and between firm & soft mattresses at the p = 0.05 level. In modeling part, the required stiffness of the sleep surface for four weight-dimensional groups was acquired quantitatively. Conclusions The mattress with a custom-made arrangement is a more appropriate choice for heavier men with pronounced body contour. After data fitting, it was observed that the variations of spinal alignment obtained from both methods have the same trend. Observing the amount of required stiffness obtained for the sleep surface, can have a significant effect on

  1. [Methodological approaches to the experimental study of the impact of environmental pollution on the human body].

    Science.gov (United States)

    Sosedova, L M

    2014-01-01

    In the materials there are presented features of methodological approaches in the performing of experimental studies concerning of the investigation of the impacts of environmental factors on the human body. There were shown the results of our experiments performed at the Institute, in the modeling of biological effects of antimicrobial nanobiocomposites with nanosilver particles, toxic encephalopathy, in the study of the combined effect of the factors of biological and chemical nature. There was proved the importance of intracellular of proteomics in the assessment of the effects of the action of nanoparticles and nanomaterials on the body. There were revealed key parts of progredient course of mercury poisoning in the long-term. The special section is presented by the study of long-term effects of anthropogenic environmental factors on subsequent generations. There are presented results witnessing to a deterioration of the functional state of the central nervous system in rats in the first and second generations, whose parents were exposed to neurotoxicants. There was proved the aggravating role of prenatal hypoxia in the development of toxicity in rats in sexually mature age. Experimental biomodeling is aimed at sighting of pathogenetically substantiated treatment and preventive measures: initially, in experimental conditions, and in the future in the rehabilitation of sick or injured patients.

  2. Experimental evidence of inter-blade cavitation vortex development in Francis turbines at deep part load condition

    Science.gov (United States)

    Yamamoto, K.; Müller, A.; Favrel, A.; Avellan, F.

    2017-10-01

    Francis turbines are subject to various types of cavitation flow depending on the operating condition. To enable a smooth integration of the renewable energy sources, hydraulic machines are now increasingly required to extend their operating range, especially down to extremely low discharge conditions called deep part load operation. The inter-blade cavitation vortex is a typical cavitation phenomenon observed at deep part load operation. However, its dynamic characteristics are insufficiently understood today. In an objective of revealing its characteristics, the present study introduces a novel visualization technique with instrumented guide vanes embedding the visualization devices, providing unprecedented views on the inter-blade cavitation vortex. The binary image processing technique enables the successful evaluation of the inter-blade cavitation vortex in the images. As a result, it is shown that the probability of the inter-blade cavitation development is significantly high close to the runner hub. Furthermore, the mean vortex line is calculated and the vortex region is estimated in the three-dimensional domain for the comparison with numerical simulation results. In addition, the on-board pressure measurements on a runner blade is conducted, and the influence of the inter-blade vortex on the pressure field is investigated. The analysis suggests that the presence of the inter-blade vortex can magnify the amplitude of pressure fluctuations especially on the blade suction side. Furthermore, the wall pressure difference between pressure and suction sides of the blade features partially low or negative values near the hub at the discharge region where the inter-blade vortex develops. This negative pressure difference on the blade wall suggests the development of a backflow region caused by the flow separation near the hub, which is closely related to the development of the inter-blade vortex. The development of the backflow region is confirmed by the numerical

  3. Sustaining a Global Social Network: a quasi-experimental study.

    Science.gov (United States)

    Benton, D C; Ferguson, S L

    2017-03-01

    To examine the longer term impact on the social network of participating nurses in the Global Nursing Leadership Institute (GNLI2013) through using differing frequencies of follow-up to assess impact on maintenance of network cohesion. Social network analysis is increasingly been used by nurse researchers, however, studies tend to use single point-in-time descriptive methods. This study utilizes a repeated measures, block group, control-intervention, quasi-experimental design. Twenty-eight nurse leaders, competitively selected through a double-blind peer review process, were allocated to five action learning-based learning groups. Network architecture, measures of cohesion and node degree frequency were all used to assess programme impact. The programme initiated and sustained connections between nurse leaders drawn from a geographically dispersed heterogeneous group. Modest inputs of two to three e-mails over a 6-month period seem sufficient to maintain connectivity as indicated by measures of network density, diameter and path length. Due to the teaching methodology used, the study sample was relatively small and the follow-up data collection took place after a relatively short time. Replication and further cohort data collection would be advantageous. In an era where many policy solutions are being debated and initiated at the global level, action learning leadership development that utilizes new technology follow-up appears to show significant impact and is worthy of wider application. The approach warrants further inquiry and testing as to its longer term effects on nursing's influence on policy formulation and implementation. © 2016 International Council of Nurses.

  4. Influence of Radial Stress Gradient on Strainbursts: An Experimental Study

    Science.gov (United States)

    Su, Guoshao; Zhai, Shaobin; Jiang, Jianqing; Zhang, Gangliang; Yan, Liubin

    2017-10-01

    Strainbursts, which are violent disasters that are accompanied by the ejection failure of rocks, usually occur in hard brittle rocks around highly stressed underground openings. The release of the radial stress at excavation boundaries is one of the major inducing factors for strainbursts in tunnels. After excavation, the radial stress usually exhibits different but apparent gradient variations along the radial direction near the boundary within a certain depth under different in situ stress conditions. In this study, the influence of the radial stress gradient on strainbursts of granite was investigated using an improved true-triaxial rockburst testing system, which was equipped with an acoustic emission monitoring system. The stress state and boundary conditions (i.e., one face free, other faces loaded and increasing tangential stress) of the representative rock element in the vicinity of the excavation boundary were simulated. High-speed cameras were used to capture the ejection failure processes during strainbursts, and the kinetic energy of ejected fragments was quantitatively estimated by analyzing the recorded videos. The experimental results indicate that with an increasing radial stress gradient, the strength increases, the apparent yield platform prior to the peak stress on the stress-strain curves decreases, the failure mode changes from strainburst characterized by tensile splitting to strainburst characterized by shear rupture, and the kinetic energy of ejected fragments during strainbursts significantly increases.

  5. Experimental Liquefaction Study of Southern Yogyakarta Using Shaking Table

    Directory of Open Access Journals (Sweden)

    Lindung Zalbuin Mase

    2017-04-01

    Full Text Available An experimental study using shaking table was conducted to learn liquefaction. Samples used were sandy soils from South of Yogyakarta Special Region Province. Analysis of liquefaction potential was performed by considering several factors, i.e. peak ground acceleration (PGA of 0.3 g to 0.4 g, vibrational frequency of 1.8 Hz, and vibration duration of 8, 16, and 32 seconds which reflect earthquake magnitudes of 5, 6, and 7. The pore water pressure was measured by using a pressure transducer. Liquefaction potential was determined by using the parameter of excess pore water pressure ratio (ru. Liquefaction potentially occurred when ru > 1, whereas ru < 1 indicated liquefaction didn’t occur. The results of test showed that liquefaction potentially occur in each applied dynamic load, that maximum excess pore wate pressure (ru max measured was equal to or larger than 1. The larger peak ground acceleration applied, the faster beginning time of liquefaction. The bigger peak ground acceleration applied, the slower dissipation time of pore water pressure. The duration of liquefaction become longer, along with the increase of applied peak ground acceleration. The bigger applied peak ground acceleration, the larger maximum excess pore water pressure.

  6. Experimental Study of Fast Neutron Irradiation on Si Transistor

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Sung Ho; Sun, Gwang Min; Baek, Ha ni; Jin, Seong Bok; Hoang, Sy Minh Tuan [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    Bipolar junction transistors (BJTs) are applied in many industrial fields. BJT is a three-terminal device with an important feature in that the current through two terminals can be controlled by small changes we make in the current or voltage at the third terminal. This control feature allows us to amplify small AC signals or to switch the device from an on state and off state and back. These two operations, amplification and switching, are the basis of a host of electronic functions. This study will investigate the electrical characteristics of a p-n-p BJT, such as the base current and collector current for fast neutron irradiation. Fast neutron irradiation can cause displacement damage in the Si bulk. In this paper, the electrical characteristics of a p-n-p BJT such as a base current and collector current are investigated for fast neutron irradiation. The experimental results show that the base current is increased and the collector current is decreased after fast neutron irradiation. These results indicate that the displacement damage caused by fast neutron irradiation increases the recombination rate of minority carriers and resistors.

  7. Experimental study of two-phase natural circulation circuit

    Energy Technology Data Exchange (ETDEWEB)

    Lemos, Wanderley Freitas; Su, Jian, E-mail: wlemos@lasme.coppe.ufrj.br, E-mail: sujian@nuclear.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Faccini, Jose Luiz Horacio, E-mail: faccini@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), RIo de Janeiro, RJ (Brazil). Lab. de Termo-Hidraulica Experimental

    2012-07-01

    This paper reports an experimental study on the behavior of fluid flow in natural circulation under single-and two-phase flow conditions. The natural circulation circuit was designed based on concepts of similarity and scale in proportion to the actual operating conditions of a nuclear reactor. This test equipment has similar performance to the passive system for removal of residual heat presents in Advanced Pressurized Water Reactors (A PWR). The experiment was carried out by supplying water to primary and secondary circuits, as well as electrical power resistors installed inside the heater. Power controller has available to adjust the values for supply of electrical power resistors, in order to simulate conditions of decay of power from the nuclear reactor in steady state. Data acquisition system allows the measurement and control of the temperature at different points by means of thermocouples installed at several points along the circuit. The behavior of the phenomenon of natural circulation was monitored by a software with graphical interface, showing the evolution of temperature measurement points and the results stored in digital format spreadsheets. Besides, the natural circulation flow rate was measured by a flowmeter installed on the hot leg. A flow visualization technique was used the for identifying vertical flow regimes of two-phase natural circulation. Finally, the Reynolds Number was calculated for the establishment of a friction factor correlation dependent on the scale geometrical length, height and diameter of the pipe. (author)

  8. A molecular machine biosensor: construction, predictive models and experimental studies.

    Science.gov (United States)

    Moradi-Monfared, Sahar; Krishnamurthy, Vikram; Cornell, Bruce

    2012-04-15

    This paper describes the construction, operation and predictive modeling of a molecular machine, functioning as a high sensitivity biosensor. Embedded gramicidin A (gA) ionchannels in a self-assembled tethered lipid bilayer act as biological switches in response to target molecules and provide a signal amplification mechanism that results in high sensitivity molecular detection. The biosensor can be used as a rapid and sensitive point of care diagnostic device in different media such as human serum, plasma and whole blood without the need for pre and post processing steps required in an enzyme-linked immunosorbent assay. The electrical reader of the device provides the added advantage of objective measurement. Novel ideas in the construction of the molecular machine, including fabrication of biochip arrays, and experimental studies of its ability to detect analyte molecules over a wide range of concentrations are presented. Remarkably, despite the complexity of the device, it is shown that the response can be predicted by modeling the analyte fluid flow and surface chemical reactions. The derived predictive models for the sensing dynamics also facilitate determining important variables in the design of a molecular machine such as the ion channel lifetime and diffusion dynamics within the bilayer lipid membrane as well as the bio-molecular interaction rate constants. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Experimental study on behavior of steel channel strengthened with CFRP

    Directory of Open Access Journals (Sweden)

    Tang Hongyuan

    2017-11-01

    Full Text Available This paper describes the behaviour of axially loaded long and eccentrically loaded short thin-walled steel channels, strengthened with transversely bonded carbon fibre reinforced polymer (CFRP sheets. Seven long members, each 1400 mm long, and seven short members, each 750mmlong, were tested. The main parameters were the number of CFRP plies (one or two and the clear spacing between the CFRP strips (50, 100 or 150 mm. The effect of CFRP sheet layer and clear spacing was studied. All the ultimate load capacity of the reinforced members was improved in different extent. A maximum strength gain of 9.13% was achieved for long members with two CFRP layers and 50 mm spacing of CFRP strips. The experimental results show that the global buckling happens to all the long specimens. For short members, the maximum strength gain of 12.1% was achieved with two CFRP layers and 50 mm spacing of CFRP strips. With the exception of the most heavily reinforced (2 plies at 50 and 100 mm, local buckling was observed prior to global buckling for short members, which was completely opposite of the control specimens. Meanwhile, when the clear spacing of CFRP strips is greater than theweb height of steel channel, the transversely bonded CFRP does not have a significant improvement in buckling load capacity of the short- and long-channel components. While the clear spacing is less than the web height, the more number of CFRP layer, the more enhancement of buckling load capacity.

  10. Augmented reality in bone tumour resection: An experimental study.

    Science.gov (United States)

    Cho, H S; Park, Y K; Gupta, S; Yoon, C; Han, I; Kim, H-S; Choi, H; Hong, J

    2017-03-01

    We evaluated the accuracy of augmented reality (AR)-based navigation assistance through simulation of bone tumours in a pig femur model. We developed an AR-based navigation system for bone tumour resection, which could be used on a tablet PC. To simulate a bone tumour in the pig femur, a cortical window was made in the diaphysis and bone cement was inserted. A total of 133 pig femurs were used and tumour resection was simulated with AR-assisted resection (164 resection in 82 femurs, half by an orthropaedic oncology expert and half by an orthopaedic resident) and resection with the conventional method (82 resection in 41 femurs). In the conventional group, resection was performed after measuring the distance from the edge of the condyle to the expected resection margin with a ruler as per routine clinical practice. The mean error of 164 resections in 82 femurs in the AR group was 1.71 mm (0 to 6). The mean error of 82 resections in 41 femurs in the conventional resection group was 2.64 mm (0 to 11) (p Augmented reality in bone tumour resection: An experimental study. Bone Joint Res 2017;6:137-143. © 2017 Cho et al.

  11. Inflation of stressed cylindrical tubes: an experimental study

    Science.gov (United States)

    Guo, Zhiming; Wang, Shibin; Li, Linan; Ji, Hongwei; Wang, Zhiyong; Cai, Songbao

    2014-06-01

    The inflation of an initially stressed cylindrical shell provides a good illustration of the phenomenon of the initiation and propagation of an instability, which shares the same mathematical and mechanical features with a variety of other strain localization phenomena in engineering structures and materials. The high speed CCD camera and digital image processing system were used to measure the 3D shape of the inflated cylindrical tube. The localized bulge of a cylindrical tube with closed ends forms when the internal pressure reaches a critical value Pcr. As more air is filled into the tube, the pressure drops but the radius at the centre of the bulge will increase until it reaches a maximum value rmax. With continued inflation, the pressure stays at a constant value Pp. The purpose of this study is to investigate the critical and propagation pressures in the tubes and the profile outside when the shells under axial tension and internal pressure were inflating. We focus on the influence of the axial tension on the critical pressure. In this paper the problem is explored through experimental efforts. A series of experiments were conducted on commercially available natural rubber latex tubes involving different geometries and initial axial tensions, which were regarded as isotropic, homogeneous, incompressible and hyper-elastic materials.

  12. Experimental Study on Effect of Electrode Location on Ion Current

    Directory of Open Access Journals (Sweden)

    Xu Hanqing

    2017-01-01

    Full Text Available In an attempt to use ion current method on a suction flame holder for combustion diagnosis, the position of the detection electrode that has the significant effect on ion current, should be investigated. The objective of this study was to experimentally investigate the ion current distribution in different combustion zones by changing the electrode length and streamwise location. An ion current acquisition system was built on basis of the principle of Langmuir probe, and experiments were conducted under different fuel-air ratios ranging from 0.008~0.022. The results suggest that the ion current distribution obeys the same regulation at different fuel-air ratios. With the electrode length increasing, the ion current increases first, then decreases, and finally presents a unimodal curve. As the electrode streamwise location increases, the ion current demonstrates a linear decrease rule. The maximum ion current is obtained in the case that the electrode length and streamwise location equals 60mm and 0.75. Since the larger ion current provides the wider range for setting the misfire threshold, the position where the maximum ion current occurs can be a better choice for arranging the electrode.

  13. Experimental studies on power transformer model winding provided with MOVs

    Directory of Open Access Journals (Sweden)

    G.H. Kusumadevi

    2017-05-01

    Full Text Available Surge voltage distribution across a HV transformer winding due to appearance of very fast rise time (rise time of order 1 μs transient voltages is highly non-uniform along the length of the winding for initial time instant of occurrence of surge. In order to achieve nearly uniform initial time instant voltage distribution along the length of the HV winding, investigations have been carried out on transformer model winding. By connecting similar type of metal oxide varistors across sections of HV transformer model winding, it is possible to improve initial time instant surge voltage distribution across length of the HV transformer winding. Transformer windings with α values 5.3, 9.5 and 19 have been analyzed. The experimental studies have been carried out using high speed oscilloscope of good accuracy. The initial time instant voltage distribution across sections of winding with MOV remains nearly uniform along length of the winding. Also results of fault diagnostics carried out with and without connection of MOVs across sections of winding are reported.

  14. 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.

  15. Experimental study of drop impacts on soap films

    Science.gov (United States)

    Yawar, Ali; Basu, Saikat; Concha, Andres; Bandi, Mahesh

    2015-11-01

    Impinging drops on flowing and static soap films demonstrate at least three distinct types of impact regimes: (a) the drop bounces off the film surface, (b) it coalesces with the downstream flow for a moving film and for static films it gets assimilated within the film, and (c) it pierces through the film. The interaction presents a unique opportunity to explore the impact of a quasi one-dimensional object on a two-dimensional fluid, much like a comet impacting on a thin atmosphere. We present a detailed experimental study of droplet impacts on soap film flow, for a number of film inclination angles and falling heights of the drop. Imaging techniques employed include sodium lamp interferometry to measure film thickness fluctuations and particle tracking velocimetry to measure the velocity field. Film thickness measures approximately 10 microns and the drop diameter is 1 mm. We mostly observe the bouncing-off regime for smaller inclination angles. However, at higher impact angles, puncturing of the film becomes a more common occurrence. We show that when the drop bounces off the film, there is a momentum transfer leading to vortex dipole shedding, along with the generation of capillary waves; an impulsive regime that may share correspondence with the locomotion of water striders.

  16. Immunology and Homeopathy. 3. Experimental Studies on Animal Models

    Directory of Open Access Journals (Sweden)

    Paolo Bellavite

    2006-01-01

    Full Text Available A search of the literature and the experiments carried out by the authors of this review show that there are a number of animal models where the effect of homeopathic dilutions or the principles of homeopathic medicine have been tested. The results relate to the immunostimulation by ultralow doses of antigens, the immunological models of the ‘simile’, the regulation of acute or chronic inflammatory processes and the use of homeopathic medicines in farming. The models utilized by different research groups are extremely etherogeneous and differ as the test medicines, the dilutions and the outcomes are concerned. Some experimental lines, particularly those utilizing mice models of immunomodulation and anti-inflammatory effects of homeopathic complex formulations, give support to a real effect of homeopathic high dilutions in animals, but often these data are of preliminary nature and have not been independently replicated. The evidence emerging from animal models is supporting the traditional ‘simile’ rule, according to which ultralow doses of compounds, that in high doses are pathogenic, may have paradoxically a protective or curative effect. Despite a few encouraging observational studies, the effectiveness of the homeopathic prevention or therapy of infections in veterinary medicine is not sufficiently supported by randomized and controlled trials.

  17. Ileoanal anastomosis with proximal ileal reservoir: an experimental study.

    Science.gov (United States)

    Schraut, W H; Block, G E

    1982-03-01

    Endorectal ileoanal anastomosis with proximal interposition of an ileal reservoir was evaluated experimentally in dogs as an approach to retain sphincteric control of defecation after proctocolectomy. Two months after the operative procedure, eight animals with a reservoir had four to eight semisolid stools per day and were continent. In contrast, six animals with straight ileoanal anastomosis were incontinent with 10 to 14 evacuations per day. Motility studies demonstrated a reduction of propulsive peristalsis within the undistended reservoir, which is considered the responsible factor for increased intestinal transit time and reduced stool frequency. Filling of the reservoir to capacity elicited strong peristaltic contractions, which may assure a more complete evacuation of the reservoir during defecation. Reservoir capacity increased substantially (150% to 200%) within 2 months but only to a minor degree thereafter, indicating that the reservoir does not dilate progressively into an atonic viscus. Motility patterns remained unaltered as the reservoir became more complaint with time. Mucosal alterations (flattening of villi, submucosal inflammation) were detected in the reservoir but did not result in nutritional defects within an observation period of 1 year.

  18. Experimental study of liquid drop impact onto a powder surface

    KAUST Repository

    Marston, Jeremy

    2010-11-01

    The initial dynamics of liquid drop impact onto powder surfaces is studied experimentally using high-speed photography. For a range of bed packing fractions, φ, liquid physical properties and impact velocities, ui, we observe a variety of phenomena that can be representative of a hydrophobic surface, a rough surface or a porous medium. The solids packing fraction in the bed, 0.38≤φ≤0.65, and the impact Weber number, 3.5≤We=ρDui 2/φ≤750, (where ρ, D and φ are the drop density, diameter and surface tension respectively) are shown to be the critical parameters governing the outcome of an impact. For high packing fractions, φ≳0.5, we show that the observed spreading, rebound and splashing can be broadly characterised in terms of the Weber number while for looser packing fractions, φ≲0.5, we observe powder ejectas and provide a qualitative description of the granule nucleation at the centre of the impact sites. © 2010 Elsevier B.V.

  19. Experimental study on titanium wire drawing with ultrasonic vibration.

    Science.gov (United States)

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

    2018-02-01

    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.

  20. Experimental Study Of Fog Water Harvesting By Stainless Steel Mesh

    Directory of Open Access Journals (Sweden)

    Nikhil R. Pawar

    2017-06-01

    Full Text Available The collection of fog water is a simple and sustainable technology to get hold of fresh water for various purposes. In areas where a substantial amount of fog can be obtained it is feasible to set up a stainless steel as well as black double layer plastic mesh structure for fog water harvesting. The mesh structure is directly exposed to the weather and the fog containing air is pushed through the active mesh surface by the wind. Afterward fog droplets are deposited on the active mesh area which combines to form superior droplets and run down into a gutter to storage by gravity. Fog water harvesting rates show a discrepancy from site to site. The scope of this experimental work is to review fog collection at SCOE Pune campus and to examine factors of success. This study is to synthesize the understanding of fog water harvesting in the institutional era and to analyze its benefits and boundaries for future development. The rate of fog water harvesting depends on the science of fog physics chemistry and its starring role in the hydrological cycle. This technology runs on zero energy and zeroes pollution level with cost of the benefit. The collected or treated clear water mainly could be used for different purposes as per requirement. For further development this technology public as well as government participation is needed.

  1. Numerical and experimental study of bistable plates for morphing structures

    Science.gov (United States)

    Nicassio, F.; Scarselli, G.; Avanzini, G.; Del Core, G.

    2017-04-01

    This study is concerned with the activation energy threshold of bistable composite plates in order to tailor a bistable system for specific aeronautical applications. The aim is to explore potential configurations of the bistable plates and their dynamic behavior for designing novel morphing structure suitable for aerodynamic surfaces and, as a possible further application, for power harvesters. Bistable laminates have two stable mechanical shapes that can withstand aerodynamic loads without additional constraint forces or locking mechanisms. This kind of structures, when properly loaded, snap-through from one stable configuration to another, causing large strains that can also be used for power harvesting scopes. The transition between the stable states of the composite laminate can be triggered, in principle, simply by aerodynamic loads (pilot, disturbance or passive inputs) without the need of servo-activated control systems. Both numerical simulations based on Finite Element models and experimental testing based on different activating forcing spectra are used to validate this concept. The results show that dynamic activation of bistable plates depend on different parameters that need to be carefully managed for their use as aircraft passive wing flaps.

  2. Scale dependence of acoustic velocities. An experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Gotusso, Angelamaria Pillitteri

    2001-06-01

    Reservoir and overburden data (e.g. seismic, sonic log and core data) are collected at different stages of field development, at different scales, and under different measurement conditions. A more precise reservoir characterization could be obtained by combining all the collected data. Reliable data may also be obtained from drill cuttings. This methodology can give data in quasi-real time, it is easily applicable, and cheap. It is then important, to understand the relationship between results obtained from measurements at different scales. In this Thesis acoustic velocities measured at several different laboratory scales are presented. This experimental study was made in order to give the base for the development of a model aiming to use/combine appropriately the data collected at different scales. The two main aspects analyzed are the experimental limitations due to the decrease in sample size and the significance of measurements in relation to material heterogeneities. Plexiglas, an isotropic, non-dispersive artificial material, with no expected scale effect, was used to evaluate the robustness of the measurement techniques. The results emphasize the importance of the wavelength used with respect to the sample length. If the sample length (L) is at least 5 time bigger than wavelength used ({lambda}), then the measured velocities do not depend on sample size. Leca stone, an artificial isotropic material containing spherical grains was used to evaluate the combined effects of technique, heterogeneities and sample length. The ratio between the scale of the heterogeneities and the sample length has to be taken in to account. In this case velocities increase with decreasing sample length when the ratio L/{lambda} is smaller than 10-15 and at the same time the ratio between sample length and grain size is greater than 10. Measurements on natural rocks demonstrate additional influence of grain mineralogy, shape and orientation. Firenzuola sandstone shows scale and

  3. Extremal quantum correlations: Experimental study with two-qubit states

    Energy Technology Data Exchange (ETDEWEB)

    Chiuri, A.; Mataloni, P. [Dipartimento di Fisica, Sapienza Universita di Roma, Piazzale Aldo Moro 5, I-00185 Roma (Italy); Istituto Nazionale di Ottica (INO-CNR), L.go E. Fermi 6, I-50125 Firenze (Italy); Vallone, G. [Dipartimento di Fisica, Sapienza Universita di Roma, Piazzale Aldo Moro 5, I-00185 Roma (Italy); Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Via Panisperna 89/A, Compendio del Viminale, I-00184 Roma (Italy); Paternostro, M. [Centre for Theoretical Atomic, Molecular, and Optical Physics, School of Mathematics and Physics, Queen' s University, Belfast BT7 1NN (United Kingdom)

    2011-08-15

    We explore experimentally the space of two-qubit quantum-correlated mixed states, including frontier states as defined by the use of quantum discord and von Neumann entropy. Our experimental setup is flexible enough to allow for high-quality generation of a vast variety of states. We address quantitatively the relation between quantum discord and a recently suggested alternative measure of quantum correlations.

  4. Bargaining Power in Relational Contracts: An Experimental Study

    OpenAIRE

    Cordero Salas, Paula

    2011-01-01

    This paper provides experimental evidence of the economic impact from shifting bargaining power in relational contracts. I implement an experimental design that adjusts the bargaining power of sellers (agents) and the enforceability of the contract. I find that the vast majority of contracts take the form of efficiency wage contracts instead of contingent performance contracts when enforcement is partially incomplete and sellers have more bargaining power than buyers. The total contracted and...

  5. An Experimental Study on Assessment of Pavement Interlayer Bond Strength

    Directory of Open Access Journals (Sweden)

    Mahabir Panda

    2013-06-01

    Full Text Available It is a common practice to apply a tack coat usually in the form of bituminous emulsion over an existing bituminous surface before laying another bituminous layer. The boundary between these two consecutive bituminous layers is the layer interface and the pavement stress distribution is highly influenced by the adhesion conditions at this interface. Poor adhesion causes adverse effects on the structural strength of the pavement system. A number of premature failures such as slippage failure and delamination failures result thus defeating the construction objectives. In the absence of a standard method and apparatus to address this field problem, an attempt has been made in this study to develop a simple testing arrangement to be used in a laboratory to determine the interlayer bond strength. Normal Marshall procedure has been used to prepare the specimens consisting of two different types of bituminous materials in lower and upper part of the same specimen. It is observed within the scope of study that Cationic rapid setting (CRS-1 emulsion applied at 0.25 Kg/m2 offers the best results of interlayer bond strength.

  6. Increasing the rate of recycled asphalt: an experimental study

    Directory of Open Access Journals (Sweden)

    Marjan TUŠAR

    2014-09-01

    Full Text Available Asphalt is material that can be recycled. In particular reclaimed asphalt (RA contains aged binder, which limits the reuse of RA. In this study the rate of recycled asphalt was increased by adding a rejuvenator containing paraffin. The authors investigated the effect of the rejuvenator in laboratory and in plant prepared samples of asphalt mixture. In laboratory samples with different percentage of RA (0%, 10%, 30%, 50% and rejuvenator were prepared. In asphalt plant only asphalt mixture with highest amount of RA and rejuvenator and control mixture without RA were prepared. On samples were conducted different tests, e.g. determining softening point, Fraass breaking point, penetration, indirect tensile strength. Results on extracted bitumen showed increase in softening point and decrease in Fraass breaking point with increasing percentage of RA and rejuvenator, meaning that service temperature of binders increased. Asphalt samples prepared in asphalt plant were laid on test field. Asphalt with RA and rejuvenator was built in at lower temperature (round 100 °C. Mixtures with RA and rejuvenator have better low temperature properties confirmed with Thermal Stress Restrained Specimen Test (TSRST method, but are less resistant to compaction and less sensitive to water than control mixture. For comparison of long term behaviour wheel tracking test was performed on mixtures built in test field. A week after paving, the control mixture showed better properties, but one year later the results were opposite, asphalt containing RA and rejuvenator was more resistant to rutting. From the results of this experimental study the following was concluded: the amount of RA can be increased by using rejuvenator and the quality of such asphalt mixture is in most cases equal or even better than asphalt mixture made of virgin materials. By using RA we preserve nature, reduce usage of virgin raw materials, but it is cost effective only if recycling degree is high

  7. Rheology of lava flows on Mercury: An analog experimental study

    Science.gov (United States)

    Sehlke, A.; Whittington, A. G.

    2015-11-01

    We experimentally determined the rheological evolution of three basaltic analog compositions appropriate to Mercury's surface, during cooling, and crystallization. Investigated compositions are an enstatite basalt, and two magnesian basalts representing the compositional end-members of the northern volcanic plains with 0.19 wt % (NVP) and 6.26 wt % Na2O (NVP-Na). The viscosity-strain rate dependence of lava was quantified using concentric cylinder viscometry. We measured the viscosities of the crystal-free liquids from 1600°C down to the first detection of crystals. Liquidus temperatures of the three compositions studied are around 1360°C, and all three compositions are more viscous than Hawaiian basalt at the same temperature. The onset of pseudoplastic behavior was observed at crystal fractions ~0.05 to 0.10, which is consistent with previous studies on mafic lavas. We show that all lavas develop detectable yield strengths at crystal fractions around 0.20, beyond which the two-phase suspensions are better described as Herschel-Bulkley fluids. By analogy with the viscosity-strain rate conditions at which the pahoehoe to `a`a transition occurs in Kilauea basalt, this transition is predicted to occur at ~1260 ± 10°C for the enstatite basalt, at ~1285 ± 20°C for the NVP, and at ~1240 ± 40°C for the NVP-Na lavas. Our results indicate that Mercury lavas are broadly similar to terrestrial ones, which suggests that the extensive smooth lava plains of Mercury could be due to large effusion rates (flood basalts) and not to unusually fluid lavas.

  8. U-stitching splenorraphy technique: experimental and clinical study.

    Science.gov (United States)

    Tsaroucha, Alexandra K; Pitiakoudis, Michail S; Chanos, Georgios; Chiotis, Anestis S; Argyropoulou, Paraskevi I; Prassopoulos, Panos; Simopoulos, Constantinos E

    2005-04-01

    The aim of the present study was to describe the laboratory development and the subsequent clinical utility of the U-stitching technique for splenorraphy over the recent years in a general non-trauma hospital. Patients with splenectomies and patients treated conservatively during the same time period, are also presented. In the 15-year period from September 1988 until September 2003, 65 patients were diagnosed with splenic injury following admission to 2nd Department of Surgery, Democritus University Hospital, after blunt abdominal trauma. During the first 3 years, 14 patients were admitted; one of them was treated conservatively and 13 had splenectomies. Because computed tomography (CT) was not available at that time, these 14 patients form a control group. During the remaining 12-year period, 51 patients (39 male and 12 female; age, 4-82 years; mean, 31.1 years; SD, 19.7 years) were treated conservatively or surgically, either with splenectomy or with splenorraphy. Splenorraphy was performed using the U-stitching technique. This alternative splenorraphy technique was first tested on experimental models at 2nd Department of Surgery, Democritus University Hospital, then followed by successful clinical application. The medical records for these patients were reviewed to extract the data for the present study. Thirty-six patients (70.6% of 51 patients) were treated surgically; of these, 21 (41.2% of 51 patients) had splenectomy and 15 (29.4% of 51 patients) had splenorraphy. Non-operative treatment was initially given to 15 patients (29.4% of 51 patients). Two of them had delayed rupture of the spleen and underwent splenectomy (at 8 and 40 days). The total number of preserved spleens was 28 of 51 (54.9%). None of the patients with conservative treatment or splenorraphy died. One patient with splenectomy died later from overwhelming sepsis. Splenic salvage is now a treatment goal. If the patient is haemodynamically unstable and splenorraphy is possible, the U

  9. Laser welding of biological tissue: experimental studies in ophthalmology

    Science.gov (United States)

    Pini, Roberto; Rossi, Francesca; Menabuoni, Luca

    2006-04-01

    In this paper we present an original approach to laser welding of ocular media. Attention is focused on laser welding of the cornea and lens capsule. The process is based on the interaction of near infrared diode laser radiation (at 810 nm) with tissue that was previously stained with an Indocyanine Green solution in sterile water. The topical application of the chromophore makes possible a selective heating of the tissue, which results in a homogenous welding effect with low thermal damage to the surrounding tissue. Experimental tests were performed ex vivo on both capsule and cornea, and in vivo (rabbits) only on the cornea, in order to characterize the process as a whole. Spectrophotometric, biomechanical, and thermal measurements were carried out in order to study the laser-tissue interaction, while morphological, histological and auto-florescence microscopy analyses made during a follow-up study provided information on the healing process in welded rabbit corneas. The welding procedure was set up according to the type of tissue, with the staining procedure and irradiation conditions being optimized in each case. Our test indicated that: 1) laser welding of corneal wounds, which is a non contact technique performed at low continuous wave laser power (12 W/cm2), can be proposed as a support to or substitute for the standard suturing technique in cataract surgery and in penetrating keratoplasty (in corneal transplants); 2) laser welding of the lens capsule requires a "contact irradiating technique" in order to be efficiently performed, since the tissue is in underwater conditions, with single spot pulses of about 100 J/cm2 fluence and pulse duration around 100 ms. In the latter case, laser welding was proposed as a tool for assisting closure of the lens capsule after the lens refilling procedure (Phaco-ersatz), or for repairing capsular breaks induced by accidental traumas or produced intraoperatively.

  10. Mechanisms of Osteoarthritic Pain. Studies in Humans and Experimental Models

    Directory of Open Access Journals (Sweden)

    Annett Eitner

    2017-11-01

    Full Text Available Pain due to osteoarthritis (OA is one of the most frequent causes of chronic pain. However, the mechanisms of OA pain are poorly understood. This review addresses the mechanisms which are thought to be involved in OA pain, derived from studies on pain mechanisms in humans and in experimental models of OA. Three areas will be considered, namely local processes in the joint associated with OA pain, neuronal mechanisms involved in OA pain, and general factors which influence OA pain. Except the cartilage all structures of the joints are innervated by nociceptors. Although the hallmark of OA is the degradation of the cartilage, OA joints show multiple structural alterations of cartilage, bone and synovial tissue. In particular synovitis and bone marrow lesions have been proposed to determine OA pain whereas the contribution of the other pathologies to pain generation has been studied less. Concerning the peripheral neuronal mechanisms of OA pain, peripheral nociceptive sensitization was shown, and neuropathic mechanisms may be involved at some stages. Structural changes of joint innervation such as local loss and/or sprouting of nerve fibers were shown. In addition, central sensitization, reduction of descending inhibition, descending excitation and cortical atrophies were observed in OA. The combination of different neuronal mechanisms may define the particular pain phenotype in an OA patient. Among mediators involved in OA pain, nerve growth factor (NGF is in the focus because antibodies against NGF significantly reduce OA pain. Several studies show that neutralization of interleukin-1β and TNF may reduce OA pain. Many patients with OA exhibit comorbidities such as obesity, low grade systemic inflammation and diabetes mellitus. These comorbidities can significantly influence the course of OA, and pain research just began to study the significance of such factors in pain generation. In addition, psychologic and socioeconomic factors may aggravate

  11. Early differentiation of the Moon: Experimental and modeling studies and experimental and modeling studies of massif anorthosites

    Science.gov (United States)

    Longhi, John

    1994-01-01

    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

  12. Experimental study on anelasticty of polycrystalline material for seismological application

    Science.gov (United States)

    Takei, Y.; Karasawa, F.

    2012-12-01

    Due to the recent progress in seismology, we can obtain highly-resolved seismic velocity structures in the upper mantle. In order to interpret the velocity structures in terms of temperature heterogeneity, chemical heterogeneity, and fluid/melt distribution, it is important to assess the quantitative effects of temperature, chemical composition, and fluid/melt on Vp and Vs. Although these effects at the ultrasonic frequencies (anharmonic effect, poroelastic effect) have been measured and assessed quantitatively, these effects at the seismic frequencies are subject to large uncertainty due to the uncertainty in rock anelasticity, which additionally causes modulus relaxation at lower frequencies (anelastic effect). Previous studies have shown that anelasticity of polycrystalline materials follows the similarity rule in which frequency normalized to the Maxwell frequency, f/fM, can be used as a master variable (Morris & Jackson, 2009a; McCarthy et al, 2012). The general applicability of this Maxwell frequency scaling shows that the anelastic relaxation in those experiments is caused by diffusionally accommodated grain boundary sliding (GBS) (Gribb & Cooper, 1998; McCarthy et al, 2012). However, normalized frequency of the existing experimental data is usually considerably lower than the seismic frequencies normalized to the Maxwell frequency of the upper mantle (f/fM=106-1010). Therefore, in order to clarify the mechanism and scaling law applicable to the seismic waves, we have to measure anelasticity at higher normalized frequencies. Theoretical models (e.g., Raj, 1975; Morris & Jackson, 2009b) predict that at higher normalized frequencies, dominant GBS mechanism changes from diffusionally accommodated GBS to elastically accommodated GBS. However, the transition frequency and total relaxation strength associated with the elastically accommodated GBS, which are important in the application to seismology, have so far been difficult to constrain theoretically

  13. An experimental and numerical study of a jetfire stop material and a new helical flow heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Austegard, Anders

    1997-12-31

    This thesis consists of two parts. Part 1: Experimental and numerical study of jetfire stop, and Part 2: Experimental and numerical study of a new kind of shell and tube heat exchanger with helical flow on shell side. Part 1 describes the development of the model for simulation of the temperature development through Viking jetfirestop. A simulation program is developed that calculates the temperature development through Viking jetfire stop. In the development of the model, measurements of reaction energy, pyrolysis and heat conductivity at low temperatures are made. The conductivity at higher temperatures and when pyrolysis reactions are going on is estimated experimentally and by numerical calculations. Full-scale jet fire test and small-scale xenon lamp experiments are made to test the simulation model. Part 2 contains the development of a model that simulate the fluid flow and heat transfer in a helical flow shell and tube heat exchanger. It consists of the development of a porosity model and a model for pressure drop and heat transfer as well as experiments in non-standard tube layouts. Results from the simulation program are compared with experiments on a helical flow shell and tube heat exchanger. There is a separate appendix volume. 62 refs., 152 figs., 22 tabs.

  14. Experimental plan for the fuel-oil study

    Energy Technology Data Exchange (ETDEWEB)

    Ternes, M.P.; Levins, W.P.; Brown, M.A.

    1992-01-01

    An up-to-date assessment of the Weatherization Assistance Program (WAP) is being performed by the US Department of Energy WAP Division and the Oak Ridge National Laboratory. Five studies form the evaluation. Major goals of the Fuel-Oil Study are to estimate the fuel oil saved by the WAP in the Northeast during the 1990 and 1991 program years, identify and quantify non-energy impacts of the WAP, assess the cost effectiveness of the WAP within this submarket, and assess factors which may cause savings and cost effectiveness to vary. The study will only analyze single-family houses in the nine states in the Northeast census region and will be carried out over two heating seasons (1990 and 1991 WAP program years). A split-winter, pre- and post-weatherization experimental design with a control group will be used. Houses will be monitored over one winter. Energy conservation measures will be installed in the weatherized houses in January of each winter by the local WAP subgrantee. One hundred twenty five weatherized houses and 75 control houses will be monitored over the 1990--1991 winter; a different set of 200 houses will be monitored over the 1991--1992 winter. The houses will be evenly distributed among 25 subgrantees. Space-heating fuel-oil consumption, indoor temperature, and outdoor temperature data will be collected for all houses. Fuel-oil delivery data will be collected for each house monitored over the 1990--1991 winter for at least a year before weatherization. The delivery data will be analyzed to determine if the accuracy of the study can be improved by collecting fuel-oil delivery data on a larger sample of houses over the 1991--1992 winter. Detailed survey information will be obtained on all the houses. This information includes descriptive details of the house and its mechanical systems, details on household size and other demographics, and occupant answers to questions regarding comfort, safety, and operation of their space-heating system and house.

  15. An experimental study of plastic deformation of materials

    DEFF Research Database (Denmark)

    Knudsen, Tine

    2008-01-01

    The thesis falls in three parts, focusing on different aspects of plastic deformation of metals. Part I investigates the dislocation structures induced by hot deformation and compares these with the structures after cold deformation. In particular, it is shown that the dislocation structures...... after cold deformation by calorimetry and by analysis of the dislocation structure. The stored energy measured by calorimetry is found to be larger than that determined from the dislocation structure by a factor between 1.9 and 2.7, and this factor decreases with the plastic strain. Part III aimed...

  16. Food additives and Hymenolepis nana infection: an experimental study.

    Science.gov (United States)

    El-Nouby, Kholoud A; Hamouda, Hala E; Abd El Azeem, Mona A; El-Ebiary, Ahmad A

    2009-12-01

    The effect of sodium benzoate (SB) on the pathogenesis of Hymenolepis nana (H. nana) and its neurological manifestations was studied in the present work. One hundred and thirty five mice were classified into three groups. GI: received SB alone. GII: received SB before & after infection with H. nana and GIII: infected with H. nana. All groups were subjected to parasitological, histopathological, immunohistochemical and biochemical assays. The results revealed a significant decrease in IL-4 serum level with a significant increase in gamma amino butyric acid (GABA) and decrease in zinc brain levels in GI, while GII showed non significant increase in IL-4 level that resulted in a highly significant increase in the mean number of cysticercoids and adult worms with delayed expulsion as compared to GIII. This was reflected on histopathological and immunohistochemical changes in the brain. Also, there was a highly significant increase in GABA and decrease in zinc brain levels in GII to the degree that induced behavioral changes. This emphasizes the possible synergistic effect of SB on the neurological manifestations of H. nana and could, in part, explain the increased incidence of behavioral changes in children exposed to high doses of SB and unfortunately have H. nana infection.

  17. Cell therapy for fibrotic interstitial pulmonary disease: experimental study.

    Science.gov (United States)

    Cabral, Rosa M; Branco, Érika; Rizzo, Márcia Dos S; Ferreira, Guilherme J; Gregores, Guilherme B; Samoto, Vivian Y; Stopiglia, Angelo J; Maiorka, Paulo C; Fioretto, Emerson T; Capelozzi, Vera L; Borges, João B; Gomes, Susimeire; Beraldo, Marcelo A; Carvalho, Carlos R R; Miglino, Maria A

    2011-10-01

    Parte superior do formulário Digite um texto ou endereço de um site ou traduza um documento. The aim of this study is to evaluate the histological changes in lung parenchyma of pigs affected by interstitial lung disease induced after the infusion of bone marrow mononuclear cells (BMMCs). Ten female swines were submitted to pulmonary fibrosis induced by a single dose of intratracheal bleomicine sulfate. Animals were arranged into two groups: Group 1: induced-disease control and Group 2: cell therapy using BMMCs. Both groups were clinically evaluated for 180 days. High-resolution computed tomography (HRCT) was performed at 90 and 180 days. BMMC sampling was performed in cell therapy group at 90 days. Euthanasia was performed, and samples were collected for histology and immunohistochemistry. The 90-days HRCT demonstrated typical interstitial lesions in pulmonary parenchyma similarly to human disease. The 180-days HRCT in Group 1 demonstrated advanced stages of the disease when compared with Group 2. Immunohistochemistry analysis suggests the presence of pre-existent vessels and neoformed vessels as well as predominant young cells in the injured parenchyma of Group 2. Immunohistochemistry analysis suggests that cell therapy would promote a reconstructive response. Histology and HRCT analysis suggest a positive application of swine as a model for a bleomicine inducing of fibrotic interstitial pulmonary disease. Copyright © 2011 Wiley-Liss, Inc.

  18. Improved Spare Parts Inventory Management : A Case Study

    NARCIS (Netherlands)

    Strijbosch, L.W.G.; Heuts, R.M.J.; van der Schoot, E.H.M.

    1998-01-01

    This paper examines the performance of two different (s,Q) inventory models for spare parts in a production plant of confectionery in The Netherlands, a simple and an advanced model. The simple approach is more or less standard: undershoot of the reorder level is not taken into account, the normal

  19. EXPERIMENTAL STUDIES ON YELLOW FEVER OCCURRING IN MERIDA, YUCATAN.

    Science.gov (United States)

    Noguchi, H; Kligler, I J

    1920-10-31

    necessarily exclude the presence of the organism in small numbers. Likewise, the dark-field work with the material from guinea pigs was confined to a brief examination and was omitted in many instances. Under these circumstances no leptospira was encountered in any of the material from Case 1. On the other hand, the results obtained with the specimens of blood from Case 2 were definitely positive, not only in the transmission of the disease directly, or indirectly by means of cultures, into guinea pigs, but also in the demonstration of the leptospira in the primary cultures and in the blood and organ emulsions of guinea pigs experimentally infected with such cultures. Definite positive direct transmissions were obtained with the specimens of blood drawn on the 2nd and 3rd days. No blood was taken on the 4th or 6th days. There were indications of abortive or mild leptospira infection in the guinea pigs inoculated with the blood taken on the 5th day. Regarding the inoculation of cultures from Case 2, it may be stated that only the cultures (leptospira +) made with the blood drawn on the 2nd day caused a definite fatal infection in guinea pigs. From this series a continuous passage in the guinea pig has been successfully accomplished. One of the guinea pigs (No. 48) inoculated with the culture 5 days old (leptospira +) made from the blood taken on the 3rd day presented typical symptoms, and a positive transfer from this to another animal (No. 98) was also made. Cultures of the blood drawn on the 5th and 7th days gave unsatisfactory results, owing to a secondary contamination. Leptospiras were detected in some of the culture tubes containing 2nd and 3rd day specimens of blood from Case 2; they were few in number and for the most part immotile, owing perhaps to some unfavorable cultural condition such as a fungus contamination. Charts 17, 18, and 19 give a summary of the experiments. See PDF for Structure.

  20. A comprehensive experimental and modeling study of isobutene oxidation

    KAUST Repository

    Zhou, Chong-Wen

    2016-03-17

    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

  1. 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

    2011-01-01

    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....

  2. Experimental and numerical study on mechanical properties of aluminum alloy under uniaxial tensile test

    Directory of Open Access Journals (Sweden)

    O. Daghfas

    2017-01-01

    Full Text Available The main objective is to model the behavior of 7075 aluminum alloy and built an experimental database to identify the model parameters. The first part of the paper presents an experimental database on 7075 aluminum alloy. Thus, uniaxial tensile tests are carried in three loading directions relative to the rolling direction, knowing that the fatigue of aircraft structures is traditionally managed based on the assumption of uniaxial loads. From experimental database, the mechanical properties are extracted, particularly the various fractures owing to pronounced anisotropy relating to material. In second part, plastic anisotropy is then modeled using the identification strategy which depends on yield criteria, hardening law and evolution law. In third part, a comparison with experimental data shows that behavior model can successfully describe the anisotropy of the Lankford coefficient.

  3. Experimental study on viscosity reduction for residual oil by ultrasonic.

    Science.gov (United States)

    Huang, Xintong; Zhou, Cuihong; Suo, Quanyu; Zhang, Lanting; Wang, Shihan

    2018-03-01

    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.

  4. An experimental study on cerebral paragonimiasis using cats

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seon Kyu; Chang, Kee Hyun; Goo, Jin Mo; Han, Moon Hee; Shin, Yong Moon; Choo, Sung Wook; Yu, In Kyu [Seoul National University College of Medicine, Seoul (Korea, Republic of); Cho, Seung Yull; Kong, Yoon [Chung-Ang University College of Medicine, Seoul (Korea, Republic of)

    1994-06-15

    It is important to diagnosis paragonimiasis in early active because it can be dared by chemotherapy. However, it is difficult to make a correct diagnosis of cerebral paragonimiasis in the early active stage, and the radiographic findings of cerebral paragonimiasis have been rarely reported. Thus, this experimental study was designed to produce early active cerebral paragonimiasis and to demonstrate radiologic-pathologic correlations. In 8 cats, 7-8 metacercariae of Paragonimus Westermani were directly introduced into brain parenchyma of each cat's after trephination of the skull. In another 16 cats, the juvenile worms and the adult worms that had developed for varying periods (2 weeks, 4 weeks, 6 weeks, 8 weeks and 12 weeks) in the lunges of another cats were introduced into the brain parenchyma of each cat's with the same procedure described above. Follow -up MR images and chest radiographs were obtained at 2 days, 1 weeks, 2 weeks, 4 weeks and 8 weeks after inoculation. The autopsies and histopathological examinations of the cat's brain were undertaken in 22 cats. In 9 cats that were suspected with pulmonary lesion on chest radiograph, the soft tissue radiographs of inflated-fixed lungs were obtained. In one cat with inoculation of adult worm, acute suppurative inflammation of the brain parenchyma was demonstrated. But the other cats with inoculation of adult worm or juvenile worm and the cats with intentional of metacercaris did not reveal any evidence of acute cerebral paragonimiasis. More than half of the introduce metacercariae (5 out of 8 cats) were found in the lung parenchyma, while only 25% (4 out of 16 cats) of the adult worm inoculated cats were. Acute suppurative inflammation suggesting acute stage cerebral paragonimiasis was obtained in one case of adult worm inoculated cat. Most of the inoculated metacercariae and some of the juvenile worms or adult worms were migrated to the lungs.

  5. Composition of intraocular foreign bodies: experimental study of ultrasonographic presentation.

    Science.gov (United States)

    Costa, Márcio Augusto Nogueira; Garcia, Patrícia Novita; Barroso, Letícia Fernandes; Ferreira, Marco Antonio; Okuda, Érika Araki; Allemann, Norma

    2013-01-01

    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

  6. Composition of intraocular foreign bodies: experimental study of ultrasonographic presentation

    Directory of Open Access Journals (Sweden)

    Márcio Augusto Nogueira Costa

    2013-02-01

    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

  7. Experimental study of voltage fluctuations in a glow discharge

    Science.gov (United States)

    Yunusov, R. F.; Garipov, M. M.

    2017-11-01

    The article is devoted to the experimental study of voltage pulsations in a glow discharge. The longitudinal discharge was ignited in a stream of air moving in a cylindrical discharge chamber (DC). Copper hollow electrodes were located at a distance of a = (2-8) cm from each other along the axis of the DC. The gas pressure P = (4.7 - 26) kPa and its flow rate G = (0-0.06) g/s were monitored. The discharge current and voltage varied accordingly in the ranges: I = (20-100) mA, U = (1, 5 - 4, 2) kV. The current-voltage characteristics of the discharge were measured. The voltage decreased with increasing current, which is typical for a given type of discharge. The oscillations of the discharge voltage were registered by an oscilloscope; the current-voltage characteristic of the discharge was recorded by a two-coordinate recorder. Three regions of the current-voltage characteristic were detected. The luminous positive discharge column (PC) occupied the entire interelectrode space in the current region I = (100-70) mA. In the current range I = (70-40) mA there is a smooth transition to the discharge without visible glow of the PC with a significant increase in the discharge voltage. With further reduction of the current intensity (the third region), the discharge exists almost at a constant voltage until its quenching. Low-frequency and high-frequency oscillations of the discharge voltage were observed at the boundary of the second and third regions of the current-voltage characteristic.

  8. Mechanisms of blast induced brain injuries, experimental studies in rats.

    Science.gov (United States)

    Risling, M; Plantman, S; Angeria, M; Rostami, E; Bellander, B-M; Kirkegaard, M; Arborelius, U; Davidsson, J

    2011-01-01

    Traumatic brain injuries (TBI) potentially induced by blast waves from detonations result in significant diagnostic problems. It may be assumed that several mechanisms contribute to the injury. This study is an attempt to characterize the presumed components of the blast induced TBI. Our experimental models include a blast tube in which an anesthetized rat can be exposed to controlled detonations of explosives that result in a pressure wave with a magnitude between 130 and 260 kPa. In this model, the animal is fixed with a metal net to avoid head acceleration forces. The second model is a controlled penetration of a 2mm thick needle. In the third model the animal is subjected to a high-speed sagittal rotation angular acceleration. Immunohistochemical labeling for amyloid precursor protein revealed signs of diffuse axonal injury (DAI) in the penetration and rotation models. Signs of punctuate inflammation were observed after focal and rotation injury. Exposure in the blast tube did not induce DAI or detectable cell death, but functional changes. Affymetrix Gene arrays showed changes in the expression in a large number of gene families including cell death, inflammation and neurotransmitters in the hippocampus after both acceleration and penetration injuries. Exposure to the primary blast wave induced limited shifts in gene expression in the hippocampus. The most interesting findings were a downregulation of genes involved in neurogenesis and synaptic transmission. These experiments indicate that rotational acceleration may be a critical factor for DAI and other acute changes after blast TBI. The further exploration of the mechanisms of blast TBI will have to include a search for long-term effects. Copyright © 2010 Elsevier Inc. All rights reserved.

  9. Holding Strength of Suture: An Experimental Study Using Porcine Kidney

    Science.gov (United States)

    Akpinar, Haluk; Karadag, Mert Ali; Dönmez, Muhammet İrfan; Altunrende, Fatih

    2017-01-01

    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

  10. Holding Strength of Suture: An Experimental Study Using Porcine Kidney.

    Science.gov (United States)

    Özkuvanci, Ünsal; Akpinar, Haluk; Karadag, Mert Ali; Dönmez, Muhammet İrfan; Altunrende, Fatih

    2017-01-01

    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.

  11. Radiation efficiency during slow crack propagation: an experimental study.

    Science.gov (United States)

    Jestin, Camille; Lengliné, Olivier; Schmittbuhl, Jean

    2017-04-01

    Creeping faults are known to host a significant aseismic deformation. However, the observations of micro-earthquake activity related to creeping faults (e.g. San Andreas Faults, North Anatolian Fault) suggest the presence of strong lateral variabilities of the energy partitioning between radiated and fracture energies. The seismic over aseismic slip ratio is rather difficult to image over time and at depth because of observational limitations (spatial resolution, sufficiently broad band instruments, etc.). In this study, we aim to capture in great details the energy partitioning during the slow propagation of mode I fracture along a heterogeneous interface, where the toughness is strongly varying in space.We lead experiments at laboratory scale on a rock analog model (PMMA) enabling a precise monitoring of fracture pinning and depinning on local asperities in the brittle-creep regime. Indeed, optical imaging through the transparent material allows the high resolution description of the fracture front position and velocity during its propagation. At the same time, acoustic emissions are also measured by accelerometers positioned around the rupture. Combining acoustic records, measurements of the crack front position and the loading curve, we compute the total radiated energy and the fracture energy. We deduce from them the radiation efficiency, ηR, characterizing the proportion of the available energy that is radiated in form of seismic wave. We show an increase of ηR with the crack rupture speed computed for each of our experiments in the sub-critical crack propagation domain. Our experimental estimates of ηR are larger than the theoretical model proposed by Freund, stating that the radiation efficiency of crack propagation in homogeneous media is proportional to the crack velocity. Our results are demonstrated to be in agreement with existing studies which showed that the distribution of crack front velocity in a heterogeneous medium can be well described by a

  12. Alexander von Humboldt: galvanism, animal electricity, and self-experimentation part 2: the electric eel, animal electricity, and later years.

    Science.gov (United States)

    Finger, Stanley; Piccolino, Marco; Stahnisch, Frank W

    2013-01-01

    After extensive experimentation during the 1790s, Alexander von Humboldt remained skeptical about "animal electricity" (and metallic electricity), writing instead about an ill-defined galvanic force. With his worldview and wishing to learn more, he studied electric eels in South America just as the new century began, again using his body as a scientific instrument in many of his experiments. As had been the case in the past and for many of the same reasons, some of his findings with the electric eel (and soon after, Italian torpedoes) seemed to argue against biological electricity. But he no longer used galvanic terminology when describing his electric fish experiments. The fact that he now wrote about animal electricity rather than a different "galvanic" force owed much to Alessandro Volta, who had come forth with his "pile" (battery) for multipling the physical and perceptable effects of otherwise weak electricity in 1800, while Humboldt was deep in South America. Humboldt probably read about and saw voltaic batteries in the United States in 1804, but the time he spent with Volta in 1805 was probably more significant in his conversion from a galvanic to an electrical framework for understanding nerve and muscle physiology. Although he did not continue his animal electricity research program after this time, Humboldt retained his worldview of a unified nature and continued to believe in intrinsic animal electricity. He also served as a patron to some of the most important figures in the new field of electrophysiology (e.g., Hermann Helmholtz and Emil du Bois-Reymond), helping to take the research that he had participated in to the next level.

  13. Experimental pragmatics: a Gricean turn in the study of language.

    Science.gov (United States)

    Noveck, Ira A; Reboul, Anne

    2008-11-01

    Discerning the meaning of an utterance requires not only mastering grammar and knowing the meanings of words but also understanding the communicative (i.e., pragmatic) features of language. Although it has been an ever present aspect of linguistic analyses and discussions, it is only over the last ten years or so that cognitive scientists have been investigating--in a concerted fashion--the pragmatic features of language experimentally. We begin by highlighting Paul Grice's contributions to ordinary language philosophy and show how it has led to this active area of experimental investigation. We then focus on two exemplary phenomena--'scalar inference' and 'reference resolution'--before considering other topics that fit into the paradigm known as 'experimental pragmatics'.

  14. Condiciones térmicas de un dispositivo electrónico en caso de incendio Primera parte: estudio experimental

    Directory of Open Access Journals (Sweden)

    Bruno Chine

    2007-11-01

    Full Text Available En este trabajo se presentan los resultados de un estudio experimental para determinar las condiciones térmicas a la cual un sistema electrónico, usado para radiocomunicaciones en túneles, podría estar sujeto en caso de incendio. El sistema se compone de un dispositivo electrónico contenido en una caja metálica de acero inoxidable 316, un cable coaxial interno y un cable coaxial externo de cobre. Sobre el sistema, que se alberga en una cámara de polímero concreto, ha sido realizada una prueba al fuego con registro experimental de los valores de temperatura en diferentes puntos del sistema mismo. El trabajo experimental ha permitido analizar eficazmente la respuesta del dispositivo electrónico y de los distintos materiales que lo componen a las severas condiciones térmicas de prueba.

  15. Experimental Evaluation of Indoor Air Distribution in High-Performance Residential Buildings: Part I. General Descriptions and Qualification Tests

    Energy Technology Data Exchange (ETDEWEB)

    Jalalzadeh, A. A.; Hancock, E.; Powell, D.

    2007-12-01

    The main objective of this project is to experimentally characterize an air distribution system in heating mode during a period of recovery from setback. The specific air distribution system under evaluation incorporates a high sidewall supply-air register/diffuser and a near-floor wall return air grille directly below. With this arrangement, the highest temperature difference between the supply air and the room can occur during the recovery period and create a favorable condition for stratification. The experimental approach will provide realistic input data and results for verification of computational fluid dynamics modeling.

  16. Experimental study of self-compacted concrete in hardened state

    Science.gov (United States)

    Parra Costa, Carlos Jose

    The main aim of this work is to investigate the hardened behaviour of Self-Compacting Concrete (SCC). Self compacting Concrete is a special concrete that can flow in its gravity and fill in the formwork alone to its self-weight, passing through the bars and congested sections without the need of any internal or external vibration, while maintaining adequate homogeneity. SCC avoids most of the materials defects due to bleeding or segregation. With regard to its composition, SCC consists of the same components as traditional vibrated concrete (TC), but in different proportions. Thus, the high amount of superplasticizer and high powder content have to taken into account. The high workability of SCC does not allow to use traditional methods for measuring the fresh state properties, so new tests has developed (slump-flow, V-funnel, L-box, and others). The properties of the hardened SCC, which depend on the mix design, should be different from traditional concrete. In order to study the possible modifications of SCC hardened state properties, a review of the bibliography was done. The state of art was focused on the mechanical behaviour (compressive strength, tension strength and elastic modulus), on bond strength of reinforcement steel, and on material durability. The experimental program consisted in the production of two types of concretes: Self-Compacting Concrete and Traditional Concrete. Four different dosages was made with three different water/cement ratio and two strength types of Portland cement, in order to cover the ordinary strength used in construction. Based on this study it can be concluded that compressive strength of SCC and TC are similar (the differences are lesser than 10%), whereas the tensile strength of TC are up to 18% higher. The values of elastic modulus of both concrete are similar. On the other hand, in the ultimate state the bond strength of SCC and TC is similar, although SCC shows higher bond stiffness in the serviceability state (initial

  17. The ethics of human volunteer studies involving experimental exposure to pesticides: unanswered dilemmas

    Science.gov (United States)

    2010-01-01

    The controversy about the use of data from human volunteer studies involving experimental exposure to pesticides as part of regulatory risk assessment has been widely discussed, but the complex and interrelated scientific and ethical issues remain largely unresolved. This discussion paper, generated by authors who comprised a workgroup of the ICOH Scientific Committee on Rural Health, reviews the use of human experimental studies in regulatory risk assessment for pesticides with a view to advancing the debate as to when, if ever, such studies might be ethically justifiable. The discussion is based on three elements: (a) a review of discussion papers on the topic of human testing of pesticides and the positions adopted by regulatory agencies in developed countries; (b) an analysis of published and unpublished studies involving human testing with pesticides, both in the peer-reviewed literature and in the JMPR database; and (c) application of an ethical analysis to the problem. The paper identifies areas of agreement which include general principles that may provide a starting point on which to base criteria for judgements as to the ethical acceptability of such studies. However, the paper also highlights ongoing unresolved differences of opinion inherent in ethical analysis of contentious issues, which we propose should form a starting point for further debate and the development of guidelines to achieve better resolution of this matter. PMID:20718963

  18. The ethics of human volunteer studies involving experimental exposure to pesticides: unanswered dilemmas

    Directory of Open Access Journals (Sweden)

    London Leslie

    2010-08-01

    Full Text Available Abstract The controversy about the use of data from human volunteer studies involving experimental exposure to pesticides as part of regulatory risk assessment has been widely discussed, but the complex and interrelated scientific and ethical issues remain largely unresolved. This discussion paper, generated by authors who comprised a workgroup of the ICOH Scientific Committee on Rural Health, reviews the use of human experimental studies in regulatory risk assessment for pesticides with a view to advancing the debate as to when, if ever, such studies might be ethically justifiable. The discussion is based on three elements: (a a review of discussion papers on the topic of human testing of pesticides and the positions adopted by regulatory agencies in developed countries; (b an analysis of published and unpublished studies involving human testing with pesticides, both in the peer-reviewed literature and in the JMPR database; and (c application of an ethical analysis to the problem. The paper identifies areas of agreement which include general principles that may provide a starting point on which to base criteria for judgements as to the ethical acceptability of such studies. However, the paper also highlights ongoing unresolved differences of opinion inherent in ethical analysis of contentious issues, which we propose should form a starting point for further debate and the development of guidelines to achieve better resolution of this matter.

  19. Phytochemical study of aerial parts from Phlomis tuberosa L

    Directory of Open Access Journals (Sweden)

    S Javzan

    2014-10-01

    Full Text Available Three iridoid glycoside lamiide(I, Ipolamiide(II and ipolamiide(III were isolated from N-butanol fractions obtained from the column chromatography of methanol extract from the aerial parts of Phlomis tuberosa. In addition, iridoid cyclopenta[c]pyran-4-carboxylic acid, 7-methyl-, methyl ester and phenol, 4-(3-hydroxy-1-propenyl-2-methoxy were determined from the chloroform fraction of methanol extract of aerial parts from Phlomis tuberosa. Isolation and structural elucidation of compounds were accomplished by PTLC, TLC, CC and spectroscopic methods (UV, 13C and 1H NMR and DEPT, GC-MS. DOI: http://dx.doi.org/10.5564/mjc.v14i0.192 Mongolian Journal of Chemistry 14 (40, 2013, p20-24

  20. Nuestras cuentas diarias: Matematicas. Primaria para adultos, Segunda parte, Volumens 1 y 2. Edicion Experimental (Our Daily Accounting: Mathematics. Primer for Adults, Part Two, Volumes 1 and 2. Experimental Edition).

    Science.gov (United States)

    Instituto Nacional para la Educacion de los Adultos, Mexico City (Mexico).

    These workbooks are part of a Mexican series of instructional materials designed for Spanish speaking adults who are in the process of becoming literate or have recently become literate in their native language. The workbooks are designed to teach skills needed to manage ordinary financial transactions and daily tasks requiring a knowledge of…

  1. Nuestras cuentas diarias: Matematicas. Primaria para adultos, Primera parte, Volumens 1 y 2. Edicion Experimental (Our Daily Accounting: Mathematics. Primer for Adults, Part One, Volumes 1 and 2. Experimental Edition).

    Science.gov (United States)

    Instituto Nacional para la Educacion de los Adultos, Mexico City (Mexico).

    These workbooks are part of a Mexican series of instructional materials designed for Spanish speaking adults who are in the process of becoming literate or have recently become literate in their native language. The workbooks, divided in two volumes, are designed to teach skills required in managing ordinary financial transactions and daily tasks…

  2. La Palabra es Nuestra: Primaria para Adultos. Segunda Parte, Volumen 1-2. Edicion Experimental (The Language Is Ours: Primer for Adults. Part Two, Volumes 1-2. Experimental Edition).

    Science.gov (United States)

    Instituto Nacional para la Educacion de los Adultos, Mexico City (Mexico).

    These workbooks are part of a Mexican series of instructional materials designed for Spanish speaking adults who are in the process becoming literate or have recently become literate in their native language. They provide readings and exercises for developing literacy skills. Pictures and fill-in-the blank exercises appear frequently. Volume 1…

  3. La Palabra es Nuestra: Primaria para Adultos. Primera Parte, Volumen 1-2. Edicion Experimental. (The Language Is Ours: Primer for Adults. Part One, Volumes 1-2. Experimental Edition).

    Science.gov (United States)

    Instituto Nacional para la Educacion de los Adultos, Mexico City (Mexico).

    These workbooks are part of a Mexican series of instructional materials designed for Spanish speaking adults who are in the process of becoming literate or have recently become literate in their native language. These workbooks, designed to continue developing literacy skills, include pictures, dialogues, crossword puzzles, and fill-in-the blank…

  4. Experimental and numerical study of drill bit drop tests on Kuru granite

    Science.gov (United States)

    Fourmeau, Marion; Kane, Alexandre; Hokka, Mikko

    2017-01-01

    This paper presents an experimental and numerical study of Kuru grey granite impacted with a seven-buttons drill bit mounted on an instrumented drop test machine. The force versus displacement curves during the impact, so-called bit-rock interaction (BRI) curves, were obtained using strain gauge measurements for two levels of impact energy. Moreover, the volume of removed rock after each drop test was evaluated by stereo-lithography (three-dimensional surface reconstruction). A modified version of the Holmquist-Johnson-Cook (MHJC) material model was calibrated using Kuru granite test results available from the literature. Numerical simulations of the single drop tests were carried out using the MHJC model available in the LS-DYNA explicit finite-element solver. The influence of the impact energy and additional confining pressure on the BRI curves and the volume of the removed rock is discussed. In addition, the influence of the rock surface shape before impact was evaluated using two different mesh geometries: a flat surface and a hyperbolic surface. The experimental and numerical results are compared and discussed in terms of drilling efficiency through the mechanical specific energy. This article is part of the themed issue 'Experimental testing and modelling of brittle materials at high strain rates'.

  5. The Healthy Primary School of the Future: study protocol of a quasi-experimental study

    Directory of Open Access Journals (Sweden)

    M. Willeboordse

    2016-07-01

    Full Text Available Abstract Background Unhealthy lifestyles in early childhood are a major global health challenge. These lifestyles often persist from generation to generation and contribute to a vicious cycle of health-related and social problems. This design article presents a study evaluating the effects of two novel healthy school interventions. The main outcome measure will be changes in children’s body mass index (BMI. In addition, lifestyle behaviours, academic achievement, child well-being, socio-economic differences, and societal costs will be examined. Methods In close collaboration with various stakeholders, a quasi-experimental study was developed, for which children of four intervention schools (n = 1200 in the southern part of the Netherlands are compared with children of four control schools (n = 1200 in the same region. The interventions started in November 2015. In two of the four intervention schools, a whole-school approach named ‘The Healthy Primary School of the Future’, is implemented with the aim of improving physical activity and dietary behaviour. For this intervention, pupils are offered an extended curriculum, including a healthy lunch, more physical exercises, and social and educational activities, next to the regular school curriculum. In the two other intervention schools, a physical-activity school approach called ‘The Physical Activity School’, is implemented, which is essentially similar to the other intervention, except that no lunch is provided. The interventions proceed during a period of 4 years. Apart from the effectiveness of both interventions, the process, the cost-effectiveness, and the expected legal implications are studied. Data collection is conducted within the school system. The baseline measurements started in September 2015 and yearly follow-up measurements are taking place until 2019. Discussion A whole-school approach is a new concept in the Netherlands. Due to its innovative, multifaceted

  6. Synthesis, experimental and theoretical vibrational studies of 1 ...

    Indian Academy of Sciences (India)

    M Drai

    DMPrIM. +][(CF3SO2)2N. −]). The under- standing of the vibrational structures is important to explain the influence of the methyl group at C2 posi- tion (effect of methylation) between the two synthesized. ILs. For this purpose, experimental and ...

  7. A Simplified Experimental Scheme for the Study of Mitosis.

    Science.gov (United States)

    Gill, John

    1980-01-01

    A procedure is described for providing preparations of dividing cells from root apical meristems, requiring only inexpensive equipment and minimal experimental skill, and using 8-Hydroxyquinoline and Toluidene-blue as a chromosome stain. The method has been sucessfully tested in schools and yields permanent preparations of adequate quality for…

  8. Students' Experimental Research Competences in the Study of Physics

    Science.gov (United States)

    Kurbanbekov, Bakytzhan A.; Turmambekov, Torebai A.; Baizak, Usen A.; Saidakhmetov, Pulat A.; Abdraimov, Rakhymzhan T.; Bekayeva, Aigerim E.; Orazbayeva, Kuldarkhan O.

    2016-01-01

    The actuality of the investigated problem is caused by the need for students' training at pedagogical high schools to meet the challenges of research activities and the insufficient development of the theoretical, content-technological, scientific and methodological aspects of the formation of their experimental research competencies at the…

  9. Experimental studies on multicellular GFRP bridge deck panels ...

    Indian Academy of Sciences (India)

    M P MUTHURAJ

    2017-11-20

    Nov 20, 2017 ... Abstract. This paper presents the experimental investigations carried out on hand lay-up prototype multi- cellular glass fibre reinforced polymer (GFRP) composite bridge deck panels under static and fatigue loading. Various sustainability aspects with regard to GFRP structural members were discussed.

  10. Experimental studies on multicellular GFRP bridge deck panels ...

    Indian Academy of Sciences (India)

    This paper presents the experimental investigations carried out on hand lay-up prototype multicellular glass fibre reinforced polymer (GFRP) composite bridge deck panels under static and fatigue loading. Various sustainability aspects with regard to GFRP structural members were discussed. The aspects include(i) social ...

  11. Experimental and numerical study of high intensity argon cluster beams

    Energy Technology Data Exchange (ETDEWEB)

    Korobeishchikov, N. G.; Kalyada, V. V.; Shmakov, A. A.; Zarvin, A. E. [Department of Applied Physics, Novosibirsk State University, 2, Pirogova str., Novosibirsk, 630090 (Russian Federation); Skovorodko, P. A. [Department of Applied Physics, Novosibirsk State University, 2, Pirogova str., Novosibirsk, 630090, Russia and Kutateladze Institute of Thermophysics SB RAS,1, Lavrentyev Ave., Novosibirsk, 630090 (Russian Federation)

    2014-12-09

    Experimental and numerical investigations of expansion of argon with homogeneous condensation in supersonic conical nozzle and in free jet behind it were carried out. Optimal parameters (stagnation pressure, nozzle-skimmer distance) for the formation of cluster beam with maximum intensity were determined. Two available models for nonequilibrium nucleation were tested. The numerical results are in satisfactory agreement with the measured data.

  12. Experimental Study of Heat Dissipation in Indoor Sports Shoes

    NARCIS (Netherlands)

    Dessing, O.; Jansen, A.J.; Leihitu, C.; Overhage, D.

    2014-01-01

    As indoor sports shoes are intensively used in a warm and sweaty environment for periods of up to three consecutive hours, the built-up heat inside is insufficiently released causing warm and perspiring feet. This results in an increased chance of blisters and skin irritations. Experimental research

  13. Nanoscale experimental study of the morphology of a microcrack in ...

    Indian Academy of Sciences (India)

    A microcrack in a silicon single crystal was experimentally investigated using highresolution transmission electron microscopy (HRTEM). In particular, the numerical Moiré (NM) method was used to visualize the deformations and defects. The lattice structure of the microcrack was carefully observed at the nanoscale. HRTEM ...

  14. Experimental study of yttrium barium copper oxide superconducting ...

    Indian Academy of Sciences (India)

    Abstract. Critical current (Ic) characteristics of 2G YBCO superconducting tape under the influ- ence of twisting moment was experimentally investigated at varying current ramp rates in the self-field. Under a uniform twist, the degradation in the current-carrying capacity of YBCO tape up to 30% was observed at 77 K. The ...

  15. Experimental and theoretical study of precast beam-slab construction

    African Journals Online (AJOL)

    The use of partially precast beam elements with shear connectors in slab construction relieves the requirement of extensive use of soffit formwork and props and will have the advantage of faster construction. It also reduces adverse effects associated deforestation. Experimental and theoretical investigations were conducted ...

  16. Numerical and Experimental Study of Electromagnetically Driven Vortical Flows

    NARCIS (Netherlands)

    Kenjeres, S.; Verdoold, J.; Tummers, M.J.; Hanjalic, K.; Kleijn, C.R.

    2009-01-01

    The paper reports on numerical and experimental investigations of electromagnetically driven vortical flows of an electrically conductive fluid in a generic setup. Two different configurations of permanent magnets are considered: a 3-magnet configuration in which the resulting Lorentz force is

  17. A precision nutrient variability study of an experimental plot in ...

    African Journals Online (AJOL)

    The spatial soil fertility status of a 2.5 ha experimental plot was generated by mapping the soil nutrient concentration and fertility status using GIS kriging technique. The research was conducted in Mukono Zonal Agricultural Research and Development Institute, Mukono, Uganda in October 2013. Soil samples across the ...

  18. Comparison of Experimental and Theoretical study of Solvent effect ...

    African Journals Online (AJOL)

    Furthermore, the simulated model in solvents was confirmed experimentally by solution nmr technique. Results show that some of the obtained results on DPPC and its head group were different obviously. On the other hand hydrophobic force in tail group caused most atoms to show ordinary constant behavior.And high ...

  19. Experimental and Theoretical Studies of Atmosphereic Inorganic Chlorine Chemistry

    Science.gov (United States)

    Sander, Stanley P.; Friedl, Randall R.

    1993-01-01

    Over the last five years substantial progress has been made in defining the realm of new chlorine chemistry in the polar stratosphere. Application of existing experimental techniques to potentially important chlorine-containing compounds has yielded quantitative kinetic and spectroscopic data as well as qualitative mechanistic insights into the relevant reactions.

  20. Experimental study on iodine chemistry (EXSI) - Containment experiments with methyl iodide

    Energy Technology Data Exchange (ETDEWEB)

    Holm, J.; Glaenneskog, H.; Ekberg, C. (Chalmers Univ. of Technology (Sweden)); Kaerkelae, T.; Auvinen, A. (VTT Technical Research Centre of Finland (Finland))

    2010-05-15

    An experimental study on radiolytic decomposition of methyl iodide was conducted in co-operation between VTT and Chalmers University of Technology as a part of the NKS-R programs. The behaviour of iodine during a severe accident has been studied in several experimental programs, ranging from the large-scale PHEBUS FP tests and intermediate-scale ThAI tests to numerous separate effect studies. In year 2008 the NROI project, a Nordic collaboration studying iodine chemistry in the containment was started. During 2009, oxidation of iodine, especially organic iodine, was studied within the NROI project. The chemistry of organic iodine in the gas phase is still one of the greatest remaining uncertainties concerning iodine behaviour during a severe accident. During the first year of the NROI project the oxidation of elemental iodine, I2, with ozone and UV-light was investigated. In this study organic iodide, in this case methyl iodide, was investigated in similar conditions as in the NROI-1 project. The experimental facility applied in this study is based on the sampling system built at VTT for the ISTP project CHIP conducted by IRSN. The experimental facility and the measuring technology are sophisticated and unique in the area of nuclear research as well as in the field of aerosol science. Experimental results showed that the methyl iodide concentration in the facility was reduced with increasing temperature and increasing UVC intensity. Similar behaviour occurred when ozone was present in the system. Formed organic gas species during the decomposition of methyl iodide was mainly formaldehyde and methanol. Instant and extensive particle formation occurred when methyl iodide was transported through a UVC radiation field and/or when ozone was present. The size of the formed primary particles was about 10 nm and the size of secondary particles was between 50-150 nm. From the SEM-EDX analyses of the particles, the conclusion was drawn that these were some kind of iodine

  1. Methods for resolving fan/motor vibration problems in air-conditioning units. Part 3: Experimental procedures for investigating torsional vibration in air-conditioning units

    Energy Technology Data Exchange (ETDEWEB)

    Teng, C. [Carrier Corp., Indianapolis, IN (United States); Reynolds, D.D. [Univ. of Nevada, Las Vegas, NV (United States). Dept. of Mechanical Engineering

    1998-10-01

    Vibration modes associated with a fan impeller, motor, and motor mounting assembly in small air-conditioning units can be excited by motor torque pulsations in single-phase motors. Experimental procedures were developed that can be used to measure the torsional resonance frequencies of the stationary parts (motor stator and motor mounting assembly) and the rotating parts (fan impeller and motor rotor and shaft assembly) of a propeller fan assembly. Impact test procedures, test procedures in which the fan motor is set up to act as a torsional shaker, and procedures that employ the use of a microphone in an anechoic room are presented in this paper.

  2. Transarterial nephrectomy: the current status of experimental and clinical studies.

    Science.gov (United States)

    Rassweiler, Jens; Prager, Peter; Haferkamp, Axel; Alken, Peter; Kauffmann, Günther W; Richter, Götz

    2008-04-01

    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

  3. Androgen receptors and experimental bone loss - an in vivo and in vitro study.

    Science.gov (United States)

    Steffens, Joao Paulo; Coimbra, Leila Santana; Rossa, Carlos; Kantarci, Alpdogan; Van Dyke, Thomas E; Spolidorio, Luis Carlos

    2015-12-01

    Testosterone is a sex hormone that exhibits many functions beyond reproduction; one such function is the regulation of bone metabolism. The role played by androgen receptors during testosterone-mediated biological processes associated with bone metabolism is largely unknown. This study aims to use a periodontal disease model in vivo in order to assess the involvement of androgen receptors on microbial-induced inflammation and alveolar bone resorption in experimental bone loss. The impact of hormone deprivation was tested through both orchiectomy and chemical blockage of androgen receptor using flutamide (FLU). Additionally, the direct effect of exogenous testosterone, and the role of the androgen receptor, on osteoclastogenesis were investigated. Thirty male adult rats (n=10/group) were subjected to: 1-orchiectomy (OCX); 2-OCX sham surgery; or 3-OCX sham surgery plus FLU, four weeks before the induction of experimental bone loss. Ten OCX sham-operated rats were not subjected to experimental bone loss and served as healthy controls. The rats were euthanized two weeks later, so as to assess bone resorption and the production of inflammatory cytokines in the gingival tissue and serum. In order to study the in vitro impact of testosterone, osteoclasts were differentiated from RAW264.7 cells and testosterone was added at increasing concentrations. Both OCX and FLU increased bone resorption, but OCX alone was observed to increase osteoclast count. IL-1β production was increased only in the gingival tissue of OCX animals, whereas FLU-treated animals presented a decreased expression of IL-6. Testosterone reduced the osteoclast formation in a dose-dependent manner, and significantly impacted the production of TNF-α; FLU partially reversed these actions. When taken together, our results indicate that testosterone modulates experimental bone loss, and that this action is mediated, at least in part, via the androgen receptor. Copyright © 2015 Elsevier Inc. All rights

  4. Use of homeopathic preparations in experimental studies with abiotically stressed plants.

    Science.gov (United States)

    Jäger, Tim; Scherr, Claudia; Shah, Devika; Majewsky, Vera; Betti, Lucietta; Trebbi, Grazia; Bonamin, Leoni; Simões-Wüst, Ana Paula; Wolf, Ursula; Simon, Meinhard; Heusser, Peter; Baumgartner, Stephan

    2011-10-01

    Experimental research on the effects of homeopathic treatments on impaired plants was last reviewed in 1990. To compile a systematic review of the existing literature on basic research in homeopathy with abiotically stressed plants using predefined criteria. The literature search was carried out on publications that reported experiments on homeopathy using abiotically stressed whole plants, seeds, plant parts and cells from 1920 to 2010. Outcomes had to be measured by established procedures and statistically evaluated. Using of a Manuscript Information Score (MIS) we identified those publications that provided sufficient information for proper interpretation (MIS≥5). A further evaluation was based on the use of adequate controls to investigate specific effects of homeopathic preparations and on the use of systematic negative control experiments. A total of 34 publications with abiotically stressed plants was identified, published between 1965 and 2010. The 34 publications described a total of 37 experimental studies. Twenty-two studies included statistics, 13 had a MIS≥5, 8 were identified with adequate controls and 4 with negative control experiments. Significant and reproducible effects with decimal and centesimal potencies were found, including dilution levels beyond Avogadro's number. One experimental model was independently assessed by another research team and yielded inverted results compared to the original trial. Abiotically stressed plant models seem to be a useful approach to investigate homeopathic basic research questions, but more experimentation and especially more independent replication trials are needed. Systematic negative control experiments should be implemented on a routine basis to exclude false-positive results. Copyright © 2011 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

  5. Granular metal–carbon nanocomposites as piezoresistive sensor films – Part 1: Experimental results and morphology

    Directory of Open Access Journals (Sweden)

    G. Schultes

    2018-01-01

    Full Text Available We have produced granular films based on carbon and different transition metals by means of plasma deposition processes. Some of the films possess an increased strain sensitivity compared to metallic films. They respond to strain almost linearly with gauge factors of up to 30 if strained longitudinally, while in the transverse direction about half of the effect is still measured. In addition, the film's thermal coefficient of resistance is adjustable by the metal concentration. The influence of metal concentration was investigated for the elements Ni, Pd, Fe, Pt, W, and Cr, while the elements Co, Au, Ag, Al, Ti, and Cu were studied briefly. Only Ni and Pd have a pronounced strain sensitivity at 55 ± 5 at. % (atomic percent of metal, among which Ni–C is far more stable. Two phases are identified by transmission electron microscopy and X-ray diffraction: metal-containing nanocolumns densely packed in a surrounding carbon phase. We differentiate three groups of metals, due to their respective affinity to carbon. It turns out that only nickel has the capability to bond and form a stable and closed encapsulation of GLC around each nanoparticle. In this structure, the electron transport is in part accomplished by tunneling processes across the basal planes of the graphitic encapsulation. Hence, we hold these tunneling processes responsible for the increased gauge factors of Ni–C composites. The other elements are unable to form graphitic encapsulations and thus do not exhibit elevated gauge factors.

  6. "Teamwork in hospitals": a quasi-experimental study protocol applying a human factors approach.

    Science.gov (United States)

    Ballangrud, Randi; Husebø, Sissel Eikeland; Aase, Karina; Aaberg, Oddveig Reiersdal; Vifladt, Anne; Berg, Geir Vegard; Hall-Lord, Marie Louise

    2017-01-01

    Effective teamwork and sufficient communication are critical components essential to patient safety in today's specialized and complex healthcare services. Team training is important for an improved efficiency in inter-professional teamwork within hospitals, however the scientific rigor of studies must be strengthen and more research is required to compare studies across samples, settings and countries. The aims of the study are to translate and validate teamwork questionnaires and investigate healthcare personnel's perception of teamwork in hospitals (Part 1). Further to explore the impact of an inter-professional teamwork intervention in a surgical ward on structure, process and outcome (Part 2). To address the aims, a descriptive, and explorative design (Part 1), and a quasi-experimental interventional design will be applied (Part 2). The study will be carried out in five different hospitals (A-E) in three hospital trusts in Norway. Frontline healthcare personnel in Hospitals A and B, from both acute and non-acute departments, will be invited to respond to three Norwegian translated teamwork questionnaires (Part 1). An inter-professional teamwork intervention in line with the TeamSTEPPS recommend Model of Change will be implemented in a surgical ward at Hospital C. All physicians, registered nurses and assistant nurses in the intervention ward and two control wards (Hospitals D and E) will be invited to to survey their perception of teamwork, team decision making, safety culture and attitude towards teamwork before intervention and after six and 12 months. Adult patients admitted to the intervention surgical unit will be invited to survey their perception of quality of care during their hospital stay before intervention and after six and 12 month. Moreover, anonymous patient registry data from local registers and data from patients' medical records will be collected (Part 2). This study will help to understand the impact of an inter-professional teamwork

  7. Efficacy of glutathione mesotherapy in burns: an experimental study.

    Science.gov (United States)

    Buz, A; Görgülü, T; Olgun, A; Kargi, E

    2016-12-01

    Thermal burns are the leading cause of trauma worldwide. Currently, no consensus on optimal treatment of deep partial-thickness (second-degree) burns has emerged, as reflected by the wide variability in available wound-care materials. The relative efficacies of products used for treatment of partial-thickness thermal burns remain unclear. Mesotherapy features intradermal administration of various agents, depending on burn location. In the present experimental study, we explored the efficacy of mesotherapy used to treat partial-thickness thermal burns in 50 male Wistar rats divided into five groups of equal number. No procedure was performed after infliction of thermal burns in control group (Group 1). Mesotherapy was applied with physiological saline in sham group (Group 2), glutathione, taurine, and L-carnitine were separately applied in Group 3, Group 4, and Group 5, respectively. Mesotherapeutic agents were injected intradermally into the reticular layer of the dermis using the point technique. The first course of mesotherapy was given within the first 2 h after infliction of thermal burns, and therapy was continued to day 10. On day 22, unhealed thermal burn areas were measured prior to sacrifice, and biopsies covering the total areas of burns were performed to allow of pathological evaluation. Group 3 (the glutathione group) showed the best extent of healing, followed by Group 4 (the taurine group) and Group 5 (the L-carnitine group). The healed thermal burn areas in these groups were significantly greater than those in the control and sham groups (P = 0.001). All of healing, acute and chronic inflammation, the amount of granulation tissue, the level of fibroblast maturation, the amount of collagen, the extent of re-epithelization and neovascularization, and ulcer depth were scored upon pathological examination of tissue cross-sections. The best outcomes were evident in the glutathione group, with statistical significance. Although wound healing in the L

  8. Experimental studies of pion-nucleus interactions at intermediate energies. Annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    1991-12-31

    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.

  9. Tailoring laser wakefield accelerated electron beams. An experimental study on the influence of experimental conditions on electron beam parameters

    Energy Technology Data Exchange (ETDEWEB)

    Couperus, Jurjen P.; Koehler, Alexander; Zarini, Omid; Huebl, Axel; Schramm, Ulrich [Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf (Germany); Technische Universitaet Dresden (Germany); Jochmann, Axel; Debus, Alexander; Irman, Arie [Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf (Germany)

    2016-07-01

    Laser wakefield acceleration (LWFA) has emerged as a promising concept for the next generation of high energy electron accelerators. In LFWA a high intensity ultrashort laser pulse drives plasma density waves, inducing a high accelerating field gradient in the order of GV/m. To create stable reproducible electron beams, tailoring of experimental parameters like gas density, laser energy and laser pulse duration is required. In this talk we present an overview of our experimental studies with the DRACO (3 J on target, 30 fs) laser on ultrasonic gas-jet targets (He and He-N{sub 2} mixtures). We discuss the influence of experimental parameters on beam parameters like beam charge, shot-to-shot stability and energy distribution, both in the self-injecting bubble regime as well as in the ionisation injection regime.

  10. An experimental study on the aluminum nitride flux detector

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Byung Soo; Hwang, In Koo; Chung, Chong Eun; Kwon, Kee Choon

    2004-06-01

    The result of a study on the 'development of a solid state flux monitor' performed as a part of the I-NERI project 'development of enhanced reactor operation through improved sensing and control at nuclear power pants' is described in this report. Dozens of aluminum nitride based flux sensors have been fabricated with different sizes 3mm x 3mm x 0.635mm and 3mm x 3mm x 0.381mm by ORNL and were packaged with MGO insulation by KAERI for a feasibility study to use them as the in-core flux monitor in the nuclear power plants. In chapter 1, we describe the basic properties of the aluminum nitride and the geometric shape of the fabricated detectors with the signal cables attached. In chapter 2, we describe the calculation results based on the EGS4 and MCNP4B code to determine the neutron sensitivity of the aluminum nitride and the optimal thickness for the gamma rejection for the case of the detectors being used in the pulse mode operation. In chapter 3, we describe the results of measurements for the insulation resistance and of the experiments to determine the optimum operating voltage of the sensors after the packaging with long cables attached. In chapter 4, we describe the results of experiments to measure the high gamma flux from the 187Ci Co60, 77,000Ci Co60, and the 200,000Ci Co60 at the high level irradiation facility at KAERI at various distances and compared the results with the EGS4 based calculation results. In chapter 5, we describe the results of pulse counts at the IR beam port of the Hanaro reactor, the low flux measurements in the current mode at the Pohang accelerator, and the high flux measurements in the current mode inside the cold neutron source hole of the Hanaro reacter. Finally, in chapter 6, we analyze the results of the above experiments and describe the necessary future work.

  11. Estudio experimental de la aglomeración de partículas en un lecho fluidizado

    OpenAIRE

    Prada Díaz, Ángel de

    2014-01-01

    Muchos han sido los estudios y aplicaciones realizadas acerca del fenómeno de la fluidización de partículas sólidas desde el primer cuarto del siglo pasado. Para establecer una primera toma de contacto con el fenómeno, podemos definir éste en términos de un simple experimento en el que un lecho de partículas sólidas es mantenido en suspensión por una corriente de gas o líquido que pasa a través de ellas. El comportamiento de dichas partículas guarda ciertas similitudes con el comportamiento d...

  12. Masculinities and experimental practices in physics: The view from three case studies

    Science.gov (United States)

    Gonsalves, Allison J.; Danielsson, Anna; Pettersson, Helena

    2016-12-01

    [This paper is part of the Focused Collection on Gender in Physics.] This article analyzes masculinity and experimental practices within three different physics communities. This work is premised on the understanding that the discipline of physics is not only dominated by men, but also is laden with masculine connotations on a symbolical level, and that this limited and limiting construction of physics has made it difficult for many women to find a place in the discipline. Consequently, we argue that in order to further the understanding of gender dynamics within physics communities and enrich the current understandings about the lack of women in physics, perspectives from masculinity studies are crucial. The article draws on three different ethnographic case studies dealing with undergraduate students, graduate students, and research scientists.

  13. Experimental and theoretical studies of manganite and magnetite compounds Transition oxide compounds

    CERN Document Server

    Srinitiwarawong, C

    2002-01-01

    In the recent years interest in the transition oxide compounds has renewed among researchers in the field of condensed matter physics. This thesis presents the studies of the two families of the transition oxides, the manganite and magnetite compounds. Manganite has regained the interest since the discovery of the large magnetoresistance around its Curie temperature in 1990s. Magnetite on the other hand is the oldest magnetic material known to man however some of its physical properties are still controversial. The experimental works address some basic properties of these compounds when fabricated in the form of thin films. These include the resistivity measurements and magnetic measurements as well as the Hall effect. The various models of transport mechanism have been compared. The magnetic field and the temperature dependence of magnetoresistance have also been studied. Simple devices such as an artificial grain boundary and bilayers thin film have been investigated. The second part of this thesis concentr...

  14. Clinical and Experimental Study of Gaalas Phototherapy for Tемрoromandibular Disorders

    Directory of Open Access Journals (Sweden)

    Nencheva-Svechtarova S.

    2014-12-01

    Full Text Available The objective of this study was to test the clinical effectiveness of the gallium-aluminum-arsenide laser (GaAlAs; 785 nm and superluminiscent diodes (633 nm phototherapy (MedX 1100 device for the treatment of patients with temporomandibular disorders and myofascial pain syndrome. The results demonstrated a positive effect in pain relief. A significant reduction (p < 0.05 in the level of pain was observed for the temporomandibular joint and for the masseter muscles using paired samples t-test and Wilcoxon signed rank test. The experimental study on pork muscle samples showed that a the main part of laser radiation is absorbed by the tissue in thin layer of 3-4 mm, b in the spectral region 650-950 nm the intensity of light penetration is about 0.2-0.25 percent of the initial light intensity.

  15. Experimental Study into the Stability of Whitlockite in Basaltic Magmas

    Science.gov (United States)

    McCubbin, F. M.; Barnes, J. J.; Srinivasan, P.; Whitson, E. S.; Vander Kaaden, K. E.; Boyce, J. W.

    2017-01-01

    latter treatment resulted in the dehydrogenation of whitlockite to form merrillite. The presence of merrillite vs. whitlockite was widely thought to serve as an indication that magmas were anhydrous [e.g., 6-7]. However, McCubbin et al., [8] determined that merrillite in the martian meteorite Shergotty had no discernible whitlockite component despite its coexistence with OH-rich apatite. Consequently, McCubbin et al., (2014) speculated that the absence of a whitlockite component in Shergotty merrillite and other planetary merrillites may be a consequence of the limited thermal stability of H in whitlockite (stable only at T less than1050degC), which would prohibit merrillite-whitlockite solid-solution at high temperatures. In the present study, we have aimed to test this hypothesis experimentally by examining the stability of whitlockite in basaltic magmas at 1.2 GPa and a temperature range of -1000- 1300degC.

  16. An experimental and theoretical study of decentralized gas fired liquid heating

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, Rolf

    1996-12-01

    The effects on the energy situation in industry when gas fired liquid heaters replace steam have been determined by energy surveys performed in a brewery and a slaughterhouse, measurements of the performance and emissions from liquid heaters installed in these industries, and theoretical analyses of the potential energy. The theoretical study in the first part of the project provides information that allows assessment of the effects on the energy situation, of a part or complete conversion to decentralized heating, under the conditions prevailing in the industries concerned. The second part of the project focused on increasing the liquid heater efficiency and reducing emissions of carbon monoxide and hydrocarbons. Heat transfer and pressure drop for a corrugated tube was investigated experimentally. Empirical correlations for heat transfer and pressure drop for a corrugated tube were developed. These correlations were used in the design model that was developed within this project. The design model was validated against experimental data and data from an industrial application, where a section of the smooth heat exchanger tube was replaced with a corrugated tube. The results show that the design model predicts the outlet flue gas temperature and the heater efficiency quite accurately. The wall temperature at the first corrugation is also predicted with reasonable accuracy. These results make it possible to calculate the location where a corrugated tube can be inserted without causing subcooled boiling or severe fouling. It is shown that emissions of carbon monoxide and hydrocarbons can be held at low levels, even when conventional industrial burners are used. The use of nozzles that produce long soft flames increase the risk for large emissions of hydrocarbons and carbon monoxide. 125 refs, 89 figs, 16 tabs

  17. Experimental study on heat transfer characteristics of ice slurry

    Energy Technology Data Exchange (ETDEWEB)

    Kumano, Hiroyuki; Hirata, Tetsuo [Department of Mechanical Systems Engineering, Shinshu University, 4-17-1, Wakasato, Nagano-shi, Nagano 380-8553 (Japan); Shouji, Ryouta [Chubu Plant Service Co., Ltd., 11-22, Gohommatsu-cho, Atsuta-ku, Nagoya, Aichi 456-8516 (Japan); Shirakawa, Michito [Toyota Motor Corp., 1 Toyota-cho, Toyota, Aichi 471-8571 (Japan)

    2010-12-15

    Heat transfer characteristics of ice slurry were investigated experimentally. The Reynolds number, diameter of the tubes and ice packing factor (IPF) were varied as experimental parameters. For laminar flow, it was found that the ratio of the Nusselt numbers increased with the IPF, and an approximation equation of the Nusselt number could be derived using the apparent Reynolds number, IPF and the ratio of the average diameter of the ice particles to the diameter of the test tube. For turbulent flow, the ratio of the Nusselt numbers was 1 for each condition in the case of a low IPF. However, the ratio of the Nusselt numbers increased with the IPF in the high-IPF region. Moreover, the apparent Reynolds number, which can be derived by treating the ice slurry as a pseudoplastic fluid, can be used to determine the condition under which variation in the heat transfer characteristics of ice slurry in turbulent flow occurs. (author)

  18. Experimental and Numerical Studies of Magnetorheological (MR Damper

    Directory of Open Access Journals (Sweden)

    S. K. Mangal

    2014-01-01

    Full Text Available The design of a MR damper, consisting of piston and cylinder arrangement, is presented in this paper. In this paper, a 2D axisymmetric model based on finite element method (FEM concept has been developed on the ANSYS platform to analyze and examine the MR damper characteristics. Based on the FEM model, a prototype of the MR damper is fabricated and tested experimentally in the semi active vibration laboratory of the department. The comparison of both these model analyses indicates that the FEM based model is effectively portraying the experimental behavior of the MR damper in terms of its damping force. The results obtained in this paper will be helpful for the designers to create more efficient and reliable MR dampers and also to predict its damping force characteristics.

  19. Ignition characteristics of 2-methyltetrahydrofuran: An experimental and kinetic study

    KAUST Repository

    Tripathi, Rupali

    2016-10-15

    The present paper elucidates oxidation behavior of 2-methyltetrahydrofuran (2-MTHF), a novel second-generation biofuel. New experimental data sets for 2-MTHF including ignition delay time measurements in two different combustion reactors, i.e. rapid compression machine and high-pressure shock tube, are presented. Measurements for 2-MTHF/oxidizer/diluent mixtures were performed in the temperature range of . 639-1413 K, at pressures of 10, 20, and 40 bar, and at three different equivalence ratios of 0.5, 1.0, and 2.0. A detailed chemical kinetic model describing both low-and high-temperature chemistry of 2-MTHF was developed and validated against new ignition delay measurements and already existing flame species profiles and ignition delay measurements. The mechanism provides satisfactory agreement with the experimental data. For identifying key reactions at various combustion conditions and to attain a better understanding of the combustion behavior, reaction path and sensitivity analyses were performed.

  20. An experimental study on crib fires in a closed compartment

    Directory of Open Access Journals (Sweden)

    Dhurandher Bhisham Kumar

    2017-01-01

    Full Text Available An experimental investigation on burning behavior of fire in closed compartments is presented. Fire experiments were performed in a closed compartment of interior dimensions 4 × 4 × 4 m (length × width × height with ply board cribs as fire source. The parameters including the gas temperature, mass loss rate, heat flux, flame temperature, and compartment pressure were measured during the experiments. Experimental results indicated that the providing sudden ventilation to the closed compartment had great influence on the behavior of fire. The mass loss rate of the burning crib increased by 150% due to sudden ventilation which results in the increase in heat release rate by 198 kW. From the perspective of total heat flux, compartment pressure, and gas temperatures closed compartment with sudden ventilation were more hazardous.