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Sample records for unit cell parameter

  1. Effect of Yttria Content on the Zirconia Unit Cell Parameters

    Energy Technology Data Exchange (ETDEWEB)

    Krogstad, Jessica A.; Lepple, Maren; Gao, Yan; Lipkin, Don M.; Levi, Carlos G. (UCSB); (GE Global)

    2012-02-06

    The relationship between yttria concentration and the unit cell parameters in partially and fully stabilized zirconia has been reassessed, motivated by the need to improve the accuracy of phase analysis upon decomposition of t{prime}-based thermal barrier coatings. Compositions ranging from 6 to 18 mol% YO{sub 1.5} were synthesized and examined by means of high-resolution X-ray diffraction. Lattice parameters were determined using the Rietveld refinement method, a whole-pattern fitting procedure. The revised empirical relationships fall within the range of those published previously. However, efforts to achieve superior homogeneity of the materials, as well as accuracy of the composition and lattice parameters, provide increased confidence in the reliability of these correlations for use in future studies. Additional insight into the potential sources for scatter previously reported for the transition region ({approx}12-14 mol% YO{sub 1.5}), where tetragonal and cubic phases have been observed to coexist, is also provided. Implications on the current understanding of stabilization mechanisms in zirconia are discussed.

  2. Algorithm and program for precise determination of unit-cell parameters of single crystal taking into account the sample eccentricity

    Science.gov (United States)

    Dudka, A. P.; Smirnova, E. S.; Verin, I. A.; Bolotina, N. B.

    2017-07-01

    A technique has been developed to refine the unit-cell parameters of single crystals with minimization of the influence of instrumental errors on the result. The corresponding computational procedure HuberUB is added to the software package of Huber-5042 diffractometer with a point detector and closedcycle helium cryostat Displex DE-202. The parameters of unit cell, its orientation, the goniometer zero angles, the sample eccentricity, the distances in the goniometer, and the radiation wavelength were refined by the nonlinear least-squares method, which allows imposition of constraints on the unit-cell parameters, depending on the crystal symmetry. The technique is approved on a LuB12 single crystal. The unit-cell parameters are determined in a temperature range of 20-295 K, with an absolute error not larger than 0.0004 Å (the relative error is of 5 × 10-5). The estimates of the unit-cell parameters obtained by the proposed method are evidenced to be unbiased. Some specific features of the behavior of parameters in the ranges of 120-140 and 20-50 K are revealed, which correlate with the anomalies of the physical properties of the crystal.

  3. On the Effect of Unit-Cell Parameters in Predicting the Elastic Response of Wood-Plastic Composites

    Directory of Open Access Journals (Sweden)

    Fatemeh Alavi

    2013-01-01

    Full Text Available This paper presents a study on the effect of unit-cell geometrical parameters in predicting elastic properties of a typical wood plastic composite (WPC. The ultimate goal was obtaining the optimal values of representative volume element (RVE parameters to accurately predict the mechanical behavior of the WPC. For each unit cell, defined by a given combination of the above geometrical parameters, finite element simulation in ABAQUS was carried out, and the corresponding stress-strain curve was obtained. A uniaxial test according to ASTM D638-02a type V was performed on the composite specimen. Modulus of elasticity was determined using hyperbolic tangent function, and the results were compared to the sets of finite element analyses. Main effects of RVE parameters and their interactions were demonstrated and discussed, specially regarding the inclusion of two adjacent wood particles within one unit cell of the material. Regression analysis was performed to mathematically model the RVE parameter effects and their interactions over the modulus of elasticity response. The model was finally employed in an optimization analysis to arrive at an optimal set of RVE parameters that minimizes the difference between the predicted and experimental moduli of elasticity.

  4. QtUCP-A program for determining unit-cell parameters in electron diffraction experiments using double-tilt and rotation-tilt holders

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Hongsheng [Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011 (China); Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China)], E-mail: zhaohscas@yahoo.com.cn; Wu Deqi [Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011 (China); Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Yao Jincheng; Chang Aimin [Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083 (China)

    2008-11-15

    A computer program, QtUCP, has been developed based on several well-established algorithms using GCC 4.0 and Qt 4.0 (Open Source Edition) under Debian GNU/Linux 4.0r0. It can determine the unit-cell parameters from an electron diffraction tilt series obtained from both double-tilt and rotation-tilt holders. In this approach, two or more primitive cells of the reciprocal lattice are determined from experimental data, in the meantime, the measurement errors of the tilt angles are checked and minimized. Subsequently, the derived primitive cells are converted into the reduced form and then transformed into the reduced direct primitive cell. Finally all the patterns are indexed and the least-squares refinement is employed to obtain the optimized results of the lattice parameters. Finally, two examples are given to show the application of the program, one is based on the experiment, the other is from the simulation.

  5. QtUCP-a program for determining unit-cell parameters in electron diffraction experiments using double-tilt and rotation-tilt holders.

    Science.gov (United States)

    Zhao, Hongsheng; Wu, Deqi; Yao, Jincheng; Chang, Aimin

    2008-11-01

    A computer program, QtUCP, has been developed based on several well-established algorithms using GCC 4.0 and Qt 4.0 (Open Source Edition) under Debian GNU/Linux 4.0r0. It can determine the unit-cell parameters from an electron diffraction tilt series obtained from both double-tilt and rotation-tilt holders. In this approach, two or more primitive cells of the reciprocal lattice are determined from experimental data, in the meantime, the measurement errors of the tilt angles are checked and minimized. Subsequently, the derived primitive cells are converted into the reduced form and then transformed into the reduced direct primitive cell. Finally all the patterns are indexed and the least-squares refinement is employed to obtain the optimized results of the lattice parameters. Finally, two examples are given to show the application of the program, one is based on the experiment, the other is from the simulation.

  6. Bi-Cell Unit for Fuel Cell.

    Science.gov (United States)

    The patent concerns a bi-cell unit for a fuel cell . The bi-cell unit is comprised of two electrode packs. Each of the electrode packs includes an...invention relates in general to a bi-cell unit for a fuel cell and in particular, to a bi-cell unit for a hydrazine-air fuel cell .

  7. Sickle Cell Unit.

    Science.gov (United States)

    Canipe, Stephen L.

    Included in this high school biology unit on sickle cell anemia are the following materials: a synopsis of the history of the discovery and the genetic qualities of the disease; electrophoresis diagrams comparing normal, homozygous and heterozygous conditions of the disease; and biochemical characteristics and population genetics of the disease. A…

  8. Analysis and Optimization of Central Processing Unit Process Parameters

    Science.gov (United States)

    Kaja Bantha Navas, R.; Venkata Chaitana Vignan, Budi; Durganadh, Margani; Rama Krishna, Chunduri

    2017-05-01

    The rapid growth of computer has made processing more data capable, which increase the heat dissipation. Hence the system unit CPU must be cooled against operating temperature. This paper presents a novel approach for the optimization of operating parameters on Central Processing Unit with single response based on response graph method. These methods have a series of steps from of proposed approach which are capable of decreasing uncertainty caused by engineering judgment in the Taguchi method. Orthogonal Array value was taken from ANSYS report. The method shows a good convergence with the experimental and the optimum process parameters.

  9. Fuel Cell Equivalent Electric Circuit Parameter Mapping

    DEFF Research Database (Denmark)

    Jeppesen, Christian; Zhou, Fan; Andreasen, Søren Juhl

    In this work a simple model for a fuel cell is investigated for diagnostic purpose. The fuel cell is characterized, with respect to the electrical impedance of the fuel cell at non-faulty conditions and under variations in load current. Based on this the equivalent electrical circuit parameters c...

  10. Parameter estimation in a spatial unit root autoregressive model

    CERN Document Server

    Baran, Sándor

    2011-01-01

    Spatial autoregressive model $X_{k,\\ell}=\\alpha X_{k-1,\\ell}+\\beta X_{k,\\ell-1}+\\gamma X_{k-1,\\ell-1}+\\epsilon_{k,\\ell}$ is investigated in the unit root case, that is when the parameters are on the boundary of the domain of stability that forms a tetrahedron with vertices $(1,1,-1), \\ (1,-1,1),\\ (-1,1,1)$ and $(-1,-1,-1)$. It is shown that the limiting distribution of the least squares estimator of the parameters is normal and the rate of convergence is $n$ when the parameters are in the faces or on the edges of the tetrahedron, while on the vertices the rate is $n^{3/2}$.

  11. Wnt signalling pathway parameters for mammalian cells.

    Directory of Open Access Journals (Sweden)

    Chin Wee Tan

    Full Text Available Wnt/β-catenin signalling regulates cell fate, survival, proliferation and differentiation at many stages of mammalian development and pathology. Mutations of two key proteins in the pathway, APC and β-catenin, have been implicated in a range of cancers, including colorectal cancer. Activation of Wnt signalling has been associated with the stabilization and nuclear accumulation of β-catenin and consequential up-regulation of β-catenin/TCF gene transcription. In 2003, Lee et al. constructed a computational model of Wnt signalling supported by experimental data from analysis of time-dependent concentration of Wnt signalling proteins in Xenopus egg extracts. Subsequent studies have used the Xenopus quantitative data to infer Wnt pathway dynamics in other systems. As a basis for understanding Wnt signalling in mammalian cells, a confocal live cell imaging measurement technique is developed to measure the cell and nuclear volumes of MDCK, HEK293T cells and 3 human colorectal cancer cell lines and the concentrations of Wnt signalling proteins β-catenin, Axin, APC, GSK3β and E-cadherin. These parameters provide the basis for formulating Wnt signalling models for kidney/intestinal epithelial mammalian cells. There are significant differences in concentrations of key proteins between Xenopus extracts and mammalian whole cell lysates. Higher concentrations of Axin and lower concentrations of APC are present in mammalian cells. Axin concentrations are greater than APC in kidney epithelial cells, whereas in intestinal epithelial cells the APC concentration is higher than Axin. Computational simulations based on Lee's model, with this new data, suggest a need for a recalibration of the model.A quantitative understanding of Wnt signalling in mammalian cells, in particular human colorectal cancers requires a detailed understanding of the concentrations of key protein complexes over time. Simulations of Wnt signalling in mammalian cells can be initiated

  12. Scheduling parameters in flexible manufacturing cells

    NARCIS (Netherlands)

    Slomp, J.; Gaalman, G.J.C.; Ahmad, M.M.; Sullivan, W.G.; Migliore, H.; Randhawa, S.

    1998-01-01

    The existence of a well-designed scheduling procedure is a major condition for an effective integration of a flexible manufacturing cell (FMC) in the material flow of a firm. This paper shows the presence and relative importance of three parameter types in the scheduling of operations on a flexible

  13. Scheduling parameters in flexible manufacturing cells

    NARCIS (Netherlands)

    Slomp, J.; Gaalman, G.J.C.; Ahmad, M.M.; Sullivan, W.G.; Migliore, H.; Randhawa, S.

    1998-01-01

    The existence of a well-designed scheduling procedure is a major condition for an effective integration of a flexible manufacturing cell (FMC) in the material flow of a firm. This paper shows the presence and relative importance of three parameter types in the scheduling of operations on a flexible

  14. Cord blood unit bankability can be predicted by prenatal sonographic parameters.

    Science.gov (United States)

    Cobellis, L; Castaldi, M A; Trabucco, E; Imparato, G; Perricone, F; Frega, V; Signoriello, G; Colacurci, N

    2013-10-01

    To identify possible sonographic prenatal parameters and postnatal parameters in order to obtain more bankable cord blood units (CBUs) containing a high number of primitive progenitor cells, allowing CBUs to be used as a source of haematopoietic progenitors for clinical transplantation. Prospective study undertaken in the Department of Gynaecology, Obstetrics and Reproductive Science, Second University of Naples, Italy. In total, 219 unrelated CBU donors were enrolled. Ultrasound parameters (biparietal diameter, head circumference, abdominal circumference, femur length, estimation of fetal weight, umbilical artery pulsatility index), collected at hospital admission, together with birth weight and placental weight, were correlated with bankable CBU parameters (CBU volume, total nucleated cell count, CD34+ cell count). Femur length and abdominal circumference correlated positively with bankable CBUs. Receiver operating curve analysis showed that these parameters can identify bankable CBUs. This is the first prospective study to show the relationship between ultrasonographic fetal parameters at term and the possibility of obtaining high-quality CBUs. As such, cord blood banking could be improved worldwide by performing low-cost ultrasonographic scans. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  15. Unit: Cells, Inspection Set, National Trial Print.

    Science.gov (United States)

    Australian Science Education Project, Toorak, Victoria.

    This trial version of a unit is the series being produced by the Australian Science Education Project provides instructions for students to prepare a variety of cell types and examine them with microscopes. It also gives some information about the variety and function of cells. The core of the unit, which all students are expected to complete,…

  16. Lumped Parameter Modeling for Rapid Vibration Response Prototyping and Test Correlation for Electronic Units

    Science.gov (United States)

    Van Dyke, Michael B.

    2013-01-01

    Present preliminary work using lumped parameter models to approximate dynamic response of electronic units to random vibration; Derive a general N-DOF model for application to electronic units; Illustrate parametric influence of model parameters; Implication of coupled dynamics for unit/board design; Demonstrate use of model to infer printed wiring board (PWB) dynamics from external chassis test measurement.

  17. Relevant parameters in models of cell division control

    Science.gov (United States)

    Grilli, Jacopo; Osella, Matteo; Kennard, Andrew S.; Lagomarsino, Marco Cosentino

    2017-03-01

    A recent burst of dynamic single-cell data makes it possible to characterize the stochastic dynamics of cell division control in bacteria. Different models were used to propose specific mechanisms, but the links between them are poorly explored. The lack of comparative studies makes it difficult to appreciate how well any particular mechanism is supported by the data. Here, we describe a simple and generic framework in which two common formalisms can be used interchangeably: (i) a continuous-time division process described by a hazard function and (ii) a discrete-time equation describing cell size across generations (where the unit of time is a cell cycle). In our framework, this second process is a discrete-time Langevin equation with simple physical analogues. By perturbative expansion around the mean initial size (or interdivision time), we show how this framework describes a wide range of division control mechanisms, including combinations of time and size control, as well as the constant added size mechanism recently found to capture several aspects of the cell division behavior of different bacteria. As we show by analytical estimates and numerical simulations, the available data are described precisely by the first-order approximation of this expansion, i.e., by a "linear response" regime for the correction of size fluctuations. Hence, a single dimensionless parameter defines the strength and action of the division control against cell-to-cell variability (quantified by a single "noise" parameter). However, the same strength of linear response may emerge from several mechanisms, which are distinguished only by higher-order terms in the perturbative expansion. Our analytical estimate of the sample size needed to distinguish between second-order effects shows that this value is close to but larger than the values of the current datasets. These results provide a unified framework for future studies and clarify the relevant parameters at play in the control of

  18. Extraction parameters for metabolomics from cell extracts

    Science.gov (United States)

    Ser, Zheng; Liu, Xiaojing; Tang, Ngoc Nu; Locasale, Jason W

    2015-01-01

    The successful extraction of metabolites is a critical step in metabolite profiling. By optimizing metabolite extraction, the range and quantitative capacity of metabolomics studies can be improved. We considered eight separate extraction protocols for the preparation of a metabolite extract from cultured mammalian cells. Parameters considered included temperature, pH, and cell washing before extraction. The effects on metabolite recovery were studied using a high resolution liquid chromatography mass spectrometry (LC-HRMS) platform that measures metabolites of diverse chemical classes including among others amino acids, lipids, and sugar derivatives. The temperature considered during the extraction or the presence of formic acid, a commonly used additive, was shown to have minimal effects on the measured ion intensities of metabolites. However, washing of samples before metabolite extraction whether with water or PBS (both commonly considered practices) exhibited dramatic effects on measured intensities of both intra- and extra-cellular metabolites. Together these findings present a systematic assessment of extraction conditions for metabolite profiling. PMID:25613493

  19. Electronic structure calculations of ESR parameters of melanin units.

    Science.gov (United States)

    Batagin-Neto, Augusto; Bronze-Uhle, Erika Soares; Graeff, Carlos Frederico de Oliveira

    2015-03-21

    Melanins represent an important class of natural pigments present in plants and animals that are currently considered to be promising materials for applications in optic and electronic devices. Despite their interesting properties, some of the basic features of melanins are not satisfactorily understood, including the origin of their intrinsic paramagnetism. A number of experiments have been performed to investigate the electron spin resonance (ESR) response of melanin derivatives, but until now, there has been no consensus regarding the real structure of the paramagnetic centers involved. In this work, we have employed electronic structure calculations to evaluate the ESR parameters of distinct melanin monomers and dimers in order to identify the possible structures associated with unpaired spins in this biopolymer. The g-factors and hyperfine constants of the cationic, anionic and radicalar structures were investigated. The results confirm the existence of at least two distinct paramagnetic centers in melanin structure, identifying the chemical species associated with them and their roles in electrical conductivity.

  20. Silicon (BSFR) solar cell AC parameters at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, R Anil; Suresh, M.S. [ISRO Satellite Center, Bangalore- 560 017 (India); Nagaraju, J. [Solar Energy and Thermodynamic Laboratory, Department of Instrumentation, Indian Institute of Science, Bangalore- 560 012 (India)

    2005-01-31

    The AC parameters of back surface field reflected (BSFR) silicon solar cell are measured at different cell temperatures (198-348K) both in forward and reverse bias under dark condition using impedance spectroscopy technique. It is found that cell capacitance increases with temperature whereas cell resistance decreases, in forward bias voltage. Beyond maximum power point voltage, the cell inductance (0.28{mu}H) is measured, as the inductive reactance is comparable with cell series resistance. The measured cell parameters (cell capacitance, dynamic resistance, etc) are used to calculate the mean carrier lifetime and diode factor at different cell temperatures.

  1. Reversible (unitized) PEM fuel cell devices

    Energy Technology Data Exchange (ETDEWEB)

    Mitlitsky, F; Myers, B; Smith, W F; Weisberg, Molter, T M

    1999-06-01

    Regenerative fuel cells (RFCs) are enabling for many weight-critical portable applications, since the packaged specific energy (>400 Wh/kg) of properly designed lightweight RFC systems is several-fold higher than that of the lightest weight rechargeable batteries. RFC systems can be rapidly refueled (like primary fuel cells), or can be electrically recharged (like secondary batteries) if a refueling infrastructure is not conveniently available. Higher energy capacity systems with higher performance, reduced weight, and freedom from fueling infrastructure are the features that RFCs promise for portable applications. Reversible proton exchange membrane (PEM) fuel cells, also known as unitized regenerative fuel cells (URFCs), or reversible regenerative fuel cells, are RFC systems which use reversible PEM cells, where each cell is capable of operating both as a fuel cell and as an electrolyzer. URFCs further economize portable device weight, volume, and complexity by combining the functions of fuel cells and electrolyzers in the same hardware, generally without any system performance or efficiency reduction. URFCs are being made in many forms, some of which are already small enough to be portable. Lawrence Livermore National Laboratory (LLNL) has worked with industrial partners to design, develop, and demonstrate high performance and high cycle life URFC systems. LLNL is also working with industrial partners to develop breakthroughs in lightweight pressure vessels that are necessary for URFC systems to achieve the specific energy advantages over rechargeable batteries. Proton Energy Systems, Inc. (Proton) is concurrently developing and commercializing URFC systems (UNIGEN' product line), in addition to PEM electrolyzer systems (HOGEN' product line), and primary PEM fuel cell systems. LLNL is constructing demonstration URFC units in order to persuade potential sponsors, often in their own conference rooms, that advanced applications based on URFC s are

  2. The influence of change software of engine control unit on chosen parameters of its work

    Directory of Open Access Journals (Sweden)

    Piotr GUSTOF

    2007-01-01

    Full Text Available In this work was presented the influence of changes software of engine control unit Fiat Stilo 1,9 JTD on chosen parameters of its work: maximum power, engine torque, acceleration, maximum speed and average fuel consumption.

  3. X-ray powder diffraction data and unit cells of ammonium paratungstate tetrahydrate

    NARCIS (Netherlands)

    Put, J.W. van; Verkroost, T.W.; Sonneveld, E.J.

    1990-01-01

    X-Ray powder diffraction data and unit cell parameters of industrially produced, as well as bench scale prepared, ammonium paratungstate tetrahydrate are reported and compared with current Powder Data file (PDF) (1989) patterns. A least-squares refinement resulted in two slightly different unit cell

  4. Summary of the DREAM8 Parameter Estimation Challenge: Toward Parameter Identification for Whole-Cell Models.

    Directory of Open Access Journals (Sweden)

    Jonathan R Karr

    2015-05-01

    Full Text Available Whole-cell models that explicitly represent all cellular components at the molecular level have the potential to predict phenotype from genotype. However, even for simple bacteria, whole-cell models will contain thousands of parameters, many of which are poorly characterized or unknown. New algorithms are needed to estimate these parameters and enable researchers to build increasingly comprehensive models. We organized the Dialogue for Reverse Engineering Assessments and Methods (DREAM 8 Whole-Cell Parameter Estimation Challenge to develop new parameter estimation algorithms for whole-cell models. We asked participants to identify a subset of parameters of a whole-cell model given the model's structure and in silico "experimental" data. Here we describe the challenge, the best performing methods, and new insights into the identifiability of whole-cell models. We also describe several valuable lessons we learned toward improving future challenges. Going forward, we believe that collaborative efforts supported by inexpensive cloud computing have the potential to solve whole-cell model parameter estimation.

  5. GaAs/Ge solar cell AC parameters under illumination

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, R.A.; Suresh, M.S. [ISRO Satellite Center, Bangalore (India); Nagaraju, J. [Indian Institute of Science, Bangalore (India). Department of Instrumentation, Solar Energy Laboratory

    2004-04-01

    The ac parameters of GaAs/Ge solar cell were measured under illumination at different cell temperatures using impedance spectroscopy technique. They are compared with the dark measurements. It is found that the cell capacitance is higher and cell resistance is lower under illumination than in dark for all cell terminal voltages. The cell capacitances at the corresponding maximum power point voltage (terminal) do not vary with temperature where as the cell resistance decreases. The cell capacitance under illumination is estimated from the dark cell capacitance and it is in good agreement with the measured illumination data. (author)

  6. Measurement of solar cell parameters using impedance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Suresh, M.S. [Battery Division, ISRO Satellite Centre, Bangalore (India)

    1996-08-15

    Measurement of solar cell parameters is important for the design of satellite power systems. These parameters can be measured using impedance spectroscopy and an equivalent circuit model developed. In this study parameters of a Back Surface Reflector Field solar cell (BSFR) have been measured using impedance spectroscopy. The results show high diffusion capacitance of BSFR cells and their exponential relation to the operating voltage. Cell dynamic resistance, diode factor, transition capacitance, and series resistance could also be measured. The minority carrier life time also has been calculated

  7. Parameters Identification of Photovoltaic Cells Based on Differential Evolution Algorithm

    Directory of Open Access Journals (Sweden)

    Liao Hui

    2016-01-01

    Full Text Available For the complex nonlinear model of photovoltaic cells, traditional evolution strategy is easy to fall into the local optimal and its identification time is too long when taking parameters identification, then the difference algorithm is proposed in this study, which is to solve the problems of parameter identification in photovoltaic cell model, where it is very difficult to achieve with other identification algorithms. In this method, the random data is selected as the initial generation; the successful evolution to the next generation is done through a certain strategy of difference algorithm, which can achieve the effective identification of control parameters. It is proved that the method has a good global optimization and the fast convergence ability, and the simulation results are shown that the differential evolution has high identification ability and it is an effective method to identify the parameters of photovoltaic cells, where the photovoltaic cells can be widely used in other places with these parameters.

  8. Parameter estimation method for blurred cell images from fluorescence microscope

    Science.gov (United States)

    He, Fuyun; Zhang, Zhisheng; Luo, Xiaoshu; Zhao, Shulin

    2016-10-01

    Microscopic cell image analysis is indispensable to cell biology. Images of cells can easily degrade due to optical diffraction or focus shift, as this results in low signal-to-noise ratio (SNR) and poor image quality, hence affecting the accuracy of cell analysis and identification. For a quantitative analysis of cell images, restoring blurred images to improve the SNR is the first step. A parameter estimation method for defocused microscopic cell images based on the power law properties of the power spectrum of cell images is proposed. The circular radon transform (CRT) is used to identify the zero-mode of the power spectrum. The parameter of the CRT curve is initially estimated by an improved differential evolution algorithm. Following this, the parameters are optimized through the gradient descent method. Using synthetic experiments, it was confirmed that the proposed method effectively increased the peak SNR (PSNR) of the recovered images with high accuracy. Furthermore, experimental results involving actual microscopic cell images verified that the superiority of the proposed parameter estimation method for blurred microscopic cell images other method in terms of qualitative visual sense as well as quantitative gradient and PSNR.

  9. Parameter regionalization of a monthly water balance model for the conterminous United States

    Science.gov (United States)

    Bock, Andrew R.; Hay, Lauren E.; McCabe, Gregory J.; Markstrom, Steven L.; Atkinson, R. Dwight

    2016-07-01

    A parameter regionalization scheme to transfer parameter values from gaged to ungaged areas for a monthly water balance model (MWBM) was developed and tested for the conterminous United States (CONUS). The Fourier Amplitude Sensitivity Test, a global-sensitivity algorithm, was implemented on a MWBM to generate parameter sensitivities on a set of 109 951 hydrologic response units (HRUs) across the CONUS. The HRUs were grouped into 110 calibration regions based on similar parameter sensitivities. Subsequently, measured runoff from 1575 streamgages within the calibration regions were used to calibrate the MWBM parameters to produce parameter sets for each calibration region. Measured and simulated runoff at the 1575 streamgages showed good correspondence for the majority of the CONUS, with a median computed Nash-Sutcliffe efficiency coefficient of 0.76 over all streamgages. These methods maximize the use of available runoff information, resulting in a calibrated CONUS-wide application of the MWBM suitable for providing estimates of water availability at the HRU resolution for both gaged and ungaged areas of the CONUS.

  10. Frequency Selective Surfaces with Nanoparticles Unit Cell

    Directory of Open Access Journals (Sweden)

    Nga Hung Poon

    2015-09-01

    Full Text Available The frequency selective surface (FSS is a periodic structure with filtering performance for optical and microwave signals. The general periodic arrays made with patterned metallic elements can act as an aperture or patch on a substrate. In this work, two kinds of materials were used to produce unit cells with various patterns. Gold nanoparticles of 25 nm diameter were used to form periodic monolayer arrays by a confined photocatalytic oxidation-based surface modification method. As the other material, silver gel was used to create multiple layers of silver. Due to the ultra-thin nature of the self-assembled gold nanoparticle monolayer, it is very easy to penetrate the FSS with terahertz radiation. However, the isolated silver islands made from silver gel form thicker multiple layers and contribute to much higher reflectance. This work demonstrated that multiple silver layers are more suitable than gold nanoparticles for use in the fabrication of FSS structures.

  11. Filtration parameters influencing circulating tumor cell enrichment from whole blood.

    Directory of Open Access Journals (Sweden)

    Frank A W Coumans

    Full Text Available Filtration can achieve circulating tumor cell (CTC enrichment from blood. Key parameters such as flow-rate, applied pressure, and fixation, vary largely between assays and their influence is not well understood. Here, we used a filtration system, to monitor these parameters and determine their relationships. Whole blood, or its components, with and without spiked tumor cells were filtered through track-etched filters. We characterize cells passing through filter pores by their apparent viscosity; the viscosity of a fluid that would pass with the same flow. We measured a ratio of 5·10(4∶10(2∶1 for the apparent viscosities of 15 µm diameter MDA-231 cells, 10 µm white cells and 90 fl red cells passing through a 5 µm pore. Fixation increases the pressure needed to pass cells through 8 µm pores 25-fold and halves the recovery of spiked tumor cells. Filtration should be performed on unfixed samples at a pressure of ∼10 mbar for a 1 cm(2 track-etched filter with 5 µm pores. At this pressure MDA-231 cells move through the filter in 1 hour. If fixation is needed for sample preservation, a gentle fixative should be selected. The difference in apparent viscosity between CTC and blood cells is key in optimizing recovery of CTC.

  12. Lithium-Ion Cell Charge-Control Unit Developed

    Science.gov (United States)

    Reid, Concha M.; Manzo, Michelle A.; Buton, Robert M.; Gemeiner, Russel

    2005-01-01

    A lithium-ion (Li-ion) cell charge-control unit was developed as part of a Li-ion cell verification program. This unit manages the complex charging scheme that is required when Li-ion cells are charged in series. It enables researchers to test cells together as a pack, while allowing each cell to charge individually. This allows the inherent cell-to-cell variations to be addressed on a series string of cells and reduces test costs substantially in comparison to individual cell testing.

  13. Novel negative mass density resonant metamaterial unit cell

    Energy Technology Data Exchange (ETDEWEB)

    Cselyuszka, Norbert, E-mail: cselyu@yahoo.com; Sečujski, Milan, E-mail: secujski@uns.ac.rs; Crnojević-Bengin, Vesna, E-mail: bengin@uns.ac.rs

    2015-01-02

    In this paper a novel resonant unit cell of one-dimensional acoustic metamaterials is presented, which exhibits negative effective mass density. We theoretically analyze the unit cell and develop a closed analytical formula for its effective mass density. Then we proceed to demonstrate left-handed propagation of acoustic waves using the proposed unit cell. Finally, we present its dual-band version, capable of operating at two independent frequencies. - Highlights: • A novel acoustic metamaterial unit cell provides Lorentz-type resonant effective mass density. • Analytical formula for effective mass density is derived. • Acoustic bandstop medium and left-handed metamaterial based on the novel unit cell are presented. • Modified version of the unit cell, operating at two independent frequencies, is proposed.

  14. DESIGN NOTE: A video synchronization unit for capture of pulsed laser parameters

    Science.gov (United States)

    Oak, S. M.; Navathe, C. P.

    1996-04-01

    An electronic circuit called a video synchronization unit (VSU) is developed to synchronize TV grade CCTV cameras, CCTV monitors and video frame grabbers for the capture of pulsed laser parameters. The VSU accepts a video signal from the camera and generates triggers for the laser and frame grabber at required times. It also generates a trigger at any pre-set horizontal line in the video signal, so that the intensity profile of the selected line can be viewed on an oscilloscope. The unit can drive a laser or be driven by the laser either in single-shot or in repetitive mode of operation. With the help of this unit, a video system is built for the capture of pulsed laser beam profiles and fluorescence traces of a picosecond autocorrelator. It is an inexpensive and more readily available alternative to commercial asynchronous video systems.

  15. APPLICATION OF GEOGRAPHICAL PARAMETER DATABASE TO ESTABLISHMENT OF UNIT POPULATION DATABASE

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Now GIS is turning into a good tool in handling geographical, economical, and population data, so we can obtain more and more information from these data. On the other hand, in some cases, for a calamity, such as hurricane, earthquake, flood, drought etc., or a decision-making, such as setting up a broadcasting transmitter, building a chemical plant etc., we have to evaluate the total population in the region influenced by a calamity or a project. In this paper, a method is put forward to evaluate the population in such special region. Through exploring the correlation of geographical parameters and the distribution of people in the same region by means of quantitative analysis and qualitative analysis, unit population database (1km× 1km) is established. In this way, estimating the number of people in a special region is capable by adding up the population in every grid involved in this region boundary. The geographical parameters are obtained from topographic database and DEM database on the scale of 1∶ 250 000. The fundamental geographical parameter database covering county administrative boundaries and 1km× 1km grid is set up and the population database at county level is set up as well. Both geographical parameter database and unit population database are able to offer sufficient conditions for quantitative analysis. They will have important role in the research fields of data mining (DM), Decision-making Support Systems (DSS), and regional sustainable development.

  16. Flow field measurements in the cell culture unit

    Science.gov (United States)

    Walker, Stephen; Wilder, Mike; Dimanlig, Arsenio; Jagger, Justin; Searby, Nancy

    2002-01-01

    The cell culture unit (CCU) is being designed to support cell growth for long-duration life science experiments on the International Space Station (ISS). The CCU is a perfused loop system that provides a fluid environment for controlled cell growth experiments within cell specimen chambers (CSCs), and is intended to accommodate diverse cell specimen types. Many of the functional requirements depend on the fluid flow field within the CSC (e.g., feeding and gas management). A design goal of the CCU is to match, within experimental limits, all environmental conditions, other than the effects of gravity on the cells, whether the hardware is in microgravity ( micro g), normal Earth gravity, or up to 2g on the ISS centrifuge. In order to achieve this goal, two steps are being taken. The first step is to characterize the environmental conditions of current 1g cell biology experiments being performed in laboratories using ground-based hardware. The second step is to ensure that the design of the CCU allows the fluid flow conditions found in 1g to be replicated from microgravity up to 2g. The techniques that are being used to take these steps include flow visualization, particle image velocimetry (PIV), and computational fluid dynamics (CFD). Flow visualization using the injection of dye has been used to gain a global perspective of the characteristics of the CSC flow field. To characterize laboratory cell culture conditions, PIV is being used to determine the flow field parameters of cell suspension cultures grown in Erlenmeyer flasks on orbital shakers. These measured parameters will be compared to PIV measurements in the CSCs to ensure that the flow field that cells encounter in CSCs is within the bounds determined for typical laboratory experiments. Using CFD, a detailed simulation is being developed to predict the flow field within the CSC for a wide variety of flow conditions, including microgravity environments. Results from all these measurements and analyses of the

  17. Determination of technical and economic parameters of an ionic transport membrane air separation unit working in a supercritical power plant

    Directory of Open Access Journals (Sweden)

    Kotowicz Janusz

    2016-09-01

    Full Text Available In this paper an air separation unit was analyzed. The unit consisted of: an ionic transport membrane contained in a four-end type module, an air compressor, an expander fed by gas that remains after oxygen separation and heat exchangers which heat the air and recirculated flue gas to the membrane operating temperature (850 °C. The air separation unit works in a power plant with electrical power equal to 600 MW. This power plant additionally consists of: an oxy-type pulverized-fuel boiler, a steam turbine unit and a carbon dioxide capture unit. Life steam parameters are 30 MPa/650 °C and reheated steam parameters are 6 MPa/670 °C. The listed units were analyzed. For constant electrical power of the power plant technical parameters of the air separation unit for two oxygen recovery rate (65% and 95% were determined. One of such parameters is ionic membrane surface area. In this paper the formulated equation is presented. The remaining technical parameters of the air separation unit are, among others: heat exchange surface area, power of the air compressor, power of the expander and auxiliary power. Using the listed quantities, the economic parameters, such as costs of air separation unit and of individual components were determined. These quantities allowed to determine investment costs of construction of the air separation unit. In addition, they were compared with investment costs for the entire oxy-type power plant.

  18. Research on Optimization of GLCM Parameter in Cell Classification

    Science.gov (United States)

    Zhang, Xi-Kun; Hou, Jie; Hu, Xin-Hua

    2016-05-01

    Real-time classification of biological cells according to their 3D morphology is highly desired in a flow cytometer setting. Gray level co-occurrence matrix (GLCM) algorithm has been developed to extract feature parameters from measured diffraction images ,which are too complicated to coordinate with the real-time system for a large amount of calculation. An optimization of GLCM algorithm is provided based on correlation analysis of GLCM parameters. The results of GLCM analysis and subsequent classification demonstrate optimized method can lower the time complexity significantly without loss of classification accuracy.

  19. Effects of laser parameters on the geometrical characteristics of peg-shaped bionic coupling unit

    Science.gov (United States)

    Zhang, Baoyu; Zhang, Zhihui; Liang, Yunhong; Yan, Qiongqiong; Ren, Luquan

    2014-12-01

    Peg-shaped bionic coupling unit (PBCU) processed by pulse laser is effective in anti-adhesion, anti-drag, anti-wear and anti-fatigue application. To obtain desired structural and morphological characteristics of the PBCU for industrial manufacturing, selection of proper processing parameters gradually becomes a growing important problem. Traditionally, the procedure of parameter selecting is often cost-plus and time-consuming. In this work, a statistical analysis of fabricating PBCU on the surface of medium carbon steel was conducted. The laser processing parameters utilized in the experiment and analysis are peak power 4-8 kW, pulse duration 6-16 ms and defocusing amount 6-10 mm. A series of mathematical models regarding the relationship between geometrical characteristics of PBCU and laser processing parameters were developed and checked. The results indicate that the developed models can be adequately used to control the structural and morphological characteristics of PBCU within the scope of analysis. Based on the models, the formation mechanism of the structural and morphological characteristics under different laser parameters were analyzed and discussed.

  20. A Unit Cell Laboratory Experiment: Marbles, Magnets, and Stacking Arrangements

    Science.gov (United States)

    Collins, David C.

    2011-01-01

    An undergraduate first-semester general chemistry laboratory experiment introducing face-centered, body-centered, and simple cubic unit cells is presented. Emphasis is placed on the stacking arrangement of solid spheres used to produce a particular unit cell. Marbles and spherical magnets are employed to prepare each stacking arrangement. Packing…

  1. Estimating the effect of a phase change material on the performance of a photovoltaic unit using a five parameter model approach

    Directory of Open Access Journals (Sweden)

    Panagiotis Kladisios, Athina Stegou-Sagia

    2017-01-01

    Full Text Available Photovoltaic modules operate under a large range of conditions. This, combined with the fact that manufacturers provide electrical parameters at specific conditions (STC, Standard Test Conditions renders the prediction of a PV module’s power efficiency very difficult. The most common model for calculating the electric characteristics and, consequently, the generated power of a photovoltaic unit under real transient conditions is the five-parameter model. It is noteworthy that this model demands a relatively small amount of data that are normally available from the manufacturer. The purpose of this paper is to determine the actual benefit in the power efficiency of a photovoltaic unit that has its cell temperature reduced using a phase change material. All approaches of the five-parameter model involve simulating the solar cell, photovoltaic module or photovoltaic array with an one-diode equivalent electrical circuit. The operation of such a circuit is defined by a characteristic I-V equation which contains five parameters: the photocurrent I0, the reverse saturation current Il, the series resistance Rs, the parallel resistance Rp and, depending on the approach, either the diode’s ideality factor m or the modified ideality factor α. For every pair of cell temperature T and solar radiation G, a new characteristic I-V is in effect and, therefore, the above parameters must be calculated anew using correlations between reference and non-reference values of the parameters.

  2. Relevant parameters in models of cell division control

    CERN Document Server

    Grilli, Jacopo; Kennard, Andrew S; Lagomarsino, Marco Cosentino

    2016-01-01

    A recent burst of dynamic single-cell growth-division data makes it possible to characterize the stochastic dynamics of cell division control in bacteria. Different modeling frameworks were used to infer specific mechanisms from such data, but the links between frameworks are poorly explored, with relevant consequences for how well any particular mechanism can be supported by the data. Here, we describe a simple and generic framework in which two common formalisms can be used interchangeably: (i) a continuous-time division process described by a hazard function and (ii) a discrete-time equation describing cell size across generations (where the unit of time is a cell cycle). In our framework, this second process is a discrete-time Langevin equation with a simple physical analogue. By perturbative expansion around the mean initial size (or inter-division time), we show explicitly how this framework describes a wide range of division control mechanisms, including combinations of time and size control, as well a...

  3. Characterizing parameters of Jatropha curcas cell cultures for microgravity studies

    Science.gov (United States)

    Vendrame, Wagner A.; Pinares, Ania

    2013-06-01

    Jatropha (Jatropha curcas) is a tropical perennial species identified as a potential biofuel crop. The oil is of excellent quality and it has been successfully tested as biodiesel and in jet fuel mixes. However, studies on breeding and genetic improvement of jatropha are limited. Space offers a unique environment for experiments aiming at the assessment of mutations and differential gene expression of crops and in vitro cultures of plants are convenient for studies of genetic variation as affected by microgravity. However, before microgravity studies can be successfully performed, pre-flight experiments are necessary to characterize plant material and validate flight hardware environmental conditions. Such preliminary studies set the ground for subsequent spaceflight experiments. The objectives of this study were to compare the in vitro growth of cultures from three explant sources (cotyledon, leaf, and stem sections) of three jatropha accessions (Brazil, India, and Tanzania) outside and inside the petriGAP, a modified group activation pack (GAP) flight hardware to fit petri dishes. In vitro jatropha cell cultures were established in petri dishes containing a modified MS medium and maintained in a plant growth chamber at 25 ± 2 °C in the dark. Parameters evaluated were surface area of the explant tissue (A), fresh weight (FW), and dry weight (DW) for a period of 12 weeks. Growth was observed for cultures from all accessions at week 12, including subsequent plantlet regeneration. For all accessions differences in A, FW and DW were observed for inside vs. outside the PetriGAPs. Growth parameters were affected by accession (genotype), explant type, and environment. The type of explant influenced the type of cell growth and subsequent plantlet regeneration capacity. However, overall cell growth showed no abnormalities. The present study demonstrated that jatropha in vitro cell cultures are suitable for growth inside PetriGAPs for a period of 12 weeks. The parameters

  4. Fukushima Daiichi unit 1 uncertainty analysis--Preliminary selection of uncertain parameters and analysis methodology

    Energy Technology Data Exchange (ETDEWEB)

    Cardoni, Jeffrey N.; Kalinich, Donald A.

    2014-02-01

    Sandia National Laboratories (SNL) plans to conduct uncertainty analyses (UA) on the Fukushima Daiichi unit (1F1) plant with the MELCOR code. The model to be used was developed for a previous accident reconstruction investigation jointly sponsored by the US Department of Energy (DOE) and Nuclear Regulatory Commission (NRC). However, that study only examined a handful of various model inputs and boundary conditions, and the predictions yielded only fair agreement with plant data and current release estimates. The goal of this uncertainty study is to perform a focused evaluation of uncertainty in core melt progression behavior and its effect on key figures-of-merit (e.g., hydrogen production, vessel lower head failure, etc.). In preparation for the SNL Fukushima UA work, a scoping study has been completed to identify important core melt progression parameters for the uncertainty analysis. The study also lays out a preliminary UA methodology.

  5. Real-Time Computation of Parameter Fitting and Image Reconstruction Using Graphical Processing Units

    CERN Document Server

    Locans, Uldis; Suter, Andreas; Fischer, Jannis; Lustermann, Werner; Dissertori, Gunther; Wang, Qiulin

    2016-01-01

    In recent years graphical processing units (GPUs) have become a powerful tool in scientific computing. Their potential to speed up highly parallel applications brings the power of high performance computing to a wider range of users. However, programming these devices and integrating their use in existing applications is still a challenging task. In this paper we examined the potential of GPUs for two different applications. The first application, created at Paul Scherrer Institut (PSI), is used for parameter fitting during data analysis of muSR (muon spin rotation, relaxation and resonance) experiments. The second application, developed at ETH, is used for PET (Positron Emission Tomography) image reconstruction and analysis. Applications currently in use were examined to identify parts of the algorithms in need of optimization. Efficient GPU kernels were created in order to allow applications to use a GPU, to speed up the previously identified parts. Benchmarking tests were performed in order to measure the ...

  6. Evaluation of the pneumatic tube system for transportation of packed red cell units

    Directory of Open Access Journals (Sweden)

    Supriya Dhar

    2015-01-01

    Full Text Available Background: Pneumatic tube system (PTS is commonly used in hospital settings to transport blood samples to diagnostic laboratories. At our blood center, we receive blood requisitions via the PTS, but units are carried to the ward by human courier. Recently we considered using the PTS for transporting blood units. Since, there are reports of hemolysis in blood samples sent through the PTS, we evaluated this system for transporting red cell units. Aims: The aim was to assess the effect of PTS transport on the quality of packed red cell units. Materials and Methods: A total of 50 red blood cells units (RBC, (25 non-irradiated and 25 irradiated were subjected to transportation through the PTS. The control arm in the study was age-matched RBC units not subjected to PTS transport. Each RBC unit was evaluated for hemoglobin (Hb, lactate dehydrogenase, potassium and plasma hemoglobin (Hb. The paired t-test was used to compare these parameters, and the P value was calculated. Results and Conclusion: The percentage of hemolysis after transportation through PTS was below the recommended guidelines. Delivery of the blood unit to the wrong station, bags lying unattended at the destination were few of the problems that had to be addressed. To conclude, though the PTS is a safe means of transporting blood products with reduction in the turn-around-time, it must be validated before use.

  7. A novel validation algorithm allows for automated cell tracking and the extraction of biologically meaningful parameters.

    Directory of Open Access Journals (Sweden)

    Daniel H Rapoport

    Full Text Available Automated microscopy is currently the only method to non-invasively and label-free observe complex multi-cellular processes, such as cell migration, cell cycle, and cell differentiation. Extracting biological information from a time-series of micrographs requires each cell to be recognized and followed through sequential microscopic snapshots. Although recent attempts to automatize this process resulted in ever improving cell detection rates, manual identification of identical cells is still the most reliable technique. However, its tedious and subjective nature prevented tracking from becoming a standardized tool for the investigation of cell cultures. Here, we present a novel method to accomplish automated cell tracking with a reliability comparable to manual tracking. Previously, automated cell tracking could not rival the reliability of manual tracking because, in contrast to the human way of solving this task, none of the algorithms had an independent quality control mechanism; they missed validation. Thus, instead of trying to improve the cell detection or tracking rates, we proceeded from the idea to automatically inspect the tracking results and accept only those of high trustworthiness, while rejecting all other results. This validation algorithm works independently of the quality of cell detection and tracking through a systematic search for tracking errors. It is based only on very general assumptions about the spatiotemporal contiguity of cell paths. While traditional tracking often aims to yield genealogic information about single cells, the natural outcome of a validated cell tracking algorithm turns out to be a set of complete, but often unconnected cell paths, i.e. records of cells from mitosis to mitosis. This is a consequence of the fact that the validation algorithm takes complete paths as the unit of rejection/acceptance. The resulting set of complete paths can be used to automatically extract important biological parameters

  8. Device analysis methods for physical cell parameters of CdTe/CdS solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Baetzner, D.L. [Eidgenoessische Technische Hochschule, Zurich (Switzerland). Inst. fuer Quantenelektronik; Oezsan, M.E. [BP Solar Technology Centre, Sunbury-on-Thames, Middlesex (United Kingdom); Bonnet, D. [ANTEC Angewandte Neue Technologien GmbH, Kelkheim (Germany); Buecher, K. [Fraunhofer-Institut fuer Solare Energiesysteme (ISE), Freiburg im Breisgau (Germany). Abt. Thermische und Optische Systeme

    2000-02-21

    CdTe/CdS solar cells are thin film solar cells made of several different materials. As front contact serves a TCO, the p-n junction is an intermixed CdS/CdTe heterojunction and the metallization on the CdTe layer, which is needed for the back contact, usually shows a Schottky diode behaviour. Therefore the optoelectrical properties of the cells are complex and can often not be explained straight forward like in silicon solar cells. In order to determine the physical cell parameters like the Schottky barrier height and the minority carrier diffusion length in the absorber layer, we investigated the temperature dependence of the dark I-V characteristics and the spectral response. By modelling the temperature and wavelength dependence of the cell parameters, physical quantities such as the barrier height of the Schottky contact can be determined. (orig.)

  9. Unit cell geometry of multiaxial preforms for structural composites

    Science.gov (United States)

    Ko, Frank; Lei, Charles; Rahman, Anisur; Du, G. W.; Cai, Yun-Jia

    1993-01-01

    The objective of this study is to investigate the yarn geometry of multiaxial preforms. The importance of multiaxial preforms for structural composites is well recognized by the industry but, to exploit their full potential, engineering design rules must be established. This study is a step in that direction. In this work the preform geometry for knitted and braided preforms was studied by making a range of well designed samples and studying them by photo microscopy. The structural geometry of the preforms is related to the processing parameters. Based on solid modeling and B-spline methodology a software package is developed. This computer code enables real time structural representations of complex fiber architecture based on the rule of preform manufacturing. The code has the capability of zooming and section plotting. These capabilities provide a powerful means to study the effect of processing variables on the preform geometry. the code also can be extended to an auto mesh generator for downstream structural analysis using finite element method. This report is organized into six sections. In the first section the scope and background of this work is elaborated. In section two the unit cell geometries of braided and multi-axial warp knitted preforms is discussed. The theoretical frame work of yarn path modeling and solid modeling is presented in section three. The thin section microscopy carried out to observe the structural geometry of the preforms is the subject in section four. The structural geometry is related to the processing parameters in section five. Section six documents the implementation of the modeling techniques into the computer code MP-CAD. A user manual for the software is also presented here. The source codes and published papers are listed in the Appendices.

  10. Fabrication and characteristics of unit cell for SOFC

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Gwi-Yeol; Eom, Seung-Wook; Moon, Seong-In [Korea Electrotechnology Research Institute, Kyongnam (Korea, Republic of)] [and others

    1996-12-31

    Research and development on solid oxide fuel cells in Korea have been mainly focused on unit cell and small stack. Fuel cell system is called clean generation system which not cause NOx or SOx. It is generation efficiency come to 50-60% in contrast to 40% of combustion generation system. Among the fuel cell system, solid oxide fuel cell is constructed of ceramics, so stack construction is simple, power density is very high, and there are no corrosion problems. The object of this study is to develop various composing material for SOFC generation system, and to test unit cell performance manufactured. So we try to present a guidance for developing mass power generation system. We concentrated on development of manufacturing process for cathode, anode and electrolyte.

  11. Hole transport parameters in a PTOPT based organic solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Gebremichael, B. [Addis Ababa Univ., Addis Ababa (Ethiopia). Dept. of Physics; Tessema, G. [Addis Ababa Univ., Addis Ababa (Ethiopia). Dept. of Physics; National Univ. of Lesotho (Lesotho). Dept. of Physics and Electronics

    2010-05-15

    Semiconductor polymers are light-weight and inexpensive to manufacture. As such, they are in demand for solar cell applications. In this study, a single layer photovoltaic (PV) device was used to examine the charge transport phenomena in a photoactive layer made of poly[3-(4-octylphenyl)-2, 2{sup '}-bithiophene] (PTOPT). The devices were prepared in a sandwich-type structure of the form Al/PTOPT/PEDOT:PSS/ITO. The diodes exhibited good rectification which is required in a PV cell. The device rectified at room temperature and lost rectification at around 273 K. The loss of rectification at low temperatures was due to the injection of holes from the aluminium electrode that rendered the device hole-dominated. The symmetric nature of the semilogarithmic J-V plot under dark and low temperature demonstrated that there is a unipolar charge injection in both sides of the electrodes. Based on the space charge limited region J-V data, it was possible to examine the electric field dependence of the hole transport. Important parameters such as the zero field mobility and the field activation factor were then derived. 9 refs., 4 figs.

  12. Source mechanisms and source parameters of March 10 and September 13, 2007, United Arab Emirates Earthquakes

    Energy Technology Data Exchange (ETDEWEB)

    Marzooqi, Y A; Abou Elenean, K M; Megahed, A S; El-Hussain, I; Rodgers, A; Khatibi, E A

    2008-02-29

    On March 10 and September 13, 2007 two felt earthquakes with moment magnitudes 3.66 and 3.94 occurred in the eastern part of United Arab Emirates (UAE). The two events were accompanied by few smaller events. Being well recorded by the digital UAE and Oman digital broadband stations, they provide us an excellent opportunity to study the tectonic process and present day stress field acting on this area. In this study, we determined the focal mechanisms of the two main shocks by two methods (polarities of P and regional waveform inversion). Our results indicate a normal faulting mechanism with slight strike slip component for the two studied events along a fault plane trending NNE-SSW in consistent a suggested fault along the extension of the faults bounded Bani Hamid area. The Seismicity distribution between two earthquake sequences reveals a noticeable gap that may be a site of a future event. The source parameters (seismic moment, moment magnitude, fault radius, stress drop and displacement across the fault) were also estimated based on the far field displacement spectra and interpreted in the context of the tectonic setting.

  13. Total monitor units influence on plan quality parameters in volumetric modulated arc therapy for breast case.

    Science.gov (United States)

    Mancosu, P; Reggiori, G; Alongi, F; Cozzi, L; Fogliata, A; Lobefalo, F; Navarria, P; Stravato, A; Tomatis, S; Scorsetti, M

    2014-05-01

    To investigate the correlation between total monitor units (MU), dosimetric findings, and pre-treatment quality assurance for volumetric modulated arc therapy (VMAT) by RapidArc (RA). Ten patients with breast cancer were considered. Dose prescriptions were: 48 Gy and 40.5 Gy in 15 fractions to, respectively, PTV(Boost) and PTVWholeBreast. A reference plan was optimized and four more plans using the "MU Objective", a tool for total MU controlling, were prepared imposing ± 20 and ± 50% total MU for inducing different complexities. Plan objectives were: D95% > 95% for both PTVs, and D2% Plans were evaluated in terms of technical parameters, dosimetric plan objectives findings and pre-treatment quality assurance (QA). Concerning PTVs, there were no significant differences for target coverage (D95%); mean doses for ipsilateral lung and controlateral breast, and V18 Gy for heart decreased with MUs increasing, reaching a plateau with reference plan. Body volume receiving low dose (V5-10 Gy) was minimized for reference plans. All plans had GAI (3 mm, 3%) > 95%. The data suggest that the best plan is the reference one, where the "MU Objective" tool was not used during optimisation. Nevertheless, it is advisable to use the "MU Objective" tool for re-planning when low GAI is found to increase its value. In this case, attention should be paid to OARs dose limits, since their values may be increased. Copyright © 2013 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  14. Motor unit firing intervals and other parameters of electrical activity in normal and pathological muscle

    DEFF Research Database (Denmark)

    Fuglsang-Frederiksen, Anders; Smith, T; Høgenhaven, H

    1987-01-01

    The analysis of the firing intervals of motor units has been suggested as a diagnostic tool in patients with neuromuscular disorders. Part of the increase in number of turns seen in patients with myopathy could be secondary to the decrease in motor unit firing intervals at threshold force...... of the motor units, as noted in previous studies. In the brachial biceps muscle we have studied the firing intervals of 164 motor units in 14 controls, 140 motor units in 13 patients with myopathy and 86 motor units in 8 patients with neurogenic disorders, and related the findings to those of the turns...... analysis and the analysis of properties of individual motor unit potentials. To ensure comparable conditions we have examined motor unit firing intervals and turns at a force of 10% of maximum. The average of motor unit firing intervals and of interval variability was the same in controls and in patients...

  15. Impact of the irregular microgeometry of polyurethane foam on the macroscopic acoustic behavior predicted by a unit-cell model.

    Science.gov (United States)

    Doutres, O; Ouisse, M; Atalla, N; Ichchou, M

    2014-10-01

    This paper deals with the prediction of the macroscopic sound absorption behavior of highly porous polyurethane foams using two unit-cell microstructure-based models recently developed by Doutres, Atalla, and Dong [J. Appl. Phys. 110, 064901 (2011); J. Appl. Phys. 113, 054901 (2013)]. In these models, the porous material is idealized as a packing of a tetrakaidecahedra unit-cell representative of the disordered network that constitutes the porous frame. The non-acoustic parameters involved in the classical Johnson-Champoux-Allard model (i.e., porosity, airflow resistivity, tortuosity, etc.) are derived from characteristic properties of the unit-cell and semi-empirical relationships. A global sensitivity analysis is performed on these two models in order to investigate how the variability associated with the measured unit-cell characteristics affects the models outputs. This allows identification of the possible limitations of a unit-cell micro-macro approach due to microstructure irregularity. The sensitivity analysis mainly shows that for moderately and highly reticulated polyurethane foams, the strut length parameter is the key parameter since it greatly impacts three important non-acoustic parameters and causes large uncertainty on the sound absorption coefficient even if its measurement variability is moderate. For foams with a slight inhomogeneity and anisotropy, a micro-macro model associated to cell size measurements should be preferred.

  16. Flattening filter free beams from TrueBeam and Versa HD units: Evaluation of the parameters for quality assurance.

    Science.gov (United States)

    Fogliata, Antonella; Fleckenstein, Jens; Schneider, Frank; Pachoud, Marc; Ghandour, Sarah; Krauss, Harald; Reggiori, Giacomo; Stravato, Antonella; Lohr, Frank; Scorsetti, Marta; Cozzi, Luca

    2016-01-01

    Flattening filter free (FFF) beams generated by medical linear accelerators are today clinically used for stereotactical and non-stereotactical radiotherapy treatments. Such beams differ from the standard flattened beams (FF) in the high dose rate and the profile shape peaked on the beam central axis. Definition of new parameters as unflatness and slope for FFF beams has been proposed based on a renormalization factor for FFF profiles. The present study aims to assess the dosimetric differences between FFF beams generated by linear accelerators from different vendors, and to provide renormalization and parameter data of the two kinds of units. Dosimetric data from two Varian TrueBeam and two Elekta Versa HD linear accelerators, all with 6 and 10 MV nominal accelerating potentials, FF and FFF modes have been collected. Renormalization factors and related fit parameters according to Fogliata et al. ["Definition of parameters for quality assurance of flattening filter free (FFF) photon beams in radiation therapy," Med. Phys. 39, 6455-6464 (2012)] have been evaluated for FFF beams of both units and energies. Unflatness and slope parameters from profile curves were evaluated. Dosimetric differences in terms of beam penetration and near-the-surface dose were also assessed. FFF profile parameters have been updated; renormalization factors and unflatness from the Varian units are consistent with the published data. Elekta FFF beam qualities, different from the Varian generated beams, tend to express similar behaviour as the FF beam of the corresponding nominal energy. TPR20,10 for 6 and 10 MV FF and FFF TrueBeam beams are 0.665, 0.629 (6 MV) and 0.738, 0.703 (10 MV). The same figures for Versa HD units are 0.684, 0.678 (6 MV) and 0.734, 0.721 (10 MV). Renormalization factor and unflatness parameters evaluated from Varian and Elekta FFF beams are provided, in particular renormalization factors table and fit parameters.

  17. The relationship between stroke mortality and red blood cell parameters.

    Directory of Open Access Journals (Sweden)

    Hamidreza Hatamian

    2014-12-01

    Full Text Available Several factors influence on the outcome of ischemic stroke. The aim of this study was determination the relationship between stroke mortality and red blood cell parameters.This cross-sectional study was conducted from 2011 July to June 2012. For all patients with ischemic stroke in middle cerebral artery (MCA territory, the cell blood count test was performed. We recorded their mortality on the 1(st week and the 1(st month after ischemic stroke. Data analysis was performed using t-test, χ(2, Mann-Whitney U-test, logistic regression and receiver operating characteristic curve in SPSS for Windows 19.0.A total of 98 subjects (45.9% men and 54.1% women with the mean age of 71.0 ± 13.9 years were assessed, while 67.3% of them were anemic. The prevalence of 1(st week mortality among anemic and non-anemic patients was 40.9% and 34.4% (P = 0.534. The prevalence of mortality after 1(st week till 1(st month was 19.6% and 21.0% respectively (P = 0.636. In univariant analysis, only 1(st month mortality had a significant relationship with red blood cell (RBC count (P = 0.022. However, the result of logistic regression model showed that RBC (P = 0.012 and mean corpuscular volume (MCV (P = 0.021 remained as predictors of the 1(st week and the 1(st month mortality (P = 0.011 and P = 0.090 respectively. The best cutoff point of RBC for the prediction of the 1(st week mortality with 44.7% specificity and 69.5% sensitivity was estimated 4.07 million/μl and for the 1(st month mortality with 46.6% specificity and 72.2% sensitivity was estimated 4.16 million/μl.The RBC count and MCV are independent predictors of ischemic stroke short-term mortality.

  18. Motor unit firing intervals and other parameters of electrical activity in normal and pathological muscle

    DEFF Research Database (Denmark)

    Fuglsang-Frederiksen, Anders; Smith, T; Høgenhaven, H

    1987-01-01

    analysis and the analysis of properties of individual motor unit potentials. To ensure comparable conditions we have examined motor unit firing intervals and turns at a force of 10% of maximum. The average of motor unit firing intervals and of interval variability was the same in controls and in patients......, and the diagnostic yield of the motor unit firing intervals analysis was none. Although the number of turns increased with decreasing motor unit firing intervals, this relation was physiological rather than pathophysiological. In patients with neurogenic disorders, interval variability indicated unstable firing...

  19. Learning about the Unit Cell and Crystal Lattice with Computerized Simulations and Games: A Pilot Study

    Science.gov (United States)

    Luealamai, Sutha; Panijpan, Bhinyo

    2012-01-01

    The authors have developed a computer-based learning module on the unit cell of various types of crystal. The module has two components: the virtual unit cell (VUC) part and the subsequent unit cell hunter part. The VUC is a virtual reality simulation for students to actively arrive at the unit cell from exploring, from a broad view, the crystal…

  20. Learning about the Unit Cell and Crystal Lattice with Computerized Simulations and Games: A Pilot Study

    Science.gov (United States)

    Luealamai, Sutha; Panijpan, Bhinyo

    2012-01-01

    The authors have developed a computer-based learning module on the unit cell of various types of crystal. The module has two components: the virtual unit cell (VUC) part and the subsequent unit cell hunter part. The VUC is a virtual reality simulation for students to actively arrive at the unit cell from exploring, from a broad view, the crystal…

  1. GaAs/Ge solar cell AC parameters at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, R. Anil; Suresh, M.S. [ISRO Satellite centre, ISRO, Bangalore 560 017 (India); Nagaraju, J. [Department of Instrumentation, Indian Institute of Science, Bangalore 560 012 (India)

    2003-05-15

    The AC parameters of Gallium Arsenide (GaAs/Ge) solar cell were measured at different cell temperatures (198-348K) by varying the cell bias voltage (forward and reverse) under dark condition using impedance spectroscopy technique. It was found that the cell capacitance increases with the cell temperature where as the cell resistance decreases, at any bias voltage. The measured cell parameters were used to calculate the intrinsic concentration of electron-hole pair, cell material relative permittivity and its band gap energy. The diode factor and the cell dynamic resistance at the corresponding maximum power point decrease with the cell temperature.

  2. Biology 23. Unit One -- The Cell: Structure and Physiology.

    Science.gov (United States)

    Nederland Independent School District, TX.

    GRADES OR AGES: Not given. SUBJECT MATTER: Biology, the structure and physiology of the cell. ORGANIZATION AND PHYSICAL APPEARANCE: There are four sections: a) objectives for the unit, b) bibliography, c) activities, and d) evaluation. The guide is directed to the student rather than the teacher. The guide is mimeographed and stapled, with no…

  3. Advancement of a soil parameters geodatabase for the modeling assessment of conservation practice outcomes in the United States

    Science.gov (United States)

    US-ModSoilParms-TEMPLE is a database composed of a set of geographic databases functionally storing soil-spatial units and soil hydraulic, physical, and chemical parameters for three agriculture management simulation models, SWAT, APEX, and ALMANAC. This paper introduces the updated US-ModSoilParms-...

  4. Polymer electrolyte fuel cell mini power unit for portable application

    Science.gov (United States)

    Urbani, F.; Squadrito, G.; Barbera, O.; Giacoppo, G.; Passalacqua, E.; Zerbinati, O.

    This paper describes the design, realisation and test of a power unit based on a polymer electrolyte fuel cell, operating at room temperature, for portable application. The device is composed of an home made air breathing fuel cell stack, a metal hydride tank for H 2 supply, a dc-dc converter for power output control and a fan for stack cooling. The stack is composed by 10 cells with an active surface of 25 cm 2 and produces a rated power of 15 W at 6 V and 2 A. The stack successfully runs with end-off fed hydrogen without appreciable performance degradation during the time. The final assembled system is able to generate 12 W at 9.5 V, and power a portable DVD player for 3 h in continuous. The power unit has collected about 100 h of operation without maintenance.

  5. Polymer electrolyte fuel cell mini power unit for portable application

    Energy Technology Data Exchange (ETDEWEB)

    Urbani, F.; Squadrito, G.; Barbera, O.; Giacoppo, G.; Passalacqua, E. [CNR-ITAE, via Salita S. Lucia sopra Contesse n. 5, 98126 S. Lucia, Messina (Italy); Zerbinati, O. [Universita del Piemonte Orientale, Dip. di Scienze dell' Ambiente e della Vita, via Bellini 25/g, 15100 Alessandria (Italy)

    2007-06-20

    This paper describes the design, realisation and test of a power unit based on a polymer electrolyte fuel cell, operating at room temperature, for portable application. The device is composed of an home made air breathing fuel cell stack, a metal hydride tank for H{sub 2} supply, a dc-dc converter for power output control and a fan for stack cooling. The stack is composed by 10 cells with an active surface of 25 cm{sup 2} and produces a rated power of 15 W at 6 V and 2 A. The stack successfully runs with end-off fed hydrogen without appreciable performance degradation during the time. The final assembled system is able to generate 12 W at 9.5 V, and power a portable DVD player for 3 h in continuous. The power unit has collected about 100 h of operation without maintenance. (author)

  6. Measurement of silicon and GaAs/Ge solar cells ac parameters

    Energy Technology Data Exchange (ETDEWEB)

    Deshmukh, M.P.; Nagaraju, J. [Indian Institute of Science, Bangalore (India). Dept. of Instrumentation

    2005-01-01

    The ac parameters (cell capacitance and cell resistance) of Silicon (Si) and Gallium Arsenide (GaAs/Ge) solar cells are measured at different temperatures using time domain technique. The cell capacitance is calculated from the Open circuit voltage decay (OCVD) and the cell resistance from solar cell I-V characteristics measured under dark condition. It is observed that the solar cell capacitance increases whereas the cell resistance decreases with increase in temperature. (author)

  7. Microbial fuel cells as pollutant treatment units: Research updates.

    Science.gov (United States)

    Zhang, Quanguo; Hu, Jianjun; Lee, Duu-Jong

    2016-10-01

    Microbial fuel cells (MFC) are a device that can convert chemical energy in influent substances to electricity via biological pathways. Based on the consent that MFC technology should be applied as a waste/wastewater treatment unit rather than a renewable energy source, this mini-review discussed recent R&D efforts on MFC technologies for pollutant treatments and highlighted the challenges and research and development needs. Owing to the low power density levels achievable by larger-scale MFC, the MFC should be used as a device other than energy source such as being a pollutant treatment unit.

  8. An Evaluation of Kinetic Parameters of Cadmium and Copper Biosorption by Immobilized Cells

    Directory of Open Access Journals (Sweden)

    Nelly Georgieva

    2007-10-01

    Full Text Available Bioremediation is the use of living organisms to reduce or eliminate environmental hazards resulting from the accumulation of toxic chemicals and other hazardous wastes. This technology is based on the utilization of microorganisms to transform organic and inorganic compounds. The filamentous yeast Trichosporon cutaneum strain R57, immobilized and free cells was cultivated as batch culture on a liquid medium in the presence of various concentrations of cadmium and copper ions. The simultaneous uptake and accumulation of Cd2+ and Cu2+ ions by Tr. cutaneum cells depending on the initial concentration of Cd2+ and Cu2+ in the medium were studied. The potential use of the free and immobilized cells of Trichosporon cutaneum to remove cadmium and copper ions, from aqueous solutions was evaluated. Two important physicochemical aspects for the evaluation of the sorption process as a unit operation are the equilibrium of sorption and the kinetics. The Cd2+ and Cu2+ ions biosorption capacities of all tested adsorbent were presented as a function of the initial concentration of metal ions within the aqueous biosorption medium. The individual, as well as bicomponent sorption kinetics of copper and cadmium ions by immobilised cells of Trichosporon cutaneum R57 is presented. A second order kinetic model obtains kinetic parameters for the copper and cadmium ions.

  9. Relationship between Microcellular Foaming Injection Molding Process Parameters and Cell Size

    Institute of Scientific and Technical Information of China (English)

    HU Guang-hong; JIANG Chao-dong; CUI Zhen-shan

    2008-01-01

    In order to study the relationship between the main process parameters and the cell size, the mathematical model of cell growth of microcellular foaming injection process is built. Then numeric simulation is employed as experimental method, and the Taguchi method is used to analyze significance of effect of process parameters on the cell size. At last the process parameters are focused on melt temperature, injection time, mold temperature and pre- filled volume. The significance order from big to small of the effect of each process parameters on cell size is melt temperature, pre-filled volume, injection time, and mold temperature. On the basis of above research, the effect of each process parameter on cell size is further researched.Appropriate reduction of the melt temperature and increase of the we-filled volume can optimize the cell size effectively, while the effects of injection time and mold temperature on cell size are less significant.

  10. Parameters influencing derivation of embryonic stem cells from murine embryos.

    Science.gov (United States)

    Batlle-Morera, Laura; Smith, Austin; Nichols, Jennifer

    2008-12-01

    The derivation of ES cells is poorly understood and varies in efficiency between different strains of mice. We have investigated potential differences between embryos of permissive and recalcitrant strains during diapause and ES cell derivation. We found that in diapause embryos of the recalcitrant C57BL/6 and CBA strains, the epiblast failed to expand during the primary explant phase of ES cell derivation, whereas in the permissive 129 strain, it expanded dramatically. Epiblasts from the recalcitrant strains could be expanded by reducing Erk activation. Isolation of 129 epiblasts facilitated very efficient derivation of ES cell lines in serum- and feeder-free conditions, but reduction of Erk activity was required for derivation of ES cells from isolated C57BL/6 or CBA epiblasts. The results suggest that the discrepancy in ES cell derivation efficiency is not attributable merely to variable prodifferentiative effects of the extra-embryonic lineages but also to an intrinsic variability within the epiblast to maintain pluripotency.

  11. Flattening filter free beams from TrueBeam and Versa HD units: Evaluation of the parameters for quality assurance

    Energy Technology Data Exchange (ETDEWEB)

    Fogliata, Antonella, E-mail: antonella.fogliata@humanitas.it; Reggiori, Giacomo; Stravato, Antonella; Scorsetti, Marta; Cozzi, Luca [Radiotherapy and Radiosurgery Department, Humanitas Research Hospital, Milan-Rozzano I-20098 (Italy); Fleckenstein, Jens; Schneider, Frank; Lohr, Frank [Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Mannheim D-68167 (Germany); Pachoud, Marc; Ghandour, Sarah [Radiation Oncology Department, Hôpital Riviera Chablais, Vevey CH-1800 (Switzerland); Krauss, Harald [Radio-Oncology Department, Kaiser Franz Josef Spital, Vienna A-1100 (Austria)

    2016-01-15

    Purpose: Flattening filter free (FFF) beams generated by medical linear accelerators are today clinically used for stereotactical and non-stereotactical radiotherapy treatments. Such beams differ from the standard flattened beams (FF) in the high dose rate and the profile shape peaked on the beam central axis. Definition of new parameters as unflatness and slope for FFF beams has been proposed based on a renormalization factor for FFF profiles. The present study aims to assess the dosimetric differences between FFF beams generated by linear accelerators from different vendors, and to provide renormalization and parameter data of the two kinds of units. Methods: Dosimetric data from two Varian TrueBeam and two Elekta Versa HD linear accelerators, all with 6 and 10 MV nominal accelerating potentials, FF and FFF modes have been collected. Renormalization factors and related fit parameters according to Fogliata et al. [“Definition of parameters for quality assurance of flattening filter free (FFF) photon beams in radiation therapy,” Med. Phys. 39, 6455–6464 (2012)] have been evaluated for FFF beams of both units and energies. Unflatness and slope parameters from profile curves were evaluated. Dosimetric differences in terms of beam penetration and near-the-surface dose were also assessed. Results: FFF profile parameters have been updated; renormalization factors and unflatness from the Varian units are consistent with the published data. Elekta FFF beam qualities, different from the Varian generated beams, tend to express similar behaviour as the FF beam of the corresponding nominal energy. TPR{sub 20,10} for 6 and 10 MV FF and FFF TrueBeam beams are 0.665, 0.629 (6 MV) and 0.738, 0.703 (10 MV). The same figures for Versa HD units are 0.684, 0.678 (6 MV) and 0.734, 0.721 (10 MV). Conclusions: Renormalization factor and unflatness parameters evaluated from Varian and Elekta FFF beams are provided, in particular renormalization factors table and fit parameters.

  12. Zero loss magnetic metamaterials using powered active unit cells.

    Science.gov (United States)

    Yuan, Yu; Popa, Bogdan-Ioan; Cummer, Steven A

    2009-08-31

    We report the design and experimental measurement of a powered active magnetic metamaterial with tunable permeability. The unit cell is based on the combination of an embedded radiofrequency amplifier and a tunable phase shifter, which together control the response of the medium. The measurements show that a negative permeability metamaterial with zero loss or even gain can be achieved through an array of such metamaterial cells. This kind of active metamaterial can find use in applications that are performance limited due to material losses.

  13. A heated vapor cell unit for DAVLL in atomic rubidium

    OpenAIRE

    McCarron, Daniel J.; Hughes, Ifan G.; Tierney, Patrick; Cornish, Simon L

    2007-01-01

    The design and performance of a compact heated vapor cell unit for realizing a dichroic atomic vapor laser lock (DAVLL) for the D2 transitions in atomic rubidium is described. A 5 cm-long vapor cell is placed in a double-solenoid arrangement to produce the required magnetic field; the heat from the solenoid is used to increase the vapor pressure and correspondingly the DAVLL signal. We have characterized experimentally the dependence of important features of the DAVLL signal on magnetic field...

  14. Composite Bipolar Plate for Unitized Fuel Cell/Electrolyzer Systems

    Science.gov (United States)

    Mittelsteadt, Cortney K.; Braff, William

    2009-01-01

    In a substantial improvement over present alkaline systems, an advanced hybrid bipolar plate for a unitized fuel cell/electrolyzer has been developed. This design, which operates on pure feed streams (H2/O2 and water, respectively) consists of a porous metallic foil filled with a polymer that has very high water transport properties. Combined with a second metallic plate, the pore-filled metallic plates form a bipolar plate with an empty cavity in the center.

  15. Parameter-elevation Regressions on Independent Slopes Model Monthly Climate Data for the Continental United States.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset was created using the PRISM (Parameter-elevation Regressions on Independent Slopes Model) climate mapping system, developed by Dr. Christopher Daly,...

  16. Estimation of lifespan and economy parameters of steam-turbine power units in thermal power plants using varying regimes

    Science.gov (United States)

    Aminov, R. Z.; Shkret, A. F.; Garievskii, M. V.

    2016-08-01

    The use of potent power units in thermal and nuclear power plants in order to regulate the loads results in intense wear of power generating equipment and reduction in cost efficiency of their operation. We review the methodology of a quantitative assessment of the lifespan and wear of steam-turbine power units and estimate the effect of various operation regimes upon their efficiency. To assess the power units' equipment wear, we suggest using the concept of a turbine's equivalent lifespan. We give calculation formulae and an example of calculation of the lifespan of a steam-turbine power unit for supercritical parameters of steam for different options of its loading. The equivalent lifespan exceeds the turbine's assigned lifespan only provided daily shutdown of the power unit during the night off-peak time. We obtained the engineering and economical indices of the power unit operation for different loading regulation options in daily and weekly diagrams. We proved the change in the prime cost of electric power depending on the operation regimes and annual daily number of unloading (non-use) of the power unit's installed capacity. According to the calculation results, the prime cost of electric power for the assumed initial data varies from 11.3 cents/(kW h) in the basic regime of power unit operation (with an equivalent operation time of 166700 hours) to 15.5 cents/(kW h) in the regime with night and holiday shutdowns. The reduction of using the installed capacity of power unit at varying regimes from 3.5 to 11.9 hours per day can increase the prime cost of energy from 4.2 to 37.4%. Furthermore, repair and maintenance costs grow by 4.5% and by 3 times, respectively, in comparison with the basic regime. These results indicate the need to create special maneuverable equipment for working in the varying section of the electric load diagram.

  17. Solid Oxide Fuel Cells coupled with a biomass gasification unit

    Directory of Open Access Journals (Sweden)

    Skrzypkiewicz Marek

    2016-01-01

    Full Text Available A possibility of fuelling a solid oxide fuel cell stack (SOFC with biomass fuels can be realized by coupling a SOFC system with a self-standing gasification unit. Such a solution enables multi-fuel operation, elasticity of the system as well as the increase of the efficiency of small-scale biomass-to-electricity conversion units. A system of this type, consisting of biomass gasification unit, gas purification unit, SOFC stack, anode off-gas afterburner and peripherals was constructed and operated successfully. During the process, biomass fuel (wood chips was gasified with air as gasification agent. The gasifier was capable of converting up to 30 kW of fuel to syngas with efficiencies up to 75%. Syngas leaving the gasification unit is delivered to a medium temperature adsorber for sulphur compounds removal. Steam is added to the purified fuel to maintain steam to carbon ratio higher than 2. The syngas then is passed to a SOFC stack through a fuel preheater. In such a configuration it was possible to operate a commercial 1.3 kW stack within its working regime. Conducted tests confirmed successful operation of a SOFC stack fuelled by biomass-sourced syngas.

  18. Effect of plate asymmetric rolling parameters on the change of the total unit pressure of roll

    Directory of Open Access Journals (Sweden)

    A. Kawalek

    2011-07-01

    Full Text Available This work shows the results of theoretical analysis of asymmetric rolling process of plates in the finishing mill of plate rolling. Its aim was to determine the influence of asymmetry velocity of working rolls on decrease of unit pressure of metal on the rolls. The lower value of the unit pressure will reduce the elastic deflection of the finishing stand and improve the cross-section shape of plate. Three-dimensional simulation of asymmetric hot rolling of S355J2G3 steel plates was done with the aid of FORGE 2008® software. The tensor polynomial interpolation was used for comparing the values of the unit pressure obtaining from symmetric and asymmetric rolling.

  19. Automated Parameters for Troubled-Cell Indicators Using Outlier Detection

    NARCIS (Netherlands)

    Vuik, M.J.; Ryan, J.K.

    2016-01-01

    In Vuik and Ryan [J. Comput. Phys., 270 (2014), pp. 138--160] we studied the use of troubled-cell indicators for discontinuity detection in nonlinear hyperbolic partial differential equations and introduced a new multiwavelet technique to detect troubled cells. We found that these methods perform we

  20. Efficiency of the unit cell in rectangular finned tube arrangements

    Energy Technology Data Exchange (ETDEWEB)

    Buzzoni, Luca; Dall' Olio, Roberto; Spiga, Marco [Bologna Univ., DIENCA, Bologna (Italy)

    1999-11-01

    This paper is aimed at presenting an investigation concerning the efficiency of the single unit in finned air-cooled heat exchangers with staggered and in-line bundles of rectangular ducts, where a hot process fluid flows inside extended-surface tubes and atmospheric air is circulated outside, over the extended surface. The differential energy equation is numerically solved by a finite difference technique, in order to determine the spatial temperature profiles, then the fin efficiency and the augmentation factor are calculated by a simple numerical integration. The results show that the temperature distribution and the fin performance depend on four dimensionless parameters (m,{beta},p{sub x},p{sub y}), the first accounting for the heat transfer condition, the other ones accounting for the geometry of the extended surface (tube aspect ratio and pitches). Several tables are presented, allowing the efficiency of the extended surface to be deduced as a function of the thermal and geometric parameters. (Author)

  1. Sensitivity analysis of high-efficiency silicon solar-cell design parameters

    Science.gov (United States)

    Mokashi, A. R.

    1984-01-01

    Silicon solar cell design parameters were investigated to determine their bearing on cell efficiency. Among the parameters reviewed were: (1) bulk resistivity, (2) minority carrier lifetime cell thickness, (3) front junction depth, (4) front surface doping concentration, (5) front surface recombination velocity, and (6) back surface contact. The following were concluded: (1) there is good agreement between experimental and simulation results; (2) sheet material quality improvement is needed for high efficiency cells; (3) 20% cell of this design is feasible with 10 ms bulk lifetime material; and (4) for achieving efficiencies higher than 20% new cell designs including thin cells with light trapping and back surface field should be considered.

  2. Thermodynamics of Condensed Phases: Formula Unit Volume, "V[subscript m]", and the Determination of the Number of Formula Units, "Z", in a Crystallographic Unit Cell

    Science.gov (United States)

    Glasser, Leslie

    2011-01-01

    Formula unit (or molecular) volume, "V[subscript m]", is related to many thermodynamic and physical properties of materials, so that knowledge of "V[subscript m]" is useful in prediction of such properties for known and even hypothetical materials. The symbol "Z" represents the number of formula units in a crystallographic unit cell; "Z" thus…

  3. SU-E-J-274: Responses of Medulloblastoma Cells to Radiation Dosimetric Parameters in Intensity-Modulated Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Park, J [Dept. of Pediatrics, Stanford University School of Medicine, Stanford, CA (United States); Molecular Imaging Program at Stanford, Stanford, CA (United States); Bio-X Program, Stanford, CA (United States); Research Institute of Biomedical Engineering, The Catholic University of Korea, Seoul (Korea, Republic of); Park, J [Proton Therapy Center, National Cancer Center, Goyang (Korea, Republic of); Rogalla, S; Contag, C [Dept. of Pediatrics, Stanford University School of Medicine, Stanford, CA (United States); Molecular Imaging Program at Stanford, Stanford, CA (United States); Bio-X Program, Stanford, CA (United States); Woo, D [Asan Institute for Life Sciences, Asan Medical Center, Seoul (Korea, Republic of); Lee, D [Research Institute of Biomedical Engineering, The Catholic University of Korea, Seoul (Korea, Republic of); Asan Institute for Life Sciences, Asan Medical Center, Seoul (Korea, Republic of); Park, H [Dept. of Radiation Oncology, Ajou University School of Medicine, Suwon (Korea, Republic of); Suh, T [Research Institute of Biomedical Engineering, The Catholic University of Korea, Seoul (Korea, Republic of); Dept. of Biomedical Engineering, The Catholic University of Korea, Seoul (Korea, Republic of)

    2015-06-15

    Purpose: To evaluate radiation responses of the medulloblastoma cell line Daoy in intensity-modulated radiation therapy (IMRT), quantitative variations to variable radiation dosimetic parameters were tracked by bioluminescent images (BLIs). Methods: The luciferase and green fluorescent protein positive Daoy cells were cultured on dishes. The medulloblastoma cells irradiated to different dose rate, interval of fractionated doses, field margin and misalignment, and dose uniformity in IMRT were monitored using bioluminescent images. The cultured cells were placed into a dedicated acrylic phantom to deliver intensity-modulated fluences and calculate accurate predicted dose distribution. The radiation with dose rate from 0.5 Gy/min to 15 Gy/min was irradiated by adjusting monitor unit per minute and source-to-surface distances. The intervals of fractionated dose delivery were changed considering the repair time of double strand breaks (DSB) revealed by straining of gamma-H2AX.The effect of non-uniform doses on the cells were visualized by registering dose distributions and BLIs. The viability according to dosimetric parameters was correlated with bioluminescent intensities for cross-check of radiation responses. Results: The DSB and cell responses due to the first fractionated dose delivery significantly affected final tumor control rather than other parameters. The missing tumor volumes due to the smaller field margin than the tumor periphery or field misalignment caused relapse of cell responses on BLIs. The dose rate and gradient had effect on initial responses but could not bring out the distinguishable killing effect on cancer cells. Conclusion: Visualized and quantified bioluminescent images were useful to correlate the dose distributions with spatial radiation effects on cells. This would derive the effective combination of dose delivery parameters and fractionation. Radiation responses in particular IMRT configuration could be reflected to image based-dose re-optimization.

  4. Zeroing in on red blood cell unit expiry.

    Science.gov (United States)

    Ayyalil, Fathima; Irwin, Greg; Ross, Bryony; Manolis, Michael; Enjeti, Anoop K

    2017-09-20

    Expiry of red blood cell (RBC) units is a significant contributor to wastage of precious voluntary donations. Effective strategies aimed at optimal resource utilization are required to minimize wastage. This retrospective study analyzed the strategic measures implemented to reduce expiry of RBC units in an Australian tertiary regional hospital. The measures, which included inventory rearrangement, effective stock rotation, and the number of emergency courier services required during a 24-month period, were evaluated. There was no wastage of RBC units due to expiry over the 12 months after policy changes. Before these changes, approximately half of RBC wastage (261/511) was due to expiry. The total number of transfusions remained constant in this period and there was no increase in the use of emergency couriers. Policy changes implemented were decreasing the RBC inventory level by one-third and effective stock rotation and using a computerized system to link the transfusion services across the area. Effective stock rotation resulted in a reduction in older blood (>28 days) received in the main laboratory rotated from peripheral hospitals, down from 6%-41% to 0%-2.5%. Age-related expiry of blood products is preventable and can be significantly reduced by improving practices in the pathology service. This study provides proof of principle for "zero tolerance for RBC unit expiry" across a large networked blood banking service. © 2017 The Authors Transfusion published by Wiley Periodicals, Inc. on behalf of AABB.

  5. Cochlear outer hair cell bio-inspired metamaterial with negative effective parameters

    Science.gov (United States)

    Ma, Fuyin; Wu, Jiu Hui; Huang, Meng; Zhang, Siwen

    2016-05-01

    Inspired by periodical outer hair cells (OHCs) and stereocilia clusters of mammalian cochlear, a type of bio-inspired metamaterial with negative effective parameters based on the OHC structure is proposed. With the structural parameters modified and some common engineering materials adopted, the bio-inspired structure design with length scales of millimeter and lightweight is presented, and then, a bending wave bandgap in a favorable low-frequency with width of 55 Hz during the interval 21-76 or 116 Hz during the interval 57-173 Hz is obtained, i.e., the excellent low-frequency acoustic performance turns up. Compared with the local resonance unit in previous literatures, both the size and weight are greatly reduced in our bio-inspired structure. In addition, the lower edge of low-frequency bandgap is reduced by an order of magnitude, almost to the lower limit frequency of the hearing threshold as well, which achieves an important breakthrough on the aspect of low-frequency and great significance on the noise and vibration reduction in low-frequency range.

  6. An annular-furnace boiler for the 660-MW power unit for ultrasupercritical parameters intended for firing brown slagging coals

    Science.gov (United States)

    Serant, F. A.; Belorutskii, I. Yu.; Ershov, Yu. A.; Gordeev, V. V.; Stavskaya, O. I.; Katsel, T. V.

    2013-12-01

    We present the main technical solutions adopted in designing annular-furnace boilers intended for operation on brown coals of the prospective Maikubensk open-cast mine in Kazakhstan as part of 660-MW power units for ultrasupercritical steam conditions. Results from 3D modeling of combustion processes are presented, which clearly show the advantages furnaces of this kind have over a traditional furnace in burning heavily slagging brown coals. The layout of the main and boiler auxiliary equipment in the existing boiler cell of the 500-MW power unit at the Ekibastuz GRES-1 district power station is shown. Appropriate attention is paid to matters concerned with decreasing harmful emissions.

  7. Oral squamous cell carcinoma. Cytometric parameters of prognostic interest.

    Science.gov (United States)

    Saiz-Bustillo, Ramón; Corchero-Martín, Guadalupe; García-Montesinos-Perea, Belén; Gonzalez-Terán, Tomás; Sánchez-Santolino, Sergio

    2005-01-01

    The present study was made in order to find possible prognostic factors in oral squamous cell carcinoma, given that it is a frequent disease (3-4% of all malignant tumors) and is the cause of a high morbidity and mortality which justifies any attempt to contribute something towards the understanding of this pathology. 81 oral squamous cell carcinomas, treated with the same procedure, and retrieved from the archive of the Hospital Universitario Marqués de Valdecilla (Santander) were studied. Flow cytometry was carried out on 67 of the samples. No statistically significant differences were found between the cellular proliferative index and the mitotic index, ploidy and the S-phase factor. Likewise, none of the cytometric variables studied presented any association with the appearance of local relapse, distant metastases or survival. These variables cannot be used as a prognostic factors in squamous cell carcinomas of the oral cavity.

  8. Cell volume and geometric parameters determination in living cells using confocal microscopy and 3D reconstruction

    OpenAIRE

    sprotocols

    2015-01-01

    Authors: David Hevia, Aida Rodriguez-Garcia, Marta Alonso-Gervós, Isabel Quirós-González, Henar M Cimadevilla, Carmen Gómez-Cordovés, Rosa M Sainz & Juan C Mayo ### Abstract The protocol reported here describes a simple, easy, fast and reproducible method aimed to know the geometric parameters of living cells based on confocal laser scanning microscopy combined with 3D reconstruction software. Briefly, the method is based on intrinsic fluorescence properties of acridine orange (AO...

  9. Effects of cell phone use on semen parameters: Results from the MARHCS cohort study in Chongqing, China.

    Science.gov (United States)

    Zhang, Guowei; Yan, Huan; Chen, Qing; Liu, Kaijun; Ling, Xi; Sun, Lei; Zhou, Niya; Wang, Zhi; Zou, Peng; Wang, Xiaogang; Tan, Lu; Cui, Zhihong; Zhou, Ziyuan; Liu, Jinyi; Ao, Lin; Cao, Jia

    2016-05-01

    Epidemiological and experimental evidence for detrimental effects of cell phone use on semen quality is still equivocal. And that recruiting participants from infertility clinic not from general population may raise the possibility of a selection bias. To investigate effects of cell phone use on semen parameters in a general population,We screened and documented the cell phone use information of 794 young men from the Male Reproductive Health in Chongqing College students (MARHCS) cohort study in 2013, followed by 666 and 568 in 2014 and 2015, respectively. In the univariate regression analyses, we found that the daily duration of talking on the cell phone was significantly associated with decreased semen parameters, including sperm concentration [β coefficient=-6.32% per unit daily duration of talking on the cell phone (h); 95% confidence interval (CI), -11.94, -0.34] and total sperm count (-8.23; 95% CI, -14.38, -1.63) in 2013; semen volume (-8.37; 95% CI, -15.93, -0.13) and total sperm count (-16.59; 95% CI, -29.91, -0.73) in 2015]. Internet use via cellular networks was also associated with decreased sperm concentration and total sperm counts in 2013 and decreased semen volume in 2015. Multivariate analyses were used to adjust for the effects of potential confounders, and significant negative associations between internet use and semen parameters remained. Consistent but nonsignificant negative associations between talking on the cell phone and semen parameters persisted throughout the three study years, and the negative association was statistically significant in a mixed model that considered all three years of data on talking on the cell phone and semen quality. Our results showed that certain aspects of cell phone use may negatively affect sperm quality in men by decreasing the semen volume, sperm concentration, or sperm count, thus impairing male fertility.

  10. Mathematical Modeling for the Clarifier Units and Turbidity Parameters in AL-KARAMA Treatment Plant

    Directory of Open Access Journals (Sweden)

    Hayder Mohammed Abdul-Hameed

    2005-01-01

    Full Text Available The high cost of chemical analysis of water has necessitated various researches into finding alternative method of determining portable water quality. This paper is aimed at modelling the turbidity value as a water quality parameter. Mathematical models for turbidity removal were developed based on the relationships between water turbidity and other water criteria. Results showed that the turbidity of water is the cumulative effect of the individual parameters/factors affecting the system. A model equation for the evaluation and prediction of a clarifier’s performance was developed:Model: T = T0(-1.36729 + 0.037101∙10λpH + 0.048928t + 0.00741387∙alkThe developed model will aid the predictive assessment of water treatment plant performance. The limitations of the models are as a result of insufficient variable considered during the conceptualization.

  11. Implementation of Data Drive Heart Rate and Respiratory Rate parameters on a Pediatric Acute Care Unit.

    Science.gov (United States)

    Goel, Veena; Poole, Sarah; Kipps, Alaina; Palma, Jonathan; Platchek, Terry; Pageler, Natalie; Longhurst, Christopher; Sharek, Paul

    2015-01-01

    The majority of hospital physiologic monitor alarms are not clinically actionable and contribute to alarm fatigue. In 2014, The Joint Commission declared alarm safety as a National Patient Safety Goal and urged prompt action by hospitals to mitigate the issue [1]. It has been demonstrated that vital signs in hospitalized children are quite different from currently accepted reference ranges [2]. Implementation of data-driven, age stratified vital sign parameters (Table 1) for alarms in this patient population could reduce alarm frequency.

  12. Comparison of life history parameters for landed and discarded fish captured off the southeastern United States

    OpenAIRE

    Stephen, Jessica A.; Harris, Patrick J; Reichert, Marcel J.M.

    2011-01-01

    Commercial fisheries that are managed with minimum size limits protect small fish of all ages and may affect size-selective mortality by the differential removal of fast growing fish. This differential removal may decrease the average size at age, maturation, or sexual transition of the exploited population. When fishery-independent data are not available, a comparison of life history parameters of landed with those of discarded fish (by regulation) will indicate if differential mortali...

  13. New photosensitizer with phenylenebisthiophene central unit and cyanovinylene 4-nitrophenyl terminal units for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Mikroyannidis, J.A., E-mail: mikroyan@chemistry.upatras.gr [Chemical Technology Laboratory, Department of Chemistry, University of Patras, GR-26500 Patras (Greece); Suresh, P. [Physics Department, Molecular Electronic and Optoelectronic Device Laboratory, JNV University, Jodhpur (Raj.) 342005 (India); Roy, M.S. [Defence Laboratory, Jodhpur (Raj.) 342011 (India); Sharma, G.D., E-mail: sharmagd_in@yahoo.com [Physics Department, Molecular Electronic and Optoelectronic Device Laboratory, JNV University, Jodhpur (Raj.) 342005 (India); R and D Centre for Engineering and Science, Jaipur Engineering College, Kukas, Jaipur (Raj.) (India)

    2011-06-30

    Graphical abstract: A novel dye D was synthesized and used as photosensitizer for quasi solid state dye-sensitized solar cells. A power conversion efficiency of 4.4% was obtained which was improved to 5.52% when diphenylphosphinic acid (DPPA) was added as coadsorbent. Display Omitted Highlights: > A new low band gap photosensitizer with cyanovinylene 4-nitrophenyl terminal units was synthesized. > A power conversion efficiency of 4.4% was obtained for the dye-sensitized solar cell based on this photosensitizer. > The power conversion efficiency of the dye-sensitized solar cell was further improved to 5.52% when diphenylphosphinic acid was added as coadsorbent. - Abstract: A new low band gap photosensitizer, D, which contains 2,2'-(1,4-phenylene) bisthiophene central unit and cyanovinylene 4-nitrophenyl terminal units at both sides was synthesized. The two carboxyls attached to the 2,5-positions of the phenylene ring act as anchoring groups. Dye D was soluble in common organic solvents, showed long-wavelength absorption maximum at 620-636 nm and optical band gap of 1.72 eV. The electrochemical parameters, i.e. the highest occupied molecular orbital (HOMO) (-5.1 eV) and the lowest unoccupied molecular orbital (LUMO) (-3.3 eV) energy levels of D show that this dye is suitable as molecular sensitizer. The quasi solid state dye-sensitized solar cell (DSSC) based on D shows a short circuit current (J{sub sc}) of 9.95 mA/cm{sup 2}, an open circuit voltage (V{sub oc}) of 0.70 V, and a fill factor (FF) of 0.64 corresponding to an overall power conversion efficiency (PCE) of 4.40% under 100 mW/cm{sup 2} irradiation. The overall PCE has been further improved to 5.52% when diphenylphosphinic acid (DPPA) coadsorbent is incorporated into the D solution. This increased PCE has been attributed to the enhancement in the electron lifetime and reduced recombination of injected electrons with the iodide ions present in the electrolyte with the use of DPPA as coadsorbant. The

  14. Unit Cell Structure of Crystal Polytypes in InAs and InSb Nanowires

    DEFF Research Database (Denmark)

    Kriegner, Dominik; Panse, Christian; Mandl, Bernhard

    2011-01-01

    , wurtzite, and 4H polytypes for InAs and InSb nanowires, using X-ray diffraction and transmission electron microscopy. The results are compared to density functional theory calculations. Experiment and theory show that the occurrence of hexagonal bilayers tends to stretch the distances of atomic layers...... parallel to the c axis and to reduce the in-plane distances compared to those in zinc blende. The change of the lattice parameters scales linearly with the hexagonality of the polytype, defined as the fraction of bilayers with hexagonal character within one unit cell....

  15. Parameters extraction for perovskite solar cells based on Lambert W-function

    Directory of Open Access Journals (Sweden)

    Ge Junyu

    2016-01-01

    Full Text Available The behaviors of the solar cells are decided by the device parameters. Thus, it is necessary to extract these parameters to achieve the optimal working condition. Because the five-parameter model of solar cells has the implicit equation of current-voltage relationship, it is difficult to obtain the parameters with conventional methods. In this work, an optimized method is presented to extract device parameters from the actual test data of photovoltaic cell. Based on Lambert W-function, explicit formulation of the model can be deduced. The proposed technique takes suitable method of selecting sample points, which are used to calculate the values of the model parameters. By comparing with the Quasi-Newton method, the results verify accuracy and reliability of this method.

  16. A Powerful Test of the Autoregressive Unit Root Hypothesis Based on a Tuning Parameter Free Statistic

    DEFF Research Database (Denmark)

    Nielsen, Morten Ørregaard

    reflects the parameter chosen to implement the test, and (iii) since the asymptotic distribution depends on d and the test remains consistent for all d > 0, it is possible to analyze the power of the test for different values of d. The usual Phillips-Perron or Dickey-Fuller type tests are indexed...... good size properties, with finite sample power that is higher than that of Breitung's (2002) test and even rivals the (nearly) optimal parametric GLS detrended augmented Dickey-Fuller test with lag length chosen by an information criterion....

  17. Measurement of CuInSe{sub 2} solar cell AC parameters

    Energy Technology Data Exchange (ETDEWEB)

    Deshmukh, M.P.; Nagaraju, J. [Solar Energy and Thermodynamics Laboratory, Department of Instrumentation, Indian Institute of Science, Bangalore 560 012 (India)

    2005-01-31

    The AC parameters (cell capacitance and cell resistance) of Copper Indium Diselenide (CuInSe{sub 2}) solar cell are measured using time-domain technique. The cell capacitance is calculated from the open circuit voltage decay (OCVD) and cell resistance with solar cell I-V characteristics measured in dark. The solar cell exhibits high parallel resistance and low parallel capacitance. The doping concentration and built in voltage are derived from the 1/C{sub P}{sup 2} versus bias voltage graph. The built-in voltage of the solar cell shows good agreement with measurements published in the literature.

  18. Parameter identification for model of T cell proliferation in lymphopenia conditions.

    Science.gov (United States)

    Ayoub, H; Ainseba, B E; Langlais, M; Hogan, T; Callard, R; Seddon, B; Thiébaut, R

    2014-05-01

    The number of T Lymphocytes (T cells) in the body is under homeostatic control. At equilibrium, the majority of naive T cells are non-dividing and express low levels of the surface protein CD44. In conditions of T cell deficiency (lymphopenia), naive T cells enter into a proliferative phase, undergoing cell division accompanied by a subtle change in their surface expression of CD44. In this study, we use a mathematical modelling approach to analyse the proliferative response of transgenic T cells in lymphopenic conditions. Our nonlinear model is composed of ordinary differential equations and partial differential equations structured by age (maturity of cell) and CD44 expression. To better understand the evolution of CD44 expression on the surface of T cells during cell division, we present a numerical analysis to solve a parameter identification problem. Finally, we show the parameters and the simulations that we obtain from the model and compare them to experimental data.

  19. Application of Artificial Bee Colony in Model Parameter Identification of Solar Cells

    Directory of Open Access Journals (Sweden)

    Rongjie Wang

    2015-07-01

    Full Text Available The identification of values of solar cell parameters is of great interest for evaluating solar cell performances. The algorithm of an artificial bee colony was used to extract model parameters of solar cells from current-voltage characteristics. Firstly, the best-so-for mechanism was introduced to the original artificial bee colony. Then, a method was proposed to identify parameters for a single diode model and double diode model using this improved artificial bee colony. Experimental results clearly demonstrate the effectiveness of the proposed method and its superior performance compared to other competing methods.

  20. A survey of short-term and long-term stability of tube parameters in a mammography unit

    Directory of Open Access Journals (Sweden)

    Praskalo Jovica Ž.

    2014-01-01

    Full Text Available In order to set up a successful mammography screening program in the Republic of Srpska, a Siemens Mammomat 1000 X-ray machine was selected for analysis as the said mammography system is widely used in clinical practice. The variations in tube parameters (specific air kerma, high-voltage accuracy and reproducibility, linearity between exposure and dose exposure time were monitored over a five-year period, from 2008 to 2012. In addition, due to observed daily fluctuations for chosen parameters, a series of measurements were performed three times a day within a single-month period (mainly October 2012. The goal of such an experimental set up is to assess short-term and long-term stability of tube parameters in the given mammography unit and to make a comparison between them. The present paper shows how an early detection of significant parameter fluctuations can help eliminate irregularities and optimize the performance of mammography systems. [Projekat Ministarstva nauke Republike Srbije, br. 171007

  1. Mechanical behavior of regular open-cell porous biomaterials made of diamond lattice unit cells.

    Science.gov (United States)

    Ahmadi, S M; Campoli, G; Amin Yavari, S; Sajadi, B; Wauthle, R; Schrooten, J; Weinans, H; Zadpoor, A A

    2014-06-01

    Cellular structures with highly controlled micro-architectures are promising materials for orthopedic applications that require bone-substituting biomaterials or implants. The availability of additive manufacturing techniques has enabled manufacturing of biomaterials made of one or multiple types of unit cells. The diamond lattice unit cell is one of the relatively new types of unit cells that are used in manufacturing of regular porous biomaterials. As opposed to many other types of unit cells, there is currently no analytical solution that could be used for prediction of the mechanical properties of cellular structures made of the diamond lattice unit cells. In this paper, we present new analytical solutions and closed-form relationships for predicting the elastic modulus, Poisson׳s ratio, critical buckling load, and yield (plateau) stress of cellular structures made of the diamond lattice unit cell. The mechanical properties predicted using the analytical solutions are compared with those obtained using finite element models. A number of solid and porous titanium (Ti6Al4V) specimens were manufactured using selective laser melting. A series of experiments were then performed to determine the mechanical properties of the matrix material and cellular structures. The experimentally measured mechanical properties were compared with those obtained using analytical solutions and finite element (FE) models. It has been shown that, for small apparent density values, the mechanical properties obtained using analytical and numerical solutions are in agreement with each other and with experimental observations. The properties estimated using an analytical solution based on the Euler-Bernoulli theory markedly deviated from experimental results for large apparent density values. The mechanical properties estimated using FE models and another analytical solution based on the Timoshenko beam theory better matched the experimental observations. Copyright © 2014 Elsevier Ltd

  2. Retrospective Parameter Estimation and Forecast of Respiratory Syncytial Virus in the United States

    Science.gov (United States)

    Shaman, Jeffrey

    2016-01-01

    Recent studies have shown that systems combining mathematical modeling and Bayesian inference methods can be used to generate real-time forecasts of future infectious disease incidence. Here we develop such a system to study and forecast respiratory syncytial virus (RSV). RSV is the most common cause of acute lower respiratory infection and bronchiolitis. Advanced warning of the epidemic timing and volume of RSV patient surges has the potential to reduce well-documented delays of treatment in emergency departments. We use a susceptible-infectious-recovered (SIR) model in conjunction with an ensemble adjustment Kalman filter (EAKF) and ten years of regional U.S. specimen data provided by the Centers for Disease Control and Prevention. The data and EAKF are used to optimize the SIR model and i) estimate critical epidemiological parameters over the course of each outbreak and ii) generate retrospective forecasts. The basic reproductive number, R0, is estimated at 3.0 (standard deviation 0.6) across all seasons and locations. The peak magnitude of RSV outbreaks is forecast with nearly 70% accuracy (i.e. nearly 70% of forecasts within 25% of the actual peak), four weeks before the predicted peak. This work represents a first step in the development of a real-time RSV prediction system. PMID:27716828

  3. Multi-parameter vital sign database to assist in alarm optimization for general care units.

    Science.gov (United States)

    Welch, James; Kanter, Benjamin; Skora, Brooke; McCombie, Scott; Henry, Isaac; McCombie, Devin; Kennedy, Rosemary; Soller, Babs

    2016-12-01

    Continual vital sign assessment on the general care, medical-surgical floor is expected to provide early indication of patient deterioration and increase the effectiveness of rapid response teams. However, there is concern that continual, multi-parameter vital sign monitoring will produce alarm fatigue. The objective of this study was the development of a methodology to help care teams optimize alarm settings. An on-body wireless monitoring system was used to continually assess heart rate, respiratory rate, SpO2 and noninvasive blood pressure in the general ward of ten hospitals between April 1, 2014 and January 19, 2015. These data, 94,575 h for 3430 patients are contained in a large database, accessible with cloud computing tools. Simulation scenarios assessed the total alarm rate as a function of threshold and annunciation delay (s). The total alarm rate of ten alarms/patient/day predicted from the cloud-hosted database was the same as the total alarm rate for a 10 day evaluation (1550 h for 36 patients) in an independent hospital. Plots of vital sign distributions in the cloud-hosted database were similar to other large databases published by different authors. The cloud-hosted database can be used to run simulations for various alarm thresholds and annunciation delays to predict the total alarm burden experienced by nursing staff. This methodology might, in the future, be used to help reduce alarm fatigue without sacrificing the ability to continually monitor all vital signs.

  4. Estimating a-priori kinematic wave model parameters based on regionalization for flash flood forecasting in the Conterminous United States

    Science.gov (United States)

    Vergara, Humberto; Kirstetter, Pierre-Emmanuel; Gourley, Jonathan J.; Flamig, Zachary L.; Hong, Yang; Arthur, Ami; Kolar, Randall

    2016-10-01

    This study presents a methodology for the estimation of a-priori parameters of the widely used kinematic wave approximation to the unsteady, 1-D Saint-Venant equations for hydrologic flow routing. The approach is based on a multi-dimensional statistical modeling of the macro scale spatial variability of rating curve parameters using a set of geophysical factors including geomorphology, hydro-climatology and land cover/land use over the Conterminous United States. The main goal of this study was to enable prediction at ungauged locations through regionalization of model parameters. The results highlight the importance of regional and local geophysical factors in uniquely defining characteristics of each stream reach conforming to physical theory of fluvial hydraulics. The application of the estimates is demonstrated through a hydrologic modeling evaluation of a deterministic forecasting system performed on 1672 gauged basins and 47,563 events extracted from a 10-year simulation. Considering the mean concentration time of the basins of the study and the target application on flash flood forecasting, the skill of the flow routing simulations is significantly high for peakflow and timing of peakflow estimation, and shows consistency as indicated by the large sample verification. The resulting a-priori estimates can be used in any hydrologic model that employs the kinematic wave model for flow routing. Furthermore, probabilistic estimates of kinematic wave parameters are enabled based on uncertainty information that is generated during the multi-dimensional statistical modeling. More importantly, the methodology presented in this study enables the estimation of the kinematic wave model parameters anywhere over the globe, thus allowing flood modeling in ungauged basins at regional to global scales.

  5. Porous silicon for micro-sized fuel cell reformer units

    Energy Technology Data Exchange (ETDEWEB)

    Presting, H.; Konle, J.; Starkov, V.; Vyatkin, A.; Koenig, U

    2004-04-25

    Randomly, self-organized and ordered anodically etched porous silicon with pore sizes down to hundred nanometers have been fabricated for a variety of automotive applications which range from carrier structures in fuel cell technology up to shower heads for fuel injection in combustion engines. The porous wafers are produced by deep anodic etching which is a very effective and cheap fabrication method compatible to standard Si CMOS fabrication technology. The density of nano- (and micro-) pores can be varied in a wide range by choice of substrate doping level and appropriate electrolyte solution. Surface enlargement up to a factor of 1000 can be achieved [J. Electrochem. Soc. 149 (1) (2002) G70]. After deposition of a catalyst on the inner surface of the pores these structures can be used as an effective catalytic reaction area for the injected hydrocarbons in a micro-steam reformer unit with a small reaction volume. In addition deep anodic etching (DAE) of a pinhole array with very high aspect ratios is demonstrated using a pre-patterned inverted pyramidal array which is produced by lithography and subsequent wet chemical potassium hydroxide (KOH) etch. The structures can also be used as carrier structures for the hydrogen separation membrane of the reforming gas in a reformer unit when a thin layer of palladium is evaporated prior to the anodic etching of the pores. The noble metal foil serves as anode contact during the etch as well as hydrogen separating membrane of the device.

  6. Hematological parameters in association with outcomes in sickle cell anemia patients

    Directory of Open Access Journals (Sweden)

    Okocha Emmanuelchide

    2011-01-01

    Full Text Available Introduction: Sickle cell disease (SCD has a wide range of clinical presentation. We evaluated hematological parameters, which are widely evaluable and assessable, as indices of clinical outcome in SCD. These parameters, although largely established as indices of clinical outcome in other SCD populations, have not been widely evaluated in African patients. Materials and Methods: One hundred and thirty six consecutive stable SCD patients who presented in the sickle cell clinic of a teaching hospital were studied retrospectively using a questionnaire. Hematological parameters of full blood count (FBC for each patient were obtained using a cell counter. FBC parameters such as White blood cell count (WBC were then statistically correlated with complications such as ankle ulcers, osteomylitis and others. A Chi-square text was used to compare frequencies and generate P values. Results: The presence of sickle cell complications was significantly associated with raised white blood cell count (WBC above 11 × 10 >9 /l (P0 = 0.03.The WBC of the patients increased with increasing numbers of complications ( P = 0.07. Mean packed cell volume (PCV and WBC tended toward the reference range for age and sex (in apparently normal individuals as the age at diagnosis of SCD increased. This trend was significant for PCV (P = 0.01. Conclusion: Our data provide additional support that widely evaluable and assessable hematological parameters such as PCV and WBC can be used as indices to predict SCD outcome in African patients. This is likely to impart positively on individualized therapy.

  7. Identification of resting cells by dual-parameter flow cytometry of statin expression and DNA content

    Energy Technology Data Exchange (ETDEWEB)

    Pellicciari, C.; Mangiarotti, R.; Bottone, M.G.; Danova, M. [Univ. of Pavia (Italy); Wang, E. [Jewish General Hospital, Montreal, Quebec (Canada)

    1995-12-01

    Statin, a 57-kDa nuclear protein, has been recognized as a unique marker of quiescent (G{sub 0}) cells; specific monoclonal antibodies (MoAb) against statin have been produced and used to label resting cells in tissue sections and in cultured cells. We present an improved method for the identification of G{sub 0} cells by dual-parameter flow cytometry of statin expression and DNA content. The appropriate technical conditions were set up by using resting and cycling human fibroblasts as a model cell system. Several fixatives proved to be suitable for the immunocytochemical detection of statin; among them, 70% ethanol was selected because this fixation procedure is suitable for DNA staining with intercalating dyes and is routinely used for the immunolabeling of proliferation markers (such as proliferating cell nuclear antigen [PCNA] and Ki-67) and of bromodeoxyuridine (BrdUrd) incorporation. Following cell permeabilization with detergent, exposure to the antistatin antibody (S-44), and indirect fluorescein isothiocyanate immunolabeling, cells were counterstained for DNA with propidium iodide and analyzed by dual-parameter flow cytometry. In cells from several animal sources (rat thymocytes and C6 glioma cells, mouse 3T3 cells, and human MCF-7 cells), under different experimental conditions, the expression of statin was found to correlate inversely with that of PCNA and Ki-67, and with the BrdUrd labeling index. In dual-parameter flow scattergrams, G{sub 0} (statin positive) cells can be discriminated from the potentially cycling (statin negative) G{sub 1} cells, i.e., within a cell fraction having the same DNA content. This approach can be envisaged as a powerful tool both for monitoring changes in the resting cell fraction and for investigating the process of G{sub 0}-G{sub 1} transition in unperturbed and drug-treated cell populations. 48 refs., 5 figs., 1 tab.

  8. Evaluation of Aqua MODIS Collection 6 AOD Parameters for Air Quality Research over the Continental United States

    Directory of Open Access Journals (Sweden)

    J. H. Belle

    2016-10-01

    Full Text Available Satellite-retrieved aerosol optical depth (AOD has become an important predictor of ground-level particulate matter (PM and greatly empowered air pollution research worldwide. We evaluated the AOD parameters included in the Collection 6 aerosol product of the Moderate Resolution Imaging Spectroradiometer (MODIS for two key factors affecting their applications in air quality research—coverage and accuracy—over the continental US. For the high confidence retrievals (QAC 3, the 10 km DB-DT combined AOD has the best coverage nationwide (29.7% of the days in a year in any given 12 km grid cell. While the Eastern US generally had more successful AOD retrievals, the highest spatial coverage of AOD parameters were found in California (>55% and other vegetated parts of the Western US. If lower QAC retrievals were included, the coverage of the 10 km DB AOD was dramatically increased to 49.6%. In the Eastern US, the QAC 3 retrievals of all four AOD parameters are highly correlated with AERONET observations (correlation coefficients between 0.80 and 0.92. In the Western US, positive retrieval errors existed in all MODIS AOD parameters, resulting in lower correlations with AERONET. AOD retrieval errors showed significant dependence on flight geometry, land cover type, and weather conditions. To ensure appropriate use of these AOD values, air quality researchers should carefully balance the needs for coverage and accuracy, and develop additional data screening criteria based on their study design.

  9. Contaminant Transport Parameters for the Groundwater Flow and Contaminant Transport Model of Corrective Action Units 101 and 102: Central and Western Pahute Mesa, Nye County, Nevada, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Drici, Warda

    2003-08-01

    This report documents the analysis of the available transport parameter data conducted in support of the development of a Corrective Action Unit (CAU) groundwater flow model for Central and Western Pahute Mesa: CAUs 101 and 102.

  10. Bifurcations, chaos, and sensitivity to parameter variations in the Sato cardiac cell model

    Science.gov (United States)

    Otte, Stefan; Berg, Sebastian; Luther, Stefan; Parlitz, Ulrich

    2016-08-01

    The dynamics of a detailed ionic cardiac cell model proposed by Sato et al. (2009) is investigated in terms of periodic and chaotic action potentials, bifurcation scenarios, and coexistence of attractors. Starting from the model's standard parameter values bifurcation diagrams are computed to evaluate the model's robustness with respect to (small) parameter changes. While for some parameters the dynamics turns out to be practically independent from their values, even minor changes of other parameters have a very strong impact and cause qualitative changes due to bifurcations or transitions to coexisting attractors. Implications of this lack of robustness are discussed.

  11. The Effects of Continuous One-Arm Kettlebell Swing Training on Physiological Parameters in United States Air Force Personnel: A Pilot Study

    Science.gov (United States)

    2016-11-01

    AFRL-SA-WP-SR-2016-0024 The Effects of Continuous One-Arm Kettlebell Swing Training on Physiological Parameters in United States Air ...November 2016 Air Force Research Laboratory 711th Human Performance Wing U.S. Air Force School of Aerospace Medicine Aeromedical...2016 4. TITLE AND SUBTITLE The Effects of Continuous One-Arm Kettlebell Swing Training on Physiological Parameters in United States Air Force

  12. A reliable parameter to standardize the scoring of stem cell spheres.

    Directory of Open Access Journals (Sweden)

    Xiaochen Zhou

    Full Text Available Sphere formation assay is widely used in selection and enrichment of normal stem cells or cancer stem cells (CSCs, also known as tumor initiating cells (TICs, based on their ability to grow in serum-free suspension culture for clonal proliferation. However, there is no standardized parameter to accurately score the spheres, which should be reflected by both the number and size of the spheres. Here we define a novel parameter, designated as Standardized Sphere Score (SSS, which is expressed by the total volume of selected spheres divided by the number of cells initially plated. SSS was validated in quantification of both tumor spheres from cancer cell lines and embryonic bodies (EB from mouse embryonic stem cells with high sensitivity and reproducibility.

  13. Development of some exergetic parameters for PEM fuel cells for measuring environmental impact and sustainability

    Energy Technology Data Exchange (ETDEWEB)

    Midilli, Adnan [Energy Division, Mechanical Engineering Dept., Nigde University, 51100 Nigde (Turkey); Dincer, Ibrahim [Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ontario (Canada)

    2009-05-15

    This paper presents some new exergy-based parameters for PEM fuel cells to study how some of their operating aspects and system characteristics affect the environment and sustainability, based on some actual and literature data. The exergetic parameters of a PEM fuel cell developed here, in conjunction with environmental impact and sustainable development, are exergy efficiency, exergetic stability factor, environmental benign index and exergetic sustainability index. Any increase in efficiency improves exergetic sustainability. However, any increase in waste exergy ratio, exergy destruction factor, environmental destruction coefficient and environmental destruction index results in an increasing environmental impact of the PEM fuel cell and hence, a decreasing sustainability. Such parameters are expected to quantify how PEM fuel cells become more environmentally benign and sustainable. (author)

  14. Numerical Procedure to Forecast the Tsunami Parameters from a Database of Pre-Simulated Seismic Unit Sources

    Science.gov (United States)

    Jiménez, César; Carbonel, Carlos; Rojas, Joel

    2017-09-01

    We have implemented a numerical procedure to forecast the parameters of a tsunami, such as the arrival time of the front of the first wave and the maximum wave height in real and virtual tidal stations along the Peruvian coast, with this purpose a database of pre-computed synthetic tsunami waveforms (or Green functions) was obtained from numerical simulation of seismic unit sources (dimension: 50 × 50 km2) for subduction zones from southern Chile to northern Mexico. A bathymetry resolution of 30 arc-sec (approximately 927 m) was used. The resulting tsunami waveform is obtained from the superposition of synthetic waveforms corresponding to several seismic unit sources contained within the tsunami source geometry. The numerical procedure was applied to the Chilean tsunami of April 1, 2014. The results show a very good correlation for stations with wave amplitude greater than 1 m, in the case of the Arica tide station an error (from the maximum height of the observed and simulated waveform) of 3.5% was obtained, for Callao station the error was 12% and the largest error was in Chimbote with 53.5%, however, due to the low amplitude of the Chimbote wave (tsunami early warning, where speed is required rather than accuracy, so the results should be taken as preliminary.

  15. Solar Cell Parameters Extraction from a Current-Voltage Characteristic Using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Sanjaykumar J. Patel

    2013-05-01

    Full Text Available The determination of solar cell parameters is very important for the evaluation of the cell performance as well as to extract maximum possible output power from the cell. In this paper, we propose a computational based binary-coded genetic algorithm (GA to extract the parameters (I0, Iph and n for a single diode model of solar cell from its current-voltage (I-V characteristic. The algorithm was implemented using LabVIEW as a programming tool and validated by applying it to the I-V curve synthesized from the literature using reported values. The values of parameters obtained by GA are in good agreement with those of the reported values for silicon and plastic solar cells. change to “After the validation of the program, it was used to extract parameters for an experimental I-V characteristic of 4 × 4 cm2 polycrystalline silicon solar cell measured under 900 W/m. The I-V characteristic obtained using GA shows excellent match with the experimental one.

  16. Super Unit Cells in Aperture-Based Metamaterials

    Directory of Open Access Journals (Sweden)

    Dragan Tanasković

    2015-01-01

    Full Text Available An important class of electromagnetic metamaterials are aperture-based metasurfaces. Examples include extraordinary optical transmission arrays and double fishnets with negative refractive index. We analyze a generalization of such metamaterials where a simple aperture is now replaced by a compound object formed by superposition of two or more primitive objects (e.g., rectangles, circles, and ellipses. Thus obtained “super unit cell” shows far richer behavior than the subobjects that comprise it. We show that nonlocalities introduced by overlapping simple subobjects can be used to produce large deviations of spectral dispersion even for small additive modifications of the basic geometry. Technologically, some super cells may be fabricated by simple spatial shifting of the existing photolithographic masks. In our investigation we applied analytical calculations and ab initio finite element modeling to prove the possibility to tailor the dispersion including resonances for plasmonic nanocomposites by adjusting the local geometry and exploiting localized interactions at a subwavelength level. Any desired form could be defined using simple primitive objects, making the situation a geometrical analog of the case of series expansion of a function. Thus an additional degree of tunability of metamaterials is obtained. The obtained designer structures can be applied in different fields like waveguiding and sensing.

  17. Correlated parameter fit of arrhenius model for thermal denaturation of proteins and cells.

    Science.gov (United States)

    Qin, Zhenpeng; Balasubramanian, Saravana Kumar; Wolkers, Willem F; Pearce, John A; Bischof, John C

    2014-12-01

    Thermal denaturation of proteins is critical to cell injury, food science and other biomaterial processing. For example protein denaturation correlates strongly with cell death by heating, and is increasingly of interest in focal thermal therapies of cancer and other diseases at temperatures which often exceed 50 °C. The Arrhenius model is a simple yet widely used model for both protein denaturation and cell injury. To establish the utility of the Arrhenius model for protein denaturation at 50 °C and above its sensitivities to the kinetic parameters (activation energy E a and frequency factor A) were carefully examined. We propose a simplified correlated parameter fit to the Arrhenius model by treating E a, as an independent fitting parameter and allowing A to follow dependently. The utility of the correlated parameter fit is demonstrated on thermal denaturation of proteins and cells from the literature as a validation, and new experimental measurements in our lab using FTIR spectroscopy to demonstrate broad applicability of this method. Finally, we demonstrate that the end-temperature within which the denaturation is measured is important and changes the kinetics. Specifically, higher E a and A parameters were found at low end-temperature (50 °C) and reduce as end-temperatures increase to 70 °C. This trend is consistent with Arrhenius parameters for cell injury in the literature that are significantly higher for clonogenics (45-50 °C) vs. membrane dye assays (60-70 °C). Future opportunities to monitor cell injury by spectroscopic measurement of protein denaturation are discussed.

  18. Evaluating alternate models to estimate genetic parameters of calving traits in United Kingdom Holstein-Friesian dairy cattle

    Directory of Open Access Journals (Sweden)

    Eaglen Sophie A E

    2012-07-01

    Full Text Available Abstract Background The focus in dairy cattle breeding is gradually shifting from production to functional traits and genetic parameters of calving traits are estimated more frequently. However, across countries, various statistical models are used to estimate these parameters. This study evaluates different models for calving ease and stillbirth in United Kingdom Holstein-Friesian cattle. Methods Data from first and later parity records were used. Genetic parameters for calving ease, stillbirth and gestation length were estimated using the restricted maximum likelihood method, considering different models i.e. sire (−maternal grandsire, animal, univariate and bivariate models. Gestation length was fitted as a correlated indicator trait and, for all three traits, genetic correlations between first and later parities were estimated. Potential bias in estimates was avoided by acknowledging a possible environmental direct-maternal covariance. The total heritable variance was estimated for each trait to discuss its theoretical importance and practical value. Prediction error variances and accuracies were calculated to compare the models. Results and discussion On average, direct and maternal heritabilities for calving traits were low, except for direct gestation length. Calving ease in first parity had a significant and negative direct-maternal genetic correlation. Gestation length was maternally correlated to stillbirth in first parity and directly correlated to calving ease in later parities. Multi-trait models had a slightly greater predictive ability than univariate models, especially for the lowly heritable traits. The computation time needed for sire (−maternal grandsire models was much smaller than for animal models with only small differences in accuracy. The sire (−maternal grandsire model was robust when additional genetic components were estimated, while the equivalent animal model had difficulties reaching convergence. Conclusions

  19. Cell Churches and Stem Cell Marketing in South Korea and the United States.

    Science.gov (United States)

    Sipp, Douglas

    2016-05-23

    The commercial provision of putative stem cell-based medical interventions in the absence of conclusive evidence of safety and efficacy has formed the basis of an unregulated industry for more than a decade. Many clinics offering such supposed stem cell treatments include statements about the 'ethical' nature of somatic (often colloquially referred to as 'adult' stem cells) stem cells, in specific contrast to human embryonic stem cells (hESCs), which have been the subject of intensive political, legal, and religious controversy since their first derivation in 1998. Christian groups-both Roman Catholic and evangelical Protestant-in many countries have explicitly promoted the medical potential and current-day successes in the clinical application of somatic stem cells, lending indirect support to the activities of businesses marketing stem cells ahead of evidence. In this article, I make a preliminary examination of how the structures and belief systems of certain churches in South Korea and the United States, both of which are home to significant stem cell marketing industries, has complemented other factors, including national biomedical funding initiatives, international economic rivalries, permissive legal structures, which have lent impetus to a problematic and often exploitative sector of biomedical commerce.

  20. Identification of biomolecule mass transport and binding rate parameters in living cells by inverse modeling

    Directory of Open Access Journals (Sweden)

    Shirmohammadi Adel

    2006-10-01

    Full Text Available Abstract Background Quantification of in-vivo biomolecule mass transport and reaction rate parameters from experimental data obtained by Fluorescence Recovery after Photobleaching (FRAP is becoming more important. Methods and results The Osborne-Moré extended version of the Levenberg-Marquardt optimization algorithm was coupled with the experimental data obtained by the Fluorescence Recovery after Photobleaching (FRAP protocol, and the numerical solution of a set of two partial differential equations governing macromolecule mass transport and reaction in living cells, to inversely estimate optimized values of the molecular diffusion coefficient and binding rate parameters of GFP-tagged glucocorticoid receptor. The results indicate that the FRAP protocol provides enough information to estimate one parameter uniquely using a nonlinear optimization technique. Coupling FRAP experimental data with the inverse modeling strategy, one can also uniquely estimate the individual values of the binding rate coefficients if the molecular diffusion coefficient is known. One can also simultaneously estimate the dissociation rate parameter and molecular diffusion coefficient given the pseudo-association rate parameter is known. However, the protocol provides insufficient information for unique simultaneous estimation of three parameters (diffusion coefficient and binding rate parameters owing to the high intercorrelation between the molecular diffusion coefficient and pseudo-association rate parameter. Attempts to estimate macromolecule mass transport and binding rate parameters simultaneously from FRAP data result in misleading conclusions regarding concentrations of free macromolecule and bound complex inside the cell, average binding time per vacant site, average time for diffusion of macromolecules from one site to the next, and slow or rapid mobility of biomolecules in cells. Conclusion To obtain unique values for molecular diffusion coefficient and

  1. Parameter Optimization of Single-Diode Model of Photovoltaic Cell Using Memetic Algorithm

    Directory of Open Access Journals (Sweden)

    Yourim Yoon

    2015-01-01

    Full Text Available This study proposes a memetic approach for optimally determining the parameter values of single-diode-equivalent solar cell model. The memetic algorithm, which combines metaheuristic and gradient-based techniques, has the merit of good performance in both global and local searches. First, 10 single algorithms were considered including genetic algorithm, simulated annealing, particle swarm optimization, harmony search, differential evolution, cuckoo search, least squares method, and pattern search; then their final solutions were used as initial vectors for generalized reduced gradient technique. From this memetic approach, we could further improve the accuracy of the estimated solar cell parameters when compared with single algorithm approaches.

  2. Parameter extraction of an organic solar cell using asymptotic estimation and Lambert W function

    Science.gov (United States)

    Bǎrar, Ana; Mǎnǎilǎ-Maximean, Doina; Dǎnilǎ, Octavian; Vlǎdescu, Marian

    2016-12-01

    A theoretical characterization of an organic solar cell has been realized based on its equivalent model and an I-V curve corresponding to ITO/PEDOT/MEH-PPV:PCBM(1:4)/LiF/Al cell, taken from the literature. The parameters of the equivalent model have been determined using two methods: the approximation method and the Lambert W function. For the considered curve, the parameter values that have been obtained are similar to the results presented in literature. It has also been shown that the Lambert W function presents a considerably smaller error compared to the approximation method.

  3. EVALUATION OF ANAEMIA USING RED CELL AND RETICULOCYTE PARAMETERS USING AUTOMATED HAEMATOLOGY ANALYSER

    Directory of Open Access Journals (Sweden)

    Vidyadhar Rao

    2016-06-01

    Full Text Available Use of current models of Automated Haematology Analysers help in calculating the haemoglobin contents of the mature Red cells, Reticulocytes and percentages of Microcytic and hypochromic Red cells. This has helped the clinician in reaching early diagnosis and management of Different haemopoietic disorders like Iron Deficiency Anaemia, Thalassaemia and anaemia of chronic diseases. AIM This study is conducted using an Automated Haematology Analyser to evaluate anaemia using the Red Cell and Reticulocyte parameters. Three types of anaemia were evaluated; iron deficiency anaemia, anaemia of long duration and anaemia associated with chronic disease and Iron deficiency. MATERIALS AND METHODS The blood samples were collected from 287 adult patients with anaemia differentiated depending upon their iron status, haemoglobinopathies and inflammatory activity. Iron deficiency anaemia (n=132, anaemia of long duration (ACD, (n=97 and anaemia associated with chronic disease with iron deficiency (ACD Combi, (n=58. Microcytic Red cells, hypochromic red cells percentage and levels of haemoglobin in reticulocytes and matured RBCs were calculated. The accuracy of the parameters was analysed using receiver operating characteristic analyser to differentiate between the types of anaemia. OBSERVATIONS AND RESULTS There was no difference in parameters between the iron deficiency group or anaemia associated with chronic disease and iron deficiency. The hypochromic red cells percentage was the best parameter in differentiating anaemia of chronic disease with or without absolute iron deficiency with a sensitivity of 72.7% and a specificity of 70.4%. CONCLUSIONS The parameters of red cells and reticulocytes were of reasonably good indicators in differentiating the absolute iron deficiency anaemia with chronic disease.

  4. A Novel Three-parameter Flow Cytornetric Analysis for Cell Cycle

    Institute of Scientific and Technical Information of China (English)

    FENGYongdong; TAODeding; QINJichao; GAOChun; SHENManli; LENGYan; YUYuan; GONGJianping

    2005-01-01

    Objective: To set up a three-parameter method for cell cycle analysis by two-laser flow cytometer, which can detect two types of cyclin plus DNA content in one measurement, and that analyze unscheduled expression of cyclins. Methods: Three-color fluorescence was used for analysis of two types of cyclins and DNA content simultaneously in individual cells by two-laser flow cytometry. MOLT-4 cell swere used to study the expression of major cyclins in mammalian cells. A Triton-X100 permeabilization procedure was optimized for detection of two types of cyclins. One cyclin was stained directly with a FITC-conjugated monoclonal antibody (mAb), and the other, indirectly with RPE-Cy5-conjugated secondary antibody, while DNA was stained with the fluorochrome DAPI. mAMSA and mimosine treated MOLT-4 cells were used to test this three-parameter method. Results: Permeabilization with 0.5% Triton-X100 in PBS containing 1% BSA for 5 rain on ice provided optimal conditions for the simultaneous labelling of two cyclins plus DNA in single cells. It was found that the emission spectrum of the three dyes (DAPI, FITC and RPE-Cy5) could be measured with no compensation. Based on cyclinA/cyclinE/DNA flow cytometric analysis, asynchronously growing MOLT-4 cells could be divided into 6 compartments (Glo, Gle, G11,S, G2, and M) simultaneously, allowing for analysis of cell cycle phase specific perturbations without the necessity of cell synchronization. Unscheduled cyclin B1 expression was observed in G1 cells treated with mimosine and cyclin E in G2 cells treated with mAMSA. We found that unscheduled cyclin expression paralleled expected cyclin expression. Conclusion: Thus, three-color FCM analysis of cells may not only be applied to measure unscheduled vs. expected cyclin expression but may also be used to estimate the fraction of cycling cells in up to 6 cell populations.

  5. Single fibre and multifibre unit cell analysis of strength and cracking of unidirectional composites

    DEFF Research Database (Denmark)

    Wang, H.W.; Zhou, H.W.; Mishnaevsky, Leon

    2009-01-01

    Numerical simulations of damage evolution in composites reinforced with single and multifibre are presented. Several types of unit cell models are considered: single fibre unit cell, multiple fibre unit cell with one and several damageable sections per fibres, unit cells with homogeneous...... damageable parts in composites (matrix cracks, fibre/matrix interface damage and fibre fracture) was observed in the simulations. The strength of interface begins to influence the deformation behaviour of the cell only after the fibre is broken. In this case, the higher interface layer strength leads...... and inhomogeneous interfaces, etc. Two numerical damage models, cohesive elements, and damageable layers are employed for the simulation of the damage evolution in single fibre and multifibre unit cells. The two modelling approaches were compared and lead to the very close results. Competition among the different...

  6. An explicit algorithm for fully flexible unit cell simulation with recursive thermostat chains.

    Science.gov (United States)

    Jung, Kwangsub; Cho, Maenghyo

    2008-10-28

    Through the combination of the recursive multiple thermostat (RMT) Nose-Poincare and Parrinello-Rahman methods, the recursive multiple thermostat chained fully flexible unit cell (RMT-NsigmaT) molecular dynamics method is proposed for isothermal-isobaric simulation. The RMT method is known to have the advantage of achieving the ergodicity that is required for canonical sampling of the harmonic oscillator. Thus, an explicit time integration algorithm is developed for RMT-NsigmaT. We examine the ergodicity for various parameters of RMT-NsigmaT using bulk and thin film structures with different numbers of copper atoms and thicknesses in various environments. Through the numerical simulations, we conclude that the RMT-NsigmaT method is advantageous in the cases of lower temperatures.

  7. A Central Composite Face-Centered Design for Parameters Estimation of PEM Fuel Cell Electrochemical Model

    OpenAIRE

    Khaled MAMMAR; CHAKER, Abdelkader

    2013-01-01

    In this paper, a new approach based on Experimental of design methodology (DoE) is used to estimate the optimal of unknown model parameters proton exchange membrane fuel cell (PEMFC). This proposed approach combines the central composite face-centered (CCF) and numerical PEMFC electrochemical. Simulation results obtained using electrochemical model help to predict the cell voltage in terms of inlet partial pressures of hydrogen and oxygen, stack temperature, and operating current. The value o...

  8. Automated assembling of single fuel cell units for use in a fuel cell stack

    Science.gov (United States)

    Jalba, C. K.; Muminovic, A.; Barz, C.; Nasui, V.

    2017-05-01

    The manufacturing of PEMFC stacks (POLYMER ELEKTROLYT MEMBRAN Fuel Cell) is nowadays still done by hand. Over hundreds of identical single components have to be placed accurate together for the construction of a fuel cell stack. Beside logistic problems, higher total costs and disadvantages in weight the high number of components produce a higher statistic interference because of faulty erection or material defects and summation of manufacturing tolerances. The saving of costs is about 20 - 25 %. Furthermore, the total weight of the fuel cells will be reduced because of a new sealing technology. Overall a one minute cycle time has to be aimed per cell at the manufacturing of these single components. The change of the existing sealing concept to a bonded sealing is one of the important requisites to get an automated manufacturing of single cell units. One of the important steps for an automated gluing process is the checking of the glue application by using of an image processing system. After bonding the single fuel cell the sealing and electrical function can be checked, so that only functional and high qualitative cells can get into further manufacturing processes.

  9. The optimal parameter design for a welding unit of manufacturing industry by Taguchi method and computer simulation

    Energy Technology Data Exchange (ETDEWEB)

    Zahraee, S.M.; Chegeni, A.; Toghtamish, A.

    2016-07-01

    Manufacturing systems include a complicated combination of resources, such as materials, labors, and machines. Hence, when the manufacturing systems are faced with a problem related to the availability of resources it is difficult to identify the root of the problem accurately and effectively. Managers and engineers in companies are trying to achieve a robust production line based on the maximum productivity. The main goal of this paper is to design a robust production line, taking productivity into account in the selected manufacturing industry. This paper presents the application of Taguchi method along with computer simulation for finding an optimum factor setting for three controllable factors, which are a number of welding machines, hydraulic machines, and cutting machines by analyzing the effect of noise factors in a selected manufacturing industry. Based on the final results, the optimal design parameter of welding unit of in the selected manufacturing industry will be obtained when factor A is located at level 2 and B and C are located at level 1. Therefore, maximum productive desirability is achieved when the number of welding machines, hydraulic machines, and cutting machines is equal to 17, 2, and 1, respectively. This paper has a significant role in designing a robust production line by considering the lowest cost and timely manner based on the Taguchi method. (Author)

  10. The optimal parameter design for a welding unit of manufacturing industry by Taguchi method and computer simulation

    Directory of Open Access Journals (Sweden)

    Seyed Mojib Zahraee

    2016-05-01

    Full Text Available Purpose: Manufacturing systems include a complicated combination of resources, such as materials, labors, and machines. Hence, when the manufacturing systems are faced with a problem related to the availability of resources it is difficult to identify the root of the problem accurately and effectively. Managers and engineers in companies are trying to achieve a robust production line based on the maximum productivity. The main goal of this paper is to design a robust production line, taking productivity into account in the selected manufacturing industry. Design/methodology/approach: This paper presents the application of Taguchi method along with computer simulation for finding an optimum factor setting for three controllable factors, which are a number of welding machines, hydraulic machines, and cutting machines by analyzing the effect of noise factors in a selected manufacturing industry. Findings and Originality/value: Based on the final results, the optimal design parameter of welding unit of in the selected manufacturing industry will be obtained when factor A is located at level 2 and B and C are located at level 1. Therefore, maximum productive desirability is achieved when the number of welding machines, hydraulic machines, and cutting machines is equal to 17, 2, and 1, respectively. This paper has a significant role in designing a robust production line by considering the lowest cost and timely manner based on the Taguchi method.

  11. Four-Parameter white blood cell differential counting based on light scattering measurements

    NARCIS (Netherlands)

    Terstappen, L.W.M.M.; Grooth, de B.G.; Visscher, K.; Kouterik, F.A.; Greve, J.

    1988-01-01

    Measurement of the depolarized orthogonal light scattering in flow cytometry enables one to discriminate human eosinephilic granulocytes from neutrophilic granulocytes. We use this method to perform a four-parameter differential white blood cell analysis. A simple flow cytometer was built equipped

  12. A Central Composite Face-Centered Design for Parameters Estimation of PEM Fuel Cell Electrochemical Model

    Directory of Open Access Journals (Sweden)

    Khaled MAMMAR

    2013-11-01

    Full Text Available In this paper, a new approach based on Experimental of design methodology (DoE is used to estimate the optimal of unknown model parameters proton exchange membrane fuel cell (PEMFC. This proposed approach combines the central composite face-centered (CCF and numerical PEMFC electrochemical. Simulation results obtained using electrochemical model help to predict the cell voltage in terms of inlet partial pressures of hydrogen and oxygen, stack temperature, and operating current. The value of the previous model and (CCF design methodology is used for parametric analysis of electrochemical model. Thus it is possible to evaluate the relative importance of each parameter to the simulation accuracy. However this methodology is able to define the exact values of the parameters from the manufacture data. It was tested for the BCS 500-W stack PEM Generator, a stack rated at 500 W, manufactured by American Company BCS Technologies FC.

  13. The influence of printing parameters on cell survival rate and printability in microextrusion-based 3D cell printing technology.

    Science.gov (United States)

    Zhao, Yu; Li, Yang; Mao, Shuangshuang; Sun, Wei; Yao, Rui

    2015-11-02

    Three-dimensional (3D) cell printing technology has provided a versatile methodology to fabricate cell-laden tissue-like constructs and in vitro tissue/pathological models for tissue engineering, drug testing and screening applications. However, it still remains a challenge to print bioinks with high viscoelasticity to achieve long-term stable structure and maintain high cell survival rate after printing at the same time. In this study, we systematically investigated the influence of 3D cell printing parameters, i.e. composition and concentration of bioink, holding temperature and holding time, on the printability and cell survival rate in microextrusion-based 3D cell printing technology. Rheological measurements were utilized to characterize the viscoelasticity of gelatin-based bioinks. Results demonstrated that the bioink viscoelasticity was increased when increasing the bioink concentration, increasing holding time and decreasing holding temperature below gelation temperature. The decline of cell survival rate after 3D cell printing process was observed when increasing the viscoelasticity of the gelatin-based bioinks. However, different process parameter combinations would result in the similar rheological characteristics and thus showed similar cell survival rate after 3D bioprinting process. On the other hand, bioink viscoelasticity should also reach a certain point to ensure good printability and shape fidelity. At last, we proposed a protocol for 3D bioprinting of temperature-sensitive gelatin-based hydrogel bioinks with both high cell survival rate and good printability. This research would be useful for biofabrication researchers to adjust the 3D bioprinting process parameters quickly and as a referable template for designing new bioinks.

  14. The impact of Ag nanoparticles on the parameters of DSS- cells sensitized by Z907

    Science.gov (United States)

    Ibrayev, N. Kh; Aimukhanov, A. K.; Zeinidenov, A. K.

    2016-02-01

    Research of influence of Ag nanoparticles are in-process undertaken on absorption and on parameters CVC DSS-cells sensitized Z907. It is set that with the height of concentration Ag nanoparticles in tape to the concentration of 0.3% wt%. the absorbance of Z907 in a short-wave stripe grew to the value 1,6. It is set that under reaching the concentration of Ag nanoparticles in the cell of value the 0.3% wt%. efficiency of cell increased to 2.2%.

  15. Improvement of parameters in a-Si(p)/c-Si(n)/a-Si(n) solar cells

    Science.gov (United States)

    Moustafa Bouzaki, Mohammed; Aillerie, Michel; Ould Saad Hamady, Sidi; Chadel, Meriem; Benyoucef, Boumediene

    2016-10-01

    We analyzed and discussed the influence of thickness and doping concentration of the different layers in a-Si(p)/c-Si(n)/a-Si(n) photovoltaic (PV) cells with the aim of increasing its efficiency while decreasing its global cost. Compared to the efficiency of a standard marketed PV cell, elaborated with a ZnO transparent conductive oxide (TCO) layer but without Back Surface Field (BSF) layer, an optimization of the thickness and dopant concentration of both the emitter a-Si(p) and absorber c-Si(n) layers will gain about 3% in the global efficiency of the cell. The results also reveal that with introduction of the third layer, i.e. the BSF layer, the efficiency always achieves values above 20% and all other parameters of the cell, such as the open-circuit voltage, the short-circuit current and the fill-factor, are strongly affected by the thickness and dopant concentration of the layers. The values of all parameters are given and discussed in the paper. Thereby, the simulation results give for an optimized a-Si(p)/c-Si(n)/a-Si(n) PV cells the possibility to decrease the thickness of the absorber layer down to 50 μm which is lower than in the state-of-the-art. This structure of the cell achieves suitable properties for high efficiency, cost-effectiveness and reliable heterojunction (HJ) solar cell applications.

  16. Evaluation of Experimental Parameters in the Accelerated Aging of Closed-Cell Foam Insulation

    Energy Technology Data Exchange (ETDEWEB)

    Stovall, Therese K [ORNL; Vanderlan, Michael [ORNL; Atchley, Jerald Allen [ORNL

    2012-12-01

    The thermal conductivity of many closed-cell foam insulation products changes over time as production gases diffuse out of the cell matrix and atmospheric gases diffuse into the cells. Thin slicing has been shown to be an effective means of accelerating this process in such a way as to produce meaningful results. Efforts to produce a more prescriptive version of the ASTM C1303 standard test method led to the ruggedness test described here. This test program included the aging of full size insulation specimens for time periods of five years for direct comparison to the predicted results. Experimental parameters under investigation include: slice thickness, slice origin (at the surface or from the core of the slab), thin slice stack composition, product facings, original product thickness, product density, and product type. The test protocol has been completed and this report provides a detailed evaluation of the impact of the test parameters on the accuracy of the 5-year thermal conductivity prediction.

  17. Measurement of Solar Cell Parameters with Dark Forward I-V Characteristics

    Directory of Open Access Journals (Sweden)

    J. Salinger

    2006-01-01

    Full Text Available The grade of a solar cell depends mainly on the quality of the starting material. During the production of this material, many impurities are left in the bulk material and form defect levels in the band-gap, which act as generation-recombination centers or charge carrier traps. These levels influence the efficiency of solar cells. Therefore knowledge of the parameters of these levels, e.g., energy position, capture cross section and concentration, is very useful for solar cell engineering. In this paper emphasis is placed on a simple and fast method for obtaining these parameters, namely measurements of dark characteristics. Preliminary results are introduced, together with the difficulties and limits of this method. 

  18. Cardiac tissue engineering: cell seeding, cultivation parameters, and tissue construct characterization.

    Science.gov (United States)

    Carrier, R L; Papadaki, M; Rupnick, M; Schoen, F J; Bursac, N; Langer, R; Freed, L E; Vunjak-Novakovic, G

    1999-09-01

    Cardiac tissue engineering has been motivated by the need to create functional tissue equivalents for scientific studies and cardiac tissue repair. We previously demonstrated that contractile cardiac cell-polymer constructs can be cultivated using isolated cells, 3-dimensional scaffolds, and bioreactors. In the present work, we examined the effects of (1) cell source (neonatal rat or embryonic chick), (2) initial cell seeding density, (3) cell seeding vessel, and (4) tissue culture vessel on the structure and composition of engineered cardiac muscle. Constructs seeded under well-mixed conditions with rat heart cells at a high initial density ((6-8) x 10(6) cells/polymer scaffold) maintained structural integrity and contained macroscopic contractile areas (approximately 20 mm(2)). Seeding in rotating vessels (laminar flow) rather than mixed flasks (turbulent flow) resulted in 23% higher seeding efficiency and 20% less cell damage as assessed by medium lactate dehydrogenase levels (p laminar and dynamic, yielded constructs with a more active, aerobic metabolism as compared to constructs cultured in mixed or static flasks. After 1-2 weeks of cultivation, tissue constructs expressed cardiac specific proteins and ultrastructural features and had approximately 2-6 times lower cellularity (p < 0.05) but similar metabolic activity per unit cell when compared to native cardiac tissue.

  19. Map service: United States Decadal Production History Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map service displays present and past oil and gas production in the United States, as well as the location and intensity of exploratory drilling outside...

  20. The selection of light emitting diode irradiation parameters for stimulation of human mesenchymal stem cells proliferation

    Science.gov (United States)

    Lewandowski, Rafał; Trafny, ElŻbieta A.; Stepińska, Małgorzata; Gietka, Andrzej; Kotowski, Paweł; Dobrzyńska, Monika; Łapiński, Mariusz P.

    2016-12-01

    Human mesenchymal stem cells (hMSCs) with their vast differentiation potential are very useful for cell-based regenerative medicine. To achieve sufficient numbers of cells for tissue engineering, many different methods have been used to reach the effective increase of cell proliferation. Low-energy red light provided by light emitting diodes (LEDs) have been recently introduced as a method that promoted biomodulation and proliferation of hMSCs in vitro. The purpose of this study was to find the optimum stimulatory dosimetric parameters of LED (630 nm) irradiation on the hMSCs proliferation. The energy density was 2, 3, 4, 10, 20 J/cm2 and the power density used was 7, 17 or 30 mW/cm2. Human MSCs were irradiated with single or triple exposures daily at room temperature and the cell proliferation rate was evaluated during nine days after irradiation. The results showed that after irradiation 4 J/cm2 and 17 mW/cm2 at a single dose the proliferation rate of hMSCs increased on day 5 and 9 (13% and 7%, respectively) when compared to nonirradiated cells. However, triple LED irradiation under the same parameters resulted in the decline in the cell proliferation rate on day 5, but the proliferation rate was at the same level on day 9, when compared with the cell proliferation after irradiation with a single dose. The effect of a single dose irradiation with 4 J/cm2 and 17 mW/cm2 on the proliferation of cells was the highest when the cells were irradiated in phosphate-buffered saline (PBS) instead of MSCGM culture medium.

  1. Correlation between Dynamic Spiral-CT Enhancement Parameters and Tumor Angiogenesis in Renal Cell Carcinomas

    Institute of Scientific and Technical Information of China (English)

    Jinhong Wang; Weixia Chen; Xiuhui Zhang; Pengqiu Min; Rongbo Liu; Hengxuan Yang

    2005-01-01

    OBJECTIVE To prospectively investigate the correlation between the enhancement parameters of a dynamic-CT (D-CT) scan for renal cell carcinomas (RCC) and the carcinoma tissue microvessel density (MVD) in renal cell carcinomas (RCC).METHODS Twenty-four cases of renal cell carcinoma verifyied by histopathology were scanned via dynamic-CT, followed by a whole kidney scan. Enhancement parameters were derived as follows .The slope of the contrast media uptake curve (S), area under the curve(AR), the density difference before and after tissue enhancement (△HU) and tissue blood ratio (TBR) were calculated for all lesions. Time-density curve types were ranked from the lowest to the highest of the slope of the contrast media uptake curve (S) as type A, B and C. Pathologic slides corresponding to the CT imagings were subjected to CD34 monoclonal antibodies, then were evaluated with an image analyzer to count hot spots of MVD. By using the Spearman rank correlation tests, statistical analysis was performed to determine the strength of the relationship between enhancement parameters and MVD determinations.RESULTS The carcinoma tissue MVD showed a direct correlation with the enhancement parameters of D-CT (r=0.54, r=0.62, r=0.55, r=0.64, r=0.44,P< 0.05). Moreover the S, △HU, TBR and type curves all demonstrated a strong correlation with the MVD. By analyzing the various enhancement parameters of the time-density curves, the relationship between the enhancement CT parameters corresponding to the tumor's MVD was identified.CONCLUSION A dynamic spiral-CT scan may be a helpful method as a measurement of tumor angiogenesis in vivo in RCC.

  2. Surface and Interface Properties of 10–12 Unit Cells Thick Sputter Deposited Epitaxial CeO2 Films

    Directory of Open Access Journals (Sweden)

    L. V. Saraf

    2008-01-01

    Full Text Available Ultrathin and continuous epitaxial films with relaxed lattice strain can potentially maintain more of its bulk physical and chemical properties and are useful as buffer layers. We study surface, interface, and microstructural properties of ultrathin (∼10–12 unit cells thick epitaxial ceria films grown on single crystal YSZ substrates. The out-of -plane and in-plane lattice parameters indicate relaxation in the continuous film due to misfit dislocations seen by high-resolution transmission electron microscopy (HRTEM and substrate roughness of ∼1-2 unit cells, confirmed by atomic force microscopy and HRTEM. A combination of secondary sputtering, lattice mismatch, substrate roughness, and surface reduction creating secondary phase was likely the cause of surface roughness which should be reduced to a minimum level for effective use of it as buffer layers.

  3. Techno-economic analysis of fuel cell auxiliary power units as alternative to idling

    Science.gov (United States)

    Jain, Semant; Chen, Hsieh-Yeh; Schwank, Johannes

    This paper presents a techno-economic analysis of fuel-cell-based auxiliary power units (APUs), with emphasis on applications in the trucking industry and the military. The APU system is intended to reduce the need for discretionary idling of diesel engines or gas turbines. The analysis considers the options for on-board fuel processing of diesel and compares the two leading fuel cell contenders for automotive APU applications: proton exchange membrane fuel cell and solid oxide fuel cell. As options for on-board diesel reforming, partial oxidation and auto-thermal reforming are considered. Finally, using estimated and projected efficiency data, fuel consumption patterns, capital investment, and operating costs of fuel-cell APUs, an economic evaluation of diesel-based APUs is presented, with emphasis on break-even periods as a function of fuel cost, investment cost, idling time, and idling efficiency. The analysis shows that within the range of parameters studied, there are many conditions where deployment of an SOFC-based APU is economically viable. Our analysis indicates that at an APU system cost of 100 kW -1, the economic break-even period is within 1 year for almost the entire range of conditions. At 500 kW -1 investment cost, a 2-year break-even period is possible except for the lowest end of the fuel consumption range considered. However, if the APU investment cost is 3000 kW -1, break-even would only be possible at the highest fuel consumption scenarios. For Abram tanks, even at typical land delivered fuel costs, a 2-year break-even period is possible for APU investment costs as high as 1100 kW -1.

  4. Red cell parameters in infant and children from the Arabian Peninsula.

    Science.gov (United States)

    Mekaini, Lolowa A Al; Denic, Srdjan; Jabri, Omar N Al; Narchi, Hassib; Souid, Abdul-Kader; Al-Hammadi, Suleiman

    2015-01-01

    α+-Thalassemia trait and iron deficiency anemia are frequent causes of microcytosis and a common diagnostic challenge in Arabian children. In this study, their prevalences and effects on the red cell parameters were evaluated in 28,457 children aged one day to 6 years. α+-Thalassemia trait was considered to be present when mean cell volume (MCV) was iron deficiency anemia when red cell distribution width (RDW) was >14.5%. The prevalence of α+-thalassemia trait was 15.7% (502/3,191), which was similar to previously reported values for adults (9-14%). Iron deficiency anemia peaked at 7 months (53%) and then declined at a rate of 8% per year. The nadirs of red blood cell count (RBC) and hemoglobin concentration (Hb) occurred at two months of age (physiological anemia). Subsequently, Hb increased at a rate similar to that of MCV, demonstrating the two processes are coupled. The third percentile MCV in children older than 3 months was ≤64 fL, which was significantly lower than that in European children. The third percentile Hb, on the other hand, was similar to that in European children. Thus, α+-thalassemia trait and iron deficiency anemia are exceptionally frequent in Arabian children and their red cell indices are considerably different from European-based norms. Careful interpretation of red cell parameters is required for the evaluation of microcytic anemia in Arabian children.

  5. PHIV-RootCell: a supervised image analysis tool for rice root anatomical parameter quantification

    Directory of Open Access Journals (Sweden)

    Marc eLartaud

    2015-01-01

    Full Text Available We developed the PHIV-RootCell software to quantify anatomical traits of rice roots transverse section images. Combined with an efficient root sample processing method for image acquisition, this program permits supervised measurements of areas (those of whole root section, stele, cortex and central metaxylem vessels, number of cell layers and number of cells per cell layer. The PHIV-RootCell toolset runs under ImageJ, an independent operating system that has a license-free status. To demonstrate the usefulness of PHIV-RootCell, we conducted a genetic diversity study and an analysis of salt-stress responses of root anatomical parameters in rice (Oryza sativa L.. Using 16 cultivars, we showed that we could discriminate between some of the varieties even at the 6 day-old stage, and that tropical japonica varieties had larger root sections due to an increase in cell number. We observed, as described previously, that root sections become enlarged under salt stress. However, our results show an increase in cell number in ground tissues (endodermis and cortex but a decrease in external (peripheral tissues (sclerenchyma, exodermis and epidermis. Thus, the PHIV-RootCell program is a user-friendly tool that will be helpful for future genetic and physiological studies that investigate root anatomical trait variations.

  6. Hydrogen Fuel Cell Performance as Telecommunications Backup Power in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, Jennifer [National Renewable Energy Lab. (NREL), Golden, CO (United States); Saur, Genevieve [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sprik, Sam [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-03-01

    Working in collaboration with the U.S. Department of Energy (DOE) and industry project partners, the National Renewable Energy Laboratory (NREL) acts as the central data repository for the data collected from real-world operation of fuel cell backup power systems. With American Recovery and Reinvestment Act of 2009 (ARRA) co-funding awarded through DOE's Fuel Cell Technologies Office, more than 1,300 fuel cell units were deployed over a three-plus-year period in stationary, material handling equipment, auxiliary power, and backup power applications. This surpassed a Fuel Cell Technologies Office ARRA objective to spur commercialization of an early market technology by installing 1,000 fuel cell units across several different applications, including backup power. By December 2013, 852 backup power units out of 1,330 fuel cell units deployed were providing backup service, mainly for telecommunications towers. For 136 of the fuel cell backup units, project participants provided detailed operational data to the National Fuel Cell Technology Evaluation Center for analysis by NREL's technology validation team. NREL analyzed operational data collected from these government co-funded demonstration projects to characterize key fuel cell backup power performance metrics, including reliability and operation trends, and to highlight the business case for using fuel cells in these early market applications. NREL's analyses include these critical metrics, along with deployment, U.S. grid outage statistics, and infrastructure operation.

  7. Endothelial cell seeding on crosslinked collagen : Effects of crosslinking on endothelial cell proliferation and functional parameters

    NARCIS (Netherlands)

    Wissink, MJB; van Luyn, MJA; Dijk, F; Poot, AA; Engbers, GHM; Beugeling, T; van Aken, WG; Feijen, J

    Endothelial cell seeding, a promising method to improve the performance of small-diameter vascular grafts, requires a suitable substrate, such as crosslinked collagen. Commonly used crosslinking agents such as glutaraldehyde and formaldehyde cause, however, cytotoxic reactions and thereby hamper

  8. Do trichothecenes reduce viability of circulating blood cells and modify haemostasis parameters?

    Science.gov (United States)

    Froquet, R; Arnold, F; Batina, P; Parent-Massin, D

    2003-01-01

    This manuscript describes the results of experiments conducted using human blood cells to determine the ability of T-2 toxin and DON to cause changes in clotting time, platelet aggregation, red blood cell haemolysis, RBC glucose content, lactate release, glutathione depletion, as well as white blood cell viability. In vitro results showed that haemostasis parameters and erythrocytes were not affected at concentrations able to induce inhibition of haematopoietic progenitor proliferation. In the presence of 10(-8) M and 10(-6) M T-2, the leucocyte number decreased at 24 h by 30% and 50% respectively. A 50% decrease in leucocyte number was observed for 10(-5) M DON. Results were compared with haematopoietic progenitor sensitivities. Due to the differences in sensitivities between mature blood cells and haematopoietic progenitors, haematological problems associated with trichothecene intoxication could be attributed to haematopoiesis inhibition.

  9. Parameter estimation and characterization of a single-chamber microbial fuel cell for dairy wastewater treatment.

    Science.gov (United States)

    Sedaqatvand, Ramin; Nasr Esfahany, Mohsen; Behzad, Tayebeh; Mohseni, Madjid; Mardanpour, Mohammad Mahdi

    2013-10-01

    In this study, for the first time, the conduction-based model is extended, and then combined with Genetic Algorithm to estimate the design parameters of a MFC treating dairy wastewater. The optimized parameters are, then, validated. The estimated half-saturation potential of -0.13 V (vs. SHE) is in good agreement while the biofilm conductivity of 8.76×10(-4) mS cm(-1) is three orders of magnitude lower than that previously-reported for pure-culture biofilm. Simulations show that the ohmic and concentration overpotentials contribute almost equally in dropping cell voltage in which the concentration film and biofilm conductivity comprise the main resistances, respectively. Thus, polarization analysis and determining the controlling steps will be possible through that developed extension. This study introduces a reliable method to estimate the design parameters of a particular MFC and to characterize it.

  10. Red cell parameters in infant and children from the Arabian Peninsula

    OpenAIRE

    Mekaini, Lolowa A Al; Denic, Srdjan; Jabri, Omar N Al; Narchi, Hassib; Souid, Abdul-Kader; Al-Hammadi, Suleiman

    2015-01-01

    α+-Thalassemia trait and iron deficiency anemia are frequent causes of microcytosis and a common diagnostic challenge in Arabian children. In this study, their prevalences and effects on the red cell parameters were evaluated in 28,457 children aged one day to 6 years. α+-Thalassemia trait was considered to be present when mean cell volume (MCV) was 14.5%. The prevalence of α+-thalassemia trait was 15.7% (502/3,191), which was similar to previously reported values for adults (9-14%). Iron def...

  11. Relationship between endothelial cell loss and microcoaxial phacoemulsification parameters in noncomplicated cataract surgery.

    Science.gov (United States)

    Mahdy, Mohamed Ae Soliman; Eid, Mohamed Z; Mohammed, Mahmoud Abdel-Badei; Hafez, Amr; Bhatia, Jagdish

    2012-01-01

    To assess the relationship between postoperative endothelial cell loss and microcoaxial phaco parameters using Ozil IP (Alcon Laboratories, Inc, Fort Worth, TX) in noncomplicated cataract surgery. In this prospective observational study, 120 consecutive cases of cataract patients with different grades of nuclear hardness underwent microcoaxial phacoemulsification through a 2.2-mm clear corneal incision. An Alcon Infinity Vision System with Ozil IP (Alcon Laboratories) was used with an Ozil torsional handpiece and a Kelman-style 45° phacoemulsification tip. Patients underwent preoperative and postoperative central endothelial cell counts. The study included 120 cases of age-related cataract whose mean age (standard deviation [SD]) was 59.68 years (9.47). There was a highly statistically significant endothelial cell loss (P phaco parameters. The Spearman's rank-order correlation coefficient values, rho, (ρ) were as follows: CDE (ρ = 0.425), aspiration time (ρ = 0.176), and volume (ρ = 0.278). Also, ECLoss% was significantly correlated with the grade of nuclear opalescence (Kendall's tau τ = 0.42). Microcoaxial phacoemulsification was efficient in removing noncomplicated cataracts; however a statistically significant endothelial cell loss was noted, especially with increased nuclear hardness. This endothelial cell loss was mostly related to the increased cumulative dissipated energy (CDE), aspiration time, and volume of balanced salt solution used.

  12. Thermally induced changes of optical and vital parameters in human cancer cells

    Science.gov (United States)

    Dressler, C.; Schwandt, D.; Beuthan, J.; Mildaziene, V.; Zabarylo, U.; Minet, O.

    2010-11-01

    Minimally invasive laser-induced thermotherapy (LITT) presents an alternative method to conventional tumor therapeutically interventions, such as surgery, chemotherapy, radiotherapy or nuclear medicine. Optical tissue characteristics of tumor cells and their heat-induced changes are essential issues for controlling LITT progressions. Therefore, it is indispensable to exactly know the absorption coefficient μa, the scattering coefficient μs and the anisotropy factor g as well as their changes under rising temperatures in order to simulate the treatment parameters successfully. Optical parameters of two different cancer model tissues - breast cancer cells species MX1 and colon cancer cells species CX1 - were measured in the spectral range 400 - 1100 nm as well as in the temperature range 37 - 60°C. The absorption coefficient of both cell species was low throughout the spectral range analyzed, while μs of both species rose with increasing temperatures. The anisotropy factor g however dropped for both tissues with increasing temperatures. Light scatterings inside tissues proceeded continuously forward for all species tested. It was demonstrated that optical tissue properties undergo significant changes along with the vital status of the cells when the temperature increases.

  13. Relationship of mast cell density with lymphangiogenesis and prognostic parameters in breast carcinoma

    Directory of Open Access Journals (Sweden)

    Sevinc H. Keser

    2017-04-01

    Full Text Available In many cancers, mast cell density (MCD in the tumor microenvironment is associated with tumor progression and, to a greater extent, angiogenesis. Our study was designed to investigate the correlation between MCD, tumor lymphangiogenesis, and several well-established prognostic parameters in breast cancer. One hundred and four cases of invasive breast carcinoma diagnosed in our clinic between 2007 and 2011 were included. Mast cells and lymphatic vessels were stained with toluidine blue and D2-40, respectively, and their densities were calculated in various areas of tumors and lymph nodes. The variables of MCD and lymphatic vessel density (LVD were compared using prognostic parameters as well as with each other. As tumor size and volume increased, MCD increased comparably in metastatic lymph nodes; intratumoral and peritumoral LVD also increased. Lymphovascular invasion, lymphatic invasion, perineural invasion, and estrogen receptor positivity were positively related to intratumoral MCD. The relationship between peritumoral MCD and nontumoral breast tissue MCD was statistically significant. Stage was correlated with MCD in metastatic lymph nodes. Metastatic lymph node MCD and intratumoral MCD were also significantly related. Stage, lymphatic invasion, perineural invasion, lymphovascular invasion, and metastatic lymph node MCD were all correlated with intratumoral and/or peritumoral LVD. As nuclear grade increased, intratumoral LVD became higher. In breast carcinoma, MCD, depending on its location, was related to several prognostic parameters. Notably, mast cells may have at least some effect on lymphangiogenesis, which appears to be a predictor of tumor progression.

  14. Comparison of Different Electroporation Parameters on Transfection Efficiency of Sheep Testicular Cells

    Directory of Open Access Journals (Sweden)

    Sarah Niakanrisi

    2016-09-01

    Full Text Available Objective: Electroporation can be a highly efficient method for introducing the foreign genetic materials into the targeted cells for transient and/or permanent genetic modification. Considering the application of this technique as a very efficient method for drug, oligonucleotide, antibody and plasmid delivery for clinical applications and production of transgenic animals, the present study aimed to optimize the transfection efficiency of sheep testicular cells including spermatogonial stem cells (SSCs via electroporation. Materials and Methods: This study is an experimental research conducted in Biotechnology Research Center (Avicenna Research Institute, Tehran, Iran from September 2013 to March 2014. Following isolation and propagation of one-month lamb testicular cells (SSCs and somatic testicular cells including; Sertoli, Leydig, and myoid cells, the effect of different electroporation parameters including total voltages (280, 320, and 350 V, burst durations (10, 8, and 5 milliseconds, burst modes (single or double and addition of dimethyl sulfoxide (DMSO were evaluated on transfection efficiency, viability rate and mean fluorescent intensity (MFI of sheep testicular cells. Results: The most transfection efficiency was obtained in 320 V/8 milliseconds/single burst group in transduction medium with and without DMSO. There was a significantly inverse correlation between transfection efficiency with application of both following parameters: addition of DMSO and double burst. After transfection, the highest and lowest viability rates of testicular cells were demonstrated in 320 V/8 milliseconds with transduction medium without DMSO and 350 V/5 milliseconds in medium containing DMSO. Addition of DMSO to transduction medium in all groups significantly decreased the viability rate. The comparison of gene expression indicated that Sertoli and SSCs had the most fluorescence intensity in 320 V/double burst/DMSO positive. However, myoid and Leydig

  15. Optimization of injection molding process parameters for a plastic cell phone housing component

    Science.gov (United States)

    Rajalingam, Sokkalingam; Vasant, Pandian; Khe, Cheng Seong; Merican, Zulkifli; Oo, Zeya

    2016-11-01

    To produce thin-walled plastic items, injection molding process is one of the most widely used application tools. However, to set optimal process parameters is difficult as it may cause to produce faulty items on injected mold like shrinkage. This study aims at to determine such an optimum injection molding process parameters which can reduce the fault of shrinkage on a plastic cell phone cover items. Currently used setting of machines process produced shrinkage and mis-specified length and with dimensions below the limit. Thus, for identification of optimum process parameters, maintaining closer targeted length and width setting magnitudes with minimal variations, more experiments are needed. The mold temperature, injection pressure and screw rotation speed are used as process parameters in this research. For optimal molding process parameters the Response Surface Methods (RSM) is applied. The major contributing factors influencing the responses were identified from analysis of variance (ANOVA) technique. Through verification runs it was found that the shrinkage defect can be minimized with the optimal setting found by RSM.

  16. Advanced Composite Bipolar Plate for Unitized Regenerative Fuel Cell/Electrolyzer Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of an advanced composite bipolar plate is proposed for a unitized regenerative fuel cell and electrolyzer system that operates on pure feed streams...

  17. Super Unit Cells in Aperture-Based Metamaterials

    OpenAIRE

    Dragan Tanasković; Zoran Jakšić; Marko Obradov; Olga Jakšić

    2015-01-01

    An important class of electromagnetic metamaterials are aperture-based metasurfaces. Examples include extraordinary optical transmission arrays and double fishnets with negative refractive index. We analyze a generalization of such metamaterials where a simple aperture is now replaced by a compound object formed by superposition of two or more primitive objects (e.g., rectangles, circles, and ellipses). Thus obtained “super unit cell” shows far richer behavior than the subobjects that compris...

  18. A selective hybrid stochastic strategy for fuel-cell multi-parameter identification

    Science.gov (United States)

    Guarnieri, Massimo; Negro, Enrico; Di Noto, Vito; Alotto, Piergiorgio

    2016-11-01

    The in situ identification of fuel-cell material parameters is crucial both for guiding the research for advanced functionalized materials and for fitting multiphysics models, which can be used in fuel cell performance evaluation and optimization. However, this identification still remains challenging when dealing with direct measurements. This paper presents a method for achieving this aim by stochastic optimization. Such techniques have been applied to the analysis of fuel cells for ten years, but typically to specific problems and by means of semi-empirical models, with an increased number of articles published in the last years. We present an original formulation that makes use of an accurate zero-dimensional multi-physical model of a polymer electrolyte membrane fuel cell and of two cooperating stochastic algorithms, particle swarm optimization and differential evolution, to extract multiple material parameters (exchange current density, mass transfer coefficient, diffusivity, conductivity, activation barriers …) from the experimental data of polarization curves (i.e. in situ measurements) under some controlled temperature, gas back pressure and humidification. The method is suitable for application in other fields where fitting of multiphysics nonlinear models is involved.

  19. Overview of commercialization of stationary fuel cell power plants in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Hooie, D.T.; Williams, M.C.

    1995-07-01

    In this paper, DOE`s efforts to assist private sector organizations to develop and commercialize stationary fuel cell power plants in the United States are discussed. The paper also provides a snapshot of the status of stationary power fuel cell development occurring in the US, addressing all fuel cell types. This paper discusses general characteristics, system configurations, and status of test units and demonstration projects. The US DOE, Morgantown Energy Technology Center is the lead center for implementing DOE`s program for fuel cells for stationary power.

  20. Dielectric Behavior of Low Microwave Loss Unit Cell for All Dielectric Metamaterial

    OpenAIRE

    Tianhuan Luo; Bo Li; Qian Zhao; Ji Zhou

    2015-01-01

    With a deep study of the metamaterial, its unit cells have been widely extended from metals to dielectrics. The dielectric based unit cells attract much attention because of the advantage of easy preparation, tunability, and higher frequency response, and so forth. Using the conventional solid state method, we prepared a kind of incipient ferroelectrics (calcium titanate, CaTiO3) with higher microwave permittivity and lower loss, which can be successfully used to construct metamaterials. The ...

  1. Recent insights into the cell biology of thyroid angiofollicular units.

    OpenAIRE

    Colin, Ides M.; Denef, Jean-François; Lengelé, Benoît; Many, Marie-Christine; Gérard, Anne-Catherine

    2013-01-01

    In thyrocytes, cell polarity is of crucial importance for proper thyroid function. Many intrinsic mechanisms of self-regulation control how the key players involved in thyroid hormone (TH) biosynthesis interact in apical microvilli, so that hazardous biochemical processes may occur without detriment to the cell. In some pathological conditions, this enzymatic complex is disrupted, with some components abnormally activated into the cytoplasm, which can lead to further morphological and functio...

  2. Theoretical studies on the solar cell parameters of n-C/p-Si heterojunction

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, B.; Shishodia, P.K.; Kapoor, A.; Mehra, R.M. [Department of Electronic Science, University of Delhi, South Campus, Benito Juarez Road, 110021 New Delhi (India); Krishna, K.M.; Umeno, M. [Research Center for Microstructure Devices, Nagoya Institute of Technology, 466 8555 Nagoya (Japan); Soga, T.; Jimbo, T. [Department of Environmental Technology and Urban Planning, Nagoya Institute of Technology, 466 8555 Nagoya (Japan)

    2002-01-01

    Amorphous carbon (a-C) is a potential material for the development of low cost solar cells. The heterojunction n-C/p-Si solar cell has been recently developed by Krishna et al. It has been shown that the maximum quantum efficiency (25%) appears at wavelength {lambda} (600 nm). In the present work, theoretical quantum efficiency has been calculated taking into account the contribution of hole photocurrent density, electron photocurrent density and the photocurrent within the depletion region. The variation of quantum efficiency with wavelength is found to be qualitatively similar to the experimentally observed variation. The solar cell parameters namely V{sub oc}, I{sub sc}, FF and efficiency have also been calculated and compared with the experimental values.

  3. Application of the collection probability of a solar cell for extracting recombination parameters from the spectral response

    Energy Technology Data Exchange (ETDEWEB)

    Tuominen, E.; Yli-Koski, M.; Haerkoenen, J.; Sinkkonen, J.

    1998-12-31

    Getting reliable information about charge carrier recombination properties is extremely important in monitoring and controlling solar cell fabrication processes. We have developed a mathematical method to extract solar cell parameters, such as diffusion lengths and surface recombination velocities directly from the spectral response of a solar cell by inverse Laplace transform. In this paper we present an improved analytical calculation of the explicit formula for the theoretical collection probability function of a solar cell. Further, we apply the obtained function in order to extract solar cell recombination parameters from spectral responses measured from solar cells processed in our laboratory. (orig.) 20 refs.

  4. Alginate encapsulation parameters influence the differentiation of microencapsulated embryonic stem cell aggregates.

    Science.gov (United States)

    Wilson, Jenna L; Najia, Mohamad Ali; Saeed, Rabbia; McDevitt, Todd C

    2014-03-01

    Pluripotent embryonic stem cells (ESCs) have tremendous potential as tools for regenerative medicine and drug discovery, yet the lack of processes to manufacture viable and homogenous cell populations of sufficient numbers limits the clinical translation of current and future cell therapies. Microencapsulation of ESCs within microbeads can shield cells from hydrodynamic shear forces found in bioreactor environments while allowing for sufficient diffusion of nutrients and oxygen through the encapsulation material. Despite initial studies examining alginate microbeads as a platform for stem cell expansion and directed differentiation, the impact of alginate encapsulation parameters on stem cell phenotype has not been thoroughly investigated. Therefore, the objective of this study was to systematically examine the effects of varying alginate compositions on microencapsulated ESC expansion and phenotype. Pre-formed aggregates of murine ESCs were encapsulated in alginate microbeads composed of a high or low ratio of guluronic to mannuronic acid residues (High G and High M, respectively), with and without a poly-L-lysine (PLL) coating, thereby providing four distinct alginate bead compositions for analysis. Encapsulation in all alginate compositions was found to delay differentiation, with encapsulation within High G alginate yielding the least differentiated cell population. The addition of a PLL coating to the High G alginate prevented cell escape from beads for up to 14 days. Furthermore, encapsulation within High M alginate promoted differentiation toward a primitive endoderm phenotype. Taken together, the findings of this study suggest that distinct ESC expansion capacities and differentiation trajectories emerge depending on the alginate composition employed, indicating that encapsulation material physical properties can be used to control stem cell fate.

  5. Alginate Encapsulation Parameters Influence the Differentiation of Microencapsulated Embryonic Stem Cell Aggregates

    Science.gov (United States)

    Wilson, Jenna L.; Najia, Mohamad Ali; Saeed, Rabbia; McDevitt, Todd C.

    2014-01-01

    Pluripotent embryonic stem cells (ESCs) have tremendous potential as tools for regenerative medicine and drug discovery, yet the lack of processes to manufacture viable and homogenous cell populations of sufficient numbers limits the clinical translation of current and future cell therapies. Microencapsulation of ESCs within microbeads can shield cells from hydrodynamic shear forces found in bioreactor environments while allowing for sufficient diffusion of nutrients and oxygen through the encapsulation material. Despite initial studies examining alginate microbeads as a platform for stem cell expansion and directed differentiation, the impact of alginate encapsulation parameters on stem cell phenotype has not been thoroughly investigated. Therefore, the objective of this study was to systematically examine the effects of varying alginate compositions on microencapsulated ESC expansion and phenotype. Pre-formed aggregates of murine ESCs were encapsulated in alginate microbeads composed of a high or low ratio of guluronic to mannuronic acid residues (High G and High M, respectively), with and without a poly-l-lysine (PLL) coating, thereby providing four distinct alginate bead compositions for analysis. Encapsulation in all alginate compositions was found to delay differentiation, with encapsulation within High G alginate yielding the least differentiated cell population. The addition of a PLL coating to the High G alginate prevented cell escape from beads for up to 14 days. Furthermore, encapsulation within High M alginate promoted differentiation toward a primitive endoderm phenotype. Taken together, the findings of this study suggest that distinct ESC expansion capacities and differentiation trajectories emerge depending on the alginate composition employed, indicating that encapsulation material physical properties can be used to control stem cell fate. PMID:24166004

  6. Relationship between endothelial cell loss and microcoaxial phacoemulsification parameters in noncomplicated cataract surgery

    Directory of Open Access Journals (Sweden)

    Soliman Mahdy MAE

    2012-03-01

    Full Text Available Mohamed AE Soliman Mahdy1,2, Mohamed Z Eid1, Mahmoud Abdel-Badei Mohammed3, Amr Hafez4,5, Jagdish Bhatia21Ophthalmic Department, Al-Hussein University Hospital, Al-Azhar University, Cairo, Egypt; 2Ophthalmic Department, Rustaq Hospital, Rustaq, Sultanate of Oman; 3Research Institute of Ophthalmology, Cairo, Egypt; 4Magrabi Eye and Ear Center, Muscat, Sultanate of Oman; 5Ophthalmic Department, Al-Azhar University Hospital, Assuit, EgyptPurpose: To assess the relationship between postoperative endothelial cell loss and microcoaxial phaco parameters using Ozil IP (Alcon Laboratories, Inc, Fort Worth, TX in noncomplicated cataract surgery.Methods: In this prospective observational study, 120 consecutive cases of cataract patients with different grades of nuclear hardness underwent microcoaxial phacoemulsification through a 2.2-mm clear corneal incision. An Alcon Infinity Vision System with Ozil IP (Alcon Laboratories was used with an Ozil torsional handpiece and a Kelman-style 45° phacoemulsification tip. Patients underwent preoperative and postoperative central endothelial cell counts.Results: The study included 120 cases of age-related cataract whose mean age (standard deviation [SD] was 59.68 years (9.47. There was a highly statistically significant endothelial cell loss (P < 0.001. The endothelial cell loss ranged 11–1149 cells/mm2 with a median (interquartile range of 386 cells/mm2 (184.5–686 cells/mm2. The percentage of postoperative ECLoss% ranged from 0.48% to 47.8% with a median (interquartile range of 15.4% (7.2% to 26.8%. A significant positive correlation was found between the ECLoss% and different phaco parameters. The Spearman’s rank-order correlation coefficient values, rho, (ρ were as follows: CDE (ρ = 0.425, aspiration time (ρ = 0.176, and volume (ρ = 0.278. Also, ECLoss% was significantly correlated with the grade of nuclear opalescence (Kendall’s tau τ = 0.42.Conclusion: Microcoaxial phacoemulsification was efficient

  7. Simulating tubulin-associated unit transport in an axon: using bootstrapping for estimating confidence intervals of best-fit parameter values obtained from indirect experimental data.

    Science.gov (United States)

    Kuznetsov, I A; Kuznetsov, A V

    2017-05-01

    In this paper, we first develop a model of axonal transport of tubulin-associated unit (tau) protein. We determine the minimum number of parameters necessary to reproduce published experimental results, reducing the number of parameters from 18 in the full model to eight in the simplified model. We then address the following questions: Is it possible to estimate parameter values for this model using the very limited amount of published experimental data? Furthermore, is it possible to estimate confidence intervals for the determined parameters? The idea that is explored in this paper is based on using bootstrapping. Model parameters were estimated by minimizing the objective function that simulates the discrepancy between the model predictions and experimental data. Residuals were then identified by calculating the differences between the experimental data and model predictions. New, surrogate 'experimental' data were generated by randomly resampling residuals. By finding sets of best-fit parameters for a large number of surrogate data the histograms for the model parameters were produced. These histograms were then used to estimate confidence intervals for the model parameters, by using the percentile bootstrap. Once the model was calibrated, we applied it to analysing some features of tau transport that are not accessible to current experimental techniques.

  8. Dominant unit CD34+ cell dose predicts engraftment after double-unit cord blood transplantation and is influenced by bank practice.

    Science.gov (United States)

    Purtill, Duncan; Smith, Katherine; Devlin, Sean; Meagher, Richard; Tonon, Joann; Lubin, Marissa; Ponce, Doris M; Giralt, Sergio; Kernan, Nancy A; Scaradavou, Andromachi; Stevens, Cladd E; Barker, Juliet N

    2014-11-06

    We investigated the unit characteristics associated with engraftment after double-unit cord blood (CB) transplantation (dCBT) and whether these could be reliably identified during unit selection. Cumulative incidence of neutrophil engraftment in 129 myeloablative dCBT recipients was 95% (95% confidence interval: 90-98%). When precryopreservation characteristics were analyzed, the dominant unit CD34(+) cell dose was the only characteristic independently associated with engraftment (hazard ratio, 1.43; P = .002). When postthaw characteristics were also included, only dominant unit infused viable CD34(+) cell dose independently predicted engraftment (hazard ratio, 1.95; P banks were more likely to have low recovery (P banks and units with cryovolumes other than 24.5 to 26.0 mL were more likely to have poor postthaw viability. Precryopreservation CD34(+) cell dose and banking practices should be incorporated into CB unit selection.

  9. A Population Classification Evolution Algorithm for the Parameter Extraction of Solar Cell Models

    Directory of Open Access Journals (Sweden)

    Yiqun Zhang

    2016-01-01

    Full Text Available To quickly and precisely extract the parameters for solar cell models, inspired by simplified bird mating optimizer (SBMO, a new optimization technology referred to as population classification evolution (PCE is proposed. PCE divides the population into two groups, elite and ordinary, to reach a better compromise between exploitation and exploration. For the evolution of elite individuals, we adopt the idea of parthenogenesis in nature to afford a fast exploitation. For the evolution of ordinary individuals, we adopt an effective differential evolution strategy and a random movement of small probability is added to strengthen the ability to jump out of a local optimum, which affords a fast exploration. The proposed PCE is first estimated on 13 classic benchmark functions. The experimental results demonstrate that PCE yields the best results on 11 functions by comparing it with six evolutional algorithms. Then, PCE is applied to extract the parameters for solar cell models, that is, the single diode and the double diode. The experimental analyses demonstrate that the proposed PCE is superior when comparing it with other optimization algorithms for parameter identification. Moreover, PCE is tested using three different sources of data with good accuracy.

  10. MEASUREMENT OF ATM LAYER QUALITY OF SERVICE PARAMETERS USING OAM CELLS

    Directory of Open Access Journals (Sweden)

    J. García-Hernández

    2004-08-01

    Full Text Available The measurement of the quality of service in ATM* networks involves the activation of the ATM layer managementOAM functions. Once an ATM connection is set up, in-service performance monitoring based on OAM cells can beused to measure and estimate the ATM layer QoS parameters. In-service measurement of ATM layer QoS parameterssuch as cell delay variation, cell transfer delay, cell loss ratio, etc., is necessary to verify on one hand, if the networkis meeting the requested QoS and on the other hand, if the users are receiving their promised QoS. Congestionconditions in ATM switches may cause gradual deteriorations in the quality of virtual paths or virtual channelconnections in an ATM network. QoS measurement using OAM cells can accurately measure the overall quality ofmonitored ATM layer QoS parameters in order to detect such deteriorations before the service quality has droppedbellow an acceptable level. Several factors such as network load, congestion, bottlenecks, and incremenTS innetwork load may affect the cell delay variation of video transmissions in an ATM network. In this work, several ATMlayer QoS parameters have been measured on a VBR video source using OAM cells. The simulation resulTS obtainedshow that with low network loads, the contribution of each individual ATM switch to the local and to the end-to-endCDV is not significant. In the presence of a bottleneck switch, the CDV presented by this switch becomes thedominant one at both local and end-to-end sides. When the network load is between 0.5 and 0.6, small incremenTSin network load do not alter the buffer performance of the non-congested ATM switches, and low values of CDVcan be obtained. In contrast, it was found that there is a critical load between 0.65 and 0.7 where small incremenTSin network load may force the CDV to grow abruptly.

  11. ROLE OF THE MORPHOMETRIC PARAMETERS OF INTRATUMORAL MICROVESSELS AND THE PROLIFERATIVE ACTIVITY OF TUMOR CELLS IN RENAL CELL CARCINOMA

    Directory of Open Access Journals (Sweden)

    N. A. Gorban

    2014-08-01

    Full Text Available Tumor cell proliferation and angiogenesis are essential factors for tumor growth, progression, and metastasis.Objective: to assess the relationship between the values of proliferative activity and the morphometric parameters of intratumoral microvessels in metastatic and localized carcinomas of the kidney.Materials and methods. Surgical specimens taken from 54 patients (32 men and 22 women aged 26 to 69 years (mean age 55 ± 1.5 years with the verified diagnosis of clear-cell renal cell carcinoma (RCC were studied.Conclusion. Proliferative activity and angioarchitectonics are an important biological characteristic of a tumor of unequal clinical value in RCC. Metastatic carcinoma has a higher proliferative activity and a low tumor vascularization than those of localized carcinoma.

  12. Fuel cell repeater unit including frame and separator plate

    Energy Technology Data Exchange (ETDEWEB)

    Yamanis, Jean; Hawkes, Justin R; Chiapetta, Jr., Louis; Bird, Connie E; Sun, Ellen Y; Croteau, Paul F

    2013-11-05

    An example fuel cell repeater includes a separator plate and a frame establishing at least a portion of a flow path that is operative to communicate fuel to or from at least one fuel cell held by the frame relative to the separator plate. The flow path has a perimeter and any fuel within the perimeter flow across the at least one fuel cell in a first direction. The separator plate, the frame, or both establish at least one conduit positioned outside the flow path perimeter. The conduit is outside of the flow path perimeter and is configured to direct flow in a second, different direction. The conduit is fluidly coupled with the flow path.

  13. Mast cell density and the context of clinicopathological parameters and expression of p185,estrogen receptor,and proliferating cell nuclear antigen in gastric carcinoma

    Institute of Scientific and Technical Information of China (English)

    Ying-AnJiang; You-YuanZhang; He-ShengLuo; Shou-FuXing

    2002-01-01

    AIM:To investigate the relationship between the mast cell density(MCD)and the context of clinicopathological parameters and expression of p185,estrogen receptor(ER),and proliferating cell nuclear antigen(PCNA)in gastric carcinoma.

  14. Mid-infrared spectroscopy-based analysis of mammalian cell culture parameters.

    Science.gov (United States)

    Capito, Florian; Zimmer, Aline; Skudas, Romas

    2015-01-01

    Within the framework of process analytical technology, infrared spectroscopy (IR) has been used for characterization of biopharmaceutical production processes. Although noninvasive attenuated total reflection (ATR) spectroscopy can be regarded as gold standard within IR-based process analytics, simpler and more cost-effective mid-infrared (MIR) instruments might improve acceptability of this technique for high-level monitoring of small scale experiments as well as for academia where financial restraints impede the use of costly equipment. A simple and straightforward at-line mid-IR instrument was used to monitor cell viability parameters, activity of lactate dehydrogenase (LDH), amount of secreted antibody, and concentration of glutamate and lactate in a Chinese hamster ovary cell culture process, applying multivariate prediction models, including only 25-28 calibration samples per model. Glutamate amount could be predicted with high accuracy (R(2) 0.91 for independent test-set) while antibody concentration achieved good prediction for concentrations >0.4 mg L(-1) . Prediction of LDH activity was accurate except for the low activity regime. The model for lactate monitoring was only moderately good and requires improvements. Relative cell viability between 20 and 95% could be predicted with low error (8.82%) in comparison to reference methods. An initial model for determining the number of nonviable cells displayed only acceptable accuracy and requires further improvement. In contrast, monitoring of viable cell number showed better accuracy than previously published ATR-based results. These results prove the principal suitability of less sophisticated MIR instruments to monitor multiple parameters in biopharmaceutical production with relatively low investments and rather fast calibration procedures. © 2015 American Institute of Chemical Engineers.

  15. Control of an afterburner in a diesel fuel cell power unit under variable load

    Science.gov (United States)

    Dolanc, Gregor; Pregelj, Boštjan; Petrovčič, Janko; Samsun, Remzi Can

    2017-01-01

    In this paper, the control system for a catalytic afterburner in a diesel fuel cell auxiliary power unit is presented. The catalytic afterburner is used to burn the non-utilised hydrogen and other possible combustible components of the fuel cell anode off-gas. To increase the energy efficiency of the auxiliary power unit, the thermal energy released in the catalytic afterburner is utilised to generate the steam for the fuel processor. For optimal operation of the power unit in all modes of operation including load change, stable steam generation is required and overall energy balance must be kept within design range. To achieve this, the reaction temperature of the catalytic afterburner must be stable in all modes of operation. Therefore, we propose the afterburner temperature control based on mass and thermal balances. Finally, we demonstrate the control system using the existing prototype of the diesel fuel cell auxiliary power unit.

  16. RASSF1A protein expression and correlation with clinicopathological parameters in renal cell carcinoma

    Directory of Open Access Journals (Sweden)

    Machtens Stefan

    2008-09-01

    Full Text Available Abstract Background Epigenetic silencing of RAS association family 1A (RASSF1A tumor suppressor gene occurs in various histological subtypes of renal cell carcinoma (RCC but RASSF1A protein expression in clear cell RCC as well as a possible correlation with clinicopathological parameters of patients has not been analyzed at yet. Methods 318 primary clear cell carcinomas were analyzed using tissue microarray analysis and immunohistochemistry. Survival analysis was carried out for 187 patients considering a follow-up period of 2–240 month. Results Expression of RASSF1A was found to be significantly decreased in tumoral cells when compared to normal tubular epithelial cells. RASSF1A immunopositivity was significantly associated with pT stage, group stage and histological grade of tumors and showed a tendency for impaired survival in Kaplan-Meier analysis. Conclusion While most tumors demonstrate a loss of RASSF1A protein, a subset of tumors was identified to exhibit substantial RASSF1A protein expression and show increased tumor progression. Thus RCC tumorigenesis without depletion of RASSF1A may be associated with an adverse clinical outcome.

  17. Quantification of Cell-Free DNA in Red Blood Cell Units in Different Whole Blood Processing Methods

    Directory of Open Access Journals (Sweden)

    Andrew W. Shih

    2016-01-01

    Full Text Available Background. Whole blood donations in Canada are processed by either the red cell filtration (RCF or whole blood filtration (WBF methods, where leukoreduction is potentially delayed in WBF. Fresh WBF red blood cells (RBCs have been associated with increased in-hospital mortality after transfusion. Cell-free DNA (cfDNA is released by neutrophils prior to leukoreduction, degraded during RBC storage, and is associated with adverse patient outcomes. We explored cfDNA levels in RBCs prepared by RCF and WBF and different storage durations. Methods. Equal numbers of fresh (stored ≤14 days and older RBCs were sampled. cfDNA was quantified by spectrophotometry and PicoGreen. Separate regression models determined the association with processing method and storage duration and their interaction on cfDNA. Results. cfDNA in 120 RBC units (73 RCF, 47 WBF were measured. Using PicoGreen, WBF units overall had higher cfDNA than RCF units (p=0.0010; fresh WBF units had higher cfDNA than fresh RCF units (p=0.0093. Using spectrophotometry, fresh RBC units overall had higher cfDNA than older units (p=0.0031; fresh WBF RBCs had higher cfDNA than older RCF RBCs (p=0.024. Conclusion. Higher cfDNA in fresh WBF was observed compared to older RCF blood. Further study is required for association with patient outcomes.

  18. [The time course of changes in cell immunological parameters during administration of live dry plague vaccine].

    Science.gov (United States)

    Bogacheva, N V; Darmov, I V; Borisevich, I V; Kriuchkov, A V; Pechenkin, D V

    2009-08-01

    The study of the time course of changes in cell immunological parameters by a magnetic separation technique in human beings during the administration of plague vaccine in relation to the immunological load revealed the higher blood levels of all T lymphocyte subpopulations on day 14 after vaccination. These changes are most typical of a primary vaccinated cohort. The increased frequency of plague vaccine administration and multiple immunizations with live plague, anthrax, and tularemia vaccines produce the time-course of changes in T lymphocyte populations (subpopulations) in response to the regular administration of plague vaccine. A high immunological load in man also promotes a significant reduction in the level of B lymphocytes.

  19. High performance internal reforming unit for high temperature fuel cells

    Science.gov (United States)

    Ma, Zhiwen; Venkataraman, Ramakrishnan; Novacco, Lawrence J.

    2008-10-07

    A fuel reformer having an enclosure with first and second opposing surfaces, a sidewall connecting the first and second opposing surfaces and an inlet port and an outlet port in the sidewall. A plate assembly supporting a catalyst and baffles are also disposed in the enclosure. A main baffle extends into the enclosure from a point of the sidewall between the inlet and outlet ports. The main baffle cooperates with the enclosure and the plate assembly to establish a path for the flow of fuel gas through the reformer from the inlet port to the outlet port. At least a first directing baffle extends in the enclosure from one of the sidewall and the main baffle and cooperates with the plate assembly and the enclosure to alter the gas flow path. Desired graded catalyst loading pattern has been defined for optimized thermal management for the internal reforming high temperature fuel cells so as to achieve high cell performance.

  20. The modeling of a standalone solid-oxide fuel cell auxiliary power unit

    Science.gov (United States)

    Lu, N.; Li, Q.; Sun, X.; Khaleel, M. A.

    In this research, a Simulink model of a standalone vehicular solid-oxide fuel cell (SOFC) auxiliary power unit (APU) is developed. The SOFC APU model consists of three major components: a controller model; a power electronics system model; and an SOFC plant model, including an SOFC stack module, two heat exchanger modules, and a combustor module. This paper discusses the development of the nonlinear dynamic models for the SOFC stacks, the heat exchangers and the combustors. When coupling with a controller model and a power electronic circuit model, the developed SOFC plant model is able to model the thermal dynamics and the electrochemical dynamics inside the SOFC APU components, as well as the transient responses to the electric loading changes. It has been shown that having such a model for the SOFC APU will help design engineers to adjust design parameters to optimize the performance. The modeling results of the SOFC APU heat-up stage and the output voltage response to a sudden load change are presented in this paper. The fuel flow regulation based on fuel utilization is also briefly discussed.

  1. The reliability assessment of the electromagnetic valve of high-speed electric multiple units braking system based on two-parameter exponential distribution

    Directory of Open Access Journals (Sweden)

    Jianwei Yang

    2016-06-01

    Full Text Available In order to solve the reliability assessment of braking system component of high-speed electric multiple units, this article, based on two-parameter exponential distribution, provides the maximum likelihood estimation and Bayes estimation under a type-I life test. First of all, we evaluate the failure probability value according to the classical estimation method and then obtain the maximum likelihood estimation of parameters of two-parameter exponential distribution by performing and using the modified likelihood function. On the other hand, based on Bayesian theory, this article also selects the beta and gamma distributions as the prior distribution, combines with the modified maximum likelihood function, and innovatively applies a Markov chain Monte Carlo algorithm to parameters assessment based on Bayes estimation method for two-parameter exponential distribution, so that two reliability mathematical models of the electromagnetic valve are obtained. Finally, through type-I life test, the failure rates according to maximum likelihood estimation and Bayes estimation method based on Markov chain Monte Carlo algorithm are, respectively, 2.650 × 10−5 and 3.037 × 10−5. Compared with the failure rate of a electromagnetic valve 3.005 × 10−5, it proves that the Bayes method can use a Markov chain Monte Carlo algorithm to estimate reliability for two-parameter exponential distribution and Bayes estimation is more closer to the value of electromagnetic valve. So, by fully integrating multi-source, Bayes estimation method can preferably modify and precisely estimate the parameters, which can provide a certain theoretical basis for the safety operation of high-speed electric multiple units.

  2. Employment of the covariance matrix in parameter estimation for stochastic processes in cell biology

    Science.gov (United States)

    Preuss, R.; Dieterich, P.

    2013-08-01

    The dynamics of movements of biological cells can be described with models from correlated stochastic processes. In order to overcome problems from correlated and insufficient data in the determination of the model parameters of such processes we employ the covariance matrix of the data. Since the covariance suffers itself from statistical uncertainty it is corrected by a renormalization treatment [1]. For the example of normal and fractional Brownian motion, which allows both to access all quantities on full theoretical grounds and to generate data similar to experiment, we discuss our results and those of previous works by Gregory [2] and Sivia [3]. The presented approach has the potential to estimate the aging correlation function of observed cell paths and can be applied to more complicated models.

  3. Results of Current Density Distribution Mapping in PEM Fuel Cells Dependent on Operation Parameters

    Directory of Open Access Journals (Sweden)

    Zbigniew A. Styczynski

    2013-07-01

    Full Text Available This paper presents in situ measurements of a newly developed current density measurement system for proton exchange membrane fuel cells (PEMFC. While the functional principle and technical evaluation of the measurement system were presented in a previous paper, this paper analyzes the influence of various operation parameters, including multiple start-stop operation, at the anode, cathode and cooling locations on the distribution and long-term development of the current density. The system was operated for 500 h over two years with long periods of inactivity between measurements. The measurement results are evaluated and provide additional information on how to optimize the operation modes of fuel cells, including the start and stop of such systems as well as the water balance.

  4. The Daniell cell, Ohm's law, and the emergence of the International System of Units

    Science.gov (United States)

    Jayson, Joel S.

    2014-01-01

    Telegraphy originated in the 1830s and 40 s and flourished in the following decades but with a patchwork of electrical standards. Electromotive force was for the most part measured in units of the predominant Daniell cell, but each telegraphy company had their own resistance standard. In 1862, the British Association for the Advancement of Science formed a committee to address this situation. By 1873, they had given definition to the electromagnetic system of units (emu) and defined the practical units of the ohm as 109 emu units of resistance and the volt as 108 emu units of electromotive force. These recommendations were ratified and expanded upon in a series of international congresses held between 1881 and 1904. A proposal by Giovanni Giorgi in 1901 took advantage of a coincidence between the conversion of the units of energy in the emu system (the erg) and in the practical system (the Joule). As it was, the same conversion factor existed between the cgs based emu system and a theretofore undefined MKS system. By introducing another unit X (where X could be any of the practical electrical units), Giorgi demonstrated that a self-consistent MKSX system was tenable without the need for multiplying factors. Ultimately, the ampere was selected as the fourth unit. It took nearly 60 years, but in 1960, Giorgi's proposal was incorporated as the core of the newly inaugurated International System of Units (SI). This article surveys the physics, physicists, and events that contributed to those developments.

  5. The influence of selected parameters on the efficiency and economic charactersistics of the oxy-type coal unit with a membrane-cryogenic oxygen separator

    Directory of Open Access Journals (Sweden)

    Kotowicz Janusz

    2016-03-01

    Full Text Available In this paper a 600 MW oxy-type coal unit with a pulverized bed boiler and a membrane-cryogenic oxygen separator and carbon capture installation was analyzed. A membrane-cryogenic oxygen separation installation consists of a membrane module and two cryogenic distillation columns. In this system oxygen is produced with the purity equal to 95%. Installation of carbon capture was based on the physical separation method and allows to reduce the CO2 emission by 90%. In this work the influence of the main parameter of the membrane process – the selectivity coefficient, on the efficiency of the coal unit was presented. The economic analysis with the use of the break-even point method was carried out. The economic calculations were realized in view of the break-even price of electricity depending on a coal unit availability.

  6. Compensation of Cable Voltage Drops and Automatic Identification of Cable Parameters in 400 Hz Ground Power Units

    DEFF Research Database (Denmark)

    Borup, Uffe; Nielsen, Bo Vork; Blaabjerg, Frede

    2004-01-01

    In this paper a new cable voltage drop compensation scheme for ground power units (GPU) is presented. The scheme is able to predict and compensate the voltage drop in an output cable by measuring the current quantities at the source. The prediction is based on an advanced cable model that includes...

  7. Optimisation of manufacturing parameters for a Ni-Ag fuel cell electrode

    Energy Technology Data Exchange (ETDEWEB)

    Pishbin, M.H. [School of Metallurgy and Materials Engineering, Faculty of Engineering, University of Tehran, Tehran (Iran); Mohammadi, A.R. [Department of Mechanical Engineering, University of British Columbia, Vancouver (Canada); Nasri, M. [Information Technology Company of Iran, Tehran (Iran)

    2007-08-15

    The aim of this research is to optimise manufacturing parameters for a fuel cell electrode. The combination of nickel oxide, silver oxide and ammonium bicarbonate powders is used to produce the electrode. The main role of silver element is to increase the activity in the electrode. Ni-Ag electrode can be used in fuel cells as positive and negative electrodes. All powders are mixed in the benzene solution by a magnetic mixer and then compressed to form green electrode. The range of pressure in this step is between 40 and 160 MPa. The green electrode is sintered in hydrogen atmosphere through a tube furnace and then cooled to 200 C under argon atmosphere. The range of sintering temperature and time is 500-800 C and 10-60 min, respectively. Also, silver oxide and ammonium bicarbonate percentages are varied from 20 to 65 and 15 to 35%, respectively. All parameters including composition, pressure, sintering temperature and time are changed during electrode fabrication to achieve optimised properties in the electrode. So, it is necessary to perform several tests measuring porosity, surface area, density, weight loss, mechanical strength, shrinkage, exchange current density and metallographic photos. The optimum conditions of the electrode production resulting from this investigation include compacting pressure 60 MPa, sintering temperature 560 C, sintering time 15 min, silver oxide percentage 50% and ammonium bicarbonate percentage 27%. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  8. Antioxidant status and selected biochemical parameters of porcine ovarian granulosa cells exposed to lead in vitro.

    Science.gov (United States)

    Capcarová, Marcela; Kolesárová, Adriana; Lukác, Norbert; Sirotkin, Alexander; Roychoudhury, Shubhadeep

    2009-12-01

    The objective of this study was to determine the activity of superoxide dismutase (SOD), total antioxidant status (TAS) and release of calcium, phosphorus, magnesium, sodium, potassium, total lipids, totals proteins, glucose, cholesterol and triglycerides by porcine ovarian granulosa cells cultured in vitro after lead acetate administration. The parameters were analyzed using semi-automated clinical chemistry analyzer Microlab 300, microprocessor-controlled analyzer EasyLite and spectrophotometer Genesys 10. Cells were cultured with lead acetate trihydrate [Pb(CH(3)COO)(2).3H(2)O] as follows: group Max (5 mg Pb(CH(3)COO)(2).3H(2)O/10 mL), group A (2.5 mg/10 mL), group B (0.83 mg/10 mL), group C (0.625 mg/10 mL), group D (0.455 mg/10 mL) and the control group without lead exposure for 18 hrs. The highest TAS was estimated in the control group without lead treatment in comparison with other groups (MAX, A, B, C, D). Statistical analyses showed significantly lower value (P 0.05) were detected in concentration of other studied parameters among observed groups, too.

  9. [THE MODEL OF NEUROVASCULAR UNIT IN VITRO CONSISTING OF THREE CELLS TYPES].

    Science.gov (United States)

    Khilazheva, E D; Boytsova, E B; Pozhilenkova, E A; Solonchuk, Yu R; Salmina, A B

    2015-01-01

    There are many ways to model blood brain barrier and neurovascular unit in vitro. All existing models have their disadvantages, advantages and some peculiarities of preparation and usage. We obtained the three-cells neurovascular unit model in vitro using progenitor cells isolated from the rat embryos brain (Wistar, 14-16 d). After withdrawal of the progenitor cells the neurospheres were cultured with subsequent differentiation into astrocytes and neurons. Endothelial cells were isolated from embryonic brain too. During the differentiation of progenitor cells the astrocytes monolayer formation occurs after 7-9 d, neurons monolayer--after 10-14 d, endothelial cells monolayer--after 7 d. Our protocol for simultaneous isolation and cultivation of neurons, astrocytes and endothelial cells reduces the time needed to obtain neurovascular unit model in vitro, consisting of three cells types and reduce the number of animals used. It is also important to note the cerebral origin of all cell types, which is also an advantage of our model in vitro.

  10. Importance of unit cells in accurate evaluation of the characteristics of graphene

    Energy Technology Data Exchange (ETDEWEB)

    Sabzyan, Hassan; Sadeghpour, Narges [Isfahan Univ. (Iran, Islamic Republic of). Dept. of Chemistry

    2016-08-01

    Effects of the size of the unit cell on energy, atomic charges, and phonon frequencies of graphene at the Γ point of the Brillouin zone are studied in the absence and presence of an electric field using density functional theory (DFT) methods (LDA and DFT-PBE functionals with Goedecker-Teter-Hutter (GTH) and Troullier-Martins (TM) norm-conserving pseudopotentials). Two types of unit cells containing n{sub c}=4-28 carbon atoms are considered. Results show that stability of graphene increases with increasing size of the unit cell. Energy, atomic charges, and phonon frequencies all converge above n{sub c}=24 for all functional-pseudopotentials used. Except for the LDA-GTH calculations, application of an electric field of 0.4 and 0.9 V/nm strengths does not change the trends with the size of the unit cell but instead slightly decreases the binding energy of graphene. Results of this study show that the choice of unit cell size and type is critical for calculation of reliable characteristics of graphene.

  11. Unit cell sparger test program and analysis of test results

    Energy Technology Data Exchange (ETDEWEB)

    Park, Choon Kyung; Song, C. H.; Cho, S.; Yoon, Y. J

    2003-11-01

    This report presents the results of test data from CPT-3 test and the effect of important parameters on the IRWST load. The object of CPT-3 test is to determine the influence of air mass in the piping on the IRWST (In-containment Refueling Water Storage Tank) boundary during an operation of Safety Depressurization and Vent System (SDVS). The test was conducted from an initial system pressure of 15.2 MPa, a steam temperature of 343.3 .deg. C, and an air mass of 3.34 lb. Following valve actuation, the pressure within the discharge line underwent pressure transient due to high pressure steam from the pressurizer and the discharged high pressure air formed air bubbles, which expanded and compressed periodically in the simulated IRWST. Air bubble oscillation was terminated within 2 s into the test. The magnitude of the pressure wave during the air clearing period was inversely proportional to the distance and very abrupt pressure spikes were observed in case the distance from the sparger holes to the submerged structure was less than 0.9 m. After the isolation valves were closed, the water in the simulated IRWST was considered to rise up to the 2.4m from the water surface in the quench tank. The amount of air mass in the piping, water temperature in the simulated IRWST, air temperature in the piping had not significant effect on the pressure loading during an air clearing period. However, the opening time of the isolation valve, steam mass flow rate, and submergence of an sparger have been shown to have great effects on the pressure loading during an air clearing period. 2 % of sparger flow area seems to be sufficient for the vacuum breaker area to mitigate the water hammering caused by abrupt water level rising during valve closure.

  12. Operational control and diagnostics of the equipment by the parameters of the electric drive power supply by the example of deep well pump units

    Science.gov (United States)

    Shishlyannikov, D. I.; Vasilyeva, M. A.

    2017-02-01

    Currently, the vast majority of Russian oil wells use oil well pumping units (OPU), equipped with a mechanical drive - a balancing pumping unit. The significant lifetime of balancing pumping units used in oil fields of Russia amounts to full or close to full resource generation and to a high accident rate of the mechanical drive rod of OPU. Reduced material costs for operation and maintenance of OPU may be provided by the rejection of the system of preventive maintenance and service during the transition to the actual technical condition. The article analyzes the statistics of the most frequent crash balancing pumping units of OPU and their causes. The prospect of applying the method of instrument control parameters is proved, and the technical condition of the OPU is assessed based on the analysis of the magnitude and the nature of changes in load drive motors, determined by the recording of the instantaneous values of power consumption. The authors consider the construction and operation of the programmable controller ‘AKD-SK’ manufactured by JSC R&D company ‘ROS’ (Perm). Fundamentals of vattmetrogramm analysis of OPU drive motors are stated, and the character of displaying key defects of submersible pumps and balanced beam unit is described.

  13. Chromosomal aberrations, sister-chromatid exchanges, cells with high frequency of SCE, micronuclei and comet assay parameters in 1, 3-butadiene-exposed workers.

    Science.gov (United States)

    Srám, R J; Rössner, P; Peltonen, K; Podrazilová, K; Mracková, G; Demopoulos, N A; Stephanou, G; Vlachodimitropoulos, D; Darroudi, F; Tates, A D

    1998-11-09

    The association of occupational exposure to 1,3-butadiene (BD) and induction of cytogenetic damage in peripheral lymphocytes was studied in 19 male workers from a monomer production unit and 19 control subjects from a heat production unit. The exposure to BD was measured by passive personal monitors. The following biomarkers were used: chromosomal aberrations (CA), sister chromatid exchanges (SCE), cells with a high frequency of SCE (HFC), micronuclei, comet assay parameters like tail length (TL) and percentage of DNA in tail [T (%)] and polymorphisms of GSTM1 and GSTT1 genotypes. BD exposure with a median value of 0.53 mg/m3 (range: 0.024-23.0) significantly increased (a) the percentage of cells with chromosomal aberrations in exposed vs. control groups (3.11% vs. 2.03%, P<0.01), (b) the frequency of SCE per cell (6.96 vs. 4.87, P<0.001), and (c) the percentage of HFC (19.9% vs. 4.1%, P<0.001). BD exposure had no significant effects on formation of micronuclei and on comet assay parameters. Effect of smoking was observed only for HFC in BD-exposed group. GSTM1 genotype affected chromosomal aberrations in exposed group, while GSTT1 genotype affected chromosomal aberrations in controls. No effect of GSTM1 or GSTT1 genotypes was observed on any other biomarkers used.

  14. Prediction of stress-strain behavior of ceramic matrix composites using unit cell model

    Directory of Open Access Journals (Sweden)

    Suzuki Takuya

    2015-01-01

    Full Text Available In this study, the elastic modulus and the stress-strain curve of ceramic matrix composites (CMCs were predicted by using the unit cell model that consists of fiber bundles and matrix. The unit cell model was developed based on the observation of cross sections of CMCs. The elastic modulus of CMCs was calculated from the results of finite element analysis using the developed model. The non-linear behavior of stress-strain curve of CMCs was also predicted by taking the degradation of the elastic modulus into consideration, where the degradation was related to the experimentally measured crack density in CMCs. The approach using the unit cell model was applied to two kinds of CMCs, and good agreement was obtained between the experimental and the calculated results.

  15. Effect of automated red cell exchanges on oxygen saturation on-air, blood parameters and length of hospitalization in sickle cell disease patients with acute chest syndrome

    Directory of Open Access Journals (Sweden)

    John C Aneke

    2016-01-01

    Full Text Available Background: Red cell exchanges (RCEs lead to improvement in tissue oxygenation and reduction in inflammatory markers in sickle cell disease (SCD patients who present with acute chest syndrome (ACS. The aim of this study is to evaluate the effects of automated-RCE (auto-RCE on oxygen saturation (SpO 2 on-air, blood counts, the time to correct the parameters and length of hospitalization after the exchange in SCD patients presenting with ACS. Subjects and Methods: This was 2 years study involving five SCD patients; the time for SpO 2 on air to increase to ≥95% and chest symptoms to resolve, postprocedure, as well as the length of in-patient hospitalization was recorded. All data were entered into Statistical Package for Social Sciences Version 20.0 (SPSS Inc., Chicago, IL, USA computer software for analyses. Results: The study involved 4 (80% hemoglobin (Hb SS and 1 (20% HbSC patients. The median time of SpO 2 recovery was 24 h, ranging from 6 to 96 h. About 60% (3/5 of patients achieved optimal SpO 2 within 24 h post-RCE, while discharge from intensive care unit was 24 h after auto-RCE in one patient. The Hb concentration was significantly higher, while the total white cell and absolute neutrophil counts were significantly lower at the time of resolution of symptoms, compared to before auto-RCE (P < 0.05. The average post auto-red cell transfusion symptoms duration was 105.6 (24-240 h while mean inpatient stay was 244.8 (144-456 h. Conclusion: Auto-RCE could reverse hypoxia in ACS within 24 h.

  16. Reduction in potassium concentration of stored red blood cell units using a resin filter.

    Science.gov (United States)

    Yamada, Chisa; Heitmiller, Eugenie S; Ness, Paul M; King, Karen E

    2010-09-01

    Hyperkalemia is a serious complication of rapid and massive blood transfusion due to high plasma potassium (K) in stored red blood cell (RBC) units. A potassium adsorption filter (PAF) was developed in Japan to remove K by exchanging with sodium (Na). We performed an in vitro evaluation of its efficacy and feasibility of use. Three AS-3 RBC units were filtered by each PAF using gravity; 10 PAFs were tested. Blood group, age, flow rate, and irradiation status were recorded. Total volume, K, Na, Cl, Mg, total Ca (tCa), RBC count, hemoglobin (Hb), hematocrit (Hct), and plasma Hb were measured before and after filtering each unit. Ionized Ca (iCa), pH, and glucose were measured for some units. After filtration, the mean decrease in K was 97.5% in the first RBC unit, 91.2% in the second unit, and 64.4% in the third unit. The mean increases in Na, Mg, and tCa were 33.0, 151.4, and 116.1%, respectively. iCa and pH remained low; glucose was unchanged. RBC count, Hb, and Hct decreased slightly after filtration of first units; plasma Hb was unchanged. After filtration, there was no visual evidence of increased hemolysis or clot formation. The PAF decreased K concentration in stored AS-3 RBC units to minimal levels in the first and second RBC units. Optimally, one filter could be used for 2 RBC units. Although Na increased, the level may not be clinically significant. PAF may be useful for at-risk patients receiving older units or blood that has been stored after gamma irradiation. © 2010 American Association of Blood Banks.

  17. Comparison of cytological parameters of exfoliated buccal mucosal cells in different temperament groups

    Directory of Open Access Journals (Sweden)

    Zahra Zendehboodi

    2017-05-01

    Full Text Available Introduction: Temperament (Mizaj forms the basic concept of Iranian traditional medicine (ITM, and greatly influences the diagnosis and treatment of diseases, as well as maintains the ideal healthy state of an individual. In particular, temperament is presumed to affect the morphological, physiological, and psychological features of a person; however, its influence on biological features remains unclear in practical ITM. This study aimed to evaluate the association between the temperament and the cytological features of buccal mucosa in healthy people. Methods: The study sample included 75 healthy individuals from Fars province, southern Iran. The temperament was determined using a self-reported temperament identification scale. Based on the questionnaire, volunteers were classified in nine temperaments including one equilibrium, four simple temperaments (warm, cold, moist, and dry, and four combined temperaments (warm–moist, warm–dry, cold–moist, cold–dry. Smears collected from the buccal mucosa of participants were analyzed for biomarkers of DNA damage, cytokinetic defects, proliferative potential, and cell death using micronucleus (MN assay. Student’s t-test or Mann–Whitney U test was applied to identify the differences between groups. Results: DNA damage (nuclear buds and cell death biomarkers (condensed chromatin, karyorrhexic, pyknotic, and karyolitic cells reported significant differences between certain temperament groups. Conclusions: The present study reported that the aforementioned cytological parameters could be affected by the temperament; however, more studies with greater sample sizes are warranted.

  18. An Estimation of Radiobiological Parameters for Head-and-Neck Cancer Cells and the Clinical Implications

    Science.gov (United States)

    Qi, X. Sharon; Yang, Qiuhui; Lee, Steve P.; Li, X. Allen; Wang, Dian

    2012-01-01

    In vitro survival measurements using two human head-and-neck cancer (HNC) cell lines were performed. The specially designed split-dose surviving fraction was obtained and fitted to the linear-quadratic formalism. The repair halftime (Tr), the potential doubling time (Td), α/β and radiosensitivity α, were estimated. Other radiobiological models: EUD, BED, TCP, etc., were used to examine the potential treatment effectiveness of different IMRT techniques. Our data indicated the repair halftime of ~17 min based on two HNC cell lines. The combined α/β, α and Td are α/β = 8.1 ± 4.1 Gy, α = 0.22 ± 0.08 Gy−1, Td = 4.0 ± 1.8 day, respectively. The prolonged IMRT dose delivery for entire HNC treatment course could possibly result in the loss of biological effectiveness, i.e., the target EUDs decreased by 11% with fraction dose delivery time varying from 5 to 30 min. We determined the sublethal damage repair halftime and other radiobiological parameters for HNC cells, and to evaluate treatment effectiveness of the prolonged dose delivery times associated with different IMRT techniques. The estimated repair halftime for HNC is relatively short and may be comparable to the step-and-shoot IMRT fraction dose delivery time. The effectiveness of IMRT treatment may be improved by reducing the fraction delivery time for HNC treatment. PMID:24213325

  19. Important parameters affecting the cell voltage of aqueous electrical double-layer capacitors

    Science.gov (United States)

    Wu, Tzu-Ho; Hsu, Chun-Tsung; Hu, Chi-Chang; Hardwick, Laurence J.

    2013-11-01

    This study discusses and demonstrates how the open-circuit potential and charges stored in the working potential window on positive and negative electrodes affect the cell voltage of carbon-based electrical double-layer capacitors (EDLCs) in aqueous electrolytes. An EDLC consisting of two activated carbon electrodes is employed as the model system for identifying these key parameters although the potential window of water decomposition can be simply determined by voltammetric methods. First, the capacitive performances of an EDLC with the same charge on positive and negative electrodes are evaluated by cyclic voltammetric, charge-discharge, electrochemical impedance spectroscopic (EIS) analyses, and inductance-capacitance-resistance meter (LCR meter). The principles for obtaining the highest acceptable cell voltage of such symmetric ECs with excellent reversibility and capacitor-like behaviour are proposed. Aqueous charge-balanced EDLCs can be operated as high as 2.0 V with high energy efficiency (about 90%) and only 4% capacitance loss after the 600-cycle stability checking. The necessity of charge balance (but not capacitance balance) for positive and negative electrodes is substantiated from the lower acceptable cell voltage of charge-unbalanced EDLCs.

  20. Growth of Casting Microcrack and Micropore in Single-crystal Superalloys Analysed by Three-Dimensional Unit Cell

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Finite element (FE) analysis was employed to investigate the casting microcrack and micropore growth in nickel-base single-crystal superalloys DD3. Based on the finite deformation rate-dependent crystallographic constitutive equation, the simulations of casting microcrack and micropore growth in three-dimensional unit cell model were carried out in a range of parameters including stress triaxiality, Lode parameter and type of activated slip systems. The FE results show that the stress triaxiality has profound effects on growth behavior,and the Lode parameter is also important for the casting microcrack and micropore growth. The type of operative slip systems has remarkable effect on casting microcrack and micropore growth, so the life of singlecrystal component is associated with the type of activated slip systems, which is related to Schmid factor and the number of activated slip systems. The growth comparison between microcrack and micropore reveals that when the material is subjected to large deformation, the growth rate of microcrack is faster than that of micropore, i.e. microcrack is more dangerous than micropore; the microcrack is easier to result in brittle fracture than micropore. The stress triaxiality and Lode parameter have strong influence on the growth of microcrack and micropore.

  1. Correlation between the physical parameters of the i-nc-Si absorber layer grown by 27.12 MHz plasma with the nc-Si solar cell parameters

    Science.gov (United States)

    Das, Debajyoti; Mondal, Praloy

    2017-09-01

    Growth of highly conducting nanocrystalline silicon (nc-Si) thin films of optimum crystalline volume fraction, involving dominant crystallographic preferred orientation with simultaneous low fraction of microstructures at a low substrate temperature and high growth rate, is a challenging task for its promising utilization in nc-Si solar cells. Utilizing enhanced electron density and superior ion flux densities of the high frequency (∼27.12 MHz) SiH4 plasma, improved nc-Si films have been produced by simple optimization of H2-dilution, controlling the ion damage and enhancing supply of atomic-hydrogen onto the growing surface. Single junction nc-Si p-i-n solar cells have been prepared with i-nc-Si absorber layer and optimized. The physical parameters of the absorber layer have been systematically correlated to variations of the solar cell parameters. The preferred alignment of crystallites, its contribution to the low recombination losses for conduction of charge carriers along the vertical direction, its spectroscopic correlation with the dominant growth of ultra-nanocrystalline silicon (unc-Si) component and corresponding longer wavelength absorption, especially in the neighborhood of i/n-interface region recognize scientific and technological key issues that pave the ground for imminent advancement of multi-junction silicon solar cells.

  2. High light-extraction-efficiency OLED based on photonic crystal slab structures with taper unit cells

    Institute of Scientific and Technical Information of China (English)

    YAN Rong-jin; WANG Qing-kang

    2006-01-01

    To improve the light-extraction-efficiency of OLED,we introduced PCS (Photonic Crystal Slab) structures into the interface of ITO layer and glass substrate.PCS structures with Taper unit cells are proved to be effective in reducing the energy of guided wave trapped in high refractive index material,and an increase of light-extraction-efficiency to 95.26% is gained.This enhancement is much greater than the traditional PCS with cylinder unit cells (60%-70%).Physical mechanisms of light-extraction-efficiency enhancement in these structures are further discussed.

  3. IMPACT OF ZOOTECHNICAL PARAMETERS ON CELL QUALITY OF CATTLE MILK (SEMI-ARID COSTAL TUNISIA

    Directory of Open Access Journals (Sweden)

    R. HAJ MBAREK

    2015-09-01

    Full Text Available The work was realized on a sample of 50 cattle herds, conducted in aboveground, in a coastal area of the semi-arid Tunisia, by using investigation related to cows and their breeding and milking conditions as well as despoliation in milk control data. Analysis of the data relating to the parameters of udder conformation and cow cleanliness revealed that “Udder depth” settings “Udder cleanliness” have been shown to affect the ICC and are considered factors risk of bovine mastitis. The study of breeding and milking conditions highlight some significant factors on changes on the variation of cell counts and the probability of the spread of mastitis, especially the "No disinfection of teat." The level of housing, the analysis revealed that the use of a litter reduced to half the average of ICC which proved highly related to the cleanliness of both the sleeping area as the udder.

  4. Novel cell parameter determination of a twisted-nematic liquid crystal display

    Institute of Scientific and Technical Information of China (English)

    Huang Xia; Jing Hai; Fu Guo-Zhu

    2008-01-01

    In this paper a novel method is proposed to determine the cell parameters including the twist angle, optic retardation and rubbing direction of twisted-nematic liquid crystal displays (TNLCD) by rotating the TNLCD. It is a single-wavelength method. Because using subtraction equation of transmittance as curve fitting equation, the influence of the light from environment and the absorption by polarizer, the sample of TNLCD and analyser on the transmittance is eliminated. Accurate results can also be obtained in imperfect darkness. By large numbers of experiments, we found that not only the experimental setup is quite simple and can be easily adopted to be carried out, but also the results are accurate.

  5. Effects of Butter and Phytanic acid intake on metabolic parameters and T-cell polarization

    DEFF Research Database (Denmark)

    Drachmann, Tue

    The still growing obesity epidemic is a major risk for our society, as it is associated with the development of the so called metabolic syndrome, which is a clinical diagnosis correlated to development of metabolic disorders. Lack of physical activity, excess energy intake, and nutritional factors...... dairy fat in general and phytanic acid on metabolic parameters, we performed several studies. First, we investigated effects on hepatic lipid metabolism, glucose homeostasis, and circulating metabolic markers, of high fat diets based on butter from high- or low-yield production, a diet based on high...... addition of phytanic acid. Third, we investigated butter and phytanic acid effects on human T-cell polarization, both by in vitro incubation with phytanic acid, and by a 12 weeks intervention with intake of butter. Finally, we performed two human interventions, first one with intake of butter and cheese...

  6. Evaluation of a Multi-Parameter Sensor for Automated, Continuous Cell Culture Monitoring in Bioreactors

    Science.gov (United States)

    Pappas, D.; Jeevarajan, A.; Anderson, M. M.

    2004-01-01

    Compact and automated sensors are desired for assessing the health of cell cultures in biotechnology experiments in microgravity. Measurement of cell culture medium allows for the optirn.jzation of culture conditions on orbit to maximize cell growth and minimize unnecessary exchange of medium. While several discrete sensors exist to measure culture health, a multi-parameter sensor would simplify the experimental apparatus. One such sensor, the Paratrend 7, consists of three optical fibers for measuring pH, dissolved oxygen (p02), dissolved carbon dioxide (pC02) , and a thermocouple to measure temperature. The sensor bundle was designed for intra-arterial placement in clinical patients, and potentially can be used in NASA's Space Shuttle and International Space Station biotechnology program bioreactors. Methods: A Paratrend 7 sensor was placed at the outlet of a rotating-wall perfused vessel bioreactor system inoculated with BHK-21 (baby hamster kidney) cells. Cell culture medium (GTSF-2, composed of 40% minimum essential medium, 60% L-15 Leibovitz medium) was manually measured using a bench top blood gas analyzer (BGA, Ciba-Corning). Results: A Paratrend 7 sensor was used over a long-term (>120 day) cell culture experiment. The sensor was able to track changes in cell medium pH, p02, and pC02 due to the consumption of nutrients by the BHK-21. When compared to manually obtained BGA measurements, the sensor had good agreement for pH, p02, and pC02 with bias [and precision] of 0.02 [0.15], 1 mm Hg [18 mm Hg], and -4.0 mm Hg [8.0 mm Hg] respectively. The Paratrend oxygen sensor was recalibrated (offset) periodically due to drift. The bias for the raw (no offset or recalibration) oxygen measurements was 42 mm Hg [38 mm Hg]. The measured response (rise) time of the sensor was 20 +/- 4s for pH, 81 +/- 53s for pC02, 51 +/- 20s for p02. For long-term cell culture measurements, these response times are more than adequate. Based on these findings , the Paratrend sensor could

  7. Effects of physical parameters on the cell-to-dendrite transition in directional solidification

    Science.gov (United States)

    Wei, Lei; Lin, Xin; Wang, Meng; Huang, Wei-Dong

    2015-07-01

    A quantitative cellular automaton model is used to study the cell-to-dendrite transition (CDT) in directional solidification. We give a detailed description of the CDT by carefully examining the influence of the physical parameters, including: the Gibbs-Thomson coefficient Γ, the solute diffusivity Dl, the solute partition coefficient k0, and the liquidus slope ml. It is found that most of the parameters agree with the Kurz and Fisher (KF) criterion, except for k0. The intrinsic relations among the critical velocity Vcd, the cellular primary spacing λc,max, and the critical spacing λcd are investigated. Project supported by the National Natural Science Foundation of China (Grant Nos. 51271213 and 51323008), the National Basic Research Program of China (Grant No. 2011CB610402), the National High Technology Research and Development Program of China (Grant No. 2013AA031103), the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20116102110016), and the China Postdoctoral Science Foundation (Grant No. 2013M540771).

  8. Investigation of IrO2/Pt Electrocatalysts in Unitized Regenerative Fuel Cells

    Directory of Open Access Journals (Sweden)

    V. Baglio

    2011-01-01

    Full Text Available IrO2/Pt catalysts (at different concentrations were synthesized by incipient wetness technique and characterized by XRD, XRF, and SEM. Water electrolysis/fuel cell performances were evaluated in a 5 cm2 single cell under Unitized Regenerative Fuel Cell (URFC configuration. The IrO2/Pt composition of 14/86 showed the highest performance for water electrolysis and the lowest one as fuel cell. It is derived that for fuel cell operation an excess of Pt favours the oxygen reduction process whereas IrO2 promotes oxygen evolution. From the present results, it appears that the diffusion characteristics and the reaction rate in fuel cell mode are significantly lower than in the electrolyser mode. This requires the enhancement of the gas diffusion properties of the electrodes and the catalytic properties for cathode operation in fuel cells.

  9. Water proton configurations in structures I, II, and H clathrate hydrate unit cells.

    Science.gov (United States)

    Takeuchi, Fumihito; Hiratsuka, Masaki; Ohmura, Ryo; Alavi, Saman; Sum, Amadeu K; Yasuoka, Kenji

    2013-03-28

    Position and orientation of water protons need to be specified when the molecular simulation studies are performed for clathrate hydrates. Positions of oxygen atoms in water are experimentally determined by X-ray diffraction analysis of clathrate hydrate structures, but positions of water hydrogen atoms in the lattice are disordered. This study reports a determination of the water proton coordinates in unit cell of structure I (sI), II (sII), and H (sH) clathrate hydrates that satisfy the ice rules, have the lowest potential energy configuration for the protons, and give a net zero dipole moment. Possible proton coordinates in the unit cell were chosen by analyzing the symmetry of protons on the hexagonal or pentagonal faces in the hydrate cages and generating all possible proton distributions which satisfy the ice rules. We found that in the sI and sII unit cells, proton distributions with small net dipole moments have fairly narrow potential energy spreads of about 1 kJ∕mol. The total Coulomb potential on a test unit charge placed in the cage center for the minimum energy∕minimum dipole unit cell configurations was calculated. In the sI small cages, the Coulomb potential energy spread in each class of cage is less than 0.1 kJ∕mol, while the potential energy spread increases to values up to 6 kJ∕mol in sH and 15 kJ∕mol in the sII cages. The guest environments inside the cages can therefore be substantially different in the sII case. Cartesian coordinates for oxygen and hydrogen atoms in the sI, sII, and sH unit cells are reported for reference.

  10. Culture of human cells in experimental units for spaceflight impacts on their behavior.

    Science.gov (United States)

    Cazzaniga, Alessandra; Moscheni, Claudia; Maier, Jeanette Am; Castiglioni, Sara

    2017-05-01

    Because space missions produce pathophysiological alterations such as cardiovascular disorders and bone demineralization which are very common on Earth, biomedical research in space is a frontier that holds important promises not only to counterbalance space-associated disorders in astronauts but also to ameliorate the health of Earth-bound population. Experiments in space are complex to design. Cells must be cultured in closed cell culture systems (from now defined experimental units (EUs)), which are biocompatible, functional, safe to minimize any potential hazard to the crew, and with a high degree of automation. Therefore, to perform experiments in orbit, it is relevant to know how closely culture in the EUs reflects cellular behavior under normal growth conditions. We compared the performances in these units of three different human cell types, which were recently space flown, i.e. bone mesenchymal stem cells, micro- and macrovascular endothelial cells. Endothelial cells are only slightly and transiently affected by culture in the EUs, whereas these devices accelerate mesenchymal stem cell reprogramming toward osteogenic differentiation, in part by increasing the amounts of reactive oxygen species. We conclude that cell culture conditions in the EUs do not exactly mimic what happens in a culture dish and that more efforts are necessary to optimize these devices for biomedical experiments in space. Impact statement Cell cultures represent valuable preclinical models to decipher pathogenic circuitries. This is true also for biomedical research in space. A lot has been learnt about cell adaptation and reaction from the experiments performed on many different cell types flown to space. Obviously, cell culture in space has to meet specific requirements for the safety of the crew and to comply with the unique environmental challenges. For these reasons, specific devices for cell culture in space have been developed. It is important to clarify whether these

  11. Engineering and performance standards parameters for long distance road transport in the United States: the special case of horses

    Directory of Open Access Journals (Sweden)

    Carolyn L. Stull

    2008-03-01

    Full Text Available The transportation conditions of slaughter horses for human consumption have become a public and regulatory issue in the United States in the last two decades. Federal regulations were developed partially using the results of funded research projects that examined the types of vehicles, characteristics of slaughter horse candidates, types of injuries during transport, duration of transit, stocking densities and other behavioural and physiological indices during long-distance road transport. Additionally, the physiological responses of horses travelling long distances in vans while cross-tied by their halters in individual stalls were also studied. Both engineering- and performance-based standards were developed from the scientific studies and implemented in the federal regulations to ensure the humane movement of equines to slaughter facilities via commercial road transportation.

  12. Fukushima Daiichi Unit 1 Uncertainty Analysis-Exploration of Core Melt Progression Uncertain Parameters-Volume II.

    Energy Technology Data Exchange (ETDEWEB)

    Denman, Matthew R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brooks, Dusty Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-08-01

    Sandia National Laboratories (SNL) has conducted an uncertainty analysi s (UA) on the Fukushima Daiichi unit (1F1) accident progression wit h the MELCOR code. Volume I of the 1F1 UA discusses the physical modeling details and time history results of the UA. Volume II of the 1F1 UA discusses the statistical viewpoint. The model used was developed for a previous accident reconstruction investigation jointly sponsored by the US Department of Energy (DOE) and Nuclear Regulatory Commission (NRC). The goal of this work was to perform a focused evaluation of uncertainty in core damage progression behavior and its effect on key figures - of - merit (e.g., hydrogen production, fraction of intact fuel, vessel lower head failure) and in doing so assess the applicability of traditional sensitivity analysis techniques .

  13. Development of Site-Specific Soil Design Basis Earthquake (DBE) Parameters for the Integrated Waste Treatment Unit (IWTU)

    Energy Technology Data Exchange (ETDEWEB)

    Payne, Suzette

    2008-08-01

    Horizontal and vertical PC 3 (2,500 yr) Soil Design Basis Earthquake (DBE) 5% damped spectra, corresponding time histories, and strain-compatible soil properties were developed for the Integrated Waste Treatment Unit (IWTU). The IWTU is located at the Idaho Nuclear Technology and Engineering Center (INTEC) at the Idaho National Laboratory (INL). Mean and 84th percentile horizontal DBE spectra derived from site-specific site response analyses were evaluated for the IWTU. The horizontal and vertical PC 3 (2,500 yr) Soil DBE 5% damped spectra at the 84th percentile were selected for Soil Structure Interaction (SSI) analyses at IWTU. The site response analyses were performed consistent with applicable Department of Energy (DOE) Standards, recommended guidance of the Nuclear Regulatory Commission (NRC), American Society of Civil Engineers (ASCE) Standards, and recommendations of the Blue Ribbon Panel (BRP) and Defense Nuclear Facilities Safety Board (DNFSB).

  14. Monitoring of physical health parameters for inpatients on a child and adolescent mental health unit receiving regular antipsychotic therapy.

    Science.gov (United States)

    Pasha, Nida; Saeed, Shoaib; Drewek, Katherine

    2015-01-01

    Physical health monitoring of patients receiving antipsychotics is vital. Overall it is estimated that individuals suffering with conditions like schizophrenia have a 20% shorter life expectancy than the average population, moreover antipsychotic use has been linked to a number of conditions including diabetes, obesity, and cardiovascular disease.[1-4] The severity of possible adverse effects to antipsychotics in adults has raised awareness of the importance of monitoring physical health in this population. However, there is little literature available as to the adverse effects of these medications in the child and adolescent community, which make physical health monitoring in this predominantly antipsychotic naïve population even more important. An expert group meeting in the UK has laid down recommendations in regards to screening and management of adult patients receiving antipsychotics, however no specific guidelines have been put in place for the child and adolescent age group.[5] The aim of this audit was to establish whether in-patients receiving antipsychotics had the following investigations pre-treatment and 12 weeks after treatment initiation: body mass index, hip-waist circumference, blood pressure, ECG, urea and electrolytes, full blood count, lipid profile, random glucose level, liver function test, and prolactin. This is in addition to a pre-treatment VTE risk assessment. These standards were derived from local trust guidelines, NICE guidelines on schizophrenia [6] and The Maudsley Prescribing Guidelines.[7] We retrospectively reviewed 39 electronic case notes in total, of which 24 cases were post intervention. Intervention included the use of a prompting tool. This tool was filed in the physical health files of all patients receiving antipsychotics which was intended as a reminder to doctors regarding their patient's need for physical health monitoring. Professionals involved in the monitoring of such parameters were educated in the importance and

  15. Fermi surface properties of paramagnetic NpCd{sub 11} with a large unit cell

    Energy Technology Data Exchange (ETDEWEB)

    Homma, Yoshiya; Aoki, Dai; Shiokawa, Yoshinobu [Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Haga, Yoshinori; Sakai, Hironori; Ikeda, Shugo; Yamamoto, Etsuji; Nakamura, Akio; Onuki, Yoshichika [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Settai, Rikio [Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Takeuchi, Tetsuya [Cryogenic Center, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Yamagami, Hiroshi, E-mail: yhomma@imr.tohoku.ac.jp [Department of Physics, Faculty of Science, Kyoto Sangyo University, Kyoto 603-8555 (Japan)

    2010-03-15

    We succeeded in growing a high-quality single crystal of NpCd{sub 11} with the cubic BaHg{sub 11}-type structure by the Cd-self flux method. The lattice parameter of a = 9.2968(2) A and crystallographic positions of the atoms were determined by x-ray single-crystal structure analysis. From the results of the magnetic susceptibility and specific heat experiments, this compound is found to be a 5f-localized paramagnet with the singlet ground state in the crystalline electric field (CEF) scheme. Fermi surface properties were measured using the de Haas-van Alphen (dHvA) technique. Long-period oscillations were observed in the dHvA frequency range of 9.1 x 10{sup 5} to 1.9 x 10{sup 7} Oe, indicating small cross-sectional areas of Fermi surfaces, which is consistent with a small Brillouin zone based on a large unit cell. From the results of dHvA and magnetoresistance experiments, the Fermi surface of NpCd{sub 11} is found to consist of many kinds of closed Fermi surfaces and a multiply-connected-like Fermi surface, although the result of energy band calculations based on the 5f-localized Np{sup 3+}(5f{sup 4}) configuration reveals the existence of only closed Fermi surfaces. The corresponding cyclotron effective mass is small, ranging from 0.1 to 0.7 m{sub 0}, which is consistent with a small electronic specific heat coefficient {gamma} {approx_equal} 10mJ/K{sup 2{center_dot}}mol, revealing no hybridization between the 5f electrons and conduction electrons.

  16. Automated screening for myelodysplastic syndromes through analysis of complete blood count and cell population data parameters.

    Science.gov (United States)

    Raess, Philipp W; van de Geijn, Gert-Jan M; Njo, Tjin L; Klop, Boudewijn; Sukhachev, Dmitry; Wertheim, Gerald; McAleer, Tom; Master, Stephen R; Bagg, Adam

    2014-04-01

    The diagnosis of myelodysplastic syndromes (MDS) requires a high clinical index of suspicion to prompt bone marrow studies as well as subjective assessment of dysplastic morphology. We sought to determine if data collected by automated hematology analyzers during complete blood count (CBC) analysis might help to identify MDS in a routine clinical setting. We collected CBC parameters (including those for research use only and cell population data) and demographic information in a large (>5,000), unselected sequential cohort of outpatients. The cohort was divided into independent training and test groups to develop and validate a random forest classifier that identifies MDS. The classifier effectively identified MDS and had a receiver operating characteristic area under the curve (AUC) of 0.942. Platelet distribution width and the standard deviation of red blood cell distribution width were the most discriminating variables within the classifier. Additionally, a similar classifier was validated with an additional, independent set of >200 patients from a second institution with an AUC of 0.93. This retrospective study demonstrates the feasibility of identifying MDS in an unselected outpatient population using data routinely collected during CBC analysis with a classifier that has been validated using two independent data sets from different institutions.

  17. Non-invasive in Situ Simultaneous Measurement of Multi-parameter Mechanical Properties of Red Blood Cell Membrane

    Institute of Scientific and Technical Information of China (English)

    Jing LI; Yao-Xiong HUANG; Tao JI; Mei TU; Xuan MAO; Wen-Xin CHEN; Guang-Wei CHEN

    2005-01-01

    The purpose of this study was to develop a new dynamic image analyzing technique that will give us the ability to measure the viscoelastic parameters of individual living red blood cells non-invasively, in situ and in real time. With this technique, the bending modulus Kc, the shear elasticityμ and their ratio ε were measured under different temperatures, oxygen partial pressures and osmotic pressures. The results not only show the effects of external conditions on mechanical properties of cell membranes including deformability,flexibility, adhesive ability and plasticity, but also demonstrate that the technique can be used to measure cell membrane parameters continuously under several physiological and pathological conditions.

  18. Teaching Basic Science Environmentally, The Concept: The cell is basic unit of structure of most organisms.

    Science.gov (United States)

    Busch, Phyllis S.

    1985-01-01

    Suggests simple ways to introduce students to the concept that the cell is the basic unit of structure of most organisms. Mentions materials for microscope study that are readily available and easy to handle, e.g., membranes from between the scales of the onion bulb, thin-leaved plants, pond water, and pollen. (JHZ)

  19. 3D-Printing Crystallographic Unit Cells for Learning Materials Science and Engineering

    Science.gov (United States)

    Rodenbough, Philip P.; Vanti, William B.; Chan, Siu-Wai

    2015-01-01

    Introductory materials science and engineering courses universally include the study of crystal structure and unit cells, which are by their nature highly visual 3D concepts. Traditionally, such topics are explored with 2D drawings or perhaps a limited set of difficult-to-construct 3D models. The rise of 3D printing, coupled with the wealth of…

  20. Predication of Plastic Flow Characteristics in Ferrite/Pearlite Steel Using a Fern Unit Cell Method

    Institute of Scientific and Technical Information of China (English)

    Hong Li; Jingtao Han; Jing Liu; Lv Zhang

    2004-01-01

    The flow stress of ferrite/pearlite steel under uni-axial tension was simulated with finite element method (FEM) by applying commercial software MARC/MENTAT. Flow stress curves of ferrite/pearlite steels were calculated based on unit cell model. The effects of volume fraction, distribution and the aspect ratio of pearlite on tensile properties have been investigated.

  1. 3D-Printing Crystallographic Unit Cells for Learning Materials Science and Engineering

    Science.gov (United States)

    Rodenbough, Philip P.; Vanti, William B.; Chan, Siu-Wai

    2015-01-01

    Introductory materials science and engineering courses universally include the study of crystal structure and unit cells, which are by their nature highly visual 3D concepts. Traditionally, such topics are explored with 2D drawings or perhaps a limited set of difficult-to-construct 3D models. The rise of 3D printing, coupled with the wealth of…

  2. Mitigation of Unwanted Forward Narrow-band Radiation from PCBs with a Metamaterial Unit Cell

    DEFF Research Database (Denmark)

    Ruaro, Andrea; Thaysen, Jesper; Jakobsen, Kaj Bjarne

    2013-01-01

    Mitigation of EMI from a PCB is obtained through the use of a metamaterial unit cell. The focus is on the reduction of narrow-band radiation in the forward hemisphere when the resonant element is etched on a layer located between the source of radiation and the ground plane. As opposed to previou...

  3. Recovery Act. Solid Oxide Fuel Cell Diesel Auxilliary Power Unit Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Geiger, Gail E. [Delphi Automotive Systems, LLC., Gillingham (United Kingdom)

    2013-09-30

    Solid Oxide Fuel Cell Diesel Auxilliary Power Unit Demonstration Project. Summarizing development of Delphi’s next generation SOFC system as the core power plant to prove the viability of the market opportunity for a 3-5 kW diesel SOFC system. Report includes test and demonstration results from testing the diesel APU in a high visibility fleet customer vehicle application.

  4. Experimental broadband absorption enhancement in silicon nanohole structures with optimized complex unit cells.

    Science.gov (United States)

    Lin, Chenxi; Martínez, Luis Javier; Povinelli, Michelle L

    2013-09-09

    We design silicon membranes with nanohole structures with optimized complex unit cells that maximize broadband absorption. We fabricate the optimized design and measure the optical absorption. We demonstrate an experimental broadband absorption about 3.5 times higher than an equally-thick thin film.

  5. Aluminium sulfate as coagulant for highly polluted cork processing wastewater: Evaluation of settleability parameters and design of a clarifier-thickener unit.

    Science.gov (United States)

    González, Teresa; Domínguez, Joaquín R; Beltrán-Heredia, Jesús; García, Héctor M; Sanchez-Lavado, F

    2007-09-01

    This is the second part of a master project on the chemistry of aluminium as coagulant in the treatment of highly polluted cork-process-wastewater. The main aim of this second part was to determine the influence of the operating conditions on the system's settleability parameters. It is well known that it is just as important to achieve good settleability parameters in the physico-chemical treatment of wastewaters as it is to attain a high level of decontamination. These parameters will determine the dimensions of the required equipment, and hence the costs of the installation. This part of the study therefore analyzes the influence of the different operating variables on the following settleability parameters: sediment volumetric percentage, settling velocity, sludge volume index and total suspended solids just after mixture with the coagulant. The ranges used for the experimental variables were: coagulant dose (83-166 mgL(-1) of Al(3+)), coagulation mixing time (5-30 min), stirring rate (60-300 rpm), contamination level of the wastewater (Wastewater II COD approximately 2000 mg O(2) L(-1), Wastewater III COD approximately 3000 mg O(2) L(-1)), and pH (5-11). The optimal conditions found for the settling process were not the same as those that had been determined for the organic matter removal. In this case the optimal conditions were: coagulation mixing time (30 min), stirring rate (60 rpm), coagulant dose (83 mgL(-1) of Al(3+)) and pH (7-9). Finally, the Talmadge-Fitch method is used to apply the results to the design of a clarifier-thickener unit to treat 2m(3)h(-1) of wastewater. The required minimum area of the unit would be 4.11 m(2).

  6. Critical Parameters of the In Vitro Method of Vascular Smooth Muscle Cell Calcification.

    Directory of Open Access Journals (Sweden)

    Luis Hortells

    Full Text Available Vascular calcification (VC is primarily studied using cultures of vascular smooth muscle cells. However, the use of very different protocols and extreme conditions can provide findings unrelated to VC. In this work we aimed to determine the critical experimental parameters that affect calcification in vitro and to determine the relevance to calcification in vivo.Rat VSMC calcification in vitro was studied using different concentrations of fetal calf serum, calcium, and phosphate, in different types of culture media, and using various volumes and rates of change. The bicarbonate content of the media critically affected pH and resulted in supersaturation, depending on the concentration of Ca2+ and Pi. Such supersaturation is a consequence of the high dependence of bicarbonate buffers on CO2 vapor pressure and bicarbonate concentration at pHs above 7.40. Such buffer systems cause considerable pH variations as a result of minor experimental changes. The variations are more critical for DMEM and are negligible when the bicarbonate concentration is reduced to ¼. Particle nucleation and growth were observed by dynamic light scattering and electron microscopy. Using 2mM Pi, particles of ~200nm were observed at 24 hours in MEM and at 1 hour in DMEM. These nuclei grew over time, were deposited in the cells, and caused osteogene expression or cell death, depending on the precipitation rate. TEM observations showed that the initial precipitate was amorphous calcium phosphate (ACP, which converts into hydroxyapatite over time. In blood, the scenario is different, because supersaturation is avoided by a tightly controlled pH of 7.4, which prevents the formation of PO43--containing ACP.The precipitation of ACP in vitro is unrelated to VC in vivo. The model needs to be refined through controlled pH and the use of additional procalcifying agents other than Pi in order to reproduce calcium phosphate deposition in vivo.

  7. In vivo measurement of Pu dissolution parameters of MOX aerosols and related uncertainties in the values of the dose per unit intake.

    Science.gov (United States)

    Ramounet-Le Gall, B; Rateau, G; Abram, M C; Grillon, G; Ansoborlo, E; Bérard, P; Delforge, J; Fritsch, P

    2003-01-01

    The aim of this study was to compare dissolution parameter values for Pu from industrial MOX with different Pu contents. For this purpose, preliminary results obtained after inhalation exposure of rats to MOX containing 2.5% Pu are reported and compared to those obtained previously with MOX containing 5% Pu. Dissolution parameter values appear to increase when the amount of Pu decreases. Rapid fractions, f(r), of 4 x 10(-3) (s.d. = 2 x 10(-3)) and 1 x 10(-3) (s.d. = 6 x 10(-4)) and slow dissolution rates, s(s) of 2 x 10(-4) d(-1) (standard deviation, sigma = 5 x 10(-5)) and 5 x 10(-5) d(-1) (sigma = 1 x 10(-5)) were derived for MOX containing 2.5 and 5% of Pu, respectively. Simulations were performed to assess uncertainties on dose due to experimental errors. The relative standard deviations of the dose per unit intake (DPUI) due to f(r) (4-8%), are far less than those due to s(s) (about 20%), which is the main parameter altering the dose. Although quite different dissolution parameter values were derived, similar DPUIs were obtained for MOX aerosols containing 2.5 and 5% Pu which appear close to that for default Type S values.

  8. An easy-to-use simulation program demonstrates variations in bacterial cell cycle parameters depending on medium and temperature.

    Science.gov (United States)

    Stokke, Caroline; Flåtten, Ingvild; Skarstad, Kirsten

    2012-01-01

    Many studies are performed on chromosome replication and segregation in Escherichia coli and other bacteria capable of complex replication with C phases spanning several generations. For such investigations an understanding of the replication patterns, including copy numbers of origins and replication forks, is crucial for correct interpretation of the results.Flow cytometry is an important tool for generation of experimental DNA distributions of cell populations. Here, a Visual Basic based simulation program was written for the computation of theoretical DNA distributions for different choices of cell cycle parameters (C and D phase durations, doubling time etc). These cell cycle parameters can be iterated until the best fit between the experimental and theoretical DNA histograms is obtained. The Excel file containing the simulation software is attached as supporting information.Cultures of Escherichia coli were grown at twelve different media and temperature conditions, with following measurements by flow cytometry and simulation of the DNA distributions. A good fit was found for each growth condition by use of our simulation program. The resulting cell cycle parameters displayed clear inter-media differences in replication patterns, but indicated a high degree of temperature independence for each medium. The exception was the poorest medium (acetate), where the cells grew with overlapping replication cycles at 42 °C, but without at the lower temperatures.We have developed an easy-to-use tool for determination of bacteria's cell cycle parameters, and consequently the cells' chromosome configurations. The procedure only requires DNA distribution measurements by flow cytometry. Use of this simulation program for E. coli cultures shows that even cells growing quite slowly can have overlapping replication cycles. It is therefore always important not only to assume cells' replication patterns, but to actually determine the cell cycle parameters when changing growth

  9. An easy-to-use simulation program demonstrates variations in bacterial cell cycle parameters depending on medium and temperature.

    Directory of Open Access Journals (Sweden)

    Caroline Stokke

    Full Text Available Many studies are performed on chromosome replication and segregation in Escherichia coli and other bacteria capable of complex replication with C phases spanning several generations. For such investigations an understanding of the replication patterns, including copy numbers of origins and replication forks, is crucial for correct interpretation of the results.Flow cytometry is an important tool for generation of experimental DNA distributions of cell populations. Here, a Visual Basic based simulation program was written for the computation of theoretical DNA distributions for different choices of cell cycle parameters (C and D phase durations, doubling time etc. These cell cycle parameters can be iterated until the best fit between the experimental and theoretical DNA histograms is obtained. The Excel file containing the simulation software is attached as supporting information.Cultures of Escherichia coli were grown at twelve different media and temperature conditions, with following measurements by flow cytometry and simulation of the DNA distributions. A good fit was found for each growth condition by use of our simulation program. The resulting cell cycle parameters displayed clear inter-media differences in replication patterns, but indicated a high degree of temperature independence for each medium. The exception was the poorest medium (acetate, where the cells grew with overlapping replication cycles at 42 °C, but without at the lower temperatures.We have developed an easy-to-use tool for determination of bacteria's cell cycle parameters, and consequently the cells' chromosome configurations. The procedure only requires DNA distribution measurements by flow cytometry. Use of this simulation program for E. coli cultures shows that even cells growing quite slowly can have overlapping replication cycles. It is therefore always important not only to assume cells' replication patterns, but to actually determine the cell cycle parameters when

  10. Inulin isoforms differ by repeated additions of one crystal unit cell.

    Science.gov (United States)

    Cooper, Peter D; Barclay, Thomas G; Ginic-Markovic, Milena; Gerson, Andrea R; Petrovsky, Nikolai

    2014-03-15

    Inulin isoforms, especially delta inulin, are important biologically as immune activators and clinically as vaccine adjuvants. In exploring action mechanisms, we previously found regular increments in thermal properties of the seven-member inulin isoform series that suggested regular additions of some energetic structural unit. Because the previous isolates carried additional longer chains that masked defining ranges, these were contrasted with new isoform isolates comprising only inulin chain lengths defining that isoform. The new series began with 19 fructose units per chain (alpha-1 inulin), increasing regularly by 6 fructose units per isoform. Thus the 'energetic unit' equates to 6 fructose residues per chain. All isoforms showed indistinguishable X-ray diffraction patterns that were also identical with known inulin crystals. We conclude that an 'energetic unit' equates to one helix turn of 6 fructose units per chain as found in one unit cell of the inulin crystal. Each isoform chain comprised progressively more helix turns plus one additional fructose and glucose residues per chain.

  11. Question 7: the first units of life were not simple cells.

    Science.gov (United States)

    Norris, Vic; Hunding, Axel; Kepes, Francois; Lancet, Doron; Minsky, Abraham; Raine, Derek; Root-Bernstein, Robert; Sriram, K

    2007-10-01

    Five common assumptions about the first cells are challenged by the pre-biotic ecology model and are replaced by the following propositions: firstly, early cells were more complex, more varied and had a greater diversity of constituents than modern cells; secondly, the complexity of a cell is not related to the number of genes it contains, indeed, modern bacteria are as complex as eukaryotes; thirdly, the unit of early life was an 'ecosystem' rather than a 'cell'; fourthly, the early cell needed no genes at all; fifthly, early life depended on non-covalent associations and on catalysts that were not confined to specific reactions. We present here the outlines of a theory that connects findings about modern bacteria with speculations about their origins.

  12. Purification of Immune Cell Populations from Freshly Isolated Murine Tumors and Organs by Consecutive Magnetic Cell Sorting and Multi-parameter Flow Cytometry-Based Sorting.

    Science.gov (United States)

    Salvagno, Camilla; de Visser, Karin E

    2016-01-01

    It is well established that tumors evolve together with nonmalignant cells, such as fibroblasts, endothelial cells, and immune cells. These cells constantly entangle and interact with each other creating the tumor microenvironment. Immune cells can exert both tumor-promoting and tumor-protective functions. Detailed phenotypic and functional characterization of intra-tumoral immune cell subsets has become increasingly important in the field of cancer biology and cancer immunology. In this chapter, we describe a method for isolation of viable and pure immune cell subsets from freshly isolated murine solid tumors and organs. First, we describe a protocol for the generation of single-cell suspensions from tumors and organs using mechanical and enzymatic strategies. In addition, we describe how immune cell subsets can be purified by consecutive magnetic cell sorting and multi-parameter flow cytometry-based cell sorting.

  13. A Micromechanical Unit Cell Model of 2 × 2 Twill Woven Fabric Textile Composite for Multi Scale Analysis

    Science.gov (United States)

    Dixit, A.; Mali, H. S.; Misra, R. K.

    2014-04-01

    Woven fabric based composite materials are being considered for potential structural applications in automotive and aircraft industries due to their better out of plane strength, stiffness and toughness properties than ordinary composite laminates. This paper presents the micromechanical unit cell model of 2 × 2 twill woven fabric textile composite for the estimation of in-plane elastic properties. Modelling of unit cell and its analysis for this new model is developed by using open source coded tool TexGen and finite element software, ABAQUS® respectively. The predicted values are in good agreement with the experimental results reported in literature. To ascertain the effectiveness of the developed model parametric studies have also been conducted on the predicted elastic properties in order to investigate the effects of various geometric parameters such as yarn spacing, fabric thickness, yarn width and fibre volume fraction. The scope of altering weave pattern and yarn characteristics is facilitated in this developed model. Further this model can be implemented for the multi-scale micro/macro-mechanical analysis for the calculation of strength and stiffness of laminates structure made of 2 × 2 twill composite.

  14. Arrhenius parameter determination as a function of heating method and cellular microenvironment based on spatial cell viability analysis.

    Science.gov (United States)

    Whitney, Jon; Carswell, William; Rylander, Nichole

    2013-06-01

    Predictions of injury in response to photothermal therapy in vivo are frequently made using Arrhenius parameters obtained from cell monolayers exposed to laser or water bath heating. However, the impact of different heating methods and cellular microenvironments on Arrhenius predictions has not been thoroughly investigated. This study determined the influence of heating method (water bath and laser irradiation) and cellular microenvironment (cell monolayers and tissue phantoms) on Arrhenius parameters and spatial viability. MDA-MB-231 cells seeded in monolayers and sodium alginate phantoms were heated with a water bath for 3-20 min at 46, 50, and 54 °C or laser irradiated (wavelength of 1064 nm and fluences of 40 W/cm(2) or 3.8 W/cm(2) for 0-4 min) in combination with photoabsorptive carbon nanohorns. Spatial viability was measured using digital image analysis of cells stained with calcein AM and propidium iodide and used to determine Arrhenius parameters. The influence of microenvironment and heating method on Arrhenius parameters and capability of parameters derived from more simplistic experimental conditions (e.g. water bath heating of monolayers) to predict more physiologically relevant systems (e.g. laser heating of phantoms) were assessed. Arrhenius predictions of the treated area (Arrhenius parameters, with heating method having the greater impact.

  15. A heated vapor cell unit for dichroic atomic vapor laser lock in atomic rubidium.

    Science.gov (United States)

    McCarron, Daniel J; Hughes, Ifan G; Tierney, Patrick; Cornish, Simon L

    2007-09-01

    The design and performance of a compact heated vapor cell unit for realizing a dichroic atomic vapor laser lock (DAVLL) for the D(2) transitions in atomic rubidium is described. A 5 cm long vapor cell is placed in a double-solenoid arrangement to produce the required magnetic field; the heat from the solenoid is used to increase the vapor pressure and correspondingly the DAVLL signal. We have characterized experimentally the dependence of important features of the DAVLL signal on magnetic field and cell temperature. For the weaker transitions both the amplitude and gradient of the signal are increased by an order of magnitude.

  16. Identification of PV solar cells and modules parameters using the genetic algorithms: Application to maximum power extraction

    Energy Technology Data Exchange (ETDEWEB)

    Zagrouba, M.; Sellami, A.; Bouaicha, M. [Laboratoire de Photovoltaique, des Semi-conducteurs et des Nanostructures, Centre de Recherches et des Technologies de l' Energie, Technopole de Borj-Cedria, Tunis, B.P. 95, 2050 Hammam-Lif (Tunisia); Ksouri, M. [Unite de Recherche RME-Groupe AIA, Institut National des Sciences Appliquees et de Technologie (Tunisia)

    2010-05-15

    In this paper, we propose to perform a numerical technique based on genetic algorithms (GAs) to identify the electrical parameters (I{sub s}, I{sub ph}, R{sub s}, R{sub sh}, and n) of photovoltaic (PV) solar cells and modules. These parameters were used to determine the corresponding maximum power point (MPP) from the illuminated current-voltage (I-V) characteristic. The one diode type approach is used to model the AM1.5 I-V characteristic of the solar cell. To extract electrical parameters, the approach is formulated as a non convex optimization problem. The GAs approach was used as a numerical technique in order to overcome problems involved in the local minima in the case of non convex optimization criteria. Compared to other methods, we find that the GAs is a very efficient technique to estimate the electrical parameters of PV solar cells and modules. Indeed, the race of the algorithm stopped after five generations in the case of PV solar cells and seven generations in the case of PV modules. The identified parameters are then used to extract the maximum power working points for both cell and module. (author)

  17. Carob fibre compounds modulate parameters of cell growth differently in human HT29 colon adenocarcinoma cells than in LT97 colon adenoma cells.

    Science.gov (United States)

    Klenow, S; Glei, M; Haber, B; Owen, R; Pool-Zobel, B L

    2008-04-01

    An extract of the Mediterranean carob (Ceratonia siliqua L.) pod (carob fibre extract), products formed after its fermentation by the gut flora and the major phenolic ingredient gallic acid (GA), were comparatively investigated for their influence on survival and growth parameters of colon adenocarcinoma HT29 cells and adenoma LT97 cells. Hydrogen peroxide (H2O2) formation in the cell culture media was quantified. After 1h 97+/-4 microM or 70+/-15 microM were found in HT29 medium and 6+/-1 microM or 3+/-3 microM in LT97 medium for carob fibre extract or GA, respectively. After 72 h carob fibre extract reduced survival of rapidly proliferating HT29 cells (by 76.4+/-12.9%) whereas metabolic activity and DNA-synthesis were only transiently impaired. Survival of slower growing LT97 cells was less decreased (by 21.5+/-12.9%), but there were marked effects on DNA-synthesis (reduction by 95.6+/-7%, 72 h). GA and fermented carob fibre did not have comparable effects. Thus, carob fibre extract resulted in H2O2 formation, which, however, could not explain impairment of cell growth. The differently modulated growth of human colon cell lines was more related to proliferation rates and impairment of DNA-synthesis than to H2O2 formation.

  18. The effects of concentrated system on the electrical parameters of GaInP/GaAs solar cell

    Science.gov (United States)

    Kınacı, Barış

    2017-02-01

    III-V concentrator solar cells are suitable materials in order to reduce the cost of photovoltaic electricity. By using Fresnel lens in concentrating photovoltaic technology is an effective way to entirely use the sunlight. In the present study, the research on the efficiency analysis of the GaInP/GaAs concentrated solar cell structure with AlGaAs tunnel junction was performed. The electrical output parameters of this structure were determined by concentrated system with Fresnel lens. The current-voltage measurements of concentrated solar cell were carried out at room temperature under both dark and air mass 1.5 global radiations. The parameters of GaInP/GaAs concentrated solar cell at 1 Sun and at 32 Suns are compared. It is obtained that the integration of the concentrated system on the solar cell structure improves the device performance by ≈7.5%.

  19. Electrochemical characterization of a polybenzimidazole-based high temperature proton exchange membrane unit cell

    DEFF Research Database (Denmark)

    Jespersen, Jesper Lebæk; Schaltz, Erik; Kær, Søren Knudsen

    2009-01-01

    Equivalent Circuit (EC) modeling key parameters, such as the membrane resistance, charge transfer resistance and gas transfer resistance are identified, however the physical interpretation of the parameters derived from EC's are doubtful as discussed in this paper. The EC model proposed, which is a modified...... Randles circuit, provides a reasonably good fit at all the conditions tested. The measurements reveal that the cell temperature is an important parameter, which influences the cell performance significantly, especially the charge transfer resistance proved to be very temperature dependent. The transport...... of oxygen to the Oxygen Reduction Reaction (ORR) likewise has a substantial effect on the impedance spectra, results showed that the gas transfer resistance has an exponential-like dependency on the air stoichiometry. Based on the present results and results found in recent publications it is still...

  20. A switchable pH-differential unitized regenerative fuel cell with high performance

    Science.gov (United States)

    Lu, Xu; Xuan, Jin; Leung, Dennis Y. C.; Zou, Haiyang; Li, Jiantao; Wang, Hailiang; Wang, Huizhi

    2016-05-01

    Regenerative fuel cells are a potential candidate for future energy storage, but their applications are limited by the high cost and poor round-trip efficiency. Here we present a switchable pH-differential unitized regenerative fuel cell capable of addressing both the obstacles. Relying on a membraneless laminar flow-based design, pH environments in the cell are optimized independently for different electrode reactions and are switchable together with the cell process to ensure always favorable thermodynamics for each electrode reaction. Benefiting from the thermodynamic advantages of the switchable pH-differential arrangement, the cell allows water electrolysis at a voltage of 0.57 V, and a fuel cell open circuit voltage of 1.89 V, rendering round-trip efficiencies up to 74%. Under room conditions, operating the cell in fuel cell mode yields a power density of 1.3 W cm-2, which is the highest performance to date for laminar flow-based cells and is comparable to state-of-the-art polymer electrolyte membrane fuel cells.

  1. A fuel cell energy storage system concept for the Space Station Freedom Extravehicular Mobility Unit

    Science.gov (United States)

    Adlhart, Otto J.; Rosso, Matthew J., Jr.; Marmolejo, Jose

    1989-01-01

    An update is given on work to design and build a Fuel Cell Energy Storage System (FCESS) bench-tested unit for the Space Station Freedom Extravehicular Mobility Unit (EMU). Fueled by oxygen and hydride-stored hydrogen, the FCESS is being considered as an alternative to the EMU zinc-silver oxide battery. Superior cycle life and quick recharge are the main attributes of FCESS. The design and performance of a nonventing, 28 V, 34 Ahr system with 7 amp rating are discussed.

  2. Single-unit transfusions and hemoglobin trigger: relative impact on red cell utilization.

    Science.gov (United States)

    Yang, William W; Thakkar, Rajiv N; Gehrie, Eric A; Chen, Weiyun; Frank, Steven M

    2017-05-01

    Patient blood management (PBM) programs can reduce unnecessary transfusions, but the optimal methods used to achieve this effect are unclear. We tested the hypothesis that encouraging single-unit red blood cell (RBC) transfusions in stable patients would have a greater impact on blood use than compliance with a specific hemoglobin (Hb) transfusion trigger alone. We analyzed blood utilization data at three community hospitals without previous PBM efforts before and after implementing a PBM program. Data were analyzed at monthly intervals to determine the relative impact of a "Why give 2 when 1 will do?" campaign promoting single-unit RBC transfusions and simultaneous efforts to promote evidence-based Hb triggers of 7 or 8 g/dL. Univariate and multivariate analyses were used to identify independent effects of these two interventions on overall RBC utilization. Univariate analysis revealed that both the increase in single-unit transfusions (from 38.0% to 70.9%; p utilization. Multivariate analysis showed that the increase in single-unit transfusions was an independent predictor of decreased RBC utilization, but the Hb triggers of both 7 and 8 g/dL were not. Overall, our PBM efforts decreased RBC utilization from 0.254 to 0.185 units/patient (27.2%) across all three hospitals (p = 0.0009). A campaign promoting single-unit RBC transfusions had a greater impact on RBC utilization than did encouraging a restrictive transfusion trigger. © 2016 AABB.

  3. The Daniell Cell, Ohm's Law and the Emergence of the International System of Units

    CERN Document Server

    Jayson, Joel S

    2015-01-01

    Telegraphy originated in the 1830s and 40s and flourished in the following decades, but with a patchwork of electrical standards. Electromotive force was for the most part measured in units of the predominant Daniell cell. Each company had their own resistance standard. In 1862 the British Association for the Advancement of Science formed a committee to address this situation. By 1873 they had given definition to the electromagnetic system of units (emu) and defined the practical units of the ohm as ${10}^9$ emu units of resistance and the volt as ${10}^8$ emu units of electromotive force. These recommendations were ratified and expanded upon in a series of international congresses held between 1881 and 1904. A proposal by Giovanni Giorgi in 1901 took advantage of a coincidence between the conversion of the units of energy in the emu system (the erg) and in the practical system (the joule) in that the same conversion factor existed between the cgs based emu system and a theretofore undefined MKS system. By in...

  4. Quantification of in situ temperature measurements on a PBI-based high temperature PEMFC unit cell

    DEFF Research Database (Denmark)

    Lebæk, Jesper; Ali, Syed Talat; Møller, Per

    2010-01-01

    The temperature is a very important operating parameter for all types of fuel cells. In the present work distributed in situ temperature measurements are presented on a polybenzimidazole based high temperature PEM fuel cell (HT-PEM). A total of 16 T-type thermocouples were embedded on both...... sensors showed minimal influence on cell performance, this difference seen in performance is believed to be caused by different bipolar plate materials. The measurement method is suitable for obtaining detailed data for validation of computational models, moreover the results indicate that the method can...

  5. Parameters characterization and optimization of activated carbon (AC) cathodes for microbial fuel cell application.

    Science.gov (United States)

    Santoro, Carlo; Artyushkova, Kateryna; Babanova, Sofia; Atanassov, Plamen; Ieropoulos, Ioannis; Grattieri, Matteo; Cristiani, Pierangela; Trasatti, Stefano; Li, Baikun; Schuler, Andrew J

    2014-07-01

    Activated carbon (AC) is employed as a cost-effective catalyst for cathodic oxygen reduction in microbial fuel cells (MFC). The fabrication protocols of AC-based cathodes are conducted at different applied pressures (175-3500 psi) and treatment temperatures (25-343°C). The effects of those parameters along with changes in the surface morphology and chemistry on the cathode performances are comprehensively examined. The cathodes are tested in a three-electrode setup and explored in single chamber membraneless MFCs (SCMFCs). The results show that the best performance of the AC-based cathode is achieved when a pressure of 1400 psi is applied followed by heat treatment of 150-200°C for 1h. The influence of the applied pressure and the temperature of the heat treatment on the electrodes and SCMFCs is demonstrated as the result of the variation in the transfer resistance, the surface morphology and surface chemistry of the AC-based cathodes tested.

  6. Phenotypic classification of gastric signet ring cell carcinoma and its relationship with clinicopathologic parameters and prognosis

    Institute of Scientific and Technical Information of China (English)

    Meng-Meng Tian; Ai-Lian Zhao; Zhong-Wu Li; Ji-You Li

    2007-01-01

    AIM: To distinguish subtypes of gastric signet ring cell(SRC) carcinoma by investigating the expression of gastric and intestinal phenotypic markers, and to study the significance of phenotypic classification in predicting tumor progression and outcome.METHODS: Immunohistochemistry was performed in 66 cases of SRC carcinoma with MUC2. VILLIN, CDX2, Licadherin antibodies as intestinal phenotype markers and MUC5AC, HGM, MUC6 antibodies as gastric phenotype markers, and the relationship was analyzed between the phenotypic expression pation and clinicopathologic parameters, as well as the 3-year survival rate.RESULTS: Expression of intestinal phenotypic markers was positively associated with tumor size, wall invasion,vascular invasion, lymph node metastasis and tumornode-metastasis (TNM) stage. Cases expressing one or more intestinal markers had a significant lower survival rate than cases expressing none of the intestinal markers.CONCLUSION: The SRC carcinomas expressing intestinal phenotype markers exhibited a high proliferative potential, bad biological behaviors and poor prognosis. Examination of phenotype expression may be useful in distinguishing histological type and in prediciting the prognosis of gastric SRC carcinoma.

  7. Ensemble engineering and statistical modeling for parameter calibration towards optimal design of microbial fuel cells

    Science.gov (United States)

    Sun, Hongyue; Luo, Shuai; Jin, Ran; He, Zhen

    2017-07-01

    Mathematical modeling is an important tool to investigate the performance of microbial fuel cell (MFC) towards its optimized design. To overcome the shortcoming of traditional MFC models, an ensemble model is developed through integrating both engineering model and statistical analytics for the extrapolation scenarios in this study. Such an ensemble model can reduce laboring effort in parameter calibration and require fewer measurement data to achieve comparable accuracy to traditional statistical model under both the normal and extreme operation regions. Based on different weight between current generation and organic removal efficiency, the ensemble model can give recommended input factor settings to achieve the best current generation and organic removal efficiency. The model predicts a set of optimal design factors for the present tubular MFCs including the anode flow rate of 3.47 mL min-1, organic concentration of 0.71 g L-1, and catholyte pumping flow rate of 14.74 mL min-1 to achieve the peak current at 39.2 mA. To maintain 100% organic removal efficiency, the anode flow rate and organic concentration should be controlled lower than 1.04 mL min-1 and 0.22 g L-1, respectively. The developed ensemble model can be potentially modified to model other types of MFCs or bioelectrochemical systems.

  8. Effects of depression on parameters of cell-mediated immunity in patients with digestive tract cancers

    Institute of Scientific and Technical Information of China (English)

    Ke-Jun Nan; Yong-Chang Wei; Fu-Ling Zhou; Chun-Li Li; Chen-Guang Sui; Ling-Yun Hui; Cheng-Ge Gao

    2004-01-01

    AIM: To evaluate the effects of depression on parameters of cell-mediated immunity in patients with cancers of the digestive tract.METHODS: One hundred and eight adult patients of both sexes with cancers of the digestive tract admitted between March 2001 and February 2002 in the Department of Medical Oncology, First Affiliated Hospital of Xi'an Jiaotong University were randomly enrolled in the study. The Zung self-rating depression scale (SDS), Zung self-rating anxiety scale(SAS), numeric rating scale (NRS) and social support rating scale (SSRS) were employed to evaluate the degree of depression and their contributing factors. In terms of their SDS index scores, the patients were categorized into depression group (SDS≥50) and non-depression group(SDS<50). Immunological parameters such as T-lymphocyte subsets and natural killer (NK) cell activities in peripheral blood were determined and compared between the two groups of patients.RESULTS: The SDS index was from 33.8 to 66.2 in the 108 cases, 50% of these patients had a SDS index more than 50. Similarly, the SAS index of all the patients ranged from 35.0 to 62.0 and 46.3% of the cases had a SAS index above 50. Cubic curve estimation showed that the depression was positively correlated with anxiety and negatively with social support. Furthermore, the depression correlated with the tumor type, which manifested in a descending order as stomach, gallbladder, pancreas, intestine, esophagus,duodenum and rectum, according to their correlativity. Step-wise regression analysis suggested that hyposexuality,dispidtment, agitation, palpitation, low CD56 and anxiety were the significant factors contributing to depression. More severe anxiety (49.7±7.5 vs 45.3±6.9, P<0.05), pain (6.5±2.8 vs4.6±3.2, P<0.05), poor social support (6.8±2.0 vs 7.6±2.1,P<0.05), as well as decline of lymphocyte count (0.33±0.09vs0.39±0.87, P<0.05) and CD56 (0.26±0.11 vs0.29±0.11,P<0.05) were noted in the depression group compared

  9. Regulations in the United States for cell transplantation clinical trials in neurological diseases

    Institute of Scientific and Technical Information of China (English)

    He Zhu; Yuanqing Tan; Qi Gu; Weifang Han; Zhongwen Li; Jason S Meyer; Baoyang Hu

    2015-01-01

    Objective: This study aimed to use a systematic approach to evaluate the current utilization, safety, and effectiveness of cell therapies for neurological diseases in human. And review the present regulations, considering United States (US) as a representative country, for cell transplantation in neurological disease and discuss the challenges facing the field of neurology in the coming decades. Methods:A detailed search was performed in systematic literature reviews of cellular‐based therapies in neurological diseases, using PubMed, web of science, and clinical trials. Regulations of cell therapy products used for clinical trials were searched from the Food and Drug Administration (FDA) and the National Institutes of Health (NIH). Results: Seven most common types of cell therapies for neurological diseases have been reported to be relatively safe with varying degrees of neurological recovery. And a series of regulations in US for cellular therapy was summarized including preclinical evaluations, sourcing material, stem cell manufacturing and characterization, cell therapy product, and clinical trials. Conclusions:Stem cell‐based therapy holds great promise for a cure of such diseases and will value a growing population of patients. However, regulatory permitting activity of the US in the sphere of stem cells, technologies of regenerative medicine and substitutive cell therapy are selective, theoretical and does not fit the existing norm and rules. Compiled well‐defined regulations to guide the application of stem cell products for clinical trials should be formulated.

  10. Rate-equation modelling and ensemble approach to extraction of parameters for viral infection-induced cell apoptosis and necrosis

    Science.gov (United States)

    Domanskyi, Sergii; Schilling, Joshua E.; Gorshkov, Vyacheslav; Libert, Sergiy; Privman, Vladimir

    2016-09-01

    We develop a theoretical approach that uses physiochemical kinetics modelling to describe cell population dynamics upon progression of viral infection in cell culture, which results in cell apoptosis (programmed cell death) and necrosis (direct cell death). Several model parameters necessary for computer simulation were determined by reviewing and analyzing available published experimental data. By comparing experimental data to computer modelling results, we identify the parameters that are the most sensitive to the measured system properties and allow for the best data fitting. Our model allows extraction of parameters from experimental data and also has predictive power. Using the model we describe interesting time-dependent quantities that were not directly measured in the experiment and identify correlations among the fitted parameter values. Numerical simulation of viral infection progression is done by a rate-equation approach resulting in a system of "stiff" equations, which are solved by using a novel variant of the stochastic ensemble modelling approach. The latter was originally developed for coupled chemical reactions.

  11. Effect of inactive yeast cell wall on growth performance, survival rate and immune parameters in Pacific White Shrimp (Litopenaeus vannamei

    Directory of Open Access Journals (Sweden)

    Rutchanee Chotikachinda

    2008-10-01

    Full Text Available Effects of dietary inactive yeast cell wall on growth performance, survival rate, and immune parameters in pacific white shrimp (Litopenaeus vannamei was investigated. Three dosages of inactive yeast cell wall (0, 1, and 2 g kg-1 were tested in three replicate groups of juvenile shrimps with an average initial weight of 7.15±0.05 g for four weeks. There was no significant difference in final weight, survival rate, specific growth rate, feed conversion ratio, feed intake, protein efficiency ratio, and apparent net protein utilization of each treatments. However, different levels of inactive yeast cell wall showed an effect on certain immune parameters (p<0.05. Total hemocyte counts, granular hemocyte count, and bacterial clearance were better in shrimp fed diets supplemented with 1 and 2 g kg-1 inactive yeast cell wall as compared with thecontrol group.

  12. [Parameters of fibers cell respiration and desmin content in rat soleus muscle at early stages of gravitational unloading].

    Science.gov (United States)

    Mirzoev, T M; Biriukov, N S; Veselova, O M; Larina, I M; Shenkman, B S; Ogneva, I V

    2012-01-01

    The aim of the work was to study the parameters of fibers cell respiration and desmin content in Wistar rat soleus muscle after 1, 3, 7 and 14 days of gravitational unloading. Gravitational unloading was simulated by antiorthostatic hindlimb suspension. The parameters of cell respiration were determined using the polarography, and desmin content was assessed by means of Western blotting. The results showed that the intensity of cell respiration is reduced after three days of gravitational unloading, reaches a minimum level after seven days and slightly increases by the fourteenth day of hindlimb unloading, as well as the content of desmin, which, however, to the fourteenth day returns to the control level. Taking into account that mitochondrial function depends on the state of cytoskeleton the data allow us to assume that early reduction of the intensity of cell respiration under unloading could be caused by degradation of the protein desmin that determines intracellular localization of mitochondria.

  13. Fuel cell collaboration in the United States. Follow up report to the Danish Partnership for Hydrogen and Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-01-15

    Fuel cell technology continues to grow in the United States, with strong sales in stationary applications and early markets such as data centers, materials handling equipment, and telecommunications sites. New fuel cell customers include Fortune 500 companies Apple, eBay, Coca-Cola, and Walmart, who will use fuel cells to provide reliable power to data centers, stores, and facilities. Some are purchasing multi-megawatt (MW) systems, including three of the largest non-utility purchases of stationary fuel cells in the world by AT and T, Apple and eBay - 17 MW, 10 MW and 6 MW respectively. Others are replacing fleets of battery forklifts with fuel cells. Sysco, the food distributor, has more than 700 fuel cell-powered forklifts operating at seven facilities, with more on order. Mega-retailer Walmart now operates more than 500 fuel cell forklifts at three warehouses, including a freezer facility. Although federal government budget reduction efforts are impacting a wide range of departments and programs, fuel cell and hydrogen technology continues to be funded, albeit at a lower level than in past years. The Department of Energy (DOE) is currently funding fuel cell and hydrogen R and D and has nearly 300 ongoing projects at companies, national labs, and universities/institutes universities. The American Recovery and Reinvestment Act (ARRA) of 2009 and DOE's Market Transformation efforts have acted as a government ''catalyst'' for market success of emerging technologies. Early market deployments of about 1,400 fuel cells under the ARRA have led to more than 5,000 additional fuel cell purchases by industry with no DOE funding. In addition, interest in Congress remains high. Senators Richard Blumenthal (D-CT), Chris Coons (D-DE), Lindsey Graham (R-SC) and John Hoeven (R-ND) re-launched the bipartisan Senate Fuel Cell and Hydrogen Caucus in August 2012 to promote the continued development and commercialization of hydrogen and fuel cell technologies

  14. Data on how several physiological parameters of stored red blood cells are similar in glucose 6-phosphate dehydrogenase deficient and sufficient donors

    Directory of Open Access Journals (Sweden)

    Vassilis L. Tzounakas

    2016-09-01

    Full Text Available This article contains data on the variation in several physiological parameters of red blood cells (RBCs donated by eligible glucose-6-phosphate dehydrogenase (G6PD deficient donors during storage in standard blood bank conditions compared to control, G6PD sufficient (G6PD+ cells. Intracellular reactive oxygen species (ROS generation, cell fragility and membrane exovesiculation were measured in RBCs throughout the storage period, with or without stimulation by oxidants, supplementation of N-acetylcysteine and energy depletion, following incubation of stored cells for 24 h at 37 °C. Apart from cell characteristics, the total or uric acid-dependent antioxidant capacity of the supernatant in addition to extracellular potassium concentration was determined in RBC units. Finally, procoagulant activity and protein carbonylation levels were measured in the microparticles population. Further information can be found in “Glucose 6-phosphate dehydrogenase deficient subjects may be better “storers” than donors of red blood cells” [1].

  15. Study on Unit Cell Models and the Effective Thermal Conductivities of Silica Aerogel.

    Science.gov (United States)

    Liu, He; Li, Zeng-Yao; Zhao, Xin-Peng; Tao, Wen-Quan

    2015-04-01

    In this paper, two modified unit cell models, truncated octahedron and cubic array of intersecting square rods with 45-degree rotation, are developed in consideration of the tortuous path of heat conduction in solid skeleton of silica aerogel. The heat conduction is analyzed for each model and the expressions of effective thermal conductivity of the modified unit cell models are derived. Considering the random microstructure of silica aerogel, the probability model is presented. We also discuss the effect of the thermal conductivity of aerogel backbone. The effective thermal conductivities calculated by the proposed probability model are in good agreement with available experimental data when the density of the aerogel is 110 kg/m3.

  16. Exploring parameter space in detailed single neuron models: simulations of the mitral and granule cells of the olfactory bulb.

    Science.gov (United States)

    Bhalla, U S; Bower, J M

    1993-06-01

    1. Detailed compartmental computer simulations of single mitral and granule cells of the vertebrate olfactory bulb were constructed using previously published geometric data. Electrophysiological properties were determined by comparing model output to previously published experimental data, mainly current-clamp recordings. 2. The passive electrical properties of each model were explored by comparing model output with intracellular potential data from hyperpolarizing current injection experiments. The results suggest that membrane resistivity in both cells is nonuniform, with somatas having a substantially lower resistivity than the dendrites. 3. The active properties of these cells were explored by incorporating active ion channels into modeled compartments. On the basis of evidence from the literature, the mitral cell model included six channel types: fast sodium, fast delayed rectifier (Kfast), slow delayed rectifier (K), transient outward potassium current (KA), voltage- and calcium-dependent potassium current (KCa), and L-type calcium current. The granule cell model included four channel types: rat brain sodium, K, KA, and the non-inactivating muscarinic potassium current (KM). Modeled channels were based on the Hodgkin-Huxley formalism. 4. Representative kinetics for each of the channel classes above were obtained from the literature. The experimentally unknown spatial distributions of each included channel were obtained by systematic parameter searches. These were conducted in two ways: large-scale simulation series, in which each parameter was varied in turn, and an adaptation of a multidimensional conjugate gradient method. In each case, the simulated results were compared wtih experimental data using a curve-matching function evaluating mean squared differences of several aspects of the simulated and experimental voltage waveforms. 5. Systematic parameter variations revealed a single distinct region of parameter space in which the mitral cell model best

  17. On the Performance of Hybrid PV/Unitized Regenerative Fuel Cell System in the Tropics

    Directory of Open Access Journals (Sweden)

    Salwan Dihrab

    2012-01-01

    Full Text Available Solar hydrogen system is a unique power system that can meet the power requirements for future energy demands. Such a system uses the hydrogen as the energy carrier, which produces energy through the electrolyzer with assistance of the power from the PV during the sunny hours, and then uses stored hydrogen to produce energy through the fuel cell after sunset or on cloudy days. The current study has used premanufactured unitized regenerative fuel cells in which the electrolyzer and the fuel cell function within one cell at different modes. The system components were modeled and the one-day real operational and simulated data has been presented and compared. The measured results showed the ability of the system to meet the proposed load, and the total efficiency was about 4.5%.

  18. BioDiff - a neutron diffractometer optimized for crystals with large unit cell dimensions

    OpenAIRE

    Schrader, Tobias Erich; Ostermann, Andreas; Monkenbusch, Michael; Laatsch, Bernhard; Jüttner, Philipp; Petry, Winfried; Richter, Dieter

    2014-01-01

    The research reactor Heinz Maier-Leibnitz (FRM II) is a modern high flux neutron source which feeds some 30 state of the art neutron beam instruments. Currently 24 are operational, others in commissioning or under construction. The newly built neutron single crystal diffractometer BIODIFF is especially designed to collect data from crystals with large unit cells. The main field of application is the structural analysis of proteins, especially the determination of hydrogen atom positions. BIOD...

  19. Consistency of VDJ Rearrangement and Substitution Parameters Enables Accurate B Cell Receptor Sequence Annotation.

    Directory of Open Access Journals (Sweden)

    Duncan K Ralph

    2016-01-01

    Full Text Available VDJ rearrangement and somatic hypermutation work together to produce antibody-coding B cell receptor (BCR sequences for a remarkable diversity of antigens. It is now possible to sequence these BCRs in high throughput; analysis of these sequences is bringing new insight into how antibodies develop, in particular for broadly-neutralizing antibodies against HIV and influenza. A fundamental step in such sequence analysis is to annotate each base as coming from a specific one of the V, D, or J genes, or from an N-addition (a.k.a. non-templated insertion. Previous work has used simple parametric distributions to model transitions from state to state in a hidden Markov model (HMM of VDJ recombination, and assumed that mutations occur via the same process across sites. However, codon frame and other effects have been observed to violate these parametric assumptions for such coding sequences, suggesting that a non-parametric approach to modeling the recombination process could be useful. In our paper, we find that indeed large modern data sets suggest a model using parameter-rich per-allele categorical distributions for HMM transition probabilities and per-allele-per-position mutation probabilities, and that using such a model for inference leads to significantly improved results. We present an accurate and efficient BCR sequence annotation software package using a novel HMM "factorization" strategy. This package, called partis (https://github.com/psathyrella/partis/, is built on a new general-purpose HMM compiler that can perform efficient inference given a simple text description of an HMM.

  20. Dielectric Behavior of Low Microwave Loss Unit Cell for All Dielectric Metamaterial

    Directory of Open Access Journals (Sweden)

    Tianhuan Luo

    2015-01-01

    Full Text Available With a deep study of the metamaterial, its unit cells have been widely extended from metals to dielectrics. The dielectric based unit cells attract much attention because of the advantage of easy preparation, tunability, and higher frequency response, and so forth. Using the conventional solid state method, we prepared a kind of incipient ferroelectrics (calcium titanate, CaTiO3 with higher microwave permittivity and lower loss, which can be successfully used to construct metamaterials. The temperature and frequency dependence of dielectric constant are also measured under different sintering temperatures. The dielectric spectra showed a slight permittivity decrease with the increase of temperature and exhibited a loss of 0.0005, combined with a higher microwave dielectric constant of ~167 and quality factor Q of 2049. Therefore, CaTiO3 is a kind of versatile and potential metamaterial unit cell. The permittivity of CaTiO3 at higher microwave frequency was also examined in the rectangular waveguide and we got the permittivity of 165, creating a new method to test permittivity at higher microwave frequency.

  1. Effects of anodizing parameters and heat treatment on nanotopographical features, bioactivity, and cell culture response of additively manufactured porous titanium.

    Science.gov (United States)

    Amin Yavari, S; Chai, Y C; Böttger, A J; Wauthle, R; Schrooten, J; Weinans, H; Zadpoor, A A

    2015-06-01

    Anodizing could be used for bio-functionalization of the surfaces of titanium alloys. In this study, we use anodizing for creating nanotubes on the surface of porous titanium alloy bone substitutes manufactured using selective laser melting. Different sets of anodizing parameters (voltage: 10 or 20V anodizing time: 30min to 3h) are used for anodizing porous titanium structures that were later heat treated at 500°C. The nanotopographical features are examined using electron microscopy while the bioactivity of anodized surfaces is measured using immersion tests in the simulated body fluid (SBF). Moreover, the effects of anodizing and heat treatment on the performance of one representative anodized porous titanium structures are evaluated using in vitro cell culture assays using human periosteum-derived cells (hPDCs). It has been shown that while anodizing with different anodizing parameters results in very different nanotopographical features, i.e. nanotubes in the range of 20 to 55nm, anodized surfaces have limited apatite-forming ability regardless of the applied anodizing parameters. The results of in vitro cell culture show that both anodizing, and thus generation of regular nanotopographical feature, and heat treatment improve the cell culture response of porous titanium. In particular, cell proliferation measured using metabolic activity and DNA content was improved for anodized and heat treated as well as for anodized but not heat-treated specimens. Heat treatment additionally improved the cell attachment of porous titanium surfaces and upregulated expression of osteogenic markers. Anodized but not heat-treated specimens showed some limited signs of upregulated expression of osteogenic markers. In conclusion, while varying the anodizing parameters creates different nanotube structure, it does not improve apatite-forming ability of porous titanium. However, both anodizing and heat treatment at 500°C improve the cell culture response of porous titanium.

  2. Aging stability of complete blood count and white blood cell differential parameters analyzed by Abbott CELL-DYN Sapphire hematology analyzer.

    Science.gov (United States)

    Hedberg, P; Lehto, T

    2009-02-01

    This study presents the results of an aging stability study of complete blood count (CBC) and leukocyte differential parameters using the Abbott CELL-DYN Sapphire hematology analyzer. Stability studies showed no substantial change in CBC parameters up to 24-48 h at +23 +/- 2 degrees C (room temperature), except for optical platelet count (PLTo). For specimens aged over 24, the value of impedance platelet count yielded more reliable results than the routine PLTo. White blood cell (WBC) differential parameters, except eosinophils, were stable for up to 48 h at +23 +/- 2 degrees C. CBC parameters were stable for 72 h, except mean platelet volume, which slightly increased between 48 and 72 h, at +4 degrees C. WBC differentials were stable 48-72 h, with a slight decrease observed in absolute neutrophils and lymphocytes at +4 degrees C.

  3. Effects of anodizing parameters and heat treatment on nanotopographical features, bioactivity, and cell culture response of additively manufactured porous titanium

    Energy Technology Data Exchange (ETDEWEB)

    Amin Yavari, S., E-mail: s.aminyavari@tudelft.nl [Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft (Netherlands); Chai, Y.C. [Prometheus, Division of Skeletal Tissue Engineering, Bus 813, O& N1, Herestraat 49, KU Leuven, 3000 Leuven (Belgium); Tissue Engineering Laboratory, Skeletal Biology and Engineering Research Center, Bus 813, O& N1, Herestraat 49, KU Leuven, 3000 Leuven (Belgium); Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Böttger, A.J. [Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft (Netherlands); Wauthle, R. [KU Leuven, Department of Mechanical Engineering, Section Production Engineering, Machine Design and Automation (PMA), Celestijnenlaan 300B, 3001 Leuven (Belgium); 3D Systems — LayerWise NV, Grauwmeer 14, 3001 Leuven (Belgium); Schrooten, J. [Department of Metallurgy and Materials Engineering, KU Leuven, Kasteelpark Arenberg 44 — PB2450, B-3001 Heverlee (Belgium); Weinans, H. [Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft (Netherlands); Department of Orthopedics and Dept. Rheumatology, UMC Utrecht, Heidelberglaan100, 3584CX Utrecht (Netherlands); Zadpoor, A.A. [Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft (Netherlands)

    2015-06-01

    Anodizing could be used for bio-functionalization of the surfaces of titanium alloys. In this study, we use anodizing for creating nanotubes on the surface of porous titanium alloy bone substitutes manufactured using selective laser melting. Different sets of anodizing parameters (voltage: 10 or 20 V anodizing time: 30 min to 3 h) are used for anodizing porous titanium structures that were later heat treated at 500 °C. The nanotopographical features are examined using electron microscopy while the bioactivity of anodized surfaces is measured using immersion tests in the simulated body fluid (SBF). Moreover, the effects of anodizing and heat treatment on the performance of one representative anodized porous titanium structures are evaluated using in vitro cell culture assays using human periosteum-derived cells (hPDCs). It has been shown that while anodizing with different anodizing parameters results in very different nanotopographical features, i.e. nanotubes in the range of 20 to 55 nm, anodized surfaces have limited apatite-forming ability regardless of the applied anodizing parameters. The results of in vitro cell culture show that both anodizing, and thus generation of regular nanotopographical feature, and heat treatment improve the cell culture response of porous titanium. In particular, cell proliferation measured using metabolic activity and DNA content was improved for anodized and heat treated as well as for anodized but not heat-treated specimens. Heat treatment additionally improved the cell attachment of porous titanium surfaces and upregulated expression of osteogenic markers. Anodized but not heat-treated specimens showed some limited signs of upregulated expression of osteogenic markers. In conclusion, while varying the anodizing parameters creates different nanotube structure, it does not improve apatite-forming ability of porous titanium. However, both anodizing and heat treatment at 500 °C improve the cell culture response of porous titanium

  4. Relationships between human vitality and mitochondrial respiratory parameters, reactive oxygen species production and dNTP levels in peripheral blood mononuclear cells

    DEFF Research Database (Denmark)

    Maynard, Scott; Keijzers, Guido; Gram, Martin

    2013-01-01

    . Therefore, we measured a number of cellular parameters related to mitochondrial activity in peripheral blood mononuclear cells (PBMCs) isolated from middle-aged men, and tested for association with vitality. These parameters estimate mitochondrial respiration, reactive oxygen species (ROS) production...

  5. Major design issues of molten carbonate fuel cell power generation unit

    Energy Technology Data Exchange (ETDEWEB)

    Chen, T.P.

    1996-04-01

    In addition to the stack, a fuel cell power generation unit requires fuel desulfurization and reforming, fuel and oxidant preheating, process heat removal, waste heat recovery, steam generation, oxidant supply, power conditioning, water supply and treatment, purge gas supply, instrument air supply, and system control. These support facilities add considerable cost and system complexity. Bechtel, as a system integrator of M-C Power`s molten carbonate fuel cell development team, has spent substantial effort to simplify and minimize these supporting facilities to meet cost and reliability goals for commercialization. Similiar to other fuels cells, MCFC faces design challenge of how to comply with codes and standards, achieve high efficiency and part load performance, and meanwhile minimize utility requirements, weight, plot area, and cost. However, MCFC has several unique design issues due to its high operating temperature, use of molten electrolyte, and the requirement of CO2 recycle.

  6. Cell phone recycling experiences in the United States and potential recycling options in Brazil.

    Science.gov (United States)

    Silveira, Geraldo T R; Chang, Shoou-Yuh

    2010-11-01

    This paper presents an overview of cell phone recycling programs currently available in the United States. At the same time, it also provides analyses of the current recycling situation and possible recycling alternatives for Brazil. Although there are several recycling options in the United States, collection rates are still only 10% of all potential devices because customers are not aware of these possibilities. The whole system is financially based on reselling refurbished cell phones and recycled materials to developing countries which represent an effective and strong market. Several recyclers offer funds to collection partners who are either charities or who work with charities while obtaining the materials that they need in order to run their operations. A mobile phone recycling system for Brazil considering the United States experience and the Extended Producer Responsibility (EPR) principle is suggested. A deposit/refund/advance-recycling fee is proposed which might be implemented as a voluntary industrial initiative managed by PRO Brazil, a producer responsibility organization. One widespread public-private agreement will integrate all mobile phone stakeholders, and environmental education actions and promotional events will promote citizen's participation.

  7. Numerical evaluation of micro-structural parameters of porous supports in metal-supported solid oxide fuel cells

    Science.gov (United States)

    Reiss, Georg; Frandsen, Henrik Lund; Brandstätter, Wilhelm; Weber, André

    2015-01-01

    Metallic supported Solid Oxide Fuel Cells (SOFCs) are considered as a durable and cost effective alternative to the state-of-the-art ceramic supported cell designs. In order to understand the mass and charge transport in the metal-support of this new type of cell a novel technique involving X-ray tomography and micro-structural modelling is presented in this work. The simulation technique comprises a novel treatment of the boundary conditions, which leads to more accurate effective transport parameters compared to those, which can be achieved with the conventional homogenisation procedures. Furthermore, the porosity distribution in the metal-support was determined, which provided information about the inhomogeneous nature of the material. In addition to that, transport parameters for two identified, different dense layers of the metal-support are evaluated separately. The results of the evaluation show three significant findings. Firstly, that the effective transport parameters are up to a factor of 20 lower compared to other SOFC anodes. Secondly, that the micro-structure can have regions, which are much denser, especially the first 100 μm of the interface between gas-channel and support-structure. Thirdly, that the calculation of the transport parameters depends on the correct application of boundary conditions.

  8. Dendritic thickness: a morphometric parameter to classify mouse retinal ganglion cells

    Directory of Open Access Journals (Sweden)

    L.D. Loopuijt

    2007-10-01

    Full Text Available To study the dendritic morphology of retinal ganglion cells in wild-type mice we intracellularly injected these cells with Lucifer yellow in an in vitro preparation of the retina. Subsequently, quantified values of dendritic thickness, number of branching points and level of stratification of 73 Lucifer yellow-filled ganglion cells were analyzed by statistical methods, resulting in a classification into 9 groups. The variables dendritic thickness, number of branching points per cell and level of stratification were independent of each other. Number of branching points and level of stratification were independent of eccentricity, whereas dendritic thickness was positively dependent (r = 0.37 on it. The frequency distribution of dendritic thickness tended to be multimodal, indicating the presence of at least two cell populations composed of neurons with dendritic diameters either smaller or larger than 1.8 µm ("thin" or "thick" dendrites, respectively. Three cells (4.5% were bistratified, having thick dendrites, and the others (95.5% were monostratified. Using k-means cluster analysis, monostratified cells with either thin or thick dendrites were further subdivided according to level of stratification and number of branching points: cells with thin dendrites were divided into 2 groups with outer stratification (0-40% and 2 groups with inner (50-100% stratification, whereas cells with thick dendrites were divided into one group with outer and 3 groups with inner stratification. We postulate, that one group of cells with thin dendrites resembles cat ß-cells, whereas one group of cells with thick dendrites includes cells that resemble cat a-cells.

  9. Transport parameters of thin, supported cathode layers in solid oxide fuel cells (SOFCs); Transportparameter duenner, getraegerter Kathodenschichten der oxidkeramischen Brennstoffzelle

    Energy Technology Data Exchange (ETDEWEB)

    Wedershoven, Christian

    2010-12-22

    The aim of this work was to determine the transport properties of thin cathode layers, which are part of the composite layer of a fabricated anode-supported solid oxide fuel cell (SOFC). The transport properties of the anode and cathode have a significant influence on the electrochemical performance of a fuel cell stack and therefore represent an important parameter when designing fuel cell stacks. In order to determine the transport parameters of the cathode layers in a fabricated SOFC, it is necessary to permeate the thin cathode layer deposited on the gas-tight electrolyte with a defined gas transport. These thin cathode layers cannot be fabricated as mechanically stable single layers and cannot therefore be investigated in the diffusion and permeation experiments usually used to determine transport parameters. The setup of these experiments - particularly the sample holder - was therefore altered in this work. The result of this altered setup was a three-dimensional flow configuration. Compared to the conventional setup, it was no longer possible to describe the gas transport in the experiments with an analytical one-dimensional solution. A numerical solution process had to be used to evaluate the measurements. The new setup permitted a sufficiently symmetrical gas distribution and thus allowed the description of the transport to be reduced to a two-dimensional description, which significantly reduced the computational effort required to evaluate the measurements. For pressure-induced transport, a parametrized coherent expression of transport could be derived. This expression is equivalent to the analytical description of the transport in conventional measurement setups, with the exception of parameters that describe the geometry of the gas diffusion. In this case, a numerical process is not necessary for the evaluation. Using the transport parameters of mechanically stable anode substrates, which can be measured both in the old and the new setups, the old and

  10. Carbonate Doping in TiO2 Microsphere: The Key Parameter Influencing Others for Efficient Dye Sensitized Solar Cell

    Science.gov (United States)

    Seddigi, Zaki S.; Ahmed, Saleh A.; Sardar, Samim; Pal, Samir Kumar

    2016-03-01

    Four key parameters namely light trapping, density of light harvesting centre, photoinduced electron injection and electron transport without self-recombination are universally important across all kinds of solar cells. In the present study, we have considered the parameters in the context of a model Dye Sensitized Solar Cell (DSSC). Our experimental studies reveal that carbonate doping of TiO2 mesoporous microspheres (doped MS) makes positive influence to all the above mentioned key parameters responsible for the enhanced solar cell efficiency. A simple method has been employed to synthesize the doped MS for the photoanode of a N719 (ruthenium dye)-based DSSC. A detail electron microscopy has been used to characterize the change in morphology of the MS upon doping. The optical absorption spectrum of the doped MS reveals significant shift of TiO2 (compared to that of the MS without doping) towards maximum solar radiance (~500 nm) and the excellent scattering in the entire absorption band of the sensitizing dye (N719). Finally, and most importantly, for the first time we have demonstrated that the solar cells with doped MS offers better efficiency (7.6%) in light harvesting compared to MS without doping (5.2%) and also reveal minimum self recombination of photoelectrons in the redox chain.

  11. Planar conjugated polymers containing 9,10-disubstituted phenanthrene units for efficient polymer solar cells.

    Science.gov (United States)

    Li, Guangwu; Kang, Chong; Li, Cuihong; Lu, Zhen; Zhang, Jicheng; Gong, Xue; Zhao, Guangyao; Dong, Huanli; Hu, Wenping; Bo, Zhishan

    2014-06-01

    Four novel conjugated polymers (P1-4) with 9,10-disubstituted phenanthrene (PhA) as the donor unit and 5,6-bis(octyloxy)benzothiadiazole as the acceptor unit are synthesized and characterized. These polymers are of medium bandgaps (2.0 eV), low-lying HOMO energy levels (below -5.3 eV), and high hole mobilities (in the range of 3.6 × 10(-3) to 0.02 cm(2) V(-1) s(-1) ). Bulk heterojunction (BHJ) polymer solar cells (PSCs) with P1-4:PC71 BM blends as the active layer and an alcohol-soluble fullerene derivative (FN-C60) as the interfacial layer between the active layer and cathode give the best power conversion efficiency (PCE) of 4.24%, indicating that 9,10-disubstituted PhA are potential donor materials for high-efficiency BHJ PSCs.

  12. Mechanical properties of regular porous biomaterials made from truncated cube repeating unit cells: Analytical solutions and computational models.

    Science.gov (United States)

    Hedayati, R; Sadighi, M; Mohammadi-Aghdam, M; Zadpoor, A A

    2016-03-01

    Additive manufacturing (AM) has enabled fabrication of open-cell porous biomaterials based on repeating unit cells. The micro-architecture of the porous biomaterials and, thus, their physical properties could then be precisely controlled. Due to their many favorable properties, porous biomaterials manufactured using AM are considered as promising candidates for bone substitution as well as for several other applications in orthopedic surgery. The mechanical properties of such porous structures including static and fatigue properties are shown to be strongly dependent on the type of the repeating unit cell based on which the porous biomaterial is built. In this paper, we study the mechanical properties of porous biomaterials made from a relatively new unit cell, namely truncated cube. We present analytical solutions that relate the dimensions of the repeating unit cell to the elastic modulus, Poisson's ratio, yield stress, and buckling load of those porous structures. We also performed finite element modeling to predict the mechanical properties of the porous structures. The analytical solution and computational results were found to be in agreement with each other. The mechanical properties estimated using both the analytical and computational techniques were somewhat higher than the experimental data reported in one of our recent studies on selective laser melted Ti-6Al-4V porous biomaterials. In addition to porosity, the elastic modulus and Poisson's ratio of the porous structures were found to be strongly dependent on the ratio of the length of the inclined struts to that of the uninclined (i.e. vertical or horizontal) struts, α, in the truncated cube unit cell. The geometry of the truncated cube unit cell approaches the octahedral and cube unit cells when α respectively approaches zero and infinity. Consistent with those geometrical observations, the analytical solutions presented in this study approached those of the octahedral and cube unit cells when

  13. Equivalent Circuit Parameters Estimation for PEM Fuel Cell Using RBF Neural Network and Enhanced Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Wen-Yeau Chang

    2013-01-01

    Full Text Available This paper proposes an equivalent circuit parameters measurement and estimation method for proton exchange membrane fuel cell (PEMFC. The parameters measurement method is based on current loading technique; in current loading test a no load PEMFC is suddenly turned on to obtain the waveform of the transient terminal voltage. After the equivalent circuit parameters were measured, a hybrid method that combines a radial basis function (RBF neural network and enhanced particle swarm optimization (EPSO algorithm is further employed for the equivalent circuit parameters estimation. The RBF neural network is adopted such that the estimation problem can be effectively processed when the considered data have different features and ranges. In the hybrid method, EPSO algorithm is used to tune the connection weights, the centers, and the widths of RBF neural network. Together with the current loading technique, the proposed hybrid estimation method can effectively estimate the equivalent circuit parameters of PEMFC. To verify the proposed approach, experiments were conducted to demonstrate the equivalent circuit parameters estimation of PEMFC. A practical PEMFC stack was purposely created to produce the common current loading activities of PEMFC for the experiments. The practical results of the proposed method were studied in accordance with the conditions for different loading conditions.

  14. The Application of Load-cell Technique in the Study of Armour Unit Responses to Impact Loads Tests

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Liu, Z.

    1995-01-01

    The slender, complex types of armour units, such as Tetrapods and Dolosse are widely used for rubble mound breakwaters. Many of the recent failures of such structures were caused by unforeseen early breakage of the units, thus revealing an in balance between the strength (structural integrity....... slender armour units can be studied. by load-cell technique. Moreover, the paper presents DoJos design diagrams for the prediction of both breakage and hydraulic stability...

  15. The Application of Load-cell Technique in the Study of Armour Unit Responses to Impact Loads

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Liu, Zhou

    1994-01-01

    The slender, complex types of armour units, such as Tetrapods and Dolosse are widely used for rubble mound breakwaters. Many of the recent failures of such structures were caused by unforeseen early breakage of the units, thus revealing an inbalance between the strength (structural integrity...... on slender armour units can be studied by load-cell technique. Moreover, the paper presents Dolos design diagrams for the prediction of both breakage and hydraulic stability....

  16. Effect of silicon solar cell processing parameters and crystallinity on mechanical strength

    Energy Technology Data Exchange (ETDEWEB)

    Popovich, V.A.; Yunus, A.; Janssen, M.; Richardson, I.M. [Delft University of Technology, Department of Materials Science and Engineering, Delft (Netherlands); Bennett, I.J. [Energy Research Centre of the Netherlands, Solar Energy, PV Module Technology, Petten (Netherlands)

    2011-01-15

    Silicon wafer thickness reduction without increasing the wafer strength leads to a high breakage rate during subsequent handling and processing steps. Cracking of solar cells has become one of the major sources of solar module failure and rejection. Hence, it is important to evaluate the mechanical strength of solar cells and influencing factors. The purpose of this work is to understand the fracture behavior of silicon solar cells and to provide information regarding the bending strength of the cells. Triple junctions, grain size and grain boundaries are considered to investigate the effect of crystallinity features on silicon wafer strength. Significant changes in fracture strength are found as a result of metallization morphology and crystallinity of silicon solar cells. It is observed that aluminum paste type influences the strength of the solar cells. (author)

  17. National Assessment of Oil and Gas Project - Wind River Basin Province (035) Assessment Units Quarter-Mile Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Cell maps for each oil and gas assessment unit were created by the USGS to illustrate the degree of exploration, type of production, and distribution of production...

  18. Evaluation of Parameters in the Isolation of Viable Protoplasts from Cultured Tobacco Cells 1

    Science.gov (United States)

    Uchimiya, Hirofumi; Murashige, Toshio

    1974-01-01

    A systematic evaluation disclosed the following conditions to be optimum for the isolation of viable protoplasts from cultured cells of Nicotiana tabacum L. `Bright Yellow' grown in liquid suspensions: (a) the cell culture in the early phase of cell number increase, (b) an enzyme mixture of 1% cellulase “Onozuka” and 0.2% Macerozyme, (c) an enzyme solution pH of 4.7 or 5.7, (d) a 2- to 3-hr incubation period, (e) 5 ml of enzyme solution per 500 mg cells and contained in a 50-ml Delong flask, (f) agitation on a gyrotory shaker at 50 rpm, and (g) 0.3 to 0.8 m mannitol as osmoticum in the cell enzyme mixture. The incubation temperature may be varied from 22 to 37 C. The procedure enabled 30% of the tobacco cells to form protoplasts, 80% of which regenerated cell walls in 4 days and 40% resumed cell division activity when returned to cell culture medium. Images PMID:16659004

  19. Failure mechanisms of additively manufactured porous biomaterials: Effects of porosity and type of unit cell.

    Science.gov (United States)

    Kadkhodapour, J; Montazerian, H; Darabi, A Ch; Anaraki, A P; Ahmadi, S M; Zadpoor, A A; Schmauder, S

    2015-10-01

    Since the advent of additive manufacturing techniques, regular porous biomaterials have emerged as promising candidates for tissue engineering scaffolds owing to their controllable pore architecture and feasibility in producing scaffolds from a variety of biomaterials. The architecture of scaffolds could be designed to achieve similar mechanical properties as in the host bone tissue, thereby avoiding issues such as stress shielding in bone replacement procedure. In this paper, the deformation and failure mechanisms of porous titanium (Ti6Al4V) biomaterials manufactured by selective laser melting from two different types of repeating unit cells, namely cubic and diamond lattice structures, with four different porosities are studied. The mechanical behavior of the above-mentioned porous biomaterials was studied using finite element models. The computational results were compared with the experimental findings from a previous study of ours. The Johnson-Cook plasticity and damage model was implemented in the finite element models to simulate the failure of the additively manufactured scaffolds under compression. The computationally predicted stress-strain curves were compared with the experimental ones. The computational models incorporating the Johnson-Cook damage model could predict the plateau stress and maximum stress at the first peak with less than 18% error. Moreover, the computationally predicted deformation modes were in good agreement with the results of scaling law analysis. A layer-by-layer failure mechanism was found for the stretch-dominated structures, i.e. structures made from the cubic unit cell, while the failure of the bending-dominated structures, i.e. structures made from the diamond unit cells, was accompanied by the shearing bands of 45°.

  20. Identified metabolic signature for assessing red blood cell unit quality is associated with endothelial damage markers and clinical outcomes

    DEFF Research Database (Denmark)

    Bordbar, Aarash; Johansson, Pär I.; Paglia, Giuseppe;

    2016-01-01

    BACKGROUND: There has been interest in determining whether older red blood cell (RBC) units have negative clinical effects. Numerous observational studies have shown that older RBC units are an independent factor for patient mortality. However, recently published randomized clinical trials have...

  1. Transition-edge sensor pixel parameter design of the microcalorimeter array for the x-ray integral field unit on Athena

    Science.gov (United States)

    Smith, S. J.; Adams, J. S.; Bandler, S. R.; Betancourt-Martinez, G. L.; Chervenak, J. A.; Chiao, M. P.; Eckart, M. E.; Finkbeiner, F. M.; Kelley, R. L.; Kilbourne, C. A.; Miniussi, A. R.; Porter, F. S.; Sadleir, J. E.; Sakai, K.; Wakeham, N. A.; Wassell, E. J.; Yoon, W.; Bennett, D. A.; Doriese, W. B.; Fowler, J. W.; Hilton, G. C.; Morgan, K. M.; Pappas, C. G.; Reintsema, C. N.; Swetz, D. S.; Ullom, J. N.; Irwin, K. D.; Akamatsu, H.; Gottardi, L.; den Hartog, R.; Jackson, B. D.; van der Kuur, J.; Barret, D.; Peille, P.

    2016-07-01

    The focal plane of the X-ray integral field unit (X-IFU) for ESA's Athena X-ray observatory will consist of 4000 transition edge sensor (TES) x-ray microcalorimeters optimized for the energy range of 0.2 to 12 keV. The instrument will provide unprecedented spectral resolution of 2.5 eV at energies of up to 7 keV and will accommodate photon fluxes of 1 mCrab (90 cps) for point source observations. The baseline configuration is a uniform large pixel array (LPA) of 4.28" pixels that is read out using frequency domain multiplexing (FDM). However, an alternative configuration under study incorporates an 18 × 18 small pixel array (SPA) of 2" pixels in the central 36" region. This hybrid array configuration could be designed to accommodate higher fluxes of up to 10 mCrab (900 cps) or alternately for improved spectral performance (report on the TES pixel designs that are being optimized to meet these proposed LPA and SPA configurations. In particular we describe details of how important TES parameters are chosen to meet the specific mission criteria such as energy resolution, count-rate and quantum efficiency, and highlight performance trade-offs between designs. The basis of the pixel parameter selection is discussed in the context of existing TES arrays that are being developed for solar and x-ray astronomy applications. We describe the latest results on DC biased diagnostic arrays as well as large format kilo-pixel arrays and discuss the technical challenges associated with integrating different array types on to a single detector die.

  2. Light parameters influence cell viability in antifungal photodynamic therapy in a fluence and rate fluence-dependent manner

    Science.gov (United States)

    Prates, Renato A.; da Silva, Eriques G.; Yamada, Aécio M.; Suzuki, Luis C.; Paula, Claudete R.; Ribeiro, Martha S.

    2009-05-01

    The aim of this study was to investigate the influence of light parameters on yeast cells. It has been proposed for many years that photodynamic therapy (PDT) can inactivate microbial cells. A number of photosensitizer and light sources were reported in different light parameters and in a range of dye concentrations. However, much more knowledge concerning the importance of fluence, fluence rate and exposure time are required for a better understanding of the photodynamic efficiency. Suspensions (106 CFU/mL) of Candida albicans, Candida krusei, and Cryptococcus neoformans var. grubii were used. Two fluence rates, 100 and 300 mW/cm2 were compared at 3, 6, and 9 min of irradiation, resulting fluences from 18 to 162 J/cm2. The light source was a laser emitting at λ = 660 nm with output power adjusted at 30 and 90 mW. As photosensitizer, one hundred-μM methylene blue was used. Temperature was monitored to verify possible heat effect and reactive oxygen species (ROS) formation was evaluated. The same fluence in different fluence rates showed dissimilar levels of inactivation on yeast cells as well as in ROS formation. In addition, the increase of the fluence rate showed an improvement on cell photoinactivation. PDT was efficient against yeast cells (6 log reduction), and no significant temperature increase was observed. Fluence per se should not be used as an isolate parameter to compare photoinactivation effects on yeast cells. The higher fluence rate was more effective than the lower one. Furthermore, an adequate duration of light exposure cannot be discarded.

  3. Improved electroporation parameters of delivering silver nanoparticles into living C666 cells for surface-enhanced Raman scattering

    Energy Technology Data Exchange (ETDEWEB)

    Yu Yun; Lin Juqiang; Huang Zufang; Xi Gangqin; Lin Duo; Chen Yongjian; Chen Rong [Key Laboratory of Optoelectronic Science and Technology for Medicine, Ministry of Education, Fujian Normal University, Fuzhou 350007 (China); Zeng Haishan, E-mail: chenr@fjnu.edu.cn [Cancer Imaging Department, British Columbia Cancer Research Centre, Vancouver, B.C., V5Z 1L3 (Canada)

    2011-01-01

    Electroporation assisted metallic nanoparticle delivery has been shown by our previous work to significantly reduce the time of sample preparation for surface-enhanced Raman spectroscopy (SERS) measurements of biological cells. In this research note, we report our experimental work to optimize the electroporation parameters, including adjustment of the pulse pattern and operation temperature, for fastest delivery of silver nanoparticles into living C666 cells (a human nasopharyngeal carcinoma cell line). The delivery efficiency was evaluated by the integrated intensity of whole cell SERS spectrum. Our work concluded that the silver nanoparticle delivery rate is best under the electroporation condition of using 4 consecutive 350 V (875 V/cm) rectangular electric pulses of 1 ms, 10 ms, 10 ms, and 1 ms durations respectively. Low temperature (0{approx}4 deg. C) is necessary for improving the delivery efficiency of silver nanoparticles.

  4. Multi-parameter flow cytometry and cell sorting reveal extensive physiological heterogeneity in Bacillus cereus batch cultures.

    Science.gov (United States)

    Want, Andrew; Hancocks, Helen; Thomas, Colin R; Stocks, Stuart M; Nebe-von-Caron, Gerhard; Hewitt, Christopher J

    2011-07-01

    Based on two staining protocols, DiOC(6)(3)/propidium iodide (PI) and RedoxSensor Green (an indicator of bacterial reductase activity)/PI, multi-parameter flow cytometry and cell sorting has identified at least four distinguishable physiological states during batch cultures of Bacillus cereus. Furthermore, dependent on the position in the growth curve, single cells gave rise to varying numbers of colonies when sorted individually onto nutrient agar plates. These growing colonies derived from a single cell had widely different lag phases, inferred from differences in colony size. This further highlights the complex population dynamics of bacterial monocultures and further demonstrates that individual bacterial cells in a culture respond in markedly dissimilar ways to the environment, resulting in a physiologically heterogenous and dynamic population.

  5. High quality-factor fano metasurface comprising a single resonator unit cell

    Energy Technology Data Exchange (ETDEWEB)

    Sinclair, Michael B.; Warne, Larry K.; Basilio, Lorena I.; Langston, William L.; Campione, Salvatore; Brener, Igal; Liu, Sheng

    2017-06-20

    A new monolithic resonator metasurface design achieves ultra-high Q-factors while using only one resonator per unit cell. The metasurface relies on breaking the symmetry of otherwise highly symmetric resonators to induce intra-resonator mixing of bright and dark modes (rather than inter-resonator couplings), and is scalable from the near-infrared to radio frequencies and can be easily implemented in dielectric materials. The resulting high-quality-factor Fano metasurface can be used in many sensing, spectral filtering, and modulation applications.

  6. Unit cell modeling in support of interim performance assessment for low level tank waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Kline, N.W., Westinghouse Hanford

    1996-08-01

    A unit cell model is used to simulate the base analysis case and related sensitivity cases for the interim performance assessment of low level tank waste disposal. Simulation case results are summarized in terms of fractional contaminant release rates to the vadose zone and to the water table at the unconfined aquifer. Results suggest that the crushed glass water conditioning layer at the top of the facility and the chemical retardation pad at the bottom of the facility can be important components of the facility. Results also suggest that the release rates to the water table are dominated by the release rate from the waste form.

  7. A method for the determination of the standard deviations of the solar cell I-V characteristic parameters

    Energy Technology Data Exchange (ETDEWEB)

    Veissid, N. (Instituto de Pesquisas Espaciais, Sao Jose dos Campos (Brazil)); Cruz, M.T.F. da (Universidade de Sao Paulo, SP (Brazil). Inst. de Fisica); Andrade, A.M. de (Universidade de Sao Paulo, SP (Brazil). Lab. de Microeletronica)

    1990-05-01

    A method for the determination of the standard deviations of the solar cell characteristic curve fitting parameters is presented for the first time. In this method, a Taylor series expansion of the parameters, around their best values, is made resulting in linear functions which permit the determination of the standard deviations with the least-squares method. The parameters, with the respective standard deviations, were determined from the experimental I-V characteristic curves obtained under illuminated and dark conditions. For the studied experimental I-V curves, the diode saturation currents, the diode factor and the shunt resistance showed smaller standard deviations in the dark condition, and the series resistance appeared to be more precise in the illuminated I-V characteristic. (orig.).

  8. Modeling, Parameters Identification, and Control of High Pressure Fuel Cell Back-Pressure Valve

    Directory of Open Access Journals (Sweden)

    Fengxiang Chen

    2014-01-01

    Full Text Available The reactant pressure is crucial to the efficiency and lifespan of a high pressure PEMFC engine. This paper analyses a regulated back-pressure valve (BPV for the cathode outlet flow in a high pressure PEMFC engine, which can achieve precisely pressure control. The modeling, parameters identification, and nonlinear controller design of a BPV system are considered. The identified parameters are used in designing active disturbance rejection controller (ADRC. Simulations and extensive experiments are conducted with the xPC Target and show that the proposed controller can not only achieve good dynamic and static performance but also have strong robustness against parameters’ disturbance and external disturbance.

  9. Determination of optimal parameters for dual-layer cathode of polymer electrolyte fuel cell using computational intelligence-aided design.

    Science.gov (United States)

    Chen, Yi; Huang, Weina; Peng, Bei

    2014-01-01

    Because of the demands for sustainable and renewable energy, fuel cells have become increasingly popular, particularly the polymer electrolyte fuel cell (PEFC). Among the various components, the cathode plays a key role in the operation of a PEFC. In this study, a quantitative dual-layer cathode model was proposed for determining the optimal parameters that minimize the over-potential difference η and improve the efficiency using a newly developed bat swarm algorithm with a variable population embedded in the computational intelligence-aided design. The simulation results were in agreement with previously reported results, suggesting that the proposed technique has potential applications for automating and optimizing the design of PEFCs.

  10. Parameters influencing the deposition of methylammonium lead halide iodide in hole conductor free perovskite-based solar cells

    Directory of Open Access Journals (Sweden)

    Bat-El Cohen

    2014-08-01

    Full Text Available Perovskite is a promising light harvester for use in photovoltaic solar cells. In recent years, the power conversion efficiency of perovskite solar cells has been dramatically increased, making them a competitive source of renewable energy. An important parameter when designing high efficiency perovskite-based solar cells is the perovskite deposition, which must be performed to create complete coverage and optimal film thickness. This paper describes an in-depth study on two-step deposition, separating the perovskite deposition into two precursors. The effects of spin velocity, annealing temperature, dipping time, and methylammonium iodide concentration on the photovoltaic performance are studied. Observations include that current density is affected by changing the spin velocity, while the fill factor changes mainly due to the dipping time and methylammonium iodide concentration. Interestingly, the open circuit voltage is almost unaffected by these parameters. Hole conductor free perovskite solar cells are used in this work, in order to minimize other possible effects. This study provides better understanding and control over the perovskite deposition through highly efficient, low-cost perovskite-based solar cells.

  11. Parameters influencing the deposition of methylammonium lead halide iodide in hole conductor free perovskite-based solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, Bat-El; Gamliel, Shany; Etgar, Lioz, E-mail: lioz.etgar@mail.huji.ac.il [Institute of Chemistry, Casali Center for Applied Chemistry, The Hebrew University of Jerusalem, Jerusalem 90400 (Israel)

    2014-08-01

    Perovskite is a promising light harvester for use in photovoltaic solar cells. In recent years, the power conversion efficiency of perovskite solar cells has been dramatically increased, making them a competitive source of renewable energy. An important parameter when designing high efficiency perovskite-based solar cells is the perovskite deposition, which must be performed to create complete coverage and optimal film thickness. This paper describes an in-depth study on two-step deposition, separating the perovskite deposition into two precursors. The effects of spin velocity, annealing temperature, dipping time, and methylammonium iodide concentration on the photovoltaic performance are studied. Observations include that current density is affected by changing the spin velocity, while the fill factor changes mainly due to the dipping time and methylammonium iodide concentration. Interestingly, the open circuit voltage is almost unaffected by these parameters. Hole conductor free perovskite solar cells are used in this work, in order to minimize other possible effects. This study provides better understanding and control over the perovskite deposition through highly efficient, low-cost perovskite-based solar cells.

  12. Modelling and simulation of double chamber microbial fuel cell. Cell voltage, power density and temperature variation with process parameters

    Energy Technology Data Exchange (ETDEWEB)

    Shankar, Ravi; Mondal, Prasenjit; Chand, Shri [Indian Institute of Technology Roorkee, Uttaranchal (India). Dept. of Chemical Engineering

    2013-11-01

    In the present paper steady state models of a double chamber glucose glutamic acid microbial fuel cell (GGA-MFC) under continuous operation have been developed and solved using Matlab 2007 software. The experimental data reported in a recent literature has been used for the validation of the models. The present models give prediction on the cell voltage and cell power density with 19-44% errors, which is less (up to 20%) than the errors on the prediction of cell voltage made in some recent literature for the same MFC where the effects of the difference in pH and ionic conductivity between anodic and cathodic solutions on cell voltage were not incorporated in model equations. It also describes the changes in anodic and cathodic chamber temperature due to the increase in substrate concentration and cell current density. Temperature profile across the membrane thickness has also been studied. (orig.)

  13. Discriminating performance parameters for 50 amp-hour and 60 amp-hour nickel-cadmium plates and battery cells

    Science.gov (United States)

    Toft, Mark R.

    1994-01-01

    This is a follow-up of studies of the NASA standard 50 AH cell presented at the NASA battery workshop each of the last two years. This is a dynamic study. Data trends continue to be developed and analyzed for their utility in judging NiCd performance. The trends and parameters presented here may bear relevance to many designs of conventional NiCd batteries, not just the 50 AH and 60 AH sizes.

  14. Application of multivariate analysis toward biotech processes: case study of a cell-culture unit operation.

    Science.gov (United States)

    Kirdar, Alime Ozlem; Conner, Jeremy S; Baclaski, Jeffrey; Rathore, Anurag S

    2007-01-01

    This paper examines the feasibility of using multivariate data analysis (MVDA) for supporting some of the key activities that are required for successful manufacturing of biopharmaceutical products. These activities include scale-up, process comparability, process characterization, and fault diagnosis. Multivariate data analysis and modeling were performed using representative data from small-scale (2 L) and large-scale (2000 L) batches of a cell-culture process. Several input parameters (pCO2, pO2, glucose, pH, lactate, ammonium ions) and output parameters (purity, viable cell density, viability, osmolality) were evaluated in this analysis. Score plots, loadings plots, and VIP plots were utilized for assessing scale-up and comparability of the cell-culture process. Batch control charts were found to be useful for fault diagnosis during routine manufacturing. Finally, observations made from reviewing VIP plots were found to be in agreement with conclusions from process characterization studies demonstrating the effectiveness of MVDA as a tool for extracting process knowledge.

  15. Influence of inorganic and organic iron compounds on parameters of cell growth and survival in human colon cells.

    Science.gov (United States)

    Klenow, Stefanie; Pool-Zobel, Beatrice L; Glei, Michael

    2009-04-01

    Increased risk for development of colon cancer is associated with red meat intake and iron toxicity is discussed for one underlying mechanism. Anyhow, for iron itself only limited evidence is found. In this study, effects of different iron compounds on proliferation of HT29 carcinoma and LT97 adenoma human colon cells were investigated. After treatment of cells with inorganic (ferrous sulfate: FeSO4 and ferric nitrilotriacetate: FeNTA) and organic (hemoglobin and hemin) iron sources (24-72 h), number of cells and metabolic activity were measured. Under normal cell culture conditions, neither iron compound elevated cell growth in either cell line with the exception of FeNTA which induced LT97 cell growth significantly. Distinct inhibition of cell proliferation was measured for organic iron. Serum-free incubation of HT29 cells revealed growth promoting properties of iron under deficiency. Even though organic iron, especially hemin, was a potent growth factor, both substances showed also dose-dependent cytotoxic effects. In conclusion, these data emphasize that not iron itself, but merely organic iron may promote carcinogenic events. Since promotion of proliferation was only detectable under deficiency, cytotoxic properties of organic iron may be of more importance in colon carcinogenesis.

  16. Auxiliary power unit based on a solid oxide fuel cell and fuelled with diesel

    Science.gov (United States)

    Lawrence, Jeremy; Boltze, Matthias

    An auxiliary power unit (APU) is presented that is fuelled with diesel, thermally self-sustaining, and based on a solid oxide fuel cell (SOFC). The APU is rated at 1 kW electrical, and can generate electrical power after a 3 h warm-up phase. System features include a "dry" catalytic partial oxidation (CPOX) diesel reformer, a 30 cell SOFC stack with an open cathode, and a porous-media afterburner. The APU does not require a supply of external water. The SOFC stack is an outcome of a development partnership with H.C. Starck GmbH and Fraunhofer IKTS, and is discussed in detail in an accompanying paper.

  17. Root cause analysis of the degradation in a unitized regenerative fuel cell

    Science.gov (United States)

    Bhosale, Amit C.; Meenakshi, S.; Ghosh, Prakash C.

    2017-03-01

    The present study emphasizes the possible modes of failure of a unitized regenerative fuel cell (URFC) when operated in fuel cell as well as in electrolysis mode at different temperatures viz. 30 °C and 60 °C. The carbon based catalyst (Pt/C) and diffusion layers are used to characterize the degradation of the URFCs. The electrolysis mode of operation is found to dominate the root cause of failure with increase in temperature. Agglomeration and loss of catalyst along with delamination of electrode from membrane are observed. Membrane degradation owing to it's structural as well as chemical damage is seen to be prominent at higher temperature. Characterization techniques such as SEM, TEM and ICP-AES confirm the study showcasing the effect.

  18. Optimizing energy management of decentralized photovoltaic. Fuel cell - direct storage - power supply units

    Energy Technology Data Exchange (ETDEWEB)

    Bocklisch, Thilo; Schufft, Wolfgang; Bocklisch, Steffen [Chemnitz Univ. of Technology (TUC) (Germany)

    2010-07-01

    This paper presents a new optimizing energy management concept for decentralized power supply units. Main goal is the coordinated utilization of dynamically controllable combined-heat-and-power-plants (e.g. fuel cell cogeneration plants) and electrochemical direct storages (e.g. future electric car batteries) for the active balancing of fluctuating renewable energy generation (e.g. building integrated photovoltaics) and fluctuation electricity consumption. The self-utilization and partial storage of renewable energy helps to stabilize the grid in a ''bottom-up'' approach. The new energy mangement concept features a three-layer control structure, which aims for the optimization of the power flows, minimizing the fuel consumption and the dynamic stress imposed onto the fuel cell. (orig.)

  19. Modeling the Effects of Irrigation on Land Surface Fluxes and States over the Conterminous United States: Sensitivity to Input Data and Model Parameters

    Energy Technology Data Exchange (ETDEWEB)

    Leng, Guoyong; Huang, Maoyi; Tang, Qiuhong; Sacks, William J.; Lei, Huimin; Leung, Lai-Yung R.

    2013-09-16

    Previous studies on irrigation impacts on land surface fluxes/states were mainly conducted as sensitivity experiments, with limited analysis of uncertainties from the input data and model irrigation schemes used. In this study, we calibrated and evaluated the performance of irrigation water use simulated by the Community Land Model version 4 (CLM4) against observations from agriculture census. We investigated the impacts of irrigation on land surface fluxes and states over the conterminous United States (CONUS) and explored possible directions of improvement. Specifically, we found large uncertainty in the irrigation area data from two widely used sources and CLM4 tended to produce unrealistically large temporal variations of irrigation demand for applications at the water resources region scale over CONUS. At seasonal to interannual time scales, the effects of irrigation on surface energy partitioning appeared to be large and persistent, and more pronounced in dry than wet years. Even with model calibration to yield overall good agreement with the irrigation amounts from the National Agricultural Statistics Service (NASS), differences between the two irrigation area datasets still dominate the differences in the interannual variability of land surface response to irrigation. Our results suggest that irrigation amount simulated by CLM4 can be improved by (1) calibrating model parameter values to account for regional differences in irrigation demand and (2) accurate representation of the spatial distribution and intensity of irrigated areas.

  20. Crucial ignored parameters on nanotoxicology: the importance of toxicity assay modifications and "cell vision".

    Directory of Open Access Journals (Sweden)

    Sophie Laurent

    Full Text Available Until now, the results of nanotoxicology research have shown that the interactions between nanoparticles (NPs and cells are remarkably complex. In order to get a deep understanding of the NP-cell interactions, scientists have focused on the physicochemical effects. However, there are still considerable debates about the regulation of nanomaterials and the reported results are usually in contradictions. Here, we are going to introduce the potential key reasons for these conflicts. In this case, modification of conventional in vitro toxicity assays, is one of the crucial ignored matter in nanotoxicological sciences. More specifically, the conventional methods neglect important factors such as the sedimentation of NPs and absorption of proteins and other essential biomolecules onto the surface of NPs. Another ignored matter in nanotoxicological sciences is the effect of cell "vision" (i.e., cell type. In order to show the effects of these ignored subjects, we probed the effect of superparamagnetic iron oxide NPs (SPIONs, with various surface chemistries, on various cell lines. We found thatthe modification of conventional toxicity assays and the consideration of the "cell vision" concept are crucial matters to obtain reliable, and reproducible nanotoxicology data. These new concepts offer a suitable way to obtain a deep understanding on the cell-NP interactions. In addition, by consideration of these ignored factors, the conflict of future toxicological reports would be significantly decreased.

  1. Telomere length in relation to immunological parameters in patients with renal cell carcinoma.

    Directory of Open Access Journals (Sweden)

    Ulrika Svenson

    Full Text Available Over the last decade, telomere length (TL has gained attention as a potential biomarker in cancer disease. We previously reported that long blood TL was associated with a poorer outcome in patients with breast cancer and renal cell carcinoma. Based on these findings, we hypothesized that certain immunological components may have an impact on TL dynamics in cancer patients. One aim of the present study was to investigate a possible association between serum cytokines and TL of peripheral blood cells, tumors and corresponding kidney cortex, in patients with clear cell renal cell carcinoma. For this purpose, a multiplex cytokine assay was used. Correlation analysis revealed significant positive correlations between tumor TL and peripheral levels of three cytokines (IL-7, IL-8 and IL-10. In a parallel patient group with various kidney tumors, TL was investigated in whole blood and in immune cell subsets in relation to peripheral levels of regulatory T cells (Tregs. A significant positive association was found between whole blood TL and Treg levels. However, the strongest correlation was found between Tregs and TL of the T lymphocyte fraction. Thus, patients with higher Treg levels displayed longer T cell telomeres, which might reflect a suppressed immune system with fewer cell divisions and hence less telomere shortening. These results are in line with our earlier observation that long blood TL is an unfavorable prognostic factor for cancer-specific survival. In summary, we here show that immunological components are associated with TL in patients with renal cell carcinoma, providing further insight into the field of telomere biology in cancer.

  2. Spherical TiO2 aggregates with different building units for dye-sensitized solar cells.

    Science.gov (United States)

    Liu, Zhaohui; Su, Xunjia; Hou, Genliang; Bi, Song; Xiao, Zhou; Jia, Haipeng

    2013-09-07

    Tailoring the architectures of spherical TiO2 aggregates is crucial to obtain superior photovoltaic properties and promote their application in dye-sensitized solar cells (DSSCs). Herein, we synthesized spherical TiO2 aggregates using different building units, including nanocrystallites, nanorods, nanosheets, and nanotubes, via a hydrothermal method, and studied the effect of the building units on the performances of DSSCs. The aggregates assembled by uniform nanosheet and nanotube building units were synthesized with the use of spherical TiO2 nanorod aggregates as titanium sources in an alkaline hydrothermal reaction. Compared with TiO2 nanoparticles, the spherical TiO2 aggregates possess higher surface area, more efficient light scattering ability, and better electron transport properties. Among the four types of spherical TiO2 aggregates; the nanorod, nanotube, and nanosheet aggregates demonstrate better electron transport properties than the nanocrystallite aggregates; the nanotube and nanosheet aggregates exhibit more efficient light scattering than the nanocrystallite and nanorod aggregates; and the nanotube aggregates show the highest surface area. Thus the DSSC based on nanotube aggregates exhibited the highest energy conversion efficiency of 7.48%, which is 16.0%, 9.7%, and 19.5% higher than those of the DSSCs based on the nanosheet, nanorod, and nanocrystallite aggregates, respectively.

  3. Effects of L-NAME on morphometric parameters of stomach parietal cells in pregnant rats

    Directory of Open Access Journals (Sweden)

    Seyed Mohammad Hossein Noori Mugahi

    2014-05-01

    Results: Results of this study after analysis showed the significant changes in parietal cells count (mean 61.3±4.32 and its diameters (mean 16.12±1.18 µm in L-NAME group in comparison to control and the sham groups in pregnant rats (P≤0.05. Conclusion: Results of this study showed L-NAME with effects on NO synthesis can reduce the count of parietal cells and increase its diameter in pregnant rats and has destructive effects on structure of stomach parietal cells in pregnancy rats.

  4. Exploratory study of the prognostic value of microenvironmental parameters during fractionated irradiation in human squamous cell carcinoma xenografts.

    Science.gov (United States)

    Yaromina, Ala; Kroeber, Theresa; Meinzer, Andreas; Boeke, Simon; Thames, Howard; Baumann, Michael; Zips, Daniel

    2011-07-15

    To explore the prognostic value of microenvironmental parameters for local tumor control determined before and during fractionated irradiation. Six human squamous cell carcinoma (hSCC) lines were transplanted subcutaneously into the right hind leg of nude mice. Tumors were irradiated with 30 fractions within 6 weeks. Local tumor control was determined 120 days after irradiation. Radiation response was quantified as dose to cure 50% of tumors (TCD(50)). In parallel, untreated and irradiated tumors were excised after injection of pimonidazole (hypoxia marker) and Hoechst 33342 (perfusion marker) for histological evaluation. Pimonidazole hypoxia decreased during fractionated irradiation in the majority of tumor lines. Fraction of perfused vessels and vascular area showed modest changes during fractionated irradiation. Histological parameters before treatment and after three and five fractions did not significantly correlate with TCD(50) after irradiation with 30 fractions within 6 weeks (p > 0.05). Hypoxic volume and perfused vessels after 10 fractions showed a significant association with local tumor control after fractionated irradiation (p = 0.018 and p = 0.019, respectively). None of these parameters remained statistically significant when the p value was adjusted for multiple comparisons. The results from this exploratory study suggest that determination of microenvironmental parameters during treatment provides better prognostic information for the outcome after fractionated radiotherapy than pretreatment parameters, which warrants further investigation and confirmation in experimental and clinical studies. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. On the estimation of high frequency parameters of Proton Exchange Membrane Fuel Cells via Electrochemical Impedance Spectroscopy

    Science.gov (United States)

    Mainka, J.; Maranzana, G.; Dillet, J.; Didierjean, S.; Lottin, O.

    2014-05-01

    This paper is a discussion on the estimation of impedance parameters of H2/air fed Proton Exchange Membrane Fuel Cells (PEMFC). The impedance model corresponds to the Randles electrical equivalent circuit accounting for charge separation and transport processes in the cathode catalyst layer, as well as for oxygen diffusion through the backing layer. A sensitivity analysis confirms that the cathode parameters are not correlated and that the consideration of the anode has no significant impact on the estimation of their values. In addition, it is shown that the diffusion parameters have a significant impact in the low frequency domain only, at least with this model. The parameters characterizing charge separation and transport processes at the cathode can thus be estimated with the high frequency impedance data, independently of the oxygen transport model. Consequently, even in the absence of a fully validated oxygen transport impedance, EIS can be used as an alternative method (to classical steady-state methods) for the estimation of the parameters characterizing the cathode reaction: the Tafel slope b, the charge transfer coefficient α and possibly, the exchange current density j0. This reduces significantly the measuring time while enhancing the accuracy by comparison with steady-state methods.

  6. Supergranular Parameters

    Science.gov (United States)

    Udayashankar, Paniveni

    2016-07-01

    I study the complexity of supergranular cells using intensity patterns from Kodaikanal solar observatory. The chaotic and turbulent aspect of the solar supergranulation can be studied by examining the interrelationships amongst the parameters characterizing supergranular cells namely size, horizontal flow field, lifetime and physical dimensions of the cells and the fractal dimension deduced from the size data. The findings are supportive of Kolmogorov's theory of turbulence. The Data consists of visually identified supergranular cells, from which a fractal dimension 'D' for supergranulation is obtained according to the relation P α AD/2 where 'A' is the area and 'P' is the perimeter of the supergranular cells. I find a fractal dimension close to about 1.3 which is consistent with that for isobars and suggests a possible turbulent origin. The cell circularity shows a dependence on the perimeter with a peak around (1.1-1.2) x 105 m. The findings are supportive of Kolmogorov's theory of turbulence.

  7. New red blood cell and reticulocyte parameters and reference values for healthy individuals and in chronic kidney disease

    Directory of Open Access Journals (Sweden)

    Patrícia S. Scherer

    2015-04-01

    Full Text Available Introduction: The importance of local references values has been well described in the literature; this is because the characteristics of the population may influence the laboratory tests. Objective: To establish the reference range for traditional and extended red blood cell parameters and reticulocyte indices in order to investigate its application in patients with chronic kidney disease (CKD. Materials and methods: 249 blood donors (125 males and 124 females were selected to establish the reference values. The hemodialysis sample consisted of 62 patients with terminal CKD (48 male and 14 female. All analyzes were performed using the Sysmex XE-5000 automated hematology analyzer. Results: Differences between reference values was observed in relation to gender: red blood cells (RBC, hemoglobin (HGB, hematocrit (HCT, mean corpuscular hemoglobin concentration (MCHC, percentage of hyperchromic red blood cells (%HYPER, percentage of microcytosis (%MICRO, percentage of macrocytosis (%MACRO, absolute reticulocyte count (RET, reticulocyte hemoglobin content (RET-He, immature reticulocyte fraction (IFR, low fluorescence reticulocytes (LFR, medium fluorescence reticulocytes (MFR, and high fluorescence reticulocytes (HFR. Individuals with CKD presented RBC, HGB, HCT, MCHC, red cell distribution width expressed as coefficient of variation (RDW-CV, percentage of hypochromic red blood cells (%HYPO, percentage of reticulocytes (RET%, RET (female group, IFR, LFR, MFR, and HFR results compatible with the anemic state, which can be observed in 91.8% of patients. All studied parameters were in the area under the curve (AUC > 0.4. In male group, %HYPO (AUC: 0.806 and IFR (AUC: 0.762 presented higher AUC values, while female group presented %HYPO (AUC: 0.806, %HYPER (AUC: 0.815, and IFR (AUC: 0.660. Conclusion: The medical advancement, the development of new techniques and hematological parameters have revealed important information about functional integrity of

  8. Effects of Selected Physicochemical Parameters on Zerumbone Production of Zingiber zerumbet Smith Cell Suspension Culture

    Directory of Open Access Journals (Sweden)

    Mahanom Jalil

    2015-01-01

    Full Text Available Zingiber zerumbet Smith is an important herb that contains bioactive phytomedicinal compound, zerumbone. To enhance cell growth and production of this useful compound, we investigated the growth conditions of cell suspension culture. Embryogenic callus generated from shoot bud was used to initiate cell suspension culture. The highest specific growth rate of cells was recorded when it was cultured in liquid Murashige and Skoog basal medium containing 3% sucrose with pH 5.7 and incubated under continuous shaking condition of 70 rpm for 16 h light and 8 h dark cycle at 24°C. Our results also revealed that the type of carbohydrate substrate, light regime, agitation speed, and incubation temperature could affect the production of zerumbone. Although the zerumbone produced in this study was not abundant compared to rhizome of Z. zerumbet, the possibility of producing zerumbone during early stage could serve as a model for subsequent improvement.

  9. Unit cell-based computer-aided manufacturing system for tissue engineering.

    Science.gov (United States)

    Kang, Hyun-Wook; Park, Jeong Hun; Kang, Tae-Yun; Seol, Young-Joon; Cho, Dong-Woo

    2012-03-01

    Scaffolds play an important role in the regeneration of artificial tissues or organs. A scaffold is a porous structure with a micro-scale inner architecture in the range of several to several hundreds of micrometers. Therefore, computer-aided construction of scaffolds should provide sophisticated functionality for porous structure design and a tool path generation strategy that can achieve micro-scale architecture. In this study, a new unit cell-based computer-aided manufacturing (CAM) system was developed for the automated design and fabrication of a porous structure with micro-scale inner architecture that can be applied to composite tissue regeneration. The CAM system was developed by first defining a data structure for the computing process of a unit cell representing a single pore structure. Next, an algorithm and software were developed and applied to construct porous structures with a single or multiple pore design using solid freeform fabrication technology and a 3D tooth/spine computer-aided design model. We showed that this system is quite feasible for the design and fabrication of a scaffold for tissue engineering.

  10. Imaging the impact on cuprate superconductivity of varying the interatomic distances within individual crystal unit cells.

    Science.gov (United States)

    Slezak, J A; Lee, Jinho; Wang, M; McElroy, K; Fujita, K; Andersen, B M; Hirschfeld, P J; Eisaki, H; Uchida, S; Davis, J C

    2008-03-04

    Many theoretical models of high-temperature superconductivity focus only on the doping dependence of the CuO(2)-plane electronic structure. However, such models are manifestly insufficient to explain the strong variations in superconducting critical temperature, T(c), among cuprates that have identical hole density but are crystallographically different outside of the CuO(2) plane. A key challenge, therefore, has been to identify a predominant out-of-plane influence controlling the superconductivity, with much attention focusing on the distance d(A) between the apical oxygen and the planar copper atom. Here we report direct determination of how variations in interatomic distances within individual crystalline unit cells affect the superconducting energy-gap maximum Delta of Bi(2)Sr(2)CaCu(2)O(8+delta). In this material, quasiperiodic variations of unit cell geometry occur in the form of a bulk crystalline "supermodulation." Within each supermodulation period, we find approximately 9 +/- 1% cosinusoidal variation in local Delta that is anticorrelated with the associated d(A) variations. Furthermore, we show that phenomenological consistency would exist between these effects and the random Delta variations found near dopant atoms if the primary effect of the interstitial dopant atom is to displace the apical oxygen so as to diminish d(A) or tilt the CuO(5) pyramid. Thus, we reveal a strong, nonrandom out-of-plane effect on cuprate superconductivity at atomic scale.

  11. Intra-unit-cell nematic charge order in the titanium-oxypnictide family of superconductors

    Science.gov (United States)

    Frandsen, Benjamin A.; Bozin, Emil S.; Hu, Hefei; Zhu, Yimei; Nozaki, Yasumasa; Kageyama, Hiroshi; Uemura, Yasutomo J.; Yin, Wei-Guo; Billinge, Simon J. L.

    2014-12-01

    Understanding the role played by broken-symmetry states such as charge, spin and orbital orders in the mechanism of emergent properties, such as high-temperature superconductivity, is a major current topic in materials research. That the order may be within one unit cell, such as nematic, was only recently considered theoretically, but its observation in the iron-pnictide and doped cuprate superconductors places it at the forefront of current research. Here, we show that the recently discovered BaTi2Sb2O superconductor and its parent compound BaTi2As2O form a symmetry-breaking nematic ground state that can be naturally explained as an intra-unit-cell nematic charge order with d-wave symmetry, pointing to the ubiquity of the phenomenon. These findings, together with the key structural features in these materials being intermediate between the cuprate and iron-pnictide high-temperature superconducting materials, render the titanium oxypnictides an important new material system to understand the nature of nematic order and its relationship to superconductivity.

  12. Cell density and solvent are critical parameters affecting formazan evaluation in MTT assay

    Directory of Open Access Journals (Sweden)

    Kellen Cristina da Silva Gasque

    2014-06-01

    Full Text Available The aim of this study was to establish the more accurate protocol for fibroblast cell viability using MTT assay. NIH/3T3 fibroblasts were seeded at the following cell densities: 3.125x10³; 1.156x10(4; 3.125x10(4; 1.156x10(5 and 3.125x10(5 cells/cm². Following 24h of seeding, MTT was added to the wells. After 4h of the MTT addition, different solvents were added to solubilize the formazan crystals: 1 HCl/SDS group- 20% SDS and 0.01 M HCl; 2 EtOH/ HAc group-50% ethanol and 1% acetic acid; 3 DMSO group- 99.5% dimethyl sulfoxide; and 4 PropOH group- 99.5% isopropanol. The absorbance values were measured using a spectrophotometer at 570 nm. The data were analyzed by 2-way ANOVA (p<0.05 and showed that the absorbance average varied according to the number of cells and solvents: HCl/SDS (0 to 0.13, EtOH/HAc (0 to 0.22, DMSO (0.76 to 1.31 and PropOH (0.66 to 1.04. The DMSO and PropOH groups presented the most appropriate protocols for NIH/3T3 fibroblasts cell viability, especially at the density of 1.156x10(4 cells/cm².

  13. Evaluation of hematological parameters in partial exchange and packed cell transfusion in treatment of severe anemia in pregnancy.

    Science.gov (United States)

    Salhan, Sudha; Tripathi, Vrijesh; Singh, Rajvir; Gaikwad, Harsha S

    2012-01-01

    Objectives. Anemia is a major public health problem throughout the world which assumes prominence in pregnant mothers. Patients with severe anemia continue to present themselves at term or in labor. This study was conducted to compare the improvements in hematological parameters of patients receiving partial exchange blood transfusion and transfusion of packed cells without exchange. Methods. One hundred and twenty-five severely anemic antenatal mothers were admitted from outpatient service. Partial exchange transfusion was given to sixty-six patients while fifty-nine received transfusion of packed cells with frusemide cover. Results. The two groups were comparable in terms of age, height, weight, religion, diet, education, occupation of self and husband, and income. Hemoglobin level in Group 1 was comparatively less than Group 2 at prelevel (5.2 ± 1.5 versus 6.6 ± 2.3, P = 0.001) and postlevel (7.2 ± 1.5 versus 8.6 ± 1.8, P = 0.001), respectively, but there was no significant difference between the two modes of transfusion (2.09 ± 1.6 versus 2.01 ± 1.5, P = 0.78). Conclusion. The study produced an equally significant improvement in hematological parameters in partial exchange and packed cell transfusion. Platelet counts were significantly less in partial exchange as compared with packed cell transfusion.

  14. Evaluation of Hematological Parameters in Partial Exchange and Packed Cell Transfusion in Treatment of Severe Anemia in Pregnancy

    Directory of Open Access Journals (Sweden)

    Sudha Salhan

    2012-01-01

    Full Text Available Objectives. Anemia is a major public health problem throughout the world which assumes prominence in pregnant mothers. Patients with severe anemia continue to present themselves at term or in labor. This study was conducted to compare the improvements in hematological parameters of patients receiving partial exchange blood transfusion and transfusion of packed cells without exchange. Methods. One hundred and twenty-five severely anemic antenatal mothers were admitted from outpatient service. Partial exchange transfusion was given to sixty-six patients while fifty-nine received transfusion of packed cells with frusemide cover. Results. The two groups were comparable in terms of age, height, weight, religion, diet, education, occupation of self and husband, and income. Hemoglobin level in Group 1 was comparatively less than Group 2 at prelevel (5.2±1.5 versus 6.6±2.3, P=0.001 and postlevel (7.2±1.5 versus 8.6±1.8, P=0.001, respectively, but there was no significant difference between the two modes of transfusion (2.09±1.6 versus 2.01±1.5, P=0.78. Conclusion. The study produced an equally significant improvement in hematological parameters in partial exchange and packed cell transfusion. Platelet counts were significantly less in partial exchange as compared with packed cell transfusion.

  15. Coal flotation optimization using modified flotation parameters and combustible recovery in a Jameson cell

    Energy Technology Data Exchange (ETDEWEB)

    Vapur, Hueseyin; Bayat, Oktay [Cukurova University, Mining Engineering Department, Balcali, 01330 Adana (Turkey); Ucurum, Metin [Nigde University, Mining Engineering Department, 51100 Nigde (Turkey)

    2010-10-15

    This study discusses a new coal flotation optimization approach. It is conducted using modified flotation parameters and combustible recovery. The experimental work was evaluated in two stages. In the first stage, recoveries (1, 2, 3, 5 and 8 min of flotation times) of Jameson flotation operating parameters were fitted to first-order kinetic model, R = R{sub {infinity}} [1 - exp (-kt)] where R was recovery at t time, R{sub {infinity}} was ultimate recovery and k was the first-order rate constant to draw the time recovery curves in the experimental study. Two parameters, the ultimate recovery (R{sub {infinity}}) and first-order rate constant (k), were then obtained from the model to fit an experimental time recovery curve. A modified flotation rate constant (K{sub m}) defined as product of R{sub {infinity}} and k, i.e., K{sub m} = R{sub {infinity}}{sup *} k, and selectivity index (SI) defined as the ratio of the modified rate constant of coal to the modified rate constant of ash ((SI)=K{sub m} of Coal/K{sub m} of Ash), which could be collectively called ''modified flotation parameters''. It was used to determine of the sub and upper values of operation variables. In the second one, combustible recovery (%) and ash content (%) were used to optimization of the Jameson flotation variables and it was found that d{sub 80} = 0.250 mm particle size, 1/1 vegetable oil acids/kerosene ratio, 20% solids pulp density, 0.600 L/min wash water rate and 40 cm downcomer immersion dept could be used to separate efficiently coal from ash. Final concentrate was obtained with 94.83% combustible recovery and 17.86% ash content at optimum conditions after 8 min flotation time. (author)

  16. Fuel cell collaboration in the United States. A report to the Danish Partnership for Hydrogen and Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    2011-08-15

    The purpose of this report is to provide members of the Danish Partnership for Hydrogen and Fuel Cells with information regarding collaborative opportunities in the United States. The report is designed to provide an overview of key issues and activities and to provide guidance on strategies for finding U.S. research and commercial partners and gaining access to the U.S. market. Section 1 of this report provides an overview of the key drivers of policy at the federal and state government levels regarding hydrogen and fuel cell technologies and provides a perspective of the U.S. industry and key players. It also suggests three general pathways for accessing U.S. opportunities: enhancing visibility; developing vendor relationships; and establishing a formal presence in the U.S. The next sections summarize focus areas for commercial and research activity that currently are of the greatest interest in the U.S. Section 2 describes major programs within the federal government and national laboratories, and discusses various methods for identifying R and D funding opportunities, with an overview of federal acquisition regulations. Section 3 reviews the efforts of several state governments engaging the fuel cell industry as an economic driver and presents an overview of acquisition at the state level. Section 4 discusses university research and development (R and D) and university-industry partnerships. There are 12 appendices attached to the report. These appendices provide more detailed information regarding the key federal government agencies involved in fuel cells and hydrogen, state-specific policies and activities, national laboratories and universities, and other information regarding the fuel cell and hydrogen industry in the U.S. (Author)

  17. Influences of the geometry and acoustic parameter on acoustic radiation forces on three-layered nucleate cells

    Science.gov (United States)

    Wang, Yuan-Yuan; Yao, Jie; Wu, Xue-Wei; Wu, Da-Jian; Liu, Xiao-Jun

    2017-09-01

    Acoustic radiation forces (ARFs) on three-layered micro-shells (TLSs) are investigated using Mie scattering theory. The TLS is proposed to simulate a nucleate cell with nucleus, cytoplasm, and membrane. It is found that the existence of the inner core or outer shell greatly influences ARFs on nucleate cells. We focus on the influences of the geometry, acoustic parameters, and the surrounding medium on ARFs on TLSs. With increasing inner core radius or outer shell thickness, the ARF on the TLS shows a distinct increase. We find that the impedance of each layer of the TLS plays a dominant role with regard to the ARF, while the density and the sound velocity separately provide distinct modulations. In addition, it is found that the higher impedance of the surrounding medium induces larger ARF on the TLS. Our work may be beneficial for the acoustic manipulation of nucleate cells.

  18. Parameter study for polymer solar modules based on various cell lengths and light intensities

    Energy Technology Data Exchange (ETDEWEB)

    Slooff, L.H.; Burgers, A.R.; Bende, E.E.; Kroon, J.M. [ECN Solar Energy, P.O. Box 1, 1755 ZG Petten (Netherlands); Veenstra, S.C. [ECN Solar Energy, Solliance, High Tech Campus 5, P63, 5656AE Eindhoven (Netherlands)

    2013-10-15

    Polymer solar cells may be applied in portable electronic devices, where light intensity and spectral distribution of the illuminating source can be very different compared to outdoor applications. As the power output of solar cells depends on temperature, light intensity and spectrum, the design of the module must be optimized for the specific illumination conditions in the different applications. The interconnection area between cells in a module must be as narrow as possible to maximize the active area, also called geometrical fill factor, of the module. Laser scribing has the potential to realize this. The optimal width of the interconnection zone depends both on technological limitations, e.g. laser scribe width and the minimal distance between scribes, and electrical limitations like resistive losses. The latter depends on the generated current in the cell and thus also on illumination intensity. Besides that, also the type of junction, i.e. a single or tandem junction, will influence the optimal geometry. In this paper a calculation model is presented that can be used for electrical modeling of polymer cells and modules in order to optimize the performance for the specific illumination conditions.

  19. STREAMLINED APPROACH FOR ENVIRONMENTAL RESTORATION PLAN FOR CORRECTIVE ACTION UNIT 116: AREA 25 TEST CELL C FACILITYNEVADA TEST SITE, NEVADA

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This Streamlined Approach for Environmental Restoration Plan identifies the activities required for the closure of Corrective Action Unit 116, Area 25 Test Cell C Facility. The Test Cell C Facility is located in Area 25 of the Nevada Test Site approximately 25 miles northwest of Mercury, Nevada.

  20. Application of the SEM to the measurement of solar cell parameters

    Science.gov (United States)

    Weizer, V. G.; Andrews, C. W.

    1977-01-01

    A pair of techniques are described which make use of the SEM to measure, respectively, the minority carrier diffusion length and the metallurgical junction depth in silicon solar cells. The former technique permits the measurement of the true bulk diffusion length through the application of highly doped field layers to the back surfaces of the cells being investigated. The technique yields an absolute value of the diffusion length from a knowledge of the collected fraction of the injected carriers and the cell thickness. It is shown that the secondary emission contrast observed in the SEM on a reverse-biased diode can depict the location of the metallurgical junction if the diode has been prepared with the proper beveled geometry. The SEM provides the required contrast and the option of high magnification, permitting the measurement of extremely shallow junction depths.

  1. The effects of anodization parameters on titania nanotube arrays and dye sensitized solar cells

    Science.gov (United States)

    Xie, Z. B.; Adams, S.; Blackwood, D. J.; Wang, J.

    2008-10-01

    Ordered, closely packed, and vertically oriented titania nanotube arrays with lengths exceeding 10 µm were fabricated by anodization of titanium foils. The effects of anodization voltage and time on the microstructural morphology and the photovoltaic performance of dye sensitized solar cells based on the titania nanotube arrays were investigated. On increasing the anodization voltage or time, the increase in active surface area leads to enhanced photovoltaic currents and thereby an overall higher performance of the dye sensitized solar cells. The efficiency enhancement with rising anodization voltage exceeds the increase in the outer surface area of the nanotubes, indicating that the active surface area is further enlarged by a more accessible inner surface of the nanotube arrays grown with a higher anodization voltage. A promising efficiency of 3.67% for dye sensitized solar cells based on anodized titania nanotube arrays was achieved under AM1.5, 100 mW cm-2 illumination.

  2. The effects of anodization parameters on titania nanotube arrays and dye sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Z B; Adams, S; Blackwood, D J; Wang, J [Department of Materials Science and Engineering, National University of Singapore, Singapore 117574 (Singapore)], E-mail: msexz@nus.edu.sg

    2008-10-08

    Ordered, closely packed, and vertically oriented titania nanotube arrays with lengths exceeding 10 {mu}m were fabricated by anodization of titanium foils. The effects of anodization voltage and time on the microstructural morphology and the photovoltaic performance of dye sensitized solar cells based on the titania nanotube arrays were investigated. On increasing the anodization voltage or time, the increase in active surface area leads to enhanced photovoltaic currents and thereby an overall higher performance of the dye sensitized solar cells. The efficiency enhancement with rising anodization voltage exceeds the increase in the outer surface area of the nanotubes, indicating that the active surface area is further enlarged by a more accessible inner surface of the nanotube arrays grown with a higher anodization voltage. A promising efficiency of 3.67% for dye sensitized solar cells based on anodized titania nanotube arrays was achieved under AM1.5, 100 mW cm{sup -2} illumination.

  3. Optimization of material/device parameters of CdTe photovoltaic for solar cells applications

    Science.gov (United States)

    Wijewarnasuriya, Priyalal S.

    2016-05-01

    Cadmium telluride (CdTe) has been recognized as a promising photovoltaic material for thin-film solar cell applications due to its near optimum bandgap of ~1.5 eV and high absorption coefficient. The energy gap is near optimum for a single-junction solar cell. The high absorption coefficient allows films as thin as 2.5 μm to absorb more than 98% of the above-bandgap radiation. Cells with efficiencies near 20% have been produced with poly-CdTe materials. This paper examines n/p heterostructure device architecture. The performance limitations related to doping concentrations, minority carrier lifetimes, absorber layer thickness, and surface recombination velocities at the back and front interfaces is assessed. Ultimately, the paper explores device architectures of poly- CdTe and crystalline CdTe to achieve performance comparable to gallium arsenide (GaAs).

  4. Simultaneous analysis of mitochondrial activity and DNA content in Ehrlich ascites tumor cells by dual parameter flow cytometry.

    Science.gov (United States)

    Hämmerle, T; Löffler, M

    1989-01-01

    Ehrlich ascites tumor cells were permeabilized using low concentrations of digitonin, 8 micrograms/10(6) cells. Permeabilization was monitored by the assay of lactate dehydrogenase released into the incubation medium and of hexokinase partially bound to mitochondria. Integrity of the cellular organelles was unaffected as determined by assay of the mitochondrial enzyme glutamate dehydrogenase. Cells were stained with rhodamine 123 as a mitochondrial specific dye and propidium iodide/mithramycin as DNA specific dyes. The green fluorescence of bound rhodamine 123 versus red fluorescence of DNA in individual cells was analysed by dual parameter flow cytometry. Incubation of cells with inhibitors of mitochondrial energy metabolism, such as, potassium cyanide and carbonyl cyanide m-chlorophenylhydrazone abolished binding of rhodamine 123. Flow cytometric data allowed a correlation between cell position in the mitotic cycle with total mitochondrial activity. In addition, comparison of the characteristics of propidium iodide and ethidium bromide staining further elucidated the molecular basis of the staining with the positively-charged fluorescent dye rhodamine 123.

  5. Critical parameters in the MCF-7 cell proliferation bioassay (E-Screen)

    DEFF Research Database (Denmark)

    Rasmussen, Thomas Høj; Nielsen, Jesper Bo

    2002-01-01

    The MCF-7 cell proliferation bioassay has grown in popularity as a rapid test for detecting potentially oestrogenic compounds. Several MCF-7 cell sublines with different sensitivities to oestrogens are currently used, with maximal proliferation responses ranging from two- to 10-fold above those o...... hormone-free controls. The specificity was characterized by examining the effects of oestradiol-17beta, the anti-oestrogen ICI 182,780, and dieldrin, a recognized xeno-oestrogen. The improved proliferation bioassay will be a useful tool in identifying potential xeno-oestrogens....

  6. Consideration of Numerical Simulation Parameters and Heat Transfer Models for a Molten Carbonate Fuel Cell Stack

    Energy Technology Data Exchange (ETDEWEB)

    Koh, J.H.; Seo, H.K.; Lim, H.C. [Korea Electric Power Research Institute, Taejon (Korea)

    2001-07-01

    A fuel cell stack model based on differential heat balance equations was solved numerically with a computational fluid dynamics code. Theoretical aspects in the simulation of a molten carbonate fuel cell (MCFC) performance model were discussed with regard to numerical accuracy of temperature prediction. The effect of grid setting for gas channel depth was studied to ensure how coarse it can be. A single computational element was sufficient for temperature prediction, while more grid elements are required for calculation of flow field and pressure distribution. The use of constant velocities is not recommended because it cannot account for the change of linear velocity within fuel cells, indicating the momentum equations have to be solved together with the heat balance equations. Thermal radiation has little effect on calculation of temperature field from the model. Gas properties vary within fuel cells, but most of them can be treated constant except for specific heat capacity of anode gas. Convection heat transfer by anode gas can be overestimated when a constant specific heat capacity is used, resulting in prediction of lower temperature curves. (author). 18 refs., 12 figs., 4 tabs.

  7. Agrobacterium-mediated transformation of Vitis Cv. Monastrell suspension-cultured cells: Determination of critical parameters.

    Science.gov (United States)

    Chu, Mingyu; Quiñonero, Carmen; Akdemir, Hülya; Alburquerque, Nuria; Pedreño, María Ángeles; Burgos, Lorenzo

    2016-05-01

    Although some works have explored the transformation of differentiated, embryogenic suspension-cultured cells (SCC) to produce transgenic grapevine plants, to our knowledge this is one of the first reports on the efficient transformation of dedifferentiated Vitis vinifera cv Monastrell SCC. This protocol has been developed using the sonication-assisted Agrobacterium-mediated transformation (SAAT) method. A construct harboring the selectable nptII and the eyfp/IV2 marker genes was used in the study and transformation efficiencies reached over 50 independent transformed SCC per gram of infected cells. Best results were obtained when cells were infected at the exponential phase. A high density plating (500 mg/dish) gave significantly better results. As selective agent, kanamycin was inefficient for the selection of Monastrell transformed SCC since wild type cells were almost insensitive to this antibiotic whereas application of paromomycin resulted in very effective selection. Selected eyfp-expressing microcalli were grown until enough tissue was available to scale up a new transgenic SCC. These transgenic SCC lines were evaluated molecularly and phenotypically demonstrating the presence and integration of both transgenes, the absence of Agrobacterium contamination and the ability of the transformed SCC to grow in highly selective liquid medium. The methodology described here opens the possibility of improving the production of valuable metabolites. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:725-734, 2016.

  8. Parameters influencing in-hospital mortality in patients hospitalized in intensive cardiac care unit: is there an influence of anemia and iron deficiency?

    Science.gov (United States)

    Uscinska, Ewa; Sobkowicz, Bozena; Sawicki, Robert; Kiluk, Izabela; Baranicz, Malgorzata; Stepek, Tomasz; Dabrowska, Milena; Szmitkowski, Maciej; Musial, Wlodzimierz J; Tycinska, Agnieszka M

    2015-04-01

    We investigated the incidence and prognostic value of anemia as well as of the iron status in non-selected patients admitted to an intensive cardiac care unit (ICCU). 392 patients (mean age 70 ± 13.8 years, 43% women), 168 with acute coronary syndromes (ACS), 122 with acute decompensated heart failure, and 102 with other acute cardiac disorders were consecutively, prospectively assessed. The biomarkers of iron status-serum iron concentration (SIC), total iron binding capacity (TIBC), and transferrin saturation (TSAT) together with standard clinical, biochemical and echocardiographic variables-were analyzed. In-hospital mortality was 3.8% (15 patients). The prevalences of anemia (according to WHO criteria), and iron deficiency (ID) were 64 and 63%, respectively. The level of biomarkers of iron status, but not anemia, was lower in patients who died (p < 0.05). Anemia was less frequent in patients with ACS as compared to the remaining ICCU population (p = 0.019). The analysis by logistic regression indicated the highest risk of death for age [odds ratio (OD) 1.38, 95% CI 1.27-1.55], SIC (OR 0.85, 95% CI 0.78-0.94), TIBC (OR 0.95, 95% CI 0.91-0.98), left ventricle ejection fraction (OR 0.85, 95% CI 0.77-0.93), as well as hospitalization for non-ACS (OR 0.25, 95% CI 0.14-0.46), (p < 0.05). The risk of death during hospitalization tended to increase with decreasing levels of TIBC (p = 0.49), as well as with the absence of ACS (p = 0.54). The incidence of anemia and ID in heterogeneous ICCU patients is high. Parameters of the iron status, but not anemia per se, independently influence in-hospital mortality. The prevalence of anemia is higher in non-ACS patients, and tends to worsen the prognosis.

  9. Genetic parameters for lactation traits of milking ewes: protein content and composition, fat, somatic cells and individual laboratory cheese yield

    Directory of Open Access Journals (Sweden)

    De la Fuente Luis

    2002-09-01

    Full Text Available Abstract The effects of some environmental variation factors and the genetic parameters for total milk traits (fat content, protein content, casein content, serum protein content, lactation mean of individual laboratory cheese yield (LILCY, lactation mean of somatic cell count (LSCC, and milk yield were estimated from the records of 1 111 Churra ewes. Genetic parameters were estimated by multivariate REML. Heritability for fat content was low (0.10 as is usually found in the Churra breed. Heritabilities for protein content, casein content, serum protein content, LILCY, milk yield and somatic cell count were 0.31, 0.30, 0.22, 0.09, 0.26 and 0.11, respectively. The highest heritability estimates were for protein and casein contents. Casein content is not advisable as an alternative to protein content as a selection criterion for cheese yield improvement; it does not have any compelling advantages and its measurement is costly. Our results for LSCC indicated that efforts should focus on improving the level of management rather than selecting for somatic cells, in the actual conditions of the Churra breed.

  10. Spent metal working fluids produced alterations on photosynthetic parameters and cell-ultrastructure of leaves and roots of maize plants.

    Science.gov (United States)

    Grijalbo, Lucía; Fernandez-Pascual, Mercedes; García-Seco, Daniel; Gutierrez-Mañero, Francisco Javier; Lucas, Jose Antonio

    2013-09-15

    In this work we assess the capacity of maize (Zea mays) plants to phytoremediate spent metal working fluids (MWFs) and its effects on photosynthesis and ultrastructure of mesophyll and root cells. A corn-esparto fibre system patented by us has been used to phytoremediate MWFs in hydroponic culture. Furthermore, a plant growth promoting rhizobacteria (PGPR) has been used to improve the process. The results show that this system is capable of significantly reducing the chemical oxygen demand, under local legislation limits. However, plant systems are really damaged, mainly its photosynthetic system, as shown by the photosynthetical parameters. Nevertheless, strain inoculated improves these parameters, especially Hill reaction. The ultrastructure of photosynthetic apparatus was also affected. Chloroplast number decreased and becomes degraded in the mesophyll of MWFs treated plants. In some cases even plasmolysis of chloroplast membrane was detected. Early senescence symptoms were detected in root ultrastructural study. Severe cellular damage was observed in the parenchymal root cells of plants grown with MWFs, while vascular bundles cell remained unchanged. It seems that the inoculation minimises the damage originated by the MWFs pollutants, appearing as less degenerative organelles and higher chloroplast number than in non-inoculated ones. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Estimating Important Electrode Parameters of High Temperature PEM Fuel Cells By Fitting a Model to Polarisation Curves and Impedance Spectra

    DEFF Research Database (Denmark)

    Vang, Jakob Rabjerg; Zhou, Fan; Andreasen, Søren Juhl;

    2015-01-01

    A high temperature PEM (HTPEM) fuel cell model capable of simulating both steady state and dynamic operation is presented. The purpose is to enable extraction of unknown parameters from sets of impedance spectra and polarisation curves. The model is fitted to two polarisation curves and four...... impedance spectra measured on a Dapozol 77 MEA. The model is capable of achieving good agreement with the recorded curves. Except at OCV, where the voltage is overpredicted, the simulated polarisation curves deviate maximum 3.0% from the measurements. The impedance spectra deviate maximum 3.7%. The fitted...... parameter values are within the range reported in literature. The only exception is the catalyst layer acid content, which is an order of magnitude lower. This may derive from acid migration. The model is used to illustrate the effect of reactant dynamics on the impedance spectrum. The model can aid...

  12. Real-time multi-parameter cell-based analysis platform

    DEFF Research Database (Denmark)

    Caviglia, Claudia

    Monitoring cellular dynamics such as cell surface interactions, metabolic processes and exocytosis, can help unravelling the causes behind the evolution of diseases associated with cellular dysfunction. A better understanding of cellular behaviour opens up possibilities for the development of new...... of protocols and procedures for performing different cellular assays. (2) Electrochemical impedance spectroscopy (EIS) applied for drug screening and drug delivery in cancer research and wound healing studies. (3) Amperometry for monitoring of neurotransmitter exocytosis, relevant in research on Parkinson’s...

  13. Predictive significance of standardized uptake value parameters of FDG-PET in patients with non-small cell lung carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Duan, X-Y.; Wang, W.; Li, M.; Li, Y.; Guo, Y-M. [PET-CT Center, The First Affiliated Hospital of Xi' an, Jiaotong University, Xi' an, Shaanxi (China)

    2015-02-03

    {sup 18}F-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) is widely used to diagnose and stage non-small cell lung cancer (NSCLC). The aim of this retrospective study was to evaluate the predictive ability of different FDG standardized uptake values (SUVs) in 74 patients with newly diagnosed NSCLC. {sup 18}F-FDG PET/CT scans were performed and different SUV parameters (SUV{sub max}, SUV{sub avg}, SUV{sub T/L}, and SUV{sub T/A}) obtained, and their relationship with clinical characteristics were investigated. Meanwhile, correlation and multiple stepwise regression analyses were performed to determine the primary predictor of SUVs for NSCLC. Age, gender, and tumor size significantly affected SUV parameters. The mean SUVs of squamous cell carcinoma were higher than those of adenocarcinoma. Poorly differentiated tumors exhibited higher SUVs than well-differentiated ones. Further analyses based on the pathologic type revealed that the SUV{sub max}, SUV{sub avg}, and SUV{sub T/L} of poorly differentiated adenocarcinoma tumors were higher than those of moderately or well-differentiated tumors. Among these four SUV parameters, SUV{sub T/L} was the primary predictor for tumor differentiation. However, in adenocarcinoma, SUV{sub max} was the determining factor for tumor differentiation. Our results showed that these four SUV parameters had predictive significance related to NSCLC tumor differentiation; SUV{sub T/L} appeared to be most useful overall, but SUV{sub max} was the best index for adenocarcinoma tumor differentiation.

  14. Parameters Influencing the Growth of ZnO Nanowires as Efficient Low Temperature Flexible Perovskite-Based Solar Cells

    Directory of Open Access Journals (Sweden)

    Alex Dymshits

    2016-01-01

    Full Text Available Hybrid organic-inorganic perovskite has proved to be a superior material for photovoltaic solar cells. In this work we investigate the parameters influencing the growth of ZnO nanowires (NWs for use as an efficient low temperature photoanode in perovskite-based solar cells. The structure of the solar cell is FTO (SnO2:F-glass (or PET-ITO (In2O3·(SnO2 (ITO on, polyethylene terephthalate (PET/ZnAc seed layer/ZnO NWs/CH3NH3PbI3/Spiro-OMeTAD/Au. The influence of the growth rate and the diameter of the ZnO NWs on the photovoltaic performance were carefully studied. The ZnO NWs perovskite-based solar cell demonstrates impressive power conversion efficiency of 9.06% on a rigid substrate with current density over 21 mA/cm2. In addition, we successfully fabricated flexible perovskite solar cells while maintaining all fabrication processes at low temperature, achieving power conversion efficiency of 6.4% with excellent stability for over 75 bending cycles.

  15. Parameters Influencing the Growth of ZnO Nanowires as Efficient Low Temperature Flexible Perovskite-Based Solar Cells.

    Science.gov (United States)

    Dymshits, Alex; Iagher, Lior; Etgar, Lioz

    2016-01-19

    Hybrid organic-inorganic perovskite has proved to be a superior material for photovoltaic solar cells. In this work we investigate the parameters influencing the growth of ZnO nanowires (NWs) for use as an efficient low temperature photoanode in perovskite-based solar cells. The structure of the solar cell is FTO (SnO₂:F)-glass (or PET-ITO (In₂O₃·(SnO₂) (ITO)) on, polyethylene terephthalate (PET)/ZnAc seed layer/ZnO NWs/CH₃NH₃PbI₃/Spiro-OMeTAD/Au. The influence of the growth rate and the diameter of the ZnO NWs on the photovoltaic performance were carefully studied. The ZnO NWs perovskite-based solar cell demonstrates impressive power conversion efficiency of 9.06% on a rigid substrate with current density over 21 mA/cm². In addition, we successfully fabricated flexible perovskite solar cells while maintaining all fabrication processes at low temperature, achieving power conversion efficiency of 6.4% with excellent stability for over 75 bending cycles.

  16. The Effects of Cell Phone Waves (900 MHz-GSM Band on Sperm Parameters and Total Antioxidant Capacity in Rats

    Directory of Open Access Journals (Sweden)

    Masoud Ghanbari

    2013-01-01

    Full Text Available Background: There is tremendous concern regarding the possible adverse effects of cellphone microwaves. Contradictory results, however, have been reported for the effectsof these waves on the body. In the present study, the effect of cell phone microwaves onsperm parameters and total antioxidant capacity was investigated with regard to the durationof exposure and the frequency of these waves.Materials and Methods: This experimental study was performed on 28 adult male Wistarrats (200-250 g. The animals were randomly assigned to four groups (n=7: i. control; ii.two-week exposure to cell phone-simulated waves; iii. three-week exposure to cell phonesimulatedwaves; and iv. two-week exposure to cell phone antenna waves. In all groups,sperm analysis was performed based on standard methods and we determined the meansperm total antioxidant capacity according to the ferric reducing ability of plasma (FRAPmethod. Data were analyzed by one-way ANOVA followed by Tukey’s test using SPSSversion 16 software.Results: The results indicated that sperm viability, motility, and total antioxidant capacityin all exposure groups decreased significantly compared to the control group (p<0.05.Increasing the duration of exposure from 2 to 3 weeks caused a statistically significantdecrease in sperm viability and motility (p<0.05.Conclusion: Exposure to cell phone waves can decrease sperm viability and motility inrats. These waves can also decrease sperm total antioxidant capacity in rats and result inoxidative stress.

  17. [Parameters of the CD4-Cell count and viral load in human immunodeficiency virus type 1 (HIV-1) infected patients].

    Science.gov (United States)

    Selimova, L M; Serebrovskaya, L V; Ivanova, L A; Kravchenko, A V; Buravtsova, E V

    2015-01-01

    In this work the specific features of parameters of plasma CD4 T-lymphocytes count and level virus RNA in the HIV-infected patients were studied. 22% correlation between reduction of CD4 cell count and an increase in virus RNA level was observed in persons that did not receive antiretroviral treatment during the third HIV-infection phase. During this phase of infection patients exhibited a growth of the median value of virus load in cases of both rise as decline in CD4 cell count during long observation period. In addition, towards the end of the observation period, the percentage of patients with virus load > 3.3 Ig copies/ml considerably expanded. 43% correlation between CD4 cell count and duration of the HIV-infection was detected during the fourth infection phase in persons that did not receive antiretroviral treatment. Most of the patients in the third and the fourth infection phases had essential CD4 cell count growth during antiretroviral treatment. Best values were observed in patients with the initial value of CD4 > 400 cells/μl belonging to the third HIV-infection phase.

  18. Modeling of microfluidic microbial fuel cells using quantitative bacterial transport parameters

    Science.gov (United States)

    Mardanpour, Mohammad Mahdi; Yaghmaei, Soheila; Kalantar, Mohammad

    2017-02-01

    The objective of present study is to analyze the dynamic modeling of bioelectrochemical processes and improvement of the performance of previous models using quantitative data of bacterial transport parameters. The main deficiency of previous MFC models concerning spatial distribution of biocatalysts is an assumption of initial distribution of attached/suspended bacteria on electrode or in anolyte bulk which is the foundation for biofilm formation. In order to modify this imperfection, the quantification of chemotactic motility to understand the mechanisms of the suspended microorganisms' distribution in anolyte and/or their attachment to anode surface to extend the biofilm is implemented numerically. The spatial and temporal distributions of the bacteria, as well as the dynamic behavior of the anolyte and biofilm are simulated. The performance of the microfluidic MFC as a chemotaxis assay is assessed by analyzing the bacteria activity, substrate variation, bioelectricity production rate and the influences of external resistance on the biofilm and anolyte's features.

  19. Exfoliation of natural van der Waals heterostructures to a single unit cell thickness

    Science.gov (United States)

    Velický, Matěj; Toth, Peter S.; Rakowski, Alexander M.; Rooney, Aidan P.; Kozikov, Aleksey; Woods, Colin R.; Mishchenko, Artem; Fumagalli, Laura; Yin, Jun; Zólyomi, Viktor; Georgiou, Thanasis; Haigh, Sarah J.; Novoselov, Kostya S.; Dryfe, Robert A. W.

    2017-02-01

    Weak interlayer interactions in van der Waals crystals facilitate their mechanical exfoliation to monolayer and few-layer two-dimensional materials, which often exhibit striking physical phenomena absent in their bulk form. Here we utilize mechanical exfoliation to produce a two-dimensional form of a mineral franckeite and show that the phase segregation of chemical species into discrete layers at the sub-nanometre scale facilitates franckeite's layered structure and basal cleavage down to a single unit cell thickness. This behaviour is likely to be common in a wider family of complex minerals and could be exploited for a single-step synthesis of van der Waals heterostructures, as an alternative to artificial stacking of individual two-dimensional crystals. We demonstrate p-type electrical conductivity and remarkable electrochemical properties of the exfoliated crystals, showing promise for a range of applications, and use the density functional theory calculations of franckeite's electronic band structure to rationalize the experimental results.

  20. Prognosis of Allogeneic Haematopoietic Stem Cell Recipients Admitted to the Intensive Care Unit

    DEFF Research Database (Denmark)

    Lindgaard, Sidsel Christy; Nielsen, Jonas; Lindmark, Anders

    2016-01-01

    BACKGROUND: Allogeneic haematopoietic stem cell transplantation (HSCT) is a procedure with inherent complications and intensive care may be necessary. We evaluated the short- and long-term outcomes of the HSCT recipients requiring admission to the intensive care unit (ICU). METHODS: We...... ventilation had a statistically significant effect on in-ICU (p = 0.02), 6-month (p = 0.049) and 1-year (p = 0.014) mortality. Renal replacement therapy also had a statistically significant effect on in-hospital (p = 0.038) and 6-month (p = 0.026) mortality. Short ICU admissions, i.e. ... to the ICU was confirmed in our study. Mechanical ventilation, renal replacement therapy and an ICU admission of ≥10 days were each risk factors for mortality in the first year after ICU admission....

  1. Histopathological, immunohistochemical, and image analytic parameters characterizing the stromal component in primary and recurrent giant cell tumor of bone.

    Science.gov (United States)

    Saxena, Charu Chandra; Safaya, Rajni; Kawatra Madan, Neha; Khan, Shah Alam; Iyer, Venkateswaran K

    2016-01-01

    Giant cell tumor (GCT) of bone is a benign locally aggressive tumor whose biological behavior is unpredictable. Currently, there are no definitive clinical, histological, biochemical, or immunological parameters that can predict its behavior. This study was undertaken to examine whether delineation of reactive and neoplastic stromal component of GCT can help in this regard. 55 cases of GCT (30 primary, 25 recurrent) were subjected to histopathological grading, immunohistochemistry, and image analysis. Spindling of stroma was more frequent in recurrent GCT with 64% cases having more than 50% spindled stroma (p group (24.75% and 7.7%, respectively). A single numerical parameter encompassing stromal cell population and its proliferation was derived as ratio of PCNA/CD68 and PCNA/α1-ACT. Both ratios were higher in recurrent (0.81 ± 0.38; 1.58 ± 1.50) than in primary GCT (0.58 ± 0.62; 0.34 ± 0.29) (p = 0.002; 0.01). On image analysis, parameters significantly different between the two groups were nuclear area and nuclear integrated optical density. It was thus concluded that recurrent GCT shows higher grade, increased mitosis, more spindling, fewer reactive components, and higher proliferation than primary GCT. Delineation of reactive component (α1-ACT positive) and proliferating component (PCNA positive cells) using immunohistochemistry with calculation of the PCNA/ACT ratio delivers more information than image analysis.

  2. A diesel fuel processor for fuel-cell-based auxiliary power unit applications

    Science.gov (United States)

    Samsun, Remzi Can; Krekel, Daniel; Pasel, Joachim; Prawitz, Matthias; Peters, Ralf; Stolten, Detlef

    2017-07-01

    Producing a hydrogen-rich gas from diesel fuel enables the efficient generation of electricity in a fuel-cell-based auxiliary power unit. In recent years, significant progress has been achieved in diesel reforming. One issue encountered is the stable operation of water-gas shift reactors with real reformates. A new fuel processor is developed using a commercial shift catalyst. The system is operated using optimized start-up and shut-down strategies. Experiments with diesel and kerosene fuels show slight performance drops in the shift reactor during continuous operation for 100 h. CO concentrations much lower than the target value are achieved during system operation in auxiliary power unit mode at partial loads of up to 60%. The regeneration leads to full recovery of the shift activity. Finally, a new operation strategy is developed whereby the gas hourly space velocity of the shift stages is re-designed. This strategy is validated using different diesel and kerosene fuels, showing a maximum CO concentration of 1.5% at the fuel processor outlet under extreme conditions, which can be tolerated by a high-temperature PEFC. The proposed operation strategy solves the issue of strong performance drop in the shift reactor and makes this technology available for reducing emissions in the transportation sector.

  3. Investigation of the Start-up Strategy for a Solid Oxide Fuel Cell Based Auxiliary Power Unit under Transient Conditions

    Directory of Open Access Journals (Sweden)

    Michael R. von Spakovsky

    2005-06-01

    Full Text Available

    A typical approach to the synthesis/design optimization of energy systems is to only use steady state operation and high efficiency (or low total life cycle cost at full load as the basis for the synthesis/design. Transient operation as reflected by changes in power demand, shut-down, and start-up are left as secondary tasks to be solved by system and control engineers once the synthesis/design is fixed. However, start-up and shut-down may be events that happen quite often and, thus, may be quite important in the creative process of developing the system. This is especially true for small power units used in transportation applications or for domestic energy supplies, where the load demand changes frequently and peaks in load of short duration are common. The duration of start-up is, of course, a major factor which must be considered since rapid system response is an important factor in determining the feasibility of solid oxide fuel cell (SOFC based auxiliary power units (APUs. Start-up and shut-down may also significantly affect the life span of the system due to thermal stresses on all system components. Therefore, a proper balance must be struck between a fast response and the costs of owning and operating the system so that start-up or any other transient process can be accomplished in as short a time as possible yet with a minimum in fuel consumption.

    In this research work we have been studying the effects of control laws and strategies and transients on system performance. The results presented in this paper are based on a set of transient models developed and implemented for the components of a 5 kWe net power SOFC based APU and for the high-fidelity system which results from their integration. The simulation results given below are for two different start-up approaches: one with steam recirculation and component pre-heating and the second without either. These start-up simulations were performed for fixed values of a number of

  4. A Multiple Parameters Biodosimetry Tool with Various Blood Cell Counts - the Hemodose Approach

    Science.gov (United States)

    Hu, Shaowen

    2014-01-01

    There continue to be important concerns about the possibility of the occurrence of acute radiation syndromes following nuclear and radiological terrorism or accidents that may result in mass casualties in densely populated areas. To guide medical personnel in their clinical decisions for effective medical management and treatment of the exposed individuals, biological markers are usually applied to examine radiation induced biological changes to assess the severity of radiation injury to sensitive organ systems. Among these the peripheral blood cell counts are widely used to assess the extent of radiation induced bone marrow injury. This is due to the fact that the hematopoietic system is the most vulnerable part of the human body to radiation damage. Particularly, the lymphocyte, granulocyte, and platelet cells are the most radiosensitive of the blood elements, and monitoring their changes after exposure is regarded as a practical and recommended laboratory test to estimate radiation dose and injury. Based upon years of physiological and pathophysiological investigation of mammalian hematopoietic systems, and rigorous coarse-grained bio-mathematical modeling and validation on species from mouse, to dog, monkey, and human, we have developed a set of software tools Hemodose, which can use single or serial granulocyte, lymphocyte, leukocyte, or platelet counts after exposure to estimate absorbed doses of adult victims very rapidly and accurately. Some patient data from historical accidents are utilized as examples to demonstrate the capabilities of these tools as a rapid point-of-care diagnostic or centralized high-throughput assay system in a large-scale radiological disaster scenario. Most significant to the improvement of national and local preparedness of a potential nuclear/radiological disaster, this HemoDose approach establishes robust correlations between the absorbed doses and victim's various types of blood cell counts not only in the early time window (1

  5. Serum ferritin level and red blood cell parameters in healthy controls and chronic periodontitis patients

    Directory of Open Access Journals (Sweden)

    S Latha

    2015-01-01

    Full Text Available Periodontitis, which is a chronic inflammatory disease causes reduction in the number of erythrocytes and hemoglobin. It is found to be caused by specific pathogenic subgingival plaque bacteria. Periodontitis is host mediated through release of pro inflammatory cytokines by local tissues and immune cells in response to bacterial flora and its products, especially lipopolysacharides. Periodontitis is found to have systemic effect and the cytokines produced inhibit proliferation and differentiation of erythrocytes leading to anaemia. This study evaluate level of hemoglobin erythrocytes, hematocrit and serum ferritin levels in healthy subjects and periodontitis patient.

  6. Position control with parameter adaptation for a nano-robotic cell:

    OpenAIRE

    BREZOVNIK, Simon; Čas, Jure; Šafarič, Riko; Škorc, Gregor

    2011-01-01

    This paper describes the development of a nano-assembly system, built up using linear piezo motors. The so-called nano-robotic cell is based on an X/Y manipulator, supported by three serving tables, movable within a Z axis, and aposition controlled using two different types of a bang-bang control methods. The presented application has been developed as a stand-alone application with the LabVIEW Real Time software package, a PCI-7356 servo controller card and a TMCM-090 stepper driver. Our exp...

  7. An expanded model of HIV cell entry phenotype based on multi-parameter single-cell data

    Directory of Open Access Journals (Sweden)

    Bozek Katarzyna

    2012-07-01

    Full Text Available Abstract Background Entry of human immunodeficiency virus type 1 (HIV-1 into the host cell involves interactions between the viral envelope glycoproteins (Env and the cellular receptor CD4 as well as a coreceptor molecule (most importantly CCR5 or CXCR4. Viral preference for a specific coreceptor (tropism is in particular determined by the third variable loop (V3 of the Env glycoprotein gp120. The approval and use of a coreceptor antagonist for antiretroviral therapy make detailed understanding of tropism and its accurate prediction from patient derived virus isolates essential. The aim of the present study is the development of an extended description of the HIV entry phenotype reflecting its co-dependence on several key determinants as the basis for a more accurate prediction of HIV-1 entry phenotype from genotypic data. Results Here, we established a new protocol of quantitation and computational analysis of the dependence of HIV entry efficiency on receptor and coreceptor cell surface levels as well as viral V3 loop sequence and the presence of two prototypic coreceptor antagonists in varying concentrations. Based on data collected at the single-cell level, we constructed regression models of the HIV-1 entry phenotype integrating the measured determinants. We developed a multivariate phenotype descriptor, termed phenotype vector, which facilitates a more detailed characterization of HIV entry phenotypes than currently used binary tropism classifications. For some of the tested virus variants, the multivariant phenotype vector revealed substantial divergences from existing tropism predictions. We also developed methods for computational prediction of the entry phenotypes based on the V3 sequence and performed an extrapolating calculation of the effectiveness of this computational procedure. Conclusions Our study of the HIV cell entry phenotype and the novel multivariate representation developed here contributes to a more detailed

  8. Transmittance of selected nanostructurized solar glasses designated via relative change in electrical parameters of silicon solar cells

    Science.gov (United States)

    Pociask-Bialy, Malgorzata; Kalwas, Kornelia

    2016-12-01

    Photovoltaics is one of the most promising technologies for electricity production. In the future, photovoltaics could be an effective and safe source of energy. In this work were present the results of the analysis of a special solar glasses transmissivity coefficient used as protective cover of photovoltaic cell. Antireflective glass due to its unique physical properties eliminate reflections and significantly increasing light transmission. The study of the relative change in the electrical parameters of photovoltaic cells ,with and without coats, as open-circuit current ISC and the maximum power point MPP are presented in this paper. Research were undertaken with using the solar simulator QuickSun130CA, Class AAA+, under Standard Test Conditions.

  9. Expression of Syk in non-small cell lung cancer and its relationship with clinicopathological parameters

    Institute of Scientific and Technical Information of China (English)

    Fen LAN; Shengdao XIONG; Weining XIONG; Guopeng XU; Xiaoxia LU

    2009-01-01

    This study aims to research the expression of spleen tyrosine kinase (Syk) in non-small cell lung cancer (NSCLC) and the relationship between Syk and clinico-pathologic factors and p53. Immunohistochemistry was applied to detect the expression of Syk and p53 protein in 39 cases of NSCLC (23 cases of lung squamous cell can-cer, 16 cases of lung adenocarcinoma) and tumor-sur-rounding normal lung tissues. The positive rate of Syk was 46.15% (18/39) and 100% (39/39) in NSCLC and tumor-surrounding normal lung tissues, respectively. The expres-sion level of Syk in NSCLC was significantly lower than that in tumor-surrounding normal lung tissues (P = 0.000). The Syk expression was positively correlated with the p53 expression in NSCLC specimens (P = 0.025). There was no significant association between Syk expression and lymph node metastasis, differentiation degree, tumor size and tumor node metastasis (TNM). The present study demonstrated that Syk was aberrantly expressed in the NSCLC and might have a significant impact on tumor growth and progression.

  10. Fuel cell system including a unit for electrical isolation of a fuel cell stack from a manifold assembly and method therefor

    Science.gov (United States)

    Kelley; Dana A. , Farooque; Mohammad , Davis; Keith

    2007-10-02

    A fuel cell system with improved electrical isolation having a fuel cell stack with a positive potential end and a negative potential, a manifold for use in coupling gases to and from a face of the fuel cell stack, an electrical isolating assembly for electrically isolating the manifold from the stack, and a unit for adjusting an electrical potential of the manifold such as to impede the flow of electrolyte from the stack across the isolating assembly.

  11. Study of serum ferritin in donors of two red blood cells units collected by apheresis.

    Science.gov (United States)

    González, Maria Luz Dobao; Maia, Salome; Mesquita, Paula; Bessa, Milena

    2013-10-01

    To analyze the recovery of iron stores without supplementation, when keeping an interval of six months between donations. From April 2007 to May 2011, 308 regular and voluntary donors were selected. The apheresis collections were performed using ALYX® Component Collection System-Fenwal™. The hematological parameters were analyzed using the Cell DIN Sapphire - Abbot Diagnostics, and the serum ferritin by sandwich immunoassay method with fluorescence detection in final phase (ELFA) - Vidas® Ferritin-Biomérieux SA. A descriptive statistical analysis was performed for each hematological parameters and serum ferritin. The median hemoglobin concentration was 15.6g/dL (14, 18.4) in the first procedure and remains constant at subsequent donations. The ferritin median concentration was 64.6 μg/L (7.2, 886). A decrease of 15.6% was observed when compared the first to the second procedure with a median 54.6 μg/L (8.3, 213.7). Paradoxically, this decrease is not evident in the subsequent procedures, where an increase of 14.6% and 3.4% for the third and fourth procedure respectively was observed. Changes in ferritin values show statistically significant differences between the first and second collection, but this difference disappeared in subsequent donations. The analysis of MCH in each collection indicates that the significant difference between first and second donation (p1-2ferritin found between procedures and the beginning of the stabilization of ferritin levels. The determination of ferritin appears not to be the most important parameter to consider at the time of donor selection and suggests that other factors unrelated to the donation may play a significant role. A decrease in serum ferritin was observed at the beginning, but it seems to attend a recovery and stabilization in the successive procedures. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Bidirectional relationship of mast cells-neurovascular unit communication in neuroinflammation and its involvement in POCD.

    Science.gov (United States)

    Li, Nana; Zhang, Xiang; Dong, Hongquan; Hu, Youli; Qian, Yanning

    2017-03-30

    Postoperative cognitive dysfunction (POCD) has been hypothesized to be mediated by surgery-induced neuroinflammation, which is also a key element in the pathobiology of neurodegenerative diseases, stroke, and neuropsychiatric disorders. There is extensive communication between the immune system and the central nervous system (CNS). Inflammation resulting from activation of the innate immune system cells in the periphery can impact central nervous system behaviors, such as cognitive performance. Mast cells (MCs), as the"first responders" in the CNS, can initiate, amplify, and prolong other immune and nervous responses upon activation. In addition, MCs and their secreted mediators modulate inflammatory processes in multiple CNS pathologies and can thereby either contribute to neurological damage or confer neuroprotection. Neuroinflammation has been considered to be linked to neurovascular dysfunction in several neurological disorders. This review will provide a brief overview of the bidirectional relationship of MCs-neurovascular unit communication in neuroinflammation and its involvement in POCD, providing a new and unique therapeutic target for the adjuvant treatment of POCD.

  13. Two-Dimensional Simulation of Mass Transfer in Unitized Regenerative Fuel Cells under Operation Mode Switching

    Directory of Open Access Journals (Sweden)

    Lulu Wang

    2016-01-01

    Full Text Available A two-dimensional, single-phase, isothermal, multicomponent, transient model is built to investigate the transport phenomena in unitized regenerative fuel cells (URFCs under the condition of switching from the fuel cell (FC mode to the water electrolysis (WE mode. The model is coupled with an electrochemical reaction. The proton exchange membrane (PEM is selected as the solid electrolyte of the URFC. The work is motivated by the need to elucidate the complex mass transfer and electrochemical process under operation mode switching in order to improve the performance of PEM URFC. A set of governing equations, including conservation of mass, momentum, species, and charge, are considered. These equations are solved by the finite element method. The simulation results indicate the distributions of hydrogen, oxygen, water mass fraction, and electrolyte potential response to the transient phenomena via saltation under operation mode switching. The hydrogen mass fraction gradients are smaller than the oxygen mass fraction gradients. The average mass fractions of the reactants (oxygen and hydrogen and product (water exhibit evident differences between each layer in the steady state of the FC mode. By contrast, the average mass fractions of the reactant (water and products (oxygen and hydrogen exhibit only slight differences between each layer in the steady state of the WE mode. Under either the FC mode or the WE mode, the duration of the transient state is only approximately 0.2 s.

  14. OPTIMIZATION OF ELECTROPORATION PARAMETERS FOR TRANSFECTION OF PLASMID DNA INTO MURINE BONE MARROW-DERIVED DENDRITIC CELL

    Institute of Scientific and Technical Information of China (English)

    KE Shan; CHEN Xue-hua; LI Hao; LI Jian-fang; GU Qin-long; ZHU Zheng-gang; LIU Bing-ya

    2006-01-01

    Objective To explore the optimal electroporation parameters for transfection of plasmid DNA into murine bone marrow-derived dendritic cells. Methods Murine bone marrow-derived dendritic cells (DCs) were electroporated with plasmid DNA in varied conditions, such as electrical voltage, pulse time,pre-electroporation cell condition and serum concentration in electrical buffer. Inverted fluorescence microscope and flow cytometer were used to determine the transfection efficiency. Some of the DCs genetically modified under different conditions were stained with trypan-blue and its viability was observed microscopically 48h after electroporation. Results Highest transfection efficiency (22.10%) could be reached when electrical voltage was 250V and pulse time was 20ms. Refreshing the culture medium pre-electroporation may help the cells recover more easily from gene transfer.Besides, electrical buffer containing serum may benefit the viability of DC after electroporation and temperature may has little influence on transfection efficiency. Conclusion Our observations demonstrated plasmid DNA could be efficiently transferred into murine bone marrow-derived DCs by electroporation. These data may helpful for cancer research related to murine DC transfection.

  15. Influence of etching parameters on optoelectronic properties of c-Si/porous silicon heterojunction - application to solar cells

    Science.gov (United States)

    Bechiri, Fatiha; Zerdali, Mokhtar; Rahmoun, Ilham; Hamzaoui, Saad; Adnane, Mohamed; Sahraoui, Taoufik

    2013-03-01

    Thin layers of nanoporous silicon PS were synthesized by anodic etching, in order to develop photovoltaic cells. We proposed a diluted concentration of hydrofluoric acid with different etching current densities (1, 3, 5 mA/cm2) on a fairly short time anodization. Observations by scanning electron microscope, electrical measurements and optical measurements revealed that the structural properties of PS layers depended on strong conditions of prints. The reverse and forward component of the I-V characteristics showed an appropriate method to explore and extract the parameters of the diode ideality factor n. The optimum conditions of formation of PS were: HF concentration of 1% and an etching current density of mA/cm2. Unlike silicon, which has a low absorption of short visible wavelengths, it was shown that the PS had wide energy gap of ≈ 2 eV, and a marked improvement in the absorption between 400 and 600 nm. This property has been used to optimize the response of the solar cell Ni/PS/c-Si. Efficiency performance close to 4.2% was obtained with a Voc of 400 mV, and fill factor of 46%. The solar cell exhibited better response than the reference cell Ni/c-Si. These results show that PS/c-Si heterojunction has a potential for photovoltaic applications.

  16. The International Society of Urological Pathology (ISUP) grading system for renal cell carcinoma and other prognostic parameters.

    Science.gov (United States)

    Delahunt, Brett; Cheville, John C; Martignoni, Guido; Humphrey, Peter A; Magi-Galluzzi, Cristina; McKenney, Jesse; Egevad, Lars; Algaba, Ferran; Moch, Holger; Grignon, David J; Montironi, Rodolfo; Srigley, John R

    2013-10-01

    The International Society of Urological Pathology 2012 Consensus Conference made recommendations regarding classification, prognostic factors, staging, and immunohistochemical and molecular assessment of adult renal tumors. Issues relating to prognostic factors were coordinated by a workgroup who identified tumor morphotype, sarcomatoid/rhabdoid differentiation, tumor necrosis, grading, and microvascular invasion as potential prognostic parameters. There was consensus that the main morphotypes of renal cell carcinoma (RCC) were of prognostic significance, that subtyping of papillary RCC (types 1 and 2) provided additional prognostic information, and that clear cell tubulopapillary RCC was associated with a more favorable outcome. For tumors showing sarcomatoid or rhabdoid differentiation, there was consensus that a minimum proportion of tumor was not required for diagnostic purposes. It was also agreed upon that the underlying subtype of carcinoma should be reported. For sarcomatoid carcinoma, it was further agreed upon that if the underlying carcinoma subtype was absent the tumor should be classified as a grade 4 unclassified carcinoma with a sarcomatoid component. Tumor necrosis was considered to have prognostic significance, with assessment based on macroscopic and microscopic examination of the tumor. It was recommended that for clear cell RCC the amount of necrosis should be quantified. There was consensus that nucleolar prominence defined grades 1 to 3 of clear cell and papillary RCCs, whereas extreme nuclear pleomorphism or sarcomatoid and/or rhabdoid differentiation defined grade 4 tumors. It was agreed upon that chromophobe RCC should not be graded. There was consensus that microvascular invasion should not be included as a staging criterion for RCC.

  17. Additively Manufactured Open-Cell Porous Biomaterials Made from Six Different Space-Filling Unit Cells: The Mechanical and Morphological Properties

    Directory of Open Access Journals (Sweden)

    Seyed Mohammad Ahmadi

    2015-04-01

    Full Text Available It is known that the mechanical properties of bone-mimicking porous biomaterials are a function of the morphological properties of the porous structure, including the configuration and size of the repeating unit cell from which they are made. However, the literature on this topic is limited, primarily because of the challenge in fabricating porous biomaterials with arbitrarily complex morphological designs. In the present work, we studied the relationship between relative density (RD of porous Ti6Al4V EFI alloy and five compressive properties of the material, namely elastic gradient or modulus (Es20–70, first maximum stress, plateau stress, yield stress, and energy absorption. Porous structures with different RD and six different unit cell configurations (cubic (C, diamond (D, truncated cube (TC, truncated cuboctahedron (TCO, rhombic dodecahedron (RD, and rhombicuboctahedron (RCO were fabricated using selective laser melting. Each of the compressive properties increased with increase in RD, the relationship being of a power law type. Clear trends were seen in the influence of unit cell configuration and porosity on each of the compressive properties. For example, in terms of Es20–70, the structures may be divided into two groups: those that are stiff (comprising those made using C, TC, TCO, and RCO unit cell and those that are compliant (comprising those made using D and RD unit cell.

  18. Alteration of oxidative stress parameters in red blood cells of rats after chronic in vivo treatment with cisplatin and selenium

    Directory of Open Access Journals (Sweden)

    Marković Snežana D.

    2011-01-01

    Full Text Available In this study we evaluated the possible protective effects of selenium (Se on hematological and oxidative stress parameters in rats chronically treated with cisplatin (cisPt. Four groups of Wistar albino rats were examined: a control, untreated rats (I, rats treated with Se (II, rats treated with cisPt (III, and rats treated with Se and cisPt (IV. All animals were treated for 5 days successively and killed 24 h after the last treatment. Hematological and oxidative stress parameters were followed in whole blood and red blood cells (RBC. Results showed that the chronic application of Se was followed by a higher number of reticulocytes and platelets, increased lipid peroxidation and GSH content in the RBC. Cisplatin treatment induced depletion of RBC and platelet numbers and an elevation of the superoxide anion, nitrites and glutathione levels. Se and cisPt co-treatment was followed by an elevation of the hematological parameters and the recovery of the glutathione status when compared to the control and cisPt-treated rats.

  19. Measurement of a new parameter representing the gas transport properties of the catalyst layers of polymer electrolyte fuel cells.

    Science.gov (United States)

    Iden, Hiroshi; Ohma, Atsushi; Tokunaga, Tomomi; Yokoyama, Kouji; Shinohara, Kazuhiko

    2016-05-14

    The optimization of the catalyst layers is necessary for obtaining a better fuel cell performance and reducing fuel cell cost. Although the ionomer coverage of the Pt catalyst is said to be a key parameter in this regard, the proportion of Pt either directly or indirectly covered by the ionomer is thought to be an important parameter with regard to gas transport (indirectly covered Pt: its gas transport paths are completely blocked by the ionomer even if it does not directly cover Pt). In this study, a new technique has been developed for evaluating the proportion of Pt covered indirectly or directly by the ionomer, which is defined as the "capped proportion", based on the carbon monoxide (CO) adsorption properties at different temperatures. The validity of the method was thoroughly examined by identifying the CO adsorption properties of the components of the catalyst layers. The capped proportion and oxygen transport resistance in the catalyst layers showed a good correlation, indicating that the capped proportion is a dominant factor of oxygen transport resistance. This technique thus enables the evaluation of the dominant factor of the gas transport properties of the catalyst layers. The method has another significant advantage in that it does not require a membrane electrode assembly, let alone electrochemical measurement, which should be helpful for catalyst layer optimization.

  20. Chemometrical assessment of the electrical parameters obtained by long-term operating freshwater sediment microbial fuel cells.

    Science.gov (United States)

    Mitov, Mario; Bardarov, Ivo; Mandjukov, Petko; Hubenova, Yolina

    2015-12-01

    The electrical parameters of nine freshwater sediment microbial fuel cells (SMFCs) were monitored for a period of over 20 months. The developed SMFCs, divided into three groups, were started up and continuously operated under different constant loads (100, 510 and 1100 Ω) for 2.5 months. At this stage of the experiment, the highest power density values, reaching 1.2 ± 0.2 mW/m(2), were achieved by the SMFCs loaded with 510 Ω. The maximum power obtained at periodical polarization during the rest period, however, ranged between 26.2 ± 2.8 and 35.3 ± 2.8 mW/m(2), strongly depending on the internal cell resistance. The statistical evaluation of data derived from the polarization curves shows that after 300 days of operation all examined SMFCs reached a steady-state and the system might be assumed as homoscedastic. The estimated values of standard and expanded uncertainties of the electric parameters indicate a high repeatability and reproducibility of the SMFCs' performance. Results obtained in subsequent discharge-recovery cycles reveal the opportunity for practical application of studied SMFCs as autonomous power sources.

  1. Variability of DTM-derived, morphometric parameters versus cell size. An example of application in Calabria (Southern Italy)

    Science.gov (United States)

    Rago, Valeria; Caloiero, Paola; Pellegrino, Annamaria Daniela; Iovine, Giulio G. R.; Terranova, Oreste G.; Pascale, Stefania

    2016-04-01

    Applications of DTM-derived morphometry are nowadays common in many fields of land-use planning, including the protection from natural hazards (cf. e.g. Iovine et al. 2013; 2014). For example, the mathematical modelling of physical processes that occur at slope or basin scales makes extensive use of quantitative parameters that describe the shape of Earth surface. Unfortunately, the values of these parameters depend on the detail with which the territory is represented. Therefore, different relationships must be adopted to describe the same physical processes at different scales. In this study, as part of a wide-ranging research aimed at modelling of geo-hydrological processes, a systematic and rigorous assessment of variability of the morphometric parameters against cell sizes is addressed. The study area under consideration is the whole Calabrian territory, extended about 15075 square kilometres. The region has recently been zoned into eleven homogeneous geomorphological sectors (Antronico et al., 2010). For each geomorphological sector, DTMs have been derived from topographic maps at 1:5000 scale, with cell sizes of 5, 10, 20 and 40 m. The following morphometric parameters - among those most frequently used in land management - have then been evaluated for the above DTMs: altitude, steepness of slope, aspect, plan and profile curvatures, slope length, topographical wetness index, stream power index, topographic position index, terrain ruggedness index, slope length factor. The first results show a marked dependence on cell size for some of the considered parameters. In other cases, such dependence seems not significant. Mathematical relationships are proposed between cell size and considered parameters, also taking into account the geomorphological contexts examined. Based on the above relationships, the most suitable scale to be used for modelling physical processes in a given area of interest can be selected. References Antronico L., L. Borselli, R. Coscarelli

  2. The genetic heterozygosity and fitness of tetraploid embryos and embryonic stem cells are crucial parameters influencing survival of mice derived from embryonic stem cells by tetraploid embryo aggregation.

    Science.gov (United States)

    Li, Xiangyun; Wei, Wei; Yong, Jun; Jia, Qing; Yu, Yuansong; Di, Keqian

    2005-07-01

    The aim of this paper was to determine whether the genetic background of tetraploid embryos contributed to the survival of mice derived from embryonic stem (ES) cells by tetraploid embryo complementation. Twenty-five newborns were produced by aggregation of hybrid ES cells and tetraploid embryos with different genetic backgrounds. These newborns were entirely derived from ES cells judged by microsatellite DNA (A specific sequence of DNA bases or nucleotides that contains mono, di, tri or tetra repeats) and coat colour phenotype and germline transmission. Fifteen survived to adulthood while seven died of respiratory failure. All newborns were derived from outbred or hybrid tetraploid aggregates and no newborns were from the inbreds. Our results demonstrate that the genetic heterozygosity, fitness of tetraploid embryos and fitness of ES cells are crucial parameters influencing survival of mice derived from ES cells by tetraploid embryo aggregation. In addition, this method represents a simple and efficient procedure for immediate generation of targeted mouse mutants from genetically modified ES cell clones, in contrast to the standard protocol, which involves the production of chimeras and several breeding steps.

  3. Synthesis of solar cells sensitized using natural photosynthetic pigments & study for the cell performance under different synthesis parameters

    Science.gov (United States)

    Roa, Simon; Radhakrishnan, Sivakumar; Manidurai, Paulraj

    2016-05-01

    In this study we used photosynthetic pigments extracted from spinach and purple cabbage for their potential application in dye sensitized solar cells (DSSC). Pigments were extracted by dissolving small amounts of each one of these plant products in methanol and distilled water. The extraction was also done at two different temperatures (70° C and 80° C respectively). This was to assess for the solvent that promotes better extraction of the pigments. A parallel study was also carried out using a mixture of both these dyes in 1:1 ratio. Good absorption, about 60% to 80% was obtained for spinach pigments diluted in methanol in the visible range between 400-480nm, and between 9% to 15% for purple cabbage pigments in the wavelength range between 480-630 nm when extracted using distilled water at 80°C. In contrast, the diluted mixture in methanol shows good absorption of 20% and 32% for wavelengths in the range 400-480nm. Solar cells sensitized using these natural dyes were studied for their photovoltaic properties by measuring current-voltage behavior. Efficiencies ranging from 0.011% to 0.0719% were observed. Mixture of spinach & purple cabbage pigments extracted using methanol was found to have the highest efficiency of 0.0719%.

  4. Measurement and comparison of AC parameters of silicon (BSR and BSFR) and gallium arsenide (GaAs/Ge) solar cells used in space applications

    Energy Technology Data Exchange (ETDEWEB)

    Anil Kumar, R.; Suresh, M.S. [ISRO Satellite Centre, ISRO, Bangalore 560, 017 Kolhapur (India); Nagaraju, J. [Department of Instrumentation, Indian Institute of Science, Bangalore 560, 012 Kolhapur (India)

    2000-01-15

    The AC parameters of silicon (BSR and BSFR) solar cells and GaAs/Ge solar cell have been measured using impedance spectroscopy. Each cell capacitance, dynamic resistance and series resistance were measured and compared. GaAs/Ge solar cell has shown only the transition capacitance throughout its operating range while silicon (BSR and BSFR) solar cells exhibited both transition and diffusion capacitance. The theoretical and experimental values of dynamic resistance were compared and found in good agreement while the diode factor in silicon solar cells varies from 2 to 1, where as in GaAs/Ge solar cell it varies from 4 to 2 to 1.

  5. Possible determination of the physical parameters of the first living cells based on the fundamental physical constants

    Science.gov (United States)

    Atanasov, Atanas Todorov

    2016-12-01

    Here is developed the hypothesis that the cell parameters of unicellular organisms (Prokaryotes and Eukaryotes) are determined by the gravitational constant (G, N.m2 /kg2), Planck constant (h, J.s) and growth rate of cells. By scaling analyses it was shown that the growth rate vgr(m/s) of unicellular bacteria and protozoa is relatively constant parameter, ranging in a narrow window of 10-12 - 10-10 m/s, in comparison to the diapason of cell mass, ranging 10 orders of magnitudes from 10-17 kg in bacteria to 10-7 kg in amoebas. By dimensional analyses it was shown that the combination between the growth rate of cells, gravitational constant and Planck constant gives equations with dimension of mass M(vgr)=(h.vgr/G)½ in kg, length L(v gr)=(hṡG/vgr3)1/2 in meter, time T(vgr)=(hṡG/vgr5)1/2 in seconds, and density ρ ((vgr)=vgr.3.5/hG2 in kg/m3 . For growth rate vgr in diapason of 1×10-11 m/s - 1×10-9.5 m/s the calculated numerical values for mass (3×10-18 -1×10-16 kg), length (5×10-8 -1×10-5 m), time (1×102 -1×106 s) and density (1×10-1 - 1×104 kg/m3) overlaps with diapason of experimentally measured values for cell mass (3×10-18 -1×10-15 kg), volume to surface ratio (1×10-7 -1×10-4 m), doubling time (1×103 -1×107 s), and density (1050 - 1300 kg/m3) in bacteria and protozoa. These equations show that appearance of the first living cells could be mutually connected to the physical constants.

  6. Effects of ZnO nanowire synthesis parameters on the photovoltaic performance of dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Juneui; Myoung, Jihyun; Lim, Sangwoo, E-mail: swlim@yonsei.ac.kr

    2012-06-30

    Determination of the effects of ZnO nanowires on the efficiency of ZnO nanowire-based dye-sensitized solar cells (DSSCs) is important. In this study, we determined the effects of different OH{sup -} precursors, concentrations, the ratio of zinc nitrate to hexamethylene tetramine (HMT), and the hydrothermal synthesis temperature on the physical, crystal, and optical properties of ZnO nanowires and investigated the performance of the resulting DSSCs. We observed that ZnO nanowires synthesized using an equimolar ratio of HMT to zinc nitrate yielded a DSSC with high incident photon-to-current efficiency (IPCE), cell efficiency, short circuit current density (J{sub sc}), and fill factor (FF), and low ZnO-dye-electrolyte interface resistance due to an increased amount of dye and a decreased density of defects. Furthermore, ZnO nanowires made using optimal concentrations and ratios of zinc nitrate to HMT had a high surface area and low defect density. All the photovoltaic performance parameters of DSSCs assessed such as IPCE, cell efficiency, J{sub sc}, open circuit potential (V{sub oc}), and FF increased with synthesis temperature, which was related to a decrease in the resistance at the ZnO-dye-electrolyte interface. We attributed these results to an increased amount of dye facilitated by a large nanowire surface area and fast electron transfer because of the improved crystalline structure of the ZnO nanowires and their low defect density. By optimizing the ZnO nanowires, we increased DSSC efficiency to 0.26% using ZnO nanowires synthesized with 25 mM of both zinc nitrate and HMT at 90 Degree-Sign C, while only a 0.02% increase in efficiency was obtained when NH{sub 4}OH was used as OH{sup -} precursor. - Highlights: Black-Right-Pointing-Pointer Fabrication of ZnO nanowire-based dye-sensitized solar cells (DSSCs) Black-Right-Pointing-Pointer Correlation of synthesis parameters with ZnO nanowires' properties and DSSC performance Black

  7. Inhibition of Autophagy Enhances Curcumin United light irradiation-induced Oxidative Stress and Tumor Growth Suppression in Human Melanoma Cells

    Science.gov (United States)

    Niu, Tianhui; Tian, Yan; Mei, Zhusong; Guo, Guangjin

    2016-01-01

    Malignant melanoma is the most aggressive form of skin carcinoma, which possesses fast propagating and highly invasive characteristics. Curcumin is a natural phenol compound that has various biological activities, such as anti-proliferative and apoptosis-accelerating impacts on tumor cells. Unfortunately, the therapeutical activities of Cur are severely hindered due to its extremely low bioavailability. In this study, a cooperative therapy of low concentration Cur combined with red united blue light irradiation was performed to inspect the synergistic effects on the apoptosis, proliferation and autophagy in human melanoma A375 cell. The results showed that red united blue light irradiation efficaciously synergized with Cur to trigger oxidative stress-mediated cell death, induce apoptosis and inhibit cell proliferation. Meanwhile, Western blotting revealed that combined disposure induced the formation of autophagosomes. Conversely, inhibition of the autophagy enhanced apoptosis, obstructed cell cycle arrest and induced reversible proliferation arrest to senescence. These findings suggest that Cur combined with red united blue light irradiation could generate photochemo-preventive effects via enhancing apoptosis and triggering autophagy, and pharmacological inhibition of autophagy convert reversible arrested cells to senescence, therefore reducing the possibility that damaged cells might escape programmed death. PMID:27502897

  8. Evaluation of pancreatic cancer cell migration with multiple parameters in vitro by using an optical real-time cell mobility assay device.

    Science.gov (United States)

    Yamauchi, Akira; Yamamura, Masahiro; Katase, Naoki; Itadani, Masumi; Okada, Naoko; Kobiki, Kayoko; Nakamura, Masafumi; Yamaguchi, Yoshiyuki; Kuribayashi, Futoshi

    2017-03-31

    Migration of cancer cell correlates with distant metastasis and local invasion, which are good targets for cancer treatment. An optically accessible device "TAXIScan" was developed, which provides considerably more information regarding the cellular dynamics and less quantity of samples than do the existing methods. Here, we report the establishment of a system to analyze the nature of pancreatic cancer cells using TAXIScan and we evaluated lysophosphatidic acid (LPA)-elicited pancreatic cell migration. Pancreatic cancer cell lines, BxPC3, PANC-1, AsPC1, and MIAPaCa-2, were analyzed for adhesion as well as migration towards LPA by TAXIScan using parameters such as velocity and directionality or for the number of migrated cells by the Boyden chamber methods. To confirm that the migration was initiated by LPA, the expression of LPA receptors and activation of intracellular signal transductions were examined by quantitative reverse transcriptase polymerase reaction and western blotting. Scaffold coating was necessary for the adhesion of pancreatic cancer cells, and collagen I and Matrigel were found to be good scaffolds. BxPC3 and PANC-1 cells clearly migrated towards the concentration gradient formed by injecting 1 μL LPA, which was abrogated by pre-treatment with LPA inhibitor, Ki16425 (IC50 for the directionality ≈ 1.86 μM). The LPA dependent migration was further confirmed by mRNA and protein expression of LPA receptors as well as phosphorylation of signaling molecules. LPA1 mRNA was highest among the 6 receptors, and LPA1, LPA2 and LPA3 proteins were detected in BxPC3 and PANC-1 cells. Phosphorylation of Akt (Thr308 and Ser473) and p42/44MAPK in BxPC3 and PANC-1 cells was observed after LPA stimulation, which was clearly inhibited by pre-treatment with a compound Ki16425. We established a novel pancreatic cancer cell migration assay system using TAXIScan. This assay device provides multiple information on migrating cells simultaneously, such as their

  9. A new formalism for modelling parameters α and β of the linear quadratic model of cell survival for hadron therapy.

    Science.gov (United States)

    Vassiliev, Oleg N; Grosshans, David R; Mohan, Radhe

    2017-08-23

    We propose a new formalism for calculating parameters α and β of the linear quadratic model of cell survival. This formalism, primarily intended for calculating relative biological effectiveness (RBE) for treatment planning in hadron therapy, is based on a recently proposed microdosimetric revision of the single-target multi-hit model. The main advantage of our formalism is that it reliably produces α and β that have correct general properties with respect to their dependence on physical properties of the beam, including the asymptotic behavior for very low and high linear energy transfer (LET) beams. For example, in the case of monoenergetic beams, our formalism predicts that, as a function of LET, (a) α has a maximum and (b) the α/β ratio increases monotonically with increasing LET. No prior models reviewed in this study predict both properties (a) and (b) correctly, and therefore, these prior models are valid only within a limited LET range. We first present our formalism in a general form, for polyenergetic beams. A signicant new result in this general case is that parameter β is represented as an average over the joint distribution of energies E1 and E2 of two particles in the beam. This result is consistent with the role of the quadratic term in the linear quadratic model. It accounts for the two-track mechanism of cell kill, in which two particles, one after another, damage the same site in the cell nucleus. We then present simplified versions of the formalism and discuss predicted properties of α and β. Finally, to demonstrate consistency of our formalism with experimental data, we apply it to fit two sets of experimental data: (1) α for heavy ions, covering a broad range of LETs, and (2) β for protons. In both cases, good agreement was achieved. © 2017 Institute of Physics and Engineering in Medicine.

  10. Growth Factor Independence-1 (Gfi1) Is Required for Pancreatic Acinar Unit Formation and Centroacinar Cell Differentiation

    DEFF Research Database (Denmark)

    Qu, Xiaoling; Nyeng, Pia; Xiao, Fan

    2015-01-01

    BACKGROUND & AIMS: The genetic specification of the compartmentalized pancreatic acinar/centroacinar unit is poorly understood. Growth factor independence-1 (Gfi1) is a zinc finger transcriptional repressor that regulates hematopoietic stem cell maintenance, pre-T-cell differentiation, formation...... of pancreatic acinar cells as well as the centroacinar cells (CACs) in Gfi1(-/-) mice when compared with wild-type littermates. Pancreatic endocrine differentiation, islet architecture, and function were unaffected. Organ domain patterning and the formation of ductal cells occurred normally during the murine...... of granulocytes, inner ear hair cells, and the development of secretory cell types in the intestine. As GFI1/Gfi1 is expressed in human and rodent pancreas, we characterized the potential function of Gfi1 in mouse pancreatic development. METHODS: Gfi1 knockout mice were analyzed at histological and molecular...

  11. Assessment of nitrate transport parameters using the advection-diffusion cell.

    Science.gov (United States)

    Aljazzar, Taiseer; Al-Qinna, Mohammed

    2016-11-01

    This study aimed to better understand nitrate transport in the soil system in a part of the state of North Rhine-Westphalia, in Germany, and to aid in the development of groundwater protection plans. An advection-diffusion (AD) cell was used in a miscible displacement experiment setup to characterize nitrate transport in 12 different soil samples from the study area. The three nitrate sorption isotherms were tested to define the exact nitrate interaction with the soil matrix. Soils varied in their properties which in its turn explain the variations in nitrate transport rates. Soil texture and organic matter content showed to have the most important effect on nitrate recovery and retardation. The miscible displacement experiment indicated a decrease in retardation by increasing sand fraction, and an increase in retardation by increasing soil organic matter content. Soil samples with high sand fractions (up to 94 %) exhibited low nitrate sorption capacity of less than 10 %, while soils with high organic matter content showed higher sorption of about 30 %. Based on parameterization for nitrate transport equation, the pore water velocity for both sandy and loamy soils were significantly different (P nitrate transport in soils associated with high organic matter was due to fine pore pathways clogged by fine organic colloids. It is expected that the existing micro-phobicity increased the nitrate recovery from 9 to 32 % resulting in maximum diffusion rates of about 3.5 × 10(-5) m/s(2) in sandy soils (sample number CS-04) and about 1.4 × 10(-7) m/s(2) in silt loam soils (sample number FS-02).

  12. Some properties of 2-D dielectric-based ENG/MNG material parameters extracted using the S-parameter method

    DEFF Research Database (Denmark)

    Wu, Yunqiu; Arslanagic, Samel

    This work presents a systematic investigation of material parameters for two-dimensional epsilon-negative (ENG) and mu-negative (MNG) materials as obtained by the scattering parameter method. The unit cell consists of infinite dielectric cylinders, their sizes and permittivities are chosen...... to enable the ENG and MNG behaviors. For the both configurations, the permittivity and the permeability is reported. Influence of several effects on the extracted material parameters is examined, including the loss inside the cylinders and the size of the unit cells...

  13. A study of V79 cell survival after for proton and carbon ion beams as represented by the parameters of Katz' track structure model

    DEFF Research Database (Denmark)

    Grzanka, Leszek; Waligórski, M. P. R.; Bassler, Niels

    Katz’s theory of cellular track structure (1) is an amorphous analytical model which applies a set of four cellular parameters representing survival of a given cell line after ion irradiation. Usually the values of these parameters are best fitted to a full set of experimentally measured survival...... curves available for a variety of ions. Once fitted, using these parameter values and the analytical formulae of the model calculations, cellular survival curves and RBE may be predicted for that cell line after irradiation by any ion, including mixed ion fields. While it is known that the Katz model...... of the proton response. This suggests that for increased accuracy of a therapy planning system based on Katz’s model, different sets of parameters may need to be used to represent cell survival after proton irradiation from those representing survival of this cell line after heavier ions, up to and including...

  14. Improvement of proton exchange membrane fuel cell electrical performance by optimization of operating parameters and electrodes preparation

    Energy Technology Data Exchange (ETDEWEB)

    Kadjo, A.J.-J.; Garnier, J.-P.; Martemianov, S. [Laboratoire d' Etudes Thermiques, UMR6608, ESIP-Universite de Poitiers, CNRS, Poitiers F-86022 (France); Brault, P.; Caillard, A. [Groupe de Recherche sur l' Energetique des Milieux Ionises, UMR6606 Universite d' Orleans, CNRS Polytech' Orleans BP6744, F-45067 Orleans Cedex 2 (France); Coutanceau, C. [Laboratoire de Catalyse en Chimie Organique, UMR6503 Universite de Poitiers, CNRS, Poitiers F-86022 (France)

    2007-10-25

    The effect of operating parameters (cell temperature, humidifiers temperature, gases flows and pressures) on the performance of a 25 cm{sup 2} surface area fuel cell is performed. After optimization, a homemade MEA fitted with electrodes prepared via the colloidal route leads to achieve reproducibly maximum power densities higher than 1.2 W cm{sup -2} with a total catalyst loading of 0.7 mg{sub Pt} cm{sup -2} (corresponding to 1.7kW g{sub Pt}{sup -1}). This electrical performance is higher to that obtained with a commercial MEA provided by fuel cell store (total platinum loading of 1.2 mg cm{sup -2} and power density close to 1 W cm{sup -2}, corresponding to 0.75kW g{sub Pt}{sup -1}). Based on this experience, two different homemade MEAs are tested under optimal operating conditions and compared to the commercial one. The final goal is to decrease significantly the platinum loading preserving at least equivalent PEMFC electrical performance. The method of catalyst deposition by plasma sputtering is used to further decrease the total catalyst loading down to 0.45 mg{sub Pt} cm{sup -2}. Very interesting performances (close to 0.7 W cm{sup -2}) were obtained with this low-platinum loading MEA (corresponding to 1.6kW g{sub Pt}{sup -1}). However, it was shown that the decrease of the platinum loading in the cathode from 0.35 to 0.1 mg cm{sup -2} affects the kinetics of oxygen reduction (exchange current density j{sub 0} and Tafel slope b) and the resistance of the cell R, and hence the cell electrical performance. (author)

  15. The influence of selected parameters on the efficiency and economic charactersistics of the oxy-type coal unit with a membrane-cryogenic oxygen separator

    National Research Council Canada - National Science Library

    Janusz Kotowicz; Sylwia Berdowska

    2016-01-01

    .... The economic analysis with the use of the break-even point method was carried out. The economic calculations were realized in view of the break-even price of electricity depending on a coal unit availability.

  16. Anodization parameters influencing the morphology and electrical properties of TiO2 nanotubes for living cell interfacing and investigations.

    Science.gov (United States)

    Khudhair, D; Bhatti, A; Li, Y; Hamedani, H Amani; Garmestani, H; Hodgson, P; Nahavandi, S

    2016-02-01

    Nanotube structures have attracted tremendous attention in recent years in many applications. Among such nanotube structures, titania nanotubes (TiO2) have received paramount attention in the medical domain due to their unique properties, represented by high corrosion resistance, good mechanical properties, high specific surface area, as well as great cell proliferation, adhesion and mineralization. Although lot of research has been reported in developing optimized titanium nanotube structures for different medical applications, however there is a lack of unified literature source that could provide information about the key parameters and experimental conditions required to develop such optimized structure. This paper addresses this gap, by focussing on the fabrication of TiO2 nanotubes through anodization process on both pure titanium and titanium alloys substrates to exploit the biocompatibility and electrical conductivity aspects, critical factors for many medical applications from implants to in-vivo and in-vitro living cell studies. It is shown that the morphology of TiO2 directly impacts the biocompatibility aspects of the titanium in terms of cell proliferation, adhesion and mineralization. Similarly, TiO2 nanotube wall thickness of 30-40nm has shown to exhibit improved electrical behaviour, a critical factor in brain mapping and behaviour investigations if such nanotubes are employed as micro-nano-electrodes.

  17. Influence of charge carrier mobility and morphology on solar cell parameters in devices of mono- and bis-fullerene adducts

    Science.gov (United States)

    Muth, Mathis-Andreas; Mitchell, William; Tierney, Steven; Lada, Thomas A.; Xue, Xiang; Richter, Henning; Carrasco-Orozco, Miguel; Thelakkat, Mukundan

    2013-12-01

    Herein, we analyze charge carrier mobility and morphology of the active blend layer in thin film organic solar cells and correlate them with device parameters. A low band gap donor-acceptor copolymer in combination with phenyl-C61-butyric acid methyl ester (PCBM) or two bis-adduct fullerenes, bis-PCBM and bis-o-quino-dimethane C60 (bis-oQDMC), is investigated. We study the charge transport of polymer:fullerene blends in hole- and electron-only devices using the space-charge limited current method. Lower electron mobilities are observed in both bis-adduct fullerene blends. Hole mobility, however, is decreased only in the blend containing bis-oQDMC. Both bis-adduct fullerene blends show very high open circuit voltage in solar cell devices, but poor photocurrent compared to the standard PCBM blend for an active layer thickness of 200 nm. Therefore, a higher short circuit current is feasible for the polymer:bis-PCBM blend by reducing the active layer thickness in order to compensate for the low electron mobility, which results in a PCE of 4.3%. For the polymer:bis-oQDMC blend, no such improvement is achieved due to an unfavorable morphology in this particular blend system. The results are supported by external quantum efficiency measurements, atomic force microscopy, transmission electron microscopy and UV/vis spectroscopy. Based on these results, the investigations presented herein give a more scientific basis for the optimization of solar cells.

  18. Mathematical Modeling Analysis and Optimization of Key Design Parameters of Proton-Conductive Solid Oxide Fuel Cells

    Directory of Open Access Journals (Sweden)

    Hong Liu

    2014-01-01

    Full Text Available A proton-conductive solid oxide fuel cell (H-SOFC has the advantage of operating at higher temperatures than a PEM fuel cell, but at lower temperatures than a SOFC. This study proposes a mathematical model for an H-SOFC in order to simulate the performance and optimize the flow channel designs. The model analyzes the average mass transfer and species’ concentrations in flow channels, which allows the determination of an average concentration polarization in anode and cathode gas channels, the proton conductivity of electrolyte membranes, as well as the activation polarization. An electrical circuit for the current and proton conduction is applied to analyze the ohmic losses from an anode current collector to a cathode current collector. The model uses relatively less amount of computational time to find the V-I curve of the fuel cell, and thus it can be applied to compute a large amount of cases with different flow channel dimensions and operating parameters for optimization. The modeling simulation results agreed satisfactorily with the experimental results from literature. Simulation results showed that a relatively small total width of flow channel and rib, together with a small ratio of the rib’s width versus the total width, are preferable for obtaining high power densities and thus high efficiency.

  19. Understanding red blood cell parameters in the context of the frailty phenotype: interpretations of the FIBRA (Frailty in Brazilian Seniors) study.

    Science.gov (United States)

    Silva, João Carlos; Moraes, Zélia Vieira de; Silva, Conceição; Mazon, Silvia de Barros; Guariento, Maria Elena; Neri, Anita Liberalesso; Fattori, André

    2014-01-01

    Frailty and anemia in the elderly appear to share a common pathophysiology associated with chronic inflammatory processes. This study uses an analytical, cross-sectional, population-based methodology to investigate the probable relationships between frailty, red blood cell parameters and inflammatory markers in 255 community-dwelling elders aged 65 years or older. The frailty phenotype was assessed by non-intentional weight loss, fatigue, low grip strength, low energy expenditure and reduced gait speed. Blood sample analyses were performed to determine hemoglobin level, hematocrit and reticulocyte count, as well as the inflammatory variables IL-6, IL-1ra and hsCRP. In the first multivariate analysis (model I), considering only the erythroid parameters, Hb concentration was a significant variable for both general frailty status and weight loss: a 1.0g/dL drop in serum Hb concentration represented a 2.02-fold increase (CI 1.12-3.63) in an individual's chance of being frail. In the second analysis (model II), which also included inflammatory cytokine levels, hsCRP was independently selected as a significant variable. Each additional year of age represented a 1.21-fold increase in the chance of being frail, and each 1-unit increase in serum hsCRP represented a 3.64-fold increase in the chance of having the frailty phenotype. In model II reticulocyte counts were associated with weight loss and reduced metabolic expenditure criteria. Our findings suggest that reduced Hb concentration, reduced RetAbs count and elevated serum hsCRP levels should be considered components of frailty, which in turn is correlated with sarcopenia, as evidenced by weight loss.

  20. Spray pyrolysed Cu2ZnSnS4/In2S3 thin film solar cell: Effect of varying copper concentration on cell parameters

    Science.gov (United States)

    Menon, M. R. Rajesh; Rajeshmon, V. G.; Thomas, Titu; Kartha, C. Sudha; Vijayakumar, K. P.

    2016-05-01

    A double layer Cu2ZnSnS4 absorber was employed for the first time to improve the performance of spray pyrolysed Cu2ZnSnS4/In2S3 thin film solar cell. Copper concentration in the two layers of Cu2ZnSnS4 was adjusted and effect on performance parameters was studied. It was observed that higher copper concentration in the absorber layer adjacent to the electrode is beneficial for device performance, whereas, lower copper concentration in absorber layer near to the junction has detrimental effect on the device properties.

  1. THE CHANGE OF KINETIK PARAMETERS OF THE WEAK-ASSOCIATED WITH WALL CELL PEROXIDASE IN THE SUSPENSION CULTURE OF POTATO CELLS IN THE BEGINNING OF INFECTION

    Directory of Open Access Journals (Sweden)

    Graskova I.A.

    2006-03-01

    Full Text Available The change in kinetic parameters of extracellular peroxidase of suspension cells of resistant potato variety (Lugovskoi and sensitive variety (Luk,ynovskii in the initial period of infection by 5369 Clavibacter michiganensis subsp. sepedonicus (Spieck. et Kotth. Skapt et Burkh. pathogen was examined. Extracellular peroxidases of resistant and sensitive potato variety without pathogens were shown to be concurrently inhibited. At the beginning of infection enzyme activity was extremely increased due to enhanced affinity to substrate as a result of reducing of competitive inhibiting. In increasing enzyme activity is sensitive potato variant evidently caused by other mechanism.

  2. Clinical and Metabolic Parameters in Non-Small Cell Lung Carcinoma and Colorectal Cancer Patients with and without KRAS Mutations

    Directory of Open Access Journals (Sweden)

    Ahmet Yilmaz

    2014-08-01

    Full Text Available Lung cancer (LC and colorectal cancer (CRC are the first and second deadliest types of cancer worldwide. EGFR-based therapy has been used in the treatment of these cancers with variable success. Presence of mutations in the KRAS driver oncogene, possibly induced by environmental factors such as carcinogens in diet and cigarette smoke, may confer worse prognosis and resistance to treatment for reasons not fully understood. Data on possible associations between KRAS mutational status and clinical and metabolic parameters, which may help in clinical management, as well as in identifying risk factors for developing these cancers, are limited in the current literature. We sequenced the KRAS gene and investigated the associations of variations in 108 patients with non-small cell lung carcinoma (NSCLC, the most common form of LC, and in 116 patients with CRC. All of the mutations originated from the guanosine nucleotide and over half of all transversions in NSCLC and CRC were c.34 G>T and c.35 G>T, respectively. c.35 G>A was the most frequent type of transition in both cancers. Excluding smoking, the clinical and metabolic parameters in patients carrying mutant and wild type KRAS were similar except that the CRC patients with transversion mutations were 8.6 years younger than those carrying the transitions (P < 0.01. Dyslipidemia, hypertension, family cancer history, and age of diagnosis older than 60 years were more frequent in NSCLC than CRC (P ≤ 0.04. These results suggest that most of the clinical and metabolic parameters investigated in this study are probably not associated with the more aggressive phenotype and differences in response to EGFR-based treatment previously reported in patients with KRAS mutations. However, the increased rates of abnormal metabolic parameters in patients with NSCLC in comparison to CRC indicate that these parameters may be more important in the management of NSCLC. CRC patients carrying transition mutations are

  3. Effects of Dexamethasone on Satellite Cells and Tissue Engineered Skeletal Muscle Units.

    Science.gov (United States)

    Syverud, Brian C; VanDusen, Keith W; Larkin, Lisa M

    2016-03-01

    Tissue engineered skeletal muscle has potential for application as a graft source for repairing soft tissue injuries, a model for testing pharmaceuticals, and a biomechanical actuator system for soft robots. However, engineered muscle to date has not produced forces comparable to native muscle, limiting its potential for repair and for use as an in vitro model for pharmaceutical testing. In this study, we examined the trophic effects of dexamethasone (DEX), a glucocorticoid that stimulates myoblast differentiation and fusion into myotubes, on our tissue engineered three-dimensional skeletal muscle units (SMUs). Using our established SMU fabrication protocol, muscle isolates were cultured with three experimental DEX concentrations (5, 10, and 25 nM) and compared to untreated controls. Following seeding onto a laminin-coated Sylgard substrate, the administration of DEX was initiated on day 0 or day 6 in growth medium or on day 9 after the switch to differentiation medium and was sustained until the completion of SMU fabrication. During this process, total cell proliferation was measured with a BrdU assay, and myogenesis and structural advancement of muscle cells were observed through immunostaining for MyoD, myogenin, desmin, and α-actinin. After SMU formation, isometric tetanic force production was measured to quantify function. The histological and functional assessment of the SMU showed that the administration of 10 nM DEX beginning on either day 0 or day 6 yielded optimal SMUs. These optimized SMUs exhibited formation of advanced sarcomeric structure and significant increases in myotube diameter and myotube fusion index, compared with untreated controls. Additionally, the optimized SMUs matured functionally, as indicated by a fivefold rise in force production. In conclusion, we have demonstrated that the addition of DEX to our process of engineering skeletal muscle tissue improves myogenesis, advances muscle structure, and increases force production in the

  4. Progress in human embryonic stem cell research in the United States between 2001 and 2010.

    Directory of Open Access Journals (Sweden)

    Keyvan Vakili

    Full Text Available On August 9th, 2001, the federal government of the United States announced a policy restricting federal funds available for research on human embryonic stem cell (hESCs out of concern for the "vast ethical mine fields" associated with the creation of embryos for research purposes. Until the policy was repealed on March 9th, 2009, no U.S. federal funds were available for research on hESCs extracted after August 9, 2001, and only limited federal funds were available for research on a subset of hESC lines that had previously been extracted. This paper analyzes how the 2001 U.S. federal funding restrictions influenced the quantity and geography of peer-reviewed journal publications on hESC. The primary finding is that the 2001 policy did not have a significant aggregate effect on hESC research in the U.S. After a brief lag in early 2000s, U.S. hESC research maintained pace with other areas of stem cell and genetic research. The policy had several other consequences. First, it was tied to increased hESC research funding within the U.S. at the state level, leading to concentration of related activities in a relatively small number of states. Second, it stimulated increased collaborative research between US-based scientists and those in countries with flexible policies toward hESC research (including Canada, the U.K., Israel, China, Spain, and South Korea. Third, it encouraged independent hESC research in countries without restrictions.

  5. Mast cell density and the context of clinicopathological parameters and expression of p185, estrogen receptor, and proliferating cell nuclear antigen in gastric carcinoma

    Institute of Scientific and Technical Information of China (English)

    Ying-An Jiang; You-Yuan Zhang; He-Sheng Luo; Shou-Fu Xing

    2002-01-01

    AIM: To investigate the relationship between the mast cell density (MCD) and the context of clinicopathological parameters and expression of p185, estrogen receptor (ER), and proliferating cell nuclear antigen (PCNA) in gastric carcinoma.METHODS: Mast cell, p185, ER, and PCNA were detected using immunohistochemical S-P labeling method. Mast cell was counted in tissue of gastric carcinoma and regional lymph nodes respectively, and involved lymph nodes (TLN) were examined as usual.RESULTS: MCD was significantly related to both age and depth of penetration (χ2=4.688,P<0.05 for age and χ2=9.350,P<0.01 for depth of penetration) between MCD>21/0.03 mm2 and MCD≤21/0.03 mm2 in 100 patients; MCD in 1-6 ILN group patients was significantly higher than that in 7-15 TLN or >15 TLN group patients (u=6.881, 8.055, P<0.01);There were significant differences intergroup in positive expression rate of p185, ER and PCNA between MCD >21/0.03 mm2 and MCD≤21/0.03 mm2 in 100 patients.CONCLUSION: Mast cell may have effect on inhibiting invasive growth of tumor, especially in the aged patients; The number of mast cells, in certain degree, may predicate the number of involved lymph nodes, which is valuable for assessment of prognosis; MCD was related to the expression of p185, ER, and PCNA in gastric carcinoma. Tt suggests that mast cell accumulation may inhibit the proliferation and the dissemination of the gastric carcinoma.

  6. Highly Efficient and Exceptionally Durable CO2 Photoreduction to Methanol over Freestanding Defective Single-Unit-Cell Bismuth Vanadate Layers.

    Science.gov (United States)

    Gao, Shan; Gu, Bingchuan; Jiao, Xingchen; Sun, Yongfu; Zu, Xiaolong; Yang, Fan; Zhu, Wenguang; Wang, Chengming; Feng, Zimou; Ye, Bangjiao; Xie, Yi

    2017-03-08

    Unearthing an ideal model for disclosing the role of defect sites in solar CO2 reduction remains a great challenge. Here, freestanding gram-scale single-unit-cell o-BiVO4 layers are successfully synthesized for the first time. Positron annihilation spectrometry and X-ray fluorescence unveil their distinct vanadium vacancy concentrations. Density functional calculations reveal that the introduction of vanadium vacancies brings a new defect level and higher hole concentration near Fermi level, resulting in increased photoabsorption and superior electronic conductivity. The higher surface photovoltage intensity of single-unit-cell o-BiVO4 layers with rich vanadium vacancies ensures their higher carriers separation efficiency, further confirmed by the increased carriers lifetime from 74.5 to 143.6 ns revealed by time-resolved fluorescence emission decay spectra. As a result, single-unit-cell o-BiVO4 layers with rich vanadium vacancies exhibit a high methanol formation rate up to 398.3 μmol g(-1) h(-1) and an apparent quantum efficiency of 5.96% at 350 nm, much larger than that of single-unit-cell o-BiVO4 layers with poor vanadium vacancies, and also the former's catalytic activity proceeds without deactivation even after 96 h. This highly efficient and spectrally stable CO2 photoconversion performances hold great promise for practical implementation of solar fuel production.

  7. Definition of a simple statistical parameter for the quantification of orientation in two dimensions: application to cells on grooves of nanometric depths.

    Science.gov (United States)

    Davidson, P; Bigerelle, M; Bounichane, B; Giazzon, M; Anselme, K

    2010-07-01

    Contact guidance is generally evaluated by measuring the orientation angle of cells. However, statistical analyses are rarely performed on these parameters. Here we propose a statistical analysis based on a new parameter sigma, the orientation parameter, defined as the dispersion of the distribution of orientation angles. This parameter can be used to obtain a truncated Gaussian distribution that models the distribution of the data between -90 degrees and +90 degrees. We established a threshold value of the orientation parameter below which the data can be considered to be aligned within a 95% confidence interval. Applying our orientation parameter to cells on grooves and using a modelling approach, we established the relationship sigma=alpha(meas)+(52 degrees -alpha(meas))/(1+C(GDE)R) where the parameter C(GDE) represents the sensitivity of cells to groove depth, and R the groove depth. The values of C(GDE) obtained allowed us to compare the contact guidance of human osteoprogenitor (HOP) cells across experiments involving different groove depths, times in culture and inoculation densities. We demonstrate that HOP cells are able to identify and respond to the presence of grooves 30, 100, 200 and 500 nm deep and that the deeper the grooves, the higher the cell orientation. The evolution of the sensitivity (C(GDE)) with culture time is roughly sigmoidal with an asymptote, which is a function of inoculation density. The sigma parameter defined here is a universal parameter that can be applied to all orientation measurements and does not require a mathematical background or knowledge of directional statistics. Copyright 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  8. Measurement of Dosimetric Parameters for Hi-ART Helical Tomotherapy Unit%Hi-ART螺旋断层治疗机剂量学参数的测量

    Institute of Scientific and Technical Information of China (English)

    王运来; 沙翔燕; 戴相坤; 马林; 冯林春; 曲宝林

    2008-01-01

    Objective To develop a measurement method of dosimetric parameters for Hi-ART tomotherapy unit. Methods Percentage depth doses and beam profiles were measured using the dedicated mini water phantom, and compared to the results of 6 MV X-ray from Primus accelerator. Following the AAPM TG51 protocol, absolute dose calibration was carried out under SSD of 85 cm at depth of 1.5 cm for field of 5 cm ×40 cm. The output linearity and reproducibility were evaluated. The output variation with the gantry rotation was also investigated using 0.6 cm3 ion chamber in cylindrical perplex phantom and on-board MVCT detectors. Leaf fluence output factors were quantified for the leaf of interest and its adjacent leaves.Results The buildup depth was around 1.0 cm. The PDD values at 10 cm for Hi-ART and Primus were 59.7% and 64.7%, respectively. Varying with the field width, the lateral and longitudinal beam profiles were not so homogeneous as the Primus fields. The measured dose rate was 848.38 cGy/min. The fitted lint(sec) ,with a relative coefficient of 0. 999. The maximum deviation and standard deviation of output were 1.6% and less than 0.5% ; The maximum deviation and standard deviation of output changed by gantry angle were 1.1% and 0.5 % , respectively. Leaf fluence output factors did not increase significantly when leaves were opened beyond the two adjacent leaves. Conclusions Hi-ART Tomotherapy unit has a very high dose output and inhomogeneous beam profiles owing to its special design of the treatment head. This may be useful in dose calculation and treatment delivery.%目的 探讨Hi-ART螺旋断层治疗机照射野剂量学参数测量的内容和方法.方法 用断层治疗机专门配置的微型扫描水箱在治疗条件下测量了6 MV X线的百分深度剂量和射野离轴比,并与常规Primus加速器6 MV X线进行比较.根据AAPM TG51号报告用Tomotrometer剂量仪和A1SL电离室在源皮距85 cm、照射野40 cm×5 cm、1.5 cm深度条件下对断层

  9. Investigation of potential fluctuating intra-unit cell magnetic order in cuprates by μ SR

    Science.gov (United States)

    Pal, A.; Akintola, K.; Potma, M.; Ishikado, M.; Eisaki, H.; Hardy, W. N.; Bonn, D. A.; Liang, R.; Sonier, J. E.

    2016-10-01

    We report low temperature muon spin relaxation (μ SR ) measurements of the high-transition-temperature (Tc) cuprate superconductors Bi2 +xSr2 -xCaCu2O8 +δ and YBa2Cu3O6.57 , aimed at detecting the mysterious intra-unit cell (IUC) magnetic order that has been observed by spin-polarized neutron scattering in the pseudogap phase of four different cuprate families. A lack of confirmation by local magnetic probe methods has raised the possibility that the magnetic order fluctuates slowly enough to appear static on the time scale of neutron scattering, but too fast to affect μ SR or nuclear magnetic resonance signals. The IUC magnetic order has been linked to a theoretical model for the cuprates, which predicts a long-range ordered phase of electron-current loop order that terminates at a quantum crictical point (QCP). Our study suggests that lowering the temperature to T ˜25 mK and moving far below the purported QCP does not cause enough of a slowing down of fluctuations for the IUC magnetic order to become detectable on the time scale of μ SR . Our measurements place narrow limits on the fluctuation rate of this unidentified magnetic order.

  10. Results and analysis of saltstone cores taken from saltstone disposal unit cell 2A

    Energy Technology Data Exchange (ETDEWEB)

    Reigel, M. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hill, K. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-01

    As part of an ongoing Performance Assessment (PA) Maintenance Plan, Savannah River Remediation (SRR) has developed a sampling and analyses strategy to facilitate the comparison of field-emplaced samples (i.e., saltstone placed and cured in a Saltstone Disposal Unit (SDU)) with samples prepared and cured in the laboratory. The primary objectives of the Sampling and Analyses Plan (SAP) are; (1) to demonstrate a correlation between the measured properties of laboratory-prepared, simulant samples (termed Sample Set 3), and the field-emplaced saltstone samples (termed Sample Set 9), and (2) to validate property values assumed for the Saltstone Disposal Facility (SDF) PA modeling. The analysis and property data for Sample Set 9 (i.e. six core samples extracted from SDU Cell 2A (SDU2A)) are documented in this report, and where applicable, the results are compared to the results for Sample Set 3. Relevant properties to demonstrate the aforementioned objectives include bulk density, porosity, saturated hydraulic conductivity (SHC), and radionuclide leaching behavior.

  11. Fungal spore concentrations in two haematopoietic stem cell transplantation (HSCT) units containing distinct air control systems.

    Science.gov (United States)

    Brun, C P; Miron, D; Silla, L M R; Pasqualotto, A C

    2013-04-01

    Invasive fungal diseases have emerged as important causes of morbidity and mortality in haematological patients. In this study air samples were collected in two haematopoietic stem cell transplantation (HSCT) units, in which distinct air-control systems were in place. In hospital 1 no high-efficiency particulate air (HEPA) filter was available whereas in hospital 2 HSCT rooms were equipped with HEPA filters, with positive air pressure in relation to the corridor. A total of 117 samples from rooms, toilets and corridors were obtained during December 2009 to January 2011, using a six-stage Andersen sampler. In both hospitals, the concentration of potentially pathogenic fungi in the air was reduced in patients' rooms compared to corridors (P < 0·0001). Despite the presence of a HEPA filter in hospital 2, rooms in both hospitals showed similar concentrations of potentially pathogenic fungi (P = 0·714). These findings may be explained by the implementation of additional protective measures in hospital 1, emphasizing the importance of such measures in protected environments.

  12. High-temperature superconductivity in one-unit-cell FeSe films

    Science.gov (United States)

    Wang, Ziqiao; Liu, Chaofei; Liu, Yi; Wang, Jian

    2017-04-01

    Since the dramatic enhancement of the superconducting transition temperature (T c) was reported in a one-unit-cell FeSe film grown on a SrTiO3 substrate (1-UC FeSe/STO) by molecular beam epitaxy (MBE), related research on this system has become a new frontier in condensed matter physics. In this paper, we present a brief review on this rapidly developing field, mainly focusing on the superconducting properties of 1-UC FeSe/STO. Experimental evidence for high-temperature superconductivity in 1-UC FeSe/STO, including direct evidence revealed by transport and diamagnetic measurements, as well as other evidence from scanning tunneling microscopy (STM) and angle-resolved photoemission spectroscopy (ARPES), are overviewed. The potential mechanisms of the enhanced superconductivity are also discussed. There are accumulating arguments to suggest that the strengthened Cooper pairing in 1-UC FeSe/STO originates from the interface effects, specifically the charge transfer and coupling to phonon modes in the TiO2 plane. The study of superconductivity in 1-UC FeSe/STO not only sheds new light on the mechanism of high-temperature superconductors with layered structures, but also provides an insight into the exploration of new superconductors by interface engineering.

  13. Giant repeater F-wave in patients with anterior horn cell disorders. Role of motor unit size.

    Science.gov (United States)

    Ibrahim, I K; el-Abd, M A

    1997-01-01

    Conventional F-wave responses as well as single motor unit F-wave responses together with the volitionally recruited motor unit action potentials (MUAP) were studied in hand and feet muscles of 10 healthy subjects and 32 patients with anterior horn cell disorders. The amplitude of the largest F-wave (Fl) was significantly greater in the affected patients compared with healthy subjects. Giant repeater F-wave responses "up to 4 mV" were recorded in muscles having volitionally recruited giant MUAPs. Although, the group mean percentage of motor unit F-wave responses per stimulation in all tested orthodromic MUAPs was significantly decreased in amyotrophic lateral sclerosis patients, the group mean percentage of motor unit F-wave responses per stimulation in all tested orthodromic MUAPs that gave motor unit F-wave response was significantly increased compared with healthy subjects. The responding orthodromic MUAP gave identical motor unit F-wave response, even for complex polyphasic units. Enhanced monosynaptic (H-) reflex, proximal axon reflex (A-wave), and repetitive muscle response as possible explanations for the giant F-wave responses could be discounted. The electrophysiologic behavior of the giant late responses described here fits well with the criteria of F-waves modulated by newly formed distal (and or proximal) axonal branching.

  14. Clear Cell Cancer of the Uterine Corpus: The Association of Clinicopathologic Parameters and Treatment on Disease Progression

    Directory of Open Access Journals (Sweden)

    Joyce Varughese

    2011-01-01

    Full Text Available This paper presents a single-institution experience regarding the clinicopathologic features and treatment strategies used in uterine clear cell cancer (UCC, a rare, aggressive histologic subtype of uterine cancer with poor prognosis and discusses parameters associated with progression-free survival (PFS and overall survival (OS. A retrospective chart review was performed on all patients (=80 diagnosed with UCC and treated between 1994 and 2009 at a single academic institution. Data on demographics, FIGO stage, treatment regimens, and recurrences were collected. Patients with early-stage UCC had an excellent survival regardless of adjuvant therapy. Advanced-stage patients had a worse survival. Vaginal apex brachytherapy was associated with an increased OS (=0.02 but not PFS (=0.10. The use of platinum-based chemotherapy in combination with vaginal apex brachytherapy did not significantly improve survival. Innovative therapies still need to be identified for this uncommon uterine cancer.

  15. A parametric study of cathode catalyst layer structural parameters on the performance of a PEM fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Khajeh-Hosseini-Dalasm, N.; Kermani, M.J.; Moghaddam, D. Ghadiri [Department of Mechanical Engineering, Energy Conversion Research Laboratory, and The New Technologies Research Center, 424 Hafez Avenue, Amirkabir University of Technology (Tehran Polytechnic), Tehran 15875-4413 (Iran); Stockie, J.M. [Department of Mathematics, Simon Fraser University, Burnaby, BC (Canada)

    2010-03-15

    This paper is a computational study of the cathode catalyst layer (CL) of a proton exchange membrane fuel cell (PEMFC) and how changes in its structural parameters affect performance. The underlying mathematical model assumes homogeneous and steady-state conditions, and consists of equations that include the effects of oxygen diffusion, electrochemical reaction rates, and transport of protons and electrons through the Nafion ionomer (PEM) and solid phases. Simulations are concerned with the problem of minimizing activation overpotential for a given current density. The CL consists of four phases: ionomer, solid substrate, catalyst particles and void spaces. The void spaces are assumed to be fully flooded by liquid water so that oxygen within the CL can diffuse to reaction sites via two routes: within the flooded void spaces and dissolved within the ionomer phase. The net diffusive flux of oxygen through the cathode CL is obtained by incorporating these two diffusive fluxes via a parallel resistance type model. The effect of six structural parameters on the CL performance is considered: platinum and carbon mass loadings, ionomer volume fraction, the extent to which the gas diffusion layer (GDL) extends into the CL, the GDL porosity and CL thickness. Numerical simulations demonstrate that the cathode CL performance is most strongly affected by the ionomer volume fraction, CL thickness and carbon mass loading. These results give useful guidelines for manufactures of PEMFC catalyst layers. (author)

  16. The Effect of Sputtering Parameters on the Film Properties of Molybdenum Back Contact for CIGS Solar Cells

    Directory of Open Access Journals (Sweden)

    Peng-cheng Huang

    2013-01-01

    Full Text Available Molybdenum (Mo thin films are widely used as a back contact for CIGS-based solar cells. This paper determines the optimal settings for the sputtering parameters for an Mo thin film prepared on soda lime glass substrates, using direct current (dc magnetron sputtering, with a metal Mo target, in an argon gas environment. A Taguchi method with an L9 orthogonal array, the signal-to-noise ratio, and an analysis of variances is used to determine the performance characteristics of the coating operation. The main sputtering parameters, such as working pressure (mTorr, dc power (W, and substrate temperature (°C, are optimized with respect to the structural features, surface morphology, and electrical properties of the Mo films. An adhesive tape test is performed on each film to determine the adhesion strength of the films. The experimental results show that the working pressure has the dominant effect on electrical resistivity and reflectance. The intensity of the main peak (110 for the Mo film increases and the full width at half maximum decreases gradually as the sputtering power is increased. Additionally, the application of an Mo bilayer demonstrates good adherence and low resistivity.

  17. Associations between endothelial dysfunction and clinical and laboratory parameters in children and adolescents with sickle cell anemia

    Science.gov (United States)

    Ferreira, Tatiane Anunciação; Machado, Vinícius Ramos; Perdiz, Marya Izadora; Lyra, Isa Menezes; Nascimento, Valma Lopes; Boa-Sorte, Ney; Andrade, Bruno B.; Ladeia, Ana Marice

    2017-01-01

    Background Hematological changes can drive damage of endothelial cells, which potentially lead to an early endothelial dysfunction in patients with sickle cell anemia (SCA). An association may exist between endothelial dysfunction and several clinical manifestations of SCA. The present study aims to evaluate the links between changes in endothelial function and clinical and laboratory parameters in children and adolescents with SCA. Methods This study included 40 children and adolescents with stable SCA as well as 25 healthy children; aged 6–18 years. All study subjects were evaluated for endothelial function using Doppler ultrasonography. In addition, a number of laboratory assays were performed, including reticulocyte and leukocyte counts as well as measurement of circulating levels of total bilirubin, C-reactive protein (CRP), glucose, lipoproteins and peripheral oxyhemoglobin saturation. These parameters were also compared between SCA patients who were undertaking hydroxyurea (HU) and those who were not. Results Flow-mediated vasodilation (FMD) values were found to be reduced in SCA patients compared with those detected in healthy controls. SCA individuals with lower FMD values exhibited higher number of hospital admissions due to vaso-occlusive events. Additional analyses revealed that patients who had decreased FMD values exhibited higher odds of acute chest syndrome (ACS) episodes. A preliminary analysis with limited number of individuals failed to demonstrate significant differences in FMD values between SCA individuals who were treated with HU and those who were not. Conclusions Children and adolescents with SCA exhibit impaired endothelial function. Reductions in FMD values are associated with ACS. These findings underline the potential use of FMD as screening strategy of SCA patients with severe prognosis at early stages. PMID:28863145

  18. Study of the electrical parameters degradation of GaAs sub-cells for triple junction space solar cells by computer simulation

    Science.gov (United States)

    Cappelletti, M. A.; Casas, G. A.; Morales, D. M.; Hasperue, W.; Blancá, E. L. Peltzer y.

    2016-11-01

    In this paper, a theoretical study of the electrical parameters degradation of different n-type GaAs sub-cells for InGaP/GaAs/Ge triple junction solar cells irradiated with 1 and 5 MeV electrons has been performed by means of computer simulation. Effects of base carrier concentration upon the maximum power point, short-circuit current, open circuit voltage, diffusion current, recombination current and series resistance of these devices have been researched using the displacement damage dose method, the one-dimensional PC1D device modeling program and a home-made numerical code based on genetic algorithms. The radiative recombination lifetime, damage constant for minority-carrier lifetime and carrier removal rate models for GaAs sub-cells have been used in the simulations. An analytical model has been proposed, which is useful to describe the radiation-induced degradation of diffusion current, recombination current and series resistance. Results obtained in this work can be used to predict the radiation resistance of solar cells over a wide range of energies.

  19. Does blood transfusion affect pituitary gonadal axis and sperm parameters in young males with sickle cell disease?

    Directory of Open Access Journals (Sweden)

    Ashraf T Soliman

    2013-01-01

    Full Text Available Objective: We evaluated the effect of packed red cell transfusion (PCTx on serum concentrations of gonadotropins luteinizing hormone and follicle-stimulating hormone (LH and FSH and testosterone (T levels and measured sperm parameters in young adults with sickle cell disease (SCD on top-up transfusion (TTx and those on exchange transfusion (ETx regimen. Materials and Methods: Basal serum concentrations of FSH, LH, and T and semen parameters were evaluated before and 7 days after PCTx in 18 young adults with transfusion-dependent SCD, aged 20.7 ± 2.88 years. They had full pubertal development (Tanner′s stage 5, and capacity to ejaculate. They were regularly transfused since early childhood. Chelation therapy was started early during the first 2 years of life using desferrioxamine and was replaced by deferasirox for the last 4-5 years. Ten patients were on TTx and eight were on ETx regimen. Results: PCTx significantly increased hemoglobin (Hb from 8.5 ± 1.17 g/dl to 10.5 ± 0.4 g/dl, T from 12.3 ± 1.24 nmol/L to 14.23 ± 1.22 nmol/L and gonadotropins′ concentrations. Sperm parameters improved significantly after PCTx including: total sperm count from 87.4 ± 24.6 million/ml to 146.2 ± 51.25 million/ml, total progressive sperm motility (TPM from 40.8 ± 11.1 million/ml to 93.4 ± 38.3 million/ml, rapid progressive sperm motility (RPM progressive motility from 29.26 ± 8.75 million/ml to 67.4 ± 29 million/ml. After PCTx the total sperm count, TPM and RPM were significantly better in the ETx group versus the TTx group. Before and after PCTx, T concentrations were correlated significantly with sperm total count, volume, TPM and RPM (r = 0.53, 0.55, 0.42, and 0.38, respectively, P < 0.01. Hb concentrations were correlated significantly with sperm count, TPM, RPM, and % of sperms with normal morphology (r = 0.60, 0.69, 0.66, and 0.86, respectively, P < 0.001. Conclusion: Our study suggests that in males with SCD blood transfusion is associated

  20. The Gruneisen parameter for silver azide

    Science.gov (United States)

    Zhuravlyov, Yu. N.; Lisitsyn, V. M.

    2011-12-01

    A first-principle procedure is proposed to determine the Gruneisen parameter for a crystal by calculating the external pressure and the vibration spectrum as functions of the volume of a unit cell. In the gradient approximation of the electron density functional theory, on the basis of a linear combination of atomic orbitals, the elastic and the thermodynamic Gruneisen parameters of silver azide, which decrease with volume (with increasing pressure), are calculated with the use of the CRYSTAL09 code. The equilibrium values of the parameter γ0 for various cold equations of state of crystals and for the thermodynamic models used are, respectively, ~2.3 and 1.6.

  1. Effects of carbon nanotubes on liquid crystal order parameter and Freedericksz transition in electro-optic cells

    Science.gov (United States)

    Georgiev, Georgi; Gombos, Erin; McIntyre, Michael; Mattera, Michael; Gati, Peter; Cabrera, Yaniel; Cebe, Peggy

    2010-03-01

    We studied the effects of multiwalled carbon nanotubes (MWCTs) at low concentrations (0.01 wt %) on the Freedericksz transition of a 4-Cyano-4'-pentylbipenyl (5CB) liquid crystal using transmission ellipsometry. In addition, we calibrated the altitudinal angle of CNTs as a function of the electric field and directed the azimuthal angle which gave us complete control of the 3D orientation of the CNTs. Our results show that in the presence of CNTs the voltage and width for the Freedericksz transition are reduced by a factor of 1.8 as compared to the control electro-optic cell without CNTs. The shift in transition voltage correlates with increase in order parameter of the electro-optic cell as measured by our polarized UV/Vis absorption spectroscopy results. Research supported by: Assumption College Faculty Development Grant, funding for students' stipends, instrumentation and supplies, the NSF Polymers Program of the DME, grant (DMR-0602473) and NASA grant (NAG8-1167).

  2. Mathematical model for the analysis of structure and optimal operational parameters of a solid oxide fuel cell generator

    Science.gov (United States)

    Coralli, Alberto; Villela de Miranda, Hugo; Espiúca Monteiro, Carlos Felipe; Resende da Silva, José Francisco; Valadão de Miranda, Paulo Emílio

    2014-12-01

    Solid oxide fuel cells are globally recognized as a very promising technology in the area of highly efficient electricity generation with a low environmental impact. This technology can be advantageously implemented in many situations in Brazil and it is well suited to the use of ethanol as a primary energy source, an important feature given the highly developed Brazilian ethanol industry. In this perspective, a simplified mathematical model is developed for a fuel cell and its balance of plant, in order to identify the optimal system structure and the most convenient values for the operational parameters, with the aim of maximizing the global electric efficiency. In this way it is discovered the best operational configuration for the desired application, which is the distributed generation in the concession area of the electricity distribution company Elektro. The data regarding this configuration are required for the continuation of the research project, i.e. the development of a prototype, a cost analysis of the developed system and a detailed perspective of the market opportunities in Brazil.

  3. Modelling on c-Si/a-Si:H wire solar cells: some key parameters to optimize the photovoltaic performance

    Directory of Open Access Journals (Sweden)

    Alvarez J.

    2012-07-01

    Full Text Available Solar cells based on silicon nano- or micro-wires have attracted much attention as a promising path for low cost photovoltaic technology. The key point of this structure is the decoupling of the light absorption from the carriers collection. In order to predict and optimize the performance potential of p- (or n- doped c-Si/ n-(or p- doped a-Si:H nanowire-based solar cells, we have used the Silvaco-Atlas software to model a single-wire device. In particular, we have noticed a drastic decrease of the open-circuit voltage (Voc when increasing the doping density of the silicon core beyond an optimum value. We present here a detailed study of the parameters that can alter the Voc of c-Si(p/a-Si:H (n wires according to the doping density in c-Si. A comparison with simulation results obtained on planar c-Si/a-Si:H heterojunctions shows that the drop in Voc, linked to an increase of the dark current in both structures, is more pronounced for radial junctions due to geometric criteria. These numerical modelling results have lead to a better understanding of transport phenomena within the wire.

  4. Additively Manufactured Open-Cell Porous Biomaterials Made from Six Different Space-Filling Unit Cells: The Mechanical and Morphological Properties

    NARCIS (Netherlands)

    Ahmadi, S.M.; Yavari, S.A.; Wauthle, R.; Pouran, B.; Schrooten, J.; Weinans, H.; Zadpoor, A.A.

    2015-01-01

    It is known that the mechanical properties of bone-mimicking porous biomaterials are a function of the morphological properties of the porous structure, including the configuration and size of the repeating unit cell from which they are made. However, the literature on this topic is limited, primari

  5. Optimizing parameters for clinical-scale production of high IL-12 secreting dendritic cells pulsed with oxidized whole tumor cell lysate

    Directory of Open Access Journals (Sweden)

    Chiang Cheryl L-L

    2011-11-01

    Full Text Available Abstract Background Dendritic cells (DCs are the most potent antigen-presenting cell population for activating tumor-specific T cells. Due to the wide range of methods for generating DCs, there is no common protocol or defined set of criteria to validate the immunogenicity and function of DC vaccines. Methods Monocyte-derived DCs were generated during 4 days of culture with recombinant granulocyte-macrophage colony stimulating factor and interleukin-4, and pulsed with tumor lysate produced by hypochlorous acid oxidation of tumor cells. Different culture parameters for clinical-scale DC preparation were investigated, including: 1 culture media; 2 culture surface; 3 duration of activating DCs with lipopolysaccharide (LPS and interferon (IFN-gamma; 4 method of DC harvest; and 5 cryomedia and final DC product formulation. Results DCs cultured in CellGenix DC media containing 2% human AB serum expressed higher levels of maturation markers following lysate-loading and maturation compared to culturing with serum-free CellGenix DC media or AIM-V media, or 2% AB serum supplemented AIM-V media. Nunclon™Δ surface, but not Corning® tissue-culture treated surface and Corning® ultra-low attachment surface, were suitable for generating an optimal DC phenotype. Recombinant trypsin resulted in reduced major histocompatibility complex (MHC Class I and II expression on mature lysate-loaded DCs, however presentation of MHC Class I peptides by DCs was not impaired and cell viability was higher compared to cell scraping. Preservation of DCs with an infusible cryomedia containing Plasma-Lyte A, dextrose, sodium chloride injection, human serum albumin, and DMSO yielded higher cell viability compared to using human AB serum containing 10% DMSO. Finally, activating DCs for 16 hours with LPS and IFN-γ stimulated robust mixed leukocyte reactions (MLRs, and high IL-12p70 production in vitro that continued for 24 hours after the cryopreserved DCs were thawed and

  6. The effect of oxidation time on the parameters of ITO/Si solar cell prepared by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Kandil, S. A; Afifi, H. H; El-hefnawi, S. H; Eliwa, A.Y [Electronic Research Institute, Dokki, Cairo (Egypt)

    2000-07-01

    The indium tin oxide (ITO/N-Si) solar cells have been fabricated by spray pyrolysis technique. The silicon wafers are heated at 500 Celsius degrees with different oxidation time (2-20 min). The best values obtained for ITO/Si solar cell output parameters; open circuit voltage V{sub o}c, short circuit current density J{sub s}c, fill factor FF and efficiency {eta} are 0.48 V, 15 mA/cm{sup 2}, 0.7 and 10.1% respectively. The preceding results were obtained under conditions of 5 minutes oxidation time and the surface area equal to 8 mm{sup 2} when the light intensity is 50 MW/ cm{sup 2}. The values of V{sub o}c, J{sub s}c, FF and {eta} are affected strongly by the varying the oxidation time. This paper is devoted to explain the effect of the interfacial layer SiO{sub 2} thickness on the ITO/Si solar cell parameters as deduced from the I-V and C-V measurements. [Spanish] Mediante tecnicas de pirolisis de dispersion se han fabricado celdas solares de oxido de Indio estanado ITO/N-Si. Las obleas de silicon se calientan a 500 con diferentes tiempos de oxidacion (2-20 min.) Los mejores valores obtenidos para los parametros de produccion de las celdas solares ITO-Si de voltaje en circuito abierto V{sub o}c densidad de corriente de corto circuito J{sub s}c factor de llenado FF y eficiencia {eta} son de 0.48 V, 15 mA/cm{sup 2}, 0.7% y 10.1% respectivamente los resultados precedentes se obtuvieron bajo condiciones de 5 minutos de tiempo de oxidacion y la superficie del area=8 mm{sup 2} cuando la intensidad de la luz es de 50mW/Cm{sup 2}. Los valores de V{sub o}c, J{sub s}c, FF y {eta} se afectan fuertemente por la variacion del tiempo de oxidacion. Este articulo esta dedicado a explicar el efecto del espesor de la capa interfacial de SiO{sub 2} en los parametros de la celda solar ITO-Si como se deduce de las mediciones I-V y C-V.

  7. Phase II Contaminant Transport Parameters for the Groundwater Flow and Contaminant Transport Model of Corrective Action Unit 98: Frenchman Flat, Nye County, Nevada, Rev. No.: 0

    Energy Technology Data Exchange (ETDEWEB)

    DeNovio, Nicole M.; Bryant, Nathan; King, Chrissi B.; Bhark, Eric; Drellack, Sigmund L.; Pickens, John F.; Farnham, Irene; Brooks, Keely M.; Reimus, Paul; Aly, Alaa

    2005-04-01

    This report documents pertinent transport data and data analyses as part of the Phase II Corrective Action Investigation (CAI) for Frenchman Flat (FF) Corrective Action Unit (CAU) 98. The purpose of this data compilation and related analyses is to provide the primary reference to support parameterization of the Phase II FF CAU transport model.

  8. Justification for parameters of a dynamic stabilizer of the experimental stand mobile unit in studying of active rotational working tools of tiller machines

    Directory of Open Access Journals (Sweden)

    Vladimir F. Kupryashkin

    2017-03-01

    Full Text Available Introduction: The article deals with design options and technological modes of the dynamic stabilizer of the experimental stand mobile unit for studying tillage machine active rotating work tools. Based on theoretical and experimental studies, the possibility the movable module instability was discovered. This negatively affects on implementing the experiment program trough the especific method. The need in engineering solutions for the defect correction is shown. In addition, the authors consider the structural features and characteristics of the used devices for providing the stabilization of the movable module in the study of active rotating work tools of tillage machines. An electromagnetic brake dynamic stabilizer in the structure of the existing rolling module was proposed as an engineering device. Materials and Methods: A theoretical study of rolling module stability, based on synthesis of basic regulations and laws of mechanics related to active rotating work tools was conducted. As a result of the theoretical research, a design scheme of movable module loading was created. This scheme includes the design features and structural power factors. Results: A database representing the settings of power specification in the motion stability determining the mobile unit was created. Further use of the database values allow supporting the most optimal location of the electromagnetic brake with its design options. Discussion and Conclusions: The research of the electromagnetic brake in a mobile unit promoted stabilizing the unit movement, increased the frequency of its use and provided data that are more precise during experiments.

  9. Study of some parameters affecting the in vitro cultivation of Plasmodium falciparum within saimiri sciureus red blood cells

    Directory of Open Access Journals (Sweden)

    T. Fandeur

    1986-06-01

    Full Text Available The in vitro growth and multiplication of the erythrocytic stages of Plasmodium falciparum within Saimiri sciureus (squirrel monkey red blood cells have been studied. Various parameters, such as the origin of the red blood cells and serum supplement, nature of the buffer, influence of the final pH of the medium, role of proteose peptone and glucose addition, were investigated. The selection of the best culture conditions led to the obtention of a reproducible in vitro growth of two parasite cycles in Saimiri erythrocytes, which is an useful achievement for in vitro studies. Our failure to establish a continuous culture line for longer than 19 days, could be explained by a dramatic increasing of osmotic fragility of the Saimiri red blood cells related to their small size.O crescimento e a multiplicação dos estágios eritrocíticos do Plasmodium falciparum in vitro foi estudado em cultivos com hemácias do Saimiri sciureus (macaco de cheiro. Foram investigados vários parâmetros tais como, origem das hemácias e suplementação de soro, tipo de tampão, influência do pH final do meio, papel da proteose-peptona e da glicose adicionados. A seleção das condições ideais de cultivo permitiram, de maneira reprodutível, a obtenção de crescimento do parasita durante dois ciclos nas hemácias do Saimiri. Nosso fracasso em estabelecer uma linhagem contínua de cultivo por mais de 19 dias poderia ser explicado pelo aumento dramático da fragilidade osmótica das hemácias do Saimiri relacionado com seu pequeno tamanho.

  10. Theoretical characterization and design of small molecule donor material containing naphthodithiophene central unit for efficient organic solar cells.

    Science.gov (United States)

    Duan, Yu-Ai; Geng, Yun; Li, Hai-Bin; Jin, Jun-Ling; Wu, Yong; Su, Zhong-Min

    2013-07-15

    To seek for high-performance small molecule donor materials used in heterojunction solar cell, six acceptor-donor-acceptor small molecules based on naphtho[2,3-b:6,7-b']dithiophene (NDT) units with different acceptor units were designed and characterized using density functional theory and time-dependent density functional theory. Their geometries, electronic structures, photophysical, and charge transport properties have been scrutinized comparing with the reported donor material NDT(TDPP)2 (TDPP  =  thiophene-capped diketopyrrolopyrrole). The open circuit voltage (V(oc)), energetic driving force(ΔE(L-L)), and exciton binding energy (E(b)) were also provided to give an elementary understanding on their cell performance. The results reveal that the frontier molecular orbitals of 3-7 match well with the acceptor material PC61 BM, and compounds 3-5 were found to exhibit the comparable performances to 1 and show promising potential in organic solar cells. In particular, comparing with 1, system 7 with naphthobisthiadiazole acceptor unit displays broader absorption spectrum, higher V(oc), lower E(b), and similar carrier mobility. An in-depth insight into the nature of the involved excited states based on transition density matrix and charge density difference indicates that all S1 states are mainly intramolecular charge transfer states with the charge transfer from central NDT unit to bilateral acceptor units, and also imply that the exciton of 7 can be dissociated easily due to its large extent of the charge transfer. In a word, 7 maybe superior to 1 and may act as a promising donor candidate for organic solar cell. Copyright © 2013 Wiley Periodicals, Inc.

  11. In vitro fertilization and stem cell harvesting from human embryos: the law and practice in the United States.

    Science.gov (United States)

    Hook, C Christopher

    2010-07-01

    The challenges before science and medicine are these: science must explore the natural world as thoroughly as possible, while still honoring, protecting, serving and preserving the subject of its investigations, and the human beings for whom it is a tool; medicine must confront disease and disability as effectively as possible, while also honoring, protecting, and preserving those beings for whom it serves - all of those beings, not just some, or even most, at the potential expense of others. These goals are challenged by embryo-destructive human embryonic stem cell research. The human embryo is a human being as clearly defined by embryology, and as such should be protected by the codes governing human subject research. However, because of the "potential" benefits offered by pluripotent stem cells, coupled with abortion politics and a very poorly regulated infertility industry, United States governmental advisory commissions and the scientific, medical, and political communities have attempted to define away the humanity of the human embryo, with a few notable exceptions. Because infertility treatments in the United States are poorly regulated, there are large numbers of supernumerary embryos in cryopreservation. However, only a tiny portion of these will ever be potentially available for research, and thus are not a realistic source of the cells necessary to provide treatments to the millions who might benefit from proposed stem cell based therapies. Cloning will not be the answer either, given the millions of women who must be exploited to provide sufficient numbers of eggs to generate the cloned cell lines. Moreover, the disposition decisions parents must make for their extra embryos are often agonizing, and not uncommonly change. The use of supernumerary embryos as a source for human embryonic stem cells is unethical, will never be a sufficient source for the medical treatments expected from stem cell research, and is often a source of great distress for the

  12. In vitro fertilization and stem cell harvesting from human embryos: the law and practice in the United States

    Directory of Open Access Journals (Sweden)

    C. Christopher Hook

    2010-07-01

    Full Text Available The challenges before science and medicine are these: science must explore the natural world as thoroughly as possible, while still honoring, protecting, serving and preserving the subject of its investigations, and the human beings for whom it is a tool; medicine must confront disease and disability as effectively as possible, while also honoring, protecting, and preserving those beings for whom it serves – all of those beings, not just some, or even most, at the potential expense of others. These goals are challenged by embryo-destructive human embryonic stem cell research. The human embryo is a human being as clearly defined by embryology, and as such should be protected by the codes governing human subject research. However, because of the “potential” benefits offered by pluripotent stem cells, coupled with abortion politics and a very poorly regulated infertility industry, United States governmental advisory commissions and the scientific, medical, and political communities have attempted to define away the humanity of the human embryo, witha few notable exceptions. Because infertility treatments in the United States are poorly regulated, there are large numbersof supernumerary embryos in cryopreservation. However, only a tiny portion of these will ever be potentially available for research, and thus are not a realistic source of the cells necessary to provide treatments to the millions who might benefit from proposed stem cell based therapies. Cloning willnot be the answer either, given the millions of women who must be exploited to provide sufficient numbers of eggs to generate the cloned cell lines. Moreover, the disposition decisions parents must make for their extra embryos are often agonizing, and not uncommonly change.The use of supernumerary embryos as a source for human embryonic stem cells is unethical, will never be a sufficient source for the medical treatments expected from stem cell research, and is often a source of

  13. Genetic parameters between feed-intake-related traits and conformation in 2 separate dairy populations-the Netherlands and United States

    NARCIS (Netherlands)

    Manzanilla-Pech, C.I.V.; Veerkamp, R.F.; Tempelman, R.J.; Pelt, van M.L.; Weigel, K.A.; VandeHaar, M.; Lawlor, T.J.; Spurlock, D.M.; Armentano, L.E.; Staples, C.R.; Hanigan, M.; Haas, De Y.

    2016-01-01

    To include feed-intake-related traits in the breeding goal, accurate estimates of genetic parameters of feed intake, and its correlations with other related traits (i.e., production, conformation) are required to compare different options. However, the correlations between feed intake and

  14. Frequency and Risk Factors Associated with Cord Graft Failure after Transplant with Single-Unit Umbilical Cord Cells Supplemented by Haploidentical Cells with Reduced-Intensity Conditioning.

    Science.gov (United States)

    Tsai, Stephanie B; Liu, Hongtao; Shore, Tsiporah; Fan, Yun; Bishop, Michael; Cushing, Melissa M; Gergis, Usama; Godley, Lucy; Kline, Justin; Larson, Richard A; Martinez, Guadalupe; Mayer, Sebastian; Odenike, Olatoyosi; Stock, Wendy; Wickrema, Amittha; van Besien, Koen; Artz, Andrew S

    2016-06-01

    Delayed engraftment and cord graft failure (CGF) are serious complications after unrelated cord blood (UCB) hematopoietic stem cell transplantation (HSCT), particularly when using low-cell-dose UCB units. The haplo-cord HSCT approach allows the use of a lower dose single UCB unit by co-infusion of a CD34(+) selected haploidentical graft, which provides early transient engraftment while awaiting durable UCB engraftment. We describe the frequency, complications, and risk factors of CGF after reduced-intensity conditioning haplo-cord HSCT. Among 107 patients who underwent haplo-cord HSCT, 94 were assessable for CGF, defined as risk of CGF. We conclude that assessing chimerism at day 30 may foretell impending CGF, and avoidance of high haploidentical cell doses may reduce risk of CGF after haplo-cord HSCT. However, long-term survival is possible after CGF because of predominant haploidentical or mixed chimerism and hematopoietic function.

  15. Development of integrated DMFC and PEM fuel cell units. Final report; Udvikling af integrerede DMFC og PEM braendselscelle enheder. Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Odgaard, M. (IRD Fuel Cell Technology, Svendborg (DK))

    2007-06-15

    The 36-month long project 'Development of integrated DMFC and PEM fuel cell units' has been completed. The project goal was to develop a completely new MEA concept for integrated PEM and DMFC unit cells with enhanced power density and in this way obtain a price reduction. The integrated unit cell consists of a MEA, a gas diffusion layer with flow fields completed with bipolar plates and seals. The main focus of the present project was to: 1) Develop new catalyst materials fabricated by the use of FSD (flame spray deposition method). 2) Optimisation of the state-of-the-art MEA materials and electrode structure. 3) Implementation of a model to account for the CO poisoning of PEM fuel cells. Results and progress obtained in the project established that the individual unit cell components were able to meet and follow the road map of LT-PEM FC regarding electrode catalyst loading and fulfilled the targets for Year 2006. The project has resulted in some important successes. The highlights are as follows: The project has resulted in some important successes. The highlights are as follows: 1) MEA structure knowledge acquired in the project provide a sound basis for further progress. 2) A novel method for the synthesis of electrode by using flame spray synthesis was explored. 3) Electrochemical and catalytic behaviours of catalysts activity for CH{sub 3}OH explored. 4) Implementation of a sub model to account for the CO poisoning of PEM FC has been developed. 5) Numerical study of the flow distribution in FC manifolds was developed and completed with experimental data. 6) The electrode catalyst loading targets for year 2006 achieved. 7) The DMFC MEA performance has been improved by 35%. 8) Optimisation of the MEAs fabrication process has been successfully developed. 9) A new simple flow field design has been designed. 10) A procedure for integrated seals has been developed (au)

  16. THE FEATURES OF CONNEXINS EXPRESSION IN THE CELLS OF NEUROVASCLAR UNIT IN NORMAL CONDITIONS AND HYPOXIA IN VITRO

    Directory of Open Access Journals (Sweden)

    A. V. Morgun

    2014-01-01

    Full Text Available The aim of this research was to assess a role of connexin 43 (Cx43 and associated molecule CD38 in the regulation of cell-cell interactions in the neurovascular unit (NVU in vitro in physiological conditions and in hypoxia.Materials and methods. The study was done using the original neurovascular unit model in vitro. The NVU consisted of three cell types: neurons, astrocytes, and cerebral endothelial cells derived from rats. Hypoxia was induced by incubating cells with sodium iodoacetate for 30 min at37 °C in standard culture conditions.Results. We investigated the role of connexin 43 in the regulation of cell interactions within the NVU in normal and hypoxic injury in vitro. We found that astrocytes were characterized by high levels of expression of Cx43 and low level of CD38 expression, neurons demonstrated high levels of CD38 and low levels of Cx43. In hypoxic conditions, the expression of Cx43 and CD38 in astrocytes markedly increased while CD38 expression in neurons decreased, however no changes were found in endothelial cells. Suppression of Cx43 activity resulted in down-regulation of CD38 in NVU cells, both in physiological conditions and at chemical hypoxia.Conclusion. Thus, the Cx-regulated intercellular NAD+-dependent communication and secretory phenotype of astroglial cells that are the part of the blood-brain barrier is markedly changed in hypoxia.

  17. Tool for Generation of MAC/GMC Representative Unit Cell for CMC/PMC Analysis

    Science.gov (United States)

    Murthy, Pappu L. N.; Pineda, Evan J.

    2016-01-01

    This document describes a recently developed analysis tool that enhances the resident capabilities of the Micromechanics Analysis Code with the Generalized Method of Cells (MAC/GMC) 4.0. This tool is especially useful in analyzing ceramic matrix composites (CMCs), where higher fidelity with improved accuracy of local response is needed. The tool, however, can be used for analyzing polymer matrix composites (PMCs) as well. MAC/GMC 4.0 is a composite material and laminate analysis software developed at NASA Glenn Research Center. The software package has been built around the concept of the generalized method of cells (GMC). The computer code is developed with a user friendly framework, along with a library of local inelastic, damage, and failure models. Further, application of simulated thermomechanical loading, generation of output results, and selection of architectures to represent the composite material have been automated to increase the user friendliness, as well as to make it more robust in terms of input preparation and code execution. Finally, classical lamination theory has been implemented within the software, wherein GMC is used to model the composite material response of each ply. Thus, the full range of GMC composite material capabilities is available for analysis of arbitrary laminate configurations as well. The primary focus of the current effort is to provide a graphical user interface (GUI) capability that generates a number of different user-defined repeating unit cells (RUCs). In addition, the code has provisions for generation of a MAC/GMC-compatible input text file that can be merged with any MAC/GMC input file tailored to analyze composite materials. Although the primary intention was to address the three different constituents and phases that are usually present in CMCs-namely, fibers, matrix, and interphase-it can be easily modified to address two-phase polymer matrix composite (PMC) materials where an interphase is absent. Currently, the

  18. Unit cell determination of coexisting post-perovskite and H-phase in (Mg,Fe)SiO3 using multigrain XRD: compositional variation across a laser heating spot at 119 GPa

    Science.gov (United States)

    Zhang, Li; Meng, Yue; Mao, Ho-kwang

    2016-12-01

    Multigrain X-ray diffraction (XRD) can be used to accurately calculate the unit cell parameters of individual mineral phases in a mineral assemblage contained in a diamond anvil cell (DAC). Coexisting post-perovskite (ppv) and H-phase were synthesized at 119 GPa and 2500 K from (Mg0.85Fe0.15)SiO3 in a laser-heated DAC. The unit cell parameters of the ppv and coexisting H-phase were determined using multigrain XRD with a 5 μm spatial resolution, close to the size of the X-ray beam, to understand compositional variations across the center area (20-30 μm) in a laser-heated sample. The ppv phase was Fe-depleted and the unit cell volume of ppv decreased by only 0.16 % (corresponding to ~3 % variation of FeSiO3) from the heating center to 10 μm off the center, while the sample pressure remained at 119 GPa in a Ne quasi-hydrostatic environment. The unit cell volume of the H-phase decreased by 0.54 % (~10 % variation of FeSiO3 content) over the same 10 μm distance. Both phases were more Fe-enriched in the slightly hotter center. This observation suggests that thermal diffusion may not be the major driver for the compositional variations of ppv and H-phase in the center portion of a laser-heated sample. Instead, these variations could be caused by a temperature effect on the partitioning between the ppv and H-phase over the small gradient.

  19. Indium phosphide solar cell research in the United States: Comparison with non-photovoltaic sources

    Science.gov (United States)

    Weinberg, I.; Swartz, C. K.; Hart, R. E., Jr.

    1989-01-01

    Highlights of the InP solar cell research program are presented. Homojunction cells with efficiencies approaching 19 percent are demonstrated, while 17 percent is achieved for ITO/InP cells. The superior radiation resistance of the two latter cell configurations over both Si and GaAs cells has been shown. InP cells aboard the LIPS3 satellite show no degradation after more than a year in orbit. Computed array specific powers are used to compare the performance of an InP solar cell array to solar dynamic and nuclear systems.

  20. QTLs for murine red blood cell parameters in LG/J and SM/J F(2) and advanced intercross lines.

    Science.gov (United States)

    Bartnikas, Thomas B; Parker, Clarissa C; Cheng, Riyan; Campagna, Dean R; Lim, Jackie E; Palmer, Abraham A; Fleming, Mark D

    2012-06-01

    Red blood cells are essential for oxygen transport and other physiologic processes. Red cell characteristics are typically determined by complete blood counts which measure parameters such as hemoglobin levels and mean corpuscular volumes; these parameters reflect the quality and quantity of red cells in the circulation at any particular moment. To identify the genetic determinants of red cell parameters, we performed genome-wide association analysis on LG/J×SM/J F2 and F34 advanced intercross lines using single nucleotide polymorphism genotyping and a novel algorithm for mapping in the combined populations. We identified significant quantitative trait loci for red cell parameters on chromosomes 6, 7, 8, 10, 12, and 17; our use of advanced intercross lines reduced the quantitative trait loci interval width from 1.6- to 9.4-fold. Using the genomic sequences of LG/J and SM/J mice, we identified nonsynonymous coding single nucleotide polymorphisms in candidate genes residing within quantitative trait loci and performed sequence alignments and molecular modeling to gauge the potential impact of amino acid substitutions. These results should aid in the identification of genes critical for red cell physiology and metabolism and demonstrate the utility of advanced intercross lines in uncovering genetic determinants of inherited traits.

  1. Semiempirical and DFT computations of the influence of Tb(III) dopant on unit cell dimensions of cerium(III) fluoride.

    Science.gov (United States)

    Shyichuk, Andrii; Runowski, Marcin; Lis, Stefan; Kaczkowski, Jakub; Jezierski, Andrzej

    2015-01-30

    Several computational methods, both semiempirical and ab initio, were used to study the influence of the amount of dopant on crystal cell dimensions of CeF3 doped with Tb(3+) ions (CeF3 :Tb(3+) ). AM1, RM1, PM3, PM6, and PM7 semiempirical parameterization models were used, while the Sparkle model was used to represent the lanthanide cations in all cases. Ab initio calculations were performed by means of GGA+U/PBE projector augmented wave density functional theory. The computational results agree well with the experimental data. According to both computation and experiment, the crystal cell parameters undergo a linear decrease with increasing amount of the dopant. The computations performed using Sparkle/PM3 and DFT methods resulted in the best agreement with the experiment with the average deviation of about 1% in both cases. Typical Sparkle/PM3 computation on a 2×2×2 supercell of CeF3:Tb3+ lasted about two orders of magnitude shorter than the DFT computation concerning a unit cell of this material. © 2014 Wiley Periodicals, Inc.

  2. Effects of oral powder electrolyte administration on packed cell volume, plasma chemistry parameters, and incidence of colic in horses participating in a 6-day 162-km trail ride.

    Science.gov (United States)

    Walker, Wade T; Callan, Robert J; Hill, Ashley E; Tisher, Kelly B

    2014-08-01

    This study evaluated the effects of administering oral powder electrolytes on packed cell volume (PCV), plasma chemistry parameters, and incidence of colic in horses participating on a 6-day 162-km trail ride in which water was not offered ad libitum. Twenty-three horses received grain with powder electrolytes daily while 19 control horses received grain only. Horses were ridden approximately 32 km a day at a walk or trot. Packed cell volume and plasma chemistry parameters were analyzed daily. Episodes of colic were diagnosed and treated by a veterinarian unaware of treatment group allocation. Blood parameters and incidence of colic were compared between treatment groups. Electrolyte administration did not alter PCV or plasma chemistry parameters compared to controls. The incidence of colic was significantly higher in treated horses (P = 0.05). Oral powder electrolytes did not enhance hydration status or electrolyte homeostasis and may be associated with colic in horses participating on long distance trail rides similar to this model.

  3. Tunable Multifunctional Thermal Metamaterials: Manipulation of Local Heat Flux via Assembly of Unit-Cell Thermal Shifters.

    Science.gov (United States)

    Park, Gwanwoo; Kang, Sunggu; Lee, Howon; Choi, Wonjoon

    2017-01-20

    Thermal metamaterials, designed by transformation thermodynamics are artificial structures that can actively control heat flux at a continuum scale. However, fabrication of them is very challenging because it requires a continuous change of thermal properties in materials, for one specific function. Herein, we introduce tunable thermal metamaterials that use the assembly of unit-cell thermal shifters for a remarkable enhancement in multifunctionality as well as manufacturability. Similar to the digitization of a two-dimensional image, designed thermal metamaterials by transformation thermodynamics are disassembled as unit-cells thermal shifters in tiny areas, representing discretized heat flux lines in local spots. The programmed-reassembly of thermal shifters inspired by LEGO enable the four significant functions of thermal metamaterials-shield, concentrator, diffuser, and rotator-in both simulation and experimental verification using finite element method and fabricated structures made from copper and PDMS. This work paves the way for overcoming the structural and functional limitations of thermal metamaterials.

  4. Tunable Multifunctional Thermal Metamaterials: Manipulation of Local Heat Flux via Assembly of Unit-Cell Thermal Shifters

    Science.gov (United States)

    Park, Gwanwoo; Kang, Sunggu; Lee, Howon; Choi, Wonjoon

    2017-01-01

    Thermal metamaterials, designed by transformation thermodynamics are artificial structures that can actively control heat flux at a continuum scale. However, fabrication of them is very challenging because it requires a continuous change of thermal properties in materials, for one specific function. Herein, we introduce tunable thermal metamaterials that use the assembly of unit-cell thermal shifters for a remarkable enhancement in multifunctionality as well as manufacturability. Similar to the digitization of a two-dimensional image, designed thermal metamaterials by transformation thermodynamics are disassembled as unit-cells thermal shifters in tiny areas, representing discretized heat flux lines in local spots. The programmed-reassembly of thermal shifters inspired by LEGO enable the four significant functions of thermal metamaterials—shield, concentrator, diffuser, and rotator—in both simulation and experimental verification using finite element method and fabricated structures made from copper and PDMS. This work paves the way for overcoming the structural and functional limitations of thermal metamaterials. PMID:28106156

  5. Compact Circularly Polarized Patch Antenna Using a Composite Right/Left-Handed Transmission Line Unit-Cell

    Directory of Open Access Journals (Sweden)

    L. Geng

    2013-04-01

    Full Text Available A compact circularly polarized (CP patch antenna using a composite right/left-handed (CRLH transmission line (TL unit-cell is proposed. The CRLH TL unit-cell includes a complementary split ring resonator (CSRR for shunt inductance and a gap loaded with a circular-shaped slot for series capacitance. The CSRR can decrease the TM10 mode resonance frequency, thus reducing the electrical size of the proposed antenna. In addition, the asymmetry of the CSRR brings about the TM01 mode, which can be combined with the TM10 mode by changing the slot radius. The combination of these two orthogonal modes with 90° phase shift makes the proposed antenna provide a CP property. The experimental results show that the proposed antenna has a wider axial ratio bandwidth and a smaller electrical size than the reported CP antennas. Moreover, the proposed antenna is designed without impedance transformer, 90° phase shift, dual feed and ground via.

  6. Interfacing of science, medicine and law: The stem cell patent controversy in the United States and the European Union

    Directory of Open Access Journals (Sweden)

    Sonya eDavey

    2015-11-01

    Full Text Available The patent eligibility of stem cells – particularly those derived from human embryos – has long been under debate in both the scientific and legal communities. On the basis of moral grounds, the European Patent Office (EPO has refrained from granting patents for stem cells obtained through the destruction of human embryos. On the contrary, the United States Patent and Trademark Office (USPTO has historically granted patents regarding the isolation and use of human embryonic and other stem cells. To date, these US patents remain valid despite an increasing onslaught of challenges in court. However, recent precedents established in US courts significantly narrow the scope of patent eligibility within biotechnology. This article compares the implications of recent legal changes on stem cell patent eligibility between the EU and US.

  7. Red cell storage age policy for patients with sickle cell disease: A survey of transfusion service directors in the United States.

    Science.gov (United States)

    Karafin, Matthew S; Singavi, Arun K; Irani, Mehraboon S; Puca, Kathleen E; Baumann Kreuziger, Lisa; Simpson, Pippa; Field, Joshua J

    2016-02-01

    In patients with sickle cell disease (SCD), the effects of the red cell storage lesion are not well defined. The objective of this study was to determine the prevalence of transfusion services that limit red cell units by storage age for patients with SCD. We developed a 22 question survey of transfusion service director opinions and their corresponding blood bank policies. Target subjects were systematically identified on the AABB website. Responses were recorded in SurveyMonkey and summarized using standard statistical techniques. Ninety transfusion service directors responded to the survey. Response rate was 22%. Only 23% of respondents had storage age policies in place for patients with SCD, even though 36% of respondents consider older units to be potentially harmful in this patient population. Of those with a policy, a less-than 15 day storage age requirement was most often used (75%), but practices varied, and most respondents (65%) agreed that evidence-based guidelines regarding storage age are needed for patients with SCD. Policies, practices and opinions about the risks of older units for patients with SCD vary. As patients with SCD may have unique susceptibilities to features of the red cell storage lesion, prospective studies in this population are needed to determine best practice.

  8. A CLINICO- HEMATOLOGICAL STUDY IN CASES OF PANCYTO PENIA: CORRELATION OF AUTOMATED CELL COUNTER PARAMETERS IN VARIOUS ETIOLOGIES

    Directory of Open Access Journals (Sweden)

    Soma

    2013-05-01

    Full Text Available ORIGINAL ARTICLE Journal of Evolution of Medical and Dental Sciences / Volume 2/ Issue 22/ June 3, 2013 Page 4013 A CLINICO- HEMATOLOGICAL STUDY IN CASES OF PANCYTO PENIA: CORRELATION OF AUTOMATED CELL COUNTER PARAMETERS IN VARIOUS ETIOLOGIES Soma Yadav 1 , Rashmi Kushwaha 2 , Kamal Aggrawal 3 , A.K Tripathi 4 , U.S Singh 5 , Ashutosh Kumar 6 . 1. Junior Resident, Department. Of pathology, King George’s Medical Uni versity 2. Assistant Professor, Department. Of pathology, King George’s Medical University 3. Professor, Department. Of pathology, King George’s Medical University 4. Professor and Head, Department. Of Clinical Hematol ogy, King George’s Medical University 5. Professor, Department. Of pathology, King George’s Medical University 6. Professor and officer in charge, Lymphoma- Leukemia Lab, Department. Of pathology, King George’s Medic al University. CORRESPONDING AUTHOR: Dr. Rashmi Kushwaha, King George’s Medical University, Lucknow. E-mail: docrashmi27@yahoo.co.in

  9. Optimization of the polypyrrole-coating parameters for proton exchange membrane fuel cell bipolar plates using the Taguchi method

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yan; Northwood, Derek O. [Department of Mechanical, Automotive, and Materials Engineering, University of Windsor, 401 Sunset Avenue, Windsor, Ontario (Canada)

    2008-10-15

    In order to overcome the high price, weight and volume of non-porous graphite bipolar plates, metallic bipolar plates are being investigated as a substitute material. However, metallic materials can corrode under proton exchange membrane fuel cell (PEMFC) working conditions, leading to a degradation in the performance of the membrane. Previous work had shown that a polypyrrole coating on SS316L can significantly increase the corrosion resistance of the base material. In this study, a Taguchi design of experiment method was used to optimize the process parameters for the polypyrrole coating so as to produce the maximum corrosion resistance. Potentiodynamic and potentiostatic tests were used to determine the corrosion resistance of the polypyrrole-coated SS316L. Scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) was used to characterize the coating thickness and coating appearance. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used to determine the metal ion concentration in the solution after corrosion. The interfacial contact resistance of SS316L with carbon paper was measured both before and after coating with polypyrrole. (author)

  10. Haematological, biochemical and inflammatory parameters in inactive Behçet's disease. Its association with red blood cell distribution width.

    Science.gov (United States)

    Vayá, Amparo; Rivera, Leonor; Todolí, José; Hernandez, Jose Luis; Laiz, Begoña; Ricart, José M

    2014-01-01

    Red blood cell distribution width (RDW) has been shown to be associated with disease activity in several inflammatory disorders. However only one study to show this has been conducted in patients with Behçet's disease (BD). The aim of the present study was to analyse the association of RDW with BD and its main complications; i.e.; thrombosis and posterior uveitis. A second aim was to analyse the possible correlation between RDW and both haematological and inflammatory parameters. Eighty-nine patients with BD (48 males/41 females) and 94 controls (49 males/45 females) were included in the study. Patients were in an inactive phase of the disease, showing only minimum activity. RDW was statistically higher in patients than in controls (14.02 ± 1.32 vs. 13.15 ± 0.75; p 0.05). RDW correlated negatively with haemoglobin, MCH and MCHC (p 0.05). The multivariate regression analysis revealed that haemoglobin and homocysteine were independent predictors of RDW (beta coefficient: -0.310; p = 0.003, beta coefficient: 0.379; p 14 was associated with neither thrombosis nor uveitis (p = 0.935; p = 0.553, respectively). Our results indicate that BD patients show increased RDW when compared with controls. This increase seems to be related with haematimetric indices and with homocysteine levels. Lack of correlation with inflammatory markers may be due to the fact that patients were in an inactive phase of the disease.

  11. Tailoring the Mesoscopic TiO2 Layer: Concomitant Parameters for Enabling High-Performance Perovskite Solar Cells

    Science.gov (United States)

    Hwang, Taehyun; Lee, Sangheon; Kim, Jinhyun; Kim, Jaewon; Kim, Chunjoong; Shin, Byungha; Park, Byungwoo

    2017-01-01

    Architectural control over the mesoporous TiO2 film, a common electron-transport layer for organic-inorganic hybrid perovskite solar cells, is conducted by employing sub-micron sized polystyrene beads as sacrificial template. Such tailored TiO2 layer is shown to induce asymmetric enhancement of light absorption notably in the long-wavelength region with red-shifted absorption onset of perovskite, leading to 20% increase of photocurrent and 10% increase of power conversion efficiency. This enhancement is likely to be originated from the enlarged CH3NH3PbI3(Cl) grains residing in the sub-micron pores rather than from the effect of reduced perovskite-TiO2 interfacial area, which is supported from optical bandgap change, haze transmission of incident light, and one-diode model parameters correlated with the internal surface area of microporous TiO2 layers. With the templating strategy suggested, the necessity of proper hole-blocking method is discussed to prevent any direct contact of the large perovskite grains infiltrated into the intended pores of TiO2 scaffold, further mitigating the interfacial recombination and leading to 20% improvement in power conversion efficiency compared with the control device using conventional solution-processed hole blocking TiO2. Thereby, the imperatives that originate from the structural engineering of the electron-transport layer are discussed to understand the governing elements for the improved device performance.

  12. Correlation of TP53 Overexpression and Clinical Parameters with Five-Year Survival in Oral Squamous Cell Carcinoma Patients.

    Science.gov (United States)

    Ali, Syed A; Khan, Hamza A; Irfan, Omar; Samad, Adeel; Mirza, Yumna; Awan, Muhammad S

    2017-06-27

    Introduction TP53 mutation and overexpression have been correlated with poor survival in many cancers including oral squamous cell carcinoma (OSCC). We aim to understand the role of TP53 overexpression in OSCC in our population and correlate it with five-year survival to test its viability as a prognostic marker for OSCC patients. Materials and methods Patients with biopsy proven OSCC at Aga Khan University Hospital from January 2000 to January 2008 were recruited. Immunohistochemistry was used to establish TP53 status and the results were published. Following up on these patients, five-year data were collected and correlated with TP53 status and other clinicopathologic parameters. Results Overexpression of TP53 was not significantly associated with five-year survival (hazard ratio [HR]: 1.543; 95% CI: 0.911-2.612; p = 0.107). Conclusion Although we had proven statistical relevance when correlated with overall survival in our previous study, we were unable to extend the same relevance to TP53 overexpression when it comes to five-year survival.

  13. A Miniaturized Antenna with Negative Index Metamaterial Based on Modified SRR and CLS Unit Cell for UWB Microwave Imaging Applications

    Directory of Open Access Journals (Sweden)

    Md. Moinul Islam

    2015-01-01

    Full Text Available A miniaturized antenna employing a negative index metamaterial with modified split-ring resonator (SRR and capacitance-loaded strip (CLS unit cells is presented for Ultra wideband (UWB microwave imaging applications. Four left-handed (LH metamaterial (MTM unit cells are located along one axis of the antenna as the radiating element. Each left-handed metamaterial unit cell combines a modified split-ring resonator (SRR with a capacitance-loaded strip (CLS to obtain a design architecture that simultaneously exhibits both negative permittivity and negative permeability, which ensures a stable negative refractive index to improve the antenna performance for microwave imaging. The antenna structure, with dimension of 16 × 21 × 1.6 mm3, is printed on a low dielectric FR4 material with a slotted ground plane and a microstrip feed. The measured reflection coefficient demonstrates that this antenna attains 114.5% bandwidth covering the frequency band of 3.4–12.5 GHz for a voltage standing wave ratio of less than 2 with a maximum gain of 5.16 dBi at 10.15 GHz. There is a stable harmony between the simulated and measured results that indicate improved nearly omni-directional radiation characteristics within the operational frequency band. The stable surface current distribution, negative refractive index characteristic, considerable gain and radiation properties make this proposed negative index metamaterial antenna optimal for UWB microwave imaging applications.

  14. A Miniaturized Antenna with Negative Index Metamaterial Based on Modified SRR and CLS Unit Cell for UWB Microwave Imaging Applications.

    Science.gov (United States)

    Islam, Md Moinul; Islam, Mohammad Tariqul; Samsuzzaman, Md; Faruque, Mohammad Rashed Iqbal; Misran, Norbahiah; Mansor, Mohd Fais

    2015-01-23

    A miniaturized antenna employing a negative index metamaterial with modified split-ring resonator (SRR) and capacitance-loaded strip (CLS) unit cells is presented for Ultra wideband (UWB) microwave imaging applications. Four left-handed (LH) metamaterial (MTM) unit cells are located along one axis of the antenna as the radiating element. Each left-handed metamaterial unit cell combines a modified split-ring resonator (SRR) with a capacitance-loaded strip (CLS) to obtain a design architecture that simultaneously exhibits both negative permittivity and negative permeability, which ensures a stable negative refractive index to improve the antenna performance for microwave imaging. The antenna structure, with dimension of 16 × 21 × 1.6 mm³, is printed on a low dielectric FR4 material with a slotted ground plane and a microstrip feed. The measured reflection coefficient demonstrates that this antenna attains 114.5% bandwidth covering the frequency band of 3.4-12.5 GHz for a voltage standing wave ratio of less than 2 with a maximum gain of 5.16 dBi at 10.15 GHz. There is a stable harmony between the simulated and measured results that indicate improved nearly omni-directional radiation characteristics within the operational frequency band. The stable surface current distribution, negative refractive index characteristic, considerable gain and radiation properties make this proposed negative index metamaterial antenna optimal for UWB microwave imaging applications.

  15. A Miniaturized Antenna with Negative Index Metamaterial Based on Modified SRR and CLS Unit Cell for UWB Microwave Imaging Applications

    Science.gov (United States)

    Islam, Md. Moinul; Islam, Mohammad Tariqul; Samsuzzaman, Md.; Faruque, Mohammad Rashed Iqbal; Misran, Norbahiah; Mansor, Mohd Fais

    2015-01-01

    A miniaturized antenna employing a negative index metamaterial with modified split-ring resonator (SRR) and capacitance-loaded strip (CLS) unit cells is presented for Ultra wideband (UWB) microwave imaging applications. Four left-handed (LH) metamaterial (MTM) unit cells are located along one axis of the antenna as the radiating element. Each left-handed metamaterial unit cell combines a modified split-ring resonator (SRR) with a capacitance-loaded strip (CLS) to obtain a design architecture that simultaneously exhibits both negative permittivity and negative permeability, which ensures a stable negative refractive index to improve the antenna performance for microwave imaging. The antenna structure, with dimension of 16 × 21 × 1.6 mm3, is printed on a low dielectric FR4 material with a slotted ground plane and a microstrip feed. The measured reflection coefficient demonstrates that this antenna attains 114.5% bandwidth covering the frequency band of 3.4–12.5 GHz for a voltage standing wave ratio of less than 2 with a maximum gain of 5.16 dBi at 10.15 GHz. There is a stable harmony between the simulated and measured results that indicate improved nearly omni-directional radiation characteristics within the operational frequency band. The stable surface current distribution, negative refractive index characteristic, considerable gain and radiation properties make this proposed negative index metamaterial antenna optimal for UWB microwave imaging applications. PMID:28787945

  16. Intra-unit-cell magnetic correlations near optimal doping in YBa2Cu3O6.85.

    Science.gov (United States)

    Mangin-Thro, L; Sidis, Y; Wildes, A; Bourges, P

    2015-07-03

    The pseudo-gap phenomenon in copper oxide superconductors is central to any description of these materials as it prefigures the superconducting state itself. A magnetic intra-unit-cell order was found to occur just at the pseudo-gap temperature in four cuprate high-Tc superconducting families. Here we present polarized neutron-scattering measurements of nearly optimally doped YBa2Cu3O6.85, carried out on two different spectrometers, that reveal several features. The intra-unit-cell order consists of finite-sized planar domains that are very weakly correlated along the c axis. At high temperature, only the out-of-plane magnetic components correlate, indicating a strong Ising anisotropy. An aditional in-plane response develops at low temperature, giving rise to an apparent tilt of the magnetic moment. The discovery of these two regimes puts stringent constraints, which are tightly bound to the pseudo-gap physics, on the intrinsic nature of intra-unit-cell order.

  17. Simultaneous multi-parameter observation of Harring-tonine-treating HL-60 cells with both two-photon and confo-cal laser scanning microscopy

    Institute of Scientific and Technical Information of China (English)

    张春阳; 李艳平; 马辉; 李素文; 薛绍白; 陈瓞延

    2001-01-01

    Harringtonine (HT), a kind of anticancer drug isolated from Chinese herb-Cephalotaxus hainanensis Li, can induce apoptosis in promyelocytic leukemia HL-60 cells. With both two-photon laser scanning microscopy and confocal laser scanning microscopy in combination with the fluores-cent probe Hoechst 33342, tetramethyrhodamine ethyl ester (TMRE) and Fluo 3-AM, we simulta-neously observed HT-induced changes in nuclear morphology, mitochondrial membrane potential and intracellular calcium concentration ([Ca2+]i) in HL-60 cells, and developed a real-time, sensitive and invasive method for simultaneous multi-parameter observation of drug- treating living cells at the level of single cell.

  18. Theoretical Study of the π-Bridge Influence with Different Units of Thiophene and Thiazole in Coumarin Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Rody Soto-Rojo

    2016-01-01

    Full Text Available Eight coumarin derivative dyes were studied by varying the π-bridge size with different thiophene and thiazole units for their potential use in dye-sensitized solar cells (DSSC. Geometry optimization, the energy levels and electron density of the Highest Occupied Molecular Orbital and the Lowest Unoccupied Molecular Orbital, and ultraviolet-visible absorption spectra were calculated by Density Functional Theory (DFT and Time-Dependent-DFT. All molecular properties were analyzed to decide which dye was the most efficient. Furthermore, chemical reactivity parameters, such as chemical hardness, electrophilicity index, and electroaccepting power, were obtained and analyzed, whose values predicted the properties of the dyes in addition to the rest of the studied molecular properties. Our calculations allow us to qualitatively study dye molecules and choose the best for use in a DSSC. The effects of π-bridges based on thiophenes, thiazoles, and combinations of the two were reviewed; dyes with three units mainly of thiazole were chosen as the best photosensitizers for DSSC.

  19. Discrete and continuous water-quality data and hydrologic parameters from seven agricultural watersheds in the United States, 2002-09

    Science.gov (United States)

    McCarthy, Kathleen A.; Lampe, David C.; Capel, Paul D.

    2011-01-01

    Field and analytical methods; discrete organic and non-organic water-quality data and associated quality-control data; and continuous hydrologic and water-quality parameters are reported for sites in California, Indiana, Iowa, Maryland, Mississippi, Nebraska, and Washington. The sites were sampled as part of the U.S. Geological Survey National Water-Quality Assessment Program?s Agricultural Chemicals Team study to better understand how environmental processes and agricultural practices interact to determine the transport and fate of agricultural chemicals in the environment.

  20. Effects of the position of galactose units to Zn(II) phthalocyanine on the uptake and photodynamic activity towards breast cancer cells

    Science.gov (United States)

    Mantareva, V.; Kril, A.; Angelov, I.; Dimitrov, R.; Borisova, E.; Avramov, L.

    2012-06-01

    Zn(II)-phthalocyanines with tetra-substitution of D-galactose group on non-peripheral (nGalPc) and peripheral (pGalPc) positions have been studied as photodynamic sensitizers. The both complexes are water-soluble and highly aggregated in water and cell culture medium. The non-peripheral galactose units attached to the phthalocyanine macrocycle (nGalPc) lead to far red shift of absorbance maximum at 703 nm as compared to peripherally substituted pGalPc with maximum at 683 nm. The fluorescence maxima of the studied GalPcs were red shifted (8-14 nm) depending on the used solvent as compared to the absorption maxima. The relatively low fluorescence quantum yields in dimethylsulfoxide (0.06 for nGalPc and 0.21 for pGalPc) were determined. The singlet oxygen generation was determined with lower quantum yield for pGalPc (0.21) as compared to nGalPc (0.38). The lack of dark toxicity towards breast cancer cell line (MCF-7) in wide concentration range (0.125 - 10 μM) was observed. The uptake into the tumor cells and the subcellular localization in MCF-7 cells were determined with higher accumulation for pGalPc, compared to nGalPc. The in vitro photodynamic activity of GalPcs towards breast cancer cells was investigated for different dye concentrations and soft light parameters of 635 nm irradiation. The antitumor activity of nGalPc was superior to the pGalPc-induced cytotoxicity, due to higher generation of singlet oxygen and other reactive oxygen species.

  1. Device and performance parameters of Cu(In,Ga)(Se,S){sub 2}-based solar cells with varying i-ZnO layer thickness

    Energy Technology Data Exchange (ETDEWEB)

    Macabebe, E.Q.B. [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa); Sheppard, C.J. [Department of Physics, University of Johannesburg, P.O. Box 524, Auckland Park 2006 (South Africa); Dyk, E.E. van, E-mail: ernest.vandyk@nmmu.ac.z [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa)

    2009-12-01

    In pursuit of low-cost and highly efficient thin film solar cells, Cu(In,Ga)(Se,S){sub 2}/CdS/i-ZnO/ZnO:Al (CIGSS) solar cells were fabricated using a two-step process. The thickness of i-ZnO layer was varied from 0 to 454 nm. The current density-voltage (J-V) characteristics of the devices were measured, and the device and performance parameters of the solar cells were obtained from the J-V curves to analyze the effect of varying i-ZnO layer thickness. The device parameters were determined using a parameter extraction method that utilized particle swarm optimization. The method is a curve-fitting routine that employed the two-diode model. The J-V curves of the solar cells were fitted with the model and the parameters were determined. Results show that as the thickness of i-ZnO was increased, the average efficiency and the fill factor (FF) of the solar cells increase. Device parameters reveal that although the series resistance increased with thicker i-ZnO layer, the solar cells absorbed more photons resulting in higher short-circuit current density (J{sub sc}) and, consequently, higher photo-generated current density (J{sub L}). For solar cells with 303-454 nm-thick i-ZnO layer, the best devices achieved efficiency between 15.24% and 15.73% and the fill factor varied between 0.65 and 0.67.

  2. Fuel Cell Backup Power Unit Configuration and Electricity Market Participation: A Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Zhiwen [National Renewable Energy Lab. (NREL), Golden, CO (United States); Eichman, Josh [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kurtz, Jennifer [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-03-13

    This National Renewable Energy Laboratory industry-inspired Laboratory Directed Research and Development project evaluates the feasibility and economics of using fuel cell backup power systems in cell towers to provide grid services (e.g., balancing, ancillary services, demand response). The work is intended to evaluate the integration of thousands of under-utilized, clean, efficient, and reliable fuel cell systems that are already installed in cell towers for potential grid and ancillary services.

  3. Computing mammographic density from a multiple regression model constructed with image-acquisition parameters from a full-field digital mammographic unit

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Lee-Jane W [Department of Preventive Medicine and Community Health, University of Texas Medical Branch, Galveston, TX 77555-1109 (United States); Nishino, Thomas K [Department of Radiology, University of Texas Medical Branch, Galveston, TX 77555-0709 (United States); Khamapirad, Tuenchit [Department of Radiology, University of Texas Medical Branch, Galveston, TX 77555-0709 (United States); Grady, James J [Department of Preventive Medicine and Community Health, University of Texas Medical Branch, Galveston, TX 77555-1109 (United States); Jr, Morton H Leonard [Department of Radiology, University of Texas Medical Branch, Galveston, TX 77555-0709 (United States); Brunder, Donald G [Department of Academic Computing/Academic Resources, University of Texas Medical Branch, Galveston, TX 77555-1035 (United States)

    2007-08-21

    Breast density (the percentage of fibroglandular tissue in the breast) has been suggested to be a useful surrogate marker for breast cancer risk. It is conventionally measured using screen-film mammographic images by a labor-intensive histogram segmentation method (HSM). We have adapted and modified the HSM for measuring breast density from raw digital mammograms acquired by full-field digital mammography. Multiple regression model analyses showed that many of the instrument parameters for acquiring the screening mammograms (e.g. breast compression thickness, radiological thickness, radiation dose, compression force, etc) and image pixel intensity statistics of the imaged breasts were strong predictors of the observed threshold values (model R{sup 2} = 0.93) and %-density (R{sup 2} = 0.84). The intra-class correlation coefficient of the %-density for duplicate images was estimated to be 0.80, using the regression model-derived threshold values, and 0.94 if estimated directly from the parameter estimates of the %-density prediction regression model. Therefore, with additional research, these mathematical models could be used to compute breast density objectively, automatically bypassing the HSM step, and could greatly facilitate breast cancer research studies.

  4. Computing mammographic density from a multiple regression model constructed with image-acquisition parameters from a full-field digital mammographic unit

    Science.gov (United States)

    Lu, Lee-Jane W.; Nishino, Thomas K.; Khamapirad, Tuenchit; Grady, James J.; Leonard, Morton H., Jr.; Brunder, Donald G.

    2007-08-01

    Breast density (the percentage of fibroglandular tissue in the breast) has been suggested to be a useful surrogate marker for breast cancer risk. It is conventionally measured using screen-film mammographic images by a labor-intensive histogram segmentation method (HSM). We have adapted and modified the HSM for measuring breast density from raw digital mammograms acquired by full-field digital mammography. Multiple regression model analyses showed that many of the instrument parameters for acquiring the screening mammograms (e.g. breast compression thickness, radiological thickness, radiation dose, compression force, etc) and image pixel intensity statistics of the imaged breasts were strong predictors of the observed threshold values (model R2 = 0.93) and %-density (R2 = 0.84). The intra-class correlation coefficient of the %-density for duplicate images was estimated to be 0.80, using the regression model-derived threshold values, and 0.94 if estimated directly from the parameter estimates of the %-density prediction regression model. Therefore, with additional research, these mathematical models could be used to compute breast density objectively, automatically bypassing the HSM step, and could greatly facilitate breast cancer research studies.

  5. Correlation of Th17 cells and CD4+CD25+ regulatory T cells with clinical parameters in patients with systemic sclerosis

    Institute of Scientific and Technical Information of China (English)

    Jiang Nan; Li Mengtao; Zeng Xiaofeng

    2014-01-01

    Background Systemic sclerosis (SSc) is an autoimmune disease that has three major components:inflammation,fibrosis,and vasculopathy.T-helper 17 cell (Th17) and regulatory T cell (Treg) are considered to be critical for autoimmune disease pathogenesis.The role of Th17 and Treg in SSc is still unclear.The aim of this study was to detect the presence of Th17s and CD4+CD25+ Tregs in peripheral blood samples from SSc patients and to investigate the possible roles of these two T cell subsets in SSc pathogenesis.Methods Th17s (CD4 and IL-17 positive) and CD4+CD25+ Tregs (CD4,CD25 and Foxp3 positive) in the peripheral blood mononuclear cells of 53 SSc patients and 27 healthy controls were counted by flow cytometry.The differences between SSc and control patients were analyzed.Clinical parameters,including disease duration,duration of the second symptoms,Modified Rodnan Skin Score (MRSS),anti-topoisomerase I antibody,anti-U1 ribonucleoprotein (RNP) antibody,systemic involvements,pulmonary function test (PFT) and high resolution computed tomography (HRCT) score were prospectively collected following EUSTAR (EULAR scleroderma trial and research group) protocols.The correlations between the experimental and clinical data were investigated.Results The ratio of Th17 in SSc patients was significantly elevated compared to healthy controls (8.74% vs.4.41%,P <0.001).The amount of Th17 was positively correlated with disease duration (R=0.531,P=0.013) and duration of the second symptoms (R=0.505,P=0.023).The ratio of CD4+CD25+ Treg in SSc patients also significantly differed from the healthy controls (3.04% vs.2.24%,P=0.018).Elevated Tregs were more frequently observed in patients with a high interstitial lung disease (ILD) score on computed tomography (24/36) compared with patients with normal ILD scores (4/12,P=0.043).Elevated Tregs were also more often observed in patients with low carbon monoxide diffusing capacity (DLCO) (24/34) compared with patients with normal DLCO

  6. Temperature dependence of pin solar cell parameters with intrinsic layers made of pm-Si:H and low crystalline volume fraction {mu}c-Si:H

    Energy Technology Data Exchange (ETDEWEB)

    Hamadeh, H. [AECS, Physics Department, P.O. Box 6091, Damascus (Syria)

    2010-07-15

    A comparison of the temperature dependence of the IV characteristics parameters of hydrogenated silicon pin solar cells with intrinsic layers made of polymorphous silicon (pm-Si:H) and of {mu}c-Si:H with low crystalline volume fraction has been performed. When using pm-Si:H, higher efficiency and higher filling factors are achieved over a wide temperature range. Diode quality factors of both types of cells show similar temperature dependence. Recombination processes over the whole intrinsic layer dominates the forward current. A change of the cell parameters under illumination is also observed. The transport mechanism of both cells is similar in the temperature range that is important for most applications. Due to its optical and transport properties, pm-Si:H poses a very interesting alternative to {mu}c-Si:H and a-Si:H in the temperature range of normal terrestrial applications. (author)

  7. Reaggregation of human, chick, and human embryonic brain cells. Factors influencing the formation of a histiotypic unit.

    Science.gov (United States)

    Lodin, Z; Fleischmannová, V; Hájková, B; Faltin, J; Hartman, J

    1981-01-01

    1. Aggregation of embryo human, mouse, and chick brain cells was studied. The optimum age interval of donors from different species was determined. 2. The significance of different dissociation procedures (mild trypsinisation followed by sieving, trypsinisation + DNA digestion, mechanical dissociation in 1 or 2 steps, and Ca2+ chelation by EGTA) for the rate of aggregation was estimated. A significant reduction of aggregation was observed after one step mechanical dissociation. Nonspecific adhesion of cells on DNA molecules was found only during the first stages of aggregation. 3. The curve of aggregation kinetics follows the curve of floculation kinetics. 90% free cells disappear from the medium after 2 h of aggregation and a large number of microaggregates are formed which condense after 20 to 24 h into compact aggregates. The time course of aggregation was similar for all cells dissociated by different means. Small differences in the rate of aggregation, caused by dissociation procedures, were apparent only during the first stages of aggregation. 4. The histiotypic unit formed by aggregation of human, mouse, and chick embryo brain cells exhibits some common and some specific features. During aggregation a multiple structural reconstruction takes place and a limited number of cells are exchanged or sorted out from aggregates into the medium. 5. The structural organisation of aggregates from differently dissociated cells differs in several aspects. This indicates that membrane surface structures are influenced differently by dissociation and behave differently during distinct stages of aggregation.

  8. Application of the MOS-C-V technique to determine impurity concentrations and surface parameters on the diffused face of silicon solar cells

    Science.gov (United States)

    Weinberg, I.

    1975-01-01

    The feasibility of using the MOS C-V technique to obtain information regarding impurity and surface state concentrations on the diffused face of silicon solar cells with Ta2O5 coatings is studied. Results indicate that the MOS C-V technique yields useful information concerning surface parameters which contribute to the high, efficiency limiting, surface recombination velocities on the n+ surface of silicon solar cells.

  9. Selection of Unit Parameters and Auxiliary Equipments of Lunzua Hydropower Station in Zambia%赞比亚LUNZUA水电站机组参数及附属设备选择

    Institute of Scientific and Technical Information of China (English)

    熊晓明; 逯鹏

    2013-01-01

    ∶为了合理选择赞比亚LUNZUA水电站的机组参数及其附属设备,在电站的基本参数的基础上做了一系列的比较和论证。通过详细的分析选定该电站水轮发电机组的主要参数和附属设备,为下一阶段的工作提供了依据。%The basic parameters of Lunzua hydropower station in Zambia are compared and demonstrated so as to reasonably select the unit parameters and the auxiliary equipments,which provides a reference for the next-stage work.

  10. Phosphatidylserine exposure on stored red blood cells as a parameter for donor-dependent variation in product quality

    NARCIS (Netherlands)

    Dinkla, S.; Peppelman, M.; Raadt, J. van der; Atsma, F.; Novotny, V.M.J.; Kraaij, M.G.J. van; Joosten, I.; Bosman, G.J.C.G.M.

    2014-01-01

    BACKGROUND: Exposure of phosphatidylserine on the outside of red blood cells contributes to recognition and removal of old and damaged cells. The fraction of phosphatidylserine-exposing red blood cells varies between donors, and increases in red blood cell concentrates during storage. The susceptibi

  11. Compressor-expander units for mobile fuel cell systems; Verdichter und Expander fuer mobile Brennstoffzellensysteme

    Energy Technology Data Exchange (ETDEWEB)

    Lang, O. [FEV Motorentechnik GmbH, Aachen (Germany).; Pischinger, S.; Schoenfelder, C.; Steidten, T. [RWTH Aachen (DE). Lehrstuhl fuer Verbrennungskraftmaschinen (VKA)

    2004-08-01

    The air supply of hydrogen-powered fuel cell systems containing PEM fuel cells has a significant impact on their efficiency and mode of operation. Therefore, several mechanical compressors and expanders were examined at the RWTH Aachen. Simulations were then performed to determine the behaviour of the fuel cell system. This article discusses the findings of a project commissioned by the Forschungsvereinigung Verbrennungskraftmaschinen e.V. (FVV). (orig.)

  12. Exploring the linkage between cell culture process parameters and downstream processing utilizing a plackett-burman design for a model monoclonal antibody.

    Science.gov (United States)

    Agarabi, Cyrus D; Chavez, Brittany K; Lute, Scott C; Read, Erik K; Rogstad, Sarah; Awotwe-Otoo, David; Brown, Matthew R; Boyne, Michael T; Brorson, Kurt A

    2017-01-01

    Linkage of upstream cell culture with downstream processing and purification is an aspect of Quality by Design crucial for efficient and consistent production of high quality biopharmaceutical proteins. In a previous Plackett-Burman screening study of parallel bioreactor cultures we evaluated main effects of 11 process variables, such as agitation, sparge rate, feeding regimens, dissolved oxygen set point, inoculation density, supplement addition, temperature, and pH shifts. In this follow-up study, we observed linkages between cell culture process parameters and downstream capture chromatography performance and subsequent antibody attributes. In depth analysis of the capture chromatography purification of harvested cell culture fluid yielded significant effects of upstream process parameters on host cell protein abundance and behavior. A variety of methods were used to characterize the antibody both after purification and buffer formulation. This analysis provided insight in to the significant impacts of upstream process parameters on aggregate formation, impurities, and protein structure. This report highlights the utility of linkage studies in identifying how changes in upstream parameters can impact downstream critical quality attributes. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:163-170, 2017.

  13. Q Fever Outbreak Among Travelers to Germany Who Received Live Cell Therapy--United States and Canada, 2014.

    Science.gov (United States)

    Robyn, Misha P; Newman, Alexandra P; Amato, Michael; Walawander, Mary; Kothe, Cynthia; Nerone, James D; Pomerantz, Cynthia; Behravesh, Casey Barton; Biggs, Holly M; Dahlgren, F Scott; Pieracci, Emily G; Whitfield, Yvonne; Sider, Doug; Ozaldin, Omar; Berger, Lisa; Buck, Peter A; Downing, Mark; Blog, Debra

    2015-10-02

    During September–November 2014, the New York State Department of Health (NYSDOH) was notified of five New York state residents who had tested seropositive for Coxiella burnetii, the causative agent of Q fever. All five patients had symptoms compatible with Q fever (e.g., fever, fatigue, chills, and headache) and a history of travel to Germany to receive a medical treatment called "live cell therapy" (sometimes called "fresh cell therapy") in May 2014. Live cell therapy is the practice of injecting processed cells from organs or fetuses of nonhuman animals (e.g., sheep) into human recipients. It is advertised to treat a variety of health conditions. This practice is unavailable in the United States; however, persons can travel to foreign locations to receive injections. Local health departments interviewed the patients, and NYSDOH notified CDC and posted a report on CDC’s Epidemic Information Exchange to solicit additional cases. Clinical and exposure information for each patient was reported to the Robert Koch Institute in Germany, which forwarded the information to local health authorities. A Canada resident who also received live cell therapy in May 2014 was diagnosed with Q fever in July 2014. Clinicians should be aware of health risks, such as Q fever and other zoonotic diseases, among patients with a history of receiving treatment with live cell therapy products.

  14. Quasi bound states in the continuum with few unit cells of photonic crystal slab

    DEFF Research Database (Denmark)

    Taghizadeh, Alireza; Chung, Il-Sug

    2017-01-01

    Bound states in the continuum (BICs) in photonic crystal slabs represent the resonances with an infinite quality (Q)-factor, occurring above the light line for an infinitely periodic structure. We show that a set of BICs can turn into quasi-BICs with a very high Q-factor even for two or three unit...

  15. Parameter Discrimination of a Combined Cycle Unit Based on the Genetic Algorithm%基于遗传算法的联合循环机组模型参数辨识

    Institute of Scientific and Technical Information of China (English)

    仇晓智; 王卫; 司派友; 黄葆华

    2012-01-01

    针对将联合循环机组模型引入电力系统稳定性分析程序的实际需求,在对常规联合循环机组数学模型分析的基础上,提出了适用于电力系统稳定性分析的联合循环机组模型.将遗传算法应用于模型参数辨识过程中,开发了基于Delphi平台的联合循环机组模型辨识软件.应用实例表明:模型的仿真结果与实测信号相一致,证明了所提模型和辨识算法的有效性,为后续联合循环机组的一次调频和动态特性分析奠定了基础.%In the light of the actual demand of introducing a model for combined cycle units into an electric power system stability analytic programme, presented was a combined cycle unit model applicable for the stability analysis of an electric power system on the basis of an analysis of the mathematical model for conventional combined cycle units. The authors have applied the genetic algorithm in the model parameter discrimination process and developed a software for discriminating a model for combined cycle units based on Delphi platform. The application cases show that the simulation results by using the model are in agreement with the actually measured signals, proving that the model under discussion and the discrimination algorithm are effective, thus laying a foundation for subsequent primary frequency modulation and dynamic characteristics analysis of a combined cycle unit.

  16. Factorial experimental design for the culture of human embryonic stem cells as aggregates in stirred suspension bioreactors reveals the potential for interaction effects between bioprocess parameters.

    Science.gov (United States)

    Hunt, Megan M; Meng, Guoliang; Rancourt, Derrick E; Gates, Ian D; Kallos, Michael S

    2014-01-01

    Traditional optimization of culture parameters for the large-scale culture of human embryonic stem cells (ESCs) as aggregates is carried out in a stepwise manner whereby the effect of varying each culture parameter is investigated individually. However, as evidenced by the wide range of published protocols and culture performance indicators (growth rates, pluripotency marker expression, etc.), there is a lack of systematic investigation into the true effect of varying culture parameters especially with respect to potential interactions between culture variables. Here we describe the design and execution of a two-parameter, three-level (3(2)) factorial experiment resulting in nine conditions that were run in duplicate 125-mL stirred suspension bioreactors. The two parameters investigated here were inoculation density and agitation rate, which are easily controlled, but currently, poorly characterized. Cell readouts analyzed included fold expansion, maximum density, and exponential growth rate. Our results reveal that the choice of best case culture parameters was dependent on which cell property was chosen as the primary output variable. Subsequent statistical analyses via two-way analysis of variance indicated significant interaction effects between inoculation density and agitation rate specifically in the case of exponential growth rates. Results indicate that stepwise optimization has the potential to miss out on the true optimal case. In addition, choosing an optimum condition for a culture output of interest from the factorial design yielded similar results when repeated with the same cell line indicating reproducibility. We finally validated that human ESCs remain pluripotent in suspension culture as aggregates under our optimal conditions and maintain their differentiation capabilities as well as a stable karyotype and strong expression levels of specific human ESC markers over several passages in suspension bioreactors.

  17. Development of a unit suitable for corrosion monitoring in district heating systems. Experiences with the LOCOR-cell test method

    DEFF Research Database (Denmark)

    Andersen, Asbjørn; Hilbert, Lisbeth Rischel

    2004-01-01

    the purpose, background and gained results of one of the used monitoring techniques, the crevice corrosion measurements obtained by the LOCOR-Cell„§. The crevice corrosion cell was developed by FORCE Technology in a previous district heating project financed by Nordic Industrial Fund (1)(2). Results from...... in 6 pressurised circulating heating systems and in one cooling system. 7 different corrosion monitoring methods have been used to study corrosion rates and types in dependency of water chemistry. This paper describes the design of the by-pass unit including water analysis methods. It also describes...... other used corrosion monitoring methods in the project are described elsewhere (3) and (4). For future district heating corrosion monitoring the by-pass unit can be recommended for permanent installation and the two methods high sensitive ER-technique (Metricorr) and the LOCOR-Cell„§ (FORCE Technology...

  18. Development of a unit suitable for corrosion monitoring in district heating systems. Experiences with the LOCOR-cell test method

    DEFF Research Database (Denmark)

    Andersen, Asbjørn; Hilbert, Lisbeth Rischel

    2004-01-01

    the purpose, background and gained results of one of the used monitoring techniques, the crevice corrosion measurements obtained by the LOCOR-Cell„§. The crevice corrosion cell was developed by FORCE Technology in a previous district heating project financed by Nordic Industrial Fund (1)(2). Results from...... in 6 pressurised circulating heating systems and in one cooling system. 7 different corrosion monitoring methods have been used to study corrosion rates and types in dependency of water chemistry. This paper describes the design of the by-pass unit including water analysis methods. It also describes...... other used corrosion monitoring methods in the project are described elsewhere (3) and (4). For future district heating corrosion monitoring the by-pass unit can be recommended for permanent installation and the two methods high sensitive ER-technique (Metricorr) and the LOCOR-Cell„§ (FORCE Technology...

  19. Heterodimeric barnase-barstar vaccine molecules: influence of one versus two targeting units specific for antigen presenting cells.

    Directory of Open Access Journals (Sweden)

    Heidi Cecilie Larsen Spång

    Full Text Available It is known that targeting of antigen to antigen presenting cells (APC increases immune responses. However, it is unclear if more than one APC-specific targeting unit in the antigenic molecule will increase responses. To address this issue, we have here made heterodimeric vaccine molecules that each express four different fusion subunits. The bacterial ribonuclease barnase and its inhibitor barstar interact with high affinity, and the barnase-barstar complex was therefore used as a dimerization unit. Barnase and barstar were fused N-terminally with single chain fragment variable (scFvs targeting units specific for either MHC class II molecules on APC or the hapten 5-iodo-4-hydroxy-3-nitrophenylacetyl (NIP. C-terminal antigenic fusions were either the fluorescent protein mCherry or scFv(315 derived from myeloma protein M315. The heterodimeric vaccine molecules were formed both in vitro and in vivo. Moreover, the four different fused moieties appeared to fold correctly since they retained their specificity and function. DNA vaccination with MHC class II-targeted vaccine induced higher mCherry-specific IgG1 responses compared to non-targeted control. Since mCherry and MHC class II are in trans in this heterodimer, this suggests that heterodimeric proteins are formed in vivo without prior protein purification. Surprisingly, one targeting moiety was sufficient for the increased IgG1 response, and addition of a second targeting moiety did not increase responses. Similar results were found in in vitro T cell assays; vaccine molecules with one targeting unit were as potent as those with two. In combination with the easy cloning strategy, the heterodimeric barnase-barstar vaccine molecule could provide a flexible platform for development of novel DNA vaccines with increased potency.

  20. Energy gradients with respect to atomic positions and cell parameters for the Kohn-Sham density-functional theory at the Gamma point.

    Science.gov (United States)

    Weber, Valéry; Tymczak, Christopher J; Challacombe, Matt

    2006-06-14

    The application of theoretical methods based on density-functional theory is known to provide atomic and cell parameters in very good agreement with experimental values. Recently, construction of the exact Hartree-Fock exchange gradients with respect to atomic positions and cell parameters within the Gamma-point approximation has been introduced. In this article, the formalism is extended to the evaluation of analytical Gamma-point density-functional atomic and cell gradients. The infinite Coulomb summation is solved with an effective periodic summation of multipole tensors. While the evaluation of Coulomb and exchange-correlation gradients with respect to atomic positions are similar to those in the gas phase limit, the gradients with respect to cell parameters needs to be treated with some care. The derivative of the periodic multipole interaction tensor needs to be carefully handled in both direct and reciprocal space and the exchange-correlation energy derivative leads to a surface term that has its origin in derivatives of the integration limits that depend on the cell. As an illustration, the analytical gradients have been used in conjunction with the QUICCA algorithm to optimize one-dimensional and three-dimensional periodic systems at the density-functional theory and hybrid Hartree-Fock/density-functional theory levels. We also report the full relaxation of forsterite supercells at the B3LYP level of theory.

  1. Hypoxic culture conditions for Mesenchymal Stromal/Stem Cells from Wharton's jelly: a critical parameter to consider in a therapeutic context.

    Science.gov (United States)

    Reppel, Loic; Margossian, Talar; Yaghi, Layale; Moreau, Philippe; Mercier, Nathalie; Leger, Leonore; Hupont, Sebastien; Stoltz, Jean-Francois; Bensoussan, Daniele; Huselstein, Celine

    2014-01-01

    Mesenchymal Stromal/Stem Cells from human Wharton's jelly (WJ-MSC) are an abundant and interesting source of stem cells for applications in cell and tissue engineering. Their fetal origin confers specific characteristics compared to Mesenchymal Stromal/Stem Cells isolated from human bone marrow (BM-MSC). The aim of this work was to optimize WJ-MSC culture conditions for their subsequent clinical use. We focused on the influence of oxygen concentration during monolayer expansion on several parameters to characterize MSC. Our work distinguished WJ-MSC from BM-MSC in terms of proliferation, telomerase activity and adipogenic differentiation. We also showed that hypoxia had a beneficial effect on proliferation potential, clonogenic capacity and to a lesser extent, on HLA-G expression of WJ-MSC during their expansion. Moreover, we reported for the first time an increase in chondrogenic differentiation when WJ-MSC were expanded under hypoxia. In an allogeneic therapeutic context, production of clinical batches requires generating high numbers of MSC whilst maintaining the cells' properties. Considering our results, hypoxia will be an important parameter to take into account. In addition, the clinical use of WJ-MSC would provide significant numbers of cells with maintenance of their proliferation and differentiation potential, particularly their chondrogenic potential. Due to their chondrogenic differentiation potential, WJ-MSC promise to be an interesting source of MSC for cell therapy or tissue engineering for cartilage repair and/or regeneration.

  2. [Cytogenetic and other cariological parameters of exfoliative buccal cells in Vietnamese children from areas where dioxin-containing herbicides were applied].

    Science.gov (United States)

    Sycheva, L P; Mozhaeva, T E; Umnova, N V; Zhuchenko, N A; Diep, Vu Hong; Tuyet, Hoang Anh

    2008-01-01

    In a cohort of 69 South Vietnam children, full cariological analysis of buccal epithelial cells was performed. In order to evaluate the significance of cariological changes, all the parameters under study were divided into three groups: cytogenetic indices, apoptotic indices, and indirect indices of proliferation; integral indexes in each group were determined and the relations between them were found while assessing the effects of environment pollution on public health. The number of cells with cytogenetic alterations (micronuclei and protrusions) was increased, the process of tissue proliferation was intensified, and the apoptotic process was decelerated in children li-ing in areas polluted with Agent Orange/dioxins, which evidenced that the complex of environmental factors these superecotoxicants were part of had a harmful effect on the population. The parameters studied did not depend on age and sex of the children; the number of congenital morphogenetic variants per one child significantly correlated with the sum of cells with cytogenetic alterations.

  3. Maximizing power generation from dark fermentation effluents in microbial fuel cell by selective enrichment of exoelectrogens and optimization of anodic operational parameters.

    Science.gov (United States)

    Varanasi, Jhansi L; Sinha, Pallavi; Das, Debabrata

    2017-05-01

    To selectively enrich an electrogenic mixed consortium capable of utilizing dark fermentative effluents as substrates in microbial fuel cells and to further enhance the power outputs by optimization of influential anodic operational parameters. A maximum power density of 1.4 W/m(3) was obtained by an enriched mixed electrogenic consortium in microbial fuel cells using acetate as substrate. This was further increased to 5.43 W/m(3) by optimization of influential anodic parameters. By utilizing dark fermentative effluents as substrates, the maximum power densities ranged from 5.2 to 6.2 W/m(3) with an average COD removal efficiency of 75% and a columbic efficiency of 10.6%. A simple strategy is provided for selective enrichment of electrogenic bacteria that can be used in microbial fuel cells for generating power from various dark fermentative effluents.

  4. Risk and outcome analysis of 1832 consecutively excised basal cell carcinomas in a tertiary referral plastic surgery unit.

    LENUS (Irish Health Repository)

    Malik, Vinod

    2012-02-01

    BACKGROUND: Basal cell carcinomas are the most prevalent of all skin cancers worldwide and form the majority of the surgical workload for most modern cutaneous malignancy centres. Primary surgical removal of basal cell carcinomas remains the gold standard of treatment but, despite almost two centuries of surgical experience, rates of incomplete surgical excision of up to 50% are still reported. The aim of this study was to assess, quantify and perform comparative analysis of the outcomes and predictive factors of consecutive primarily-excised basal cell carcinomas in a tertiary centre over a six-year period. METHODS: Retrospective audit was conducted on all patients who underwent surgical excision of basal cell carcinomas from January 2000 to December 2005. Assessment parameters included patient biographics, tumour management differences and detailed histopathological analysis of tumour margins and subtypes. RESULTS: One thousand eight hundred and thirty two basal cell carcinomas were excised from 1329 patients over the designated time period. Two hundred and fifty one (14%) lesions were incompletely excised with 135 (7.4%) involving the peripheral margin only, 48 (2.6%) the deep margin only and 41 (2.2%) involving both. Nasal location was the most common predictor of incomplete excision. CONCLUSIONS: Overall basal cell carcinomas excision rates compared favourably with international reported standards but attention to a variety of surgical and histological risk factors may improve this further.

  5. Inter-relationships between single carbon units' metabolism and resting energy expenditure in weight-losing patients with small cell lung cancer. Effects of methionine supply and chemotherapy

    DEFF Research Database (Denmark)

    Sengeløv, H; Hansen, O P; Simonsen, L;

    1994-01-01

    The one-carbon unit metabolism was investigated in 8 weight-losing patients with small cell carcinoma of the lung (SCLC). At diagnosis, 6 of the 8 patients had elevated formiminoglutamic acid (FIGLU) excretion after a histidine load, suggesting a lack of one-carbon units. In accordance, a signifi...

  6. Logistics and Capability Implications of a Bradley Fighting Vehicle with a Fuel Cell Auxiliary Power Unit

    Science.gov (United States)

    2003-10-13

    Husted, John MacBain Delphi Corporation Heather McKee US Army TACOM Copyright © 2003 SAE International ABSTRACT Modern military ground vehicles are...WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Delphi Corporation,5725 Delphi Drive,Troy,Mi,48098 8. PERFORMING ORGANIZATION... injector hardware change. A single, 28V, 400A permanent-magnet direct current (DC) generator is driven by a power take off (PTO) directly connected to

  7. Evaluation of eicosanoid concentrations in stored units of canine packed red blood cells.

    Science.gov (United States)

    Blake, Rachel R; Lee, Jung Hwa; Ross, Matt K; Archer, Todd M; Wills, Robert W; Mackin, Andrew J; Thomason, John M

    2017-01-15

    OBJECTIVE To evaluate eicosanoid concentrations in freshly prepared canine packed RBCs (PRBCs) and to assess changes in eicosanoid concentrations in PRBC units over time during storage and under transfusion conditions. DESIGN Prospective study. SAMPLE 25 plasma samples from 14 healthy Greyhounds. PROCEDURES Plasma samples were obtained during PRBC preparation (donation samples), and the PRBC units were then stored at 4°C until used for transfusion (≤ 21 days later; n = 17) or mock transfusion if expired (22 to 24 days later; 8). Immediately prior to use, 100 mL of saline (0.9% NaCl) solution was added to each unit and a pretransfusion sample was collected. A posttransfusion sample was collected after transfusion or mock transfusion. Concentrations of arachidonic acid, prostaglandin (PG) F2α, PGE2, PGD2, thromboxane B2, 6-keto-PGF1α, and leukotriene B4 were measured by liquid chromatography-mass spectrometry and analyzed statistically. RESULTS Median arachidonic acid concentration was significantly decreased in posttransfusion samples, compared with the concentration in donation samples. Median PGF2α, 6-keto-PGF1α, and leukotriene B4 concentrations were significantly increased in pretransfusion samples, compared with those in donation samples. Median PGF2α, thromboxane B2, and 6-keto-PGF1α concentrations were significantly increased in posttransfusion samples, compared with those in pretransfusion samples. Duration of PRBC storage had significant associations with pretransfusion and posttransfusion arachidonic acid and thromboxane B2 concentrations. CONCLUSIONS AND CLINICAL RELEVANCE Concentrations of several proinflammatory eicosanoids increased in PRBC units during storage, transfusion, or both. Accumulation of these products could potentially contribute to adverse transfusion reactions, and investigation of the potential association between eicosanoid concentrations in PRBCs and the incidence of transfusion reactions in dogs is warranted.

  8. Trapped-Mode Resonance Regime of Thin Microwave Electromagnetic Arrays with Two Concentric Rings in Unit Cell

    Directory of Open Access Journals (Sweden)

    M. N. Kawakatsu

    2011-01-01

    Full Text Available We present a theoretical study of reflection and transmission characteristics of a microwave planar array on a thin dielectric substrate with unit cell made of two concentric rings. This array possesses high quality factor transmission resonance with polarization insensitivity for normally incident plane wave. This resonance is defined by the trapped-mode regime. We show that for oblique incidence, there are some differences in characteristics of the array and a small change in quality factor of the trapped-mode resonance.

  9. Comparison of fuel-cell and diesel integrated energy systems and a conventional system for a 500-unit apartment

    Science.gov (United States)

    Simons, S. N.; Maag, W. L.

    1978-01-01

    The electrical and thermal energy utilization efficiencies of a 500 unit apartment complex are analyzed and compared for each of three energy supply systems. Two on-site integrated energy systems, one powered by diesel engines and the other by phosphoric-acid fuel cells were compared with a conventional system which uses purchased electricity and on-site boilers for heating. All fuels consumed on-site are clean, synthetic fuels (distillate fuel oil or pipeline quality gas) derived from coal. Purchased electricity was generated from coal at a central station utility. The relative energy consumption and economics of the three systems are analyzed and compared.

  10. Numerical evaluation of micro-structural parameters of porous supports in metal-supported solid oxide fuel cells

    DEFF Research Database (Denmark)

    Reiss, Georg; Frandsen, Henrik Lund; Brandstätter, Wilhelm

    2014-01-01

    Metallic supported Solid Oxide Fuel Cells (SOFCs) are considered as a durable and cost effective alternative to the state-of-the-art ceramic supported cell designs. In order to understand the mass and charge transport in the metal-support of this new type of cell a novel technique involving X-ray...

  11. Oil and Gas Exploration and Production in the United States Shown as Quarter-Mile Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A cells polygon feature class was created by the U.S. Geological Survey (USGS) to illustrate the degree of exploration, type of production, and distribution of...

  12. Optimization of operating parameters to maximize the current density without flooding at the cathode membrane interface of a PEM fuel cell using Taguchi method and genetic algorithm

    Directory of Open Access Journals (Sweden)

    S.S.L. Rao, A. Shaija, S. Jayaraj

    2014-01-01

    Full Text Available A mathematical model was developed to investigate water accumulation at the cathode membrane interface by varying different operating parameters like fuel cell operating temperature and pressure, cathode and anode humidification temperatures and cathode stoichiometry. Taguchi optimization methodology is then combined with this model to determine the optimal combination of the operating parameters to maximize current density without flooding. Results of analysis of variance (ANOVA show that fuel cell operating temperature and cathode humidification temperature are the two most significant parameters in the ratio of 56.07% and 27.89% respectively and also that higher fuel cell temperature and lower cathode humidification temperature are favourable to get the maximum current draw without flooding at the cathode membrane interface. The global optimum value of the operating parameters to maximize the current density without flooding was obtained by formulating as an optimization problem using genetic algorithm (GA. These results were compared with the results obtained using Taguchi method and it was found to be similar and slightly better.

  13. Fuel cell programs in the United States for stationary power applications

    Energy Technology Data Exchange (ETDEWEB)

    Singer, M.

    1996-04-01

    The Department of Energy (DOE), Office of Fossil Energy, is participating with the private sector in sponsoring the development of molten carbonate fuel cell (MCFC) and solid oxide fuel cell (SOFC) technologies for application in the utility, commercial and industrial sectors. Phosphoric acid fuel cell (PAFC) development was sponsored by the Office of Fossil Energy in previous years and is now being commercialized by the private sector. Private sector participants with the Department of Energy include the Electric Power Research Institute (EPRI), the Gas Research institute (GRI), electric and gas utilities, universities, manufacturing companies and their suppliers. through continued government and private sector support, fuel cell systems are emerging power generation technologies which are expected to have significant worldwide impacts. An industry with annual sales of over a billion dollars is envisioned early in the 21st century. PAFC power plants have begun to enter the marketplace and MCFC and SOFC power plants are expected to be ready to enter the marketplace in the late 1990s. In support of the efficient and effective use of our natural resources, the fuel cell program seeks to increase energy efficiency and economic effectiveness of power generation. This is to be accomplished through effectiveness of power generation. This is accomplished through the development and commercialization of cost-effective, efficient and environmentally desirable fuel cell systems which will operate on fossil fuels in multiple and end use sectors.

  14. Temperature-dependent haemolytic propensity of CPDA-1 stored red blood cells vs whole blood - Red cell fragility as donor signature on blood units.

    Science.gov (United States)

    Tzounakas, Vassilis L; Anastasiadi, Alkmini T; Karadimas, Dimitrios G; Zeqo, Redisa A; Georgatzakou, Hara T; Pappa, Olga D; Papatzitze, Olga A; Stamoulis, Konstantinos E; Papassideri, Issidora S; Antonelou, Marianna H; Kriebardis, Anastasios G

    2017-09-01

    To preserve cellular integrity and avoid bacterial growth, storage and transfer of blood and blood products follow strict guidelines in terms of temperature control. We evaluated the impact of ineligible warming of whole blood donations on the quality of blood components. One-hundred and twenty units of whole blood (WB) from eligible blood donors were collected in CPDA-1 and stored at 4±2 °C. During shipment to the blood processing centre, a gradual warming up to 17 °C was recorded within a period of less than eight hours. The warmed units were processed to packed red blood cells (PRBCs) or stored as WB units at 4±2 °C. In-bag haemolysis, osmotic fragility (mean corpuscular fragility, MCF) and bacterial growth were assessed in blood and blood components throughout the storage period. Normal basal and early storage levels of haemolysis were recorded in both PRBC and WB units. Thereafter, PRBCs exhibited higher average in-bag haemolysis and MCF index compared to the WB units throughout the storage. Moreover, 14.3 and 52.4% of the PRBC units exceeded the upper permissible limit of 0.8% haemolysis at the middle (1.220±0.269%) or late (1.754±0.866%) storage period, respectively. MCF index was similar in all PRBCs at the middle of storage but significantly lower in the non-haemolysed compared to the haemolysed units of PRBCs on the last days. The fragility of stored RBCs was proportional to the donor-related values of day 2 samples (r=0.861, punits of PRBCs. Transient, gradient warming of whole blood from 4 to 17 °C led to increased incidence of in-bag haemolysis in PRBC but not in WB units. Haemolysis is a multi-parametric phenotype of stored blood, and MCF is a donor-related and highly dynamic measure that can, in part, predict the storage lesion.

  15. Engineering aspects and hardware verification of a volume producable solid oxide fuel cell stack design for diesel auxiliary power units

    Science.gov (United States)

    Stelter, Michael; Reinert, Andreas; Mai, Björn Erik; Kuznecov, Mihail

    A solid oxide fuel cell (SOFC) stack module is presented that is designed for operation on diesel reformate in an auxiliary power unit (APU). The stack was designed using a top-down approach, based on a specification of an APU system that is installed on board of vehicles. The stack design is planar, modular and scalable with stamped sheet metal interconnectors. It features thin membrane electrode assemblies (MEAs), such as electrolyte supported cells (ESC) and operates at elevated temperatures around 800 °C. The stack has a low pressure drop in both the anode and the cathode to facilitate a simple system layout. An overview of the technical targets met so far is given. A stack power density of 0.2 kW l -1 has been demonstrated in a fully integrated, thermally self-sustaining APU prototype running with diesel and without an external water supply.

  16. Relationships between human vitality and mitochondrial respiratory parameters, reactive oxygen species production and dNTP levels in peripheral blood mononuclear cells

    DEFF Research Database (Denmark)

    Maynard, Scott; Keijzers, Guido; Gram, Martin;

    2013-01-01

    Low vitality (a component of fatigue) in middle-aged and older adults is an important complaint often identified as a symptom of a disease state or side effect of a treatment. No studies to date have investigated the potential link between dysfunctional mitochondrial ATP production and low vitality....... Therefore, we measured a number of cellular parameters related to mitochondrial activity in peripheral blood mononuclear cells (PBMCs) isolated from middle-aged men, and tested for association with vitality. These parameters estimate mitochondrial respiration, reactive oxygen species (ROS) production...

  17. Reaching the limits of prognostication in non-small cell lung cancer: an optimized biomarker panel fails to outperform clinical parameters.

    Science.gov (United States)

    Grinberg, Marianna; Djureinovic, Dijana; Brunnström, Hans Rr; Mattsson, Johanna Sm; Edlund, Karolina; Hengstler, Jan G; La Fleur, Linnea; Ekman, Simon; Koyi, Hirsh; Branden, Eva; Ståhle, Elisabeth; Jirström, Karin; Tracy, Derek K; Pontén, Fredrik; Botling, Johan; Rahnenführer, Jörg; Micke, Patrick

    2017-07-01

    Numerous protein biomarkers have been analyzed to improve prognostication in non-small cell lung cancer, but have not yet demonstrated sufficient value to be introduced into clinical practice. Here, we aimed to develop and validate a prognostic model for surgically resected non-small cell lung cancer. A biomarker panel was selected based on (1) prognostic association in published literature, (2) prognostic association in gene expression data sets, (3) availability of reliable antibodies, and (4) representation of diverse biological processes. The five selected proteins (MKI67, EZH2, SLC2A1, CADM1, and NKX2-1 alias TTF1) were analyzed by immunohistochemistry on tissue microarrays including tissue from 326 non-small cell lung cancer patients. One score was obtained for each tumor and each protein. The scores were combined, with or without the inclusion of clinical parameters, and the best prognostic model was defined according to the corresponding concordance index (C-index). The best-performing model was subsequently validated in an independent cohort consisting of tissue from 345 non-small cell lung cancer patients. The model based only on protein expression did not perform better compared to clinicopathological parameters, whereas combining protein expression with clinicopathological data resulted in a slightly better prognostic performance (C-index: all non-small cell lung cancer 0.63 vs 0.64; adenocarcinoma: 0.66 vs 0.70, squamous cell carcinoma: 0.57 vs 0.56). However, this modest effect did not translate into a significantly improved accuracy of survival prediction. The combination of a prognostic biomarker panel with clinicopathological parameters did not improve survival prediction in non-small cell lung cancer, questioning the potential of immunohistochemistry-based assessment of protein biomarkers for prognostication in clinical practice.

  18. Characterization of immune cells and cytokine localization in the rat utero-placental unit mid- to late gestation.

    Science.gov (United States)

    Tessier, Daniel R; Raha, Sandeep; Holloway, Alison C; Yockell-Lelièvre, Julien; Tayade, Chandrakant; Gruslin, Andrée

    2015-08-01

    The success of pregnancy is dependent on the precise regulation of the immune response within the utero-placental environment. Rats are beginning to be widely used as a model for human immune-related pregnancy complications. However, our knowledge of immune cells and cytokine localization in the rat utero-placental tissue is limited. The current study aimed to localize the immune cell populations, including uterine natural killer (uNK) cells, neutrophils, and macrophages within the rat utero-placental unit at two crucial gestational ages, gestational days 15.5 and 18.5. In addition, we characterized the distribution of the cytokines TNFα, IFNγ, and IL-10 in the utero-placental regions at both the above-mentioned gestational ages. Our study has demonstrated co-localization TNFα and IFNγ with uNK cells in perivascular regions of the rat mesometrial triangle at both gestational ages. Neutrophils and IL-10-positive cells were localized at the maternal-fetal interface and in the spiral artery lumen of the rat mesometrial triangle at both gestational ages. TNFα and IL-10 demonstrated a temporal change in the localization from GD15.5 to GD18.5, which coincides with the leading edge of trophoblast invasion into the mesometrial triangle. The current study furthers our knowledge of the localization of uterine immune cells and relevant cytokines, and provides a base from which to research the function of these immune cells and cytokines during rat pregnancy as a model to study human immune-related pregnancy complications.

  19. 高可靠性标准单元库性能参数的设计研究%Design of Performance Parameter for the High Reliability Standard Cell Library

    Institute of Scientific and Technical Information of China (English)

    梁曼; 蒋见花

    2013-01-01

    In order to design the performance parameter of high reliability standard cell library ,it need to research the related performance parameter of inverter which is the basic unit in a standard cell library .Balancing delay characteristics ,noise margins and power consumption etc factors ,firstly decide the PMOS-to-NMOS ratio of the inverter ,then size the specific transistor .So a suit of scheme to size the minimum inverter is presented .Finally building a set of logic circuit according to logic effort , simulation results show that the inverter has the great advantage of performance and power consumption .All of these provide some reference for sizing the cells of the deep sub-micron and nanoscale standard cell library .%为了设计高可靠性标准单元库的性能参数,需要对其最基本的单元模块反相器的性能参数进行研究。平衡考虑延时特性、噪声容限和功耗等方面的因素,首先确定反相器晶体管PMOS和NMOS的宽度比,然后根据设计需要确定具体的晶体管尺寸,提出了一套完整的确定反相器最小尺寸的方案。最后搭建一组逻辑电路验证所设计的反相器在延时特性和功耗方面体现出的优势,为深亚微米和纳米级标准单元库参数设计提供一定的依据。

  20. Measurement of X-ray-induced DNA double-strand breaks at various stages of the cell cycle using the total fluorescence as a comet assay parameter

    Energy Technology Data Exchange (ETDEWEB)

    Attia, Atef M.M. [Department of Biochemistry, Biophysical laboratory, National Research Center, Dokki, Cairo (Egypt); Nabil, Ghada M., E-mail: gmnabilnooh@hotmail.com [Department of Biochemistry, Biophysical laboratory, National Research Center, Dokki, Cairo (Egypt); Frankenberg, Dieter; Frankenberg-Schwager, M. [Abteilung Klinische Strahlenbiologie und Klinische Strahlenphysik, Zentrum, Radiologie, Georg-August-Universitaet Goettingen, Von-Siebold-Str.3 (Germany)

    2011-11-15

    The aim of the study was to develop a protocol for both estimating cell cycle position and the level of ionizing radiation-induced DNA dsb using the neutral comet assay. Using DNA histograms, cell cycle positions were determined for human dermal fibroblasts. The tail intensity was used to estimate the level of DNA damage induced by X-rays, at different positions of the cell cycle. The results of tail intensity versus DNA content bivariate analysis of exponentially growing cells showed a remarkable decrease in tail intensity with transition of cells from G1 to S-phase and increases slightly with transition to G2/M phase. This effect is observed at all doses including unirradiated cells, indicating that the effect is not caused by X-rays and the comet assay based on the current tail parameters is not relevant to measure DNA damage at various stages of the cell cycle. The results of dose response curves showed a linear decrease in the comet fluorescence with the X-ray dose. This observation provides a basis for estimating the fraction of damaged DNA, based on the fluorescence decrement induced by ionizing radiation. The results of this new approach showed a linear increase in DNA damage with dose, at various stages of the cell cycle, with rates, which vary in the following order G0>G2/M>S/G1 cells. These results suggest that G0 and G2/M cells are the most sensitive to X-rays among all phases of the cell cycle and suggest synchronization of cells at these phases to increase the cellular radiosensitivity during radiotherapy. - Display Omitted Highlights: > Increase in DNA damage with dose. > Introduction of a new technique for measuring DNA damage using a new approach of the neutral comet assay. > Estimation of DNA damage in mammalian cells.

  1. The influences of the properties of impurities and defects on the dark I-V characteristic curve and output parameters of c-Si solar cells

    Science.gov (United States)

    Lu, Xiaodong; Song, Yang; Gao, Jie; Wang, Xinxin; Zhang, Yufeng

    2017-09-01

    The influences of the coating ratio of electrode, doping concentration of substrate and type of impurities and defects on the dark I-V characteristic curves and output parameters of c-Si solar cells are studied by finite difference method and the dark I-V characteristic curves under different conditions are analyzed by their ideal factors, the results show that: the dark current values under the same bias voltage will increase with the increasing of the coating ratio of electrode or doping concentration of substrate; the influences of donor-like, acceptor-like and recombination-center-like impurities and defects on the dark I-V characteristic curves have threshold effects; the parameters of the impurities and defects smaller than their corresponding threshold will have no obvious influences on dark I-V characteristic curves; the acceptor-like impurities and defects on the surface of c-Si solar cells have no influences on their dark I-V characteristic curve, but the donor-like and recombination-center-like impurities and defects have strong influences on their dark I-V characteristic curve; the variations of the output parameters of c-Si solar cells are analyzed in detail under the different properties of the impurities and defects inside and on the surfaces of c-Si solar cells.

  2. Incubator proof miniaturized Holomonitor to in situ monitor cancer cells exposed to green tea polyphenol and preosteoblast cells adhering on nanostructured titanate surfaces: validity of the measured parameters and their corrections.

    Science.gov (United States)

    Peter, Beatrix; Nador, Judit; Juhasz, Krisztina; Dobos, Agnes; Körösi, Laszlo; Székács, Inna; Patko, Daniel; Horvath, Robert

    2015-06-01

    The in situ observation of cell movements and morphological parameters over longer periods of time under physiological conditions is critical in basic cell research and biomedical applications. The quantitative phase-contrast microscope applied in this study has a remarkably small size, therefore it can be placed directly into a humidified incubator. Here, we report on the successful application of this M4 Holomonitor to observe cancer cell motility, motility speed, and migration in the presence of the green tea polyphenol, epigallocatechin gallate, as well as to monitor the adhesion of preosteoblast cells on nanostructured titanate coatings, relevant for biomedical applications. A special mechanical stage was developed to position the sample into that range of the optical arrangement where digital autofocusing works with high reproducibility and precision. By in-depth analyzing the obtained single cell morphological parameters, we show that the limited vertical resolution of the optical setup results in underestimated single cell contact area and volume and overestimated single cell averaged thickness. We propose a simple model to correct the recorded data to obtain more precise single cell parameters. We compare the results with the kinetic data recorded by a surface sensitive optical biosensor, optical waveguide lightmode spectroscopy.

  3. Incubator proof miniaturized Holomonitor to in situ monitor cancer cells exposed to green tea polyphenol and preosteoblast cells adhering on nanostructured titanate surfaces: validity of the measured parameters and their corrections

    Science.gov (United States)

    Peter, Beatrix; Nador, Judit; Juhasz, Krisztina; Dobos, Agnes; Körösi, Laszlo; Székács, Inna; Patko, Daniel; Horvath, Robert

    2015-06-01

    The in situ observation of cell movements and morphological parameters over longer periods of time under physiological conditions is critical in basic cell research and biomedical applications. The quantitative phase-contrast microscope applied in this study has a remarkably small size, therefore it can be placed directly into a humidified incubator. Here, we report on the successful application of this M4 Holomonitor to observe cancer cell motility, motility speed, and migration in the presence of the green tea polyphenol, epigallocatechin gallate, as well as to monitor the adhesion of preosteoblast cells on nanostructured titanate coatings, relevant for biomedical applications. A special mechanical stage was developed to position the sample into that range of the optical arrangement where digital autofocusing works with high reproducibility and precision. By in-depth analyzing the obtained single cell morphological parameters, we show that the limited vertical resolution of the optical setup results in underestimated single cell contact area and volume and overestimated single cell averaged thickness. We propose a simple model to correct the recorded data to obtain more precise single cell parameters. We compare the results with the kinetic data recorded by a surface sensitive optical biosensor, optical waveguide lightmode spectroscopy.

  4. Global reorganisation of cis-regulatory units upon lineage commitment of human embryonic stem cells.

    Science.gov (United States)

    Freire-Pritchett, Paula; Schoenfelder, Stefan; Várnai, Csilla; Wingett, Steven W; Cairns, Jonathan; Collier, Amanda J; García-Vílchez, Raquel; Furlan-Magaril, Mayra; Osborne, Cameron S; Fraser, Peter; Rugg-Gunn, Peter J; Spivakov, Mikhail

    2017-03-23

    Long-range cis-regulatory elements such as enhancers coordinate cell-specific transcriptional programmes by engaging in DNA looping interactions with target promoters. Deciphering the interplay between the promoter connectivity and activity of cis-regulatory elements during lineage commitment is crucial for understanding developmental transcriptional control. Here, we use Promoter Capture Hi-C to generate a high-resolution atlas of chromosomal interactions involving ~22,000 gene promoters in human pluripotent and lineage-committed cells, identifying putative target genes for known and predicted enhancer elements. We reveal extensive dynamics of cis-regulatory contacts upon lineage commitment, including the acquisition and loss of promoter interactions. This spatial rewiring occurs preferentially with predicted changes in the activity of cis-regulatory elements and is associated with changes in target gene expression. Our results provide a global and integrated view of promoter interactome dynamics during lineage commitment of human pluripotent cells.

  5. Parameter Estimation

    DEFF Research Database (Denmark)

    2011-01-01

    of optimisation techniques coupled with dynamic solution of the underlying model. Linear and nonlinear approaches to parameter estimation are investigated. There is also the application of maximum likelihood principles in the estimation of parameters, as well as the use of orthogonal collocation to generate a set......In this chapter the importance of parameter estimation in model development is illustrated through various applications related to reaction systems. In particular, rate constants in a reaction system are obtained through parameter estimation methods. These approaches often require the application...... of algebraic equations as the basis for parameter estimation.These approaches are illustrated using estimations of kinetic constants from reaction system models....

  6. A review of high-temperature polymer electrolyte membrane fuel-cell (HT-PEMFC)-based auxiliary power units for diesel-powered road vehicles

    Science.gov (United States)

    Liu, Yongfeng; Lehnert, Werner; Janßen, Holger; Samsun, Remzi Can; Stolten, Detlef

    2016-04-01

    This paper presents an extensive review of research on the development of auxiliary power units with enhanced reformate tolerance for high temperature polymer electrolyte membrane fuel cells (HT-PEMFCs). Developments in diesel reforming for fuel cells as auxiliary power units (APUs), single fuel cells and stacks and systems are outlined in detail and key findings are presented. Summaries of HT-PEMFC APU applications and start-up times for HT-PEMFC systems are then given. A summary of cooling HT-PEMFC stacks using a classic schematic diagram of a 24-cell HT-PEMFC stack, with a cooling plate for every third cell, is also presented as part of a stack analysis. Finally, a summary of CO tolerances for fuel cells is given, along with the effects of different CO volume fractions on polarization curves, the fraction of CO coverage, hydrogen coverage, anode overpotential and cell potential.

  7. 一种新的恒加试验下双参数指数型产品的可靠性分析%Reliability Analysis for Two-parameter Exponential Unit under Content-stress Accelerated Life Test

    Institute of Scientific and Technical Information of China (English)

    谭伟; 师义民; 孙玉东

    2012-01-01

    针对双参数指数型产品,在具有二项移走(即在每个观测时刻产品的移走数服从二项分布)的分组寿命试验下,研究了分组时刻的确定方法,推导出门限参数、寿命参数和移走概率的极大似然估计。进而,讨论了双参数指数型产品在具有二项移走的恒加寿命分组试验下的可靠性分析问题。利用加速寿命方程,给出了双参数指数型产品的可靠性估计。最后给出随机模拟例子验证了结论的正确性。%Based on two-parameter exponential grouped life test with binomial removals (The number of samples removed obey the binomial distribution at each observation time), the paper studied the method to determine the grouped time, derived out and removal probability. Then, under the situation the MLE of threshold parameter, lifetime parameter of constant-stress accelerated grouped life test with binomial removals, by the aid of the accelerated life equation, the paper gave out the reliability estimation of two-parameter exponential unit. Finally, simulation example is given to verify the correctness of the result.

  8. Influencing parameters of water and methanol transport in a big direct methanol fuel cell; Einflussgroessen auf den Wasser- und Methanoltransport einer groesseren Direkt-Methanol Brennstoffzelle

    Energy Technology Data Exchange (ETDEWEB)

    Schonert, Morten

    2008-07-01

    The author investigated the influencing parameters of water and methanol transport in a big direct methanol fuel cell (Pel > 1 kW) with the intention of making the direct methanol fuel cell system water-autonomous. As water is consumed during the electrochemical reaction on the anode while more water is produced on the cathode, the difference must be removed via the air. Any further water produced on the cathode must be condensed and recirculated to the anode. With increasing ambient temperature, the air volume flow must be reduced because otherwise more water would be removed than is acceptable. Low air volume flow on the cathode causes unstable cell voltage, which is also assumed to be caused by excess water production. For this reason, an attempt was made to prevent excess water production on the cathode by a system engineering approach. It was found that at the low air volume flow required for water autonomy, water permeation through the membrane-electrode aggregate (MEA) depends on the uptake capacity and on the time of residue of air over the cathode and less on the cathode material. Water permeation stops when the concentration gradient is balanced. Apart from the water permeation, there is also water transport through the Nafion {sup registered} membrane, i.e. so-called electroosmotic drag (ESD). This is an active transport mechanism that can also work against a concentration gradient. It could be shown that the EOD can be reduced by using water-impermeable materials for the gas diffusion layer on the anode. This will reduce the water volume that reaches the membrane, i.e. the water on the cathode. On the other hand, there was no measurable effect of the cathode design on water or methanol transport. The electrochemical performance of the membrane-electrode units under investigation was robust in case of many influencing parameters, e.g. dispersion, the conditions of MEA fabrication by hot pressing, themembrane thickness and the rate of methanol permeation

  9. Measurement of X-ray-induced DNA double-strand breaks at various stages of the cell cycle using the total fluorescence as a comet assay parameter

    Science.gov (United States)

    Attia, Atef M. M.; Nabil, Ghada M.; Frankenberg, Dieter; Frankenberg-Schwager, M.

    2011-11-01

    The aim of the study was to develop a protocol for both estimating cell cycle position and the level of ionizing radiation-induced DNA dsb using the neutral comet assay. Using DNA histograms, cell cycle positions were determined for human dermal fibroblasts. The tail intensity was used to estimate the level of DNA damage induced by X-rays, at different positions of the cell cycle. The results of tail intensity versus DNA content bivariate analysis of exponentially growing cells showed a remarkable decrease in tail intensity with transition of cells from G1 to S-phase and increases slightly with transition to G2/M phase. This effect is observed at all doses including unirradiated cells, indicating that the effect is not caused by X-rays and the comet assay based on the current tail parameters is not relevant to measure DNA damage at various stages of the cell cycle. The results of dose response curves showed a linear decrease in the comet fluorescence with the X-ray dose. This observation provides a basis for estimating the fraction of damaged DNA, based on the fluorescence decrement induced by ionizing radiation. The results of this new approach showed a linear increase in DNA damage with dose, at various stages of the cell cycle, with rates, which vary in the following order G0>G2/M>S/G1 cells.These results suggest that G0 and G2/M cells are the most sensitive to X-rays among all phases of the cell cycle and suggest synchronization of cells at these phases to increase the cellular radiosensitivity during radiotherapy.

  10. Analysis of operating parameters considering flow orientation for the performance of a proton exchange membrane fuel cell using the Taguchi method

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Horng-Wen; Gu, Hui-Wen [Department of System and Naval Mechatronic Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan 701 (China)

    2010-06-01

    This study has applied the L{sub 18} 2 x 3{sup 7} orthogonal array of the Taguchi method to determine the optimal combination of six primary operating parameters (flow orientation, temperature of fuel cell, anode and cathode humidification temperatures, anode, and cathode stoichiometric flow ratios) of a PEM fuel cell. The optimal combination factor is co-flow, a cell temperature of 333 K, an anode humidification temperature of 353 K, a cathode humidification temperature of 333 K, a stoichiometric flow ratio for hydrogen of 2, and a stoichiometric flow ratio for oxygen of 3; and the amount of maximum power is 17.61 W. The results for the experiment indicate that flow orientation, temperature of fuel cell, and anode and cathode humidification temperatures are significant factors for affecting the performance. Furthermore, this study simulates the transport phenomenon and electrochemical reactions using a finite-element method at the optimal combination factor from the experimental results of Taguchi method. (author)

  11. Parameters affecting the adhesion strength between a living cell and a colloid probe when measured by the atomic force microscope.

    Science.gov (United States)

    McNamee, Cathy E; Pyo, Nayoung; Tanaka, Saaya; Vakarelski, Ivan U; Kanda, Yoichi; Higashitani, Ko

    2006-03-15

    In this study, we used the colloid probe atomic force microscopy (AFM) technique to investigate the adhesion force between a living cell and a silica colloid particle in a Leibovitz's L-15 medium (L-15). The L-15 liquid maintained the pharmaceutical conditions necessary to keep the cells alive in the outside environment during the AFM experiment. The force curves in such a system showed a steric repulsion in the compression force curve, due to the compression of the cells by the colloid probe, and an adhesion force in the decompression force curve, due to binding events between the cell and the probe. We also investigated for the first time how the position on the cell surface, the strength of the pushing force, and the residence time of the probe at the cell surface individually affected the adhesion force between a living cell and a 6.84 microm diameter silica colloid particle in L-15. The position of measuring the force on the cell surface was seen not to affect the value of the maximum adhesion force. The loading force was also seen not to notably affect the value of the maximum adhesion force, if it was small enough not to pierce and damage the cell. The residence time of the probe at the cell surface, however, clearly affected the adhesion force, where a longer residence time gave a larger maximum force. From these results, we could conclude that the AFM force measurements should be made using a loading force small enough not to damage the cell and a fixed residence time, when comparing results of different systems.

  12. Relationships between human vitality and mitochondrial respiratory parameters, reactive oxygen species production and dNTP