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Sample records for dsc experimental method

  1. Reticulation of Aqueous Polyurethane Systems Controlled by DSC Method

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    Jakov Stamenkovic

    2006-06-01

    Full Text Available The DSC method has been employed to monitor the kinetics of reticulation ofaqueous polyurethane systems without catalysts, and with the commercial catalyst of zirconium(CAT®XC-6212 and the highly selective manganese catalyst, the complex Mn(III-diacetylacetonemaleinate (MAM. Among the polyol components, the acrylic emulsions wereused for reticulation in this research, and as suitable reticulation agents the water emulsiblealiphatic polyisocyanates based on hexamethylendoisocyanate with the different contents ofNCO-groups were employed. On the basis of DSC analysis, applying the methods of Kissinger,Freeman-Carroll and Crane-Ellerstein the pseudo kinetic parameters of the reticulation reactionof aqueous systems were determined. The temperature of the examination ranged from 50oC to450oC with the heat rate of 0.5oC/min. The reduction of the activation energy and the increaseof the standard deviation indicate the catalytic action of the selective catalysts of zirconium andmanganese. The impact of the catalysts on the reduction of the activation energy is thestrongest when using the catalysts of manganese and applying all the three afore-said methods.The least aberrations among the stated methods in defining the kinetic parameters wereobtained by using the manganese catalyst.

  2. Kinetics of the thermal degradation of Erica arborea by DSC: Hybrid kinetic method

    CERN Document Server

    Cancellieri, Dominique; Rossi, Jean Louis; 10.1016/j.tca.2005.07.013

    2008-01-01

    The scope of this work was the determination of kinetic parameters of the thermal oxidative degradation of a Mediterranean scrub using a hybrid method developed at the laboratory. DSC and TGA were used in this study under air sweeping to record oxidative reactions. Two dominating and overlapped exothermic peaks were recorded in DSC and individualized using an experimental and numerical separation. This first stage allowed obtaining the enthalpy variation of each exothermic phenomenon. In a second time, a model free method was applied on each isolated curve to determine the apparent activation energies. A reactional kinetic scheme was proposed for the global exotherm composed of two independent and consecutive reactions. In fine mean values of enthalpy variation and apparent activation energy previously determined were injected in a model fitting method to obtain the reaction order and the preexponential factor of each oxidative reaction. We plan to use these data in a sub-model to be integrated in a wildland ...

  3. Thermodynamic investigations of nitroxoline sublimation by simultaneous DSC-FTIR method and isothermal TG analysis.

    Science.gov (United States)

    Gao, Gau-Yi; Lin, Shan-Yang

    2010-01-01

    To investigate the physicochemical characteristics, thermodynamics, possible sublimation process and kinetics of nitroxoline, differential scanning calorimetry (DSC), isothermal thermogravimetry (TG), and Fourier transform infrared (FTIR) microspectroscopy equipped with a micro hot-stage of DSC microscopy assembly (simultaneous DSC-FTIR method) were used. The DSC result indicates that nitroxoline exhibited a sharp endothermic peak at 182 degrees C with enthalpy of 103.1 J/g due to the melting point of nitroxoline. A sublimation behavior of nitroxoline was found from 129 degrees C by gradual weight loss in TG curve. However, the nonisothermal DSC-FTIR method reveals that the temperature at 95 degrees C was the onset temperature of nitroxoline sublimation. A significant difference between DSC-FTIR method and TG analysis suggests that the simultaneous DSC-FTIR method was more sensitive than that of the TG analysis to detect the beginning temperature of nitroxoline sublimation. The sublimation kinetics of nitroxoline determined by isothermal TG analysis evidenced that the zero-order kinetics was followed over the sublimation time. The sublimation enthalpy correction was also carried out by a group additivity approach for the estimation of heat capacity. The enthalpy of nitroxoline sublimation estimated was 86.14 KJ/mol at 298.15 K.

  4. Comparing Single-Point and Multi-point Calibration Methods in Modulated DSC

    Energy Technology Data Exchange (ETDEWEB)

    Van Buskirk, Caleb Griffith [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-06-14

    Heat capacity measurements for High Density Polyethylene (HDPE) and Ultra-high Molecular Weight Polyethylene (UHMWPE) were performed using Modulated Differential Scanning Calorimetry (mDSC) over a wide temperature range, -70 to 115 °C, with a TA Instruments Q2000 mDSC. The default calibration method for this instrument involves measuring the heat capacity of a sapphire standard at a single temperature near the middle of the temperature range of interest. However, this method often fails for temperature ranges that exceed a 50 °C interval, likely because of drift or non-linearity in the instrument's heat capacity readings over time or over the temperature range. Therefore, in this study a method was developed to calibrate the instrument using multiple temperatures and the same sapphire standard.

  5. Mechanism studies on thermal dissociation of tri-n-octylamine hydrochloride with FTIR, TG, DSC and quantum chemical methods

    Indian Academy of Sciences (India)

    CHUNHUA DONG; XINGFU SONG; EVERT JAN MEIJER; GUILAN CHEN; YANXIA XU; JIANGUO YU

    2017-09-01

    The thermal dissociation of tri-n-octylamine hydrochloride (TOAHCl) was investigated using both the quantum chemical simulation and experimental methods. The pathway through which a mixture of trin-octylamine (TOA) and hydrogen chloride (HCl), rather than di-n-octylamine (DOA) and 1-chlorooctane,are produced has been determined through transition state (TS) search with Intrinsic Reaction Coordinate (IRC) calculations. Particularly, strong agreement between the experimental FTIR spectra and that of TOA demonstrates the same result for the first time. Moreover, the thermal dissociation of TOAHCl proceeds intwo continuous steps, which is different from the low molecular mass amine hydrochlorides. The experimental enthalpy of the dissociation was 70.793 kJ mol⁻¹ with DSC measurement which is very close to the density functional theory (DFT) calculation result 69.395 kJ mol⁻¹. Furthermore, with the aid of DFT calculations, some other important thermochemical characteristics such as crystal lattice energy with the value of 510.597 kJ mol⁻¹ were evaluated by means of Born–Fajans–Haber cycle.

  6. Application of chemometric methods to differential scanning calorimeter (DSC) to estimate nimodipine polymorphs from cosolvent system.

    Science.gov (United States)

    Siddiqui, Akhtar; Rahman, Ziyaur; Khan, Mansoor A

    2015-06-01

    The focus of this study was to evaluate the applicability of chemometrics to differential scanning calorimetry data (DSC) to evaluate nimodipine polymorphs. Multivariate calibration models were built using DSC data from known mixtures of the nimodipine modification. The linear baseline correction treatment of data was used to reduce dispersion in thermograms. Principal component analysis of the treated and untreated data explained 96% and 89% of the data variability, respectively. Score and loading plots correlated variability between samples with change in proportion of nimodipine modifications. The R(2) for principal component regression (PCR) and partial lease square regression (PLS) were found to be 0.91 and 0.92. The root mean square of standard error of the treated samples for calibration and validation in PCR and PLS was found to be lower than the untreated sample. These models were applied to samples recrystallized from a cosolvent system, which indicated different proportion of modifications in the mixtures than those obtained by placing samples under different storage conditions. The model was able to predict the nimodipine modifications with known margin of error. Therefore, these models can be used as a quality control tool to expediently determine the nimodipine modification in an unknown mixture.

  7. Influência de alguns parâmetros experimentais nos resultados de análises calorimétricas diferenciais - DSC Influence of some experimental parameters on the results of differential scanning calorimetry - DSC.

    Directory of Open Access Journals (Sweden)

    Cláudia Bernal

    2002-09-01

    Full Text Available A series of experiments were performed in order to demonstrate to undergraduate students or users of the differential scanning calorimetry (DSC, that several factors can influence the qualitative and quantitative aspects of DSC results. Saccharin, an artificial sweetner, was used as a probe and its thermal behavior is also discussed on the basis of thermogravimetric (TG and DSC curves.

  8. Sensory perception of the fermented goat milk: potential application of the DSC method

    Directory of Open Access Journals (Sweden)

    Martha Eunice de BESSA

    Full Text Available Abstract Goat milk and its derivatives present proven beneficial health properties; however, some sensory aspects associated to consumers’ expectations restrict the consumption growth for these products. In this work, fermented caprine milk formulations have been evaluated utilizing the methodology of Discourse of the Collective Subject (Discurso do Sujeito Coletivo – DSC associated to sensory analysis, in order to evaluate the perception of fermented caprine milk by consumers. The physicochemical and microbiological requisites of the fermented milk formulations evaluated during the storage, were according to current legislation. The probiotic characteristics of evaluated formulations were preserved, presenting viable cells counts for Lactobacillus acidophilus LA-5, Bifidobacterium BB-12, and Streptococcus thermophilus higher than 1x106 CFU/mL, along 28 days of storage. The Discourse of the Collective Subject results have shown that the typical taste and flavor, present in products derived from caprine milk, did not influence the purchase intention, which was expressive for all fermented milks. The Discourse of the Collective Subject has elucidated the consumers’ perspective, determining then both, the consumers’ profile and the factors interfering on the acquisition of fermented caprine milk.

  9. Thermal characterization and model free kinetics of aged epoxies and foams using TGA and DSC methods.

    Energy Technology Data Exchange (ETDEWEB)

    Cordaro, Joseph Gabriel; Kruizenga, Alan Michael; Nissen, April

    2013-10-01

    Two classes of materials, poly(methylene diphenyl diisocyanate) or PMDI foam, and cross-linked epoxy resins, were characterized using thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC), to help understand the effects of aging and %E2%80%9Cbake-out%E2%80%9D. The materials were evaluated for mass loss and the onset of decomposition. In some experiments, volatile materials released during heating were analyzed via mass spectroscopy. In all, over twenty materials were evaluated to compare the mass loss and onset temperature for decomposition. Model free kinetic (MFK) measurements, acquired using variable heating rate TGA experiments, were used to calculate the apparent activation energy of thermal decomposition. From these compiled data the effects of aging, bake-out, and sample history on the thermal stability of materials were compared. No significant differences between aged and unaged materials were detected. Bake-out did slightly affect the onset temperature of decomposition but only at the highest bake-out temperatures. Finally, some recommendations for future handling are made.

  10. Influence Of Sample Preparation Method On Isothermal Studies During Compatibility Screening Of Ofloxacin; Correlation With DSC Data

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    M. Misra, A. K. MISRA,, G. M. Panpalia

    2011-05-01

    Full Text Available Objectives: The compatibility of ofloxacin with somecommonly used diluents has been investigated usingisothermal stability studies (IST to allow relative ranking.Materials and Methods: The samples were prepared usingthree methods namely physical admixtures (with 5% addedmoisture, slugging and kneading in order to evaluate theeffect of mechanical treatment on the physicochemical stabilityof drug. To further verify the results of IST fresh binarymixtures were subjected to thermal analysis and an attemptwas made to correlate the results obtained from the twostudies.Results: The results from both DSC and IST revealed thatofloxacin was compatible with all the diluents used in thestudy. Among the three methods of sample preparation usedfor the study, the extent of degradation was more or less samein all the three methods indicating least influence of method ofsample preparation on the results of IST.Conclusions: From the study it was concluded that a betterco-correlation could have been obtained had ofloxacin beenmore unstable with few of the excipients than rest, used in thestudy. This way the extent of degradation would bedistinguishing enough to rank the excipients in decreasingorder of stability.

  11. Comparison study of trapped water in human erythrocytes by EPC and DSC method and its application

    Institute of Scientific and Technical Information of China (English)

    ZHAO; Gang; HE; Liqun; GUO; Xiaojie; LIU; Zhong; LUO; Dawei

    2004-01-01

    The novel differential scanning calorimetry method for determining trapped water volume of human red blood cell during freezing process has been reexamined. Results show that the final erythrocyte volume is 53% of its isotonic volume after freezing to -40℃. An electronic particle counter (MultisizerTM III, Beckman Coulter Inc., USA) was used to measure cell volume changes in response to hypertonic solution. Using this approach, when extracellular solution was 3186 mOsm, the equilibrium cell volume was found to be 57% of its isotonic value. Both results indicate that 34%-40% of intracellular water is trapped and cannot respond to osmotic difference between intra- and extracellular solution. These findings are consistent with the published data: at least 20%-32% of the isotonic cell water volume is retained within RBCs during freezing. Some applications of the values of trapped water are addressed.

  12. Antiferroelectric liquid crystals studied by DSC, electro-optic, and dielectric methods

    Science.gov (United States)

    Marzec, M.; Fafara, A.; Wrobel, S.; Godlewska, Malgorzata; Dabrowski, Roman S.; Czuprynski, Krzysztof L.; Haase, Wolfgang

    2000-05-01

    Thermal properties of four liquid crystalline substances exhibiting antiferroelectric SmCA* and ferroelectric SmC* phases were studied using differential scanning calorimetry, texture observation, electrooptic measurements and dielectric spectroscopy. The measurements were performed both on heating and cooling of the samples. All four substances studied in this work are characterized by a complex polymorphism. The temperatures of phase transitions and enthalpy changes associated with them were determined. The transition from the liquid crystalline to the crystalline state showed significant hysteresis for all four substances studied. Textures observations and electrooptic measurements were performed using ITO cells having thickness from 6 to 10 micrometers . The measurements of spontaneous polarization were performed by means of reversal current method. Spontaneous polarization was measured for a few frequencies of the triangular voltage applied. Temperature dependencies of spontaneous polarization have been studied as a function of the side chain structure.

  13. Thermodynamic Property Study of Nanostructured Mg-H, Mg-Ni-H, and Mg-Cu-H Systems by High Pressure DSC Method

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    Huaiyu Shao

    2013-01-01

    Full Text Available Mg, Ni, and Cu nanoparticles were synthesized by hydrogen plasma metal reaction method. Preparation of Mg2Ni and Mg2Cu alloys from these Mg, Ni, and Cu nanoparticles has been successfully achieved in convenient conditions. High pressure differential scanning calorimetry (DSC technique in hydrogen atmosphere was applied to study the synthesis and thermodynamic properties of the hydrogen absorption/desorption processes of nanostructured Mg-H, Mg-Ni-H, and Mg-Cu-H systems. Van’t Hoff equation of Mg-Ni-H system as well as formation enthalpy and entropy of Mg2NiH4 was obtained by high pressure DSC method. The results agree with the ones by pressure-composition isotherm (PCT methods in our previous work and the ones in literature.

  14. Effect of milling on DSC thermogram of excipient adipic acid.

    Science.gov (United States)

    Ng, Wai Kiong; Kwek, Jin Wang; Yuen, Aaron; Tan, Chin Lee; Tan, Reginald

    2010-03-01

    The purpose of this research was to investigate why and how mechanical milling results in an unexpected shift in differential scanning calorimetry (DSC) measured fusion enthalpy (Delta(fus)H) and melting point (T(m)) of adipic acid, a pharmaceutical excipient. Hyper differential scanning calorimetry (hyper-DSC) was used to characterize adipic acid before and after ball-milling. An experimental study was conducted to evaluate previous postulations such as electrostatic charging using the Faraday cage method, crystallinity loss using powder X-ray diffraction (PXRD), thermal annealing using DSC, impurities removal using thermal gravimetric analysis (TGA) and Karl Fischer titration. DSC thermograms showed that after milling, the values of Delta(fus)H and T(m) were increased by approximately 9% and 5 K, respectively. Previous suggestions of increased electrostatic attraction, change in particle size distribution, and thermal annealing during measurements did not explain the differences. Instead, theoretical analysis and experimental findings suggested that the residual solvent (water) plays a key role. Water entrapped as inclusions inside adipic acid during solution crystallization was partially evaporated by localized heating at the cleaved surfaces during milling. The correlation between the removal of water and melting properties measured was shown via drying and crystallization experiments. These findings show that milling can reduce residual solvent content and causes a shift in DSC results.

  15. Application of experimental design in examination of the dissolution rate of carbamazepine from formulations: Characterization of the optimal formulation by DSC, TGA, FT-IR and PXRD analysis

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    Krstić Marko

    2015-01-01

    Full Text Available Poor solubility is one of the key reasons for the poor bioavailability of these drugs. This paper displays a formulation of a solid surfactant system with carbamazepine, in order to increase its dissolution rate. Solid state surfactant systems are formed by application of fractal experimental design. Poloxamer 237 and Poloxamer 338 were used as surfactants and Brij® 35 was used as the co-surfactant. The ratios of the excipients and carbamazepine were varied and their effects on the dissolution rate of carbamazepine were examined. Moreover, the effects of the addition of natural (diatomite and a synthetic adsorbent carrier (Neusiline UFL2 on the dissolution rate of carbamazepine were also tested. The prepared surfactant systems were characterized and the influence of the excipients on possible changes of the polymorphous form of carbamazepine examined by application of analytical techniques (DSC, TGA, FT-IR, PXRD. It was determined that an appropriate selection of the excipient type and ratio could provide a significant increase in the carbamazepine dissolution rate. By application of analytical techniques, it was found that that the employed excipients induce a transition of carbamazepine into the amorphous form and that the selected sample was stable for three months, when kept under ambient conditions. [Projekat Ministarstva nauke Republike Srbije, br. TR34007

  16. Oil Analysis by Fast DSC

    NARCIS (Netherlands)

    Wetten, I.A.; Herwaarden, A.W.; Splinter, R.; Ruth, van S.M.

    2014-01-01

    Thermal analysis of Olive and Sunflower Oil is done by Fast DSC to evaluate its potential to replace DSC for adulteration detection. DSC measurements take hours, Fast DSC minutes. Peak temperatures of the crystallisation peak in cooling for different Olive and Sunflower Oils are both comparable to D

  17. Oil Analysis by Fast DSC

    NARCIS (Netherlands)

    Wetten, I.A.; Herwaarden, A.W.; Splinter, R.; Ruth, van S.M.

    2014-01-01

    Thermal analysis of Olive and Sunflower Oil is done by Fast DSC to evaluate its potential to replace DSC for adulteration detection. DSC measurements take hours, Fast DSC minutes. Peak temperatures of the crystallisation peak in cooling for different Olive and Sunflower Oils are both comparable to

  18. Performance Evaluation of DSC Windows for Buildings

    Directory of Open Access Journals (Sweden)

    Jun-Gu Kang

    2013-01-01

    Full Text Available Interest in BIPV systems with dye-sensitized solar cells (DSCs that can replace building windows has increased for zero energy buildings. Although DSCs have lower efficiency in terms of electricity generation than silicon solar cells, they allow light transmission and application of various colors; they also have low production costs, which make them especially suitable for BIPV systems. DSC research is interdisciplinary, involving electrical, chemical, material, and metal engineering. A considerable amount of research has been conducted on increasing the electrical efficiency of DSC and their modules. However, there has not been sufficient research on building applications of DSC systems. The aim of this study is to evaluate the optical performance and thermal performance of DSC windows in buildings. For this study, DSC experimental models with different thicknesses and dye colors were manufactured, and their optical properties, such as transmittance and reflectivity, were measured by a spectrometer. The thermal and optical characteristics of double-glazed windows with DSC were analyzed with a window performance analysis program, WINDOW 6.0.

  19. Study on Using DSC Method for Determining the Lard Antioxidation by Inulin%DSC法测定菊粉对油脂抗氧化性的研究

    Institute of Scientific and Technical Information of China (English)

    汤锋; 易雪蓉; 江军山; 杨武

    2012-01-01

    [目的]研究菊粉对油脂的抗氧化效果,为替代市场上人工合成抗氧化剂提供参考.[方法]通过差示扫描量热法(DSC)试验确定了添加不同抗氧化剂(0.1%菊粉+猪油、0.1%TBHQ+猪油、0.05%菊粉+0.05%Vc+猪油)对猪油的抗氧化效果.[结果]特丁基对苯二酚(TBHQ)的抗氧化效果小于菊粉,而菊粉的抗氧化效果比Vc和菊粉协同作用稍差.[结论]菊粉时油脂有一定抗氧化效果,是一种较好的食用油抗氧化荆.%[Objective] To study the antioxidant effects of inulin in lard, so as to provide references for replacing the artificially synthesized antioxidants. [Method] The antioxidant effects of different antioxidants, including 0. 1 % inulin + lard, 0. 1%TBHQ + lard, 0.05%inulin + 0. 05 % Vc + lard, were determined with the method of differential scanning calorimeter ( DSC ). [ Result ] The antioxidant effect of TBHQ was worse than that of inulin, while the antioxidant effect of inulin was worse than that of the synergistic effect of Vc and inulin. [ Conclusion ] Inulin showed certain antioxidant effects in lard, it is a good antioxidant for edible oil.

  20. DSC 法研究高能炸药 TEX 与推进剂组分的相容性%Compatibility of High Energetic Explosive TEX with Components of Propellants by DSC Method

    Institute of Scientific and Technical Information of China (English)

    王瑞; 孟子晖; 薛敏; 徐志斌; 崔可建; 赵凤起; 肖立柏; 郭琪

    2015-01-01

    采用差示扫描量热法(DSC)研究了4,10-二硝基-2,6,8,12-四氧杂-4,10-二氮杂四环[5,5,0,05,9,03,11]十二烷(TEX)与黑索今(RDX)、吉纳(DINA)、硝化棉(NC)、吸收药(NC+NG)、苯二甲酸二乙酯(DEP)、邻苯二甲酸铅(Φ-Pb)和微米级铝粉(Al)等推进剂主要组分的热分解性能,并考察了 TEX 与7种组分的相容性。结果表明, TEX 的热稳定性较好,与 RDX、Φ-Pb、NC、DINA 和 Al 粉的相容性良好,与 NC+NG 和 DEP 轻微敏感、相容性较好,可应用于推进剂等含能材料领域中。%The thermal decomposition performance and compatibility of 4,10-dinitro-2,6,8,12-tatraoxa-4, 10-diazatatracyclo [5,5,0,05 ,9 ,03 ,11 ]-decane (TEX)with main components of propellants such as cyclotrimethylene-trinitramine(RDX),N-nitrodihydroxyethylaminedinitrate (DINA),nitrocellulose (NC),absorbentia (NC + NG), diethylphthalate(DEP),leadphthalate(Φ-Pb)and aluminium powder (micron order)were studied by differential scanning calorimetry(DSC).The results show that TEX is relatively stable to heat,the binary system of TEX was compatible with RDX,Φ-Pb,NC,DINA and aluminium powder,and was slightly sensitive with absorbentia(NC+NG)and NC.Thus TEX can be used as component in propellants.

  1. Phase Transformation Temperature of Heating and Cooling of X60 Steel by DSC Research Method%X60钢加热和冷却相变温度DSC法研究

    Institute of Scientific and Technical Information of China (English)

    曹建刚; 庄英菊

    2012-01-01

    采用差示扫描量热仪(DSC),分析了X60管线钢在加热与冷却过程中的相变温度.结果表明:在冷却时DSC曲线上出现三个峰值,除先共析铁素体析出和珠光体转变外,还有铌或钒的碳化物析出;相变温度随冷却速度的增大而降低;在加热至950℃时,DSC曲线上出现二个峰值,除先共析铁素体溶解和奥氏体转变外,没有明显的铌或钒的碳化物峰溶入奥氏体峰.%The phase transformation temperature of X60 pipeline steel in heating and cooling process was studied by DSC method. The results show that when cooling, the three peaks of DSC curve is proeutectoid ferrite, pearlite transformation, carbide precipitation of Nb or V, respectively. The phase transformation temperature decreases with increasing cooling rate. During heating at 900 ℃, the DSC curve shows that the two peaks are pro-eutectoid ferrite dissolution, austenite transformation and the DSC curve do not has obvious peak of Nb or V carbide dissolution in austenite peak.

  2. Differential scanning calorimetry (DSC) of semicrystalline polymers.

    Science.gov (United States)

    Schick, C

    2009-11-01

    Differential scanning calorimetry (DSC) is an effective analytical tool to characterize the physical properties of a polymer. DSC enables determination of melting, crystallization, and mesomorphic transition temperatures, and the corresponding enthalpy and entropy changes, and characterization of glass transition and other effects that show either changes in heat capacity or a latent heat. Calorimetry takes a special place among other methods. In addition to its simplicity and universality, the energy characteristics (heat capacity C(P) and its integral over temperature T--enthalpy H), measured via calorimetry, have a clear physical meaning even though sometimes interpretation may be difficult. With introduction of differential scanning calorimeters (DSC) in the early 1960s calorimetry became a standard tool in polymer science. The advantage of DSC compared with other calorimetric techniques lies in the broad dynamic range regarding heating and cooling rates, including isothermal and temperature-modulated operation. Today 12 orders of magnitude in scanning rate can be covered by combining different types of DSCs. Rates as low as 1 microK s(-1) are possible and at the other extreme heating and cooling at 1 MK s(-1) and higher is possible. The broad dynamic range is especially of interest for semicrystalline polymers because they are commonly far from equilibrium and phase transitions are strongly time (rate) dependent. Nevertheless, there are still several unsolved problems regarding calorimetry of polymers. I try to address a few of these, for example determination of baseline heat capacity, which is related to the problem of crystallinity determination by DSC, or the occurrence of multiple melting peaks. Possible solutions by using advanced calorimetric techniques, for example fast scanning and high frequency AC (temperature-modulated) calorimetry are discussed.

  3. DSC and universal bit-level combining for HARQ systems

    Directory of Open Access Journals (Sweden)

    Lv Tiejun

    2011-01-01

    Full Text Available Abstract This paper proposes a Dempster -Shafer theory based combining scheme for single-input single-output (SISO systems with hybrid automatic retransmission request (HARQ, referred to as DSC, in which two methods for soft information calculations are developed for equiprobable (EP and non-equiprobable (NEP sources, respectively. One is based on the distance from the received signal to the decision candidate set consisting of adjacent constellation points when the source bits are equiprobable, and the corresponding DSC is regarded as DSC-D. The other is based on the posterior probability of the transmitted signals when the priori probability for the NEP source bits is available, and the corresponding DSC is regarded as DSC-APP. For the diverse EP and NEP source cases, both DSCD and DSC-APP are superior to maximal ratio combining, the so-called optimal combining scheme for SISO systems. Moreover, the robustness of the proposed DSC is illustrated by the simulations performed in Rayleigh channel and AWGN channel, respectively. The results show that the proposed DSC is insensitive to and especially applicable to the fading channels. In addition, a DS detection-aided bit-level DS combining scheme is proposed for multiple-input multiple-output--HARQ systems. The bit-level DS combining is deduced to be a universal scheme, and the traditional log-likelihood-ratio combining is a special case when the likelihood probability is used as bit-level soft information.

  4. Comparative study of two methods of analysis crystallinity, x-ray and DSC, using a linear low density polyethylene (LLDPE) injected, irradiated by gamma radiation; Estudo comparativo de dois metodos de analise de cristalinidade, raios-x e DSC, usando o polietileno linear de baixa densidade (PEBDL) injetado, irradiados por radiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Ana C.F. de; Ferreto, Helio F.R.; Parra, Duclerc F.; Lugao, Ademar B., E-mail: hferreto@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Quimica e Meio Ambiente

    2015-07-01

    The linear low density polyethylene (LLDPE) is a linear polymer chain with short chain branching. In this work, the LLDPE was irradiated in {sup 60}Co gamma source with 2000 kCi of activity, in presence of air, with doses of 5, 10, 20, 50 or 100 kGy, at about 5 kGy.h-1 dose rate, at room temperature. After irradiation, the samples were heated for 60 min at 100 deg C to promote recombination and annihilation of residual radicals. LLDPE injected and irradiated samples were characterized to identity the effects of terminal degradation, scission and crosslinking occurred in each dose. In the radiation process has changes in the crystallization and thus it is possible to compare the methods to obtain the percentage of crystallization of PELDB by DSC and X-ray. (author)

  5. Characterisation of gas hydrates formation and dissociation using high pressure DSC

    Energy Technology Data Exchange (ETDEWEB)

    Le Parlouer, P. [Thermal Consulting, Caluire (France); Etherington, G. [Setaram Inc., Pennsauken, NJ (United States)

    2008-07-01

    This paper provided details of an innovative methodology that used a high pressure micro-scale differential scanning calorimetry (DSC) method to characterize the thermodynamic properties and kinetics of gas hydrate formation. The calorimeter was based on a symmetrical heat flux design that used a Peltier cooling and heating principle. No refrigerating fluids were required. The method described phase transitions in relation to time, temperature and pressure. The DSC method was designed for use with gas hydrates trapped in marine sediments; hydrate formation in drilling muds and annulars during offshore oil and gas extraction; the storage and transportation of natural gas; and gas hydrate formation and dissociation for cold storage and transportation. Tests demonstrated that the DSC accurately predicted the formation of gas hydrates under high pressure conditions. Experimental studies were conducted to investigate salt solutions under methane pressure; and hydrate dissociation in a sodium chloride (NaC1) and ethyleneglycol solution. Data obtained comparing the method with classical PVT techniques showed that the MicroDSC technique was less time-consuming and required smaller sample volumes. It was concluded that the method is suitable for use with various types of fluids. 13 refs., 7 figs.

  6. Experimental methods in behavioral teratology

    Energy Technology Data Exchange (ETDEWEB)

    Zbinden, G.

    1981-09-01

    Efforts are made to develop toxicological techniques with which new behavioral teratogens can be recognized. The review describes the most important experimental methods which are presently explored, and which are based on a rich body of knowledge accumulated by experimental psychologists. Most of the tests were developed with small animals, mostly with rats. They range from the rather straightforward determination of various reflexes to complex behavioral situations involving mechanical devices, operant conditioning techniques and procedures evaluating social behavior. In applying these methods in routine toxicology, it is important to remember, that many behavioral effects determined in newborn and adult animals are subtle. Moreover, they are influenced by a large variety of environmental factors affecting the health and the behavior of the mothers and of the offspring in the early and later phases of development. Therefore, the experiments must be conducted under highly standardized conditions and must be controlled rigorously. It is concluded that the best experimental strategy for the evaluation of potential behavioral teratogens is not yet established. Therefore, it would be premature to decide on a fixed protocol to be included in routine animal safety experiments for drugs and other chemical substances.

  7. Determination of the oxidative stability by DSC of vegetable oils from the Amazonian area.

    Science.gov (United States)

    Pardauil, Juliana J R; Souza, Luiz K C; Molfetta, Fábio A; Zamian, José R; Rocha Filho, Geraldo N; da Costa, C E F

    2011-05-01

    Differential scanning calorimetry (DSC) and a Rancimat method apparatus were applied to evaluate the oxidative stability of buriti pulp oil (Mauritia flexuosa Mart), rubber seed oil (Hevea brasiliensis), and passion fruit oil (Passiflora edulis). The Rancimat measurements taken for the oxidative induction times were performed under isothermal conditions at 100°C and in an air atmosphere. The DSC technique involved the oxidation of oil samples in an oxygen-flow DSC cell. The DSC cell temperature was set at five different isothermal temperatures: 100, 110, 120, 130 and 140°C. During the oxidation reaction, an increase in heat was observed as a sharp exothermic curve. The value T(0) represents the oxidative induction time, which is determined from the downward extrapolated DSC oxidative curve verses the time axis. These curves indicate a good correlation between the DSC T(0) and oxidative stability index (OSI) values. The DSC method is useful because it consumes less time and less sample.

  8. DSC study of martensite transformation in TiPt alloys

    CSIR Research Space (South Africa)

    Chikosha, S

    2012-09-01

    Full Text Available .J. Witcomb, L.A. Cornish, Metall. & Mat. Trans. A , 2001, 32A:1881-86 K. Otsuka & X Ren, Prog. Mat. Scie., 2005, 50:511-75 Page 6 Experimental Procedure ? CSIR 2012 www.csir.co.za Ti-50at%Pt BE powder Hot Press SPS Cold...-Press & Sinter SEM/EDS & DSC Page 7 Spark Plasma Sintering 1200?C, 60 MPa ? Incomplete homogenisation of the bulk ? Pt-rich TiPt phase is formed, coexisting with other phases ? DSC shows two overlapping peaks instead of one, possible two-stage Ti...

  9. Experimental methods for identifying failure mechanisms

    Science.gov (United States)

    Daniel, I. M.

    1983-01-01

    Experimental methods for identifying failure mechanisms in fibrous composites are studied. Methods to identify failure in composite materials includes interferometry, holography, fractography and ultrasonics.

  10. In-situ study of the thermal properties of hydrate slurry by high pressure DSC

    Energy Technology Data Exchange (ETDEWEB)

    Sari, O.; Hu, J.; Brun, F.; Erbeau, N. [Institute of Thermal Engineering, University of Applied Sciences of Western Switzerland, Yverdon-les-Bains (Switzerland); Homsy, P. [Nestec, Vevey (Switzerland); Logel, J.-C. [Axima Refrigeration, Bischheim (France)

    2008-07-01

    Knowing the enthalpy of hydrate slurry is very essential for energy balance and industrial applications. No direct measurement processes had been developed in this field in the past time. A new experimental method with special device has been developed to carry out on-line measurement of the thermal properties for hydrate slurry under dynamic conditions. With this special device, it is possible to deliver the hydrate slurry to the high pressure DSC (Differential Scanning Calorimetry) directly from the production tank or pipes. Thermal data acquisition will be performed afterwards by DSC. The investigated conditions were at pressure of 30 bar and temperature of {approx}+7 {sup o}C. The dissociation enthalpy of CO{sub 2} hydrate slurry was about 54 kJ/kg, corresponding 10.8% of solid fraction. The on-line measurement results for CO{sub 2} hydrate slurry give a good tendency to apply this phase change slurry to the industrial refrigeration process. (author)

  11. STRUCTURAL CHARACTERIZATION OF POLYETHYLENES BY DSC ANALYSIS AFTER CRYSTALLIZATION SEGREGATION

    Institute of Scientific and Technical Information of China (English)

    Yu Ma; Mao Xu

    2000-01-01

    The molecular structure of polyethylene (PE) samples with various comonomers including propylene, 1-butene and 1-hexene was investigated by DSC and 13C-NMR techniques. The density of the samples varies from 0.948 g/cm3 to 0.917 g/cm3, and the molecular weight determined by the GPC method is in the range of 1~2 × 105. The branch point content of the samples was determined by 13C-NMR measurements and was found to be less than 20 per 1000 C atoms along the main chain. Crystallization segregation DSC technique (CSDSC) was used to characterize the branch point distribution or the segment length distribution of PEs. The crystallization segregation was performed in a successive annealing process at decreasing temperatures. The interval of two successive annealing temperatures was 6 K, and the time length of each annealing step was 2.5 h. The CSDSC results clearly indicate that all the PE samples used, including some metallocene PEs,more or less exhibit their non-uniformity in segment length distribution, and bimodal or multimodal CSDSC curves were usually observed. For quantitative characterization of the CSDSC curves and the segment length distribution two parameters,the average melting point, TmAV, and the root-mean-square deviation of melting temperature, (ATm2AV)1/2, were proposed.TmAV is corresponding to the average segment length due to branching and (ATm2AV)1/2 gives information about the width of the segment length distribution. Experimental results show that both the degree of average melting temperature depression and the width of the distribution seem to increase with increasing the branching content and are dependent on the type of comonomers. Very good reproducibility and additivity of the CSDSC method were evidenced experimentally. It was concluded that the CSDSC technique is a sensitive and convenient method for characterizing the segment length distribution of branched polyethylenes and will be of great interest in structure-property relationship

  12. Nucleic acid-lipid membrane interactions studied by DSC.

    Science.gov (United States)

    Giatrellis, Sarantis; Nounesis, George

    2011-01-01

    The interactions of nucleic acids with lipid membranes are of great importance for biological mechanisms as well as for biotechnological applications in gene delivery and drug carriers. The optimization of liposomal vectors for clinical use is absolutely dependent upon the formation mechanisms, the morphology, and the molecular organization of the lipoplexes, that is, the complexes of lipid membranes with DNA. Differential scanning calorimetry (DSC) has emerged as an efficient and relatively easy-to-operate experimental technique that can straightforwardly provide data related to the thermodynamics and the kinetics of the DNA-lipid complexation and especially to the lipid organization and phase transitions within the membrane. In this review, we summarize DSC studies considering nucleic acid-membrane systems, accentuating DSC capabilities, and data analysis. Published work involving cationic, anionic, and zwitterionic lipids as well as lipid mixtures interacting with RNA and DNA of different sizes and conformations are included. It is shown that despite limitations, issues such as DNA- or RNA-induced phase separation and microdomain lipid segregation, liposomal aggregation and fusion, alterations of the lipid long-range molecular order, as well as membrane-induced structural changes of the nucleic acids can be efficiently treated by systematic high-sensitivity DSC studies.

  13. Nucleic acid-lipid membrane interactions studied by DSC

    Directory of Open Access Journals (Sweden)

    Sarantis Giatrellis

    2011-01-01

    Full Text Available The interactions of nucleic acids with lipid membranes are of great importance for biological mechanisms as well as for biotechnological applications in gene delivery and drug carriers. The optimization of liposomal vectors for clinical use is absolutely dependent upon the formation mechanisms, the morphology, and the molecular organization of the lipoplexes, that is, the complexes of lipid membranes with DNA. Differential scanning calorimetry (DSC has emerged as an efficient and relatively easy-to-operate experimental technique that can straightforwardly provide data related to the thermodynamics and the kinetics of the DNA-lipid complexation and especially to the lipid organization and phase transitions within the membrane. In this review, we summarize DSC studies considering nucleic acid-membrane systems, accentuating DSC capabilities, and data analysis. Published work involving cationic, anionic, and zwitterionic lipids as well as lipid mixtures interacting with RNA and DNA of different sizes and conformations are included. It is shown that despite limitations, issues such as DNA- or RNA-induced phase separation and microdomain lipid segregation, liposomal aggregation and fusion, alterations of the lipid long-range molecular order, as well as membrane-induced structural changes of the nucleic acids can be efficiently treated by systematic high-sensitivity DSC studies.

  14. DSC Study of Collagen in Disc Disease

    OpenAIRE

    S. Skrzyński; Sionkowska, A.; Marciniak, A.

    2009-01-01

    Differential scanning calorimetry (DSC) has been used to estimate the effect of disc disease on the collagen helix-coil transition and morphology for tissue extracted from patients during surgical operation. Forty discs were obtained from patients with degenerative disc disease undergoing surgery for low back pain. The patients were in the age between 20 and 70 years old. The specimens were kept wet during DSC experiment. The data allow the comparison between thermal stability of collagen ti...

  15. Experimental Economics method to study pupils motivation

    OpenAIRE

    Lionel Page

    2010-01-01

    Experimental Economics provide a new set of tools in the tool box of the education economist. This paper review why experimental method may be useful to study how pupils behaviour, formed from their preference and beliefs, may influence their success or failure at school, what are its advantages and what are its limits. Behavioural Economics - Education - Public Policy

  16. Experimental design methods for bioengineering applications.

    Science.gov (United States)

    Keskin Gündoğdu, Tuğba; Deniz, İrem; Çalışkan, Gülizar; Şahin, Erdem Sefa; Azbar, Nuri

    2016-01-01

    Experimental design is a form of process analysis in which certain factors are selected to obtain the desired responses of interest. It may also be used for the determination of the effects of various independent factors on a dependent factor. The bioengineering discipline includes many different areas of scientific interest, and each study area is affected and governed by many different factors. Briefly analyzing the important factors and selecting an experimental design for optimization are very effective tools for the design of any bioprocess under question. This review summarizes experimental design methods that can be used to investigate various factors relating to bioengineering processes. The experimental methods generally used in bioengineering are as follows: full factorial design, fractional factorial design, Plackett-Burman design, Taguchi design, Box-Behnken design and central composite design. These design methods are briefly introduced, and then the application of these design methods to study different bioengineering processes is analyzed.

  17. Experimental test of airplane boarding methods

    CERN Document Server

    Steffen, Jason H

    2011-01-01

    We report the results of an experimental comparison of different airplane boarding methods. This test was conducted in a mock 757 fuselage, located on a Southern California soundstage, with 12 rows of six seats and a single aisle. Five methods were tested using 72 passengers of various ages. We found a significant reduction in the boarding times of optimized methods over traditional methods. These improved methods, if properly implemented, could result in a significant savings to airline companies.

  18. Vapor pressure data for fatty acids obtained using an adaptation of the DSC technique

    Energy Technology Data Exchange (ETDEWEB)

    Matricarde Falleiro, Rafael M. [LPT, Departamento de Processos Quimicos (DPQ), Faculdade de Engenharia Quimica, Universidade de Campinas (UNICAMP), 13083-852 Campinas - SP (Brazil); Akisawa Silva, Luciana Y. [Departamento de Ciencias Exatas e da Terra, Universidade Federal de Sao Paulo (UNIFESP), 09972-270 Diadema - SP (Brazil); Meirelles, Antonio J.A. [EXTRAE, Departamento de Engenharia de Alimentos (DEA), Faculdade de Engenharia de Alimentos, Universidade de Campinas (UNICAMP), 13083-862 Campinas - SP (Brazil); Kraehenbuehl, Maria A., E-mail: mak@feq.unicamp.br [LPT, Departamento de Processos Quimicos (DPQ), Faculdade de Engenharia Quimica, Universidade de Campinas (UNICAMP), 13083-852 Campinas - SP (Brazil)

    2012-11-10

    Highlights: Black-Right-Pointing-Pointer Vapor pressure data of fatty acids were measured by Differential Scanning Calorimetry. Black-Right-Pointing-Pointer The DSC technique is especially advantageous for expensive chemicals. Black-Right-Pointing-Pointer High heating rate was used for measuring the vapor pressure data. Black-Right-Pointing-Pointer Antoine constants were obtained for the selected fatty acids. - Abstract: The vapor pressure data for lauric (C{sub 12:0}), myristic (C{sub 14:0}), palmitic (C{sub 16:0}), stearic (C{sub 18:0}) and oleic (C{sub 18:1}) acids were obtained using Differential Scanning Calorimetry (DSC). The adjustments made in the experimental procedure included the use of a small sphere (tungsten carbide) placed over the pinhole of the crucible (diameter of 0.8 mm), making it possible to use a faster heating rate than that of the standard method and reducing the experimental time. The measurements were made in the pressure range from 1333 to 9333 Pa, using small sample quantities of fatty acids (3-5 mg) at a heating rate of 25 K min{sup -1}. The results showed the effectiveness of the technique under study, as evidenced by the low temperature deviations in relation to the data reported in the literature. The Antoine constants were fitted to the experimental data whose values are shown in Table 5.

  19. Report on HOM experimental methods and code

    CERN Document Server

    Shinton, I R R; Flisgen, T

    2013-01-01

    Experimental methods and various codes used are reported on with the aim to understand the signals picked up from the higher order modes in the third harmonic cavities within the ACC39 module at FLASH. Both commercial computer codes have been used, and also codes written for the express purpose of understanding the sensitivity of the modal profiles to geometrical errors and other sources of experimental errors.

  20. 非等温DSC研究低共熔点芳胺/环氧E44固化动力学%Curing Kinetics of an Eutectic Aromatic Amine/Epoxy Resin E44 by Nonisothermal DSC Method

    Institute of Scientific and Technical Information of China (English)

    谢建军; 王爱民; 曼亚珂; 潘勤敏

    2012-01-01

    The curing reaction kinetics of an eutectic aromatic amine/epoxy resin E44 system is investigated by nonisothermal DSC method. The kinetic parameters of this system are calculated by Kissinger, Ozawa and Crane e-quations; the apparent activation energy E= 49.2 kJ/mol(by Kissinger and Ozawa methods) , the reaction order n = 0. 95(by Crane equation) , the frequent factor A-2. 60×l05 s-1(by Kissinger method). The kinetic model of the curing process based on n order reaction equation is established, which is used for modeling the curing reaction characteristics. The curing conditions are defined as follow; 50t/2 h, 140t/2 h, post-curing 200℃/2 h. The curing behavior of the system is hardly affected by the change in the amount of the filler boron carbide ( B4 C ) added into the eutectic aromatic amine/epoxy resin E44 system.%采用非等温DSC法对低共熔点芳胺固化剂/环氧E44体系进行了固化动力学研究,通过Kissinger、Ozawa和Crane方法获得了该体系固化动力学参数:表观活化能E=49.2 kJ/mol,固化反应级数n=0.95,频率因子A=2.60×105s-1.固化动力学方程可表示为:((dα)/(dt))=2.60×105(1-α)0.95exp(-(49200/RT)).初步确定了该体系固化工艺条件为50℃/2 h、140℃/2 h、200℃后处理2h.填料B4C加入量对该体系固化过程的DSC曲线几乎无影响.

  1. Thermogravimetric and DSC testing of poly(lactic acid) nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Mróz, Patrycja; Białas, Sylwia [Faculty of Process and Environmental Engineering, Technical University of Łódź, Wólczańska 15 Street, 90-924 Łódź (Poland); Mucha, Maria, E-mail: muchama@wipos.p.lodz.pl [Faculty of Process and Environmental Engineering, Technical University of Łódź, Wólczańska 15 Street, 90-924 Łódź (Poland); Kaczmarek, Halina [Nicolaus Copernicus University, Faculty of Chemistry, Gagarin 7 Street, 87-100 Toruń (Poland)

    2013-12-10

    Highlights: • The presence of nanoadditivities in PLA matrix improves thermal stability of PLA. • Shielding effect main reason for PLA thermal stability by nanofillers. • Thermal degradation suppression in UV-irradiated PLA by the removing of unstable compounds. - Abstract: Polymer nanocomposites based on poly(lactic acid), PLA, and two types of nanofillers: nanosilver and nanoclay were obtained by casting method. The thermal properties of PLA and nanocomposites have been studied by thermogravimetric analysis (TA) and differential scanning calorimetry (DSC). All samples have been UV-irradiated and the effect of photoprocess on their thermal stability has been estimated. It was found that nanoadditives and UV irradiation causes an increase of the activation energy of PLA thermal decomposition. DSC result supplies information on glass transition and crystallization/melting processes in PLA in the presence of nanosilver or nanoclay, also after exposure to UV.

  2. Using Experimental Methods in Higher Education Research

    Science.gov (United States)

    Ross, Steven M.; Morrison, Gary R.; Lowther, Deborah L.

    2005-01-01

    Experimental methods have been used extensively for many years to conduct research in education and psychology. However, applications of experiments to investigate technology and other instructional innovations in higher education settings have been relatively limited. The present paper examines ways in which experiments can be used productively…

  3. A method for experimental modal separation

    Science.gov (United States)

    Hallauer, W. L., Jr.

    1977-01-01

    A method is described for the numerical simulation of multiple-shaker modal survey testing using simulated experimental data to optimize the shaker force-amplitude distribution for the purpose of isolating individual modes of vibration. Inertia, damping, stiffness, and model data are stored on magnetic disks, available by direct access to the interactive FORTRAN programs which perform all computations required by this relative force amplitude distribution method.

  4. Experimental validation of structural optimization methods

    Science.gov (United States)

    Adelman, Howard M.

    1992-01-01

    The topic of validating structural optimization methods by use of experimental results is addressed. The need for validating the methods as a way of effecting a greater and an accelerated acceptance of formal optimization methods by practicing engineering designers is described. The range of validation strategies is defined which includes comparison of optimization results with more traditional design approaches, establishing the accuracy of analyses used, and finally experimental validation of the optimization results. Examples of the use of experimental results to validate optimization techniques are described. The examples include experimental validation of the following: optimum design of a trussed beam; combined control-structure design of a cable-supported beam simulating an actively controlled space structure; minimum weight design of a beam with frequency constraints; minimization of the vibration response of helicopter rotor blade; minimum weight design of a turbine blade disk; aeroelastic optimization of an aircraft vertical fin; airfoil shape optimization for drag minimization; optimization of the shape of a hole in a plate for stress minimization; optimization to minimize beam dynamic response; and structural optimization of a low vibration helicopter rotor.

  5. Prediction of the self-accelerating decomposition temperature (SADT) for liquid organic peroxides from differential scanning calorimetry (DSC) measurements.

    Science.gov (United States)

    Malow, M; Wehrstedt, K D

    2005-04-11

    We present a prediction (estimation, calculation, screening) method for the estimation of the self-accelerating decomposition temperature (SADT) for liquid organic peroxides from differential scanning calorimetry (DSC) measurements based on the concepts of thermal explosion theory originally introduced by Semonov which are adopted to our problem assuming nth-order reaction kinetics. For the peroxides under investigation, we demonstrate good agreement with the experimental SADT. This method can be used as a quick and easy applicable method for the estimation of the critical temperatures.

  6. Experimental methods of shock wave research

    CERN Document Server

    Seiler, Friedrich

    2016-01-01

    This comprehensive and carefully edited volume presents a variety of experimental methods used in Shock Waves research. In 14 self contained chapters this 9th volume of the “Shock Wave Science and Technology Reference Library” presents the experimental methods used in Shock Tubes, Shock Tunnels and Expansion Tubes facilities. Also described is their set-up and operation. The uses of an arc heated wind tunnel and a gun tunnel are also contained in this volume. Whenever possible, in addition to the technical description some typical scientific results obtained using such facilities are described. Additionally, this authoritative book includes techniques for measuring physical properties of blast waves and laser generated shock waves. Information about active shock wave laboratories at different locations around the world that are not described in the chapters herein is given in the Appendix, making this book useful for every researcher involved in shock/blast wave phenomena.

  7. Remote Evaluation of Rotational Velocity Using a Quadrant Photo-Detector and a DSC Algorithm.

    Science.gov (United States)

    Zeng, Xiangkai; Zhu, Zhixiong; Chen, Yang

    2016-04-25

    This paper presents an approach to remotely evaluate the rotational velocity of a measured object by using a quadrant photo-detector and a differential subtraction correlation (DSC) algorithm. The rotational velocity of a rotating object is determined by two temporal-delay numbers at the minima of two DSCs that are derived from the four output signals of the quadrant photo-detector, and the sign of the calculated rotational velocity directly represents the rotational direction. The DSC algorithm does not require any multiplication operations. Experimental calculations were performed to confirm the proposed evaluation method. The calculated rotational velocity, including its amplitude and direction, showed good agreement with the given one, which had an amplitude error of ~0.3%, and had over 1100 times the efficiency of the traditional cross-correlation method in the case of data number N > 4800. The confirmations have shown that the remote evaluation of rotational velocity can be done without any circular division disk, and that it has much fewer error sources, making it simple, accurate and effective for remotely evaluating rotational velocity.

  8. DSC Study of Collagen in Disc Disease

    Directory of Open Access Journals (Sweden)

    S. Skrzyński

    2009-01-01

    Full Text Available Differential scanning calorimetry (DSC has been used to estimate the effect of disc disease on the collagen helix-coil transition and morphology for tissue extracted from patients during surgical operation. Forty discs were obtained from patients with degenerative disc disease undergoing surgery for low back pain. The patients were in the age between 20 and 70 years old. The specimens were kept wet during DSC experiment. The data allow the comparison between thermal stability of collagen tissue from healthy patients and from patients suffering from disc disease. In the paper the comparison between thermal helix-coil transition for collagen fibers from patients suffering from disc disease and collagen fibers from healthy organisms has been discussed. The heating rate has an influence on the position on denaturation temperatures of collagen in disc tissues. Higher helix-coil transition temperature of collagen in degenerated disc suggests that additional intermolecular cross linking of collagen fibers occurs. Denaturation temperatures of collagen in degenerated male disc possess smaller values than in female ones. Disc disease induces changes in collagen structure and leads to formation of additional crosslinks between collagen fibers.

  9. The non-isothermal DSC kinetics of polyethylene tereftalate–epoxy compatible blends

    Energy Technology Data Exchange (ETDEWEB)

    Zvetkov, V.L., E-mail: zvetval@yahoo.com [Institute of Mechanics, Bulgarian Academy of Sciences, bl. I, Sofia 1113 (Bulgaria); Djoumaliisky, S.; Simeonova-Ivanova, E. [Institute of Mechanics, Bulgarian Academy of Sciences, bl. I, Sofia 1113 (Bulgaria)

    2013-02-10

    Highlights: ► The non-isothermal DSC kinetics of the reaction of DGEBA with DDS, in particular in the presence of phase separating PET, has been studied. ► The specific features in the kinetics of PET formulations in comparison to the pure system have been discussed. ► The fast pre-curing of the epoxy phase allows supposing sub-micro phase separation of PET and efficient toughening of the epoxy matrix. - Abstract: Polyethylene tereftalate has been dissolved in an epoxy resin based on diglycidyl ether of bisphenol-A, DGEBA, and the epoxy component has been cross-linked with the aid of two diamine hardeners. Two series of samples have been tested at the epoxy-amine stoichiometry applying the differential scanning calorimetry, DSC, in scanning mode. One of the series of samples was pre-cured at low temperatures with the aid of an aliphatic diamine hardener near the gel point and post-cured with diaminodiphenyl sulfone, DDS. The other series of samples contained the higher temperature hardener only. Consequently, the experimental data obtained in this study on both systems relate to the non-isothermal curing of DGEBA with DDS. The kinetics has been estimated applying preferably isoconversional (model free) methods. It has been established that the fast pre-curing allows performing a sub-micro phase separation and efficient toughening of the epoxy matrix.

  10. A DSC STUDY OF PHOTOPOLYMERIZATION OF POLYESTERS CONTAINING CONJUGATED DIACETYLENES

    Institute of Scientific and Technical Information of China (English)

    Yao-wen Bai; Xiao-fang Chen; Dong Zhang; Xin-hua Wan; Qi-feng Zhou

    2000-01-01

    The photopolymerization of two kinds of prepolyesters containing conjugated diacetylene (PDA-6 and PDA-12)was investigated using DSC. By measuring the endothermic enthalpy of the prepolymers after different UV-irradiation times,the polymerizations were found to follow the first-order rate law which agreed with the results of other investigators using a different method. The endothermic enthalpy measurements of PDA-6 and PDA-12 before UV-irradiation precluded the possibility that the decrease of endothermic enthalpy was caused by thermal polymerization.

  11. Applications of differential scanning calorimetry for thermal stability analysis of proteins: qualification of DSC.

    Science.gov (United States)

    Wen, Jie; Arthur, Kelly; Chemmalil, Letha; Muzammil, Salman; Gabrielson, John; Jiang, Yijia

    2012-03-01

    Differential scanning calorimetry (DSC) has been used to characterize protein thermal stability, overall conformation, and domain folding integrity by the biopharmaceutical industry. Recently, there have been increased requests from regulatory agencies for the qualification of characterization methods including DSC. Understanding the method precision can help determine what differences between samples are significant and also establish the acceptance criteria for comparability and other characterization studies. In this study, we identify the parameters for the qualification of DSC for thermal stability analysis of proteins. We use these parameters to assess the precision and sensitivity of DSC and demonstrate that DSC is suitable for protein thermal stability analysis for these purposes. Several molecules from different structural families were studied. The experiments and data analyses were performed by different analysts using different instruments at different sites. The results show that the (apparent) thermal transition midpoint (T(m)) values obtained for the same protein by same and different instruments and/or analysts are quite reproducible, and the profile similarity values obtained for the same protein from the same instrument are also high. DSC is an appropriate method for assessing protein thermal stability and conformational changes.

  12. STUDY ON CURING BEHAVIOR OF UNSATURATED POLYESTER AND ITS TOUGHED COMPOSITES THROUGH DSC METHOD%DSC法研究UP树脂及增韧剂改性UP树脂的固化行为

    Institute of Scientific and Technical Information of China (English)

    宫文娟; 戚嵘嵘; 史子兴

    2008-01-01

    通过差示扫描量热(DSC)法确定了不饱和聚酯(UP)树脂采用过氧化二苯甲酰(BPO)、过氧化二异丙苯(DCP)和过氧化二特丁烷(DTBP)3种不同固化剂固化时的最佳固化温度,同时对BPO和DCP体系的固化反应动力学进行了详细研究,包括体系凝胶时间和活化能的确定;研究了液体聚异丁烯(PIB)、马来酸酐接枝PIB(PIB-g-MAH)及甲基丙烯酸缩水甘油酯接枝PIB(PIB-g-GMA)对UP树脂固化行为的影响.

  13. Experimental methods in studying child language acquisition.

    Science.gov (United States)

    Ambridge, Ben; Rowland, Caroline F

    2013-03-01

    This article reviews the some of the most widely used methods used for studying children's language acquisition including (1) spontaneous/naturalistic, diary, parental report data, (2) production methods (elicited production, repetition/elicited imitation, syntactic priming/weird word order), (3) comprehension methods (act-out, pointing, intermodal preferential looking, looking while listening, conditioned head turn preference procedure, functional neuroimaging) and (4) judgment methods (grammaticality/acceptability judgments, yes-no/truth-value judgments). The review outlines the types of studies and age-groups to which each method is most suited, as well as the advantage and disadvantages of each. We conclude by summarising the particular methodological considerations that apply to each paradigm and to experimental design more generally. These include (1) choosing an age-appropriate task that makes communicative sense (2) motivating children to co-operate, (3) choosing a between-/within-subjects design, (4) the use of novel items (e.g., novel verbs), (5) fillers, (6) blocked, counterbalanced and random presentation, (7) the appropriate number of trials and participants, (8) drop-out rates (9) the importance of control conditions, (10) choosing a sensitive dependent measure (11) classification of responses, and (12) using an appropriate statistical test. WIREs Cogn Sci 2013, 4:149-168. doi: 10.1002/wcs.1215 For further resources related to this article, please visit the WIREs website. The authors declare no conflict of interest. Copyright © 2013 John Wiley & Sons, Ltd.

  14. Antimycobacterial, antimicrobial activity, experimental (FT-IR, FT-Raman, NMR, UV-Vis, DSC) and DFT (transition state, chemical reactivity, NBO, NLO) studies on pyrrole-isonicotinyl hydrazine.

    Science.gov (United States)

    Rawat, Poonam; Singh, R N; Ranjan, Alok; Ahmad, Sartaj; Saxena, Rajat

    2017-05-15

    As part of a study of pyrrole hydrazone, we have investigated quantum chemical calculations, molecular geometry, relative energy, vibrational properties and antimycobacterial/antimicrobial activity of pyrrole-2-carboxaldehyde isonicotinyl hydrazone (PCINH), by applying the density functional theory (DFT) and Hartree Fock (HF). Good reproduction of experimental values is obtained and with small percentage error in majority of the cases in comparison to theoretical result (DFT). The experimental FT-IR and Raman wavenumbers were compared with the respective theoretical values obtained from DFT calculations and found to agree well. In crystal structure studies the hydrated PCINH (syn-syn conformer) shows different conformation than from anhydrous form (syn-anti conformer). The rotational barrier between syn-syn and syn-anti conformers of PCINH is 12.7kcal/mol in the gas phase. In this work, use of FT-IR, FT-Raman, (1)H NMR, (13)C NMR and UV-Vis spectroscopies has been made for full characterization of PCINH. A detailed interpretation of the vibrational spectrum was carried out with the aid of normal coordinate analysis using single scaling factor. Our results support the hydrogen bonding pattern proposed by reported crystalline structure. The calculated nature of electronic transitions within molecule found to be π→π*. The electronic descriptors study indicates that PCINH can be used as robust synthon for synthesis of new heterocyclic compounds. The first static hyperpolarizability (β0) of PCINH is calculated as 33.89×10(-30)esu, (gas phase); 68.79×10(-30) (CHCl3), esu; 76.76×10(-30)esu (CH2Cl2), 85.16×10(-30)esu (DMSO). The solvent induced effects on the first static hyperpolarizability were studied and found to increase as dielectric constants of the solvents increases. Investigated molecule shows better NLO value than Para nitroaniline (PNA). The compound PCINH shows good antifungal and antibacterial activity against Aspergillus niger and gram

  15. Determination of melting point of vegetable oils and fats by differential scanning calorimetry (DSC technique.

    Directory of Open Access Journals (Sweden)

    Nassu, Renata Tieko

    1999-02-01

    Full Text Available Melting point of fats is used to characterize oils and fats and is related to their physical properties, such as hardness and thermal behaviour. The present work shows the utilization of DSC technique on the determination of melting point of fats. In a comparison with softening point (AOCS method Cc 3-25, DSC values were higher than those obtained by AOCS method. It has occurred due to the fact that values obtained by DSC technique were taken when the fat had melted completely. DSC was also useful for determining melting point of liquid oils, such as soybean and cottonseed ones.

    El punto de fusión de grasas es usado para caracterizar aceites y grasas, y está relacionado con sus propiedades físicas, tales como dureza y comportamiento térmico. El presente trabajo muestra la utilización de la técnica de Calorimetría Diferencial de Barrido (DSC en la determinación del punto de fusión de grasas. En comparación con el punto de ablandamiento (AOCS método Cc 3-25, los valores de DSC fueron más altos que los obtenidos por los métodos de AOCS. Esto ha ocurrido debido al hecho que los valores obtenidos por la técnica de DSC fueron tomados cuando la grasa había fundido completamente. DSC fue también útil para determinar puntos de fusión de aceites líquidos, tales como los de soya y algodón.

  16. Thermooxidative stability of poppy seeds studied by non-isothermal DSC measurements.

    Science.gov (United States)

    Cibulková, Zuzana; Čertík, Milan; Dubaj, Tibor

    2014-05-01

    Papaver somniferum L. is an important crop cultivated mostly for seed production. Poppy seeds have a high nutritive value and are used as a food and as a source of edible oil. This oil is a rich source of polyunsaturated fatty acids. It is well known that the unsaturated fatty acids easily undergo oxidation reactions, which lead to the reduction of shelf life, nutritional quality, development of unpleasant tastes and odors. The goal of this study was to develop the methodology for testing the stability of poppy seeds using non-isothermal DSC. For the treatment of the experimental data a method based on non-Arrhenian temperature function has been applied and the values the kinetic parameters have been obtained. In order to assess the durability of the commercial poppy seeds, the lengths of induction periods have been calculated.

  17. Analytic heuristics for a fast DSC-MRI

    Science.gov (United States)

    Virgulin, M.; Castellaro, M.; Marcuzzi, F.; Grisan, E.

    2014-03-01

    Hemodynamics of the human brain may be studied with Dynamic Susceptibility Contrast MRI (DSC-MRI) imaging. The sequence of volumes obtained exhibits a strong spatiotemporal correlation, that can be exploited to predict which measurements will bring mostly the new information contained in the next frames. In general, the sampling speed is an important issue in many applications of the MRI, so that the focus of many current researches is to study methods to reduce the number of measurement samples needed for each frame without degrading the image quality. For the DSC-MRI, the frequency under-sampling of single frame can be exploited to make more frequent space or time acquisitions, thus increasing the time resolution and allowing the analysis of fast dynamics not yet observed. Generally (and also for MRI), the recovery of sparse signals has been achieved by Compressed Sensing (CS) techniques, which are based on statistical properties rather than deterministic ones.. By studying analytically the compound Fourier+Wavelet transform, involved in the processes of reconstruction and sparsification of MR images, we propose a deterministic technique for a rapid-MRI, exploiting the relations between the wavelet sparse representation of the recovered and the frequency samples. We give results on real images and on artificial phantoms with added noise, showing the superiority of the methods both with respect to classical Iterative Hard Thresholding (IHT) and to Location Constraint Approximate Message Passing (LCAMP) reconstruction algorithms.

  18. Methods and experimental techniques in computer engineering

    CERN Document Server

    Schiaffonati, Viola

    2014-01-01

    Computing and science reveal a synergic relationship. On the one hand, it is widely evident that computing plays an important role in the scientific endeavor. On the other hand, the role of scientific method in computing is getting increasingly important, especially in providing ways to experimentally evaluate the properties of complex computing systems. This book critically presents these issues from a unitary conceptual and methodological perspective by addressing specific case studies at the intersection between computing and science. The book originates from, and collects the experience of, a course for PhD students in Information Engineering held at the Politecnico di Milano. Following the structure of the course, the book features contributions from some researchers who are working at the intersection between computing and science.

  19. Spin crossover in iron(II) tris(2-(2 '-pyridyl)benzimidazole) complex monitored by variable temperature methods: synchrotron powder diffraction, DSC, IR spectra, Mössbauer spectra, and magnetic susceptibility

    Science.gov (United States)

    Boča, R.; Boča, M.; Ehrenberg, H.; Fuess, H.; Linert, W.; Renz, F.; Svoboda, I.

    2003-09-01

    The thermal expansion of the spin crossover system [Fe(pybzim) 3](ClO 4) 2 · H 2O (pybzim=2-(2 '-pyridyl)benzimidazole) has been determined from powder X-ray data between 50 and 250 K; the wavelength of the synchrotron source was 1.21888(1) Å. The unit cell parameters of the triclinic crystal system were a=12.091 Å, b=12.225 Å, c=14.083 Å, α=77.70°, β=80.35°, γ=74.35°, and V=1944.9 Å 3 at 250 K. In addition to the linear thermal expansion of the unit cell volume, an extra expansion due to the low-spin (LS) to high-spin (HS) transition is observed. The V( T) function shows a sudden increase comparable with the step in the effective magnetic moment at the transition region (140 K). A similar behavior is obtained on the basis of the infrared spectra. The absorption bands corresponding to the metal-ligand stretching modes change their intensities upon heating: the bands corresponding to the low-spin molecules (at ca. 409, 430, 443, and 460 cm -1) disappear in the gain of the high-spin bands (at 259 and 285 cm -1). The variable-temperature data obtained by different techniques (powder diffraction, EXAFS, IR spectra, Mössbauer spectra, magnetic susceptibility, DSC) have been transformed to a common basis - the temperature dependence of the high-spin mole fraction xHS( T). The application of the Ising-like (two-level) model of the spin crossover led to the thermodynamic data Δ H=2.6 kJ mol -1 and Δ S=19 J K -1 mol -1 as well as to the cooperativeness J/ k≈110 K (subtracted from the susceptibility data) that characterizes the abruptness of the spin crossover in the solid state.

  20. 更加完美索尼DSC-TX9C/DSC-WX5C魅力出击

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    DSC-TX9C和DSC-WX5C分别为一代经典大热机型DSC-TXTC和DSC—WX1的后继产品。延续Exmor RCMOS影像传感器所带来的强大功能,在设计细节和功能应用上均有大幅提升。

  1. Spin crossover in iron(II) tris(2-(2{sup '}-pyridyl)benzimidazole) complex monitored by variable temperature methods: synchrotron powder diffraction, DSC, IR spectra, Moessbauer spectra, and magnetic susceptibility

    Energy Technology Data Exchange (ETDEWEB)

    Boca, R.; Boca, M.; Ehrenberg, H.; Fuess, H.; Linert, W.; Renz, F.; Svoboda, I

    2003-09-15

    The thermal expansion of the spin crossover system [Fe(pybzim){sub 3}](ClO{sub 4}){sub 2} {center_dot} H{sub 2}O (pybzim=2-(2{sup '}-pyridyl)benzimidazole) has been determined from powder X-ray data between 50 and 250 K; the wavelength of the synchrotron source was 1.21888(1) A. The unit cell parameters of the triclinic crystal system were a=12.091 A, b=12.225 A, c=14.083 A, {alpha}=77.70 deg., {beta}=80.35 deg., {gamma}=74.35 deg., and V=1944.9 A{sup 3} at 250 K. In addition to the linear thermal expansion of the unit cell volume, an extra expansion due to the low-spin (LS) to high-spin (HS) transition is observed. The V(T) function shows a sudden increase comparable with the step in the effective magnetic moment at the transition region (140 K). A similar behavior is obtained on the basis of the infrared spectra. The absorption bands corresponding to the metal-ligand stretching modes change their intensities upon heating: the bands corresponding to the low-spin molecules (at ca. 409, 430, 443, and 460 cm{sup -1}) disappear in the gain of the high-spin bands (at 259 and 285 cm{sup -1}). The variable-temperature data obtained by different techniques (powder diffraction, EXAFS, IR spectra, Moessbauer spectra, magnetic susceptibility, DSC) have been transformed to a common basis - the temperature dependence of the high-spin mole fraction x{sub HS}(T). The application of the Ising-like (two-level) model of the spin crossover led to the thermodynamic data {delta}H=2.6 kJ mol{sup -1} and {delta}S=19 J K{sup -1} mol{sup -1} as well as to the cooperativeness J/k{approx}110 K (subtracted from the susceptibility data) that characterizes the abruptness of the spin crossover in the solid state.

  2. Experimental characterization of composites. [load test methods

    Science.gov (United States)

    Bert, C. W.

    1975-01-01

    The experimental characterization for composite materials is generally more complicated than for ordinary homogeneous, isotropic materials because composites behave in a much more complex fashion, due to macroscopic anisotropic effects and lamination effects. Problems concerning the static uniaxial tension test for composite materials are considered along with approaches for conducting static uniaxial compression tests and static uniaxial bending tests. Studies of static shear properties are discussed, taking into account in-plane shear, twisting shear, and thickness shear. Attention is given to static multiaxial loading, systematized experimental programs for the complete characterization of static properties, and dynamic properties.

  3. Experimental Mathemataics: Examples, Methods andImplications

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, David H.; Borwein, Jonathan M.

    2005-01-31

    Recent years have seen the flowering of ''experimental'' mathematics, namely the utilization of modern computer technology as an active tool in mathematical research. This development is not limited to a handful of researchers, nor to a handful of universities, nor is it limited to one particular field of mathematics. Instead, it involves hundreds of individuals, at many different institutions, who have turned to the remarkable new computational tools now available to assist in their research, whether it be in number theory, algebra, analysis, geometry or even topology. These tools are being used to work out specific examples, generate plots, perform various algebraic and calculus manipulations, test conjectures, and explore routes to formal proof. Using computer tools to test conjectures is by itself a major time saver for mathematicians, as it permits them to quickly rule out false notions.

  4. Experimental and analysis methods in radiochemical experiments

    Science.gov (United States)

    Cattadori, C. M.; Pandola, L.

    2016-04-01

    Radiochemical experiments made the history of neutrino physics by achieving the first observation of solar neutrinos (Cl experiment) and the first detection of the fundamental pp solar neutrinos component (Ga experiments). They measured along decades the integral νe charged current interaction rate in the exposed target. The basic operation principle is the chemical separation of the few atoms of the new chemical species produced by the neutrino interactions from the rest of the target, and their individual counting in a low-background counter. The smallness of the expected interaction rate (1 event per day in a ˜ 100 ton target) poses severe experimental challenges on the chemical and on the counting procedures. The main aspects related to the analysis techniques employed in solar neutrino experiments are reviewed and described, with a special focus given to the event selection and the statistical data treatment.

  5. Experimental Mathemataics: Examples, Methods andImplications

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, David H.; Borwein, Jonathan M.

    2005-01-31

    Recent years have seen the flowering of ''experimental'' mathematics, namely the utilization of modern computer technology as an active tool in mathematical research. This development is not limited to a handful of researchers, nor to a handful of universities, nor is it limited to one particular field of mathematics. Instead, it involves hundreds of individuals, at many different institutions, who have turned to the remarkable new computational tools now available to assist in their research, whether it be in number theory, algebra, analysis, geometry or even topology. These tools are being used to work out specific examples, generate plots, perform various algebraic and calculus manipulations, test conjectures, and explore routes to formal proof. Using computer tools to test conjectures is by itself a major time saver for mathematicians, as it permits them to quickly rule out false notions.

  6. Experimental and analysis methods in radiochemical experiments

    Energy Technology Data Exchange (ETDEWEB)

    Cattadori, C.M. [INFN, Milano (Italy); Pandola, L. [Laboratori Nazionali del Sud, INFN, Catania (Italy); Gran Sasso Science Institute, INFN, L' Aquila (Italy)

    2016-04-15

    Radiochemical experiments made the history of neutrino physics by achieving the first observation of solar neutrinos (Cl experiment) and the first detection of the fundamental pp solar neutrinos component (Ga experiments). They measured along decades the integral ν{sub e} charged current interaction rate in the exposed target. The basic operation principle is the chemical separation of the few atoms of the new chemical species produced by the neutrino interactions from the rest of the target, and their individual counting in a low-background counter. The smallness of the expected interaction rate (1 event per day in a ∝ 100 ton target) poses severe experimental challenges on the chemical and on the counting procedures. The main aspects related to the analysis techniques employed in solar neutrino experiments are reviewed and described, with a special focus given to the event selection and the statistical data treatment. (orig.)

  7. Multispectral image compression based on DSC combined with CCSDS-IDC.

    Science.gov (United States)

    Li, Jin; Xing, Fei; Sun, Ting; You, Zheng

    2014-01-01

    Remote sensing multispectral image compression encoder requires low complexity, high robust, and high performance because it usually works on the satellite where the resources, such as power, memory, and processing capacity, are limited. For multispectral images, the compression algorithms based on 3D transform (like 3D DWT, 3D DCT) are too complex to be implemented in space mission. In this paper, we proposed a compression algorithm based on distributed source coding (DSC) combined with image data compression (IDC) approach recommended by CCSDS for multispectral images, which has low complexity, high robust, and high performance. First, each band is sparsely represented by DWT to obtain wavelet coefficients. Then, the wavelet coefficients are encoded by bit plane encoder (BPE). Finally, the BPE is merged to the DSC strategy of Slepian-Wolf (SW) based on QC-LDPC by deep coupling way to remove the residual redundancy between the adjacent bands. A series of multispectral images is used to test our algorithm. Experimental results show that the proposed DSC combined with the CCSDS-IDC (DSC-CCSDS)-based algorithm has better compression performance than the traditional compression approaches.

  8. Two MIS Analysis Methods: An Experimental Comparison.

    Science.gov (United States)

    Wang, Shouhong

    1996-01-01

    In China, 24 undergraduate business students applied data flow diagrams (DFD) to a mini-case, and 20 used object-oriented analysis (OOA). DFD seemed easier to learn, but after training, those using the OOA method for systems analysis made fewer errors. (SK)

  9. Differential Scanning Calorimetry (DSC) for planetary surface exploration

    Science.gov (United States)

    Gooding, James L.; Ming, Douglas W.

    1993-01-01

    Differential Scanning Calorimetry (DSC) is the quantitative measurement of the enthalpic response of a material to a systematic change in temperature. In practice, the heat flow into or outward from a sample is measured as the sample is heated or cooled at a carefully controlled rate. DSC superficially resembles, but is not the same as differential thermal analysis (DTA), which is the measurement of temperature differences between a sample and reference material as the pair is heated or cooled. The fundamental properties measured by DSC are enthalpies and temperatures of phase transitions and constant-pressure heat capacities. Depending on instrument design and the nature of the sample, high-quality DSC analyses can be obtained on only a few milligrams of solid materials. DSC requires direct contact with the sample and generally degrades, if not destroys, the sample as a consequence of heating. In laboratory applications, it is common to subject the gaseous effluent from the DSC to analysis by a separate evolved-gas analyzer (EGA).

  10. Cure Kinetics of DGEBA with Hyperbranched Poly(3-hydroxyphenyl) Phosphate as Curing Agent Studied by Non-isothermal DSC

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The cure kinetics of diglycidyl ether of bisphenol A(DGEBA) with hyperbranched poly(3-hydroxyphenyl) phosphate(HHPP) as the curing agent was investigated by means of non-isothermal differential scanning calorimetry(DSC) at various heating rates. The results were compared with the corresponding results by using 1,3-dihydroxybenzene(DHB) as a model compound. The results show that HHPP can enhance the cure reaction of DGEBA, resulting in the decrease of the peak temperature of the curing curve as well as the decrease of the activation energy because of the flexible -P-O- groups in the backbone of HHPP. However, both the activation energy of the cured polymer and the peak temperature of the curing curve are increased with DHB as a curing agent. The cure kinetics of the DGEBA/HHPP system was calculated by using the isoconversional method given by Málek. It was found that the two-parameter autocatalytic model(esták-Berggren equation) is the most adequate one to describe the cure kinetics of the studied system at various heating rates. The obtained non-isothermal DSC curves from the experimental data show the results being accordant with those theoretically calculated.

  11. Puppet Masters in the Lab : Experimental Methods in Leadership Research

    NARCIS (Netherlands)

    Rietzschel, Eric; Wisse, Barbara; Rus, Diana; Schyns, Birgit; Hall, Rosalie; Neves, Pedro

    2016-01-01

    The use of experimental research methods can be of great benefit to researchers who want to gain more insight into causal relationships in leadership processes. In this chapter, we first explain which experimental paradigms and methods are often used by leadership researchers (e.g., vignette

  12. DSC modelling for predicting resilient modulus of crushed rock base as a road base material for Western Australia roads

    Institute of Scientific and Technical Information of China (English)

    KHOBKLANG Pakdee; VIMONSATIT Vanissorn; JITSANGIAM Peerapong; NIKRAZ Hamid

    2013-01-01

    In order to increase the applied efficiency of crushed rock base (CRB) in pavement structure design for Western Australia roads,the material modelling based on the experimental results was investigated,and the disturbed state concept (DSC) was used to predict the resilient modulus of CRB because of its simplicity and strong ability in capturing the elastic and inelastic responses of materials to loads.The actual deformation of DSC,at any loading state,was determined from its assumed relative intact (RI) state.The DSC equation of CRB was constructed by using a set of experimental results of resilient modulus tests,and an idealized material model,namely the linear elastic model,of relative intact (RI) part was considered.Analysis results reveal that the resilient modulus-applied stress relationships back-predicted by using the DSC modelling are consistent with the experimental results,so,the DSC equation is suited for predicting the resilient modulus of CRB specimen.However,the model and the equation coming from the test results are conducted in accordance with the Austroads standard,so further investigation and validation with respect to the field behaviours of pavement structure should be performed.7 figs,11 refs.

  13. Review of experimental methods for evaluating effective delayed neutron fraction

    Energy Technology Data Exchange (ETDEWEB)

    Yamane, Yoshihiro [Nagoya Univ. (Japan). School of Engineering

    1997-03-01

    The International Effective Delayed Neutron Fraction ({beta}{sub eff}) Benchmark Experiments have been carried out at the Fast Critical Assembly of Japan Atomic Energy Research Institute since 1995. Researchers from six countries, namely France, Italy, Russia, U.S.A., Korea, and Japan, participate in this FCA project. Each team makes use of each experimental method, such as Frequency Method, Rossi-{alpha} Method, Nelson Number Method, Cf Neutron Source Method, and Covariance Method. In this report these experimental methods are reviewed. (author)

  14. Radiation Induced Aging Effects in Polymeric Cable Insulators at CERN. Compilation of the DSC and ATR-FTIR data on irradiated CERN cables.

    CERN Document Server

    Sorin, I

    2009-01-01

    This second part of the Report on Radiation Induced Aging Effects in Polymeric Cable Insulators at CERN [1] summarizes in a tabulated form all the experimental DSC results obtained in this work, concerning the life-time evaluation of the selected CERN cables irradiated in different conditions. Several examples of DSC curves and ATR-FTIR spectra were included to support the future polymeric materials analysis. Information on the experimental conditions, the instruments, the basic concept of life-time evaluation using the DSC data, as well as the examples of data processing and interpretation are presented and discussed in reference [1].

  15. Estimation of hydrogen bondings in coal utilizing FTir and differential scanning calorimetry (DSC); FTir to DSC wo mochiita sekitannai suiso ketsugo no teiryoteki hyoka no kokoromi

    Energy Technology Data Exchange (ETDEWEB)

    Mae, K.; Miura, K. [Kyoto University, Kyoto (Japan). Faculty of Engineering

    1996-10-28

    With an objective to know coal condensation structure which has influence on coal conversion reaction, an attempt was made on quantitative evaluation of hydrogen bonding in coal. Using as test samples the VDC made from Taiheiyo coal swollen by tetralin and vacuum-dried, and its pyrolyzed char, DSC measurement and Fourier transform infrared spectroscopy (FT) were performed. An FT spectrum comparison revealed that the VDC swollen at 220{degree}C has the hydrogen bonding relaxed partly from the original coal. However, since the change is in a huge coal molecular structure restraining space, it has stopped at relaxation of the bonding energy without causing separation as far as free radicals. On the other hand, the DSC curve shows that the VDC has slower endothermic velocity than the original coal. In other words, the difference in heat absorption amounts in both materials is equivalent to the difference of enthalpy ({Delta} H) of both materials, which corresponds to the relaxation of the hydrogen bonding. Therefore, the {Delta} H was related to wavenumber shift of the FT spectra (which corresponds to change in the hydrogen bonding condition). By using this relationship, a method for evaluating hydrogen bonding distribution was proposed from an O-H contracting vibration change that can be measured by using the FT spectra and a thermal change that can be measured by using the DSC. 3 refs., 7 figs.

  16. Experimental Methods in Psychology and Cognitive and Affective Neuroscience

    DEFF Research Database (Denmark)

    Habekost, Thomas; Nielsen, Julie Hassing

    2014-01-01

    studies are central. Recently, experimental studies within the field of affective neuroscience have also received attention. Notwithstanding, experimental methods remain controversial also in psychology, and one should carefully weigh their advantages against their drawbacks.......Laboratory experiments have always been important in psychology and are as commonly used today as ever due to the dominating position of cognitive research in international psychology. This trend has been further strengthened by recent developments in cognitive neuroscience, where experimental...

  17. Experimental Methods in Psychology and Cognitive and Affective Neuroscience

    OpenAIRE

    Habekost, Thomas; Nielsen, Julie Hassing

    2014-01-01

    Laboratory experiments have always been important in psychology and are as commonly used today as ever due to the dominating position of cognitive research in international psychology. This trend has been further strengthened by recent developments in cognitive neuroscience, where experimental studies are central. Recently, experimental studies within the fi eld of affective neuroscience have also received attention. Notwithstanding, experimental methods remain controversial also in psychology...

  18. Low Complexity DCT-based DSC approach forHyperspectral Image Compression with Arithmetic Code

    Directory of Open Access Journals (Sweden)

    Meena Babu Vallakati

    2012-09-01

    Full Text Available This paper proposes low complexity codec for lossy compression on a sample hyperspectral image. These images have two kinds of redundancies: 1 spatial; and 2 spectral. A discrete cosine transform (DCT- based Distributed Source Coding(DSC paradigm with Arithmetic code for low complexity is introduced. Here, Set-partitioning based approach is applied to reorganize DCT coefficients into wavelet like tree structure as Setpartitioning works on wavelet transform, and extract the sign, refinement, and significance bitplanes. The extracted refinement bits are Arithmetic encoded, then by applying low density parity check based (LDPC-based Slepian-Wolf coder is implement to our DSC strategy. Experimental results for SAMSON (Spectroscopic Aerial Mapping System with Onboard Navigation data show that proposed scheme achieve peak signal to noise ratio and compression to a very good extent for water cube compared to building, land or forest cube.

  19. Characterization of the polycaprolactone melt crystallization: complementary optical microscopy, DSC, and AFM studies.

    Science.gov (United States)

    Speranza, V; Sorrentino, A; De Santis, F; Pantani, R

    2014-01-01

    The first stages of the crystallization of polycaprolactone (PCL) were studied using several techniques. The crystallization exotherms measured by differential scanning calorimetry (DSC) were analyzed and compared with results obtained by polarized optical microscopy (POM), rheology, and atomic force microscope (AFM). The experimental results suggest a strong influence of the observation scale. In particular, the AFM, even if limited on time scale, appears to be the most sensitive technique to detect the first stages of crystallization. On the contrary, at least in the case analysed in this work, rheology appears to be the least sensitive technique. DSC and POM provide closer results. This suggests that the definition of induction time in the polymer crystallization is a vague concept that, in any case, requires the definition of the technique used for its characterization.

  20. Thermal degradation of ligno-cellulosic fuels: DSC and TGA studies

    CERN Document Server

    Leroy, Valérie; Leoni, Eric; 10.1016/j.tca.2006.09.017

    2008-01-01

    The scope of this work was to show the utility of thermal analysis and calorimetric experiments to study the thermal oxidative degradation of Mediterranean scrubs. We investigated the thermal degradation of four species; DSC and TGA were used under air sweeping to record oxidative reactions in dynamic conditions. Heat released and mass loss are important data to be measured for wildland fires modelling purpose and fire hazard studies on ligno-cellulosic fuels. Around 638 and 778 K, two dominating and overlapped exothermic peaks were recorded in DSC and individualized using a experimental and numerical separation. This stage allowed obtaining the enthalpy variation of each exothermic phenomenon. As an application, we propose to classify the fuels according to the heat released and the rate constant of each reaction. TGA experiments showed under air two successive mass loss around 638 and 778 K. Both techniques are useful in order to measure ignitability, combustibility and sustainability of forest fuels.

  1. Experimental Study for the Different Methods of Generating Millimeter Waves

    Directory of Open Access Journals (Sweden)

    Aamer Jamal Albaghdadi

    2014-08-01

    Full Text Available In this paper a analytical comparison and experimental implementation of different methods used in generating a low phase noise millimeter wave signals is presented. Four techniques were experimented and compared, Multiplication, phase lock loop (PLL, Injection locking (IL, and Injection locking with phase lock loop (ILPLL. The comparison and experimental results of a laboratory discussed.

  2. Experimental Methodology in English Teaching and Learning: Method Features, Validity Issues, and Embedded Experimental Design

    Science.gov (United States)

    Lee, Jang Ho

    2012-01-01

    Experimental methods have played a significant role in the growth of English teaching and learning studies. The paper presented here outlines basic features of experimental design, including the manipulation of independent variables, the role and practicality of randomised controlled trials (RCTs) in educational research, and alternative methods…

  3. DSC Study on the Polyacrylonitrile Precursors for Carbon Fibers

    Institute of Scientific and Technical Information of China (English)

    Wangxi ZHANG; Musen LI

    2005-01-01

    Different polyacrylonitrile (PAN) precursor fibers that displayed various thermal properties were studied by using differential scanning calorimetry (DSC). Results showed that some commercial PAN precursor fibers displayed double separated peaks and these fibers were of high quality because of their process stability during their conversion to carbon fibers of high performance. Some fabrication processes, such as spinning, drawing, could not apparently change the DSC features of a PAN precursor fiber. It was concluded that the thermal properties of a PAN precursor fiber was mainly determined from its comonomer content type and compositions.

  4. Experimental implementation of the modified independent modal space control method

    Science.gov (United States)

    Baz, A.; Poh, S.

    1990-01-01

    An experimental realization of a modified independent modal space control (MIMSC) method to control the vibration of a flexible cantilevered beam is presented. In its operation the method relies on the use of one piezoelectric actuator to control several vibration modes through a time-sharing strategy. The effectiveness of the MIMSC method in damping out the beam vibration is demonstrated by comparing the results with those obtained by other modal control methods. Two methods are considered, the independent modal space control method and the pseudo-inverse method. The feasibility of the MIMSC method as a viable alternative for controlling large flexible structures with a very small number of actuators is emphasized.

  5. A New Curve Fitting Method for Forming Limit Experimental Data

    Institute of Scientific and Technical Information of China (English)

    Jieshi CHEN; Xianbin ZHOU

    2005-01-01

    The forming limit curve (FLC) can be obtained by. means of curve fitting the limit strain points of different strain paths. The theory of percent regression analysis is applied to the curve fitting of forming limit experimental data.Forecast intervals of FLC percentiles can be calculated. Thus reliability and confidence level can be considered. The theoretical method to get the limits of limit strain points distributing region is presented, and the FLC position can be adjusted according to practical requirement. Method for establishing FLC with high reliability using small samples is presented at the same time. This method can make full use of the current experimental data and the previous data.Compared with the traditional method that can only use current experimental data, fewer specimens are required in the present method to obtain the same precision and the result is more accurate with the same number of specimens.

  6. Laser-high-speed-DSC: Process-oriented Thermal Analysis of PA 12 in Selective Laser Sintering

    Science.gov (United States)

    Lanzl, Lydia; Wudy, Katrin; Drexler, Maximilian; Drummer, Dietmar

    In the Selective Laser Sintering process very high heating rates occur due to the melting of the material by a laser. Extreme scanning rates could not be measured by conventional thermal analysis methods, since typical heating rates for DSC (differential scanning calorimetry) are between 5-20K min-1. By using a Laser-High-Speed-DSC, a self-developed combination of a Flash-DSC and a fitted laser head, the sample is directly heated by a CO2 laser like in the SLS process. These experiments allow a process-oriented thermal analyzation of the material. In this paper, the set-up and function of this new measuring method is introduced. Furthermore, the reliability of the measurements is evaluated by statistical design of experiment methods. By using this new measuring method, the time-dependent melting behavior of the polymer can be analyzed. Moreover, sample temperatures and heating rates dependent on laser exposure times can be quantified.

  7. Temperature Dependence of Dynamic Viscosity and DSC Analysis of the Plantohyd samples

    Directory of Open Access Journals (Sweden)

    Vlasta Vozarova

    2015-06-01

    Full Text Available The present work deals with physical properties – dynamic viscosity and DSC analysis of biodegradable hydraulic fluids and lubricating oils based on vegetable oils or on synthetic esters – PLANTOHYD S series (15S, 46S and PLANTOHYD N series (40N. The brief characterization of investigated material is presented. This article presents the experimental results of measuring the main rheological characteristic – dynamic viscosity of samples of Plantohyd. Measurements were made under laboratory conditions with digital viscometer DV-3P Anton Paar. Examination of the dynamic viscosity in the temperature interval from -10 °C to 50 °C was made. The exponential dependency of viscosity on the temperature for the each sample was obtained in accordance with Arrhenius equation. DSC (Differential Scanning Calorimetry analysis providing information on thermal effects in the sample subjected to the temperature programme was realised in the temperature range from -30 °C to 100 °C by using differential scanning calorimeter DSC 822e METTLER TOLEDO. It was determined endo/exo thermal effects and temperature interval with no thermal effects for each sample of Plantohyd.

  8. Experimental Verification of Doppler Effect with the Refraction Method

    Institute of Scientific and Technical Information of China (English)

    Lie FENG; Jia-bi CHEN; Jing-bin HU; Song-lin ZHUANG

    2010-01-01

    The traditional methad of measuring Dopplr Effect is either reflection or dispersion.This article clarifies that it can also verify the Doppler Effect with the refraction method.We have designed the experimental system with the method of optical heterodyne,using the refraction light beam from a prism,and made the experiment.The experimental results are in accordance with the theoreticai calculation.It is very useful in some particular case,such as in Negative-Index Materials(NIM),to verify the Doppler Effect with this method.

  9. Comparison as an Approach to the Experimental Method

    Science.gov (United States)

    Turner, David A.

    2017-01-01

    In his proposal for comparative education, Marc Antoinne Jullien de Paris argues that the comparative method offers a viable alternative to the experimental method. In an experiment, the scientist can manipulate the variables in such a way that he or she can see any possible combination of variables at will. In comparative education, or in…

  10. Taguchi method of experimental design in materials education

    Science.gov (United States)

    Weiser, Martin W.

    1993-01-01

    Some of the advantages and disadvantages of the Taguchi Method of experimental design as applied to Materials Science will be discussed. This is a fractional factorial method that employs the minimum number of experimental trials for the information obtained. The analysis is also very simple to use and teach, which is quite advantageous in the classroom. In addition, the Taguchi loss function can be easily incorporated to emphasize that improvements in reproducibility are often at least as important as optimization of the response. The disadvantages of the Taguchi Method include the fact that factor interactions are normally not accounted for, there are zero degrees of freedom if all of the possible factors are used, and randomization is normally not used to prevent environmental biasing. In spite of these disadvantages it is felt that the Taguchi Method is extremely useful for both teaching experimental design and as a research tool, as will be shown with a number of brief examples.

  11. Electron scattering by molecules. II - Experimental methods and data

    Science.gov (United States)

    Trajmar, S.; Chutjian, A.; Register, D. F.

    1983-01-01

    Experimental techniques for measuring electron-molecule collision cross sections are briefly summarized. A survey of the available experimental cross section data is presented. The emphasis here is on elastic scattering, rotational, vibrational and electronic excitations, total electron scattering, and momentum transfer in the few eV to few hundred eV impact energy range. Reference is made to works concerned with high energy electron scattering, innershell and multi-electron excitations, conicidence methods and electron scattering in laser fields.

  12. Experimental Methods for the Analysis of Optimization Algorithms

    DEFF Research Database (Denmark)

    of solution quality, runtime and other measures; and the third part collects advanced methods from experimental design for configuring and tuning algorithms on a specific class of instances with the goal of using the least amount of experimentation. The contributor list includes leading scientists...... in algorithm design, statistical design, optimization and heuristics, and most chapters provide theoretical background and are enriched with case studies. This book is written for researchers and practitioners in operations research and computer science who wish to improve the experimental assessment...

  13. New experimental and analysis methods in I-DLTS

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, S.U.; Middelkamp, P.; Li, Z.; Eremin, V.

    1998-02-01

    A new experimental apparatus to perform I-DLTS measurements is presented. The method is shown to be faster and more sensitive than traditional double boxcar I-DLTS systems. A novel analysis technique utilizing multiple exponential fits to the I-DLTS signal from a highly neutron irradiated silicon sample is presented with a discussion of the results. It is shown that the new method has better resolution and can deconvolute overlapping peaks more accurately than previous methods.

  14. Experimental methods for phase equilibria at high pressures.

    Science.gov (United States)

    Dohrn, Ralf; Fonseca, José M S; Peper, Stephanie

    2012-01-01

    Knowledge of high-pressure phase equilibria is crucial in many fields, e.g., for the design and optimization of high-pressure chemical and separation processes, carbon capture and storage, hydrate formation, applications of ionic liquids, and geological processes. This review presents the variety of methods to measure phase equilibria at high pressures and, following a classification, discusses the measurement principles, advantages, challenges, and error sources. Examples of application areas are given. A detailed knowledge and understanding of the different methods is fundamental not only for choosing the most suitable method for a certain task but also for the evaluation of experimental data. The discrepancy between the (sometimes low) true accuracy of published experimental data and the (high) accuracy claimed by authors is addressed. Some essential requirements for the generation of valuable experimental results are summarized.

  15. Estimation of water-coal surface interaction during heat treatment of coal by use of FTir and DSC; FTir to DSC wo mochiita sekitan-mizu kan sogo sayo no teiryoteki hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Miura, K.; Mae, K.; Morozumi, F.; Kusakawa, T. [Kyoto University, Kyoto (Japan)

    1997-10-30

    The authors have recently presented a method to estimate the strength distribution of hydrogen bondings in coal using FTir and DSC. The method was applied to estimate the strength of coal-water interaction in two different coals and to estimate the enthalpy change deriving from the change in hydrogen bondings during the desorption of water. The estimated enthalpy change was compared with the total enthalpy change estimated by DSC measurement to examine the importance of hydrogen bondings during the desertion of water. 1 ref., 6 figs.

  16. Classification of tumor area using combined DCE and DSC MRI in patients with glioblastoma.

    Science.gov (United States)

    Artzi, Moran; Blumenthal, Deborah T; Bokstein, Felix; Nadav, Guy; Liberman, Gilad; Aizenstein, Orna; Ben Bashat, Dafna

    2015-01-01

    This study proposes an automatic method for identification and quantification of different tissue components: the non-enhanced infiltrative tumor, vasogenic edema and enhanced tumor areas, at the subject level, in patients with glioblastoma (GB) based on dynamic contrast enhancement (DCE) and dynamic susceptibility contrast (DSC) MRI. Nineteen MR data sets, obtained from 12 patients with GB, were included. Seven patients were scanned before and 8 weeks following bevacizumab initiation. Segmentation of the tumor area was performed based on the temporal data of DCE and DSC at the group-level using k-means algorithm, and further at the subject-level using support vector machines algorithm. The obtained components were associated to different tissues types based on their temporal characteristics, calculated perfusion and permeability values and MR-spectroscopy. The method enabled the segmentation of the tumor area into the enhancing permeable component; the non-enhancing hypoperfused component, associated with vasogenic edema; and the non-enhancing hyperperfused component, associated with infiltrative tumor. Good agreement was obtained between the group-level, unsupervised and subject-level, supervised classification results, with significant correlation (r = 0.93, p DSC can be used to differentiate between vasogenic edema and infiltrative tumors in patients with GB, which is of major clinical importance in therapy response assessment.

  17. Experimental Methods in Psychology and Cognitive and Affective Neuroscience

    DEFF Research Database (Denmark)

    Habekost, Thomas; Nielsen, Julie Hassing

    2014-01-01

    Laboratory experiments have always been important in psychology and are as commonly used today as ever due to the dominating position of cognitive research in international psychology. This trend has been further strengthened by recent developments in cognitive neuroscience, where experimental st...... studies are central. Recently, experimental studies within the field of affective neuroscience have also received attention. Notwithstanding, experimental methods remain controversial also in psychology, and one should carefully weigh their advantages against their drawbacks.......Laboratory experiments have always been important in psychology and are as commonly used today as ever due to the dominating position of cognitive research in international psychology. This trend has been further strengthened by recent developments in cognitive neuroscience, where experimental...

  18. A soil irrigation method for experimental plant growth

    Science.gov (United States)

    Pop, M. N.; Soran, M. L.

    2015-12-01

    An irrigation method developed in order to ensure periodic wetting of several batches of soil, for experimental plant growth, is proposed. An experimental irrigation installation, intended to perform real-time soil moisturizing, by adding known quantities (preset for a certain batch of soil) of aqueous solutions has been built and tested. The prototype installation comprises six miniature pumps for water dosage, each meant to moisturize a batch of soil. Each pump is actuated from the mains power supply, with zero-crossing synchronization. The administrated quantity of aqueous solution is a multiple of the minimum volume, 0.2±0.01 ml of fluid. Due to its structure, the system allows the administration of different aqueous solutions for each batch of soil. Due to its modular construction the experimental installation can be expanded in order to ensure water disposal over an increased number of soil batches and the method may be suited also for micro irrigation systems.

  19. Some Remarks on the Degree of Crystallinity Measured on DSC

    Institute of Scientific and Technical Information of China (English)

    邱高; 唐志廉; 黄南薰

    2001-01-01

    A modified mathematical model based on the melting and recrystallization of an initial distribution of melting temperatures predicts the melting behavior of polymer in differential scanning calorimetry ( DSC ), taking into account of changes in heat of fusion with melting temperature of crystal and average heat capacity of sample. It has been used to analytically prove that the crystallinity measured on a DSC diagram could not be equal to the weight percentage of crystalline state in the initial specimen. The deviation of the measured crystallinity, as observed relevant to the melting and recrystallization processes, is caused by the changes of the heat of fusion with the melting temperature of crystals, as well as the difference of heat capacities of liquld and solid state polymer. Furthermore, upper and lower limits of the deviation have been discussed.

  20. An experimental method for validating compressor valve vibration theory

    NARCIS (Netherlands)

    Habing, R.A.; Peters, M.C.A.M.

    2006-01-01

    This paper presents an experimental method for validating traditional compressor valve theory for unsteady flow conditions. Traditional valve theory considers the flow force acting on the plate and the flow rate as quasi-steady variables. These variables are related via semi-empirical coefficients

  1. An experimental method for validating compressor valve vibration theory

    NARCIS (Netherlands)

    Habing, R.A.; Peters, M.C.A.M.

    2006-01-01

    This paper presents an experimental method for validating traditional compressor valve theory for unsteady flow conditions. Traditional valve theory considers the flow force acting on the plate and the flow rate as quasi-steady variables. These variables are related via semi-empirical coefficients w

  2. Using Propensity Score Methods to Approximate Factorial Experimental Designs

    Science.gov (United States)

    Dong, Nianbo

    2011-01-01

    The purpose of this study is through Monte Carlo simulation to compare several propensity score methods in approximating factorial experimental design and identify best approaches in reducing bias and mean square error of parameter estimates of the main and interaction effects of two factors. Previous studies focused more on unbiased estimates of…

  3. New experimental and analysis methods in I-DLTS

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, S.U. E-mail: sanjeev@bnl.gov; Middelkamp, P.; Li, Z.; Eremin, V

    1999-04-21

    A simple modification to traditional experimental apparatus to perform I-DLTS measurements is presented. This setup is shown to be faster and more sensitive than traditional double boxcar I-DLTS systems. A novel analysis technique utilising multiple exponential fits to the I-DLTS signal from a highly neutron irradiated silicon sample is presented along with a discussion of the results. It is shown that the new method has better resolution and can deconvolute overlapping peaks more accurately than previous methods.

  4. Comparison of dual-echo DSC-MRI- and DCE-MRI-derived contrast agent kinetic parameters.

    Science.gov (United States)

    Quarles, C Chad; Gore, John C; Xu, Lei; Yankeelov, Thomas E

    2012-09-01

    The application of dynamic susceptibility contrast (DSC) MRI methods to assess brain tumors is often confounded by the extravasation of contrast agent (CA). Disruption of the blood-brain barrier allows CA to leak out of the vasculature leading to additional T(1), T(2) and T(2) relaxation effects in the extravascular space, thereby affecting the signal intensity time course in a complex manner. The goal of this study was to validate a dual-echo DSC-MRI approach that separates and quantifies the T(1) and T(2) contributions to the acquired signal and enables the estimation of the volume transfer constant, K(trans), and the volume fraction of the extravascular extracellular space, v(e). To test the validity of this approach, DSC-MRI- and dynamic contrast enhanced (DCE) MRI-derived K(trans) and v(e) estimates were spatially compared in both 9L and C6 rat brain tumor models. A high degree of correlation (concordance correlation coefficients >0.83, Pearson's r>0.84) and agreement was found between the DSC-MRI- and DCE-MRI-derived measurements. These results indicate that dual-echo DSC-MRI can be used to simultaneously extract reliable DCE-MRI kinetic parameters in brain tumors in addition to conventional blood volume and blood flow metrics.

  5. The effects of urea and n-propanol on collagen denaturation: using DSC, circular dicroism and viscosity

    Energy Technology Data Exchange (ETDEWEB)

    Usha, R.; Ramasami, T

    2004-01-30

    The effect of urea and n-propanol on circular dichroism (CD) and viscosity of purified type1 collagen solution at various temperatures and differential scanning calorimetry (DSC) of rat-tail tendon (RTT) collagen fibre have been studied. CD reveals a spectrum with a positive peak at around 220 nm and a negative peak at 200 nm characteristics of collagen triple helix. The molar ellipticity decreases as the concentration of urea increases up to particular concentration (collagen solution treated with 265 {mu}M of urea) and after that it increases (collagen solution treated with 500 {mu}M of urea). There is a linear decrease in molar ellipticity as the concentration of n-propanol increases. Denaturation temperature of urea and n-propanol treated with purified collagen solution has been studied using viscosity method. Additives such as urea and n-propanol decrease the thermal stability of collagen triple helix in solution and in RTT collagen fibre. Thermal helix to coil transition of urea and n-propanol treated collagen depends on the degree of hydration and the concentration of these additives. Thermodynamic parameters such as the peak temperature, enthalpy of activation, and energy of activation for collagen-gelatin transition for native, urea and n-propanol treated RTT collagen fibre has been calculated using DSC. The change in the thermodynamic parameters has been observed for native, urea and n-propanol treated RTT collagen fibres. The experimental results show that the change in the water structure, dehydration and desolvation induced by different additives such as urea and n-propanol on RTT may vary with the type of denaturation.

  6. Experimental Method for Measuring Dust Load on Surfaces in Rooms

    DEFF Research Database (Denmark)

    Lengweiler, Philip; Nielsen, Peter V.; Moser, Alfred

    A new experimental setup to investigate the physical process of dust deposition and resuspension on and from surfaces is introduced. Dust deposition can reduce the airborne dust concentration considerably. As a basis for developing methods to eliminate dust-related problems in rooms......, there is a need for better understanding of the mechanism of dust deposition and resuspension. With the presented experimental setup, the dust load on surfaces in a channel can be measured as a function of the environmental and surface conditions and the type of particles under controlled laboratory conditions....

  7. DSC法测试PCB之Tg的影响因素探讨%Discussion on the influence factors of using DSC to test Tg of PCB

    Institute of Scientific and Technical Information of China (English)

    陈小飞; 方军良

    2013-01-01

    在PCB行业中,DSC法主要用来测定PCB基板的玻璃化转变温度和固化度,运用DSC法测试PCB的Tg时,影响测试结果的因素有很多。文章重点对运用DSC法测试PCB的Tg过程中存在的影响因素分类进行讨论分析。%This paper mainly introduces DSC (differential scanning calorimeter), one of thermal analysis method. In the PCB industry, DSC technology is mainly used to test the glass transition temperature and curing degree of PCB. Using DSC method to test the glass transition temperature of PCB, there are many factors that influence the test result. This paper focuses on discussing and analyzing the influence factors which exists in the process of the test of glass transition temperature of PCB by DSC method.

  8. Experimental methods for the analysis of optimization algorithms

    CERN Document Server

    Bartz-Beielstein, Thomas; Paquete, Luis; Preuss, Mike

    2010-01-01

    In operations research and computer science it is common practice to evaluate the performance of optimization algorithms on the basis of computational results, and the experimental approach should follow accepted principles that guarantee the reliability and reproducibility of results. However, computational experiments differ from those in other sciences, and the last decade has seen considerable methodological research devoted to understanding the particular features of such experiments and assessing the related statistical methods. This book consists of methodological contributions on diffe

  9. ESTIMATION OF THE CRITICAL RATE OF TEMPERATURE INCREASE OF THERMAL EXPLOSION OF NITROCELLULOSE USING NON-ISOTHERMAL DSC

    Institute of Scientific and Technical Information of China (English)

    Rorng-zu Hu; Peng-jiang Guo; Sheng-li Gao; Hai Zhang; Zhi-ming Xia; Bin-ke Ning; Yan Fang; Qi-zhen Shi; Rong Liu

    2003-01-01

    A method of estimating the critical rate of temperature increase of thermal explosion for the first order autocatalytic decomposition reaction system using non-isothermal DSC is presented. Information is obtained on the increasing rate of temperature in nitrocellulose containing 13.54% of nitrogen when the first order autocatalytic decomposition converts into thermal explosion.

  10. Study on the non-isothermal curing kinetics of a polyfurfuryl alcohol bioresin by DSC using different amounts of catalyst

    DEFF Research Database (Denmark)

    Dominguez Toribio, Juan Carlos; Grivel, Jean-Claude; Madsen, Bo

    2012-01-01

    The curing kinetics of a biomass-based polyfurfuryl alcohol resin with three different amounts of catalyst was studied by DSC non-isothermal measurements using seven heating rates. The change of the activation energy of the curing process was obtained by the isoconversional methods of Kissinger...

  11. 索尼DSC-P200数码相机

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    作为面向普通家用的时尚主打机型,索尼DSC-P系列一直保持着相当高的市场份额,在DSC-P150把家用数码相机带到700万像素级后,索尼继续推出了DSC-P150的升级机型DSC-P200。

  12. Experimental Method to Determine Some Physical Properties in Physics Classes

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Pires

    2015-10-01

    Full Text Available ABSTRACT Particle density, gravimetric and volumetric water contents and porosity are important basic concepts to characterize porous systems such as soils. This paper presents a proposal of an experimental method to measure these physical properties, applicable in experimental physics classes, in porous media samples consisting of spheres with the same diameter (monodisperse medium and with different diameters (polydisperse medium. Soil samples are not used given the difficulty of working with this porous medium in laboratories dedicated to teaching basic experimental physics. The paper describes the method to be followed and results of two case studies, one in monodisperse medium and the other in polydisperse medium. The particle density results were very close to theoretical values for lead spheres, whose relative deviation (RD was -2.9 % and +0.1 % RD for the iron spheres. The RD of porosity was also low: -3.6 % for lead spheres and -1.2 % for iron spheres, in the comparison of procedures – using particle and porous medium densities and saturated volumetric water content – and monodisperse and polydisperse media.

  13. Discrimination of approved drugs from experimental drugs by learning methods

    Directory of Open Access Journals (Sweden)

    Li Yixue

    2011-05-01

    Full Text Available Abstract Background To assess whether a compound is druglike or not as early as possible is always critical in drug discovery process. There have been many efforts made to create sets of 'rules' or 'filters' which, it is hoped, will help chemists to identify 'drug-like' molecules from 'non-drug' molecules. However, among the chemical space of the druglike molecules, the minority will be approved drugs. Classifying approved drugs from experimental drugs may be more helpful to obtain future approved drugs. Therefore, discrimination of approved drugs from experimental ones has been done in this paper by analyzing the compounds in terms of existing drugs features and machine learning methods. Results Four methodologies were compared by their performance to classify approved drugs from experimental ones. The best results were obtained by SVM, in which the accuracy is 0.7911, the sensitivity is 0.5929, and the specificity is 0.8743. Based on the results, consensus model was developed to effectively discriminate drugs, which further pushed the correct classification rate up to 0.8517, sensitivity up to 0.7242, specificity up to 0.9352. The applications on the Traditional Chinese Medicine Ingredients Database (TCM-ID tested the methods. Therefore this model has been proven to be a potent tool for identifying drug molecules. Conclusion The studies would have potential applications in the research of combinatorial library design and virtual high throughput screening for drug discovery.

  14. RESEARCH METHODS OF SATURATED VAPOR PRESSURE AND EXPERIMENTAL INSTALLATIONS

    Directory of Open Access Journals (Sweden)

    Kharchenko P. M.

    2015-02-01

    Full Text Available The static method is the most common, because it is applicable for measuring SVP of substances in wide ranges of temperatures and pressures. The essence of the method consists in measuring of vapor pressure in equilibrium with its liquid at a given temperature. Dynamic method is based on measurement of the boiling point of the liquid at a certain pressure. Saturation method of moving gas used in the case when the SVP does not exceed a few mm Hg. The method consists the following: the liquid is passed through the inert gas and saturated with vapor of liquids and then it flows into a cooler where the absorbed vapors are condensed. Knowing the amount of absorbed liquid and gas, as well as their molecular weight, allow us calculate saturated vapor pressure of the liquid. Knudsen effusion method is applicable for the measurement of very low pressures (up to 100 Pa. This method consists in researching of depending between the pressure and volume of saturated steam at a constant temperature. At the point of saturation an isotherm should have a break and turn into a straight line. Chromatographic method is based on complete chromatographic analysis of liquid and calculating the sum of partial pressures of all mixture components. Also, the article has a description of existing experimental installation for these researches and their advantages and disadvantages compared with each other

  15. Experimental Evaluation of RGB-D Visual Odometry Methods

    Directory of Open Access Journals (Sweden)

    Zheng Fang

    2015-03-01

    Full Text Available RGB-D cameras that can provide rich 2D visual and 3D depth information are well suited to the motion estimation of indoor mobile robots. In recent years, several RGBD visual odometry methods that process data from the sensor in different ways have been proposed. This paper first presents a brief review of recently proposed RGBD visual odometry methods, and then presents a detailed analysis and comparison of eight state-of-the-art realtime 6DOF motion estimation methods in a variety of challenging scenarios, with a special emphasis on the trade-off between accuracy, robustness and computation speed. An experimental comparison is conducted using publicly available benchmark datasets and author-collected datasets in various scenarios, including long corridors, illumination changing environments and fast motion scenarios. Experimental results present both quantitative and qualitative differences between these methods and provide some guidelines on how to choose the right algorithm for an indoor mobile robot according to the quality of the RGB-D data and environmental characteristics.

  16. Experimental Evaluation of RGB-D Visual Odometry Methods

    Directory of Open Access Journals (Sweden)

    Zheng Fang

    2015-03-01

    Full Text Available RGB-D cameras that can provide rich 2D visual and 3D depth information are well suited to the motion estimation of indoor mobile robots. In recent years, several RGB-D visual odometry methods that process data from the sensor in different ways have been proposed. This paper first presents a brief review of recently proposed RGB-D visual odometry methods, and then presents a detailed analysis and comparison of eight state-of-the-art real-time 6DOF motion estimation methods in a variety of challenging scenarios, with a special emphasis on the trade-off between accuracy, robustness and computation speed. An experimental comparison is conducted using publicly available benchmark datasets and author-collected datasets in various scenarios, including long corridors, illumination changing environments and fast motion scenarios. Experimental results present both quantitative and qualitative differences between these methods and provide some guidelines on how to choose the right algorithm for an indoor mobile robot according to the quality of the RGB-D data and environmental characteristics.

  17. Profiles in Leadership: Clifton J. Latiolais, MSc, DSc.

    Science.gov (United States)

    White, Sara; Godwin, Harold N; Weber, Robert J

    2013-09-01

    The Director's Forum series is designed to guide pharmacy leaders in establishing patient-centered services in hospitals and health systems. August 2013 marks the 50th anniversary of the publication of the Mirror to Hospital Pharmacy, which was a comprehensive study of pharmacy services in the United States. The late Clifton J. Latiolais, MS, DSc, served as the assistant program director for the study and was a co-author of the Mirror. The late Don E. Francke, MS, DSc, was the lead author of the Mirror and the principal investigator of the federally funded study that reviewed hospital pharmacy services across the United States. The next 2 articles in Director's Forum profile the leadership of Drs. Latiolais and Francke. This article highlights Dr. Latiolais ("Clif") by briefly reviewing his biography and key career accomplishments, describing his leadership philosophy, and translating that philosophy to today's health care challenges. Clif's influence on health system pharmacy serves as an example of effective leadership. This historical perspective on Clif's leadership, as seen through the eyes of those who knew him, provides directors of pharmacy a valuable leadership viewpoint as they develop strategies to enhance patient-centered pharmacy services.

  18. Study on biodegradation process of lignin by FTIR and DSC.

    Science.gov (United States)

    Liu, Yang; Hu, Tianjue; Wu, Zhengping; Zeng, Guangming; Huang, Danlian; Shen, Ying; He, Xiaoxiao; Lai, Mingyong; He, Yibin

    2014-12-01

    The biodegradation process of lignin by Penicillium simplicissimum was studied to reveal the lignin biodegradation mechanisms. The biodegradation products of lignin were detected using Fourier transform infrared spectroscopy (FTIR), UV-Vis spectrophotometer, different scanning calorimeter (DSC), and stereoscopic microscope. The analysis of FTIR spectrum showed the cleavage of various ether linkages (1,365 and 1,110 cm(-1)), oxidation, and demethylation (2,847 cm(-1)) by comparing the different peak values in the corresponding curve of each sample. Moreover, the differences (Tm and ΔHm values) between the DSC curves indirectly verified the FTIR analysis of biodegradation process. In addition, the effects of adding hydrogen peroxide (H2O2) to lignin biodegradation process were analyzed, which indicated that H2O2 could accelerate the secretion of the MnP and LiP and improve the enzymes activity. What is more, lignin peroxidase and manganese peroxidase catalyzed the lignin degradation effectively only when H2O2 was presented.

  19. Experimental Methods for Implementing Graphene Contacts to Finite Bandgap Semiconductors

    DEFF Research Database (Denmark)

    Meyer-Holdt, Jakob

    was a graphene-C60 monolayergraphene vertical transistor named the Carbon Burger. The fabrication of such device proved increasingly difficult to achieve and many experimental methods to handle graphene were implemented and improved in attempt to fabricate the Carbon Burger. In the end, a device platform...... contacts to semiconductor nanowires, more specifically, epitaxially grown InAs nanowires. First, we tried a top down method where CVD graphene was deposited on substrate supported InAs nanowires followed by selective graphene ashing to define graphene electrodes. While electrical contact between...... the nanowires and graphene was achieved, the contact resistance was higher (>100 kΩ) than what is achieved for optimum metal contacts (~5 kΩ). We therefore developed a method to directly grow InAs nanowires on graphitic flakes. This was achieved by using silver seed particles for epitaxial growth of In...

  20. An experimental design method leading to chemical Turing patterns.

    Science.gov (United States)

    Horváth, Judit; Szalai, István; De Kepper, Patrick

    2009-05-08

    Chemical reaction-diffusion patterns often serve as prototypes for pattern formation in living systems, but only two isothermal single-phase reaction systems have produced sustained stationary reaction-diffusion patterns so far. We designed an experimental method to search for additional systems on the basis of three steps: (i) generate spatial bistability by operating autoactivated reactions in open spatial reactors; (ii) use an independent negative-feedback species to produce spatiotemporal oscillations; and (iii) induce a space-scale separation of the activatory and inhibitory processes with a low-mobility complexing agent. We successfully applied this method to a hydrogen-ion autoactivated reaction, the thiourea-iodate-sulfite (TuIS) reaction, and noticeably produced stationary hexagonal arrays of spots and parallel stripes of pH patterns attributed to a Turing bifurcation. This method could be extended to biochemical reactions.

  1. An experimental comparison of various methods of nearfield acoustic holography

    Science.gov (United States)

    Chelliah, Kanthasamy; Raman, Ganesh; Muehleisen, Ralph T.

    2017-09-01

    An experimental comparison of four different methods of nearfield acoustic holography (NAH) for planar acoustic sources is presented in this study. The four NAH methods considered in this study are based on: (1) spatial Fourier transform, (2) equivalent sources model, (3) boundary element methods and (4) statistically optimized NAH. Two dimensional measurements were obtained at distances ranging from one-half to sixteen microphone spacings away from a sound source and the NAH methods were used to reconstruct the sound field at the source surface. Reconstructed particle velocity and acoustic pressure fields presented in this study showed that the equivalent sources model based algorithm along with Tikhonov regularization provided the best localization of the sources. Reconstruction errors were found to be smaller for the equivalent sources model based algorithm and the statistically optimized NAH algorithm. The effects of hologram distance on the performance of various algorithms are discussed in detail. The study also compares the computational time required by each algorithm to calculate the reconstruction. Four different regularization parameter choice methods were compared. The L-curve method provided more accurate reconstructions than the generalized cross validation and the Morozov discrepancy principle at larger measurement distances. The performance of fixed parameter regularization was comparable to that of the L-curve method.

  2. STRUCTURAL AND MECHANICAL CHARACTERIZATION OF DEFORMED POLYMER USING CONFOCAL RAMAN MICROSCOPY AND DSC

    Directory of Open Access Journals (Sweden)

    Birgit Neitzel

    2016-02-01

    Full Text Available Polymers have various interesting properties, which depend largely on their inner structure. One way to influence the macroscopic behaviour is the deformation of the polymer chains, which effects the change in microstructure. For analyzing the microstructure of non-deformed and deformed polymer materials, Raman spectroscopy as well as differential scanning calorimetry (DSC were used. In the present study we compare the results for crystallinity measurements of deformed polymers using both methods in order to characterize the differences in micro-structure due to deformation. The study is ongoing, and we present the results of the first tests.

  3. DSC study on the undercooling of droplet solidification of metal melt

    Institute of Scientific and Technical Information of China (English)

    GUAN Wanbing; GAO Yulai; ZHAI Qijie; XU Kuangdi

    2005-01-01

    In this paper, the influence of cooling rate on the undercooling of droplet solidification of metal melt has been investigated by employing the differential scanning calorimetry (DSC) method. The effect of cooling rate on the undercooling as well as its change tendency is analyzed theoretically. It is shown that the undercooling degree increases whereas the change rate of undercooling decreases with increasing cooling rate. Moreover, the change tendency approaches zero when the cooling rate exceedingly increased, indicating that an extremum of undercooling exists with increasing cooling rate.

  4. Cerebral perfusion alterations in epileptic patients during peri-ictal and post-ictal phase: PASL vs DSC-MRI.

    Science.gov (United States)

    Pizzini, Francesca B; Farace, Paolo; Manganotti, Paolo; Zoccatelli, Giada; Bongiovanni, Luigi G; Golay, Xavier; Beltramello, Alberto; Osculati, Antonio; Bertini, Giuseppe; Fabene, Paolo F

    2013-07-01

    Non-invasive pulsed arterial spin labeling (PASL) MRI is a method to study brain perfusion that does not require the administration of a contrast agent, which makes it a valuable diagnostic tool as it reduces cost and side effects. The purpose of the present study was to establish the viability of PASL as an alternative to dynamic susceptibility contrast (DSC-MRI) and other perfusion imaging methods in characterizing changes in perfusion patterns caused by seizures in epileptic patients. We evaluated 19 patients with PASL. Of these, the 9 affected by high-frequency seizures were observed during the peri-ictal period (within 5hours since the last seizure), while the 10 patients affected by low-frequency seizures were observed in the post-ictal period. For comparison, 17/19 patients were also evaluated with DSC-MRI and CBF/CBV. PASL imaging showed focal vascular changes, which allowed the classification of patients in three categories: 8 patients characterized by increased perfusion, 4 patients with normal perfusion and 7 patients with decreased perfusion. PASL perfusion imaging findings were comparable to those obtained by DSC-MRI. Since PASL is a) sensitive to vascular alterations induced by epileptic seizures, b) comparable to DSC-MRI for detecting perfusion asymmetries, c) potentially capable of detecting time-related perfusion changes, it can be recommended for repeated evaluations, to identify the epileptic focus, and in follow-up and/or therapy-response assessment.

  5. Optimal experimental design with the sigma point method.

    Science.gov (United States)

    Schenkendorf, R; Kremling, A; Mangold, M

    2009-01-01

    Using mathematical models for a quantitative description of dynamical systems requires the identification of uncertain parameters by minimising the difference between simulation and measurement. Owing to the measurement noise also, the estimated parameters possess an uncertainty expressed by their variances. To obtain highly predictive models, very precise parameters are needed. The optimal experimental design (OED) as a numerical optimisation method is used to reduce the parameter uncertainty by minimising the parameter variances iteratively. A frequently applied method to define a cost function for OED is based on the inverse of the Fisher information matrix. The application of this traditional method has at least two shortcomings for models that are nonlinear in their parameters: (i) it gives only a lower bound of the parameter variances and (ii) the bias of the estimator is neglected. Here, the authors show that by applying the sigma point (SP) method a better approximation of characteristic values of the parameter statistics can be obtained, which has a direct benefit on OED. An additional advantage of the SP method is that it can also be used to investigate the influence of the parameter uncertainties on the simulation results. The SP method is demonstrated for the example of a widely used biological model.

  6. The Assessment of Experimental Methods of Serial Number Restoration

    Science.gov (United States)

    Argo, Mackenzie

    Serial number restoration is a common and successful process of revealing obliterated serial numbers on firearms. In a crime laboratory setting, obliterated serial numbers are commonly processed in order to tie a person to a crime scene or provide an investigative lead for officers. Currently serial numbers are restored using a chemical etchant method that can eat away at the metal on the firearm even after the examination is complete. It can also take several hours to complete and only provide an examiner with a partial number. There are other nondestructive options however little to no literature is available. The purpose of this study is to discover new methods for nondestructive serial number restoration and to compare them to the traditional chemical method used. Metal bars of premeasured obliteration depths and different compositions were examined using three proposed experimental methods: near infrared imaging, cold frost, and scanning acoustic microscopy. Results did not indicate significant difference in the median number of visible digits recovered for each of the three proposed methods compared to the traditional chemical method. There were significant results in the median number of composition utilized and depth of obliteration. This indicates that different firearm compositions and depth of obliteration has an effect on serial number restoration.

  7. Overriding "doing wrong" and "not doing right": validation of the Dispositional Self-Control Scale (DSC).

    Science.gov (United States)

    Ein-Gar, Danit; Sagiv, Lilach

    2014-01-01

    We present the Dispositional Self-Control (DSC) Scale, which reflects individuals' tendency to override 2 types of temptations, termed doing wrong and not doing right. We report a series of 5 studies designed to test the reliability and validity of the scale. As hypothesized, high DSC predicts distant future orientation and low DSC predicts deviant behaviors such as aggression, alcohol misuse, and aberrant driving. DSC also predicts task performance among resource-depleted participants. Taken together, these findings suggest that the DSC Scale could be a useful tool toward further understanding the role of personality in overcoming self-control challenges.

  8. 自我增值这选:Sony DSC-F717

    Institute of Scientific and Technical Information of China (English)

    高飞

    2002-01-01

    近年的10月都是Sony推出旗舰级数码相机的日子,2000年的DSC-505v、2001年的DSC-F707,2002年有这部终极强化版的DSC-F717。改用回DSC-F505银色机身的F717,外形与DSC-F707无甚分别。不过,在机能上则作出了自我增值!

  9. Experimental evaluation of the certification-trail method

    Science.gov (United States)

    Sullivan, Gregory F.; Wilson, Dwight S.; Masson, Gerald M.; Itoh, Mamoru; Smith, Warren W.; Kay, Jonathan S.

    1993-01-01

    Certification trails are a recently introduced and promising approach to fault-detection and fault-tolerance. A comprehensive attempt to assess experimentally the performance and overall value of the method is reported. The method is applied to algorithms for the following problems: huffman tree, shortest path, minimum spanning tree, sorting, and convex hull. Our results reveal many cases in which an approach using certification-trails allows for significantly faster overall program execution time than a basic time redundancy-approach. Algorithms for the answer-validation problem for abstract data types were also examined. This kind of problem provides a basis for applying the certification-trail method to wide classes of algorithms. Answer-validation solutions for two types of priority queues were implemented and analyzed. In both cases, the algorithm which performs answer-validation is substantially faster than the original algorithm for computing the answer. Next, a probabilistic model and analysis which enables comparison between the certification-trail method and the time-redundancy approach were presented. The analysis reveals some substantial and sometimes surprising advantages for ther certification-trail method. Finally, the work our group performed on the design and implementation of fault injection testbeds for experimental analysis of the certification trail technique is discussed. This work employs two distinct methodologies, software fault injection (modification of instruction, data, and stack segments of programs on a Sun Sparcstation ELC and on an IBM 386 PC) and hardware fault injection (control, address, and data lines of a Motorola MC68000-based target system pulsed at logical zero/one values). Our results indicate the viability of the certification trail technique. It is also believed that the tools developed provide a solid base for additional exploration.

  10. 鼻咽癌放射治疗后“正常脑白质”的DTI及DSC-PWI研究%DTI and DSC-PWI on normal appearing white matter after radiotherapy for nasopharyngeal carcinoma

    Institute of Scientific and Technical Information of China (English)

    冯霞; 邱士军

    2013-01-01

    Objective To detect the changes of temporal lobes white mater after radiation therapy (RT) for nasopharyngeal carcinoma (NPC) using diffusion tensor imaging (DTI) and dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI).Methods The study included 32 subjects,who had or had not undergone radiotherapy for nasopharyngeal carcinoma of these,16 were pre-treatment patients; the remaining 16 were post-radiation patients.The pre-radiation subjects constituted the control group.The post-radiation patients,who had undergone radiation therapy less than 6 months prior,representing an acute response in the early period after radiation therapy,were the experimental group.There were no statistically significant differences between the groups with respect to age,gender,duration of education,cigarette smoking or alcohol consumption.DTI and DSC-PWI were performed for each subject.After data post-processing,the mean fractional anisotropy (FA),axial diffusivity (λ |),radial diffusivity (λ⊥) and relative celebral blood flow (rCBF) were calculated in bilateral temporal lobe.To find the layer of cerebral peduncle,one ROI was then marked on unilateral temporal lobe white matter in each subject.These ROIs were of equal area.The average of these values in the temporal lobes white matter was accepted as the final value.For all the data,two-sample t-test was performed.Results FA value and λ| decreased significantly in the post-radiation group compared to the pre-radiation group; λ⊥ increased significantly in the post-radiation group compared to the pre-radiation group; rCBF decreased significantly in the post-radiation group compared to the pre-radiation group.Conclusion The results of the present study illustrated micro injury of nerve tissue and blood vessel can be detected by DTI and DSC-PWI.Vascular damage and the resulting decrease in blood flow may participant in neural tissue injury in the early stage after radiotherapy.%目的 探讨鼻咽癌放

  11. Experimental validation of boundary element methods for noise prediction

    Science.gov (United States)

    Seybert, A. F.; Oswald, Fred B.

    1992-01-01

    Experimental validation of methods to predict radiated noise is presented. A combined finite element and boundary element model was used to predict the vibration and noise of a rectangular box excited by a mechanical shaker. The predicted noise was compared to sound power measured by the acoustic intensity method. Inaccuracies in the finite element model shifted the resonance frequencies by about 5 percent. The predicted and measured sound power levels agree within about 2.5 dB. In a second experiment, measured vibration data was used with a boundary element model to predict noise radiation from the top of an operating gearbox. The predicted and measured sound power for the gearbox agree within about 3 dB.

  12. Theoretical and experimental physical methods of neutron-capture therapy

    Science.gov (United States)

    Borisov, G. I.

    2011-09-01

    This review is based to a substantial degree on our priority developments and research at the IR-8 reactor of the Russian Research Centre Kurchatov Institute. New theoretical and experimental methods of neutron-capture therapy are developed and applied in practice; these are: A general analytical and semi-empiric theory of neutron-capture therapy (NCT) based on classical neutron physics and its main sections (elementary theories of moderation, diffuse, reflection, and absorption of neutrons) rather than on methods of mathematical simulation. The theory is, first of all, intended for practical application by physicists, engineers, biologists, and physicians. This theory can be mastered by anyone with a higher education of almost any kind and minimal experience in operating a personal computer.

  13. Literature in Focus: Statistical Methods in Experimental Physics

    CERN Multimedia

    2007-01-01

    Frederick James was a high-energy physicist who became the CERN "expert" on statistics and is now well-known around the world, in part for this famous text. The first edition of Statistical Methods in Experimental Physics was originally co-written with four other authors and was published in 1971 by North Holland (now an imprint of Elsevier). It became such an important text that demand for it has continued for more than 30 years. Fred has updated it and it was released in a second edition by World Scientific in 2006. It is still a top seller and there is no exaggeration in calling it «the» reference on the subject. A full review of the title appeared in the October CERN Courier.Come and meet the author to hear more about how this book has flourished during its 35-year lifetime. Frederick James Statistical Methods in Experimental Physics Monday, 26th of November, 4 p.m. Council Chamber (Bldg. 503-1-001) The author will be introduced...

  14. Experimental facility and void fraction calibration methods for impedance probes

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Fernando L. de; Rocha, Marcelo S., E-mail: floliveira@ipen.br, E-mail: msrocha@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    An experimental facility was designed and constructed with aims of to calibrate a capacitance probe for gas-liquid flow void fraction measurements. The facility is composed of a metallic hack with a vertical 2,300 mm high glass tube with 38 mm ID with stagnant water and compressed air bubbling system simulating the gas phase (vapor). At the lower part, a mixing section with a porous media element releases the air bubbles into the water, and the compressed air flow is measured by two calibrated rotameters. At the upper part a stagnant water tank separates the liquid and gas. Two pressure taps are located near the lower and upper sides of the glass tube for pressure difference measurement. The pressure difference is used for low void fraction values (0-15%) calibration methods, as described in the work. Two electrically controlled quick closing valves are installed between the porous media element and the upward separation tank for high void fraction values measurement (15-50%) used to calibrate the capacitance probe. The experimental facility design, construction, capacitance probe calibration methods and results, as well as flow pattern visualization, are presented. Finally, the capacitance probe will be installed on a natural circulation circuit mounted at the Nuclear Engineering Center (CEN/IPEN/CNEN-SP) for measurement of the instantaneous bulk void. Instantaneous signals generated by the capacitance probe will allow the determination of natural circulation loop global energy balance. (author)

  15. Drug-polymer interaction between glucosamine sulfate and alginate nanoparticles: FTIR, DSC and dielectric spectroscopy studies

    Science.gov (United States)

    El-Houssiny, A. S.; Ward, A. A.; Mostafa, D. M.; Abd-El-Messieh, S. L.; Abdel-Nour, K. N.; Darwish, M. M.; Khalil, W. A.

    2016-06-01

    This work involves the preparation and characterization of alginate nanoparticles (Alg NPs) as a new transdermal carrier for site particular transport of glucosamine sulfate (GS). The GS-Alg NPs were examined through transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and dielectric spectroscopy. GS-Alg NPs was efficiently prepared via ionic gelation method which generates favorable conditions for the entrapment of hydrophilic drugs. The TEM studies revealed that GS-Alg NPs are discrete and have spherical shapes. FTIR studies showed a spectral change of the characteristic absorptions bands of Alg NPs after encapsulation with GS because of the amine groups of GS and the carboxylic acid groups of Alg. The DSC data showed changes in the thermal behavior of GS-Alg NPs after the addition of GS indicating signs of main chemical interaction among the drug (GS) and the polymer (Alg). The absence of the drug melting endothermic peak within the DSC thermogram of GS-Alg NPs indicating that GS is molecularly dispersed in the NPs and not crystallize. From the dielectric study, it was found modifications within the dielectric loss (ɛ″) and conductivity (σ) values after the addition of GS. The ɛ″ and σ values of Alg NPs decreased after the addition of GS which indicated the successful encapsulation of GS within Alg NPs. Furthermore, the dielectric study indicated an increase of the activation energy and the relaxation time for the first process in the GS-Alg NPs as compared to Alg NPs. Consequently, the existing observations indicated an initiation of electrostatic interaction among the amine group of GS and carboxyl group of Alg indicating the successful encapsulation of GS inside Alg NPs which could provide favorable circumstance for the encapsulation of GS for topical management.

  16. Experimental Investigation of Low-Cost Cooling Methods

    Science.gov (United States)

    Mazumder, M.

    2016-12-01

    An estimated 1.2 billion people in the world do not have access to constant supply of electricity. The goal of this research project is experimental investigation of cooling mechanisms for low cost refrigeration without constant supply of electricity. Experimental investigations were performed in 3 separate phases: 1) We first tested common literature method of evaporative cooling mechanism of the pot-in-pot refrigeration system, developed by Mohammed Bah Abba. Experiments showed that the cooling power of the original system is theoretically limited to the wet bulb temperature, and in an environment with 70º F ambient temperature, cooling never exceeded 7-8 degrees. 2) Next, we conducted an experimental study of heat transfer processes through the use of a simple glass model. The results of the glass model showed that thorough insulation and ice were crucial to improving cooling. Hence, we incorporated the use of ice and insulating fabrics in the system. This improved the existing methods by 2x but required much maintenance, with constant watering of sand and replacement of ice packs. Our next set of experiments with a 60-liter clay pot filled with water and 3.5-8 kg ice blocks showed that more than 20 degree cooling can be achieved with moderate amount of ice and insulation for over a few days. 3) Next, we used HOBO temperature sensors, a 60-liter pot, water, ice, and several layers of insulation, and proved that with proper insulation and even just one 8-kg block of ice, the system yielded a greater cooling for over two weeks, with temperatures ranging from 61.8 and 68.9 ºF even when the ambient temperature was as high as 109º F. The temperature inside the system stayed relatively constant, with changes only corresponding to day and night. Additional experimentation showed that initial cooling was proportional to the amount of ice put in the system, and thus with double the ice, temperatures could reach as low as 34.9 ºF. This research proves that the

  17. DSC analysis of irradiated proteins from Crotalus durissus terrificus

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Karina Corleto de; Silva, Monica Nascimento da; Goncalves, Karina de Oliveira; Spencer, Patrick Jack; Nascimento, Nanci do [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Full text: Snake bites are a serious public health problem, especially in subtropical countries. In Brazil, the serum, the only effective treatment in case of snake bites, is produced in horses which, despite the large size, have a reduced lifespan due to the high toxicity of the antigen. It is known that ionizing radiation effects - direct and indirect - can modify the molecular structure, affecting the biological properties of proteins. Ionizing radiation has been employed to attenuate the toxicity of snake venoms, aiming to generate an improved antigen with low toxicity. Two proteins, purified from Crotalus durissus terrificus (Cdt) venom were tested in this work: crotoxin and crotamine. Crotoxin, the main toxic compound of Cdt venom, is a heterodimeric protein composed of two subunits: crotapotin and phospholipase A2. Crotamine is a highly basic polypeptide (pI - 10.3), with myotoxic activity and molecular weight of 4882 Da. It is composed of 42 amino acids residues and reticulated by three disulfide bonds. This study aimed to investigate the effects of radiation on crotoxin and crotamine using Differential Scanning Calorimetry (DSC). After isolation of the toxins by chromatographic techniques, they were irradiated with 2.0 kGy from {sup 60}Co source. The thermodynamics analysis, carried out in a METTLER TOLEDO, DSC 822e calorimeter, showed that irradiation promoted changes of the calorimetric profile. These changes suggest that, although radiation induced structural modifications of the protein, denaturation was only partial, since transition states could still be detected, suggesting that some structural elements were still present after irradiation. Taken together, our data suggest that following irradiation, the molecules underwent conformational changes, and that the remaining structural elements displayed a lower enthalpy, clearly indicating that the previously described loss of toxicity of irradiated toxins can be mostly ascribed to structural changes

  18. Decentralized Adaptive Neural Output-Feedback DSC for Switched Large-Scale Nonlinear Systems.

    Science.gov (United States)

    Long, Lijun; Zhao, Jun

    2016-03-08

    In this paper, for a class of switched large-scale uncertain nonlinear systems with unknown control coefficients and unmeasurable states, a switched-dynamic-surface-based decentralized adaptive neural output-feedback control approach is developed. The approach proposed extends the classical dynamic surface control (DSC) technique for nonswitched version to switched version by designing switched first-order filters, which overcomes the problem of multiple ``explosion of complexity.'' Also, a dual common coordinates transformation of all subsystems is exploited to avoid individual coordinate transformations for subsystems that are required when applying the backstepping recursive design scheme. Nussbaum-type functions are utilized to handle the unknown control coefficients, and a switched neural network observer is constructed to estimate the unmeasurable states. Combining with the average dwell time method and backstepping and the DSC technique, decentralized adaptive neural controllers of subsystems are explicitly designed. It is proved that the approach provided can guarantee the semiglobal uniformly ultimately boundedness for all the signals in the closed-loop system under a class of switching signals with average dwell time, and the tracking errors to a small neighborhood of the origin. A two inverted pendulums system is provided to demonstrate the effectiveness of the method proposed.

  19. The slow relaxation dynamics in active pharmaceutical ingredients studied by DSC and TSDC: Voriconazole, miconazole and itraconazole.

    Science.gov (United States)

    Ramos, Joaquim J Moura; Diogo, Hermínio P

    2016-03-30

    The slow molecular mobility of three active pharmaceutical drugs (voriconazole, miconazole and itraconazole) has been studied by differential scanning calorimetry (DSC) and thermally stimulated depolarization currents (TSDC). This study yielded the main kinetic features of the secondary relaxations and of the main (glass transition) relaxation, in particular their distribution of relaxation times. The dynamic fragility of the three glass formers was determined from DSC data (using two different procedures) and from TSDC data. According to our results voriconazole behaves as a relatively strong liquid, while miconazole is moderately fragile and itraconazole is a very fragile liquid. There are no studies in this area published in the literature relating to voriconazole. Also not available in the literature is a slow mobility study by dielectric relaxation spectroscopy in the amorphous miconazole. Apart from that, the results obtained are in reasonable agreement with published works using different experimental techniques. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Experimental and Theoretical Methods in Algebra, Geometry and Topology

    CERN Document Server

    Veys, Willem; Bridging Algebra, Geometry, and Topology

    2014-01-01

    Algebra, geometry and topology cover a variety of different, but intimately related research fields in modern mathematics. This book focuses on specific aspects of this interaction. The present volume contains refereed papers which were presented at the International Conference “Experimental and Theoretical Methods in Algebra, Geometry and Topology”, held in Eforie Nord (near Constanta), Romania, during 20-25 June 2013. The conference was devoted to the 60th anniversary of the distinguished Romanian mathematicians Alexandru Dimca and Ştefan Papadima. The selected papers consist of original research work and a survey paper. They are intended for a large audience, including researchers and graduate students interested in algebraic geometry, combinatorics, topology, hyperplane arrangements and commutative algebra. The papers are written by well-known experts from different fields of mathematics, affiliated to universities from all over the word, they cover a broad range of topics and explore the research f...

  1. Experimental Data Mining Techniques(Using Multiple Statistical Methods

    Directory of Open Access Journals (Sweden)

    Mustafa Zaidi

    2012-05-01

    Full Text Available This paper discusses the possible solutions of non-linear multivariable by experimental Data mining techniques using on orthogonal array. Taguchi method is a very useful technique to reduce the time and cost of the experiment but the ignoring all kind of interaction effects. The results are not much encouraging and motivate to study Laser cutting process of non-linear multivariable is modeled by one and two way analysis of variance also linear and non linear regression analysis. These techniques are used to explore better analysis techniques and improve the laser cutting quality by reducing process variations caused by controllable process parameters. The size of data set causes difficulties in modeling and simulation of the problem such as decision tree is useful technique but it is not able to predict better results. The results of analysis of variance are encouraging. Taguchi and regression normally optimizes input process parameters for single characteristics.

  2. Experimental Methods for Implementing Graphene Contacts to Finite Bandgap Semiconductors

    DEFF Research Database (Denmark)

    Meyer-Holdt, Jakob

    for molecular electronics with parallel CVD graphene bottom electrodes with SiO2 passivation was successfully fabricated and electronically characterized. A functioning Carbon Burger was not achieved. Along the work on the Carbon Burger, the scope was broadened and focus was put on implementing graphene......Present Ph.D. thesis describes my work on implanting graphene as electrical contact to finite bandgap semiconductors. Different transistor architectures, types of graphene and finite bandgap semiconductors have been employed. The device planned from the beginning of my Ph.D. fellowship...... was a graphene-C60 monolayergraphene vertical transistor named the Carbon Burger. The fabrication of such device proved increasingly difficult to achieve and many experimental methods to handle graphene were implemented and improved in attempt to fabricate the Carbon Burger. In the end, a device platform...

  3. Experimental Methods for UAV Aerodynamic and Propulsion Performance Assessment

    Directory of Open Access Journals (Sweden)

    Stefan ANTON

    2015-06-01

    Full Text Available This paper presents an experimental method for assessing the performances and the propulsion power of a UAV in several points based on telemetry. The points in which we make the estimations are chosen based on several criteria and the fallowing parameters are measured: airspeed, time-to-climb, altitude and the horizontal distance. With the estimated propulsion power and knowing the shaft motor power, the propeller efficiency is determined at several speed values. The shaft motor power was measured in the lab using the propeller as a break. Many flights, using the same UAV configuration, were performed before extracting flight data, in order to reduce the instrumental or statistic errors. This paper highlights both the methodology of processing the data and the validation of theoretical results.

  4. Experimental methods of molecular matter-wave optics.

    Science.gov (United States)

    Juffmann, Thomas; Ulbricht, Hendrik; Arndt, Markus

    2013-08-01

    We describe the state of the art in preparing, manipulating and detecting coherent molecular matter. We focus on experimental methods for handling the quantum motion of compound systems from diatomic molecules to clusters or biomolecules.Molecular quantum optics offers many challenges and innovative prospects: already the combination of two atoms into one molecule takes several well-established methods from atomic physics, such as for instance laser cooling, to their limits. The enormous internal complexity that arises when hundreds or thousands of atoms are bound in a single organic molecule, cluster or nanocrystal provides a richness that can only be tackled by combining methods from atomic physics, chemistry, cluster physics, nanotechnology and the life sciences.We review various molecular beam sources and their suitability for matter-wave experiments. We discuss numerous molecular detection schemes and give an overview over diffraction and interference experiments that have already been performed with molecules or clusters.Applications of de Broglie studies with composite systems range from fundamental tests of physics up to quantum-enhanced metrology in physical chemistry, biophysics and the surface sciences.Nanoparticle quantum optics is a growing field, which will intrigue researchers still for many years to come. This review can, therefore, only be a snapshot of a very dynamical process.

  5. Interaction of formin FH2 with skeletal muscle actin. EPR and DSC studies.

    Science.gov (United States)

    Kupi, Tünde; Gróf, Pál; Nyitrai, Miklós; Belágyi, József

    2013-10-01

    Formins are highly conserved proteins that are essential in the formation and regulation of the actin cytoskeleton. The formin homology 2 (FH2) domain is responsible for actin binding and acts as an important nucleating factor in eukaryotic cells. In this work EPR and DSC were used to investigate the properties of the mDia1-FH2 formin fragment and its interaction with actin. MDia1-FH2 was labeled with a maleimide spin probe (MSL). EPR results suggested that the MSL was attached to a single SH group in the FH2. In DSC and temperature-dependent EPR experiments we observed that mDia1-FH2 has a flexible structure and observed a major temperature-induced conformational change at 41 °C. The results also confirmed the previous observation obtained by fluorescence methods that formin binding can destabilize the structure of actin filaments. In the EPR experiments the intermolecular connection between the monomers of formin dimers proved to be flexible. Considering the complex molecular mechanisms underlying the cellular roles of formins this internal flexibility of the dimers is probably important for manifestation of their biological functions.

  6. Optical bandgap of semiconductor nanostructures: Methods for experimental data analysis

    Science.gov (United States)

    Raciti, R.; Bahariqushchi, R.; Summonte, C.; Aydinli, A.; Terrasi, A.; Mirabella, S.

    2017-06-01

    Determination of the optical bandgap (Eg) in semiconductor nanostructures is a key issue in understanding the extent of quantum confinement effects (QCE) on electronic properties and it usually involves some analytical approximation in experimental data reduction and modeling of the light absorption processes. Here, we compare some of the analytical procedures frequently used to evaluate the optical bandgap from reflectance (R) and transmittance (T) spectra. Ge quantum wells and quantum dots embedded in SiO2 were produced by plasma enhanced chemical vapor deposition, and light absorption was characterized by UV-Vis/NIR spectrophotometry. R&T elaboration to extract the absorption spectra was conducted by two approximated methods (single or double pass approximation, single pass analysis, and double pass analysis, respectively) followed by Eg evaluation through linear fit of Tauc or Cody plots. Direct fitting of R&T spectra through a Tauc-Lorentz oscillator model is used as comparison. Methods and data are discussed also in terms of the light absorption process in the presence of QCE. The reported data show that, despite the approximation, the DPA approach joined with Tauc plot gives reliable results, with clear advantages in terms of computational efforts and understanding of QCE.

  7. A projection method for under determined optimal experimental designs

    KAUST Repository

    Long, Quan

    2014-01-09

    A new implementation, based on the Laplace approximation, was developed in (Long, Scavino, Tempone, & Wang 2013) to accelerate the estimation of the post–experimental expected information gains in the model parameters and predictive quantities of interest. A closed–form approximation of the inner integral and the order of the corresponding dominant error term were obtained in the cases where the parameters are determined by the experiment. In this work, we extend that method to the general cases where the model parameters could not be determined completely by the data from the proposed experiments. We carry out the Laplace approximations in the directions orthogonal to the null space of the corresponding Jacobian matrix, so that the information gain (Kullback–Leibler divergence) can be reduced to an integration against the marginal density of the transformed parameters which are not determined by the experiments. Furthermore, the expected information gain can be approximated by an integration over the prior, where the integrand is a function of the projected posterior covariance matrix. To deal with the issue of dimensionality in a complex problem, we use Monte Carlo sampling or sparse quadratures for the integration over the prior probability density function, depending on the regularity of the integrand function. We demonstrate the accuracy, efficiency and robustness of the proposed method via several nonlinear under determined numerical examples.

  8. Advances in simultaneous DSC-FTIR microspectroscopy for rapid solid-state chemical stability studies: some dipeptide drugs as examples.

    Science.gov (United States)

    Lin, Shan-Yang; Wang, Shun-Li

    2012-04-01

    The solid-state chemistry of drugs has seen growing importance in the pharmaceutical industry for the development of useful API (active pharmaceutical ingredients) of drugs and stable dosage forms. The stability of drugs in various solid dosage forms is an important issue because solid dosage forms are the most common pharmaceutical formulation in clinical use. In solid-state stability studies of drugs, an ideal accelerated method must not only be selected by different complicated methods, but must also detect the formation of degraded product. In this review article, an analytical technique combining differential scanning calorimetry and Fourier-transform infrared (DSC-FTIR) microspectroscopy simulates the accelerated stability test, and simultaneously detects the decomposed products in real time. The pharmaceutical dipeptides aspartame hemihydrate, lisinopril dihydrate, and enalapril maleate either with or without Eudragit E were used as testing examples. This one-step simultaneous DSC-FTIR technique for real-time detection of diketopiperazine (DKP) directly evidenced the dehydration process and DKP formation as an impurity common in pharmaceutical dipeptides. DKP formation in various dipeptides determined by different analytical methods had been collected and compiled. Although many analytical methods have been applied, the combined DSC-FTIR technique is an easy and fast analytical method which not only can simulate the accelerated drug stability testing but also at the same time enable to explore phase transformation as well as degradation due to thermal-related reactions. This technique offers quick and proper interpretations.

  9. Theoretical and experimental investigation of multispectral photoacoustic osteoporosis detection method

    Science.gov (United States)

    Steinberg, Idan; Hershkovich, Hadas Sara; Gannot, Israel; Eyal, Avishay

    2014-03-01

    Osteoporosis is a widespread disorder, which has a catastrophic impact on patients lives and overwhelming related to healthcare costs. Recently, we proposed a multispectral photoacoustic technique for early detection of osteoporosis. Such technique has great advantages over pure ultrasonic or optical methods as it allows the deduction of both bone functionality from the bone absorption spectrum and bone resistance to fracture from the characteristics of the ultrasound propagation. We demonstrated the propagation of multiple acoustic modes in animal bones in-vitro. To further investigate the effects of multiple wavelength excitations and of induced osteoporosis on the PA signal a multispectral photoacoustic system is presented. The experimental investigation is based on measuring the interference of multiple acoustic modes. The performance of the system is evaluated and a simple two mode theoretical model is fitted to the measured phase signals. The results show that such PA technique is accurate and repeatable. Then a multiple wavelength excitation is tested. It is shown that the PA response due to different excitation wavelengths revels that absorption by the different bone constitutes has a profound effect on the mode generation. The PA response is measured in single wavelength before and after induced osteoporosis. Results show that induced osteoporosis alters the measured amplitude and phase in a consistent manner which allows the detection of the onset of osteoporosis. These results suggest that a complete characterization of the bone over a region of both acoustic and optical frequencies might be used as a powerful tool for in-vivo bone evaluation.

  10. Experimental method to predict avalanches based on neural networks

    Directory of Open Access Journals (Sweden)

    V. V. Zhdanov

    2016-01-01

    Full Text Available The article presents results of experimental use of currently available statistical methods to classify the avalanche‑dangerous precipitations and snowfalls in the Kishi Almaty river basin. The avalanche service of Kazakhstan uses graphical methods for prediction of avalanches developed by I.V. Kondrashov and E.I. Kolesnikov. The main objective of this work was to develop a modern model that could be used directly at the avalanche stations. Classification of winter precipitations into dangerous snowfalls and non‑dangerous ones was performed by two following ways: the linear discriminant function (canonical analysis and artificial neural networks. Observational data on weather and avalanches in the gorge Kishi Almaty in the gorge Kishi Almaty were used as a training sample. Coefficients for the canonical variables were calculated by the software «Statistica» (Russian version 6.0, and then the necessary formula had been constructed. The accuracy of the above classification was 96%. Simulator by the authors L.N. Yasnitsky and F.М. Cherepanov was used to learn the neural networks. The trained neural network demonstrated 98% accuracy of the classification. Prepared statistical models are recommended to be tested at the snow‑avalanche stations. Results of the tests will be used for estimation of the model quality and its readiness for the operational work. In future, we plan to apply these models for classification of the avalanche danger by the five‑point international scale.

  11. Pengaruh pengawetan kulit ikan buntal (Arothon reticularis terhadap suhu kerut ditinjau melalui analisis differential scanning calorimeter (DSC

    Directory of Open Access Journals (Sweden)

    RLM. Satrio Ari Wibowo

    2015-12-01

    Full Text Available The aim of this study was to determine the effect of the skin preservation type against shrinkage temperature of leather. The material used in this study was the skin of pufferfish (Arothon reticularis that have been preserved by salting, formaldehyde and pickling and also raw skin as a reference. The method used to measure the shrinkage temperature was thermal analysis using Differential Scanning Calorimeter (DSC that operated from 4°C up to 440°C with nitrogen stream. DSC measurement results showed that shrinkage temperature of puffer fish preserved with formaldehyde was higher than salting and pickling, which is 63.64°C; 47.95°C; 57.37oC respectively. The advantage of using formaldehyde compared to others preservation technique was not only can protect the skin from damage by microorganisms, but also can create a bond with the collagen .

  12. Rheological and DSC study of sol-gel transition in aqueous dispersions of industrially important polymers and colloids

    Energy Technology Data Exchange (ETDEWEB)

    Nishinari, K. [Osaka City Univ. (Japan). Dept. of Food and Nutrition

    1997-12-01

    Gelation kinetics, mechanical spectra, thermal scanning rheology (TSR), and differential scanning calorimetry (DSC) in aqueous solutions of gelling polymers and colloids such as seaweed polysaccharides (agarose, carrageenans), microbial polysaccharides (gellan, curdlan), plant polysaccharides (methylcellulose), globular proteins (casein, glycinin, {beta}-conglycinin), fibrous proteins (gelatin, fibrin), and polyvinyl alcohol, which are related to foods, cosmetics, biomedical and pharmaceutical applications, are described. Some gelation processes at a constant temperature have been treated successfully by an equation of first order kinetics or by other modified equations, and the molecular mechanism of gel formation is discussed briefly. For water-soluble polymers, the criterion of the gel or sol based on the frequency dependence of storage and loss moduli gives valuable informations. TSR and DSC are complementary, and the combination of these methods has been proved to be useful. (orig.) 81 refs.

  13. Crystallization Kinetics of Lithium Aluminum Germanium Phosphate Glass by DSC Technique

    Institute of Scientific and Technical Information of China (English)

    HE Kun; WANG Yanhang; ZU Chengkui; LIU Yonghua; ZHAO Huifeng; HAN Bin; CHENG Jiang

    2012-01-01

    The crystallization kinetics of Li2O-Al2O3-GeO2-P2O5 (LAGP) glass fabricated via the conventional melt-quenching method was studied by differential scanning calorimetry (DSC) under nonisothermal condition at different heating rates.The activation energy of glass transition Eg is 634.4 kJ/mol,indicating that LAGP glass is easy to crystallize at an elevated temperature.The activation energy of crystallization Ec and Avrami index n obtained from Matusita's model are 442.01 kJ/mol and 1.7,respectively.The value of n reveals that bulk crystallization predominates slightly over surface crystallization during crystallization process.LAGP glass-ceramics after different heat treatments have the same crystalline phases determined as major phase LiGe2(PO4)3,with AlPO4 and GeO2 as their impurity phases.

  14. DSC and curing kinetics study of epoxy grouting diluted with furfural -acetone slurry

    Science.gov (United States)

    Yin, H.; Sun, D. W.; Li, B.; Liu, Y. T.; Ran, Q. P.; Liu, J. P.

    2016-07-01

    The use of furfural-acetone slurry as active diluents of Bisphenol-A epoxy resin (DGEBA) groutings has been studied by dynamic and non-isothermal DSC for the first time. Curing kinetics study was investigated by non-isothermal differential scanning calorimetries at different heating rates. Activation enery (Ea) was calculated based on Kissinger and Ozawa Methods, and the results showed that Ea increased from 58.87 to 71.13KJ/mol after the diluents were added. The furfural-acetone epoxy matrix could cure completely at the theoretical curing temperature of 365.8K and the curing time of 139mins, which were determined by the kinetic model parameters.

  15. Physical ageing studies of poly(ethylene terephthalate) using SANS and DSC

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, Andrew [Department of Metallurgy and Materials, University of Birmingham, Birmingham B15 2TT (United Kingdom); Gordon, Duncan [Department of Metallurgy and Materials, University of Birmingham, Birmingham B15 2TT (United Kingdom); King, Stephen [ISIS Spallation Neutron Source, Rutherford-Appleton Laboratory, Didcot, Oxfordshire OX11 0QX (United Kingdom); Jenkins, Mike [Department of Metallurgy and Materials, University of Birmingham, Birmingham B15 2TT (United Kingdom)]. E-mail: M.J.Jenkins@bham.ac.uk

    2006-11-15

    The process of physical ageing in a blend of deuterated and hydrogenated poly(ethylene terephalate) has been investigated using a combination of differential scanning calorimetry (DSC) and small-angle neutron scattering (SANS). The development of an endothermic peak on the glass transition has been shown using DSC. Furthermore, the radius of gyration was found to decrease during physical ageing.

  16. 47 CFR 80.359 - Frequencies for digital selective calling (DSC).

    Science.gov (United States)

    2010-10-01

    ... this incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of this... 47 Telecommunication 5 2010-10-01 2010-10-01 false Frequencies for digital selective calling (DSC... for digital selective calling (DSC). (a) General purpose calling. The following table describes...

  17. 7 CFR 1710.114 - TIER, DSC, OTIER and ODSC requirements.

    Science.gov (United States)

    2010-01-01

    ... substantially in their entirety are in 7 CFR 1717.155. (4) If a distribution borrower has in service or under... 7 Agriculture 11 2010-01-01 2010-01-01 false TIER, DSC, OTIER and ODSC requirements. 1710.114... AND GUARANTEES Loan Purposes and Basic Policies § 1710.114 TIER, DSC, OTIER and ODSC requirements....

  18. 47 CFR 80.103 - Digital selective calling (DSC) operating procedures.

    Science.gov (United States)

    2010-10-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of this standard can be inspected at the Federal... 47 Telecommunication 5 2010-10-01 2010-10-01 false Digital selective calling (DSC) operating... Procedures-General § 80.103 Digital selective calling (DSC) operating procedures. (a) Operating...

  19. Gelatinisation kinetics of corn and chickpea starches using DSC, RVA, and dynamic rheometry

    Science.gov (United States)

    The gelatinisation kinetics (non-isothermal) of corn and chickpea starches at different heating rates were calculated using differential scanning calorimetry (DSC), rapid visco analyser (RVA), and oscillatory dynamic rheometry. The data obtained from the DSC thermogram and the RVA profiles were fitt...

  20. Characterization and kinetic modeling of secondary phases in squeeze cast Al alloy A380 by DSC thermal analysis

    Directory of Open Access Journals (Sweden)

    Xin-ping Hu

    2017-03-01

    Full Text Available Thermal analyses on squeeze cast aluminum alloy A380 (SC A380 solidified under 90 MPa were carried out to study the microstructure development of the alloy, in which a differential scanning calorimeter (DSC was employed. During the DSC runs, heating and cooling rates of 1, 3, 10, and 20 °C•min-1 were applied to investigate the heating and cooling effects on dissolution of secondary eutectic phases and microstructure evolution. Various reactions corresponding to troughs and peaks of the DSC curves were identified as corresponding to phase transformations taking place during dissolution or precipitation suggested by the principles of thermodynamics and kinetics. The comparison of the identified characteristic temperatures in the measured heating and cooling curves are generally in good agreement with the computed equilibrium temperatures. The microstructure analyses by scanning electron microscopy (SEM with energy dispersive X-ray spectroscopy (EDS indicate that the distribution and morphology of secondary phases present in the microstructure of the annealed sample are similar to the as-cast A380, i.e., strip β(Si, buck bone like or dot distributed θ(Al2Cu, β(Al5FeSi and Al15(FeMn3Si2. Two kinetic methods are employed to calculate the activation energies of the three common troughs and three common peaks in DSC curves of SC A380. The activation energies of the identified reaction θCuAl2 = α(Al+β(Si is 188.7 and 187.1 kJ∙mol-1 when the activation energies of reaction α(Al+β(Si→θCuAl2 is -122.7 and -121.8 kJ∙mol-1, by the Kissinger and Starink methods, respectively.

  1. Combination of TREF, high-temperature HPLC, FTIR and HPer DSC for the comprehensive analysis of complex polypropylene copolymers.

    Science.gov (United States)

    Cheruthazhekatt, Sadiqali; Pijpers, Thijs F J; Mathot, Vincent B F; Pasch, Harald

    2013-11-01

    A novel, powerful analytical technique, preparative temperature rising elution fractionation (prep TREF)/high-temperature (HT)-HPLC/Fourier transform infrared spectroscopy (FTIR)/high-performance differential scanning calorimetry (HPer DSC)), has been introduced to study the correlation between the polymer chain microstructure and the thermal behaviour of various components in a complex impact polypropylene copolymer (IPC). For the comprehensive analysis of this complex material, in a first step, prep TREF is used to produce less complex but still heterogeneous fractions. These chemically heterogeneous fractions are completely separated by using a highly selective chromatographic separation method--high-temperature solvent gradient HPLC. The detailed structural and thermal analysis of the HPLC fractions was conducted by offline coupling of HT-HPLC with FTIR spectroscopy and a novel DSC method--HPer DSC. Three chemically different components were identified in the mid-elution temperature TREF fractions. For the first component, identified as isotactic polypropylene homopolymer by FTIR, the macromolecular chain length is found to be an important factor affecting the melting and crystallisation behaviour. The second component relates to ethylene-propylene copolymer molecules with varying ethylene monomer distributions and propylene tacticity distributions. For the polyethylene component (last eluting component in all semi-crystalline TREF fractions), it was found that branching produced defects in the long crystallisable ethylene sequences that affected the thermal properties. The different species exhibit distinctively different melting and crystallisation behaviour, as documented by HPer DSC. Using this novel approach of hyphenated techniques, the chain structure and melting and crystallisation behaviour of different components in a complex copolymer were investigated systematically.

  2. Comparative study of DSC-PWI and 3D-ASL in ischemic stroke patients.

    Science.gov (United States)

    Zhang, Shui-xia; Yao, Yi-hao; Zhang, Shun; Zhu, Wen-jie; Tang, Xiang-yu; Qin, Yuan-yuan; Zhao, Ling-yun; Liu, Cheng-xia; Zhu, Wen-zhen

    2015-12-01

    The purpose of this study was to quantitatively analyze the relationship between three dimensional arterial spin labeling (3D-ASL) and dynamic susceptibility contrast-enhanced perfusion weighted imaging (DSC-PWI) in ischemic stroke patients. Thirty patients with ischemic stroke were included in this study. All subjects underwent routine magnetic resonance imaging scanning, diffusion weighted imaging (DWI), magnetic resonance angiography (MRA), 3D-ASL and DSC-PWI on a 3.0T MR scanner. Regions of interest (ROIs) were drawn on the cerebral blood flow (CBF) maps (derived from ASL) and multi-parametric DSC perfusion maps, and then, the absolute and relative values of ASL-CBF, DSC-derived CBF, and DSC-derived mean transit time (MTT) were calculated. The relationships between ASL and DSC parameters were analyzed using Pearson's correlation analysis. Receiver operative characteristic (ROC) curves were performed to define the thresholds of relative value of ASL-CBF (rASL) that could best predict DSC-CBF reduction and MTT prolongation. Relative ASL better correlated with CBF and MTT in the anterior circulation with the Pearson correlation coefficients (R) values being 0.611 (P1.0 were 75.7%, 89.2% and 87.8% respectively. ASL-CBF map has better linear correlations with DSC-derived parameters (DSC-CBF and MTT) in anterior circulation in ischemic stroke patients. Additionally, when rASL is lower than 0.585, it could predict DSC-CBF decrease with moderate accuracy. If rASL values range from 0.585 to 0.952, we just speculate the prolonged MTT.

  3. Determination of diametral error using finite elements and experimental method

    Directory of Open Access Journals (Sweden)

    A. Karabulut

    2010-01-01

    Full Text Available This study concerns experimental and numerical analysis on a one-sided bound workpiece on the lathe machine. Cutting force creates deflection on workpiece while turning process is on. Deflection quantity is estimated utilizing Laser Distance Sensor (LDS with no contact achieved. Also diametral values are detected from different sides of workpiece after each turning operation. It is observed that diametral error differs due to the quantity of the deflection. Diametral error reached a peak where deflection reached a peak. Model which constituted finite elements is verified by experimental results. And also, facts which caused diametral error are determined.

  4. Process induced transformations during tablet manufacturing: phase transition analysis of caffeine using DSC and low frequency micro-Raman spectroscopy.

    Science.gov (United States)

    Hubert, Sébastien; Briancon, Stéphanie; Hedoux, Alain; Guinet, Yannick; Paccou, Laurent; Fessi, Hatem; Puel, François

    2011-11-25

    The phase transition of a model API, caffeine Form I, was studied during tableting process monitored with an instrumented press. The formulation used had a plastic flow behavior according to the Heckel model in the compression pressure range of 70-170 MPa. The quantitative methods of analysis used were Differential Scanning Calorimetry (DSC) and low frequency Micro Raman Spectroscopy (MRS) which was used for the first time for the mapping of polymorphs in tablets. They brought complementary contributions since MRS is a microscopic spectral analysis with a spatial resolution of 5 μm(3) and DSC takes into account a macroscopic fraction (10mg) of the tablet. Phase transitions were present at the surfaces, borders and center of the tablets. Whatever the pressure applied during the compression process, the transition degree of caffeine Form I toward Form II was almost constant. MRS provided higher transition degrees (50-60%) than DSC (20-35%). MRS revealed that caffeine Form I particles were partially transformed in all parts of the tablets at a microscopic scale. Moreover, tablet surfaces showed local higher transition degree compared to the other parts.

  5. DSC and TMA studies on freezing and thawing gelation of galactomannan polysaccharide

    Energy Technology Data Exchange (ETDEWEB)

    Iijima, Mika, E-mail: m-iijima@nagasaki-u.ac.jp [Faculty of Education, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521 (Japan); Hatakeyama, Tatsuko [Lignocell Research, 73-8 Yatsumata, Fukui 910-3558 (Japan); Hatakeyama, Hyoe [Department of Environment and Biotechnology, Faculty of Engineering, Fukui University of Technology, 3-6-1, Gakuen, Fukui 910-8505 (Japan)

    2012-03-20

    Research highlights: Black-Right-Pointing-Pointer Locust bean gum forms hydrogels by freezing and thawing. Black-Right-Pointing-Pointer Syneresis was observed when freezing and thawing cycle (n) increased. Black-Right-Pointing-Pointer Dynamic Young's modulus increased with increasing n. Black-Right-Pointing-Pointer Non-freezing water content restrained by hydrogels decreased with increasing n. Black-Right-Pointing-Pointer Strong gel with densely packed network structure formed with increasing n. - Abstract: Among various kinds of polysaccharides known to form hydrogels, locust bean gum (LBG) consisting of a mannose backbone and galactose side chains has unique characteristics, since LBG forms hydrogels by freezing and thawing. In this study, effect of thermal history on gelation was investigated by differential scanning calorimetry (DSC) and thermomechanical analysis (TMA). Gel/sol ratio calculated by weighing method was found to be affected by sol concentration, freezing rate and the number of freezing and thawing cycle (n). Once LBG hydrogels are formed, they are thermally stable, although syneresis was observed when n increased. Dynamic Young's modulus (E Prime ) of hydrogels measured by TMA in water increased with increasing n and decreasing freezing rate. Non-freezing water calculated from DSC melting peak of ice in the gel decreased with increasing n and decreasing freezing rate. Morphological observation of freeze-dried gels was carried out by scanning electron microscopy (SEM). The above results indicate that weak hydrogel having large molecular network structure transformed into strong gel with densely packed network structure by increasing n and decreasing freezing rate.

  6. Evaluation of peritoneal tissue by means of differential scanning calorimetry (DSC

    Directory of Open Access Journals (Sweden)

    Łukasz Pietrzyk

    2012-01-01

    Full Text Available Abdominal surgeries alter the integrity of the peritoneal layer and cause imbalances among immunological, inflammatory and angiogenic mechanisms within the tissue. During laparoscopic procedures a protective function of the peritoneal layer can be disturbed by the gas used to create a pneumoperitoneum. The aim of this study was to characterize peritoneal tissue by means of differential scanning calorimetry (DSC as a reference for future investigations on the influence of surgical procedures on the physicochemical state of the peritoneum. Thirty-seven patients participated in the study. Patients were divided into three groups according to the type of surgery: group H — patients who underwent hernia repair; group Ch — patients who underwent laparoscopic cholecystectomy; and group C — patients operated due to rectal cancer. It was observed that onset temperature (To, denaturation temperature (Tm and change of enthalpy (ΔH during thermal denaturation of peritoneal collagen in were significantly different for these three groups of patients. The mean values of onset temperature (To and denaturation temperature (Tm in group H were significantly lower, while DH in this group was significantly higher than in the two other groups (Ch and C. This preliminary study does not answer whether the differences in collagen denaturation found in peritoneal tissue from different groups of patients resulted from a different inherent state of the tissue, or from surgical procedures. However, the results suggest that DSC is an appropriate method to study subtle changes in the physicochemical condition of the peritoneum using small samples obtained during surgical procedures. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 4, pp. 700–705

  7. Does thermodynamic stability of peritoneal collagen change during laparoscopic cholecystectomies? A differential scanning calorimetry (DSC) study.

    Science.gov (United States)

    Torres, Kamil; Trębacz, Hanna; Bącik-Donica, Magdalena; Atras, Agnieszka; Torres, Anna; Plewa, Zbigniew

    2014-09-01

    Carbon dioxide pneumoperitoneum used during laparoscopic surgeries alters the integrity of the peritoneum and results in denudation of the basal lamina that might cause altered immune response, inhibited fibrinolysis, hypoxia, and acidosis. The changes in the structure of pneumoperitoneum were described as bulging of mesothelial cells, irregular cell junction's cell membrane degradation, and mesodermal edema. As denaturation of peritoneal proteins reflects overall condition of its structure and interactions with the surrounding molecules, the physical status of collagen was assessed on the basis of parameters of thermal denaturation measured by DSC method. Twenty-four female patients operated on due to cholelithiasis were enrolled in this study. Laparoscopic cholecystectomy was performed using standard four-trocar technique, and standard values of insufflated carbon dioxide pneumoperitoneum were used. After trocar placement, the first collection of peritoneal sample (sample A) was performed. The second peritoneal sample (sample B) was collected after the removal of gall bladder. Differential scanning calorimetry (Q200 calorimeter, TA Instruments) was performed on samples defrosted at room temperature. In all samples of peritoneum, a nonreversible endothermal process recognized as denaturation was observed. Sample B obtained at the end of surgery did not differ from sample A obtained at the beginning in terms of all parameters under study. Temperature of denaturation in A and B was correlated only marginally, but enthalpy and specific heat were significantly correlated. The analysis of data from DSC measurements did not reveal differences in physical stability of collagen in peritoneal samples obtained at the beginning and at the end of surgery. Significant negative correlations between duration of CO2 pneumoperitoneum and enthalpy of denaturation in sample B were found. Differences in enthalpy of denaturation may reflect a quantitative relation between amount of

  8. Using Experimental Methods to Investigate Discriminatory Tendencies: A Lesson Report

    Science.gov (United States)

    Chen, Yu-Wen; Masch, Lena; Finze, Kristin

    2014-01-01

    Using dictator games in experimental analysis, this lesson report demonstrates the process and results of a postgraduate class project in which university students were instructed to scientifically investigate and explore one of German society's most hotly-contested issues: the level of discriminatory tendencies of non-Muslims towards Muslims. The…

  9. Leveraging the Experimental Method to Inform Solar Cell Design

    Science.gov (United States)

    Rose, Mary Annette; Ribblett, Jason W.; Hershberger, Heather Nicole

    2010-01-01

    In this article, the underlying logic of experimentation is exemplified within the context of a photoelectrical experiment for students taking a high school engineering, technology, or chemistry class. Students assume the role of photochemists as they plan, fabricate, and experiment with a solar cell made of copper and an aqueous solution of…

  10. Applied Nonlinear Dynamics Analytical, Computational, and Experimental Methods

    CERN Document Server

    Nayfeh, Ali H

    1995-01-01

    A unified and coherent treatment of analytical, computational and experimental techniques of nonlinear dynamics with numerous illustrative applications. Features a discourse on geometric concepts such as Poincaré maps. Discusses chaos, stability and bifurcation analysis for systems of differential and algebraic equations. Includes scores of examples to facilitate understanding.

  11. Leveraging the Experimental Method to Inform Solar Cell Design

    Science.gov (United States)

    Rose, Mary Annette; Ribblett, Jason W.; Hershberger, Heather Nicole

    2010-01-01

    In this article, the underlying logic of experimentation is exemplified within the context of a photoelectrical experiment for students taking a high school engineering, technology, or chemistry class. Students assume the role of photochemists as they plan, fabricate, and experiment with a solar cell made of copper and an aqueous solution of…

  12. Experimental methods of determining thermal properties of granite

    Science.gov (United States)

    Determination of thermal properties of granite using the block method is discussed and compared with other methods. Problems that limit the accuracy of contact method in determining thermal properties of porous media are evaluated. Thermal properties of granite is determined in the laboratory with a...

  13. Collection methods of trematode eggs using experimental animal models.

    Science.gov (United States)

    Tsubokawa, Daigo; Sugiyama, Hiromu; Mikami, Fusako; Shibata, Katsumasa; Shibahara, Toshiyuki; Fukuda, Koichi; Takamiya, Shinzaburo; Yamasaki, Hiroshi; Nakamura, Takeshi; Tsuji, Naotoshi

    2016-10-01

    Although observing the eggs of human parasitic helminth is essential for medical education in parasitology, opportunities for collection of the eggs are limited. Collection of the eggs using experimental animal models is needed for a sustainable supply. The metacercariae of three trematode species, Paragonimus westermani, Clonorchis sinensis and Metagonimus yokogawai, were collected from the second intermediate hosts: freshwater crabs and fishes, which were obtained using online shopping in Japan, and inoculated to experimental animal rat and dog. Consequently, eggs of the three trematode species were obtained abundantly from the feces of the animals. The eggs are being used for student training in several Japanese universities. In this article, we introduce the collection procedures for trematode eggs.

  14. Experimental Comparison of Signal Subspace Based Noise Reduction Methods

    DEFF Research Database (Denmark)

    Hansen, Peter Søren Kirk; Hansen, Per Christian; Hansen, Steffen Duus

    1999-01-01

    The signal subspace approach for non-parametric speech enhancement is considered. Several algorithms have been proposed in the literature but only partly analyzed. Here, the different algorithms are compared, and the emphasis is put onto the limiting factors and practical behavior of the estimato....... Experimental results show that the signal subspace approach may lead to a significant enhancement of the signal to noise ratio of the output signal....

  15. Experimental Comparison of Signal Subspace Based Noise Reduction Methods

    OpenAIRE

    Hansen, Peter Søren Kirk; Hansen, Per Christian; Hansen, Steffen Duus; Sørensen, John Aasted

    1999-01-01

    The signal subspace approach for non-parametric speech enhancement is considered. Several algorithms have been proposed in the literature but only partly analyzed. Here, the different algorithms are compared, and the emphasis is put onto the limiting factors and practical behavior of the estimators. Experimental results show that the signal subspace approach may lead to a significant enhancement of the signal to noise ratio of the output signal.

  16. Gradient-based stochastic optimization methods in Bayesian experimental design

    OpenAIRE

    2012-01-01

    Optimal experimental design (OED) seeks experiments expected to yield the most useful data for some purpose. In practical circumstances where experiments are time-consuming or resource-intensive, OED can yield enormous savings. We pursue OED for nonlinear systems from a Bayesian perspective, with the goal of choosing experiments that are optimal for parameter inference. Our objective in this context is the expected information gain in model parameters, which in general can only be estimated u...

  17. [Ergopsychometry. New methods in experimental psychodiagnosis of pathologic stress reactions].

    Science.gov (United States)

    Beiglböck, W; Feselmayer, S; Bischof, B

    1989-01-01

    Ergopsychometry--testing under physiological and/or psychological stress--has proved to be increasingly successful in recent years. In particular in sports psychology, in which only physiological stress had been considered, have experimental results been successfully implemented into practice. The fact that some subjects appear unchanged or even yield better results under stress than under stress-free conditions applies not only to physiological stress, but also holds true for psychological stress. These results have consequences for the experimental psychodiagnoses of pathological stress reactions, e.g., with alcoholics or psychosomatic patients. Proceeding from the above hypothesis we investigated 20 gamma-alcoholics (so-called relieve drinkers) and 20 psychosomatic inpatients under stress-free as well as under stress conditions, according to the ergopsychometric approach. The control group consisted of 23 subjects matched with respect to age, sex, and profession. We used a test battery to assess concentration, memory, and choice-reaction as well as the subjective state of activation, stress-coping-mechanisms, and self-concepts. Essentially, the validity of ergopsychometric designs was confirmed by our results. In accordance with our expectations, 27.5% of the experimental group showed increasing efficiency scores, compared to 56.5% in the control group. Possible explanations for the findings can be derived from the assessment of subjective activity, but not from of the personality questionnaires.

  18. Systematic study of exciton diffusion length in organic semiconductors by six experimental methods

    NARCIS (Netherlands)

    Lin, Jason D. A.; Mikhnenko, Oleksandr V.; Chen, Jingrun; Masri, Zarifi; Ruseckas, Arvydas; Mikhailovsky, Alexander; Raab, Reilly P.; Liu, Jianhua; Blom, Paul W. M.; Loi, Maria Antonietta; Garcia-Cervera, Carlos J.; Samuel, Ifor D. W.; Thuc-Quyen Nguyen, [No Value

    Six experimental methods have been used to investigate the exciton diffusion length in materials with systematic chemical modifications. We find that exciton diffusion length correlates with molecular ordering. We discuss situations in which certain experimental techniques are more appropriate.

  19. Thermodynamic properties of three-ring aza-aromatics. 1. Experimental results for phenazine and acridine, and mutual validation of experiments and computational methods

    Energy Technology Data Exchange (ETDEWEB)

    Chirico, Robert D., E-mail: chirico@boulder.nist.go [Thermophysical Properties Division, National Institute of Standards and Technology, Boulder, CO 80305-3337 (United States); Kazakov, Andrei F., E-mail: akazakov@boulder.nist.go [Thermophysical Properties Division, National Institute of Standards and Technology, Boulder, CO 80305-3337 (United States); Steele, William V., E-mail: wsteele@utk.ed [Physical Properties Research Facility, Chemical Engineering Department, 327 Dougherty Engineering Bldg., 1512 Middle Drive, University of Tennessee, Knoxville, TN 37996-2200 (United States)

    2010-05-15

    Measurements leading to the calculation of thermodynamic properties for phenazine (Chemical Abstracts registry number [92-82-0]) in the ideal-gas state are reported. Experimental methods included adiabatic heat-capacity calorimetry, inclined-piston manometry, and combustion calorimetry. Thermodynamic properties for acridine (Chemical Abstracts registry number [260-94-6]) were reported previously and included those measured with adiabatic heat-capacity calorimetry, comparative ebulliometry, inclined-piston manometry, and combustion calorimetry. New measurement results for acridine reported here are densities determined with a vibrating-tube densimeter and heat capacities for the liquid phase at saturation pressure determined with a differential-scanning calorimeter (d.s.c.). All critical properties were estimated. Molar entropies for the ideal-gas state were derived for both compounds at selected temperatures. Independent calculations of entropies for the ideal-gas state were performed at the B3LYP/6-31+G(d, p) model chemistry for phenazine and acridine. These are shown to be in excellent accord with the calorimetric results. All results are compared with experimental property values reported in the literature.

  20. An experimental-analytical method to study steady spray combustion.

    Science.gov (United States)

    Bracco, F. V.

    1973-01-01

    Description of a method for determining the local parameters of the gas mixture resulting from the combustion of sprayed fuel in a gaseous oxidizer. The method is based on the measurement of local static pressures in the gas mixture and does not require the knowledge of the droplet distribution function, drag, and vaporization characteristics. A set of equations with substituted local pressure values is used for calculations. Application of the method is demonstrated on a liquid oxygen-ethanol rocket fuel.

  1. Method for experimental determination of flutter speed by parameter identification

    Science.gov (United States)

    Nissim, E.; Gilyard, Glenn B.

    1989-01-01

    A method for flight flutter testing is proposed which enables one to determine the flutter dynamic pressure from flights flown far below the flutter dynamic pressure. The method is based on the identification of the coefficients of the equations of motion at low dynamic pressures, followed by the solution of these equations to compute the flutter dynamic pressure. The initial results of simulated data reported in the present work indicate that the method can accurately predict the flutter dynamic pressure, as described. If no insurmountable difficulties arise in the implementation of this method, it may significantly improve the procedures for flight flutter testing.

  2. Introduction to experimental infrared spectroscopy fundamentals and practical methods

    CERN Document Server

    Tasumi, Mitsuo; Ochiai, Shukichi

    2014-01-01

    Infrared spectroscopy is generally understood to mean the science of spectra relating to infrared radiation, namely electromagnetic waves, in the wavelength region occurring intermediately between visible light and microwaves. Measurements of infrared spectra have been providing useful information, for a variety of scientific research and industrial studies, for over half a century; this is set to continue in the foreseeable future. Introduction to Experimental Infrared Spectroscopy is intended to be a handy guide for those who have no, or limited, experience in infrared spectroscopi

  3. 一种基于特征向量的改进DSC网页去重算法%An Improved DSC Removing Duplicated Webpages Algorithm Based on Feature Vector

    Institute of Scientific and Technical Information of China (English)

    徐朝辉; 赵淑梅; 闫付亮; 秦杰

    2013-01-01

    网页去重具有很重要的实际意义,也是信息检索领域近几年研究的热点.分析现有的网页去重算法,并对经典的DSC(digital syntactic clustering)网页去重算法进行改进.为每篇文档生成一个特征向量集合,用该特征向量集合筛选shingles;然后进行相似性比较.实验表明,该算法对重复网页判定具有很好的准确率和召回率.%Removing duplicated Webpages can improve the performance of search engines, and it has been one of research issues in todays information retrieving research. The main popular duplicated Webpages detecting methods is analysed, and algorithm is modified the traditional DSC to select the shingles through the feature vectors of the document, and then compared the similarity of two documents. The experimental results show that the method has achieved a good performance in recall and precision.

  4. DSC及IR联合测定环氧树脂-双氰胺体系固化工艺参数%Determination of Curing Parameter for Epoxy Resin-Dicyandiamide System by DSC and IR

    Institute of Scientific and Technical Information of China (English)

    蔡晋; 董如林; 陈智栋; 金长春; 方敏

    2011-01-01

    The effect of the amount of dicyandiamide on the curing reaction of epoxy resin has been investigated , using non-isothermal DSC method and the reaction kinetics of the epoxy resin -dicyandiamide system has been studied, using DSC curves measured at different heating rates. Simultaneously, the optimum curing condition has been established , using DSC and IR analytical technique. The experimental results indicate that the optimum amount of dicyandiamide is 5. 6%, curing temperature 403K and curing time 70 min. The activation energy and reaction rate for the curing reaction of the epoxy resin-dicyandiamide system were calculated to be 96. 82 Kj/mol and 0. 93, respectively.%采用非等温DSC法研究了固化剂用量对环氧树脂固化反应的影响,同时利用不同升温速率下测得的DSC曲线研究了环氧树脂-双氰胺体系的固化反应动力学,并由DSC及IR分析技术确定了该体系的最佳反应条件.实验结果表明:固化剂双氰胺最佳用量为5.6%,最佳固化温度为403 K,固化时间为70 min,该体系的反应活化能为96.82 kJ/mol,反应级数为0.93.

  5. Experimental Methods in Reduced-gravity Soldering Research

    Science.gov (United States)

    Pettegrew, Richard D.; Struk, Peter M.; Watson, John K.; Haylett, Daniel R.

    2002-01-01

    The National Center for Microgravity Research, NASA Glenn Research Center, and NASA Johnson Space Center are conducting an experimental program to explore the influence of reduced gravity environments on the soldering process. An improved understanding of the effects of the acceleration environment is important to application of soldering during current and future human space missions. Solder joint characteristics that are being considered include solder fillet geometry, porosity, and microstructural features. Both through-hole and surface mounted devices are being investigated. This paper focuses on the experimental methodology employed in this project and the results of macroscopic sample examination. The specific soldering process, sample configurations, materials, and equipment were selected to be consistent with those currently on-orbit. Other apparatus was incorporated to meet requirements imposed by operation onboard NASA's KC-135 research aircraft and instrumentation was provided to monitor both the atmospheric and acceleration environments. The contingent of test operators was selected to include both highly skilled technicians and less skilled individuals to provide a population cross-section that would be representative of the skill mix that might be encountered in space mission crews.

  6. Estimation of Critical Rate of Temperature Rise for Thermal Explosion of First Order Autocatalytic Decomposition Reaction Systems by Using Non-isothermal DSC

    Institute of Scientific and Technical Information of China (English)

    GUO Peng-jiang; LU Gui-e; JIANG Ji-you; HU Rong-zu; ZHANG Hai; XIA Zhi-ming; SONG Ji-rong; GAO Sheng-li; NING Bin-ke; SHI Qi-zhen; LIU Rong

    2004-01-01

    A method of estimating the critical rate of temperature rise for the thermal explosion of first order autocatalytic decomposition reaction systems by using non-isothermal DSC is presented. The information was obtained on the increasing rate of temperature for the first order autocatalytic decomposition of nitrocellulose containing 13.86% nitrogen converting into the thermal explosion.

  7. Experimental precision in corn trials using the Papadakis method

    National Research Council Canada - National Science Library

    Storck, Lindolfo; Lopes, Sidinei José; Cargnelutti Filho, Alberto; Lúcio, Alessandro Dal'Col; Toebe, Marcos

    2010-01-01

    The objective of this work was to verify whether the use of the Papadakis method in competing corn hybrid trials would lead to modifications in the validity of assumptions for the mathematical model...

  8. Theoretical and Experimental Research of Error of Method of Thermocouple with Controlled Profile of Temperature Field

    Science.gov (United States)

    Jun, Su; Kochan, O.; Chunzhi, Wang; Kochan, R.

    2015-12-01

    The method of study and experimental researches of the error of method of the thermocouple with controlled profile of temperature field along the main thermocouple are considered in this paper. Experimentally determined values of error of method are compared to the theoretical estimations done using Newton's law of cooling. They converge well.

  9. Theoretical and Experimental Research of Error of Method of Thermocouple with Controlled Profile of Temperature Field

    OpenAIRE

    Jun Su; Kochan O.; Chunzhi Wang; Kochan R.

    2015-01-01

    The method of study and experimental researches of the error of method of the thermocouple with controlled profile of temperature field along the main thermocouple are considered in this paper. Experimentally determined values of error of method are compared to the theoretical estimations done using Newton’s law of cooling. They converge well.

  10. DSC study of cold and heat denaturation processes of β-lactoglobulin A with guanidine hydrochloride

    Institute of Scientific and Technical Information of China (English)

    王邦宁; 谈夫

    1997-01-01

    The cold and heat denaturations of bovine β-lactoglobuhn A (β-lg A) has been studied in solutions of guanidine hydrochloride (GuHCl) by differential scanning calorimelry (DSC) The experimental results are presented and discussed.It is shown that the number of protons bound by the monomeric molecules of β-lg A was unchanged before and after its heat denaturation below pH 3,and that the activation energy of the heat denaturation was depressed owing to the presence of GuHCl.In the solutions with 2.50 and 3.06 mol/L of GuHCl,both the cold and heat denat-urations of β-lg A were observed.In comparison with the heat denaturation,the activation energy of cold denaturation was far lower and the number of GuHCl molecules bound by the unfolded polypeptide chains after cold denaturation increased a lot.The absolute value of the enthalpy of cold denaturation was larger than that of heat denaturation It was found by the analysis that the contribution to the total denaturational enthalpy of conformational change i

  11. Photoelectrochemical water splitting standards, experimental methods, and protocols

    CERN Document Server

    Chen, Zhebo; Miller, Eric

    2014-01-01

    This book outlines many of the techniques involved in materials development and characterization for photoelectrochemical (PEC) - for example, proper metrics for describing material performance, how to assemble testing cells and prepare materials for assessment of their properties, and how to perform the experimental measurements needed to achieve reliable results towards better scientific understanding. For each technique, proper procedure, benefits, limitations, and data interpretation are discussed. Consolidating this information in a short, accessible, and easy to read reference guide will allow researchers to more rapidly immerse themselves into PEC research and also better compare their results against those of other researchers to better advance materials development. This book serves as a "how-to" guide for researchers engaged in or interested in engaging in the field of photoelectrochemical (PEC) water splitting. PEC water splitting is a rapidly growing field of research in which the goal is to deve...

  12. Experimental optimization of a landmine detection facility using PGNAA method

    Institute of Scientific and Technical Information of China (English)

    Hashem MIRI-HAKIMABAD; Hamed PANJEH; Alireza VEJDANI-NOGHREIYAN

    2008-01-01

    The optimum moderator geometry increases the performance of prompt gamma neutron activation analysis (PGNAA) method considerably. In this work an 241Am-Be source was used in the moderator geometry for detecting buried landmines by PGNAA method. Experiments were done to find the best moderator geometry for the moderated 241 Am-Be source, by replacing the mine with a neutron detector and counting the thermal neutron flux. The flux of thermal neutrons at the place of mine was used as a determining factor to introduce the best moderator geometry.

  13. Identification of the thermal transitions in potato starch at a low water content as studied by preparative DSC

    NARCIS (Netherlands)

    Steeneken, P.A.M.; Woortman, A.J.J.

    2009-01-01

    The aim of this work was to identify the transitions in the complex DSC profiles of potato starch at a low water content. Preparative DSC involves the thermal processing of samples in stainless steel DSC pans in a way that allows their subsequent structural characterization. The low temperature (LT)

  14. Identification of the thermal transitions in potato starch at a low water content as studied by preparative DSC

    NARCIS (Netherlands)

    Steeneken, P.A.M.; Woortman, A.J.J.

    2009-01-01

    The aim of this work was to identify the transitions in the complex DSC profiles of potato starch at a low water content. Preparative DSC involves the thermal processing of samples in stainless steel DSC pans in a way that allows their subsequent structural characterization. The low temperature

  15. An Experimental Method for the Active Learning of Greedy Algorithms

    Science.gov (United States)

    Velazquez-Iturbide, J. Angel

    2013-01-01

    Greedy algorithms constitute an apparently simple algorithm design technique, but its learning goals are not simple to achieve.We present a didacticmethod aimed at promoting active learning of greedy algorithms. The method is focused on the concept of selection function, and is based on explicit learning goals. It mainly consists of an…

  16. An Experimental Method for the Active Learning of Greedy Algorithms

    Science.gov (United States)

    Velazquez-Iturbide, J. Angel

    2013-01-01

    Greedy algorithms constitute an apparently simple algorithm design technique, but its learning goals are not simple to achieve.We present a didacticmethod aimed at promoting active learning of greedy algorithms. The method is focused on the concept of selection function, and is based on explicit learning goals. It mainly consists of an…

  17. Magnetic characterisation of recording materials: design, instrumentation and experimental methods

    NARCIS (Netherlands)

    Samwel, E.O.

    1995-01-01

    The progress being made in the field of magnetic recording is extremely fast. The need to keep this progress going, leads to new types of recording materials which require advanced measurement systems and measurement procedures. Furthermore, the existing measurement methods need to be reviewed as

  18. Interleaved Carbon Minibeams: An Experimental Radiosurgery Method With Clinical Potential

    Energy Technology Data Exchange (ETDEWEB)

    Dilmanian, F. Avraham, E-mail: dilmanian@bnl.gov [Medical Department, Brookhaven National Laboratory, Upton, NY (United States); Department of Radiation Oncology, Stony Brook University Medical Center, NY (United States); Department of Neurology, Stony Brook University Medical Center, NY (United States); Rusek, Adam [NASA Space Radiation Laboratory, Brookhaven National Laboratory, Upton, NY (United States); Fois, Giovanna R. [Medical Department, Brookhaven National Laboratory, Upton, NY (United States); Physics Department, University of Cagliari, Sardinia (Italy); Olschowka, John [Department of Neurobiology and Anatomy, University of Rochester, Rochester, NY (United States); Desnoyers, Nicolle R. [Medical Department, Brookhaven National Laboratory, Upton, NY (United States); Ross University School of Veterinary Medicine, Basseterre, St. Kitts, West Indies (Country Unknown); Park, Jane Y. [Medical Department, Brookhaven National Laboratory, Upton, NY (United States); College of Veterinary Medicine, Cornell University, Ithaca, NY (United States); Dioszegi, Istvan [Nonproliferation and National Security Department, Brookhaven National Laboratory, Upton, NY (United States); Dane, Bari; Wang Ruiliang [Medical Department, Brookhaven National Laboratory, Upton, NY (United States); Tomasi, Dardo [Medical Department, Brookhaven National Laboratory, Upton, NY (United States); National Institute on Alcoholism and Alcohol Abuse, Bethesda, MD (United States); Lee, Hedok [Medical Department, Brookhaven National Laboratory, Upton, NY (United States); Hurley, Sean D. [Department of Neurobiology and Anatomy, University of Rochester, Rochester, NY (United States); Coyle, Patricia K. [Department of Neurology, Stony Brook University Medical Center, NY (United States); Meek, Allen G. [Department of Radiation Oncology, Stony Brook University Medical Center, NY (United States); O' Banion, M. Kerry [Department of Neurobiology and Anatomy, University of Rochester, Rochester, NY (United States)

    2012-10-01

    Purpose: To evaluate the efficacy of 'interleaved carbon minibeams' for ablating a 6.5-mm target in a rabbit brain with little damage to the surrounding brain. The method is based on the well-established tissue-sparing effect of arrays of thin planes of radiation. Methods and Materials: Broad carbon beams from the National Aeronautics and Space Agency Space Radiation Facility at Brookhaven National Laboratory were segmented into arrays of parallel, horizontal, 0.3-mm-thick planar beams (minibeams). The minibeams' gradual broadening in tissues resulted in 0.525-mm beam thickness at the target's proximal side in the spread-out Bragg peak. Interleaving was therefore implemented by choosing a 1.05 mm beam spacing on-center. The anesthetized rabbit, positioned vertically on a stage capable of rotating about a vertical axis, was exposed to arrays from four 90 Degree-Sign angles, with the stage moving up by 0.525 mm in between. This produced a solid radiation field at the target while exposing the nontargeted tissues to single minibeam arrays. The target 'physical' absorbed dose was 40.2 Gy. Results: The rabbit behaved normally during the 6-month observation period. Contrast magnetic resonance imaging and hematoxylin and eosin histology at 6 months showed substantial focal target damage with little damage to the surrounding brain. Conclusion: We plan to evaluate the method's therapeutic efficacy by comparing it with broad-beam carbon therapy in animal models. The method's merits would combine those of carbon therapy (i.e., tight target dose because of the carbon's Bragg-peak, sharp dose falloff, and high relative biological effectiveness at the target), together with the method's low impact on the nontargeted tissues. The method's smaller impact on the nontargeted brain might allow carbon therapy at higher target doses and/or lower normal tissue impact, thus leading to a more effective treatment of radioresistant

  19. A new method for nonlinear optimization - experimental results

    Energy Technology Data Exchange (ETDEWEB)

    Loskovska, S.; Percinkova, B.

    1994-12-31

    In this paper an application of a new method for nonlinear optimization problems suggested and presented by B. Percinkova is performed. The method is originally developed and applicated on nonlinear systems. Basis of the method is following: A system of n-nonlinear equations gives as F{sub i}(x{sub 1}, x{sub 2}, x{sub 3}, ..., x{sub n}) = 0; 1 = 1, 2, ..., n and solution domain x{sub pi} {<=} x{sub i} {<=} x{sub ki} i = 1, 2, ..., n is modified by introducing a new variable z. The new system is given by: F{sub i}(x{sub 1}, x{sub 2}, x{sub 3}, ..., x{sub n}) = z; i = 1, 2, ..., n. The system defines a curve in (n + 1) dimensional space. System`s point X = (x{sub i}, x{sub 2}, x{sub 3}, ..., x{sub n}, z) that, the solution of the system is obtained using an interative procedure moving along the curve until the point with z = 0 is reached. In order to applicate method on optimization problems, a basic optimization model given with (min, max)F{sub i}(x{sub 1}, x{sub 2}, x{sub 3}, ..., x{sub n}) with the following optimization space: F{sub i}(x{sub 1}, x{sub 2}, x{sub 3}, ..., x{sub n}) ({<=}{>=})0 : i = 1, 2, ..., n is transformed into a system equivalent to system (2) by (dF/dx{sub i}) = z; i - 1, 2, ..., n. The main purpose of this work is to make relevant evaluation of the method by standard test problems.

  20. Recent advances and potential applications of modulated differential scanning calorimetry (mDSC) in drug development.

    Science.gov (United States)

    Knopp, Matthias Manne; Löbmann, Korbinian; Elder, David P; Rades, Thomas; Holm, René

    2016-05-25

    Differential scanning calorimetry (DSC) is frequently the thermal analysis technique of choice within preformulation and formulation sciences because of its ability to provide detailed information about both the physical and energetic properties of a substance and/or formulation. However, conventional DSC has shortcomings with respect to weak transitions and overlapping events, which could be solved by the use of the more sophisticated modulated DSC (mDSC). mDSC has multiple potential applications within the pharmaceutical field and the present review provides an up-to-date overview of these applications. It is aimed to serve as a broad introduction to newcomers, and also as a valuable reference for those already practising in the field. Complex mDSC was introduced more than two decades ago and has been an important tool for the quantification of amorphous materials and development of freeze-dried formulations. However, as discussed in the present review, a number of other potential applications could also be relevant for the pharmaceutical scientist.

  1. Changes of multi-scale structure during mimicked DSC heating reveal the nature of starch gelatinization.

    Science.gov (United States)

    Wang, Shujun; Zhang, Xiu; Wang, Shuo; Copeland, Les

    2016-06-20

    A thorough understanding of starch gelatinization is extremely important for precise control of starch functional properties for food processing and human nutrition. Here we reveal the molecular mechanism of starch gelatinization by differential scanning calorimetry (DSC) in conjunction with a protocol using the rapid viscosity analyzer (RVA) to generate material for analysis under conditions that simulated the DSC heating profiles. The results from DSC, FTIR, Raman, X-ray diffraction and small angle X-ray scattering (SAXS) analyses all showed that residual structural order remained in starch that was heated to the DSC endotherm end temperature in starch:water mixtures of 0.5 to 4:1 (v/w). We conclude from this study that the DSC endotherm of starch at a water:starch ratio of 2 to 4 (v/w) does not represent complete starch gelatinization. The DSC endotherm of starch involves not only the water uptake and swelling of amorphous regions, but also the melting of starch crystallites.

  2. Changes of multi-scale structure during mimicked DSC heating reveal the nature of starch gelatinization

    Science.gov (United States)

    Wang, Shujun; Zhang, Xiu; Wang, Shuo; Copeland, Les

    2016-06-01

    A thorough understanding of starch gelatinization is extremely important for precise control of starch functional properties for food processing and human nutrition. Here we reveal the molecular mechanism of starch gelatinization by differential scanning calorimetry (DSC) in conjunction with a protocol using the rapid viscosity analyzer (RVA) to generate material for analysis under conditions that simulated the DSC heating profiles. The results from DSC, FTIR, Raman, X-ray diffraction and small angle X-ray scattering (SAXS) analyses all showed that residual structural order remained in starch that was heated to the DSC endotherm end temperature in starch:water mixtures of 0.5 to 4:1 (v/w). We conclude from this study that the DSC endotherm of starch at a water:starch ratio of 2 to 4 (v/w) does not represent complete starch gelatinization. The DSC endotherm of starch involves not only the water uptake and swelling of amorphous regions, but also the melting of starch crystallites.

  3. ADVANTAGES AND THERMODYNAMIC LIMITATIONS OF THE EXPERIMENTAL SORPTION ISOSTERIC METHOD

    Directory of Open Access Journals (Sweden)

    FARID B. CORTÉS

    2013-01-01

    Full Text Available Una revisión de las ventajas y las limitaciones termodinámicas presentes en el método experimental sorción isostérica (SIM muestra que el SIM no garantiza una cantidad adsorbida constante. Las isósteras calculadas que consideran comportamiento de gas ideal muestran que en el SIM la masa de gas en el volumen muerto del sistema al incrementar la presión de equilibrio debido a los materiales desorbidos. El SIM es útil y efectivo para obtener datos termodinámicos de alta precisión para la sorción de gases en materiales micro y nanoporosos a bajas presiones y temperaturas. Por el contrario, cuando la presión y la temperatura son altas la desorción no es despreciable, por lo tanto el SIM no es aplicable. Los errores en los cálculos del calor isostérico usando SIM pueden ser reducidos usando procedimientos experimentales tradicionales como las isobaras e isotermas de adsorción para generar las isósteras a altas presiones y temperaturas. Como alternativa, correcciones por presión y temperatura, o un experimento que, después de cada incremento de temperatura permita a la dosis de gas compensar la masa desorbida, garantizaría una cantidad adsorbida constante y, por consiguiente, un comportamiento isostérico mediante medidas directas.

  4. Using Experimental Methods to Investigate Discriminatory Tendencies: A Lesson Report

    Directory of Open Access Journals (Sweden)

    Yu-Wen Chen

    2013-08-01

    Full Text Available Using dictator games in experimental analysis, this lesson report demonstrates the process and results of a postgraduate class project in which university students were instructed to scientifically investigate and explore one of German society’s most hotly-contested issues: the level of discriminatory tendencies of non-Muslims towards Muslims. The results of this class project show little or no discriminatory tendencies toward Muslims. Instead, the university students under our investigation tended to act favorably, or at the very least, fairly toward Muslims. We expect that this lesson report can demonstrate how a postgraduate course can be conducted in an innovative way, empowering students to collect primary data and finishing a small scientific project during the span of a semester. Dieser Bericht stellt die Prozesse und Ergebnisse einer experimentellen Studie eines Postgraduierten-Kurses der Universität Greifswald dar. Wir zeigen, wie Studierende das Thema Migration innovativ untersuchen können, indem sie neben theoretischen Lerninhalten an experimentelle Methoden sowie die Primärforschung herangeführt werden. Anhand eines Diktatorspiels wurden die teilnehmenden Studenten angeleitet, ein in der Öffentlichkeit kontrovers debattiertes Thema wissenschaftlich zu untersuchen: Diskriminierende Tendenzen von Nicht-Muslimen gegenüber Muslimen. Die Ergebnisse dieser Studie lassen jedoch nicht auf diskriminierende Tendenzen der Studenten schließen. Stattdessen deuten sie darauf hin, dass sich die Studierenden zumindest fair gegenüber Muslimen verhalten.

  5. Experimental method for calculation of effective doses in interventional radiology; Metodo experimental para calculo de dosis efectivas en radiologia intervencionista

    Energy Technology Data Exchange (ETDEWEB)

    Herraiz Lblanca, M. D.; Diaz Romero, F.; Casares Magaz, O.; Garrido Breton, C.; Catalan Acosta, A.; Hernandez Armas, J.

    2013-07-01

    This paper proposes a method that allows you to calculate the effective dose in any interventional radiology procedure using an anthropomorphic mannequin Alderson RANDO and dosimeters TLD 100 chip. This method has been applied to an angio Radiology procedure: the biliary drainage. The objectives that have been proposed are: to) put together a method that, on an experimental basis, allows to know dosis en organs to calculate effective dose in complex procedures and b) apply the method to the calculation of the effective dose of biliary drainage. (Author)

  6. Microangiography - a sensitive method for studying experimental diabetic nephropathy

    Energy Technology Data Exchange (ETDEWEB)

    Merikanto, J. (Dept. of Radiology, Univ. Central Hospital, Oulu (Finland)); Hietala, S.O. (Depts. of Diagnostic Radiology and Internal Medicine, Univ. Hospital, Umeaa (Sweden) Dept. of Radiology, Univ. Central Hospital, Oulu (Finland)); Lithner, F. (Depts. of Diagnostic Radiology and Internal Medicine, Univ. Hospital, Umeaa (Sweden) Dept. of Radiology, Univ. Central Hospital, Oulu (Finland)); Haegg, E. (Depts. of Diagnostic Radiology and Internal Medicine, Univ. Hospital, Umeaa (Sweden) Dept. of Radiology, Univ. Central Hospital, Oulu (Finland)); Paeivaensalo, M. (Depts. of Diagnostic Radiology and Internal Medicine, Univ. Hospital, Umeaa (Sweden) Dept. of Radiology, Univ. Central Hospital, Oulu (Finland))

    1993-07-01

    Microangiographic and conventional histopathologic investigations of the kidney were compared in 15 alloxan diabetic and 7 nondiabetic control rats. Contrary to the relatively sparse histologic lesions, microangiography disclosed advanced vascular abnormalities, including arteriolar aneurysms, which increased with the duration of diabetes. It is concluded that microangiography is a sensitive and suitable method for studying the development of microvascular lesions of the kidney in experiment diabetes. (orig.).

  7. Prediction of skin sensitizers using alternative methods to animal experimentation.

    Science.gov (United States)

    Johansson, Henrik; Lindstedt, Malin

    2014-07-01

    Regulatory frameworks within the European Union demand that chemical substances are investigated for their ability to induce sensitization, an adverse health effect caused by the human immune system in response to chemical exposure. A recent ban on the use of animal tests within the cosmetics industry has led to an urgent need for alternative animal-free test methods that can be used for assessment of chemical sensitizers. To date, no such alternative assay has yet completed formal validation. However, a number of assays are in development and the understanding of the biological mechanisms of chemical sensitization has greatly increased during the last decade. In this MiniReview, we aim to summarize and give our view on the recent progress of method development for alternative assessment of chemical sensitizers. We propose that integrated testing strategies should comprise complementary assays, providing measurements of a wide range of mechanistic events, to perform well-educated risk assessments based on weight of evidence. © 2014 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

  8. Development and validation of an open source quantification tool for DSC-MRI studies.

    Science.gov (United States)

    Gordaliza, P M; Mateos-Pérez, J M; Montesinos, P; Guzmán-de-Villoria, J A; Desco, M; Vaquero, J J

    2015-03-01

    This work presents the development of an open source tool for the quantification of dynamic susceptibility-weighted contrast-enhanced (DSC) perfusion studies. The development of this tool is motivated by the lack of open source tools implemented on open platforms to allow external developers to implement their own quantification methods easily and without the need of paying for a development license. This quantification tool was developed as a plugin for the ImageJ image analysis platform using the Java programming language. A modular approach was used in the implementation of the components, in such a way that the addition of new methods can be done without breaking any of the existing functionalities. For the validation process, images from seven patients with brain tumors were acquired and quantified with the presented tool and with a widely used clinical software package. The resulting perfusion parameters were then compared. Perfusion parameters and the corresponding parametric images were obtained. When no gamma-fitting is used, an excellent agreement with the tool used as a gold-standard was obtained (R(2)>0.8 and values are within 95% CI limits in Bland-Altman plots). An open source tool that performs quantification of perfusion studies using magnetic resonance imaging has been developed and validated using a clinical software package. It works as an ImageJ plugin and the source code has been published with an open source license. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Spiral Perfusion Imaging With Consecutive Echoes (SPICE™) for the Simultaneous Mapping of DSC- and DCE-MRI Parameters in Brain Tumor Patients: Theory and Initial Feasibility

    Science.gov (United States)

    Paulson, Eric S.; Prah, Douglas E.; Schmainda, Kathleen M.

    2017-01-01

    Dynamic contrast-enhanced (DCE) and dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI) are the perfusion imaging techniques most frequently used to probe the angiogenic character of brain neoplasms. With these methods, T1- and T2/T2*-weighted imaging sequences are used to image the distribution of gadolinium (Gd)-based contrast agents. However, it is well known that Gd exhibits combined T1, T2, and T2* shortening effects in tissue, and therefore, the results of both DCE- and DSC-MRI can be confounded by these opposing effects. In particular, residual susceptibility effects compete with T1 shortening, which can confound DCE-MRI parameters, whereas dipolar T1 and T2 leakage and residual susceptibility effects can confound DSC-MRI parameters. We introduce here a novel perfusion imaging acquisition and postprocessing method termed Spiral Perfusion Imaging with Consecutive Echoes (SPICE) that can be used to simultaneously acquire DCE- and DSC-MRI data, which requires only a single dose of the Gd contrast agent, does not require the collection of a precontrast T1 map for DCE-MRI processing, and eliminates the confounding contrast agent effects due to contrast extravasation. A detailed mathematical description of SPICE is provided here along with a demonstration of its utility in patients with high-grade glioma. PMID:28090589

  10. Experimental Validation for Hot Stamping Process by Using Taguchi Method

    Science.gov (United States)

    Fawzi Zamri, Mohd; Lim, Syh Kai; Razlan Yusoff, Ahmad

    2016-02-01

    Due to the demand for reduction in gas emissions, energy saving and producing safer vehicles has driven the development of Ultra High Strength Steel (UHSS) material. To strengthen UHSS material such as boron steel, it needed to undergo a process of hot stamping for heating at certain temperature and time. In this paper, Taguchi method is applied to determine the appropriate parameter of thickness, heating temperature and heating time to achieve optimum strength of boron steel. The experiment is conducted by using flat square shape of hot stamping tool with tensile dog bone as a blank product. Then, the value of tensile strength and hardness is measured as response. The results showed that the lower thickness, higher heating temperature and heating time give the higher strength and hardness for the final product. In conclusion, boron steel blank are able to achieve up to 1200 MPa tensile strength and 650 HV of hardness.

  11. Translocations of amphibians: Proven management method or experimental technique

    Science.gov (United States)

    Seigel, Richard A.; Dodd, C. Kenneth

    2002-01-01

    In an otherwise excellent review of metapopulation dynamics in amphibians, Marsh and Trenham (2001) make the following provocative statements (emphasis added): If isolation effects occur primarily in highly disturbed habitats, species translocations may be necessary to promote local and regional population persistence. Because most amphibians lack parental care, they areprime candidates for egg and larval translocations. Indeed, translocations have already proven successful for several species of amphibians. Where populations are severely isolated, translocations into extinct subpopulations may be the best strategy to promote regional population persistence. We take issue with these statements for a number of reasons. First, the authors fail to cite much of the relevant literature on species translocations in general and for amphibians in particular. Second, to those unfamiliar with current research in amphibian conservation biology, these comments might suggest that translocations are a proven management method. This is not the case, at least in most instances where translocations have been evaluated for an appropriate period of time. Finally, the authors fail to point out some of the negative aspects of species translocation as a management method. We realize that Marsh and Trenham's paper was not concerned primarily with translocations. However, because Marsh and Trenham (2001) made specific recommendations for conservation planners and managers (many of whom are not herpetologists or may not be familiar with the pertinent literature on amphibians), we believe that it is essential to point out that not all amphibian biologists are as comfortable with translocations as these authors appear to be. We especially urge caution about advocating potentially unproven techniques without a thorough review of available options.

  12. Teaching Experimental Method Using the Feature-Present/Feature-Absent Effect

    Science.gov (United States)

    Balch, William R.

    2010-01-01

    To determine whether a classroom experiment improved the learning of experimental method, at the start of the semester 2 introductory psychology classes took a 10-question multiple-choice pretest on experimental method. Two days later, before the instructor covered the relevant material in the course, 1 class took part in a classroom experiment on…

  13. MM97.96 Experimental Method for Evaluation Of Combined Strain Paths

    DEFF Research Database (Denmark)

    Lindegren, Maria; Nielsen, Morten Sturgård; Wanheim, Tarras

    1997-01-01

    An experimental method is suggested for which the evolution of the yield surfaces for all strain paths represented within a process, in this case the extrusion process, can be determined.......An experimental method is suggested for which the evolution of the yield surfaces for all strain paths represented within a process, in this case the extrusion process, can be determined....

  14. Topics on Test Methods for Space Systems and Operations Safety: Applicability of Experimental Data

    Science.gov (United States)

    Hirsch, David B.

    2009-01-01

    This viewgraph presentation reviews topics on test methods for space systems and operations safety through experimentation and analysis. The contents include: 1) Perception of reality through experimentation and analysis; 2) Measurements, methods, and correlations with real life; and 3) Correlating laboratory aerospace materials flammability data with data in spacecraft environments.

  15. Calculation-experimental method justifies the life of wagons

    Directory of Open Access Journals (Sweden)

    Валерія Сергіївна Воропай

    2015-11-01

    Full Text Available The article proposed a method to evaluate the technical state of tank wagons operating in chemical industry. An algorithm for evaluation the technical state of tank wagons was developed, that makes it possible on the basis of diagnosis and analysis of current condition to justify a further period of operation. The complex of works on testing the tanks and mathematical models for calculations of the design strength and reliability were proposed. The article is devoted to solving the problem of effective exploitation of the working fleet of tank wagons. Opportunities for further exploitation of cars, the complex of works on the assessment of their technical state and the calculation of the resources have been proposed in the article. Engineering research of the chemical industries park has reduced the shortage of the rolling stock for transportation of ammonia. The analysis of the chassis numerous faults and the main elements of tank wagons supporting structure after 20 years of exploitation was made. The algorithm of determining the residual life of the specialized tank wagons operating in an industrial plant has been proposed. The procedure for resource conservation of tank wagons carrying cargo under high pressure was first proposed. The improved procedure for identifying residual life proposed in the article has both theoretical and practical importance

  16. Nano-DTA and nano-DSC with cantilever-type calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Nakabeppu, Osamu, E-mail: onakabep@meiji.ac.jp [Meiji University, School of Science and Technology, Department of Mechanical Engineering, Higashimita 1-1-1, Tama-ku, Kawasaki 214-8571 (Japan); Deno, Kohei [Tokyo Institute of Technology, Graduate School of Science and Engineering, Department of Mechanical Sciences and Engineering (Japan)

    2016-08-10

    Highlights: • Nanocalorimetry with original cantilever type calorimeters. • The calorimeters showed the enthalpy resolution of 200 nJ level. • Nano-DTA of a binary alloy captured a probabilistic peak after solidification. • Power compensation DSC of a microgram level sample was demonstrated. • The DSC and DTA behavior were explained with a lumped model. - Abstract: Differential thermal analysis (DTA) and differential scanning calorimetry (DSC) of the minute samples in the range of microgram to nanogram were studied using original cantilever-type calorimeters. The micro-fabricated calorimeter with a heater and thermal sensors was able to perform a fast temperature scan at above 1000 K/s and a high-resolution heat measurement. The DTA of minuscule metal samples demonstrated some advances such as the thermal analysis of a 20 ng level indium and observation of a strange phase transition of a binary alloy. The power compensation type DSC using a thermal feedback system was also performed. Thermal information of a microgram level sample was observed as splitting into the DSC and DTA signals because of a mismatch between the sample and the calorimeter. Although there remains some room for improvement in terms of the heat flow detection, the behavior of the compensation system in the DSC was theoretically understood through a lumped model. Those experiments also produced some findings, such as a fin effect with sample loading, a measurable weight range, a calibration of the calorimeter and a product design concept. The development of the nano-DTA and nano-DSC will enable breakthroughs for the fast calorimetry of the microscopic size samples.

  17. Evaluation of integrated Raman-DSC technology in early pharmaceutical development: characterization of polymorphic systems.

    Science.gov (United States)

    Huang, Jun; Dali, Manisha

    2013-12-01

    Differential Scanning Calorimetry and Raman spectroscopy are both powerful tools used heavily in pharmaceutical development. For many studies such as polymorph characterization these two techniques are complimentary and provide data on different yet important aspects of material properties when combined together. In this work we describe an integrated Raman-DSC technology that simultaneously generates both DSC thermogram and Raman spectra of the pharmaceutical material being studied. The integrated system consists of a DSC with a Raman fiber optic probe inserted right on top of the sample furnace. The technology integrates synchronized Raman acquisition into DSC scan, enabling collection of molecular and structural information coupled with observation of thermal events. We first establish the technology by optimizing the instrumental set-up that offers relatively high-quality results for simultaneous DSC and Raman data collection. We then demonstrate the application of the technology by studying the polymorphs of d-mannitol, a common pharmaceutical excipient and BMS-A, an investigational drug candidate that exhibits multiple coexisting polymorphs. In both cases, the Raman-DSC technology was able to provide valuable information on the process of phase change and polymorph identification. Although similar information may be obtained by using various characterization techniques together, the integrated Raman-DSC indicated special advantages for industrial development such as high efficiency, material sparing and comprehensive data analysis. Moreover the technology provides an alternative to better correlate real-time phase behavior to molecular understanding. The technology thus has the potential to be used for Process Analytical Technology (PAT) purpose.

  18. Endoplasmic Reticulum Exit of Golgi-resident Defective for SREBP Cleavage (Dsc) E3 Ligase Complex Requires Its Activity.

    Science.gov (United States)

    Raychaudhuri, Sumana; Espenshade, Peter J

    2015-06-01

    Layers of quality control ensure proper protein folding and complex formation prior to exit from the endoplasmic reticulum. The fission yeast Dsc E3 ligase is a Golgi-localized complex required for sterol regulatory element-binding protein (SREBP) transcription factor activation that shows architectural similarity to endoplasmic reticulum-associated degradation E3 ligases. The Dsc E3 ligase consists of five integral membrane proteins (Dsc1-Dsc5) and functionally interacts with the conserved AAA-ATPase Cdc48. Utilizing an in vitro ubiquitination assay, we demonstrated that Dsc1 has ubiquitin E3 ligase activity that requires the E2 ubiquitin-conjugating enzyme Ubc4. Mutations that specifically block Dsc1-Ubc4 interaction prevent SREBP cleavage, indicating that SREBP activation requires Dsc E3 ligase activity. Surprisingly, Golgi localization of the Dsc E3 ligase complex also requires Dsc1 E3 ligase activity. Analysis of Dsc E3 ligase complex formation, glycosylation, and localization indicated that Dsc1 E3 ligase activity is specifically required for endoplasmic reticulum exit of the complex. These results define enzyme activity-dependent sorting as an autoregulatory mechanism for protein trafficking.

  19. A comparison of different experimental methods for general recombination correction for liquid ionization chambers

    DEFF Research Database (Denmark)

    Andersson, Jonas; Kaiser, Franz-Joachim; Gomez, Faustino

    2012-01-01

    experimental methods for general recombination correction for LICs are compared and investigated for both pulsed and continuous beams. The experimental methods are all based on one of two approaches: either measurements at two different dose rates (two-dose-rate methods), or measurements at three different LIC...... recommended by the manufacturer of the LICs used, the agreement between the different methods is generally within the experimental uncertainties. For pulsed beams, the agreement between the methods is poor. The inaccuracies found in the results from the three-voltage methods are associated with numerical...... difficulties in solving the resulting equation systems, which also make these methods sensitive to small variations in the experimental data. These issues are more pronounced for the case of pulsed beams. Furthermore, the results suggest that the theoretical modelling of initial recombination used in the three...

  20. An efficient computational approach to characterize DSC-MRI signals arising from three-dimensional heterogeneous tissue structures.

    Science.gov (United States)

    Semmineh, Natenael B; Xu, Junzhong; Boxerman, Jerrold L; Delaney, Gary W; Cleary, Paul W; Gore, John C; Quarles, C Chad

    2014-01-01

    The systematic investigation of susceptibility-induced contrast in MRI is important to better interpret the influence of microvascular and microcellular morphology on DSC-MRI derived perfusion data. Recently, a novel computational approach called the Finite Perturber Method (FPM), which enables the study of susceptibility-induced contrast in MRI arising from arbitrary microvascular morphologies in 3D has been developed. However, the FPM has lower efficiency in simulating water diffusion especially for complex tissues. In this work, an improved computational approach that combines the FPM with a matrix-based finite difference method (FDM), which we call the Finite Perturber the Finite Difference Method (FPFDM), has been developed in order to efficiently investigate the influence of vascular and extravascular morphological features on susceptibility-induced transverse relaxation. The current work provides a framework for better interpreting how DSC-MRI data depend on various phenomena, including contrast agent leakage in cancerous tissues and water diffusion rates. In addition, we illustrate using simulated and micro-CT extracted tissue structures the improved FPFDM along with its potential applications and limitations.

  1. Experimental innovations in surface science a guide to practical laboratory methods and instruments

    CERN Document Server

    Yates, John T

    2015-01-01

    This book is a new edition of a classic text on experimental methods and instruments in surface science. It offers practical insight useful to chemists, physicists, and materials scientists working in experimental surface science. This enlarged second edition contains almost 300 descriptions of experimental methods. The more than 50 active areas with individual scientific and measurement concepts and activities relevant to each area are presented in this book. The key areas covered are: Vacuum System Technology, Mechanical Fabrication Techniques, Measurement Methods, Thermal Control, Delivery of Adsorbates to Surfaces, UHV Windows, Surface Preparation Methods, High Area Solids, Safety. The book is written for researchers and graduate students.

  2. Perfusion deconvolution in DSC-MRI with dispersion-compliant bases.

    Science.gov (United States)

    Pizzolato, Marco; Boutelier, Timothé; Deriche, Rachid

    2017-02-01

    Perfusion imaging of the brain via Dynamic Susceptibility Contrast MRI (DSC-MRI) allows tissue perfusion characterization by recovering the tissue impulse response function and scalar parameters such as the cerebral blood flow (CBF), blood volume (CBV), and mean transit time (MTT). However, the presence of bolus dispersion causes the data to reflect macrovascular properties, in addition to tissue perfusion. In this case, when performing deconvolution of the measured arterial and tissue concentration time-curves it is only possible to recover the effective, i.e. dispersed, response function and parameters. We introduce Dispersion-Compliant Bases (DCB) to represent the response function in the presence and absence of dispersion. We perform in silico and in vivo experiments, and show that DCB deconvolution outperforms oSVD and the state-of-the-art CPI+VTF techniques in the estimation of effective perfusion parameters, regardless of the presence and amount of dispersion. We also show that DCB deconvolution can be used as a pre-processing step to improve the estimation of dispersion-free parameters computed with CPI+VTF, which employs a model of the vascular transport function to characterize dispersion. Indeed, in silico results show a reduction of relative errors up to 50% for dispersion-free CBF and MTT. Moreover, the DCB method recovers effective response functions that comply with healthy and pathological scenarios, and offers the advantage of making no assumptions about the presence, amount, and nature of dispersion. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. TG/DSC-FTIR and Py-GC investigation on pyrolysis characteristics of petrochemical wastewater sludge.

    Science.gov (United States)

    Chen, Jianbiao; Mu, Lin; Jiang, Bo; Yin, Hongchao; Song, Xigeng; Li, Aimin

    2015-09-01

    The pyrolysis characteristics of petrochemical wastewater sludge (PS) were evaluated using TG/DSC-FTIR and fixed-bed reactor with GC. TGA experiments indicated that the pyrolysis of PS proceeded in three phases, and the thermographs shifted to higher temperatures with increasing heating rate. Chars FTIR showed that the absorption of O-H, C-H, C=O and C-C decreased with pyrolysis temperatures increasing. Gases FTIR correspondingly showed that H2O, CO, and CH4 generated at higher temperatures. For the fixed-bed reactor tests, H2 and CO were relatively higher in the pyrolysis gases, and CH4 was negligible at 436K. The kinetic triplets of PS pyrolysis were estimated by Flynn-Wall-Ozawa, Kissinger-Akahira-Sunose, and integral master-plots method. The results suggested that the most potential kinetic models for the first and second phase were the order reaction model, while the random nucleation and nuclei growth model for the third phase.

  4. Monitoring of butter and animal fat oxidation stability by differential scanning calorimetry (DSC

    Directory of Open Access Journals (Sweden)

    Jasminka Sadadinović

    2005-07-01

    Full Text Available Oxidation of fat is one of the basic reactions which causes the depletion of butter and animal fat quality as well as other products containing them. Since the most of reaction products of fat oxidation are harmful for consumers' health, inadequate and scarce monitoring of edible fats and fat containing products quality, presents increased health risk as well as financial loss for the producers. In fat oxidation stability estimation, standard chemical methods were used (iodine number, acid number, peroxide number, anisidine number etc., which require time and chemical usage. Differential scanning calorimetry (DSC analysis presents the simple and efficient way for butter and animal fats oxidation stability estimation. Laboratory investigations were performed to monitor oxidation stability of butter and animal fat in fresh state, as well as in spent phase, used in frying process. The results obtained were compared to the results of standard chemical analysis, and they confirmed the reproducibility and applicability of differential scanning calorimetry in oxidation stability of butter and animal fats monitoring.

  5. Comparative study by TG and DSC Of membranes polyamide66/bentonite clay nanocomposite; Estudo comparativo por TG e DSC de membranas de nanocompositos poliamida66/argila bentonitica

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, K.M. de; Kojuch, L.R.; Araujo, E.M.; Lira, H.L., E-mail: keilamm@ig.com.b [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais; Lima, F. [Universidade Estadual da Paraiba (UEPB), Campina Grande, PB (Brazil). Dept. de Quimica

    2010-07-01

    In this study, it was obtained membranes of nanocomposites polyamide66 with 3 and 5% bentonite clay consists of silicates in layers from the interior of Paraiba. The clay was treated with a quaternary ammonium salt in order to make it organophilic. The membranes were prepared by phase inversion technique from the nanocomposites in solution. The clays were characterized by X-ray diffraction (XRD) and thermogravimetry (TG). Also the membranes were characterized by differential scanning calorimetry (DSC) and TG. The XRD and TG confirmed the presence of salt in the clay and thermal stability of the treated clay. For DSC, it was observed that there was no change in melting temperature of the membranes of nanocomposites compared to membrane pure polyamide66. By TG, it was found that the decomposition of the membranes of polyamide66 with treated clay were higher compared with the untreated clay. (author)

  6. Fast-Scan DSC and its role in pharmaceutical physical form characterisation and selection.

    Science.gov (United States)

    Ford, James L; Mann, Timothy E

    2012-04-01

    Conventional rate Differential Scanning Calorimetry (DSC) has been used for many years as a tool in the analysis of pharmaceutical materials. In recent years an extension of the technique to include fast heating and cooling rates has become more prevalent. Broadly termed Fast-Scan DSC, this review examines the current applications of this technique to the characterisation and selection of pharmaceutical materials. Its increasing use encompasses the characterisation of amorphousness in crystalline materials, the characterisation of polymorphs and polymorphic transitions, the solubility of drugs in polymers, and characterisation of dosage forms. Notwithstanding the advantages of analytical speed in analytical turnover, the review emphasises the advantages of Fast-Scan DSC in its sensitivity which allows the separation of overlapping thermal events, the reduction it provides in degradation during the scanning process and its role in determining solubility in waxy and polymeric based systems. A comparison of the uses of Fast-Scan DSC to modulated DSC techniques and localised thermal analysis is also given.

  7. DSC: software tool for simulation-based design of control strategies applied to wastewater treatment plants.

    Science.gov (United States)

    Ruano, M V; Ribes, J; Seco, A; Ferrer, J

    2011-01-01

    This paper presents a computer tool called DSC (Simulation based Controllers Design) that enables an easy design of control systems and strategies applied to wastewater treatment plants. Although the control systems are developed and evaluated by simulation, this tool aims to facilitate the direct implementation of the designed control system to the PC of the full-scale WWTP (wastewater treatment plants). The designed control system can be programmed in a dedicated control application and can be connected to either the simulation software or the SCADA of the plant. To this end, the developed DSC incorporates an OPC server (OLE for process control) which facilitates an open-standard communication protocol for different industrial process applications. The potential capabilities of the DSC tool are illustrated through the example of a full-scale application. An aeration control system applied to a nutrient removing WWTP was designed, tuned and evaluated with the DSC tool before its implementation in the full scale plant. The control parameters obtained by simulation were suitable for the full scale plant with only few modifications to improve the control performance. With the DSC tool, the control systems performance can be easily evaluated by simulation. Once developed and tuned by simulation, the control systems can be directly applied to the full-scale WWTP.

  8. Yeast SREBP cleavage activation requires the Golgi Dsc E3 ligase complex.

    Science.gov (United States)

    Stewart, Emerson V; Nwosu, Christine C; Tong, Zongtian; Roguev, Assen; Cummins, Timothy D; Kim, Dong-Uk; Hayles, Jacqueline; Park, Han-Oh; Hoe, Kwang-Lae; Powell, David W; Krogan, Nevan J; Espenshade, Peter J

    2011-04-22

    Mammalian lipid homeostasis requires proteolytic activation of membrane-bound sterol regulatory element binding protein (SREBP) transcription factors through sequential action of the Golgi Site-1 and Site-2 proteases. Here we report that while SREBP function is conserved in fungi, fission yeast employs a different mechanism for SREBP cleavage. Using genetics and biochemistry, we identified four genes defective for SREBP cleavage, dsc1-4, encoding components of a transmembrane Golgi E3 ligase complex with structural homology to the Hrd1 E3 ligase complex involved in endoplasmic reticulum-associated degradation. The Dsc complex binds SREBP and cleavage requires components of the ubiquitin-proteasome pathway: the E2-conjugating enzyme Ubc4, the Dsc1 RING E3 ligase, and the proteasome. dsc mutants display conserved aggravating genetic interactions with components of the multivesicular body pathway in fission yeast and budding yeast, which lacks SREBP. Together, these data suggest that the Golgi Dsc E3 ligase complex functions in a post-ER pathway for protein degradation.

  9. Determination of microplastic polyethylene (PE) and polypropylene (PP) in environmental samples using thermal analysis (TGA-DSC).

    Science.gov (United States)

    Majewsky, Marius; Bitter, Hajo; Eiche, Elisabeth; Horn, Harald

    2016-10-15

    Microplastics are increasingly detected in the environment and the consequences on water resources and ecosystems are not clear to date. The present study provides a cost-effective and straightforward method to determine the mass concentrations of polymer types using thermal analysis. Characteristic endothermic phase transition temperatures were determined for seven plastic polymer types using TGA-DSC. Based on that, extracts from wastewater samples were analyzed. Results showed that among the studied polymers, only PE and PP could be clearly identified, while the phase transition signals of the other polymers largely overlap each other. Subsequently, calibration curves were run for PE and PP for qualitative measurements. 240 and 1540mg/m(3) of solid material (12µm to 1mm) was extracted from two wastewater effluent samples of a municipal WWTP of which 34% (81mg/m(3)) and 17% (257mg/m(3)) could be assigned to PE, while PP was not detected in any of the samples. The presented application of TGA-DSC provides a complementary or alternative method to FT-IR analyses for the determination of PE and PP in environmental samples.

  10. Use of the DSC technique to characterize water-in-crude oil emulsions stability; Utilisation de la DSC pour la caracterisation de la stabilite des emulsions eau dans petrole

    Energy Technology Data Exchange (ETDEWEB)

    Dalmazzone, C.; Seris, H. [Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France)

    1998-07-01

    The DSC technique (Differential Scanning Calorimetry) was applied to the study of water-in-crude oil emulsions, which naturally form after an oil spill. The resulting emulsions contain between 50 and 80 % seawater and they are often heavy materials, hard recover mechanically, treat or burn. It is therefore important to assess their stability in order to optimize their treatments. A great variety of techniques are available for the assessment of emulsions stability. They are generally based on the analysis of the droplets size distribution. Unfortunately, most of the usual techniques can not be applied to opaque water-in-oil emulsions. The most useful method to characterize the stability of emulsions is of course the `bottle test`. It consists in monitoring the extent of phase separation with time. This type of test provides a significant amount of information relating to both the stability of the emulsion phase and the clarity of he separated water, but it is very empirical. The DSC technique is generally used to determine the composition of water-in-oil emulsions. It is the only technique capable of distinguishing free water from emulsified water. It was shown in this study that it is a very useful technique, which allows the study of the evolution of the droplet size distribution as well as a precise determination of the water content. (authors) 15 refs.

  11. Theoretical Study of Similar Experimental Method for Durability of Concrete under Artiifcial Climate Environment

    Institute of Scientific and Technical Information of China (English)

    GENG Ou; FENG Tai; LI Debao; LI Qingtao

    2016-01-01

    Based on the similarity theory, a new experimental method named Similar Experimental Method for Durability of Concrete (SEMDC) was established. The existing experimental methods for durability of concrete were summarized, and the merits and demerits of these experimental methods were analyzed. Major factors affecting the durability of concrete were found through literature review. These factors were analyzed and the similarity criteria were established according to the similarity theory, and then the SEMDC was established according to the rules of these criteria. The various influential factors of the experimental method were analyzed and the merits and demerits of this new experimental method were discussed. According to SEMDC, changing the geometry shrinkage ratio was the only way to accelerate the test in order to keep the experiment similar to the reality. There were few other parameters which need to be changed in SEMDC, making the test easy to be achieved. According to SEMDC, time shrinkage ratio was the square of geometric shrinkage ratio, so an appropriate increase of the geometric shrinkage ratio could accelerate the test. Finally, an example of experimental design for durability of concrete was devised theoretically base on SEMDC theory.

  12. A method of analysing experimental data of nuclear reaction cross sections

    Institute of Scientific and Technical Information of China (English)

    FengJun; ShenWen-Qing

    1997-01-01

    A method of analysing experimental data of nuclear reaction cross sections σr induced by radioactive beam is described.It can be used in analysis of experimental unclear reaction cross section data obtained by Na-isopope radioactive beams on different targets.Neutron halo has not been found in these nuclei.

  13. Scaffolded Instruction Improves Student Understanding of the Scientific Method & Experimental Design

    Science.gov (United States)

    D'Costa, Allison R.; Schlueter, Mark A.

    2013-01-01

    Implementation of a guided-inquiry lab in introductory biology classes, along with scaffolded instruction, improved students' understanding of the scientific method, their ability to design an experiment, and their identification of experimental variables. Pre- and postassessments from experimental versus control sections over three semesters…

  14. A new experimental method for the accelerated characterization of composite materials

    Science.gov (United States)

    Yeow, Y. T.; Morris, D. H.; Brinson, H. F.

    1978-01-01

    The use of composite materials for a variety of practical structural applications is presented and the need for an accelerated characterization procedure is assessed. A new experimental and analytical method is presented which allows the prediction of long term properties from short term tests. Some preliminary experimental results are presented.

  15. Validation of Experimental whole-body SAR Assessment Method in a Complex Indoor Environment

    DEFF Research Database (Denmark)

    Bamba, Aliou; Joseph, Wout; Vermeeren, Gunter

    2012-01-01

    Assessing experimentally the whole-body specific absorption rate (SARwb) in a complex indoor environment is very challenging. An experimental method based on room electromagnetics theory (accounting only the Line-Of-Sight as specular path) to assess the whole-body SAR is validated by numerical...

  16. 更胜一筹:Sony DSC-H20

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Sony DSC-H20是H10的后续版本,相比之下新款相机的像素值提高至1010万像素,具备720P、1280×720、30fps高画质录像能力.搭载3英寸、23万像素LCD屏幕。DSC-H20支持双重防抖功能,相机采用10倍光学变焦镜头.

  17. One-step Real-time Food Quality Analysis by Simultaneous DSC-FTIR Microspectroscopy.

    Science.gov (United States)

    Lin, Shan-Yang; Lin, Chih-Cheng

    2016-01-01

    This review discusses an analytical technique that combines differential scanning calorimetry and Fourier-transform infrared (DSC-FTIR) microspectroscopy, which simulates the accelerated stability test and detects decomposition products simultaneously in real time. We show that the DSC-FTIR technique is a fast, simple and powerful analytical tool with applications in food sciences. This technique has been applied successfully to the simultaneous investigation of: encapsulated squid oil stability; the dehydration and intramolecular condensation of sweetener (aspartame); the dehydration, rehydration and solidification of trehalose; and online monitoring of the Maillard reaction for glucose (Glc)/asparagine (Asn) in the solid state. This technique delivers rapid and appropriate interpretations with food science applications.

  18. Formation of cholesterol bilayer domains precedes formation of cholesterol crystals in cholesterol/dimyristoylphosphatidylcholine membranes: EPR and DSC studies.

    Science.gov (United States)

    Mainali, Laxman; Raguz, Marija; Subczynski, Witold K

    2013-08-01

    Saturation-recovery EPR along with DSC were used to determine the cholesterol content at which pure cholesterol bilayer domains (CBDs) and cholesterol crystals begin to form in dimyristoylphosphatidylcholine (DMPC) membranes. To preserve compositional homogeneity throughout the membrane suspension, lipid multilamellar dispersions were prepared using a rapid solvent exchange method. The cholesterol content increased from 0 to 75 mol %. With spin-labeled cholesterol analogues, it was shown that the CBDs begin to form at ~50 mol % cholesterol. It was confirmed by DSC that the cholesterol solubility threshold for DMPC membranes is detected at ~66 mol % cholesterol. At levels above this cholesterol content, monohydrate cholesterol crystals start to form. The major finding is that the formation of CBDs precedes formation of cholesterol crystals. The region of the phase diagram for cholesterol contents between 50 and 66 mol % is described as a structured one-phase region in which CBDs have to be supported by the surrounding DMPC bilayer saturated with cholesterol. Thus, the phase boundary located at 66 mol % cholesterol separates the structured one-phase region (liquid-ordered phase of DMPC with CBDs) from the two-phase region where the structured liquid-ordered phase of DMPC coexists with cholesterol crystals. It is likely that CBDs are precursors of monohydrate cholesterol crystals.

  19. A Dynamic Calibration Method for Experimental and Analytical Hub Load Comparison

    Science.gov (United States)

    2017-03-01

    ARL-RP-0592 ● Mar 2017 US Army Research Laboratory A Dynamic Calibration Method for Experimental and Analytical Hub Load Comparison by Robert P... A Dynamic Calibration Method for Experimental and Analytical Hub Load Comparison by Robert P Thornburgh, Andrew R Kreshock, and Matthew L...other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a

  20. Optimization of experimental conditions of hot wire method in thermal conductivity measurements

    OpenAIRE

    Ma, Luyao

    2012-01-01

    This work studied the hot wire method in measuring thermal conductivity at room temperature. The purpose is to find the optimized experimental conditions to minimize natural convection in liquid for this method, which will be taken as reference for high temperature thermal conductivity measurement of slag. Combining room temperature experiments and simulation with COMSOL Multiphysics 4.2a, the study on different experimental parameters which may influence the accuracy of the measured thermal ...

  1. High-pressure fluid-phase equilibria: Experimental methods and systems investigated (2000-2004)

    DEFF Research Database (Denmark)

    Dohrn, Ralf; Peper, Stephanie; Fonseca, José

    2010-01-01

    , and the experimental method used for the measurements are given in 54 tables. Most of experimental data in the literature have been given for binary systems. Of the 1204 binary systems, 681 (57%) have carbon dioxide as one of the components. Information on 156 pure components, 451 ternary systems of which 267 (62......%) contain carbon dioxide, 150 multicomponent and complex systems, and 129 systems with hydrates is given. Experimental methods for the investigation of high-pressure phase equilibria are classified and described. Work on the continuation of the review series is under way, covering the period between 2005...

  2. Contributions and limitations of experimentation as a method to investigate the educational effects of media

    Directory of Open Access Journals (Sweden)

    Pierre FASTREZ

    2013-07-01

    Full Text Available Communication sciences generally analyse media either as texts, or from the standpoint of their production and reception contexts. Experimental methods are of little use in these cases. Instead, the study of educational communication in a semio-cognitive perspective needs appropriate methods to investigate interactions between the semiotic formats used by the media and their users’ cognitive operations. This article considers the contributions and limitations of the experimental method in this context. We conclude on the necessary articulation of methods in communication sciences, depending on the research questions being examined.

  3. Experimental apparatus for measuring heat transfer coefficients by the Wilson plot method

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Seara, Jose [Area de Maquinas y Motores Termicos, Escuela Superior de Ingenieros Industriales, Campus Lagoas-Marcosende, No 9, 36200 Vigo (Spain); UhIa, Francisco Jose [Area de Maquinas y Motores Termicos, Escuela Superior de Ingenieros Industriales, Campus Lagoas-Marcosende, No 9, 36200 Vigo (Spain); Sieres, Jaime [Area de Maquinas y Motores Termicos, Escuela Superior de Ingenieros Industriales, Campus Lagoas-Marcosende, No 9, 36200 Vigo (Spain); Campo, Antonio [Mechanical Engineering Department, University of Vermont, Burlington, VT 05405 (United States)

    2005-05-01

    The Wilson plot is a technique to estimate the film coefficients in several types of heat transfer processes and to obtain general heat transfer correlations. This method is an outstanding tool in practical applications and in laboratory research activities that involve analysis of heat exchangers. Moreover, the application of this method is simple enough to be taught in laboratory practices for students at university and doctoral level of physics and engineering. Therefore, an experimental apparatus has been designed and built in our laboratory that allows the students to carry out experiments based on the application of the Wilson plot method. In this note, the principles of the method are explained, the experimental apparatus is described and representative results of the experimental data taken from the apparatus and the application of the Wilson plot method are shown. (note)

  4. Recent advances and potential applications of modulated differential scanning calorimetry (mDSC) in drug development

    DEFF Research Database (Denmark)

    Knopp, Matthias Manne; Löbmann, Korbinian; Elder, David P.

    2016-01-01

    of these applications. It is aimed to serve as a broad introduction to newcomers, and also as a valuable reference for those already practising in the field. Complex mDSC was introduced more than two decades ago and has been an important tool for the quantification of amorphous materials and development of freeze...

  5. DSC and NMR Study on the Inclusion Complex of Lappaconitine with β—Cyclodextrin

    Institute of Scientific and Technical Information of China (English)

    KaiJunLIAO; XiaoHuaYAN; 等

    2002-01-01

    The inclusion complex of lappaconitine(Lap) with β-cyclodextrin (β-CD) has been studied by the differential scanning calorimetry (DSC) and 1H-NMR,2D-NMR spectroscopy. The structure of the complex has been deduced.

  6. DSC and NMR Study on the Inclusion Complex of Lappaconitine with β-Cyclodextrin

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The inclusion complex of lappaconitine (Lap) with β-cyclodextrin (β-CD) has been studied by the differential scanning calorimetry (DSC) and 1H-NMR, 2D-NMR spectroscopy.The structure of the complex has been deduced.``

  7. Brain Metastases from Different Primary Carcinomas: an Evaluation of DSC MRI Measurements.

    Science.gov (United States)

    Zhang, H; Zhang, G; Oudkerk, M

    2012-03-01

    This study evaluated the roles of different dynamic susceptibility contrast magnetic imaging (DSC MRI) measurements in discriminating between brain metastases derived from four common primary carcinomas. Thirty-seven patients with brain metastases were enrolled. Relative cerebral blood volume (rCBV), cerebral blood flow (rCBF) and relative mean transit time (rMTT) in both tumor and peritumoral edema were measured. Metastases were grouped by their primary tumor (lung, gastrointestinal, breast and renal cell carcinoma). DSC MRI measurements were compared between groups. Mean rCBV, rCBF, rMTT in tumor and peritumoral edema of all brain metastases (n=37) were 2.79 ± 1.73, 2.56 ± 2.11, 1.21 ± 0.48 and 1.05 ± 0.53, 0.86 ± 0.40, 1.99 ± 0.41, respectively. The tumoral rCBV (5.26 ± 1.89) and rCBF (5.32 ± 3.28) of renal metastases were greater than those of the other three metastases (P0.05). Evaluating various DSC MRI measurements can provide complementary hemodynamic information on brain metastases. The tumoral rCBV, rCBF and likely rMTT can help discriminate between brain metastases originating from different primary carcinomas. The peritumoral DSC MRI measurements had limited value in discriminating between brain metastases.

  8. Rheological and DSC Studies on the Interaction between κ-Carrageenan and Cellulose Nanocrystals (CNC)

    Institute of Scientific and Technical Information of China (English)

    Rui GUO; En Yong DING

    2006-01-01

    Rheometer and differential scanning calorimetry (DSC) have been used to probe the mechanism of gelation in gels formed by mixture of κ-carrageenan and cellulose nanocrystals (CNC). The results indicated that an association occurred between CNC chains and aggregated κ-carrageenan helices.

  9. Thermal analysis on parchments I: DSC and TGA combined approach for heat damage assessment

    DEFF Research Database (Denmark)

    Fessas, D.; Signorelli, M.; Schiraldi, A.;

    2006-01-01

    Ancient, new and artificially aged parchments were investigated with both differential scanning calorimetry (DSC) and thermogravimetry (TGA). Criteria to define a quantitative ranking of the damage experienced by the bulk collagen of historical parchments were assessed. A damage-related correlati...

  10. Determining the main thermodynamic parameters of caffeine melting by means of DSC

    Science.gov (United States)

    Agafonova, E. V.; Moshchenskii, Yu. V.; Tkachenko, M. L.

    2012-06-01

    The temperature and enthalpy of the melting of caffeine, which are 235.5 ± 0.1°C and 19.6 ± 0.2 kJ/mol, respectively, are determined by DSC. The melting entropy and the cryoscopic constant of caffeine are calculated.

  11. Thermal analysis on parchments I: DSC and TGA combined approach for heat damage assessment

    DEFF Research Database (Denmark)

    Fessas, D.; Signorelli, M.; Schiraldi, A.

    2006-01-01

    Ancient, new and artificially aged parchments were investigated with both differential scanning calorimetry (DSC) and thermogravimetry (TGA). Criteria to define a quantitative ranking of the damage experienced by the bulk collagen of historical parchments were assessed. A damage-related correlati...

  12. Rapid examination of the kinetic process of intramolecular lactamization of gabapentin using DSC-FTIR

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, C.-H. [Lab. Pharm. Biopharm., Department of Biotechnology, Yuanpei University, Hsin Chu, Taiwan (China); Lin, S.-Y. [Lab. Pharm. Biopharm., Department of Biotechnology, Yuanpei University, Hsin Chu, Taiwan (China)], E-mail: sylin@mail.ypu.edu.tw

    2009-03-20

    The thermal stability and thermodynamics of gabapentin (GBP) in the solid state were investigated by DSC and TG techniques, and FTIR microspectroscopy. The detailed intramolecular lactamization process of GBP to form gabapentin-lactam (GBP-L) was also determined by thermal FTIR microspectroscopy. GBP exhibited a DSC endothermic peak at 169 deg. C. The weight loss in TG curve of GBP suggested that the evaporation process of water liberated via intramolecular lactamization was simultaneously combined with the evaporation process of GBP-L having a DSC endothermic peak at 91 deg. C. A thermal FTIR microspectroscopy clearly evidenced the IR spectra at 3350 cm{sup -1} for water liberated and at 1701 cm{sup -1} for lactam structure formed due to the lactam formation of GBP. This study indicates that the activation energy for combined processes of intramolecular lactamization of GBP and evaporation of GBP-L was about 114.3 {+-} 23.3 kJ/mol, but for the evaporation of GBP-L alone was 76.2 {+-} 1.5 kJ/mol. A powerful simultaneous DSC-FTIR combined technique was easily used to quickly examine the detailed kinetic processes of intramolecular cyclization of GPB and evaporation of GBP-L in the solid state.

  13. DSC of human hair: a tool for claim support or incorrect data analysis?

    Science.gov (United States)

    Popescu, C; Gummer, C

    2016-10-01

    Differential scanning calorimetry (DSC) data are increasingly used to substantiate product claims of hair repair. Decreasing peak temperatures may indicate structural changes and chemical damage. Increasing the DSC, wet peak temperature is, therefore, often considered as proof of hair repair. A detailed understanding of the technique and hair structure indicates that this may not be a sound approach. Surveying the rich literature on the use of dynamic thermal analysis (DTA) and differential scanning calorimetry (DSC) for the analyses of human hair and the effect of cosmetic treatments, we underline some of the problems of hair structure and data interpretation. To overcome some of the difficulties of data interpretation, we advise that DSC acquired data should be supported by other techniques when used for claim substantiation. In this way, one can provide meaningful interpretation of the hair science and robust data for product claims support. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  14. 触,爱 SONY DSC-T2索尼数码相机

    Institute of Scientific and Technical Information of China (English)

    邢瑜

    2007-01-01

    索尼DSC-T2数码相机是DSC-T1的升级产品.与DSC-T1相比.要小巧秀气了许多.在没有打开镜头的时候,很多人都会误以为它是一个播放器或是小首饰盒之类的物件,无意中DSC-T2迷惑了众人的眼睛。

  15. Kinetics of thermolysis of lanthanum nitrate with hexamethylenetetramine: Crystal structure, TG-DSC, impact and friction sensitivity studies, Part-96

    Science.gov (United States)

    Nibha; Baranwal, B. P.; Singh, Gurdip; Singh, C. P.; Daniliuc, Constantin G.; Soni, P. K.; Nath, Yogeshwar

    2014-11-01

    The development of high energetic materials includes process ability and the ability to attain insensitive munitions (IM). This paper investigates the preparation of lanthanum metal nitrate complex of hexamethylenetetramine in water at room temperature. This complex of molecular formulae [La (NO3)2(H2O)6] (2HMTA) (NO3-) (H2O) was characterized by X-ray crystallography. Thermal decomposition was investigated using TG, TG-DSC and ignition delay measurements. Kinetic analysis of isothermal TG data has been investigated using model fitting methods as well as model free isoconversional methods. The sensitivity measurements towards mechanical destructive stimuli such as impact and friction were carried out and the complex was found to be insensitive. In order to identify the end product of thermolysis, X-ray diffraction patterns of end product was carried out which proves the formation of La2O3.

  16. DSC “peak temperature” versus “maximum slope temperature” in determining TSSD temperature

    Science.gov (United States)

    Khatamian, D.

    2010-10-01

    One of the concerns of the nuclear industry is the deleterious effect of hydrogen on the structural integrity of the reactor core components due to delayed hydride cracking (DHC). The DHC process occurs when hydrogen concentration exceeds the terminal solid solubility (TSS) in the component. Thus, the accurate knowledge of TSS is necessary to predict the lifetime of the components. Differential scanning calorimetry (DSC) is normally used to measure the hydrogen TSS in zirconium alloys. There is a measurable change in the amount of heat absorbed by the specimen when the hydrides dissolve. The hydride dissolution process does not exhibit a well-defined "sharp" change in the heat-flow signal at the transition temperature. A typical DSC heat-flow curve for hydride dissolution has three definite features; "peak temperature" (PT), "maximum slope temperature" (MST) and "completion temperature". The present investigation aims to identify the part of the heat-flow signal that closely corresponds to the TSS temperature for hydride dissolution ( TTSSD). Coupons were cut from a Zr-2.5Nb specimen, which had been previously hydrided using an electrolytic cell to create a surface hydride layer of ˜20 μm thick on all sides of the specimen. The coupons were then annealed isothermally at various temperatures to establish the TTSSD under equilibrium conditions. Subsequently the hydride layer was removed and the coupons were analyzed for TSSD temperature using DSC. The PT and MST for each DSC run were determined and compared to the annealing temperature of the coupon. The results show that the annealing temperature (the equilibrium TTSSD) is much closer to the DSC PT than any other feature of the heat-flow curve.

  17. Choices for Studying Choice: Assessing Charter School Effectiveness Using Two Quasi-Experimental Methods

    Science.gov (United States)

    Davis, Devora H.; Raymond, Margaret E.

    2012-01-01

    Two quasi-experimental methods--fixed effects (FE) and virtual control records (VCR)--were used to measure charter schooling in 14 states and two districts. The new VCR method uses all available observable charter student characteristics and prior performance to create a composite comparison record. A head-to-head comparison of the FE and VCR…

  18. An experimental method to determine the electrostatic field enhancement factor of a practical conductor surface

    DEFF Research Database (Denmark)

    McAllister, Iain Wilson; Crichton, George C

    1989-01-01

    A method of determining the field enhancement factor of a practical conductor is presented. The method is developed from a modified theory of discharge onset in a gaseous medium. This modification incorporates the influence of conductor surface roughness. Onset data from an experimental study tha...

  19. Inhibitors of thermally induced burn incidents – characterization by microbiological procedure, electrophoresis, SEM, DSC and IR spectroscopy.

    Science.gov (United States)

    Pielesz, Anna; Machnicka, Alicja; Gawłowski, Andrzej; Fabia, Janusz; Sarna, Ewa; Biniaś, Włodzimierz

    2015-07-01

    Differential scanning calorimetry (DSC) and thermogravimetric (TGA) investigations, acetate electrophoresis (CAE), Fourier-transform infrared spectrometry (FTIR), scanning electron microscopy (SEM) analysis and microbiological procedures were all carried out after heating the samples to a temperature sufficient for simulating a burn incident. In particular, the purpose of the present study was to analyze the effect of antioxidants, such as fucoidan from brown seaweed and flame-retardant cyclic organophosphates and phosphonates, on an organic chicken skin that gets changed by a burn incident. DSC was considered to be a useful tool in assessing in vitro temperature-mediated cross-linking; an innovative analytical conclusion was obtained from the experimentation described in the paper. FTIR tests revealed that heating a dry organic chicken skin to the boiling point leads to the disappearance of a wide band in the 1650-1550 cm(-1) area or the conversion of a band, which may be attributed to the intermolecular β-sheet aggregates. Fucoidan from brown seaweed and flame-retardant cyclic organophosphates and phosphonates probably bind with the collagen that is changed by the burn (in addition to the influence of antioxidant solutions on samples of a blank or not boiled organic chicken skin) incident forming a polymer film with the collagen of the chicken skin surface (SEM analysis), decreasing the aggregation process and native collagen recovery. Good bacteriostatic properties were determined for fucoidan samples from brown seaweed and flame-retardant cyclic organophosphates and phosphonates against the pathogenic bacteria Escherichia coli and Staphylococcus aureus. Thus, it was observed that the fucoidan incorporated into collagen films can be used as a therapeutically active biomaterial that speeds up the wound-healing process.

  20. METHODS OF EXPERIMENTAL VERIFICATION OF STEINER THEOREM IN PHYSICAL PRACTICUM AND LABORATORY WORK

    Directory of Open Access Journals (Sweden)

    Zharilkasin Iskakov

    2014-07-01

    Full Text Available In this paper, the technique of laboratory work on experimental verification of Steiner’s Theorem in laboratory conditions is developed. To do this, specially designed experimental device was used. The main part of such device is a simple physical pendulum, swinging freely about the axis of suspension, consisting of a cylindrical disc set on a thin rod. To determine the moment of inertia of cylindrical body about the axis of vibrations, property of a physical quantity additivity was used. When processing experimental results, functional approximation by a least squares method was applied; as a result, the empirical expression of Steiner’s Theorem was achieved. Results of experimental studies were very close to the results of theoretical calculations. Laboratory work can be easily repeated for a body of arbitrary shape. The methodology used can be recommended for physical practicum in universities as an effective and easy way of experimental verification of Steiner’s theorem.

  1. Distinct roles of the DmNav and DSC1 channels in the action of DDT and pyrethroids.

    Science.gov (United States)

    Rinkevich, Frank D; Du, Yuzhe; Tolinski, Josh; Ueda, Atsushi; Wu, Chun-Fang; Zhorov, Boris S; Dong, Ke

    2015-03-01

    Voltage-gated sodium channels (Nav channels) are critical for electrical signaling in the nervous system and are the primary targets of the insecticides DDT and pyrethroids. In Drosophila melanogaster, besides the canonical Nav channel, Para (also called DmNav), there is a sodium channel-like cation channel called DSC1 (Drosophila sodium channel 1). Temperature-sensitive paralytic mutations in DmNav (para(ts)) confer resistance to DDT and pyrethroids, whereas DSC1 knockout flies exhibit enhanced sensitivity to pyrethroids. To further define the roles and interaction of DmNav and DSC1 channels in DDT and pyrethroid neurotoxicology, we generated a DmNav/DSC1 double mutant line by introducing a para(ts1) allele (carrying the I265N mutation) into a DSC1 knockout line. We confirmed that the I265N mutation reduced the sensitivity to two pyrethroids, permethrin and deltamethrin of a DmNav variant expressed in Xenopus oocytes. Computer modeling predicts that the I265N mutation confers pyrethroid resistance by allosterically altering the second pyrethroid receptor site on the DmNav channel. Furthermore, we found that I265N-mediated pyrethroid resistance in para(ts1) mutant flies was almost completely abolished in para(ts1);DSC1(-/-) double mutant flies. Unexpectedly, however, the DSC1 knockout flies were less sensitive to DDT, compared to the control flies (w(1118A)), and the para(ts1);DSC1(-/-) double mutant flies were even more resistant to DDT compared to the DSC1 knockout or para(ts1) mutant. Our findings revealed distinct roles of the DmNav and DSC1 channels in the neurotoxicology of DDT vs. pyrethroids and implicate the exciting possibility of using DSC1 channel blockers or modifiers in the management of pyrethroid resistance.

  2. Automatic query generation using word embeddings for retrieving passages describing experimental methods.

    Science.gov (United States)

    Aydın, Ferhat; Hüsünbeyi, Zehra Melce; Özgür, Arzucan

    2017-01-01

    Information regarding the physical interactions among proteins is crucial, since protein-protein interactions (PPIs) are central for many biological processes. The experimental techniques used to verify PPIs are vital for characterizing and assessing the reliability of the identified PPIs. A lot of information about PPIs and the experimental methods are only available in the text of the scientific publications that report them. In this study, we approach the problem of identifying passages with experimental methods for physical interactions between proteins as an information retrieval search task. The baseline system is based on query matching, where the queries are generated by utilizing the names (including synonyms) of the experimental methods in the Proteomics Standard Initiative-Molecular Interactions (PSI-MI) ontology. We propose two methods, where the baseline queries are expanded by including additional relevant terms. The first method is a supervised approach, where the most salient terms for each experimental method are obtained by using the term frequency-relevance frequency (tf.rf) metric over 13 articles from our manually annotated data set of 30 full text articles, which is made publicly available. On the other hand, the second method is an unsupervised approach, where the queries for each experimental method are expanded by using the word embeddings of the names of the experimental methods in the PSI-MI ontology. The word embeddings are obtained by utilizing a large unlabeled full text corpus. The proposed methods are evaluated on the test set consisting of 17 articles. Both methods obtain higher recall scores compared with the baseline, with a loss in precision. Besides higher recall, the word embeddings based approach achieves higher F-measure than the baseline and the tf.rf based methods. We also show that incorporating gene name and interaction keyword identification leads to improved precision and F-measure scores for all three evaluated methods

  3. Automatic query generation using word embeddings for retrieving passages describing experimental methods

    Science.gov (United States)

    Aydın, Ferhat; Hüsünbeyi, Zehra Melce; Özgür, Arzucan

    2017-01-01

    Information regarding the physical interactions among proteins is crucial, since protein–protein interactions (PPIs) are central for many biological processes. The experimental techniques used to verify PPIs are vital for characterizing and assessing the reliability of the identified PPIs. A lot of information about PPIs and the experimental methods are only available in the text of the scientific publications that report them. In this study, we approach the problem of identifying passages with experimental methods for physical interactions between proteins as an information retrieval search task. The baseline system is based on query matching, where the queries are generated by utilizing the names (including synonyms) of the experimental methods in the Proteomics Standard Initiative–Molecular Interactions (PSI-MI) ontology. We propose two methods, where the baseline queries are expanded by including additional relevant terms. The first method is a supervised approach, where the most salient terms for each experimental method are obtained by using the term frequency–relevance frequency (tf.rf) metric over 13 articles from our manually annotated data set of 30 full text articles, which is made publicly available. On the other hand, the second method is an unsupervised approach, where the queries for each experimental method are expanded by using the word embeddings of the names of the experimental methods in the PSI-MI ontology. The word embeddings are obtained by utilizing a large unlabeled full text corpus. The proposed methods are evaluated on the test set consisting of 17 articles. Both methods obtain higher recall scores compared with the baseline, with a loss in precision. Besides higher recall, the word embeddings based approach achieves higher F-measure than the baseline and the tf.rf based methods. We also show that incorporating gene name and interaction keyword identification leads to improved precision and F-measure scores for all three evaluated

  4. Experimental parameter estimation method for nonlinear viscoelastic composite material models: an application on arterial tissue.

    Science.gov (United States)

    Sunbuloglu, Emin; Bozdag, Ergun; Toprak, Tuncer; Islak, Civan

    2013-01-01

    This study is aimed at setting a method of experimental parameter estimation for large-deforming nonlinear viscoelastic continuous fibre-reinforced composite material model. Specifically, arterial tissue was investigated during experimental research and parameter estimation studies, due to medical, scientific and socio-economic importance of soft tissue research. Using analytical formulations for specimens under combined inflation/extension/torsion on thick-walled cylindrical tubes, in vitro experiments were carried out with fresh sheep arterial segments, and parameter estimation procedures were carried out on experimental data. Model restrictions were pointed out using outcomes from parameter estimation. Needs for further studies that can be developed are discussed.

  5. SU-D-18C-02: Feasibility of Using a Short ASL Scan for Calibrating Cerebral Blood Flow Obtained From DSC-MRI

    Energy Technology Data Exchange (ETDEWEB)

    Wang, P; Chang, T; Huang, K; Yeh, C; Chien, C; Wai, Y; Lee, T; Liu, H [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Taoyuan County, Taiwan (R.O.C.). (China)

    2014-06-01

    Purpose: This study aimed to evaluate the feasibility of using a short arterial spin labeling (ASL) scan for calibrating the dynamic susceptibility contrast- (DSC-) MRI in a group of patients with internal carotid artery stenosis. Methods: Six patients with unilateral ICA stenosis enrolled in the study on a 3T clinical MRI scanner. The ASL-cerebral blood flow (-CBF) maps were calculated by averaging different number of dynamic points (N=1-45) acquired by using a Q2TIPS sequence. For DSC perfusion analysis, arterial input function was selected to derive the relative cerebral blood flow (rCBF) map and the delay (Tmax) map. Patient-specific CF was calculated from the mean ASL- and DSC-CBF obtained from three different masks: (1)Tmax< 3s, (2)combined gray matter mask with mask 1, (3)mask 2 with large vessels removed. One CF value was created for each number of averages by using each of the three masks for calibrating the DSC-CBF map. The CF value of the largest number of averages (NL=45) was used to determine the acceptable range(< 10%, <15%, and <20%) of CF values corresponding to the minimally acceptable number of average (NS) for each patient. Results: Comparing DSC CBF maps corrected by CF values of NL (CBFL) in ACA, MCA and PCA territories, all masks resulted in smaller CBF on the ipsilateral side than the contralateral side of the MCA territory(p<.05). The values obtained from mask 1 were significantly different than the mask 3(p<.05). Using mask 3, the medium values of Ns were 4(<10%), 2(<15%) and 2(<20%), with the worst case scenario (maximum Ns) of 25, 4, and 4, respectively. Conclusion: This study found that reliable calibration of DSC-CBF can be achieved from a short pulsed ASL scan. We suggested use a mask based on the Tmax threshold, the inclusion of gray matter only and the exclusion of large vessels for performing the calibration.

  6. DSC Study on the Thermal Hysteresis Activity of Plant Antifreeze Proteins%沙冬青抗冻蛋白热滞活性的DSC研究

    Institute of Scientific and Technical Information of China (English)

    周晓蕾; 陈滔滔; 王保怀; 李芝芬; 费云标; 魏令波; 高素琴

    2001-01-01

    Differential scanning calorimetry (DSC) was used to measure thethermal hysteresis activity(THA) of plant antifreeze proteins(AFPs). The results reveal that DSC is a good method to screen and study AFPs. In the sixteen components extracted from Ammopipanthus mongolicus leaves, one(P3S1) was found to have apparent thermal hysteresis activity by DSC. As the amount of ice nuclei in the sample decreased, the THA of P3S1 increased from 0.01 ℃ to 0.65 ℃ . It is notable that the two-peak thermal hysteresis effect was observed. Two endothermic peaks appeared in the melting process of P3S1, while the freezing peak also consisted of two peaks. The peaks appeared antecedently showed larger thermal effect. This phenomenon shows P3S1 has two different kinds of interaction with water and ice crystal. It is probably an important property of a class of AFPs.

  7. Method Experimental Definition of Efficiency Fuelburn in a Gas Reactors with Mini Channels

    OpenAIRE

    Slesareva Ekaterina; Elistratov Sergey; Ovchinnikov Valeriy

    2016-01-01

    Approbation of a method of experimental definition of efficiency of a fuelburn in minichanneling gas reactors has been carried out. The method of visualisation of a field of temperatures by the temperature transducer made of fine-meshed with low-inertia use for definition of thermal structure of gas streams. A field of temperatures on an outlet the simulator of a gas reactor with minichannels registered on thermogram by infrared imager. Experiments have shown that the thermal imaging method p...

  8. Experimental implementation of a low-frequency global sound equalization method based on free field propagation

    DEFF Research Database (Denmark)

    Santillan, Arturo Orozco; Pedersen, Christian Sejer; Lydolf, Morten

    2007-01-01

    An experimental implementation of a global sound equalization method in a rectangular room using active control is described in this paper. The main purpose of the work has been to provide experimental evidence that sound can be equalized in a continuous three-dimensional region, the listening zone......, which occupies a considerable part of the complete volume of the room. The equalization method, based on the simulation of a progressive plane wave, was implemented in a room with inner dimensions of 2.70 m x 2.74 m x 2.40 m. With this method,the sound was reproduced by a matrix of 4 x 5 loudspeakers...... filter for each transducer. The optimal arrangement of the loudspeakers and the maximum frequency that can be equalized is analyzed theoretically in this paper. The presented experimental results show that sound equalization was possible from 10 Hz to approximately 425 Hz in the listening zone. A flat...

  9. Systematic investigation of lard polymorphism using combined DSC and time-resolved synchrotron X-ray diffraction

    NARCIS (Netherlands)

    Kalnin, D.J.E.; Lesieur, P.; Artzner, F.; Keller, G.; Ollivon, M.

    2005-01-01

    The polymorphic behavior of lard was systematically investigated by differential scanning calorimetry (DSC) while simultaneously monitoring the formation of the different crystal forms with X-ray diffraction (XRDT). To interpret the complex polymorphic evolution of the sample analyzed by regular DSC

  10. Comparison between experimental and computational methods for scattering anisotropy coefficient determination in dental-resin composites

    Science.gov (United States)

    Fernández-Oliveras, Alicia; Carrasco, Irene M.; Ghinea, Razvan; Pérez, María M.; Rubiño, Manuel

    2012-06-01

    Understanding the behaviour of light propagation in biological materials is essential for biomedical engineering and its applications. Among the key optical properties of biological media is the angular distribution of the scattered light, characterized by the average cosine of the scattering angle, called the scattering anisotropy coefficient (g). The value of g can be determined by experimentally irradiating the material with a laser beam and making angular-scattering measurements in a goniometer. In this work, an experimental technique was used to determine g by means of goniometric measurements of the laser light scattered off two different dental-resin composites (classified as nano and hybrid). To assess the accuracy of the experimental method, a Mie theory-based computational model was used. Independent measurements were used to determine some of the required input parameters for computation of the theoretical model. The g values estimated with the computational method (nano-filled: 0.9399; hybrid: 0.8975) and the values calculated with the experimental method presented (nano-filled: 0.98297 +/- 0.00021; hybrid: 0.95429 +/- 0.00014) agreed well for both dental resins, with slightly higher experimental values. The higher experimental values may indicate that the scattering particle causes more narrow-angle scattering than does a perfect sphere of equal volume, assuming that with more spherical scattering particles the scattering anisotropy coefficient increases. Since g represents the angular distribution of the scattered light, values provided by both the experimental and the computational methods show a strongly forward-directed scattering in the dental resins studied, more pronounced in the nano-filled composite than in the hybrid composite.

  11. Effect of experimental methods for selective development of motor skills of young karatists

    Directory of Open Access Journals (Sweden)

    Volodymir Galimskyi

    2014-11-01

    Full Text Available Purpose: justify, develop and experimentally verify the effectiveness of the pilot program of development of physical qualities of young karate during pre-basic training. Material and Methods: The study was conducted on 52 karate 10–12 years. Applied pedagogical experiment, teacher testing and statistical methods. Results: identify the means program development and evaluation criteria of physical fitness of young karate. Conclusions: The use of the author's program contributed to a more significant increase in special physical preparedness karate experimental group.

  12. CISM-Course on Modern Optical Methods in Experimental Solid Mechanics

    CERN Document Server

    2000-01-01

    The book covers the theories and physics of advanced new optical measuring methods and problems of experimental performance, recent achievements in the basic interferometric methods holography, speckle-interferometry, shearography as well as linear/non-linear photoelasticity and photoviscoelasticity, Moiré- and grid-techniques. It deals with theory and application of digital image processing, methods of data recording, data processing and -visualisation, with mathematical/numerical procedures for final evaluation of digitised measured data and the principle of hybrid techniques. It introduces into the new perceptions of methods in experimental solid mechanics and it should encourage scientists to deal intensively with the theories for further developments, and enables practitioners, to understand theory and physics of the new achievements at least and to apply the methods in research als well as in developments in practice.

  13. Reverse Schreinemakers Method for Experimental Analysis of Mixed-Solvent Electrolyte Systems

    DEFF Research Database (Denmark)

    Fosbøl, Philip Loldrup; Thomsen, Kaj; Stenby, Erling Halfdan

    2009-01-01

    from determining the composition of salt mixtures by pH titration are discussed, and the derived method significantly improves the obtained result from titration. Furthermore, the method reduces the required experimental work needed for analysis of phase composition. The method is applicable to multi......A method based on Schreinemakers's tie-line theory of 1893 is derived for determining the composition and phase amounts in solubility experiments for multi-solvent electrolyte systems. The method uses the lever rule in reverse compared to Schreinemakers's wet residue method, and is therefore called...... the reverse Schreinemakers (RS) method. The method is based on simple mass balance principles similar to the wet residues method. It allows for accurate determination of the mixed-solvent phase composition even though part of the solvent may precipitate as complexes between solvent and salt. Discrepancies...

  14. Evaluating the osseointegration of nanostructured titanium implants in animal models: Current experimental methods and perspectives (Review).

    Science.gov (United States)

    Babuska, Vaclav; Moztarzadeh, Omid; Kubikova, Tereza; Moztarzadeh, Amin; Hrusak, Daniel; Tonar, Zbynek

    2016-09-15

    The aim of this paper is to review the experimental methods currently being used to evaluate the osseointegration of nanostructured titanium implants using animal models. The material modifications are linked to the biocompatibility of various types of oral implants, such as laser-treated, acid-etched, plasma-coated, and sand-blasted surface modifications. The types of implants are reviewed according to their implantation site (endoosseous, subperiosteal, and transosseous implants). The animal species and target bones used in experimental implantology are carefully compared in terms of the ratio of compact to spongy bone. The surgical technique in animal experiments is briefly described, and all phases of the histological evaluation of osseointegration are described in detail, including harvesting tissue samples, processing undemineralized ground sections, and qualitative and quantitative histological assessment of the bone-implant interface. The results of histological staining methods used in implantology are illustrated and compared. A standardized and reproducible technique for stereological quantification of bone-implant contact is proposed and demonstrated. In conclusion, histological evaluation of the experimental osseointegration of dental implants requires careful selection of the experimental animals, bones, and implantation sites. It is also advisable to use larger animal models and older animals with a slower growth rate rather than small or growing experimental animals. Bones with a similar ratio of compact to spongy bone, such as the human maxilla and mandible, are preferred. A number of practical recommendations for the experimental procedures, harvesting of samples, tissue processing, and quantitative histological evaluations are provided.

  15. Highly Efficient Design-of-Experiments Methods for Combining CFD Analysis and Experimental Data

    Science.gov (United States)

    Anderson, Bernhard H.; Haller, Harold S.

    2009-01-01

    It is the purpose of this study to examine the impact of "highly efficient" Design-of-Experiments (DOE) methods for combining sets of CFD generated analysis data with smaller sets of Experimental test data in order to accurately predict performance results where experimental test data were not obtained. The study examines the impact of micro-ramp flow control on the shock wave boundary layer (SWBL) interaction where a complete paired set of data exist from both CFD analysis and Experimental measurements By combining the complete set of CFD analysis data composed of fifteen (15) cases with a smaller subset of experimental test data containing four/five (4/5) cases, compound data sets (CFD/EXP) were generated which allows the prediction of the complete set of Experimental results No statistical difference were found to exist between the combined (CFD/EXP) generated data sets and the complete Experimental data set composed of fifteen (15) cases. The same optimal micro-ramp configuration was obtained using the (CFD/EXP) generated data as obtained with the complete set of Experimental data, and the DOE response surfaces generated by the two data sets were also not statistically different.

  16. In Situ Stability of Substrate-Associated Cellulases Studied by DSC

    DEFF Research Database (Denmark)

    Borch, Kim; Cruys-Bagger, Nicolaj; Badino, Silke Flindt

    2014-01-01

    . There was no correlation between the intrinsic stability, specified by the transition temperature in the DSC, and the long-term stability derived from the peak area. The results are discussed with respect to the role of enzyme denaturation for the ubiquitous slowdown observed in the enzymatic hydrolysis of cellulose.......This work shows that differential scanning calorimetry (DSC) can be used to monitor the stability of substrate-adsorbed cellulases during long-term hydrolysis of insoluble cellulose. Thermal transitions of adsorbed enzyme were measured regularly in subsets of a progressing hydrolysis, and the size...... of the transition peak was used as a gauge of the population of native enzyme. Analogous measurements were made for enzymes in pure buffer. Investigations of two cellobiohydrolases, Cel6A and Cel7A, from Trichoderma reesei, which is an anamorph of the fungus Hypocrea jerorina, showed that these enzymes were...

  17. A new experimental design method to optimize formulations focusing on a lubricant for hydrophilic matrix tablets.

    Science.gov (United States)

    Choi, Du Hyung; Shin, Sangmun; Khoa Viet Truong, Nguyen; Jeong, Seong Hoon

    2012-09-01

    A robust experimental design method was developed with the well-established response surface methodology and time series modeling to facilitate the formulation development process with magnesium stearate incorporated into hydrophilic matrix tablets. Two directional analyses and a time-oriented model were utilized to optimize the experimental responses. Evaluations of tablet gelation and drug release were conducted with two factors x₁ and x₂: one was a formulation factor (the amount of magnesium stearate) and the other was a processing factor (mixing time), respectively. Moreover, different batch sizes (100 and 500 tablet batches) were also evaluated to investigate an effect of batch size. The selected input control factors were arranged in a mixture simplex lattice design with 13 experimental runs. The obtained optimal settings of magnesium stearate for gelation were 0.46 g, 2.76 min (mixing time) for a 100 tablet batch and 1.54 g, 6.51 min for a 500 tablet batch. The optimal settings for drug release were 0.33 g, 7.99 min for a 100 tablet batch and 1.54 g, 6.51 min for a 500 tablet batch. The exact ratio and mixing time of magnesium stearate could be formulated according to the resulting hydrophilic matrix tablet properties. The newly designed experimental method provided very useful information for characterizing significant factors and hence to obtain optimum formulations allowing for a systematic and reliable experimental design method.

  18. 索尼DSC-S85数码相机试用记

    Institute of Scientific and Technical Information of China (English)

    杨明

    2003-01-01

    @@ Cyber-shot DSC-S85是索尼公司于2001年推出的第一款410万像素Super HAD CCD的数码照相机,但其太传统化的外形设计,几度要毁掉我购买它的信心,不过最终还是把它抱回家,因为是它的品质打动我.

  19. Advanced Life Analysis Methods. Volume 3. Experimental Evaluation of Crack Growth Analysis Methods for Attachment Lugs

    Science.gov (United States)

    1984-09-17

    Structural Lugs 10 6.00 TETM TESX, MARI LOCKHEED L𔃼.0 GRUP IIhA AND 2Rii * 2~~~~.0 .RUPINI .01 .05 1 .2 .5. 9 99PROABLTY F*ý,r 1-40 4oprsno R ato nTs rga...monitor loads and perform failsafe functions . A sinewave function generator provides load commands to the servo loop and a calibrated amplitude measurement...Simple Compounding Solution o 2-D Cracked Finite Element Procedure o Green’s Function Method 0 3-D Cracked Finite Element PrTocedure Parameters and

  20. Utilisation de la DSC pour la caractérisation de la stabilité des émulsions eau dans pétrole Use of the Dsc Technique to Characterize Water-In-Crude Oil Emulsions Stability

    Directory of Open Access Journals (Sweden)

    Dalmazzone C.

    2006-12-01

    the assessment of emulsions stability. They are generally based on the analysis of the droplets size distribution. Unfortunately, most of the usual techniques can not be applied to opaque water-in-oil emulsions. The most useful method to characterize the stability of emulsions is of course the bottle test . It consists in monitoring the extent of phase separation with time. This type of test provides a significant amount of information relating to both the stability of the emulsion phase and the clarity of the separated water, but it is very empirical. The DSC technique is generally used to determine the composition of water-in-oil emulsions. It is the only technique capable of distinguishing free water from emulsified water. It was shown in this study that it is a very useful technique, which allows the study of the evolution of the droplet size distribution as well as a precise determination of the water content.

  1. High-pressure fluid-phase equilibria: Experimental methods and systems investigated (2005-2008)

    DEFF Research Database (Denmark)

    Fonseca, José; Dohrn, Ralf; Peper, Stephanie

    2011-01-01

    A review of systems is given, for which experimental high-pressure phase-equilibrium data were published in the period between 2005 and 2008, continuing a series of reviews. To find candidates for articles that are of interest for this survey a three-stage search strategy was used including...... a systematic search of the contents of the 17 most important journals of the field. Experimental methods for the investigation of high-pressure phase equilibria were classified, described and illustrated using examples from articles of the period between 2005 and 2008. For the systems investigated......, the reference, the temperature and pressure range of the data, and the experimental method used for the measurements is given in 54 tables. Vapor–liquid equilibria, liquid–liquid equilibria, vapor–liquid–liquid equilibria, solid–liquid equilibria, solid–vapor equilibria, solid–vapor–liquid equilibria, critical...

  2. An improved mixed numerical-experimental method for stress field calculation

    Science.gov (United States)

    Lopes, H. M. R.; Guedes, R. M.; Vaz, M. A.

    2007-07-01

    In this work a numerical-experimental method is used to study the dynamic behavior of an aluminum plate subjected to a small mass impact. The out-of-plane displacements, due to transient bending wave propagation, were assessed for successive time instants, using double pulse TV-holography, also known as pulsed ESPI. The experimental setup and the image processing methods were improved to allow the calculation of the plate transient stress field. Integral transforms are used to obtain the strain fields from spatial derivatives of displacements noisy data. A numerical simulation of the plate transient response was carried out with FEM Ansys ®. For this purpose a PZT transducer was used to record the impact force history, which was inputted in the numerical model. Finally, the comparisons between numerical and experimental results are presented in order to validate the present methodology.

  3. Recent mouse and rat methods for the study of experimental oral candidiasis

    Science.gov (United States)

    Costa, Anna CBP; Pereira, Cristiane A; Junqueira, Juliana C; Jorge, Antonio OC

    2013-01-01

    The Candida genus expresses virulence factors that, when combined with immunosuppression and other risk factors, can cause different manifestations of oral candidiasis. The treatment of mucosal infections caused by Candida and the elucidation of the disease process have proven challenging. Therefore, the study of experimentally induced oral candidiasis in rats and mice is useful to clarify the etiopathology of this condition, improve diagnosis, and search for new therapeutic options because the disease process in these animals is similar to that of human candidiasis lesions. Here, we describe and discuss new studies involving rat and mouse models of oral candidiasis with respect to methods for inducing experimental infection, methods for evaluating the development of experimental candidiasis, and new treatment strategies for oral candidiasis. PMID:23715031

  4. High fidelity studies of exploding foil initiator bridges, Part 1: Experimental method

    Science.gov (United States)

    Bowden, Mike; Neal, William

    2017-01-01

    Simulations of high voltage detonators, such as Exploding Bridgewire (EBW) and Exploding Foil Initiators (EFI), have historically been simple, often empirical, one-dimensional models capable of predicting parameters such as current, voltage and in the case of EFIs, flyer velocity. Correspondingly, experimental methods have in general been limited to the same parameters. With the advent of complex, first principles magnetohydrodynamic codes such as ALEGRA and ALE-MHD, it is now possible to simulate these components in three dimensions, predicting a much greater range of parameters than before. A significant improvement in experimental capability was therefore required to ensure these simulations could be adequately validated. In this first paper of a three part study, the experimental method for determining the current, voltage, flyer velocity and multi-dimensional profile of detonator components is presented. This improved capability, along with high fidelity simulations, offer an opportunity to gain a greater understanding of the processes behind the functioning of EBW and EFI detonators.

  5. Recent mouse and rat methods for the study of experimental oral candidiasis.

    Science.gov (United States)

    Costa, Anna C B P; Pereira, Cristiane A; Junqueira, Juliana C; Jorge, Antonio O C

    2013-07-01

    The Candida genus expresses virulence factors that, when combined with immunosuppression and other risk factors, can cause different manifestations of oral candidiasis. The treatment of mucosal infections caused by Candida and the elucidation of the disease process have proven challenging. Therefore, the study of experimentally induced oral candidiasis in rats and mice is useful to clarify the etiopathology of this condition, improve diagnosis, and search for new therapeutic options because the disease process in these animals is similar to that of human candidiasis lesions. Here, we describe and discuss new studies involving rat and mouse models of oral candidiasis with respect to methods for inducing experimental infection, methods for evaluating the development of experimental candidiasis, and new treatment strategies for oral candidiasis.

  6. Experimental study on the compressive strength of grouted concrete block masonry based on nondestructive detection methods

    Institute of Scientific and Technical Information of China (English)

    JIANG Hong-bin; LI Long-fei

    2009-01-01

    Existing nondestructive detection methods were adopted to test the compressive strength of grouted concrete block masonry, i.e. the rebound method, pulling-out method and core drilling method were employed to test the strength of block, mortar and grouted concrete, respectively. The suitability of these methods for the testing of strength of grouted concrete block masonry was discussed, and the comprehensive strength of block masonry was appraised by combining existing nondestructive or micro-destructive detection methods. The nondestructive detection test on 25 grouted concrete block masonry specimens was carried out. Experimental results show that these methods mentioned above are applicable for the strength detection of grouted concrete block masonry. Moreover, the formulas of compressive strength, detection methods and proposals are given as well.

  7. Monitoring of Pentoxifylline Thermal Behavior by Novel Simultaneous Laboratory Small and Wide X-Ray Scattering (SWAXS) and Differential Scanning Calorimetry (DSC).

    Science.gov (United States)

    Hodzic, Aden; Kriechbaum, Manfred; Schrank, Simone; Reiter, Franz

    2016-01-01

    The thermal and structural evolutions associated to active pharmaceutical ingredient (API) purity are monitored using a laboratory instrument (S3-MicroCaliX) allowing simultaneous time-resolved X-ray scattering at both wide and small angles (SWAXS) as a function of temperature. This is performed simultaneously with differential scanning calorimetric (DSC) that is carried out in the same apparatus at scanning rate of 2 K/min on the same sample in the range from 20° to 200°C. We have studied simultaneous thermal and structural properties of pentoxifylline, as an active pharmaceutical ingredient (API), for its purity quality control. We have found a satisfying API purity, due to obtained melting temperature and enthalpy values, which are in a well agreement with literature. We have also found that the combination of these techniques allows the thermal monitoring of scanning rates of 2 K/min, continuously without the need for static thermal equilibration, particularly for X-ray spectra. Hence, DSC and SWAXS allowing better identification of the structural thermal events recorded by following of the phase transitions simultaneously. This interpretation is much better possible when X-ray scattering at small and wide angles is coupled with DSC from the same sample. Hence, as a laboratory tool, the method presents a reproducible thermal and crystallographic API purity quality control of non-complex samples, as crucial information for pharmaceutical technology.

  8. A Toxocara cati eggs concentration method from cats' faeces, for experimental and diagnostic purposes.

    Science.gov (United States)

    Cardillo, N; Sommerfelt, I; Fariña, F; Pasqualetti, M; Pérez, M; Ercole, M; Rosa, A; Ribicich, M

    2014-09-01

    Toxocariosis is a zoonotic parasite infection worldwide distributed, now considered a neglected disease associated to poverty. For experimental infection in animals and to develop the diagnosis in humans it is necessary to obtain large number of Toxocara spp. larval eggs. Toxocara cati eggs recovered percentage from faeces of infected cats was determined employing a novel egg concentration method. The McMaster egg counting technique and the concentration method were applied on 20 positive cats' sample faeces obtained from naturally infected cats. The mean percentage of eggs recovered by the concentration method was 24.37% higher than the count obtained by McMaster egg counting technique. The main advantage of this method is that it can be obtained a small final volume with a high number of recovered eggs and a good quality inoculum for experimental and diagnostic purposes.

  9. Efficient and Minimal Method to Bias Molecular Simulations with Experimental Data.

    Science.gov (United States)

    White, Andrew D; Voth, Gregory A

    2014-08-12

    A primary goal in molecular simulations is to modify the potential energy of a system so that properties of the simulation match experimental data. This is traditionally done through iterative cycles of simulation and reparameterization. An alternative approach is to bias the potential energy so that the system matches experimental data. This can be done while minimally changing the underlying free energy of the molecular simulation. Current minimal biasing methods require replicas, which can lead to unphysical dynamics and introduces new complexity: the choice of replica number and their properties. Here, we describe a new method, called experiment directed simulation that does not require replicas, converges rapidly, can match many data simultaneously, and minimally modifies the potential. The experiment directed simulation method is demonstrated on model systems and a three-component electrolyte simulation. The theory used to derive the method also provides insight into how changing a molecular force-field impacts the expected value of observables in simulation.

  10. Validation of Experimental whole-body SAR Assessment Method in a Complex Indoor Environment

    DEFF Research Database (Denmark)

    Bamba, Aliou; Joseph, Wout; Vermeeren, Gunter

    2012-01-01

    Assessing experimentally the whole-body specific absorption rate (SARwb) in a complex indoor environment is very challenging. An experimental method based on room electromagnetics theory (accounting only the Line-Of-Sight as specular path) to assess the whole-body SAR is validated by numerical...... simulations with the Finite-Difference Time-Domain method. Furthermore, the method accounts for the diffuse multipath components (DMC) in the total absorption rate by considering the reverberation time of the investigated room, which describes all the losses in a complex indoor environment. The advantage...... of the proposed method is that it allows discarding the computation burden because it does not use any discretizations. Results show good agreement between measurement and computation at 2.8 GHz, as long as the plane wave assumption is valid, i.e., for high distances from the transmitter. Relative deviations 0...

  11. The Measurement of Electron-Induced Erosion of Condensed Gases: Experimental Methods

    DEFF Research Database (Denmark)

    Schou, Jørgen; Sørensen, H.; Børgesen, P.

    1984-01-01

    Two experimental methods for measuring the erosion yield of condensed gases are described. One, the frequency-change method, utilizes a quartz-crystal microbalance operating at liquid-helium temperature. The other, the emissivity-change method is based on the strongly varying electron emission...... as a function of the condensed-gas film thickness. Satisfactory results have been obtained for both methods for solid Ne and D2 at electron energies up to 3 keV, and the mutual agreement is good as well. Accurate measurements are affected critically by the beam conditions, particularly if the erosion yield...

  12. Yeast sterol regulatory element-binding protein (SREBP) cleavage requires Cdc48 and Dsc5, a ubiquitin regulatory X domain-containing subunit of the Golgi Dsc E3 ligase.

    Science.gov (United States)

    Stewart, Emerson V; Lloyd, S Julie-Ann; Burg, John S; Nwosu, Christine C; Lintner, Robert E; Daza, Riza; Russ, Carsten; Ponchner, Karen; Nusbaum, Chad; Espenshade, Peter J

    2012-01-01

    Schizosaccharomyces pombe Sre1 is a membrane-bound transcription factor that controls adaptation to hypoxia. Like its mammalian homolog, sterol regulatory element-binding protein (SREBP), Sre1 activation requires release from the membrane. However, in fission yeast, this release occurs through a strikingly different mechanism that requires the Golgi Dsc E3 ubiquitin ligase complex and the proteasome. The mechanistic details of Sre1 cleavage, including the link between the Dsc E3 ligase complex and proteasome, are not well understood. Here, we present results of a genetic selection designed to identify additional components required for Sre1 cleavage. From the selection, we identified two new components of the fission yeast SREBP pathway: Dsc5 and Cdc48. The AAA (ATPase associated with diverse cellular activities) ATPase Cdc48 and Dsc5, a ubiquitin regulatory X domain-containing protein, interact with known Dsc complex components and are required for SREBP cleavage. These findings provide a mechanistic link between the Dsc E3 ligase complex and the proteasome in SREBP cleavage and add to a growing list of similarities between the Dsc E3 ligase and membrane E3 ligases involved in endoplasmic reticulum-associated degradation.

  13. Subunit architecture of the Golgi Dsc E3 ligase required for sterol regulatory element-binding protein (SREBP) cleavage in fission yeast.

    Science.gov (United States)

    Lloyd, S Julie-Ann; Raychaudhuri, Sumana; Espenshade, Peter J

    2013-07-19

    The membrane-bound sterol regulatory element-binding protein (SREBP) transcription factors regulate lipogenesis in mammalian cells and are activated through sequential cleavage by the Golgi-localized Site-1 and Site-2 proteases. The mechanism of fission yeast SREBP cleavage is less well defined and, in contrast, requires the Golgi-localized Dsc E3 ligase complex. The Dsc E3 ligase consists of five integral membrane subunits, Dsc1 through Dsc5, and resembles membrane E3 ligases that function in endoplasmic reticulum-associated degradation. Using immunoprecipitation assays and blue native electrophoresis, we determined the subunit architecture for the complex of Dsc1 through Dsc5, showing that the Dsc proteins form subcomplexes and display defined connectivity. Dsc2 is a rhomboid pseudoprotease family member homologous to mammalian UBAC2 and a central component of the Dsc E3 ligase. We identified conservation in the architecture of the Dsc E3 ligase and the multisubunit E3 ligase gp78 in mammals. Specifically, Dsc1-Dsc2-Dsc5 forms a complex resembling gp78-UBAC2-UBXD8. Further characterization of Dsc2 revealed that its C-terminal UBA domain can bind to ubiquitin chains but that the Dsc2 UBA domain is not essential for yeast SREBP cleavage. Based on the ability of rhomboid superfamily members to bind transmembrane proteins, we speculate that Dsc2 functions in SREBP recognition and binding. Homologs of Dsc1 through Dsc4 are required for SREBP cleavage and virulence in the human opportunistic pathogen Aspergillus fumigatus. Thus, these studies advance our organizational understanding of multisubunit E3 ligases involved in endoplasmic reticulum-associated degradation and fungal pathogenesis.

  14. Development of an experimental method to determine the axial rigidity of a strut-node joint

    Science.gov (United States)

    Brewer, W. V.; Shih, Hui-Ru

    1993-01-01

    The following are presented: the experimental procedure and the results that have been performed to determine the axial rigidity of the strut-node joint; and the method for modifying a simple testing machine to make it capable of performing more accurate tests over a specific load range and able to accept larger test assemblies.

  15. On determination of microphone response and other parameters by a hybrid experimental and numerical method

    DEFF Research Database (Denmark)

    Barrera Figueroa, Salvador; Jacobsen, Finn; Rasmussen, Knud

    2008-01-01

    such as the acoustic centres. In this work, a hybrid method is presented. The velocity distributions of condenser Laboratory Standard microphones were measured using a laser vibrometer. This measured velocity distribution was used for estimating the microphone responses and parameters. The agreement with experimental...

  16. Synergy between experimental and theoretical methods in the exploration of homogeneous transition metal catalysis

    DEFF Research Database (Denmark)

    Lupp, Daniel; Christensen, Niels Johan; Fristrup, Peter

    2014-01-01

    n this Perspective, we will focus on the use of both experimental and theoretical methods in the exploration of reaction mechanisms in homogeneous transition metal catalysis. We briefly introduce the use of Hammett studies and kinetic isotope effects (KIE). Both of these techniques can be complem...

  17. Student's perception and experience of computer assisted learning as a teaching method in experimental pharmacology

    Directory of Open Access Journals (Sweden)

    Deepika Tikoo

    2015-12-01

    Conclusion: The study demonstrates the effectiveness of CAL in teaching experimental pharmacology concepts and the students felt that this method helped them in a better understanding of the topic as the effects were clearly visualized on the screen and that such simulations need to be a part of the standard curriculum. [Int J Basic Clin Pharmacol 2015; 4(6.000: 1168-1174

  18. A Statistical Comparison Method of the Differences among Single Points for Linear Dynamic Experimental Data

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The experimental random error and desired valuse of non-observed points in dynamic indexes were estimated by establishing the linear regression equations about variety regulations of dynamic indexes. The methods for difference significant test among different treatments using dynamic point as indexes were presented without setting the replication on each dynamic point observed.

  19. Methods of computer processing of experimental data on the intensity of bunches in synchrotrons

    Science.gov (United States)

    Zhabitsky, V. M.

    2016-12-01

    Methods of computer processing of experimental data on the intensity of bunches in synchrotrons for the purpose of receiving functional dependences from time during the accelerating cycle for a number of circulating particles and the mean-square length of a bunch are discussed. Examples of such dependences for the beam at the nuclotron (JINR) and PSB (CERN) are presented.

  20. The Use of Techniques of Sensory Evaluation as a Framework for Teaching Experimental Methods.

    Science.gov (United States)

    Bennett, R.; Hamilton, M.

    1981-01-01

    Describes sensory assessment techniques and conditions for their satisfactory performance, including how they can provide open-ended exercises and advantages as relatively inexpensive and simple methods of teaching experimentation. Experiments described focus on diffusion of salt into potatoes after being cooked in boiled salted water. (Author/JN)

  1. TRANSPLANTATION OF HEPATOCYTES AS THE METHOD OF TREATMENT OF LIVER FAILURE: EXPERIMENTAL AND CLINICAL EXPERIENCE

    Directory of Open Access Journals (Sweden)

    M. Y. Shagidulin

    2010-01-01

    Full Text Available For correction and treatment of liver failure before liver transplantation were proposed severe methods such as: extracorporal devices, transplantation of hepatocytes and implanted tissue-engineering units. The function of healthy hepatocytes presumes to stabilize the state of patients with chronic liver diseases and to wait a donor organ transplantation. In this review the results of experimental and clinical therapy of liver diseases by method of hepatocyte transplantation were summarized. 

  2. Polymeric Materials Review on Oxidation, Stabilization and Evaluation using CL and DSC Methods

    CERN Document Server

    Ilie, Sorin; CERN. Geneva. TE Department

    2009-01-01

    Within TE - VSC Group, the Chemistry Laboratory actually works on the project entitled “Studies of Radiation Induced Aging Effects in Polymeric Cable Insulators”. The aim of the project is the characterization and the evaluation of the aging effects mainly induced by ionizing radiations on the various polymeric materials in cables structure. It is expected, using the accumulated data, to foresee the life-time of these materials in the specific CERN accelerator systems and, also, to assure an acceptance quality control of the supplied cables in CERN.

  3. Determination of the melting temperature, heat of fusion, and purity analysis of different samples of zidovudine (AZT using DSC

    Directory of Open Access Journals (Sweden)

    Adriano Antunes Souza Araújo

    2010-03-01

    Full Text Available The determination of chemical purity, melting range, and variation of enthalpy in the process of characterizing medicines is one of the principal requirements evaluated in quality control of the pharmaceutical industry. In this study, the method of purity determination using DSC was outlined, as well as the application of this technique for the evaluation of commercial samples of zidovudine (AZT (raw material supplied by different laboratories. To this end, samples from six different laboratories (A, B, C, D, E, and F and the standard reference (R from the United States Pharmacopeia (USP were analyzed. The DSC curves were obtained in the temperature range of 25 to 200 ºC under the dynamic atmosphere of N2 (50 mL min-1, heating rate of β=2 ºC min-1, using an Al capsule containing approximately 2 mg of sample material. The results demonstrated that the standard reference presented a proportion of 99.83% whereas the AZT samples presented a variation ranging from 97.59 to 99.54%. In addition, the standard reference was found to present a temperature of onset of melting point of 122.80 °C. Regarding the samples of active agents provided by the different laboratories, a variation ranging from 118.70 to 122.87 °C was measured. In terms of ΔHm, the samples presented an average value of 31.12 kJ mol-1.A determinação da pureza química, a faixa de fusão e a variação de entalpia envolvida no processo de caracterização de fármacos é um dos principais requisitos avaliados no controle de qualidade em indústrias farmacêuticas. Neste trabalho é feita uma breve abordagem sobre o método de determinação de pureza utilizando DSC, assim como a aplicação desta técnica para avaliação de amostras comerciais de zidovudina (AZT (matéria-prima fornecida por diferentes laboratórios. Para tal, foram analisadas amostras de seis diferentes laboratórios (A,B,C,D,E e F e a substância química de referência (R da United States Pharmacopeia (USP. As

  4. An improved experimental method for simulating erosion processes by concentrated channel flow.

    Science.gov (United States)

    Chen, Xiao-Yan; Zhao, Yu; Mo, Bin; Mi, Hong-Xing

    2014-01-01

    Rill erosion is an important process that occurs on hill slopes, including sloped farmland. Laboratory simulations have been vital to understanding rill erosion. Previous experiments obtained sediment yields using rills of various lengths to get the sedimentation process, which disrupted the continuity of the rill erosion process and was time-consuming. In this study, an improved experimental method was used to measure the rill erosion processes by concentrated channel flow. By using this method, a laboratory platform, 12 m long and 3 m wide, was used to construct rills of 0.1 m wide and 12 m long for experiments under five slope gradients (5, 10, 15, 20, and 25 degrees) and three flow rates (2, 4, and 8 L min(-1)). Sediment laden water was simultaneously sampled along the rill at locations 0.5 m, 1 m, 2 m, 3 m, 4 m, 5 m, 6 m, 7 m, 8 m, 10 m, and 12 m from the water inlet to determine the sediment concentration distribution. The rill erosion process measured by the method used in this study and that by previous experimental methods are approximately the same. The experimental data indicated that sediment concentrations increase with slope gradient and flow rate, which highlights the hydraulic impact on rill erosion. Sediment concentration increased rapidly at the initial section of the rill, and the rate of increase in sediment concentration reduced with the rill length. Overall, both experimental methods are feasible and applicable. However, the method proposed in this study is more efficient and easier to operate. This improved method will be useful in related research.

  5. 75 FR 71155 - Market Test of Experimental Product: “Alternative Postage Payment Method for Greeting Cards”

    Science.gov (United States)

    2010-11-22

    ... of Experimental Product: ``Alternative Postage Payment Method for Greeting Cards'' AGENCY: Postal Service TM . ACTION: Notice. SUMMARY: The Postal Service gives notice of a market test of an experimental... Postage Payment Method for Greeting Cards'' experimental product on January 2, 2011. The Postal...

  6. 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

  7. Application of Differential Scanning Calorimetry (DSC) in Analysis of Oils%差示扫描量热法(DSC)在油脂分析中的应用

    Institute of Scientific and Technical Information of China (English)

    宋菲; 王挥; 陈卫军; 赵松林

    2014-01-01

    In the research of physical properties and the processing products of oils, differential scanning calorimetry (DSC) as a thermal analysis technology is widely used. This paper introduces the application of DSC in the determination of oil composition, crystallization and melting, oxidation and oxidation kinetics and adulteration of oils. This thermal analysis method has very broad prospects in oil scientific research and actual production.%介绍差示扫描量热法(DSC)在测定油脂的组分、结晶与融化、氧化及氧化动力学和油脂掺假等方面的应用,以及热分析法在油脂的科学理论研究和实际生产中的应用前景。

  8. Experimental and statistical approaches in method cross-validation to support pharmacokinetic decisions.

    Science.gov (United States)

    Thway, Theingi M; Ma, Mark; Lee, Jean; Sloey, Bethlyn; Yu, Steven; Wang, Yow-Ming C; Desilva, Binodh; Graves, Tom

    2009-04-05

    A case study of experimental and statistical approaches for cross-validating and examining the equivalence of two ligand binding assay (LBA) methods that were employed in pharmacokinetic (PK) studies is presented. The impact of changes in methodology based on the intended use of the methods was assessed. The cross-validation processes included an experimental plan, sample size selection, and statistical analysis with a predefined criterion of method equivalence. The two methods were deemed equivalent if the ratio of mean concentration fell within the 90% confidence interval (0.80-1.25). Statistical consideration of method imprecision was used to choose the number of incurred samples (collected from study animals) and conformance samples (spiked controls) for equivalence tests. The difference of log-transformed mean concentration and the 90% confidence interval for two methods were computed using analysis of variance. The mean concentration ratios of the two methods for the incurred and spiked conformance samples were 1.63 and 1.57, respectively. The 90% confidence limit was 1.55-1.72 for the incurred samples and 1.54-1.60 for the spiked conformance samples; therefore, the 90% confidence interval was not contained within the (0.80-1.25) equivalence interval. When the PK parameters of two studies using each of these two methods were compared, we determined that the therapeutic exposure, AUC((0-168)) and C(max), from Study A/Method 1 was approximately twice that of Study B/Method 2. We concluded that the two methods were not statistically equivalent and that the magnitude of the difference was reflected in the PK parameters in the studies using each method. This paper demonstrates the need for method cross-validation whenever there is a switch in bioanalytical methods, statistical approaches in designing the cross-validation experiments and assessing results, or interpretation of the impact of PK data.

  9. INVESTIGATIONS OF THE FLOW INTO A STORAGE TANK BY MEANS OF ADVANCED EXPERIMENTAL AND THEORETICAL METHODS

    DEFF Research Database (Denmark)

    Jordan, Ulrike; Shah, Louise Jivan; Furbo, Simon

    2003-01-01

    Advanced experimental methods were applied to study flow structures of a water jet entering a tank from the bottom. A squared experimental glass tank with a volume of about 140 l was used. Above the inlet pipe a flat plate was installed, as shown in the figure. The goal of the investigations...... is to study the influence of the inlet device geometry and of the operating conditions (the flow rate, draw-off volume, and temperatures) on the thermal stratification in the tank. Measurements of the flow and temperature fields were carried out with two visualization techniques: - To visualize the flow field...

  10. Experimental methods for quantifying the activity of platinum electrocatalysts for the oxygen reduction reaction.

    Science.gov (United States)

    Garsany, Yannick; Baturina, Olga A; Swider-Lyons, Karen E; Kocha, Shyam S

    2010-08-01

    A tutorial is provided for methods to accurately and reproducibly determine the activity of Pt-based electrocatalysts for the oxygen reduction reaction in proton exchange membrane fuel cells and other applications. The impact of various experimental parameters on electrocatalyst activity is demonstrated, and explicit experimental procedures and measurement protocols are given for comparison of electrocatalyst activity to fuel cell standards. (To listen to a podcast about this article, please go to the Analytical Chemistry multimedia page at pubs.acs.org/page/ancham/audio/index.html.).

  11. Experimental Method for Characterizing Electrical Steel Sheets in the Normal Direction

    Directory of Open Access Journals (Sweden)

    Thierry Belgrand

    2010-10-01

    Full Text Available This paper proposes an experimental method to characterise magnetic laminations in the direction normal to the sheet plane. The principle, which is based on a static excitation to avoid planar eddy currents, is explained and specific test benches are proposed. Measurements of the flux density are made with a sensor moving in and out of an air-gap. A simple analytical model is derived in order to determine the permeability in the normal direction. The experimental results for grain oriented steel sheets are presented and a comparison is provided with values obtained from literature.

  12. Disorder Prediction Methods, Their Applicability to Different Protein Targets and Their Usefulness for Guiding Experimental Studies

    Directory of Open Access Journals (Sweden)

    Jennifer D. Atkins

    2015-08-01

    Full Text Available The role and function of a given protein is dependent on its structure. In recent years, however, numerous studies have highlighted the importance of unstructured, or disordered regions in governing a protein’s function. Disordered proteins have been found to play important roles in pivotal cellular functions, such as DNA binding and signalling cascades. Studying proteins with extended disordered regions is often problematic as they can be challenging to express, purify and crystallise. This means that interpretable experimental data on protein disorder is hard to generate. As a result, predictive computational tools have been developed with the aim of predicting the level and location of disorder within a protein. Currently, over 60 prediction servers exist, utilizing different methods for classifying disorder and different training sets. Here we review several good performing, publicly available prediction methods, comparing their application and discussing how disorder prediction servers can be used to aid the experimental solution of protein structure. The use of disorder prediction methods allows us to adopt a more targeted approach to experimental studies by accurately identifying the boundaries of ordered protein domains so that they may be investigated separately, thereby increasing the likelihood of their successful experimental solution.

  13. Synchronizing chaos in an experimental chaotic pendulum using methods from linear control theory.

    Science.gov (United States)

    Kaart, S; Schouten, J C; van den Bleek, C M

    1999-05-01

    Linear feedback control, specifically model predictive control (MPC), was used successfully to synchronize an experimental chaotic pendulum both on unstable periodic and aperiodic orbits. MPC enables tuning of the controller to give an optimal controller performance. That is, both the fluctuations around the target trajectory and the necessary control actions are minimized using a least-squares solution of the linearized problem. It is thus shown that linear control methods can be applied to experimental chaotic systems, as long as an adequate model is available that can be linearized along the desired trajectory. This model is used as an observer, i.e., it is synchronized with the experimental pendulum to estimate the state of the experimental pendulum. In contrast with other chaos control procedures like the map-based Ott, Grebogi, and York method [Phys. Rev. Lett. 64, 1196 (1990)], the continuous type feedback control proposed by Pyragas [Phys. Lett. A 170, 421 (1992)], or the feedback control method recently proposed by Brown and Rulkov [Chaos 7 (3), 395 (1997)], the procedure outlined in this paper automatically results in a choice for the feedback gains that gives optimum performance, i.e., minimum fluctuations around the desired trajectory using minimum control actions.

  14. A Novel Method for Curvefitting the Stretched Exponential Function to Experimental Data.

    Science.gov (United States)

    June, Ronald K; Cunningham, John P; Fyhrie, David P

    2013-12-01

    The stretched exponential function has many applications in modeling numerous types of experimental relaxation data. However, problems arise when using standard algorithms to fit this function: we have observed that different initializations result in distinct fitted parameters. To avoid this problem, we developed a novel algorithm for fitting the stretched exponential model to relaxation data. This method is advantageous both because it requires only a single adjustable parameter and because it does not require initialization in the solution space. We tested this method on simulated data and experimental stress-relaxation data from bone and cartilage and found favorable results compared to a commonly-used Quasi-Newton method. For the simulated data, strong correlations were found between the simulated and fitted parameters suggesting that this method can accurately determine stretched exponential parameters. When this method was tested on experimental data, high quality fits were observed for both bone and cartilage stress-relaxation data that were significantly better than those determined with the Quasi-Newton algorithm.

  15. Methods for determining the internal thrust of scramjet engine modules from experimental data

    Science.gov (United States)

    Voland, Randall T.

    1990-01-01

    Methods for calculating zero-fuel internal drag of scramjet engine modules from experimental measurements are presented. These methods include two control-volume approaches, and a pressure and skin-friction integration. The three calculation techniques are applied to experimental data taken during tests of a version of the NASA parametric scramjet. The methods agree to within seven percent of the mean value of zero-fuel internal drag even though several simplifying assumptions are made in the analysis. The mean zero-fuel internal drag coefficient for this particular engine is calculated to be 0.150. The zero-fuel internal drag coefficient when combined with the change in engine axial force with and without fuel defines the internal thrust of an engine.

  16. An experimental method for measuring the moment of inertia of an electric power wheelchair.

    Science.gov (United States)

    Wang, Hongwu; Grindle, Garrett G; Connor, Samuel; Cooper, Rory A

    2007-01-01

    This study describe an experiment measuring the moment of inertia of an electric powered wheelchair (EPW) using a torsional pendulum method. Inertia of the wheelchair is an important factor for control, which is a key issue in wheelchair driving. The experimental test platform consisted of a bottom circular wood plate, an upper metal plate, and four ropes. Materials with known moments of inertia such as the metal disk and cylinder were used to test the accuracy of the system. The EPW used in the experiment was Invacare G3 Torque SP Storm Series. The measured result of the moment inertia of the wheelchair was 5.2280 kg.m(2) and the errors of the system are less than 10% even when the object is only 25lbs. The results are consistent when compared with other approximate methods. In addition, the experimental method could be used to measure the moment of inertia of manual wheelchairs and other irregular objects.

  17. Experimental Validation of Methods for Prophylaxis against Deep Venous Thrombosis: A Review and Proposal

    Directory of Open Access Journals (Sweden)

    Paul S. Agutter

    2012-01-01

    Full Text Available The experimental procedure by which the valve cusp hypoxia (VCH hypothesis of the etiology of deep venous thrombosis (DVT was confirmed lends itself to testing of methods of prophylaxis. Similar animal experiments could end the present exclusive reliance on statistical analysis of data from large patient cohorts to evaluate prophylactic regimes. The reduction of need for such (usually retrospective analyses could enable rationally-based clinical trials of prophylactic methods to be conducted more rapidly, and the success of such trials would lead to decreased incidences of DVT-related mortality and morbidity. This paper reviews the VCH hypothesis (“VCH thesis”, following its corroboration and its implications for understanding DVT and its sequelae, and outlines the experimental protocol for testing prophylactic methods. The advantages and limitations of the protocol are briefly discussed.

  18. Experimental Comparison of Representation Methods and Distance Measures for Time Series Data

    CERN Document Server

    Wang, Xiaoyue; Trajcevski, Goce; Scheuermann, Peter; Keogh, Eamonn

    2010-01-01

    The previous decade has brought a remarkable increase of the interest in applications that deal with querying and mining of time series data. Many of the research efforts in this context have focused on introducing new representation methods for dimensionality reduction or novel similarity measures for the underlying data. In the vast majority of cases, each individual work introducing a particular method has made specific claims and, aside from the occasional theoretical justifications, provided quantitative experimental observations. However, for the most part, the comparative aspects of these experiments were too narrowly focused on demonstrating the benefits of the proposed methods over some of the previously introduced ones. In order to provide a comprehensive validation, we conducted an extensive experimental study re-implementing eight different time series representations and nine similarity measures and their variants, and testing their effectiveness on thirty-eight time series data sets from a wide ...

  19. Experimental Validation of Methods for Prophylaxis against Deep Venous Thrombosis: A Review and Proposal.

    Science.gov (United States)

    Agutter, Paul S; Malone, P Colm; Silver, Ian A

    2012-01-01

    The experimental procedure by which the valve cusp hypoxia (VCH) hypothesis of the etiology of deep venous thrombosis (DVT) was confirmed lends itself to testing of methods of prophylaxis. Similar animal experiments could end the present exclusive reliance on statistical analysis of data from large patient cohorts to evaluate prophylactic regimes. The reduction of need for such (usually retrospective) analyses could enable rationally-based clinical trials of prophylactic methods to be conducted more rapidly, and the success of such trials would lead to decreased incidences of DVT-related mortality and morbidity. This paper reviews the VCH hypothesis ("VCH thesis", following its corroboration) and its implications for understanding DVT and its sequelae, and outlines the experimental protocol for testing prophylactic methods. The advantages and limitations of the protocol are briefly discussed.

  20. Experimental validation of the buildings energy performance (PEC assessment methods with reference to occupied spaces heating

    Directory of Open Access Journals (Sweden)

    Cristian PETCU

    2010-01-01

    Full Text Available This paper is part of the series of pre-standardization research aimed to analyze the existing methods of calculating the Buildings Energy Performance (PEC in view of their correction of completing. The entire research activity aims to experimentally validate the PEC Calculation Algorithm as well as the comparative application, on the support of several case studies focused on representative buildings of the stock of buildings in Romania, of the PEC calculation methodology for buildings equipped with occupied spaces heating systems. The targets of the report are the experimental testing of the calculation models so far known (NP 048-2000, Mc 001-2006, SR EN 13790:2009, on the support provided by the CE INCERC Bucharest experimental building, together with the complex calculation algorithms specific to the dynamic modeling, for the evaluation of the occupied spaces heat demand in the cold season, specific to the traditional buildings and to modern buildings equipped with solar radiation passive systems, of the ventilated solar space type. The schedule of the measurements performed in the 2008-2009 cold season is presented as well as the primary processing of the measured data and the experimental validation of the heat demand monthly calculation methods, on the support of CE INCERC Bucharest. The calculation error per heating season (153 days of measurements between the measured heat demand and the calculated one was of 0.61%, an exceptional value confirming the phenomenological nature of the INCERC method, NP 048-2006. The mathematical model specific to the hourly thermal balance is recurrent – decisional with alternating paces. The experimental validation of the theoretical model is based on the measurements performed on the CE INCERC Bucharest building, within a time lag of 57 days (06.01-04.03.2009. The measurements performed on the CE INCERC Bucharest building confirm the accuracy of the hourly calculation model by comparison to the values

  1. EXPERIMENTAL STUDY OF AN ANTI-EROSION METHOD FOR BEND IN GAS-PARTICLE FLOWS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Bend erosion is a fairly serious problem in conveyer pipe system. This paper intends to introduce a new anti-erosion method for bend: ribbed anti-erosion method. An experimental research was done by fixing ribs in the range of 10°~70° on the outer-wall of inside 90°-bend. As a result, the anti-erosion efficiency 93.02% was obtained in the experiments. It shows that ribbed bend technology is a simple and efficient anti-erosion method. Besides, it was found that rectangular ribs had more obvious anti-erosion effect than square ribs do when they have equal height.

  2. Effect of recording/playback technique and experimental method on assessments of noise

    DEFF Research Database (Denmark)

    Celik, Emine; Persson-Waye, Kerstin; Møller, Henrik

    2008-01-01

    The study investigated possible effects of recording/playback technique and experimental method on assessments of annoyance, loudness and unpleasantness. A possible effect of exposure duration was also studied. Sounds were recorded with two different techniques: monophonic and binaural (dummy......-head technique). In addition, they were reproduced with three different techniques: monophonic recordings presented through a loudspeaker system, binaural recordings presented through closed (circum-aural) and completely open (free-of-the-ear headphones. The study adopted three psychometric methods...... of experiments and interpretation of results. The results also show that long-term annoyance and unpleasantness are poorly predicted by short-duration methods....

  3. An Experimental Study on Voltage Compensation Method using Autonomous Decentralized Control of Distributed Generators

    Science.gov (United States)

    Tanaka, Shunsuke; Suzuki, Hirokazu

    When many distributed generators (DGs) are connected to a distribution line, the upward power flow from DGs causes the difficulty in line voltage regulation. As the countermeasure, we propose several methods to control the line voltage by use of DGs' reactive power outputs. These methods using only DGs' reactive power are implemented in an autonomous decentralized way. DGs with the function to estimate the line impedance provide the power system with reactive power according to the estimated impedance value, and regulate the line voltage. We evaluate the effect of the proposed methods for voltage compensation by experimental studies using commercial grid-connected inverters for PV system.

  4. Experimental comparison and validation of hot-ball method with guarded hot plate method on polyurethane foams

    Science.gov (United States)

    Hudec, Ján; Glorieux, Christ; Dieška, Peter; Kubičár, Ľudovít

    2016-07-01

    The Hot-ball method is an innovative transient method for measuring thermophysical properties. The principle is based on heating of a small ball, incorporated in measured medium, by constant heating power and simultaneous measuring of the ball's temperature response since the heating was initiated. The shape of the temperature response depends on thermophysical properties of the medium, where the sensor is placed. This method is patented by Institute of Physics, SAS, where the method and sensors based on this method are being developed. At the beginning of the development of sensors for this method we were oriented on monitoring applications, where relative precision is much more important than accuracy. Meanwhile, the quality of sensors was improved good enough to be used for a new application - absolute measuring of thermophysical parameters of low thermally conductive materials. This paper describes experimental verification and validation of measurement by hot-ball method. Thanks to cooperation with Laboratory of Soft Matter and Biophysics of Catholic University of Leuven in Belgium, established Guarded Hot Plate method was used as a reference. Details about measuring setups, description of the experiments and results of the comparison are presented.

  5. Experimental study on new monitoring method of radon release rate from uranium tailings

    CERN Document Server

    Fu Jin; HanYaozHao; He Wen Xing; Zhang Biao

    2002-01-01

    Two new monitoring methods of radon release rate from uranium tailings are introduced. They are the active carbon absorption and gamma energy spectrum method. The instrument and sampler of active carbon absorption is presented with the manufacture, function, performance and calibration, the conditional test of the method and its measuring contrast to that of local static method. One-year continuous in-site monitoring of radon release rate of uranium tailings was done. The annual change regularity of radon release rate from uranium tailings was observed. The optimum season and condition of monitoring the annual average radon release rate are summarized. The parameter monitoring, calculating method and experimentation of gamma energy spectrum method is discussed

  6. Comparative experimental study on several methods for measuring elastic wave velocities in rocks at high pressure

    Institute of Scientific and Technical Information of China (English)

    XIE; Hongsen(谢鸿森); ZHOU; Wenge; 周文戈); LIU; Yonggang; (刘永刚); GUO; Jie; (郭捷); HOU; Wei; (侯渭); ZHAO; Zhidan(赵志丹)

    2002-01-01

    To measure elastic wave velocities in rocks at high temperature and high pressure is an important way to acquire the mechanics and thermodynamics data of rocks in the earth's interior and also a substantial approach to studying the structure and composition of materials there. In recent years, a rapid progress has been made in methodology pertaining to the measurements of elastic wave velocities in rocks at high temperature and high pressure with solids as the pressure-transfer media. However, no strict comparisons have been made of the elastic wave velocity data of rocks measured at high temperature and high pressure by various laboratories. In order to compare the experimental results from various laboratories, we have conducted a comparative experimental study on three measuring methods and made a strict comparison with the results obtained by using the transmission method with fluid as the pressure-transfer medium. Our experimental results have shown that the measurements obtained by the three methods are comparable in the pressure ranges of their application. The cubic sample pulse transmission method used by Kern is applicable to measuring elastic wave velocities in crustal rocks at lower temperature and lower pressure. The prism sample pulse reflection-transmission method has some advantages in pressure range, heating temperature and measuring precision. Although the measurements obtained under relatively low pressure conditions by the prism sample pulse transmission method are relatively low in precision, the samples are large in length and their assemblage is simple. So this method is suitable to the experiments that require large quantities of samples and higher pressures. Therefore, in practical application the latter two methods are usually recommended because their measurements can be mutually corrected and supplemented.

  7. Experimental validation of normalized uniform load surface curvature method for damage localization.

    Science.gov (United States)

    Jung, Ho-Yeon; Sung, Seung-Hoon; Jung, Hyung-Jo

    2015-10-16

    In this study, we experimentally validated the normalized uniform load surface (NULS) curvature method, which has been developed recently to assess damage localization in beam-type structures. The normalization technique allows for the accurate assessment of damage localization with greater sensitivity irrespective of the damage location. In this study, damage to a simply supported beam was numerically and experimentally investigated on the basis of the changes in the NULS curvatures, which were estimated from the modal flexibility matrices obtained from the acceleration responses under an ambient excitation. Two damage scenarios were considered for the single damage case as well as the multiple damages case by reducing the bending stiffness (EI) of the affected element(s). Numerical simulations were performed using MATLAB as a preliminary step. During the validation experiments, a series of tests were performed. It was found that the damage locations could be identified successfully without any false-positive or false-negative detections using the proposed method. For comparison, the damage detection performances were compared with those of two other well-known methods based on the modal flexibility matrix, namely, the uniform load surface (ULS) method and the ULS curvature method. It was confirmed that the proposed method is more effective for investigating the damage locations of simply supported beams than the two conventional methods in terms of sensitivity to damage under measurement noise.

  8. Videotaped Feedback Method to Enhance Learning in Preclinical Operative Dentistry: An Experimental Study.

    Science.gov (United States)

    Shah, Dipali Yogesh; Dadpe, Ashwini Manish; Kalra, Dheeraj Deepak; Garcha, Vikram P

    2015-12-01

    The aim of this study was to investigate if a videotaped feedback method enhanced teaching and learning outcomes in a preclinical operative laboratory setting for novice learners. In 2013, 60 dental students at a dental school in India were randomly assigned to two groups: control (n=30) and experimental (n=30). The control group prepared a Class II tooth preparation for amalgam after receiving a video demonstration of the exercise. The experimental group received the same video demonstration as the control group, but they also participated in a discussion and analysis of the control groups' videotaped performance and then performed the same exercise. The self-evaluation scores (SS) and examiner evaluation scores (ES) of the two groups were compared using the unpaired t-test. The experimental group also used a five-point Likert scale to rate each item on the feedback form. The means of SS (13.65±2.43) and ES (14.75±1.97) of the experimental group were statistically higher than the means of SS (11.55±2.09) and ES (11.60±1.82) of the control group. Most students in the experimental group perceived that this technique enhanced their learning experience. Within the limits of this study, the videotaped feedback using both ideal and non-ideal examples enhanced the students' performance.

  9. COMPARATIVE KINETICS STUDY OF THE THERMAL AND THERMO-OXIDATIVE DEGRADATION OF A POLYSTYRENE-CLAY NANOCOMPOZITE BY TGA AND DSC

    Directory of Open Access Journals (Sweden)

    Ion Dranca

    2010-12-01

    Full Text Available The methods of thermogravimetry (TGA and differential scanning calorimetry (DSC have been used to study the thermal and thermo-oxidative degradation of polystyrene (PS and a PS-clay nanocomposite. An advanced isoconversional method has been applied for kinertic analysis. Introduction of the clay phase increasers the activation energy and affects the total heat of degradation, which suggests a change in the reaction mechanism. The obtained kinetic data permit a comparative assessment of the fire resistance of the studied materials

  10. Methods for obtaining and reducing experimental droplet impingement data on arbitrary bodies

    Science.gov (United States)

    Papadakis, Michael; Elangovan, R.; Freund, George A., Jr.; Breer, Marlin D.

    1991-01-01

    Experimental water droplet impingement data are used to validate particle trajectory computer codes used in the analysis and certification of aircraft de-icing/anti-icing systems. Water droplet impingement characteristics of aerodynamic surfaces are usually obtained from wind-tunnel dye tracer experiments. This paper presents a dye tracer method for measuring water droplet impingement characteristics on arbitrary geometries and a new data reduction method, based on laser reflectance measurements, for extracting impingement data. Extraction of impingement data has been a very time-consuming process in the past. The new data reduction method developed is at least an order of magnitude more efficient than the method previously used. The accuracy of the method is discussed and results obtained are presented.

  11. Spreading Simulation of Droplet Impact on Solid Surface with CLSVOF Method and Its Experimental Verification

    Science.gov (United States)

    Zhang, Yan-Jun; Li, Ping

    2016-04-01

    A coupled volume-of-fluid and level set (CLSVOF) method is applied for the simulation of droplet impacting on a solid surface. This two-phase flow approach combines the advantages of VOF and level set (LS) methods. Three cases are listed and simulated by CLSVOF method, and the wettability is evaluated by tracking the three-phase contact line (TPCL). Results showed that the change of liquid spreading ratio with time has a good fit with the experimental results of the above three cases and high accuracy is achieved by CLSVOF method compared with VOF method, which indicated that this model is suitable for researching the wetting problem. The spreading speed on good wettability surfaces is faster than that of on poor wettability surfaces significantly, and the recoiling phenomenon appears after the droplet spreading to its maximum.

  12. Entalpia reticular, entalpia de fusão e temperatura de fusão de adutos: algumas correlações empíricas utilizando DSC

    OpenAIRE

    Farias Robson Fernandes de

    1999-01-01

    By using DSC data is shown that there are empirical correlations between lattice enthalpy, melting enthalpy and the temperature of melting for adducts, and that is possible, using only a single DSC curve, estimate the value of DM Hmq.

  13. Theoretical research and experimental study for a new measurement method of standing wave levitation force

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xinbo; Jiang, Hai; Jiao, Xiaoyang; Zhang, Kai; Liu, Guojun; Liu, Jianfang [Jilin University, Changchun (China)

    2015-05-15

    Based on the lever principle, a novel measurement method for the standing wave levitation force is investigated and the measurement device is developed. The relative levitation force was simulated by MATLAB software, from which the relative levitation force distribution and the curves of relative levitation force in vertical and horizontal directions were obtained. To verify the rationale of the measurement method, a series of experiments were carried out with the designed measurement device system. The levitation force distribution and the curves of levitation force in vertical and horizontal directions were also obtained from the experiment. Comparing the experimental results with the simulation, the levitation force distribution situation from the experimental results and the simulation is identical.

  14. An Experimental Test of a Biodynamic Method of Weed Suppression: The Biodynamic Seed Peppers

    Directory of Open Access Journals (Sweden)

    Bruce Kenneth Kirchoff

    2016-04-01

    Full Text Available An experimental test of a biodynamic agriculture method of weed suppression was carried out in growth chambers to establish the feasibility of the method as a preliminary to field trials. Four generations of Brassica rapa plants were used in a randomized block design. Treated flats received ashed seeds prepared according to biodynamic indications. Seed weight and counts were measured at the end of each generation, and germination of the control and experimental seed was investigated at the end of generation four. The biodynamic seed peppers, created and applied as described here, had no effect on seed production or viability, and did not effectively inhibit reproduction of the targeted species over the course of four consecutive treatments.

  15. CO2 Capture in Ionic Liquids: A Review of Solubilities and Experimental Methods

    Directory of Open Access Journals (Sweden)

    Elena Torralba-Calleja

    2013-01-01

    Full Text Available The growing concern of climate change and global warming has in turn given rise to a thriving research field dedicated to finding solutions. One particular area which has received considerable attention is the lowering of carbon dioxide emissions from large-scale sources, that is, fossil fuel power. This paper focuses on ionic liquids being used as novel media for CO2 capture. In particular, solubility data and experimental techniques are used at a laboratory scale. Cited CO2 absorption data for imidazolium-, pyrrolidinium-, pyridinium-, quaternary-ammonium-, and tetra-alkyl-phosphonium-based ionic liquids is reviewed, expressed as mole fractions (X of CO2 to ionic liquid. The following experimental techniques are featured: gravimetric analysis, the pressure drop method, and the view-cell method.

  16. Advances in experimental methods for root system architecture and root development

    Institute of Scientific and Technical Information of China (English)

    Jun-bang Wang; Xiu-juan Zhang; Chu Wu

    2015-01-01

    Plant roots play important roles in acquisition of water and nutrients, storage, anchoring, transport, and symbiosis with soil microorganisms, thus quantitative researches on root developmental processes are essential to understand root functions and root turnover in ecosystems, and at the same time such researches are the most difficult because roots are hidden underground. Therefore, how to investigate efficiently root functions and root dynamics is the core aspect in underground ecology. In this article, we reviewed some experimental methods used in root resear-ches on root development and root system architecture, and summarized the advantages and shortages of these meth-ods. Based on the analyses, we proposed three new ways to more understand root processes: (1) new experimental materials for root development; (2) a new observatory system comprised of multiple components, including many observatory windows installed in field, analysis software, and automatic data transport devices; (3) new techniques used to analyze quantitatively functional roots.

  17. Raman and DSC studies of fragility in tellurium-zinc oxide glass formers

    Energy Technology Data Exchange (ETDEWEB)

    Stavrou, Elissaios [Department of Physics, National Technical University of Athens (Greece); Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany); Kripotou, Sotiria; Raptis, Constantine [Department of Physics, National Technical University of Athens (Greece); Turrell, Sylvia [Laboratoire de Spectrochimie Infrarouge et Raman (CNRS 8516), Centre d' Etudes et de Recherches Lasers et Applications (CERLA-FR CNRS 2416), Universite de Sciences et Technologies de Lille, Villeneuve d' Ascq cedex (France); Syassen, Karl [Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany)

    2011-11-15

    Raman scattering and differential scanning calorimetry (DSC) measurements have been carried out in four mixed (TeO{sub 2}){sub 1-x}(ZnO){sub x} (x = 0.1, 0.2, 0.3, 0.4) glasses at high temperatures (Raman and DSC through the glass transition) and high pressures (Raman) with the aim of determining the fragility of these glass forming oxides. Four different criteria, corresponding to four parameters, were applied to assess the fragility of the glasses. From the DSC studies, we have obtained the fragility parameter m which corresponds to the slopes of Arrhenius (lnQ vs. 1/T{sub g}, were Q is the heating rate) plots, and the glass transition width {delta}T{sub g}. Also, from the low-frequency Raman scattering, and in particular the boson peak intensity of the glasses at T{sub g}, we have estimated the fragility ratio r{sub R} (T{sub g}) = I{sub min}/I{sub max} whose value serves as another (empirical) fragility criterion. Finally, from high pressure Raman measurements on the glasses, we have estimated the Grueneisen parameter {gamma}{sub T} for each glass, which constitutes the fourth fragility parameter adopted in this work. Considering the four parameters {delta}T{sub g}, m, r (T{sub g}) and {gamma}{sub T} and the generally accepted (empirical) fragility criteria, we conclude that the mixed tellurium-zinc oxides constitute strong-to-intermediate glass formers (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. The Experimental Study of the Inductive Heating Process by the cleating Method

    Directory of Open Access Journals (Sweden)

    Dorel Anton HOBLE

    2009-05-01

    Full Text Available The paper focuses on onemethod of welding of two coaxial cylinders, made ofdifferent materials. The method of welding usesinductive heating technology, and it is based on thedifferent dilatation coefficient of the materials, theinside material has an upper value of the dilatationcoefficient. In the paper it was analyzed the inducedpower density inside the ferromagnetic material, andthe distribution of the temperature field inside thestructure. The theoretical results were utilized tomake an experimental model.

  19. Experimental validation of finite element and boundary element methods for predicting structural vibration and radiated noise

    Science.gov (United States)

    Seybert, A. F.; Wu, T. W.; Wu, X. F.

    1994-01-01

    This research report is presented in three parts. In the first part, acoustical analyses were performed on modes of vibration of the housing of a transmission of a gear test rig developed by NASA. The modes of vibration of the transmission housing were measured using experimental modal analysis. The boundary element method (BEM) was used to calculate the sound pressure and sound intensity on the surface of the housing and the radiation efficiency of each mode. The radiation efficiency of each of the transmission housing modes was then compared to theoretical results for a finite baffled plate. In the second part, analytical and experimental validation of methods to predict structural vibration and radiated noise are presented. A rectangular box excited by a mechanical shaker was used as a vibrating structure. Combined finite element method (FEM) and boundary element method (BEM) models of the apparatus were used to predict the noise level radiated from the box. The FEM was used to predict the vibration, while the BEM was used to predict the sound intensity and total radiated sound power using surface vibration as the input data. Vibration predicted by the FEM model was validated by experimental modal analysis; noise predicted by the BEM was validated by measurements of sound intensity. Three types of results are presented for the total radiated sound power: sound power predicted by the BEM model using vibration data measured on the surface of the box; sound power predicted by the FEM/BEM model; and sound power measured by an acoustic intensity scan. In the third part, the structure used in part two was modified. A rib was attached to the top plate of the structure. The FEM and BEM were then used to predict structural vibration and radiated noise respectively. The predicted vibration and radiated noise were then validated through experimentation.

  20. Experimental verification of color flow imaging based on wideband Doppler method.

    Science.gov (United States)

    Tanaka, Naohiko

    2014-01-01

    The purpose of this study is to eliminate the aliasing in color flow imaging. The wideband Doppler method is applied to generate a color flow image, and the validity of the method is experimentally confirmed. The single beam experiment is carried out to confirm the velocity estimation based on the wideband Doppler method. The echo data for the conventional pulsed Doppler method and the wideband Doppler method are obtained using a flow model, and the estimated velocity for each method is compared. The color flow images for each method are also generated using several types of flow model. The generated images are compared, and the characteristics of the imaging based on the wideband Doppler method are discussed. The high velocity beyond the Nyquist limit is successfully estimated by the wideband Doppler method, and the availability in low velocity estimation is also confirmed. The aliasing in color flow images is eliminated, and the generated images show the significance of the elimination of the aliasing in the flow imaging. The aliasing in color flow imaging can be eliminated by the wideband Doppler method. This technique is useful for the exact understanding of blood flow dynamics.

  1. DTA and DSC study on the effect of mechanical dispersion on poly(tetrafluorethylene properties

    Directory of Open Access Journals (Sweden)

    Dumitraşa Mihai

    2014-12-01

    Full Text Available Poly(tetrafluorethylene particles were obtained by mechanical processing of the formed polymer (Teflon bar. In order to assess the effect of mechanical wear on polymer properties, their melting and crystallization behaviour was investigated by DSC and DTA, and the results were compared to the ones obtained for the native polymer. An increase of the crystallinity degree and an accentuated decrease of the average molecular weight were found for the samples submitted to mechanical wear, as a result of mechanical degradation of the polymer

  2. DSC study on temperature memory effect of NiTi shape memory alloy

    Institute of Scientific and Technical Information of China (English)

    N. LIU; W. M. HUANG

    2006-01-01

    A systematic study on the temperature memory effect (TME) in a polycrystalline NiTi shape memory alloy was presented. The investigation was carried out through a series of differential scanning calorimeter (DSC) tests. Two types of tests were conducted,namely single-step test and multi-step test. The influence of the step temperature on the peak/trough temperatures in the subsequent heating process and the associated energy absorption/release in the phase transformations was investigated. Using a simple theoretical model,the exact mechanism behind TME was studied.

  3. 轻薄易用动你心——索尼DSC-T5

    Institute of Scientific and Technical Information of China (English)

    赵欣

    2005-01-01

    作为拥有目前世界轻薄机身记录的DSC—T7的下一代机型,DSC—T5并不刻意再在“薄”字上做文章,却走一条更时尚.更易用的道路。从名字上也可以看出.DSC-T5并没有要超越DSC—T7的意思.DSC—T5将以更适合大众使用的形象出现。

  4. Experimental study to explore the $\\rm ^8Be$ induced nuclear reaction via the Trojan Horse Method

    CERN Document Server

    Qun-Gang, Wen; Shu-Hua, Zhou; Irgaziev, Bakhadir; Yuan-Yong, Fu; Spitaleri, Claudio; La Cognata, Marco; Jing, Zhou; Qiu-Ying, Meng; Lamia, Livio; Lattuada, Marcello

    2014-01-01

    To explore a possible indirect method for $\\rm ^8Be$ induced astrophysical reactions, the $\\rm ^9Be=({}^8Be+\\it n)$ cluster structure was studied via the Trojan Horse Method. It is the first time to study a super short life nucleus $\\rm ^8Be$ via the Trojan Horse Method, and it is the first time to make a valid test for $l=1$ Trojan-horse nucleus. The $\\rm ^9Be$ nucleus is assumed to have a ($\\rm {}^8Be+\\it n$) cluster structure and used as the Trojan-horse nucleus. The $\\rm ^8Be$ nucleus acts as a participant, while the neutron is a spectator to the virtual $\\rm ^8Be +{\\it d}\\rightarrow \\alpha + {}^6Li$ reaction via a suitable 3-body reaction $\\rm ^9Be +{\\it d}\\rightarrow \\alpha + {}^6Li +\\it n$. The experimental neutron momentum distribution inside $\\rm ^9Be$ was reconstructed. The agreement between experimental and theoretical momentum distribution indicates that there should be a ($\\rm {}^8Be+\\it n$) cluster structure inside $\\rm ^9Be$. Therefor the experimental study of $\\rm ^8Be$ induced reactions, for ...

  5. Experimental study to explore the 8Be-induced nuclear reaction via the Trojan horse method

    Science.gov (United States)

    Wen, Qun-Gang; Li, Cheng-Bo; Zhou, Shu-Hua; Irgaziev, Bakhadir; Fu, Yuan-Yong; Spitaleri, Claudio; La Cognata, Marco; Zhou, Jing; Meng, Qiu-Ying; Lamia, Livio; Lattuada, Marcello

    2016-03-01

    To explore a possible indirect method for 8Be induced astrophysical reactions, the 8Be=(8Be+n ) cluster structure has been studied via the Trojan horse method. For the first time a 8Be nucleus having an ultrashort lifetime is studied by the Trojan horse method and a 9Be nucleus in the ground state is used for this purpose. The 9Be nucleus is assumed to have a (8Be+n ) cluster structure and used as a Trojan horse nucleus. The 8Be nucleus acts as a participant, while the neutron is a spectator to the virtual 8Be+d →α +6Li reaction via the 3-body reaction 8Be+d →α +6Li+n . The experimental neutron momentum distribution inside 9Be has been reconstructed. The agreement between the experimental momentum distribution and the theoretical one indicates that a (8Be+n ) cluster structure inside 9Be is very likely. Therefore, the experimental study of 8Be induced reactions, for example, the measurement of the 8Be+α →12C reaction proceeding through the Hoyle state, is possible.

  6. Experimental stem cell therapies on burn wound: do source, dose, timing and method matter?

    Science.gov (United States)

    Ozturk, Sinan; Karagoz, Huseyin

    2015-09-01

    Stem cell therapy has been introduced as a new and promising modality of wound covering in recent decade. It has been used for improvement of burn wound, post burn scar and saving stasis zone of burn with good results. However, there have been some differences between the various experimental burn wound trials in stem cell source, therapeutic dose, delivery method and timing of stem cell delivery. In our study, we aimed to review stem cell biology and investigate discrepancies in animal trials of use of stem cells in burn wound account for the variation in, stem cell source, therapeutic dose, delivery method and timing of stem cell delivery.

  7. A statistical method for evaluation of the experimental phase equilibrium data of simple clathrate hydrates

    DEFF Research Database (Denmark)

    Eslamimanesh, Ali; Gharagheizi, Farhad; Mohammadi, Amir H.

    2012-01-01

    , and the residuals of a selected correlation results lead to define the probable outliers. This method not only contributes to outliers diagnostics but also identifies the range of applicability of the applied model and quality of the existing experimental data. The available correlation in the literature......We, herein, present a statistical method for diagnostics of the outliers in phase equilibrium data (dissociation data) of simple clathrate hydrates. The applied algorithm is performed on the basis of the Leverage mathematical approach, in which the statistical Hat matrix, Williams Plot...

  8. Experimental investigation of the systematic error on photomechanic methods induced by camera self-heating.

    Science.gov (United States)

    Ma, Qinwei; Ma, Shaopeng

    2013-03-25

    The systematic error for photomechanic methods caused by self-heating induced image expansion when using a digital camera was systematically studied, and a new physical model to explain the mechanism has been proposed and verified. The experimental results showed that the thermal expansion of the camera outer case and lens mount, instead of mechanical components within the camera, were the main reason for image expansion. The corresponding systematic error for both image analysis and fringe analysis based photomechanic methods were analyzed and measured, then error compensation techniques were proposed and verified.

  9. Planar near-field acoustical holography based on equivalent source method and its experimental investigation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yongbin; CHEN Xinzhao; BI Chuanxing; CHEN Jian

    2008-01-01

    The current main approach to reconstruct and predict the acoustic field of a planar source is Near-field Acoustical Holography (NAH) based on FFT. But this method has some disadvantages such as wraparound error and edge Gibbs phenomena which will contaminate the results badly. A planar NAH based on equivalent source approach is developed, which has no wraparound error and edge Gibbs phenomena, and it is beneficial for engineering application.The experimental results of acoustic radiation generated by a point-driven plate with clamped boundaries validate the correctness and availability of the method.

  10. Experimental validation of efficient methods for the prediction of patterning effects in SOA-based optical switches

    DEFF Research Database (Denmark)

    Xu, Jing; Ding, Yunhong; Xue, Weiqi

    2010-01-01

    We experimentally investigate and verify simple and efficient methods for characterizing the patterning effects (PE) of SOA-based optical switches. The onset of PE saturation is well predicted by the theory. an experimental method to capture the maximum PE is developed.......We experimentally investigate and verify simple and efficient methods for characterizing the patterning effects (PE) of SOA-based optical switches. The onset of PE saturation is well predicted by the theory. an experimental method to capture the maximum PE is developed....

  11. An experimental method for quantitatively evaluating the elemental processes of indoor radioactive aerosol behavior.

    Science.gov (United States)

    Yamazawa, H; Yamada, S; Xu, Y; Hirao, S; Moriizumi, J

    2015-11-01

    An experimental method for quantitatively evaluating the elemental processes governing the indoor behaviour of naturally occurring radioactive aerosols was proposed. This method utilises transient response of aerosol concentrations to an artificial change in aerosol removal rate by turning on and off an air purifier. It was shown that the indoor-outdoor exchange rate and the indoor deposition rate could be estimated by a continuous measurement of outdoor and indoor aerosol number concentration measurements and by the method proposed in this study. Although the scatter of the estimated parameters is relatively large, both the methods gave consistent results. It was also found that the size distribution of radioactive aerosol particles and hence activity median aerodynamic diameter remained not largely affected by the operation of the air purifier, implying the predominance of the exchange and deposition processes over other processes causing change in the size distribution such as the size growth by coagulation and the size dependence of deposition.

  12. Causal attribution and Mill's methods of experimental inquiry: past, present and prospect.

    Science.gov (United States)

    White, P A

    2000-09-01

    J. S. Mill proposed a set of Methods of Experimental Inquiry that were intended to guide causal inference under every conceivable set of circumstances in which experiments or observations could be carried out. The conceptual and historical relationship between these Methods and modern models of causal attribution is investigated. Mill's work retains contemporary relevance because his insights show how research can progress into presently uncharted waters. Following Mill, it is proposed that people use many different methods of causal attribution, the nature of which remains to be ascertained, and that the conditions that affect choice of method include the need to eliminate alternative causal candidates, whether single or multiple events are to be explained, the use of intervention or experiment as opposed to mere observation, and practical concerns.

  13. Study on the response of thermoluminescent dosemeters to synchrotron radiation: experimental method and Monte Carlo calculations.

    Science.gov (United States)

    Bakshi, A K; Chatterjee, S; Palani Selvam, T; Dhabekar, B S

    2010-07-01

    In the present study, the energy dependence of response of some popular thermoluminescent dosemeters (TLDs) have been investigated such as LiF:Mg,Ti, LiF:Mg,Cu,P and CaSO(4):Dy to synchrotron radiation in the energy range of 10-34 keV. The study utilised experimental, Monte Carlo and analytical methods. The Monte Carlo calculations were based on the EGSnrc and FLUKA codes. The calculated energy response of all the TLDs using the EGSnrc and FLUKA codes shows excellent agreement with each other. The analytically calculated response shows good agreement with the Monte Carlo calculated response in the low-energy region. In the case of CaSO(4):Dy, the Monte Carlo-calculated energy response is smaller by a factor of 3 at all energies in comparison with the experimental response when polytetrafluoroethylene (PTFE) (75 % by wt) is included in the Monte Carlo calculations. When PTFE is ignored in the Monte Carlo calculations, the difference between the calculated and experimental response decreases (both responses are comparable >25 keV). For the LiF-based TLDs, the Monte Carlo-based response shows reasonable agreement with the experimental response.

  14. Damage detection of flexural structural systems using damage index methodExperimental

    Directory of Open Access Journals (Sweden)

    Atef Eraky

    2015-09-01

    Full Text Available In the framework of structural health monitoring, continuous dynamic records are essential for good judgment of structures. Overall degradation of structures can be obtained with reasonable accuracy using various system identification techniques. It is however, challenging to obtain precisely the position and size of local damages. The current research focuses on Damage Index Method (DIM as a tool for determining local damages occurred in flexural structural elements. The DIM technique depends on comparing modal strain energies of structures at different degradation stages. Self-made computer module was developed to encounter DIM for damage detection. First, the method was verified experimentally. Simply supported steel beam of 1500 mm (length, 50 mm (width and 6 mm (thickness, in addition to steel plate of area 930 × 910 mm and 3 mm (thickness was implemented in the experimental program. Both the beam and plate were subjected to different damage configurations. Collected acceleration time history was processed and used to verify the adequacy of DIM in identifying damages in the used physical models. Numerical parametric study was also conducted on a variety of beams and plates with various damage degrees and locations. It was noticed that both the experimental and numerical results showed good agreement in identifying damages in flexural structural elements.

  15. Thermal properties of poly(ethylene oxide)/lauric acid blends. A SSA-DSC study

    Energy Technology Data Exchange (ETDEWEB)

    Pielichowski, Krzysztof; Flejtuch, Kinga [Department of Chemistry and Technology of Polymers, Cracow University of Technology, ul. Warszawska 24, 31-155 Krakow (Poland)

    2006-03-15

    A series of poly(ethylene oxide) (PEO)/lauric acid blends with different compositions has been prepared and characterised by differential scanning calorimetry (DSC) in dynamic mode. It has been found that the enthalpy of melting and crystallisation reaches its highest value for PEO/lauric acid blend (1:1, w/w) which makes this system a promising candidate for thermal energy storage applications. Further studies by step-scan alternating (SSA)-DSC revealed that an increase of the temperature step causes that the average total heating rate is also increasing and the heat flow is characterised by higher values. Reversing component of the heat flow during melting reaches lowest values at highest step (step=1{sup o}) when the re-crystallisation of PEO is hindered. An increase of step generally leads to an increase of the number of non-equilibrium effects and facilitates the activation of kinetic non-reversing processes, hindering the overall crystallisation of PEO. For lauric acid, due to facile crystallisation and self-association, formation of ordered regular structures takes place faster and is influenced by non-reversing processes in higher proportion. (author)

  16. Multivariate statistical analysis treatment of DSC thermal properties for animal fat adulteration.

    Science.gov (United States)

    Dahimi, Omar; Rahim, Alina Abdul; Abdulkarim, S M; Hassan, Mohd Sukri; Hashari, Shazamawati B T Zam; Mashitoh, A Siti; Saadi, Sami

    2014-09-01

    The adulteration of edible fats is a kind of fraud that impairs the physical and chemical features of the original lipid materials. It has been detected in various food, pharmaceutical and cosmeceutical products. Differential scanning calorimetry (DSC) is the robust thermo-analytical machine that permits to fingerprint the primary crystallisation of triacylglycerols (TAGs) molecules and their transition behaviours. The aims of this study was to assess the cross-contamination caused by lard concentration of 0.5-5% in the mixture systems containing beef tallow (BT) and chicken fat (CF) separately. TAGs species of pure and adulterated lipids in relation to their crystallisation and melting parameters were studied using principal components analysis (PCA). The results showed that by using the heating profiles the discrimination of LD from BT and CF was very clear even at low dose of less than 1%. Same observation was depicted from the crystallisation profiles of BT adulterated by LD doses ranging from 0.1% to 1% and from 2% to 5%, respectively. Furthermore, CF adulterated with LD did not exhibit clear changes on its crystallisation profiles. Consequently, DSC coupled with PCA is one of the techniques that might use to monitor and differentiate the minimum adulteration levels caused by LD in different animal fats.

  17. Interactions of tamoxifen with distearoyl phosphatidylcholine multilamellar vesicles: FTIR and DSC studies.

    Science.gov (United States)

    Bilge, Duygu; Sahin, Ipek; Kazanci, Nadide; Severcan, Feride

    2014-09-15

    Interactions of a non-steroidal antiestrogen drug, tamoxifen (TAM), with distearoyl-sn-glycero-3-phosphatidylcholine (DSPC) multilamellar liposomes (MLVs) were investigated as a function of drug concentration (1-15 mol%) by using two noninvasive techniques, namely Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). FTIR spectroscopy results show that increasing TAM concentrations (except 1 mol%) increased the wavenumbers of the CH2 stretching modes, implying an disordering effect for DSPC MLVs both in the gel and liquid crystalline phases. The bandwidth values of the CH2 stretchings except for 1 mol% increased when TAM concentrations increased for DSPC liposomes, indicating an increase in the dynamics of liposomes. The CO stretching and PO2- antisymmetric double bond stretching bands were analyzed to study interactions of TAM with head groups of lipids. As the concentrations of TAM increased, dehydration occurred around these functional groups in the polar part of the lipids. The DSC studies on thermal properties of DSPC lipids indicate that TAM eliminated the pre transition, shifted the main phase transition to lower temperatures and broadened the phase transition curve of the liposomes.

  18. Thermal stability of the DSC ruthenium dye C106 in robust electrolytes

    DEFF Research Database (Denmark)

    Lund, Torben; Phuong, Nguyen Tuyet; Pechy, Peter

    2014-01-01

    the dye from the TiO2 particles and analyzed its by HPLC coupled to UV/Vis and electro spray mass spectrometry. Samples prepared in the glove box gave the highest stability with a steady state photo anode surface concentration of 80% C106 intact and the remaining ∼20% being the N-butylbenzimidazole (NBB......We have investigated the thermal stability of the heteroleptic ruthenium complex C106 employed as a sensitizer in dye-sensitized solar cells. The C106 was adsorbed on TiO2 particles and exposed to 2 different iodide/triidode based redox electrolytes A and B at 80 °C for up to 1500 h in sealed glass...... of the degree of dye loading of the TiO2 particles and the ratio between the amount of dyed TiO2 particles and electrolyte volume. Assuming that this substitution is the predominant loss mechanism in a DSC during thermal stress, we estimate the reduction in the DSC efficiency after long term heat to be 12...

  19. Structure of rat skin after application of electret characterized by DSC

    Energy Technology Data Exchange (ETDEWEB)

    Cui, L L; Tu, Y; Liu, H Y [School of Pharmacy, Second Military Medical University (China); Liang, Y Y; Dong, F J; Ma, L; Jiang, J, E-mail: jjiang@smmu.edu.cn [College of Basic Medical Sciences, Second Military Medical University (China)

    2011-06-23

    Polypropylene (PP) electrets with surface potential of -500V, -1000V and -2000V were prepared by constant voltage corona charging. The electrets were applied to excised rat skin for 2 hours respectively and then the skin samples were analyzed with the differential scanning calorimetry (DSC) technique to study the alteration of lipid organization of the skin. There were three peaks at 63 deg. C, 82.7 deg. C and 115.1 deg. C in the DSC spectra for rat skin untreated, which have been assigned essentially to lipid, lipid-protein and protein alterations. For -500V electret treated-skin sample, only a single peak appeared at 79.1 deg. C. With the increase of electret surface potential from -500V to -2000V, the transition temperature and peak areas at moderate decreased first and then increased. The negative electret could result in the transition of stratum corneum (SC) lipid from gel to liquid crystal and protein transition from {alpha} helix structure to {beta} folding structure. The regulation action of electret to skin mircostructure presented an effect of {sup p}otential window{sup .}

  20. Validation of experimental whole-body SAR assessment method in a complex indoor environment.

    Science.gov (United States)

    Bamba, Aliou; Joseph, Wout; Vermeeren, Gunter; Tanghe, Emmeric; Gaillot, Davy Paul; Andersen, Jørgen B; Nielsen, Jesper Ødum; Lienard, Martine; Martens, Luc

    2013-02-01

    Experimentally assessing the whole-body specific absorption rate (SAR(wb) ) in a complex indoor environment is very challenging. An experimental method based on room electromagnetics theory (accounting only the line-of-sight as specular path) is validated using numerical simulations with the finite-difference time-domain method. Furthermore, the method accounts for diffuse multipath components (DMC) in the total absorption rate by considering the reverberation time of the investigated room, which describes all the losses in a complex indoor environment. The advantage of the proposed method is that it allows discarding the computational burden because it does not use any discretizations. Results show good agreement between measurement and computation at 2.8 GHz, as long as the plane wave assumption is valid, that is, at large distances from the transmitter. Relative deviations of 0.71% and 4% have been obtained for far-field scenarios, and 77.5% for the near field-scenario. The contribution of the DMC in the total absorption rate is also quantified here, which has never been investigated before. It is found that the DMC may represent an important part of the total absorption rate; its contribution may reach up to 90% for certain scenarios in an indoor environment.

  1. Thermophysical properties of medium density fiberboards measured by quasi-stationary method: experimental and numerical evaluation

    Science.gov (United States)

    Troppová, Eva; Tippner, Jan; Hrčka, Richard

    2017-01-01

    This paper presents an experimental measurement of thermal properties of medium density fiberboards with different thicknesses (12, 18 and 25 mm) and sample sizes (50 × 50 mm and 100 × 100 mm) by quasi-stationary method. The quasi-stationary method is a transient method which allows measurement of three thermal parameters (thermal conductivity, thermal diffusivity and heat capacity). The experimentally gained values were used to verify a numerical model and furthermore served as input parameters for the numerical probabilistic analysis. The sensitivity of measured outputs (time course of temperature) to influential factors (density, heat transfer coefficient and thermal conductivities) was established and described by the Spearman's rank correlation coefficients. The dependence of thermal properties on density was confirmed by the data measured. Density was also proved to be an important factor for sensitivity analyses as it highly correlated with all output parameters. The accuracy of the measurement method can be improved based on the results of the probabilistic analysis. The relevancy of the experiment is mainly influenced by the choice of a proper ratio between thickness and width of samples.

  2. A DSC study on the effect of marination on the stability of skin collagen from chicken wings

    Directory of Open Access Journals (Sweden)

    Jolanta Tomaszewska-Gras

    2010-12-01

    Full Text Available   Background. Marination is a good method to enhance attractiveness of chicken wings, which are considered by consumers as least attractive. Sensory value of marinated wings is dependent largely on the flavour of skin, because they contain proportionally more skin than other carcass elements. Moreover, skin constitutes a natural barrier, which may facilitate or hinder the penetration of marinade components, depending on the conformation state of proteins it is composed of primarily collagen. The aim of the study was to investigate the effect of specific marinades on thermal stability of collagen – the main component of skin proteins using differential scanning calorimetry (DSC. Material and methods. Chicken wings were marinated using model marinades, marinades prepared according to original recipes and ready-to-use marinades used in industrial practice. Marinated skin samples were weighted (approx. 10 mg and analyzed by DSC. Heating rate was 5°C/min, within the range from 20 to 100°C. Results. In analyses using model marinades denaturation temperature (Tmax of collagen was reduced by approx. 3°C and enthalpy (ΔH was lowered by approx. 40%. An even bigger reduction of collagen denaturation temperature (by approx. 7°C and enthalpy ΔH (by approx. 48% was found after the application of marinades prepared following original recipes (W1, W2, W3. In turn, the application of model marinades containing NaCl and organic acids (acetic or citric resulted in stabilization of collagen, which was manifested by an increase of enthalpy (ΔH by approx. 50% (for marinade containing 2% citric acid. Conclusions. Temperature and enthalpy of collagen denaturation was dependent on type of marinade. The extent of collagen denaturation affects nutritional and sensory value. Considering that time and temperature of intensive heat treatment are important factors in the formation process of carcinogenic compounds i.e. heterocyclic aromatic amines, it bis

  3. Direction and Integration of Experimental Ground Test Capabilities and Computational Methods

    Science.gov (United States)

    Dunn, Steven C.

    2016-01-01

    This paper groups and summarizes the salient points and findings from two AIAA conference panels targeted at defining the direction, with associated key issues and recommendations, for the integration of experimental ground testing and computational methods. Each panel session utilized rapporteurs to capture comments from both the panel members and the audience. Additionally, a virtual panel of several experts were consulted between the two sessions and their comments were also captured. The information is organized into three time-based groupings, as well as by subject area. These panel sessions were designed to provide guidance to both researchers/developers and experimental/computational service providers in defining the future of ground testing, which will be inextricably integrated with the advancement of computational tools.

  4. Adaptive support for aircraft panel testing: New method and its experimental verification on a beam structure

    Science.gov (United States)

    Sachau, Delf; Baschke, Manuel

    2017-04-01

    Acoustic transmissibility of aircraft panels is measured in full-scale test rigs. The panels are supported at their frames. These boundary conditions do not take into account the dynamic influence of the fuselage, which is significant in the frequency range below 300 Hz. This paper introduces a new adaptive boundary system (ABS). It combines accelerometers and electrodynamic shakers with real-time signal processing. The ABS considers the dynamic effect of the fuselage on the panel. The frames are dominating the dynamic behaviour of a fuselage in the low-frequency range. Therefore, the new method is applied to a beam representing a frame of the aircraft structure. The experimental results are evaluated and the precision of the ABS is discussed. The theoretical apparent mass representing the cut-off part of a frame is calculated and compared with the apparent mass, as provided by the ABS. It is explained how the experimental set-up limits the precision of the ABS.

  5. Synergy between experimental and theoretical methods in the exploration of homogeneous transition metal catalysis.

    Science.gov (United States)

    Lupp, D; Christensen, N J; Fristrup, P

    2014-08-01

    In this Perspective, we will focus on the use of both experimental and theoretical methods in the exploration of reaction mechanisms in homogeneous transition metal catalysis. We briefly introduce the use of Hammett studies and kinetic isotope effects (KIE). Both of these techniques can be complemented by computational chemistry - in particular in cases where interpretation of the experimental results is not straightforward. The good correspondence between experiment and theory is only possible due to recent advances within the applied theoretical framework. We therefore also highlight the innovations made in the last decades with emphasis on dispersion-corrected DFT and solvation models. The current state-of-the-art is highlighted using examples from the literature with particular focus on the synergy between experiment and theory.

  6. Experimental design applied to spin coating of 2D colloidal crystal masks: a relevant method?

    Science.gov (United States)

    Colson, Pierre; Cloots, Rudi; Henrist, Catherine

    2011-11-01

    Monolayers of colloidal spheres are used as masks in nanosphere lithography (NSL) for the selective deposition of nanostructured layers. Several methods exist for the formation of self-organized particle monolayers, among which spin coating appears to be very promising. However, a spin coating process is defined by several parameters like several ramps, rotation speeds, and durations. All parameters influence the spreading and drying of the droplet containing the particles. Moreover, scientists are confronted with the formation of numerous defects in spin coated layers, limiting well-ordered areas to a few micrometers squared. So far, empiricism has mainly ruled the world of nanoparticle self-organization by spin coating, and much of the literature is experimentally based. Therefore, the development of experimental protocols to control the ordering of particles is a major goal for further progress in NSL. We applied experimental design to spin coating, to evaluate the efficiency of this method to extract and model the relationships between the experimental parameters and the degree of ordering in the particles monolayers. A set of experiments was generated by the MODDE software and applied to the spin coating of latex suspension (diameter 490 nm). We calculated the ordering by a homemade image analysis tool. The results of partial least squares (PLS) modeling show that the proposed mathematical model only fits data from strictly monolayers but is not predictive for new sets of parameters. We submitted the data to principal component analysis (PCA) that was able to explain 91% of the results when based on strictly monolayered samples. PCA shows that the ordering was positively correlated to the ramp time and negatively correlated to the first rotation speed. We obtain large defect-free domains with the best set of parameters tested in this study. This protocol leads to areas of 200 μm(2), which has never been reported so far.

  7. Experimental and Analytical Method for Determining a Drag Coefficient of the Double-Layer Liquid Separator

    Directory of Open Access Journals (Sweden)

    A. A. Pozhalostin

    2015-01-01

    Full Text Available The paper considers a problem of small axisymmetric oscillations of two-layer liquid with a foam-based separator. The separator is supposed to be rigid and non-deformable, liquid flow through the separator is modeled as a stream with a certain linear-viscous resistance. The liquid is assumed to be ideal and incompressible, its stream being potential. The paper presents experimental and analytical method for finding such a drag coefficient.The work [1] considered the problem of oscillations of a two-layer liquid divided by nondeforming permeable separator where, taking into consideration the interaction between liquid and separator, a reduced drag coefficient is introduced, which is expected to be determined experimentally, thereby generalizing the results of works [4] and [5] in case of moving two-layer liquid through a resistance. The work [6] investigated the motion of ideal incompressible and non-stratified liquid together with the elastic bottom. The work [7] studied a stability of the free liquid surface in low gravity. The paper [8] examined free axially symmetric oscillations of a two-layer liquid with an impermeable separator.Analytical dependence for the drag coefficient obtained in the paper [1] contains the frequency values of free harmonic oscillation system with no resistance (with a missing delimiter and the damping coefficient for the system with resistance (with a separator available. These values can be obtained experimentally if the tank model oscillations with a separator and without it are excited and the natural frequencies of these oscillations are determined. The model under consideration can be used to analyze dynamic interaction between liquid and phase separator of the upper stage or launch vehicle stage and provide ground experimental method for the starting systems from the gravity-free state and low gravity one.The article shows the relationship of the analytic dependence of the damping coefficient at symmetric

  8. Experimental Study on the Compressive Strength of Big Mobility Concrete with Nondestructive Testing Method

    Directory of Open Access Journals (Sweden)

    Huai-Shuai Shang

    2012-01-01

    Full Text Available An experimental study of C20, C25, C30, C40, and C50 big mobility concrete cubes that came from laboratory and construction site was completed. Nondestructive testing (NDT was carried out using impact rebound hammer (IRH techniques to establish a correlation between the compressive strengths and the rebound number. The local curve for measuring strength of the regression method is set up and its superiority is proved. The rebound method presented is simple, quick, and reliable and covers wide ranges of concrete strengths. The rebound method can be easily applied to concrete specimens as well as existing concrete structures. The final results were compared with previous ones from the literature and also with actual results obtained from samples extracted from existing structures.

  9. A simple method of catalase purification for the undergraduate experimental course.

    Science.gov (United States)

    Chen, Qian; Cheng, Meng; Wang, Yinnan; Yao, Ming; Chen, Yongchun; Gao, Yuan; Ding, Wenyuan

    2015-02-01

    Catalase is a characteristic enzyme of peroxisomes, of which it is the most abundant protein. This enzyme serves as a typical example of a peroxisomal enzyme and is important in the teaching of biochemistry and molecular biology. Although there is substantial information regarding catalase purification, purifying catalase for the junior‑grade undergraduate experimental course face challenges in obtaining materials and increasingly expensive purification equipment. This study presents a simple method for the purification of mouse liver catalase using ethanol‑chloroform treatment, sodium sulfate fractionation, dialysis and Sephadex G‑200 gel filtration chromatography. Catalase was purified 31.8‑fold with an 18.3% yield. The advantages of this method were its low operating environment requirements, simple procedure and reduced cost. Furthermore, the method was designed to improve students' comprehensive ability and manipulative ability and to introduce a sense of innovation in the fields of biochemistry and molecular biology during their junior year.

  10. A Numerical Method of Large-Scale Concrete Displacing Boom Dynamic and Experimental Validation

    Directory of Open Access Journals (Sweden)

    Wu Ren

    2014-01-01

    Full Text Available Concrete displacing boom is large-scale motion manipulator. During the long distance pouring the postures needs to frequently change. This makes the real-time dynamic analysis and health monitoring difficult. Virtual spring-damper method is adopted to establish the equivalent hydraulic actuator model. Besides boom cylinder joint clearance is taken into account. Then transfer matrix method is used to build the multibody concrete placing boom model by dividing the system into two substructures. Next typical working conditions displacements and accelerations during the pouring process are studied. The results of the numerical method are correct and feasible compared with Recurdyn software and the experimental ones. So it provides reference to the real-time monitoring and structure design for such light weight large scale motion manipulators.

  11. Current methods of the modeling of experimental diabetes mellitus type 2: a literature review

    Directory of Open Access Journals (Sweden)

    Yu. M. Kolesnyk

    2016-01-01

    Full Text Available Background. Diabetes mellitus (DM became a major problem of the healthcare in Ukraine. The rapid increase in the incidence was noticed especially in recent decade. The treatment of diabetes and its complications become a difficult task. From this standpoint the experimental modeling of diabetes is rather essential. Using the experimental models gives the possibility to assess the significance of the activity of pharmacological substances or to find out new mechanism in the action of medicaments. The aim of this review is to light up the most studied and common experimental models of diabetes mellitus type 2 (T2DM in small rodents and find out their drawbacks. It is known the background of T2DM is the violation of the insulin homeostasis such as the resistance of peripheral tissues to insulin as well as the dysfunction of the pancreatic beta-cells, which both lead to appearance of such phenomena as the glucosetoxicity and the lipotoxicity. In the end they both could result in life threatening vascular complications. Considering the steady growth of T2DM patients, the development both of the drug and non-drug methods of its treatment with the high therapeutically efficiency and the perfect safety profile becomes essential. The most important stage of the search of new ways of influence on pathogenetic links of T2DM is the preclinical stage. From this standpoint the usage of experimental models of T2DM has a huge importance. There are a lot of models of T2DM developed by different scientists. These models could be spontaneous or be induced by different chemical diabetogenic substances, diet or surgical interventions or be a combination of methods listed above. Conclusions. We should underline the adequate modeling of DM2T is the necessary basis for the pre-clinical study of drug-based and not-drug methods of correction of the hyperglycemic states. Using different models makes it possible for infer the obtained experimental results to the society

  12. Air cooling : an experimental method of evaluating the cooling effect of air streams on air-cooled cylinders

    Science.gov (United States)

    Alcock, J F

    1927-01-01

    In this report is described an experimental method which the writer has evolved for dealing with air-cooled engines, and some of the data obtained by its means. Methods of temperature measurement and cooling are provided.

  13. Thermo-kinetic prediction of metastable and stable phase precipitation in Al–Zn–Mg series aluminium alloys during non-isothermal DSC analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lang, Peter, E-mail: pl404@cam.ac.uk [Department of Materials Science and Metallurgy, University of Cambridge, Charles Babbage Road 27, Cambridge CB3 0FS (United Kingdom); Wojcik, Tomasz [Institute of Materials Science and Technology, Vienna University of Technology, Favoritenstraße 9-11, Vienna 1040 (Austria); Povoden-Karadeniz, Erwin [Institute of Materials Science and Technology, Vienna University of Technology, Favoritenstraße 9-11, Vienna 1040 (Austria); Christian Doppler Laboratory “Early Stages of Precipitation”, Institute of Materials Science and Technology, Vienna University of Technology, Favoritenstraße 9-11, Vienna 1040 (Austria); Falahati, Ahmad [Institute of Materials Science and Technology, Vienna University of Technology, Favoritenstraße 9-11, Vienna 1040 (Austria); Kozeschnik, Ernst [Institute of Materials Science and Technology, Vienna University of Technology, Favoritenstraße 9-11, Vienna 1040 (Austria); Christian Doppler Laboratory “Early Stages of Precipitation”, Institute of Materials Science and Technology, Vienna University of Technology, Favoritenstraße 9-11, Vienna 1040 (Austria)

    2014-10-01

    Highlights: • Comparison of laboratory Al–Zn–Mg alloy to industrial Al 7xxx series. • Heat flow evolution during non-isothermal DSC analysis is calculated. • TEM investigations of laboratory Al–Zn–Mg alloy at three pronounced temperatures. • Simulation and modelling of precipitation sequence. • Calculation and prediction of heat flow curves of Al 7xxx series. - Abstract: The technological properties of heat treatable Al–Zn–Mg alloys originate in the morphology and distribution of metastable particles. Starting from the solution-annealed condition, this paper describes the precipitate evolution during non-isothermal temperature changes, namely continuous heating differential scanning calorimetry (DSC) analysis. The distribution and the morphology of the metastable and stable precipitates and the heat flow accompanying the precipitation process is investigated experimentally and calculated by numerical thermo-kinetic simulations. The computer simulation results of the sizes and distributions are confirmed by transmission electron microscopy (TEM). The theoretical background and the results of the investigations are discussed.

  14. Application of Computational-Experimental Methods for Designing Optimized Semitrailer Axle Supports

    Directory of Open Access Journals (Sweden)

    David Valladares

    2015-01-01

    Full Text Available Computational and experimental methods were applied to the design and optimization of a semitrailer axle support subjected to fatigue loads. Numerical results based on the finite element method (FEM were correlated with extensometric tests to assess the accuracy of the computational method. This paper is focused on the “minimum radius manoeuvre.” This situation represents the highly critical load case occurring in a semitrailer operation where the tractor vehicle pulls the semitrailer's kingpin at approximately 90° with respect to its longitudinal axis, and high stress and strain phenomena take place in the axle supports’ structure. Loads and boundary conditions that correspond to this load case were first adjusted by means of experimental tests and could be later applied to each semitrailer axle support in the numerical model. In this analysis, the stress-strain elastic-plastic curves of the base material, the welding, and the HAZ have been incorporated to the numerical models. Fatigue S-N curves combined with the maximum Von Mises equivalent stresses obtained in the computational analysis provided a maximum number of cycles that the semitrailer axle support could reach in case of the minimum radius manoeuvre being applied to the vehicle in a repeated manner. The initial design could then be optimized to improve its fatigue life.

  15. A comparison of analytical methods with experimental data for earthquake ductility assessment

    Energy Technology Data Exchange (ETDEWEB)

    Adelson, B.L.; Steinmetz, R.L.

    1983-05-01

    A two-part study was conducted to help evaluate analytical methods used to assess the ductile behavior of offshore structures subjected to severe earthquake ground motion. Part I of the study consisted of a comparison between analytical time-history responses predicted using the Inelastic Tower Response Analysis (INTRA) program and experimental data gathered during a shake-table experiment performed by the University of California at Berkeley in March 1981. The experiment involved a series of tests on a scaled, two-dimensional model of a prototype offshore platform subjected to various levels of simulated ground motion. Part II of the study consisted of a comparison between the ductile behavior predicted using simplified analysis methods (static pushover and impulse velocity) and the ductile behavior demonstrated by the experimental and analytical time-history results. Results of Part I indicated that the analytical time-history analyses predicted within reasonable accuracy the response of the test structure as measured during the experiment. The results of Part II demonstrated that the simplified methods produce conservative estimates of the test structure's energy absorption capacity and ductile behavior during intense ground motion.

  16. Uncovering noisy social signals: Using optimization methods from experimental physics to study social phenomena

    Science.gov (United States)

    2017-01-01

    Due to the ubiquitous presence of treatment heterogeneity, measurement error, and contextual confounders, numerous social phenomena are hard to study. Precise control of treatment variables and possible confounders is often key to the success of studies in the social sciences, yet often proves out of the realm of control of the experimenter. To amend this situation we propose a novel approach coined “lock-in feedback” which is based on a method that is routinely used in high-precision physics experiments to extract small signals out of a noisy environment. Here, we adapt the method to noisy social signals in multiple dimensions and evaluate it by studying an inherently noisy topic: the perception of (subjective) beauty. We show that the lock-in feedback approach allows one to select optimal treatment levels despite the presence of considerable noise. Furthermore, through the introduction of an external contextual shock we demonstrate that we can find relationships between noisy variables that were hitherto unknown. We therefore argue that lock-in methods may provide a valuable addition to the social scientist’s experimental toolbox and we explicitly discuss a number of future applications. PMID:28306728

  17. Experimental results and validation of a method to reconstruct forces on the ITER test blanket modules

    Energy Technology Data Exchange (ETDEWEB)

    Zeile, Christian, E-mail: christian.zeile@kit.edu; Maione, Ivan A.

    2015-10-15

    Highlights: • An in operation force measurement system for the ITER EU HCPB TBM has been developed. • The force reconstruction methods are based on strain measurements on the attachment system. • An experimental setup and a corresponding mock-up have been built. • A set of test cases representing ITER relevant excitations has been used for validation. • The influence of modeling errors on the force reconstruction has been investigated. - Abstract: In order to reconstruct forces on the test blanket modules in ITER, two force reconstruction methods, the augmented Kalman filter and a model predictive controller, have been selected and developed to estimate the forces based on strain measurements on the attachment system. A dedicated experimental setup with a corresponding mock-up has been designed and built to validate these methods. A set of test cases has been defined to represent possible excitation of the system. It has been shown that the errors in the estimated forces mainly depend on the accuracy of the identified model used by the algorithms. Furthermore, it has been found that a minimum of 10 strain gauges is necessary to allow for a low error in the reconstructed forces.

  18. Experimental study of permanent displacement estimate method based on strong-motion earthquake accelerograms

    Science.gov (United States)

    Lu, Tao; Hu, Guorui

    2016-04-01

    In the engineering seismology studies, the seismic permanent displacement of the near-fault site is often obtained by the process of the ground motion accelerogram recorded by the instrument on the station. Because of the selection differences of the estimate methods and the algorithm parameters, the strongly different results of the permanent displacement is gotten often. And the reliability of the methods has not only been proved in fact, but also the selection of the algorithm parameters has to be carefully considered. In order to solve this problem, the experimental study on the permanent displacement according to the accelerogram was carried out with the experiment program of using the large shaking table and the sliding mechanism in the earthquake engineering laboratory. In the experiments,the large shaking table genarated the dynamincs excitation without the permanent displacement,the sliding mechanism fixed on the shaking table genarated the permanent displacement, and the accelerogram including the permant information had been recorded by the instrument on the sliding mechanism.Then the permanent displacement value had been obtained according to the accelerogram, and been compared with the displacement value gotten by the displacement meter and the digital close range photogrammetry. The experimental study showed that the reliable permanent displacement could be obtained by the existing processing method under the simple laboratory conditions with the preconditions of the algorithm parameters selection carefully.

  19. Experimental Methods Applied in a Study of Stall Flutter in an Axial Flow Fan

    Directory of Open Access Journals (Sweden)

    John D. Gill

    2004-01-01

    Full Text Available Flutter testing is an integral part of aircraft gas turbine engine development. In typical flutter testing blade mounted sensors in the form of strain gages and casing mounted sensors in the form of light probes (NSMS are used. Casing mounted sensors have the advantage of being non-intrusive and can detect the vibratory response of each rotating blade. Other types of casing mounted sensors can also be used to detect flutter of rotating blades. In this investigation casing mounted high frequency response pressure transducers are used to characterize the part-speed stall flutter response of a single stage unshrouded axial-flow fan. These dynamic pressure transducers are evenly spaced around the circumference at a constant axial location upstream of the fan blade leading edge plane. The pre-recorded experimental data at 70% corrected speed is analyzed for the case where the fan is back-pressured into the stall flutter zone. The experimental data is analyzed using two probe and multi-probe techniques. The analysis techniques for each method are presented. Results from these two analysis methods indicate that flutter occurred at a frequency of 411 Hz with a dominant nodal diameter of 2. The multi-probe analysis technique is a valuable method that can be used to investigate the initiation of flutter in turbomachines.

  20. Effect Sizes as Result Interpretation Aids in Single-Subject Experimental Research: Description and Application of Four Nonoverlap Methods

    Science.gov (United States)

    Rakap, Salih

    2015-01-01

    Single-subject experimental research (SSER), one of the most commonly used research methods in special education and applied behaviour analysis, is a scientific, rigorous and valid method to evaluate the effectiveness of behavioural, educational and psychological treatments. However, studies using single-subject experimental research designs are…

  1. Experimental method for characterizing CVOC removal from fractured clays during boiling.

    Science.gov (United States)

    Liu, Xiaoling; Tan, Tianwu; Falta, Ronald W; Murdoch, Lawrence C

    2013-09-01

    Conventional remediation methods that rely on contact with contaminants can be ineffective in fractured media, but thermal methods of remediation involving CVOC stripping at boiling temperature show promise. However, limited experimental data are available to characterize thermal remediation because of challenges associated with high temperature. This research reports an experimental method using uniformly contaminated clay packed into two types of experimental cells, a rigid-wall stainless steel tube and a flexible-wall Teflon tube in a pressurized chamber. Both tubes are 5 cm in diameter and approximately 25 cm long. This laboratory apparatus was developed as a 1D physical model for contaminant transport in a cylindrical matrix towards a fracture, which is represented by one end of the cylinder and serves as the outlet of vapor and contaminant. The clay was contaminated with dissolved 1,2-dichloroethane (DCA) and bromide, and the columns were heated to more than 100 °C and then the top end was depressurized to atmospheric pressure to induce boiling. The outflow was condensed and analyzed for contaminant mass. The flexible-wall cell was confined to 100 kPa (gage), allowing equilibrium boiling temperatures of approximately 120 °C to be maintained. The clay was sampled before and after heating and extracted to determine the DCA distribution along the length of the column. During a typical test in the rigid-wall cell, internal temperatures and pressures along the column during heating reached the saturated vapor pressure curve. DCA concentrations in the recovered condensate were up to 12 times of the initial pore concentration in the clay. Less than 5% of non-volatile bromide was recovered. Significant removal of DCA and water occurred along the entire length of the clay column. This suggests that boiling was occurring in the clay matrix.

  2. Analysis of the Experimental and CFD-Based Theoretical Methods for Studying Rotordynamic Characteristics of Labyrinth Gas Seals

    OpenAIRE

    Pugachev, A. O.;Deckner, M.;Kwanka, K.;Helm, P.;Schettel, J.

    2017-01-01

    This paper presents an analysis of the experimental and theoretical methods used to study rotordynamic characteristics of short staggered labyrinth gas seal. Two experimental identification procedures referred to as static and dynamic methods are presented. The static method allows determining direct and cross-coupled stiffness coefficients of the seal by integrating measured circumferential pressure distribution in cavities at various shaft eccentric positions. In the dynamic method, identif...

  3. Highly porous thermal protection materials: Modelling and prediction of the methodical experimental errors

    Science.gov (United States)

    Cherepanov, Valery V.; Alifanov, Oleg M.; Morzhukhina, Alena V.; Budnik, Sergey A.

    2016-11-01

    The formation mechanisms and the main factors affecting the systematic error of thermocouples were investigated. According to the results of experimental studies and mathematical modelling it was established that in highly porous heat resistant materials for aerospace application the thermocouple errors are determined by two competing mechanisms provided correlation between the errors and the difference between radiation and conduction heat fluxes. The comparative analysis was carried out and some features of the methodical error formation related to the distances from the heated surface were established.

  4. An experimental method for directly determining the interconnectivity of melt in a partially molten system

    Science.gov (United States)

    Daines, Martha J.; Richter, Frank M.

    1988-01-01

    An experimental method for directly determining the degree of interconnectivity of melt in a partially molten system is discussed using an olivine-basalt system as an example. Samarium 151 is allowed time to diffuse through mixtures of olivine and basalt powder which have texturally equilibrated at 1350 C and 13 to 15 kbars. The final distribution of samarium is determined through examination of developed radiographs of the samples. Results suggest an interconnected melt network is established at melt fractions at least as low as 1 wt pct and all melt is completely interconnected at melt fractions at least as low as 2 wt pct for the system examined.

  5. A novel experimental method for the measurement of the caloric curves of clusters

    CERN Document Server

    Chirot, Fabien; Zamith, Sébastien; Labastie, Pierre; L'Hermite, Jean-Marc; 10.1063/1.3000628

    2008-01-01

    A novel experimental scheme has been developed in order to measure the heat capacity of mass selected clusters. It is based on controlled sticking of atoms on clusters. This allows one to construct the caloric curve, thus determining the melting temperature and the latent heat of fusion in the case of first-order phase transitions. This method is model-free. It is transferable to many systems since the energy is brought to clusters through sticking collisions. As an example, it has been applied to Na\\_90\\^+ and Na\\_140\\^+. Our results are in good agreement with previous measurements.

  6. A review of methods for experimentally determining linear optics in storage rings

    Energy Technology Data Exchange (ETDEWEB)

    Safranek, J.

    1995-12-31

    In order to maximize the brightness and provide sufficient dynamic aperture in synchrotron radiation storage rings, one must understand and control the linear optics. Control of the horizontal beta function and dispersion is important for minimizing the horizontal beam size. Control of the skew gradient distribution is important for minimizing the vertical size. In this paper, various methods for experimentally determining the optics in a storage ring will be reviewed. Recent work at the National Synchrotron Light Source X-Ray Ring will be presented as well as work done at laboratories worldwide.

  7. Methods for processing experimental data in microwave diagnostics of shock waves and detonation

    Science.gov (United States)

    Sedov, Alexander; Rodionov, Alexey; Kanakov, Vladimir

    2013-06-01

    Microwave interferometry is a promising method of unperturbing diagnostics of short-time processes. It is a bit less effective than the optical methods in accuracy, but it provides a researcher with more capabilities, in particular, for measurements in optically opaque media. The classic methods for processing experimental interferograms using extremums allow to obtain data on motion of investigated objects with the resolution of a quarter of wavelength of probing radiation. It is insufficient for majority of practical applications. Use of the mathematical methods for processing output signals of the receiver allows to improve the method resolution significantly and to obtain motion measurement errors of 0.05...0.1 of wavelength or even less. This paper presents schemes of conduction and brief description of the methods for processing a series of tests, which were performed in RFNC-VNIIEF with use of radio interferometer having length of wave of probing radiation λ = 3.2 mm, namely: to measure velocity of stationary detonation; to measure depth of detonation initiation by shock wave; to investigate shock compressibility of dielectric materials; to investigate dynamics of constructions.

  8. Experimental testing method for solar light simulator with an attached evacuated solar collector

    Directory of Open Access Journals (Sweden)

    Mahmoud Shatat, Saffa Riffat, Francis Agyenim

    2013-01-01

    Full Text Available This paper describes a novel solar simulator of high solar irradiation. It consists of an array of 30 halogen lamps of 400W each, covering a gross area of 2.32 m2. A standardized empirical method for solar simulator testing facility based on an experimental performance is presented. A uniform geometrical configuration design for a solar simulator was evaluated by its illuminance distribution to optimize the maximum source-to-target transfer efficiency of irradiative power. Experimental tests were carried out for various distances from the simulator surface. It was determined that the optimal distance between the light surface simulator and the solar collector is about 23 cm at different solar irradiance. The unevenness of solar radiation values were investigated at different points under the simulator facility and the maximum unevenness error percentage was found to be about 9.1%, which is well within the allowable limits of 15% set by British Standards for testing a solar simulator . The performance of an evacuated solar collector with an aperture area of 1.73 m2 to simulate solar insolation during March in the Middle East region was investigated and it was proved that the efficiency of the solar collector was closely correlated with the efficiency data provided by the manufacturer. The design of such a solar light simulator associated with the development of a standardized test procedure can be utilized as a reliable and efficient experimental platform to investigate various solar collectors and materials.

  9. A method for studying jaw muscle activity during standardized jaw movements under experimental jaw muscle pain.

    Science.gov (United States)

    Sae-Lee, Daraporn; Wanigaratne, Kamal; Whittle, Terry; Peck, Christopher C; Murray, Greg M

    2006-10-30

    This paper describes a method for studying superficial and deep jaw muscle activity during standardized jaw movements under experimental jaw muscle pain. In 22 healthy adults, pain was elicited in the right masseter muscle via tonic infusion of 4.5% hypertonic saline and which resulted in scores of 30-60 mm on a 100-mm visual analogue scale. Subjects performed tasks in five sessions in a repeated measures design, i.e., control 1, test 1 (during hypertonic or isotonic saline infusion), control 2 (without infusion), test 2 (during isotonic or hypertonic saline infusion), control 3 (without infusion). During each session, subjects performed maximal clenching and standardized jaw tasks, i.e., protrusion, lateral excursion, open/close, chewing. Mandibular movement was recorded with a 6-degree-of-freedom tracking system simultaneously with electromyographic (EMG) activity from the inferior head of the lateral pterygoid muscle with fine-wire electrodes (verified by computer tomography), and from posterior temporalis, the submandibular muscle group and bilateral masseter muscles with surface electrodes. EMG root mean square values were calculated at each 0.5 mm increment of mandibular incisor movement for all tasks under each experimental session. This establishes an experimental model for testing the effects of pain on jaw muscle activity where the jaw motor system is required to perform goal-directed tasks, and therefore should extend our understanding of the effects of pain on the jaw motor system.

  10. An experimental evaluation method for the performance of a laser line scanning system with multiple sensors

    Science.gov (United States)

    Tian, Qingguo; Yang, Yujie; Zhang, Xiangyu; Ge, Baozhen

    2014-01-01

    Laser line scanning 3D digitising systems have a wide range of applications. Their working performance is mainly determined by the system calibration procedure and is also affected by the working conditions, CCD camera imperfections, and object surface optical characteristics. Therefore, a comprehensive evaluation of working performance is necessary before and during use. This study proposes an experimental method for the performance evaluation of a laser line scanner (LLS) with 8 scanning sensors developed in our laboratory. This method first obtains the dense point clouds of standard parts composed of disks, cylinders, and squares. Next, the single-layer point clouds located in horizontal planes of different heights are fitted using the least squares method to obtain the enclosed contours S. Three parameters, namely, the standard deviation of the distance distribution between points and S, the mean distance of the distance distribution, and the shape feature sizes, are used to evaluate the performance. The proposed method evaluates both the scanner as a whole and each scanning sensor. Using this method, more comprehensive information can be acquired to evaluate the scanner performance. The experimental results show that the absolute dimension size error and relative error are less than 5 mm and 3%, respectively, and the relative shape error is less than 2%; therefore, the evaluated LLS system can meet the requirements for human anthropometry applications. Although each scanning sensor has different random and systematic error, these errors are the function of measurement depth. These conclusions are helpful for the further use of this scanner system and can be utilised to optimise this LLS system further.

  11. Consistent View of Polypeptide Chain Expansion in Chemical Denaturants from Multiple Experimental Methods.

    Science.gov (United States)

    Borgia, Alessandro; Zheng, Wenwei; Buholzer, Karin; Borgia, Madeleine B; Schüler, Anja; Hofmann, Hagen; Soranno, Andrea; Nettels, Daniel; Gast, Klaus; Grishaev, Alexander; Best, Robert B; Schuler, Benjamin

    2016-09-14

    There has been a long-standing controversy regarding the effect of chemical denaturants on the dimensions of unfolded and intrinsically disordered proteins: A wide range of experimental techniques suggest that polypeptide chains expand with increasing denaturant concentration, but several studies using small-angle X-ray scattering (SAXS) have reported no such increase of the radius of gyration (Rg). This inconsistency challenges our current understanding of the mechanism of chemical denaturants, which are widely employed to investigate protein folding and stability. Here, we use a combination of single-molecule Förster resonance energy transfer (FRET), SAXS, dynamic light scattering (DLS), and two-focus fluorescence correlation spectroscopy (2f-FCS) to characterize the denaturant dependence of the unfolded state of the spectrin domain R17 and the intrinsically disordered protein ACTR in two different denaturants. Standard analysis of the primary data clearly indicates an expansion of the unfolded state with increasing denaturant concentration irrespective of the protein, denaturant, or experimental method used. This is the first case in which SAXS and FRET have yielded even qualitatively consistent results regarding expansion in denaturant when applied to the same proteins. To more directly illustrate this self-consistency, we used both SAXS and FRET data in a Bayesian procedure to refine structural ensembles representative of the observed unfolded state. This analysis demonstrates that both of these experimental probes are compatible with a common ensemble of protein configurations for each denaturant concentration. Furthermore, the resulting ensembles reproduce the trend of increasing hydrodynamic radius with denaturant concentration obtained by 2f-FCS and DLS. We were thus able to reconcile the results from all four experimental techniques quantitatively, to obtain a comprehensive structural picture of denaturant-induced unfolded state expansion, and to

  12. Extensions Of The Method Of Moments For Deconvolution Of Experimental Data

    Science.gov (United States)

    Small, Enoch W.; Libertini, Louis J.; Brown, David W.; Small, Jeanne R.

    1989-05-01

    The Method of Moments is one of a series of closely related transform methods which have been developed primarily for the deconvolution and analysis of fluorescence decay data. The main distinguishing feature of the Method of Moments is that it has been designed to be robust with respect to several important nonrandom errors of instrumental origin. The historical development of the method is reviewed here. Several new extensions are also described, including a statistical theory, an improved global analysis, and a method for analyzing continuous distributions of lifetimes. The new statistical theory is the first to incorporate a combined treatment of exponential depression and moment index displacement, both necessary components of the Method of Moments. In comparisons with the more commonly used least squares iterative reconvolution (LSIR) approach, it is shown that, in analyses of ideal synthetic data with random noise, the Method of Moments gives deviations in recovered parameters which are slightly greater but essentially comparable to those found by the data fitting method. Real experimental data also contain nonrandom errors. In the presence of certain such errors, decay parameters recovered by the Method of Moments will be unaffected, whereas the least squares method may yield incorrect results, unless care is taken to fit all of the data errors. An example of the improved global analysis application of the Method of Moments is shown in which two rhodamine dyes with very close lifetimes are distinguished based on spectral data. Also, the use of the distribution analysis method is illustrated with the binding of the intercalating dye ethidium bromide to DNA and nucleosome core particles. At very low ionic strength the width and location of the lifetime distribution shows a time dependence, indicating time-dependent changes in the environment of the probe. Finally, examples of Method of Moments analyses are shown for a totally different kind of data

  13. Development of advanced methods for analysis of experimental data in diffusion

    Science.gov (United States)

    Jaques, Alonso V.

    There are numerous experimental configurations and data analysis techniques for the characterization of diffusion phenomena. However, the mathematical methods for estimating diffusivities traditionally do not take into account the effects of experimental errors in the data, and often require smooth, noiseless data sets to perform the necessary analysis steps. The current methods used for data smoothing require strong assumptions which can introduce numerical "artifacts" into the data, affecting confidence in the estimated parameters. The Boltzmann-Matano method is used extensively in the determination of concentration - dependent diffusivities, D(C), in alloys. In the course of analyzing experimental data, numerical integrations and differentiations of the concentration profile are performed. These methods require smoothing of the data prior to analysis. We present here an approach to the Boltzmann-Matano method that is based on a regularization method to estimate a differentiation operation on the data, i.e., estimate the concentration gradient term, which is important in the analysis process for determining the diffusivity. This approach, therefore, has the potential to be less subjective, and in numerical simulations shows an increased accuracy in the estimated diffusion coefficients. We present a regression approach to estimate linear multicomponent diffusion coefficients that eliminates the need pre-treat or pre-condition the concentration profile. This approach fits the data to a functional form of the mathematical expression for the concentration profile, and allows us to determine the diffusivity matrix directly from the fitted parameters. Reformulation of the equation for the analytical solution is done in order to reduce the size of the problem and accelerate the convergence. The objective function for the regression can incorporate point estimations for error in the concentration, improving the statistical confidence in the estimated diffusivity matrix

  14. Experimental study on two-dimensional film flow with local measurement methods

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jin-Hwa, E-mail: evo03@snu.ac.kr [Nuclear Thermal-Hydraulic Engineering Laboratory, Seoul National University, Gwanak 599, Gwanak-ro, Gwanak-gu, Seoul 151-742 (Korea, Republic of); Korea Atomic Energy Research Institute, 989-111, Daedeok-daero, Yuseong-gu, Daejeon 305-600 (Korea, Republic of); Cho, Hyoung-Kyu [Nuclear Thermal-Hydraulic Engineering Laboratory, Seoul National University, Gwanak 599, Gwanak-ro, Gwanak-gu, Seoul 151-742 (Korea, Republic of); Kim, Seok [Korea Atomic Energy Research Institute, 989-111, Daedeok-daero, Yuseong-gu, Daejeon 305-600 (Korea, Republic of); Euh, Dong-Jin, E-mail: djeuh@kaeri.re.kr [Korea Atomic Energy Research Institute, 989-111, Daedeok-daero, Yuseong-gu, Daejeon 305-600 (Korea, Republic of); Park, Goon-Cherl [Nuclear Thermal-Hydraulic Engineering Laboratory, Seoul National University, Gwanak 599, Gwanak-ro, Gwanak-gu, Seoul 151-742 (Korea, Republic of)

    2015-12-01

    Highlights: • An experimental study on the two-dimensional film flow with lateral air injection was performed. • The ultrasonic thickness gauge was used to measure the local liquid film thickness. • The depth-averaged PIV (Particle Image Velocimetry) method was applied to measure the local liquid film velocity. • The uncertainty of the depth-averaged PIV was quantified with a validation experiment. • Characteristics of two-dimensional film flow were classified following the four different flow patterns. - Abstract: In an accident condition of a nuclear reactor, multidimensional two-phase flows may occur in the reactor vessel downcomer and reactor core. Therefore, those have been regarded as important issues for an advanced thermal-hydraulic safety analysis. In particular, the multi-dimensional two-phase flow in the upper downcomer during the reflood phase of large break loss of coolant accident appears with an interaction between a downward liquid and a transverse gas flow, which determines the bypass flow rate of the emergency core coolant and subsequently, the reflood coolant flow rate. At present, some thermal-hydraulic analysis codes incorporate multidimensional modules for the nuclear reactor safety analysis. However, their prediction capability for the two-phase cross flow in the upper downcomer has not been validated sufficiently against experimental data based on local measurements. For this reason, an experimental study was carried out for the two-phase cross flow to clarify the hydraulic phenomenon and provide local measurement data for the validation of the computational tools. The experiment was performed in a 1/10 scale unfolded downcomer of Advanced Power Reactor 1400 (APR1400). Pitot tubes, a depth-averaged PIV method and ultrasonic thickness gauge were applied for local measurement of the air velocity, the liquid film velocity and the liquid film thickness, respectively. The uncertainty of the depth-averaged PIV method for the averaged

  15. New method of the polymeric material properties experimental investigation under powerful energy flux impact

    Science.gov (United States)

    Demidov, B. A.; Efremov, V. P.; Kalinin, Yu G.; Kazakov, E. D.; Metelkin, S. Yu; Petrov, V. A.; Potapenko, A. I.

    2015-11-01

    Investigation of the polymeric material properties under powerfull energy flux impact is relevant as for basic research (mathematical modeling of polymeric materials behavior in extreme conditions, testing the state equations), as for practical applications (for testing of protective coatings for space research and laboratory facilities). This paper presents the results of experimental studies of the interaction of polymeric materials with a relativistic electron beam produced by a high-current electron accelerator Calamary. Calamary facility provides a wide range of electron beam parameters: diameter 10-15 mm, the voltage on the diode up to 300 kV, the current through the diode up to 30 kA. New method of beam-target interaction area measurement was developed. The original method for the mechanical kick impulse measuring based on piezoelectric vibration sensor was presented. The dependence of the kick impulse from the power flux was obtained.

  16. Experimental method to determine the role of helium in neutron-induced microstructural evolution

    Energy Technology Data Exchange (ETDEWEB)

    Gelles, D. S.; Garner, F. A.

    1978-12-01

    A method is presented which allows the determination of the role of helium on microstructural evolution in complex alloys and which avoids many of the problems associated with other simulation experiments. It involves a direct comparison of the materials' response to a primary difference in fission and fusion environments, namely the rate of helium generation. This is accomplished by irradiating specimens in a fission reactor and conducting microstructural analyses which concentrate on alloy matrix regions adjacent to precipitates rich in boron or nitrogen. Procedures are outlined for calculation of background and injected helium levels as well as displacement doses generated by neutrons and alpha particles. An example of the analysis method is shown for an experimental austenitic stainless steel containing boride particles and irradiated to 3 and 7 x 10/sup 22/ n/cm/sup 2/ (E > 0.1 MeV).

  17. EQUIVALENT EXCITATION METHOD FOR VIBRATION ISOLATION DESIGN:THEORETICAL ANALYSIS AND EXPERIMENTAL RESULTS

    Institute of Scientific and Technical Information of China (English)

    Huo Rui; Shi Yin

    2005-01-01

    In view of difficulties concerned with direct measurement of excitations inside source equipments and their significant influence on vibration isolation effectiveness, a dynamical model, for vibration isolation of a rigid machine with six-degree-of-freedom mounted on a flexible foundation through multiple mounts, is analyzed, in which the complicated and multiple disturbances inside the machine are described as an equivalent excitation spectrum. And a method for the estimation of the equivalent excitation spectrum according to system dynamic responses is discussed for the quantitative prediction of isolation effectiveness.Both theoretical analysis and experimental results are demonstrated. Further work shows the quantitative prediction of transmitted power flow in a flexible vibration isolation experiment system using the proposed equivalent excitation spectrum method, by comparison with its testing results.

  18. Design of passive directional acoustic devices using Topology Optimization - from method to experimental validation

    DEFF Research Database (Denmark)

    Christiansen, Rasmus Ellebæk; Fernandez Grande, Efren

    2016-01-01

    The paper presents a topology optimization based method for designing acoustic focusing devices, capable of tailoring the sound emission pattern of one or several sources, across a chosen frequency band. The method is demonstrated numerically considering devices optimized for directional sound...... emission in two dimensions and is experimentally validated using three dimensional prints of the optimized designs. The emitted fields exhibit a level difference of at least 15 dB on axis relative to the off-axis directions, over frequency bands of approximately an octave. It is demonstrated to be possible...... to outperform the latter in terms of directivity and maximum side-lobe level over nearly an octave band. A set of frequencies are considered simultaneously in the design formulation and performance robustness toward uniform spatial production errors in the designed devices is assured by including perturbations...

  19. Experimental and Statistical Evaluation of Cutting Methods in Relation to Specific Energy and Rock Properties

    Science.gov (United States)

    Engin, Irfan Celal; Bayram, Fatih; Yasitli, Nazmi Erhan

    2013-07-01

    In a processing plant, natural stone can be cut by methods such as circular sawing (CS), frame sawing (FS), water jet cutting (WJC) and abrasive water jet cutting (AWJC). The efficiency of cutting systems can be compared using various parameters. In this study, the specific energy values were determined and compared to evaluate the efficiency of rock-cutting methods. Rock-cutting experiments were performed on 12 different types of rock samples using a circular sawing machine and an AWJC machine. The experimental results showed that the specific energy values in AWJC were generally higher than in CS. In addition, the relationships between specific energy values and rock properties were explained in this study. The Shore hardness and abrasion resistance were found to be strongly related to the specific energy values, and according to these parameters prediction charts of specific energy values were created.

  20. Experimental research on charging characteristics of a solar photovoltaic system by the pressure-control method

    Institute of Scientific and Technical Information of China (English)

    Hua ZHU; Zhang-lu XU; Zi-juan CAO

    2011-01-01

    The charging characteristics of the valve-regulated lead acid (VRLA) battery driven by solar energy were experimentally studied through the pressure-control method in this paper. The aims of the research were to increase charging efficiency to make the most of solar energy and to improve charging quality to prolong life of battery. The charging process of a 12 V 12 A.h VRLA battery has been tested under the mode of a stand-alone photovoltaic (PV) system. Results show that the pressure-control method can effectively control PV charging of the VRLA battery and make the best of PV cells through the maximum power point tracking (MPPT). The damage of VRLA battery by excess oxygen accumulation can be avoided through the inner pressure control of VRLA battery. Parameters such as solar radiation intensity, charging power, inner pressure of the battery, and charging current and voltage during the charging process were measured and analyzed.

  1. Experimental substantiation of methodic of 11-13 years old boxers’ coordination development

    Directory of Open Access Journals (Sweden)

    Liu Yong Qiang

    2015-06-01

    Full Text Available Purpose: experimental substantiation of methodic of junior boxers’ coordination training. Material: in the research 18 boxers of 11-13 year old age participated. In total, during 4 months 42 trainings were conducted. Total time of coordination load’s fulfillment at each training was 15-45 minutes. Results: dynamic of results in control tests was statistically confident in the tested parameters of movements. It proves effectiveness of usage the tasks with complex-coordination orientation, accented on impact on sensor-informational and motor systems of movements in junior boxers’ trainings. Conclusions: coordination training in boxing at initial stage shall include specialized varied means and methods, which would facilitate formation of motor condition and skills’ basis. Motor condition and skills are a reserve for further rising of coordination abilities’ level of junior sportsmen.

  2. Comparison of spectral CT imaging methods based a photon-counting detector: Experimental study

    Science.gov (United States)

    Lee, Youngjin; Lee, Seungwan; Kim, Hee-Joung

    2016-04-01

    Photon-counting detectors allow spectral computed tomography (CT) imaging using energy-resolved information from a polychromatic X-ray spectrum. The spectral CT images based on the photon-counting detectors are dependent on the energy ranges defined by energy bins for image acquisition. In this study, K-edge and energy weighting imaging methods were experimentally implemented by using a spectral CT system with a cadmium zinc telluride (CZT)-based photon-counting detector. The spectral CT images were obtained by various energy bins and compared in terms of CNR improvement for investigating the effect of energy bins and the efficiency of the spectral CT imaging methods. The results showed that the spectral CT image quality was improved by using the particular energy bins, which were optimized for each spectral CT imaging method and target material. The CNR improvement was different for the spectral CT imaging methods and target materials. It can be concluded that an appropriate selection of imaging method for each target material and the optimization of energy bin can maximize the quality of spectral CT images.

  3. Experimental results on a wall interference correction method with interface measurements

    Science.gov (United States)

    Lo, C. F.; Ulbrich, N.

    1992-01-01

    A wall interference assessment and correction method for subsonic two-dimensional wind tunnel testing is presented. This method calculates a pressure coefficient and angle of attack correction based on velocity measurements on interfaces inside of the wind tunnel. A mathematical representation of the test article is not required. An experimental verification of the suggested technique is given. A NACA 0012 airfoil is tested at a Mach number of 0.70 and at two different angles of attack. Calculated blockage corrections show reasonable agreement with results based on Hackett's method. Corrected surface pressures compare favorably to free-air flow field data if the tunnel flow field is subsonic. The present wall interference correction method can be applied to transonic tunnel flow fields with some restrictions. Errors are estimated and it is shown that the expected error in calculating the pressure coefficient correction on the model surface is in the order of the error of pressure coefficient measurement on interfaces. Necessary testing equipment in existing tunnels can easily be modified if the present method is applied.

  4. Comparison of spectral CT imaging methods based a photon-counting detector: Experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Youngjin [Department of Radiological Science, College of Health Science, Eulji University, 553 Sangseong-daero, Seongnam, Gyeonggi-do 461-713 (Korea, Republic of); Lee, Seungwan, E-mail: slee1@konyang.ac.kr [Department of Radiological Science, College of Medical Science, Konyang University, 158 Gwanjeodong-ro, Daejeon 302-812 (Korea, Republic of); Kim, Hee-Joung [Department of Radiological Science, College of Health Science, Yonsei University, 1 Yonseidae-gil, Wonju, Kangwon-do 220-710 (Korea, Republic of)

    2016-04-11

    Photon-counting detectors allow spectral computed tomography (CT) imaging using energy-resolved information from a polychromatic X-ray spectrum. The spectral CT images based on the photon-counting detectors are dependent on the energy ranges defined by energy bins for image acquisition. In this study, K-edge and energy weighting imaging methods were experimentally implemented by using a spectral CT system with a cadmium zinc telluride (CZT)-based photon-counting detector. The spectral CT images were obtained by various energy bins and compared in terms of CNR improvement for investigating the effect of energy bins and the efficiency of the spectral CT imaging methods. The results showed that the spectral CT image quality was improved by using the particular energy bins, which were optimized for each spectral CT imaging method and target material. The CNR improvement was different for the spectral CT imaging methods and target materials. It can be concluded that an appropriate selection of imaging method for each target material and the optimization of energy bin can maximize the quality of spectral CT images.

  5. Experimental Methods for Investigation of Shape Memory Based Elastocaloric Cooling Processes and Model Validation.

    Science.gov (United States)

    Schmidt, Marvin; Ullrich, Johannes; Wieczorek, André; Frenzel, Jan; Eggeler, Gunther; Schütze, Andreas; Seelecke, Stefan

    2016-05-02

    Shape Memory Alloys (SMA) using elastocaloric cooling processes have the potential to be an environmentally friendly alternative to the conventional vapor compression based cooling process. Nickel-Titanium (Ni-Ti) based alloy systems, especially, show large elastocaloric effects. Furthermore, exhibit large latent heats which is a necessary material property for the development of an efficient solid-state based cooling process. A scientific test rig has been designed to investigate these processes and the elastocaloric effects in SMAs. The realized test rig enables independent control of an SMA's mechanical loading and unloading cycles, as well as conductive heat transfer between SMA cooling elements and a heat source/sink. The test rig is equipped with a comprehensive monitoring system capable of synchronized measurements of mechanical and thermal parameters. In addition to determining the process-dependent mechanical work, the system also enables measurement of thermal caloric aspects of the elastocaloric cooling effect through use of a high-performance infrared camera. This combination is of particular interest, because it allows illustrations of localization and rate effects - both important for efficient heat transfer from the medium to be cooled. The work presented describes an experimental method to identify elastocaloric material properties in different materials and sample geometries. Furthermore, the test rig is used to investigate different cooling process variations. The introduced analysis methods enable a differentiated consideration of material, process and related boundary condition influences on the process efficiency. The comparison of the experimental data with the simulation results (of a thermomechanically coupled finite element model) allows for better understanding of the underlying physics of the elastocaloric effect. In addition, the experimental results, as well as the findings based on the simulation results, are used to improve the

  6. Experimental Analysis of a Heat Cost Allocation Method for Apartment Buildings

    Directory of Open Access Journals (Sweden)

    Fabio Saba

    2017-03-01

    Full Text Available The correct estimate of individual thermal energy consumptions, and consequently, a fair heat cost allocation among the residents of apartment buildings with centralized heating systems, represents an important driving force towards energy saving, energy efficiency and the reduction of pollutant emissions. Nowadays, in those contexts where direct heat meters cannot be used because of the layout of the hot water distribution system, electronic Heat Cost Allocators (HCAs have the highest market share for the assessment of individual thermal energy consumptions. The uncertainty associated with the parameterization of heat cost allocation devices and the installation effects arising in real applications can negatively affect the accuracy of these devices, as far as the estimation of the individual fractions of thermal energy consumption is concerned. This work deals with the experimental analysis of a novel heat cost allocation method for apartment buildings and its comparison with conventional HCAs. The method allows the indirect estimation of the thermal energy exchanged by water radiators without the need for surface temperature measurements, reducing some of the drawbacks associated with the on-site installation. The experimental analysis was carried out in a full-scale central heating system test facility available at the Italian National Metrology Institute (INRIM and characterized by SI-traceable direct heat meters installed on each water radiator.

  7. Experimental method to characterize the strain dependent permeability of tissue engineering scaffolds.

    Science.gov (United States)

    Nasrollahzadeh, Naser; Pioletti, Dominique P

    2016-11-07

    Permeability is an overarching mechanical parameter encompassing the effects of porosity, pore size, and interconnectivity of porous structures. This parameter directly influences transport of soluble particles and indirectly regulates fluid pressure and velocity in tissue engineering scaffolds. The permeability also contributes to the viscoelastic behavior of visco-porous material under loading through frictional drag mechanism. We propose a straightforward experimental method for permeability characterization of tissue engineering scaffolds. In the developed set-up a step-wise spacer was designed to facilitate measurement of the permeability under different compressive strains while maintaining similar experimental conditions during the successive measurements. As illustration of the method, we measured the permeability of scaffolds presenting different average pore sizes and subjected to different compression values. Results showed an exponential relationship between the permeability and the average pore size of the scaffolds. Furthermore, the trend of the permeability decrease with compressive strains was depending on pore sizes of the scaffolds. The permeability also appeared to play a role in relaxation behavior of the scaffolds.

  8. An Experimental Method for Measuring Water Droplet Impingement Efficiency on Two- and Three-dimensional Bodies

    Science.gov (United States)

    Papadakis, M.; Zumwalt, G. W.; Elangonan, R.; Freund, G. A., Jr.; Breer, M.; Whitmer, L.

    1989-01-01

    An experimental method was developed to determine the droplet impingement characteristics on 2-D and 3-D bodies. The experimental results provide the essential droplet impingement data required to validate water droplet trajectory codes, which are used in the analysis of aircraft icing. A body, whose water droplet impingement characteristics are required, is covered at strategic locations by thin strips of moisture absorbing (blotter) paper, and is exposed to an air stream containing a water dye solution spray cloud. Water droplet impingement data are extracted from the dyed blotter strips by measuring the optical reflectance of the dye deposit on the strips, using an automated reflectometer. Models tested include a 4-inch diameter cylinder, a NACA 652015 airfoil section, a MS(1)-0317 supercritical airfoil section, three simulated ice shapes, an axisymmetric inlet and a Boeing 737-300 inlet model. Detailed descriptions of the dye tracer technique, instrumentation, data reduction method and the results obtained are presented. Analytical predictions of collection efficiency characteristics for most test configurations are included for comparison.

  9. Optimal experimental designs for estimating Henry's law constants via the method of phase ratio variation.

    Science.gov (United States)

    Kapelner, Adam; Krieger, Abba; Blanford, William J

    2016-10-14

    When measuring Henry's law constants (kH) using the phase ratio variation (PRV) method via headspace gas chromatography (GC), the value of kH of the compound under investigation is calculated from the ratio of the slope to the intercept of a linear regression of the inverse GC response versus the ratio of gas to liquid volumes of a series of vials drawn from the same parent solution. Thus, an experimenter collects measurements consisting of the independent variable (the gas/liquid volume ratio) and dependent variable (the GC(-1) peak area). A review of the literature found that the common design is a simple uniform spacing of liquid volumes. We present an optimal experimental design which estimates kH with minimum error and provides multiple means for building confidence intervals for such estimates. We illustrate performance improvements of our design with an example measuring the kH for Naphthalene in aqueous solution as well as simulations on previous studies. Our designs are most applicable after a trial run defines the linear GC response and the linear phase ratio to the GC(-1) region (where the PRV method is suitable) after which a practitioner can collect measurements in bulk. The designs can be easily computed using our open source software optDesignSlopeInt, an R package on CRAN.

  10. A Wavelet-Based ECG Delineation Method: Adaptation to an Experimental Electrograms with Manifested Global Ischemia.

    Science.gov (United States)

    Hejč, Jakub; Vítek, Martin; Ronzhina, Marina; Nováková, Marie; Kolářová, Jana

    2015-09-01

    We present a novel wavelet-based ECG delineation method with robust classification of P wave and T wave. The work is aimed on an adaptation of the method to long-term experimental electrograms (EGs) measured on isolated rabbit heart and to evaluate the effect of global ischemia in experimental EGs on delineation performance. The algorithm was tested on a set of 263 rabbit EGs with established reference points and on human signals using standard Common Standards for Quantitative Electrocardiography Standard Database (CSEDB). On CSEDB, standard deviation (SD) of measured errors satisfies given criterions in each point and the results are comparable to other published works. In rabbit signals, our QRS detector reached sensitivity of 99.87% and positive predictivity of 99.89% despite an overlay of spectral components of QRS complex, P wave and power line noise. The algorithm shows great performance in suppressing J-point elevation and reached low overall error in both, QRS onset (SD = 2.8 ms) and QRS offset (SD = 4.3 ms) delineation. T wave offset is detected with acceptable error (SD = 12.9 ms) and sensitivity nearly 99%. Variance of the errors during global ischemia remains relatively stable, however more failures in detection of T wave and P wave occur. Due to differences in spectral and timing characteristics parameters of rabbit based algorithm have to be highly adaptable and set more precisely than in human ECG signals to reach acceptable performance.

  11. Experimental method for and theoretical research on defect tolerance of fixed plate based on damage mechanics

    Institute of Scientific and Technical Information of China (English)

    Zhan Zhixin; Hu Weiping; Zhang Miao; Zhu Yuefa; Meng Qingchun

    2013-01-01

    An experimental method and a theoretical analysis based on continuum damage mechan-ics are applied for the defects tolerance of fixed plate. The defects type studied in this article is scratch, which is considered a typical defect on fixed plate according to the engineering practice. The general approach to the defects tolerance analysis of scratched fixed plate is presented. The method of fatigue life prediction for standard notched specimens has been established on the basis of continuum damage mechanics. For the purpose of obtaining the influence law of fatigue life in consequence of scratches, fatigue experiments of standard notched specimens and scratched specimens have been done. Evalu-ation of the fatigue life of scratched fixed plate has been carried out. And the value of scratch defects permissible to the condition of safety service life has been worked out. According to the results of the-oretical calculations, the fatigue experiment of scratched fixed plate has been performed. The outcome shows that the theoretical prediction tallies with the experimental results.

  12. Performance of Higher Order Campbell methods, Part II: calibration and experimental application

    Science.gov (United States)

    Elter, Zs.; de Izarra, G.; Filliatre, P.; Jammes, C.; Pázsit, I.

    2016-11-01

    Applying Higher Order Campbelling methods in neutron flux monitoring with fission chambers is advantageous due to their capabilities to suppress the impact of unwanted noises and signal contributions (such as gamma radiation). This work aims to verify through experimental results that the basic assumptions behind the Higher Order Campelling methods are valid in critical reactors. The experiments, reported in this work, were performed at the MINERVE reactor in Cadarache. It is shown that the calibration of a fission chamber and the associated electronic system is possible in higher order mode. With the use of unbiased cumulant estimators and with digital processing, it is shown that over a wide count rate range, accurate count rate estimation can be achieved based on signal samples of a few ms, which is a significant progress compared to similar experimental results in the literature. The difference between the count rate estimated by pulse counting and by the Higher Order Campelling is less than 4%. The work also investigates the possibility of monitoring transient events. For this purpose, a control rod drop event was followed in Higher Order Campbelling mode.

  13. Designing specific protein-protein interactions using computation, experimental library screening, or integrated methods.

    Science.gov (United States)

    Chen, T Scott; Keating, Amy E

    2012-07-01

    Given the importance of protein-protein interactions for nearly all biological processes, the design of protein affinity reagents for use in research, diagnosis or therapy is an important endeavor. Engineered proteins would ideally have high specificities for their intended targets, but achieving interaction specificity by design can be challenging. There are two major approaches to protein design or redesign. Most commonly, proteins and peptides are engineered using experimental library screening and/or in vitro evolution. An alternative approach involves using protein structure and computational modeling to rationally choose sequences predicted to have desirable properties. Computational design has successfully produced novel proteins with enhanced stability, desired interactions and enzymatic function. Here we review the strengths and limitations of experimental library screening and computational structure-based design, giving examples where these methods have been applied to designing protein interaction specificity. We highlight recent studies that demonstrate strategies for combining computational modeling with library screening. The computational methods provide focused libraries predicted to be enriched in sequences with the properties of interest. Such integrated approaches represent a promising way to increase the efficiency of protein design and to engineer complex functionality such as interaction specificity.

  14. An experimental method to verify soil conservation by check dams on the Loess Plateau, China.

    Science.gov (United States)

    Xu, X Z; Zhang, H W; Wang, G Q; Chen, S C; Dang, W Q

    2009-12-01

    A successful experiment with a physical model requires necessary conditions of similarity. This study presents an experimental method with a semi-scale physical model. The model is used to monitor and verify soil conservation by check dams in a small watershed on the Loess Plateau of China. During experiments, the model-prototype ratio of geomorphic variables was kept constant under each rainfall event. Consequently, experimental data are available for verification of soil erosion processes in the field and for predicting soil loss in a model watershed with check dams. Thus, it can predict the amount of soil loss in a catchment. This study also mentions four criteria: similarities of watershed geometry, grain size and bare land, Froude number (Fr) for rainfall event, and soil erosion in downscaled models. The efficacy of the proposed method was confirmed using these criteria in two different downscaled model experiments. The B-Model, a large scale model, simulates watershed prototype. The two small scale models, D(a) and D(b), have different erosion rates, but are the same size. These two models simulate hydraulic processes in the B-Model. Experiment results show that while soil loss in the small scale models was converted by multiplying the soil loss scale number, it was very close to that of the B-Model. Obviously, with a semi-scale physical model, experiments are available to verify and predict soil loss in a small watershed area with check dam system on the Loess Plateau, China.

  15. DSC and TA characteristics of the inoculated Al-Zn20 alloy

    Directory of Open Access Journals (Sweden)

    W.K. Krajewski

    2011-01-01

    Full Text Available The paper brings information about inoculation process of the sand-cast binary Al-20 wt% Zn (AlZn20 alloy, inoculated with Ticontaining grain-refiners, i.e. AlTi5B1, AlTi3C0.15 and (AlZn-Ti3 master alloys (MA. During the experiments thermal analyses (TAand differential scanning calorimetry (DSC were used. Macrostructure observations were performed using light microscopy (LM . On thebasis of the performed examinations it was found that all the MAs used in this work caused significant grain refinement, which initiates via a heterogeneous nucleation mode. The obtained structure fineness of the inoculated AlZn20 alloy should positively influence i ts ductility, which is of great importance for the practical application of this group of foundry alloys.

  16. DSC and conductivity studies on PVA based proton conducting gel electrolytes

    Indian Academy of Sciences (India)

    S L Agrawal; Arvind Awadhia

    2004-12-01

    An attempt has been made in the present work to prepare polyvinyl alcohol (PVA) based proton conducting gel electrolytes in ammonium thiocyanate (NH4SCN) solution and characterize them. DSC studies affirm the formation of gels along with the presence of partial complexes. The cole–cole plots exhibit maximum ionic conductivity (2.58 × 10-3 S cm-1) for gel samples containing 6 wt% of PVA. The conductivity of gel electrolytes exhibit liquid like nature at low polymer concentrations while the behaviour is seen to be affected by the formation of PVA–NH4SCN complexes upon increase in polymer content beyond 5 wt%. Temperature dependence of ionic conductivity exhibits VTF behaviour.

  17. Assessment of interactions between four proteins and benzothiazole derivatives by DSC and CD

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, Natalia [Soft Matter and Molecular Biophysics Group, Department of Applied Physics, Faculty of Physics, Campus Vida, University of Santiago de Compostela, E-15782 Santiago de Compostela (Spain); Verdes, Pedro V., E-mail: pedro.vazquez@usc.e [Soft Matter and Molecular Biophysics Group, Department of Applied Physics, Faculty of Physics, Campus Vida, University of Santiago de Compostela, E-15782 Santiago de Compostela (Spain); Ruso, Juan M. [Soft Matter and Molecular Biophysics Group, Department of Applied Physics, Faculty of Physics, Campus Vida, University of Santiago de Compostela, E-15782 Santiago de Compostela (Spain)

    2011-03-15

    The thermal denaturation of ovalbumin, lysozyme, myoglobin and fibrinogen at different BTS concentrations have been investigated using differential scanning calorimetry (DSC) and circular dichroism (CD) spectroscopy. Thermodynamic parameters: melting temperatures (T{sub m}), calorimetric enthalpy ({Delta}H), van't Hoff enthalpy ({Delta}H{sub v}) were obtained for all the systems under study. Thermal denaturation of the four proteins was completely irreversible. Changes in the protein conformation due to the adsorption of BTS molecules have been monitored by using UV-CD spectra. Greater changes in {alpha}-helical contents correspond with the BTS higher concentrations. The lysozyme denaturation temperature increases at low concentrations BTS indicating that BTS acts as a structure stabilizer; meanwhile it acts as a destabilizer at higher concentrations in all the proteins studied. The major effect is observed in the case of myoglobin, the protein with the highest {alpha}-helical secondary structure (75%).

  18. Fabrication and laboratory testing of a high-temperature superconducting subsystem for DSC1800 mobile communications

    CERN Document Server

    LiuKun; Zhu Mei Hong; Wei Bin; Liu Bang Chang; Zhang Xia; Gao Long Ma; Zhang Guo Yong; He Wen Jun; Gao Bao Xin

    2002-01-01

    In this paper, we report on the design, fabrication and testing of a 20-pole high-temperature superconducting (HTS) filter for DSC1800 mobile communications with the pass band from 1710 to 1785 MHz. The test results show that the insertion loss of the pass band is less than 0.3 dB, the out-of-band rejection is better than 65 dB, and the steepness of the band edges is greater than 14 dB MHz sup - sup 1. We also tested an HTS subsystem, which consists of the HTS filter, a low-noise amplifier (LNA) with 21 dB gain and a Stirling Cooler, and a traditional subsystem, which consists of a traditional filter and a LNA with 23 dB gain. The results show that the HTS subsystem is much better than the conventional subsystem.

  19. FTIR and DSC studies of the thermal and photochemical stability of Balanites aegyptiaca oil (Toogga oil).

    Science.gov (United States)

    Gardette, Jean-Luc; Baba, Mohamed

    2013-01-01

    The oil extracted from the bean of Balanites aegyptiaca was characterized, and its photochemical and thermal stabilization were evaluated. The chemical composition was determined using gas chromatography (GC), revealing that the oil is very rich in unsaturated fatty acids (72% omega-6 and omega-9). The photochemical stability was assessed by subjecting it to artificially accelerated photo-aging and then examining the changes using infrared spectroscopy. The thermal stability was studied at six different temperatures ranging from 130 to 200°C and monitored in situ by differential scanning calorimetry (DSC). The kinetic parameters (EA and k) describing the thermal degradation of this oil were calculated. It has been shown that the antioxidants present in the oil delay the oxidation process (induction period). The degradation of the Toogga oil was compared with that of oleic and linoleic fatty acids. In addition, the degradation of the Toogga oil extracted with hexane was compared to that of the neat oil.

  20. A DSC study on the precipitation kinetics of cryorolled Al 6063 alloy

    Energy Technology Data Exchange (ETDEWEB)

    Panigrahi, S.K. [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee, Roorkee 247667 (India); Jayaganthan, R., E-mail: rjayafmt@iitr.ernet.in [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee, Roorkee 247667 (India); Pancholi, V. [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee, Roorkee 247667 (India); Gupta, Manoj [Materials Science Division, Department of Mechanical Engineering, National University of Singapore (Singapore)

    2010-07-01

    The microstructural evolution and precipitation behavior of cryorolled Al 6063 alloy were investigated. The Al 6063 alloy plates were solutionized and cryorolled with thickness reduction of 25% and 93%. The phase identification and microstructure of the cryorolled Al alloy sample were carried out by XRD, electron backscattered diffraction (EBSD) analysis and TEM. The cryorolled Al alloy upon 93% thickness reduction exhibits ultrafine grain structure. The DSC results of cryorolled Al 6063 alloy obtained at different heating rate are used to calculate activation energies for the evolution of precipitates. The influence of different reduction rates on activation energy of precipitate formation in the cryorolled Al 6063 alloy was analyzed. It was clear from the present study that an ultrafine-grained Al 6063 alloy exhibits a higher driving force for the precipitation formation when compared to bulk Al alloy.

  1. THE MODERN TRENDS AND EXPERIMENTAL METHODS OF TRAINING FUTURE SPECIALISTS IN THE FIELD OF HISTRIONIC ART

    Directory of Open Access Journals (Sweden)

    Julia Sergeevna Skvortsova

    2013-11-01

    Full Text Available This article reflects the specific ways of training specialists in the sphere of histrionic art, contemporary trends and special scientific experiments in the education of actors.We consider the traditional aspects of histrionic art specialists’ occupational fitness and modern requirements upon actor’s psycho-physical training.There also follows historical parallels in studying actor’s energy in the researches of K. Stanislavsky, M. Chekhov, T. Reebo, W. James, A. Maneggetty as well as in the modern researches of L. Gracheva.And there was proved the reason for including some Yoga elements and Academician M.Norbecov’s exercises system into the actors training practice.In the article Yoga for actors considers as a system of emotional and physical preparation to the artistic creative work, as a method of self-control that let an actor be really deep in his creative condition.There also was described an advantageous result of applying at our experimental laboratory of actors Yoga classes some exercises that reveal connection of person’s carriage and his condition in the process of working on the outward demonstration of this or that emotion in order to create appropriate inner state.Object: Studying the influence on the productivity of actors’ professional education of the Yoga elements included into the actors’ psycho-technique practice training.Methods: theoretical, experimental and observational methods of research.Results: After using these methods during the classes the rate of student’s psycho-physical APPARATUS has extremely increased.The area of application: the educational process at artistic creative high schools.DOI: http://dx.doi.org/10.12731/2218-7405-2013-7-52

  2. Experimental methods of indoor millimeter-wave radiometric imaging for personnel concealed contraband detection

    Science.gov (United States)

    Hu, Taiyang; Xiao, Zelong; Li, Hao; Lv, Rongchuan; Lu, Xuan

    2014-11-01

    The increasingly emerging terrorism attacks and violence crimes around the world have posed severe threats to public security, so carrying out relevant research on advanced experimental methods of personnel concealed contraband detection is crucial and meaningful. All of the advantages of imaging covertly, avoidance of interference with other systems, intrinsic property of being safe to persons under screening , and the superior ability of imaging through natural or manmade obscurants, have significantly combined to enable millimeter-wave (MMW) radiometric imaging to offer great potential in personnel concealed contraband detection. Based upon the current research status of MMW radiometric imaging and urgent demands of personnel security screening, this paper mainly focuses on the experimental methods of indoor MMW radiometric imaging. The reverse radiation noise resulting from super-heterodyne receivers seriously affects the image experiments carried out at short range, so both the generation mechanism and reducing methods of this noise are investigated. Then, the benefit of sky illumination no longer exists for the indoor radiometric imaging, and this leads to the decrease in radiometric temperature contrast between target and background. In order to enhance the radiometric temperature contrast for improving indoor imaging performance, the noise illumination technique is adopted in the indoor imaging scenario. In addition, the speed and accuracy of concealed contraband detection from acquired MMW radiometric images are usually restricted to the deficiencies in traditional artificial interpretation by security inspectors, thus an automatic recognition and location algorithm by integrating improved Fuzzy C-means clustering with moment invariants is put forward. A series of original results are also presented to demonstrate the significance and validity of these methods.

  3. Optimized Synthesis of HMX Nanoparticles Using Antisolvent Precipitation Method

    Science.gov (United States)

    Kumar, Raj; Siril, Prem Felix; Soni, Pramod

    2015-10-01

    Nanoparticles of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) were prepared by an antisolvent precipitation method. The effect of different experimental parameters such as temperature of antisolvent and concentration of solution on particle size of nano-HMX was studied systematically. A higher temperature (70°C) of the antisolvent and lower concentration of HMX in acetone (5 mM) favored the formation of smaller particles. Average particle size ranged from 30 to 128 nm under different experimental conditions. Nano-HMX was characterized using dynamic light scattering (DLS), field emission scanning electron microscopy (FESEM), ultraviolet-visible spectrophotometry, powder X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis coupled with differential scanning calorimetry (TGA-DSC). FTIR, XRD, and TGA-DSC studies revealed that the nano-HMX was in the β-polymorphic form.

  4. In situ stability of substrate-associated cellulases studied by DSC.

    Science.gov (United States)

    Alasepp, Kadri; Borch, Kim; Cruys-Bagger, Nicolaj; Badino, Silke; Jensen, Kenneth; Sørensen, Trine H; Windahl, Michael S; Westh, Peter

    2014-06-24

    This work shows that differential scanning calorimetry (DSC) can be used to monitor the stability of substrate-adsorbed cellulases during long-term hydrolysis of insoluble cellulose. Thermal transitions of adsorbed enzyme were measured regularly in subsets of a progressing hydrolysis, and the size of the transition peak was used as a gauge of the population of native enzyme. Analogous measurements were made for enzymes in pure buffer. Investigations of two cellobiohydrolases, Cel6A and Cel7A, from Trichoderma reesei, which is an anamorph of the fungus Hypocrea jerorina, showed that these enzymes were essentially stable at 25 °C. Thus, over a 53 h experiment, Cel6A lost less than 15% of the native population and Cel7A showed no detectable loss for either the free or substrate-adsorbed state. At higher temperatures we found significant losses in the native populations, and at the highest tested temperature (49 °C) about 80% Cel6A and 35% of Cel7A was lost after 53 h of hydrolysis. The data consistently showed that Cel7A was more long-term stable than Cel6A and that substrate-associated enzyme was less long-term stable than enzyme in pure buffer stored under otherwise equal conditions. There was no correlation between the intrinsic stability, specified by the transition temperature in the DSC, and the long-term stability derived from the peak area. The results are discussed with respect to the role of enzyme denaturation for the ubiquitous slowdown observed in the enzymatic hydrolysis of cellulose.

  5. Estimation of Critical Temperature of Thermal Explosion for Nitrosubstituted Azetidines Using Non-isothermal DSC

    Institute of Scientific and Technical Information of China (English)

    HU, Rongzu; ZHAO, Fengqi; GAO, Hongxu; ZHANG, Jiaoqiang; ZHANG, Hai; MA, Haixia

    2009-01-01

    Based on reasonable hypothesis, two general expressions and their six derived formulae for estimating the critical temperature (T_b) of thermal explosion for energetic materials (EM) were derived from the Semenov's thermal explosion theory and eight non-isothermal kinetic equations. We can easily obtain the values of the initial temperature (T_(0i)) at which DSC curve deviates from the baseline of the non-isothermal DSC curve of EM, the onset temperature (T_(ei)), the exothermic decomposition reaction kinetic parameters and the values of T_(00) and T_(e0) from the equation T_(0i or ei)=T_(00 or e0)+α_1β_i+α_2β_i~2+…+α_(L-2)β_i~(L-2), i=1,2,…,L and then calculate the values of T_b by the six derived formulae. The T_b values for seven nitrosubstituted azetidines, 3,3-dinitroazetidinium nitrate (1), 3,3-dinitroazetidinium picrate (2), 3,3-dinitroazetidinium-3-nitro-1,2,4-triazol-5-onate (3), 1,3-bis(3',3'-dinitro-azetidine group)-2,2-dinitropropane (4), 1-(2',2',2'-trinitroethyi)-3,3-dinitroazetidine (5), 3,3-dinitroazetidinium perchiorate (6) and 1-(3',Y-dinitroazetidineyl)-2,2-dinitropropane (7), obtained with the six derived formulae are agreeable to each other, whose differences are within 1.5%. The results indicate that the heat-resistance stability of the seven nitrosubstituted azetidines decreases in the order 6>7>5>4>3>2>1.

  6. Self accelerating decomposition temperature (SADT)calculation of dicumyl peroxide by using DSC tests%基于DSC试验的DCP自加速分解温度的推算

    Institute of Scientific and Technical Information of China (English)

    臧娜

    2011-01-01

    采用差示扫描量热仪(DSC)对小尺度过氧化二异丙苯(DCP)的热分解过程进行试验研究,利用基于等转化率Friedman微分法对热分析试验所得数据进行动力学分析,得出DCP的反应活化能的均值为160.82 kJ· mol-1.最后运用热爆炸理论对25 kg标准包装条件下的自加速分解温度(SADT)进行推算.结果表明,利用等转化率Friedman 微分法计算所得的动力学参数在整个反应进程中并不是常数,表明DCP的热分解反应是一个固态的复杂反应过程.多重扫描速率下计算所得的动力学参数较单个扫描速率法可信度更高,推算所得DCP的SADT值与美式全尺寸试验值基本一致.%Dicumyl peroxide is usually employed as a source of free radicals, hardener, linking agent and initiator for polymerization. Due to its unstable and reactive nature, DCP has caused many thermal explosions and runway reaction incidents. In order to elucidate its thermal hazard characteristics, DCP was tested by using DSC analyzer with small sample mass, and the thermal data obtained from different scanning rate were analyzed by the isoconversional Friedman method. The apparent activation energy Ea and pre-exponential factor A which depend on the reaction conversion are not constant, indicating that the decomposition mechanism of DCP is complex. The average apparent activation energy is 160.82 kJ·mol-1. Self-accelerating decomposition temperature (SADT) is the lowest ambient temperature at which the temperature increase of a chemical substance is at least 6 K in a specified commercial package during a period of seven days or less. The SADT is a very important parameter for assessing the safety management of reactive substances in storage, transportation and use. SADT is determined generally by one of four testing methods recommended by the UN orange book, and can be analytically and numerically evaluated by using experimental instruments. In the present study, DSC was used to

  7. Landmarks in nature to support wayfinding: the effects of seasons and experimental methods.

    Science.gov (United States)

    Kettunen, Pyry; Irvankoski, Katja; Krause, Christina M; Sarjakoski, L Tiina

    2013-08-01

    Landmarks constitute an essential basis for a structural understanding of the spatial environment. Therefore, they are crucial factors in external spatial representations such as maps and verbal route descriptions, which are used to support wayfinding. However, selecting landmarks for these representations is a difficult task, for which an understanding of how people perceive and remember landmarks in the environment is needed. We investigated the ways in which people perceive and remember landmarks in nature using the thinking aloud and sketch map methods during both the summer and the winter seasons. We examined the differences between methods to identify those landmarks that should be selected for external spatial representations, such as maps or route descriptions, in varying conditions. We found differences in the use of landmarks both in terms of the methods and also between the different seasons. In particular, the participants used passage and tree-related landmarks at significantly different frequencies with the thinking aloud and sketch map methods. The results are likely to reflect the different roles of the landmark groups when using the two methods, but also the differences in counting landmarks when using both methods. Seasonal differences in the use of landmarks occurred only with the thinking aloud method. Sketch maps were drawn similarly in summertime and wintertime; the participants remembered and selected landmarks similarly independent of the differences in their perceptions of the environment due to the season. The achieved results may guide the planning of external spatial representations within the context of wayfinding as well as when planning further experimental studies.

  8. Ensemble-Biased Metadynamics: A Molecular Simulation Method to Sample Experimental Distributions.

    Science.gov (United States)

    Marinelli, Fabrizio; Faraldo-Gómez, José D

    2015-06-16

    We introduce an enhanced-sampling method for molecular dynamics (MD) simulations referred to as ensemble-biased metadynamics (EBMetaD). The method biases a conventional MD simulation to sample a molecular ensemble that is consistent with one or more probability distributions known a priori, e.g., experimental intramolecular distance distributions obtained by double electron-electron resonance or other spectroscopic techniques. To this end, EBMetaD adds an adaptive biasing potential throughout the simulation that discourages sampling of configurations inconsistent with the target probability distributions. The bias introduced is the minimum necessary to fulfill the target distributions, i.e., EBMetaD satisfies the maximum-entropy principle. Unlike other methods, EBMetaD does not require multiple simulation replicas or the introduction of Lagrange multipliers, and is therefore computationally efficient and straightforward in practice. We demonstrate the performance and accuracy of the method for a model system as well as for spin-labeled T4 lysozyme in explicit water, and show how EBMetaD reproduces three double electron-electron resonance distance distributions concurrently within a few tens of nanoseconds of simulation time. EBMetaD is integrated in the open-source PLUMED plug-in (www.plumed-code.org), and can be therefore readily used with multiple MD engines.

  9. REVIEW: A review of in vivo experimental methods to determine the composition of the human body

    Science.gov (United States)

    Sutcliffe, J. F.

    1996-05-01

    This review of experimental methods employed in the measurement of the composition of the human body covers the developments that have occurred over the past 30 years. Early methods such as hydrodensitometry and skinfold anthropometry have been superseded by dual-energy x-ray absorptiometry and bioelectrical impedance spectroscopy. The measurement of the whole-body abundance of certain elements by isotopic dilution, neutron activation analysis and x-ray fluorescence can give important information of clinical significance, but neutron activation facilities remain available in only a few centres worldwide. The relatively simple, rapid and risk-free electrical methods such as multifrequency bioelectrical impedance analysis, which can be employed at the bedside, have been found to be more complicated in their interpretation. Electromagnetic methods may only measure the composition of the human body at its surface. X-ray computed tomography and magnetic resonance imaging have not yet been employed much in body composition measurements. Some models for the composition of the human body are reviewed.

  10. Experimental validation of a method for removing the capacitive leakage artifact from electrical bioimpedance spectroscopy measurements

    Science.gov (United States)

    Buendia, R.; Seoane, F.; Gil-Pita, R.

    2010-11-01

    Often when performing electrical bioimpedance (EBI) spectroscopy measurements, the obtained EBI data present a hook-like deviation, which is most noticeable at high frequencies in the impedance plane. The deviation is due to a capacitive leakage effect caused by the presence of stray capacitances. In addition to the data deviation being remarkably noticeable at high frequencies in the phase and the reactance spectra, the measured EBI is also altered in the resistance and the modulus. If this EBI data deviation is not properly removed, it interferes with subsequent data analysis processes, especially with Cole model-based analyses. In other words, to perform any accurate analysis of the EBI spectroscopy data, the hook deviation must be properly removed. Td compensation is a method used to compensate the hook deviation present in EBI data; it consists of multiplying the obtained spectrum, Zmeas(ω), by a complex exponential in the form of exp(-jωTd). Although the method is well known and accepted, Td compensation cannot entirely correct the hook-like deviation; moreover, it lacks solid scientific grounds. In this work, the Td compensation method is revisited, and it is shown that it should not be used to correct the effect of a capacitive leakage; furthermore, a more developed approach for correcting the hook deviation caused by the capacitive leakage is proposed. The method includes a novel correcting expression and a process for selecting the proper values of expressions that are complex and frequency dependent. The correctness of the novel method is validated with the experimental data obtained from measurements from three different EBI applications. The obtained results confirm the sufficiency and feasibility of the correcting method.

  11. Localization and interaction of hydroxyflavones with lipid bilayer model membranes: a study using DSC and multinuclear NMR.

    Science.gov (United States)

    Sinha, Ragini; Joshi, Akshada; Joshi, Urmila J; Srivastava, Sudha; Govil, Girjesh

    2014-06-10

    The localization and interaction of six naturally occurring flavones (FLV, 5HF, 6HF, 7HF, CHY and BLN) in DPPC bilayers were studied using DSC and multi-nuclear NMR. DSC results indicate that FLV and 6HF interact with alkyl chains. The (1)H NMR shows interaction of flavones with the sn-glycero region. Ring current induced chemical shifts indicate that 6HF and BLN acquire parallel orientation in bilayers. 2D NOESY spectra indicate partitioning of the B-ring into the alkyl chain region. The DSC, NMR and binding studies indicate that 5HF and 7HF are located near head group region, while 6HF, CHY and BLN are located in the vicinity of sn-glycero region, and FLV is inserted deepest in the membrane.

  12. A Direct Method for Incorporating Experimental Data into Multiscale Coarse-Grained Models.

    Science.gov (United States)

    Dannenhoffer-Lafage, Thomas; White, Andrew D; Voth, Gregory A

    2016-05-10

    To extract meaningful data from molecular simulations, it is necessary to incorporate new experimental observations as they become available. Recently, a new method was developed for incorporating experimental observations into molecular simulations, called experiment directed simulation (EDS), which utilizes a maximum entropy argument to bias an existing model to agree with experimental observations while changing the original model by a minimal amount. However, there is no discussion in the literature of whether or not the minimal bias systematically and generally improves the model by creating agreement with the experiment. In this work, we show that the relative entropy of the biased system with respect to an ideal target is always reduced by the application of a minimal bias, such as the one utilized by EDS. Using all-atom simulations that have been biased with EDS, one can then easily and rapidly improve a bottom-up multiscale coarse-grained (MS-CG) model without the need for a time-consuming reparametrization of the underlying atomistic force field. Furthermore, the improvement given by the many-body interactions introduced by the EDS bias can be maintained after being projected down to effective two-body MS-CG interactions. The result of this analysis is a new paradigm in coarse-grained modeling and simulation in which the "bottom-up" and "top-down" approaches are combined within a single, rigorous formalism based on statistical mechanics. The utility of building the resulting EDS-MS-CG models is demonstrated on two molecular systems: liquid methanol and ethylene carbonate.

  13. Stacking interactions between carbohydrate and protein quantified by combination of theoretical and experimental methods.

    Directory of Open Access Journals (Sweden)

    Michaela Wimmerová

    Full Text Available Carbohydrate-receptor interactions are an integral part of biological events. They play an important role in many cellular processes, such as cell-cell adhesion, cell differentiation and in-cell signaling. Carbohydrates can interact with a receptor by using several types of intermolecular interactions. One of the most important is the interaction of a carbohydrate's apolar part with aromatic amino acid residues, known as dispersion interaction or CH/π interaction. In the study presented here, we attempted for the first time to quantify how the CH/π interaction contributes to a more general carbohydrate-protein interaction. We used a combined experimental approach, creating single and double point mutants with high level computational methods, and applied both to Ralstonia solanacearum (RSL lectin complexes with α-L-Me-fucoside. Experimentally measured binding affinities were compared with computed carbohydrate-aromatic amino acid residue interaction energies. Experimental binding affinities for the RSL wild type, phenylalanine and alanine mutants were -8.5, -7.1 and -4.1 kcal x mol(-1, respectively. These affinities agree with the computed dispersion interaction energy between carbohydrate and aromatic amino acid residues for RSL wild type and phenylalanine, with values -8.8, -7.9 kcal x mol(-1, excluding the alanine mutant where the interaction energy was -0.9 kcal x mol(-1. Molecular dynamics simulations show that discrepancy can be caused by creation of a new hydrogen bond between the α-L-Me-fucoside and RSL. Observed results suggest that in this and similar cases the carbohydrate-receptor interaction can be driven mainly by a dispersion interaction.

  14. Experimental method and preliminary studies of the passive containment water film evaporation mass transfer

    Energy Technology Data Exchange (ETDEWEB)

    Li, Cheng [State Nuclear Power Technology Research, Beijing (China). Development Center; State Nuclear Power Research Institute, Beijing (China); Yang, Lin; Zhao, Wei; Zhou, Shan; Du, Wangfang; Gao, Zhan; Li, Honegsen [State Nuclear Power Technology Research, Beijing (China). Development Center

    2017-05-15

    For larger containments and higher operation parameters, characteristics of the outside cooling of the PCCS are very important for the analysis on the containment integrity. A preliminary analysis was made and a four-step experimental method was used to numerically analyze the falling water film evaporation for the advanced passive containment. Then, the water flow stability along the outside wall of the containment was studied. The results fit well with those correlations without airflow when the air velocity is less than 5.0 m/s. However, when the air velocity is larger than 5.0 m/s, the influence of the air velocity on the water film will appear and the mean water film thickness will be thicker. Based on the prototype operation parameters, experimental studies were carried and the results were compared with the Dittus-Boelter correlation within the operation ranges. A modification factor was proposed for the conservative application of this correlation for nuclear safety analysis.

  15. Integration of experimental and computational methods for identifying geometric, thermal and diffusive properties of biomaterials

    Science.gov (United States)

    Weres, Jerzy; Kujawa, Sebastian; Olek, Wiesław; Czajkowski, Łukasz

    2016-04-01

    Knowledge of physical properties of biomaterials is important in understanding and designing agri-food and wood processing industries. In the study presented in this paper computational methods were developed and combined with experiments to enhance identification of agri-food and forest product properties, and to predict heat and water transport in such products. They were based on the finite element model of heat and water transport and supplemented with experimental data. Algorithms were proposed for image processing, geometry meshing, and inverse/direct finite element modelling. The resulting software system was composed of integrated subsystems for 3D geometry data acquisition and mesh generation, for 3D geometry modelling and visualization, and for inverse/direct problem computations for the heat and water transport processes. Auxiliary packages were developed to assess performance, accuracy and unification of data access. The software was validated by identifying selected properties and using the estimated values to predict the examined processes, and then comparing predictions to experimental data. The geometry, thermal conductivity, specific heat, coefficient of water diffusion, equilibrium water content and convective heat and water transfer coefficients in the boundary layer were analysed. The estimated values, used as an input for simulation of the examined processes, enabled reduction in the uncertainty associated with predictions.

  16. Validation of RF CCP Discharge Model against Experimental Data using PIC Method

    Science.gov (United States)

    Icenhour, Casey; Kummerer, Theresa; Green, David L.; Smithe, David; Shannon, Steven

    2014-10-01

    The particle-in-cell (PIC) simulation method is a well-known standard for the simulation of laboratory plasma discharges. Using parallel computation on the Titan supercomputer at Oak Ridge National Laboratory (ORNL), this research is concerned with validation of a radio-frequency (RF) capacitively-coupled plasma (CCP) discharge PIC model against previously obtained experimental data. The plasma sources under simulation are 10--100 mTorr argon plasmas with a 13 MHz source and 27 MHz source operating at 50--200 W in both pulse and constant power conditions. Plasma parameters of interest in the validation include peak electron density, electron temperature, and RF plasma sheath voltages and thicknesses. The plasma is modeled utilizing the VSim plasma simulation tool, developed by the Tech-X Corporation. The implementation used here is a two-dimensional electromagnetic model, with corresponding external circuit model of the experimental setup. The goal of this study is to develop models for more complex RF plasma systems utilizing highly parallel computing technologies and methodology. This work is carried out with the support of Oak Ridge National Laboratory and the Tech-X Corporation.

  17. Experimental and theoretical analysis of a method to predict thermal runaway in Li-ion cells

    Science.gov (United States)

    Shah, Krishna; Chalise, Divya; Jain, Ankur

    2016-10-01

    Thermal runaway is a well-known safety concern in Li-ion cells. Methods to predict and prevent thermal runaway are critically needed for enhanced safety and performance. While much work has been done on understanding the kinetics of various heat generation processes during thermal runaway, relatively lesser work exists on understanding how heat removal from the cell influences thermal runaway. Through a unified analysis of heat generation and heat removal, this paper derives and experimentally validates a non-dimensional parameter whose value governs whether or not thermal runaway will occur in a Li-ion cell. This parameter is named the Thermal Runaway Number (TRN), and comprises contributions from thermal transport within and outside the cell, as well as the temperature dependence of heat generation rate. Experimental data using a 26650 thermal test cell are in good agreement with the model, and demonstrate the dependence of thermal runaway on various thermal transport and heat generation parameters. This parameter is used to predict the thermal design space in which the cell will or will not experience thermal runaway. By combining all thermal processes contributing to thermal runaway in a single parameter, this work contributes towards a unified understanding of thermal runaway, and provides the fundamental basis for design tools for safe, high-performance Li-ion batteries.

  18. Experimental design and multicriteria decision making methods for the optimization of ice cream composition

    Directory of Open Access Journals (Sweden)

    Cristian Rojas

    2012-03-01

    Full Text Available The aim of the present work was to optimize the sensorial and technological features of ice cream. The experimental work was performed in two stages: 1 optimization of lactose enzymatic hydrolysis, and 2 optimization of the process and product. For the first stage a complete factorial design was developed, optimized using both response surface and the steepest ascent method. In the second stage a mixture design was performed, combining the process variables. The product with the best sensorial acceptance, high yield and low cost was selected. The acceptance of the product was developed by an untrained taster’s panel. As a main result the sensorial and technological features of the final product were improved, establishing the optimum parameters for its elaboration.

  19. Experimental Observation of the Skeletal Adaptive Repair Mechanism and Bionic Topology Optimization Method

    Directory of Open Access Journals (Sweden)

    Kaysar Rahman

    2014-01-01

    Full Text Available Bone adaptive repair theory considers that the external load is the direct source of bone remodeling; bone achieves its maintenance by remodeling some microscopic damages due to external load during the process. This paper firstly observes CT data from the whole self-repairing process in bone defects in rabbit femur. Experimental result shows that during self-repairing process there exists an interaction relationship between spongy bone and enamel bone volume changes of bone defect, that is when volume of spongy bone increases, enamel bone decreases, and when volume of spongy bone decreases, enamel bone increases. Secondly according to this feature a bone remodeling model based on cross-type reaction-diffusion system influenced by mechanical stress is proposed. Finally, this model coupled with finite element method by using the element adding and removing process is used to simulate the self-repairing process and engineering optimization problems by considering the idea of bionic topology optimization.

  20. The Study of Cutting Conditions Effects on the Damping Process Using the Experimental Taguchi Method

    Directory of Open Access Journals (Sweden)

    Haikel Mejri

    2016-01-01

    Full Text Available This article focuses on determining the effects of cutting conditions and their interactions on the cutting process damping in the case of curvilinear milling. The tests were performed using a numerical model simulation that allows the prediction of cutting forces and damping. The effects and interactions are determined using the Taguchi experimental method. Analysis of variance (ANOVA was performed to know the level of importance of the machining parameters on the cutting damping process. The results revealed that the Depth of cut Ap “C” and cutting speed Vc “B” have the most significant influence on the Cxx and Cxy process damping. The variations of tool diameter D “A” and clearance angle α have remarkable effects on the process damping Cxx. The “BC” interaction has the greatest effect on the process damping Cxx while the “AC” interaction has the greatest effect on the process damping Cxy.

  1. The Dynamic Similitude Design Method of Thin Walled Structures and Experimental Validation

    Directory of Open Access Journals (Sweden)

    Zhong Luo

    2016-01-01

    Full Text Available For the applicability of dynamic similitude models of thin walled structures, such as engine blades, turbine discs, and cylindrical shells, the dynamic similitude design of typical thin walled structures is investigated. The governing equation of typical thin walled structures is firstly unified, which guides to establishing dynamic scaling laws of typical thin walled structures. Based on the governing equation, geometrically complete scaling law of the typical thin walled structure is derived. In order to determine accurate distorted scaling laws of typical thin walled structures, three principles are proposed and theoretically proved by combining the sensitivity analysis and governing equation. Taking the thin walled annular plate as an example, geometrically complete and distorted scaling laws can be obtained based on the principles of determining dynamic scaling laws. Furthermore, the previous five orders’ accurate distorted scaling laws of thin walled annular plates are presented and numerically validated. Finally, the effectiveness of the similitude design method is validated by experimental annular plates.

  2. nuPRISM: An experimental method to remove neutrino interaction uncertainties from oscillation experiments

    CERN Document Server

    CERN. Geneva

    2014-01-01

    Future experiments propose to make precision measurements of parameters in the neutrino mixing matrix, including the possibly maximal mixing angle theta23, and an unknown CP violating phase, dCP, by comparing the event rate of neutrinos and antineutrinos observed close to, and far from the source. Such "near to far" extrapolation methods must achieve percent level understanding of neutrino and antineutrino interactions; the interaction determines the relationship between experimental observables and the oscillation probability which depends on the neutrino energy. However, recent developments over the last 5 years demonstrate that our understanding of neutrino interactions is insufficient. In particular, the interaction of neutrinos on correlated pairs of nucleons has only recently been added to neutrino interaction simulations. The identification of these processes as interactions on a single nucleon results in a significant bias to the measured mixing parameters, even when near detector i...

  3. Experimental studies of superhard materials carbon nitride CNx prepared by ion-beam synthesis method

    Institute of Scientific and Technical Information of China (English)

    辛火平; 林成鲁; 许华平; 邹世昌; 石晓红; 吴兴龙; 朱宏; P.L.FHemment

    1996-01-01

    Formation of superhard materials carbon nitride CNt by using ion-beam synthesis method is reported.100-keV high-dose N+ ions were implanted into carbon thin films at different temperatures.The samples were evaluated by X-ray photoelectron spectroscopy (XPS),Fourier transformation-infrared absorption spectroscopy (FTIR),Raman spectroscopy,cross-sectional transmission electron microscopy (XTEM),Rutherford backscattering spectroscopy (RBS).X-ray diffraction analysis (XRD) and Vickers microhardness measurement.The results show that the buried carbon nitride CN> layer has been successfully formed by using 100-keV high-dose N+ ions implantation into carbon thin film.Implantation of reactive ions into silicon (IRIS) computer program has been used to simulate the formation of the buried β-C3N4 layer as N+ ions are implanted into carbon.A good agreement between experimental measurements and IRIS simulation is found.

  4. Marine Mammal Train Oil Production Methods: Experimental Reconstructions of Norwegian Iron Age Slab-Lined Pits

    Science.gov (United States)

    Nilsen, Gørill

    2016-08-01

    Seal hunting and whaling have played an important part of people's livelihoods throughout prehistory as evidenced by rock carvings, remains of bones, artifacts from aquatic animals and hunting tools. This paper focuses on one of the more elusive resources relating to such activities: marine mammal blubber. Although marine blubber easily decomposes, the organic material has been documented from the Mesolithic Period onwards. Of particular interest in this article are the many structures in Northern Norway from the Iron Age and in Finland on Kökar, Åland, from both the Bronze and Early Iron Ages in which these periods exhibited traits interpreted as being related to oil rendering from marine mammal blubber. The article discusses methods used in this oil production activity based on historical sources, archaeological investigations and experimental reconstruction of Iron Age slab-lined pits from Northern Norway.

  5. An experimental method of measuring the quasi-static and dynamic confined behaviour of PMMA

    Directory of Open Access Journals (Sweden)

    Siad L.

    2010-06-01

    Full Text Available A testing device is presented for the experimental study of the confined behaviour of PMMA in compression under quasi-static loading or at high strain-rates. The constitutive relation of the material ring (allowing to confine the PMMA being known, transverse gauges glued on its lateral surface allow for the measurement of the lateral confining pressure. The hydrostatic pressure and the Mises stress may be computed. Quasi-static and dynamic tests performed in a strain-rate range of 1e-3/s 1e3/s are processed with the method and compared to results of unconfined compression tests. It is found that the compressive behaviour of PMMA is weakly influenced by the level of pressure and much more sensitive to strain-rate: an elastic brittle behaviour is observed at high strain-rates in unconfined or confined conditions whereas elastoplastic behaviour is noted under quasi-static loading.

  6. Theoretical and experimental study of a new method for prediction of profile drag of airfoil sections

    Science.gov (United States)

    Goradia, S. H.; Lilley, D. E.

    1975-01-01

    Theoretical and experimental studies are described which were conducted for the purpose of developing a new generalized method for the prediction of profile drag of single component airfoil sections with sharp trailing edges. This method aims at solution for the flow in the wake from the airfoil trailing edge to the large distance in the downstream direction; the profile drag of the given airfoil section can then easily be obtained from the momentum balance once the shape of velocity profile at a large distance from the airfoil trailing edge has been computed. Computer program subroutines have been developed for the computation of the profile drag and flow in the airfoil wake on CDC6600 computer. The required inputs to the computer program consist of free stream conditions and the characteristics of the boundary layers at the airfoil trailing edge or at the point of incipient separation in the neighborhood of airfoil trailing edge. The method described is quite generalized and hence can be extended to the solution of the profile drag for multi-component airfoil sections.

  7. A New Wavelet Denoising Method for Experimental Time-Domain Signals: Pulsed Dipolar Electron Spin Resonance.

    Science.gov (United States)

    Srivastava, Madhur; Georgieva, Elka R; Freed, Jack H

    2017-03-30

    We adapt a new wavelet-transform-based method of denoising experimental signals to pulse-dipolar electron-spin resonance spectroscopy (PDS). We show that signal averaging times of the time-domain signals can be reduced by as much as 2 orders of magnitude, while retaining the fidelity of the underlying signals, in comparison with noiseless reference signals. We have achieved excellent signal recovery when the initial noisy signal has an SNR ≳ 3. This approach is robust and is expected to be applicable to other time-domain spectroscopies. In PDS, these time-domain signals representing the dipolar interaction between two electron spin labels are converted into their distance distribution functions P(r), usually by regularization methods such as Tikhonov regularization. The significant improvements achieved by using denoised signals for this regularization are described. We show that they yield P(r)'s with more accurate detail and yield clearer separations of respective distances, which is especially important when the P(r)'s are complex. Also, longer distance P(r)'s, requiring longer dipolar evolution times, become accessible after denoising. In comparison to standard wavelet denoising approaches, it is clearly shown that the new method (WavPDS) is superior.

  8. A Train-Bridge Dynamic Interaction Analysis Method and Its Experimental Validation

    Directory of Open Access Journals (Sweden)

    Nan Zhang

    2016-12-01

    Full Text Available The train-bridge dynamic interaction problem began with the development of railway technology, and requires an evaluation method for bridge design in order to ensure the safety and stability of the bridge and the running train. This problem is studied using theoretical analysis, numerical simulation, and experimental study. In the train-bridge dynamic interaction system proposed in this paper, the train vehicle model is established by the rigid-body dynamics method, the bridge model is established by the finite element method, and the wheel/rail vertical and lateral interaction are simulated by the corresponding assumption and the Kalker linear creep theory, respectively. Track irregularity, structure deformation, wind load, collision load, structural damage, foundation scouring, and earthquake action are regarded as the excitation for the system. The train-bridge dynamic interaction system is solved by inter-history iteration. A case study of the dynamic response of a CRH380BL high-speed train running through a standard-design bridge in China is discussed. The dynamic responses of the vehicle and of the bridge subsystems are obtained for speeds ranging from 200 km·h−1 to 400 km·h−1, and the vibration mechanism are analyzed.

  9. Experimental method for determination of a suitable temperature range for glasses used in precision molding

    Science.gov (United States)

    Ma, Tao; Chen, Fan; Yu, Jingchi

    2010-10-01

    Viscosity of glass is one of its important technological properties. It is usually adopted as a mark in controlling and evaluating the workability of glass. The viscous features in a glass forming process are strongly relevant to the temperature distribution. Appropriate procedure setting and controlling of temperature is an essential issue for precision glass molding. But the characteristic viscosity of glass is difficult to be observed directly in a practical lens molding. It's not convenient to set up the molding conditions caused by the differences between theoretical data and actual system. The purpose of this experimental study is intended to provide a simple and reliable method for determination of suitable temperature intervals of glasses used in the precision molding fabrication which meets the requirements of process tolerances in the industrial productions. The average glass deforming force and center thickness of molded lens are taken as the two conditions of determination principle for molding temperature ranges. The average force should not less than the minimum value of measurement accuracy and the lens thickness should reach the design target in these temperature ranges. These two conditions are easy to be measured and fit for application in the engineering. The molding temperature ranges of several kinds of glass were obtained in this project. One of them is Schott optical glass P-LASF51 which is selected for evaluating and validating this method. Its suitable molding temperature range is from 590 to 614 . The results of molding experiments demonstrate the method is effective and feasible.

  10. Experimental Method for Determination of Self-Heating at the Point of Measurement

    Science.gov (United States)

    Sestan, D.; Zvizdic, D.; Grgec-Bermanec, L.

    2017-09-01

    This paper presents a new experimental method and algorithm for the determination of self-heating of platinum resistance thermometer (PRT) when the temperature instability of medium of interest would prevent an accurate self-heating determination using standard methods. In temperature measurements performed by PRT, self-heating is one of the most common sources of error and arises from the increase in sensor temperature caused by the dissipation of electrical heat when measurement current is applied to the temperature sensing element. This increase depends mainly on the applied current and the thermal resistances between thermometer sensing element and the environment surrounding the thermometer. The method is used for determination of self-heating of a 100 Ω industrial PRT which is intended for measurement of air temperature inside the saturation chamber of the primary dew/frost point generator at the Laboratory for Process Measurement (HMI/FSB-LPM). Self-heating is first determined for conditions present during the comparison calibration of the thermometer, using the calibration bath. The measurements were then repeated with thermometer being placed in an air stream inside the saturation chamber. The experiment covers the temperature range between -65°C and 10°C. Self-heating is determined for two different air velocities and two different vertical positions of PRT in relation to the chamber bottom.

  11. Experimental Study on Solar Cooling Tube Using Thermal/Vacuum Emptying Method

    Directory of Open Access Journals (Sweden)

    Huizhong Zhao

    2012-01-01

    Full Text Available A solar cooling tube using thermal/vacuum emptying method was experimentally studied in this paper. The coefficient of performance (COP of the solar cooling tube was mostly affected by the vacuum degree of the system. In past research, the thermal vacuum method, using an electric oven and iodine-tungsten lamp to heat up the adsorbent bed and H2O vapor to expel the air from the solar cooling tube, was used to manufacture solar cooling tubes. This paper presents a novel thermal vacuum combined with vacuum pump method allowing an increased vacuum state for producing solar cooling tubes. The following conclusions are reached: the adsorbent bed temperature of solar cooling tube could reaches up to 233°C, and this temperature is sufficient to meet desorption demand; the refrigerator power of a single solar cooling tube varies from 1 W to 12 W; the total supply refrigerating capacity is about 287 kJ; and the COP of this solar cooling tube is about 0.215.

  12. An experimental method for the optimization of anti-Compton spectrometer

    CERN Document Server

    Badran, H M

    1999-01-01

    The reduction of the Compton continuum can be achieved using a Compton suppression shield. For the first time, an experimental method is purposed for estimating the optimum dimensions of such a shield. The method can also provide information on the effect of the air gap, source geometry, gamma-ray energy, etc., on the optimum dimension of the active shield. The method employs the measurements of the Compton suppression efficiency in two dimensions using small size scintillation detectors. Two types of scintillation materials; NaI(Tl) and NE-102A plastic scintillators, were examined. The effect of gamma-ray energy and source geometry were also investigated using sup 1 sup 3 sup 7 Cs and sup 6 sup 0 Co sources with three geometries; point, cylindrical, and Marinelli shapes. The results indicate the importance of both NaI(Tl) and NE-102A guard detectors in surrounding the main detector rather than the distance above it. The ratio between the part of the guard detector above the surface of the main detector to th...

  13. Experimental cocrystal screening and solution based scale-up cocrystallization methods.

    Science.gov (United States)

    Malamatari, Maria; Ross, Steven A; Douroumis, Dennis; Velaga, Sitaram P

    2017-08-12

    Cocrystals are crystalline single phase materials composed of two or more different molecular and/or ionic compounds generally in a stoichiometric ratio which are neither solvates nor simple salts. If one of the components is an active pharmaceutical ingredient (API), the term pharmaceutical cocrystal is often used. There is a growing interest among drug development scientists in exploring cocrystals, as means to address physicochemical, biopharmaceutical and mechanical properties and expand solid form diversity of the API. Conventionally, coformers are selected based on crystal engineering principles, and the equimolar mixtures of API and coformers are subjected to solution-based crystallization that are commonly employed in polymorph and salt screening. However, the availability of new knowledge on cocrystal phase behaviour in solid state and solutions has spurred the development and implementation of more rational experimental cocrystal screening as well as scale-up methods. This review aims to provide overview of commonly employed solid form screening techniques in drug development with an emphasis on cocrystal screening methodologies. The latest developments in understanding and the use of cocrystal phase diagrams in both screening and solution based scale-up methods are also presented. Final section is devoted to reviewing the state of the art research covering solution based scale-up cocrystallization process for different cocrystals besides more recent continuous crystallization methods. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Experimental comparison of micro-PIXE with other methods utilized for biomineralization studies

    Science.gov (United States)

    Cichocki, T.; Heck, D.; Jarczyk, L.; Rokita, E.; Strzalkowski, A.; Sych, M.

    1988-05-01

    The present study deals with the investigation of arterial wall mineralization i.e. of inorganic compound development within artery wall under normal or pathologic conditions. Autopsy samples of human aorta as well as fragments of aorta obtained from hypercholesterolemic rabbits were used for the experiments. The samples were investigated using micro-PIXE, PIXE and PIGE techniques, infrared and Raman spectroscopy, X-ray powder diffraction and a variety of histochemical methods in order to compare the techniques based on a proton microprobe with the other methods which aimed at the investigation of inorganic deposits. Proton microprobe measurements confirm the different composition of mineral deposits found in rabbit and human aorta samples. In the case of animal aorta the apatite crystals constitute the mineral form of deposits while for human samples we deal with a mixture of different compounds. Moreover, for rabbit aorta samples the deposits were found always in the atheromas, while in human aorta sections the mineral deposits were localized in the media of the aortic wall. The proton microprobe can be considered to be a valuable addition to the experimental methods that have been applied in the study of the biomineralization process. It permits a qualitative determination of mineral deposits in situ while infrared and Raman spectroscopy as well as X-ray powder diffraction measurements may be performed only for ashed aorta samples. The possibility of in situ measurements and high detection sensitivity seem to be the most significant advantages of a proton microprobe in the study of artery wall mineralization.

  15. An experimental study of rill sediment delivery in purple soil, using the volume-replacement method.

    Science.gov (United States)

    Huang, Yuhan; Chen, Xiaoyan; Luo, Banglin; Ding, Linqiao; Gong, Chunming

    2015-01-01

    Experimental studies provide a basis for understanding the mechanisms of rill erosion and can provide estimates for parameter values in physical models simulating the erosion process. In this study, we investigated sediment delivery during rill erosion in purple soil. We used the volume-replacement method to measure the volume of eroded soil and hence estimate the mass of eroded soil. A 12 m artificial rill was divided into the following sections: 0-0.5 m, 0.5-1 m, 1-2 m, 2-3 m, 3-4 m, 4-5 m, 5-6 m, 6-7 m, 7-8 m, 8-10 m, and 10-12 m. Erosion trials were conducted with three flow rates (2 L/min, 4 L/min, and 8 L/min) and five slope gradients (5°, 10°, 15°, 20°, and 25°). The eroded rill sections were refilled with water to measure the eroded volume in each section and subsequently calculate the eroded sediment mass. The cumulative sediment mass was used to compute the sediment concentration along the length of the rill. The results show that purple soil sediment concentration increases with rill length before eventually reaching a maximal value; that is, the rate of increase in sediment concentration is greatest at the rill inlet and then gradually slows. Steeper slopes and higher flow rates result in sediment concentration increasing more rapidly along the rill length and the maximum sediment concentration being reached at an earlier location in the rill. Slope gradient and flow rate both result in an increase in maximal sediment concentration and accumulated eroded amount. However, slope gradient has a greater influence on rill erosion than flow rate. The results and experimental method in this study may provide a reference for future rill-erosion experiments.

  16. Inferring regulatory networks from experimental morphological phenotypes: a computational method reverse-engineers planarian regeneration.

    Science.gov (United States)

    Lobo, Daniel; Levin, Michael

    2015-06-01

    Transformative applications in biomedicine require the discovery of complex regulatory networks that explain the development and regeneration of anatomical structures, and reveal what external signals will trigger desired changes of large-scale pattern. Despite recent advances in bioinformatics, extracting mechanistic pathway models from experimental morphological data is a key open challenge that has resisted automation. The fundamental difficulty of manually predicting emergent behavior of even simple networks has limited the models invented by human scientists to pathway diagrams that show necessary subunit interactions but do not reveal the dynamics that are sufficient for complex, self-regulating pattern to emerge. To finally bridge the gap between high-resolution genetic data and the ability to understand and control patterning, it is critical to develop computational tools to efficiently extract regulatory pathways from the resultant experimental shape phenotypes. For example, planarian regeneration has been studied for over a century, but despite increasing insight into the pathways that control its stem cells, no constructive, mechanistic model has yet been found by human scientists that explains more than one or two key features of its remarkable ability to regenerate its correct anatomical pattern after drastic perturbations. We present a method to infer the molecular products, topology, and spatial and temporal non-linear dynamics of regulatory networks recapitulating in silico the rich dataset of morphological phenotypes resulting from genetic, surgical, and pharmacological experiments. We demonstrated our approach by inferring complete regulatory networks explaining the outcomes of the main functional regeneration experiments in the planarian literature; By analyzing all the datasets together, our system inferred the first systems-biology comprehensive dynamical model explaining patterning in planarian regeneration. This method provides an automated

  17. An experimental study of rill sediment delivery in purple soil, using the volume-replacement method

    Directory of Open Access Journals (Sweden)

    Yuhan Huang

    2015-09-01

    Full Text Available Experimental studies provide a basis for understanding the mechanisms of rill erosion and can provide estimates for parameter values in physical models simulating the erosion process. In this study, we investigated sediment delivery during rill erosion in purple soil. We used the volume-replacement method to measure the volume of eroded soil and hence estimate the mass of eroded soil. A 12 m artificial rill was divided into the following sections: 0–0.5 m, 0.5–1 m, 1–2 m, 2–3 m, 3–4 m, 4–5 m, 5–6 m, 6–7 m, 7–8 m, 8–10 m, and 10–12 m. Erosion trials were conducted with three flow rates (2 L/min, 4 L/min, and 8 L/min and five slope gradients (5°, 10°, 15°, 20°, and 25°. The eroded rill sections were refilled with water to measure the eroded volume in each section and subsequently calculate the eroded sediment mass. The cumulative sediment mass was used to compute the sediment concentration along the length of the rill. The results show that purple soil sediment concentration increases with rill length before eventually reaching a maximal value; that is, the rate of increase in sediment concentration is greatest at the rill inlet and then gradually slows. Steeper slopes and higher flow rates result in sediment concentration increasing more rapidly along the rill length and the maximum sediment concentration being reached at an earlier location in the rill. Slope gradient and flow rate both result in an increase in maximal sediment concentration and accumulated eroded amount. However, slope gradient has a greater influence on rill erosion than flow rate. The results and experimental method in this study may provide a reference for future rill-erosion experiments.

  18. Robust experimental methods to study in-vivo pre-steady state kinetics of primary metabolism in Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Mashego, M.R.

    2005-01-01

    In this thesis, robust experimental methods and experimental designs for quantitative analysis of the metabolome (concentrations of relevant metabolites in the cell) of Saccharomyces cerevisiae (Bakers yeast) have been presented. In this research, it is essential to obtain a snapshot of intracellula

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-07-01

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

  20. Experimental study and finite element analysis based on equivalent load method for laser ultrasonic measurement of elastic constants.

    Science.gov (United States)

    Zhan, Yu; Liu, Changsheng; Zhang, Fengpeng; Qiu, Zhaoguo

    2016-07-01

    The laser ultrasonic generation of Rayleigh surface wave and longitudinal wave in an elastic plate is studied by experiment and finite element method. In order to eliminate the measurement error and the time delay of the experimental system, the linear fitting method of experimental data is applied. The finite element analysis software ABAQUS is used to simulate the propagation of Rayleigh surface wave and longitudinal wave caused by laser excitation on a sheet metal sample surface. The equivalent load method is proposed and applied. The pulsed laser is equivalent to the surface load in time and space domain to meet the Gaussian profile. The relationship between the physical parameters of the laser and the load is established by the correction factor. The numerical solution is in good agreement with the experimental result. The simple and effective numerical and experimental methods for laser ultrasonic measurement of the elastic constants are demonstrated.

  1. "Tie over ring" sutureless compression based gastrointestinal anastomotic method: experimental rat model.

    Science.gov (United States)

    Hiradfar, Mehran; Shojaeian, Reza; Zabolinejad, Nona; Gharavifard, Mohammad; Sabzevari, Alireza; Joodi, Marjan; Yal, Nazila; Saeedi Sharifabad, Parisa; Hajian, Sara; Nazarzadeh, Reza; Lotfinejad, Nasim

    2014-03-01

    Giving the ever-rising trend of pediatric minimally invasive surgery besides early neonatal surgical interventions, intestinal anastomosis turns out to be a time consuming stage due to several anatomical as well as technical difficulties. A perfect bowel anastomosis method should be easy, rapid, safe and reliable in creation of bowel continuity with minimal tissue damage. In this light, sutureless anastomotic methods have been introduced, using compression based anastomosis with biofragmentable rings or powerful magnets. Accordingly, this experimental animal model study has evaluated the result of an easy, rapid intestinal sutureless anastomotic technique via simple tying over an intraluminal ring, in comparison with conventional handsewn bowel anastomosis. Thirty Wistar-Albino male rats were enrolled and small bowel was transected via a midline laparotomy. A grooved plastic ring was inserted into the ileal lumen and both intestinal cutting ends were fixed over the ring with a simple tie in the first group. On the other hand, enteroenterostomy was performed by the conventional method of handsewn anastomosis in the second group. After 14 days, rats were sacrificed to evaluate for intraperitoneal adhesion and abscess formation in addition to other evidences of anastomotic leakage. Furthermore, the anastomotic site integrity, tensile strength and healing stage were assessed microscopically. The mean operative time and intraoperative bleeding in the tie over ring group were significantly less than those in the handsewn anastomosis group. Anastomotic stricture was more common in the conventional anastomosis group while the anastomotic tensile strength was significantly higher in the tie over ring group. Histopathological healing parameters and final healing score were almost similar in both groups but mean inflammatory cell infiltration in handsewn anastomosis was significantly higher. "Tie over ring" is a simple method of anastomosis that is feasible, fast, safe and

  2. The Experimental Plant and Modeling Method for Spatial Waves in Multicoupled Quasi-Optical Systems with Periodic Inhomogeneities

    Directory of Open Access Journals (Sweden)

    G.S. Vorobjov

    2010-01-01

    Full Text Available The experimental plant and the general method of modeling of electromagnetic wave processes in multicoupled quasi-optical systems are described. Examples of choosing the optimum regimes of modeling and basic parameters of the investigated electrodynamic systems are shown. The functional scheme of the experimental plant is also described. The general method of modeling of electromagnetic phenomena in resonant and waveguide multicoupled quasi-optical systems is presented for the first time.

  3. Statistical method for the determination of the ignition energy of dust cloud - experimental validation

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, S.; Lebecki, K.; Gillard, P.; Youinou, L.; Baudry, G. [University of Orleans, Bourges (France)

    2010-05-15

    Powdery materials such as metallic or polymer powders play a considerable role in many industrial processes. Their use requires the introduction of preventive safeguard to control the plants safety. The mitigation of an explosion hazard, according to the ATEX 137 Directive (1999/92/EU), requires the assessment of the dust ignition sensitivity. PRISME laboratory (University of Orleans) has developed an experimental set-up and methodology, using the Langlie test, for the quick determination of the explosion sensitivity of dusts. This method requires only 20 shots and ignition sensitivity is evaluated through the E{sub 50} (energy with an ignition probability of 0.5) A Hartmann tube, with a volume of 1.3l, was designed and built. Many results on the energy ignition thresholds of partially oxidised aluminium were obtained using this experimental device and compared to literature. E-50 evolution is the same as MIE but their respective values are different and MIE is lower than E{sub 50} however the link between E{sub 50} and MIE has not been elucidated In this paper, the Langlie method is explained in detail for the determination of the parameters (mean value E{sub 50} and standard deviation {sigma}) of the associated statistic law. The ignition probability versus applied energy is firstly measured for Lycopodium in order to validate the method A comparison between the normal and the lognormal law was achieved and the best fit was obtained with the lognormal law. In a second part, the Langlie test was performed on different dusts such as aluminium, cornstarch, lycopodium, coal, and PA12 in order to determine E-50 and {sigma} for each dust. The energies E{sub 05} and E{sub 10} corresponding respectively to an ignition probability of 0.05 and 0.1 are determined with the lognormal law and compared to MIE find in literature. E{sub 05} and E{sub 10} values of ignition energy were found to be very close and were in good agreement with MIE in the literature.

  4. Vapor-Liquid Equilibrium of Carbon Dioxide + Ethanol: Experimental Measurements with Acoustic Method and Thermodynamic Modeling

    Directory of Open Access Journals (Sweden)

    Ana Mehl

    2011-01-01

    Full Text Available Phase behavior of systems composed by supercritical carbon dioxide and ethanol is of great interest, especially in the processes involving supercritical extraction in which ethanol is used as a cosolvent. The development of an apparatus, which is able to perform the measurements of vapor-liquid equilibrium (VLE at high pressure using a combination of the visual and the acoustic methods, was successful and was proven to be suited for determining the isothermal VLE data of this system. The acoustic method, based on the variation of the amplitude of an ultra-sound signal passing through a mixture during a phase transition, was applied to investigate the phase equilibria of the system carbon dioxide + ethanol at temperatures ranging from 298.2 K to 323.2 K and pressures from 3.0 MPa to 9.0 MPa. The VLE data were correlated with Peng-Robinson equation of state combined with two different mixing rules and the SAFT equations of state as well. The compositions calculated with the models are in good agreement with the experimental data for the isotherms evaluated.

  5. Experimental Validation of Volume of Fluid Method for a Sluice Gate Flow

    Directory of Open Access Journals (Sweden)

    A. A. Oner

    2012-01-01

    Full Text Available Laboratory experiments are conducted for 2D turbulent free surface flow which interacts with a vertical sluice gate. The velocity field, on the centerline of the channel flow upstream of the gate is measured using the particle image velocimetry technique. The numerical simulation of the same flow is carried out by solving the governing equations, Reynolds-averaged continuity and Navier-Stokes equations, using finite element method. In the numerical solution of the governing equations, the standard k-ε turbulence closure model is used to define the turbulent viscosity. The measured horizontal velocity distribution at the inflow boundary of the solution domain is taken as the boundary condition. The volume of fluid (VOF method is used to determine the flow profile in the channel. Taking into account of the flow characteristics, the computational domain is divided into five subdomains, each having different mesh densities. Three different meshes with five subdomains are employed for the numerical model. A grid convergence analysis indicates that the discretization error in the predicted velocities on the fine mesh remains within 2%. The computational results are compared with the experimental data, and, the most suitable mesh in predicting the velocity field and the flow profile among the three meshes is selected.

  6. Optimal Control of Diesel Engines: Numerical Methods, Applications, and Experimental Validation

    Directory of Open Access Journals (Sweden)

    Jonas Asprion

    2014-01-01

    become complex systems. The exploitation of any leftover potential during transient operation is crucial. However, even an experienced calibration engineer cannot conceive all the dynamic cross couplings between the many actuators. Therefore, a highly iterative procedure is required to obtain a single engine calibration, which in turn causes a high demand for test-bench time. Physics-based mathematical models and a dynamic optimisation are the tools to alleviate this dilemma. This paper presents the methods required to implement such an approach. The optimisation-oriented modelling of diesel engines is summarised, and the numerical methods required to solve the corresponding large-scale optimal control problems are presented. The resulting optimal control input trajectories over long driving profiles are shown to provide enough information to allow conclusions to be drawn for causal control strategies. Ways of utilising this data are illustrated, which indicate that a fully automated dynamic calibration of the engine control unit is conceivable. An experimental validation demonstrates the meaningfulness of these results. The measurement results show that the optimisation predicts the reduction of the fuel consumption and the cumulative pollutant emissions with a relative error of around 10% on highly transient driving cycles.

  7. A framework program for the teaching of alternative methods (replacement, reduction, refinement) to animal experimentation.

    Science.gov (United States)

    Daneshian, Mardas; Akbarsha, Mohammad A; Blaauboer, Bas; Caloni, Francesca; Cosson, Pierre; Curren, Rodger; Goldberg, Alan; Gruber, Franz; Ohl, Frauke; Pfaller, Walter; van der Valk, Jan; Vinardell, Pilar; Zurlo, Joanne; Hartung, Thomas; Leist, Marcel

    2011-01-01

    Development of improved communication and education strategies is important to make alternatives to the use of animals, and the broad range of applications of the 3Rs concept better known and understood by different audiences. For this purpose, the Center for Alternatives to Animal Testing in Europe (CAAT-Europe) together with the Transatlantic Think Tank for Toxicology (t(4)) hosted a three-day workshop on "Teaching Alternative Methods to Animal Experimentation". A compilation of the recommendations by a group of international specialists in the field is summarized in this report. Initially, the workshop participants identified the different audience groups to be addressed and also the communication media that may be used. The main outcome of the workshop was a framework for a comprehensive educational program. The modular structure of the teaching program presented here allows adaptation to different audiences with their specific needs; different time schedules can be easily accommodated on this basis. The topics cover the 3Rs principle, basic research, toxicological applications, method development and validation, regulatory aspects, case studies and ethical aspects of 3Rs approaches. This expert consortium agreed to generating teaching materials covering all modules and providing them in an open access online repository.

  8. A practical method to determine the effective resolution in incoherent experimental electron tomography

    Energy Technology Data Exchange (ETDEWEB)

    Heidari Mezerji, Hamed, E-mail: Hamed.Heidari@ua.ac.be [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Van den Broek, Wouter; Bals, Sara [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

    2011-04-15

    It is not straightforward to determine resolution for a 3D reconstruction when performing an electron tomography experiment. Different contributions such as missing wedge and misalignment add up and often influence the final resolution in an anisotropic manner. The conventional resolution measures can not be used for all of the reconstruction techniques, especially for iterative techniques which are more commonly used for electron tomography in materials science. Here we define a quantitative resolution measure that determines the resolution in three orthogonal directions of the reconstruction. As an application we use this measure to determine the optimum number of simultaneous iterative reconstruction technique (SIRT) iterations to reconstruct the gold nanoparticles, based on a high angle annular dark field STEM (HAADF-STEM) tilt series. -- Research highlights: {yields} We developed a model-based resolution measure for experimental electron tomography. {yields} It measures the resolution along the main directions in the reconstruction. {yields} It is applied to nano-size gold particles reconstructed with SIRT and WBP. {yields} The method is space invariant and independent of the particle size. {yields} The method yields the optimal number of 'SIRT iterations'; 20 in our case.

  9. The Laue diffraction method to search for a neutron EDM. Experimental test of the sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Fedorov, V.V. E-mail: vfedorov@mail.pnpi.spb.ru; Lapin, E.G.; Lelievre-Berna, E.; Nesvizhevsky, V.V.; Petoukhov, A.K.; Semenikhin, S.Yu.; Soldner, T.; Tasset, F.; Voronin, V.V

    2005-01-01

    The feasibility of an experiment to search for the neutron electric dipole moment (EDM) by Laue diffraction in crystals without a center of symmetry was tested. At the PF1A beam of the ILL reactor a record time delay of {tau}{approx}2 ms for the passage of neutrons through a quartz crystal was reached for the (1 1 0) plane and diffraction angles equal to 88.5 degrees. That corresponds to an effective neutron velocity in the crystal of 20 m/s, while the velocity of the incident neutron was 800 m/s. It was shown experimentally that the value {tau}N{sup 1/2}, determining the method's sensitivity, has a maximum for the Bragg angle equal to 86 deg. The results allow us to estimate the statistical sensitivity of the method for the neutron EDM. For the PF1B beam of the ILL reactor the sensitivity can reach {approx}6x10{sup -25} e cm per day for the available quartz crystal.

  10. Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials.

    Science.gov (United States)

    Hagmann, Joseph A; Le, Son T; Richter, Curt A; Seiler, David G

    2016-01-21

    Novel electronic materials are often produced for the first time by synthesis processes that yield bulk crystals (in contrast to single crystal thin film synthesis) for the purpose of exploratory materials research. Certain materials pose a challenge wherein the traditional bulk Hall bar device fabrication method is insufficient to produce a measureable device for sample transport measurement, principally because the single crystal size is too small to attach wire leads to the sample in a Hall bar configuration. This can be, for example, because the first batch of a new material synthesized yields very small single crystals or because flakes of samples of one to very few monolayers are desired. In order to enable rapid characterization of materials that may be carried out in parallel with improvements to their growth methodology, a method of device fabrication for very small samples has been devised to permit the characterization of novel materials as soon as a preliminary batch has been produced. A slight variation of this methodology is applicable to producing devices using exfoliated samples of two-dimensional materials such as graphene, hexagonal boron nitride (hBN), and transition metal dichalcogenides (TMDs), as well as multilayer heterostructures of such materials. Here we present detailed protocols for the experimental device fabrication of fragments and flakes of novel materials with micron-sized dimensions onto substrate and subsequent measurement in a commercial superconducting magnet, dry helium close-cycle cryostat magnetotransport system at temperatures down to 0.300 K and magnetic fields up to 12 T.

  11. Application of experimental plans method to formulate a self compacting cement paste

    Directory of Open Access Journals (Sweden)

    Mebrouki, A.

    2010-06-01

    Full Text Available The self-compacting concrete formulation means to elaborate a self-compacting cement paste to which will be injected aggregates. The purpose of this work is to find the composition of this cement paste containing local materials (pozzolanic cement, limestone fillers, superplasticizer and water having self-compacting properties. The use of the experimental plans method shows that it is possible to delimit an experimental field bounded by the volumetric proportions of materials composing the paste. The field was transformed in equations form conditioned by implicit constraints, defining zones of minimal shearing threshold and maximum viscosity; numerical resolution submitted to the optimization criteria permitted to define the volumetric proportions of each mixing parameter contributing to the preparation of an optimal paste. After experimental checking to validate obtained results, conclusions are that, from results given by ternary diagrams and desirability’s functions, a composition of an optimal self-compacting cement pas was obtained.

    En este trabajo se estudia la constitución de una pasta autocompactante a base de materiales locales argelinos (cemento binario de base puzolánica natural de Beni Saf y filler calizo de cantera. La reología de la pasta se estudia en función de las dosificaciones de cemento, caliza, superplastificante y agua. La fluidez de las pastas así formadas se deducen de los ensayos de escurrimiento del mini cono y del tiempo de flujo en el cono de Marsh. Utilizando el diseño estadístico de mezclas, el número de ensayos se ha visto considerablemente reducido, el problema se transformó en ecuaciones y después se resolvió numéricamente. A partir de las curvas de los diagramas ternarios, uniendo las respuestas de escurrimiento y el tiempo de flujo de las pastas en función de las dosificaciones en constituyentes y estudiando las funciones de conveniencia para cada respuesta, se terminará por deducir una

  12. Linking experimental results, biological networks and sequence analysis methods using Ontologies and Generalised Data Structures.

    Science.gov (United States)

    Koehler, Jacob; Rawlings, Chris; Verrier, Paul; Mitchell, Rowan; Skusa, Andre; Ruegg, Alexander; Philippi, Stephan

    2005-01-01

    The structure of a closely integrated data warehouse is described that is designed to link different types and varying numbers of biological networks, sequence analysis methods and experimental results such as those coming from microarrays. The data schema is inspired by a combination of graph based methods and generalised data structures and makes use of ontologies and meta-data. The core idea is to consider and store biological networks as graphs, and to use generalised data structures (GDS) for the storage of further relevant information. This is possible because many biological networks can be stored as graphs: protein interactions, signal transduction networks, metabolic pathways, gene regulatory networks etc. Nodes in biological graphs represent entities such as promoters, proteins, genes and transcripts whereas the edges of such graphs specify how the nodes are related. The semantics of the nodes and edges are defined using ontologies of node and relation types. Besides generic attributes that most biological entities possess (name, attribute description), further information is stored using generalised data structures. By directly linking to underlying sequences (exons, introns, promoters, amino acid sequences) in a systematic way, close interoperability to sequence analysis methods can be achieved. This approach allows us to store, query and update a wide variety of biological information in a way that is semantically compact without requiring changes at the database schema level when new kinds of biological information is added. We describe how this datawarehouse is being implemented by extending the text-mining framework ONDEX to link, support and complement different bioinformatics applications and research activities such as microarray analysis, sequence analysis and modelling/simulation of biological systems. The system is developed under the GPL license and can be downloaded from http://sourceforge.net/projects/ondex/

  13. Experimental investigation of a new method for advanced fast reactor shutdown cooling

    Science.gov (United States)

    Pakholkov, V. V.; Kandaurov, A. A.; Potseluev, A. I.; Rogozhkin, S. A.; Sergeev, D. A.; Troitskaya, Yu. I.; Shepelev, S. F.

    2017-07-01

    We consider a new method for fast reactor shutdown cooling using a decay heat removal system (DHRS) with a check valve. In this method, a coolant from the decay heat exchanger (DHX) immersed into the reactor upper plenum is supplied to the high-pressure plenum and, then, inside the fuel subassemblies (SAs). A check valve installed at the DHX outlet opens by the force of gravity after primary pumps (PP-1) are shut down. Experimental studies of the new and alternative methods of shutdown cooling were performed at the TISEY test facility at OKBM. The velocity fields in the upper plenum of the reactor model were obtained using the optical particle image velocimetry developed at the Institute of Applied Physics (Russian Academy of Sciences). The study considers the process of development of natural circulation in the reactor and the DHRS models and the corresponding evolution of the temperature and velocity fields. A considerable influence of the valve position in the displacer of the primary pump on the natural circulation of water in the reactor through the DHX was discovered (in some modes, circulation reversal through the DHX was obtained). Alternative DHRS designs without a shell at the DHX outlet with open and closed check valve are also studied. For an open check valve, in spite of the absence of a shell, part of the flow is supplied through the DHX pipeline and then inside the SA simulators. When simulating power modes of the reactor operation, temperature stratification of the liquid was observed, which increased in the cooling mode via the DHRS. These data qualitatively agree with the results of tests at BN-600 and BN-800 reactors.

  14. On the Use of Experimental Methods to Improve Confidence in Educed Impedance

    Science.gov (United States)

    Jones, Michael G.; Watson, Willie R.

    2011-01-01

    Results from impedance eduction methods developed by NASA Langley Research Center are used throughout the acoustic liner community. In spite of recent enhancements, occasional anomalies persist with these methods, generally at frequencies where the liner produces minimal attenuation. This investigation demonstrates an experimental approach to educe impedance with increased confidence over a desired frequency range, by combining results from successive tests with different cavity depths. A series of tests is conducted with three wire-mesh facesheets, for which the results should be weakly dependent on source sound pressure level and mean grazing flow speed. First, a raylometer is used to measure the DC flow resistance of each facesheet. These facesheets are then mounted onto a frame and a normal incidence tube is used to determine their respective acoustic impedance spectra. A comparison of the acoustic resistance component with the DC flow resistance for each facesheet is used to validate the measurement process. Next, each facesheet is successively mounted onto three frames with different cavity depths, and a grazing flow impedance tube is used to educe their respective acoustic impedance spectra with and without mean flow. The no-flow results are compared with those measured in the normal incidence tube to validate the impedance eduction method. Since the anti-resonance frequency varies with cavity depth, each sample provides robust results over a different frequency range. Hence, a combination of results can be used to determine the facesheet acoustic resistance. When combined with the acoustic reactance, observed to be weakly dependent on the source sound pressure level and grazing flow Mach number, the acoustic impedance can be educed with increased confidence. Representative results of these tests are discussed, and the complete database is available in electronic format upon request.

  15. A Laplace method for under-determined Bayesian optimal experimental designs

    KAUST Repository

    Long, Quan

    2014-12-17

    In Long et al. (2013), a new method based on the Laplace approximation was developed to accelerate the estimation of the post-experimental expected information gains (Kullback–Leibler divergence) in model parameters and predictive quantities of interest in the Bayesian framework. A closed-form asymptotic approximation of the inner integral and the order of the corresponding dominant error term were obtained in the cases where the parameters are determined by the experiment. In this work, we extend that method to the general case where the model parameters cannot be determined completely by the data from the proposed experiments. We carry out the Laplace approximations in the directions orthogonal to the null space of the Jacobian matrix of the data model with respect to the parameters, so that the information gain can be reduced to an integration against the marginal density of the transformed parameters that are not determined by the experiments. Furthermore, the expected information gain can be approximated by an integration over the prior, where the integrand is a function of the posterior covariance matrix projected over the aforementioned orthogonal directions. To deal with the issue of dimensionality in a complex problem, we use either Monte Carlo sampling or sparse quadratures for the integration over the prior probability density function, depending on the regularity of the integrand function. We demonstrate the accuracy, efficiency and robustness of the proposed method via several nonlinear under-determined test cases. They include the designs of the scalar parameter in a one dimensional cubic polynomial function with two unidentifiable parameters forming a linear manifold, and the boundary source locations for impedance tomography in a square domain, where the unknown parameter is the conductivity, which is represented as a random field.

  16. DSC studies of retrogradation and amylose lipid complex transition taking place in gamma irradiated wheat starch

    Science.gov (United States)

    Cieśla, K.; Eliasson, A. C.

    2007-12-01

    The effect of gamma irradiation ( 60Co) with doses of 5-30 kGy on the amylose-lipid complex transition and retrogradation occurring in gels containing ca. 50% and ca. 20% wheat starch was studied by differential scanning calorimetry (DSC) during heating-cooling-heating cycles (up to three cycles). Transition of the amylose-lipid complex occurs in all the irradiated samples at a lower temperature as compared to the non-irradiated starch. That effect was larger when the radiation dose was higher. A further thermal treatment causes a decrease of the transition temperature in the irradiated samples, with no effect or increase of that temperature observed for the non-irradiated ones. Irradiation hinders retrogradation taking place in 50% gels but facilitates the process occurring in 20% gels. The differences between the irradiated and the non-irradiated samples are more evident in the every next heating or cooling cycle as well as after storage and in the case of ca. 50% suspensions as compared to ca. 20% suspensions. The results point out to the deterioration of the structure of the complexes formed in the irradiated starch as compared to the non-irradiated one.

  17. Qualitative and kinetic analysis of torrefaction of lignocellulosic biomass using DSC-TGA-FTIR

    Directory of Open Access Journals (Sweden)

    Bimal Acharya

    2015-11-01

    Full Text Available Torrefaction is a thermochemical conversion technique to improve the fuel properties of lignocellulosic biomass by treating at temperature 200 ℃-300 ℃ in the minimum oxygen environment for a reasonable residence time. In this study, thermal decomposition and thermal activities of miscanthus and wheat straw during the torrefaction at 200 ℃, 275 ℃, and 300 ℃ in a nitrogen environment for 45 minutes of residence time are analyzed in a simultaneous thermogravimetric analyzer (micro TGA with a differential scanning calorimetry (DSC, and a macro-TGA. The output of the micro TGA is fed into the Fourier transform infrared spectrometry (FTIR and qualitative analysis of the gaseous product is carried out. The composition of different gas products during the torrefaction of biomass are compared critically and kinetics were analyzed. It is found that the weight loss due to degradation of initial biomass in second stage (torrefaction process is a much faster conversion process than the weight loss process in the first stage (drying process. The weight loss of biomass increases with increase in the residence time and torrefaction treatment temperatures. The yield after torrefaction is a solid bio-coal product. The torrefied product were less reactive and has nearly 25% better heating value than the raw biomass. Between the two feedstocks studied, torrefied miscanthus proved to be a more stable fuel than the torrefied wheat straw. The major gaseous components observed during torrefaction are water, carbon dioxide, carbon monoxide, 1,2-Dibromethylene.

  18. The terminal solid solubility of hydrogen in Zircaloy-4 and Opt-ZIRLO with a DSC

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae-hoon; Kim, Yong-soo [Hanyang Univ., Seoul (Korea, Republic of); Kim, Ju-seong [Korea Atomic Energy Institute, Daejeon (Korea, Republic of)

    2014-10-15

    Due to low neutron absorption cross section, good mechanical properties at high temperature and proper corrosion resistance; zirconium-based materials have been used commonly for nuclear core structural components. When the hydrogen content in cladding exceeds the terminal solid solubility (TSS) of hydrogen, the brittle hydrides can be precipitated. The brittle hydrides can threaten the integrity of cladding such as hydride re-orientation or DHC in dry storage conditions as well as in reactor operating conditions. In addition, it is known that the terminal solid solubility of hydrogen in zirconium alloys for dissolution (TSSD) and precipitation (TSSP) has a significant hysteresis. Thus, the TSS of hydrogen in zirconium alloys is an important factor and accurate knowledge of the TSS is required for evaluation of cladding integrity. In this study, the TSSD and TSSP for Zircaloy-4 and Opt-ZIRLO were measured. The TSS of hydrogen in Zry-4 and Opt-ZIRLO was investigated with a DSC in this study. The hydrogen concentrations in zirconium alloys ranged 40-741 wppm. Both TSSD and TSSP were similar to literature TSS results. However, Opt-ZIRLO had a higher terminal solid solubility of hydrogen than Zry-4 at the same temperature for less than about 400 wppm. The activation energy of Zircaloy-4 was relatively high compared with references, while the activation energy of Opt-ZIRLO was relatively low. It was considered that the chemical composition affects the TSS.

  19. Application of Differential Scanning Calorimetry (DSC in study of phase transformations in ductile iron

    Directory of Open Access Journals (Sweden)

    R. Przeliorz

    2010-04-01

    Full Text Available The effect of heating rate on phase transformations to austenite range in ductile iron of the EN-GJS-450-10 grade was investigated. For studies of phase transformations, the technique of differential scanning calorimetry (DSC was used. Microstructure was examined by optical microscopy. The calorimetric examinations have proved that on heating three transformations occur in this grade of ductile iron, viz. magnetic transformation at the Curie temperature, pearlite→austenite transformation and ferrite→austenite transformation. An increase in the heating rate shifts the pearlite→austenite and ferrite→austenite transformations to higher temperature range. At the heating rate of 5 and 15°C/min, local extrema have been observed to occur: for pearlite→austenite transformation at 784°C and 795°C, respectively, and for ferrite→austenite transformation at 805°C and 821°C, respectively. The Curie temperature of magnetic transformation was extrapolated to a value of 740°C. Each transformation is related with a specific thermal effect. The highest value of enthalpy is accompanying the ferrite→austenite transformation, the lowest occurs in the case of pearlite→austenite transformation.

  20. A Shortened Norwegian Adaptation of the Lie Scale for Children (LSC) and the Defensiveness Scale for Children (DSC)

    Science.gov (United States)

    Haugen, Richard

    1978-01-01

    Ten items consisting of five DSC items and five LSC items were translated into Norwegian in order (a) to control the verbal anxiety responses from defensive tendencies, (b) to handle the problem of response set (the tendency to answer a questionnaire in a stereotyped way), and (c) to permit research concerning the nature of defensiveness itself.…

  1. KINETIC-STUDY OF THE PHOTOINITIATED POLYMERIZATION OF A LIQUID-CRYSTALLINE DIACRYLATE MONOMER BY DSC IN THE ISOTHERMAL MODE

    NARCIS (Netherlands)

    Doornkamp, Annette; VANEKENSTEIN, GORA; TAN, YY

    1992-01-01

    The photoinitiated polymerization of the liquid crystalline (LC) diacrylate monomer 1,4-(-2-methyl phenylene)-bis[4-(6-acryloyloxy-hexamethyleneoxy)benzoate] with T(k,n) = 85-degrees-C and T(i) = 118-degrees-C, was studied by d.s.c. at various temperatures under different conditions. In the

  2. SIMULTANEOUS SAXS/WAXS/DSC STUDIES ON MICROSTRUCTURE OF CONVENTIONAL AND METALLOCENE-BASED ETHYLENE-BUTENE COPOLYMERS

    Institute of Scientific and Technical Information of China (English)

    Jun-ting Xu; Bo-tao Li; Zhi-qiang Fan; Anthony J. Ryan

    2004-01-01

    The fractions of one metallocene-based (mPE) and one conventional (znPE) ethylene-butene copolymer eluted at 80-82℃ from temperature rising elution fractionation were selected for DSC and time-resolved small angle X-ray scattering (SAXS) and wide angle X-ray scattering (WAXS) characterization. The DSC and WAXS results show that two crystal structures exist in both mPE and znPE: structure A with higher melting temperature and structure B with lower melting temperature. It was found that original znPE (s-znPE) contains more highly ordered structure A than original mPE (s-mPE)in spite of the higher comonomer content of znPE. Another structure C is also identified because of higher crystallinity measured by WAXS than by DSC and is attributed to the interfacial region. The SAXS data were analyzed with correlation function and two maxima were observed in s-mPE and s-znPE, in agreement with the conclusion of two crystal populations drawn from DSC and WAXS results. These two crystal populations have close long periods in s-mPE, but very different long periods in s-znPE. In contrast, freshly crystallized mPE and znPE (f-mPE and f-znPE) contain only a single crystal population with a broader distribution of long period.

  3. Effects of pH and buffer concentration on the thermal stability of etanercept using DSC and DLS.

    Science.gov (United States)

    Kim, Nam Ah; An, In Bok; Lim, Dae Gon; Lim, Jun Yeul; Lee, Sang Yeol; Shim, Woo Sun; Kang, Nae-Gyu; Jeong, Seong Hoon

    2014-01-01

    The protein size, electrical interaction, and conformational stability of etanercept (marketed as Enbrel®) were examined by thermodynamic and light scattering methods with changing pH and buffer concentration. As pH of etanercept increased from pH 6.6 to 8.6, electrical repulsion in the solution increased, inducing a decrease in protein size. However, the size changed less in high buffer concentration and irreversible aggregation issues were not observed; in contrast, aggregates of about 1000 nm were observed in low buffer concentration at the pH range. Three significant unfolding transitions (Tm) were observed by differential scanning calorimetry (DSC). Unlikely to Tm1, Tm2 and Tm3 were increased as the pH increased. Higher Tm at high buffer concentration was observed, indicating increased conformational stability. The apparent activation energy of unfolding was further investigated since continuous increase of Tm2 and Tm3 was not sufficient to determine optimal conditions. A higher energy barrier was calculated at Tm2 than at Tm3. In addition, the energy barriers were the highest at pH from 7.4 to 7.8 where higher Tm1 was also observed. Therefore, the conformational stability of protein solution significantly changed with pH dependent steric repulsion of neighboring protein molecules. An optimized pH range was obtained that satisfied the stability of all three domains. Electrostatic circumstances and structural interactions resulted in irreversible aggregation at low buffer concentrations and were suppressed by increasing the concentration. Therefore, increased buffer concentration is recommended during protein formulation development, even in the earlier stages of investigation, to avoid protein instability issues.

  4. Experimental research on application of mutual-aid teaching method in technique teaching of university’s football elective course

    OpenAIRE

    Wu Jiarong

    2016-01-01

    With the social development and reform of education system, the quality-oriented education and lifelong education gradually become education reform goals of colleges and universities, the physical education of the higher education and university are also developed. This research adopts the literature data method, ques-tionnaire method, experimental method, mathematical statistics or other methods to do experiments for the stu-dents who take the football elective course (a total of 36 class ho...

  5. Minor Components and Oxidative Stability as Determined by DSC of Fractionated and Lipase-catalyzed Structured Rapeseed Oil

    Directory of Open Access Journals (Sweden)

    Alim, M. A.

    2013-06-01

    Full Text Available Natural fats and oils can be modified by various methods to prepare products with desired physical, chemical and nutritional properties. The enrichment and retention of the minor lipid components, the incorporation of capric acid and oxidative stability in low temperature fractionated rapeseed oil (RSO in acetone were assessed in this study. The fractionated liquid part (L-RSO, the solid part (S-RSO and the RSO were transesterified with capric acid (CA at different mole ratios using lipase. The yields of L-RSO and S-RSO were 30 and 70 g per 100 g, respectively. The L-RSO contained higher levels of linoleic acid and linolenic acid, and a lower level of oleic acid compared to the S-RSO. The S-RSO contained a higher amount of total sterols than the RSO and the L-RSO. In contrast, the L-RSO contained a higher amount of total tocopherols than the RSO and the S-RSO. The incorporation of CA was ideal at a mole ratio of 1:3. The content of sterols and tocopherols gradually decreased with an increased mole ratio for the CA incorporation. The oxidative stability shown as onset temperature, determined by DSC, of the S-RSO was higher compared to those of the L-RSO and RSO.Las grasas y aceites naturales pueden ser modificados mediante diversos métodos para preparar productos con propiedades físicas, químicas y nutricionales deseadas. El enriquecimiento y la retención de componentes lipídicos menores, la incorporación de ácido cáprico y estabilidad a la oxidación a baja temperatura de aceites de colza (RSO fraccionado en acetona, se evaluaron en este estudio. La fracción líquida (L-RSO, la fracción sólida (S-RSO y el RSO son transesterificados con ácido cáprico (CA en diversas relaciones molares utilizando lipasa. Los rendimientos de las fracciones L-RSO y RSO-S fueron de 30 y 70 g por 100 g, respectivamente. La fracción líquida L-RSO contenía un mayor nivel de los ácidos linoleico y linolénico, y un menor nivel de ácido oleico en

  6. Experimental validation of a multi-energy x-ray adapted scatter separation method

    Science.gov (United States)

    Sossin, A.; Rebuffel, V.; Tabary, J.; Létang, J. M.; Freud, N.; Verger, L.

    2016-12-01

    Both in radiography and computed tomography (CT), recently emerged energy-resolved x-ray photon counting detectors enable the identification and quantification of individual materials comprising the inspected object. However, the approaches used for these operations require highly accurate x-ray images. The accuracy of the images is severely compromised by the presence of scattered radiation, which leads to a loss of spatial contrast and, more importantly, a bias in radiographic material imaging and artefacts in CT. The aim of the present study was to experimentally evaluate a recently introduced partial attenuation spectral scatter separation approach (PASSSA) adapted for multi-energy imaging. For this purpose, a prototype x-ray system was used. Several radiographic acquisitions of an anthropomorphic thorax phantom were performed. Reference primary images were obtained via the beam-stop (BS) approach. The attenuation images acquired from PASSSA-corrected data showed a substantial increase in local contrast and internal structure contour visibility when compared to uncorrected images. A substantial reduction of scatter induced bias was also achieved. Quantitatively, the developed method proved to be in relatively good agreement with the BS data. The application of the proposed scatter correction technique lowered the initial normalized root-mean-square error (NRMSE) of 45% between the uncorrected total and the reference primary spectral images by a factor of 9, thus reducing it to around 5%.

  7. Experimental methods in bio electromagnetic research; Metodologie sperimentali nella ricerca bioelettromagnetica

    Energy Technology Data Exchange (ETDEWEB)

    Lovisolo, G.A.; Ardonio, L.; Asta, D.; Galloni, P.; Pinto, R.; Marino, C. [ENEA, Casaccia (Italy). Dipt. Ambiente

    1999-08-01

    The Who Organization in 1997 have underlined the necessity of increase the experimental activities 'in vivo' and 'in vitro' for assessment of biological risk exposure to electromagnetic fields. Standardization for reference conditions and evaluation of uncertainty in measuring methods are explained in this paper. [Italian] Con la necessita' espressa dall'OMS nella riunione della fine del 1997 di promuovere attivita' sperimentali 'in vivo' e 'in vitro' per valutare il rischio di esposizione ai campi elettromagnetici, si presenta il problema della completa caratterizzazione delle condizioni di esposizione, da cui la realizzazione di sistemi espositivi con requisiti ben definiti. A tal uopo sono stati messi a punto sistemi per riprodurre le condizioni di esposizione in campo lontano ed altri per quella localizzata, tipica di dispositivi di comunicazione mobili. Sono state inoltre pubblicate linee guida CENELEC relative alle procedure di test per la verifica di conformita' dei dispositivi mobili. Sono da standardizzare le condizioni di riferimento (tesa antropomorfa con o senza braccio, casi canonici quali il cubo, multistrato, ecc.) e le valutazioni sull'incertezza dei valori misurati. In generale nella dosimetria sperimentale le operazioni di misura sono eseguite utilizzando fantocci dielettrici riempiti di materiale simulante i tessuti (cervello, muscolo, osso, ecc.) alle frequenze di interesse ed esposti a sorgenti 'ad hoc'.

  8. Detection of Entamoeba histolytica in experimentally induced amoebic liver abscess:comparison of three staining methods

    Institute of Scientific and Technical Information of China (English)

    Tan Zi Ning; Wong Weng Kin; Shaymoli Mustafa; Arefuddin Ahmed; Rahmah Noordin; Tan Gim Cheong; Olivos-Garcia Alfonso; Lim Boon Huat

    2012-01-01

    Objective: To compare the efficacy of three different tissue stains, namely haematoxylin and eosin (H&E), periodic-acid Schiff (PAS) and immunohistochemical (IHC) stains for detection of Entamoeba histolytica (E. histolytica) trophozoites in abscessed liver tissues of hamster.Methods:Amoebic liver abscess was experimentally induced in a hamster by injecting 1 × 106 of axenically cultured virulent E. histolytica trophozoites (HM1-IMSS strain) into the portal vein. After a week post-inoculation, the hamster was sacrificed and the liver tissue sections were stained with H&E, PAS and IHC stains to detect the amoebic trophozoite. Results: The three stains revealed tissue necrosis and amoebic trophozoites, but with varying clarity. H&E and PAS stained the trophozoites pink and magenta, respectively, however it was difficult to differentiate the stained trophozoites from the macrophages because of their similarity in size and morphology. On the other hand, IHC stain revealed distinct brown appearance of the trophozoites in the infected liver tissues. Conclusions: It can be concluded that out of the three stains, IHC is the best for identification of E. histolytica trophozoites in tissue sections.

  9. The birth of experimental psychology in Germany between psychophysical methods and physiological theories.

    Science.gov (United States)

    Sinatra, Maria

    2006-01-01

    In 1879 Wundt's laboratory of psychology was opened in Leipzig, and it has been the landmark ever since for the beginning of modern experimental psychology. Its founder, Wilhelm Maximilian Wundt, was the first to successfully demarcate the areas of scientific psychology as being distinct from either physiology or philosophy, thus guaranteeing the survival of psychology, which was regarded as an autonomous discipline set upon a secure institutional framework. This paper attempts to clarify the basic facts and concepts related to the roots of scientific psychology in Germany, i.e., the context in which the "Founding Father" worked, as well as of those predecessors who proposed the topics and apparatus of his laboratory. Attention will be paid in particular to the psychophysical methods of Weber and Fechner, especially in regard to colour perception. In this context, an outline is presented of the history of reaction time experiments in astronomy, physiology, and psychology, and of the role played by the scientific instruments. It is shown how the methodology of physics and physiology contributed to the emancipation of scientific psychology and to the formation of its orientation.

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

    Directory of Open Access Journals (Sweden)

    Vitor Mayer de Moura

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

  11. Failure criterion for adhesively bonded joints using Arcan´s experimental method

    Directory of Open Access Journals (Sweden)

    Demetrio Jackson dos Santos

    2014-08-01

    Full Text Available Characterization of polymeric materials mechanical behavior requires some previous knowledge about their structure, which allows the choice of more appropriated models and methods. Polymeric materials, below their glass transition temperature (Tg, may be handled as perfect elastic solids, allowing the use of classic mechanics to characterize their behavior. Polymers above their Tg present a viscous contribution to mechanical behavior, which has to be taken into consideration by modeling it. Adhesively bonded joint, joining of different materials using a polymer as adhesive, adds to the mentioned requirements more parameters, such as surface roughness, adhesive thickness and different types of contributions to adhesively bonded joint strength. This work has the purpose of presenting a mechanical behavior characterization of adhesive bonded joints, concerning their average stress at rupture. A modified Arcan´s device was used to obtain the average stress at rupture under different angles or loading conditions, such as pure shear 0°, pure tensile strength 90° and combined conditions. The experimental results were applied to a theoretical model, which takes into consideration the hydrostatic contribution to the mechanical behavior, called Drucker-Prager Model, which was initially developed to characterize soils.

  12. Experimental and Numerical Method for the Analysis of Warm Titanium Sheet Stamping of an Automotive Component

    Directory of Open Access Journals (Sweden)

    Antonio Fiorentino

    2015-01-01

    Full Text Available Product design involves many aspects as geometry and material or mechanical requirements that have to be chosen on the base of the part requirements. Manufacturing process is the link between them representing a fundamental aspect of the product design process. Designers and technicians have a consolidated set of tools and knowledge based on long time experience, but the request of more new performing products characterized by more complex geometries or harder to form materials as Titanium alloys stimulated the use of numerical models. They allow us to study the product feasibility but they require reliable inputs for their development and validation. The present research focuses on sheet stamping processes and proposes a methodology that uses the Nakazima test to characterize the formability of the material and to develop and validate the model. In particular, the method is applied to cold (20°C and warm (300°C stamping of a complex automotive component made of CP Titanium. After characterizing the material and validating the model at the different temperatures, the stamping process is studied and results are compared. In particular, this approach allowed joining the experimental tests required to develop and validate the model, therefore reducing the resources required for the product design.

  13. Internal stress distribution of X-ring using photoelastic experimental hybrid method

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, Alunda Ouma [Dedan Kimathi University of Technology, Nyeri (Kenya); Hawong, Jai Sug; Lim, Hyun Seok [Yeungnam University, Gyeongsan (Korea, Republic of); Shin, Dong Chul [Koje College, Geoje (Korea, Republic of)

    2014-05-15

    Sealing elements are essential parts of many machines, and are used to prevent the loss of a fluid or gas. When such fluids are not properly sealed, catastrophic failures may result. Many different types of rings have been developed to suit various industrial needs. Considerable research has been done on the O-ring. We analyze the internal stresses developed in an X-ring under a uniform squeeze rate of 20%, which is suitable for static applications, using a photoelastic experimental hybrid method. The internal pressures applied were 0.98, 1.96, 2.94, 3.92, 4.90, and 5.88 MPa. We show that sealing rings with X geometry have considerably higher internal stresses than O-ring seals. In addition, we demonstrate that after extrusion, for an internal pressure of 5.88 MPa, the two lobes on the upper contact surface merge, thereby increasing the contact length of the upper side significantly. Extrusion in the X-ring occurred when the internal pressure was 4.90 MPa.

  14. Detecting method of subjects' 3D positions and experimental advanced camera control system

    Science.gov (United States)

    Kato, Daiichiro; Abe, Kazuo; Ishikawa, Akio; Yamada, Mitsuho; Suzuki, Takahito; Kuwashima, Shigesumi

    1997-04-01

    Steady progress is being made in the development of an intelligent robot camera capable of automatically shooting pictures with a powerful sense of reality or tracking objects whose shooting requires advanced techniques. Currently, only experienced broadcasting cameramen can provide these pictures.TO develop an intelligent robot camera with these abilities, we need to clearly understand how a broadcasting cameraman assesses his shooting situation and how his camera is moved during shooting. We use a real- time analyzer to study a cameraman's work and his gaze movements at studios and during sports broadcasts. This time, we have developed a detecting method of subjects' 3D positions and an experimental camera control system to help us further understand the movements required for an intelligent robot camera. The features are as follows: (1) Two sensor cameras shoot a moving subject and detect colors, producing its 3D coordinates. (2) Capable of driving a camera based on camera movement data obtained by a real-time analyzer. 'Moving shoot' is the name we have given to the object position detection technology on which this system is based. We used it in a soccer game, producing computer graphics showing how players moved. These results will also be reported.

  15. Vibration Prediction Method of Electric Machines by using Experimental Transfer Function and Magnetostatic Finite Element Analysis

    Science.gov (United States)

    Saito, A.; Kuroishi, M.; Nakai, H.

    2016-09-01

    This paper concerns the noise and structural vibration caused by rotating electric machines. Special attention is given to the magnetic-force induced vibration response of interior-permanent magnet machines. In general, to accurately predict and control the vibration response caused by the electric machines, it is inevitable to model not only the magnetic force induced by the fluctuation of magnetic fields, but also the structural dynamic characteristics of the electric machines and surrounding structural components. However, due to complicated boundary conditions and material properties of the components, such as laminated magnetic cores and varnished windings, it has been a challenge to compute accurate vibration response caused by the electric machines even after their physical models are available. In this paper, we propose a highly-accurate vibration prediction method that couples experimentally-obtained discrete structural transfer functions and numerically-obtained distributed magnetic-forces. The proposed vibration synthesis methodology has been applied to predict vibration responses of an interior permanent magnet machine. The results show that the predicted vibration response of the electric machine agrees very well with the measured vibration response for several load conditions, for wide frequency ranges.

  16. Nanostructure Characterization of Bismuth Telluride-Based Powders and Extruded Alloys by Various Experimental Methods

    Science.gov (United States)

    Vasilevskiy, D.; Bourbia, O.; Gosselin, S.; Turenne, S.; Masut, R. A.

    2011-05-01

    High-resolution transmission electron microscopy (HRTEM) observations of mechanically alloyed powders and bulk extruded alloys give experimental evidence of nanosized grains in bismuth telluride-based materials. In this study we combine HRTEM observations and x-ray diffraction (XRD) measurements, of both mechanically alloyed powders and extruded samples, with mechanical spectroscopy (MS) of extruded rods. Both HRTEM and XRD show that nanostructures with an average grain size near 25 nm can be achieved within 2 h of mechanical alloying from pure elements in an attritor-type milling machine. Residual strain orthogonal to the c-axis of powder nanoparticles has been evaluated at about 1.2% by XRD peak broadening. In contrast, XRD has been found unreliable for evaluation of grain size in highly textured extruded materials for which diffraction conditions are similar to those of single crystals, while MS appears promising for study of bulk extruded samples. Nanostructured extruded alloys at room temperature exhibit an internal friction (IF) background that is one order of magnitude higher than that of conventional zone-melted material with a grain size of several millimeters. IF as a function of sample temperature gives activation energies that are also different between bulk materials having nano- and millimeter-size grains, a result that is attributed to different creep mechanisms. Nanograin size, as well as orientation and volumetric proportion, provide valuable information for optimization of technological parameters of thermoelectric alloys and should be carefully cross-examined by various independent methods.

  17. Convergent methods assessing bone growth in an experimental model at dental implants in the minipig.

    Science.gov (United States)

    Friedmann, Anton; Friedmann, Asisa; Grize, Leticia; Obrecht, Marcel; Dard, Michel

    2014-05-01

    Implant dentistry demonstrated its reliability in treating successfully an increased amount of patients with dental implants exhibiting hydrophilic (modSLA) or non-hydrophilic (SLA) surfaces. Objectives of this minipig study consisted in assessing bone regeneration at both types of dental implants in a new experimental model (lateral bone defects) by implementing a convergent analysis approach combining histology and contact radiography. In six adult female minipigs standardized acute alveolar defects were created, then receiving two implants in the mandibles bilaterally (modSLA and SLA, one of each combined with Guided Bone Regeneration). Animals were sacrificed after 28 days of healing. Mid-crestal specimen were analyzed assessing missing BIC to implant shoulder (fBIC); vertical bone growth upon implant surface, bone:tissue ratio and grafting material area occupied by material remnants for GBR sites. Values obtained from both analyses were compared and statistical correlations scrutinized. Although dimensions of mean differences and adjusted means given by radiographic method were lower than histological ones, comparison of different implants yielded similar results. Statistical analyses of correlation and concordance coefficients used to evaluate radiological method of measurement showed high level of concordance (concordance coefficient=0.912 and correlation coefficient=0.939) for fBIC. Similar results were observed for vertical new bone and for remnants of graft. Discrepancies for new bone and for mineralized tissue resulted in concordance coefficient of 0.182 and 0.054. The results indicate that contact X-rays can be used for morphometric assessments regarding defect fill; however, histological staining remains beneficial if greater resolution for distinguishing qualitative differences in the tissues is required.

  18. Technology Acceptance and Course Completion Rates in Online Education: A Non-experimental, Mixed Method Study

    Science.gov (United States)

    Allison, Colelia

    As the need for quality online courses increase in demand, the acceptance of technology and completion rates become the focus of higher education. The purpose of this non-experimental, mixed method study was to examine the relationship between the university students' perceptions and acceptance of technology and learner completion rates with respect to the development of online courses. This study involved 61 participants from two universities regarding their perceived usefulness (PU) of technology, intent to use technology, and intent to complete a course. Two research questions were examined regarding student perceptions regarding technology employed in an online course and the relationship, if any, between technology acceptance and completion of an online university course. The technology acceptance model (TAM) was used to collect data on the usefulness of course activities and student intent to complete the course. An open-ended questionnaire was administered to collect information concerning student perceptions of course activities. Quantitative data was analyzed using SPSS and Qualtrics, which indicated there was not a significant relationship between technology acceptance and course completion (p = .154). Qualitative data were examined by pattern matching to create a concept map of the theoretical patterns between constructs. Pattern matching revealed many students favored the use of the Internet over Canvas. Furthermore, data showed students enrolled in online courses because of the flexibility and found the multimedia used in the courses as helpful in course completion. Insight was investigated to offer reasons and decisions concerning choice that were made by the students. Future recommendations are to expand mixed methods studies of technology acceptance in various disciplines to gain a better understanding of student perceptions of technology uses, intent to use, and course completion.

  19. Validation of the stream function method used for reconstruction of experimental ionospheric convection patterns

    Directory of Open Access Journals (Sweden)

    P.L. Israelevich

    Full Text Available In this study we test a stream function method suggested by Israelevich and Ershkovich for instantaneous reconstruction of global, high-latitude ionospheric convection patterns from a limited set of experimental observations, namely, from the electric field or ion drift velocity vector measurements taken along two polar satellite orbits only. These two satellite passes subdivide the polar cap into several adjacent areas. Measured electric fields or ion drifts can be considered as boundary conditions (together with the zero electric potential condition at the low-latitude boundary for those areas, and the entire ionospheric convection pattern can be reconstructed as a solution of the boundary value problem for the stream function without any preliminary information on ionospheric conductivities. In order to validate the stream function method, we utilized the IZMIRAN electrodynamic model (IZMEM recently calibrated by the DMSP ionospheric electrostatic potential observations. For the sake of simplicity, we took the modeled electric fields along the noon-midnight and dawn-dusk meridians as the boundary conditions. Then, the solution(s of the boundary value problem (i.e., a reconstructed potential distribution over the entire polar region is compared with the original IZMEM/DMSP electric potential distribution(s, as well as with the various cross cuts of the polar cap. It is found that reconstructed convection patterns are in good agreement with the original modelled patterns in both the northern and southern polar caps. The analysis is carried out for the winter and summer conditions, as well as for a number of configurations of the interplanetary magnetic field.

    Key words: Ionosphere (electric fields and currents; plasma convection; modelling and forecasting

  20. Experimental Investigation of Pressure-volume-Temperature Mass Gauging Method Under Microgravity Condition by Parabolic Flight

    Science.gov (United States)

    Seo, Mansu; Park, Hana; Yoo, DonGyu; Jung, Youngsuk; Jeong, Sangkwon

    Gauging the volume or mass of liquid propellant of a rocket vehicle in space is an important issue for its economic feasibility and optimized design of loading mass. Pressure-volume-temperature (PVT) gauging method is one of the most suitable measuring techniques in space due to its simplicity and reliability. This paper presents unique experimental results and analyses of PVT gauging method using liquid nitrogen under microgravity condition by parabolic flight. A vacuum-insulated and cylindrical-shaped liquid nitrogen storage tank with 9.2 L volume is manufactured by observing regulation of parabolic flight. PVT gauging experiments are conducted under low liquid fraction condition from 26% to 32%. Pressure, temperature, and the injected helium mass into the storage tank are measured to obtain the ullage volume by gas state equation. Liquid volume is finally derived by the measured ullage volume and the known total tank volume. Two sets of parabolic flights are conducted and each set is composed of approximately 10 parabolic flights. In the first set of flights, the short initial waiting time (3 ∼ 5 seconds) cannot achieve sufficient thermal equilibrium condition at the beginning. It causes inaccurate gauging results due to insufficient information of the initial helium partial pressure in the tank. The helium injection after 12 second waiting time at microgravity condition with high mass flow rate in the second set of flights achieves successful initial thermal equilibrium states and accurate measurement results of initial helium partial pressure. Liquid volume measurement errors in the second set are within 11%.