WorldWideScience

Sample records for cells measuring devices

  1. Photovoltaic material and device measurements workshop: focus on polycrystalline thin film cells

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-01-01

    The general purpose of the workshop was to accelerate the development of thin film solar cells by improving the versatility and reliability of material and device measurement techniques. Papers were presented under the following sessions: structural/chemical session; optical/electro-optical session; charge transport session; and poster session. Each paper was processed for EDB.

  2. For whom the cells pull: Hydrogel and micropost devices for measuring traction forces.

    Science.gov (United States)

    Ribeiro, Alexandre J S; Denisin, Aleksandra K; Wilson, Robin E; Pruitt, Beth L

    2016-02-01

    While performing several functions, adherent cells deform their surrounding substrate via stable adhesions that connect the intracellular cytoskeleton to the extracellular matrix. The traction forces that deform the substrate are studied in mechanotrasduction because they are affected by the mechanics of the extracellular milieu. We review the development and application of two methods widely used to measure traction forces generated by cells on 2D substrates: (i) traction force microscopy with polyacrylamide hydrogels and (ii) calculation of traction forces with arrays of deformable microposts. Measuring forces with these methods relies on measuring substrate displacements and converting them into forces. We describe approaches to determine force from displacements and elaborate on the necessary experimental conditions for this type of analysis. We emphasize device fabrication, mechanical calibration of substrates and covalent attachment of extracellular matrix proteins to substrates as key features in the design of experiments to measure cell traction forces with polyacrylamide hydrogels or microposts. We also report the challenges and achievements in integrating these methods with platforms for the mechanical stimulation of adherent cells. The approaches described here will enable new studies to understand cell mechanical outputs as a function of mechanical inputs and advance the understanding of mechanotransduction mechanisms.

  3. Emission rate measuring device

    Science.gov (United States)

    Luckat, S.

    1980-09-01

    The development and application of an emission rate measuring device for gaseous components is explored. The device contains absorption fluid from a supply container that moistens a cylindrical paper sleeve. A newer model is provided with a direct current motor requiring less electricity than an older model. The hose pump is modified to avoid changing it and the filter sleeve is fastened more securely to the distributor head. Application of the measuring devices is discussed, particularly at the Cologne Cathedral, where damage to the stone is observed.

  4. Monitoring of TGF-β 1-Induced Human Lung Adenocarcinoma A549 Cells Epithelial-Mesenchymal Transformation Process by Measuring Cell Adhesion Force with a Microfluidic Device.

    Science.gov (United States)

    Li, Yuan; Gao, AnXiu; Yu, Ling

    2016-01-01

    The epithelial-mesenchymal transition (EMT) is a process in which epithelial cells lose their cell polarity and cell-cell adhesion, and gain migratory and invasive properties. It is believed that EMT is associated with initiation and completion of the invasion-metastasis cascade. In this study, an economic approach was developed to fabricate a microfluidic device with less instrumentation requirement for the investigation of EMT by quantifying cell adhesion force. Fluid shear force was precisely controlled by a homemade microfluidic perfusion apparatus and interface. The adhesion capability of the human lung adenocarcinoma cell line A549 on different types of extracellular matrix protein was studied. In addition, effects of transforming growth factor-β (TGF-β) on EMT in A549 cells were investigated by characterizing the adhesion force changes and on-chip fluorescent staining. The results demonstrate that the microfluidic device is a potential tool to characterize the epithelial-mesenchymal transition process by measuring cell adhesion force.

  5. Microfluidic Cell Culture Device

    Science.gov (United States)

    Takayama, Shuichi (Inventor); Cabrera, Lourdes Marcella (Inventor); Heo, Yun Seok (Inventor); Smith, Gary Daniel (Inventor)

    2014-01-01

    Microfluidic devices for cell culturing and methods for using the same are disclosed. One device includes a substrate and membrane. The substrate includes a reservoir in fluid communication with a passage. A bio-compatible fluid may be added to the reservoir and passage. The reservoir is configured to receive and retain at least a portion of a cell mass. The membrane acts as a barrier to evaporation of the bio-compatible fluid from the passage. A cover fluid may be added to cover the bio-compatible fluid to prevent evaporation of the bio-compatible fluid.

  6. Optical diffraction tomography using a digital micromirror device for stable measurements of 4-D refractive index tomography of cells

    CERN Document Server

    Shin, Seungwoo; Kim, Taeho; Yoon, Jonghee; Hong, Kihyun; Park, Jinah; Park, YongKeun

    2016-01-01

    Optical diffraction tomography (ODT) is an interferometric microscopy technique capable of measuring 3-D refractive index (RI) distribution of transparent samples. Multiple 2-D holograms of a sample illuminated with various angles are measured, from which 3-D RI map of the sample is reconstructed via the diffraction theory. ODT has been proved as a powerful tool for the study of biological cells, due to its non-invasiveness, label-free and quantitative imaging capability. Recently, our group has demonstrated that a digital micromirror device (DMD) can be exploited for fast and precise control of illumination beams for ODT. In this work, we systematically study the precision and stability of the ODT system equipped with a DMD and present measurements of 3-D and 4-D RI maps of various types of live cells including human red blood cells, white blood cells, hepatocytes, and HeLa cells. Furthermore, we also demonstrate the effective visualization of 3-D RI maps of live cells utilizing the measured information abou...

  7. Optical diffraction tomography using a digital micromirror device for stable measurements of 4D refractive index tomography of cells

    Science.gov (United States)

    Shin, Seungwoo; Kim, Kyoohyun; Kim, Taeho; Yoon, Jonghee; Hong, Kihyun; Park, Jinah; Park, YongKeun

    2016-03-01

    Optical diffraction tomography (ODT) is an interferometric microscopy technique capable of measuring 3-D refractive index (RI) distribution of transparent samples. Multiple 2-D holograms of a sample illuminated with various angles are measured, from which 3-D RI map of the sample is reconstructed via the diffraction theory. ODT has been proved as a powerful tool for the study of biological cells, due to its non-invasiveness, label-free and quantitative imaging capability. Recently, our group has demonstrated that a digital micromirror device (DMD) can be exploited for fast and precise control of illumination beams for ODT. In this work, we systematically study the precision and stability of the ODT system equipped with a DMD and present measurements of 3-D and 4-D RI maps of various types of live cells including human red blood cells, white blood cells, hepatocytes, and HeLa cells. Furthermore, we also demonstrate the effective visualization of 3-D RI maps of live cells utilizing the measured information about the values and gradient of RI tomograms.

  8. Miniature ceramic-anvil high-pressure cell for magnetic measurements in a commercial superconducting quantum interference device magnetometer.

    Science.gov (United States)

    Tateiwa, Naoyuki; Haga, Yoshinori; Fisk, Zachary; Ōnuki, Yoshichika

    2011-05-01

    A miniature opposed-anvil high-pressure cell has been developed for magnetic measurement in a commercial superconducting quantum interference device magnetometer. Non-magnetic anvils made of composite ceramic material were used to generate high-pressure with a Cu-Be gasket. We have examined anvils with different culet sizes (1.8, 1.6, 1.4, 1.2, 1.0, 0.8, and 0.6 mm). The pressure generated at low temperature was determined by the pressure dependence of the superconducting transition of lead (Pb). The maximum pressure P(max) depends on the culet size of the anvil: the values of P(max) are 2.4 and 7.6 GPa for 1.8 and 0.6 mm culet anvils, respectively. We revealed that the composite ceramic anvil has potential to generate high-pressure above 5 GPa. The background magnetization of the Cu-Be gasket is generally two orders of magnitude smaller than the Ni-Cr-Al gasket for the indenter cell. The present cell can be used not only with ferromagnetic and superconducting materials with large magnetization but also with antiferromagnetic compounds with smaller magnetization. The production cost of the present pressure cell is about one tenth of that of a diamond anvil cell. The anvil alignment mechanism is not necessary in the present pressure cell because of the strong fracture toughness (6.5 MPa m(1∕2)) of the composite ceramic anvil. The simplified pressure cell is easy-to-use for researchers who are not familiar with high-pressure technology. Representative results on the magnetization of superconducting MgB(2) and antiferromagnet CePd(5)Al(2) are reported.

  9. Device Measures Angle Of Deployment

    Science.gov (United States)

    Jermakian, Joel B.

    1991-01-01

    Simple electromechanical device indicates angular position of unfolding panel during and after deployment. Resistance of potentiometer gradually increases as unfolding of solar panel about hinge moves wiper of potentiometer. At full deployment, panel pushes and opens normally closed switch. Designed for use on panel of solar photovoltaic cells in spacecraft, modified for use in other, similar position-indicating applications.

  10. The Biopotentials and Measuring Devices

    Directory of Open Access Journals (Sweden)

    Mustafa Guven

    2012-06-01

    Full Text Available Many organs in the human body, produces many different types of the electric activity, such as the muscle groups, heart, brain and eyes. These electric activities are also called biopotentials. Measurement of the biopotentials from the human body can indicated vital clues as to normal or pathological functions of the organs. Biopotential signals are small in amplitude and consists of very low frequencies. Therefore, the signals need to be amplified and filtered to make them compatible with devices such as displays, recorders, or analog to digital converters for computerized equipment. In addition, biopotential measurements are corrupted by environmental and biological sources of interference. Amplifiers and filters adequate to measure these signals have to satisfy very specific requirements. This study reviews the origins, acuisition of biopotentials, and design of the medical instruments used in biopotential measurement. [Archives Medical Review Journal 2012; 21(3.000: 174-188

  11. Measuring ionizing radiation with a mobile device

    Science.gov (United States)

    Michelsburg, Matthias; Fehrenbach, Thomas; Puente León, Fernando

    2012-02-01

    In cases of nuclear disasters it is desirable to know one's personal exposure to radioactivity and the related health risk. Usually, Geiger-Mueller tubes are used to assess the situation. Equipping everyone with such a device in a short period of time is very expensive. We propose a method to detect ionizing radiation using the integrated camera of a mobile consumer device, e.g., a cell phone. In emergency cases, millions of existing mobile devices could then be used to monitor the exposure of its owners. In combination with internet access and GPS, measured data can be collected by a central server to get an overview of the situation. During a measurement, the CMOS sensor of a mobile device is shielded from surrounding light by an attachment in front of the lens or an internal shutter. The high-energy radiation produces free electrons on the sensor chip resulting in an image signal. By image analysis by means of the mobile device, signal components due to incident ionizing radiation are separated from the sensor noise. With radioactive sources present significant increases in detected pixels can be seen. Furthermore, the cell phone application can make a preliminary estimate on the collected dose of an individual and the associated health risks.

  12. Development of measurement device for evaluation of solar cell module output. 2; Taiyo denchi module shutsuryoku hyokayo sokuteiki no kaihatsu. 2

    Energy Technology Data Exchange (ETDEWEB)

    Minoda, M.; Itsumi, J. [Kumamoto Institute of Technology, Kumamoto (Japan)

    1996-10-27

    Enhancement in design efficiency may be attained as well as utilization in maintenance if on-the-spot data is made available, for the purpose of flexibly dealing with changes in design or matching with a house structure, in calculating the power generation output of a solar cell (PV) module. Under the circumstances, a small-sized compound measuring device was produced as a prototype which, using an I-V curve tracer, measured output and condition of a roof at the time of installation, compared with the optimum operation and predicted the power generation. The device was structured with the main body consisting of a computing part, measurement controller and power supply and with various sensor modules. The electron load control method was employed in order to measure I-V characteristics of the PV module, since it was desirable to use a variable load and to cover the range from the release voltage of a solar cell to the short-circuit state through the maximum output point. The reference module method was used for the system evaluation. The device was presumably applicable to a PV system design by incorporating a sensor module for measuring design environment data, which was essential at the time of a system design, in addition to those for measuring output. 9 refs., 4 figs., 3 tabs.

  13. Device for monitoring cell voltage

    Science.gov (United States)

    Doepke, Matthias [Garbsen, DE; Eisermann, Henning [Edermissen, DE

    2012-08-21

    A device for monitoring a rechargeable battery having a number of electrically connected cells includes at least one current interruption switch for interrupting current flowing through at least one associated cell and a plurality of monitoring units for detecting cell voltage. Each monitoring unit is associated with a single cell and includes a reference voltage unit for producing a defined reference threshold voltage and a voltage comparison unit for comparing the reference threshold voltage with a partial cell voltage of the associated cell. The reference voltage unit is electrically supplied from the cell voltage of the associated cell. The voltage comparison unit is coupled to the at least one current interruption switch for interrupting the current of at least the current flowing through the associated cell, with a defined minimum difference between the reference threshold voltage and the partial cell voltage.

  14. Magnetic measurements at pressures above 10 GPa in a miniature ceramic anvil cell for a superconducting quantum interference device magnetometer.

    Science.gov (United States)

    Tateiwa, Naoyuki; Haga, Yoshinori; Matsuda, Tatsuma D; Fisk, Zachary

    2012-05-01

    A miniature ceramic anvil high pressure cell (mCAC) was earlier designed by us for magnetic measurements at pressures up to 7.6 GPa in a commercial superconducting quantum interference magnetometer [N. Tateiwa et al., Rev. Sci. Instrum. 82, 053906 (2011)]. Here, we describe methods to generate pressures above 10 GPa in the mCAC. The efficiency of the pressure generation is sharply improved when the Cu-Be gasket is sufficiently preindented. The maximum pressure for the 0.6 mm culet anvils is 12.6 GPa when the Cu-Be gasket is preindented from the initial thickness of 300-60 μm. The 0.5 mm culet anvils were also tested with a rhenium gasket. The maximum pressure attainable in the mCAC is about 13 GPa. The present cell was used to study YbCu(2)Si(2) which shows a pressure induced transition from the non-magnetic to magnetic phases at 8 GPa. We confirm a ferromagnetic transition from the dc magnetization measurement at high pressure. The mCAC can detect the ferromagnetic ordered state whose spontaneous magnetic moment is smaller than 1 μ(B) per unit cell. The high sensitivity for magnetic measurements in the mCAC may result from the simplicity of cell structure. The present study shows the availability of the mCAC for precise magnetic measurements at pressures above 10 GPa.

  15. A device for measuring electron beam characteristics

    Directory of Open Access Journals (Sweden)

    M. Andreev

    2017-01-01

    Full Text Available This paper presents a device intended for diagnostics of electron beams and the results obtained with this device. The device comprises a rotating double probe operating in conjunction with an automated probe signal collection and processing system. This provides for measuring and estimating the electron beam characteristics such as radius, current density, power density, convergence angle, and brightness.

  16. Microfabricated devices for single cell analysis

    Science.gov (United States)

    Gao, Yuanfang

    BioMEMS or lab-on-a-chip technology is promising technology and enables the possibility of microchip devices with higher throughput or better performance for single cell analysis. We have designed and fabricated microdevices for single cell analysis, with impedance based device for fast cell screening and microchannel based flow systems for high throughput, high time resolution quantal exocytosis measurement with automatic cell positioning and reusability. The automatic cell positioning is realized by differential forces of fluidic dynamics. Microelectrodes are patterned at automatic trap positions for electrochemical detection quantal release of hormones like catecholamines secreted by cells. We also developed diamond-like carbon (DLC) microelectrodes onto chip device for low noise exocytosis measurement. The DLC microelectrodes were deposited by magnetron sputtering process with nitrogen doping and a bottom ITO conductive layer. Test results show the developed DLC can detect exocytosis with low noise and a stable background current which are comparable to that of carbon-fiber electrodes. They are batch producible at low cost and can realize high-throughput on-chip measurement of quantal exocytosis. The technology developed in this research can have wide ranging applications in fields such as electrophysiology, cell based sensors, high throughput screening of new drug development.

  17. Zero G Mass Measurement Device (ZGMMD) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Zero Gravity Mass Measurement Device (ZGMMD) provides the ability to measure the mass of samples in a microgravity environment, like that found on the...

  18. Probing cell mechanical properties with microfluidic devices

    Science.gov (United States)

    Rowat, Amy

    2012-02-01

    Exploiting flow on the micron-scale is emerging as a method to probe cell mechanical properties with 10-1000x advances in throughput over existing technologies. The mechanical properties of cells and the cell nucleus are implicated in a wide range of biological contexts: for example, the ability of white blood cells to deform is central to immune response; and malignant cells show decreased stiffness compared to benign cells. We recently developed a microfluidic device to probe cell and nucleus mechanical properties: cells are forced to deform through a narrow constrictions in response to an applied pressure; flowing cells through a series of constrictions enables us to probe the ability of hundreds of cells to deform and relax during flow. By tuning the constriction width so it is narrower than the width of the cell nucleus, we can specifically probe the effects of nuclear physical properties on whole cell deformability. We show that the nucleus is the rate-limiting step in cell passage: inducing a change in its shape to a multilobed structure results in cells that transit more quickly; increased levels of lamin A, a nuclear protein that is key for nuclear shape and mechanical stability, impairs the passage of cells through constrictions. We are currently developing a new class of microfluidic devices to simultaneously probe the deformability of hundreds of cell samples in parallel. Using the same soft lithography techniques, membranes are fabricated to have well-defined pore distribution, width, length, and tortuosity. We design the membranes to interface with a multiwell plate, enabling simultaneous measurement of hundreds of different samples. Given the wide spectrum of diseases where altered cell and nucleus mechanical properties are implicated, such a platform has great potential, for example, to screen cells based on their mechanical phenotype against a library of drugs.

  19. Measuring the state of charge of the electrolyte solution in a vanadium redox flow battery using a four-pole cell device

    Science.gov (United States)

    Ngamsai, Kittima; Arpornwichanop, Amornchai

    2015-12-01

    The decrease in the efficiency and capacity of a vanadium redox flow battery (VRB) caused by an electrolyte imbalance is an important impediment to its long-term operation. Knowing the state of charge (SOC) of an electrolyte solution can quantify the level of the electrolyte imbalance in the VRB. In this study, a four-pole cell device is devised and employed to predict the SOC. The proposed method directly measures the ionic resistance of the electrolyte solution and is sufficiently precise to be applied in real-time mode. Experimental studies on the effects of the operating current on the four-pole cell and the concentrations of vanadium and sulfuric acid in the electrolyte solution are carried out. The results show that the four-pole cell method can be utilized to measure the electrolyte SOC. The concentrations of vanadium and sulfuric acid in the electrolyte solution affect the ionic resistance of the solution. Regarding the capacity and efficiency of the VRB system, the results indicate that the electrical charge is determined from the concentration of vanadium and that the cell voltage depends on the concentration of sulfuric acid in the electrolyte solution. The decreased vanadium concentration and increased sulfuric acid concentration improves the cell voltage efficiency.

  20. Interoperability of wearable cuffless BP measuring devices.

    Science.gov (United States)

    Liu, Jing; Zhang, Yuan-Ting

    2014-01-01

    While a traditional cuff-based Blood Pressure (BP) measuring device can only take a snap shot of BP, real-time and continuous measurement of BP without an occluding cuff is preferred which usually use the pulse transit time (PTT) in combination with other physiological parameters to estimate or track BP over a certain period of time after an initial calibration. This article discusses some perspectives of interoperability of wearable medical devices, based on IEEE P1708 draft standard that focuses on the objective performance evaluation of wearable cuffless BP measuring devices. The ISO/IEEE 11073 family of standards, supporting the plug-and play feature, is intended to enable medical devices to interconnect and interoperate with other medical devices and with computerized healthcare information systems in a manner suitable for the clinical environment. In this paper, the possible adoption of ISO/IEEE 11073 for the interoperability of wearable cuffless BP devices is proposed. In the consideration of the difference of the continuous and cuffless BP measuring methods from the conventional ones, the existing device specialization standards of ISO/IEEE 11073 cannot be directly followed when designing the cuffless BP device. Specifically, this paper discusses how the domain information model (DIM), in which vital sign information is abstracted as objects, is used to structure the information about the device and that generated from the device. Though attention should also be paid to adopt the communication standards for other parts for the communication system, applying communication standards that enable plug-and-play feature allows achieving the interoperability of different cuffless BP measuring devices with possible different configurations.

  1. Vacuum measurement on vacuum packaged MEMS devices

    Energy Technology Data Exchange (ETDEWEB)

    Gan Zhiyin; Lin Dong; Wang Xuefang; Chenggang; Zhang Honghai; Liu Sheng [Institute of Microsystems and Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China, 430074 (China)

    2007-07-15

    This paper investigates the relationship between the resonance impedance of a tuning fork quartz oscillator and the small size cavity vacuum pressure and develops an on-line vacuum measurement system to track real-time vacuum pressure in MEMS devices. Furthermore, authors completely analyze all facts that affect the resonance impedance. A set of metal vacuum packaged devices have been monitored for more than 10 months using this on-line vacuum measurement system. The results indicate that it is very critical to investigate vacuum packaging processes, reliability and durability of the vacuum devices by using this on-line vacuum measurement system.

  2. 21 CFR 886.1450 - Corneal radius measuring device.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Corneal radius measuring device. 886.1450 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1450 Corneal radius measuring device. (a) Identification. A corneal radius measuring device is an AC-powered device intended to...

  3. Zero G Mass Measurement Device (ZGMMD) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Zero G Mass Measurement Device (ZGMMD) will provide the ability to quantify the mass of objects up to 2,000 grams, including live animal specimens in a zero G...

  4. Simulation and measurement of complete dye sensitised solar cells: including the influence of trapping, electrolyte, oxidised dyes and light intensity on steady state and transient device behaviour.

    Science.gov (United States)

    Barnes, Piers R F; Anderson, Assaf Y; Durrant, James R; O'Regan, Brian C

    2011-04-07

    A numerical model of the dye sensitised solar cell (DSSC) is used to assess the importance of different loss pathways under various operational conditions. Based on our current understanding, the simulation describes the processes of injection, regeneration, recombination and transport of electrons, oxidised dye molecules and electrolyte within complete devices to give both time dependent and independent descriptions of performance. The results indicate that the flux of electrons lost from the nanocrystalline TiO(2) film is typically at least twice as large under conditions equivalent to 1 sun relative to dark conditions at matched TiO(2) charge concentration. This is in agreement with experimental observations (Barnes et al. Phys. Chem. Chem. Phys. [DOI: 10.1039/c0cp01855d]). The simulated difference in recombination flux is shown to be due to variation in the concentration profile of electron accepting species in the TiO(2) pores between light and dark conditions and to recombination to oxidised dyes in the light. The model is able to easily incorporate non-ideal behaviour of a cell such as the variation of open circuit potential with light intensity and non-first order recombination of conduction band electrons. The time dependent simulations, described by the multiple trapping model of electron transport and recombination, show good agreement with both small and large transient photocurrent and photovoltage measurements at open circuit, including photovoltage rise measurements. The simulation of photovoltage rise also suggests the possibility of assessing the interfacial resistance between the TiO(2) and substrate. When cells with a short diffusion length relative to film thickness were modelled, the simulated small perturbation photocurrent transients at short circuit (but not open circuit) yielded significantly higher effective diffusion coefficients than expected from the mean concentration of electrons and the electrolyte in the cell. This implies that

  5. Control Device for Temperature Characteristics of a Solar Cell

    OpenAIRE

    N.I. Slipchenko; V.A. Pismenetskiy; N.V. Gerasimenko; A.D. Sheremet`ev

    2013-01-01

    The device for measuring of the temperature coefficients of the photovoltaic characteristics of a solar cell is developed. This device provides a real-time monitoring and study of the energy and photovoltaic parameters of a solar cells and its temperature dependence.

  6. Control Device for Temperature Characteristics of a Solar Cell

    Directory of Open Access Journals (Sweden)

    N.I. Slipchenko

    2013-10-01

    Full Text Available The device for measuring of the temperature coefficients of the photovoltaic characteristics of a solar cell is developed. This device provides a real-time monitoring and study of the energy and photovoltaic parameters of a solar cells and its temperature dependence.

  7. Calibration of imaging luminance measuring devices (ILMD)

    Science.gov (United States)

    Liu, Liying; Zheng, Feng; Zhu, Lingxi; Li, Ye; Huan, Kewei; Shi, Xiaoguang

    2015-11-01

    A method of calibration of imaging luminance measuring devices has been studied. By the device-independent color space transformation, the color image by digital camera could be converted to the CIE's absolute color space lab. Then, the calibration model is fitted between ln(L/t) and luminance. At last, luminance image is obtained and the dynamic range of luminance image could be adjusted by shutter speed.

  8. Performance of an in-plane detection cell with integrated waveguides for UV/Vis absorbance measurements on microfluidic separation devices

    DEFF Research Database (Denmark)

    Petersen, Nickolaj Jacob; Mogensen, Klaus Bo; Kutter, Jörg Peter

    2002-01-01

    A microfluidic device with integrated waveguides and a long path length detection cell for UV/Vis absorbance detection is presented. The 750 mum U-cell detection geometry was evaluated in terms of its optical performance as well as its influence on efficiency for electrophoretic separations...

  9. Design of a network performance measuring device

    Energy Technology Data Exchange (ETDEWEB)

    Badr, O.A.; Miniesy, M.S.; Labib, G.A.

    1983-01-01

    A network performance measuring device (NPMD) was designed. The NPMD is a multiprocessor built around the 8080a microprocessor. The NPMD can be regarded as a tool for measuring important parameters affecting performance in computer networks as a step to improve computer services to the users. With the aid of the NPMD, optimum design of a data communication network, serviced by an existing computer system, becomes easier. NPMD combines the basic features of terminal and link simulators, data test sets, and data acquisition devices. 4 references.

  10. Pressure measurements in magnetic-fusion devices

    Energy Technology Data Exchange (ETDEWEB)

    Dylla, H.F.

    1981-11-01

    Accurate pressure measurements are important in magnetic fusion devices for: (1) plasma diagnostic measurements of particle balance and ion temperature; (2) discharge cleaning optimization; (3) vacuum system performance; and (4) tritium accountability. This paper reviews the application, required accuracy, and suitable instrumentation for these measurements. Demonstrated uses of ionization-type and capacitance-diaphragm gauges for various pressure and gas-flow measurements in tokamaks are presented, with specific reference to the effects of magnetic fields on gauge performance and the problems associated with gauge calibration.

  11. Coherence measurement with digital micromirror device.

    Science.gov (United States)

    Partanen, Henri; Turunen, Jari; Tervo, Jani

    2014-02-15

    We measure the complex-valued spatial coherence function of a multimode broad-area laser diode using Young's classical double slit experiment realized with a digital micromirror device. We use this data to construct the coherent modes of the beam and to simulate its propagation before and after the measurement plane. When comparing the results to directly measured intensity profiles, we find excellent correspondence to the extent that even small details of the beam can be predicted. We also consider the number of measurement points required to model the beam with sufficient accuracy.

  12. 21 CFR 864.6160 - Manual blood cell counting device.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Manual blood cell counting device. 864.6160... (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Manual Hematology Devices § 864.6160 Manual blood cell counting device. (a) Identification. A manual blood cell counting device is a device used...

  13. Digital Camera as Gloss Measurement Device

    Directory of Open Access Journals (Sweden)

    Mihálik A.

    2016-05-01

    Full Text Available Nowadays digital cameras with both high resolution and the high dynamic range (HDR can be considered as parallel multiple sensors producing multiple measurements at once. In this paper we describe a technique for processing the captured HDR data and than fit them to theoretical surface reflection models in the form of bidirectional reflectance distribution function (BRDF. Finally, the tabular BRDF can be used to calculate the gloss reflection of the surface. We compare the captured glossiness by digital camera with gloss measured with the industry device and conclude that the results fit well in our experiments.

  14. 46 CFR 154.1340 - Temperature measuring devices.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Temperature measuring devices. 154.1340 Section 154.1340... Instrumentation § 154.1340 Temperature measuring devices. (a) Each cargo tank must have devices that measure the... level allowed under § 154.1844. (b) Each device required by paragraph (a) must have a readout at...

  15. Microfluidic devices for cell cultivation and proliferation

    OpenAIRE

    Tehranirokh, Masoomeh; Kouzani, Abbas Z.; Francis, Paul S.; Kanwar, Jagat R.

    2013-01-01

    Microfluidic technology provides precise, controlled-environment, cost-effective, compact, integrated, and high-throughput microsystems that are promising substitutes for conventional biological laboratory methods. In recent years, microfluidic cell culture devices have been used for applications such as tissue engineering, diagnostics, drug screening, immunology, cancer studies, stem cell proliferation and differentiation, and neurite guidance. Microfluidic technology allows dynamic cell cul...

  16. Mass measurements based on nanomechanical devices: differential measurements

    Energy Technology Data Exchange (ETDEWEB)

    Arcamone, J; Rius, G; Llobet, J; Borrise, X; Perez-Murano, F [CNM-IMB (CSIC). Campus UAB. E-08193 Bellaterra (Barcelona) (Spain)], E-mail: francesc.perez@cnm.es, E-mail: julien.arcamone@cnm.es

    2008-03-15

    In the last few years, there has been a strong interest in implementing nano-mechanical devices as mass sensors. Regarding this application, an important question to address is to know to what extent the observed frequency shift is exclusively due to the targeted mass loading. For this purpose, we present a device, a polysilicon double cantilever, with an innovative design that allows the direct determination of the measurement uncertainty. Two almost identical nanomechanical resonators are simultaneously operated: one serves as sensor and the other as reference. In this way, rapid and reliable measurements in air are made possible. In first experimental measurements, some masses in the order of 300 fg, locally deposited by focused ion beam, have been measured with an uncertainty of 30 fg. These results are corroborated by the determination of the deposits size based on SEM images.

  17. Device for measuring flow of wet steam

    Energy Technology Data Exchange (ETDEWEB)

    Turchaninov, Yu.N.; Dichenko, M.A.; Irodenko, V.V.; Nikiforov, Yu.V.; Vestelesnyy, A.G.

    1982-01-01

    A device is proposed for measuring the flow of wet steam into productive beds of injection wells during thermal modification. It contains a housing with measurement channel, straightblade blade wheel installed on the shaft and electric motor; rotor of the electric motor is arranged on the blade wheel, and the stator of the housing. The device guarantees the possibility of measuring flow in the well with the use of a flexible cable suspension. For this purpose it is equipped with an inertia brake arranged on one end of the housing made in the form of a bushing freely installed in the housing with pins. On the pins there are spring-loaded brake shoes interacting with the supports attached to the housing. In order to improve transverse stability of the housing, the device is equipped with an additional inertia brake installed on the other end of the housing, and in order to guarantee packing of the well, an initial inertia brake installed under the first with shifting in relation to the axis to cover by the brake shoes the section of the well. After lowering of the flow meter into the well to the required depth, an electrical current is fed into the winding of the electric motor on the cable; the blade wheel begins to turn, simultaneously on the stator attached in the instrument housing a reactive rotating momentum develops. The housing sharply turns to the side opposite the direction of rotation of the blade wheel, the brake shoes are separated up to the support in the well wall. The flow of controllable medium loads the electric motor rotating the blade wheel by the momentum of resistance to rotation that is proportional to mass flow. The magnitude of the momentum (flow) is judged from the magnitude of consumed current.

  18. Measurement-device-independent quantum digital signatures

    Science.gov (United States)

    Puthoor, Ittoop Vergheese; Amiri, Ryan; Wallden, Petros; Curty, Marcos; Andersson, Erika

    2016-08-01

    Digital signatures play an important role in software distribution, modern communication, and financial transactions, where it is important to detect forgery and tampering. Signatures are a cryptographic technique for validating the authenticity and integrity of messages, software, or digital documents. The security of currently used classical schemes relies on computational assumptions. Quantum digital signatures (QDS), on the other hand, provide information-theoretic security based on the laws of quantum physics. Recent work on QDS Amiri et al., Phys. Rev. A 93, 032325 (2016);, 10.1103/PhysRevA.93.032325 Yin, Fu, and Zeng-Bing, Phys. Rev. A 93, 032316 (2016), 10.1103/PhysRevA.93.032316 shows that such schemes do not require trusted quantum channels and are unconditionally secure against general coherent attacks. However, in practical QDS, just as in quantum key distribution (QKD), the detectors can be subjected to side-channel attacks, which can make the actual implementations insecure. Motivated by the idea of measurement-device-independent quantum key distribution (MDI-QKD), we present a measurement-device-independent QDS (MDI-QDS) scheme, which is secure against all detector side-channel attacks. Based on the rapid development of practical MDI-QKD, our MDI-QDS protocol could also be experimentally implemented, since it requires a similar experimental setup.

  19. Live cell refractometry using microfluidic devices.

    Science.gov (United States)

    Lue, Niyom; Popescu, Gabriel; Ikeda, Takahiro; Dasari, Ramachandra R; Badizadegan, Kamran; Feld, Michael S

    2006-09-15

    Using Hilbert phase microscopy for extracting quantitative phase images, we measured the average refractive index associated with live cells in culture. To decouple the contributions to the phase signal from the cell refractive index and thickness, we confined the cells in microchannels. The results are confirmed by comparison with measurements of spherical cells in suspension.

  20. Device for measuring mechanical drilling velocity

    Energy Technology Data Exchange (ETDEWEB)

    Turchaninov, Y.N.; Ippolitova, L.G.; Khizgilov, A.I.; Rolik, V.A.

    1980-12-17

    A device is proposed for measuring the mechanical drilling velocity which includes a primary drilling tool supply transformer, control block, trigger, range switch; control block, block for determining motion direction, time counter and measurement instrument. In order to guarantee continuous measurement of the mechanical velocity and to improve the accuracy of measuring the average mechanical velocity during drilling at sea, it is equipped with a block for multiplying the number of pulses, four I circuits, supply counter, supply recorder, primary neutral transformer, two controllable frequency dividers, first frequency divider, generator of prime pulses consisting of a generatror of reference frequencies and second frequency divider, time recorder, counter and velocity recorder, time recorder and digital-analog transformer. In this case the outlet of the primary transformer for drilling tool supply is connected through a in-series connected block for determining the movement direction, block for multiplying the number of pulses, first circuit I and supply counter to one of the inlets of the supply counter. Its second inlet is connected through a block of control to the primary neutral transformer and one of the inlets of the time recorder. Its second inlet is connected through a in-series connected time counter, fourth I circuit, second frequency divider, generator of reference frequency, first frequency divider, third circuit I, second controllable frequency divider, counter and velocity recorder and digital-analog transformer of the measurement instrument. The outlet of the supply recorder is connected to one of the inlets of the first controllable divider. Its second inlet is connected to the second I circuit to the outlet of the first frequency divider, and the outlet is connected to one of the trigger inlets.

  1. An Algorithm to Estimate Time Offset between Measurement Devices

    Institute of Scientific and Technical Information of China (English)

    HUANG Zhou-song; LEI Zhen-ming

    2004-01-01

    This paper analyzes the necessity of the measurement of one-way delay, and it also points out the errors caused by the time offset between measurement devices. Then we propose an algorithm to estimate time offset between measurement devices in network. With the estimated time offset, we can correct our measuring results. Simulation shows the effectiveness of our algorithm.

  2. THE INEXPENSIVE DEVICE FOR SEA LEVEL MEASUREMENTS

    Directory of Open Access Journals (Sweden)

    A. Annunziato

    2015-10-01

    Full Text Available A new mareograph device has been designed at the Joint Research Centre (JRC of the European Commission (EC in order improve the sea level network in use for the Tsunami Hazard monitoring in the Mediterranean Sea and in the North Atlantic area (NEAMTWS area of UNESCO. The instrument has the characteristic to be cheap and very effective but its reliability, duration and quality need to be determined and qualified. For this reason a number of experimental campaigns are being conducted, whose first results are presented here. In collaboration with the UNESCO/IOC (Intergovernmental Oceanographic Commission, responsible of the definition of the Tsunami Warning System of this geographical area, a set of 20 devices has been offered by JRC for a period of 1 year of testing of the devices; the surveys for the installation of the devices is under way and the installation should be completed by the end of 2015.

  3. Cell biology apps for Apple devices.

    Science.gov (United States)

    Stark, Louisa A

    2012-01-01

    Apps for touch-pad devices hold promise for guiding and supporting learning. Students may use them in the classroom or on their own for didactic instruction, just-in-time learning, or review. Since Apple touch-pad devices (i.e., iPad and iPhone) have a substantial share of the touch-pad device market (Campbell, 2012), this Feature will explore cell biology apps available from the App Store. My review includes iPad and iPhone apps available in June 2012, but does not include courses, lectures, podcasts, audiobooks, texts, or other books. I rated each app on a five-point scale (1 star = lowest; 5 stars = highest) for educational and production values; I also provide an overall score.

  4. 21 CFR 864.5300 - Red cell indices device.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Red cell indices device. 864.5300 Section 864.5300....5300 Red cell indices device. (a) Identification. A red cell indices device, usually part of a larger... corpuscular hemoglobin (MCH), and the mean corpuscular hemoglobin concentration (MCHC). The red cell...

  5. Development of a wireless blood pressure measuring device with smart mobile device.

    Science.gov (United States)

    İlhan, İlhan; Yıldız, İbrahim; Kayrak, Mehmet

    2016-03-01

    Today, smart mobile devices (telephones and tablets) are very commonly used due to their powerful hardware and useful features. According to an eMarketer report, in 2014 there were 1.76 billion smartphone users (excluding users of tablets) in the world; it is predicted that this number will rise by 15.9% to 2.04 billion in 2015. It is thought that these devices can be used successfully in biomedical applications. A wireless blood pressure measuring device used together with a smart mobile device was developed in this study. By means of an interface developed for smart mobile devices with Android and iOS operating systems, a smart mobile device was used both as an indicator and as a control device. The cuff communicating with this device through Bluetooth was designed to measure blood pressure via the arm. A digital filter was used on the cuff instead of the traditional analog signal processing and filtering circuit. The newly developed blood pressure measuring device was tested on 18 patients and 20 healthy individuals of different ages under a physician's supervision. When the test results were compared with the measurements made using a sphygmomanometer, it was shown that an average 93.52% accuracy in sick individuals and 94.53% accuracy in healthy individuals could be achieved with the new device.

  6. Device to measure elastic modulus of superconducting windings

    CERN Multimedia

    1979-01-01

    This device was made to measure elastic modulus of the Po dipole superconducting coils. More elaborated devices, but based on the same concept, were later used to measure the apparent elastic moduli of the LHC superconducting magnet coils. See also 7903547X, 7901386.

  7. 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

  8. Correlation Measurements on Small Mobile Devices

    DEFF Research Database (Denmark)

    Yanakiev, Boyan Radkov; Nielsen, Jesper Ødum; Christensen, Morten

    2012-01-01

    Here, analysis of the antenna correlation at the design stage is done, with focus on measurement techniques. Various theoretical definitions of correlations are used with the corresponding measured data required. The problems related to the coaxial measurement cables, when calculating correlation...

  9. Measuring directional characteristics of in-ear recording devices

    DEFF Research Database (Denmark)

    Christensen, Flemming; Hoffmann, Pablo F.; Hammershøi, Dorte

    2013-01-01

    With the availability of small in-ear headphones and miniature microphones it is possible to construct combined in-ear devices for binaural recording and playback. When mounting a microphone on the outside of an insert earphone the microphone position deviates from ideal positions in the ear canal....... The pinna and thereby also the natural sound transmission are altered by the inserted device. This paper presents a methodology for accurately measuring the directional dependent transfer functions of such in-ear devices. Pilot measurements on a commercial available device are presented and possibilities...

  10. Perovskite solar cells: from materials to devices.

    Science.gov (United States)

    Jung, Hyun Suk; Park, Nam-Gyu

    2015-01-07

    Perovskite solar cells based on organometal halide light absorbers have been considered a promising photovoltaic technology due to their superb power conversion efficiency (PCE) along with very low material costs. Since the first report on a long-term durable solid-state perovskite solar cell with a PCE of 9.7% in 2012, a PCE as high as 19.3% was demonstrated in 2014, and a certified PCE of 17.9% was shown in 2014. Such a high photovoltaic performance is attributed to optically high absorption characteristics and balanced charge transport properties with long diffusion lengths. Nevertheless, there are lots of puzzles to unravel the basis for such high photovoltaic performances. The working principle of perovskite solar cells has not been well established by far, which is the most important thing for understanding perovksite solar cells. In this review, basic fundamentals of perovskite materials including opto-electronic and dielectric properties are described to give a better understanding and insight into high-performing perovskite solar cells. In addition, various fabrication techniques and device structures are described toward the further improvement of perovskite solar cells.

  11. Device Physics of Nanoscale Interdigitated Solar Cells (Poster)

    Energy Technology Data Exchange (ETDEWEB)

    Metzger, W.; Levi, D.

    2008-05-01

    Nanoscale interdigitated solar cell device architectures are being investigated for organic and inorganic solar cell devices. Due to the inherent complexity of these device designs quantitative modeling is needed to understand the device physics. Theoretical concepts have been proposed that nanodomains of different phases may form in polycrystalline CIGS solar cells. These theories propose that the nanodomains may form complex 3D intertwined p-n networks that enhance device performance.Recent experimental evidence offers some support for the existence of nanodomains in CIGS thin films. This study utilizes CIGS solar cells to examine general and CIGS-specific concepts in nanoscale interdigitated solar cells.

  12. Nanostructured Semiconductor Device Design in Solar Cells

    Science.gov (United States)

    Dang, Hongmei

    We demonstrate the use of embedded CdS nanowires in improving spectral transmission loss and the low mechanical and electrical robustness of planar CdS window layer and thus enhancing the quantum efficiency and the reliability of the CdS-CdTe solar cells. CdS nanowire window layer enables light transmission gain at 300nm-550nm. A nearly ideal spectral response of quantum efficiency at a wide spectrum range provides an evidence for improving light transmission in the window layer and enhancing absorption and carrier generation in absorber. Nanowire CdS/CdTe solar cells with Cu/graphite/silver paste as back contacts, on SnO2/ITO-soda lime glass substrates, yield the highest efficiency of 12% in nanostructured CdS-CdTe solar cells. Reliability is improved by approximately 3 times over the cells with the traditional planar CdS counterpart. Junction transport mechanisms are delineated for advancing the basic understanding of device physics at the interface. Our results prove the efficacy of this nanowire approach for enhancing the quantum efficiency and the reliability in windowabsorber type solar cells (CdS-CdTe, CdS-CIGS and CdS-CZTSSe etc) and other optoelectronic devices. We further introduce MoO3-x as a transparent, low barrier back contact. We design nanowire CdS-CdTe solar cells on flexible foils of metals in a superstrate device structure, which makes low-cost roll-to-roll manufacturing process feasible and greatly reduces the complexity of fabrication. The MoO3 layer reduces the valence band offset relative to the CdTe, and creates improved cell performance. Annealing as-deposited MoO3 in N 2 reduces series resistance from 9.98 O/cm2 to 7.72 O/cm2, and hence efficiency of the nanowire solar cell is improved from 9.9% to 11%, which efficiency comparable to efficiency of planar counterparts. When the nanowire solar cell is illuminated from MoO 3-x /Au side, it yields an efficiency of 8.7%. This reduction in efficiency is attributed to decrease in Jsc from 25.5m

  13. Optical vibration measurement of mechatronics devices

    Science.gov (United States)

    Yanabe, Shigeo

    1993-09-01

    An optical vibration measuring system which enables to detect both linear and angular displacement of 25 nm and 5 prad was developed. The system is mainly composed of a He-Ne laser, a displacement detecting photo-diode and lenses, and has linear and angular displacement magnification mechanism using two different principles of optical lever. The system was applied to measure vibrational characteristics of magnetic head slider of hard disk drives and to measure stator teeth driving velocities of ultrasonic motor.

  14. Test device for measuring permeability of a barrier material

    Science.gov (United States)

    Reese, Matthew; Dameron, Arrelaine; Kempe, Michael

    2014-03-04

    A test device for measuring permeability of a barrier material. An exemplary device comprises a test card having a thin-film conductor-pattern formed thereon and an edge seal which seals the test card to the barrier material. Another exemplary embodiment is an electrical calcium test device comprising: a test card an impermeable spacer, an edge seal which seals the test card to the spacer and an edge seal which seals the spacer to the barrier material.

  15. Device for Measuring Landslide Critical Angle

    Institute of Scientific and Technical Information of China (English)

    Li Xueling; Xia Weisheng; Huang Daoyou; Yu Yun

    2016-01-01

    The mountain landslide has high destructive effects, discussion of its landslide critical angle has always been one of the major concerns, and we designed a system that can automatically measure the landslide critical angle. This equipment consists of the

  16. Small Device For Short-Range Antenna Measurements Using Optics

    DEFF Research Database (Denmark)

    Yanakiev, Boyan Radkov; Nielsen, Jesper Ødum; Christensen, Morten

    2011-01-01

    This paper gives a practical solution for implementing an antenna radiation pattern measurement device using optical fibers. It is suitable for anechoic chambers as well as short range channel sounding. The device is optimized for small size and provides a cheap and easy way to make optical antenna...

  17. Video integrated measurement system. [Diagnostic display devices

    Energy Technology Data Exchange (ETDEWEB)

    Spector, B.; Eilbert, L.; Finando, S.; Fukuda, F.

    1982-06-01

    A Video Integrated Measurement (VIM) System is described which incorporates the use of various noninvasive diagnostic procedures (moire contourography, electromyography, posturometry, infrared thermography, etc.), used individually or in combination, for the evaluation of neuromusculoskeletal and other disorders and their management with biofeedback and other therapeutic procedures. The system provides for measuring individual diagnostic and therapeutic modes, or multiple modes by split screen superimposition, of real time (actual) images of the patient and idealized (ideal-normal) models on a video monitor, along with analog and digital data, graphics, color, and other transduced symbolic information. It is concluded that this system provides an innovative and efficient method by which the therapist and patient can interact in biofeedback training/learning processes and holds considerable promise for more effective measurement and treatment of a wide variety of physical and behavioral disorders.

  18. A microfluidic cell culture device with integrated microelectrodes for barrier studies

    DEFF Research Database (Denmark)

    Tan, Hsih-Yin; Dufva, Martin; Kutter, Jörg P.

    We present an eight cell culture microfluidic device fabricated using thiol-ene ‘click’ chemistry with embedded microelectrodes for evaluating barrier properties of human intestinal epithelial cells. The capability of the microelectrodes for trans-epithelial electrical resistance (TEER) measureme......We present an eight cell culture microfluidic device fabricated using thiol-ene ‘click’ chemistry with embedded microelectrodes for evaluating barrier properties of human intestinal epithelial cells. The capability of the microelectrodes for trans-epithelial electrical resistance (TEER......) measurements was demonstrated by using confluent human colorectal epithelial cells (Caco-2) and rat fibroblast (CT 26) cells cultured in the microfluidic device....

  19. An improved device to measure cottonseed strength

    Science.gov (United States)

    During processing, seeds of cotton cultivars with fragile seeds often break and produce seed coat fragments that can cause processing problems at textile mills. A cottonseed shear tester, previously developed to measure cottonseed strength, was modified with enhancements to the drive system to provi...

  20. A Strip Cell in Pyroelectric Devices

    Directory of Open Access Journals (Sweden)

    An-Shen Siao

    2016-03-01

    Full Text Available The pyroelectric effect affords the opportunity to convert temporal temperature fluctuations into usable electrical energy in order to develop abundantly available waste heat. A strip pyroelectric cell, used to enhance temperature variation rates by lateral temperature gradients and to reduce cell capacitance to further promote the induced voltage, is described as a means of improving pyroelectric energy transformation. A precision dicing saw was successfully applied in fabricating the pyroelectric cell with a strip form. The strip pyroelectric cell with a high-narrow cross section is able to greatly absorb thermal energy via the side walls of the strips, thereby inducing lateral temperature gradients and increasing temperature variation rates in a thicker pyroelectric cell. Both simulation and experimentation show that the strip pyroelectric cell improves the electrical outputs of pyroelectric cells and enhances the efficiency of pyroelectric harvesters. The strip-type pyroelectric cell has a larger temperature variation when compared to the trenched electrode and the original type, by about 1.9 and 2.4 times, respectively. The measured electrical output of the strip type demonstrates a conspicuous increase in stored energy as compared to the trenched electrode and the original type, by of about 15.6 and 19.8 times, respectively.

  1. Design of Residues Measurement Device of Uranium

    Institute of Scientific and Technical Information of China (English)

    SUI; Hong-zhi; XU; Zheng; LU; Wen-guang; HE; Li-xia; GAN; Lin

    2012-01-01

    <正>Nuclear materials will be deposited in the pipeline or various process equipment during the operation of nuclear facilities, such as dissolution reactor, because the recovery residue of uranium not dissolved, and a metal tubularis in the dissolution reactor cannot insert to the bottom of the container, so that part of the residual slag and the solution stored in the bottom of the reactor. When the equipment is used for treatment of nuclear material, it is difficult to put out all the nuclear material in the equipment. Therefore, measurement of these residues for nuclear material accountancy, the safe operation of the facilities,

  2. A Device for Measuring Sonic Velocity and Compressor Mach Number

    Science.gov (United States)

    1948-07-01

    resonator (the only 4 NACA TN No. 1664 accurate measurement required) is measured, as shomn in figure 1, by means of a mercury manometer . The compressor Mach...tube vs not connected to the ccmpressor inlet until after calibration. The pressure in the device was measured by means of the mercury manometer . Fram

  3. Device-Independent Certification of a Nonprojective Qubit Measurement

    Science.gov (United States)

    Gómez, Esteban S.; Gómez, Santiago; González, Pablo; Cañas, Gustavo; Barra, Johanna F.; Delgado, Aldo; Xavier, Guilherme B.; Cabello, Adán; Kleinmann, Matthias; Vértesi, Tamás; Lima, Gustavo

    2016-12-01

    Quantum measurements on a two-level system can have more than two independent outcomes, and in this case, the measurement cannot be projective. Measurements of this general type are essential to an operational approach to quantum theory, but so far, the nonprojective character of a measurement can only be verified experimentally by already assuming a specific quantum model of parts of the experimental setup. Here, we overcome this restriction by using a device-independent approach. In an experiment on pairs of polarization-entangled photonic qubits we violate by more than 8 standard deviations a Bell-like correlation inequality that is valid for all sets of two-outcome measurements in any dimension. We combine this with a device-independent verification that the system is best described by two qubits, which therefore constitutes the first device-independent certification of a nonprojective quantum measurement.

  4. Low-cost optoelectronic devices to measure velocity of detonation

    Science.gov (United States)

    Chan, Edwin M.; Lee, Vivian; Mickan, Samuel P.; Davies, Phil J.

    2005-02-01

    Velocity of Detonation (VoD) is an important measured characteristic parameter of explosive materials. When new explosives are developed, their VoD must be determined. Devices used to measure VoD are always destroyed in the process, however replacing these devices represents a considerable cost in the characterisation of new explosives. This paper reports the design and performance of three low-cost implementations of a point-to-point VoD measurement system, two using optical fibre and a third using piezoelectric polymers (PolyVinyliDine Flouride, PVDF). The devices were designed for short charges used under controlled laboratory conditions and were tested using the common explosive 'Composition B'. These new devices are a fraction of the cost of currently available VoD sensors and show promise in achieving comparable accuracy. Their future development will dramatically reduce the cost of testing and aid the characterisation of new explosives.

  5. Cryocup - Compact spherical neutron polarimetry device for small angle measurement

    Science.gov (United States)

    Wang, Tianhao

    In my thesis I describe my research work of developing a compact device for Spherical Neutron Polarimetry (SNP) measurements at small neutron scattering angles. The thesis first introduced the purpose of this research project, which is developing an easy to use and maintain version of an advanced neutron experiment technique (SNP). After the introduction, the design principle and construction detail of the prototype device is demonstrated. The design principle is based on our finite element simulation of the device's magnetic field profile, and is later verified by the performance test experiment. The prototype device is tested at the SESAME neutron beamline at Indiana University and the HB-2D beamline at Oak Ridge National laboratory. The performance test data are analyzed and proof that the design is successful and the prototype is capable of perform accurate SNP measurement. Based on the test result, the prototype device is utilized to perform SNP measurement on two types of magnetic film sample: Permalloy and Metglas. Combined with other characterization method such as SQUID and MFM, I study the magnetization of these two samples both at zero magnetic field environment and in external field. The SNP data provided by the prototype device is discussed in the thesis and provide detailed information about the magnetization, which is also not accessible through other method. In the end, the possible improvement and the future application of the device is discussed.

  6. Computational device design: measuring esophageal distensibility using EndoFLIP

    Science.gov (United States)

    Acharya, Shashank; Kou, Wenjun; Kahrilas, Peter J.; Pandolfino, John E.; Patankar, Neelesh A.

    2016-11-01

    Characterizing the strength of sphincters in the human body is valuable from a diagnostic and surgical standpoint. We develop a numerical model for the EndoFLIP device (Endolumenal Functional Lumen Imaging Probe) that is crucial to the biomechanical study of the Lower Esophageal Sphincter (LES). The simulations demonstrate how the device operates in vivo. From this model, we suggest additional use cases for the device that can give insight into the state of the esophageal wall. Currently, the device measures a single steady quantity (distensibility) that is calculated from pressure and area. Our analysis shows that by capturing and analyzing spatio-temporal pressure variations during peristalsis, the effectiveness of the contractions and health of the surrounding tissue can be quantified. Furthermore, there is an opportunity to validate tissue models by comparing dilation results with clinical data from the device. This work is supported by the Cabell Fellowship at Northwestern Unviersity.

  7. Hybrid Optical Devices: The Case of the Unification of the Electrochromic Device and the Organic Solar Cell

    Directory of Open Access Journals (Sweden)

    Andre F. S. Guedes

    2016-06-01

    Full Text Available The development of Hybrid Optical Devices, using some flexible optically transparent substrate material and organic semiconductor materials, has been widely utilized by the organic electronic industry, when manufacturing new technological products. The Hybrid Optical Device is constituted by the union of the electrochromic device and the organic solar cell. The flexible organic photovoltaic solar cells, in this hybrid optical device, have been the Poly base (3-hexyl thiophene, P3HT, Phenyl-C61-butyric acid methyl ester, PCBM and Polyaniline, PANI, all being deposited in Indium Tin Oxide, ITO. In addition, the thin film, obtained by the deposition of PANI, and prepared in perchloric acid solution, has been identified through PANI-X1. In the flexible electrochromic device, the Poly base (3,4-ethylenedioxythiophene, PEDOT, has been prepared in Propylene Carbonate, PC, being deposited in Indium Tin Oxide, ITO. Also, both devices have been united by an electrolyte solution prepared with Vanadium Pentoxide, V2O5, Lithium Perchlorate, LiClO4, and Polymethylmethacrylate, PMMA. This device has been characterized through Electrical Measurements, such as UV-Vis Spectroscopy and Scanning Electron Microscopy (SEM. Thus, the result obtained through electrical measurements has demonstrated that the flexible organic photovoltaic solar cell presented the characteristic curve of standard solar cell after spin-coating and electrodeposition. Accordingly, the results obtained with optical and electrical characterization have revealed that the electrochromic device demonstrated some change in optical absorption, when subjected to some voltage difference. Moreover, the inclusion of the V2O5/PANI-X1 layer reduced the effects of degradation that this hybrid organic device caused, that is, solar irradiation. Studies on Scanning Electron Microscopy (SEM have found out that the surface of V2O5/PANI-X1 layers can be strongly conditioned by the surface morphology of the

  8. A Microfluidic Device for Spatiotemporal Delivery of Stimuli to Cells

    Directory of Open Access Journals (Sweden)

    Zubaidah Ningsih

    2015-03-01

    Full Text Available Living cells encounter many stimuli from the immediate environment. Receptors recognize these environmental cues and transduce signals to produce cell responses. The frequency of a signal is now emerging as an important factor determining cell responses. As a componentry system in understanding temporal stimulation, microfluidic devices allow the observation of cell behaviour under dynamic stimulation and controllable environment. In this paper we describe the design, construction and characterization of a microfluidic device suitable for cell stimulation studies.

  9. Urbmobi. A mobile measurement device for urban environmental monitoring

    NARCIS (Netherlands)

    Klok, E.J.; Mark, P.J. van der; Nieuwkoop, E.

    2014-01-01

    Within the Urbmobi research project, a novel mobile measurement device is developed for urban areas. It provides temporally and spatially distributed environmental data and fulfills the need for monitoring at various places without the costs for a large number of fixed measurement stations. Urbmobi

  10. Measurement of Electromagnetic Fields Emitted from Some Medical Devices

    Directory of Open Access Journals (Sweden)

    Shaker Faisel

    2013-04-01

    Full Text Available     New medical devices such as surgery devices, physiotherapy devices, cosmetological devices and Magnetic Resonance Imaging (MRI systems generate a complex electromagnetic fields, so they consider as a potential   hazard for medical personnel during surgical procedures. The aim of this research is to detect the EMFs emitted from medical devices and determine the safety ranges from these devices which emit EMF radiations in order to protect Medical staff from its risks. The research has been performed in two parts, numerical calculation and practical measurement. Practical measurements are done in Dijlah hospital at Tikrit city. Obtaining results shows that the practical measurements are consistent with the mathematical calculation results. Comparison of these results with the safety standard guideline limits shows that they   are within the acceptable exposure limits recommended by the International Commission on Non-Ionizing Radiation Protection (ICNIRP and that means there is no health risk from exposure to these fields if the exposure is for a short and not continued periods and lay within the acceptable limits.    

  11. On-Demand Cell Internal Short Circuit Device

    Science.gov (United States)

    Darcy, Eric; Keyser, Matthew

    2014-01-01

    A device implantable in Li-ion cells that can generate a hard internal short circuit on-demand by exposing the cell to 60?C has been demonstrated to be valuable for expanding our understanding of cell responses. The device provides a negligible impact to cell performance and enables the instigation of the 4 general categories of cell internal shorts to determine relative severity and cell design susceptibility. Tests with a 18650 cell design indicates that the anode active material short to the aluminum cathode current collector tends to be more catastrophic than the 3 other types of internal shorts. Advanced safety features (such as shutdown separators) to prevent or mitigate the severity of cell internal shorts can be verified with this device. The hard short success rate achieved to date in 18650 cells is about 80%, which is sufficient for using these cells in battery assemblies for field-failure-relevant, cell-cell thermal runaway propagation verification tests

  12. Wireless induction heating in a microfluidic device for cell lysis.

    Science.gov (United States)

    Baek, Seung-ki; Min, Junghong; Park, Jung-Hwan

    2010-04-07

    A wireless induction heating system in a microfluidic device was devised for cell lysis to extract DNA and RNA from Escherichia coli. The thermal responses of nickel, iron and copper heating units were studied by applying an alternating magnetic field as a function of geometry of unit, strength of magnetic field, and kind of metal. Heating units were prepared by cutting metal film using a fiber laser, and the units were integrated into a microchannel system using a soft lithographic process. Variation and distribution of temperature on the surface of the heating units was observed using a thermographic camera and temperature labels. The amount of protein released from E. coli by thermal lysis was determined by protein concentration measurement. Hemoglobin released from red blood cells was observed using colorimetric intensity measurement. Extracted DNA was quantified by real-time polymerase chain reaction, and the profile was compared with that of a positive control of ultrasonically disrupted E. coli. The stability of RNA extracted by induction heating was quantified by the measurement of 23S/16S rRNA ratio and comparison with that by normal RNA extraction kit as a gold standard. A solid-shaped nickel structure was selected as the induction heating element in the microfluidic device because of the relatively small influence of geometries and faster thermal response.The amount of protein extracted from E. coli and hemoglobin released from red blood cells by induction heating of the nickel unit in the microfluidic device was proportional to the strength of the applied magnetic field. The lysis of E. coli by induction heating was as effective as lysis of DNA by the ultrasonication method because the threshold cycle values of the sample were compatible with those of the positive control as measured by ultrasonication. Thermal lysis of E. coli by induction heating represents a reasonable alternative to a commercial RNA extraction method as shown by the comparative

  13. Measurement Devices and the Psychophysiology of Consumer Behaviour

    DEFF Research Database (Denmark)

    Schwarzkopf, Stefan

    2015-01-01

    of the type of subjectivity that underlies consumer behaviour. I argue instead that a posthuman view of the relationship between brain, mind and behaviour underpinned neurophysiological research into consumers from its very beginning in the late nineteenth century. By tracing the biopolitical potentialities......From the 1890s, psychophysiological measurement devices have played an important, but as yet under-theorized role in marketing and consumer research. Because of the recent advances made in neuromarketing, it is often assumed that these measurement devices ushered in a radically new understanding...... of neuromarketing back to the Fin-de-Siècle neurophysiological laboratory, I show that consumers' bodies and later on their brains became reconfigured as part of a dispositif made up of laboratory-based artefacts (measurement devices) and new ways of seeing the human brain and human behaviour. This dispositif...

  14. Measurement-device-independent entanglement-based quantum key distribution

    Science.gov (United States)

    Yang, Xiuqing; Wei, Kejin; Ma, Haiqiang; Sun, Shihai; Liu, Hongwei; Yin, Zhenqiang; Li, Zuohan; Lian, Shibin; Du, Yungang; Wu, Lingan

    2016-05-01

    We present a quantum key distribution protocol in a model in which the legitimate users gather statistics as in the measurement-device-independent entanglement witness to certify the sources and the measurement devices. We show that the task of measurement-device-independent quantum communication can be accomplished based on monogamy of entanglement, and it is fairly loss tolerate including source and detector flaws. We derive a tight bound for collective attacks on the Holevo information between the authorized parties and the eavesdropper. Then with this bound, the final secret key rate with the source flaws can be obtained. The results show that long-distance quantum cryptography over 144 km can be made secure using only standard threshold detectors.

  15. Measurements of Elastic Moduli of Silicone Gel Substrates with a Microfluidic Device

    OpenAIRE

    Edgar Gutierrez; Alex Groisman

    2011-01-01

    Thin layers of gels with mechanical properties mimicking animal tissues are widely used to study the rigidity sensing of adherent animal cells and to measure forces applied by cells to their substrate with traction force microscopy. The gels are usually based on polyacrylamide and their elastic modulus is measured with an atomic force microscope (AFM). Here we present a simple microfluidic device that generates high shear stresses in a laminar flow above a gel-coated substrate and apply the d...

  16. Electroporation of cells in microfluidic devices: a review

    NARCIS (Netherlands)

    Fox, M.B.; Esveld, D.C.; Valero, A.; Luttge, R.; Mastwijk, H.C.; Bartels, P.V.; Berg, van den A.; Boom, R.M.

    2006-01-01

    In recent years, several publications on microfluidic devices have focused on the process of electroporation, which results in the poration of the biological cell membrane. The devices involved are designed for cell analysis, transfection or pasteurization. The high electric field strengths needed a

  17. A non-invasive device to objectively measure tibial rotation: verification of the device.

    Science.gov (United States)

    Lorbach, Olaf; Wilmes, P; Maas, S; Zerbe, T; Busch, L; Kohn, D; Seil, R

    2009-07-01

    The purpose of this study was the correlation of the results of a new measurement device for tibial rotation (Rotameter) in comparison with the measurements of a knee navigation system as standard method. In a biomechanical laboratory study, all soft tissues were removed from 20 human cadaveric knees leaving only the intact capsule and the bone. Specific tracers were bicortically fixed in the bone in order to measure tibial rotation using a knee navigation system. The knees were fixed to a custom-made inside-boot to rule out undesirable rotation of the reconstruction inside the Rotameter measurement device. Internal and external rotation values were measured at an applied torque of 5, 10 and 15 Nm. The different methods to evaluate tibial rotation were compared using the Pearson correlation coefficient. The correlations were deemed to be reliable if a value of >or=0.80 was achieved. At 5 Nm of applied torque, high correlations for the internal rotation, external rotation and the entire rotational range were found in the Pearson correlation coefficient between the Rotameter testing device in comparison with the knee navigation system as invasive reference method. These results were also confirmed at an applied torque of 10 and 15 Nm. In conclusion, the Rotameter testing device showed high correlations compared with the knee navigation system as an invasive standard method. It might be used as a non-invasive and easy alternative to investigate tibial rotation.

  18. Survey of spectral response measurements for photovoltaic devices

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, J.S.; Lind, M.A.

    1981-11-01

    A survey of the photovoltaic community was conducted to ascertain the present state-of-the-art for PV spectral response measurements. Specific topics explored included measurement system designs, good and bad features of the systems, and problems encountered in the evaluation of specific cell structures and materials. The survey showed that most spectral response data are used in diagnostic analysis for the optimization of developmental solar cells. Measurement systems commonly utilize a chopped narrowband source in conjunction with a constant bias illumination which simulates the ambient end use environment. Researchers emphasized the importance of bias illumination for all types of cells in order to minimize the effects of nonlinearities in cell response. Not surprisingly single crystal silicon cells present the fewest measurement problems to the researcher and have been studied more thoroughly than any other type of solar cell. But, the accurate characterization of silicon cells is still difficult and laboratory intercomparison studies have yielded data scatter ranging from +-5% to +-15%. The measurement experience with other types of cells is less extensive. The development of reliable data bases for some solar cells is complicated by problems of cell nonuniformity, environmental instability, nonlinearity, etc. Cascade cells present new problems associated with their structue (multiple cells in series) which are just beginning to be understood. In addition, the importance of many measurement parameters (spectral content of bias light, bias light intensity, bias voltage, chopping frequency, etc.) are not fully understood for most types of solar cells.

  19. Experimental measurement-device-independent quantum random-number generation

    Science.gov (United States)

    Nie, You-Qi; Guan, Jian-Yu; Zhou, Hongyi; Zhang, Qiang; Ma, Xiongfeng; Zhang, Jun; Pan, Jian-Wei

    2016-12-01

    The randomness from a quantum random-number generator (QRNG) relies on the accurate characterization of its devices. However, device imperfections and inaccurate characterizations can result in wrong entropy estimation and bias in practice, which highly affects the genuine randomness generation and may even induce the disappearance of quantum randomness in an extreme case. Here we experimentally demonstrate a measurement-device-independent (MDI) QRNG based on time-bin encoding to achieve certified quantum randomness even when the measurement devices are uncharacterized and untrusted. The MDI-QRNG is randomly switched between the regular randomness generation mode and a test mode, in which four quantum states are randomly prepared to perform measurement tomography in real time. With a clock rate of 25 MHz, the MDI-QRNG generates a final random bit rate of 5.7 kbps. Such implementation with an all-fiber setup provides an approach to construct a fully integrated MDI-QRNG with trusted but error-prone devices in practice.

  20. Miniaturized Cell Lysis Device Using Spherically Focused Ultrasound

    Institute of Scientific and Technical Information of China (English)

    李刚; 肖宏; 郭旻; 程京

    2003-01-01

    A prototype of a miniaturized cell lysis device developed using a concave spherical transducer is capable of lysing bacteria without added chemical denaturants, enzymes or microparticles and is capable of efficiently lysing yeast without any mechanical or enzymatic pretreatment.The device is designed for miniature bio-analysis systems where cell lysing is needed to obtain intracellular materials for further analysis such as DNA identification.The device lysis efficiency was evaluated using viable cell counts and microscopy.Additionally, the device efficiency was compared with that of traditional chemical cell lysis methods using standard molecular biological techniques such as agarose gels and ultraviolet (UV) spectroscopy.The results indicate that efficient bacteria and cell disruption can be achieved through a low-voltage-driven and spherically focused high-frequency ultrasonic device.

  1. A new CR-39 nuclear track passive thoron measuring device

    Energy Technology Data Exchange (ETDEWEB)

    Calamosca, M., E-mail: calamosc@enea.i [ENEA-ION-IRP, Montecuccolino, V. dei Colli 16, 40136 Bologna (Italy); Penzo, S. [ENEA-ION-IRP, Montecuccolino, V. dei Colli 16, 40136 Bologna (Italy)

    2009-10-15

    {sup 220}Rn monitoring in dwellings and in workplaces is seldom performed, both because usually the associated risk is considered negligible and for the difficulties of properly measuring it. As a consequence the state of art of thoron measurements by using solid-state nuclear track detectors shows a significant lag compared with radon. However the demand of determining the thoron contribution to natural dose assessment is worldwide increasing, and in the presence of some building materials as tuff, should be mandatory. To tackle this problem, the ENEA Radon Measuring Service has developed a dose evaluation procedure based on the measurement of the {sup 220}Rn concentration at a standard distance from the wall, by using a new (patent pending) CR-39 alpha track detector thoron passive device (ATD-TnPD), coupled to our own radon passive device (ATD-RnPD). The two devices are geometrically similar and their responses were extensively evaluated to optimise the uncertainty of the thoron measurement. This paper depicts the prime features of the new device, and the introduced changes aimed at reducing the device's equilibrium time constant from 20.8 min to 3.1 min. Since no reliable thoron calibration facility has resulted available up to now, we had to state the ATD-TnPD's sensitivity parameter by performing the calibration step by our own. A closed circuit thoron exposure facility was set up to provide thoron exposures at 3 different levels. The exposed detectors were chemically etched at 7 increasing etching times to study the relationship between sensitivity and etching conditions, so to optimise the detector response and the measurement uncertainty.

  2. 27 CFR 24.36 - Instruments and measuring devices.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Instruments and measuring devices. 24.36 Section 24.36 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Administrative and Miscellaneous Provisions...

  3. Device enables measurement of moments of inertia about three axes

    Science.gov (United States)

    Conn, J.

    1965-01-01

    Device measures moments of inertia of an irregularly shaped mass about three mutually perpendicular axes by the standard pendulum and torque methods. A fixture suspends the test mass at one point and can be adjusted to allow oscillation of the mass.

  4. Multichannel measuring device of deformation for research materials of constructions

    Directory of Open Access Journals (Sweden)

    Druzhinin A.

    2008-06-01

    Full Text Available Possibility of Atmel ATMega microcontrollers use was shown for the interfacing of sensors devices with the modern computer systems. On the basis of Atmel ATMega16 microcontroller the multichannel system of treatment of information was developed for strain gauges, in which the amount of measuring channels is substantially increased.

  5. Experimental Measurements of Belt Gears in Newly Developed Device

    Directory of Open Access Journals (Sweden)

    Jozef Mascenik

    2016-05-01

    Full Text Available The paper deals with the alternative of determination of state of the belt gear. To realize themeasurements a newly developed device was designed for measurement and diagnostics of the belt gears. The main task is to detect the V-belt slip expressed by the coefficient of elastic creep and of specific slip with a measuring device. The measurements regarding can be performed if input revolutions of the electric motor and torque of the belt gear are constant whereas the tensioning force of the belt gear changes. It is also possible to perform the measurement if the input revolutions of the electric motor and the tensioning forces are constant and the torque changes.

  6. Production, characterization and stability of organic solar cell devices

    Energy Technology Data Exchange (ETDEWEB)

    Gevorgyan, S.A.

    2010-01-15

    Despite the fact that the field of organic photovoltaics (OPVs) is in a rapid progress, organic solar cells continue taking backstage roll in the growing markets of various solar technologies. The main challenge of the field is to develop devices that would possess all the optimal properties required for efficient, stable and cheap solar cells, i.e. devices that can deliver high photoconversion efficiencies and long lifetimes and can be efficiently produced in large scales using roll-to-roll coating technologies. This dissertation is primarily devoted to the issues of photoconversion efficiency and device lifetimes. In particular, descriptions of some practical approaches for different device designs and processing of active layer for typical small scale OPV devices were presented. The emphasis was put on some optimizing techniques for processing of active layer that can significantly improve the device photoconversion efficiency. The techniques were further applied for manufacturing and characterization of solar cell devices based on various materials. In particular, a number of thermocleavable polymers were studied and devices based on such materials were produced and characterized. The applicability of such materials in photovoltaic devices was shown and further challenges were discussed. Another task of this work was to manufacture and study inverted device structures and compare their properties with normal structure based devices. Device based on both structure were successfully produced with same level of performance in terms of photoconversion efficiency, yet with totally different stability performance. As another task, metal oxides, such as MoO{sub 3} or V{sub 2}O{sub 5} were studied in solar cell devices as buffer layers instead of PEDOT:PSS. Although the device efficiencies obtained with metal oxides were inferior to PEDOT based device, it was shown that such materials can possibly improve the device efficiency if the processing of the layers is

  7. Photon absorption models in nanostructured semiconductor solar cells and devices

    CERN Document Server

    Luque, Antonio

    2015-01-01

    This book is intended to be used by materials and device physicists and also solar cells researchers. It models the performance characteristics of nanostructured solar cells and resolves the dynamics of transitions between several levels of these devices. An outstanding insight into the physical behaviour of these devices is provided, which complements experimental work. This therefore allows a better understanding of the results, enabling the development of new experiments and optimization of new devices. It is intended to be accessible to researchers, but also to provide engineering tools w

  8. Calibration of Laser Beam Direction for Inner Diameter Measuring Device

    Directory of Open Access Journals (Sweden)

    Tongyu Yang

    2017-02-01

    Full Text Available The laser triangulation method is one of the most advanced methods for large inner diameter measurement. Our research group proposed a kind of inner diameter measuring device that is principally composed of three laser displacement sensors known to be fixed in the same plane measurement position. It is necessary to calibrate the direction of the laser beams that are emitted by laser displacement sensors because they do not meet the theoretical model accurately. For the purpose of calibrating the direction of laser beams, a calibration method and mathematical model were proposed. The inner diameter measuring device is equipped with the spindle of the machine tool. The laser beams rotate and translate in the plane and constitute the rotary rays which are driven to scan the inner surface of the ring gauge. The direction calibration of the laser beams can be completed by the sensors’ distance information and corresponding data processing method. The corresponding error sources are analyzed and the validity of the method is verified. After the calibration, the measurement error of the inner diameter measuring device reduced from ± 25 μ m to ± 15 μ m and the relative error was not more than 0.011%.

  9. Methane metering devices and systems for continuous measurements

    Energy Technology Data Exchange (ETDEWEB)

    Gralewski, K.; Krupa, M.

    1982-01-01

    Brief characteristics are presented for the advantages and shortcomings of the existing methane devices and systems developed in the Polish People's Republic, FRG, Great Britain, United States, CSSR and USSR. Among the main requirements made for the modern methane metering devices designed for continuous measurements of methane concentration in the coal mines, requirements such as rapid reaction to the spasmodic change in methane concentration, resistance to contamination of the catalyst, low consumed power etc. are named. Trends are outlined for improvement in the coal industry of the Polish People's Republic.

  10. Assembly for electrical conductivity measurements in the piston cylinder device

    Science.gov (United States)

    Watson, Heather Christine [Dublin, CA; Roberts, Jeffrey James [Livermore, CA

    2012-06-05

    An assembly apparatus for measurement of electrical conductivity or other properties of a sample in a piston cylinder device wherein pressure and heat are applied to the sample by the piston cylinder device. The assembly apparatus includes a body, a first electrode in the body, the first electrode operatively connected to the sample, a first electrical conductor connected to the first electrode, a washer constructed of a hard conducting material, the washer surrounding the first electrical conductor in the body, a second electrode in the body, the second electrode operatively connected to the sample, and a second electrical conductor connected to the second electrode.

  11. Implementation of a measurement-device-independent entanglement witness.

    Science.gov (United States)

    Xu, Ping; Yuan, Xiao; Chen, Luo-Kan; Lu, He; Yao, Xing-Can; Ma, Xiongfeng; Chen, Yu-Ao; Pan, Jian-Wei

    2014-04-11

    Entanglement, the essential resource in quantum information processing, should be witnessed in many tasks such as quantum computing and quantum communication. The conventional entanglement witness method, relying on an idealized implementation of measurements, could wrongly conclude a separable state to be entangled due to imperfect detections. Inspired by the idea of a time-shift attack, we construct an attack on the conventional entanglement witness process and demonstrate that a separable state can be falsely identified to be entangled. To close such detection loopholes, based on a recently proposed measurement-device-independent entanglement witness method, we design and experimentally demonstrate a measurement-device-independent entanglement witness for a variety of two-qubit states. By the new scheme, we show that an entanglement witness can be realized without detection loopholes.

  12. Resource-Efficient Measurement-Device-Independent Entanglement Witness

    Science.gov (United States)

    Verbanis, E.; Martin, A.; Rosset, D.; Lim, C. C. W.; Thew, R. T.; Zbinden, H.

    2016-05-01

    Imperfections in experimental measurement schemes can lead to falsely identifying, or over estimating, entanglement in a quantum system. A recent solution to this is to define schemes that are robust to measurement imperfections—measurement-device-independent entanglement witness (MDI-EW). This approach can be adapted to witness all entangled qubit states for a wide range of physical systems and does not depend on detection efficiencies or classical communication between devices. Here we extend the theory to remove the necessity of prior knowledge about the two-qubit states to be witnessed. Moreover, we tested this model via a novel experimental implementation for MDI-EW that significantly reduces the experimental complexity. By applying it to a bipartite Werner state, we demonstrate the robustness of this approach against noise by witnessing entanglement down to an entangled state fraction close to 0.4.

  13. Device for measurement of thermal emissivity at cryogenic temperatures

    CERN Document Server

    Kralik, Tomas; Musilova, Vera; Srnka, Ales

    2016-01-01

    In the described device, the thermal emissivity or absorptivity of the sample is measured by substitution of the radiative heat flow between two parallel surfaces by thermal output of a heater. Fast measurements of the mutual emissivity for the range of the temperature of the radiating surface 25 K-150 K are possible. The absorbing surface has a temperature between 5 K and 10 K when LHe is used as cryoliquid. The desired measurement sensitivity is 1 mK for temperature and 0.1 {\\mu}W for heat power, respectively. The diameter of the whole device is 50 mm and so it is possible to use a commercial dewar can for the cooling. The form of the sample is a round plate 40 mm in diameter and 1 mm in thickness with one tested side. The emissivity and its temperature dependency for various surface treatments can be checked immediately before application in a cryogenic system.

  14. Methods of measurement for semiconductor materials, process control, and devices

    Science.gov (United States)

    Bullis, W. M. (Editor)

    1972-01-01

    Significant accomplishments include development of a procedure to correct for the substantial differences of transistor delay time as measured with different instruments or with the same instrument at different frequencies; association of infrared response spectra of poor quality germanium gamma ray detectors with spectra of detectors fabricated from portions of a good crystal that had been degraded in known ways; and confirmation of the excellent quality and cosmetic appearance of ultrasonic bonds made with aluminum ribbon wire. Work is continuing on measurement of resistivity of semiconductor crystals; study of gold-doped silicon, development of the infrared response technique; evaluation of wire bonds and die attachment; and measurement of thermal properties of semiconductor devices, delay time and related carrier transport properties in junction devices, and noise properties of microwave diodes.

  15. Liquid Drop Measuring Device for Analyzing Liquid Properties

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Based on the correlation between certain properties of liquid and the properties of the corresponding liquid drop formed under given conditions, a liquid drop measuring device is utilized to monitor the drop formation process of the liquid sample with photoelectric measuring methods. The mechanical and optical characteristic of the liquid is explored with the optical fibers from the internal of the liquid drop during its formation. The drop head capacitor is utilized to monitor the growth process of the liquid drop to gain the drop volume information related to the physical property of liquid. The unique liquid drop trace containing the integrated properties of liquid is generated, and it is proved by experiment that for different liquids their liquid drop traces are different. The analysis on liquid properties and discrimination between different liquids can be proceeded with the liquid drop trace obtained by the liquid drop measuring device.

  16. Improving the accuracy of smart devices to measure noise exposure.

    Science.gov (United States)

    Roberts, Benjamin; Kardous, Chucri; Neitzel, Richard

    2016-11-01

    Occupational noise exposure is one of the most frequent hazards present in the workplace; up to 22 million workers have potentially hazardous noise exposures in the U.S. As a result, noise-induced hearing loss is one of the most common occupational injuries in the U.S. Workers in manufacturing, construction, and the military are at the highest risk for hearing loss. Despite the large number of people exposed to high levels of noise at work, many occupations have not been adequately evaluated for noise exposure. The objective of this experiment was to investigate whether or not iOS smartphones and other smart devices (Apple iPhones and iPods) could be used as reliable instruments to measure noise exposures. For this experiment three different types of microphones were tested with a single model of iPod and three generations of iPhones: the internal microphones on the device, a low-end lapel microphone, and a high-end lapel microphone marketed as being compliant with the International Electrotechnical Commission's (IEC) standard for a Class 2-microphone. All possible combinations of microphones and noise measurement applications were tested in a controlled environment using several different levels of pink noise ranging from 60-100 dBA. Results were compared to simultaneous measurements made using a Type 1 sound level measurement system. Analysis of variance and Tukey's honest significant difference (HSD) test were used to determine if the results differed by microphone or noise measurement application. Levels measured with external microphones combined with certain noise measurement applications did not differ significantly from levels measured with the Type 1 sound measurement system. Results showed that it may be possible to use iOS smartphones and smart devices, with specific combinations of measurement applications and calibrated external microphones, to collect reliable, occupational noise exposure data under certain conditions and within the limitations of the

  17. Real-time precision measuring device of tree diameter growth

    Science.gov (United States)

    Guo, Mingming; Chen, Aijun; Li, Dongsheng; Liu, Nan; Yao, Jingyuan

    2016-01-01

    DBH(diameter at breast height) is an important factor to reflect of the quality of plant growth, also an important parameter indispensable in forest resources inventory and forest carbon sink, the accurate measurement of DBH or not is directly related to the research of forest resources inventory and forest carbon sink. In this paper, the principle and the mathematical model of DBH measurement device were introduced, the fixture measuring device and the hardware circuit for this tree diameter were designed, the measurement software programs were compiled, and the precision measuring device of tree diameter growth was developed. Some experiments with Australia fir were conducted. Based on experiment data, the correlations among the DBH variation of Australian fir, the environment temperature, air humility and PAR(photosynthetically active radiation) were obtained. The effects of environmental parameters (environment temperature, air humility and PAR) on tree diameter were analyzed. Experimental results show that there is a positive correlation between DBH variation of Australian fir and environment temperature, a negative correlation between DBH variation of Australian fir and air humility , so is PAR.

  18. Biomechanical Measurement of Rabbit Cornea by a Modified Scheimpflug Device

    Science.gov (United States)

    Zhang, Bo; Gu, Jianjun; Zhang, Xiaoxiao; Yang, Bin

    2016-01-01

    Purpose. To explore the probability and variation in biomechanical measurements of rabbit cornea by a modified Scheimpflug device. Methods. A modified Scheimpflug device was developed by imaging anterior segment of the model imitating the intact eye at various posterior pressures. The eight isolated rabbit corneas were mounted on the Barron artificial chamber and images of the anterior segment were taken at posterior pressures of 15, 30, 45, 60, and 75 mmHg by the device. The repeatability and reliability of the parameters including CCT, ACD, ACV, and CV were evaluated at each posterior pressure. All the variations of the parameters at the different posterior pressures were calculated. Results. All parameters showed good intraobserver reliability (Cronbach's alpha; intraclass correlation coefficient, α, ICC > 0.96) and repeatability in the modified Scheimpflug device. With the increase of posterior pressures, the ratio of CCT decreased linearly and the bulk modulus gradually reduced to a platform. The increase of ACD was almost linear with the posterior pressures elevated. Conclusions. The modified Scheimpflug device was a valuable tool to investigate the biomechanics of the cornea. The posterior pressure 15–75 mmHg range produced small viscoelastic deformations and nearly linear pressure-deformation response in the rabbit cornea. PMID:27446608

  19. Microfluidic device with dual mechanical cues for cell migration investigation.

    Science.gov (United States)

    Tsai, Chin-Hsiung; Kuo, Po-Ling

    2013-01-01

    Cell migration plays an important role in numerous physiological and pathological conditions, such as angiogenesis, wound healing and cancer metastasis. Understanding the fundamental mechanisms of cell migration is crucial to develop strategies for disease treatment and regenerative medicine. Several biomechanical cues have been well studied about their effects on guiding cell migration. However, the effects of dual or multiple cues on cell migration are barely addressed. In this work, we developed a microfluidic-based device to study the combinatory effects of osmotic and stiffness gradient on cell migration. Computer simulation and experimental validation showed that the device was capable of providing stable osmotic and stiffness gradient to cultured cells at the same time. Preliminary results suggest that our device has a valuable potential in studying cell migration in complex conditions which better recapitulate the complex environmental conditions in vivo.

  20. A new 3D levitation force measuring device for REBCO bulk superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S.L. [School of Physics, Shaanxi Normal University, Xi’an 710062 (China); Yang, W.M., E-mail: yangwm@snnu.edu.cn [School of Physics, Shaanxi Normal University, Xi’an 710062 (China); Li, J.W.; Yuan, X.C. [School of Physics, Shaanxi Normal University, Xi’an 710062 (China); Ma, J. [School of Physics, Shaanxi Normal University, Xi’an 710062 (China); Department of Physics, Qinghai Normal University, Xining 810008 (China); Wang, M. [School of Physics, Shaanxi Normal University, Xi’an 710062 (China)

    2014-01-15

    Highlights: •A new 3D levitation force measuring device has been designed and constructed. •It can measure the 3D real-time interaction force simultaneously and directly. •Performance, accuracy and effectiveness has been demonstrate by tests. -- Abstract: A new 3D levitation force measuring device for ReBa{sub 2}Cu{sub 3}O{sub 7−x} (REBCO) bulk superconductors has been designed and constructed. Three pull pressure load cells are orthogonally set on a fixing bracket to test the interaction force between a bulk superconductor and a magnet in three dimensions. To realize the simple, rapid and accurate measurement of the levitation force, a non-magnetic hollow cylinder flange, three pull pressure load cells, a piece of iron plate, a NbFeB permanent magnet (PM) and some steel balls are elaborately constructed with the fixing bracket, thus the magnet or REBCO bulk superconductor can be well and rigidly connected with the load cells, and the mutual interference from the three pull pressure load cells can be effectively avoided during the levitation force measuring processes. This device can be used to measure the interaction (or levitation) force between a superconductor and a magnet, that between a magnet and a magnet, or the magnetic force among magnetic materials in three dimensions.

  1. Radiation detection and measurement concepts, methods and devices

    CERN Document Server

    McGregor, Douglas

    2017-01-01

    This text on radiation detection and measurement is a response to numerous requests expressed by students at various universities, in which the most popularly used books do not provide adequate background material, nor explain matters in understandable terms. This work provides a modern overview of radiation detection devices and radiation measurement methods. The topics selected in the book have been selected on the basis of the author’s many years of experience designing radiation detectors and teaching radiation detection and measurement in a classroom environment.

  2. Improving Perovskite Solar Cells: Insights From a Validated Device Model

    NARCIS (Netherlands)

    Sherkar, Tejas S.; Momblona, Cristina; Gil-Escrig, Lidon; Bolink, Henk J.; Koster, L. Jan Anton

    2017-01-01

    To improve the efficiency of existing perovskite solar cells (PSCs), a detailed understanding of the underlying device physics during their operation is essential. Here, a device model has been developed and validated that describes the operation of PSCs and quantitatively explains the role of conta

  3. A Novel Device for Measuring Forces in Endoluminal Procedures

    Directory of Open Access Journals (Sweden)

    Tommaso Ranzani

    2015-08-01

    Full Text Available In this paper a simple but effective measuring system for endoluminal procedures is presented. The device allows measuring forces during the endoluminal manipulation of tissues with a standard surgical instrument for laparoscopic procedures. The force measurement is performed by recording both the forces applied directly by the surgeon at the instrument handle and the reaction forces on the access port. The measuring system was used to measure the forces necessary for appropriate surgical manipulation of tissues during transanal endoscopic microsurgery (TEM. Ex-vivo and in-vivo measurements were performed, reported and discussed. The obtained data can be used for developing and appropriately dimensioning novel dedicated instrumentation for TEM procedures.

  4. 21 CFR 886.1430 - Ophthalmic contact lens radius measuring device.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic contact lens radius measuring device... lens radius measuring device. (a) Identification. An ophthalmic contact lens radius measuring device is an AC-powered device that is a microscope and dial gauge intended to measure the radius of a...

  5. Surface photovoltage measurements and finite element modeling of SAW devices.

    Energy Technology Data Exchange (ETDEWEB)

    Donnelly, Christine

    2012-03-01

    Over the course of a Summer 2011 internship with the MEMS department of Sandia National Laboratories, work was completed on two major projects. The first and main project of the summer involved taking surface photovoltage measurements for silicon samples, and using these measurements to determine surface recombination velocities and minority carrier diffusion lengths of the materials. The SPV method was used to fill gaps in the knowledge of material parameters that had not been determined successfully by other characterization methods. The second project involved creating a 2D finite element model of a surface acoustic wave device. A basic form of the model with the expected impedance response curve was completed, and the model is ready to be further developed for analysis of MEMS photonic resonator devices.

  6. Device and materials modeling in PEM fuel cells

    CERN Document Server

    Promislow, Keith

    2009-01-01

    Device and Materials Modeling in PEM Fuel Cells is a specialized text that compiles the mathematical details and results of both device and materials modeling in a single volume. Proton exchange membrane (PEM) fuel cells will likely have an impact on our way of life similar to the integrated circuit. The potential applications range from the micron scale to large scale industrial production. Successful integration of PEM fuel cells into the mass market will require new materials and a deeper understanding of the balance required to maintain various operational states. This book contains articles from scientists who contribute to fuel cell models from both the materials and device perspectives. Topics such as catalyst layer performance and operation, reactor dynamics, macroscopic transport, and analytical models are covered under device modeling. Materials modeling include subjects relating to the membrane and the catalyst such as proton conduction, atomistic structural modeling, quantum molecular dynamics, an...

  7. Device operation of organic tandem solar cells

    NARCIS (Netherlands)

    Hadipour, A.; de Boer, B.; Blom, P. W. M.

    2008-01-01

    A generalized methodology is developed to obtain the current-voltage characteristic of polymer tandem solar cells by knowing the electrical performance of both sub cells. We demonstrate that the electrical characteristics of polymer tandem solar cells are correctly predicted for both the series and

  8. Single cell electroporation using microfluidic devices

    NARCIS (Netherlands)

    Le Gac, S.; Berg, van den A.; Lindstrom, S.; Andersson-Svahn, S.M.H.

    2012-01-01

    Electroporation is a powerful technique to increase the permeability of cell membranes and subsequently introduce foreign materials into cells. Pores are created in the cell membrane upon application of an electric fi eld (kV/cm). Most applications employ bulk electroporation, at the scale of 1 mL o

  9. Optical Measurement Techniques for Optical Fiber and Waveguide Devices

    Institute of Scientific and Technical Information of China (English)

    D.Y.; Kim; Y.; Park; N.H.; Seong; Y.C.Youk; J.Y.; Lee; S.; Moon; I.H.; Shin; H.S.; Ryu

    2003-01-01

    We describe three major optical characterization methods for fiber and fiber devices. A simple servo controlled scanning fiber-optic confocal microscope is proposed for determining the refractive index profile of an optical fiber. To measure the chromatic dispersion of a short length fiber a Mach-Zehnder fiber interferometer with a novel interferometric distance meter is introduced. At the end, a tomographic method is demonstrated for determining the 2-D stress profile of a fiber.

  10. Femtosecond laser fabrication of optofluidic devices for single cell manipulation

    Directory of Open Access Journals (Sweden)

    Bragheri Francesca

    2015-01-01

    Full Text Available In this work we fabricate and validate two optofludic devices for the manipulation and analysis of single cells. The chips are fabricated by femtosecond laser micromachining exploiting the 3D capabilities of the technique and the inherent perfect alignment between microfluidic channels and optical networks. Both devices have been validated by probing the mechanical properties of different cancer cell lines, which are expected to show different elasticity because of their different metastatic potential.

  11. DATA PROCESSING FROM THE MEASURING DEVICE BALLBAR QC20

    Directory of Open Access Journals (Sweden)

    Matúš Košinár

    2014-03-01

    Full Text Available The paper presents an innovative method of data processing from the measurement device – Ballbar QC20W. It was created with a program for data transformation (Visual Basic.NET and it used Fourier transformation. The paper deals with the measuring method of CNC machine tools using Ballbar QC20W. There is an influence between qualitative parameters of machine tools and qualitative parameters of products (tolerances, roughness, etc.. It is very important to hold the stability of qualitative parameters of products as a key factor of production quality. Therefore, is also important to evaluate the accuracy of machine tools and make prediction of possible accuracy.

  12. Development of a Force Measurement Device for Lower-Body Muscular Strength Measuring of Skaters

    Science.gov (United States)

    Kim, Dong Ki; Lee, Jeong Tae

    This paper presents a force measurement system that can measure a lower-body muscular strength of skaters. The precise measurement and analysis of the left and right lower-body strength of skaters is necessary, because a left/right lower-body strength balance is helpful to improve the athletes' performance and to protect them from injury. The system is constructed with a skate sliding board, a couple of sensor-units with load cell, indicator and control box, guard, force pad, and support bracket. The developed force measurement system is calibrated by the calibration setup, and the uncertainty of the force sensing unit on the left is within 0.087% and the uncertainty of the force sensing unit on the right is within 0.109%. In order to check the feasibility of the developed measurement device, a kinematic analysis is conducted with skater. As a result, the subject shows the deviation of left and right of 12.1 N with respect to average strength and 39.1 N with respect to the maximum strength. This evaluation results are reliable enough to make it possible to measure a lower-body muscular strength of skaters. The use of this measurement system will be expected to correct the posture of skaters and record the sports dynamics data for each athlete. It is believed that through the development of this equipment, skaters in elementary, middle, high schools, colleges, and the professional level have the systematic training to compete with world-class skaters.

  13. Organic solar cells fundamentals, devices, and upscaling

    CERN Document Server

    Rand, Barry P

    2014-01-01

    Solution-Processed DonorsB. Burkhart, B. C. ThompsonSmall-Molecule and Vapor-Deposited Organic Photovoltaics R. R. Lunt, R. J. HolmesAcceptor Materials for Solution-Processed Solar Cells Y. HeInterfacial Layers R. Po, C. Carbonera, A. BernardiElectrodes in Organic Photovoltaic Cells S. Yoo, J.-Y. Lee, H. Kim, J. LeeTandem and Multi-Junction Organic Solar Cells J. Gilot, R. A. J. JanssenBulk Heterojunction Morphology Control and Characterization T. Wang, D. G. LidzeyOptical Modeling and Light Management

  14. An unheated permeation device for calibrating atmospheric VOC measurements

    Directory of Open Access Journals (Sweden)

    J. Brito

    2011-10-01

    Full Text Available The development of an unpowered permeation device for continuous calibration of in-situ instruments measuring atmospheric volatile organic compounds (VOCs is described. Being lightweight and compact, and containing only negligible amounts of chemicals, the device is especially suited for field use such as on board aircraft. Its speciality is to maintain the permeation process in thermal equilibrium, so that the instantaneous permeation rate can be ascribed to a simple temperature measurement. This equilibrium state is maintained by a combination of three features: (i a thin PTFE membrane as permeation medium which guarantees short stabilization times, (ii a water bath as heat buffer, and (iii a vacuum-panel based insulation, in which features (ii and (iii minimize temperature drifts to ~30 mK h−1 per Kelvin temperature difference to the environment. The respective uncertainty of the permeation rate due to thermal non-equilibrium is kept below 1%. An extensive theory part details the major permeation processes of gases through porous polymers, being Fick's diffusion, Knudsen flow, and viscous flow. Both the measured stabilization time and the measured temperature dependence of the permeation rate independently indicate that the permeation can be described by a viscous flow model, where diffusion of the gas molecules in large pores (having a diameter of >0.05 μm dominates.

  15. An unheated permeation device for calibrating atmospheric VOC measurements

    Directory of Open Access Journals (Sweden)

    J. Brito

    2011-05-01

    Full Text Available The development of an unpowered permeation device for continuous calibration of in-situ instruments measuring atmospheric volatile organic compounds (VOCs is described. Being lightweight and compact, and containing only negligible amounts of chemicals, the device is especially suited for field use such as onboard aircraft. Its speciality is to maintain the permeation process in thermal equilibrium, i.e. the instantaneous permeation rate can be ascribed via a simple temperature measurement. This equilibrium state is maintained by a combination of three features: (i a thin PTFE membrane as permeation medium which guarantees short stabilization times, (ii a water bath as heat buffer, and (iii a vacuum-panel based insulation, in which features (ii and (iii minimize temperature drifts. The uncertainty of the permeation rate due to thermal non-equilibrium is kept below 1 %. An extensive theory part details the major permeation processes of gases through porous polymers, being Fick's diffusion, Knudsen flow, and viscous flow. Both the measured stabilization time and the measured temperature dependence of the permeation rate independently indicate that the permeation can be described by a viscous flow model, where diffusion of the gas molecules in large pores (having a diameter of >0.05 μm dominates.

  16. Microfluidic Device for Continuous Magnetophoretic Separation of Red Blood Cells

    CERN Document Server

    Iliescu, Ciprian; Avram, Marioara; Xu, G; Avram, Andrei

    2008-01-01

    This paper presents a microfluidic device for magnetophoretic separation red blood cells from blood under contionous flow. The separation method consist of continous flow of a blood sample (diluted in PBS) through a microfluidic channel which presents on the bottom "dots" of feromagnetic layer. By appling a magnetic field perpendicular on the flowing direction, the feromagnetic "dots" generates a gradient of magnetic field which amplifies the magnetic force. As a result, the red blood cells are captured on the bottom of the microfluidic channel while the rest of the blood is collected at the outlet. Experimental results show that an average of 95 % of red blood cells are trapped in the device

  17. Measurement device for ankle joint kinematic and dynamic characterisation.

    Science.gov (United States)

    Giacomozzi, C; Cesinaro, S; Basile, F; De Angelis, G; Giansanti, D; Maccioni, G; Masci, E; Panella, A; Paolizzi, M; Torre, M; Valentini, P; Macellari, V

    2003-07-01

    The paper describes a measurement device for obtaining the kinematic characterisation and isometric loading of ankle joints under different working conditions. Non-invasive, in vivo experiments can be conducted with this experimental apparatus, the potential of which could be usefully exploited in basic biomedical research, prosthesis design, clinical applications, sports medicine and rehabilitation. The device determines the 3D movement of the foot with respect to the shank and evaluates the torques and moments around the three articular axes in relation to any desired angular position of the ankle complex. When integrated with superficial electromyographic techniques and electrical stimulation, it allows the assessment of the functionality of the lower leg in both mechanical and myo-electrical terms. The paper reports the main mechanical and electronic features of the device (high linearity; maximum moment ranges +/- 300 Nm for flexion-extension, +/- 35 Nm for both pronation-supination and internal-external rotation; angular ranges: +/- 100 degrees of dorsi-plantar flexion, +/- 50 degrees of internal-external rotation and prono-supination; linear ranges: +/- 25 mm along each axis). Results from a healthy volunteer, under voluntary or stimulated conditions, helped in testing its operatability, reliability, robustness, repeatability and effectiveness. Preliminary simplified protocols have been also applied to 20 healthy volunteers, and the main results were 80.8 +/- 11.9 degrees of internalexternal rotation, 46.2 +/- 9.1 degrees of prono-supination and 74.6 +/- 13.1 degrees of flexion-extension. Torques and moments were normalised with respect to a body mass index of 30. The maximum plantar flexion moment (57.5 + 21.3 Nm) was measured with the foot at 150 of dorsal flexion; the maximum dorsal flexion moment (50.2 + 20.3 Nm) was measured with the foot at 150 of plantar flexion.

  18. Quantitative Study of Cell Invasion Process under Extracellular Stimulation of Cytokine in a Microfluidic Device

    Science.gov (United States)

    Lei, Kin Fong; Tseng, Hsueh-Peng; Lee, Chia-Yi; Tsang, Ngan-Ming

    2016-05-01

    Cell invasion is the first step of cancer metastasis that is the primary cause of death for cancer patients and defined as cell movement through extracellular matrix (ECM). Investigation of the correlation between cell invasive and extracellular stimulation is critical for the inhabitation of metastatic dissemination. Conventional cell invasion assay is based on Boyden chamber assay, which has a number of limitations. In this work, a microfluidic device incorporating with impedance measurement technique was developed for quantitative investigation of cell invasion process. The device consisted of 2 reservoirs connecting with a microchannel filled with hydrogel. Malignant cells invaded along the microchannel and impedance measurement was concurrently conducted by measuring across electrodes located at the bottom of the microchannel. Therefore, cell invasion process could be monitored in real-time and non-invasive manner. Also, cell invasion rate was then calculated to study the correlation between cell invasion and extracellular stimulation, i.e., IL-6 cytokine. Results showed that cell invasion rate was directly proportional to the IL-6 concentration. The microfluidic device provides a reliable and convenient platform for cell-based assays to facilitate more quantitative assessments in cancer research.

  19. Single cell array impedance analysis in a microfluidic device

    Science.gov (United States)

    Altinagac, Emre; Taskin, Selen; Kizil, Huseyin

    2016-10-01

    Impedance analysis of single cells is presented in this paper. Following the separation of a target cell type by dielectrophoresis in our previous work, this paper focuses on capturing the cells as a single array and performing impedance analysis to point out the signature difference between each cell type. Lab-on-a-chip devices having a titanium interdigitated electrode layer on a glass substrate and a PDMS microchannel are fabricated to capture each cell in a single form and perform impedance analysis. HCT116 (homosapiens colon colorectal carcin) and HEK293 (human embryonic kidney) cells are used in our experiments.

  20. Alternative schemes for measurement-device-independent quantum key distribution

    CERN Document Server

    Ma, Xiongfeng

    2012-01-01

    A practical scheme for measurement-device-independent quantum key distribution using phase and path/time encoding is presented. In addition to immunity to existing loopholes in detection systems, our setup employs simple encoding and decoding modules without relying on polarization maintenance or optical switches. Moreover, by handling, with a modified sifting technique, the dead time limitations in single-photon detectors, our scheme can be run with only two single-photon detectors. With a phase-post-selection technique, a decoy-state variant of our scheme is also proposed, whose secret key generation rate scales linearly with the channel transmittance.

  1. Different Device Architectures for Bulk-Heterojunction Solar Cells

    Directory of Open Access Journals (Sweden)

    Getachew Adam

    2016-08-01

    Full Text Available We report different solar cell designs which allow a simple electrical connection of subsequent devices deposited on the same substrate. By arranging so-called standard and inverted solar-cell architectures next to each other, a serial connection of the two devices can easily be realized by a single compound electrode. In this work, we tested different interfacial layer materials like polyethylenimine (PEI and PEDOT:PSS, and silver as a non-transparent electrode material. We also built organic light emitting diodes applying the same device designs demonstrating the versatility of applied layer stacks. The proposed design should allow the preparation of organic bulk-heterojunction modules with minimized photovoltaically inactive regions at the interconnection of individual devices.

  2. Using a microfluidic device for high-content analysis of cell signaling.

    Science.gov (United States)

    Cheong, Raymond; Wang, Chiaochun Joanne; Levchenko, Andre

    2009-06-16

    Quantitative analysis and understanding of signaling networks require measurements of the location and activities of key proteins over time, at the level of single cells, in response to various perturbations. Microfluidic devices enable such analyses to be conducted in a high-throughput and in a highly controlled manner. We describe in detail how to design and use a microfluidic device to perform such information-rich experiments.

  3. A Device to Measure the Propulsive Power of Nematodes

    CERN Document Server

    Yuan, J; Gnatt, M; Raizen, D M; Bau, H H

    2011-01-01

    In the fluid dynamics video, we present a microfluidic device to measure the propulsive power of nematodes. The device consists of a tapered conduit filled with aqueous solution. The conduit is subjected to a DC electric field with the negative pole at the narrow end and to pressure-driven flow directed from the narrow end. The nematode is inserted at the conduit's wide end. Directed by the electric field (through electrotaxis), the nematode swims deliberately upstream toward the negative pole of the DC field. As the conduit narrows, the average fluid velocity and the drag force on the nematode increase. Eventually, the nematode arrives at an equilibrium position, at which its propulsive force balances the viscous drag force induced by the adverse flow. The equilibrium position of different animals, with similar body lengths, was measured as a function of the flow rate. The flow field around the nematode was obtained by direct numerical simulations with the experimentally imaged gait and the tapered geometry ...

  4. Design of a Device for Sky Light Polarization Measurements

    Directory of Open Access Journals (Sweden)

    Yujie Wang

    2014-08-01

    Full Text Available ky polarization patterns can be used both as indicators of atmospheric turbidity and as a sun compass for navigation. The objective of this study is to improve the precision of sky light polarization measurements by optimal design of the device used. The central part of the system is composed of a Charge Coupled Device (CCD camera; a fish-eye lens and a linear polarizer. Algorithms for estimating parameters of the polarized light based on three images are derived and the optimal alignments of the polarizer are analyzed. The least-squares estimation is introduced for sky light polarization pattern measurement. The polarization patterns of sky light are obtained using the designed system and they follow almost the same patterns of the single-scattering Rayleigh model. Deviations of polarization angles between observation and the theory are analyzed. The largest deviations occur near the sun and anti-sun directions. Ninety percent of the deviations are less than 5° and 40% percent of them are less than 1°. The deviations decrease evidently as the degree of polarization increases. It also shows that the polarization pattern of the cloudy sky is almost identical as in the blue sky.

  5. Design and Fabrication a Microfluidic Device for Fetal Cells Dielectrophoretic Properties Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Xu Guolin [Institute of Bioengineering and Nanotechnologies, 31 Biopolis, Way, The Nanos, hashmark 04-01, Singapore 138669 (Singapore); Chan, M B [Nanyang Technological University, Singapore. 16 Nanyang Drive, Singapore 637722 (Singapore); Yang, Charles [Nanyang Technological University, Singapore. 16 Nanyang Drive, Singapore 637722 (Singapore); Sukumar, P [National University Hospital, Singapore. 10 Medical Drive, Singapore 117597 (Singapore); Choolani, M [National University Hospital, Singapore. 10 Medical Drive, Singapore 117597 (Singapore); Ying, Jackie Y [Institute of Bioengineering and Nanotechnologies, 31 Biopolis, Way, The Nanos, hashmark 04-01, Singapore 138669 (Singapore)

    2006-04-01

    The present work presents a microfluidic device with interdigitated microelectrode and microchannel for fetal nucleated red blood cell dielectrophoresis properties characterization using crossover frequency method. To obtain the electric field and its gradient along the microchannel, simulation study was done by using MAXWELL{sup TM} software. Results show maximum electric field and gradient are obtained near the electrode edge and they are affected by electrode width and the electrode gap. The crossover frequency should be obtained by keeping the cell moving near the electrode edge. The device has been successfully used in fetal cell characterization with better than 1KHz frequency repeatability, which is about 2% of the measured crossover frequency.

  6. Sublimation measurements and analysis of high temperature thermoelectric materials and devices

    Science.gov (United States)

    Shields, V.; Noon, L.

    1983-01-01

    High temperature thermoelectric device sublimation effects are compared for rare earth sulfides, selenides, and state-of-the-art Si-Ge alloys. Although rare earth calcogenides can potentially exhibit superior sublimation characteristics, the state-of-the-art Si-Ge alloy with silicon nitride sublimation-inhibitive coating has been tested to 1000 C. Attention is given to the ceramic electrolyte cells, forming within electrical and thermal insulation, which affect leakage conductance measurements in Si-Ge thermoelectric generators.

  7. Testing limits to airflow perturbation device (APD measurements

    Directory of Open Access Journals (Sweden)

    Jamshidi Shaya

    2008-10-01

    Full Text Available Abstract Background The Airflow Perturbation Device (APD is a lightweight, portable device that can be used to measure total respiratory resistance as well as inhalation and exhalation resistances. There is a need to determine limits to the accuracy of APD measurements for different conditions likely to occur: leaks around the mouthpiece, use of an oronasal mask, and the addition of resistance in the respiratory system. Also, there is a need for resistance measurements in patients who are ventilated. Method Ten subjects between the ages of 18 and 35 were tested for each station in the experiment. The first station involved testing the effects of leaks of known sizes on APD measurements. The second station tested the use of an oronasal mask used in conjunction with the APD during nose and mouth breathing. The third station tested the effects of two different resistances added in series with the APD mouthpiece. The fourth station tested the usage of a flexible ventilator tube in conjunction with the APD. Results All leaks reduced APD resistance measurement values. Leaks represented by two 3.2 mm diameter tubes reduced measured resistance by about 10% (4.2 cmH2O·sec/L for control and 3.9 cm H2O·sec/L for the leak. This was not statistically significant. Larger leaks given by 4.8 and 6.4 mm tubes reduced measurements significantly (3.4 and 3.0 cm cmH2O·sec/L, respectively. Mouth resistance measured with a cardboard mouthpiece gave an APD measurement of 4.2 cm H2O·sec/L and mouth resistance measured with an oronasal mask was 4.5 cm H2O·sec/L; the two were not significantly different. Nose resistance measured with the oronasal mask was 7.6 cm H2O·sec/L. Adding airflow resistances of 1.12 and 2.10 cm H2O·sec/L to the breathing circuit between the mouth and APD yielded respiratory resistance values higher than the control by 0.7 and 2.0 cm H2O·sec/L. Although breathing through a 52 cm length of flexible ventilator tubing reduced the APD

  8. Performance Measurement of a Multi-Level/Analog Ferroelectric Memory Device Design

    Science.gov (United States)

    MacLeod, Todd C.; Phillips, Thomas A.; Ho, Fat D.

    2007-01-01

    Increasing the memory density and utilizing the unique characteristics of ferroelectric devices is important in making ferroelectric memory devices more desirable to the consumer. This paper describes the characterization of a design that allows multiple levels to be stored in a ferroelectric based memory cell. It can be used to store multiple bits or analog values in a high speed nonvolatile memory. The design utilizes the hysteresis characteristic of ferroelectric transistors to store an analog value in the memory cell. The design also compensates for the decay of the polarization of the ferroelectric material over time. This is done by utilizing a pair of ferroelectric transistors to store the data. One transistor is used a reference to determinethe amount of decay that has occurred since the pair was programmed. The second transistor stores the analog value as a polarization value between zero and saturated. The design allows digital data to be stored as multiple bits in each memory cell. The number of bits per cell that can be stored will vary with the decay rate of the ferroelectric transistors and the repeatability of polarization between transistors. This paper presents measurements of an actual prototype memory cell. This prototype is not a complete implementation of a device, but instead, a prototype of the storage and retrieval portion of an actual device. The performance of this prototype is presented with the projected performance of the overall device. This memory design will be useful because it allows higher memory density, compensates for the environmental and ferroelectric aging processes, allows analog values to be directly stored in memory, compensates for the thermal and radiation environments associated with space operations, and relies only on existing technologies.

  9. Microfluidic Devices for the Measurement of Cellular Secretion

    Science.gov (United States)

    Schrell, Adrian M.; Mukhitov, Nikita; Yi, Lian; Wang, Xue; Roper, Michael G.

    2016-06-01

    The release of chemical information from cells and tissues holds the key to understanding cellular behavior and dysfunction. The development of methodologies that can measure cellular secretion in a time-dependent fashion is therefore essential. Often these measurements are made difficult by the high-salt conditions of the cellular environment, the presence of numerous other secreted factors, and the small mass samples that are produced when frequent sampling is used to resolve secretory dynamics. In this review, the methods that we have developed for measuring hormone release from islets of Langerhans are dissected to illustrate the practical difficulties of studying cellular secretions. Other methods from the literature are presented that provide alternative approaches to particularly challenging areas of monitoring cellular secretion. The examples presented in this review serve as case studies and should be adaptable to other cell types and systems for unique applications.

  10. Measurements of elastic moduli of silicone gel substrates with a microfluidic device.

    Science.gov (United States)

    Gutierrez, Edgar; Groisman, Alex

    2011-01-01

    Thin layers of gels with mechanical properties mimicking animal tissues are widely used to study the rigidity sensing of adherent animal cells and to measure forces applied by cells to their substrate with traction force microscopy. The gels are usually based on polyacrylamide and their elastic modulus is measured with an atomic force microscope (AFM). Here we present a simple microfluidic device that generates high shear stresses in a laminar flow above a gel-coated substrate and apply the device to gels with elastic moduli in a range from 0.4 to 300 kPa that are all prepared by mixing two components of a transparent commercial silicone Sylgard 184. The elastic modulus is measured by tracking beads on the gel surface under a wide-field fluorescence microscope without any other specialized equipment. The measurements have small and simple to estimate errors and their results are confirmed by conventional tensile tests. A master curve is obtained relating the mixing ratios of the two components of Sylgard 184 with the resulting elastic moduli of the gels. The rigidity of the silicone gels is less susceptible to effects from drying, swelling, and aging than polyacrylamide gels and can be easily coated with fluorescent tracer particles and with molecules promoting cellular adhesion. This work can lead to broader use of silicone gels in the cell biology laboratory and to improved repeatability and accuracy of cell traction force microscopy and rigidity sensing experiments.

  11. Measurements of elastic moduli of silicone gel substrates with a microfluidic device.

    Directory of Open Access Journals (Sweden)

    Edgar Gutierrez

    Full Text Available Thin layers of gels with mechanical properties mimicking animal tissues are widely used to study the rigidity sensing of adherent animal cells and to measure forces applied by cells to their substrate with traction force microscopy. The gels are usually based on polyacrylamide and their elastic modulus is measured with an atomic force microscope (AFM. Here we present a simple microfluidic device that generates high shear stresses in a laminar flow above a gel-coated substrate and apply the device to gels with elastic moduli in a range from 0.4 to 300 kPa that are all prepared by mixing two components of a transparent commercial silicone Sylgard 184. The elastic modulus is measured by tracking beads on the gel surface under a wide-field fluorescence microscope without any other specialized equipment. The measurements have small and simple to estimate errors and their results are confirmed by conventional tensile tests. A master curve is obtained relating the mixing ratios of the two components of Sylgard 184 with the resulting elastic moduli of the gels. The rigidity of the silicone gels is less susceptible to effects from drying, swelling, and aging than polyacrylamide gels and can be easily coated with fluorescent tracer particles and with molecules promoting cellular adhesion. This work can lead to broader use of silicone gels in the cell biology laboratory and to improved repeatability and accuracy of cell traction force microscopy and rigidity sensing experiments.

  12. Infrared Emissivity Measurements of Building and Civil Engineering Materials: A New Device for Measuring Emissivity

    Science.gov (United States)

    Monchau, Jean-Pierre; Marchetti, Mario; Ibos, Laurent; Dumoulin, Jean; Feuillet, Vincent; Candau, Yves

    2014-10-01

    The knowledge of the infrared emissivity of materials used in buildings and civil engineering structures is useful for two specific approaches. First, quantitative diagnosis of buildings or civil engineering infrastructures by infrared thermography requires emissivity values in the spectral bandwidth of the camera used for measurements, in order to obtain accurate surface temperatures; for instance, emissivity in the band III domain is required when using cameras with uncooled detectors (such as micro-bolometer arrays). Second, setting up accurate thermal balances by numerical modeling requires the total emissivity value for a large wavelength domain; this is, for instance, the case for computing the road surface temperature to predict ice occurrence. Furthermore, periodical surveys of emissivity variations due to aging or soiling of surfaces could be useful in many situations such as thermal mapping of roads or building insulation diagnosis. The use of portable emissivity measurement devices is required for that purpose. A device using an indirect measurement method was previously developed in our lab; the method uses measurement of the reflectivity from a modulated IR source and requires calibration with a highly reflective surface. However, that device uses a low-frequency, thermal modulation well adapted to laboratory measurements but unfit for fast and in situ measurements. Therefore, a new, portable system which retains the principle of an indirect measurement but uses a faster-frequency, mechanical modulation more appropriate to outdoor measurements was developed. Both devices allow measurements in the broad m to m) and narrow m to m) bands. Experiments were performed on a large number of materials commonly used in buildings and civil engineering structures. The final objective of this work is to build a database of emissivity of these materials. A comparison of laboratory and on-site measurements of emissivity values obtained in both spectral bands will be

  13. Crack Offset Measurement With the Projected Laser Target Device

    Science.gov (United States)

    2008-01-01

    The device and associated analysis methodology summarized in this report were developed for the purpose of estimating the size of discontinuities in the surface of the foam that covers the Space Shuttle External Tank. These surface offsets are thought to be due to subsurface cracks in the foam insulation. The mathematical analysis and procedure described here provide a method to quantity the dimensions of the crack offset in a direction perpendicular to the surface, making use of the projected laser target device (PLTD) tool and a laser line projector. The keys to the construction and use of the PLTD are the following geometrical design requirements: Laser dots are on a square grid: length on a side. Laser beams are perpendicular to projected surface. Beams are parallel out to the distance being projected. The PLTD can be used to (1) calibrate fixed cameras of unknown magnification and orientation (far-field solution); (2) provide equivalent calibration to multiple cameras, previously achieved only by the use of known target points, for example, in 3.D foreign-object debris tracking on a fixed launch platform; (3) compute scaling for conventional 2.D images, and depth of field for 3.D images (near-field solution); and (4) in conjunction with a laser line projector, achieve accurate measurements of surface discontinuity (cracks) in a direction perpendicular to the surface.

  14. Device-independent quantum key distribution based on measurement inputs

    Science.gov (United States)

    Rahaman, Ramij; Parker, Matthew G.; Mironowicz, Piotr; Pawłowski, Marcin

    2015-12-01

    We provide an analysis of a family of device-independent quantum key distribution (QKD) protocols that has the following features. (a) The bits used for the secret key do not come from the results of the measurements on an entangled state but from the choices of settings. (b) Instead of a single security parameter (a violation of some Bell inequality) a set of them is used to estimate the level of trust in the secrecy of the key. The main advantage of these protocols is a smaller vulnerability to imperfect random number generators made possible by feature (a). We prove the security and the robustness of such protocols. We show that using our method it is possible to construct a QKD protocol which retains its security even if the source of randomness used by communicating parties is strongly biased. As a proof of principle, an explicit example of a protocol based on the Hardy's paradox is presented. Moreover, in the noiseless case, the protocol is secure in a natural way against any type of memory attack, and thus allows one to reuse the device in subsequent rounds. We also analyze the robustness of the protocol using semidefinite programming methods. Finally, we present a postprocessing method, and observe a paradoxical property that rejecting some random part of the private data can increase the key rate of the protocol.

  15. Nanostructured cavity devices for extracellular stimulation of HL-1 cells.

    Science.gov (United States)

    Czeschik, Anna; Rinklin, Philipp; Derra, Ulrike; Ullmann, Sabrina; Holik, Peter; Steltenkamp, Siegfried; Offenhäusser, Andreas; Wolfrum, Bernhard

    2015-01-01

    Microelectrode arrays (MEAs) are state-of-the-art devices for extracellular recording and stimulation on biological tissue. Furthermore, they are a relevant tool for the development of biomedical applications like retina, cochlear and motor prostheses, cardiac pacemakers and drug screening. Hence, research on functional cell-sensor interfaces, as well as the development of new surface structures and modifications for improved electrode characteristics, is a vivid and well established field. However, combining single-cell resolution with sufficient signal coupling remains challenging due to poor cell-electrode sealing. Furthermore, electrodes with diameters below 20 µm often suffer from a high electrical impedance affecting the noise during voltage recordings. In this study, we report on a nanocavity sensor array for voltage-controlled stimulation and extracellular action potential recordings on cellular networks. Nanocavity devices combine the advantages of low-impedance electrodes with small cell-chip interfaces, preserving a high spatial resolution for recording and stimulation. A reservoir between opening aperture and electrode is provided, allowing the cell to access the structure for a tight cell-sensor sealing. We present the well-controlled fabrication process and the effect of cavity formation and electrode patterning on the sensor's impedance. Further, we demonstrate reliable voltage-controlled stimulation using nanostructured cavity devices by capturing the pacemaker of an HL-1 cell network.

  16. Practical, microfabrication-free device for single-cell isolation.

    Directory of Open Access Journals (Sweden)

    Liang-I Lin

    Full Text Available Microfabricated devices have great potential in cell-level studies, but are not easily accessible for the broad biology community. This paper introduces the Microscale Oil-Covered Cell Array (MOCCA as a low-cost device for high throughput single-cell analysis that can be easily produced by researchers without microengineering knowledge. Instead of using microfabricated structures to capture cells, MOCCA isolates cells in discrete aqueous droplets that are separated by oil on patterned hydrophilic areas across a relatively more hydrophobic substrate. The number of randomly seeded Escherichia coli bacteria in each discrete droplet approaches single-cell levels. The cell distribution on MOCCA is well-fit with Poisson distribution. In this pioneer study, we created an array of 900-picoliter droplets. The total time needed to seed cells in approximately 3000 droplets was less than 10 minutes. Compared to traditional microfabrication techniques, MOCCA dramatically lowers the cost of microscale cell arrays, yet enhances the fabrication and operational efficiency for single-cell analysis.

  17. Diffusion phenomena of cells and biomolecules in microfluidic devices.

    Science.gov (United States)

    Yildiz-Ozturk, Ece; Yesil-Celiktas, Ozlem

    2015-09-01

    Biomicrofluidics is an emerging field at the cross roads of microfluidics and life sciences which requires intensive research efforts in terms of introducing appropriate designs, production techniques, and analysis. The ultimate goal is to deliver innovative and cost-effective microfluidic devices to biotech, biomedical, and pharmaceutical industries. Therefore, creating an in-depth understanding of the transport phenomena of cells and biomolecules becomes vital and concurrently poses significant challenges. The present article outlines the recent advancements in diffusion phenomena of cells and biomolecules by highlighting transport principles from an engineering perspective, cell responses in microfluidic devices with emphases on diffusion- and flow-based microfluidic gradient platforms, macroscopic and microscopic approaches for investigating the diffusion phenomena of biomolecules, microfluidic platforms for the delivery of these molecules, as well as the state of the art in biological applications of mammalian cell responses and diffusion of biomolecules.

  18. Memory-assisted measurement-device-independent quantum key distribution

    Science.gov (United States)

    Panayi, Christiana; Razavi, Mohsen; Ma, Xiongfeng; Lütkenhaus, Norbert

    2014-04-01

    A protocol with the potential of beating the existing distance records for conventional quantum key distribution (QKD) systems is proposed. It borrows ideas from quantum repeaters by using memories in the middle of the link, and that of measurement-device-independent QKD, which only requires optical source equipment at the user's end. For certain memories with short access times, our scheme allows a higher repetition rate than that of quantum repeaters with single-mode memories, thereby requiring lower coherence times. By accounting for various sources of nonideality, such as memory decoherence, dark counts, misalignment errors, and background noise, as well as timing issues with memories, we develop a mathematical framework within which we can compare QKD systems with and without memories. In particular, we show that with the state-of-the-art technology for quantum memories, it is potentially possible to devise memory-assisted QKD systems that, at certain distances of practical interest, outperform current QKD implementations.

  19. A device model for the tandem junction solar cell

    Science.gov (United States)

    Matzen, W. T.; Chiang, S. Y.; Carbajal, B. G.

    1979-01-01

    A conceptual device model has been developed to explain operation of the tandem junction cell (TJC) when back contacts only are used. Operation and parameters of the cell are explained by transistor action. Experimental observations are presented which confirm that current is collected for carrier generation in the front uncontacted n(plus) region. The model should be useful as a guideline to optimize the TJC by application of transistor design principles.

  20. Integrated Love Wave Device Dedicated to Biomolecular Interactions Measurements in Aqueous Media

    Directory of Open Access Journals (Sweden)

    Sylvain Ballandras

    2007-09-01

    Full Text Available Mass-sensitive electro-acoustic devices such as surface acoustic wave (SAWmicro-balances, capable to operate with aqueous media are particularly favorable for thedevelopment of biosensors. Their dimensions and physical properties offer a large potentialin biological fluid investigations, especially for measuring physical phenomenon (massdeposition, adsorption, pressure.... In this work, we propose a specific gratingconfiguration to lower the influence of viscosity of fluids which reduces the signal dynamicsof the surface wave transducers. A dedicated liquid cell also has been developed to isolatethe electro-active part of the device. The fabrication of the cell is achieved using theSU-8TMphoto-resist, allowing for manufacturing thick structures preventing any contact between thetested liquids and the transducers. Furthermore, the sensing area has been optimized tooptimize the sensor gravimetric sensitivity. The operation of the sensor is illustrated bydetecting bovine serum albumin (BSA adsorption in the sensing area.

  1. Characterization of perovskite solar cells: Towards a reliable measurement protocol

    Directory of Open Access Journals (Sweden)

    Eugen Zimmermann

    2016-09-01

    Full Text Available Lead halide perovskite solar cells have shown a tremendous rise in power conversion efficiency with reported record efficiencies of over 20% making this material very promising as a low cost alternative to conventional inorganic solar cells. However, due to a differently severe “hysteretic” behaviour during current density-voltage measurements, which strongly depends on scan rate, device and measurement history, preparation method, device architecture, etc., commonly used solar cell measurements do not give reliable or even reproducible results. For the aspect of commercialization and the possibility to compare results of different devices among different laboratories, it is necessary to establish a measurement protocol which gives reproducible results. Therefore, we compare device characteristics derived from standard current density-voltage measurements with stabilized values obtained from an adaptive tracking of the maximum power point and the open circuit voltage as well as characteristics extracted from time resolved current density-voltage measurements. Our results provide insight into the challenges of a correct determination of device performance and propose a measurement protocol for a reliable characterisation which is easy to implement and has been tested on varying perovskite solar cells fabricated in different laboratories.

  2. Characterization of perovskite solar cells: Towards a reliable measurement protocol

    Science.gov (United States)

    Zimmermann, Eugen; Wong, Ka Kan; Müller, Michael; Hu, Hao; Ehrenreich, Philipp; Kohlstädt, Markus; Würfel, Uli; Mastroianni, Simone; Mathiazhagan, Gayathri; Hinsch, Andreas; Gujar, Tanaji P.; Thelakkat, Mukundan; Pfadler, Thomas; Schmidt-Mende, Lukas

    2016-09-01

    Lead halide perovskite solar cells have shown a tremendous rise in power conversion efficiency with reported record efficiencies of over 20% making this material very promising as a low cost alternative to conventional inorganic solar cells. However, due to a differently severe "hysteretic" behaviour during current density-voltage measurements, which strongly depends on scan rate, device and measurement history, preparation method, device architecture, etc., commonly used solar cell measurements do not give reliable or even reproducible results. For the aspect of commercialization and the possibility to compare results of different devices among different laboratories, it is necessary to establish a measurement protocol which gives reproducible results. Therefore, we compare device characteristics derived from standard current density-voltage measurements with stabilized values obtained from an adaptive tracking of the maximum power point and the open circuit voltage as well as characteristics extracted from time resolved current density-voltage measurements. Our results provide insight into the challenges of a correct determination of device performance and propose a measurement protocol for a reliable characterisation which is easy to implement and has been tested on varying perovskite solar cells fabricated in different laboratories.

  3. Single vegetal cell handling and fixing in a microfluidic device

    Science.gov (United States)

    Denoual, Matthieu J.; Koh, Aoki; Mita-Tixier, Agnes; Fujita, Hiroyuki

    2003-04-01

    The basic advantage of the microfluidic systems is that they enable reducing consumption of biological material and chemicals. But another major advantage of the microfluidic systems, not widely explored so far, is that with feature sizes reduced toward the size of cells, one can easily handle and fix a single cell. The interest of single cell handling and fixing appears when one wants to study biochemical exchanges between single cells or internal biochemical reactions inside an isolated cell. This work uses the shape of the microfluidc device to control the migration and placement of single vegetal cells. Three-dimensional micro-molding and poly-dimethylsiloxane (PDMS) patterning techniques have been used to realize device prototypes. Double-height micro-molds are made of thick negative photoresist (SU8) Experiments have been undergone to optimize fluid rate flow and cell concentration regarding to right cell placement percentage. The PDMS prototypes systems confirm the good operation of the design to migrate cells, place and fix them. The placement rate, even if it is enough for statistical biochemical experiments, will be improved by the use of new material. New material will allow to get rid of air bubbles due to PDMS long-term hydrophobicity that render up to 25% settlement places unserviceable.

  4. [Mobile Health: IEEE Standard for Wearable Cuffless Blood Pressure Measuring Devices].

    Science.gov (United States)

    Zhou, Xia; Wu, Wenli; Bao, Shudi

    2015-07-01

    IEEE Std 1708-2014 breaks through the traditional standards of cuff based blood pressure measuring devices and establishes a normative definition of wearable cuffless blood pressure measuring devices and the objective performance evaluation of this kind of devices. This study firstly introduces the background of the new standard. Then, the standard details will be described, and the impact of cuffless blood pressure measuring devices with the new standard on manufacturers and end users will be addressed.

  5. Material and Device Stability in Perovskite Solar Cells.

    Science.gov (United States)

    Kim, Hui-Seon; Seo, Ja-Young; Park, Nam-Gyu

    2016-09-22

    Organic-inorganic halide perovskite solar cells have attracted great attention because of their superb efficiency reaching 22 % and low-cost, facile fabrication processing. Nevertheless, stability issues in perovskite solar cells seem to block further advancements toward commercialization. Thus, device stability is one of the important topics in perovskite solar cell research. In the beginning, the poor moisture resistivity of the perovskite layer was considered as a main problem that hindered further development of perovskite solar cells, which encouraged engineering of the perovskite or protection of the perovskite by a buffer layer. Soon after, other parameters affecting long-term stability were sequentially found and various attempts have been made to enhance intrinsic and extrinsic stability. Here we review the recent progresses addressing stability issues in perovskite solar cells. In this report, we investigated factors affecting stability from material and device points of view. To gain a better understanding of the stability of the bulk perovskite material, decomposition mechanisms were investigated in relation to moisture, photons, and heat. Stability of full device should also be carefully examined because its stability is dependent not only on bulk perovskite but also on the interfaces and selective contacts. In addition, ion migration and current-voltage hysteresis were found to be closely related to stability.

  6. Acoustic Devices for Particle and Cell Manipulation and Sensing

    Directory of Open Access Journals (Sweden)

    Yongqiang Qiu

    2014-08-01

    Full Text Available An emerging demand for the precise manipulation of cells and particles for applications in cell biology and analytical chemistry has driven rapid development of ultrasonic manipulation technology. Compared to the other manipulation technologies, such as magnetic tweezing, dielectrophoresis and optical tweezing, ultrasonic manipulation has shown potential in a variety of applications, with its advantages of versatile, inexpensive and easy integration into microfluidic systems, maintenance of cell viability, and generation of sufficient forces to handle particles, cells and their agglomerates. This article briefly reviews current practice and reports our development of various ultrasonic standing wave manipulation devices, including simple devices integrated with high frequency (>20 MHz ultrasonic transducers for the investigation of biological cells and complex ultrasonic transducer array systems to explore the feasibility of electronically controlled 2-D and 3-D manipulation. Piezoelectric and passive materials, fabrication techniques, characterization methods and possible applications are discussed. The behavior and performance of the devices have been investigated and predicted with computer simulations, and verified experimentally. Issues met during development are highlighted and discussed. To assist long term practical adoption, approaches to low-cost, wafer level batch-production and commercialization potential are also addressed.

  7. Characterization of a novel miniature cell culture device

    Science.gov (United States)

    Moore, Sandra K.; Kleis, Stanley J.

    2008-05-01

    Recent advancements in the field of microfluidics have generated much interest in the advent of a miniaturized cell culture device. In this study, we developed a novel miniature culture system (cells, either prokaryotic or eukaryotic in type, for both 1 g and microgravity applications. The miniature culture system may advance the development of microanalytical remote monitoring tools such as biological sentinels, biosensors, and lab-on-a-chip. Integrating the autonomous miniature culture system with a microanalytical device makes a powerful biological tool. Cells can be cultured long-term, harvested, and released directly into an analytical tool without the need for human interaction through fluid dynamic manipulations. This work characterizes the miniature bioreactor system through numerical and experimental proof of concept studies.

  8. Evaluation of spectrum measurement devices for operational use

    CERN Document Server

    Devine, R T; Gray, D W; Seagraves, D T; Olsher, R H; Johnson, J P

    2002-01-01

    Several neutron spectrometers manufactured by Bubble Technology Industries (BTI) were tested and evaluated in a variety of neutron fields. Findings and conclusions are presented for the following BTI instruments: a modification of the Rotational Spectrometer (ROSPEC) that includes a thermal and epithermal capability, the Simple Scintillation Spectrometer that is used in conjunction with the ROSPEC to extend its high-energy range, and the MICROSPEC N-Probe which is capable of providing a crude spectrum over the energy range from thermal to 18 MeV. The main objective of these measurements was to determine the accuracy of both the energy spectrum and dose equivalent information generated by these devices. In addition, the dose response of the Wide-Energy Neutron Detection Instrument (WENDI-II) was measured in all neutron fields relative to a bare sup 2 sup 5 sup 2 Cf calibration. The performance of the WENDI-II rem meter was compared to the dose information generated by the neutron spectrometers. The instruments...

  9. Measurement of radial artery spasm using an automatic pullback device.

    Science.gov (United States)

    Kiemeneij, F; Vajifdar, B U; Eccleshall, S C; Laarman, G; Slagboom, T; van der Wieken, R

    2001-12-01

    Current evaluation of radial artery spasm (RAS), a frequent finding during the transradial approach for coronary angiography and angioplasty (TRA), is subjective. A quantitative measure of RAS will help in evaluation and comparison of management strategies. The objectives of the study were to assess the feasibility and safety of using an automatic pullback device (APD) for removal of transradial introducer sheaths and to establish a parameter to quantify RAS. In 50 consecutive transradial procedures, the APD was used to measure the force required for sheath removal. The mean maximal pullback force (MPF) was 0.53 +/- 0.52 kg (range, 0.1-3.0 kg). In 48 (96%) cases, the MPF was reached within the first 5 sec of pullback. All patients with clinical RAS (n = 4) had an MPF greater than 1.0 kg, while the remaining had an MPF less than 1.0 kg. All patients with severe pain during sheath removal (n = 3) had an MPF greater than 1.0 kg, while no patient with an MPF less than 1.0 kg had severe pain. It is feasible and safe to remove transradial introducer sheaths using the APD. The MPF is achieved within the first 5 sec of pullback and is a reliable parameter to quantify RAS. An MPF more than 1.0 kg correlates with clinical RAS and is associated with severe pain during sheath removal.

  10. Novel Hydrogen Purification Device Integrated with PEM Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Joseph Schwartz; Hankwon Lim; Raymond Drnevich

    2010-12-31

    A prototype device containing twelve membrane tubes was designed, built, and demonstrated. The device produced almost 300 scfh of purified hydrogen at 200 psig feed pressure. The extent of purification met the program target of selectively removing enough impurities to enable industrial-grade hydrogen to meet purity specifications for PEM fuel cells. An extrusion process was developed to produce substrate tubes. Membranes met several test objectives, including completing 20 thermal cycles, exceeding 250 hours of operating life, and demonstrating a flux of 965 scfh/ft2 at 200 psid and 400 C.

  11. A device for rapid and quantitative measurement of cardiac myocyte contractility

    Science.gov (United States)

    Gaitas, Angelo; Malhotra, Ricky; Li, Tao; Herron, Todd; Jalife, José

    2015-03-01

    Cardiac contractility is the hallmark of cardiac function and is a predictor of healthy or diseased cardiac muscle. Despite advancements over the last two decades, the techniques and tools available to cardiovascular scientists are limited in their utility to accurately and reliably measure the amplitude and frequency of cardiomyocyte contractions. Isometric force measurements in the past have entailed cumbersome attachment of isolated and permeabilized cardiomyocytes to a force transducer followed by measurements of sarcomere lengths under conditions of submaximal and maximal Ca2+ activation. These techniques have the inherent disadvantages of being labor intensive and costly. We have engineered a micro-machined cantilever sensor with an embedded deflection-sensing element that, in preliminary experiments, has demonstrated to reliably measure cardiac cell contractions in real-time. Here, we describe this new bioengineering tool with applicability in the cardiovascular research field to effectively and reliably measure cardiac cell contractility in a quantitative manner. We measured contractility in both primary neonatal rat heart cardiomyocyte monolayers that demonstrated a beat frequency of 3 Hz as well as human embryonic stem cell-derived cardiomyocytes with a contractile frequency of about 1 Hz. We also employed the β-adrenergic agonist isoproterenol (100 nmol l-1) and observed that our cantilever demonstrated high sensitivity in detecting subtle changes in both chronotropic and inotropic responses of monolayers. This report describes the utility of our micro-device in both basic cardiovascular research as well as in small molecule drug discovery to monitor cardiac cell contractions.

  12. Single cell analysis of yeast replicative aging using a new generation of microfluidic device.

    Directory of Open Access Journals (Sweden)

    Yi Zhang

    Full Text Available A major limitation to yeast aging study has been the inability to track mother cells and observe molecular markers during the aging process. The traditional lifespan assay relies on manual micro-manipulation to remove daughter cells from the mother, which is laborious, time consuming, and does not allow long term tracking with high resolution microscopy. Recently, we have developed a microfluidic system capable of retaining mother cells in the microfluidic chambers while removing daughter cells automatically, making it possible to observe fluorescent reporters in single cells throughout their lifespan. Here we report the development of a new generation of microfluidic device that overcomes several limitations of the previous system, making it easier to fabricate and operate, and allowing functions not possible with the previous design. The basic unit of the device consists of microfluidic channels with pensile columns that can physically trap the mother cells while allowing the removal of daughter cells automatically by the flow of the fresh media. The whole microfluidic device contains multiple independent units operating in parallel, allowing simultaneous analysis of multiple strains. Using this system, we have reproduced the lifespan curves for the known long and short-lived mutants, demonstrating the power of the device for automated lifespan measurement. Following fluorescent reporters in single mother cells throughout their lifespan, we discovered a surprising change of expression of the translation elongation factor TEF2 during aging, suggesting altered translational control in aged mother cells. Utilizing the capability of the new device to trap mother-daughter pairs, we analyzed mother-daughter inheritance and found age dependent asymmetric partitioning of a general stress response reporter between mother and daughter cells.

  13. Nanostructured cavity devices for extracellular stimulation of HL-1 cells

    Science.gov (United States)

    Czeschik, Anna; Rinklin, Philipp; Derra, Ulrike; Ullmann, Sabrina; Holik, Peter; Steltenkamp, Siegfried; Offenhäusser, Andreas; Wolfrum, Bernhard

    2015-05-01

    Microelectrode arrays (MEAs) are state-of-the-art devices for extracellular recording and stimulation on biological tissue. Furthermore, they are a relevant tool for the development of biomedical applications like retina, cochlear and motor prostheses, cardiac pacemakers and drug screening. Hence, research on functional cell-sensor interfaces, as well as the development of new surface structures and modifications for improved electrode characteristics, is a vivid and well established field. However, combining single-cell resolution with sufficient signal coupling remains challenging due to poor cell-electrode sealing. Furthermore, electrodes with diameters below 20 µm often suffer from a high electrical impedance affecting the noise during voltage recordings. In this study, we report on a nanocavity sensor array for voltage-controlled stimulation and extracellular action potential recordings on cellular networks. Nanocavity devices combine the advantages of low-impedance electrodes with small cell-chip interfaces, preserving a high spatial resolution for recording and stimulation. A reservoir between opening aperture and electrode is provided, allowing the cell to access the structure for a tight cell-sensor sealing. We present the well-controlled fabrication process and the effect of cavity formation and electrode patterning on the sensor's impedance. Further, we demonstrate reliable voltage-controlled stimulation using nanostructured cavity devices by capturing the pacemaker of an HL-1 cell network.Microelectrode arrays (MEAs) are state-of-the-art devices for extracellular recording and stimulation on biological tissue. Furthermore, they are a relevant tool for the development of biomedical applications like retina, cochlear and motor prostheses, cardiac pacemakers and drug screening. Hence, research on functional cell-sensor interfaces, as well as the development of new surface structures and modifications for improved electrode characteristics, is a vivid and

  14. Simple uniaxial pressure device for ac-susceptibility measurements suitable for closed cycle refrigerator system.

    Science.gov (United States)

    Arumugam, S; Manivannan, N; Murugeswari, A

    2007-06-01

    A simple design of the uniaxial pressure device for the measurement of ac-susceptibility at low temperatures using closed cycle refrigerator system is presented for the first time. This device consists of disc micrometer, spring holder attachment, uniaxial pressure cell, and the ac-susceptibility coil wound on stycast bobbin. It can work under pressure till 0.5 GPa and at the temperature range of 30-300 K. The performance of the system at ambient pressure is tested and calibrated with standard paramagnetic salts [Gd(2)O(3), Er(2)O(3), and Fe(NH(4)SO(4))(2)6H(2)O], Fe(3)O(4), Gd metal, Dy metal, superconductor (YBa(2)Cu(3)O(7)), manganite (La(1.85)Ba(0.15)MnO(3)), and spin glass material (Pr(0.8)Sr(0.2)MnO(3)). The performance of the uniaxial pressure device is demonstrated by investigating the uniaxial pressure dependence of La(1.85)Ba(0.15)MnO(3) single crystal with P||c axis. The Curie temperature (T(c)) decreases as a function of pressure with P||c axis (dT(c)dP(||c axis)=-11.65 KGPa) up to 46 MPa. The design is simple, is user friendly, and does not require pressure calibration. Measurement can even be made on thin and small size oriented crystals. The failure of the coil is remote under uniaxial pressure. The present setup can be used as a multipurpose uniaxial pressure device for the measurement of Hall effect and thermoelectric power with a small modification in the pressure cell.

  15. Rapid light transmittance measurements in paper-based microfluidic devices

    Directory of Open Access Journals (Sweden)

    Christina Swanson

    2015-09-01

    Full Text Available We developed methodology and built a portable reader to assess light transmittance in paper-based microfluidic devices in a highly sensitive, user-friendly and field-appropriate manner. By sandwiching the paper assay between micro-light-emitting diodes and micro-photodetectors, the reader quantifies light transmittance through the paper independent of ambient light conditions. To demonstrate the utility of the reader, we created a single-use paper-based microfluidic assay for measurement of alanine aminotransferase, an indicator of liver health in blood. The paper assay and reader system accurately differentiated alanine aminotransferase levels across the human reference range and demonstrated significant differences at clinically relevant cutoff values. Results were provided within 10 min and were automatically generated without complex image analysis. Performance of this point-of-care diagnostic rivals the accuracy of lab-based spectrometer tests at a fraction of the cost, while matching the timeliness of low-cost portable assays, which have historically shown lower accuracy. This combination of features allows flexible deployment of low cost and quantitative diagnostics to resource-poor settings.

  16. Measurement of active shoulder proprioception: dedicated system and device.

    Science.gov (United States)

    Lubiatowski, Przemyslaw; Ogrodowicz, Piotr; Wojtaszek, Marcin; Kaniewski, Ryszard; Stefaniak, Jakub; Dudziński, Witold; Romanowski, Leszek

    2013-02-01

    Proprioception is an essential part of shoulder stability and neuromuscular control. The purpose of the study was the development of a precise system of shoulder proprioception assessment in the active mode (Propriometr). For that purpose, devices such as the electronic goniometer and computer software had been designed. A pilot study was carried out on a control group of 27 healthy subjects, the average age being 23.8 (22-29) in order to test the system. The result of the assessment was the finding of the error of active reproduction of the joint position (EARJP). EARJP was assessed for flexion, abduction, external and internal rotation. For every motion, reference positions were used at three different angles. The results showed EARJP to range in 3-6.1°. The proprioception evaluation system (propriometr) allows a precise measurement of active joint position sense. The designed system can be used to assess proprioception in both shoulder injuries and treatment. In addition, all achieved results of normal shoulders may serve as reference to be compared with the results of forthcoming studies.

  17. Loss-tolerant measurement-device-independent quantum private queries

    Science.gov (United States)

    Zhao, Liang-Yuan; Yin, Zhen-Qiang; Chen, Wei; Qian, Yong-Jun; Zhang, Chun-Mei; Guo, Guang-Can; Han, Zheng-Fu

    2017-01-01

    Quantum private queries (QPQ) is an important cryptography protocol aiming to protect both the user’s and database’s privacy when the database is queried privately. Recently, a variety of practical QPQ protocols based on quantum key distribution (QKD) have been proposed. However, for QKD-based QPQ the user’s imperfect detectors can be subjected to some detector- side-channel attacks launched by the dishonest owner of the database. Here, we present a simple example that shows how the detector-blinding attack can damage the security of QKD-based QPQ completely. To remove all the known and unknown detector side channels, we propose a solution of measurement-device-independent QPQ (MDI-QPQ) with single- photon sources. The security of the proposed protocol has been analyzed under some typical attacks. Moreover, we prove that its security is completely loss independent. The results show that practical QPQ will remain the same degree of privacy as before even with seriously uncharacterized detectors.

  18. A simple indentation device for measuring micrometer-scale tissue stiffness

    Energy Technology Data Exchange (ETDEWEB)

    Levental, I; Levental, K R; Janmey, P A [Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104 (United States); Klein, E A; Assoian, R [Department of Pharmacology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Miller, R T [Departments of Medicine and Physiology, Louis Stokes VAMC, Cleveland, OH (United States); Wells, R G, E-mail: janmey@mail.med.upenn.ed [Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104 (United States)

    2010-05-19

    Mechanical properties of cells and extracellular matrices are critical determinants of function in contexts including oncogenic transformation, neuronal synapse formation, hepatic fibrosis and stem cell differentiation. The size and heterogeneity of biological specimens and the importance of measuring their mechanical properties under conditions that resemble their environments in vivo present a challenge for quantitative measurement. Centimeter-scale tissue samples can be measured by commercial instruments, whereas properties at the subcellular (nm) scale are accessible by atomic force microscopy, optical trapping, or magnetic bead microrheometry; however many tissues are heterogeneous on a length scale between micrometers and millimeters which is not accessible to most current instrumentation. The device described here combines two commercially available technologies, a micronewton resolution force probe and a micromanipulator for probing soft biological samples at sub-millimeter spatial resolution. Several applications of the device are described. These include the first measurement of the stiffness of an intact, isolated mouse glomerulus, quantification of the inner wall stiffness of healthy and diseased mouse aortas, and evaluation of the lateral heterogeneity in the stiffness of mouse mammary glands and rat livers with correlation of this heterogeneity with malignant or fibrotic pathology as evaluated by histology.

  19. Characterization of Organic Solar Cell Devices and their Interfaces under Degradation: Imaging, Electrical and Mechanical Methods

    DEFF Research Database (Denmark)

    Corazza, Michael

    techniques were also employed in order to study the effect of degradation on the device structure and its interfaces. This was done by exploiting different techniques that measured different properties of the device: mechanical, imaging, and electrical. Mechanical characterization of roll-to-roll processed....... Finally, imaging of cross sections of an ITO-free roll-to-roll processed device was performed successfully using transmission electron microscopy. The cross sections were prepared both with focused-ion-beam and ultramicrotomy, which gave the possibility for effectively comparing these two techniques...... energy is one of the answers for renewable energy. In this thesis, the research has been conducted on polymer solar cells. In particular, the thesis deals with the extensive study of device lifetime, characterized with several methods: from bare benchmarking of the lifetimes, to more advanced...

  20. 2-Dimensional MEMS dielectrophoresis device for osteoblast cell stimulation.

    Science.gov (United States)

    Zou, H; Mellon, S; Syms, R R A; Tanner, K E

    2006-12-01

    A fixed microelectrode device for cell stimulation has been designed and fabricated using micro-electro-mechanical systems (MEMS) technology. Dielectrophoretic forces obtained from non-uniform electric fields were used for manipulating and positioning osteoblasts. The experiments show that the osteoblasts experience positive dielectrophoresis (p-DEP) when suspended in iso-osmotic culture medium and exposed to AC fields at 5 MHz frequency. Negative dielectrophoresis (n-DEP) is obtained at 0.1 MHz. The viability of osteoblasts under dielectrophoresis has been investigated. The viability values for cells exposed to DEP are nearly three times higher than the control values, indicating that dielectrophoresis may have an anabolic effect on osteoblasts.

  1. Development of a microfluidic device for cell concentration and blood cell-plasma separation.

    Science.gov (United States)

    Maria, M Sneha; Kumar, B S; Chandra, T S; Sen, A K

    2015-12-01

    This work presents design, fabrication and test of a microfluidic device which employs Fahraeus-Lindqvist and Zweifach-Fung effects for cell concentration and blood cell-plasma separation. The device design comprises a straight main channel with a series of branched channels placed symmetrically on both sides of the main channel. The design implements constrictions before each junction (branching point) in order to direct cells that would have migrated closer to the wall (naturally or after liquid extraction at a junction) towards the centre of the main channel. Theoretical and numerical analysis are performed for design of the microchannel network to ensure that a minimum flow rate ratio (of 2.5:1, main channel-to-side channels) is maintained at each junction and predict flow rate at the plasma outlet. The dimensions and location of the constrictions were determined using numerical simulations. The effect of presence of constrictions before the junctions was demonstrated by comparing the performances of the device with and without constrictions. To demonstrate the performance of the device, initial experiments were performed with polystyrene microbeads (10 and 15 μm size) and droplets. Finally, the device was used for concentration of HL60 cells and separation of plasma and cells in diluted blood samples. The cell concentration and blood-plasma purification efficiency was quantified using Haemocytometer and Fluorescence-Activated Cell Sorter (FACS). A seven-fold cell concentration was obtained with HL60 cells and a purification efficiency of 70 % and plasma recovery of 80 % was observed for diluted (1:20) blood sample. FACS was used to identify cell lysis and the cell viability was checked using Trypan Blue test which showed that more than 99 % cells are alive indicating the suitability of the device for practical use. The proposed device has potential to be used as a sample preparation module in lab on chip based diagnostic platforms.

  2. Evaluating the performance of microbial fuel cells powering electronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Dewan, Alim; Beyenal, Haluk [Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Center for Environmental, Sediment and Aquatic Research, Pullman, WA (United States); Donovan, Conrad; Heo, Deukhyoun [School of Electrical Engineering and Computer Science, Washington State University, Pullman, WA 99163-2710 (United States)

    2010-01-01

    A microbial fuel cell (MFC) is capable of powering an electronic device if we store the energy in an external storage device, such as a capacitor, and dispense that energy intermittently in bursts of high-power when needed. Therefore its performance needs to be evaluated using an energy-storing device such as a capacitor which can be charged and discharged rather than other evaluation techniques, such as continuous energy dissipation through a resistor. In this study, we develop a method of testing microbial fuel cell performance based on storing energy in a capacitor. When a capacitor is connected to a MFC it acts like a variable resistor and stores energy from the MFC at a variable rate. In practice the application of this method to testing microbial fuel cells is very challenging and time consuming; therefore we have custom-designed a microbial fuel cell tester (MFCT). The MFCT evaluates the performance of a MFC as a power source. It uses a capacitor as an energy storing device and waits until a desired amount of energy is stored then discharges the capacitor. The entire process is controlled using an analog-to-digital converter (ADC) board controlled by a custom-written computer program. The utility of our method and the MFCT is demonstrated using a laboratory microbial fuel cell (LMFC) and a sediment microbial fuel cell (SMFC). We determine (1) how frequently a MFC can charge a capacitor, (2) which electrode is current-limiting, (3) what capacitor value will allow the maximum harvested energy from a MFC, which is called the ''optimum charging capacitor value,'' and (4) what capacitor charging potential will harvest the maximum energy from a MFC, which is called the ''optimum charging potential.'' Using a LMFC we find that (1) the time needed to charge a 3-F capacitor from 0 to 500 mV is 108 min, (2) the optimum charging capacitor value is 3 F, and (3) the optimum charging potential is 300 mV. Using a SMFC we find that (1

  3. 78 FR 27441 - NIJ Evaluation of Hand-Held Cell Phone Detector Devices

    Science.gov (United States)

    2013-05-10

    ... of Justice Programs NIJ Evaluation of Hand-Held Cell Phone Detector Devices AGENCY: National...) is soliciting interest in supplying hand-held cell phone detector devices for participation in an... soliciting interest in supplying hand-held cell phone detector devices for participation in an evaluation...

  4. Advanced materials and processes for polymer solar cell devices

    DEFF Research Database (Denmark)

    Petersen, Martin Helgesen; Søndergaard, Roar; Krebs, Frederik C

    2010-01-01

    The rapidly expanding field of polymer and organic solar cells is reviewed in the context of materials, processes and devices that significantly deviate from the standard approach which involves rigid glass substrates, indium-tin-oxide electrodes, spincoated layers of conjugated polymer....../fullerene mixtures and evaporated metal electrodes in a flat multilayer geometry. It is likely that significant advances can be found by pursuing many of these novel ideas further and the purpose of this review is to highlight these reports and hopefully spark new interest in materials and methods that may...

  5. Design and dynamic analysis of single-axis integrated inertia measurement device

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The structure and measurement theory of a single-axis integrated inertia measurement device are discussed in this paper.The acceleration and angle velocity can be detected by the proposed sensor at the same time.The kinetic model of the device is also established.In addition,the signal generation of the single-axis integrated inertiameasurement device is analyzed and simulated.The results of the model are consistent with simulation result.

  6. Conductive Polymer Microelectrodes for on-chip measurement of transmitter release from living cells

    DEFF Research Database (Denmark)

    Larsen, Simon Tylsgaard; Matteucci, Marco; Taboryski, Rafael J.

    2012-01-01

    driven cell trapping inside closed chip devices. Conductive polymer microelectrodes were used to measure transmitter release using electrochemical methods such as cyclic voltammetry and constant potential amperometry. By measuring the oxidation current at a cyclic voltammogram, the concentration...

  7. An analog device to facilitate occlusion pressure measurements.

    Science.gov (United States)

    Delavault, E; Saumon, G

    1980-06-01

    The "oclusion pressure" technique is widely used to test the response of respiratory centers to CO2. The graphic treatment of the test necessitates a fast recording of the mouth pressure signal, thus using a great deal of paper and requiring a tedious interpretation. The device described here controls an electromagnetic valve closing it during expiration and opening it after a given time delay, following the onset of inspiration. During that time only, the mouth pressure signal goes through an analog switch, the highest signal value is then equal to the occlusion pressure. This device allows the use of a slow recorder without loss of information. In addition, it has the advantage of generating very short respiratory occlusions, thus sparing the subject being tested from interferences in subsequent respiratory cycles. It can be used as a pretreatment unit to be associated with a microprocessor.

  8. Signal-to-Noise Ratio Measures Efficacy of Biological Computing Devices and Circuits

    Directory of Open Access Journals (Sweden)

    Jacob eBeal

    2015-06-01

    Full Text Available Engineering biological cells to perform computations has a broad range of important potential applications, including precision medical therapies, biosynthesis process control, and environmental sensing. Implementing predictable and effective computation, however, has been extremely difficult to date, due to a combination of poor composability of available parts and of insufficient characterization of parts and their interactions with the complex environment in which they operate. In this paper, I argue that this situation can be improved by quantitative signal-to-noise analysis of the relationship between computational abstractions and the variation and uncertainty endemic in biological organisms. This analysis takes the form of a ∆SNR function for each computational device, which can be computed from measurements of a device's input/output curve and expression noise. These functions can then be combined to predict how well a circuit will implement an intended computation, as well as evaluating the general suitability of biological devices for engineering computational circuits. Applying signal-to-noise analysis to current repressor libraries shows that no library is currently sufficient for general circuit engineering, but also indicates key targets to remedy this situation and vastly improve the range of computations that can be used effectively in the implementation of biological applications.

  9. Signal-to-Noise Ratio Measures Efficacy of Biological Computing Devices and Circuits.

    Science.gov (United States)

    Beal, Jacob

    2015-01-01

    Engineering biological cells to perform computations has a broad range of important potential applications, including precision medical therapies, biosynthesis process control, and environmental sensing. Implementing predictable and effective computation, however, has been extremely difficult to date, due to a combination of poor composability of available parts and of insufficient characterization of parts and their interactions with the complex environment in which they operate. In this paper, the author argues that this situation can be improved by quantitative signal-to-noise analysis of the relationship between computational abstractions and the variation and uncertainty endemic in biological organisms. This analysis takes the form of a ΔSNRdB function for each computational device, which can be computed from measurements of a device's input/output curve and expression noise. These functions can then be combined to predict how well a circuit will implement an intended computation, as well as evaluating the general suitability of biological devices for engineering computational circuits. Applying signal-to-noise analysis to current repressor libraries shows that no library is currently sufficient for general circuit engineering, but also indicates key targets to remedy this situation and vastly improve the range of computations that can be used effectively in the implementation of biological applications.

  10. High-rate measurement-device-independent quantum cryptography

    DEFF Research Database (Denmark)

    Pirandola, Stefano; Ottaviani, Carlo; Spedalieri, Gaetana

    2015-01-01

    Quantum cryptography achieves a formidable task - the remote distribution of secret keys by exploiting the fundamental laws of physics. Quantum cryptography is now headed towards solving the practical problem of constructing scalable and secure quantum networks. A significant step in this direction...... than those currently achieved. Our protocol could be employed to build high-rate quantum networks where devices securely connect to nearby access points or proxy servers....

  11. Quantitative Electrochemical Measurements using in situ ec-S/TEM Devices

    Energy Technology Data Exchange (ETDEWEB)

    Unocic, Raymond R [ORNL; Sacci, Robert L [ORNL; Brown, Gilbert M [ORNL; Veith, Gabriel M [ORNL; Dudney, Nancy J [ORNL; More, Karren Leslie [ORNL; Gardiner, Daniel [Protochips Inc., Raleigh, NC; Walden II, Franklin S [Protochips Inc., Raleigh, NC; Damiano, John [Protochips Inc., Raleigh, NC; Nackashi, David P. [Protochips Inc., Raleigh, NC

    2014-01-01

    Insight into dynamic electrochemical processes can be obtained with in situ ec-S/TEM, which utilizes microfluidic electrochemical cells to characterize electrochemical processes with S/TEM imaging, diffraction or spectroscopy. The microfluidic electrochemical cell is composed of microfabricated devices with glassy carbon and platinum microband electrodes in a three-electrode cell configuration. To establish the validity of this method for quantitative in situ electrochemistry research, cyclic voltammetry, choronoamperometry and electrochemical impedance spectroscopy were performed using a standard one electron transfer redox couple using a [Fe(CN)6]3-/4- based electrolyte. Established relationships of the electrode geometry and microfluidic conditions were fitted with cyclic voltammetry and chronoamperometic measurements of analyte diffusion coefficients and was found to agree with well-accepted values that are on the order of 10-5 cm2 s-1. Influence of the electron beam on electrochemical measurements was found to be negligible during CV scans where the current profile varied only within a few nA with the electron beam on and off which is well within the hysteresis between multiple CV scans. The combination of experimental results provides a validation that quantitative electrochemistry experiments can be performed with these small-scale microfluidic electrochemical cells provided that accurate geometrical electrode configurations, diffusion boundary layers and microfluidic conditions are accounted for.

  12. Quantitative electrochemical measurements using in situ ec-S/TEM devices.

    Science.gov (United States)

    Unocic, Raymond R; Sacci, Robert L; Brown, Gilbert M; Veith, Gabriel M; Dudney, Nancy J; More, Karren L; Walden, Franklin S; Gardiner, Daniel S; Damiano, John; Nackashi, David P

    2014-04-01

    Insight into dynamic electrochemical processes can be obtained with in situ electrochemical-scanning/transmission electron microscopy (ec-S/TEM), a technique that utilizes microfluidic electrochemical cells to characterize electrochemical processes with S/TEM imaging, diffraction, or spectroscopy. The microfluidic electrochemical cell is composed of microfabricated devices with glassy carbon and platinum microband electrodes in a three-electrode cell configuration. To establish the validity of this method for quantitative in situ electrochemistry research, cyclic voltammetry (CV), choronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) were performed using a standard one electron transfer redox couple [Fe(CN)6]3-/4--based electrolyte. Established relationships of the electrode geometry and microfluidic conditions were fitted with CV and chronoamperometic measurements of analyte diffusion coefficients and were found to agree with well-accepted values that are on the order of 10-5 cm2/s. Influence of the electron beam on electrochemical measurements was found to be negligible during CV scans where the current profile varied only within a few nA with the electron beam on and off, which is well within the hysteresis between multiple CV scans. The combination of experimental results provides a validation that quantitative electrochemistry experiments can be performed with these small-scale microfluidic electrochemical cells provided that accurate geometrical electrode configurations, diffusion boundary layers, and microfluidic conditions are accounted for.

  13. Digital cell counting device integrated with a single-cell array.

    Science.gov (United States)

    Saeki, Tatsuya; Hosokawa, Masahito; Lim, Tae-kyu; Harada, Manabu; Matsunaga, Tadashi; Tanaka, Tsuyoshi

    2014-01-01

    In this paper, we present a novel cell counting method accomplished using a single-cell array fabricated on an image sensor, complementary metal oxide semiconductor sensor. The single-cell array was constructed using a microcavity array, which can trap up to 7,500 single cells on microcavities periodically arranged on a plane metallic substrate via the application of a negative pressure. The proposed method for cell counting is based on shadow imaging, which uses a light diffraction pattern generated by the microcavity array and trapped cells. Under illumination, the cell-occupied microcavities are visualized as shadow patterns in an image recorded by the complementary metal oxide semiconductor sensor due to light attenuation. The cell count is determined by enumerating the uniform shadow patterns created from one-on-one relationships with single cells trapped on the microcavities in digital format. In the experiment, all cell counting processes including entrapment of non-labeled HeLa cells from suspensions on the array and image acquisition of a wide-field-of-view of 30 mm(2) in 1/60 seconds were implemented in a single integrated device. As a result, the results from the digital cell counting had a linear relationship with those obtained from microscopic observation (r(2)  = 0.99). This platform could be used at extremely low cell concentrations, i.e., 25-15,000 cells/mL. Our proposed system provides a simple and rapid miniaturized cell counting device for routine laboratory use.

  14. A microfluidic device integrating plasmonic nanodevices for Raman spectroscopy analysis on trapped single living cells

    KAUST Repository

    Perozziello, Gerardo

    2013-11-01

    In this work we developed a microfluidic device integrating nanoplasmonic devices combined with fluidic trapping regions. The microfuidic traps allow to capture single cells in areas where plasmonic sensors are placed. In this way it is possible to perform Enhanced Raman analysis on the cell membranes. Moreover, by changing direction of the flux it is possible to change the orientation of the cell in the trap, so that it is possible to analyze different points of the membrane of the same cell. We shows an innovative procedure to fabricate and assembly the microfluidic device which combine photolithography, focused ion beam machining, and hybrid bonding between a polymer substrate and lid of Calcium fluoride. This procedure is compatible with the fabrication of the plasmonic sensors in close proximity of the microfluidic traps. Moreover, the use of Calcium fluoride as lid allows full compatibility with Raman measurements producing negligible Raman background signal and avoids Raman artifacts. Finally, we performed Raman analysis on cells to monitor their oxidative stress under particular non physiological conditions. © 2013 Elsevier B.V. All rights reserved.

  15. Methods and devices used to measure friction in rolling

    DEFF Research Database (Denmark)

    Jeswiet, J.; Arentoft, Mogens; Henningsen, Poul

    2006-01-01

    a good understanding of the mechanisms at the interface and to be able to verify the friction and tribology models that exist, friction sensors are needed. Designing sensors to measure frictional stress in metal working has been pursued by many researchers. This paper surveys methods that have been used...... to measure friction in rolling in the past and discusses some of the recent sensor designs that can now be used to measure friction both in production situations and for research purposes....

  16. Capacitive Cells for Dielectric Constant Measurement

    Science.gov (United States)

    Aguilar, Horacio Munguía; Maldonado, Rigoberto Franco

    2015-01-01

    A simple capacitive cell for dielectric constant measurement in liquids is presented. As an illustrative application, the cell is used for measuring the degradation of overheated edible oil through the evaluation of their dielectric constant.

  17. Influence of Biphasic Stimulation on Olfactory Ensheathing Cells for Neuroprosthetic Devices

    Directory of Open Access Journals (Sweden)

    Rachelle Therese Hassarati

    2016-10-01

    Full Text Available The recent success of olfactory ensheathing cell (OEC assisted regeneration of injured spinal cord has seen a rising interest in the use of these cells in tissue-engineered systems. Previously shown to support neural cell growth through glial scar tissue, OECs have the potential to assist neural network formation in living electrode systems to produce superior neuroprosthetic electrode surfaces. The following study sought to understand the influence of biphasic electrical stimulation (ES, inherent to bionic devices, on cell survival and function, with respect to conventional metallic and developmental conductive hydrogel (CH coated electrodes. The CH utilised in this study was a biosynthetic hydrogel consisting of methacrylated poly(vinyl-alcohol (PVA, heparin and gelatin through which poly(3,4-ethylenedioxythiophene (PEDOT was electropolymerised. OECs cultured on Pt and CH surfaces were subjected to biphasic ES. Image-based cytometry yielded little significant difference between the viability and cell cycle of OECs cultured on the stimulated and passive samples. The significantly lower voltages measured across the CH electrodes (147 ± 3 mV compared to the Pt (317 ± 5 mV, had shown to influence a higher percentage of viable cells on CH (91 - 93 % compared to Pt (78 - 81 %. To determine the functionality of these cells following electrical stimulation, OECs co-cultured with PC12 cells were found to support neural cell differentiation (an indirect measure of neurotrophic factor production following ES.

  18. Influence of Biphasic Stimulation on Olfactory Ensheathing Cells for Neuroprosthetic Devices

    Science.gov (United States)

    Hassarati, Rachelle T.; Foster, L. John R.; Green, Rylie A.

    2016-01-01

    The recent success of olfactory ensheathing cell (OEC) assisted regeneration of injured spinal cord has seen a rising interest in the use of these cells in tissue-engineered systems. Previously shown to support neural cell growth through glial scar tissue, OECs have the potential to assist neural network formation in living electrode systems to produce superior neuroprosthetic electrode surfaces. The following study sought to understand the influence of biphasic electrical stimulation (ES), inherent to bionic devices, on cell survival and function, with respect to conventional metallic and developmental conductive hydrogel (CH) coated electrodes. The CH utilized in this study was a biosynthetic hydrogel consisting of methacrylated poly(vinyl-alcohol) (PVA), heparin and gelatin through which poly(3,4-ethylenedioxythiophene) (PEDOT) was electropolymerised. OECs cultured on Pt and CH surfaces were subjected to biphasic ES. Image-based cytometry yielded little significant difference between the viability and cell cycle of OECs cultured on the stimulated and passive samples. The significantly lower voltages measured across the CH electrodes (147 ± 3 mV) compared to the Pt (317 ± 5 mV), had shown to influence a higher percentage of viable cells on CH (91–93%) compared to Pt (78–81%). To determine the functionality of these cells following electrical stimulation, OECs co-cultured with PC12 cells were found to support neural cell differentiation (an indirect measure of neurotrophic factor production) following ES. PMID:27757072

  19. A Simple Laser-Based Device for Simultaneous Microbial Culture and Absorbance Measurement

    CERN Document Server

    Abrevaya, X C; Areso, O; Mauas, P J D

    2012-01-01

    In this work we present a device specifically designed to study microbial growth with several applications related to environmental microbiology and other areas of research as astrobiology. The Automated Measuring and Cultivation device (AMC-d) enables semi-continuous absorbance measurements directly during cultivation. It can measure simultaneously up to 16 samples. Growth curves using low and fast growing microorganism were plotted, including: Escherichia coli, and Haloferax volcanii, an halophilic archaeon.

  20. Information measurement system based on the device for evaluation of optical surface quality

    Science.gov (United States)

    Izotov, Pavel Y.

    2016-03-01

    The work describes steps taken in order to create the information-measurement system based on the device for evaluation of surface cleanliness and smoothness of optical substrates. The approach used leads to the improvement the stability and accuracy of measurements. Structural changes applied to both the software and hardware of the device which allowed retrieval of better quality images during the course of measurements are designated. Problems emerged during the implementation of the system and their solutions are described.

  1. Calculation of smoke plume mass from passive UV satellite measurements by GOME-2 polarization measurement devices

    Science.gov (United States)

    Penning de Vries, M. J. M.; Tuinder, O. N. E.; Wagner, T.; Fromm, M.

    2012-04-01

    The Wallow wildfire of 2011 was one of the most devastating fires ever in Arizona, burning over 2,000 km2 in the states of Arizona and New Mexico. The fire originated in the Bear Wallow Wilderness area in June, 2011, and raged for more than a month. The intense heat of the fire caused the formation of a pyro-convective cloud. The resulting smoke plume, partially located above low-lying clouds, was detected by several satellite instruments, including GOME-2 on June 2. The UV Aerosol Index, indicative of aerosol absorption, reached a maximum of 12 on that day, pointing to an elevated plume with moderately absorbing aerosols. We have performed extensive model calculations assuming different aerosol optical properties to determine the total aerosol optical depth of the plume. The plume altitude, needed to constrain the aerosol optical depth, was obtained from independent satellite measurements. The model results were compared with UV Aerosol Index and UV reflectances measured by the GOME-2 polarization measurement devices, which have a spatial resolution of roughly 10x40 km2. Although neither the exact aerosol optical properties nor optical depth can be obtained with this method, the range in aerosol optical depth values that we calculate, combined with the assumed specific extinction mass factor of 5 m2/kg lead us to a rough estimate of the smoke plume mass that cannot, at present, be assessed in another way.

  2. A pilot study of a new spectrophotometry device to measure tissue oxygen saturation.

    Science.gov (United States)

    Abel, Gemma; Allen, John; Drinnan, Michael

    2014-09-01

    Tissue oxygen saturation (SO2) measurements have the potential for far wider use than at present but are limited by device availability and portability for many potential applications. A device based on a small, low-cost general-purpose spectrophotometer (the Harrison device) might facilitate wider use. The aim of this study was to compare the Harrison device with a commercial instrument, the LEA O2C.Measurements were carried out on the forearm and finger of 20 healthy volunteers, using a blood pressure cuff on the upper arm to induce different levels of oxygenation. Repeatability of both devices was assessed, and the Bland-Altman method was used to assess agreement between them.The devices showed agreement in overall tracking of changes in SO2. Test-retest agreement for the Harrison device was worse than for O2C, with SD repeatability of 10.6% (forearm) or 18.6% (finger). There was no overall bias between devices, but mean (SD) difference of 1.2 (11.8%) (forearm) or 4.4 (11.5%) (finger) were outside of a clinically acceptable range.Disagreements were attributed to the stability of the Harrison probe and the natural SO2 variations across the skin surface increasing the random error. Therefore, though not equivalent to the LEA O2C, a probe redesign and averaged measurements may help establish the Harrison device as a low cost alternative.

  3. Classification of methods for measuring current-voltage characteristics of semiconductor devices

    Directory of Open Access Journals (Sweden)

    Iermolenko Ia. O.

    2014-06-01

    Full Text Available It is shown that computer systems for measuring current-voltage characteristics are very important for semiconductor devices production. The main criteria of efficiency of such systems are defined. It is shown that efficiency of such systems significantly depends on the methods for measuring current-voltage characteristics of semiconductor devices. The aim of this work is to analyze existing methods for measuring current-voltage characteristics of semiconductor devices and to create the classification of these methods in order to specify the most effective solutions in terms of defined criteria. To achieve this aim, the most common classifications of methods for measuring current-voltage characteristics of semiconductor devices and their main disadvantages are considered. Automated and manual, continuous, pulse, mixed, isothermal and isodynamic methods for measuring current-voltage characteristics are analyzed. As a result of the analysis and generalization of existing methods the next classification criteria are defined: the level of automation, the form of measurement signals, the condition of semiconductor device during the measurements, and the use of mathematical processing of the measurement results. With the use of these criteria the classification scheme of methods for measuring current-voltage characteristics of semiconductor devices is composed and the most effective methods are specified.

  4. Comparison of the methods for determination of calibration and verification intervals of measuring devices

    Directory of Open Access Journals (Sweden)

    Toteva Pavlina

    2017-01-01

    Full Text Available The paper presents different determination and optimisation methods for verification intervals of technical devices for monitoring and measurement based on the requirements of some widely used international standards, e.g. ISO 9001, ISO/IEC 17020, ISO/IEC 17025 etc., maintained by various organizations implementing measuring devices in practice. Comparative analysis of the reviewed methods is conducted in terms of opportunities for assessing the adequacy of interval(s for calibration of measuring devices and their optimisation accepted by an organization – an extension or reduction depending on the obtained results. The advantages and disadvantages of the reviewed methods are discussed, and recommendations for their applicability are provided.

  5. Trustworthiness of measurement devices in round-robin differential-phase-shift quantum key distribution

    Science.gov (United States)

    Cao, Zhu; Yin, Zhen-Qiang; Han, Zheng-Fu

    2016-02-01

    Round-robin differential-phase-shift quantum key distribution (RRDPS QKD) has been proposed to raise the noise tolerability of the channel. However, in practice, the measurement device in RRDPS QKD may be imperfect. Here, we show that, with these imperfections, the security of RRDPS may be damaged by proposing two attacks for RRDPS systems with uncharacterized measurement devices. One is valid even for a system with unit total efficiency, while the other is valid even when a single-photon state is sent. To prevent these attacks, either security arguments need to be fundamentally revised or further practical assumptions on the measurement device should be put.

  6. Characterization and Measurement of Passive and Active Metamaterial Devices

    Science.gov (United States)

    2010-03-01

    guidance, discussions, and teachings. I need to thank the technical support crew at Sonnet Software for their help with CST Microwave Studio R©. Also...R© S-parameter results from structure in [17] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 xi Figure Page 39 Dimensions of the...113 73 S-parameter results from four cell non-periodic model with two different geometries . . . . . . . . . . . . . . . . . . . . . . 114 74 AFIT’s

  7. Measurement campaign on connectivity of mesh networks formed by mobile devices

    DEFF Research Database (Denmark)

    Pietrarca, Beatrice; Sasso, Giovanni; Perrucci, Gian Paolo

    2007-01-01

    This paper reports the results of a measurement campaign on the connectivity level of mobile devices using Bluetooth (BT) to form cooperative mobile mesh networks. Such mobile mesh networks composed of mobile devices are the basis for any peer-to-peer communication like wireless grids or social...

  8. A novel closed cell culture device for fabrication of corneal epithelial cell sheets.

    Science.gov (United States)

    Nakajima, Ryota; Kobayashi, Toyoshige; Moriya, Noboru; Mizutani, Manabu; Kan, Kazutoshi; Nozaki, Takayuki; Saitoh, Kazuo; Yamato, Masayuki; Okano, Teruo; Takeda, Shizu

    2015-11-01

    Automation technology for cell sheet-based tissue engineering would need to optimize the cell sheet fabrication process, stabilize cell sheet quality and reduce biological contamination risks. Biological contamination must be avoided in clinical settings. A closed culture system provides a solution for this. In the present study, we developed a closed culture device called a cell cartridge, to be used in a closed cell culture system for fabricating corneal epithelial cell sheets. Rabbit limbal epithelial cells were cultured on the surface of a porous membrane with 3T3 feeder cells, which are separate from the epithelial cells in the cell cartridges and in the cell-culture inserts as a control. To fabricate the stratified cell sheets, five different thicknesses of the membranes which were welded to the cell cartridge, were examined. Multilayered corneal epithelial cell sheets were fabricated in cell cartridges that were welded to a 25 µm-thick gas-permeable membrane, which was similar to the results with the cell-culture inserts. However, stratification of corneal epithelial cell sheets did not occur with cell cartridges that were welded to 100-300 µm-thick gas-permeable membranes. The fabricated cell sheets were evaluated by histological analyses to examine the expression of corneal epithelial-specific markers. Immunohistochemical analyses showed that a putative stem cell marker, p63, a corneal epithelial differentiation maker, CK3, and a barrier function marker, Claudin-1, were expressed in the appropriate position in the cell sheets. These results suggest that the cell cartridge is effective for fabricating corneal epithelial cell sheets.

  9. Direct measurement of cell detachment force on single cells using a new electromechanical method.

    Science.gov (United States)

    Francis, G W; Fisher, L R; Gamble, R A; Gingell, D

    1987-05-01

    We describe a new device in which an accurately measured force is applied to individual adherent cells while the topography of the adhesion zone is simultaneously monitored. The force is applied via a flexible glass micropipette, attached by suction to the cell under study, and is calculated directly from the measured pipette deflection. Regions of close contact in the adhesion zone are observed using interference reflection microscopy. We have used the device to measure the force required to detach human red blood cells from hydrophobic and hydrophilic glass surfaces, and to detach Dictyostelium discoideum amoebae from a hydrophobic glass surface. The measured forces per unit length of contact perimeter are within an order of magnitude of the tensions required for membrane rupture.

  10. Single-cell cloning and expansion of human induced pluripotent stem cells by a microfluidic culture device.

    Science.gov (United States)

    Matsumura, Taku; Tatsumi, Kazuya; Noda, Yuichiro; Nakanishi, Naoyuki; Okonogi, Atsuhito; Hirano, Kunio; Li, Liu; Osumi, Takashi; Tada, Takashi; Kotera, Hidetoshi

    2014-10-10

    The microenvironment of cells, which includes basement proteins, shear stress, and extracellular stimuli, should be taken into consideration when examining physiological cell behavior. Although microfluidic devices allow cellular responses to be analyzed with ease at the single-cell level, few have been designed to recover cells. We herein demonstrated that a newly developed microfluidic device helped to improve culture conditions and establish a clonality-validated human pluripotent stem cell line after tracing its growth at the single-cell level. The device will be a helpful tool for capturing various cell types in the human body that have not yet been established in vitro.

  11. Aberration-free FTIR spectroscopic imaging of live cells in microfluidic devices.

    Science.gov (United States)

    Chan, K L Andrew; Kazarian, Sergei G

    2013-07-21

    The label-free, non-destructive chemical analysis offered by FTIR spectroscopic imaging is a very attractive and potentially powerful tool for studies of live biological cells. FTIR imaging of live cells is a challenging task, due to the fact that cells are cultured in an aqueous environment. While the synchrotron facility has proven to be a valuable tool for FTIR microspectroscopic studies of single live cells, we have demonstrated that high quality infrared spectra of single live cells using an ordinary Globar source can also be obtained by adding a pair of lenses to a common transmission liquid cell. The lenses, when placed on the transmission cell window, form pseudo hemispheres which removes the refraction of light and hence improve the imaging and spectral quality of the obtained data. This study demonstrates that infrared spectra of single live cells can be obtained without the focus shifting effect at different wavenumbers, caused by the chromatic aberration. Spectra of the single cells have confirmed that the measured spectral region remains in focus across the whole range, while spectra of the single cells measured without the lenses have shown some erroneous features as a result of the shift of focus. It has also been demonstrated that the addition of lenses can be applied to the imaging of cells in microfabricated devices. We have shown that it was not possible to obtain a focused image of an isolated cell in a droplet of DPBS in oil unless the lenses are applied. The use of the approach described herein allows for well focused images of single cells in DPBS droplets to be obtained.

  12. 32 CFR 634.27 - Speed-measuring devices.

    Science.gov (United States)

    2010-07-01

    ... CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.27 Speed-measuring.... (v) Demonstrate basic skills in checking calibration and operating the specific radar instrument(s). (vi) Demonstrate basic skills in preparing and presenting records and courtroom testimony relating...

  13. 40 CFR 1065.275 - N2O measurement devices.

    Science.gov (United States)

    2010-07-01

    ... infra-red (NDIR) analyzer. You may use an NDIR analyzer that has compensation algorithms that are... for any compensation algorithm is 0.0% (that is, no bias high and no bias low), regardless of the... has compensation algorithms that are functions of other gaseous measurements and the engine's known...

  14. Device for Measuring Low Flow Speed in a Duct

    Science.gov (United States)

    Quinn, Frank; Magee, Kevin

    2009-01-01

    A multiple-throat venturi system has been invented for measuring laminar flow of air or other gas at low speed (1 to 30 cm/s) in a duct while preserving the laminar nature of the flow and keeping the velocity profile across the duct as nearly flat as possible. While means for measuring flows at higher speeds are well established, heretofore, there have been no reliable means for making consistent, accurate measurements in this speed range. In the original application for which this system was invented, the duct leads into the test section of a low-speed wind tunnel wherein uniform, low-speed, laminar flow is required for scientific experiments. The system could also be used to monitor a slow flow of gas in an industrial process like chemical vapor deposition. In the original application, the multiple- throat venturi system is mounted at the inlet end of the duct having a rectangular cross section of 19 by 14 cm, just upstream of an assembly of inlet screens and flow straighteners that help to suppress undesired flow fluctuations (see Figure 1). The basic venturi measurement principle is well established: One measures the difference in pressure between (1) a point just outside the inlet, where the pressure is highest and the kinetic energy lowest; and (2) the narrowest part (the throat) of the venturi passage, where the kinetic energy is highest and the pressure is lowest. Then by use of Bernoulli s equation for the relationship between pressure and kinetic energy, the volumetric flow speed in the duct can be calculated from the pressure difference and the inlet and throat widths. The design of this system represents a compromise among length, pressure recovery, uniformity of flow, and complexity of assembly. Traditionally, venturis are used to measure faster flows in narrower cross sections, with longer upstream and downstream passages to maintain accuracy. The dimensions of the passages of the present venturi system are sized to provide a readily measurable

  15. Digital cell counting device integrated with a single-cell array.

    Directory of Open Access Journals (Sweden)

    Tatsuya Saeki

    Full Text Available In this paper, we present a novel cell counting method accomplished using a single-cell array fabricated on an image sensor, complementary metal oxide semiconductor sensor. The single-cell array was constructed using a microcavity array, which can trap up to 7,500 single cells on microcavities periodically arranged on a plane metallic substrate via the application of a negative pressure. The proposed method for cell counting is based on shadow imaging, which uses a light diffraction pattern generated by the microcavity array and trapped cells. Under illumination, the cell-occupied microcavities are visualized as shadow patterns in an image recorded by the complementary metal oxide semiconductor sensor due to light attenuation. The cell count is determined by enumerating the uniform shadow patterns created from one-on-one relationships with single cells trapped on the microcavities in digital format. In the experiment, all cell counting processes including entrapment of non-labeled HeLa cells from suspensions on the array and image acquisition of a wide-field-of-view of 30 mm(2 in 1/60 seconds were implemented in a single integrated device. As a result, the results from the digital cell counting had a linear relationship with those obtained from microscopic observation (r(2  = 0.99. This platform could be used at extremely low cell concentrations, i.e., 25-15,000 cells/mL. Our proposed system provides a simple and rapid miniaturized cell counting device for routine laboratory use.

  16. Localized corrosion information using high resolution measurement devices

    DEFF Research Database (Denmark)

    Ambat, Rajan

    2005-01-01

    to control the solution flow at the tip. Through addition of reference and counter electrodes, the pipette system becomes a microscopic electrochemical cell, which can then be used with high precision to determine the electrochemical characteristics of the microstructural region of interest. The capability...... of the technique could be further enhanced by adding new features such as high resolution video visualization systems, fretting/tribo-corroson attachments, and also by integrating it with stress corrosion testing, corrosion investigation of concrete for a few to name with. The corrosion group in MPT, Technical...

  17. Influence of measurement conditions and used devices on consequential creep modulus

    Directory of Open Access Journals (Sweden)

    Reznicek Martin

    2016-01-01

    Full Text Available This research deals with study of the possibilities of the creep properties measurement on dedicated devices for the creep measurement and on devices, which enable the creep properties measurement. A comparison of these two different measurement methods show the influence of boundary conditions on the measurement result. Simultaneously, the effort to shorten the long-term tests, because of time saving during research and development of new materials, is confronted here. Radiation crosslinking samples of high-density polyethylene (HDPE, which enable the change of the internal structure to the spatial network by the influence of beta radiation, were chosen as an example for comparison.

  18. Device for Measuring Sliding Friction on Highloft Nonwovens

    Directory of Open Access Journals (Sweden)

    Stephen Michielsen

    2006-08-01

    Full Text Available When measuring the sliding friction on highly compliant materials such as fabric batting and foam rubber, a substantial portion of the apparent friction is due to the deformation of the substrate. A new friction instrument consisting of a sled within a sled has been developed that eliminates the contribution of this deformation and provides the true sliding friction as well as the force required to deform the substrate. The friction coefficient as measured using a conventional steel sled sliding on high loft polyester batts increased as the number of polyester batts increased. Using the new, guarded friction sled, the friction coefficient was independent of the number of supporting batts, thus separating the deformation forces from the sliding forces.

  19. The wave vane - A device to measure the breaker angle

    Digital Repository Service at National Institute of Oceanography (India)

    Chandramohan, P.; Nayak, B.U.; Anand, N.M.

    11 February 1992; accepted after revision 11 November 1992) ABSTRACT Estimation of the breaker angle in the littoral environmental observation (LEO) programme is still based on visual methods and therefore is subjective in nature. In the absence... directional wave gauge at a considerable cost. For economic and practical considerations, visual measurements on the breaker height, the breaker period and the breaker angle are generally made in the LEO pro- gramme. The breaker height is recorded...

  20. Characterizing heralded single-photon sources with imperfect measurement devices

    Energy Technology Data Exchange (ETDEWEB)

    Razavi, M; Soellner, I; Bocquillon, E; Couteau, C; Laflamme, R; Weihs, G [Institute for Quantum Computing, University of Waterloo, 200 University Ave. W, Waterloo, ON N2L 3G1 (Canada)], E-mail: mrazavi@iqc.ca

    2009-06-14

    Any characterization of a single-photon source is not complete without specifying its second-order degree of coherence, i.e., its g{sup (2)} function. An accurate measurement of such coherence functions commonly requires high-precision single-photon detectors, in whose absence only time-averaged measurements are possible. It is not clear, however, how the resulting time-averaged quantities can be used to properly characterize the source. In this paper, we investigate this issue for a heralded source of single photons that relies on continuous-wave parametric down-conversion. By accounting for major shortcomings of the source and the detectors-i.e., the multiple-photon emissions of the source, the time resolution of photodetectors and our chosen width of coincidence window-our theory enables us to infer the true source properties from imperfect measurements. Our theoretical results are corroborated by an experimental demonstration using a PPKTP crystal pumped by a blue laser that results in a single-photon generation rate about 1.2 millions per second per milliwatt of pump power. This work takes an important step towards the standardization of such heralded single-photon sources.

  1. Cell pairing using a dielectrophoresis-based device with interdigitated array electrodes.

    Science.gov (United States)

    Şen, Mustafa; Ino, Kosuke; Ramón-Azcón, Javier; Shiku, Hitoshi; Matsue, Tomokazu

    2013-09-21

    We present a chip device with an array of 900 gourd-shaped microwells designed to pair single cells of different types. The device consists of interdigitated array (IDA) electrodes and uses positive dielectrophoresis to trap cells within the microwells. Each side of a microwell is on a different comb of the IDA, so that cells of different types are trapped on opposite sides of the microwells, leading to close cell pairing. Using this device, a large number of cell pairs can be formed easily and rapidly, making it a highly attractive tool for controllable cell pairing in a range of biological applications.

  2. Light collection optics for measuring flux and spectrum from light-emitting devices

    Science.gov (United States)

    McCord, Mark A.; DiRegolo, Joseph A.; Gluszczak, Michael R.

    2016-05-24

    Systems and methods for accurately measuring the luminous flux and color (spectra) from light-emitting devices are disclosed. An integrating sphere may be utilized to directly receive a first portion of light emitted by a light-emitting device through an opening defined on the integrating sphere. A light collector may be utilized to collect a second portion of light emitted by the light-emitting device and direct the second portion of light into the integrating sphere through the opening defined on the integrating sphere. A spectrometer may be utilized to measure at least one property of the first portion and the second portion of light received by the integrating sphere.

  3. Compact disk (CD)-shaped device for single cell isolation and PCR of a specific gene in the isolated cell.

    Science.gov (United States)

    Furutani, Shunsuke; Nagai, Hidenori; Takamura, Yuzuru; Kubo, Izumi

    2010-12-01

    For immediate discrimination among isolated cells we propose a novel device and technique for isolation of cells and sequential detection of specific gene(s) within them by polymerase chain reaction (PCR). In this study, we isolated Salmonella enterica cells and detected the Salmonella-specific invA gene from isolated cells by PCR on a compact disk (CD)-shaped device. This device enabled liquid flow by centrifugal force without a micro pump, and was fabricated from silicon wafer and glass to avoid evaporation of a small amount of reagent. One device has 24 microchannels, and 313 microchambers integrated on each microchannel. One microliter of PCR mixture containing cells was separated into microchambers on the device at 5000 rpm for 30 s. Each microchamber contained approximately 1.5 nL PCR mixture. A Poisson distribution of S. enterica cells was observed for different densities of cell suspension. At 200 cells μL(-1) of S. enterica or less, isolated single cells could be determined on the device by amplification of DNA of the invA gene; at 400 cells μL(-1), chambers containing no, one, two, or three cells could be determined on the device. Selective detection of S. enterica was achieved by PCR from a mixture of S. enterica and Escherichia coli on the CD-shaped device.

  4. Bring-Your-Own-Device: Turning Cell Phones into Forces for Good

    Science.gov (United States)

    Imazeki, Jennifer

    2014-01-01

    Over the last few years, classroom response systems (or "clickers") have become increasingly common. Although most systems require students to use a standalone handheld device, bring-your-own-device (BYOD) systems allow students to use devices they already own (e.g., a cell phone, tablet or laptop) to submit responses via text message or…

  5. 3D microfilter device for viable circulating tumor cell (CTC) enrichment from blood.

    Science.gov (United States)

    Zheng, Siyang; Lin, Henry K; Lu, Bo; Williams, Anthony; Datar, Ram; Cote, Richard J; Tai, Yu-Chong

    2011-02-01

    Detection of circulating tumor cells has emerged as a promising minimally invasive diagnostic and prognostic tool for patients with metastatic cancers. We report a novel three dimensional microfilter device that can enrich viable circulating tumor cells from blood. This device consists of two layers of parylene membrane with pores and gap precisely defined with photolithography. The positions of the pores are shifted between the top and bottom membranes. The bottom membrane supports captured cells and minimize the stress concentration on cell membrane and sustain cell viability during filtration. Viable cell capture on device was investigated with scanning electron microscopy, confocal microscopy, and immunofluorescent staining using model systems of cultured tumor cells spiked in blood or saline. The paper presents and validates this new 3D microfiltration concept for circulation tumor cell enrichment application. The device provides a highly valuable tool for assessing and characterizing viable enriched circulating tumor cells in both research and clinical settings.

  6. Experimental arrangement to measure dispersion in optical fiber devices

    Energy Technology Data Exchange (ETDEWEB)

    Armas Rivera, Ivan [Benemerita Universidad Autonoma de Puebla, Facultad de Ciencias de la Electronica (Mexico); Beltran Perez, Georgina; Castillo Mixcoatl, Juan; Munoz Aguirre, Severino [Benemerita Universidad Autonoma de Puebla, Facultad de Ciencias Fisico Matematicas (Mexico); Zaca Moran, Placido, E-mail: ivan_rr1@hotmail.com [Benemerita Universidad Autonoma de Puebla, Fisicoquimica de Materiales ICUAP (Mexico)

    2011-01-01

    Dispersion is a quite important parameter in systems based on optical fiber, especially in pulsed emission lasers, where the temporal width is affected by such parameter. Therefore, it is necessary to consider the dispersion provoked by each component in the cavity. There are various experimental interferometric arrangements to evaluate this parameter. Generally, these systems modify the wavelength to obtain information about the n({lambda}) dependency, which is contained in the interferogram phase. However, this makes the system quite slow and it requires tunable and narrow bandwidth laser sources. In the present work, results obtained from an arrangement based on Mach-Zehnder interferometer where one of the arms is the optical fiber under study, while the reference one is air, are presented. In order to determine the n({lambda}) dependency, a wide spectrum light source was used in the wavelength range of interest. The phase information was evaluated from the interferometric signal measured by an optical spectrum analyzer.

  7. Comparison of Minority Carrier Lifetime Measurements in Superstrate and Substrate CdTe PV Devices: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Gessert, T. A.; Dhere, R. G.; Duenow, J. N.; Kuciauskas, D.; Kanevce, A.; Bergeson, J. D.

    2011-07-01

    We discuss typical and alternative procedures to analyze time-resolved photoluminescence (TRPL) measurements of minority carrier lifetime (MCL) with the hope of enhancing our understanding of how this technique may be used to better analyze CdTe photovoltaic (PV) device functionality. Historically, TRPL measurements of the fast recombination rate (t1) have provided insightful correlation with broad device functionality. However, we have more recently found that t1 does not correlate as well with smaller changes in device performance, nor does it correlate well with performance differences observed between superstrate and substrate CdTe PV devices. This study presents TRPL data for both superstrate and substrate CdTe devices where both t1 and the slower TRPL decay (t2) are analyzed. The study shows that changes in performance expected from small changes in device processing may correlate better with t2. Numerical modeling further suggests that, for devices that are expected to have similar drift field in the depletion region, effects of changes in bulk MCL and interface recombination should be more pronounced in t2. Although this technique may provide future guidance to improving CdS/CdTe device performance, it is often difficult to extract statistically precise values for t2, and therefore t2 data may demonstrate significant scatter when correlated with performance parameters.

  8. The TESS camera: modeling and measurements with deep depletion devices

    Science.gov (United States)

    Woods, Deborah F.; Vanderspek, Roland; MacDonald, Robert; Morgan, Edward; Villasenor, Joel; Thayer, Carolyn; Burke, Barry; Chesbrough, Christian; Chrisp, Michael; Clark, Kristin; Furesz, Gabor; Gonzales, Alexandria; Nguyen, Tam; Prigozhin, Gregory; Primeau, Brian; Ricker, George; Sauerwein, Timothy; Suntharalingam, Vyshnavi

    2016-07-01

    The Transiting Exoplanet Survey Satellite, a NASA Explorer-class mission in development, will discover planets around nearby stars, most notably Earth-like planets with potential for follow up characterization. The all-sky survey requires a suite of four wide field-of-view cameras with sensitivity across a broad spectrum. Deep depletion CCDs with a silicon layer of 100 μm thickness serve as the camera detectors, providing enhanced performance in the red wavelengths for sensitivity to cooler stars. The performance of the camera is critical for the mission objectives, with both the optical system and the CCD detectors contributing to the realized image quality. Expectations for image quality are studied using a combination of optical ray tracing in Zemax and simulations in Matlab to account for the interaction of the incoming photons with the 100 μm silicon layer. The simulations include a probabilistic model to determine the depth of travel in the silicon before the photons are converted to photo-electrons, and a Monte Carlo approach to charge diffusion. The charge diffusion model varies with the remaining depth for the photo-electron to traverse and the strength of the intermediate electric field. The simulations are compared with laboratory measurements acquired by an engineering unit camera with the TESS optical design and deep depletion CCDs. In this paper we describe the performance simulations and the corresponding measurements taken with the engineering unit camera, and discuss where the models agree well in predicted trends and where there are differences compared to observations.

  9. Study on DeviceNet communication mechanism and its application in protection measurement and control system

    Institute of Scientific and Technical Information of China (English)

    Tong Weiming; Li Zhongwei; Sun Fanjin; Cheng Shukang

    2007-01-01

    To fit in with the developing requirement of integrated functions of protection measurement, control and communication of protective relays,a protection measurement and control system based on DeviceNet fieldbus is designed.The communication mechanism of DeviceNet is studied and data trigger modes.communication connection,message types and other key technologies are analyzed.The object modeling and device description of the device are realized too.Results of network test,dynamic simulation and test in the field indicate that this system can accomplish all the communication tasks in real time and can make precise response to every kind of faults of the motor,transformer,line and capacitor.Moreover,this system has higher measurement precision and better control capability.

  10. Measuring steps with the Fitbit activity tracker: an inter-device reliability study.

    Science.gov (United States)

    Dontje, Manon L; de Groot, Martijn; Lengton, Remko R; van der Schans, Cees P; Krijnen, Wim P

    2015-01-01

    Activity trackers like Fitbit are used for self-tracking of physical activity by an increasing number of individuals. Comparing physical activity scores with peers can contribute to the desired behavioural change. However, for meaningful social comparison a high inter-device reliability is paramount. This study aimed to determine the inter-device reliability of Fitbit activity trackers in measuring steps. Ten activity trackers (Fitbit Ultra) were worn by a single person (male, 46 years) during eight consecutive days. Inter-device reliability was assessed on three different levels of aggregation (minutes, hours, days) with various methods, including intra-class correlation coefficient (ICC), Bland-Altman plots, limits of agreement (LOA) and Mixed Model Analysis. Results showed that the inter-device reliability of the Fitbit in measuring steps is good at all levels of aggregation (minutes, hours, days), but especially when steps were measured per day. This implies that individuals can reliably compare their daily physical activity scores with peers.

  11. Digital Measuring Devices Used for Injector Hydraulic Test

    Directory of Open Access Journals (Sweden)

    S. N. Leontiev

    2015-01-01

    Full Text Available To ensure a high specific impulse of the LRE (liquid-propellant engine chamber it is necessary to have optimally organized combustion of the fuel components. This can be ensured by choosing the optimum geometry of gas-dynamic contour of the LRE combustor, as well as by improving the sputtering processes and mixing the fuel components, for example, by selection of the optimum type, characteristics, and location of injectors on the mixing unit of the chamber.These particular reasons arise the interest in the injector characteristics in terms of science, and technological aspects determine the need for control of underlying design parameters in their manufacture.The objective of this work is to give an experimental justification on used digital measurement instrumentation and research the hydraulic characteristics of injectors.To determine injector parameters most widely were used the units with sectional collectors. A technique to control injector parameters using the sectional collectors involves spraying the liquid by injector at a given pressure drop on it for a certain time (the longer, the higher the accuracy and reliability of the results and then determining the amount of liquid in each section to calculate the required parameters of injector.In this work the liquid flow through the injector was determined by high-precision flowmeters FLONET FN2024.1 of electromagnetic type, which have very high metrological characteristics, in particular a flow rate error does not exceed 0.5% in a range of water flow from Qmin= 0.0028 l/s to Qmax Qmax = 0.28 l/s. To determine the coefficient of uneven spray were used differential pressure sensors DMD 331-ASLX of company "DB Sensors RUS", which have an error of 0.075% with a range of differential pressure 0 ... 5 kPa. Measuring complex MIC-200 of company "NPP Measure" and WinPos software for processing array information provided entry, recording, and processing of all the data of the experiment.In this

  12. Strategies to Optimizing Dye-Sensitized Solar Cells: Organic Sensitizers, Tandem Device Structures, and Numerical Device Modeling

    OpenAIRE

    Wenger, Sophie

    2010-01-01

    Dye-sensitized solar cells (DSCs) constitute a novel class of hybrid organic-inorganic solar cells. At the heart of the device is a mesoporous film of titanium dioxide (TiO2) nanoparticles, which are coated with a monolayer of dye sensitive to the visible region of the solar spectrum. The role of the dye is similar to the role of chlorophyll in plants; it harvests solar light and transfers the energy via electron transfer to a suitable material (here ...

  13. Acoustical measurements of expression devices in pipe organs.

    Science.gov (United States)

    Braasch, Jonas

    2008-03-01

    In this investigation, three different swell systems known in pipe organs, the swell box, the crescendo wheel, and the historic wind swell were measured and compared to each other. The dynamic range of the crescendo wheel was found to be most effective, and for frequencies near 2 kHz the increase in sound pressure level could be up to 50 dB between the softest and the loudest adjustment. The maximum dynamic range for the wind swell and the swell box were found to be 10-20 dB in the same frequency range. With its step-wise crescendo procedure, the crescendo wheel simulates the type of orchestra crescendo which is reached by successively adding further musical instruments. In contrast, the swell box and the wind swell produce a crescendo effect similar to the crescendo in which individual musical instruments perform a dynamic movement. This type of crescendo requires a continuous level increase but allows a smaller dynamic range. The disappearance of the wind swell is not surprising because it offers no advantage over the swell box, while being restricted to stops with free reeds.

  14. Rotational knee laxity: Reliability of a simple measurement device in vivo

    Directory of Open Access Journals (Sweden)

    Zantop Thore

    2008-03-01

    Full Text Available Abstract Background Double bundle ACL reconstruction has been demonstrated to decrease rotational knee laxity. However, there is no simple, commercially-available device to measure knee rotation. The investigators developed a simple, non-invasive device to measure knee rotation. In conjunction with a rigid boot to rotate the tibia and a force/moment sensor to allow precise determination of torque about the knee, a magnetic tracking system measures the axial rotation of the tibia with respect to the femur. This device has been shown to have acceptable levels of test re-test reliability to measure knee rotation in cadaveric knees. Methods The objective of this study was to determine reliability of the device in measuring knee rotation of human subjects. Specifically, the intra-tester reliability within a single testing session, test-retest reliability between two testing sessions, and inter-tester reliability were assessed for 11 male subjects with normal knees. Results The 95% confidence interval for rotation was less than 5° for intra-tester, test-retest, and inter-tester reliability, and the standard error of measurement for the differences between left and right knees was found to be less than 3°. Conclusion It was found that the knee rotation measurements obtained with this device have acceptable limits of reliability for clinical use and interpretation.

  15. Design and preliminary evaluation of a portable device for the measurement of bioimpedance spectroscopy.

    Science.gov (United States)

    Yang, Yuxiang; Wang, Jue; Yu, Gang; Niu, Feilong; He, Ping

    2006-12-01

    Portable bioimpedance spectroscopy (BIS) devices are of great value for monitoring the pathological status of biological tissues in clinical and home environments. The two traditional techniques for measuring complex bioimpedance, the bridge method and quadrature demodulation method, are either time-consuming or often associated with high cost, high power consumption, and large board space, and therefore are not ideally suitable for designing a portable device for BIS measurement. This paper describes a novel design of a portable BIS device based on the magnitude-ratio and phase-difference detection method and its implementation using the newest generation of analog electronic products which greatly decrease the complexity of both hardware and software. In order to improve the accuracy of the device, a three-reference calibration algorithm was applied. Experimental sweep-frequency measurements on RC circuits were carried out to preliminarily evaluate the performances of the device. The results obtained by the device were found to be in good agreement with the results measured by a commercial impedance analyzer HP4194, with an overall mean error of 0.014% in magnitude and 0.136 degrees in phase over a frequency range of 20 kHz to 1 MHz.

  16. Measuring Visual Function Using the MultiQuity System: Comparison with an Established Device

    Directory of Open Access Journals (Sweden)

    Patrycja Smolarek-Kasprzak

    2014-01-01

    Full Text Available Purpose. To compare measures of visual acuity (VA and contrast sensitivity (CS from the Thompson Xpert 2000 and MultiQuity (MiQ devices. Methods. Corrected distance VA (CDVA and CS were measured in the right eye of 73 subjects, on an established system (Thompson Xpert and a novel system (MiQ 720. Regression was used to convert MiQ scores into the Thompson scale. Agreement between the converted MiQ and Thompson scores was investigated using standard agreement indices. Test-retest variability for both devices was also investigated, for a separate sample of 24 subjects. Results. For CDVA, agreement was strong between the MiQ and Thomson devices (accuracy = 0.993, precision = 0.889, CCC = 0.883. For CS, agreement was also strong (accuracy = 0.996, precision = 0.911, CCC = 0.907. Agreement was unaffected by demographic variables or by presence/absence of ocular pathology. Test-retest agreement indices for both devices were excellent: in the range 0.88–0.96 for CDVA and in the range 0.90–0.98 for CS. Conclusion. MiQ measurements exhibit strong agreement with corresponding Thomson measurements, and test-retest results are good for both devices. Agreement between the two devices is unaffected by age or ocular pathology.

  17. The potential and device physics of interdigitated thin-film solar cells

    Science.gov (United States)

    Metzger, Wyatt K.

    2008-05-01

    The device physics of thin-film solar cells with interdigitated p-n junctions is examined for a range of spatial sizes, band offsets, and material parameters. The results are illustrated by focusing on recent nanoscale concepts for Cu(In,Ga)Se2 solar cells. Ideally, nanoscale interdigitated junctions can improve solar cell performance relative to planar-junction devices, and make reasonably high solar cell efficiencies (>15%) attainable even with mediocre electro-optical materials.

  18. Concordance of adherence measurement using self-reported adherence questionnaires and medication monitoring devices.

    Science.gov (United States)

    Shi, Lizheng; Liu, Jinan; Koleva, Yordanka; Fonseca, Vivian; Kalsekar, Anupama; Pawaskar, Manjiri

    2010-01-01

    The primary objective of this review was to identify and examine the literature on the association between medication adherence self-reported questionnaires (SRQs) and medication monitoring devices. The primary literature search was performed for 1980-2009 using PubMed, PubMed In Process and Non-Indexed, Ovid MEDLINE, Ovid MEDLINE In-Process, PsycINFO (EBSCO), CINAHL (EBSCO), Ovid HealthStar, EMBASE (Elsevier) and Cochrane Databases and using the following search terms: 'patient compliance', 'medication adherence', 'treatment compliance', 'drug monitoring', 'drug therapy', 'electronic', 'digital', 'computer', 'monitor', 'monitoring', 'drug', 'drugs', 'pharmaceutical preparations', 'compliance' and 'medications'. We identified studies that included SRQs and electronic monitoring devices to measure adherence and focused on the SRQs that were found to be moderately to highly correlated with the monitoring devices. Of the 1679 citations found via the primary search, 41 full-text articles were reviewed for correlation between monitoring devices and SRQs. A majority (68%) of articles reported high (27%), moderate (29%) or significant (12%) correlation between monitoring devices (37 using Medication Event Monitoring System [MEMS®] and four using other devices) and SRQs (11 identified and numerous other unnamed SRQs). The most commonly used SRQs were the Adult/Pediatric AIDS Clinical Trial Group (AACTG/PACTG; 24.4%, 10/41) followed by the 4-item Morisky (9.8%, 4/41), Brief Medication Questionnaire (9.8%, 4/41) and visual analogue scale (VAS; 7.3%, 3/41). Although study designs differed across the articles, SRQs appeared to report a higher rate of medication adherence (+14.9%) than monitoring devices. In conclusion, several medication adherence SRQs were validated using electronic monitoring devices. A majority of them showed high or moderate correlation with medication adherence measured using monitoring devices, and could be considered for measuring patient

  19. Development of a Wearable Device for Motion Capturing Based on Magnetic and Inertial Measurement Units

    Directory of Open Access Journals (Sweden)

    Bin Fang

    2017-01-01

    Full Text Available This paper presents a novel wearable device for gesture capturing based on inertial and magnetic measurement units that are made up of micromachined gyroscopes, accelerometers, and magnetometers. The low-cost inertial and magnetic measurement unit is compact and small enough to wear and there are altogether thirty-six units integrated in the device. The device is composed of two symmetric parts, and either the right part or the left one contains eighteen units covering all the segments of the arm, palm, and fingers. The offline calibration and online calibration are proposed to improve the accuracy of sensors. Multiple quaternion-based extended Kalman filters are designed to estimate the absolute orientations, and kinematic models of the arm-hand are considered to determine the relative orientations. Furthermore, position algorithm is deduced to compute the positions of corresponding joint. Finally, several experiments are implemented to verify the effectiveness of the proposed wearable device.

  20. Experimental and theoretical study of hydrodynamic cell lysing of cancer cells in a high-throughput Circular Multi-Channel Microfiltration device

    KAUST Repository

    Ma, W.

    2013-04-01

    Microfiltration is an important microfluidic technique suitable for enrichment and isolation of cells. However, cell lysing could occur due to hydrodynamic damage that may be detrimental for medical diagnostics. Therefore, we conducted a systematic study of hydrodynamic cell lysing in a high-throughput Circular Multi-Channel Microfiltration (CMCM) device integrated with a polycarbonate membrane. HeLa cells (cervical cancer cells) were driven into the CMCM at different flow rates. The viability of the cells in the CMCM was examined by fluorescence microscopy using Acridine Orange (AO)/Ethidium Bromide (EB) as a marker for viable/dead cells. A simple analytical cell viability model was derived and a 3D numerical model was constructed to examine the correlation of between cell lysing and applied shear stress under varying flow rate and Reynolds number. The measured cell viability as a function of the shear stress was consistent with theoretical and numerical predictions when accounting for cell size distribution. © 2013 IEEE.

  1. Metabolic measurements in cell culture and tissue constructs

    Science.gov (United States)

    Rolfe, P.

    2008-10-01

    This paper concerns the study and use of biological cells in which there is a need for sensors and assemblies for the measurement of a diverse range of physical and chemical variables. In this field cell culture is used for basic research and for applications such as protein and drug synthesis, and in cell, tissue and organ engineering. Metabolic processes are fundamental to cell behaviour and must therefore be monitored reliably. Basic metabolic studies measure the transport of oxygen, glucose, carbon dioxide, lactic acid to, from, or within cells, whilst more advanced research requires examination of energy storage and utilisation. Assemblies are designed to incorporate bioreactor functions for cell culture together with appropriate sensing devices. Oxygen consumption by populations of cells is achieved in a flowthrough assembly that incorporates O2 micro-sensors based on either amperometry or fluorescence. Measurements in single cell are possible with intra-cellular fluorophores acting as biosensors together with optical stimulation and detection. Near infra-red spectroscopy (NIRS) is used for analysis within culture fluid, for example for estimation of glucose levels, as well as within cell populations, for example to study the respiratory enzymes.Â#

  2. Integrated microfluidic device for single-cell trapping and spectroscopy

    KAUST Repository

    Liberale, Carlo

    2013-02-13

    Optofluidic microsystems are key components towards lab-on-a-chip devices for manipulation and analysis of biological specimens. In particular, the integration of optical tweezers (OT) in these devices allows stable sample trapping, while making available mechanical, chemical and spectroscopic analyses.

  3. Similar Device Architectures for Inverted Organic Solar Cell and Laminated Solid-State Dye-Sensitized Solar Cells

    OpenAIRE

    Ishwor Khatri; Jianfeng Bao; Naoki Kishi; Tetsuo Soga

    2012-01-01

    Here, we examine the device architecture of two different types of solar cells mainly inverted organic solar cells and solid state dye-sensitized solar cells (DSSCs) that use organic materials as hole transportation. The inverted organic solar cells structure is dominated by work on titanium dioxide ( T i O 2 ) and zinc oxide (ZnO). These layers are sensitized with dye in solid state DSSCs. Because of the similar device architecture, it becomes possible to fabricate laminated solid-state DSSC...

  4. A Methodology to Measure the Environmental Impact of ICT Operating Systems across Different Device Platforms

    Institute of Scientific and Technical Information of China (English)

    Daniel R. Williams; Yinshan Tang

    2015-01-01

    Abstract-A new methodology was created to measure the energy consumption and related green house gas (GHG) emissions of a computer operating system (OS) across different device platforms. The methodology involved the direct power measurement of devices under different activity states. In order to include all aspects of an OS, the methodology included measurements in various OS modes, whilst uniquely, also incorporating measurements when running an array of defined software activities, so as to include OS application management features. The methodology was demonstrated on a laptop and phone that could each run multiple OSs, results confirmed that OS can significantly impact the energy consumption of devices. In particular, the new versions of the Microsoft Windows OS were tested and highlighted significant differences between the OS versions on the same hardware. The developed methodology could enable a greater awareness of energy consumption, during both the software development and software marketing processes.

  5. Attenuation length measurements of liquid scintillator with LabVIEW and reliability evaluation of the device

    CERN Document Server

    Gao, L; Ding, YY; Zhou, L; Wen, LJ; Xie, YG; Wang, ZG; Cai, X; Sun, XL; Fang, J; Xue, Z; Zhang, AW; LÜ, QW; Sun, LJ; Ge, YS; Liu, YB; Niu, SL; Hu, T; Cao, J; LÜ, JG

    2013-01-01

    The attenuation length measuring device was constructed by using oscilloscope and LabVIEW for signal acquisition and processing. The performance of the device has been tested with a variety of ways, the test results show that the set-up has a good stability and high precision (sigma/mean reached 0.4 percent). Besides, the accuracy of the measurement system will decrease by about 17 percent if a filter is used. The attenuation length of gadolinium-loaded liquid scintillator (Gd-LS) was measured as 15.10 plus or minus 0.35 m where Gd-LS was heavily used in Daya Bay Neutrino Experiment. In addition, one method based on the Beer-Lambert law was proposed to investigate the reliability of the measurement device, the R-square reached 0.9995. Moreover, three purification methods for Linear Alkyl Benzene (LAB) production were compared in the experiment.

  6. Optofluidic Temperature and Pressure Measurements with Fiber Bragg Gratings Embedded in Microfluidic Devices

    CERN Document Server

    Cooksey, Gregory A

    2016-01-01

    The integration of photonic sensors into microfluidic devices provides opportunities for dynamic measurement of chemical and physical properties of fluids in very small volumes. We previously reported on the use of commercially available Fiber Bragg Gratings (FBGs) and on-chip silicon waveguides for temperature sensing. In this report, we demonstrate the integration of FBGs into easy-to-fabricate microfluidic devices and report on their sensitivity for temperature and pressure measurement in microliter volumes. These sensors present new routes to measurement in microfluidic applications such as small-volume calorimetry and microflow metrology.

  7. A new device designed for direct yield stress measurements of cement spacer

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, C.L.; Tonmukayakul, P.; Morgan, R.L. [Halliburton Energy Services, Houston, TX (United States)

    2007-07-01

    The rheological properties of spacer fluids and cement slurries have a significant impact on the hydraulic shear stress of well casing walls. This paper described experimental studies and numerical models of a device designed to measure the yield stress and rheological properties of spacer and cement samples. The device was designed using the Couette principle for rheological measurements, and measured the yield stress of particle-laden samples between 4 and 150 degrees C. A sample contained in a gap between a stator and a blade located along the inside wall of a steel cup was analyzed using the device. A stator was attached to a torque device and remained static during the rheological measurement. Yield stress was measured by rotating the device at a low speed at 3 rpm and at steady state torque. Torque was recorded when the rotation stopped. Two aqueous mixtures of titanium oxide (TiO{sub 2}) particles were used for the experiment. A cement spacer comprised of a blend of barite, citric acid and water was also measured. A volume-averaged shear method was used to calculate shear rate and shear stress. Key dimensionless variables were the impeller Reynolds number; the Froude number; the Weber number; and the Weissenberg number. Accuracy was assessed by examining the data obtained with a model fluid where yield stress data was already determined. Results of the comparison showed that values obtained using the device were consistent and comparable with results obtained using other techniques. It was concluded that further research is needed to characterize the elastic fluids in the device. 13 refs., 2 tabs., 3 figs.

  8. Experimental and Theoretical Measurements of Concentration Distributions in Acoustic Focusing Devices

    Energy Technology Data Exchange (ETDEWEB)

    Rose, K A; Fisher, K; Jung, B; Ness, K; Mariella Jr., R P

    2008-06-16

    We describe a modeling approach to capture the particle motion within an acoustic focusing microfluidic device. Our approach combines finite element models for the acoustic forces with analytical models for the fluid motion and uses these force fields to calculate the particle motion in a Brownian dynamics simulation. We compare results for the model with experimental measurements of the focusing efficiency within a microfabricated device. The results show good qualitative agreement over a range of acoustic driving voltages and particle sizes.

  9. A Charge-Coupled Device CCD line-scan system for road luminance measurement.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1996-01-01

    The problems involved in measuring road luminance are discussed and a new measuring system described which is based on a line-scan Charge Coupled Device (CCD) configuration. It is designed for the assessment of average road surface luminance and degree of non-uniformity of road lighting. Additionall

  10. Detail of photo 7903109 stack of superconducting cables in the modulus measuring device

    CERN Multimedia

    1979-01-01

    The picture shows an assembly of insulated superconducting cables of the type used in the Po dipole magnet inserted in the elastic modulus measuring device (photos 7903547X and 7903169) in order to measures its mechanical properties under azimuthal compression. See also 7903547X, 7903169, 8307552X.

  11. A new highly adaptable design of shear-flow device for orientation of macromolecules for Linear Dichroism (LD) measurement

    KAUST Repository

    Lundahl, P. Johan

    2011-01-01

    This article presents a new design of flow-orientation device for the study of bio-macromolecules, including DNA and protein complexes, as well as aggregates such as amyloid fibrils and liposome membranes, using Linear Dichroism (LD) spectroscopy. The design provides a number of technical advantages that should make the device inexpensive to manufacture, easier to use and more reliable than existing techniques. The degree of orientation achieved is of the same order of magnitude as that of the commonly used concentric cylinders Couette flow cell, however, since the device exploits a set of flat strain-free quartz plates, a number of problems associated with refraction and birefringence of light are eliminated, increasing the sensitivity and accuracy of measurement. The device provides similar shear rates to those of the Couette cell but is superior in that the shear rate is constant across the gap. Other major advantages of the design is the possibility to change parts and vary sample volume and path length easily and at a low cost. © 2011 The Royal Society of Chemistry.

  12. UNIVERSAL AUTO-CALIBRATION FOR A RAPID BATTERY IMPEDANCE SPECTRUM MEASUREMENT DEVICE

    Energy Technology Data Exchange (ETDEWEB)

    Jon P. Christophersen; John L. Morrison; William H. Morrison

    2014-03-01

    Electrochemical impedance spectroscopy has been shown to be a valuable tool for diagnostics and prognostics of energy storage devices such as batteries and ultra-capacitors. Although measurements have been typically confined to laboratory environments, rapid impedance spectrum measurement techniques have been developed for on-line, embedded applications as well. The prototype hardware for the rapid technique has been validated using lithium-ion batteries, but issues with calibration had also been identified. A new, universal automatic calibration technique was developed to address the identified issues while also enabling a more simplified approach. A single, broad-frequency range is used to calibrate the system and then scaled to the actual range and conditions used when measuring a device under test. The range used for calibration must be broad relative to the expected measurement conditions for the scaling to be successful. Validation studies were performed by comparing the universal calibration approach with data acquired from targeted calibration ranges based on the expected range of performance for the device under test. First, a mid-level shunt range was used for calibration and used to measure devices with lower and higher impedance. Next, a high excitation current level was used for calibration, followed by measurements using lower currents. Finally, calibration was performed over a wide frequency range and used to measure test articles with a lower set of frequencies. In all cases, the universal calibration approach compared very well with results acquired following a targeted calibration. Additionally, the shunts used for the automated calibration technique were successfully characterized such that the rapid impedance measurements compare very well with laboratory-scale measurements. These data indicate that the universal approach can be successfully used for onboard rapid impedance spectra measurements for a broad set of test devices and range of

  13. Microfluidic application-specific integrated device for monitoring direct cell-cell communication via gap junctions between individual cell pairs

    Science.gov (United States)

    Lee, Philip J.; Hung, Paul J.; Shaw, Robin; Jan, Lily; Lee, Luke P.

    2005-05-01

    Direct cell-cell communication between adjacent cells is vital for the development and regulation of functional tissues. However, current biological techniques are difficult to scale up for high-throughput screening of cell-cell communication in an array format. In order to provide an effective biophysical tool for the analysis of molecular mechanisms of gap junctions that underlie intercellular communication, we have developed a microfluidic device for selective trapping of cell-pairs and simultaneous optical characterizations. Two different cell populations can be brought into membrane contact using an array of trapping channels with a 2μm by 2μm cross section. Device operation was verified by observation of dye transfer between mouse fibroblasts (NIH3T3) placed in membrane contact. Integration with lab-on-a-chip technologies offers promising applications for cell-based analytical tools such as drug screening, clinical diagnostics, and soft-state biophysical devices for the study of gap junction protein channels in cellular communications. Understanding electrical transport mechanisms via gap junctions in soft membranes will impact quantitative biomedical sciences as well as clinical applications.

  14. A co-culture device with a tunable stiffness to understand combinatorial cell-cell and cell-matrix interactions

    Science.gov (United States)

    Rao, Nikhil; Grover, Gregory N.; Vincent, Ludovic G.; Evans, Samantha C.; Choi, Yu Suk; Vincent, Ludovic G.; Spencer, Katrina H.; Hui, Elliot E.; Engler, Adam J.; Christman, Karen L.

    2013-01-01

    Cell behavior on 2-D in vitro cultures is continually being improved to better mimic in vivo physiological conditions by combining niche cues including multiple cell types and substrate stiffness, which are well known to impact cell phenotype. However, no system exists in which a user can systematically examine cell behavior on a substrate with a specific stiffness (elastic modulus) in culture with a different cell type, while maintaining distinct cell populations. We demonstrate the modification of a silicon reconfigurable co-culture system with a covalently linked hydrogel of user-defined stiffness. This device allows the user to control whether two separate cell populations are in contact with each other or only experience paracrine interactions on substrates of controllable stiffness. To illustrate the utility of this device, we examined the role of substrate stiffness combined with myoblast co-culture on adipose derived stem cell (ASC) differentiation and found that the presence of myoblasts and a 10 kPa substrate stiffness increased ASC myogenesis versus co-culture on stiff substrates. As this example highlights, this technology better controls the in vitro microenvironment, allowing the user to develop a more thorough understanding of the combined effects of cell-cell and cell-matrix interactions. PMID:24061208

  15. Device physics of thin-film polycrystalline cells and modules. Annual subcontract report, December 6, 1993--December 5, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Sites, J.R.

    1995-05-01

    Progress has been made in several applications of device physics to thin-film polycrystalline cells and modules. At the cell level, results include a more quantitative separation of photon losses, the impact of second barriers on cell operation, and preliminary studies of how current-voltage curves are affected by band offsets. Module analysis includes the effects of the typical monolithic, series-connected cell geometry, analytical techniques when only the two module leads are accessible, and the impact of chopping frequency, local defects, and high-intensity beams on laser-scanning measurements.

  16. Measuring The Contact Resistances Of Photovoltaic Cells

    Science.gov (United States)

    Burger, D. R.

    1985-01-01

    Simple method devised to measure contact resistances of photovoltaic solar cells. Method uses readily available equipment and applicable at any time during life of cell. Enables evaluation of cell contact resistance, contact-end resistance, contact resistivity, sheet resistivity, and sheet resistivity under contact.

  17. Device Engineering Towards Improved Tin Sulfide Solar Cell Performance and Performance Reproducibility

    Energy Technology Data Exchange (ETDEWEB)

    Steinmann, Vera; Chakraborty, Rupak; Rekemeyer, Paul; Siol, Sebastian; Martinot, Loic; Polizzotti, Alex; Yang, Chuanxi; Hartman, Katy; Gradecak, Silvija; Zakutayev, Andriy; Gordon, Roy G.; Buonassisi, Tonio

    2016-11-21

    As novel absorber materials are developed and screened for their photovoltaic (PV) properties, the challenge remains to rapidly test promising candidates in high-performing PV devices. There is a need to engineer new compatible device architectures, including the development of novel transparent conductive oxides and buffer layers. Here, we consider the two approaches of a substrate-style and a superstrate-style device architecture for novel thin-film solar cells. We use tin sulfide as a test absorber material. Upon device engineering, we demonstrate new approaches to improve device performance and performance reproducibility.

  18. Measurement of inner and/or outer profiles of pipes using ring beam devices

    Science.gov (United States)

    Wakayama, T.; Yoshizawa, T.

    2009-11-01

    Inner profile measurement is an important matter in such fields as medicine, dentistry and anthropology as well as mechanical engineering and industry. Here we propose a measurement method for inner diameter of pipes and/or holes. The key device in this technique is a ring beam device which consists of a conical mirror and a laser diode. And the fundamental principle is based on optical sectioning without any contact probe. The optically sectioned profile of an inner wall of a pipe-like object is analyzed to give the inner profile in addition to the inner diameter. This optical instrument with a simple and small configuration is now under development for practical uses. In the hitherto-tried experimental works, the availability of this instrument has been highly evaluated and usability for practical applications is expected, especially, for measurement and inspection of mechanical components and elements besides pipes. This ring beam device consisting of a conical mirror and a LD is assembled to form a disklike light beam sheet. We show measurement result of pipes and holes, and, at the same time, report a compact inner profile measuring instrument. Both the ring beam device and a miniaturized CCD camera are fabricated in a glass tube. Availability of this instrument is shown by measuring the inner profiles of various pipes. In response to this trial, there appeared a strong request that not only the internal but external profiles should be measured simultaneously. Therefore we propose an improved method for measuring the external profile in addition to the internal profile. In our arrangement, one pair of concaved conical mirrors is used for the external profile measurement. In combination with the inner profile measurement technique, simultaneous measurement of the inner and outer profiles becomes attainable. A measurement result on a bevel gear shows availability of newly proposed principle. Now we are aiming to realize simultaneous measurement of the internal

  19. Real cell overlay measurement through design based metrology

    Science.gov (United States)

    Yoo, Gyun; Kim, Jungchan; Park, Chanha; Lee, Taehyeong; Ji, Sunkeun; Jo, Gyoyeon; Yang, Hyunjo; Yim, Donggyu; Yamamoto, Masahiro; Maruyama, Kotaro; Park, Byungjun

    2014-04-01

    Until recent device nodes, lithography has been struggling to improve its resolution limit. Even though next generation lithography technology is now facing various difficulties, several innovative resolution enhancement technologies, based on 193nm wavelength, were introduced and implemented to keep the trend of device scaling. Scanner makers keep developing state-of-the-art exposure system which guarantees higher productivity and meets a more aggressive overlay specification. "The scaling reduction of the overlay error has been a simple matter of the capability of exposure tools. However, it is clear that the scanner contributions may no longer be the majority component in total overlay performance. The ability to control correctable overlay components is paramount to achieve the desired performance.(2)" In a manufacturing fab, the overlay error, determined by a conventional overlay measurement: by using an overlay mark based on IBO and DBO, often does not represent the physical placement error in the cell area of a memory device. The mismatch may arise from the size or pitch difference between the overlay mark and the cell pattern. Pattern distortion, caused by etching or CMP, also can be a source of the mismatch. Therefore, the requirement of a direct overlay measurement in the cell pattern gradually increases in the manufacturing field, and also in the development level. In order to overcome the mismatch between conventional overlay measurement and the real placement error of layer to layer in the cell area of a memory device, we suggest an alternative overlay measurement method utilizing by design, based metrology tool. A basic concept of this method is shown in figure1. A CD-SEM measurement of the overlay error between layer 1 and 2 could be the ideal method but it takes too long time to extract a lot of data from wafer level. An E-beam based DBM tool provides high speed to cover the whole wafer with high repeatability. It is enabled by using the design as a

  20. Development of a rare cell fractionation device: application for cancer detection.

    Science.gov (United States)

    Mohamed, Hisham; McCurdy, Leslie D; Szarowski, Donald H; Duva, Salvatore; Turner, James N; Caggana, Michele

    2004-12-01

    Isolating rare cells from biological fluids including whole blood or bone marrow is an interesting biological problem. Characterization of a few metastatic cells from cancer patients for further study is desirable for prognosis/diagnosis. Traditional methods have not proven adequate, due to the compositional complexity of blood, with its large numbers of cell types. To separate individual cells based on their mechanical characteristics, we have developed a series of massively parallel microfabricated sieving device. These devices were constructed with four successively narrower regions of channels numbering approximately 1800 per region. As cells traversed the device, they encountered each region and stopped at a gap width that prohibited passage due to their size. Cultured neuroblastoma cells, when mixed with whole blood and applied to the device, were retained in the 10-microm-wide by 20-microm-deep channels. All other cells migrated to the output. A derivative of the same device was utilized to characterize migration of whole blood. Adult white blood cells were retained at the 2.5-microm-wide by 5-microm-deep channels, while red blood cells passed through these channels. Devices designed to capture rare cells in peripheral circulation for downstream analysis will provide an important tool for diagnosis and treatment.

  1. The enhanced measurement-device-independent quantum key distribution with two-intensity decoy states

    Science.gov (United States)

    Zhu, Jian-Rong; Zhu, Feng; Zhou, Xing-Yu; Wang, Qin

    2016-09-01

    We put forward a new scheme for implementing the measurement-device-independent quantum key distribution (QKD) with weak coherent source, while using only two different intensities. In the new scheme, we insert a beam splitter and a local detector at both Alice's and Bob's side, and then all the triggering and non-triggering signals could be employed to process parameter estimations, resulting in very precise estimations for the two-single-photon contributions. Besides, we compare its behavior with two other often used methods, i.e., the conventional standard three-intensity decoy-state measurement-device-independent QKD and the passive measurement-device-independent QKD. Through numerical simulations, we demonstrate that our new approach can exhibit outstanding characteristics not only in the secure transmission distance, but also in the final key generation rate.

  2. Measuring Soil Moisture using the Signal Strength of Buried Bluetooth Devices.

    Science.gov (United States)

    Hut, R.; Campbell, C. S.

    2015-12-01

    A low power bluetooth Low Energy (BLE) device is burried 20cm into the soil and a smartphone is placed on top of the soil to test if bluetooth signal strength can be related to soil moisture. The smartphone continuesly records and stores bluetooth signal strength of the device. The soil is artifcially wetted and drained. Results show a relation between BLE signal strength and soil moisture that could be used to measure soil moisture using these off-the-shelf consumer electronics. This opens the possibily to develop sensors that can be buried into the soil, possibly below the plow-line. These sensors can measure local parameters such as electric conductivity, ph, pressure, etc. Readings would be uploaded to a device on the surface using BLE. The signal strength of this BLE would be an (additional) measurement of soil moisture.

  3. Measuring cell identity in noisy biological systems

    OpenAIRE

    Kenneth D Birnbaum; Kussell, Edo

    2011-01-01

    Global gene expression measurements are increasingly obtained as a function of cell type, spatial position within a tissue and other biologically meaningful coordinates. Such data should enable quantitative analysis of the cell-type specificity of gene expression, but such analyses can often be confounded by the presence of noise. We introduce a specificity measure Spec that quantifies the information in a gene's complete expression profile regarding any given cell type, and an uncertainty me...

  4. A novel LTCC electrochemical cell construction and characterization: a detection compartment for portable devices.

    Science.gov (United States)

    Pesquero, Naira Canevarolo; Gongora-Rubio, Mário Ricardo; Yamanaka, Hideko

    2013-08-07

    In this work we described for the first time the construction of a 25 μL electrochemical cell from low temperature co-fired ceramic (LTCC) material and carbon screen-printed electrode applicable in portable devices. Firstly, a carbon screen-printed electrode was prepared and characterized by cyclic voltammetry and scanning electron microscopy. Afterwards carbon polymeric film and metal pastes were dropped into the LTCC cell cavities in order to determine the device electrodes, and this arrangement was also electrochemically characterized. The great advantage of this promising device is the simple construction method and its widespread applicability in reusable portable devices.

  5. Design and implementation of automatic shading device for diffuse radiation measurement

    Institute of Scientific and Technical Information of China (English)

    LYU; Wenhua; BIAN; Zeqiang; CHONG; Wei

    2015-01-01

    Considering the problem of too large area the shading disc covered,complex shadow band coefficients and too big diffuse radiation measurement bias,an automatic shading device for diffuse radiometer is designed and realized. Set a shading ball on the automatic sun tracker,drive linkage parallelogram structure with the declination axis arm,the shading ball can rotate synchronously with the motion of the sun and shade beam radiation measured with pyranometer,thus shading beam radiation and measuring diffuse radiation can be realized automatically. The comparison test results show that the automatic shading device can realize diffuse radiation measurement automatically,the accuracy of diffuse radiation readings can get a 18. 7% improvement compared with traditional measure system,greatly improves the reliability and accuracy of the diffuse radiation measurement.

  6. The Total Deviation Index estimated by Tolerance Intervals to evaluate the concordance of measurement devices

    Directory of Open Access Journals (Sweden)

    Ascaso Carlos

    2010-04-01

    Full Text Available Abstract Background In an agreement assay, it is of interest to evaluate the degree of agreement between the different methods (devices, instruments or observers used to measure the same characteristic. We propose in this study a technical simplification for inference about the total deviation index (TDI estimate to assess agreement between two devices of normally-distributed measurements and describe its utility to evaluate inter- and intra-rater agreement if more than one reading per subject is available for each device. Methods We propose to estimate the TDI by constructing a probability interval of the difference in paired measurements between devices, and thereafter, we derive a tolerance interval (TI procedure as a natural way to make inferences about probability limit estimates. We also describe how the proposed method can be used to compute bounds of the coverage probability. Results The approach is illustrated in a real case example where the agreement between two instruments, a handle mercury sphygmomanometer device and an OMRON 711 automatic device, is assessed in a sample of 384 subjects where measures of systolic blood pressure were taken twice by each device. A simulation study procedure is implemented to evaluate and compare the accuracy of the approach to two already established methods, showing that the TI approximation produces accurate empirical confidence levels which are reasonably close to the nominal confidence level. Conclusions The method proposed is straightforward since the TDI estimate is derived directly from a probability interval of a normally-distributed variable in its original scale, without further transformations. Thereafter, a natural way of making inferences about this estimate is to derive the appropriate TI. Constructions of TI based on normal populations are implemented in most standard statistical packages, thus making it simpler for any practitioner to implement our proposal to assess agreement.

  7. Comparative measurements of the level of turbulence atmosphere by optical and acoustic devices

    Science.gov (United States)

    Lukin, V. P.; Botugina, N. N.; Gladkih, V. A.; Emaleev, O. N.; Konyaev, P. A.; Odintsov, S. L.; Torgaev, A. V.

    2014-11-01

    The complex measurements of level of atmospheric turbulence are conducted by the differential measurement device of turbulence (DMT), wave-front sensor (WFS), and also by ultrasonic weather-stations. Daytime measurements of structure parameters of refractive index of atmospheric turbulence carried out on horizontal optical paths on the Base Experimental Complex (BEC) of V.E. Zuev Institute of Atmospheric Optics SB RAS (IOA). A comparative analysis over of the got results is brought.

  8. Reliability of measuring pelvic floor elevation with a diagnostic ultrasonic imaging device

    OpenAIRE

    Ubukata, Hitomi; Maruyama, Hitoshi; Huo, Ming

    2015-01-01

    [Purpose] The purpose of this study was to investigate the reliability of measuring the amount of pelvic floor elevation during pelvic and abdominal muscle contraction with a diagnostic ultrasonic imaging device. [Subjects] The study group comprised 11 healthy women without urinary incontinence or previous birth experience. [Methods] We measured the displacement elevation of the bladder base during contraction of the abdominal and pelvic floor muscles was measured using a diagnostic ultrasoni...

  9. Measuring turbulence in a flotation cell using electrical resistance tomography

    Science.gov (United States)

    Meng, Jun; Xie, Weiguo; Runge, Kym; Bradshaw, Dee

    2015-11-01

    Measuring turbulence in an industrial flotation environment has long been problematic due to the opaque, aggressive, and abrasive three-phase environment in a flotation cell. One of the promising measurement techniques is electrical resistance tomography (ERT). By measuring the conductivity distribution across a measurement area, ERT has been adopted by many researchers to monitor and investigate many processes involving multiphase flows. In the research outlined in this paper, a compact ERT probe was built and then used to measure the conductivity distribution within a 60 l flotation cell operated with water and air. Two approaches were then developed to process the ERT data and estimate turbulence-related parameters. One is a conductivity variance method and the other is based on the Green-Kubo relations. Both rely on and use the fluctuation in the ERT measurement caused by bubbles moving through the measurement area changing the density of the fluid. The results from both approaches were validated by comparing the results produced by the ERT probe in a 60l flotation cell operated at different air rates and impeller speeds to that measured using an alternative turbulence measurement device. The second approach is considered superior to the first as the first requires the development of auxiliary information which would not usually be known for a new system.

  10. Off-axis electron holography for the measurement of active dopants in silicon semiconductor devices

    Science.gov (United States)

    Cooper, David

    2016-11-01

    There is a need in the semiconductor industry for a dopant profiling technique with nm-scale resolution. Here we demonstrate that off-axis electron holography can be used to provide maps of the electrostatic potential in semiconductor devices with nm-scale resolution. In this paper we will discuss issues regarding the spatial resolution and precision of the technique. Then we will discuss problems with specimen preparation and how this affects the accuracy of the measurements of the potentials. Finally we show results from experimental off-axis electron holography applied to nMOS and pMOS CMOS devices grown on bulk silicon and silicon- on-insulator type devices and present solutions to common problems that are encountered when examining these types of devices.

  11. Assessment of a portable device for the quantitative measurement of ankle joint stiffness in spastic individuals

    DEFF Research Database (Denmark)

    Lorentzen, Jakob; Grey, Michael J; Geertsen, Svend Sparre

    2012-01-01

    OBJECTIVE: Spasticity is a common complication with neurological diseases and CNS lesions. Instrumented systems to evaluate spasticity often cannot provide an immediate result, thus limiting their clinical usefulness. In this study we investigated the accuracy and reliability of the portable...... was measured with the portable device and a stationary torque motor. Inter- and intra-rater reliability was assessed with the intra-class correlation coefficient (ICC). RESULTS: Stiffness measures with the portable and stationary devices were significantly correlated for controls and MS participants (p...

  12. The Architecture of Colloidal Quantum Dot Solar Cells: Materials to Devices

    KAUST Repository

    Kramer, Illan J.

    2014-01-08

    The materials chemistry of Colloidal Quantum Dot (CQDs) suspended in solution and processed into films has provided a foundation onto which useful photovoltaic devices can be built. These active materials offer the benefits of solution processing paired with the flexibility of adjustable bandgaps, tailored to suit a particular need. In parallel with these advances, pursuing device geometries that better leverage the available electronic properties of CQD films has borne fruit in further advancing CQD solar cell performance. For active materials such as CQD films where 1/α, where alpha is the absorption coefficient, is of the same order as the free carrier extraction length, external quantum efficiency (EQE) measurements have proved useful in profiling the effectiveness of each nanometer of device thickness at extracting photogenerated carriers. Because CQD films have the added complications of being made of variable-sized constituent material building blocks as well as being deposited from solution, the nature of charge transport through the films can also be size-dependent and matrix dependent.

  13. Device and Method for Continuously Equalizing the Charge State of Lithium Ion Battery Cells

    Science.gov (United States)

    Schwartz, Paul D. (Inventor); Martin, Mark N. (Inventor); Roufberg, Lewis M. (Inventor)

    2015-01-01

    A method of equalizing charge states of individual cells in a battery includes measuring a previous cell voltage for each cell, measuring a previous shunt current for each cell, calculating, based on the previous cell voltage and the previous shunt current, an adjusted cell voltage for each cell, determining a lowest adjusted cell voltage from among the calculated adjusted cell voltages, and calculating a new shunt current for each cell.

  14. Effect of growth solution, membrane size and array connection on microbial fuel cell power supply for medical devices.

    Science.gov (United States)

    Roxby, Daniel N; Nham Tran; Pak-Lam Yu; Nguyen, Hung T

    2016-08-01

    Implanted biomedical devices typically last a number of years before their batteries are depleted and a surgery is required to replace them. A Microbial Fuel Cell (MFC) is a device which by using bacteria, directly breaks down sugars to generate electricity. Conceptually there is potential to continually power implanted medical devices for the lifetime of a patient. To investigate the practical potential of this technology, H-Cell Dual Chamber MFCs were evaluated with two different growth solutions and measurements recorded for maximum power output both of individual MFCs and connected MFCs. Using Luria-Bertani media and connecting MFCs in a hybrid series and parallel arrangement with larger membrane sizes showed the highest power output and the greatest potential for replacing implanted batteries.

  15. Non-Contact Stiffness Measurement of a Suspended Single Walled Carbon Nanotube Device

    Science.gov (United States)

    Zheng, Yun; Su, Chanmin; Getty, Stephanie

    2010-01-01

    A new nanoscale electric field sensor was developed for studying triboelectric charging in terrestrial and Martian dust devils. This sensor is capable to measure the large electric fields for large dust devils without saturation. However, to quantify the electric charges and the field strength it is critical to calibrate the mechanical stiffness of the sensor devices. We performed a technical feasibility study of the Nano E-field Sensor stiffness by a non-contact stiffness measurement method. The measurement is based on laser Doppler vibrometer measurement of the thermal noise due to energy flunctuations in the devices. The experiment method provides a novel approach to acquire data that is essential in analyzing the quantitative performance of the E-field Nano Sensor. To carry out the non-contact stiffness measurement, we fabricated a new Single-Walled Carbon Nanotube (SWCNT) E-field sensor with different SWCNTs suspension conditions. The power spectra of the thermal induced displacement in the nano E-field sensor were measured at the accuracy of picometer. The power spectra were then used to derive the mechanical stiffness of the sensors. Effect of suspension conditions on stiffness and sensor sensitivty was discussed. After combined deformation and resistivity measurement, we can compare with our laboratory testing and field testing results. This new non-contact measurement technology can also help to explore to other nano and MEMS devices in the future.

  16. Lessons learned: from dye-sensitized solar cells to all-solid-state hybrid devices.

    Science.gov (United States)

    Docampo, Pablo; Guldin, Stefan; Leijtens, Tomas; Noel, Nakita K; Steiner, Ullrich; Snaith, Henry J

    2014-06-25

    The field of solution-processed photovoltaic cells is currently in its second spring. The dye-sensitized solar cell is a widely studied and longstanding candidate for future energy generation. Recently, inorganic absorber-based devices have reached new record efficiencies, with the benefits of all-solid-state devices. In this rapidly changing environment, this review sheds light on recent developments in all-solid-state solar cells in terms of electrode architecture, alternative sensitizers, and hole-transporting materials. These concepts are of general applicability to many next-generation device platforms.

  17. Solar Cell Calibration and Measurement Techniques

    Science.gov (United States)

    Bailey, Sheila; Brinker, Dave; Curtis, Henry; Jenkins, Phillip; Scheiman, Dave

    2004-01-01

    The increasing complexity of space solar cells and the increasing international markets for both cells and arrays has resulted in workshops jointly sponsored by NASDA, ESA and NASA. These workshops are designed to obtain international agreement on standardized values for the AMO spectrum and constant, recommend laboratory measurement practices and establish a set of protocols for international comparison of laboratory measurements. A working draft of an ISO standard, WD15387, "Requirements for Measurement and Calibration Procedures for Space Solar Cells" was discussed with a focus on the scope of the document, a definition of primary standard cell, and required error analysis for all measurement techniques. Working groups addressed the issues of Air Mass Zero (AMO) solar constant and spectrum, laboratory measurement techniques, and te international round robin methodology. A summary is presented of the current state of each area and the formulation of the ISO document.

  18. In situ azimuthal rotation device for linear dichroism measurements in scanning transmission x-ray microscopy

    Science.gov (United States)

    Hernández-Cruz, D.; Hitchcock, A. P.; Tyliszczak, T.; Rousseau, M.-E.; Pézolet, M.

    2007-03-01

    A novel miniature rotation device used in conjunction with a scanning transmission x-ray microscope is described. It provides convenient in situ sample rotation to enable measurements of linear dichroism at high spatial resolution. The design, fabrication, and mechanical characterization are presented. This device has been used to generate quantitative maps of the spatial distribution of the orientation of proteins in several different spider and silkworm silks. Specifically, quantitative maps of the dichroic signal at the C 1s→π*amide transition in longitudinal sections of the silk fibers give information about the spatial orientation, degree of alignment, and spatial distribution of protein peptide bonds. A new approach for analyzing the dichroic signal to extract orientation distributions, in addition to magnitudes of aligned components, is presented and illustrated with results from Nephila clavipes dragline spider silk measured using the in situ rotation device.

  19. Measurement of Underwater Operational Noise Emitted by Wave and Tidal Stream Energy Devices.

    Science.gov (United States)

    Lepper, Paul A; Robinson, Stephen P

    2016-01-01

    The increasing international growth in the development of marine and freshwater wave and tidal energy harvesting systems has been followed by a growing requirement to understand any associated underwater impact. Radiated noise generated during operation is dependent on the device's physical properties, the sound-propagation environment, and the device's operational state. Physical properties may include size, distribution in the water column, and mechanics/hydrodynamics. The sound-propagation environment may be influenced by water depth, bathymetry, sediment type, and water column acoustic properties, and operational state may be influenced by tidal cycle and wave height among others This paper discusses some of the challenges for measurement of noise characteristics from these devices as well as a case study of the measurement of radiated noise from a full-scale wave energy converter.

  20. Experimental measurement-device-independent quantum key distribution with uncharacterized encoding.

    Science.gov (United States)

    Wang, Chao; Wang, Shuang; Yin, Zhen-Qiang; Chen, Wei; Li, Hong-Wei; Zhang, Chun-Mei; Ding, Yu-Yang; Guo, Guang-Can; Han, Zheng-Fu

    2016-12-01

    Measurement-device-independent quantum key distribution (MDI QKD) is an efficient way to share secrets using untrusted measurement devices. However, the assumption on the characterizations of encoding states is still necessary in this promising protocol, which may lead to unnecessary complexity and potential loopholes in realistic implementations. Here, by using the mismatched-basis statistics, we present the first proof-of-principle experiment of MDI QKD with uncharacterized encoding sources. In this demonstration, the encoded states are only required to be constrained in a two-dimensional Hilbert space, and two distant parties (Alice and Bob) are resistant to state preparation flaws even if they have no idea about the detailed information of their encoding states. The positive final secure key rates of our system exhibit the feasibility of this novel protocol, and demonstrate its value for the application of secure communication with uncharacterized devices.

  1. A portable cell-based optical detection device for rapid detection of Listeria and Bacillus toxins

    Science.gov (United States)

    Banerjee, Pratik; Banada, Padmapriya P.; Rickus, Jenna L.; Morgan, Mark T.; Bhunia, Arun K.

    2005-11-01

    A mammalian cell-based optical biosensor was built to detect pathogenic Listeria and Bacillus species. This sensor measures the ability of the pathogens to infect and induce cytotoxicity on hybrid lymphocyte cell line (Ped-2E9) resulting in the release of alkaline phosphatase (ALP) that can be detected optically using a portable spectrophotometer. The Ped-2E9 cells were encapsulated in collagen gel matrices and grown in 48-well plates or in specially designed filtration tube units. Toxin preparations or bacterial cells were introduced and ALP release was assayed after 3-5 h. Pathogenic L. monocytogenes strains or the listeriolysin toxins preparation showed cytotoxicity ranging from 55% - 92%. Toxin preparations (~20 μg/ml) from B. cereus strains showed 24 - 98% cytotoxicity. In contrast, a non-pathogenic L. innocua (F4247) and a B. substilis induced only 2% and 8% cytotoxicity, respectively. This cell-based detection device demonstrates its ability to detect the presence of pathogenic Listeria and Bacillus species and can potentially be used onsite for food safety or in biosecurity application.

  2. Endovascular biopsy: Technical feasibility of novel endothelial cell harvesting devices assessed in a rabbit aneurysm model

    Science.gov (United States)

    Bauer, Diana; Sun, Zhengda; Stillson, Carol; Nelson, Jeffrey; Barry, David; Hetts, Steven W; Higashida, Randall T; Dowd, Christopher F; Halbach, Van V; Su, Hua; Saeed, Maythem M

    2015-01-01

    The lack of safe and reliable methods to sample vascular tissue in situ limits discovery of the underlying genetic and pathophysiological mechanisms of many vascular disorders, including aneurysms. We investigated the feasibility and comparable efficacy of in vivo vascular endothelial cell sampling using a spectrum of endovascular devices. Using the rabbit elastase carotid aneurysm model we evaluated the performance of existing aneurysmal coils, intracranial stents, and stent-like devices to collect vascular endothelial cells. Additionally, we modified a subset of devices to assess the effects of alterations to coil pitch, coil wire contour, and stent surface finishing. Device performance was evaluated by (1) the number of viable endothelial cells harvested, (2) the degree of vascular wall damage analyzed using digital subtraction angiography and histopathological analysis, and (3) the ease of device navigability and retrieval. Isolated cells underwent immunohistochemical analysis to confirm cell type and viability. Coil and stent specifications, technique, and endothelial cell counts were tabulated and statistical analysis performed. Using conventional detachable-type and modified aneurysm coils 11 of 14 (78.6%) harvested endothelial cells with a mean of 7.93 (±8.33) cells/coil, while 15 of 15 (100%) conventional stents, stent-like devices and modified stents harvested endothelial cells with a mean of 831.33 (±887.73) cells/device. Coil stiffness was significantly associated with endothelial cell count in univariate analysis (p = 0.044). For stents and stent-like devices univariate analysis demonstrated stent-to-aorta diameter ratios (p = 0.001), stent length (p = 0.049), and the use of a pulling retrieval technique (p = 0.019) significantly predictive of endothelial cell counts, though a multivariate model using these variables demonstrated only the stent-to-aorta diameter ratio (p = 0.029) predictive of endothelial cell counts. Modified

  3. Single-cell measurement of red blood cell oxygen affinity

    CERN Document Server

    Caprio, Di; Higgins, John M; Schonbrun, Ethan

    2015-01-01

    Oxygen is transported throughout the body by hemoglobin in red blood cells. While the oxygen affinity of blood is well understood and is routinely assessed in patients by pulse oximetry, variability at the single-cell level has not been previously measured. In contrast, single-cell measurements of red blood cell volume and hemoglobin concentration are taken millions of times per day by clinical hematology analyzers and are important factors in determining the health of the hematologic system. To better understand the variability and determinants of oxygen affinity on a cellular level, we have developed a system that quantifies the oxygen saturation, cell volume and hemoglobin concentration for individual red blood cells in high-throughput. We find that the variability in single-cell saturation peaks at an oxygen partial pressure of 2.5%, which corresponds to the maximum slope of the oxygen-hemoglobin dissociation curve. In addition, single-cell oxygen affinity is positively correlated with hemoglobin concentr...

  4. A Simple Device for Measuring Static Compliance of Lung-Thorax Combine

    Science.gov (United States)

    Sircar, Sabyasachi

    2015-01-01

    Explaining the concept of lung compliance remains a challenge to the physiology teacher because it cannot be demonstrated easily in human subjects and all attempts until now have used only simulation models. A simple device is described in the present article to measure the compliance of the "lung-thorax" combine in human subjects with…

  5. Novel Crosstalk Measurement Method for Multi-Core Fiber Fan-In/Fan-Out Devices

    DEFF Research Database (Denmark)

    Ye, Feihong; Ono, Hirotaka; Abe, Yoshiteru;

    2016-01-01

    We propose a new crosstalk measurement method for multi-core fiber fan-in/fan-out devices utilizing the Fresnel reflection. Compared with the traditional method using core-to-core coupling between a multi-core fiber and a single-mode fiber, the proposed method has the advantages of high reliabili...

  6. The two-probe device for automatic measurement of the reflection coefficient

    Directory of Open Access Journals (Sweden)

    Л.Я. Ільницький

    2004-01-01

    Full Text Available  The two-probe device for automatic measurement of the reflection coefficient in the HF range is proposed and analyzed. The main parts in the instrument control system are the sum-and-difference bridge and the microprocessor.

  7. Design and Study of Data Acquisition System for Pulsed γ Dose Measurement Device

    Institute of Scientific and Technical Information of China (English)

    DOU; Yu-ling; YANG; Shao-hua; ZHANG; Guo-guang

    2012-01-01

    <正>A data acquisition system for online pulsed gamma dose measurement device was designed and developed (Fig. 1), and its performance was tested. The results show that the data acquisition system in both the continued and pulsed input, output electric charges and input energy have a good linear relationship. Experiments were done respectively on the XRS-3 pulsed source and re-frequency

  8. 77 FR 17457 - Work Group on Alternative Test Methods for Commercial Measuring Devices

    Science.gov (United States)

    2012-03-26

    ... National Institute of Standards and Technology Work Group on Alternative Test Methods for Commercial...: The National Institute of Standards and Technology (NIST) is forming a Work Group (WG) to examine alternative methods for testing the accuracy of commercial measuring devices including, but not limited...

  9. Concave cell design for FTIR measurements

    Institute of Scientific and Technical Information of China (English)

    Xiang Qin Lin; Zhi Xiang Zhang; Wan Qun Hu

    2011-01-01

    Wedged and V-shaped cells have advantages on depressing strong absorption bands and keeping the photo windows wide open without absorption block. Alternatively, this work presents a concave cell design, which is constructed by a plano-convex CaF2 lens in combination with a flat plate. Mathematical equations have been provided for data treatment with Matlab programs. The result indicates that the concave cell has advantages similar to the V-shaped cell. Reflection-absorption measurements of ethanol have been conducted on the cell in mid-IR region for demonstration. The spectrum obtained from the concave cell can easily be interpreted to regenerate its normal spectrum, which is fitting well with the spectrum taken in a conventional thin-layer cell. The concave cell is easier to construct and more convenient to operate, willing to have popular usages.

  10. A cell sorting and trapping microfluidic device with an interdigital channel

    Science.gov (United States)

    Tu, Jing; Qiao, Yi; Xu, Minghua; Li, Junji; Liang, Fupeng; Duan, Mengqin; Ju, An; Lu, Zuhong

    2016-12-01

    The growing interest in cell sorting and trapping is driving the demand for high performance technologies. Using labeling techniques or external forces, cells can be identified by a series of methods. However, all of these methods require complicated systems with expensive devices. Based on inherent differences in cellular morphology, cells can be sorted by specific structures in microfluidic devices. The weir filter is a basic and efficient cell sorting and trapping structure. However, in some existing weir devices, because of cell deformability and high flow velocity in gaps, trapped cells may become stuck or even pass through the gaps. Here, we designed and fabricated a microfluidic device with interdigital channels for cell sorting and trapping. The chip consisted of a sheet of silicone elastomer polydimethylsiloxane and a sheet of glass. A square-wave-like weir was designed in the middle of the channel, comprising the interdigital channels. The square-wave pattern extended the weir length by three times with the channel width remaining constant. Compared with a straight weir, this structure exhibited a notably higher trapping capacity. Interdigital channels provided more space to slow down the rate of the pressure decrease, which prevented the cells from becoming stuck in the gaps. Sorting a mixture K562 and blood cells to trap cells demonstrated the efficiency of the chip with the interdigital channel to sort and trap large and less deformable cells. With stable and efficient cell sorting and trapping abilities, the chip with an interdigital channel may be widely applied in scientific research fields.

  11. Process for cooling a solar cell and a combined photovoltaic and photothermic solar device

    Energy Technology Data Exchange (ETDEWEB)

    Arnould, J.

    1982-07-13

    A solar cell cooling process is disclosed. The device implementing this process comprises a transparent assembly disposed in front of a photovoltaic cell. The transparent assembly, through which flows the cooling fluid leaving a radiator integral with the cell, absorbs the wavelengths greater than 1.1 micron. Thus, heating of the cell is limited and the fluid leaving the radiator is heated by the beam striking the cell.

  12. Microcontroller based system for electrical breakdown time delay measurement in gas-filled devices.

    Science.gov (United States)

    Pejović, Milić M; Denić, Dragan B; Pejović, Momčilo M; Nešić, Nikola T; Vasović, Nikola

    2010-10-01

    This paper presents realization of a digital embedded system for measuring electrical breakdown time delay. The proposed system consists of three major parts: dc voltage supply, analog subsystem, and a digital subsystem. Any dc power source with the range from 100 to 1000 V can be used in this application. The analog subsystem should provide fast and accurate voltage switching on the testing device as well as transform the signals that represent the voltage pulse on the device and the device breakdown into the form suitable for detection by a digital subsystem. The insulated gate bipolar transistor IRG4PH40KD driven by TC429 MOSFET driver is used for high voltage switching on the device. The aim of a digital subsystem is to detect the signals from the analog subsystem and to measure the elapsed time between their occurrences. Moreover, the digital subsystem controls various parameters that influence time delay and provides fast data storage for a large number of measured data. For this propose, we used the PIC18F4550 microcontroller with a full-speed compatible universal serial bus (USB) engine. Operation of this system is verified on different commercial and custom made gas devices with different structure and breakdown mechanisms. The electrical breakdown time delay measurements have been carried out as a function of several parameters, which dominantly influence electrical breakdown time delay. The obtained results have been verified using statistical methods, and they show good agreement with the theory. The proposed system shows good repeatability, sensitivity, and stability for measuring the electrical breakdown time delay.

  13. Microcontroller based system for electrical breakdown time delay measurement in gas-filled devices

    Energy Technology Data Exchange (ETDEWEB)

    Pejovic, Milic M.; Denic, Dragan B.; Pejovic, Momcilo M.; Nesic, Nikola T.; Vasovic, Nikola [Faculty of Electronic Engineering, University of Nis, Aleksandra Medvedeva 14, 18000 Nis (Serbia)

    2010-10-15

    This paper presents realization of a digital embedded system for measuring electrical breakdown time delay. The proposed system consists of three major parts: dc voltage supply, analog subsystem, and a digital subsystem. Any dc power source with the range from 100 to 1000 V can be used in this application. The analog subsystem should provide fast and accurate voltage switching on the testing device as well as transform the signals that represent the voltage pulse on the device and the device breakdown into the form suitable for detection by a digital subsystem. The insulated gate bipolar transistor IRG4PH40KD driven by TC429 MOSFET driver is used for high voltage switching on the device. The aim of a digital subsystem is to detect the signals from the analog subsystem and to measure the elapsed time between their occurrences. Moreover, the digital subsystem controls various parameters that influence time delay and provides fast data storage for a large number of measured data. For this propose, we used the PIC18F4550 microcontroller with a full-speed compatible universal serial bus (USB) engine. Operation of this system is verified on different commercial and custom made gas devices with different structure and breakdown mechanisms. The electrical breakdown time delay measurements have been carried out as a function of several parameters, which dominantly influence electrical breakdown time delay. The obtained results have been verified using statistical methods, and they show good agreement with the theory. The proposed system shows good repeatability, sensitivity, and stability for measuring the electrical breakdown time delay.

  14. Microcontroller based system for electrical breakdown time delay measurement in gas-filled devices

    Science.gov (United States)

    Pejović, Milić M.; Denić, Dragan B.; Pejović, Momčilo M.; Nešić, Nikola T.; Vasović, Nikola

    2010-10-01

    This paper presents realization of a digital embedded system for measuring electrical breakdown time delay. The proposed system consists of three major parts: dc voltage supply, analog subsystem, and a digital subsystem. Any dc power source with the range from 100 to 1000 V can be used in this application. The analog subsystem should provide fast and accurate voltage switching on the testing device as well as transform the signals that represent the voltage pulse on the device and the device breakdown into the form suitable for detection by a digital subsystem. The insulated gate bipolar transistor IRG4PH40KD driven by TC429 MOSFET driver is used for high voltage switching on the device. The aim of a digital subsystem is to detect the signals from the analog subsystem and to measure the elapsed time between their occurrences. Moreover, the digital subsystem controls various parameters that influence time delay and provides fast data storage for a large number of measured data. For this propose, we used the PIC18F4550 microcontroller with a full-speed compatible universal serial bus (USB) engine. Operation of this system is verified on different commercial and custom made gas devices with different structure and breakdown mechanisms. The electrical breakdown time delay measurements have been carried out as a function of several parameters, which dominantly influence electrical breakdown time delay. The obtained results have been verified using statistical methods, and they show good agreement with the theory. The proposed system shows good repeatability, sensitivity, and stability for measuring the electrical breakdown time delay.

  15. Analysis of Uncertainty in a Middle-Cost Device for 3D Measurements in BIM Perspective.

    Science.gov (United States)

    Sánchez, Alonso; Naranjo, José-Manuel; Jiménez, Antonio; González, Alfonso

    2016-09-22

    Medium-cost devices equipped with sensors are being developed to get 3D measurements. Some allow for generating geometric models and point clouds. Nevertheless, the accuracy of these measurements should be evaluated, taking into account the requirements of the Building Information Model (BIM). This paper analyzes the uncertainty in outdoor/indoor three-dimensional coordinate measures and point clouds (using Spherical Accuracy Standard (SAS) methods) for Eyes Map, a medium-cost tablet manufactured by e-Capture Research & Development Company, Mérida, Spain. To achieve it, in outdoor tests, by means of this device, the coordinates of targets were measured from 1 to 6 m and cloud points were obtained. Subsequently, these were compared to the coordinates of the same targets measured by a Total Station. The Euclidean average distance error was 0.005-0.027 m for measurements by Photogrammetry and 0.013-0.021 m for the point clouds. All of them satisfy the tolerance for point cloud acquisition (0.051 m) according to the BIM Guide for 3D Imaging (General Services Administration); similar results are obtained in the indoor tests, with values of 0.022 m. In this paper, we establish the optimal distances for the observations in both, Photogrammetry and 3D Photomodeling modes (outdoor) and point out some working conditions to avoid in indoor environments. Finally, the authors discuss some recommendations for improving the performance and working methods of the device.

  16. Analysis of Uncertainty in a Middle-Cost Device for 3D Measurements in BIM Perspective

    Science.gov (United States)

    Sánchez, Alonso; Naranjo, José-Manuel; Jiménez, Antonio; González, Alfonso

    2016-01-01

    Medium-cost devices equipped with sensors are being developed to get 3D measurements. Some allow for generating geometric models and point clouds. Nevertheless, the accuracy of these measurements should be evaluated, taking into account the requirements of the Building Information Model (BIM). This paper analyzes the uncertainty in outdoor/indoor three-dimensional coordinate measures and point clouds (using Spherical Accuracy Standard (SAS) methods) for Eyes Map, a medium-cost tablet manufactured by e-Capture Research & Development Company, Mérida, Spain. To achieve it, in outdoor tests, by means of this device, the coordinates of targets were measured from 1 to 6 m and cloud points were obtained. Subsequently, these were compared to the coordinates of the same targets measured by a Total Station. The Euclidean average distance error was 0.005–0.027 m for measurements by Photogrammetry and 0.013–0.021 m for the point clouds. All of them satisfy the tolerance for point cloud acquisition (0.051 m) according to the BIM Guide for 3D Imaging (General Services Administration); similar results are obtained in the indoor tests, with values of 0.022 m. In this paper, we establish the optimal distances for the observations in both, Photogrammetry and 3D Photomodeling modes (outdoor) and point out some working conditions to avoid in indoor environments. Finally, the authors discuss some recommendations for improving the performance and working methods of the device. PMID:27669245

  17. Contactless graphene conductance measurements: the effect of device fabrication on terahertz time-domain spectroscopy

    DEFF Research Database (Denmark)

    Mackenzie, David; Buron, Jonas Christian Due; Bøggild, Peter

    2016-01-01

    We perform contactless full-wafer maps of the electrical conductance of a 4-inch wafer of single-layer CVD graphene using terahertz time-domain spectroscopy both before and after deposition of metal contacts and fabrication of devices via laser ablation. We find that there is no significant change...... in the measured conductance of graphene before and after device fabrication. We also show that precise terahertz time-domain spectroscopy can be performed when the beam spot is at sufficient distance (>1.2 mm) from metal contacts....

  18. The cell-stretcher: A novel device for the mechanical stimulation of cell populations

    Science.gov (United States)

    Seriani, S.; Del Favero, G.; Mahaffey, J.; Marko, D.; Gallina, P.; Long, C. S.; Mestroni, L.; Sbaizero, O.

    2016-08-01

    Mechanical stimulation appears to be a critical modulator for many aspects of biology, both of living tissue and cells. The cell-stretcher, a novel device for the mechanical uniaxial stimulation of populations of cells, is described. The system is based on a variable stroke cam-lever-tappet mechanism which allows the delivery of cyclic stimuli with frequencies of up to 10 Hz and deformation between 1% and 20%. The kinematics is presented and a simulation of the dynamics of the system is shown, in order to compute the contact forces in the mechanism. The cells, following cultivation and preparation, are plated on an ad hoc polydimethylsiloxane membrane which is then loaded on the clamps of the cell-stretcher via force-adjustable magnetic couplings. In order to show the viability of the experimentation and biocompatibility of the cell-stretcher, a set of two in vitro tests were performed. Human epithelial carcinoma cell line A431 and Adult Mouse Ventricular Fibroblasts (AMVFs) from a dual reporter mouse were subject to 0.5 Hz, 24 h cyclic stretching at 15% strain, and to 48 h stimulation at 0.5 Hz and 15% strain, respectively. Visual analysis was performed on A431, showing definite morphological changes in the form of cellular extroflections in the direction of stimulation compared to an unstimulated control. A cytometric analysis was performed on the AMVF population. Results show a post-stimulation live-dead ratio deviance of less than 6% compared to control, which proves that the environment created by the cell-stretcher is suitable for in vitro experimentation.

  19. High-throughput microfluidic device for single cell analysis using multiple integrated soft lithographic pumps.

    Science.gov (United States)

    Patabadige, Damith E W; Mickleburgh, Tom; Ferris, Lorin; Brummer, Gage; Culbertson, Anne H; Culbertson, Christopher T

    2016-05-01

    The ability to accurately control fluid transport in microfluidic devices is key for developing high-throughput methods for single cell analysis. Making small, reproducible changes to flow rates, however, to optimize lysis and injection using pumps external to the microfluidic device are challenging and time-consuming. To improve the throughput and increase the number of cells analyzed, we have integrated previously reported micropumps into a microfluidic device that can increase the cell analysis rate to ∼1000 cells/h and operate for over an hour continuously. In order to increase the flow rates sufficiently to handle cells at a higher throughput, three sets of pumps were multiplexed. These pumps are simple, low-cost, durable, easy to fabricate, and biocompatible. They provide precise control of the flow rate up to 9.2 nL/s. These devices were used to automatically transport, lyse, and electrophoretically separate T-Lymphocyte cells loaded with Oregon green and 6-carboxyfluorescein. Peak overlap statistics predicted the number of fully resolved single-cell electropherograms seen. In addition, there was no change in the average fluorescent dye peak areas indicating that the cells remained intact and the dyes did not leak out of the cells over the 1 h analysis time. The cell lysate peak area distribution followed that expected of an asynchronous steady-state population of immortalized cells.

  20. A Cell Lysis and Protein Purification - Single Molecule Assay Devices for Evaluation of Genetically Engineered Proteins

    Science.gov (United States)

    Nakyama, Tetsuya; Tabata, Kazuhito; Noji, Hiroyuki; Yokokawa, Ryuji

    We have developed two devices applicable to evaluate genetically engineered proteins in single molecule assay: on-chip cell lysis device, and protein purification - assay device. A motor protein, F1-ATPase expressed in E.coli, was focused in this report as a target protein. Cell lysis was simply performed by applying pulse voltage between Au electrodes patterned by photolithography, and its efficiency was determined by absorptiometry. The subsequent processes, purification and assay of extracted proteins, were demonstrated in order to detect F1-ATPase and to evaluate its activity. The specific bonding between his-tag in F1-ATPase and Ni-NTA coated on a glass surface was utilized for the purification process. After immobilization of F1-ATPase, avidin-coated microspheres and adenosine tri-phosphate (ATP) solution were infused sequentially to assay the protein. Microsphere rotation was realized by activity of F1-ATPase corresponding to ATP hydrolysis. Results show that the cell lysis device, at the optimum condition, extracts enough amount of protein for single molecule assay. Once cell lysate was injected to the purification - assay device, proteins were diffused in the lateral direction in a Y-shape microchannel. The gradient of protein concentratioin provides an optimal concentration for the assay i.e. the highest density of rotating beads. Density of rotating beads is also affected by the initial concentration of protein injected to the device. The optimum concentration was achieved by our cell lysis device not by the conventional method by ultrasonic wave. Rotation speed was analyzed for several microspheres assayed in the purification - assay device, and the results were compatible to that of conventional assay in which F1-ATPase was purified in bulk scale. In conclusion, we have demonstrated on-chip cell lysis and assay appropriate for the sequential analysis without any pretreatment. On-chip devices replacing conventional bioanalytical methods will be

  1. Development path and current status of the NANIVID: a new device for cancer cell studies

    Science.gov (United States)

    Raja, Waseem Khan; Padgen, Michael R.; Williams, James K.; Wyckoff, Jeffrey; Condeelis, John; Castracane, James

    2011-02-01

    Cancer cells create a unique microenvironment in vivo which enables migration to distant organs. To better understand the tumor microenvironment, special tools and devices are required to monitor the interactions between different cell types and the effects of particular chemical gradients. This study presents the design and optimization of a new, versatile chemotaxis device called the NANIVID (NANo IntraVital Device). The device is fabricated using BioMEMS techniques and consists of etched and bonded Pyrex substrates, a soluble factor reservoir, fluorescent tracking beads and a microelectrode array for cell quantification. The reservoir contains a customized hydrogel blend loaded with EGF which diffuses out of the hydrogel to create a chemotactic gradient. This reservoir sustains a steady release of growth factor into the surrounding environment for many hours and establishes a concentration gradient that attracts specific cells to the device. In addition to a cell collection tool, the NANIVID can be modified to act as a delivery vehicle for the local generation of alternate soluble factor gradients to initiate controlled changes to the microenvironment such as hypoxia, ECM stiffness and etc. The focus of this study is to design and optimize the new device for wide ranging studies of breast cancer cell dynamics in vitro and ultimately, implantation for in vivo work.

  2. State-variable control of shunt FACTS devices using phasor measurements

    Energy Technology Data Exchange (ETDEWEB)

    Machowski, J. [Warsaw University of Technology, Instytut Elektroenergetyki, Koszykowa 75, 00-662 Warszawa (Poland); Bialek, J.W. [University of Edinburgh, School of Engineering and Electronics, King' s Buildings, Mayfield Road, Edinburgh EH9 3JL (United Kingdom)

    2008-01-15

    This paper addresses the problem of state-variable stabilizing control of power system using shunt FACTS devices. This stabilizing control is activated in the transient state of a power system and is supplementary with respect to the main steady-state control of a FACTS device. Stabilizing control laws have been derived for a non-linear multi-machine system model using direct Lyapunov method with the aim to maximize the rate of energy dissipation during power swings and therefore maximization of damping. The proposed control strategy is executed by a non-linear multi-loop controller with rotor angles and speed deviations of synchronous generators used as the input signals. The input signals, obtained from a phasor measurement system, are necessary only from a small area around the controlled shunt FACTS device. Validity of the proposed state-variable control has been confirmed by computer simulation for a small multi-machine test system. (author)

  3. Jules Horowitz Reactor Project- Fuel irradiation device, innovative instrumentation proposal for experimental phenomena real time measurement

    Energy Technology Data Exchange (ETDEWEB)

    Gaillot, Stephane; Cheymol, Guy [CEA, Paris (France)

    2013-07-01

    The fuel irradiation devices used for the tests or rods allow reproducing at small scales the conditions of the studied nuclear reactors (as LWR type). During the irradiation phase, the tested fuel rod can be stressed due to thermal, mechanical, nuclear effects which can modify its geometry (dilatation, swelling effects). After the test, the return to normal conditions can have as consequence the disappearance of the phenomenon or give access to partial information (final deformation). Generally, to follow the phenomena related to the irradiation phase, the experimental rod contained in the test device is instrumented with thermocouples and LVDT. As complement of this instrumentation, new sensors using innovating technologies are studied (deformation sensor integrating optical fibres). Through the example of a fuel irradiation device foreseen for the JHR, this paper aims to describe the present development of an innovating instrumentation with the objective to measure, in real time and under flux, the fuel rod deformation phenomena during a ramp test.

  4. Some aspects of achieving an ultimate accuracy during insertion device magnetic measurements by a Hall probe.

    Science.gov (United States)

    Vasserman, I B; Strelnikov, N O; Xu, J Z

    2013-02-01

    An extensive test of a new Senis 2-axis Hall probe was done at the Advanced Photon Source using the Undulator A device and calibration system. This new probe has clear advantages compared with previously used Bell and Sentron Hall probes: very stable zero offset (less than the noise of 0.026 G) and compensated planar Hall effect. It can be used with proper calibration even for first and second field integral measurements. A comparison with reference measurements by long stretched coil shows that the difference in the first field integral measurement results for a 2.4-m-long Undulator A device is between 17 G cm for the best of four Hall probes used for the test and 51 G cm for the worst of them for all gap ranges from 10.5 mm to 150 mm.

  5. Device for measurement of power and shape of radio frequency pulses in nuclear magnetic resonance

    Science.gov (United States)

    Pfeffer, M.; Řezníček, R.; Křišťan, P.; Štěpánková, H.

    2012-05-01

    A design of an instrument to measure the power and shape of radio frequency (RF) pulses operating in a broad frequency range is described. The device is capable of measuring the pulse power up to 500 W of both CW and extremely short (˜1 μs) RF pulses of arbitrary period. The pulse envelope can be observed on a logarithmic scale on a corresponding instrument output using an inexpensive storage oscilloscope. The instrument consists of a coaxial measurement head, the RF processing circuits and an AD conversion and display unit. The whole device is based on widely available integrated circuits; thus, good reproducibility and adaptability of the design is ensured. Since the construction is intended to be used in particular (but not solely) in nuclear magnetic resonance spectroscopy, we found it useful to provide a demonstration of two typical usage scenarios. Other application fields may comprise magnetic resonance imaging, radar and laser technology, power amplifier testing, etc.

  6. Loss-tolerant measurement-device-independent quantum random number generation

    Science.gov (United States)

    Cao, Zhu; Zhou, Hongyi; Ma, Xiongfeng

    2015-12-01

    Quantum random number generators (QRNGs) output genuine random numbers based upon the uncertainty principle. A QRNG contains two parts in general—a randomness source and a readout detector. How to remove detector imperfections has been one of the most important questions in practical randomness generation. We propose a simple solution, measurement-device-independent QRNG, which not only removes all detector side channels but is robust against losses. In contrast to previous fully device-independent QRNGs, our scheme does not require high detector efficiency or nonlocality tests. Simulations show that our protocol can be implemented efficiently with a practical coherent state laser and other standard optical components. The security analysis of our QRNG consists mainly of two parts: measurement tomography and randomness quantification, where several new techniques are developed to characterize the randomness associated with a positive-operator valued measure.

  7. Use of a Computed Tomography Based Approach to Validate Noninvasive Devices to Measure Rotational Knee Laxity.

    Science.gov (United States)

    Neumann, Simon; Maas, Stefan; Waldmann, Danièle; Ricci, Pierre-Louis; Zürbes, Arno; Arnoux, Pierre-Jean; Walter, Frédéric; Kelm, Jens

    2015-01-01

    The purpose of this study is to validate a noninvasive rotational knee laxity measuring device called "Rotameter P2" with an approach based on Computed Tomography (CT). This CT-approach using X-rays is hence invasive and can be regarded as a precise reference method that may also be applied to similar devices. An error due to imperfect femur fixation was observed but can be neglected for small torques. The most significant estimation error is due to the unavoidable soft tissues rotation and hence flexibility in the measurement chain. The error increases with the applied torque. The assessment showed that the rotational knee angle measured with the Rotameter is still overestimated because of thigh and femur displacement, soft tissues deformation, and measurement artefacts adding up to a maximum of 285% error at +15 Nm for the Internal Rotation of female volunteers. This may be questioned if such noninvasive devices for measuring the Tibia-Femoral Rotation (TFR) can help diagnosing knee pathologies and investigate ligament reconstructive surgery.

  8. A flux extraction device to measure the magnetic moment of large samples; application to bulk superconductors.

    Science.gov (United States)

    Egan, R; Philippe, M; Wera, L; Fagnard, J F; Vanderheyden, B; Dennis, A; Shi, Y; Cardwell, D A; Vanderbemden, P

    2015-02-01

    We report the design and construction of a flux extraction device to measure the DC magnetic moment of large samples (i.e., several cm(3)) at cryogenic temperature. The signal is constructed by integrating the electromotive force generated by two coils wound in series-opposition that move around the sample. We show that an octupole expansion of the magnetic vector potential can be used conveniently to treat near-field effects for this geometrical configuration. The resulting expansion is tested for the case of a large, permanently magnetized, type-II superconducting sample. The dimensions of the sensing coils are determined in such a way that the measurement is influenced by the dipole magnetic moment of the sample and not by moments of higher order, within user-determined upper bounds. The device, which is able to measure magnetic moments in excess of 1 A m(2) (1000 emu), is validated by (i) a direct calibration experiment using a small coil driven by a known current and (ii) by comparison with the results of numerical calculations obtained previously using a flux measurement technique. The sensitivity of the device is demonstrated by the measurement of flux-creep relaxation of the magnetization in a large bulk superconductor sample at liquid nitrogen temperature (77 K).

  9. Gram-scale Plutonium Samples Measured by Experimental Device of Four Detectors Well-type Fast Neutron Coincidence Measurement

    Institute of Scientific and Technical Information of China (English)

    LIU; Guo-rong; LIANG; Qing-lei; LI; Jing-huai; LI; An-li

    2013-01-01

    Experimental device of four detectors well-type fast neutron coincidence measurement(see Fig.1)consists of four?127 mm×50.8 mm BC501A liquid scintillation detectors,DC271A digitizer and other circuits.Application program simultaneously acquires the waveform of each pulse output from each detector,and identifies each pulse from neutron or?particle by offline model,and gets their arrival timing.

  10. Device Physics and Recombination in Polymer:Fullerene Bulk-Heterojunction Solar Cells

    Science.gov (United States)

    Hawks, Steven Aaron

    My thesis focuses on improving and understanding a relatively new type of solar cell materials system: polymer:fullerene bulk-heterojunction (BHJ) blends. These mixtures have drawn significant interest because they are made from low-cost organic molecules that can be cast from solution, which makes them a potential cheap alternative to traditional solar cell materials like silicon. The drawback, though, is that they are not as efficient at converting sunlight into electricity. My thesis focuses on this issue, and examines the loss processes holding back the efficiency in polymer:fullerene blends as well as investigates new processing methods for overcoming the efficiency limitations. The first chapter introduces the subject of solar cells, and polymer:fullerene solar cells in particular. The second chapter presents a case study on recombination in the high-performance PBDTTT polymer family, wherein we discovered that nongeminate recombination of an anti-Langevin origin was the dominant loss process that ultimately limited the cell efficiency. Electroluminescence measurements revealed that an electron back-transfer process was prevalent in active layers with insufficient PC71BM content. This work ultimately made strong headway in understanding what factors limited the relatively unexplored but highly efficient PBDTTT family of polymers. In the next chapter, I further explore the recombination mechanisms in polymer:fullerene BHJs by examining the dark diode ideality factor as a function of temperature in several polymer:fullerene materials systems. By re-deriving the diode law for a polymer:fullerene device with Shockley-Read-Hall recombination, we were able to confirm that trap-assisted recombination through an exponential band-tail of localized states is the dominant recombination process in many polymer:fullerene active layers. In the third chapter, I present a generalized theoretical framework for understanding current transients in planar semiconductor devices

  11. A plate reader-based method for cell water permeability measurement

    DEFF Research Database (Denmark)

    Fenton, Robert A.; Moeller, H B; Nielsen, S

    2010-01-01

    Cell volume and water permeability measurements in cultured mammalian cells are typically conducted under a light microscope. Many of the employed approaches are time consuming and not applicable to a study of confluent epithelial cell monolayers. We present here an adaptation of a calcein-quenching-based......-mannitol concentrations. Similarly, according average cell volumes have been measured in suspension in a Coulter counter (particle-sizing device). Based on these measurements, we have derived an equation that facilitates the modeling of cell volume changes based on fluorescence intensity changes. We have utilized...

  12. [An implantable micro-device using wireless power transmission for measuring aortic aneurysm sac pressure].

    Science.gov (United States)

    Guo, Xudong; Ge, Bin; Wang, Wenxing

    2013-08-01

    In order to detect endoleaks after endovascular aneurysm repair (EVAR), we developed an implantable micro-device based on wireless power transmission to measure aortic aneurysm sac pressure. The implantable micro-device is composed of a miniature wireless pressure sensor, an energy transmitting coil, a data recorder and a data processing platform. Power transmission without interconnecting wires is performed by a transmitting coil and a receiving coil. The coupling efficiency of wireless power transmission depends on the coupling coefficient between the transmitting coil and the receiving coil. With theoretical analysis and experimental study, we optimized the geometry of the receiving coil to increase the coupling coefficient. In order to keep efficiency balance and satisfy the maximizing conditions, we designed a closed loop power transmission circuit, including a receiving voltage feedback module based on wireless communication. The closed loop improved the stability and reliability of transmission energy. The prototype of the micro-device has been developed and the experiment has been performed. The experiments showed that the micro-device was feasible and valid. For normal operation, the distance between the transmitting coil and the receiving coil is smaller than 8cm. Besides, the distance between the micro-device and the data recorder is within 50cm.

  13. Development, validation and application of a device to measure e-cigarette users’ puffing topography

    Science.gov (United States)

    Cunningham, Anthony; Slayford, Sandra; Vas, Carl; Gee, Jodie; Costigan, Sandra; Prasad, Krishna

    2016-01-01

    With the rapidly rising popularity and substantial evolution of electronic cigarettes (e-cigarettes) in the past 5–6 years, how these devices are used by vapers and consumers’ exposure to aerosol emissions need to be understood. We used puffing topography to measure directly product use. We adapted a cigarette puffing topography device for use with e-cigarettes. We performed validation using air and e-cigarette aerosol under multiple regimes. Consumer puffing topography was measured for 60 vapers provided with rechargeable “cig-a-like” or larger button-activated e-cigarettes, to use ad-libitum in two sessions. Under all regimes, air puff volumes were within 1 mL of the target and aerosol volumes within 5 mL for all device types, serving to validate the device. Vapers’ mean puff durations (2.0 s and 2.2 s) were similar with both types of e-cigarette, but mean puff volumes (52.2 mL and 83.0 mL) and mean inter-puff intervals (23.2 s and 29.3 s) differed significantly. The differing data show that product characteristics influence puffing topography and, therefore, the results obtained from a given e-cigarette might not read across to other products. Understanding the factors that affect puffing topography will be important for standardising testing protocols for e-cigarette emissions. PMID:27721496

  14. SEMICONDUCTOR DEVICES: Optimization of grid design for solar cells

    Science.gov (United States)

    Wen, Liu; Yueqiang, Li; Jianjun, Chen; Yanling, Chen; Xiaodong, Wang; Fuhua, Yang

    2010-01-01

    By theoretical simulation of two grid patterns that are often used in concentrator solar cells, we give a detailed and comprehensive analysis of the influence of the metal grid dimension and various losses directly associated with it during optimization of grid design. Furthermore, we also perform the simulation under different concentrator factors, making the optimization of the front contact grid for solar cells complete.

  15. Measurements of knee rotation-reliability of an external device in vivo

    Directory of Open Access Journals (Sweden)

    Almquist Per O

    2011-12-01

    Full Text Available Abstract Background Knee rotation plays an important part in knee kinematics during weight-bearing activities. An external device for measuring knee rotation (the Rottometer has previously been evaluated for validity by simultaneous measurements of skeletal movements with Roentgen Stereometric Analysis (RSA. The aim of this study was to investigate the reliability of the device. Method The within-day and test-retest reliability as well as intertester reliability of the device in vivo was calculated. Torques of 3, 6 and 9 Nm and the examiner's apprehension of end-feel were used at 90°, 60° and 30° of knee flexion. Intraclass Correlation Coefficient 2,1 (ICC 2,1, 95% confidence interval (CI of ICC and 95% CI between test trials and examiners were used as statistical tests. Result ICC2,1 ranged from 0.50 to 0.94 at all three flexion angles at 6 and 9 Nm as well as end-feel, and from 0.22 to 0.75 at 3 Nm applied torque. Conclusion The Rottometer was a reliable measurement instrument concerning knee rotation at the three different flexion angles (90°, 60° and 30° with 6 and 9 Nm applied torques as well as the examiner's apprehension of end-feel. Three Nm was not a reliable torque. The most reliable measurements were made at 9 Nm applied torque.

  16. DEVICE FOR MEASURING OF THERMAL LENS PARAMETERS IN LASER ACTIVE ELEMENTS WITH A PROBE BEAM METHOD

    Directory of Open Access Journals (Sweden)

    A. N. Zakharova

    2015-01-01

    Full Text Available We have developed a device for measuring of parameters of thermal lens (TL in laser active elements under longitudinal diode pumping. The measurements are based on the probe beam method. This device allows one to determine sign and optical power of the lens in the principal meridional planes, its sensitivity factor with respect to the absorbed pump power and astigmatism degree, fractional heat loading which make it possible to estimate integral impact of the photoelastic effect to the formation of TL in the laser element. The measurements are performed in a linearly polarized light at the wavelength of 532 nm. Pumping of the laser element is performed at 960 nm that makes it possible to study laser materials doped with Yb3+ and (Er3+, Yb3+ ions. The precision of measurements: for sensitivity factor of TL – 0,1 m-1/W, for astigmatism degree – 0,2 m-1/W, for fractional heat loading – 5 %, for the impact of the photoelastic effect – 0,5 × 10-6 K-1. This device is used for characterization of thermal lens in the laser active element from an yttrium vanadate crystal, Er3+,Yb3+:YVO .

  17. Corneal biomechanical data and biometric parameters measured with Scheimpflug-based devices on normal corneas

    Science.gov (United States)

    Nemeth, Gabor; Szalai, Eszter; Hassan, Ziad; Lipecz, Agnes; Flasko, Zsuzsa; Modis, Laszlo

    2017-01-01

    AIM To analyze the correlations between ocular biomechanical and biometric data of the eye, measured by Scheimpflug-based devices on healthy subjects. METHODS Three consecutive measurements were carried out using the corneal visualization Scheimpflug technology (CorVis ST) device on healthy eyes and the 10 device-specific parameters were recorded. Pentacam HR-derived parameters (corneal curvature radii on the anterior and posterior surfaces; apical pachymetry; corneal volume; corneal aberration data; depth, volume and angle of the anterior chamber) and axial length (AL) from IOLMaster were correlated with the 10 specific CorVis ST parameters. RESULTS Measurements were conducted in 43 eyes of 43 volunteers (age 61.24±15.72y). The 10 specific CorVis ST data showed significant relationships with corneal curvature radii both on the anterior and posterior surface, pachymetric data, root mean square (RMS) data of lower-order aberrations, and posterior RMS of higher-order aberrations and spherical aberration of the posterior cornea. Anterior chamber depth showed a significant relationship, but there were no significant correlations between corneal volume, anterior chamber volume, mean chamber angle or AL and the 10 specific CorVis ST parameters. CONCLUSIONS CorVis ST-generated parameters are influenced by corneal curvature radii, some corneal RMS data, but corneal volume, anterior chamber volume, chamber angle and AL have no correlation with the biomechanical parameters. The parameters measured by CorVis ST seem to refer mostly to corneal properties of the eye. PMID:28251079

  18. Heat Transmission Coefficient Measurements in Buildings Utilizing a Heat Loss Measuring Device

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt

    2013-01-01

    to optimize the energy performance. This paper presents a method for measuring the heat loss by utilizing a U-value meter. The U-value meter measures the heat transfer in the unit W/Km2 and has been used in several projects to upgrade the energy performance in temperate regions. The U-value meter was also...... and mechanical ventilation in the “warm countries” contribute to an enormous energy consumption and corresponding CO2 emission. In order to establish the best basis for upgrading the energy performance, it is important to make measurements of the heat losses at different places on a building facade, in order...

  19. Development of an inner profile measurement instrument using a ring beam device

    Science.gov (United States)

    Yoshizawa, T.; Wakayama, T.

    2010-11-01

    Inner profile measurement is an important matter in such fields as medicine, dentistry and anthropology as well as mechanical engineering and other industrial applications. Here we describe recent development of our measurement principle for inner diameter of pipes and/or holes. The key device in this technique is a ring beam device which consists of a conical mirror and a laser diode. And the fundamental principle is based on optical sectioning without using any contact type stylus. The optically sectioned profile of an inner wall of a pipe-like object is analyzed to give the inner profile in addition to the inner diameter. This optical instrument with a simple and small configuration is now under development for practical uses. In our hitherto trial experimental works, the availability of this instrument has been evaluated in many cases and availability for practical applications is expected, especially, for measurement and inspection of mechanical components and elements besides pipes. This ring beam device consisting of a conical mirror and a LD is assembled to form a disk-like light sheet. We show measurement result of pipes and holes, and, at the same time, report a compact inner profile measuring instrument at this point. Both the ring beam device and a miniaturized CCD camera are fabricated into a glass tube. Availability of this instrument is shown by measuring the inner profiles of various pipes. In response to this trial, there appeared a strong request that not only the internal but external profiles should be measured simultaneously. Therefore we propose potentially possible method for measurement of external profile at the same time with internal profile. If one pair of concave mirrors are used in our arrangement, external profile is captured. In combination with inner profile measurement technique, simultaneous measurement of inner and outer profiles becomes attainable. A measurement result on a bevel gear shows availability of here proposed

  20. Entropy measures of collective cell migration

    Science.gov (United States)

    Whitby, Ariadne; Parrinello, Simona; Faisal, Aldo

    2015-03-01

    Collective cell migration is a critical process during tissue formation and repair. To this end there is a need to develop tools to quantitatively measure the dynamics of collective cell migration obtained from microscopy data. Drawing on statistical physics we use entropy of velocity fields derived from dense optic flow to quantitatively measure collective migration. Using peripheral nerve repair after injury as experimental system, we study how Schwann cells, guided by fibroblasts, migrate in cord-like structures across the cut, paving a highway for neurons. This process of emergence of organised behaviour is key for successful repair, yet the emergence of leader cells and transition from a random to ordered state is not understood. We find fibroblasts induce correlated directionality in migrating Schwann cells as measured by a decrease in the entropy of motion vector. We show our method is robust with respect to image resolution in time and space, giving a principled assessment of how various molecular mechanisms affect macroscopic features of collective cell migration. Finally, the generality of our method allows us to process both simulated cell movement and microscopic data, enabling principled fitting and comparison of in silico to in vitro. ICCS, Imperial College London & MRC Clinical Sciences Centre.

  1. Next Generation Solar Cells Based on Graded Bandgap Device Structures Utilising Rod-Type Nano-Materials

    Directory of Open Access Journals (Sweden)

    Imyhamy M. Dharmadasa

    2015-06-01

    Full Text Available Current solar cells under research and development utilise mainly one absorber layer limiting the photon harvesting capabilities. In order to develop next generation solar cells, research should move towards effective photon harvesting methods utilising low-cost solar energy materials. This will lead to reduce the $W−1 figure for direct solar energy conversion to electrical energy. In this work, a graded bandgap solar cell has been designed to absorb all photons from the UV, visible and IR regions. In addition, impurity PV effect and impact ionisation have been incorporated to enhance charge carrier creation within the same device. This new design has been experimentally tested using the most researched MOCVD grown GaAs/AlGaAs system, in order to confirm its validity. Devices with high Voc ~ 1175 mV and the highest possible FF ~ (0.85–0.87 have been produced, increasing the conversion efficiency to ~20% within only two growth runs. These devices were also experimentally tested for the existence of impurity PV effect and impact ionisation. The devices are PV active in complete darkness producing over 800 mV, Voc indicating the harvesting of IR radiation from the surroundings through impurity PV effect. The quantum efficiency measurements show over 140% signal confirming the contribution to PV action from impact ionisation. Since the concept is successfully proven, the low-cost and scalable electrodeposited semiconducting layers are used to produce graded bandgap solar cell structures. The utilisation of nano- and micro-rod type materials in graded bandgap devices are also presented and discussed in this paper. Preliminary work on glass/FTO/n-ZnS/n-CdS/n-CdTe/Au graded bandgap devices show 10%–12% efficient devices indicating extremely high Jsc values ~48 mA·cm−2, showing the high potential of these devices in achieving higher efficiencies. The detailed results on these low-cost and novel graded bandgap devices are presented in a separate

  2. Cohesion and device reliability in organic bulk heterojunction photovoltaic cells

    KAUST Repository

    Brand, Vitali

    2012-04-01

    The fracture resistance of P3HT:PC 60BM-based photovoltaic devices are characterized using quantitative adhesion and cohesion metrologies that allow identification of the weakest layer or interface in the device structure. We demonstrate that the phase separated bulk heterojunction layer is the weakest layer and report quantitative cohesion values which ranged from ∼1 to 20 J m -2. The effects of layer thickness, composition, and annealing treatments on layer cohesion are investigated. Using depth profiling and X-ray photoelectron spectroscopy on the resulting fracture surfaces, we examine the gradient of molecular components through the thickness of the bulk heterojunction layer. Finally, using atomic force microscopy we show how the topography of the failure path is related to buckling of the metal electrode and how it develops with annealing. The research provides new insights on how the molecular design, structure and composition affect the cohesive properties of organic photovoltaics. © 2011 Elsevier B.V. All rights reserved.

  3. W-state Analyzer and Multi-party Measurement-device-independent Quantum Key Distribution

    Science.gov (United States)

    Zhu, Changhua; Xu, Feihu; Pei, Changxing

    2015-12-01

    W-state is an important resource for many quantum information processing tasks. In this paper, we for the first time propose a multi-party measurement-device-independent quantum key distribution (MDI-QKD) protocol based on W-state. With linear optics, we design a W-state analyzer in order to distinguish the four-qubit W-state. This analyzer constructs the measurement device for four-party MDI-QKD. Moreover, we derived a complete security proof of the four-party MDI-QKD, and performed a numerical simulation to study its performance. The results show that four-party MDI-QKD is feasible over 150 km standard telecom fiber with off-the-shelf single photon detectors. This work takes an important step towards multi-party quantum communication and a quantum network.

  4. System Design and Development of a Robotic Device for Automated Venipuncture and Diagnostic Blood Cell Analysis.

    Science.gov (United States)

    Balter, Max L; Chen, Alvin I; Fromholtz, Alex; Gorshkov, Alex; Maguire, Tim J; Yarmush, Martin L

    2016-10-01

    Diagnostic blood testing is the most prevalent medical procedure performed in the world and forms the cornerstone of modern health care delivery. Yet blood tests are still predominantly carried out in centralized labs using large-volume samples acquired by manual venipuncture, and no end-to-end solution from blood draw to sample analysis exists today. Our group is developing a platform device that merges robotic phlebotomy with automated diagnostics to rapidly deliver patient information at the site of the blood draw. The system couples an image-guided venipuncture robot, designed to address the challenges of routine venous access, with a centrifuge-based blood analyzer to obtain quantitative measurements of hematology. In this paper, we first present the system design and architecture of the integrated device. We then perform a series of in vitro experiments to evaluate the cannulation accuracy of the system on blood vessel phantoms. Next, we assess the effects of vessel diameter, needle gauge, flow rate, and viscosity on the rate of sample collection. Finally, we demonstrate proof-of-concept of a white cell assay on the blood analyzer using in vitro human samples spiked with fluorescently labeled microbeads.

  5. CdTe Photovoltaic Devices for Solar Cell Applications

    Science.gov (United States)

    2011-12-01

    July 28, 2011 14. ABSTRACT Cadmium telluride ( CdTe ) has been recognized as a promising photovoltaic material for thin - film solar cells because of...mail.mil Phone: 301 394 0963 ABSTRACT Cadmium telluride ( CdTe ) has been recognized as a promising photovoltaic material for thin - film ...absorption coefficient allows films as thin as 2 μm to absorb more than 98% of the above-bandgap radiation. Cells with efficiencies near 17% have been

  6. Eddy current nondestructive testing device for measuring variable characteristics of a sample utilizing Walsh functions

    Science.gov (United States)

    Libby, Hugo L.; Hildebrand, Bernard P.

    1978-01-01

    An eddy current testing device for measuring variable characteristics of a sample generates a signal which varies with variations in such characteristics. A signal expander samples at least a portion of this generated signal and expands the sampled signal on a selected basis of square waves or Walsh functions to produce a plurality of signal components representative of the sampled signal. A network combines these components to provide a display of at least one of the characteristics of the sample.

  7. The Device for Communication in the Tool for Measurement in Boreholes

    Directory of Open Access Journals (Sweden)

    Miloš Slankamenac

    2005-10-01

    Full Text Available In this paper an implementation and test of the device for communication between Telemetry system and Surface unit with the tool for measurement of pipe diameter, fluid velocity and direction of flow in the borehole (Calliper-Fullbore Flowmeter - CFF are presented. This communication is done according to SIPLOS (Simultaneous Production Logging String protocol and it is used by Hotwell company [1] as a part of a larger system for borehole investigations.

  8. Measurement-device-independent quantum key distribution with source state errors and statistical fluctuation

    Science.gov (United States)

    Jiang, Cong; Yu, Zong-Wen; Wang, Xiang-Bin

    2017-03-01

    We show how to calculate the secure final key rate in the four-intensity decoy-state measurement-device-independent quantum key distribution protocol with both source errors and statistical fluctuations with a certain failure probability. Our results rely only on the range of only a few parameters in the source state. All imperfections in this protocol have been taken into consideration without assuming any specific error patterns of the source.

  9. Using a Communication Model to Collect Measurement Data through Mobile Devices

    OpenAIRE

    Gabriel Urzaiz; Ramón Hervás; Vladimir Villarreal; José Bravo

    2012-01-01

    Wireless systems and services have undergone remarkable development since the first mobile phone system was introduced in the early 1980s. The use of sensors in an Ambient Intelligence approach is a great solution in a medical environment. We define a communication architecture to facilitate the information transfer between all connected devices. This model is based in layers to allow the collection of measurement data to be used in our framework monitoring architecture. An overlay-based solu...

  10. Autonomous field-deployable device for the measurement of phosphate in natural water

    Science.gov (United States)

    Slater, Conor; Cleary, John; McGraw, Christina M.; Yerazunis, William S.; Lau, King Tong; Diamond, Dermot

    2007-09-01

    This work describes the ongoing development of an autonomous platform for the measurement of phosphate levels in river water. This device is designed to operate unassisted for one year, taking a measurement every hour and relaying the result to a laptop computer. A first generation prototype has already been developed and successfully field tested. The system contains the sampling, chemical storage, fluid handling, colorimetric data acquisition and waste storage capabilities necessary to perform the phosphate measurement. In addition to this, the device has the embedded control, GSM communications system and power supply to allow independent operation. The entire system is placed inside a compact and rugged enclosure. Further work discussed here builds on the successes of the prototype design to deliver a system capable of one full year of operation. The second generation system has been built from the ground up. Although identical in operation to the prototype its design has a greater emphasis on power efficient components and power management to allow for a longer lifetime. Other improvements include an automated two-point calibration to compensate for drift and a more rugged design to further increase the lifetime of the device.

  11. Anodizing color coded anodized Ti6Al4V medical devices for increasing bone cell functions

    Directory of Open Access Journals (Sweden)

    Webster TJ

    2013-01-01

    Full Text Available Alexandra P Ross, Thomas J WebsterSchool of Engineering and Department of Orthopedics, Brown University, Providence, RI, USAAbstract: Current titanium-based implants are often anodized in sulfuric acid (H2SO4 for color coding purposes. However, a crucial parameter in selecting the material for an orthopedic implant is the degree to which it will integrate into the surrounding bone. Loosening at the bone–implant interface can cause catastrophic failure when motion occurs between the implant and the surrounding bone. Recently, a different anodization process using hydrofluoric acid has been shown to increase bone growth on commercially pure titanium and titanium alloys through the creation of nanotubes. The objective of this study was to compare, for the first time, the influence of anodizing a titanium alloy medical device in sulfuric acid for color coding purposes, as is done in the orthopedic implant industry, followed by anodizing the device in hydrofluoric acid to implement nanotubes. Specifically, Ti6Al4V model implant samples were anodized first with sulfuric acid to create color-coding features, and then with hydrofluoric acid to implement surface features to enhance osteoblast functions. The material surfaces were characterized by visual inspection, scanning electron microscopy, contact angle measurements, and energy dispersive spectroscopy. Human osteoblasts were seeded onto the samples for a series of time points and were measured for adhesion and proliferation. After 1 and 2 weeks, the levels of alkaline phosphatase activity and calcium deposition were measured to assess the long-term differentiation of osteoblasts into the calcium depositing cells. The results showed that anodizing in hydrofluoric acid after anodizing in sulfuric acid partially retains color coding and creates unique surface features to increase osteoblast adhesion, proliferation, alkaline phosphatase activity, and calcium deposition. In this manner, this study

  12. Anodizing color coded anodized Ti6Al4V medical devices for increasing bone cell functions.

    Science.gov (United States)

    Ross, Alexandra P; Webster, Thomas J

    2013-01-01

    Current titanium-based implants are often anodized in sulfuric acid (H(2)SO(4)) for color coding purposes. However, a crucial parameter in selecting the material for an orthopedic implant is the degree to which it will integrate into the surrounding bone. Loosening at the bone-implant interface can cause catastrophic failure when motion occurs between the implant and the surrounding bone. Recently, a different anodization process using hydrofluoric acid has been shown to increase bone growth on commercially pure titanium and titanium alloys through the creation of nanotubes. The objective of this study was to compare, for the first time, the influence of anodizing a titanium alloy medical device in sulfuric acid for color coding purposes, as is done in the orthopedic implant industry, followed by anodizing the device in hydrofluoric acid to implement nanotubes. Specifically, Ti6Al4V model implant samples were anodized first with sulfuric acid to create color-coding features, and then with hydrofluoric acid to implement surface features to enhance osteoblast functions. The material surfaces were characterized by visual inspection, scanning electron microscopy, contact angle measurements, and energy dispersive spectroscopy. Human osteoblasts were seeded onto the samples for a series of time points and were measured for adhesion and proliferation. After 1 and 2 weeks, the levels of alkaline phosphatase activity and calcium deposition were measured to assess the long-term differentiation of osteoblasts into the calcium depositing cells. The results showed that anodizing in hydrofluoric acid after anodizing in sulfuric acid partially retains color coding and creates unique surface features to increase osteoblast adhesion, proliferation, alkaline phosphatase activity, and calcium deposition. In this manner, this study provides a viable method to anodize an already color coded, anodized titanium alloy to potentially increase bone growth for numerous implant applications.

  13. Current Density Distribution Mapping in PEM Fuel Cells as An Instrument for Operational Measurements

    Directory of Open Access Journals (Sweden)

    Martin Geske

    2010-04-01

    Full Text Available A newly developed measurement system for current density distribution mapping has enabled a new approach for operational measurements in proton exchange membrane fuel cells (PEMFC. Taking into account previously constructed measurement systems, a method based on a multi layer printed circuit board was chosen for the development of the new system. This type of system consists of a sensor, a special electronic device and the control and visualization PC. For the acquisition of the current density distribution values, a sensor device was designed and installed within a multilayer printed circuit board with integrated shunt resistors. Varying shunt values can be taken into consideration with a newly developed and evaluated calibration method. The sensor device was integrated in a PEM fuel cell stack to prove the functionality of the whole measurement system. A software application was implemented to visualize and save the measurement values. Its functionality was verified by operational measurements within a PEMFC system. Measurement accuracy and possible negative reactions of the sensor device during PEMFC operation are discussed in detail in this paper. The developed system enables operational measurements for different operating phases of PEM fuel cells. Additionally, this can be seen as a basis for new opportunities of optimization for fuel cell design and operation modes.

  14. Microfluidic devices for label-free separation of cells through transient interaction with asymmetric receptor patterns

    Science.gov (United States)

    Bose, S.; Singh, R.; Hollatz, M. H.; Lee, C.-H.; Karp, J.; Karnik, R.

    2012-02-01

    Cell sorting serves an important role in clinical diagnosis and biological research. Most of the existing microscale sorting techniques are either non-specific to antigen type or rely on capturing cells making sample recovery difficult. We demonstrate a simple; yet effective technique for isolating cells in an antigen specific manner by using transient interactions of the cell surface antigens with asymmetric receptor patterned surface. Using microfluidic devices incorporating P-selectin patterns we demonstrate separation of HL60 cells from K562 cells. We achieved a sorting purity above 90% and efficiency greater than 85% with this system. We also present a mathematical model incorporating flow mediated and adhesion mediated transport of cells in the microchannel that can be used to predict the performance of these devices. Lastly, we demonstrate the clinical significance of the method by demonstrating single step separation of neutrophils from whole blood. When whole blood is introduced in the device, the granulocyte population gets separated exclusively yielding neutrophils of high purity (<10% RBC contamination). To our knowledge, this is the first ever demonstration of continuous label free sorting of neutrophils from whole blood. We believe this technology will be useful in developing point-of-care diagnostic devices and also for a host of cell sorting applications.

  15. Validity of a Wearable Accelerometer Device to Measure Average Acceleration Values During High-Speed Running.

    Science.gov (United States)

    Alexander, Jeremy P; Hopkinson, Trent L; Wundersitz, Daniel W T; Serpell, Benjamin G; Mara, Jocelyn K; Ball, Nick B

    2016-11-01

    Alexander, JP, Hopkinson, TL, Wundersitz, DWT, Serpell, BG, Mara, JK, and Ball, NB. Validity of a wearable accelerometer device to measure average acceleration values during high-speed running. J Strength Cond Res 30(11): 3007-3013, 2016-The aim of this study was to determine the validity of an accelerometer to measure average acceleration values during high-speed running. Thirteen subjects performed three sprint efforts over a 40-m distance (n = 39). Acceleration was measured using a 100-Hz triaxial accelerometer integrated within a wearable tracking device (SPI-HPU; GPSports). To provide a concurrent measure of acceleration, timing gates were positioned at 10-m intervals (0-40 m). Accelerometer data collected during 0-10 m and 10-20 m provided a measure of average acceleration values. Accelerometer data was recorded as the raw output and filtered by applying a 3-point moving average and a 10-point moving average. The accelerometer could not measure average acceleration values during high-speed running. The accelerometer significantly overestimated average acceleration values during both 0-10 m and 10-20 m, regardless of the data filtering technique (p < 0.001). Body mass significantly affected all accelerometer variables (p < 0.10, partial η = 0.091-0.219). Body mass and the absence of a gravity compensation formula affect the accuracy and practicality of accelerometers. Until GPSports-integrated accelerometers incorporate a gravity compensation formula, the usefulness of any accelerometer-derived algorithms is questionable.

  16. Microfluidic device for continuous single cells analysis via Raman spectroscopy enhanced by integrated plasmonic nanodimers

    DEFF Research Database (Denmark)

    Perozziello, Gerardo; Candeloro, Patrizio; De Grazia, Antonio

    2016-01-01

    In this work a Raman flow cytometer is presented. It consists of a microfluidic device that takes advantages of the basic principles of Raman spectroscopy and flow cytometry. The microfluidic device integrates calibrated microfluidic channels-where the cells can flow one-by-one -, allowing single...... cell Raman analysis. The microfluidic channel integrates plasmonic nanodimers in a fluidic trapping region. In this way it is possible to perform Enhanced Raman Spectroscopy on single cell. These allow a label-free analysis, providing information about the biochemical content of membrane and cytoplasm...

  17. Building a better cell trap: Applying Lagrangian modeling to the design of microfluidic devices for cell biology

    Science.gov (United States)

    Kim, Min-Cheol; Wang, Zhanhui; Lam, Raymond H. W.; Thorsen, Todd

    2008-02-01

    In this report, we show how computational fluid dynamics can be applied to the design of efficient hydrodynamic cell traps in microfluidic devices. Modeled hydrodynamic trap designs included a large, multiple-aperture "C-type" sieve for trapping hundreds of cells, flat single-aperture arrays for single cells, and "U-type" hydrodynamic structures with one or two apertures to confine small clusters of cells (˜10-15 cells per trap). Using 3T3 cells as a model system, the motion of each individual cell was calculated using a one-way coupled Lagrangian method. The cell was assumed to be a solid sphere, and interactions with other cells were only considered when a cell sedimented in the trap. The ordinary differential equations were solved along the cell trajectory for the three components of the velocity and location vector by using the Rosenbrock method based on an adaptive time-stepping technique. Validation of the predictive value of modeling, using 3T3 cells flowed through microfluidic devices containing "U-type sieves" under the simulation flow parameters, showed excellent agreement between experiment and simulation with respect to cell number per trap and the uniformity of cell distribution within individual microchambers. For applications such as on-chip cell culture or high-throughput screening of cell populations within a lab-on-a-chip environment, Lagrangian simulations have the potential to greatly simplify the design process.

  18. A new device for measurement of fibrin clot lysis: application to the Euglobulin Clot Lysis Time

    Science.gov (United States)

    Boudjeltia, K Zouaoui; Cauchie, Ph; Remacle, Cl; Guillaume, M; Brohée, D; Hubert, JL; Vanhaeverbeek, M

    2002-01-01

    Background Determination of clot lysis times on whole blood, diluted whole blood, plasma or plasma fraction has been used for many years to assess the overall activity of the fibrinolytic system. We designed a completely computerised semi-automatic 8-channel device for measurement and determination of fibrin clot lysis. The lysis time is evaluated by a mathematical analysis of the lysis curve and the results are expressed in minute (range: 5 to 9999). We have used this new device for Euglobulin Clot Lysis Time (ECLT) determination, which is the most common test used in laboratories to estimate plasma fibrinolytic capacity. Results The correlation between ECLT and manual method is very tight : R = 0,99; p < 10-6. The efficiency scores of the method are <4% in intra-assay and <7% in inter-assay. It allows to achieve the tests on hyperlipaemic samples. This new device has been easily integrated in laboratory routine and allows to achieve several ECLT every day without disturbance of laboratory workflow. Conclusions The routine use of this new device could be useful in various situations such as assessment in atherosclerosis and arteriosclerosis associated diseases, coagulation survey of liver transplantations, cardiovascular surgery or pharmacological research. It has already provided highly promising results in preliminary studies on the relation between fibrinolysis and cardiovascular risk factors. PMID:11985782

  19. A Systematic Review on Existing Measures for the Subjective Assessment of Rehabilitation and Assistive Robot Devices

    Directory of Open Access Journals (Sweden)

    Yiannis Koumpouros

    2016-01-01

    Full Text Available The objective of the current study is to identify and classify outcome measures currently used for the assessment of rehabilitation or assistive robot devices. We conducted a systematic review of the literature using PubMed, MEDLINE, CIRRIE, and Scopus databases for studies that assessed rehabilitation or assistive robot devices from 1980 through January 2016. In all, 31 articles met all inclusion criteria. Tailor-made questionnaires were the most commonly used tool at 66.7%, while the great majority (93.9% of the studies used nonvalidated instruments. The study reveals the absence of a standard scale which makes it difficult to compare the results from different researchers. There is a great need, therefore, for a valid and reliable instrument to be available for use by the intended end users for the subjective assessment of robot devices. The study concludes by identifying two scales that have been validated in general assistive technology devices and could support the scope of subjective assessment in rehabilitation or assistive robots (however, with limited coverage and a new one called PYTHEIA, recently published. The latter intends to close the gap and help researchers and developers to evaluate, assess, and produce products that satisfy the real needs of the end users.

  20. Versatile light-emitting-diode-based spectral response measurement system for photovoltaic device characterization.

    Science.gov (United States)

    Hamadani, Behrang H; Roller, John; Dougherty, Brian; Yoon, Howard W

    2012-07-01

    An absolute differential spectral response measurement system for solar cells is presented. The system couples an array of light emitting diodes with an optical waveguide to provide large area illumination. Two unique yet complementary measurement methods were developed and tested with the same measurement apparatus. Good agreement was observed between the two methods based on testing of a variety of solar cells. The first method is a lock-in technique that can be performed over a broad pulse frequency range. The second method is based on synchronous multifrequency optical excitation and electrical detection. An innovative scheme for providing light bias during each measurement method is discussed.

  1. Comparison of Respiratory Resistance Measurements Made with an Airflow Perturbation Device with Those from Impulse Oscillometry

    Directory of Open Access Journals (Sweden)

    J. Pan

    2013-01-01

    Full Text Available The airflow perturbation device (APD has been developed as a portable, easy to use, and a rapid response instrument for measuring respiratory resistance in humans. However, the APD has limited data validating it against the established techniques. This study used a mechanical system to simulate the normal range of human breathing to validate the APD with the clinically accepted impulse oscillometry (IOS technique. The validation system consisted of a sinusoidal flow generator with ten standardized resistance configurations that were shown to represent a total range of resistances from 0.12 to 0.95 kPa·L−1·s (1.2–9.7 cm H2O·L−1·s. Impulse oscillometry measurements and APD measurements of the mechanical system were recorded and compared at a constant airflow of 0.15 L·s−1. Both the IOS and APD measurments were accurate in assessing nominal resistance. In addition, a strong linear relationship was observed between APD measurements and IOS measurements (R2 = 0.999. A second series of measurements was made on ten human volunteers with external resistors added in their respiratory flow paths. Once calibrated with the mechanical system, the APD gave respiratory resistance measurements within 5% of IOS measurements. Because of their comparability to IOS measurements, APD measurements are shown to be valid representations of respiratory resistance.

  2. Resonance measurement of nonlocal spin torque in a three-terminal magnetic device.

    Science.gov (United States)

    Xue, Lin; Wang, Chen; Cui, Yong-Tao; Liu, Luqiao; Swander, A; Sun, J Z; Buhrman, R A; Ralph, D C

    2012-04-06

    A pure spin current generated within a nonlocal spin valve can exert a spin-transfer torque on a nanomagnet. This nonlocal torque enables new design schemes for magnetic memory devices that do not require the application of large voltages across tunnel barriers that can suffer electrical breakdown. Here we report a quantitative measurement of this nonlocal spin torque using spin-torque-driven ferromagnetic resonance. Our measurement agrees well with the prediction of an effective circuit model for spin transport. Based on this model, we suggest strategies for optimizing the strength of nonlocal torque.

  3. Imaging polychromator for density measurements of polystyrene pellet cloud on the Large Helical Device

    Energy Technology Data Exchange (ETDEWEB)

    Sharov, I. A., E-mail: i.sharov@spbstu.ru; Sergeev, V. Yu.; Miroshnikov, I. V. [Saint-Petersburg State Polytechnical University, Saint-Petersburg (Russian Federation); Tamura, N.; Sudo, S. [National Institute for Fusion Science, Toki (Japan); Kuteev, B. V. [Russian Scientific Centre Kurchatov Institute, Moscow (Russian Federation)

    2015-04-15

    Experimental data on spatial distributions of a pellet cloud electron density are necessary for the development of many applications of pellet injection, namely, plasma fuelling, discharge control, and plasma diagnostics. An improved approach of electron density measurements inside the cloud of a polystyrene pellet ablating in hot plasma of the large helical device is described. Density values of (1-30) × 10{sup 16} cm{sup −3} depending on the background plasma parameters and distance from the solid pellet were measured.

  4. Evaluation of the Solar Water Disinfection Method Using an Ultraviolet Measurement Device

    Science.gov (United States)

    Leung, H.

    2015-12-01

    Drinking water security is a growing problem for the population of planet Earth. According to WHO, more than 750 million people on our planet lack access to safe drinking water, resulting in approximately 502,000 diarrhoea deaths in 2012. In order to solve this problem, the Swiss water research institute, Eawag, has developed a method of solar water disinfection, called, "SODIS" The theory of SODIS is simple to understand: a clear plastic bottle filled with water is placed under full sunlight for at least 6 hours. The ultraviolet radiation kills the pathogens in the water, making the originally contaminated water safe for drinking. In order to improve this method, Helioz, an Austrian social enterprise, has created the WADI, a UV measurement device which determines when water is safe for drinking using the SODIS method. When using the WADI, the device should be placed under the sun and surrounded with bottles of water that need to be decontaminated. There is a UV sensor on the WADI, and since the bottles of water and the WADI will have equal exposure to sunlight, the WADI will be able to measure the impact of the sunlight on the contaminated water. This experiment tests the accuracy of the WADI device regarding the time interval needed for contaminated water to be disinfected. The experiment involves using the SODIS method to purify bottles of water contaminated with controlled samples of E. coli. Samples of the water are taken at different time intervals, and the E. coli levels are determined by growing the bacteria from the water samples on agar plates. Ultimately, this helps determine when the water is safe for drinking, and are compared against the WADI's measurements to test the reliability of the device.

  5. CdSe Quantum Dots for Solar Cell Devices

    Directory of Open Access Journals (Sweden)

    A. B. Kashyout

    2012-01-01

    Full Text Available CdSe quantum dots have been prepared with different sizes and exploited as inorganic dye to sensitize a wide bandgap TiO2 thin films for QDs solar cells. The synthesis is based on the pyrolysis of organometallic reagents by injection into a hot coordinating solvent. This provides temporally discrete nucleation and permits controlled growth of macroscopic quantities of nanocrystallites. XRD, HRTEM, UV-visible, and PL were used to characterize the synthesized quantum dots. The results showed CdSe quantum dots with sizes ranging from 3 nm to 6 nm which enabled the control of the optical properties and consequently the solar cell performance. Solar cell of 0.08% performance under solar irradiation with a light intensity of 100 mW/cm2 has been obtained. CdSe/TiO2 solar cells without and with using mercaptopropionic acid (MPA as a linker between CdSe and TiO2 particles despite a Voc of 428 mV, Jsc of 0.184 mAcm-2, FF of 0.57, and η of 0.05% but with linker despite a Voc of 543 mV, Jsc of 0.318 mAcm-2 , FF of 0.48, and η of 0.08%, respectively.

  6. Optimization of Organic Solar Cells: Materials, Devices and Interfaces

    Science.gov (United States)

    Zhou, Nanjia

    Due to the increasing demand for sustainable clean energy, photovoltaic cells have received intensified attention in the past decade in both academia and industry. Among the types of cells, organic photovoltaic (OPV) cells offer promise as alternatives to conventional inorganic-type solar cells owning to several unique advantages such as low material and fabrication cost. To maximize power conversion efficiencies (PCEs), extensive research efforts focus on frontier molecular orbital (FMO) energy engineering of photoactive materials. Towards this objective, a series of novel donor polymers incorporating a new building block, bithiophene imide (BTI) group are developed, with narrow bandgap and low-lying highest occupied molecular orbital (HOMO) energies to increase short circuit current density, Jsc, and open circuit voltage, Voc.. Compared to other PV technologies, OPVs often suffer from large internal recombination loss and relatively low fill factors (FFs) thin film morphology, OPVs with PCEs up to 8.7% and unprecedented FF approaching 80% are obtained. Such high FF are close to those typically achieved in amorphous Si solar cells. Systematic variations of polymer chemical structures lead to understanding of structure-property relationships between polymer geometry and the resulting blend film morphology characteristics which are crucial for achieving high local mobilities and long carrier lifetimes. Instead of using fullerene as the acceptors, an alternative type of OPV is developed employing a high electron mobility polymer, P(NDI2OD-T2), as the acceptor. To improve the all-polymer blend film morphology, the influence of basic solvent properties such as solvent boiling point and solubility on polymer phase separation and charge transport properties is investigated, yielding to a high PCE of 2.7% for all-polymer solar cells. To take advantages of the inherent mechanical flexibility associated with organic materials, the development of transparent, flexible

  7. Development of a simple test device for spindle error measurement using a position sensitive detector

    Science.gov (United States)

    Liu, Chien-Hung; Jywe, Wen-Yuh; Lee, Hau-Wei

    2004-09-01

    A new spindle error measurement system has been developed in this paper. It employs a design development rotational fixture with a built-in laser diode and four batteries to replace a precision reference master ball or cylinder used in the traditional method. Two measuring devices with two position sensitive detectors (one is designed for the measurement of the compound X-axis and Y-axis errors and the other is designed with a lens for the measurement of the tilt angular errors) are fixed on the machine table to detect the laser point position from the laser diode in the rotational fixture. When the spindle rotates, the spindle error changes the direction of the laser beam. The laser beam is then divided into two separated beams by a beam splitter. The two separated beams are projected onto the two measuring devices and are detected by two position sensitive detectors, respectively. Thus, the compound motion errors and the tilt angular errors of the spindle can be obtained. Theoretical analysis and experimental tests are presented in this paper to separate the compound errors into two radial errors and tilt angular errors. This system is proposed as a new instrument and method for spindle metrology.

  8. Microfluidic device for continuous single cells analysis via Raman spectroscopy enhanced by integrated plasmonic nanodimers

    KAUST Repository

    Perozziello, Gerardo

    2015-12-11

    In this work a Raman flow cytometer is presented. It consists of a microfluidic device that takes advantages of the basic principles of Raman spectroscopy and flow cytometry. The microfluidic device integrates calibrated microfluidic channels- where the cells can flow one-by-one -, allowing single cell Raman analysis. The microfluidic channel integrates plasmonic nanodimers in a fluidic trapping region. In this way it is possible to perform Enhanced Raman Spectroscopy on single cell. These allow a label-free analysis, providing information about the biochemical content of membrane and cytoplasm of the each cell. Experiments are performed on red blood cells (RBCs), peripheral blood lymphocytes (PBLs) and myelogenous leukemia tumor cells (K562). © 2015 Optical Society of America.

  9. Quantum dot heterojunction solar cells: the mechanism of device operation and impacts of quantum dot oxidation

    OpenAIRE

    Ihly, Rachelle

    2014-01-01

    This thesis explores the understanding of the chemistry and physics of colloidal quantum dots for practical solar energy photoconversion. Solar cell devices that make use of PbS quantum dots generally rely on constant and unchanged optical properties such that band gap energies remain tuned within the device. The design and development of unique experiments to ascertain mechanisms of optical band gap shifts occurring in PbS quantum dot thin-films exposed to air are discussed. The systematic s...

  10. Miniaturized bacterial biosensor system for arsenic detection holds great promise for making integrated measurement device.

    Science.gov (United States)

    Buffi, Nina; Merulla, Davide; Beutier, Julien; Barbaud, Fanny; Beggah, Siham; van Lintel, Harald; Renaud, Philippe; van der Meer, Jan Roelof

    2011-01-01

    Combining bacterial bioreporters with microfluidics systems holds great promise for in-field detection of chemical or toxicity targets. Recently we showed how Escherichia coli cells engineered to produce a variant of green fluorescent protein after contact to arsenite and arsenate can be encapsulated in agarose beads and incorporated into a microfluidic chip to create a device for in-field detection of arsenic, a contaminant of well known toxicity and carcinogenicity in potable water both in industrialized and developing countries. Cell-beads stored in the microfluidics chip at -20°C retained inducibility up to one month and we were able to reproducibly discriminate concentrations of 10 and 50 μg arsenite per L (the drinking water standards for European countries and the United States, and for the developing countries, respectively) from the blank in less than 200 minutes. We discuss here the reasons for decreasing bioreporter signal development upon increased storage of cell beads but also show how this decrease can be reduced, leading to a faster detection and a longer lifetime of the device.

  11. Low-cost chlorophyll meter (LCCM): portable measuring device for leaf chlorophyll

    Science.gov (United States)

    Hutomo E. P., Evan; Adibawa, Marcelinus Alfasisurya S.; Prilianti, Kestrilia R.; Heriyanto, Heriyanto; Brotosudarmo, Tatas H. P.

    2016-11-01

    Portable leaf chlorophyll meter, named low-cost chlorophyll meter (LCCM), has been created. This device was created to help farmer determining the health condition of plant based on the greenness level of leaf surface. According to previous studies, leaf greenness with a certain amount of chlorophyll level has a direct correlation with the amount of nitrogen in the leaf that indicates health of the plant and this fact needed to provide an estimate of further measures to keep the plants healthy. Device that enables to measure the leaf color change is soil plant analysis development (SPAD) meter 502 from Konica Minolta but it is relatively expensive. To answer the need of low-cost chlorophyll scanner device, this research conducted experiment using light reflectance as the base mechanism. Reflectance system from LCCM consists of near-infrared light emitting diode (LED) and red LED as light resources and photodiode. The output from both of light resources calculated using normalized difference vegetation index (NDVI) formula as the results fetched and displayed on the smartphone application using Bluetooth communication protocol. Finally, the scanner has been made as well as the Android application named NDVI Reader. The LCCM system which has been tested on 20 sample of cassava leaf with SPAD meter as a variable control showed coefficient of determination 0.9681 and root-mean-square error (RMSE) 0.014.

  12. Analysis of an optical gate device for measuring aeolian sand movement

    Science.gov (United States)

    Etyemezian, V.; Nikolich, G.; Nickling, W.; King, J. S.; Gillies, J. A.

    2017-02-01

    Movement of sand in response to wind is the most important feature of aeolian sediment transport on Earth and other planets. Through sand blasting during saltation, large amounts of dust are ejected into the atmosphere and transported long distances, impacting climate and human health. Despite continuing improvements, currently available devices for field measurement of sand movement have limitations. An optical gate device (OGD) for detecting the movement, size, and possibly speed of individual sand grains during aeolian sediment transport was analyzed. The approach uses the highly time resolved signal from these sensors, which consist of a light emitter and a photosensitive sensor. A specific OGD that is manufactured by Optek (Carrollton, Texas, USA) was tested in a sediment transport wind tunnel alongside trap-style devices. The OGD device provided particle counts and total signal response that were well correlated with sand trap data (R2 between 0.66 and 0.88). Inter-comparison among eight identical units of the OGD showed excellent repeatability (R2 > 0.98 for 7 of 8 units). Subsequent tests revealed that the response of the phototransistor (light sensor) can be linear when operated within certain workable limits. Practical implications of this are that there is potential for extracting size distribution information. Limits imposed by noise levels in the signal and interferences from extraneous light sources were also identified. Despite the results presented being specific to the OGD model tested, much of the approach outlined is applicable to any OGD-type device (including Wenglor®) if the signal of the photo detector can be accessed directly.

  13. Surface EMG and intra-socket force measurement to control a prosthetic device

    Science.gov (United States)

    Sanford, Joe; Patterson, Rita; Popa, Dan

    2015-06-01

    Surface electromyography (SEMG) has been shown to be a robust and reliable interaction method allowing for basic control of powered prosthetic devices. Research has shown a marked decrease in EMG-classification efficiency throughout activities of daily life due to socket shift and movement and fatigue as well as changes in degree of fit of the socket throughout the subject's lifetime. Users with the most severe levels of amputation require the most complex devices with the greatest number of degrees of freedom. Controlling complex dexterous devices with limited available inputs requires the addition of sensing and interaction modalities. However, the larger the amputation severity, the fewer viable SEMG sites are available as control inputs. Previous work reported the use of intra-socket pressure, as measured during wrist flexion and extension, and has shown that it is possible to control a powered prosthetic device with pressure sensors. In this paper, we present data correlations of SEMG data with intra-socket pressure data. Surface EMG sensors and force sensors were housed within a simulated prosthetic cuff fit to a healthy-limbed subject. EMG and intra-socket force data was collected from inside the cuff as a subject performed pre-defined grip motions with their dominant hand. Data fusion algorithms were explored and allowed a subject to use both intra-socket pressure and SEMG data as control inputs for a powered prosthetic device. This additional input modality allows for an improvement in input classification as well as information regarding socket fit through out activities of daily life.

  14. A cell sorting and trapping microfluidic device with an interdigital channel

    Directory of Open Access Journals (Sweden)

    Jing Tu

    2016-12-01

    Full Text Available The growing interest in cell sorting and trapping is driving the demand for high performance technologies. Using labeling techniques or external forces, cells can be identified by a series of methods. However, all of these methods require complicated systems with expensive devices. Based on inherent differences in cellular morphology, cells can be sorted by specific structures in microfluidic devices. The weir filter is a basic and efficient cell sorting and trapping structure. However, in some existing weir devices, because of cell deformability and high flow velocity in gaps, trapped cells may become stuck or even pass through the gaps. Here, we designed and fabricated a microfluidic device with interdigital channels for cell sorting and trapping. The chip consisted of a sheet of silicone elastomer polydimethylsiloxane and a sheet of glass. A square-wave-like weir was designed in the middle of the channel, comprising the interdigital channels. The square-wave pattern extended the weir length by three times with the channel width remaining constant. Compared with a straight weir, this structure exhibited a notably higher trapping capacity. Interdigital channels provided more space to slow down the rate of the pressure decrease, which prevented the cells from becoming stuck in the gaps. Sorting a mixture K562 and blood cells to trap cells demonstrated the efficiency of the chip with the interdigital channel to sort and trap large and less deformable cells. With stable and efficient cell sorting and trapping abilities, the chip with an interdigital channel may be widely applied in scientific research fields.

  15. Measurement of Blood Pressure Using an Arterial Pulsimeter Equipped with a Hall Device

    Directory of Open Access Journals (Sweden)

    Jong-Gu Choi

    2011-01-01

    Full Text Available To measure precise blood pressure (BP and pulse rate without using a cuff, we have developed an arterial pulsimeter consisting of a small, portable apparatus incorporating a Hall device. Regression analysis of the pulse wave measured during testing of the arterial pulsimeter was conducted using two equations of the BP algorithm. The estimated values of BP obtained by the cuffless arterial pulsimeter over 5 s were compared with values obtained using electronic or liquid mercury BP meters. The standard deviation between the estimated values and the measured values for systolic and diastolic BP were 8.3 and 4.9, respectively, which are close to the range of values of the BP International Standard. Detailed analysis of the pulse wave measured by the cuffless radial artery pulsimeter by detecting changes in the magnetic field can be used to develop a new diagnostic algorithm for BP, which can be applied to new medical apparatus such as the radial artery pulsimeter.

  16. Measurement of buried undercut structures in microfluidic devices by laser fluorescent confocal microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Li Shiguang; Liu Jing; Nguyen, Nam-Trung; Fang Zhongping; Yoon, Soon Fatt

    2009-11-20

    Measuring buried, undercut microstructures is a challenging task in metrology. These structures are usually characterized by measuring their cross sections after physically cutting the samples. This method is destructive and the obtained information is incomplete. The distortion due to cutting also affects the measurement accuracy. In this paper, we first apply the laser fluorescent confocal microscopy and intensity differentiation algorithm to obtain the complete three-dimensional profile of the buried, undercut structures in microfluidic devices, which are made by the soft lithography technique and bonded by the oxygen plasma method. The impact of material wettability and the refractive index (n) mismatch among the liquid, samples, cover layer, and objective on the measurement accuracy are experimentally investigated.

  17. Oligothiophene Materials for Organic Solar Cells - Photophysics and Device Properties

    OpenAIRE

    Körner, Christian

    2013-01-01

    The rapidly increasing power conversion efficiencies (PCEs) of organic solar cells (OSCs) above 10% were made possible by concerted international research activities in the last few years, aiming to understand the processes that lead to the generation of free charge carriers following photon absorption. Despite these efforts, many details are still unknown, especially how these processes can be improved already at the drawing board of molecular design. To unveil this information, dicyanoviny...

  18. Optomechanical measurement of photon spin angular momentum and optical torque in integrated photonic devices

    CERN Document Server

    He, Li; Li, Mo

    2016-01-01

    Photons carry linear momentum, and spin angular momentum when circularly or elliptically polarized. During light-matter interaction, transfer of linear momentum leads to optical forces, while angular momentum transfer induces optical torque. Optical forces including radiation pressure and gradient forces have long been utilized in optical tweezers and laser cooling. In nanophotonic devices optical forces can be significantly enhanced, leading to unprecedented optomechanical effects in both classical and quantum regimes. In contrast, to date, the angular momentum of light and the optical torque effect remain unexplored in integrated photonics. Here, we demonstrate the measurement of the spin angular momentum of photons propagating in a birefringent waveguide and the use of optical torque to actuate rotational motion of an optomechanical device. We show that the sign and magnitude of the optical torque are determined by the photon polarization states that are synthesized on the chip. Our study reveals the mecha...

  19. Device for measuring level of heat-transfer agent in injection wells

    Energy Technology Data Exchange (ETDEWEB)

    Putilov, M.F.; Bar-Sliva, V.I.; Chelenkov, S.V.; Dichenko, M.A.; Nikiforov, Yu.V.; Petrov, A.I.; Turchaninov, Yu.N.; Zevelev, S.Ya.

    1981-01-01

    A device is claimed for measuring level of heat-transfer agent in wells. It consists of a body, turbine, and a tachometric transformer that switches a magnet located on the turbine shaft, and the core with winding (in the housing), and a secondary transformer. To assure reliability of device, a frequency limiting generator, a comparison scheme, a control unit and source of continuous current have been included. The ends of the tachometric transformer's winding are connected to the secondary transformer and the control unit. The latter is connected to the continuous current source and the output of the comparison scheme; intakes of the comparison scheme are tied to the secondary transformer and the frequency limiting generator.

  20. Measurement-Device-Independent Quantum Key Distribution Over a 404 km Optical Fiber

    Science.gov (United States)

    Yin, Hua-Lei; Chen, Teng-Yun; Yu, Zong-Wen; Liu, Hui; You, Li-Xing; Zhou, Yi-Heng; Chen, Si-Jing; Mao, Yingqiu; Huang, Ming-Qi; Zhang, Wei-Jun; Chen, Hao; Li, Ming Jun; Nolan, Daniel; Zhou, Fei; Jiang, Xiao; Wang, Zhen; Zhang, Qiang; Wang, Xiang-Bin; Pan, Jian-Wei

    2016-11-01

    Measurement-device-independent quantum key distribution (MDIQKD) with the decoy-state method negates security threats of both the imperfect single-photon source and detection losses. Lengthening the distance and improving the key rate of quantum key distribution (QKD) are vital issues in practical applications of QKD. Herein, we report the results of MDIQKD over 404 km of ultralow-loss optical fiber and 311 km of a standard optical fiber while employing an optimized four-intensity decoy-state method. This record-breaking implementation of the MDIQKD method not only provides a new distance record for both MDIQKD and all types of QKD systems but also, more significantly, achieves a distance that the traditional Bennett-Brassard 1984 QKD would not be able to achieve with the same detection devices even with ideal single-photon sources. This work represents a significant step toward proving and developing feasible long-distance QKD.

  1. Using a communication model to collect measurement data through mobile devices.

    Science.gov (United States)

    Bravo, José; Villarreal, Vladimir; Hervás, Ramón; Urzaiz, Gabriel

    2012-01-01

    Wireless systems and services have undergone remarkable development since the first mobile phone system was introduced in the early 1980s. The use of sensors in an Ambient Intelligence approach is a great solution in a medical environment. We define a communication architecture to facilitate the information transfer between all connected devices. This model is based in layers to allow the collection of measurement data to be used in our framework monitoring architecture. An overlay-based solution is built between network elements in order to provide an efficient and highly functional communication platform that allows the connection of a wide variety of devices and technologies, and serves also to perform additional functions such as the possibility to perform some processing in the network that may help to improve overall performance.

  2. Experimental asymmetric plug-and-play measurement-device-independent quantum key distribution

    Science.gov (United States)

    Tang, Guang-Zhao; Sun, Shi-Hai; Xu, Feihu; Chen, Huan; Li, Chun-Yan; Liang, Lin-Mei

    2016-09-01

    Measurement-device-independent quantum key distribution (MDI-QKD) is immune to all security loopholes on detection. Previous experiments on MDI-QKD required spatially separated signal lasers and complicated stabilization systems. In this paper, we perform a proof-of-principle experimental demonstration of plug-and-play MDI-QKD over an asymmetric channel setting with a single signal laser in which the whole system is automatically stabilized in spectrum, polarization, arrival time, and phase reference. Both the signal laser and the single-photon detectors are in the possession of a common server. A passive timing-calibration technique is applied to ensure the precise and stable overlap of signal pulses. The results pave the way for the realization of a quantum network in which the users only need the encoding devices.

  3. Measurement of Local Reactive and Resistive Photoresponse of a Superconducting Microwave Device

    Science.gov (United States)

    Anlage, Steven M.; Zhuravel, Alexander P.; Ustinov, Alexey V.

    2006-03-01

    Despite the voluminous work on the nature of nonlinear effects in high-temperature superconductors (HTS), the causes are not completely clear and remain under debate. The Laser Scanning Microscope (LSM) is a spatially-resolved method that can simultaneously measure optical and high frequency properties of HTS devices. Earlier results showed high resolution images of non-uniform microwave current distributions near the edge of a patterned transmission line structure [A. P. Zhuravel, A. V. Ustinov, K. S. Harshavardhan, and S. M. Anlage, Appl. Phys. Lett. 81, 4979 (2002)]. We have developed a new operational mode in which the microscope separately images the resistive and inductive components of the bolometric photoresponse. The two images show interesting and dramatic differences, leading to new insights about linear and nonlinear properties of HTS microwave devices.

  4. CALIBRATION OF DEVICES FOR MEASURING ELEMENTS OF MICRO-ELECTRONIC STRUCTURES

    Directory of Open Access Journals (Sweden)

    G. Trapashko

    2012-01-01

    Full Text Available Development of microelectronics requires solution of the problem ensuring unity of linear measurements in a submicron range. The problem can be solved on the condition that calibration of measuring devices shall be made in accordance with reference samples that is a short length scale.While making calibration of measuring equipment with the help of a reference measure it is important to investigate components of the method accuracy and their influence on measuring results. The paper considers methodical errors which are specific for methods of optical and atomic force microscopy. Calibration results of an optical measuring microscope are given in the paper. The paper reveals that an additive error depends on parameters of a material and the form of measured elements for an optical measuring microscope. The methodical error of atomic force microscopes is predicated on the probe point shape. The paper considers a short length scale used for calibration of optical and atomic force microscopes. Recommendations for users of the measuring equipment are formulated in the paper.

  5. Development of measuring device for inner surfaces of embedded piping (Contract research)

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Hirokuni [Ohyo Koken Kogyo Co., Ltd., Tokyo (Japan); Hatakeyama, Mutsuo [Radioactive Waste Management and Nuclear Facility Decommissioning Technology Center, Tokyo (Japan); Tachibana, Mitsuo; Yanagihara, Satoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    The measuring device for inner surfaces of embedded piping (MISE) was developed to evaluate low-level radiological contaminations of inner surfaces of piping. The MISE consists of a cylindrically-formed double layered type detector and a piping crawling robot, which were designed and manufactured separately. In measurements of the contaminations, an outer cylindrical detector close to the surface of piping measures {beta}-rays and {gamma}-rays and an inner cylindrical detector set after a shielding plate for shield of {beta}-rays measures {gamma}-rays. The {beta}-ray counting rates are derived by subtracting {gamma}-ray counts measured by the inner detector from {gamma}- and {beta}-ray counts measured by the outer detector. The piping crawling robot transports the cylindrically-formed double layered type detector with observing inner surfaces of piping. The detection limit for the contamination of {sup 60}Co was found to be about 0.17 Bq/cm{sup 2} with measurement time of 30 seconds. It is expected that 0.2 Bq/cm{sup 2} corresponding to clearance level of {sup 60}Co (0.4 Bq/g) can be evaluated with measurement time of 2 seconds, which is equal to measurement speed of 54 m/h. (author)

  6. Active cell mechanics: Measurement and theory.

    Science.gov (United States)

    Ahmed, Wylie W; Fodor, Étienne; Betz, Timo

    2015-11-01

    Living cells are active mechanical systems that are able to generate forces. Their structure and shape are primarily determined by biopolymer filaments and molecular motors that form the cytoskeleton. Active force generation requires constant consumption of energy to maintain the nonequilibrium activity to drive organization and transport processes necessary for their function. To understand this activity it is necessary to develop new approaches to probe the underlying physical processes. Active cell mechanics incorporates active molecular-scale force generation into the traditional framework of mechanics of materials. This review highlights recent experimental and theoretical developments towards understanding active cell mechanics. We focus primarily on intracellular mechanical measurements and theoretical advances utilizing the Langevin framework. These developing approaches allow a quantitative understanding of nonequilibrium mechanical activity in living cells. This article is part of a Special Issue entitled: Mechanobiology.

  7. Stretchable living materials and devices with hydrogel–elastomer hybrids hosting programmed cells

    Science.gov (United States)

    Liu, Xinyue; Tang, Tzu-Chieh; Tham, Eléonore; Yuk, Hyunwoo; Lin, Shaoting; Lu, Timothy K.; Zhao, Xuanhe

    2017-01-01

    Living systems, such as bacteria, yeasts, and mammalian cells, can be genetically programmed with synthetic circuits that execute sensing, computing, memory, and response functions. Integrating these functional living components into materials and devices will provide powerful tools for scientific research and enable new technological applications. However, it has been a grand challenge to maintain the viability, functionality, and safety of living components in freestanding materials and devices, which frequently undergo deformations during applications. Here, we report the design of a set of living materials and devices based on stretchable, robust, and biocompatible hydrogel–elastomer hybrids that host various types of genetically engineered bacterial cells. The hydrogel provides sustainable supplies of water and nutrients, and the elastomer is air-permeable, maintaining long-term viability and functionality of the encapsulated cells. Communication between different bacterial strains and with the environment is achieved via diffusion of molecules in the hydrogel. The high stretchability and robustness of the hydrogel–elastomer hybrids prevent leakage of cells from the living materials and devices, even under large deformations. We show functions and applications of stretchable living sensors that are responsive to multiple chemicals in a variety of form factors, including skin patches and gloves-based sensors. We further develop a quantitative model that couples transportation of signaling molecules and cellular response to aid the design of future living materials and devices. PMID:28202725

  8. Stretchable living materials and devices with hydrogel-elastomer hybrids hosting programmed cells.

    Science.gov (United States)

    Liu, Xinyue; Tang, Tzu-Chieh; Tham, Eléonore; Yuk, Hyunwoo; Lin, Shaoting; Lu, Timothy K; Zhao, Xuanhe

    2017-02-28

    Living systems, such as bacteria, yeasts, and mammalian cells, can be genetically programmed with synthetic circuits that execute sensing, computing, memory, and response functions. Integrating these functional living components into materials and devices will provide powerful tools for scientific research and enable new technological applications. However, it has been a grand challenge to maintain the viability, functionality, and safety of living components in freestanding materials and devices, which frequently undergo deformations during applications. Here, we report the design of a set of living materials and devices based on stretchable, robust, and biocompatible hydrogel-elastomer hybrids that host various types of genetically engineered bacterial cells. The hydrogel provides sustainable supplies of water and nutrients, and the elastomer is air-permeable, maintaining long-term viability and functionality of the encapsulated cells. Communication between different bacterial strains and with the environment is achieved via diffusion of molecules in the hydrogel. The high stretchability and robustness of the hydrogel-elastomer hybrids prevent leakage of cells from the living materials and devices, even under large deformations. We show functions and applications of stretchable living sensors that are responsive to multiple chemicals in a variety of form factors, including skin patches and gloves-based sensors. We further develop a quantitative model that couples transportation of signaling molecules and cellular response to aid the design of future living materials and devices.

  9. Miniaturized vortex transitional Josephson memory cell by a vertically integrated device structure

    Energy Technology Data Exchange (ETDEWEB)

    Nagasawa, Shuichi; Tahara, Shuichi; Numata, Hideaki; Tsuchida, Sanae (NEC Corp., Tsukuba (Japan))

    1994-03-01

    We have developed the smallest Josephson nondestructive read-out (NDRO) memory cell, called a vortex transitional (VT) memory cell, for a Josephson high-speed 16-Kbit RAM. Its size is 22 x 22 microns(sup 2), which is only 16% of the size of previously developed VT memory cells used in Josephson 4-Kbit RAM. This is achieved by developing a vertically integrated device structure and refining small-junction technology. The cell consists of Nb/AlO(sub x)/Nb junctions, three Nb wirings, SiO2 insulators and Mo resistors. The VT memory cells operate properly, with a large operating margin of +/- 20%. 13 refs.

  10. Controllable design of solid-state perovskite solar cells by SCAPS device simulation

    Science.gov (United States)

    Tan, Kai; Lin, Peng; Wang, Gang; Liu, Yan; Xu, Zongchang; Lin, Yixin

    2016-12-01

    The highest power conversion efficiency (PCE) of solid-state perovskite solar cells (ssPSCs) has achieved 20.1% recently. There is reason to believe that ssPSCs is a strong competitor with silicon and CIGS solar cells in photovoltaic field. The deep understanding of operation mechanism of ssPSCs is essential and required to furtherly improve device performance. The configuration and excition type are similar to inorganic semiconductor solar cells. Therefore, Solar Cell Capacitance Simulator (SCAPS), a device simulator widely using in inorganic solar cells, was employed to controllably design ssPSCs. The validity of device simulation was verified by comparing with real devices from reported literatures. The influence of absorber thickness on device property was discussed, which indicate that it exists an optimal thickness range. Two hypothetical interface layers, TiO2/perovskite layer and perovskite/HTM layer, were introduced into the construction model to consider the effects of interfaces defect density on device performance. It revealed TiO2/perovskite has stronger impact than perovskite/HTM, because higher excess carrier density existing at TiO2/perovskite will cause more recombination rate. In addition, hole transport materials (HTM) parameters, hole mobility and acceptor density, were chosen to study the impact of HTM characteristics on PCE. The analysis illuminate that the design of HTM layer should balance hole mobility and acceptor density. Meanwhile, different HTM candidates were selected and replaced typical HTM layer. The discussion about the function of candidates on solar cells performance demonstrated that a thiophene group hole-transporting polymer (PTAA) and a copper-based conductor (CuI) both have relatively high PCE, which is due to their wide bandgap, high conductivity, and better chemical interaction with perovskite absorber.

  11. Desenvolvimento de um dispositivo de baixo custo para medidas por quimiluminescência Development of a low cost device for chemiluminescence measurements

    Directory of Open Access Journals (Sweden)

    Eduardo P. Borges

    2002-12-01

    Full Text Available A simple and low cost device (ca. US$ 150 that comprises two photodiodes fixed in lab-made Perspex flow cell is proposed for chemiluminescence measurements. The characteristics of the device (large observation window and reduced thickness allow maximizing the amount of the emitted radiation detected. A sensitivity improvement of ca. 50 % was observed by employing two photodiodes for signal measurements. The performance of the device was assessed by the oxidation of luminol by hydrogen peroxide, yielding a linear response within the range of 2.50 to 500 µmol L-1 H2O2. The detection limit was estimated as 0.8 µmol L-1 hydrogen peroxide which is comparable with those obtained by using equipments based on photomultipliers.

  12. Towards autonomous lab-on-a-chip devices for cell phone biosensing.

    Science.gov (United States)

    Comina, Germán; Suska, Anke; Filippini, Daniel

    2016-03-15

    Modern cell phones are a ubiquitous resource with a residual capacity to accommodate chemical sensing and biosensing capabilities. From the different approaches explored to capitalize on such resource, the use of autonomous disposable lab-on-a-chip (LOC) devices-conceived as only accessories to complement cell phones-underscores the possibility to entirely retain cell phones' ubiquity for distributed biosensing. The technology and principles exploited for autonomous LOC devices are here selected and reviewed focusing on their potential to serve cell phone readout configurations. Together with this requirement, the central aspects of cell phones' resources that determine their potential for analytical detection are examined. The conversion of these LOC concepts into universal architectures that are readable on unaccessorized phones is discussed within this context.

  13. On-chip lysis of mammalian cells through a handheld corona device.

    Science.gov (United States)

    Escobedo, C; Bürgel, S C; Kemmerling, S; Sauter, N; Braun, T; Hierlemann, A

    2015-07-21

    On-chip lysis is required in many lab-on-chip applications involving cell studies. In these applications, the complete disruption of the cellular membrane and a high lysis yield is essential. Here, we present a novel approach to lyse cells on-chip through the application of electric discharges from a corona handheld device. The method only requires a microfluidic chip and a low-cost corona device. We demonstrate the effective lysis of BHK and eGFP HCT 116 cells in the sub-second time range using an embedded microelectrode. We also show cell lysis of non-adherent K562 leukemia cells without the use of an electrode in the chip. Cell lysis has been assessed through the use of bright-field microscopy, high-speed imaging and cell-viability fluorescence probes. The experimental results show effective cell lysis without any bubble formation or significant heating. Due to the simplicity of both the components involved and the lysis procedure, this technique offers an inexpensive lysis option with the potential for integration into lab-on-a-chip devices.

  14. Development of an automatic measuring device for total sugar content in chlortetracycline fermenter based on STM32

    Science.gov (United States)

    Liu, Ruochen; Chen, Xiangguang; Yao, Minpu; Huang, Suyi; Ma, Deshou; Zhou, Biao

    2017-01-01

    Because fermented liquid in chlortetracycline fermenter has high viscosity and complex composition, conventional instruments can't directly measure its total sugar content of fermented liquid. At present, offline artificial sampling measurement is usually the way to measuring total sugar content in chlortetracycline Fermenter. it will take too much time and manpower to finish the measurement., and the results will bring the lag of control process. To realize automatic measurement of total sugar content in chlortetracycline fermenter, we developed an automatic measuring device for total sugar content based on STM32 microcomputer. It can not only realize the function of automatic sampling, filtering, measuring of fermented liquid and automatic washing of the device, but also can make the measuring results display in the field and finish data communication. The experiment results show that the automatic measuring device of total sugar content in chlortetracycline fermenter can meet the demand of practical application.

  15. Continuous-Variable Measurement-Device-Independent Multipartite Quantum Communication Using Coherent States

    Science.gov (United States)

    Zhou, Jian; Guo, Ying

    2017-02-01

    A continuous-variable measurement-device-independent (CV-MDI) multipartite quantum communication protocol is designed to realize multipartite communication based on the GHZ state analysis using Gaussian coherent states. It can remove detector side attack as the multi-mode measurement is blindly done in a suitable Black Box. The entanglement-based CV-MDI multipartite communication scheme and the equivalent prepare-and-measurement scheme are proposed to analyze the security and guide experiment, respectively. The general eavesdropping and coherent attack are considered for the security analysis. Subsequently, all the attacks are ascribed to coherent attack against imperfect links. The asymptotic key rate of the asymmetric configuration is also derived with the numeric simulations illustrating the performance of the proposed protocol.

  16. A Comparative Study of Measuring Devices Used During Space Shuttle Processing for Inside Diameters

    Science.gov (United States)

    Rodriguez, Antonio

    2006-01-01

    During Space Shuttle processing, discrepancies between vehicle dimensions and per print dimensions determine if a part should be refurbished, replaced or accepted "as-is." The engineer's job is to address each discrepancy by choosing the most accurate procedure and tool available, sometimes with up to ten thousands of an inch tolerance. Four methods of measurement are commonly used at the Kennedy Space Center: 1) caliper, 2) mold impressions, 3) optical comparator, 4) dial bore gage. During a problem report evaluation, uncertainty arose between methods after measuring diameters with variations of up to 0.0004" inches. The results showed that computer based measuring devices are extremely accurate, but when human factor is involved in determining points of reference, the results may vary widely compared to more traditional methods. iv

  17. Standard test method for calibration of surface/stress measuring devices

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1997-01-01

    Return to Contents page 1.1 This test method covers calibration or verification of calibration, or both, of surface-stress measuring devices used to measure stress in annealed and heat-strengthened or tempered glass using polariscopic or refractometry based principles. 1.2 This test method is nondestructive. 1.3 This test method uses transmitted light, and therefore, is applicable to light-transmitting glasses. 1.4 This test method is not applicable to chemically tempered glass. 1.5 Using the procedure described, surface stresses can be measured only on the “tin” side of float glass. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  18. A new device for measurement of fibrin clot lysis: application to the Euglobulin Clot Lysis Time

    Directory of Open Access Journals (Sweden)

    Brohée D

    2002-05-01

    Full Text Available Abstract Background Determination of clot lysis times on whole blood, diluted whole blood, plasma or plasma fraction has been used for many years to assess the overall activity of the fibrinolytic system. We designed a completely computerised semi-automatic 8-channel device for measurement and determination of fibrin clot lysis. The lysis time is evaluated by a mathematical analysis of the lysis curve and the results are expressed in minute (range: 5 to 9999. We have used this new device for Euglobulin Clot Lysis Time (ECLT determination, which is the most common test used in laboratories to estimate plasma fibrinolytic capacity. Results The correlation between ECLT and manual method is very tight : R = 0,99; p -6. The efficiency scores of the method are Conclusions The routine use of this new device could be useful in various situations such as assessment in atherosclerosis and arteriosclerosis associated diseases, coagulation survey of liver transplantations, cardiovascular surgery or pharmacological research. It has already provided highly promising results in preliminary studies on the relation between fibrinolysis and cardiovascular risk factors.

  19. Reply to: Discrete-variable measurement-device-independent quantum key distribution suitable for metropolitan networks

    CERN Document Server

    Pirandola, Stefano; Spedalieri, Gaetana; Weedbrook, Christian; Braunstein, Samuel L; Lloyd, Seth; Gehring, Tobias; Jacobsen, Christian S; Andersen, Ulrik L

    2015-01-01

    In a recent comment, Xu et al. claimed that discrete-variable (DV) measurement-device-independent (MDI) quantum key distribution (QKD) would compete with its continuous-variable (CV) counterpart at metropolitan distances. Actually, Xu et al.'s analysis supports the opposite by showing that the experimental rate of our CV protocol (achieved with practical room-temperature devices) remains one order of magnitude higher than their purely-numerical and over-optimistic extrapolation for qubits, based on nearly-ideal parameters and cryogenic detectors (clearly unsuitable for the construction of a realistic, cheap and scalable high-rate network, e.g., including mobile devices). The experimental rate of our protocol (bits per relay use) is confirmed to be two-three orders of magnitude higher than the rate of any realistic simulation of practical DV-MDI-QKD over short-medium distances. Of course this does not mean that DV-MDI-QKD networks should not be investigated or built, but increasing their rate is a non-trivial ...

  20. Optomechanical measurement of photon spin angular momentum and optical torque in integrated photonic devices.

    Science.gov (United States)

    He, Li; Li, Huan; Li, Mo

    2016-09-01

    Photons carry linear momentum and spin angular momentum when circularly or elliptically polarized. During light-matter interaction, transfer of linear momentum leads to optical forces, whereas transfer of angular momentum induces optical torque. Optical forces including radiation pressure and gradient forces have long been used in optical tweezers and laser cooling. In nanophotonic devices, optical forces can be significantly enhanced, leading to unprecedented optomechanical effects in both classical and quantum regimes. In contrast, to date, the angular momentum of light and the optical torque effect have only been used in optical tweezers but remain unexplored in integrated photonics. We demonstrate the measurement of the spin angular momentum of photons propagating in a birefringent waveguide and the use of optical torque to actuate rotational motion of an optomechanical device. We show that the sign and magnitude of the optical torque are determined by the photon polarization states that are synthesized on the chip. Our study reveals the mechanical effect of photon's polarization degree of freedom and demonstrates its control in integrated photonic devices. Exploiting optical torque and optomechanical interaction with photon angular momentum can lead to torsional cavity optomechanics and optomechanical photon spin-orbit coupling, as well as applications such as optomechanical gyroscopes and torsional magnetometry.

  1. An easy way to measure accurately the direct magnetoelectric voltage coefficient of thin film devices

    Science.gov (United States)

    Poullain, Gilles; More-Chevalier, Joris; Cibert, Christophe; Bouregba, Rachid

    2017-01-01

    TbxDy1-xFe2/Pt/Pb(Zrx, Ti1-x)O3 thin films were grown on Pt/TiO2/SiO2/Si substrate by multi-target sputtering. The magnetoelectric voltage coefficient αΗΜΕ was determined at room temperature using a lock-in amplifier. By adding, in series in the circuit, a capacitor of the same value as that of the device under test, we were able to demonstrate that the magnetoelectric device behaves as a voltage source. Furthermore, a simple way to subtract the stray voltage arising from the flow of eddy currents in the measurement set-up, is proposed. This allows the easy and accurate determination of the true magnetoelectric voltage coefficient. A large αΗΜΕ of 8.3 V/cm. Oe was thus obtained for a Terfenol-D/Pt/PZT thin film device, without DC magnetic field nor mechanical resonance.

  2. A NEW DEVICE AND METHOD FOR MEASURING VOLATILE COMPOUNDS IN MONITORING WELLS

    Energy Technology Data Exchange (ETDEWEB)

    Vangelas, K; Warren Hyde, W; Brian02 Looney, B; Kirk Cantrell, K; Tyler Gilmore, T

    2006-11-06

    Accurate, timely measurement of chlorinated solvents and other volatile contaminants in groundwater is crucial to support responsible environmental management. Traditionally, two distinctly different paradigms have been explored to meet this need--fixed laboratory analysis and ''real-time'' sensors. While these alternatives remain important, field based and field screening tools represent a potentially useful intermediate approach that balances some of the advantages and disadvantages of the traditional ''endmember'' paradigms. The value of accurate, in-field measurements during characterization was recognized in recent sampling/decision methods, such as the TRIAD approach (ITRC, 2003). Strategies that support gathering accurate data on the timescales representative of the rate of change of the system (e.g., months to years, not seconds to minutes) is key for long-term monitoring for chlorinated solvent plumes in which attenuation based remedies are being considered. A team of researchers developed a down-well sampling device that, when used in combination with field gas analysis tools, provides data in the field. The test results indicate this tool, as configured, will provide accurate measurements (as compared with laboratory methods) at concentrations in the hundreds of ppb or higher range, but require confirmatory traditional sampling with laboratory analysis at concentrations approaching 20 ppb and less. The logistics and costs of the sampling device were somewhat complex. The results of the study, while equivocal, generally suggest that future development of this type of in-field technique may be warranted.

  3. Simulations and measurements of coupling impedance for modern particle accelerator devices

    CERN Document Server

    AUTHOR|(CDS)2158523; Biancacci, Nicolò; Mostacci, Andrea

    In this document it has been treated the study of the coupling impedance in modern devices, already installed or not, in different particle accelerators. In the specific case: • For a device in-phase of project, several simulations for impedance calculation have been done. • For a component already realized and used, measurements of coupling impedance value have been done. Simulations are used to determine the impact of the interconnect between to magnets, designed for the future particle accelerator FCC, on the overall impedance of the machine which is about 100 km long. In particular has been done a check between theory, simulations and measurements of components already built, allowing a better and deeper study of the component we have analysed. Controls that probably will be helpful to have a clear guideline in future works. The measurements instead concern in an existing component that was already used in LHC, the longest particle accelerator ever realised on the planet, 27 km long. The coupling impe...

  4. — study of the use of two standard- and non-standard-measuring devices

    Directory of Open Access Journals (Sweden)

    Paweł Ostapkowicz

    2014-03-01

    Full Text Available This paper deals with leak detection in liquid transmission pipelines. Diagnostic method based on negative pressure wave detection is taken into account here. The paper focuses on variant of this method, related to the use of only two measurement points (devices, placed at the inlet and outlet of the pipeline. Standard transducers for measurement of pressure signals and non-standard elaborated technique for measurement of new diagnostic signals were used. New diagnostic signals, conventionally named the signals of weak interactions, result from the work of special devices (correctors joined to the pipeline. In order to compare both hardware solutions key performance attributes for the analyzed leak detection method were determined. The bases of such assessment were experimental tests. They were conducted with the use of a physical model of a pipeline. The pipeline was 380 meters long, 34 mm in internal diameter and made of polyethylene (PEHD pipes. The medium pumped through the pipeline was water. Carrying out such research, diagnostic procedures elaborated by the author were used and tested.[b]Keywords[/b]: technical diagnostics, pipelines, leak detection

  5. Lessons from wet gas flow metering systems using differential measurements devices: Testing and flow modelling results

    Energy Technology Data Exchange (ETDEWEB)

    Cazin, J.; Couput, J.P.; Dudezert, C. et al

    2005-07-01

    A significant number of wet gas meters used for high GVF and very high GVF are based on differential pressure measurements. Recent high pressure tests performed on a variety of different DP devices on different flow loops are presented. Application of existing correlations is discussed for several DP devices including Venturi meters. For Venturi meters, deviations vary from 9% when using the Murdock correlation to less than 3 % with physical based models. The use of DP system in a large domain of conditions (Water Liquid Ratio) especially for liquid estimation will require information on the WLR This obviously raises the question of the gas and liquid flow metering accuracy in wet gas meters and highlight needs to understand AP systems behaviour in wet gas flows (annular / mist / annular mist). As an example, experimental results obtained on the influence of liquid film characteristics on a Venturi meter are presented. Visualizations of the film upstream and inside the Venturi meter are shown. They are completed by film characterization. The AP measurements indicate that for a same Lockhart Martinelli parameter, the characteristics of the two phase flow have a major influence on the correlation coefficient. A 1D model is defined and the results are compared with the experiments. These results indicate that the flow regime influences the AP measurements and that a better modelling of the flow phenomena is needed even for allocation purposes. Based on that, lessons and way forward in wet gas metering systems improvement for allocation and well metering are discussed and proposed. (author) (tk)

  6. Development of a simple device for processing whole-blood samples into measured aliquots of plasma.

    Science.gov (United States)

    Burtis, C A; Johnson, W F; Walker, W A

    1986-09-01

    A capillary processor and aliquoter has been designed and fabricated that is capable of accepting aliquots of whole blood and automatically processing them into discrete aliquots of plasma. The device consists of two disks, each of which contains 16 individual capillaries and a processing rotor. One disk accepts larger capillaries that hold approximately 100 microL of whole blood each. The second disk accepts 2.54-cm-long precision capillaries of various internal diameters, which provide exact sample volumes from 1 to 10 microL. The processing rotor contains 16 individual compartments and chambers to accept both disks. Applying centrifugal force transfers the aliquots of whole blood into their respective compartments, where they are separated into cellular and plasma fractions. As the rotor speed is slowly decreased, an aliquot of plasma is withdrawn by capillary action into each measuring capillary. The disk containing the 16 measured aliquots of plasma is then removed and placed into a modified rotor for conventional centrifugal analysis. This device can entrain and deliver microliter volumes of liquids with precision and accuracy (1-2%) near that of mechanical pipettes. Assays of the separated plasma aliquots also have acceptable precision (e.g., CVs approximately 3% for measurements of serum enzymes).

  7. Reliability of metatarsophalangeal and ankle joint torque measurements by an innovative device.

    Science.gov (United States)

    Man, Hok-Sum; Leung, Aaron Kam-Lun; Cheung, Jason Tak-Man; Sterzing, Thorsten

    2016-07-01

    The toe flexor muscles maintain body balance during standing and provide push-off force during walking, running, and jumping. Additionally, they are important contributing structures to maintain normal foot function. Thus, weakness of these muscles may cause poor balance, inefficient locomotion and foot deformities. The quantification of metatarsophalangeal joint (MPJ) stiffness is valuable as it is considered as a confounding factor in toe flexor muscles function. MPJ and ankle joint stiffness measurement is still largely depended on manual skills as current devices do not have good control on alignment, angular joint speed and displacement during measurement. Therefore, this study introduces an innovative dynamometer and protocol procedures for MPJ and ankle Joint torque measurement with precise and reliable foot alignment, angular joint speed and displacement control. Within-day and between-day test-retest experiments on MPJ and ankle joint torque measurement were conducted on ten and nine healthy male subjects respectively. The mean peak torques of MPJ and ankle joint of between-day and within-day measurement were 1.50±0.38Nm/deg and 1.19±0.34Nm/deg. The corresponding torques of the ankle joint were 8.24±2.20Nm/deg and 7.90±3.18Nm/deg respectively. Intraclass-correlation coefficients (ICC) of averaged peak torque of both joints of between-day and within-day test-retest experiments were ranging from 0.91 to 0.96, indicating the innovative device is systematic and reliable for the measurements and can be used for multiple scientific and clinical purposes.

  8. Room-temperature treatments for all-inorganic nanocrystal solar cell devices

    Energy Technology Data Exchange (ETDEWEB)

    Loiudice, Anna, E-mail: anna.loiudice@iit.it [Dipartimento di Matematica e Fisica " E. De Giorgi" , Università del Salento, via Arnesano, 73100 Lecce (Italy); CBN — Center for Biomolecular Nanotechnologies, Italian Institute of Technology, Energy Platform, Via Barsanti sn, 73010 Arnesano (Lecce) (Italy); Rizzo, Aurora [CBN — Center for Biomolecular Nanotechnologies, Italian Institute of Technology, Energy Platform, Via Barsanti sn, 73010 Arnesano (Lecce) (Italy); NNL CNR-Istituto Nanoscienze, c/o Distretto Tecnologico, via per Arnesano km. 5, 73100 Lecce (Italy); Corricelli, Michela [Istituto per i Processi Chimico Fisici (IPCF-CNR) Bari, c/o Department of Chemistry, University of Bari, Via Orabona 4, I-70126 Bari (Italy); Department of Chemistry, University of Bari, Via Orabona 4, I-70126 Bari (Italy); Curri, M. Lucia [Istituto per i Processi Chimico Fisici (IPCF-CNR) Bari, c/o Department of Chemistry, University of Bari, Via Orabona 4, I-70126 Bari (Italy); Belviso, Maria R. [NNL CNR-Istituto Nanoscienze, c/o Distretto Tecnologico, via per Arnesano km. 5, 73100 Lecce (Italy); Cozzoli, P. Davide [Dipartimento di Matematica e Fisica " E. De Giorgi" , Università del Salento, via Arnesano, 73100 Lecce (Italy); NNL CNR-Istituto Nanoscienze, c/o Distretto Tecnologico, via per Arnesano km. 5, 73100 Lecce (Italy); Grancini, Giulia; Petrozza, Annamaria [Center for Nano Science and Technology at PoliMi, Istituto Italiano di Tecnologia, Via Pascoli 70/3, 20133 Milano (Italy); Gigli, Giuseppe [Dipartimento di Matematica e Fisica " E. De Giorgi" , Università del Salento, via Arnesano, 73100 Lecce (Italy); CBN — Center for Biomolecular Nanotechnologies, Italian Institute of Technology, Energy Platform, Via Barsanti sn, 73010 Arnesano (Lecce) (Italy); NNL CNR-Istituto Nanoscienze, c/o Distretto Tecnologico, via per Arnesano km. 5, 73100 Lecce (Italy)

    2014-06-02

    We have developed a room-temperature solution processing approach to integrate colloidal anatase titanium dioxide nanorods (TiO{sub 2} NRs) and lead sulfide quantum dots (PbS QDs) into a heterostructured p-n junction device. To this aim we have exploited a post-deposition treatment to remove surface-adsorbed ligands by means of UV-light-irradiation of TiO{sub 2} NRs and a dilute acid treatment of PbS QDs. Here we report a systematic study on the optimization of the post-deposition treatments and device fabrication. Our approach is fully compatible with plastic device technology and is potentially useful for the integration of crystalline TiO{sub 2} as active component into disparate solar cell architectures and organic optoelectronic devices. - Highlights: • Colloidal nanocrystals offer path to low-cost manufacturing atop flexible substrates. • We fabricate an all-inorganic solar cell under room temperature treatments. • Our approach is fully compatible with plastic device technology. • It is useful for the integration of nanocrystals into disparate device architectures.

  9. Accuracy of a new wrist cuff oscillometric blood pressure device: comparisons with intraarterial and mercury manometer measurements.

    Science.gov (United States)

    Watson, S; Wenzel, R R; di Matteo, C; Meier, B; Lüscher, T F

    1998-12-01

    Accurate measurement of arterial blood pressure is of great importance for the diagnosis and treatment of hypertension. Because of the chronic nature of antihypertensive drug therapy, the involvement of the patient in blood pressure control is desirable. Such an involvement, however, is only feasible if simple, user-friendly, and precise blood pressure measurement devices are available. In this study we tested a new wrist cuff oscillometric blood pressure measurement device in 100 consecutive patients undergoing cardiac catheterization. Blood pressures were simultaneously taken intraarterially (axillary artery) and with a mercury manometer and stethoscope or noninvasive measurement device (OMRON R3). Intraarterial measurements were directly compared with two measurements taken in random order with either an arm cuff mercury manometer or the wrist cuff device. Systolic and diastolic blood pressure as assessed with the mercury manometer was higher, especially when compared with the intraarterial and the wrist cuff values, which were comparable. Correlations of blood pressure values with intraarterial measurement were 0.86 systolic and 0.75 diastolic (P mercury manometer measurements. Reproducibility of both measurements was good for the wrist cuff device ([systolic/diastolic]: r = 0.94/0.92; P mercury manometer (r = 0.97/0.88; P mercury manometer were higher than intraarterial values and those of the wrist cuff. Both noninvasive devices overestimated high diastolic values.

  10. An enhanced proposal on decoy-state measurement device-independent quantum key distribution

    Science.gov (United States)

    Wang, Qin; Zhang, Chun-Hui; Luo, Shunlong; Guo, Guang-Can

    2016-09-01

    By employing pulses involving three-intensity, we propose a scheme for the measurement device-independent quantum key distribution with heralded single-photon sources. We make a comparative study of this scheme with the standard three-intensity decoy-state scheme using weak coherent sources or heralded single-photon sources. The advantage of this scheme is illustrated through numerical simulations: It can approach very closely the asymptotic case of using an infinite number of decoy-states and exhibits excellent behavior in both the secure transmission distance and the final key generation rate.

  11. [A device for measuring contamination of hands in work places with open radiation sources].

    Science.gov (United States)

    Husák, V; Kleinbauer, K; Erban, J

    1989-01-01

    The device manufactured is equipped with the NaI(Tl) scintillation crystal situated in a thick lead shielding. The cavity in the lead shielding allows inserting a hand which is in contact with the detector during the measurements. The apparatus exhibits low values of the minimum detectable superficial activity of radionuclides emitting low energy gamma-rays (e.g. 125I, 99mTc). The apparatus complies with the requirements for a sensitive and prompt monitoring the contamination of hands in departments of nuclear medicine with the numerous staff.

  12. Making the decoy-state measurement-device-independent quantum key distribution practically useful

    Science.gov (United States)

    Zhou, Yi-Heng; Yu, Zong-Wen; Wang, Xiang-Bin

    2016-04-01

    The relatively low key rate seems to be the major barrier to its practical use for the decoy-state measurement-device-independent quantum key distribution (MDI-QKD). We present a four-intensity protocol for the decoy-state MDI-QKD that hugely raises the key rate, especially in the case in which the total data size is not large. Also, calculations show that our method makes it possible for secure private communication with fresh keys generated from MDI-QKD with a delay time of only a few seconds.

  13. Hydrogen Passivation of Interstitial Zn Defects in Heteroepitaxial InP Cell Structures and Influence on Device Characteristics

    Science.gov (United States)

    Ringel, S. A.; Chatterjee, B.

    2004-01-01

    Hydrogen passivation of heteroepitaxial InP solar cells is of recent interest for deactivation of dislocations and other defects caused by the cell/substrate lattice mismatch that currently limit the photovoltaic performance of these devices. In this paper we present strong evidence that, in addition to direct hydrogen-dislocation interactions, hydrogen forms complexes with the high concentration of interstitial Zn defects present within the p(+) Zn-doped emitter of MOCVD-grown heteroepitaxial InP devices, resulting in a dramatic increase of the forward bias turn-on voltage by as much as 280 mV, from 680 mV to 960 mV. This shift is reproducible and thermally reversible and no such effect is observed for either n(+)p structures or homoepitaxial p(+)n structures grown under identical conditions. A combination of photoluminescence (PL), electrochemical C-V dopant profiling, SIMS and I-V measurements were performed on a set of samples having undergone a matrix of hydrogenation and post-hydrogenation annealing conditions to investigate the source of this voltage enhancement and confirm the expected role of interstitial Zn and hydrogen. A precise correlation between all measurements is demonstrated which indicates that Zn interstitials within the p(+) emitter and their interaction with hydrogen are indeed responsible for this device behavior.

  14. Characterization of size-dependent mechanical properties of tip-growing cells using a lab-on-chip device.

    Science.gov (United States)

    Hu, Chengzhi; Munglani, Gautam; Vogler, Hannes; Ndinyanka Fabrice, Tohnyui; Shamsudhin, Naveen; Wittel, Falk K; Ringli, Christoph; Grossniklaus, Ueli; Herrmann, Hans J; Nelson, Bradley J

    2016-12-20

    Quantification of mechanical properties of tissues, living cells, and cellular components is crucial for the modeling of plant developmental processes such as mechanotransduction. Pollen tubes are tip-growing cells that provide an ideal system to study the mechanical properties at the single cell level. In this article, a lab-on-a-chip (LOC) device is developed to quantitatively measure the biomechanical properties of lily (Lilium longiflorum) pollen tubes. A single pollen tube is fixed inside the microfluidic chip at a specific orientation and subjected to compression by a soft membrane. By comparing the deformation of the pollen tube at a given external load (compressibility) and the effect of turgor pressure on the tube diameter (stretch ratio) with finite element modeling, its mechanical properties are determined. The turgor pressure and wall stiffness of the pollen tubes are found to decrease considerably with increasing initial diameter of the pollen tubes. This observation supports the hypothesis that tip-growth is regulated by a delicate balance between turgor pressure and wall stiffness. The LOC device is modular and adaptable to a variety of cells that exhibit tip-growth, allowing for the straightforward measurement of mechanical properties.

  15. Development of measuring device for inner surfaces of embedded piping (Contract research)

    CERN Document Server

    Itoh, H; Tachibana, M; Yanagihara, S

    2003-01-01

    The measuring device for inner surfaces of embedded piping (MISE) was developed to evaluate low-level radiological contaminations of inner surfaces of piping. The MISE consists of a cylindrically-formed double layered type detector and a piping crawling robot, which were designed and manufactured separately. In measurements of the contaminations, an outer cylindrical detector close to the surface of piping measures beta-rays and gamma-rays and an inner cylindrical detector set after a shielding plate for shield of beta-rays measures gamma-rays. The beta-ray counting rates are derived by subtracting gamma-ray counts measured by the inner detector from gamma- and beta-ray counts measured by the outer detector. The piping crawling robot transports the cylindrically-formed double layered type detector with observing inner surfaces of piping. The detection limit for the contamination of sup 6 sup 0 Co was found to be about 0.17 Bq/cm sup 2 with measurement time of 30 seconds. It is expected that 0.2 Bq/cm sup 2 co...

  16. Investigation of the nanomorphology and device performance of organic solar cells based on polymer: fullerene bulk heterojunctions

    Energy Technology Data Exchange (ETDEWEB)

    Madena, Thomas; Wischnath, Uli; Kittel, Achim; Parisi, Juergen; Riedel, Ingo [Energy- and Semiconductor Research Laboratory, Department of Physics, University of Oldenburg (Germany)

    2009-07-01

    The coherences between structural layout of P3HT:PCBM bulk heterojunction (BHJ) solar cells and the electrical properties are not fully understood so far. The morphology of such BHJ-thin films determines the efficiency balance between separation of electron hole pairs at the phase boundary of PCBM and P3HT and the charge transport along continuous paths in the pure materials. The optimization of both fundamental mechanisms is a challenge and plays a crucial role for the efficiency of the photovoltaic device. In this presentation we investigate the interplay of nanomorphology and device properties of P3HT: PCBM solar cells. AFM measurements were carried out to profile the nanomorphology of differently composed polymer: fullerene composite films. In these films we observed substantial growth of micron-sized crystallites in the PCBM moiety upon thermal annealing which severely limits the device performance. Based on these studies we discuss the influence of the nanomorphology of different thin film formulations on the electrical characteristics of P3HT:PCBM solar cells.

  17. Compact modeling of CRS devices based on ECM cells for memory, logic and neuromorphic applications

    Science.gov (United States)

    Linn, E.; Menzel, S.; Ferch, S.; Waser, R.

    2013-09-01

    Dynamic physics-based models of resistive switching devices are of great interest for the realization of complex circuits required for memory, logic and neuromorphic applications. Here, we apply such a model of an electrochemical metallization (ECM) cell to complementary resistive switches (CRSs), which are favorable devices to realize ultra-dense passive crossbar arrays. Since a CRS consists of two resistive switching devices, it is straightforward to apply the dynamic ECM model for CRS simulation with MATLAB and SPICE, enabling study of the device behavior in terms of sweep rate and series resistance variations. Furthermore, typical memory access operations as well as basic implication logic operations can be analyzed, revealing requirements for proper spike and level read operations. This basic understanding facilitates applications of massively parallel computing paradigms required for neuromorphic applications.

  18. Enhancement of device performance of organic solar cells by an interfacial perylene derivative layer

    KAUST Repository

    Kim, Inho

    2010-05-26

    We report that device performance of organic solar cells consisting of zinc phthalocyanine and fullerene (C60) can be enhanced by insertion of a perylene derivative interfacial layer between fullerene and bathocuproine (BCP) exciton blocking layer (EBL). The morphology of the BCP is influenced by the underlying N,N′-dihexyl-perylene-3,4,9,10-bis(dicarboximide) (PTCDI-C6), which promotes migration of the cathode metal into the BCP layer. Insertion of a PTCDI-C6 layer between fullerene and BCP layers enhances the power conversion efficiency to 2.5%, an improvement of 32% over devices without PTCDI-C6 layer. The enhancement in device performance by insertion of PTCDI-C6 is attributed to a reduction in series resistance due to promoted metal migration into BCP and optimized optical interference effects in multilayered devices. © 2010 American Chemical Society.

  19. Optically transparent polymer devices for in situ assessment of cell electroporation.

    Science.gov (United States)

    Majhi, Amit Kumar; Thrivikraman, Greeshma; Basu, Bikramjit; Venkataraman, V

    2015-02-01

    In order to study cell electroporation in situ, polymer devices have been fabricated from poly-dimethyl siloxane with transparent indium tin oxide parallel plate electrodes in horizontal geometry. This geometry with cells located on a single focal plane at the interface of the bottom electrode allows a longer observation time in both transmitted bright-field and reflected fluorescence microscopy modes. Using propidium iodide (PI) as a marker dye, the number of electroporated cells in a typical culture volume of 10-100 μl was quantified in situ as a function of applied voltage from 10 to 90 V in a series of ~2-ms pulses across 0.5-mm electrode spacing. The electric field at the interface and device current was calculated using a model that takes into account bulk screening of the transient pulse. The voltage dependence of the number of electroporated cells could be explained using a stochastic model for the electroporation kinetics, and the free energy for pore formation was found to be 45.6 ± 0.5 kT at room temperature. With this device, the optimum electroporation conditions can be quickly determined by monitoring the uptake of PI marker dye in situ under the application of millisecond voltage pulses. The electroporation efficiency was also quantified using an ex situ fluorescence-assisted cell sorter, and the morphology of cultured cells was evaluated after the pulsing experiment. Importantly, the efficacy of the developed device was tested independently using two cell lines (C2C12 mouse myoblast cells and yeast cells) as well as in three different electroporation buffers (phosphate buffer saline, electroporation buffer and 10% glycerol).

  20. A system for measuring an optical spectral response and/or IV data of a photoelectric device under test

    NARCIS (Netherlands)

    Elshinawy, M.; Heirman, S.G.M.; Melsken, J.; Fischer, M.

    2015-01-01

    A system for measuring an optical spectral response or property and/or IV data of a device or object under test (9), comprising in optically coupled sequence: a broadband light source (1) for emitting light of a prede- fined spectrum, a slit and/or light guide (2), a wavelength dispersive device (3)

  1. Fluorescent sensors for the basic metabolic panel enable measurement with a smart phone device over the physiological range.

    Science.gov (United States)

    Awqatty, Becker; Samaddar, Shayak; Cash, Kevin J; Clark, Heather A; Dubach, J Matthew

    2014-10-21

    The advanced functionality of portable devices such as smart phones provides the necessary hardware to potentially perform complex diagnostic measurements in any setting. Recent research and development have utilized cameras and data acquisition properties of smart phones to create diagnostic approaches for a variety of diseases or pollutants. However, in concentration measurements, such as blood glucose, the performance of handheld diagnostic devices depends largely on the sensing mechanism. To expand measurements to multiple components, often necessary in medical tests, with a single diagnostic device, robust platform based sensors are needed. Here, we developed a suite of dual wavelength fluorescent sensors with response characteristics necessary to measure each component of a basic metabolic panel, a common clinical measurement. Furthermore, the response of these sensors could be measured with a simple optical setup to convert a smart phone into a fluorescence measurement instrument. This approach could be used as a mobile basic metabolic panel measurement system for point of care diagnostics.

  2. Device modeling of perovskite solar cells based on structural similarity with thin film inorganic semiconductor solar cells

    Science.gov (United States)

    Minemoto, Takashi; Murata, Masashi

    2014-08-01

    Device modeling of CH3NH3PbI3-xCl3 perovskite-based solar cells was performed. The perovskite solar cells employ a similar structure with inorganic semiconductor solar cells, such as Cu(In,Ga)Se2, and the exciton in the perovskite is Wannier-type. We, therefore, applied one-dimensional device simulator widely used in the Cu(In,Ga)Se2 solar cells. A high open-circuit voltage of 1.0 V reported experimentally was successfully reproduced in the simulation, and also other solar cell parameters well consistent with real devices were obtained. In addition, the effect of carrier diffusion length of the absorber and interface defect densities at front and back sides and the optimum thickness of the absorber were analyzed. The results revealed that the diffusion length experimentally reported is long enough for high efficiency, and the defect density at the front interface is critical for high efficiency. Also, the optimum absorber thickness well consistent with the thickness range of real devices was derived.

  3. Tunable Microfluidic Devices for Hydrodynamic Fractionation of Cells and Beads: A Review

    Directory of Open Access Journals (Sweden)

    Jafar Alvankarian

    2015-11-01

    Full Text Available The adjustable microfluidic devices that have been developed for hydrodynamic-based fractionation of beads and cells are important for fast performance tunability through interaction of mechanical properties of particles in fluid flow and mechanically flexible microstructures. In this review, the research works reported on fabrication and testing of the tunable elastomeric microfluidic devices for applications such as separation, filtration, isolation, and trapping of single or bulk of microbeads or cells are discussed. Such microfluidic systems for rapid performance alteration are classified in two groups of bulk deformation of microdevices using external mechanical forces, and local deformation of microstructures using flexible membrane by pneumatic pressure. The main advantage of membrane-based tunable systems has been addressed to be the high capability of integration with other microdevice components. The stretchable devices based on bulk deformation of microstructures have in common advantage of simplicity in design and fabrication process.

  4. Characterisation of a micro-plasma device sensor using electrical measurements and emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Mariotti, D

    2002-04-01

    This thesis reports on research undertaken on the characterisation of a micro-plasma device to be used for gas analysis by mean of plasma emission spectroscopy. The work covers aspects related to the micro-plasma electrical and optical emission parameters, and their importance for the utilisation of the micro-plasma device in gas analysis. Experimental results have been used to analyse the fundamental micro-plasma processes and to develop a model, which could provide additional information. This dissertation contains a general literature review of topics related to plasma physics, plasma emission spectroscopy, gas analysis (chemical analysis and artificial olfaction) and other micro-plasma applications. Experimental work focuses on two main areas: electrical measurements and emission measurements. Firstly, electrical measurements are taken and interpretations are given. Where necessary, new theoretical treatments are suggested in order to describe better the physical phenomena. Plasma emission has been considered under different working conditions. This allowed the characterisation of the micro-plasma emission and also a better understanding of the micro-plasma processes. On the basis of the experimental data obtained and other assumptions a model has been developed. A computer simulation based on this model provided additional useful information on the micro- plasma behaviour. The first fundamental implication of this new research is the peculiar behaviour of the micro-plasma. This micro-plasma exhibited deviations from Paschen law and strong dependency on cathode material, which contributed to the formation of a low current stable regime. These results have been followed by physical interpretations and theoretical descriptions. The second implication is the establishment of the boundaries and of the influencing parameters for plasma emission spectroscopy as an analytical tool in this particular micro-plasma. From the applied perspective this study has shown that

  5. Modulating chemotaxis of lung cancer cells by using electric fields in a microfluidic device.

    Science.gov (United States)

    Kao, Yu-Chiu; Hsieh, Meng-Hua; Liu, Chung-Chun; Pan, Huei-Jyuan; Liao, Wei-Yu; Cheng, Ji-Yen; Kuo, Po-Ling; Lee, Chau-Hwang

    2014-03-01

    We employed direct-current electric fields (dcEFs) to modulate the chemotaxis of lung cancer cells in a microfluidic cell culture device that incorporates both stable concentration gradients and dcEFs. We found that the chemotaxis induced by a 0.5 μM/mm concentration gradient of epidermal growth factor can be nearly compensated by a 360 mV/mm dcEF. When the effect of chemical stimulation was balanced by the electrical drive, the cells migrated randomly, and the path lengths were largely reduced. We also demonstrated electrically modulated chemotaxis of two types of lung cancer cells with opposite directions of electrotaxis in this device.

  6. Characterization of Microfluidic Devices by Measurements with μ-PIV and CLSM

    Science.gov (United States)

    Schlter, Michael; Hoffmann, Marko; Rbiger, Norbert

    Microfluidic devices are successfully in use for several applications in chemical engineering and biotechnology. Nevertheless, there is still no breakthrough for microprocess engineering because of a huge lack in understanding of the mechanisms on microscales for momentum transfer, hydrodynamics and mass transfer. Some important questions concern the design of a junction to reach acceptable mixing qualities with minimum pressure drop and narrow residence time distribution even under laminar flow conditions. The micro-particle image velocimetry (μ-PIV) in conjunction with confocal laser scanning microscopy (CLSM) have been used for the characterization of momentum and mass transfer at the Institute of Environmental Process Engineering to evaluate microfluidic devices. The calculation of three-dimensional flow and concentration fields is possible with two-dimensional measurement data for common stationary cases. Streamlines out of velocity gradients and isosurfaces out of fields of the same concentration are providing a helpful impression of the performance of microdevices based on highly reliable measurement data. A quantitative analysis of the velocity and concentration fields allows the calculation of residence-time distribution and mixing quality, which enables the adjustment of microreactor geometries for the demands of chemical, and biochemical reactions.

  7. A new portable device for automatic controlled-gradient cryopreservation of blood mononuclear cells

    DEFF Research Database (Denmark)

    Hviid, L; Albeck, G; Hansen, B

    1993-01-01

    , which has proved suitable for field conditions. We report here the development and testing of a similar micro-controller regulated device, allowing unattended and automatic controlled-gradient cell freezing. The equipment exploits the temperature gradient present between the liquid N2 surface...

  8. Digital Devices, Distraction, and Student Performance: Does In-Class Cell Phone Use Reduce Learning?

    Science.gov (United States)

    Duncan, Douglas K.; Hoekstra, Angel R.; Wilcox, Bethany R.

    2012-01-01

    The recent increase in use of digital devices such as laptop computers, iPads, and web-enabled cell phones has generated concern about how technologies affect student performance. Combining observation, survey, and interview data, this research assesses the effects of technology use on student attitudes and learning. Data were gathered in eight…

  9. Development of Platform Device in 02B Hot Cell in CRARL Facility

    Institute of Scientific and Technical Information of China (English)

    CHANG; Shang-wen; ZHU; Li-yang; LIU; Fang; LI; Gao-liang; LI; Hui-rong; GUO; Jian-hua; LUO; Fang-xiang; YAN; Tai-hong; HE; Hui; ZHENG; Wei-fang

    2015-01-01

    After examination to the former dissolving system device built in the 02Bhot cell in CRARL facility,there are some trouble including:1)The crowded space lead to the invalidated operation for the valves and fast connectors by the manipulator and the absence of partial equipment.2)In case of plugging up,the experiment would be

  10. Washing of stored red blood cells by an autotransfusion device before transfusion

    NARCIS (Netherlands)

    de Vroege, R.; Wildevuur, W. R.; Muradin, J. A. G.; Graves, D.; van Oeveren, W.

    2007-01-01

    Background and Objectives The use of an autotransfusion device to wash blood of the incision site is increasing. After washing, this blood is retransfused without side effects caused by activated plasma factors and cell release products. This procedure could be extended to washing of donor blood, wh

  11. Device model for the operation of polymer/fullerene bulk heterojunction solar cells

    NARCIS (Netherlands)

    Koster, LJA; Smits, ECP; Mihailetchi, VD; Blom, PWM

    2005-01-01

    We have developed a numerical device model that consistently describes the current-voltage characteristics of polymer:fullerene bulk heterojunction solar cells. Bimolecular recombination and a temperature- and field-dependent generation mechanism of free charges are incorporated. It is demonstrated

  12. DANCE device for measurement of (n, {gamma}) reactions on radioactive species

    Energy Technology Data Exchange (ETDEWEB)

    Wilhelmy, J.B.; Chamberlin, E.P.; Dragowsky, M.R. [Los Alamos National Laboratory, Los Alamos, New Mexico (US)] [and others

    2002-08-01

    DANCE (Device for Advanced Neutron Capture Experiments) is a 4{pi} 162 element BaF{sub 2} array under development at Los Alamos National Laboratory. It is designed to provide high granularity, fast timing and high photon detection efficiency. It will be located at the Los Alamos Neutron Scattering Center where neutrons are produced using 800 MeV proton induced spallation reactions on heavy element production targets. Using the pulsed high neutron fluence available at this facility combined with time of flight techniques it will be possible to make neutron capture measurements in the neutron energy range from eV to 100's keV on rate and radioactive target material at the milligram and below level. These measurements will provide critically needed data for the interpretation of the astrophysical s-process 'branching point' nuclei as well as information for reactions needed in understanding transmutation processes of radioactive species. (author)

  13. DANCE : Device for Measurement of (n.g.) Reactions on radioactive Species /

    Energy Technology Data Exchange (ETDEWEB)

    Chamberlin, E. P. (Edwin P.); Dragowsky, M. (Michael); Fowler, Malcolm M.; Miller, G. G. (Geoffrey G.); Palmer, P. D. (Phillip D.); Pangualt, L. N. (Laurence N.); Rundberg, R. S. (Robert S.); Haight, Robert C.; Seabury, E. H. (Edward H.); Ullmann, J. L. (John L.); Strottman, D. D. (Daniel D.); Heil, M. (Michael); Kaeppeler, F. (Franz K.); Reifarth, R. (Rene); Wisshak, K.; Wilhelmy, J. B. (Jerry B.)

    2001-01-01

    DANCE (Device for Advanced Neutron Capture Experiments) is a 4{pi} 162 element BaF{sub 2} array under development at Los Alamos National Laboratory. It is designed to provide high granularity, fast timing and high photon detection efficiency. It will be located at the Los Alamos Neutron Scattering Center where neutrons are produced using 800 MeV proton induced spallation reactions on heavy element production targets. Using the pulsed high neutron fluence available at this facility combined with time of flight techniques it will be possible to make neutron capture measurements in the neutron energy range from eV to 100's of keV on rare and radioactive target material at the milligram and below level. These measurements will provide critically needed data for the interpretation of the astrophysical s-process 'branching point' nuclei as well as information for reactions needed in understanding transmutation processes of radioactive species.

  14. Noise analysis and measurement of time delay and integration charge coupled device

    Institute of Scientific and Technical Information of China (English)

    Wang De-Jiang; Zhang Tao

    2011-01-01

    Time delay and integration(TDI)charge coupled device(CCD)noise sets a fundamental limit on image sensor performance,especially under low illumination in remote sensing applications.After introducing the complete sources of CCD noise,we study the effects of TDI operation mode on noise,and the relationship between different types of noise and number of the TDI stage.Then we propose a new technique to identify and measure sources of TDI CCD noise employing mathematical statistics theory,where theoretical analysis shows that noise estimated formulation converges well.Finally,we establish a testing platform to carry out experiments,and a standard TDI CCD is calibrated by using the proposed method.The experimental results show that the noise analysis and measurement methods presented in this paper are useful for modeling TDI CCDs.

  15. Electron cyclotron emission measurements by means of a grating polychromator on the Large Helical Device

    Energy Technology Data Exchange (ETDEWEB)

    Vries, P.C. de; Kawahata, K.; Nagayama, Y.; Inagaki, S.; Sasao, H.; Ito, Y. [National Inst. for Fusion Science, Toki, Gifu (Japan)

    2000-03-01

    The electron cyclotron emission (ECE) spectrum at the Large Helical Device (LHD) is measured by a 14-channel grating polychromator. During standard operation the polychromator monitors 2nd harmonic frequencies (100-150 GHz) with a spectral resolution of 1.5 GHz. At sufficient high density the 2nd harmonic X-mode polarization is optically thick and can be used to determine the temperature profile. However, the large magnetic field shear in LHD affects the ECE polarization. This effect has been studied numerically. The wave polarization was found to rotate in the laboratory frame. Experiments have been carried out by means of a polarization rotator in the diagnostic waveguide system, which confirmed the calculations. By a proper setting of the polarization rotator, the rotation can be corrected and pure X-mode is detected. Temperature profiles have been measured successfully by the polychromator. (author)

  16. Poster Abstract: Automatic Calibration of Device Attitude in Inertial Measurement Unit Based Traffic Probe Vehicles

    KAUST Repository

    Mousa, Mustafa

    2016-04-28

    Probe vehicles consist in mobile traffic sensor networks that evolve with the flow of vehicles, transmitting velocity and position measurements along their path, generated using GPSs. To address the urban positioning issues of GPSs, we propose to replace them with inertial measurement units onboard vehicles, to estimate vehicle location and attitude using inertial data only. While promising, this technology requires one to carefully calibrate the orientation of the device inside the vehicle to be able to process the acceleration and rate gyro data. In this article, we propose a scheme that can perform this calibration automatically by leveraging the kinematic constraints of ground vehicles, and that can be implemented on low-end computational platforms. Preliminary testing shows that the proposed scheme enables one to accurately estimate the actual accelerations and rotation rates in the vehicle coordinates. © 2016 IEEE.

  17. Corneal Topographic and Aberrometric Measurements Obtained with a Multidiagnostic Device in Healthy Eyes: Intrasession Repeatability

    Directory of Open Access Journals (Sweden)

    David P. Piñero

    2017-01-01

    Full Text Available Purpose. To evaluate the intrasession repeatability of corneal curvature, eccentricity, and aberrometric measurements obtained with a multidiagnostic device in healthy eyes. Methods. This study enrolled 107 eyes of 107 patients ranging in age from 23 to 65 years. All of them underwent a complete anterior segment examination with the VX120 system (Visionix-Luneau Technologies, Chartres, France. Three consecutive measurements were obtained. The within-subject standard deviation (Sw, intrasubject precision (1.96×Sw, and intraclass correlation coefficient (ICC were calculated. Results. All Sw for corneal power measurements were below 0.26 D, with ICC above 0.982. The Sw for corneal astigmatism at different areas (3, 5, and 7 mm was below 0.21 D, with ICC above 0.913. Concerning the axis of astigmatism, its Sw was below 11.27°, with ICC above 0.975. The Sw and ICC for corneal eccentricity were 0.067 and 0.957, respectively. The Sw and ICC for high-order aberration root mean square (RMS were 0.048 µm and 0.901, respectively. For 3rd- and 4th-order aberrometric parameters, all Sw were below 0.037 µm and all ICC were higher than 0.84, except for quadrafoil RMS (ICC: 0.689. Conclusions. The multidiagnostic device evaluated is able to provide consistent measurements of corneal power, eccentricity, and third- and fourth-order aberrations in healthy eyes.

  18. Out-of-focus effects on microscale schlieren measurements of mass transport in a microfluidic device

    Science.gov (United States)

    Chen, Shao-Tuan; Sun, Chen-li

    2016-08-01

    The microscale schlieren technique provides a means for a non-invasive, full-field measurement for mixing microfluidics with excellent sensitivity and resolution. Nevertheless, an out-of-focus effect due to microscopic optics may lead to undesirable errors in quantifying the gradient information at high degrees of magnification. If the channel in the microfluidic device under study is too deep, light deflection caused by inhomogeneity located far from the focal plane may contributes little to the intensity change on the image plane. To address this issue, we propose the use of a weighting function that approximates a Gaussian profile with an optical-system-dependable width. We assume that the resultant intensity change is proportional to a weighted sum of the gradient across the channel depth and acquire micro-schlieren images of fluid mixing in a T-junction microchannel at various positions along the optical axis. For each objective, the width of the weighting function is then determined iteratively by curve fitting the ratio of changes in grayscale readouts for out-of-focus and focus micro-schlieren images. The standard deviation in the Gaussian distribution facilitates the quantification of the out-of-focus effect. In addition, we measure the sensitivities of a microscale schlieren system equipped with different objectives and compare the values to the model. Despite its better resolution, we find that an objective with higher magnification suffers from a more severe out-of-focus effect and a loss of sensitivity. Equations are proposed for estimations of the standard deviation and the sensitivity of microscale schlieren measurements. The outcome will facilitate the selection of proper microchannel depths for various microscale schlieren systems or vice versa, thus improving the precision of micro-schlieren measurements in microfluidic devices.

  19. Comparison of sound speed measurements on two different ultrasound tomography devices

    Science.gov (United States)

    Sak, Mark; Duric, Neb; Littrup, Peter; Bey-Knight, Lisa; Sherman, Mark; Gierach, Gretchen; Malyarenko, Antonina

    2014-03-01

    Ultrasound tomography (UST) employs sound waves to produce three-dimensional images of breast tissue and precisely measures the attenuation of sound speed secondary to breast tissue composition. High breast density is a strong breast cancer risk factor and sound speed is directly proportional to breast density. UST provides a quantitative measure of breast density based on three-dimensional imaging without compression, thereby overcoming the shortcomings of many other imaging modalities. The quantitative nature of the UST breast density measures are tied to an external standard, so sound speed measurement in breast tissue should be independent of specific hardware. The work presented here compares breast sound speed measurement obtained with two different UST devices. The Computerized Ultrasound Risk Evaluation (CURE) system located at the Karmanos Cancer Institute in Detroit, Michigan was recently replaced with the SoftVue ultrasound tomographic device. Ongoing clinical trials have used images generated from both sets of hardware, so maintaining consistency in sound speed measurements is important. During an overlap period when both systems were in the same exam room, a total of 12 patients had one or both of their breasts imaged on both systems on the same day. There were 22 sound speed scans analyzed from each system and the average breast sound speeds were compared. Images were either reconstructed using saved raw data (for both CURE and SoftVue) or were created during the image acquisition (saved in DICOM format for SoftVue scans only). The sound speed measurements from each system were strongly and positively correlated with each other. The average difference in sound speed between the two sets of data was on the order of 1-2 m/s and this result was not statistically significant. The only sets of images that showed a statistical difference were the DICOM images created during the SoftVue scan compared to the SoftVue images reconstructed from the raw data

  20. Ultrasonic device for real-time sewage velocity and suspended particles concentration measurements.

    Science.gov (United States)

    Abda, F; Azbaid, A; Ensminger, D; Fischer, S; François, P; Schmitt, P; Pallarès, A

    2009-01-01

    In the frame of a technological research and innovation network in water and environment technologies (RITEAU, Réseau de Recherche et d'Innovation Technologique Eau et Environnement), our research group, in collaboration with industrial partners and other research institutions, has been in charge of the development of a suitable flowmeter: an ultrasonic device measuring simultaneously the water flow and the concentration of size classes of suspended particles. Working on the pulsed ultrasound principle, our multi-frequency device (1 to 14 MHz) allows flow velocity and water height measurement and estimation of suspended solids concentration. Velocity measurements rely on the coherent Doppler principle. A self developed frequency estimator, so called Spectral Identification method, was used and compared to the classical Pulse-Pair method. Several measurements campaigns on one wastewater collector of the French city of Strasbourg gave very satisfactory results and showed smaller standard deviation values for the Doppler frequency extracted by the Spectral Identification method. A specific algorithm was also developed for the water height measurements. It relies on the water surface acoustic impedance rupture and its peak localisation and behaviour in the collected backscattering data. This algorithm was positively tested on long time measurements on the same wastewater collector. A large part of the article is devoted to the measurements of the suspended solids concentrations. Our data analysis consists in the adaptation of the well described acoustic behaviour of sand to the behaviour of wastewater particles. Both acoustic attenuation and acoustic backscattering data over multiple frequencies are analyzed for the extrapolation of size classes and respective concentrations. Under dry weather conditions, the massic backscattering coefficient and the overall size distribution showed similar evolution whatever the measurement site was and were suggesting a global

  1. A flexible microprocessor system for the measurement of cell size.

    Science.gov (United States)

    Round, J M; Jones, D A; Edwards, R H

    1982-06-01

    A flexible system for the measurement of length and area is described. The system consists of the Reichert Jung MOP-1 area measuring device interfaced with a Commodore PET computer. Its use is illustrated by the planimetric measurement of cross sectional areas in histochemical preparations of normal and diseased muscle. While measurements are being made data can be displayed on the computer screen either in numerical form or as a frequency histogram together with simple statistical analyses. Hard copy can be obtained from an attached printer. Mean values for fibre area in normal human skeletal muscle are reported. An alternative, widely used method of calculating fibre area from the lesser diameter was found to give a consistent underestimate of approximately 30% when compared with our planimetric method. In diseased muscle with abnormally shaped fibres the discrepancy is even larger; such fibres can be identified using a "form factor" which relates the area of a cell to its perimeter. This rapid, accurate and flexible system is also suitable for the measurement of many different types of graphical record.

  2. Power loss measurement of implantable wireless power transfer components using a Peltier device balance calorimeter

    Science.gov (United States)

    Leung, Ho Yan; Budgett, David M.; Taberner, Andrew; Hu, Patrick

    2014-09-01

    Determining heat losses in power transfer components operating at high frequencies for implantable inductive power transfer systems is important for assessing whether the heat dissipated by the component is acceptable for implantation and medical use. However, this is a challenge at high frequencies and voltages due to limitations in electronic instrumentation. Calorimetric methods of power measurement are immune to the effects of high frequencies and voltages; hence, the measurement is independent of the electrical characteristics of the system. Calorimeters have been widely used to measure the losses of high power electrical components (>50 W), however it is more difficult to perform on low power components. This paper presents a novel power measurement method for components dissipating anywhere between 0.2 W and 1 W of power based on a heat balance calorimeter that uses a Peltier device as a balance sensor. The proposed balance calorimeter has a single test accuracy of ±0.042 W. The experimental results revealed that there was up to 35% difference between the power measurements obtained with electrical methods and the proposed calorimeter.

  3. Charge-coupled device spectrograph for direct solar irradiance and sky radiance measurements.

    Science.gov (United States)

    Kouremeti, Natalia; Bais, Alkiviadis; Kazadzis, Stelios; Blumthaler, Mario; Schmitt, Rainer

    2008-04-01

    The characterization of a charged-coupled device (CCD) spectrograph developed at the Laboratory of Atmospheric Physics, Thessaloniki is presented. The absolute sensitivity of the instrument for direct irradiance and sky radiance measurements was determined, respectively, with an uncertainty of 4.4% and 6.6% in the UV-B, and 3% and 6% in the UV-A, visible and near-infrared (NIR) wavelength ranges. The overall uncertainty associated with the direct irradiance and the sky radiance measurements is, respectively, of the order of 5% and 7% in the UV-B, increasing to 10% for low signals [e.g., at solar zenith angles (SZAs) larger than 70 degrees ], and 4% and 6% in the UV-A, visible, and NIR. Direct solar spectral irradiance measurements from an independently calibrated spectroradiometer (Bentham DTM 300) were compared with the corresponding CCD measurements. Their agreement in the wavelength range of 310-500nm is within 0.5% +/- 1.1% (for SZA between 20 degrees and 70 degrees ). Aerosol optical depth (AOD) derived by the two instruments using direct Sun spectra and by a collocated Cimel sunphotometer [Aerosol Robotic network (AERONET)] agree to within 0.02 +/- 0.02 in the range of 315-870 nm. Significant correlation coefficients with a maximum of 0.99 in the range of 340-360 nm and a minimum of 0.90 at 870 nm were found between synchronous AOD measurements with the Bentham and the Cimel instruments.

  4. Simple field device for measurement of dimethyl sulfide and dimethylsulfoniopropionate in natural waters, based on vapor generation and chemiluminescence detection.

    Science.gov (United States)

    Nagahata, Takanori; Kajiwara, Hidetaka; Ohira, Shin-Ichi; Toda, Kei

    2013-05-07

    A small, simple device was developed for trace analysis of dimethyl sulfide (DMS) and dimethylsulfoniopropionate (DMSP) in natural waters. These compounds are known to be the major sources of cloud condensation nuclei in the oceanic atmosphere and ideally should be measured onsite because of their volatility and instability. First, chemical and physical vapor generations were examined, and simple pressurizing by injection of 30 mL of air using a syringe was adopted. Pressurized headspace air above a 10 mL water sample was introduced to a detection cell as a result of the pressure differential and mixed with ozone to induce chemiluminescence. Although the measurement procedure was simple, the method was very sensitive: sharp peaks appeared within seconds for nanomolar levels of DMS, and the limit of detection was 0.02 nmol L(-1) (1 ng L(-1)). Although interference from methanethiol was significant, this was successfully addressed by adding a small amount of Cd(2+) before DMS vapor generation. DMSP was also measured after hydrolysis to DMS, as previously reported. Pond water and seawater samples were analyzed, and DMS was found in both types of sample, whereas DMSP was observed only in seawater. The DMS/DMSP data obtained using the developed method were compared with data obtained by purge/trap and gas chromatography-mass spectrometry, and the data from the two methods agreed, with good correlation (R(2) = 0.9956). The developed device is inexpensive, light (5 kg), simple to use, can be applied in the field, and is sensitive enough for fresh- and seawater analysis.

  5. Small and useful. A comparative evaluation of hand radiation measurement devices; Klein und nuetzlich. Handeinstrahlungsmessgeraete im Vergleich

    Energy Technology Data Exchange (ETDEWEB)

    Weinreich, Bernhard

    2009-05-15

    They exist at least as long as the photovoltaic industry itself, however they are not spread too much - we talk about hand radiation measurement devices. These devices originally come from the field of meteorology. Even though they measure the most important magnitude in the field of photovoltaics at all, namely the global radiation, the eke out a wretched existence. Hence it's about high time to draw the attention to these helpers. (orig.)

  6. A passive-flow microfluidic device for imaging latent HIV activation dynamics in single T cells.

    Science.gov (United States)

    Ramji, Ramesh; Wong, Victor C; Chavali, Arvind K; Gearhart, Larisa M; Miller-Jensen, Kathryn

    2015-09-01

    Quantifying cell-to-cell variability in drug response dynamics is important when evaluating therapeutic efficacy. For example, optimizing latency reversing agents (LRAs) for use in a clinical "activate-and-kill" strategy to purge the latent HIV reservoir in patients requires minimizing heterogeneous viral activation dynamics. To evaluate how heterogeneity in latent HIV activation varies across a range of LRAs, we tracked drug-induced response dynamics in single cells via live-cell imaging using a latent HIV-GFP reporter virus in a clonal Jurkat T cell line. To enable these studies in suspension cells, we designed a simple method to capture an array of single Jurkat T cells using a passive-flow microfluidic device. Our device, which does not require external pumps or tubing, can trap hundreds of cells within minutes with a high retention rate over 12 hours of imaging. Using this device, we quantified heterogeneity in viral activation stimulated by transcription factor (TF) activators and histone deacetylase (HDAC) inhibitors. Generally, TF activators resulted in both faster onset of viral activation and faster rates of production, while HDAC inhibitors resulted in more uniform onset times, but more heterogeneous rates of production. Finally, we demonstrated that while onset time of viral gene expression and rate of viral production together predict total HIV activation, rate and onset time were not correlated within the same individual cell, suggesting that these features are regulated independently. Overall, our results reveal drug-specific patterns of noisy HIV activation dynamics not previously identified in static single-cell assays, which may require consideration for the most effective activate-and-kill regime.

  7. MELIFT - A new device for accurate measurements in a snow rich environment

    Science.gov (United States)

    Dorninger, M.

    2012-04-01

    A deep snow pack, remote locations, no external power supply and very low temperatures are often the main ingredients when it comes to the deployment of meteorological stations in mountainous terrain. The accurate position of the sensor related to the snow surface is normally not known. A new device called METLIFT overcomes the problems. WMO recommends a height between 1.2 m and 2 m above ground level for the measurement of air temperature and humidity. The height above ground level is specified to take care of the possible strong vertical temperature and humidity gradients at the lowest layers in the atmosphere. Especially in snow rich and remote locations it may be hardly possible to follow this advice. Therefore most of the meteorological stations in mountainous terrain are situated at mountain tops where strong winds will blow off the snow or in valleys where a daily inspection of the sensors is possible. In other unpopulated mountainous areas, e.g. basins, plateaus, the distance of the sensor to the snow surface is not known or the sensor will be snow-covered. A new device was developed to guarantee the sensor height above surface within the WMO limits in harsh and remote environments. An ultrasonic snow height sensor measures the distance to the snow surface. If it exceeds certain limits due to snow accumulation or snow melt the lift adapts its height accordingly. The prototype of METLIFT has been installed in Lower Austria at an altitude of 1000m. The lift is 6 m high and can pull out for another 4 m. Sensor arms are mounted every meter to allow the connection of additional sensors or to measure a profile of a certain parameter of the lowest 5 m above surface. Sensors can be added easily since cable wiring is provided to each sensor arm. Horizontal winds are measured at 7 m height above surface. METLIFT is independent of external power supply. Three lead gel accumulators recharged by three solar panels provide the energy necessary for the sensors, the data

  8. High-performance inverted polymer solar cells: device characterization, optical modeling, and hole-transporting modifications

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Jingyu; Yip, Hin-Lap; Zhang, Yong; Chien, Shang-Chieh; Chueh, Chu-Chen [Department of Materials Science and Engineering, University of Washington, Seattle, Washington (United States); Gao, Yan; Chen, Hongzheng [Department of Materials Science and Engineering, University of Washington, Seattle, Washington (United States); State Key Laboratory of Silicon Materials, MOE Key Laboratory of Macromolecule Synthesis and Functionalization, Zhejiang-California International Nanosystems Institute, Zhejiang University, Hangzhou (China); O' Malley, Kevin; Jen, Alex K.Y. [Department of Materials Science and Engineering, University of Washington, Seattle, Washington (United States); Department of Chemistry, University of Washington, Seattle, WA (United States)

    2012-07-10

    Although high power conversion efficiencies (PCE) have already been demonstrated in conventional structure polymer solar cells (PSCs), the development of high performance inverted structure polymer solar cells is still lagging behind despite their demonstrated superior stability and feasibility for roll-to-roll processing. To address this challenge, a detailed study of solution-processed, inverted-structure PSCs based on the blends of a low bandgap polymer, poly(indacenodithiophene-co-phananthrene-quinoxaline) (PIDT-PhanQ) and [6,6]-phenyl-C{sub 71}-butyric acid methyl ester (PC{sub 71}BM) as the bulk heterojunction (BHJ) layer is carried out. Comprehensive characterization and optical modeling of the resulting devices is performed to understand the effect of device geometry on photovoltaic performance. Excellent device performance can be achieved by optimizing the optical field distribution and spatial profiles of excitons generation within the active layer in different device configurations. In the inverted structure, because the peak of the excitons generation is located farther away from the electron-collecting electrode, a higher blending ratio of fullerene is required to provide higher electron mobility in the BHJ for achieving good device performance. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Simultaneous optical losses and current measurements in photovoltaic devices at variable angle of the incident light

    Energy Technology Data Exchange (ETDEWEB)

    Maddalena, P.; Tortora, P. [Universita di Napoli ' Frederico II' , Napoli (Italy). INFM, Dipartimento di Scienze Fisiche; Parretta, A. [Centro Ricerche ENEA, Portici (Italy); Altermatt, P.; Zhao, J. [University of New South Wales, Sydney (Australia). Photovoltaic Special Research Centre

    2003-02-01

    In this work, the apparatus and the method for a simultaneous measurement of the optical losses and short-circuit current in a solar cell, at variable incidence angle of the light, is presented. The method has been applied to an n{sup +}/p c-Si cell with a polished surface. The investigation has been performed over an angular range from 8{sup o} to 80{sup o}, using a linearly polarized laser beam, either normally or parallelly polarized with respect to the incidence plane. The experimental curves of reflectance seem to be in a good agreement with the theoretical ones derived from the Fresnel equations. Since the measurements are performed inside an integrating sphere, a procedure has been developed to derive, from the total current I{sup tot}, the calculated direct one, I{sub dirCal} excluding contributions from the incoming light back-diffused to the cell under investigation; the results are compared with real direct-current measurement. Since with the proposed method both reflectance and current are measured for the same surface region and under identical illumination conditions, the results have been combined to get the internal spectral response of the n{sup +}/p c-Si polished surface solar cell. (author)

  10. Dynamic Diamond Anvil Cell (dDAC): A novel device for studying the dynamic-pressure properties of materials

    Energy Technology Data Exchange (ETDEWEB)

    Evans, W J; Yoo, C; Lee, G W; Cynn, H; Lipp, M J; Visbeck, K

    2007-02-23

    We have developed a unique device, a dynamic diamond anvil cell (dDAC), which repetitively applies a time-dependent load/pressure profile to a sample. This capability allows studies of the kinetics of phase transitions and metastable phases at compression (strain) rates of up to 500 GPa/sec ({approx}0.16 s{sup -1} for a metal). Our approach adapts electromechanical piezoelectric actuators to a conventional diamond anvil cell design, which enables precise specification and control of a time-dependent applied load/pressure. Existing DAC instrumentation and experimental techniques are easily adapted to the dDAC to measure the properties of a sample under the varying load/pressure conditions. This capability addresses the sparsely studied regime of dynamic phenomena between static research (diamond anvil cells and large volume presses) and dynamic shock-driven experiments (gas guns, explosive and laser shock). We present an overview of a variety of experimental measurements that can be made with this device.

  11. Comparison of device models for organic solar cells: Band-to-band vs. tail states recombination

    Energy Technology Data Exchange (ETDEWEB)

    Soldera, Marcos; Taretto, Kurt [Departamento de Electrotecnia, Universidad Nacional del Comahue, Buenos Aires, Neuquen (Argentina); Kirchartz, Thomas [Department of Physics, Imperial College London, South Kensington (United Kingdom)

    2012-01-15

    The efficiency-limiting recombination mechanism in bulk-heterojunction (BHJ) solar cells is a current topic of investigation and debate in organic photovoltaics. In this work, we simulate state-of-the-art BHJ solar cells using two different models. The first model takes into account band-to-band recombination and field dependent carrier generation. The second model assumes a Shockley-Read-Hall (SRH) recombination mechanism via tail states and field independent carrier generation. Additionally, we include in both cases optical modelling and, thus, position-dependent exciton generation and non-ideal exciton collection. We explore both recombination mechanisms by fitting light and dark current-voltage (JV) characteristics of BHJ cells of five materials: P3HT, MDMO-PPV, MEH-PPV, PCDTBT and PF10TBT, all blended with fullerene derivatives. We show that although main device parameters such as short circuit current, open circuit voltage, fill factor and ideality factor are accurately reproduced by both Langevin and tail recombination, only tail recombination reproduces also the ideality factor of dark characteristics accurately. Nevertheless, the model with SRH recombination via tail states needs the inclusion of external circuitry to account for the heavy shunt present in all the blends, except P3HT:PCBM, when illuminated. Finally, we propose a means to find analytical expressions for the short circuit current by assuming a linear relation between the recombination rate and the concentration of free minority carriers. The model reproduces experimental data of P3HT cells at various thickness values using realistic parameters for this material. Dark JV measurement (circles) of a PCDTBT:PC{sub 70}BM solar cell (Park et al., Nature Photon. 3, 297 (2009) [1]), the fit with the model including recombination via tail states (solid line) and the fit with the model reported by (Koster et al., Phys. Rev. B 72, 085205 (2005) [2]) that includes bimolecular band-to-band recombination

  12. The second device for measuring of the thickness of the falling condensate in the gravity assisted heat pipe

    Science.gov (United States)

    Lenhard, Richard; Malcho, Milan

    2016-06-01

    This article describes a device for measuring the thickness of a falling condensate that allowed comparison of calculations with the measurements. This article is a basic methodology for measuring the thickness of the falling condensate in gravitational heat pipes, with using the optical triangulation method, and the evaluation of risks associated with this method.

  13. Development of High Power Electron Beam Measuring and Analyzing System for Microwave Vacuum Electron Devices

    Science.gov (United States)

    Ruan, C. J.; Wu, X. L.; Li, Q. S.; Li, C. S.

    The measurement and analysis of high power electron beam during its formation and transmission are the basic scientific problems and key techniques for the development of high performance microwave vacuum electron devices, which are widely used in the fields of military weapon, microwave system and scientific instruments. In this paper, the dynamic parameters measurement and analysis system being built in Institute of Electronics, Chinese Academy of Sciences (IECAS) recently are introduced. The instrument are designed to determine the cross-section, the current density, and the energy resolution of the high power electron beam during its formation and transmission process, which are available both for the electron gun and the electron optics system respectively. Then the three dimension trajectory images of the electron beam can be rebuilt and display with computer controlled data acquisition and processing system easily. Thus, much more complicated structures are considered and solved completely to achieve its detection and analysis, such as big chamber with 10-6 Pa high vacuum system, the controlled detector movement system in axis direction with distance of 600 mm inside the vacuum chamber, the electron beam energy analysis system with high resolution of 0.5%, and the electron beam cross-section and density detector using the YAG: Ce crystal and CCD imaging system et al. At present, the key parts of the instrument have been finished, the cross-section experiment of the electron beam have been performed successfully. Hereafter, the instrument will be used to measure and analyze the electron beam with the electron gun and electron optics system for the single beam and multiple beam klystron, gyrotron, sheet beam device, and traveling wave tube etc. thoroughly.

  14. Evaluation of bioactivity of octacalcium phosphate using osteoblastic cell aggregates on a spheroid culture device

    Directory of Open Access Journals (Sweden)

    Takahisa Anada

    2016-03-01

    Full Text Available Much attention has been paid to three-dimensional cell culture systems in the field of regenerative medicine, since three-dimensional cellular aggregates, or spheroids, are thought to better mimic the in vivo microenvironments compared to conventional monolayer cultured cells. Synthetic calcium phosphate (CaP materials are widely used as bone substitute materials in orthopedic and dental surgeries. Here we have developed a technique for constructing a hybrid spheroid consisting of mesenchymal stem cells (MSCs and synthetic CaP materials using a spheroid culture device. We found that the device is able to generate uniform-sized CaP/cell hybrid spheroids rapidly and easily. The results showed that the extent of osteoblastic differentiation from MSCs was different when cells were grown on octacalcium phosphate (OCP, hydroxyapatite (HA, or β-tricalcium phosphate (β-TCP. OCP showed the greatest ability to increase the alkaline phosphatase activity of the spheroid cells. The results suggest that the spheroids with incorporated OCP may be an effective implantable hybrid consisting of scaffold material and cells for bone regeneration. It is also possible that this CaP–cell spheroid system may be used as an in vitro method for assessing the osteogenic induction ability of CaP materials.

  15. High-throughput blood cell focusing and plasma isolation using spiral inertial microfluidic devices.

    Science.gov (United States)

    Xiang, Nan; Ni, Zhonghua

    2015-12-01

    Herein, we explored the blood cell focusing and plasma isolation using a spiral inertial microfluidic device. First, the flow-rate and concentration effects on the migration dynamics of blood cells were systematically investigated to uncover the focusing mechanisms and steric crowding effects of cells in Dean-coupled inertial flows. A novel phenomenon that the focusing status of discoid red blood cells (RBCs) changes according to the channel height was discovered. These experimental data may provide valuable insights for the high-throughput processing of blood samples using inertial microfluidics. On the basis of the improved understandings on blood cell focusing, efficient isolation of plasma from whole blood with a 20-fold dilution was achieved at a throughput up to 700 μl/min. The purity of the isolated blood plasma was close to 100 %, and the plasma yield was calculated to be 38.5 %. As compared with previously-reported devices, our spiral inertial microfluidic device provides a balanced overall performance, and has overriding advantages in terms of processing throughput and operating efficiency.

  16. A hybrid microfluidic-vacuum device for direct interfacing with conventional cell culture methods

    Directory of Open Access Journals (Sweden)

    Monuki Edwin S

    2007-09-01

    Full Text Available Abstract Background Microfluidics is an enabling technology with a number of advantages over traditional tissue culture methods when precise control of cellular microenvironment is required. However, there are a number of practical and technical limitations that impede wider implementation in routine biomedical research. Specialized equipment and protocols required for fabrication and setting up microfluidic experiments present hurdles for routine use by most biology laboratories. Results We have developed and validated a novel microfluidic device that can directly interface with conventional tissue culture methods to generate and maintain controlled soluble environments in a Petri dish. It incorporates separate sets of fluidic channels and vacuum networks on a single device that allows reversible application of microfluidic gradients onto wet cell culture surfaces. Stable, precise concentration gradients of soluble factors were generated using simple microfluidic channels that were attached to a perfusion system. We successfully demonstrated real-time optical live/dead cell imaging of neural stem cells exposed to a hydrogen peroxide gradient and chemotaxis of metastatic breast cancer cells in a growth factor gradient. Conclusion This paper describes the design and application of a versatile microfluidic device that can directly interface with conventional cell culture methods. This platform provides a simple yet versatile tool for incorporating the advantages of a microfluidic approach to biological assays without changing established tissue culture protocols.

  17. A High Power-Density Mediator-Free Microfluidic Biophotovoltaic Device for Cyanobacterial Cells

    CERN Document Server

    Bombelli, Paolo; Herling, Therese W; Howe, Christopher J; Knowles, Tuomas P J

    2014-01-01

    Biophotovoltaics has emerged as a promising technology for generating renewable energy since it relies on living organisms as inexpensive, self-repairing and readily available catalysts to produce electricity from an abundant resource - sunlight. The efficiency of biophotovoltaic cells, however, has remained significantly lower than that achievable through synthetic materials. Here, we devise a platform to harness the large power densities afforded by miniaturised geometries. To this effect, we have developed a soft-lithography approach for the fabrication of microfluidic biophotovoltaic devices that do not require membranes or mediators. Synechocystis sp. PCC 6803 cells were injected and allowed to settle on the anode, permitting the physical proximity between cells and electrode required for mediator-free operation. We demonstrate power densities of above 100 mW/m2 for a chlorophyll concentration of 100 {\\mu}M under white light, a high value for biophotovoltaic devices without extrinsic supply of additional...

  18. 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).

  19. An integrated microfluidic device for rapid and high-sensitivity analysis of circulating tumor cells

    Science.gov (United States)

    Jiang, Jianing; Zhao, Hui; Shu, Weiliang; Tian, Jing; Huang, Yuqing; Song, Yongxin; Wang, Ruoyu; Li, Encheng; Slamon, Dennis; Hou, Dongmei; Du, Xiaohui; Zhang, Lichuan; Chen, Yan; Wang, Qi

    2017-01-01

    Recently there has been a more focus on the development of an efficient technique for detection of circulating tumor cells (CTCs), due to their significance in prognosis and therapy of metastatic cancer. However, it remains a challenge because of the low count of CTCs in the blood. Herein, a rapid and high-sensitivity approach for CTCs detection using an integrated microfluidic system, consisting of a deterministic lateral displacement (DLD) isolating structure, an automatic purifying device with CD45-labeled immunomagnetic beads and a capturing platform coated with rat-tail collagen was reported. We observed high capture rate of 90%, purity of about 50% and viability of more than 90% at the high throughput of 1 mL/min by capturing green fluorescent protein (GFP)-positive cells from blood. Further capturing of CTCs from metastatic cancers patients revealed a positive capture rate of 83.3%. Furthermore, our device was compared with CellSearch system via parallel analysis of 30 cancer patients, to find no significant difference between the capture efficiency of both methods. However, our device displayed advantage in terms of time, sample volume and cost for analysis. Thus, our integrated device with sterile environment and convenient use will be a promising platform for CTCs detection with potential clinical application. PMID:28198402

  20. Modelling organs, tissues, cells and devices using Matlab and Comsol multiphysics

    CERN Document Server

    Dokos, Socrates

    2017-01-01

    This book presents a theoretical and practical overview of computational modeling in bioengineering, focusing on a range of applications including electrical stimulation of neural and cardiac tissue, implantable drug delivery, cancer therapy, biomechanics, cardiovascular dynamics, as well as fluid-structure interaction for modelling of organs, tissues, cells and devices. It covers the basic principles of modeling and simulation with ordinary and partial differential equations using MATLAB and COMSOL Multiphysics numerical software. The target audience primarily comprises postgraduate students and researchers, but the book may also be beneficial for practitioners in the medical device industry.

  1. Thermal properties measurement of dry bulk materials with a cylindrical three layers device

    Science.gov (United States)

    Jannot, Y.; Degiovanni, A.

    2013-09-01

    This paper presents a new method dedicated to thermal properties (conductivity and diffusivity) measurement of dry bulk materials including powders. The cylindrical three layers experimental device (brass/bulk material/stainless steel) and the principle of the measurement method based on a crenel thermal excitation are presented. The one-dimensional modeling of the system is used for a sensitivity analysis and to calculate the standard deviation of the estimation error. Experimental measurements are carried out on three bulk materials: glass beads, cork granules, and expanded polystyrene beads. The estimated thermal properties are compared with the values obtained by other measurement methods. Results are in good agreement with theoretical predictions: both thermal conductivity and diffusivity can be estimated with a good accuracy for low density material like cork granules or expanded polystyrene beads since only thermal diffusivity can be estimated for heavier materials like glass beads. It is finally shown that this method like all transient methods is not suited to the thermal characterization of wet bulk materials.

  2. Comparison of device structures for the dielectric breakdown measurement of hexagonal boron nitride

    Science.gov (United States)

    Hattori, Yoshiaki; Taniguchi, Takashi; Watanabe, Kenji; Nagashio, Kosuke

    2016-12-01

    Improving the film quality in the synthesis of large-area hexagonal boron nitride films (h-BN) for two-dimensional material devices remains a great challenge. The measurement of electrical breakdown dielectric strength (EBD) is one of the most important methods to elucidate the insulating quality of h-BN. In this work, the EBD of high quality exfoliated single-crystal h-BN was investigated using three different electrode structures under different environmental conditions to determine the ideal electrode structure and environment for EBD measurement. A systematic investigation revealed that EBD is not sensitive to contact force or electrode area but strongly depends on the relative humidity during measurement. Once the measurement environment is properly managed, it was found that the EBD values are consistent within experimental error regardless of the electrode structure, which enables the evaluation of the crystallinity of synthesized h-BN at the microscopic and macroscopic level by utilizing the three different electrode structures properly for different purposes.

  3. Evolution of the sensor fish device for measuring physical conditions in sever hydraulic environments

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Thomas J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Duncan, J. P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2003-03-01

    To assist in deriving biological specifications for design of turbine rehabilitation measures, new “fish-friendly” turbines, and spillway designs and operations, Pacific Northwest National Laboratory (PNNL) scientists have developed and tested an autonomous multi-sensor device called a Sensor Fish that can acquire pressure and tri-axial linear acceleration data during passage through severe hydraulic conditions. The purpose of the Sensor Fish is to characterize physical conditions fish experience during passage through hydro turbines, spill stilling basins, high-discharge outfalls, and other dam passage routes. This report discusses the development and field tests of the Sensor Fish at Rock Island, McNary, The Dalles, Bonneville, and Wanapum dams on the Columbia River and the Prosser Irrigation District on the Yakima River, which have shown that the device can withstand the severe environments of turbine, spill, and fish bypass passage and provide useful environmental data that can ultimately aid in the design and operation of new and existing turbines, spill, and dam fish bypass facilities.

  4. Evolution of the Sensor Fish Device for Measuring Physical Conditions in Severe Hydraulic Environments

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Thomas J.; Duncan, Joanne P.

    2003-02-28

    To assist in deriving biological specifications for design of turbine rehabilitation measures, new ''fish-friendly'' turbines, and spillway designs and operations, scientists at the Pacific Northwest National Laboratory (PNNL) have developed and tested an autonomous multi-sensor device called a Sensor Fish that can acquire pressure and tri-axial linear acceleration data during passage through severe hydraulic conditions. The purpose of the Sensor Fish is to characterize physical conditions fish experience during passage through hydro turbines, spill stilling basins, high-discharge outfalls, and other dam passage routes. The Sensor Fish was developed with the support of the U.S. Department of Energy's Advanced Hydropower Turbine System program. Field tests of the Sensor Fish at Rock Island, McNary, The Dalles, Bonneville, and Wanapum dams on the Columbia River and the Prosser Irrigation District on the Yakima River have shown that the device can withstand the severe environments of turbine, spill, and fish bypass passage and provide useful environmental data that can ultimately aid in the design and operation of new and existing turbines, spill, and dam fish bypass facilities.

  5. More randomness from a prepare-and-measure scenario with independent devices

    Science.gov (United States)

    Han, Yun-Guang; Yin, Zhen-Qiang; Li, Hong-Wei; Chen, Wei; Wang, Shuang; Guo, Guang-Can; Han, Zheng-Fu

    2016-03-01

    How to generate genuine quantum randomness from untrusted devices is an important problem in quantum information processing. Inspired by previous work on a self-testing quantum random number generator [T. Lunghi et al., Phys. Rev. Lett. 114, 150501 (2015), 10.1103/PhysRevLett.114.150501], we present a method to generate quantum randomness from a prepare-and-measure scenario with independent devices. In existing protocols, the quantum randomness depends only on a witness value (e.g., Clauser-Horne-Shimony-Holt value), which is calculated with the observed probabilities. Differently, here all the observed probabilities are directly used to calculate the min-entropy in our method. Through numerical simulation, we find that the min-entropy of our proposed scheme is higher than that in the previous work when a typical untrusted Bennett-Brassard 1984 (BB84) setup is used. Consequently, thanks to the proposed method, more genuine quantum random numbers may be obtained than before.

  6. Relating Direct Methanol Fuel Cell Performance to Measurements in a Liquid Half Cell

    DEFF Research Database (Denmark)

    Pedersen, Christoffer Mølleskov; Tynelius, Oskar; Lund-Olesen, Torsten

    2015-01-01

    Direct methanol fuel cells (DMFC) could act as a replacement for batteries in low power electronics. For instance, micro—DMFC’s could be used to power hearing instruments[1]. The power output of a DMFC is limited by the sluggish kinetics of both the methanol oxidation reaction (MOR) on the anode......) in the presence of methanol. By comparing the two measurements, we make recommendations for performing liquid half-cell measurements under realistic conditions. [1] J.H. Hales, C. Kallesøe, T. Lund-Olesen, A.-C. Johansson, H.C. Fanøe, Y. Yu, et al., Micro fuel cells power the hearing aids of the future, Fuel...... allow further miniaturization or powering more advanced and more power hungry devices. The activity of fuel cell catalysts is often probed in the form of thin films in liquid half cells. However, it is challenging to mimic the conditions in an actual DMFC. On the other hand, it can also be problematic...

  7. A comparison and measurement standardisation of four in situ devices for determining the erosion shear stress of intertidal sediments

    Science.gov (United States)

    Tolhurst, T. J.; Black, K. S.; Paterson, D. M.; Mitchener, H. J.; Termaat, G. R.; Shayler, S. A.

    2000-07-01

    Predictive modelling of estuarine sediment erosion and transport requires a description of the erosional properties of the bed. The two main variables of interest are the critical erosion shear stress ( τcr) and the erosion rate ( ɛ). A number of different erosion devices exist to measure the erosion shear stress of intertidal sediments in situ. These devices apply different strategies to induce and measure erosion, and the area over which erosion is integrated varies greatly. In addition, the definition of erosion threshold differs between workers. This makes comparison of data collected from different devices very difficult. Four different types of erosion device, Microcosm system, In Situ Erosion Flume (ISEF), SedErode and cohesive strength meter (CSM) were used during the July 1997 EC INTRMUD Humber estuary (UK) field campaign. These devices were deployed simultaneously on the Skeffling intertidal mudflat to allow comparison of the data generated. This involved the comparison of suspended particulate matter (SPM) time series, the nature of the applied shear stress ( τo) and the area over which erosion was integrated. The initial goal was to develop a standard analysis procedure for comparison of stability measurements. The erosion threshold calculated from area normalised suspended particulate matter (SPM n) time series was relatively comparable between devices especially between the Microcosm and ISEF. However, device size and natural sediment spatial heterogeneity affected the results. The erosion rate varied by orders of magnitude between the different devices. This variation seemed to be due to the considerable differences in device deployment time. In conclusion, SPM data from different devices are broadly comparable, whilst erosion rates are only comparable if the shear stress steps are of the same duration.

  8. Reliability of Sleep Measures from Four Personal Health Monitoring Devices Compared to Research-Based Actigraphy and Polysomnography.

    Science.gov (United States)

    Mantua, Janna; Gravel, Nickolas; Spencer, Rebecca M C

    2016-05-05

    Polysomnography (PSG) is the "gold standard" for monitoring sleep. Alternatives to PSG are of interest for clinical, research, and personal use. Wrist-worn actigraph devices have been utilized in research settings for measures of sleep for over two decades. Whether sleep measures from commercially available devices are similarly valid is unknown. We sought to determine the validity of five wearable devices: Basis Health Tracker, Misfit Shine, Fitbit Flex, Withings Pulse O2, and a research-based actigraph, Actiwatch Spectrum. We used Wilcoxon Signed Rank tests to assess differences between devices relative to PSG and correlational analysis to assess the strength of the relationship. Data loss was greatest for Fitbit and Misfit. For all devices, we found no difference and strong correlation of total sleep time with PSG. Sleep efficiency differed from PSG for Withings, Misfit, Fitbit, and Basis, while Actiwatch mean values did not differ from that of PSG. Only mean values of sleep efficiency (time asleep/time in bed) from Actiwatch correlated with PSG, yet this correlation was weak. Light sleep time differed from PSG (nREM1 + nREM2) for all devices. Measures of Deep sleep time did not differ from PSG (SWS + REM) for Basis. These results reveal the current strengths and limitations in sleep estimates produced by personal health monitoring devices and point to a need for future development.

  9. Reliability of Sleep Measures from Four Personal Health Monitoring Devices Compared to Research-Based Actigraphy and Polysomnography

    Directory of Open Access Journals (Sweden)

    Janna Mantua

    2016-05-01

    Full Text Available Polysomnography (PSG is the “gold standard” for monitoring sleep. Alternatives to PSG are of interest for clinical, research, and personal use. Wrist-worn actigraph devices have been utilized in research settings for measures of sleep for over two decades. Whether sleep measures from commercially available devices are similarly valid is unknown. We sought to determine the validity of five wearable devices: Basis Health Tracker, Misfit Shine, Fitbit Flex, Withings Pulse O2, and a research-based actigraph, Actiwatch Spectrum. We used Wilcoxon Signed Rank tests to assess differences between devices relative to PSG and correlational analysis to assess the strength of the relationship. Data loss was greatest for Fitbit and Misfit. For all devices, we found no difference and strong correlation of total sleep time with PSG. Sleep efficiency differed from PSG for Withings, Misfit, Fitbit, and Basis, while Actiwatch mean values did not differ from that of PSG. Only mean values of sleep efficiency (time asleep/time in bed from Actiwatch correlated with PSG, yet this correlation was weak. Light sleep time differed from PSG (nREM1 + nREM2 for all devices. Measures of Deep sleep time did not differ from PSG (SWS + REM for Basis. These results reveal the current strengths and limitations in sleep estimates produced by personal health monitoring devices and point to a need for future development.

  10. Measuring the energy consumption of single-phase UPS-devices; Energiemessungen von 1-phasigen USV-Anlagen

    Energy Technology Data Exchange (ETDEWEB)

    Bush, E. [Bush Energie GmbH, Felsberg (Switzerland); Schalcher, M.; Bruggmann, T.; Kuehne, P.; Kammermann, S. [Hochschule fuer Technik und Wirtschaft Chur, Chur (Switzerland)

    2007-11-15

    In the present measuring project, 46 single-phase uninterruptible power supplies (UPS-devices) in the power range from 350 VA up to 3000 VA could be measured with regard to efficiency and energy consumption, at Testlabor S.A.L.T., Chur, Switzerland. The classification into VFD-, VI- and VFI-devices as well as the carrying out of the measuring was accomplished in compliance with IEC 62040-3 with resistive and nonlinear load. As expected, the VFD-devices showed the best efficiency level, followed by VI- and VFI-devices. The efficiency rate at 50%, 75% and 100% of the nominal power differs only slightly and in most cases exceeds 90%. However, at a load of 25% the efficiency decreases considerably (in individual cases to below 80%). There are large differences in the area of standby losses (switched on, without load) which can only partly be explained by the different technologies of the various types of UPS-devices. Compared to the Code of Conduct for UPS-devices with a power of more than 10 kVA, the devices with lower power compare relatively well, especially because of the small power demands for cooling. (author)

  11. On-chip acidification rate measurements from single cardiac cells confined in sub-nanoliter volumes

    OpenAIRE

    Ges, Igor A.; Dzhura, Igor A.; Baudenbacher, Franz J.

    2008-01-01

    The metabolic activity of cells can be monitored by measuring the pH in the extracellular environment. Microfabrication and microfluidic technologies allow the sensor size and the extracellular volumes to be comparable to single cells. A glass substrate with thin film pH sensitive IrOx electrodes was sealed to a replica-molded polydimethylsiloxane (PDMS) microfluidic network with integrated valves. The device, termed NanoPhysiometer, allows the trapping of single cardiac myocytes and the meas...

  12. Measurement device-independent quantum key distribution with heralded pair coherent state

    Science.gov (United States)

    Chen, Dong; Shang-Hong, Zhao; Lei, Shi

    2016-10-01

    The original measurement device-independent quantum key distribution is reviewed, and a modified protocol using heralded pair coherent state (HPCS) is proposed to overcome the quantum bit error rate associated with the dark count rate of the detectors in long-distance quantum key distribution. Our simulation indicates that the secure transmission distance can be improved evidently with HPCS owing to the lower probability of vacuum events when compared with weak coherent source scenario, while the secure key rate can be increased with HPCS due to the higher probability of single-photon events when compared with heralded single-photon source scenario. Furthermore, we apply the finite key analysis to the decoy state MDI-QKD with HPCS and obtain a practical key rate.

  13. A wearable device for measuring eye dynamics in real-world conditions.

    Science.gov (United States)

    Knopp, Simon; Bones, Philip; Weddell, Stephen; Innes, Carrie; Jones, Richard

    2013-01-01

    Drowsiness and lapses of responsiveness have the potential to cause fatalities in many occupations. One subsystem of a prototype device which aims to detect these lapses as they occur is described. A head-mounted camera measures several features of the eye that are known to correlate with drowsiness. The system was tested with eight combinations of eye colour, ambient lighting, and eye glasses to simulate typical real-world input conditions. A task was completed for each set of conditions to simulate a range of eye movement-saccades, tracking, and eye closure. Our image processing software correctly classified 99.3% of video frames as open/closed/partly closed, and the error rate was not affected by the combinations of input conditions. Most errors occurred during eyelid movement. The accuracy of the pupil localisation was also not influenced by input conditions, with the possible exception of one subject's glasses.

  14. A miniature rigid/flex salinity measurement device fabricated using printed circuit processing techniques

    Science.gov (United States)

    Broadbent, H. A.; Ketterl, T. P.; Reid, C. S.

    2010-08-01

    The design, fabrication and initial performance of a single substrate, miniature, low-cost conductivity, temperature, depth (CTD) sensor board with interconnects are presented. In combination these sensors measure ocean salinity. The miniature CTD device board was designed and fabricated as the main component of a 50 mm × 25 mm × 25 mm animal-attached biologger. The board was fabricated using printed circuit processes and consists of two distinct regions on a continuous single liquid crystal polymer substrate: an 18 mm × 28 mm rigid multi-metal sensor section and a 72 mm long flexible interconnect section. The 95% confidence intervals for the conductivity, temperature and pressure sensors were demonstrated to be ±0.083 mS cm-1, 0.01 °C, and ±0.135 dbar, respectively.

  15. Performance evaluation of aluminum/phosphate cell for powering small electronic devices

    Directory of Open Access Journals (Sweden)

    Gymama Slaughter

    2015-12-01

    Full Text Available We report on an innovative membrane-free aluminum/phosphate cell based on the activation of aluminum (Al as anodic material using ZnO nanocrystal in phosphate rich electrolyte that is capable of generating sufficient power to power a light-emitting diode (LED, selected as a model of a small electronic device. The energy from the cell is periodically supplied in high power bursts due to the charge and discharge cycle of the capacitor. The entire process is controlled by a switched capacitor regulator. The Al/phosphate cell was studied in neutral 100 mM phosphate buffer solution (7.4 at a temperature of 25 °C. We demonstrate that two Al/phosphate cells connected in series can generate an open circuit voltage (Voc up to 1.66 V to continuously power a LED via a switched capacitor regulator circuit. The switched capacitor regulator circuit enabled the 1 μF capacitor to store the incoming power from the cell and discharge it in a large power burst to supply the necessary drive strength required by the LED. This new Al/phosphate cell configuration is a ‘green’ alternative to the use of glucose abiotic and biofuel cells for powering ultra-low power implantable electronic devices.

  16. Provision Of Carbon Nanotube Bucky Paper Cages For Immune Shielding Of Cells, Tissues, and Medical Devices

    Science.gov (United States)

    Loftus, David J. (Inventor)

    2006-01-01

    System and method for enclosing cells and/or tissue, for purposes of growth, cell differentiation, suppression of cell differentiation, biological processing and/or transplantation of cells and tissues (biological inserts), and for secretion, sensing and monitoring of selected chemical substances and activation of gene expression of biological inserts implanted into a human body. Selected cells and/or tissue are enveloped in a "cage" that is primarily carbon nanotube Bucky paper, with a selected thickness and porosity. Optionally, selected functional groups, proteins and/or peptides are attached to the carbon nanotube cage, or included within the cage, to enhance the growth and/or differentiation of the cells and/or tissue, to select for certain cellular sub-populations, to optimize certain functions of the cells and/or tissue and/or to optimize the passage of chemicals across the cage surface(s). A cage system is also used as an immuns shield and to control operation of a nano-device or macroscopic device, located within the cage, to provide or transform a selected chemical and/or a selected signal.

  17. RETRACTED: Advances in colloidal quantum dot solar cells: The depleted-heterojunction device

    KAUST Repository

    Kramer, Illan J.

    2011-08-01

    Colloidal quantum dot (CQD) photovoltaics combine low-cost solution processibility with quantum size-effect tunability to match absorption with the solar spectrum. Recent advances in CQD photovoltaics have led to 3.6% AM1.5 solar power conversion efficiencies. Here we report CQD photovoltaic devices on transparent conductive oxides and show that our devices rely on the establishment of a depletion region for field-driven charge transport and separation. The resultant depleted-heterojunction solar cells provide a 5.1% AM1.5 power conversion efficiency. The devices employ infrared-bandgap size-effect-tuned PbS colloidal quantum dots, enabling broadband harvesting of the solar spectrum. © 2010 Elsevier B.V.

  18. Advances in colloidal quantum dot solar cells: The depleted-heterojunction device

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, Illan J.; Pattantyus-Abraham, Andras G.; Barkhouse, Aaron R.; Wang, Xihua [Department of Electrical and Computer Engineering, University of Toronto, 10 King' s College Rd., Toronto, Ontario M5S 3G4 (Canada); Konstantatos, Gerasimos [Department of Electrical and Computer Engineering, University of Toronto, 10 King' s College Rd., Toronto, Ontario M5S 3G4 (Canada); ICFO - Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels, Barcelona (Spain); Debnath, Ratan; Levina, Larissa [Department of Electrical and Computer Engineering, University of Toronto, 10 King' s College Rd., Toronto, Ontario M5S 3G4 (Canada); Raabe, Ines; Nazeeruddin, Md. K.; Graetzel, Michael [Laboratory for Photonics and Interfaces, Institute of Chemical Sciences and Engineering, School of Basic Sciences, Swiss Federal Institute of Technology, CH-1015 Lausanne (Switzerland); Sargent, Edward H., E-mail: ted.sargent@utoronto.ca [Department of Electrical and Computer Engineering, University of Toronto, 10 King' s College Rd., Toronto, Ontario M5S 3G4 (Canada)

    2011-08-31

    Colloidal quantum dot (CQD) photovoltaics combine low-cost solution processibility with quantum size-effect tunability to match absorption with the solar spectrum. Recent advances in CQD photovoltaics have led to 3.6% AM1.5 solar power conversion efficiencies. Here we report CQD photovoltaic devices on transparent conductive oxides and show that our devices rely on the establishment of a depletion region for field-driven charge transport and separation. The resultant depleted-heterojunction solar cells provide a 5.1% AM1.5 power conversion efficiency. The devices employ infrared-bandgap size-effect-tuned PbS colloidal quantum dots, enabling broadband harvesting of the solar spectrum.

  19. Plasma cell treatment device Plasma-on-Chip: Monitoring plasma-generated reactive species in microwells

    Science.gov (United States)

    Oh, Jun-Seok; Kojima, Shinya; Sasaki, Minoru; Hatta, Akimitsu; Kumagai, Shinya

    2017-01-01

    We have developed a plasma cell treatment device called Plasma-on-Chip that enables the real-time monitoring of a single cell culture during plasma treatment. The device consists of three parts: 1) microwells for cell culture, 2) a microplasma device for generating reactive oxygen and nitrogen species (RONS) for use in cell treatment, and 3) through-holes (microchannels) that connect each microwell with the microplasma region for RONS delivery. Here, we analysed the delivery of the RONS to the liquid culture medium stored in the microwells. We developed a simple experimental set-up using a microdevice and applied in situ ultraviolet absorption spectroscopy with high sensitivity for detecting RONS in liquid. The plasma-generated RONS were delivered into the liquid culture medium via the through-holes fabricated into the microdevice. The RONS concentrations were on the order of 10–100 μM depending on the size of the through-holes. In contrast, we found that the amount of dissolved oxygen was almost constant. To investigate the process of RONS generation, we numerically analysed the gas flow in the through-holes. We suggest that the circulating gas flow in the through-holes promotes the interaction between the plasma (ionised gas) and the liquid, resulting in enhanced RONS concentrations. PMID:28176800

  20. Analysis of Electric Fields inside Microchannels and Single Cell Electrical Lysis with a Microfluidic Device

    Directory of Open Access Journals (Sweden)

    Tofy Mussivand

    2013-06-01

    Full Text Available Analysis of electric fields generated inside the microchannels of a microfluidic device for electrical lysis of biological cells along with experimental verification are presented. Electrical lysis is the complete disintegration of cell membranes, due to a critical level of electric fields applied for a critical duration on a biological cell. Generating an electric field inside a microchannel of a microfluidic device has many advantages, including the efficient utilization of energy and low-current requirement. An ideal microchannel model was compared with a practical microchannel model using a finite element analysis tool that suggests that the overestimation error can be over 10%, from 2.5 mm or smaller, in the length of a microchannel. Two analytical forms are proposed to reduce this overestimation error. Experimental results showed that the high electric field is confined only inside the microchannel that is in agreement with the simulation results. Single cell electrical lysis was conducted with a fabricated microfluidic device. An average of 800 V for seven seconds across an 8 mm-long microchannel with the dimension of 100 μm × 20 μm was required for lysis, with electric fields exceeding 100 kV/m and consuming 300 mW.

  1. Measuring the neck frequency response function of laryngectomy patients: Implications for the design of electrolarynx devices

    Science.gov (United States)

    Meltzner, Geoffrey S.; Kobler, James B.; Hillman, Robert E.

    2003-08-01

    Measurements of the neck frequency response function (NFRF), defined as the ratio of the spectrum of the estimated volume velocity that excites the vocal tract to the spectrum of the acceleration delivered to the neck wall, were made at three different positions on the necks of nine laryngectomized subjects (five males and four females) and four normal laryngeal speakers (two males and two females). A minishaker driven by broadband noise provided excitation to the necks of subjects as they configured their vocal tracts to mimic the production of the vowels /aye/, /æ/, and /I/. The sound pressure at the lips was measured with a microphone and an impedance head mounted on the shaker measured the acceleration. The neck wall passed low-frequency sound energy better than high-frequency sound energy, and thus the NFRF was accurately modeled as a low-pass filter. The NFRFs of the different subject groups (female laryngeal, male laryngeal speakers, laryngectomized males, and laryngectomized females) differed from each other in terms of corner frequency and gain, with both types of male subjects presenting NFRFs with larger overall gains. In addition, there was a notable amount of intersubject variability within groups. Because the NFRF is an estimate of how sound energy passes through the neck wall, these results should aid in the design of improved neck-type electrolarynx devices.

  2. Microfluidic Device

    Science.gov (United States)

    Tai, Yu-Chong (Inventor); Zheng, Siyang (Inventor); Lin, Jeffrey Chun-Hui (Inventor); Kasdan, Harvey L. (Inventor)

    2017-01-01

    Described herein are particular embodiments relating to a microfluidic device that may be utilized for cell sensing, counting, and/or sorting. Particular aspects relate to a microfabricated device that is capable of differentiating single cell types from dense cell populations. One particular embodiment relates a device and methods of using the same for sensing, counting, and/or sorting leukocytes from whole, undiluted blood samples.

  3. Atomistic simulations of electrochemical metallization cells: mechanisms of ultra-fast resistance switching in nanoscale devices.

    Science.gov (United States)

    Onofrio, Nicolas; Guzman, David; Strachan, Alejandro

    2016-08-01

    We describe a new method that enables reactive molecular dynamics (MD) simulations of electrochemical processes and apply it to study electrochemical metallization cells (ECMs). The model, called EChemDID, extends the charge equilibration method to capture the effect of external electrochemical potential on partial atomic charges and describes its equilibration over connected metallic structures, on-the-fly, during the MD simulation. We use EChemDID to simulate resistance switching in nanoscale ECMs; these devices consist of an electroactive metal separated from an inactive electrode by an insulator and can be reversibly switched to a low-resistance state by the electrochemical formation of a conducting filament between electrodes. Our structures use Cu as the active electrode and SiO2 as the dielectric and have dimensions at the foreseen limit of scalability of the technology, with a dielectric thickness of approximately 1 nm. We explore the effect of device geometry on switching timescales and find that nanowires with an electroactive shell, where ions migrate towards a smaller inactive electrode core, result in faster switching than planar devices. We observe significant device-to-device variability in switching timescales and intermittent switching for these nanoscale devices. To characterize the evolution in the electronic structure of the dielectric as dissolved metallic ions switch the device, we perform density functional theory calculations on structures obtained from an EChemDID MD simulation. These results confirm the appearance of states around the Fermi energy as the metallic filament bridges the electrodes and show that the metallic ions and not defects in the dielectric contribute to the majority of those states.

  4. Reversible energy storage on a fuel cell-supercapacitor hybrid device

    Energy Technology Data Exchange (ETDEWEB)

    Zerpa Unda, Jesus Enrique

    2011-02-18

    A new concept of energy storage based on hydrogen which operates reversibly near ambient conditions and without important energy losses is investigated. This concept involves the hybridization between a proton exchange membrane fuel cell and a supercapacitor. The main idea consists in the electrochemical splitting of hydrogen at a PEM fuel cell-type electrode into protons and electrons and then in the storage of these two species separately in the electrical double layer of a supercapacitor-type electrode which is made of electrically conductive large-surface area carbon materials. The investigation of this concept was performed first using a two-electrode fuel cell-supercapacitor hybrid device. A three-electrode hybrid cell was used to explore the application of this concept as a hydrogen buffer integrated inside a PEM fuel cell to be used in case of peak power demand. (orig.)

  5. Method for contact resistivity measurements on photovoltaic cells and cell adapted for such measurement

    Science.gov (United States)

    Burger, Dale R. (Inventor)

    1986-01-01

    A method is disclosed for scribing at least three grid contacts of a photovoltaic cell to electrically isolate them from the grid contact pattern used to collect solar current generated by the cell, and using the scribed segments for determining parameters of the cell by a combination of contact end resistance (CER) measurements using a minimum of three equally or unequally spaced lines, and transmission line modal (TLM) measurements using a minimum of four unequally spaced lines. TLM measurements may be used to determine sheet resistance under the contact, R.sub.sk, while CER measurements are used to determine contact resistivity, .rho..sub.c, from a nomograph of contact resistivity as a function of contact end resistance and sheet resistivity under the contact. In some cases, such as the case of silicon photovoltaic cells, sheet resistivity under the contact may be assumed to be equal to the known sheet resistance, R.sub.s, of the semiconductor material, thereby obviating the need for TLM measurements to determine R.sub.sk.

  6. Solid-state devices for detection of DNA, protein biomarkers and cells

    Science.gov (United States)

    Asghar, Waseem

    Nanobiotechnology and BioMEMS have had tremendous impact on biosensing in the areas of cancer cell detection and therapeutics, disease diagnostics, proteomics and DNA analysis. Diseases are expressed on all levels including DNA, protein, cell and tissue. Therefore it is very critical to develop biosensors at each level. The power of the nanotechnology lies in the fact that we can fabricate devices on all scales from micro to nano. This dissertation focuses on four areas: 1) Development of nanopore sensors for DNA analysis; 2) Development of micropore sensors for early detection of circulating tumor cells (CTCs) from whole blood; 3) Synthesis of nano-textured substrates for cancer isolation and tissue culture applications; 4) Fabrication of nanoscale break-junctions. All of these sensors are fabricated using standard silicon processing techniques. Pulsed plasma polymer deposition is also utilized to control the density of the biosensor surface charges. These devices are then used for efficient detection of DNA, proteins and cells, and can be potentially used in point-of-care systems. Overall, our designed biosensing platforms offer improved selectivity, yield and reliability. Novel approaches to nanopore shrinking are simple, reliable and do not change the material composition around the pore boundary. The micropores provide a direct interface to distinguish CTCs from normal cell without requiring fluorescent dyes and surface functionalization. Nano-textured surfaces and break-junctions can be used for enhanced adhesion of cells and selective detection of proteins respectively.

  7. Use of surface enhanced blocking (SEB electrodes for microbial cell lysis in flow-through devices.

    Directory of Open Access Journals (Sweden)

    Abdossamad Talebpour

    Full Text Available By simultaneously subjecting microbial cells to high amplitude pulsed electric fields and flash heating of the cell suspension fluid, effective release of intracellular contents was achieved. The synergistic effect of the applied electric field and elevated temperature on cell lysis in a flow-through device was demonstrated for Gram-negative and Gram-positive bacteria, and Mycobacterium species. The resulting lysate is suitable for downstream nucleic acid amplification and detection without requiring further preparation. The lysis chamber employs surface enhanced blocking electrodes which possess an etched micro-structured surface and a thin layer of dielectric metal oxide which provides a large effective area and blocks transmission of electrical current. The surface enhanced blocking electrodes enable simultaneous suppression of the rapid onset of electric field screening in the bulk of the cell suspension medium and avoidance of undesired electrochemical processes at the electrode-electrolyte interface. In addition the blocking layer ensures the robustness of the cell lysis device in applications involving prolonged flow-through processing of the microbial cells.

  8. A simple optical fiber device for quantitative fluorescence microscopy of single living cells

    NARCIS (Netherlands)

    Graft, van Marja; Oosterhuis, Bernard; Werf, van der Kees O.; Grooth, de Bart G.; Greve, Jan

    1993-01-01

    simple and relatively inexpensive system is described for obtaining quantitative fluorescence measurements on single living cells loaded with a fluorescent probe to study cell physiological processes. The light emitted from the fluorescent cells is captured by and transported through an optical fibe

  9. Materials and Devices Research of PPV-ZnO Nanowires for Heterojunction Solar Cells

    Directory of Open Access Journals (Sweden)

    Zhang Xiao-Zhou

    2012-01-01

    Full Text Available Bulk heterojunction photovoltaic devices, which use the conjugated polymer poly(2-methoxyl-5-(2′-ethylhexyloxy-1,4-phenylenevinylene (MEH-PPV as the electron donor and crystalline ZnO nanowires as the electron acceptor, have been studied in this work. The ZnO nanowires were prepared through a chemical vapor deposition mechanism. The dissolved MEH-PPV polymer was spin-coated onto the nanowires. The scanning electron microscope images showed that the ZnO nanowires were covered with a single layer of the polymer, and these materials were used to design a heterojunction solar cell. This solar cell displayed improved performance compared with the devices that were made from only the MEH-PPV polymer. This observed improvement is correlated with the improved electron transport that is perpendicular to the plane of the film. A solar power conversion efficiency of 1.37% was achieved under an AM1.5 illumination.

  10. Materials Research Advances towards High-Capacity Battery/Fuel Cell Devices (Invited paper)

    Institute of Scientific and Technical Information of China (English)

    Wei-Dong He; Lu-Han Ye; Ke-Chun Wen; Ya-Chun Liang; Wei-Qiang Lv; Gao-Long Zhu; Kelvin H. L. Zhang

    2016-01-01

    The world has entered an era featured with fast transportations, instant communications, and prompt technological revolutions, the further advancement of which all relies fundamentally, yet, on the development of cost-effective energy resources allowing for durable and high-rate energy supply. Current battery and fuel cell systems are challenged by a few issues characterized either by insufficient energy capacity or by operation instability and, thus, are not ideal for such highly-demanded applications as electrical vehicles and portable electronic devices. In this mini-review, we present, from materials perspectives, a few selected important breakthroughs in energy resources employed in these applications. Prospectives are then given to look towards future research activities for seeking viable materials solutions for addressing the capacity, durability, and cost shortcomings associated with current battery/fuel cell devices.

  11. Cobalt-Based Electrolytes for Dye-Sensitized Solar Cells: Recent Advances towards Stable Devices

    Directory of Open Access Journals (Sweden)

    Federico Bella

    2016-05-01

    Full Text Available Redox mediators based on cobalt complexes allowed dye-sensitized solar cells (DSCs to achieve efficiencies exceeding 14%, thus challenging the emerging class of perovskite solar cells. Unfortunately, cobalt-based electrolytes demonstrate much lower long-term stability trends if compared to the traditional iodide/triiodide redox couple. In view of the large-scale commercialization of cobalt-based DSCs, the scientific community has recently proposed various approaches and materials to increase the stability of these devices, which comprise gelling agents, crosslinked polymeric matrices and mixtures of solvents (including water. This review summarizes the most significant advances recently focused towards this direction, also suggesting some intriguing way to fabricate third-generation cobalt-based photoelectrochemical devices stable over time.

  12. Solid State Dye Solar Cells with Metallic Regenerators towards devices with enhanced active area

    Energy Technology Data Exchange (ETDEWEB)

    Lenzmann, F.O.; Olson, C.; Pichon, P.Y.; Heurtault, B.; Goris, M.J.A.A.; Budel, T. [ECN Solar Energy, Westerduinweg 3, NL-1755 LE Petten (Netherlands)

    2007-08-15

    In an alternative approach to solid state dye solar cells a molecular dye is situated at the interface between a TiO2 film and a metallic (Au) film. In a proof of principle with flat model devices, we have shown earlier that the Au layer efficiently regenerates the charge-neutral state of the dye upon electron injection into the TiO2 conduction band under illumination. For practically more relevant devices an increased active area is required for enhanced current output. A specially adapted TiO2 morphology with nanotubular morphology can minimize reflection losses from the metallic regenerator. In this paper the preparation of such films on transparent SnO2:F-coated glass substrates by electrochemical anodization of titanium layers is described. The focus is on preparative parameters with direct influence on film properties relevant to the application in solid-state dye solar cells (transparency and mechanical integrity of the layers)

  13. Impact of Fullerene Mixing Behavior on the Microstructure, Photophysics, and Device Performance of Polymer/Fullerene Solar Cells.

    Science.gov (United States)

    Huang, Wenchao; Chandrasekaran, Naresh; Prasad, Shyamal K K; Gann, Eliot; Thomsen, Lars; Kabra, Dinesh; Hodgkiss, Justin M; Cheng, Yi-Bing; McNeill, Christopher R

    2016-11-02

    Here, a comprehensive study of the influence of polymer:fullerene mixing behavior on the performance, thin-film microstructure, photophysics, and device physics of polymer solar cells is presented. In particular, blends of the donor polymer PBDTTT-EFT with the acceptor PC71BM that exhibit power conversion efficiencies over 9% are investigated. Through tuning of the fullerene concentration in PBDTTT-EFT:PC71BM blends, the impact of fullerene mixing behavior is systematically investigated via a combination of synchrotron-based X-ray scattering and spectroscopy techniques. The impact of fullerene loading on photophysics and device physics is further explored with steady-state photoluminescence measurements, ultrafast transient absorption spectroscopy, and transient photovoltage measurements. In the low fullerene concentration regime (70 wt %), large fullerene domains result in incomplete PC71BM exciton harvesting with the presence of fullerene molecules also disrupting the molecular packing of polymer crystallites. The optimum fullerene concentration of ∼60-67 wt % balances the requirements of charge generation and charge collection. These findings demonstrate that controlling the fullerene concentration in the mixed phase and optimizing the balance between pure and mixed phases are critical for maximizing the efficiency of highly mixed polymer/fullerene solar cells.

  14. Attenuation length measurements of a liquid scintillator with LabVIEW and reliability evaluation of the device

    Science.gov (United States)

    Gao, Long; Yu, Bo-Xiang; Ding, Ya-Yun; Zhou, Li; Wen, Liang-Jian; Xie, Yu-Guang; Wang, Zhi-Gang; Cai, Xiao; Sun, Xi-Lei; Fang, Jian; Xue, Zhen; Zhang, Ai-Wu; Lü, Qi-Wen; Sun, Li-Jun; Ge, Yong-Shuai; Liu, Ying-Biao; Niu, Shun-Li; Hu, Tao; Cao, Jun; Lü, Jun-Guang

    2013-07-01

    An attenuation length measurement device was constructed using an oscilloscope and LabVIEW for signal acquisition and processing. The performance of the device has been tested in a variety of ways. The test results show that the set-up has a good stability and high precision (sigma/mean reached 0.4 percent). Besides, the accuracy of the measurement system will decrease by about 17 percent if a filter is used. The attenuation length of a gadolinium-loaded liquid scintillator (Gd-LS) was measured as 15.10±0.35 m where Gd-LS was heavily used in the Daya Bay Neutrino Experiment. In addition, one method based on the Beer-Lambert law was proposed to investigate the reliability of the measurement device, the R-square reached 0.9995. Moreover, three purification methods for Linear Alkyl Benzene (LAB) production were compared in the experiment.

  15. Attenuation length measurements of a liquid scintillator with LabVIEW and reliability evaluation of the device

    Institute of Scientific and Technical Information of China (English)

    GAO Long; YU Bo-Xiang; DING Ya-Yun; ZHOU Li; WEN Liang-Jian; XIE Yu-Guang; WANG Zhi-Gang

    2013-01-01

    An attenuation length measurement device was constructed using an oscilloscope and LabVIEW for signal acquisition and processing.The performance of the device has been tested in a variety of ways.The test results show that the set-up has a good stability and high precision (sigma/mean reached 0.4 percent).Besides,the accuracy of the measurement system will decrease by about 17 percent if a filter is used.The attenuation length of a gadolinium-loaded liquid scintillator (Gd-LS) was measured as 15.10±0.35 m where Gd-LS was heavily used in the Daya Bay Neutrino Experiment.In addition,one method based on the Beer-Lambert law was proposed to investigate the reliability of the measurement device,the R-square reached 0.9995.Moreover,three purification methods for Linear Alkyl Benzene (LAB) production were compared in the experiment.

  16. In-channel printing-device opening assay for micropatterning multiple cells and gene analysis.

    Science.gov (United States)

    Zhou, Hao; Zhao, Liang; Zhang, Xueji

    2015-02-17

    Herein we report an easy but versatile method for patterning different cells on a single substrate by using a microfluidic approach that allows not only spatial and temporal control of multiple microenvironments but also retrieval of specific treated cells to profile their expressed genetic information at around 10-cell resolution. By taking advantages of increased surface area of gold nanoparticles on a poly(dimethylsiloxane) (PDMS) coated substrate, cell adhesive-promotive protein, human fibronectin (hFN) can be significantly accumulated on designed regions where cells can recognize the protein and spread out. Moreover, the whole device can be easily opened by hand without any loss of patterned cells which could be retrieved by mouth-pipet. Consequently, we demonstrate the possibility of analyzing the difference of gene expression patterns between wild type MCF-7 cell and MCF/Adr (drug-resistant cell line) from less than 400 cells in total for a single comprehensive assay, including parallel experiments, controls, and multiple dose treatments. Certain genes, especially the P-glycoprotein coding gene (ABCB1), show high expression level in resistant cells compared with the wild type, suggesting a possible pathway that may contribute to the antidrug mechanism.

  17. Electro-Deformation of Fused Cells in a Microfluidic Array Device

    Directory of Open Access Journals (Sweden)

    Yan Liu

    2016-11-01

    Full Text Available We present a new method of analyzing the deformability of fused cells in a microfluidic array device. Electrical stresses—generated by applying voltages (4–20 V across discrete co-planar microelectrodes along the side walls of a microfluidic channel—have been used to electro-deform fused and unfused stem cells. Under an electro-deformation force induced by applying an alternating current (AC signal, we observed significant electro-deformation phenomena. The experimental results show that the fused stem cells were stiffer than the unfused stem cells at a relatively low voltage (<16 V. However, at a relatively high voltage, the fused stem cells were more easily deformed than were the unfused stem cells. In addition, the electro-deformation process is modeled based on the Maxwell stress tensor and structural mechanics of cells. The theoretical results show that a positive correlation is found between the deformation of the cell and the applied voltage, which is consistent with the experimental results. Combined with a numerical analysis and experimental study, the results showed that the significant difference of the deformation ratio of the fused and unfused cells is not due to their size difference. This demonstrates that some other properties of cell membranes (such as the membrane structure were also changed in the electrofusion process, in addition to the size modification of that process.

  18. Growing Uniform Graphene Disks and Films on Molten Glass for Heating Devices and Cell Culture.

    Science.gov (United States)

    Chen, Yubin; Sun, Jingyu; Gao, Junfeng; Du, Feng; Han, Qi; Nie, Yufeng; Chen, Zhaolong; Bachmatiuk, Alicja; Priydarshi, Manish Kr; Ma, Donglin; Song, Xiuju; Wu, Xiaosong; Xiong, Chunyang; Rümmeli, Mark H; Ding, Feng; Zhang, Yanfeng; Liu, Zhongfan

    2015-12-16

    The direct growth of uniform graphene disks and their continuous film is achieved by exploiting the molten state of glass. The use of molten glass enables highly uniform nucleation and an enhanced growth rate (tenfold) of graphene, as compared to those scenarios on commonly used insulating solids. The obtained graphene glasses show promising application potentials in daily-life scenarios such as smart heating devices and biocompatible cell-culture mediums.

  19. Development of a Handmade Conductivity Measurement Device for a Thin-Film Semiconductor and Its Application to Polypyrrole

    Science.gov (United States)

    Seng, Set; Shinpei, Tomita; Yoshihiko, Inada; Masakazu, Kita

    2014-01-01

    The precise measurement of conductivity of a semiconductor film such as polypyrrole (Ppy) should be carried out by the four-point probe method; however, this is difficult for classroom application. This article describes the development of a new, convenient, handmade conductivity device from inexpensive materials that can measure the conductivity…

  20. Photometric Compliance of Tablet Screens and Retro-Illuminated Acuity Charts As Visual Acuity Measurement Devices.

    Directory of Open Access Journals (Sweden)

    I A T Livingstone

    Full Text Available Mobile technology is increasingly used to measure visual acuity. Standards for chart-based acuity tests specify photometric requirements for luminance, optotype contrast and luminance uniformity. Manufacturers provide some photometric data but little is known about tablet performance for visual acuity testing. This study photometrically characterised seven tablet computers (iPad, Apple inc. and three ETDRS (Early Treatment Diabetic Retinopathy Study visual acuity charts with room lights on and off, and compared findings with visual acuity measurement standards. Tablet screen luminance and contrast were measured using nine points across a black and white checkerboard test screen at five arbitrary brightness levels. ETDRS optotypes and adjacent white background luminance and contrast were measured. All seven tablets (room lights off exceeded the most stringent requirement for mean luminance (≥ 120 cd/m2 providing the nominal brightness setting was above 50%. All exceeded contrast requirement (Weber ≥ 90% regardless of brightness setting, and five were marginally below the required luminance uniformity threshold (Lmin/Lmax ≥ 80%. Re-assessing three tablets with room lights on made little difference to mean luminance or contrast, and improved luminance uniformity to exceed the threshold. The three EDTRS charts (room lights off had adequate mean luminance (≥ 120 cd/m2 and Weber contrast (≥ 90%, but all three charts failed to meet the luminance uniformity standard (Lmin/Lmax ≥ 80%. Two charts were operating beyond manufacturer's recommended lamp replacement schedule. With room lights on, chart mean luminance and Weber contrast increased, but two charts still had inadequate luminance uniformity. Tablet computers showed less inter-device variability, higher contrast, and better luminance uniformity than charts in both lights-on and lights-off environments, providing brightness setting was >50%. Overall, iPad tablets matched or marginally out

  1. Measurement of cell traction forces with ImageJ.

    Science.gov (United States)

    Martiel, Jean-Louis; Leal, Aldo; Kurzawa, Laetitia; Balland, Martial; Wang, Irene; Vignaud, Timothée; Tseng, Qingzong; Théry, Manuel

    2015-01-01

    The quantification of cell traction forces requires three key steps: cell plating on a deformable substrate, measurement of substrate deformation, and the numerical estimation of the corresponding cell traction forces. The computing steps to measure gel deformation and estimate the force field have somehow limited the adoption of this method in cell biology labs. Here we propose a set of ImageJ plug-ins so that every lab equipped with a fluorescent microscope can measure cell traction forces.

  2. A device for continuous measurement of head position during PET brain imaging

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, S.R.; Daube-Witherspoon, M.E.; Green, M.V. [National Inst. of Health, Bethesda, MD (United States)

    1994-05-01

    Head motion during PET brain imaging can seriously degrade image quality. We have shown previously (1) that the effects of such movements can be eliminated if the position of the head relative to the scanner is accurately known throughout the study. To this end, we designed, built, and tested a tracking device (TD) and head attachment fixture. The TD consists of 3 miniature lamps, attached to a rigid wire frame, that are sequentially illuminated within the field of view of two positions of the lamps are computed every 5 sec and these values are used to compute the 3 rotational and 3 translational coordinates of the frame. The accuracy of the TD was evaluated by attaching the frame to a precision mechanical rotation-translation apparatus and comparing motions in all coordinate direction. The maximum error observed in the range {plus_minus}10 mm, {plus_minus}4 deg was 0.7 mm and 0.4 deg, with largest uncertainties in the azimuthal direction. The head attachment mechanism was evaluated in 8 subjects by connecting the rigid lamp wire frame to the top of a lightweight tubular structure fitted into the ears and attached by adhesive pads to the forehead. Simultaneously, the transducer of a commercially available tracking system was attached by adhesive to the forehead. With head position being monitored by both systems, each subject was first instructed to perform a set of controlled head movements in each of the coordinate directions and then to rest normally for 5 minutes. The largest angular difference observed between the two devices in these subjects was 2 deg (azimuthal), with most differences being less than 1 deg and less than 10%. These results suggest that the TD is capable of accurately measuring small rotational and translational displacements and that the head attachment mechanism to which the lamp array is fixed follows head movement within acceptable limits.

  3. Comparison of speech intelligibility measures for an electronic amplifying earmuff and an identical passive attenuation device

    Directory of Open Access Journals (Sweden)

    David C. Byrne

    2012-02-01

    Full Text Available The purpose of this study was to identify any differences between speech intelligibility measures obtained with MineEars electronic earmuffs (ProEars, Westcliffe, CO, USA and the Bilsom model 847 (Sperian Hearing Protection, San Diego, CA, USA, which is a conventional passive-attenuation earmuff. These two devices are closely related, since the MineEars device consisted of a Bilsom 847 earmuff with the addition of electronic amplification circuits. Intelligibility scores were obtained by conducting listening tests with 15 normalhearing human subject volunteers wearing the earmuffs. The primary research objective was to determine whether speech understanding differs between the passive earmuffs and the electronic earmuffs (with the volume control set at three different positions in a background of 90 dB(A continuous noise. As expected, results showed that speech intelligibility increased with higher speech-to-noise ratios; however, the electronic earmuff with the volume control set at full-on performed worse than when it was set to off or the lowest on setting. This finding suggests that the maximum volume control setting for these electronic earmuffs may not provide any benefits in terms of increased speech intelligibility in the background noise condition that was tested. Other volume control settings would need to be evaluated for their ability to produce higher speech intelligibility scores. Additionally, since an extensive electro-acoustic evaluation of the electronic earmuff was not performed as a part of this study, the exact cause of the reduced intelligibility scores at full volume remains unknown.

  4. Accuracy of thermistors and thermocouples as flow-measuring devices for detecting hypopnoeas.

    Science.gov (United States)

    Farré, R; Montserrat, J M; Rotger, M; Ballester, E; Navajas, D

    1998-01-01

    The aim of this work was to assess the accuracy of thermistors/thermocouples as devices for detecting hypopnoeas in sleep studies. Conventional thermistor/thermocouples were studied with a respiratory model allowing the simulation of inspiratory (22 degrees C) and expiratory (37 degrees C) flows. The thermistor signal (V'th) was compared with a pneumotachograph (V'th): 1) for sinusoidal and square-wave airflows (+/-0.05 to +/-0.8 L.s(-1), 10-20 breaths.min(-1) (bpm)); 2) when changing the distance from the thermistor to the nose (0-20 mm); and 3) when doubling the section of the nostrils. The thermistor was strongly nonlinear and flow reductions (hypopnoeas) were underestimated: a 50% reduction in V' (+/-0.5 L.s(-1), 15 bpm, sinusoidal) resulted in only an 18% reduction in V'th. V'th depended considerably on the airflow pattern: for V'=+/-0.5 L.s(-1), V'th increased by 100% from sinusoidal (20 bpm) to square-wave (10 bpm). For V'=+/-0.5 L.s(-1), 15 bpm, sinusoidal flow, V'th increased by 79% when the distance thermistor-nose varied from 20-0 mm, and V'th decreased by 37% when doubling the nose section. We concluded that thermistor/thermocouples are inaccurate flow-measuring devices when used at the airflow conditions typical of sleep studies. Their use for quantifying hypopnoeas may lead to considerable underdetection of these respiratory events.

  5. A bioMEMS device for the study of mechanical properties of cells

    Science.gov (United States)

    Sanders, Joseph M.; Butt, Logan; Clark, Ashley; Williams, James; Padgen, Michael; Leung, Edison; Keely, Patricia; Condeelis, John S.; Aguirre-Ghiso, Julio; Castracane, James

    2015-03-01

    The tumor microenvironment is a complex system which is not fully understood. New technologies are needed to provide a better understanding of the role of the tumor microenvironment in promoting metastasis. The Nano Intravital Device, or NANIVID, has been developed as an optically transparent, implantable tool to study the tumor microenvironment. Two etched glass substrates are sealed using a thin polymer membrane to create a reservoir with a single outlet. This reservoir is loaded with a custom hydrogel blend that contains selected factors for delivery to the tumor microenvironment. When the device is implanted in the tumor, the hydrogel swells and releases these entrapped molecules, forming a sustained concentration gradient. The NANIVID has previously been successful in manipulating the tumor microenvironment both in vitro as well as in vivo. As metastatic cells intravasate, it has been shown that some are able to do so unscathed and reach their new location, while others are cleaved during the process1. There appears to be a correlation between cell migration and the mechanical properties of these cells. It is believed that these properties can be detected in real time by atomic force microscopy. In this study, metastatic MTLn3 rat mammary cells are seeded onto 1-dimensional microfibers and directed up a stable gradient of growth factor. The NANIVID device is placed behind our AFM tip, where it generates a stable chemotactic gradient of epidermal growth factor. Scanning confocal laser microscopy is also used to monitor movement of the cells over time. This experiment will shed light on the mechanical changes in metastatic cells as they undergo directed migration.

  6. NOTE: Radiological thickness measurement using a liquid ionization chamber electronic portal imaging device

    Science.gov (United States)

    Evans, Philip M.; Donovan, Ellen M.; Partridge, Mike; Bidmead, A. Margaret; Garton, Andrew; Mubata, Cephas

    1999-06-01

    We present a method of calibrating the Portal Vision electronic portal imaging device to obtain radiological thickness maps for compensator design. In this method, coefficients are derived to describe the relationship between intensity and thickness for a set of water-equivalent blocks. The effects of four parameters were studied: (a) The dose response of the system was measured and found to be describable by a square-root function. (b) The calibration data and images were taken with a wedge in situ. The effects of using different wedges and different wedge orientations were investigated. The intrinsic accuracy of the accelerator/imager system was found to be 1.9 mm, for both 15° and 30° wedges. Changing the wedge orientation between calibration and imaging and rotating the calibration coefficients accordingly led to an error of 3.5 mm. (c) The variation in detector response with gantry angle was measured and corrected. The residual error in this process was 2.4 mm. (d) The use of a model to correct the effects of imaging with different field sizes was investigated and found to yield a residual error of 2.9 mm. The overall error in image calibrations was 4 mm or 2% in dose. This is considered to be sufficiently small for the intended use of designing compensators for tangential breast irradiation.

  7. Photovoltaic device

    Energy Technology Data Exchange (ETDEWEB)

    Reese, Jason A; Keenihan, James R; Gaston, Ryan S; Kauffmann, Keith L; Langmaid, Joseph A; Lopez, Leonardo; Maak, Kevin D; Mills, Michael E; Ramesh, Narayan; Teli, Samar R

    2017-03-21

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device with a multilayered photovoltaic cell assembly and a body portion joined at an interface region and including an intermediate layer, at least one interconnecting structural member, relieving feature, unique component geometry, or any combination thereof.

  8. Photovoltaic device

    Science.gov (United States)

    Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.

    2015-06-02

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device with a multilayered photovoltaic cell assembly and a body portion joined at an interface region and including an intermediate layer, at least one interconnecting structural member, relieving feature, unique component geometry, or any combination thereof.

  9. Photovoltaic device

    Science.gov (United States)

    Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.

    2015-09-01

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device (10) with a multilayered photovoltaic cell assembly (100) and a body portion (200) joined at an interface region (410) and including an intermediate layer (500), at least one interconnecting structural member (1500), relieving feature (2500), unique component geometry, or any combination thereof.

  10. Method of fabricating a back-contact solar cell and device thereof

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bo; Smith, David; Cousins, Peter

    2016-08-02

    Methods of fabricating back-contact solar cells and devices thereof are described. A method of fabricating a back-contact solar cell includes forming an N-type dopant source layer and a P-type dopant source layer above a material layer disposed above a substrate. The N-type dopant source layer is spaced apart from the P-type dopant source layer. The N-type dopant source layer and the P-type dopant source layer are heated. Subsequently, a trench is formed in the material layer, between the N-type and P-type dopant source layers.

  11. Fluid Flow Shear Stress Stimulation on a Multiplex Microfluidic Device for Rat Bone Marrow Stromal Cell Differentiation Enhancement

    Directory of Open Access Journals (Sweden)

    Chia-Wen Tsao

    2015-12-01

    Full Text Available Microfluidic devices provide low sample consumption, high throughput, high integration, and good environment controllability advantages. An alternative to conventional bioreactors, microfluidic devices are a simple and effective platform for stem cell investigations. In this study, we describe the design of a microfluidic device as a chemical and mechanical shear stress bioreactor to stimulate rat bone marrow stromal cells (rBMSCs into neuronal cells. 1-methyl-3-isobutylxanthine (IBMX was used as a chemical reagent to induce rBMSCs differentiation into neurons. Furthermore, the shear stress applied to rBMSCs was generated by laminar microflow in the microchannel. Four parallel microfluidic chambers were designed to provide a multiplex culture platform, and both the microfluidic chamber-to-chamber, as well as microfluidic device-to-device, culture stability were evaluated. Our research shows that rBMSCs were uniformly cultured in the microfluidic device and differentiated into neuronal cells with IBMX induction. A three-fold increase in the neuronal cell differentiation ratio was noted when rBMSCs were subjected to both IBMX and fluid flow shear stress stimulation. Here, we propose a microfluidic device which is capable of providing chemical and physical stimulation, and could accelerate neuronal cell differentiation from bone marrow stromal cells.

  12. Regeneration of the lung: Lung stem cells and the development of lung mimicking devices.

    Science.gov (United States)

    Schilders, Kim A A; Eenjes, Evelien; van Riet, Sander; Poot, André A; Stamatialis, Dimitrios; Truckenmüller, Roman; Hiemstra, Pieter S; Rottier, Robbert J

    2016-04-23

    Inspired by the increasing burden of lung associated diseases in society and an growing demand to accommodate patients, great efforts by the scientific community produce an increasing stream of data that are focused on delineating the basic principles of lung development and growth, as well as understanding the biomechanical properties to build artificial lung devices. In addition, the continuing efforts to better define the disease origin, progression and pathology by basic scientists and clinicians contributes to insights in the basic principles of lung biology. However, the use of different model systems, experimental approaches and readout systems may generate somewhat conflicting or contradictory results. In an effort to summarize the latest developments in the lung epithelial stem cell biology, we provide an overview of the current status of the field. We first describe the different stem cells, or progenitor cells, residing in the homeostatic lung. Next, we focus on the plasticity of the different cell types upon several injury-induced activation or repair models, and highlight the regenerative capacity of lung cells. Lastly, we summarize the generation of lung mimics, such as air-liquid interface cultures, organoids and lung on a chip, that are required to test emerging hypotheses. Moreover, the increasing collaboration between distinct specializations will contribute to the eventual development of an artificial lung device capable of assisting reduced lung function and capacity in human patients.

  13. On-Orbit Measurement of Next Generation Space Solar Cell Technology on the International Space Station

    Science.gov (United States)

    Wolford, David S.; Myers, Matthew G.; Prokop, Norman F.; Krasowski, Michael J.; Parker, David S.; Cassidy, Justin C.; Davies, William E.; Vorreiter, Janelle O.; Piszczor, Michael F.; McNatt, Jeremiah S.

    2015-01-01

    Measurement is essential for the evaluation of new photovoltaic (PV) technology for space solar cells. NASA Glenn Research Center (GRC) is in the process of measuring several solar cells in a supplemental experiment on NASA Goddard Space Flight Center's (GSFC) Robotic Refueling Mission's (RRM) Task Board 4 (TB4). Four industry and government partners have provided advanced PV devices for measurement and orbital environment testing. The experiment will be on-orbit for approximately 18 months. It is completely self-contained and will provide its own power and internal data storage. Several new cell technologies including four- junction (4J) Inverted Metamorphic Multijunction (IMM) cells will be evaluated and the results compared to ground-based measurements.

  14. Investigation of Junction Properties in CdS/CdTe Solar Cells and Their Correlation to Device Properties: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Dhere, R. G.; Zhang, Y.; Romero, M. J.; Asher, S. E.; Young, M.; To, B.; Noufi, R.; Gessert, T. A.

    2008-05-01

    Secondary-ion mass spectrometry analysis of the CdS/CdTe interface shows that S diffusion in CdTe increases with substrate temperature and CdCl2 heat treatment. There is also an accumulation of Cl at the interface for CdCl2-treated samples. Modulated photo-reflectance studies shows that devices with CdCl2 heat treatment and open-circuit voltage (Voc) of 835 mV have a distinct high electric-field region in the layer with bandgap of 1.45 eV. Electron-beam induced current measurements reveal a one-sided junction for high Voc devices. The nature of the junction changes with processing. For heterojunction devices, the depletion region includes the highly defective CdS/CdTe interface, which would increase the recombination current and consequently the dark current, leading to lower Voc. In the case of CdCl2-treated cells, the n+-p junction and its high electric-field results in the junction between structurally compatible CdTe and the Te-rich CdSTe alloy, and thus, in higher Voc.

  15. Optical Flow Cell for Measuring Size, Velocity and Composition of Flowing Droplets

    Directory of Open Access Journals (Sweden)

    Sammer-ul Hassan

    2017-02-01

    Full Text Available Here an optical flow cell with two light paths is reported that can accurately quantify the size and velocity of droplets flowing through a microchannel. The flow cell can measure the time taken for droplets to pass between and through two conjoined light paths, and thereby is capable of measuring the velocities (0.2–5.45 mm/s and sizes of droplets (length > 0.8 mm. The composition of the droplet can also be accurately quantified via optical absorption measurements. The device has a small footprint and uses low-powered, low-cost components, which make it ideally suited for use in field-deployable and portable analytical devices.

  16. Relationship Between Absorber Layer Properties and Device Operation Modes For High Efficiency Thin Film Solar Cells

    Science.gov (United States)

    Ravichandran, Ram; Kokenyesi, Robert; Wager, John; Keszler, Douglas; CenterInverse Design Team

    2014-03-01

    A thin film solar cell (TFSC) can be differentiated into two distinct operation modes based on the transport mechanism. Current TFSCs predominantly exploit diffusion to extract photogenerated minority carriers. For efficient extraction, the absorber layer requires high carrier mobilities and long minority carrier lifetimes. Materials exhibiting a strong optical absorption onset near the fundamental band gap allows reduction of the absorber layer thickness to significantly less than 1 μm. In such a TFSC, a strong intrinsic electric field drives minority carrier extraction, resulting in drift-based transport. The basic device configuration utilized in this simulation study is a heterojunction TFSC with a p-type absorber layer. The diffusion/drift device operation modes are simulated by varying the thickness and carrier concentration of the absorber layer, and device performance between the two modes is compared. In addition, the relationship between device operation mode and transport properties, including carrier mobility and minority carrier lifetime are explored. Finally, candidate absorber materials that enable the advantages of a drift-based TFSC developed within the Center for Inverse Design are presented. School of Electrical Engineering and Computer Science.

  17. Comparison of two dependent within subject coefficients of variation to evaluate the reproducibility of measurement devices

    Directory of Open Access Journals (Sweden)

    Kaya Namik

    2008-04-01

    Full Text Available Abstract Background The within-subject coefficient of variation and intra-class correlation coefficient are commonly used to assess the reliability or reproducibility of interval-scale measurements. Comparison of reproducibility or reliability of measurement devices or methods on the same set of subjects comes down to comparison of dependent reliability or reproducibility parameters. Methods In this paper, we develop several procedures for testing the equality of two dependent within-subject coefficients of variation computed from the same sample of subjects, which is, to the best of our knowledge, has not yet been dealt with in the statistical literature. The Wald test, the likelihood ratio, and the score tests are developed. A simple regression procedure based on results due to Pitman and Morgan is constructed. Furthermore we evaluate the statistical properties of these methods via extensive Monte Carlo simulations. The methodologies are illustrated on two data sets; the first are the microarray gene expressions measured by two plat- forms; the Affymetrix and the Amersham. Because microarray experiments produce expressions for a large number of genes, one would expect that the statistical tests to be asymptotically equivalent. To explore the behaviour of the tests in small or moderate sample sizes, we illustrated the methodologies on data from computer-aided tomographic scans of 50 patients. Results It is shown that the relatively simple Wald's test (WT is as powerful as the likelihood ratio test (LRT and that both have consistently greater power than the score test. The regression test holds its empirical levels, and in some occasions is as powerful as the WT and the LRT. Conclusion A comparison between the reproducibility of two measuring instruments using the same set of subjects leads naturally to a comparison of two correlated indices. The presented methodology overcomes the difficulty noted by data analysts that dependence between

  18. Context classification during blood pressure self-measurement using the sensor seat and the audio classification device

    DEFF Research Database (Denmark)

    Wagner, Stefan Rahr; Rasmussen, Niels Holm; Ahrendt, Peter

    2012-01-01

    pressure (BP) devices cannot verify whether the patient has followed these recommendations or not. As a result, the data quality of BP measurements could be biased. We present a proof-of-concept demonstration prototype that uses audio context classification for detecting speech during the measurement...... process, as well as a sensor seat for measuring patient posture and activity before and during the BPSM process....

  19. A flexible microprocessor system for the measurement of cell size.

    OpenAIRE

    1982-01-01

    A flexible system for the measurement of length and area is described. The system consists of the Reichert Jung MOP-1 area measuring device interfaced with a Commodore PET computer. Its use is illustrated by the planimetric measurement of cross sectional areas in histochemical preparations of normal and diseased muscle. While measurements are being made data can be displayed on the computer screen either in numerical form or as a frequency histogram together with simple statistical analyses. ...

  20. Anti-static measures of CMOS devices%CMOS器件抗静电措施的研究

    Institute of Scientific and Technical Information of China (English)

    谭婕娟

    2012-01-01

    As CMOS devices are static damage to 90% delay failure,the reliability of the whole application too much influence,hence the need for anti-static measures of CMOS devices.This paper describes the CMOS devices from electrostatic damage mechanism,which made several of the designer how the anti-static circuit design,to protect CMOS devices from damage.%由于CMOS器件静电损伤90%是延迟失效,对整机应用的可靠性影响太大,因而有必要对CMOS器件进行抗静电措施。本文描述了CMOS器件受静电损伤的机理,从而对设计人员提出了几种在线路设计中如何抗静电,以保护CMOS器件不受损伤。

  1. The intercell dynamics of T cells and dendritic cells in a lymph node-on-a-chip flow device.

    Science.gov (United States)

    Moura Rosa, Patrícia; Gopalakrishnan, Nimi; Ibrahim, Hany; Haug, Markus; Halaas, Øyvind

    2016-10-01

    T cells play a central role in immunity towards cancer and infectious diseases. T cell responses are initiated in the T cell zone of the lymph node (LN), where resident antigen-bearing dendritic cells (DCs) prime and activate antigen-specific T cells passing by. In the present study, we investigated the T cell : DC interaction in a microfluidic device to understand the intercellular dynamics and physiological conditions in the LN. We show random migration of antigen-specific T cells onto the antigen-presenting DC monolayer independent of the flow direction with a mean T cell : DC dwell time of 12.8 min and a mean velocity of 6 μm min(-1). Furthermore, we investigated the antigen specific vs. unspecific attachment and detachment of CD8(+) and CD4(+) T cells to DCs under varying shear stress. In our system, CD4(+) T cells showed long stable contacts with APCs, whereas CD8(+) T cells presented transient interactions with DCs. By varying the shear stress from 0.01 to 100 Dyn cm(-2), it was also evident that there was a much stronger attachment of antigen-specific than unspecific T cells to stationary DCs up to 1-12 Dyn cm(-2). The mechanical force of the cell : cell interaction associated with the pMHC-TCR match under controlled tangential shear force was estimated to be in the range of 0.25-4.8 nN. Finally, upon performing attachment & detachment tests, there was a steady accumulation of antigen specific CD8(+) T cells and CD4(+) T cells on DCs at low shear stresses, which were released at a stress of 12 Dyn cm(-2). This microphysiological model provides new possibilities to recreate a controlled mechanical force threshold of pMHC-TCR binding, allowing the investigation of intercellular signalling of immune synapses and therapeutic targets for immunotherapy.

  2. Effect of Mesostructured Layer upon Crystalline Properties and Device Performance on Perovskite Solar Cells.

    Science.gov (United States)

    Listorti, Andrea; Juarez-Perez, Emilio J; Frontera, Carlos; Roiati, Vittoria; Garcia-Andrade, Laura; Colella, Silvia; Rizzo, Aurora; Ortiz, Pablo; Mora-Sero, Ivan

    2015-05-07

    One of the most fascinating characteristics of perovskite solar cells (PSCs) is the retrieved obtainment of outstanding photovoltaic (PV) performances withstanding important device configuration variations. Here we have analyzed CH3NH3PbI3-xClx in planar or in mesostructured (MS) configurations, employing both titania and alumina scaffolds, fully infiltrated with perovskite material or presenting an overstanding layer. The use of the MS scaffold induces to the perovskite different structural properties, in terms of grain size, preferential orientation, and unit cell volume, in comparison to the ones of the material grown with no constraints, as we have found out by X-ray diffraction analyses. We have studied the effect of the PSC configuration on photoinduced absorption and time-resolved photoluminescence, complementary techniques that allow studying charge photogeneration and recombination. We have estimated electron diffusion length in the considered configurations observing a decrease when the material is confined in the MS scaffold with respect to a planar architecture. However, the presence of perovskite overlayer allows an overall recovering of long diffusion lengths explaining the record PV performances obtained with a device configuration bearing both the mesostructure and a perovskite overlayer. Our results suggest that performance in devices with perovskite overlayer is mainly ruled by the overlayer, whereas the mesoporous layer influences the contact properties.

  3. Processing and modeling issues for thin-film solar cell devices. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Birkmire, R.W.; Phillips, J.E. [Univ. of Delaware, Newark, DE (United States). Institute of Energy Conversion

    1997-11-01

    During the third phase of the subcontract, IEC researchers have continued to provide the thin film PV community with greater depth of understanding and insight into a wide variety of issues including: the deposition and characterization of CuIn{sub 1-x}Ga{sub x}Se{sub 2}, a-Si, CdTe, CdS, and TCO thin films; the relationships between film and device properties; and the processing and analysis of thin film PV devices. This has been achieved through the systematic investigation of all aspects of film and device production and through the analysis and quantification of the reaction chemistries involved in thin film deposition. This methodology has led to controlled fabrications of 15% efficient CuIn{sub 1-x}Ga{sub x}Se{sub 2} solar cells over a wide range of Ga compositions, improved process control of the fabrication of 10% efficient a-Si solar cells, and reliable and generally applicable procedures for both contacting and doping films. Additional accomplishments are listed below.

  4. Research on measurement-device-independent quantum key distribution based on an air-water channel

    Science.gov (United States)

    Zhou, Yuan-yuan; Zhou, Xue-jun; Xu, Hua-bin; Cheng, Kang

    2016-11-01

    A measurement-device-independent quantum key distribution (MDI-QKD) method with an air-water channel is researched. In this method, the underwater vehicle and satellite are the legitimate parties, and the third party is at the airwater interface in order to simplify the unilateral quantum channel to water or air. Considering the condition that both unilateral transmission distance and transmission loss coefficient are unequal, a perfect model of the asymmetric channel is built. The influence of asymmetric channel on system loss tolerance and secure transmission distance is analyzed. The simulation results show that with the increase of the channel's asymmetric degree, the system loss tolerance will descend, one transmission distance will be reduced while the other will be increased. When the asymmetric coefficient of channel is between 0.068 and 0.171, MDI-QKD can satisfy the demand of QKD with an air-water channel, namely the underwater transmission distance and atmospheric transmission distance are not less than 60 m and 12 km, respectively.

  5. International scientific consensus on medical plantar pressure measurement devices: technical requirements and performance

    Directory of Open Access Journals (Sweden)

    Claudia Giacomozzi

    2012-01-01

    Full Text Available BACKGROUND: Since 2006, the Italian National Institute of Health (ISS has been conducting independent scientific activities to standardize the technical assessment of plantar pressure measurement devices (PMDs. MATERIAL AND METHODS: On the basis of the ISS results, in 2010 the Pedobarographic Group of the International Foot and Ankle Biomechanics community (i-FAB-PG promoted a consensus activity about the main technical requirements for the appropriate use of PMDs. The activity relied on a moodlebased on-line forum, documents exchange, discussions, reviews, meetings and a final survey. RESULTS: The participation of clinical and technical researchers, users, and manufacturers, contributed to the delivery of the hereby reported recommendations which specifically regard Medical PMDs in the form of platforms. CONCLUSIONS: The i-FAB-PG community reached overall agreement on the recommendations, with a few minor objections which are reported and commented in the document. RELEVANCE: The present document, the highest result achievable within a small scientific community, will hopefully represent the starting point of the wider process of establishing official international guidelines or standards, within scientific communities and standardization organizations.

  6. An improved device for bioimpedance deviation measurements based on 4-electrode half bridge

    Science.gov (United States)

    Liu, Yang; Qiao, Xiaoyan; Li, Gang; Lin, Ling

    2016-10-01

    Researches on monitoring the body fluid changes have attracted much attention during recent years. Real-time bioimpedance deviation detection has good potential for evaluating body fluid changes. In this paper, an improved device based on the self-balancing half bridge and the 4-electrode technique is proposed, which is able to detect minor bioimpedance deviations. The 4-electrode technique is used to remove the interference from contact impedance. Furthermore, the automatic balancing half bridge is utilized to deduct the high-level static impedance baseline, and thus, the dynamic range is enlarged. Moreover, a digital lock-in algorithm based on oversampling improved the effective resolution of the system. Validation experiments show that the minimum bioimpedance deviation measured in the experiment can reach 1 Ω even when the bioimpedance baseline is 10 kΩ and the noise level is low. The system has advantages of high resolution, high magnification, large dynamic range, and good self-adaptability for bioimpedance deviation detection.

  7. Measurement-device-independent quantum key distribution with nitrogen vacancy centers in diamond

    Science.gov (United States)

    Lo Piparo, Nicoló; Razavi, Mohsen; Munro, William J.

    2017-02-01

    Memory-assisted measurement-device-independent quantum key distribution (MA-MDI-QKD) has recently been proposed as a possible intermediate step towards the realization of quantum repeaters. Despite its relaxing some of the requirements on quantum memories, the choice of memory in relation to the layout of the setup and the protocol has a stark effect on our ability to beat existing no-memory systems. Here, we investigate the suitability of nitrogen vacancy (NV) centers, as quantum memories, in MA-MDI-QKD. We particularly show that moderate cavity enhancement is required for NV centers if we want to outperform no-memory QKD systems. Using system parameters mostly achievable by today's state of the art, we then anticipate some total key rate advantage in the distance range between 300 and 500 km for cavity-enhanced NV centers. Our analysis accounts for major sources of error including the dark current, the channel loss, and the decoherence of the quantum memories.

  8. Fabrication and measurement of devices in Si/SiGe nanomembranes

    Science.gov (United States)

    Mohr, Robert

    Silicon/silicon-germanium (Si/SiGe) heterostructures are useful as hosts for gated quantum dots. The quality of the as-grown Si/SiGe heterostructure has a large impact on the final quality of the quantum dot as a qubit host. For many years, quantum dots have been fab- ricated on strain-graded heterostructures. Commonly used strain-graded heterostructures inevitably develop plastic defects that lead to interface roughness, crosshatch, and mosaic tilt. All of these factors are sources of disorder in Si/SiGe quantum electronics. In this dissertation, I report the fabrication of Hall bars and gated quantum dots on heterostructures grown on fully elastically relaxed SiGe nanomembranes, rather than strain-graded heterostructures. I report measurements of Hall bars demonstrating the creation of two-dimensional electron gases in these structures. I report the fabrication procedures used to create pairs of Hall bars and quantum dots on individual membranes. In addition, I explain a general process flow for the creation of Si/SiGe quantum devices. I focus especially on an ion-implantation technique I implemented for the fabrication of Hall bars and quantum dots in Si/SiGe heterostructures without modulation doping layers.

  9. Electrical field manipulation of cancer cell behavior monitored by whole cell biosensing device.

    Science.gov (United States)

    Hondroulis, Evangelia; Melnick, Steven J; Zhang, Xueji; Wu, Ze-Zhi; Li, Chen-Zhong

    2013-08-01

    All living cells possess electrical characteristics and are thus responsive to, and even generate electric fields and currents. It has been shown that the electrical properties of cancer cells differ from normal proliferating cells, thus electric fields may induce differential effects in normal and cancer cells. Manipulation of these electrical properties may provide a powerful direct and/or adjuvant therapeutic option for cancer. A whole cell impedance-based biosensor to monitor the effects of a range of different frequencies (50 kHz-2 MHz) at low-intensity (growth rate of human SKOV3 ovarian cancer cells versus non-cancerous HUVECs is reported. Rapid real-time monitoring of the SKOV3 behavior was observed as the alternating electric fields were applied and the impedimetric response of the cells was recorded. The cells were also labeled with propidium iodide to examine morphological changes and cell viability with fluorescence microscopy with trypan blue for comparison. A noticeable decrease in the growth profile of the SKOV3 was observed with the application of 200 kHz alternating electric fields indicating specific inhibitory effects on dividing cells in culture in contrast to the HUVECs. The outcome of this research will improve our fundamental understanding of the behavior of cancer cells when exposed to alternating electric fields at specific frequencies and foster the development strategies and optimal parameters for alternating electric field therapies for clinical and drug delivery applications.

  10. MEMS device for bending test: measurements of fatigue and creep of electroplated nickel

    DEFF Research Database (Denmark)

    Larsen, Kristian Pontoppidan; Rasmussen, Anette Alsted; Ravnkilde, Jan Tue;

    2003-01-01

    In situ bending test devices with integrated electrostatic actuator were fabricated in electroplated nanocrystalline nickel. The device features approximately pure in-plane bending of the test beam. The excitation of the test beam has fixed displacement amplitude as the actuation electrodes are o...

  11. Evaluation of the Hair Cell Regeneration in Zebrafish Larvae by Measuring and Quantifying the Startle Responses

    Science.gov (United States)

    Wang, Changquan; Zhong, Zhenmin; Sun, Peng

    2017-01-01

    The zebrafish has become an established model organism for the study of hearing and balance systems in the past two decades. The classical approach to examine hair cells is to use dye to conduct selective staining, which shows the number and morphology of hair cells but does not reveal their function. Startle response is a behavior closely related to the auditory function of hair cells; therefore it can be used to measure the function of hair cells. In this study, we developed a device to measure the startle response of zebrafish larvae. By applying various levels of stimulus, it showed that the system can discern a 10 dB difference. The hair cell in zebrafish can regenerate after damage due to noise exposure or drug treatment. With this device, we measured the startle response of zebrafish larvae during and after drug treatment. The results show a similar trend to the classical hair cell staining method. The startle response was reduced with drug treatment and recovered after removal of the drug. Together it demonstrated the capability of this behavioral assay in evaluating the hair cell functions of fish larvae and its potential as a high-throughput screening tool for auditory-related gene and drug discovery.

  12. Evaluation of the Hair Cell Regeneration in Zebrafish Larvae by Measuring and Quantifying the Startle Responses

    Directory of Open Access Journals (Sweden)

    Changquan Wang

    2017-01-01

    Full Text Available The zebrafish has become an established model organism for the study of hearing and balance systems in the past two decades. The classical approach to examine hair cells is to use dye to conduct selective staining, which shows the number and morphology of hair cells but does not reveal their function. Startle response is a behavior closely related to the auditory function of hair cells; therefore it can be used to measure the function of hair cells. In this study, we developed a device to measure the startle response of zebrafish larvae. By applying various levels of stimulus, it showed that the system can discern a 10 dB difference. The hair cell in zebrafish can regenerate after damage due to noise exposure or drug treatment. With this device, we measured the startle response of zebrafish larvae during and after drug treatment. The results show a similar trend to the classical hair cell staining method. The startle response was reduced with drug treatment and recovered after removal of the drug. Together it demonstrated the capability of this behavioral assay in evaluating the hair cell functions of fish larvae and its potential as a high-throughput screening tool for auditory-related gene and drug discovery.

  13. 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.

  14. Napoleon Cybulski--Polish pioneer in developing of the device for measuring blood flow velocity.

    Science.gov (United States)

    Pawlik, W W; Konturek, S J; Bilski, R

    2006-04-01

    Napoleon Cybulski (1854-1919) was the most prominent Polish physiologist who chaired the Department of Physiology at the Faculty of Medicine of Jagiellonian University between 1885 and 1919. One of his greatest achievements was the construction of a device for precise measurements of blood movement in the vessels - the photohemotachometer, which provided a better insight into the physiology and pathophysiology of the circulatory system. In the field of endocrinology Cybulski together with Szymonowicz, found out that adrenal extracts contain biologically active substances that elevate blood pressure. He was also a constructor of an extremely clever microcalorimeter to measure the quantity of heat produced during isolated muscle contraction. He applied, for the first time, condensator discharges to stimulate nerves and analyzed changes in the excitability of the muscles. Cybulski proved that the cause of the electrical excitability of tissue depends on the electrical energy and the time of its duration. Together with Beck, he performed the experiments on the sensory centers in the central nervous system by means of the observations of the electrical evoked potentials. They discovered the continuous electrical oscillations in the brain - the brain waves and recorded the negative electrical potentials in certain brain areas induced by sensory impulses coming from the periphery. Using this technique Beck and Cybulski localized various centers in the brain of dogs and Macaccus rhesus monkeys. The names of Beck and Cybulski were quoted in many publications on neurophysiology and electroencephalography. The present paper describes Napoleon Cybulski as a constructor of an original instrument for studying the movement of blood under various experimental conditions an emphasizes the contribution of this invention to the development of physiology.

  15. Utility of Ochrobactrum anthropi YC152 in a Microbial Fuel Cell as an Early Warning Device for Hexavalent Chromium Determination.

    Science.gov (United States)

    Wang, Guey-Horng; Cheng, Chiu-Yu; Liu, Man-Hai; Chen, Tzu-Yu; Hsieh, Min-Chi; Chung, Ying-Chien

    2016-08-16

    Fast hexavalent chromium (Cr(VI)) determination is important for environmental risk and health-related considerations. We used a microbial fuel cell-based biosensor inoculated with a facultatively anaerobic, Cr(VI)-reducing, and exoelectrogenic Ochrobactrum anthropi YC152 to determine the Cr(VI) concentration in water. The results indicated that O. anthropi YC152 exhibited high adaptability to pH, temperature, salinity, and water quality under anaerobic conditions. The stable performance of the microbial fuel cell (MFC)-based biosensor indicated its potential as a reliable biosensor system. The MFC voltage decreased as the Cr(VI) concentration in the MFC increased. Two satisfactory linear relationships were observed between the Cr(VI) concentration and voltage output for various Cr(VI) concentration ranges (0.0125-0.3 mg/L and 0.3-5 mg/L). The MFC biosensor is a simple device that can accurately measure Cr(VI) concentrations in drinking water, groundwater, and electroplating wastewater in 45 min with low deviations (<10%). The use of the biosensor can help in preventing the violation of effluent regulations and the maximum allowable concentration of Cr(VI) in water. Thus, the developed MFC biosensor has potential as an early warning detection device for Cr(VI) determination even if O. anthropi YC152 is a possible opportunistic pathogen.

  16. Utility of Ochrobactrum anthropi YC152 in a Microbial Fuel Cell as an Early Warning Device for Hexavalent Chromium Determination

    Directory of Open Access Journals (Sweden)

    Guey-Horng Wang

    2016-08-01

    Full Text Available Fast hexavalent chromium (Cr(VI determination is important for environmental risk and health-related considerations. We used a microbial fuel cell-based biosensor inoculated with a facultatively anaerobic, Cr(VI-reducing, and exoelectrogenic Ochrobactrum anthropi YC152 to determine the Cr(VI concentration in water. The results indicated that O. anthropi YC152 exhibited high adaptability to pH, temperature, salinity, and water quality under anaerobic conditions. The stable performance of the microbial fuel cell (MFC-based biosensor indicated its potential as a reliable biosensor system. The MFC voltage decreased as the Cr(VI concentration in the MFC increased. Two satisfactory linear relationships were observed between the Cr(VI concentration and voltage output for various Cr(VI concentration ranges (0.0125–0.3 mg/L and 0.3–5 mg/L. The MFC biosensor is a simple device that can accurately measure Cr(VI concentrations in drinking water, groundwater, and electroplating wastewater in 45 min with low deviations (<10%. The use of the biosensor can help in preventing the violation of effluent regulations and the maximum allowable concentration of Cr(VI in water. Thus, the developed MFC biosensor has potential as an early warning detection device for Cr(VI determination even if O. anthropi YC152 is a possible opportunistic pathogen.

  17. Proposal of methodology and test protocol for evaluating and qualifying pH measuring devices

    Directory of Open Access Journals (Sweden)

    Niza Helena de Almeida

    2006-01-01

    Full Text Available We present a proposal for evaluating and qualifying pH measuring devices based on the requirements of relevant standards. The proposal presented is based on ASTM E70, NBR 7353, JIS Z 8805, BS 3145, DIN 19268, NBR ISO 17025 and other standards, as well as the results of field research carried out in conjunction with professionals performing pH measurements in public health laboratories. Evaluation is performed by inspection of a form which records data from the measuring system. The form gives acceptable variations in the parameters being tested and allows a conclusion to be reached regarding acceptability of the system. Using the proposed protocol allows definition of suitable analysis criteria, while taking into account the influence pH measurement is subject and the need for correct results. This is particularly true when analyzing products already on the market, thus underlining the protocol's importance to the public health area.Este artigo apresenta uma proposta de protocolo de avaliação e qualificação de medidores de pH fundamentada no que prescrevem as normas ASTM E 70, NBR 7353, JIS Z 8805, BS 3145, DIN 19268, NBR ISO 17025 e outras, complementada com os resultados de pesquisa de campo junto a profissionais que realizam ensaio de medição de pH em laboratórios de saúde pública. A proposta consiste em avaliar o medidor de pH com auxílio de um formulário, cujo preenchimento baseia-se, principalmente, na inspeção e ensaios no sistema medidor. O formulário fornece variações aceitáveis para os parâmetros testados, propiciando parecer conclusivo quanto à adequação do instrumento. A aplicação do protocolo permite definir um critério adequado de análise, tendo em vista a influência que sofre tal ensaio de medição, especialmente, em análises de amostras de produtos decorrentes de finalidade fiscal, no âmbito da saúde pública

  18. Validity and Reliability of the PUSH Wearable Device to Measure Movement Velocity During the Back Squat Exercise.

    Science.gov (United States)

    Balsalobre-Fernández, Carlos; Kuzdub, Matt; Poveda-Ortiz, Pedro; Campo-Vecino, Juan Del

    2016-07-01

    Balsalobre-Fernández, C, Kuzdub, M, Poveda-Ortiz, P, and Campo-Vecino, Jd. Validity and reliability of the PUSH wearable device to measure movement velocity during the back squat exercise. J Strength Cond Res 30(7): 1968-1974, 2016-The purpose of this study was to analyze the validity and reliability of a wearable device to measure movement velocity during the back squat exercise. To do this, 10 recreationally active healthy men (age = 23.4 ± 5.2 years; back squat 1 repetition maximum [1RM] = 83 ± 8.2 kg) performed 3 repetitions of the back squat exercise with 5 different loads ranging from 25 to 85% 1RM on a Smith Machine. Movement velocity for each of the total 150 repetitions was simultaneously recorded using the T-Force linear transducer (LT) and the PUSH wearable band. Results showed a high correlation between the LT and the wearable device mean (r = 0.85; standard error of estimate [SEE] = 0.08 m·s) and peak velocity (r = 0.91, SEE = 0.1 m·s). Moreover, there was a very high agreement between these 2 devices for the measurement of mean (intraclass correlation coefficient [ICC] = 0.907) and peak velocity (ICC = 0.944), although a systematic bias between devices was observed (PUSH peak velocity being -0.07 ± 0.1 m·s lower, p ≤ 0.05). When measuring the 3 repetitions with each load, both devices displayed almost equal reliability (Test-retest reliability: LT [r = 0.98], PUSH [r = 0.956]; ICC: LT [ICC = 0.989], PUSH [ICC = 0.981]; coefficient of variation [CV]: LT [CV = 4.2%], PUSH [CV = 5.0%]). Finally, individual load-velocity relationships measured with both the LT (R = 0.96) and the PUSH wearable device (R = 0.94) showed similar, very high coefficients of determination. In conclusion, these results support the use of an affordable wearable device to track velocity during back squat training. Wearable devices, such as the one in this study, could have valuable practical applications for strength and conditioning coaches.

  19. Device for equalizing molten electrolyte content in a fuel cell stack

    Science.gov (United States)

    Smith, J.L.

    1985-12-23

    A device for equalizing the molten electrolyte content throughout the height of a fuel cell stack is disclosed. The device includes a passageway for electrolyte return with electrolyte wettable wicking material in the opposite end portions of the passageway. One end portion is disposed near the upper, negative end of the stack where electrolyte flooding occurs. The second end portion is placed near the lower, positive end of the stack where electrolyte is depleted. Heating means are provided at the upper portion of the passageway to increase electrolyte vapor pressure in the upper wicking material. The vapor is condensed in the lower passageway portion and conducted as molten electrolyte in the lower wick to the positive end face of the stack. An inlet is provided to inject a modifying gas into the passageway and thereby control the rate of electrolyte return.

  20. A microfluidic device for 2D to 3D and 3D to 3D cell navigation

    Science.gov (United States)

    Shamloo, Amir; Amirifar, Leyla

    2016-01-01

    Microfluidic devices have received wide attention and shown great potential in the field of tissue engineering and regenerative medicine. Investigating cell response to various stimulations is much more accurate and comprehensive with the aid of microfluidic devices. In this study, we introduced a microfluidic device by which the matrix density as a mechanical property and the concentration profile of a biochemical factor as a chemical property could be altered. Our microfluidic device has a cell tank and a cell culture chamber to mimic both 2D to 3D and 3D to 3D migration of three types of cells. Fluid shear stress is negligible on the cells and a stable concentration gradient can be obtained by diffusion. The device was designed by a numerical simulation so that the uniformity of the concentration gradients throughout the cell culture chamber was obtained. Adult neural cells were cultured within this device and they showed different branching and axonal navigation phenotypes within varying nerve growth factor (NGF) concentration profiles. Neural stem cells were also cultured within varying collagen matrix densities while exposed to NGF concentrations and they experienced 3D to 3D collective migration. By generating vascular endothelial growth factor concentration gradients, adult human dermal microvascular endothelial cells also migrated in a 2D to 3D manner and formed a stable lumen within a specific collagen matrix density. It was observed that a minimum absolute concentration and concentration gradient were required to stimulate migration of all types of the cells. This device has the advantage of changing multiple parameters simultaneously and is expected to have wide applicability in cell studies.