In the framework of the development of new generations of surface ships, the Royal Netherlands Navy is studying the option of the all-electric ship concept. Background is the growing demand of electric power on board of naval ships for various services (including weapons and sensors). Important features of such an all-electric ship concept are decentralized electric energy generation and storage. In such an all-electric ship concept, fuel cells are expected to play an important role in the future, not only for reasons of energy efficiency and low emissions, but also because of their potential military advantages. Especially polymer electrolyte fuel cell systems appear to be very interesting for this application.
Formaldehyde, a well-identified indoor pollutant, was recently classified as carcinogenic. New regulations for the air quality are expected and therefore there is a need for low-cost sensors, sensitive and selective with a fast response time for the detection of formaldehyde at ppb level. In the present work, we had developed a chemical sensor based on nano-porous matrices doped with Fluoral-P and optical methods of detection. The nano-porous matrices, elaborated via the Sol-Gel process, display nano-pores whose cavity is tailored for the trapping of the targeted pollutant. They provide a first selectivity with the discrimination of the pollutants by their size. A second selectivity is obtained with a molecular probe, Fluoral-P, which reacts specifically with formaldehyde leading to the 3,5- di-acetyl-1,4-dihydro-lutidine (DDL). The kinetics of formation of DDL was studied as function of many parameters such as the concentration of Fluoral-P in ...
Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr2N, CrN, TiN, V2N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of proton exchange membrane (PEM) single-cell fuel cell studies of stamped and pre-oxidized/nitrided developmental Fe-20Cr-4V weight percent (wt.%) and commercial type 2205 stainless steel alloy foils. The single-cell fuel cell behavior of the stamped and pre-oxidized/nitrided material was compared to as-stamped (no surface treatment) 904L, 2205, and Fe-20Cr-4V stainless steel alloy foils and machined graphite of similar flow field design. The best fuel cell behavior among the alloys was exhibited...
This book contains the proceedings of the International Topical Meeting on Remote Systems and Robotics in Hostile Environments. It is organized under the following sessions: Worldwide Applications Overview; Operating Mobile Systems; Sensors and Control Systems; Space Applications; Reactor Operations and Surveillance; Remote Equipment for Hazardous Operations; Future Mobile System; Mining and Construction Operations; Special Applications; Hot Cell Applications; Processing; Reactor Operations and Maintenance; Decontamination and Waste Handling; Remote Handling Development and Demonstration.
During thirty years the techniques used for sensing the environment have changed dramatically. This paper describes the latest generation of sensors available. This new generation of sensors includes those two most critical gas sensors for methane and carbon monoxide and new sensors for airflow and air temperature. When these sensors are combined with the new sensors for machine condition monitoring it forms the heart of the Sentex system. 2 figs.
... Tunnel Sensors Equipment on Environmental Expert Find and compare a variety of tunnel sensors equipment on the world's largest environmental industry portal. View ...
Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr{sub 2}N, CrN, TiN, V{sub 2}N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of proton exchange membrane (PEM) single-cell fuel cell studies of stamped and pre-oxidized/nitrided developmental Fe-20Cr-4V weight percent (wt.%) and commercial type 2205 stainless steel alloy foils. The single-cell fuel cell behavior of the stamped and pre-oxidized/nitrided material was compared to as-stamped (no surface treatment) 904L, 2205, and Fe-20Cr-4V stainless steel alloy foils and machined graphite of similar flow field design. The best fuel cell behavior among the alloys was exhibited by the pre-oxidized/nitrided Fe-20Cr-4V, ...
Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr{sub 2}N, CrN, TiN, V{sub 2}N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of proton exchange membrane (PEM) single-cell fuel cell studies of stamped and pre-oxidized/nitrided developmental Fe-20Cr-4V weight percent (wt.%) and commercial type 2205 stainless steel alloy foils. The single-cell fuel cell behavior of the stamped and pre-oxidized/nitrided material was compared to as-stamped (no surface treatment) 904L, 2205, and Fe-20Cr-4V stainless steel alloy foils and machined graphite of similar flow field design. The best fuel cell behavior among the alloys was exhibited by the pre-oxidized/nitrided Fe-20Cr-4V, ...
... is the sensor that converts incoming photons into a ... with CCD foundries to acquire such a sensor. ... 2007, Journal of Spacecraft and Rockets, 44, 910 ...
This paper summarizes results of preliminary experiments to develop cytological and biochemical indicators for estimating damage to respiratory cells in test animals exposed by inhalation to toxic agents associated with nonnuclear energy production, the specific goal being the application of advanced multiparameter flow-systems technologies to the detection of early atypical cellular changes in lung epithelium. Normal Syrian hamster lung cell samples composed of histiocytes, leukocytes, macrophages, ciliated columnar cells, and epithelial cells were stained with fluorescent dyes specific for different biochemical parameters and were analyzed in liquid suspension as they flowed through a chamber intersecting a laser beam of exciting light. Multiple sensors measured the total or two-color fluorescence and light scatter on a cell-by-cell basis. Cellular parameters ...
Nitridation of Cr-bearing alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant CrN or Cr2N base surfaces of interest for a range of electrochemical devices, including fuel cells, batteries, and sensors. This paper presents results of exploratory studies of the nitridation of commercially available, high Cr (30-35wt%) Ni-Cr alloys and a ferritic high Cr (29wt%) stainless steel for proton exchange membrane fuel cell (PEMFC) bipolar plates. A high degree of corrosion resistance in sulfuric acid solutions designed to simulate bipolar plate conditions and low ICR values were achieved. Oxygen impurities in the nitriding environment were observed to play a significant role in the nitrided surface structures that formed, with detrimental effect...
Unmanned Aerial Vehicles (UAV) are being proposed for many applications including surveillance, mapping and atmospheric studies. These applications require a lightweight, low speed, medium to long duration airplane. Due to the weight, speed, and altitude constraints imposed on such aircraft, solar array generated electric power is a viable alternative to air-breathing engines. Development of such aircraft is currently being funded under the Environmental Research Aircraft and Sensor Technology (ERAST) program. NASA Lewis Research Center (LeRC) is currently building a Solar Electric Airplane to demonstrate UAV technology. This aircraft utilizes high efficiency Applied Solar Energy Corporation (ASEC) GaAs/Ge space solar cells. The cells have been provided by the Air Force through the ManTech Office. Expected completion of the plane is early 1995, with the airplane currently undergoing flight testing using battery power.
The advancement of bioprocess monitoring will play a crucial role to meet the future requirements of bioprocess technology. Major issues are the acceleration of process development to reduce the time to the market and to ensure optimal exploitation of the cell factory and further to cope with the requirements of the Process Analytical Technology initiative. Due to the enormous complexity of cellular systems and lack of appropriate sensor systems microbial production processes are still poorly understood. This holds generally true for the most microbial production processes, in particular for the recombinant protein production due to strong interaction between recombinant gene expression and host cell metabolism. Therefore, it is necessary to scrutinise the role of the different cellular compartments in the biosynthesis process in order to develop comprehensive process monitoring concepts by involving the most significant ...
'Full text:' The use of fuel cell technology in military applications will depend on safe, high energy density systems being developed. An important part of using this technology is also the development of alternative hydrogen producing fuels with high energy densities and are easy to transport. Fuel cells are now a very large R and D effort for several military applications around the world. The major reason is because of the high power demands needed requires electrical energy sources that far exceed the capabilities of batteries currently being fielded for portable applications. Fuel cells are regarded as highly efficient, tactical energy converters that can be adapted for wide range of power requirements. They are potentially the lowest weight power source when coupled with batteries or capacitors to form hybrid systems. Generally electrical power is needed to support a number of applications from ultra-high power for ...
Nitridation of Cr-bearing alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant CrN or Cr{sub 2}N base surfaces of interest for a range of electrochemical devices, including fuel cells, batteries, and sensors. This paper presents results of exploratory studies of the nitridation of commercially available, high Cr (30-35 wt%) Ni-Cr alloys and a ferritic high Cr (29 wt%) stainless steel for proton exchange membrane fuel cell (PEMFC) bipolar plates. A high degree of corrosion resistance in sulfuric acid solutions designed to simulate bipolar plate conditions and low ICR values were achieved. Oxygen impurities in the nitriding environment were observed to play a significant role in the nitrided surface structures that formed, with detrimental effects for the Ni-Cr base alloys, but beneficial effects for the stainless steel alloy. Positive results from ...
Nitridation of Cr-bearing alloys can yield low interfacial contact resistance (ICR), electrically- conductive and corrosion-resistant CrN or Cr2N base surfaces of interest for a range of electrochemical devices, including fuel cells, batteries, and sensors. This paper presents results of exploratory studies of the nitridation of two high Cr (30-35 wt%) commercially available Ni-Cr alloys and a ferritic high Cr (29 wt.%) stainless steel for proton exchange membrane fuel cell (PEMFC) bipolar plates. A high degree of corrosion resistance in sulfuric acid solutions designed to simulate bipolar plate conditions and low ICR values were achieved via nitridation. Oxygen impurities in the nitriding environment were observed to play a significant role in the nitrided surface structures that formed, with detrimental effects for the Ni-Cr base alloys, but beneficial effects for the stainless steel alloy. Results of ...
Solar High Altitude Powered Platform (Solar HAPP) aircraft are unmanned remote sensing vehicles designed for cruises lasting up to one year at 20-km altitude, while carrying up to 250 pounds of cameras and electrooptic sensors in an underslung payload pod. It is anticipated that real time IR and UV images of earth features may be more inexpensively and accurately obtained by this means than by the conventional geosynchronous earth resources satellites. Solar HAPPs, with wing spans of over 300 ft and weights of only 2000 lb, require ultralight composite structures with external wire bracing. Solar cells will cover both sides of the vertical wing stabilizers and wing tips, which hinge up in daytime to capture the maximum amount of sunlight. A 15-hp electric propulsion unit drives a low-rpm, large diameter propeller; power will be derived from the solar cells diurnally, and from hydrogen-oxygen fuel cells ...
Ultraviolet light can be used to immobilize biomolecules onto thiol reactive surfaces in order to, e.g., make biosensors. The mechanism involves light-induced formation of free, reactive thiol groups in disulphide containing molecules. This technology allows for the creation of arrays of biomolecules with a high degree of reproducibility, circumventing the need for often expensive nano/micro-dispensing technologies. The ultimate size of the immobilized spots is defined by the focal area of the UV beam. Light-induced immobilization has the added benefit that the immobilized molecules will be spatially oriented and covalently bound to the surface. In this paper, we demonstrate the utility of a sensor array created with the new sensor technology when integrated into a microfluidic system. Protein arrays made using light-induced immobilization showed successful antigen/antibody binding in a flow cell allowing the visualisation ...
The thermophotovoltaic (TPV) option was not selected for further deep space mission technology development in NASA for several reasons. Chief among them was the large radiator required to keep the photovoltaic cells at a sufficiently low operating temperature. This led to significant integration problems with the spacecraft and limited sensor view angles. It is clear that the issue of cell temperature is crucial for space applications because of radiator size and system impact. Many efforts have focused on matching cell band gap to appropriate emitters in the 1 to 2 {mu}m range, resulting in band gaps in the 0.5 to 0.8 eV range. However, low band gaps lead to low open circuit voltages ({approximately}0.25 to 0.45 V) caused by high intrinsic carrier concentrations (n{sub i}{sup 2}). Thus, in order to obtain high performance. Photovoltaic cell temperatures must be kept near room ...
There is a rapidly growing need to evaluate sensor network functionality and performance in the context of the larger environment of infrastructure and applications in which the sensor network is organically embedded. This need, which is motivated by complex applications related to national security operations, leads to a paradigm fundamentally different from that of traditional data networks. In the sensor networks of interest to us, the network dynamics depend strongly on sensor activity, which in turn is triggered by events in the environment. Because the behavior of sensor networks is sensitive to these driving phenomena, the integrity of the sensed observations, measurements and resource usage by the network can widely vary. It is therefore imperative to accurately capture the environmental phenomena, and drive the simulation of the sensor network operation ...
Laser guide star systems based on Rayleigh scattering require some means to deal with the flash of low altitude laser light that follows immediately after each laser pulse. These systems also need a fast shutter to isolate the high altitude portion of the focused laser beam to make it appear star-like to the wavefront sensor. We describe how these tasks are accomplished with UnISIS, the Rayleigh laser guided adaptive optics system at the Mt. Wilson Observatory 2.5-m telescope. We use several methods: a 10,000 RPM rotating disk, dichroics, a fast sweep and clear mode of the CCD readout electronics on a 10 $\\mu$s timescale, and a Pockel's cell shutter system. The Pockel's cell shutter would be conventional in design if the laser light were naturally polarized, but the UnISIS 351 nm laser is unpolarized. So we have designed and put into operation a dual Pockel's cell shutter in a unique bow tie ...
Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr2N, CrN, TiN, V2N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of scale-up studies to determine the feasibility of extending the nitridation approach to thin 0.1mm stainless steel alloy foils for proton exchange membrane fuel cell (PEMFC) bipolar plates. Developmental Fe-20Cr-4V alloy and type 2205 stainless steel foils were treated by pre-oxidation and nitridation to form low-ICR, corrosion-resistant surfaces. As-treated Fe-20Cr-4V foil exhibited target (low) ICR values, whereas 2205 foil suffered from run-to-run variation in ICR values, ranging up to 2x the...
On-board reforming of liquid fuels to hydrogen for use in proton exchange membrane (PEM) fuel cell electric vehicles (FCEVs) has been the subject of numerous investigations. In many respects, liquid fuels represent a more attractive method of carrying hydrogen than compressed hydrogen itself, promising greater vehicle range, shorter refilling times, increased safety, and perhaps most importantly, utilization of the current fuel distribution infrastructure. The drawbacks of on-board reformers include their inherent complexity [for example a POX reactor includes: a fuel vaporizer, a reformer, water-gas shift reactors, a preferential oxidation (PROX) unit for CO cleanup, heat exchangers for thermal integration, sensors and controls, etc.], weight, and expense relative to compressed H{sub 2}, as well as degraded fuel cell performance due to the presence of inert gases and impurities in the reformate. Partial oxidation (POX) of ...
5 days ago... Sun sensors, 2 secondary Sun sensors, and an Earth sensor. ... This continued intermittently until the rocket burn, at which time ... with incoming asymptotic direction at an angle of -13.6 degrees from the lunar equator. ...
Drosophila melanogaster is a model organism rich in genetic tools to manipulate and identify neural circuits involved in specific behaviors. Here we present a technique for two-photon calcium imaging in the central brain of head-fixed Drosophila walking on an air-supported ball. The ball's motion is tracked at high resolution and can be treated as a proxy for the fly's own movements. We used the genetically encoded calcium sensor, GCaMP3.0, to record from important elements of the motion-processing pathway, the horizontal-system lobula plate tangential cells (LPTCs) in the fly optic lobe. We presented motion stimuli to the tethered fly and found that calcium transients in horizontal-system neurons correlated with robust optomotor behavior during walking. Our technique allows both behavior ...
Abstract Toll-like receptor 2 (TLR2) is an immune sensor for gram-positive bacterial cell wall components. Single-nucleotide polymorphisms (SNPs) in the TLR2 gene that impair its function may, therefore, influence the risk and outcomes of gram-positive bacterial infections. In a cohort of 694 liver transplant recipients, we assessed the TLR2 SNP that is translated into an amino acid substitution of arginine for glutamine at position 753 (R753Q), and we found that its presence was associated with the clinical characteristics and outcomes of gram-positive bacterial infections. The proportions of patients with the TLR2 R753Q SNP did not significantly differ between those with gram-positive bacterial infections and those without gram-positive bacterial infections (9.6% versus 9.6%, P = 0.999)....
The interaction between molecules and solid surfaces plays important roles in various applications, including catalysis, sensors, nanoelectronics, and solar cells. Surprisingly, a full understanding of molecule-surface interaction at the quantum mechanical level has not been achieved even for very simple molecules, such as water. In this mini-review, we report recent progresses and current status of studies on interaction between representative molecules and surfaces. Taking water/metal, DNA bases/carbon nanotube, and organic dye molecule/oxide as examples, we focus on the understanding on the microstructure, electronic property, and electron-ion dynamics involved in these systems obtained from first-principles quantum mechanical calculations. We find that a quantum mechanical description ...
Course website from Cambridge on ceramic materials. This site contains eight lectures in PDF format (Adobe Reader required), two question sheets, five practicals (including answers), digital movies and further useful links. "There is a strong relationship between the structure of a material and its physical properties. The properties of a material whether mechanical, electrical, optical or magnetic, determine how it can be used in practical applications. In this course, the focus is on the structure / property relationship for ionic materials with electrical properties utilised in various transducer devices. The materials considered include perovskites, which have special polarisation properties exploited in ferroelectric, pyroelectric and piezoelectric devices. Other oxides, such as zirconia, have structures permitting rapid diffusion of ions, making them suitable for use in sensors, fuel cells and batteries. The scientific principles ...
BackgroundIn recent years, near-infrared fluorescence (NIRF)-labeled iron nanoparticles have been synthesized and applied in a number of applications, including the labeling of human cells for monitoring the engraftment process, imaging tumors, sensoring the in vivo molecular environment surrounding nanoparticles and tracing their in vivo biodistribution. These studies demonstrate that NIRF-labeled iron nanoparticles provide an efficient probe for cell labeling. Furthermore, the in vivo imaging studies show excellent performance of the NIR fluorophores. However, there is a limited selection of NIRF-labeled iron nanoparticles with an optimal wavelength for imaging around 800 nm, where tissue autofluorescence is minimal. Therefore, it is necessary to develop additional alternative NIRF-labeled iron nanoparticles for application in this area.ResultsThis study manufactured 12-nm DMSA-coated Fe3O4 nanoparticles labeled with a ...
USGS scientists Laura Clor and Tim Moloney installing a temperature sensor under a public boardwalk in Norris Geyser Basin, Yellowstone National Park....
The operating principle is examined for an optical sensor for the angle of rotation of the drag ODUP-1 developed and manufactured by the VNII-1. Basic technical data are presented for the experimental model.
In this paper, we report an optical fiber sensor for measuring temperature based on bimetallic concept. The sensor is designed by following the basic principle of Fabry-Perot interferometer and theoretical detail of the sensor has been outlined here with a numerical study. An important feature of the proposed sensor is that the fabrication will be done on a commercial multimode optical fiber. The Micro-Electro-Mechanical Systems (MEMS) based fabrication process could be performed directly on a multimode optical fiber end face which will eliminate the need for adhesive in packaging. The sensor could be fabricated as sensor arrays for micro level applications. The potential application of the proposed optical sensor includes biomedical applications, nano research, microfluidics, and other ME...
This research deals with in the study of the use of innovating magnetic sensors in eddy current non destructive inspection. The author reports an analysis survey of magnetic sensor performances. This survey enables the selection of magnetic sensor technologies used in non destructive inspection. He presents the state-of-the-art of eddy current probes exploiting the qualities of innovating magnetic sensors, and describes the methods enabling the use of these magnetic sensors in non destructive testing. Two main applications of innovating magnetic sensors are identified: the detection of very small defects by means of magneto-resistive sensors, and the detection of deep defects by means of giant magneto-impedances. Based on the use of modelling, optimization, signal processing tools, probes are manufactured for these both applications.
This paper contains literature from American Power Conference Air Toxics Being Measured Accurately, Controlled Effectively NO{sub x} and SO{sub 2} Emissions Reduced; Surface Condensers Improve Heat Rate; Usable Fuel from Municipal Solid Waste; Cofiring Technology Reduces Gas Turbine Emissions; Trainable, Rugged Microsensor Identifies of Gases; High-Tc Superconductors Fabricated; High-Temperature Superconducting Current Leads; Vitrification of Low-Level Radioactive and Mixed Wastes; Characterization, Demolition, and Disposal of Contaminated Structures; On-Line Plant Diagnostics and Management; Sulfide Ceramic Materials for Improved Batteries; Flywheel Provides Efficient Energy Storage; Battery Systems for Electric Vehicles; Polymer-Electrolyte Fuel Cells for Transportation; Solid-Oxide Fuel Cells for Transportation; Surface Acoustic Wave Sensor Monitors Emissions in Real-Time; Advance Alternative-Fueled Automotive ...
The development of solid state chemical sensors, and more specifically of gas sensors, is carried out with great strength in the present time since the environmental pollution and the security in work and domestic ambient are problems of great interest and social impact. The main fields of application, are: automobile, domestic sensors, control of industrial process, bio medicine, environment. These chemical sensors are experimenting a great advance because of the advantages they offer, as low cost, simple operation, possibility of measure continuous and ''In situ'' and small size, in contrast with analytical techniques that need complex instrumentation and large size equipments. In the present work, a sensor for CO detecting concentrations as low as 50 p.p.m., is studied showing great interest since this gas is highly toxic even to such a low ...
The anodic reaction kinetics and interfacial mass transport of a direct polymer electrolyte membrane formic acid fuel cell have been investigated in an all solid-state electrochemical cell using a highly active nanostructured palladium-gold alloy microelectrode as an in situ probe. Well-defined 'S-shaped' steady-state cyclic voltammograms exhibiting current-rising region at lower overpotentials and limiting current region at higher overpotentials have been first obtained for the electrochemical oxidation of formic acid at varying temperature. The 'S-shaped' steady state polarization curves and chronoamperometric curves enable convenient measurements of the anodic reaction kinetics and interfacial mass transport of formic acid under real polymer electrolyte membrane conditions. It is encouragingly found that formic acid can be directly oxidized to CO2 with the first electron transfer being the likely rate-determining step and the formation of ...
We studied the effect of extracellular Ca"2"+ concentration ([Ca"2"+]_e) on adipocyte differentiation. Preadipocytes exposed to continuous [Ca"2"+]_e higher than 2.5 mmol/l accumulated little or no cytoplasmic lipid compared to controls in 1.8 mmol/l [Ca"2"+]_e. Differentiation was monitored by Oil Red O staining of cytoplasmic lipid and triglyceride assay of accumulated lipid, by RT-PCR analysis of adipogenic markers, and by the activity of glycerol-3-phosphate dehydrogenase (GPDH). Elevated [Ca"2"+]_e inhibited expression of peroxisome proliferator-activated receptor #gamma#, CCAAT/enhancer binding protein #alpha#, and steroid regulatory binding element protein. High [Ca"2"+]_e significantly inhibited differentiation marker expression including adipocyte fatty acid binding protein, and GPDH. The decrease in Pref-1 expression that accompanied differentiation also was prevented by high [Ca"2"+]_e. Treatment of 3T3-L1 cells with high [Ca"2"+]_e did not significantly ...
Sensitive and quick-response nonlinear inductance characteristics are found for high Tc superconducting (YBa/sub 2/Cu/sub 3/O/sub 7-chi/) disk cores at 77K in which soft magnetic BH hysteresis loops are observed. Various quick response magnetic devices such as modulators, amplifiers and sensors are built using these cores. The magnetizing frequency can be set to more than 20 MHz, which is difficult for conventional ferromagnetic bulk materials such as Permalloy amorphous alloys and ferrite. New quick-response fluxgate type magnetic-field sensors are made using ac and dc voltage sources. The former is used for second-harmonic type sensors, while the latter is for voltage-output multivibrator type sensors. Stable and quick-response sensor characteristics were obtained for two-core type multivibrators.
Purpose. The paper introduces a novel design of air-core inductive sensors in printed circuit board (PCB) technology for a tongue control system. The tongue control system provides a quadriplegic person with a keyboard and a joystick type of mouse for interaction with a computer or for control of an assistive device. Method. Activation of inductive sensors was performed with a cylindrical, soft ferromagnetic material (activation unit). Comparative analysis of inductive sensors in PCB technology with existing hand-made inductive sensors was performed with respect to inductance, resistance, and sensitivity to activation when the activation unit was placed in the center of the sensor. Optimisation of the activation unit was performed in a finite element model. Results. PCBs with air-core indu...
Self-assembled monolayers (SAMs) on various metal, semiconductor or insulator substrates can be easily modified with specific functional groups of interest and have promising applications in surface wetting (hydrophobic/hydrophilic modification), tribology, corrosion protection, sensor electrodes modification, molecular and biomolecular recognition, protein adsorption, cell adhesion, and molecular- or organic-electronic device fabrications. In this paper, we highlight recent progress in the development of SAMs on solid substrates as well as their practical applications, with particular emphasis on the characterization of self-assembled aromatic thiol monolayers with different functional groups on Au(1 1 1) using synchrotron-based photoemission spectroscopy and near-edge X-ray absorption fine structure measurements. The SAM-related molecular orientation, electronic structures, and chemical bonding are presented. Using copper(II) phthalocyanine ...
Newly commercialized Fourier transform Raman spectroscopic instrumentation provides a simpler alternative for vibrational spectroscopic analysis. Instrument vendors currently design for laboratory use, but there are many potential process applications of these stable, easy to use instruments. Raman spectroscopy is highly suited to analysis of aqueous samples. Near infrared excitation minimized fluorescence interference and allows for remote operation via fiber optic probes. The Department of Energy has funded research at the Measurement and Control Center to establish the utility of this method for on-line composition analysis in distillation columns. Laboratory evaluation and instrument employs an air-cooled laser and a thermoelectrically cooled detector. The device is mounted on a three by foot cart for convenient location in control rooms. Current fiber optic extension cables allow for analysis in a cell thirty five meters from the instrument. Application of the ...
The present volume on energy and the environment discusses space power requirements, space power systems, space power systems hardware, space radioisotope systems, space solar arrays, space solar cells, space station power, and terrestrial applications of aerospace technology. Attention is given to NASA future space power requirements and issues, the design of a battery charger for the NASA EOS Space Platform, in situ carbon dioxide fixation on Mars, and a preliminary design update of the CRAF/Cassini Power Subsystem. Topics addressed include concentrator testing using projected images, solar power satellites and demonstraton platforms from nonterrestrial materials, a mass sensitivity analysis of lunar orbiting beam power systems, and a power-beaming-based infrastructure for space power. Also discussed are fiber-optic sensors for aerospace electrical measurements, the preliminary design of a mobile lunar power supply, advanced power systems for ...
Composed of Sun sensors, the Canopus sensor, the inertial reference unit, ... The heart of the system was a 100-pound-thrust rocket whose hypergolic, ... The spacecraft's low-gain antenna picked up all incoming signals from the NASA-JPL ...
A roller bearing hot box sensor utilizing a metallic temperature sensitive elongated wire element. The wire element contacts at temperatures in the range of about 125 F to about 225 F so that when the contraction movement of the wire is attached to a conn...
The Aer protein in Escherichia coli is a membrane-bound, FAD-containing aerotaxis and energy sensor that putatively monitors the redox state of the electron transport system. Binding...Full Text Available
Four temperature sensors were provided instead of the previous two sensors. 4. ... Incoming signals from either one or two ground stations at a frequency of .... The propulsion subsystem consists of a single solid-propellant rocket motor. ...
We have developed miniature (≈1 μm diameter) microcavity surface-plasmon-resonance sensors (MSPRS), integrated them with microfluidics and tested...Full Text Available
Aug 25, 2004 ... Current Developments in Future Planetary Probe Sensors: .... Data: Outgoing and incoming EIA RS-422 interface for serial data transmission (for electrical purposes only, .... Milos, et. al, Journal of Spacecraft & Rockets 1999 ...
We report on a high resolution, monolithic crystal PET detector design concept that provides depth of interaction (DOI) positioning within the crystal. Our design utilizes a novel sensor on...Full Text Available
... from theory to practice will be significantly reduced while intrinsically revolutionizing the approach to engineering network security architectures. ...
based sensors, and a host of other scientific ... and change the balance between incoming and outgoing energy. ..... have launched on a larger rocket, flown in ...
This annex provides a description of the sensor schemes and the non-destructive testing (NDT) methods that have been investigated in this project. Acoustic emission and fibre optic sensors are described in some detail whereas only the key features of well-established NDT methods are presented. Estimates of the cost of different sensor systems are given and the advantages and disadvantages of the different schemes is discussed. (au)
... is disengaged from the spent rocket motor by a ... of the outbound and incoming modu- ... meteorological sensor and reference resistor is accomplished ...
The aim of this thesis is the study of new systems devoted to the real time neutron spectrometry and dosimetry. The microelectronics technologies have been used to research a micro system integrating sensor and data processing in real time. The multi range sensor is based on many pair of semiconductor diodes placed face to face and covered by lithium fluoride. The sensor has been designed and its behavior has been simulated. Its operating in reference neutrons beams has been analyzed. (A.L.B.)
... and airborne sensors to track incoming ICBMs. The experiment was designed to determine how the intentional release of rocket propellants from an incoming ...
Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr{sub 2}N, CrN, TiN, V{sub 2}N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of scale-up studies to determine the feasibility of extending the nitridation approach to thin 0.1 mm stainless steel alloy foils for proton exchange membrane fuel cell (PEMFC) bipolar plates. Developmental Fe-20Cr-4V alloy and type 2205 stainless steel foils were treated by pre-oxidation and nitridation to form low-ICR, corrosion-resistant surfaces. As-treated Fe-20Cr-4V foil exhibited target (low) ICR values, whereas 2205 foil suffered from run-to-run variation in ICR values, ranging up to 2 x the target value. Pre-oxidized and nitrided surface structure examination revealed surface-through-layer-thickness V-nitride ...
Thermal (gas) nitridation of stainless steels can yield low interfacial contact resistance (ICR), electrically-conductive and corrosion-resistant nitride containing surfaces (Cr2N, CrN, TiN, V2N, VN, etc) of interest for fuel cells, batteries, and sensors. This paper presents the results of scale up studies to determine the feasibility of extending the nitridation approach to thin 0.1 mm stainless steel alloy foils for proton exchange membrane fuel cell (PEMFC) bipolar plates. A major emphasis was placed on selection of alloy foil composition and nitidation conditions potentially capable of meeting the stringent cost goals for automotive PEMFC applications. Developmental Fe-20Cr-4V alloy and type 2205 stainless steel foils were treated by pre-oxidation and nitridation to form low-ICR, corrosion-resistant surfaces. Promising behavior was observed under simulated aggressive anode- and cathode- side bipolar plate conditions ...
The present study was designed to assess the radioprotective effects of amifostine on ovarian follicles. Three week-old female mice with or without pretreatment of amifostine were irradiated with 6.42 Gy of #gamma# -ray. Ovaries were collected 0 and 6h after irradiation. DNA fragmentation pattern and expression of genes and activity of proteins related with apoptosis were investigated by means of RT-PCR and Western blot. Proliferation of granulosa cells was reduced and incidence rate of follicular atresia was increased in ovarian follicles in #gamma# -ray irradiated mice compared to those in control or amifostine-treated group. DNA fragmentation was increased in time-dependent manner in granulosa cells of all irradiated groups. However, no difference between amifostine pre-treated group and irradiated groups was found and the expression of p53 as tumor suppressor gene and Bax as one of pro-apoptotic Bcl-2 family was increased in irradiated mice ...
An apparatus for sensing chemicals over extended range of concentrations. In particular, first and second sensors each having separate, but overlapping ranges for sensing concentrations of hydrogen are provided. Preferably, the first sensor is a MOS solid state device wherein the metal electrode or gate is a nickel alloy. The second sensor is a chemiresistor comprising a nickel alloy.
The device, aimed at non destructive control of the inner side of tubes such as steam generator tubes, is composed of a control sensor mounted on a support; the sensor head may rotate in the tube and a measuring system and signal processing allow for the exact determination of the angular position of the sensor head (application to ultrasonic or eddy current probes).
Nano photonic materials are synthetically manufactured crystals at the nano scale with the target of creating a microstructure with a special electro-magnetic periodicity. Such nano photonic materials have the ability to control light propagation and thus are capable of creating photonic bandgaps in the frequency domain. We propose using nano photonic crystals as sensors to detect microdamage in composite materials. We demonstrate using a simulation model that a nano photonic sensor attached to a composite bar experiences a significant change in its bandgap profile when damage is induced in the composite bar. The model predicts the frequency response of the nano photonic sensor using the transfer matrix method. A damage metric to evaluate the change in the frequency response is developed. Successful developments of nano photonic sensors allow damage identification at scales not attainable using current ...
In the food, chemical and safety industry there is a demand for gas detectors for process control applications, like quality control of food or leakage control in chemical plants. Gas sensor array systems have the potential to be used in this areas, with the advantage of being also affordable systems compared to other systems like gaschromatographs (GC) or infrared detectors (NIR, FTIR). One of the main drawbacks of the gas sensors is their response to non interesting ambient factors like temperature, pressure and humidity. Metal oxide sensors (MOS) have a low ambient temperature and pressure dependency. Some of them (SnO + dopands) have some sensitivity to humidity. In many cases the response of the sensors is often non-linear, which implies a concentration dependant pattern of the samples. (orig.)
A novel electrogenerated chemiluminescence (ECL) sensor based on natural clay and ionic liquid was fabricated. Tris(2,2prime-bipyridine)ruthenium(II) (Ru(bpy)32+) was immobilized on natural clay surface through simple adsorption. An ECL sensor was prepared by mixing Ru(bpy)32+-incorporated clay, graphite powder and an ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) as the binder. The electrochemical behavior and ECL of the immobilized Ru(bpy)32+ was investigated. It was observed that the ECL of immobilized Ru(bpy)32+ was activated by the ionic liquid. The proposed ECL sensor showed high sensitivity to tri-n-propylamine (TPrA) and the detection limit was found to be 20 pM. In addition, the ECL sensor displayed good stability for TPrA detection and long-term storage stability.
To establish secure (point-to-point and/or broadcast) communication channels among the nodes of a wireless sensor network is a fundamental task. To this end, a plethora of (socalled) key pre-distribution schemes have been proposed in the past. All these schemes, however, rely on shared secret(s), which are assumed to be somehow pre-loaded onto the sensor nodes. In this paper, we propose a novel method for secure initialization of sensor nodes based on a visual out-of-band channel. Using the proposed method, the administrator of a sensor network can distribute keys onto the sensor nodes, necessary to bootstrap key pre-distribution. Our secure initialization method requires only a little extra cost, is efficient and scalable with respect to the number of sensor nodes. Moreover, based on a usability study that we conducted, the method turns out to be quite ...
Mixed-conducting ceramic oxides have potential uses in high-temperature electrochemical applications such as solid oxide fuel cells, advanced batteries, sensors, and oxygen-permeable membranes. The Sr-Fe-Co-O system combines high electronic/ionic conductivity with appreciable oxygen permeability at elevated temperatures. Dense ceramic membranes made of this material can be used to separate high-purity oxygen from air without the need for external electrical circuitry, or to partially oxidize methane to produce syngas. Samples of Sr{sub 2}Fe{sub 3{minus}x}Co{sub x}O{sub y} (with x = 0, 0.6, 1.0, and 1.4) were prepared by solid-state reaction in atmospheres with various oxygen partial pressures (pO{sub 2}) and were characterized by X-ray diffraction, scanning electron microscopy, and electrical conductivity measurements. Phase components of the samples are dependent on cobalt concentration and synthesis pO{sub 2}. Total conductivity increases ...
This paper reports on the protection of opening that are exposed to the environment in nuclear facilities which presents an almost overwhelming engineering challenge. Intakes and outflows must permit the passage of large volumes of air or water without impeding their flow, and they are often exposed to corrosive salt and chemicals. An intrusion detection sensor that is intended to protect these openings must be capable of operating reliably under environmentally harsh conditions, and at the same time either provide a physical delay barrier or attach to an existing barrier. A new fiber optic sensor technology has now been developed specifically for protecting environmentally exposed openings. This sensor uses a fiber optic cable embedded in a neoprene rubber frame which is reinforced with Kevlar threads or braided steel cable. The sensor is configured in a mesh pattern with openings sufficiently large to ...
The use of capacitance sensors for measuring phase concentrations in two-phase flow has gained popularity in recent years. In designing such sensors, there are many issues which must be considered in order to optimize performance: two-phase flow regime, permittivity of the phases, duct geometry, electrical shielding, desired spacial resolution of film thickness, and temperature variation in the flow field. These design issues are discussed and are used to optimize the design of a capacitance sensor which is used to measure vapor volume fraction in annular, two-phase vertical upflow and downflow in a square duct. The sensor was tested and implemented in a 12.7 mm square duct mounted in a flow boiling facility containing FC-72, a low permittivity dielectric fluid ({epsilon}{sub r} = 1.75). Using analytical modeling, an adjustable-length, parallel-plate design was developed and refined to achieve good ...
Sensor has been developed for the measurement of seismic wave rotary components. The vertical axis rotary component sensor is constituted of four L22Ds, similar to each other in performance, fixed in a ring formation on a metal bed. The ring is 22cm in diameter, and the four coils are connected so that their outputs will be added up. A horizontal axis rotary component sensor is built in the similar way. The rotary component sensors are all connected to a spectrum analyzer for the measurement of micromotions. It is found that the four-L22D combination can detect a rotary component of 335mV/deg/s. The sensor can detect both vertical and horizontal components with roughly the same sensitivity. A ring-form combination of conventional electromagnetic seismometers, though only as a temporary expedient, can perform high-resolution detection of rotary components and determine the absolute ...
Wireless sensor networks can revolutionize soil ecology by providing measurements at temporal and spatial granularities previously impossible. This paper presents a soil monitoring system we developed and deployed at an urban forest in Baltimore as a first step towards realizing this vision. Motes in this network measure and save soil moisture and temperature in situ every minute. Raw measurements are periodically retrieved by a sensor gateway and stored in a central database where calibrated versions are derived and stored. The measurement database is published through Web Services interfaces. In addition, analysis tools let scientists analyze current and historical data and help manage the sensor network. The article describes the system design, what we learned from the deployment, and initial results obtained from the sensors. The system measures soil factors with unprecedented temporal precision. ...
This paper presents direct measurements of the aerodynamic forces on the wing of a free-flying, insect-like ornithopter that was modeled on a hawk moth (Manduca sexta). A micro differential pressure sensor was fabricated with micro electro mechanical systems (MEMS) technology and attached to the wing of the ornithopter. The sensor chip was less than 0.1% of the wing area. The mass of the sensor chip was 2.0 mg, which was less than 1% of the wing mass. Thus, the sensor was both small and light in comparison with the wing, resulting in a measurement system that had a minimal impact on the aerodynamics of the wing. With this sensor, the 'pressure coefficient' of the ornithopter wing was measured during both steady airflow and actual free flight. The maximum pressure coefficient observed for steady airflow conditions was 1.4 at an angle of attack of 30"0. In flapping flight, the ...
A risk-based sensor placement methodology is proposed to solve the problem of optimal location of sensors or detectors to protect population against the exposure to and effects of known and/or postulated chemical, biological, and/or radiological threats. Risk is calculated as a quantitative value representing population at risk from exposure against standard exposure levels. Historical meteorological data are used to characterize weather conditions as the frequency of wind speed and direction pairs. The meteorological data drive atmospheric transport and dispersion modeling of the threats, the results of which are used to calculate risk values. Sensor locations are determined via an iterative dynamic programming algorithm whereby threats captured or detected by sensors placed in prior stages are removed from consideration in subsequent stages. In addition to the risk-based placement algorithm, the ...
This paper presents a novel design methodology, based on shaping the system frequency response, for the generation of an appropriate residual signal that is sensitive to sensor faults in the presence of model uncertainty and exogenous unknown (unmeasured) disturbances. An integrated feedback controller design and robust frequency-based fault detection approach is proposed for Single-Input/Single-Output systems. The effciency of the proposed method is demonstrated on a Single Machine Innite Bus (SMIB) power system that achieves a coordinate power system stabilizer with satisfactory sensor fault detection capabilities.
Systems MEMS sensors C11-20 Lifetime Distributions of Aluminum Electrolytic Capacitors C11-22 Adhesion Strength of Advanced Polymer Films for Flexible and Rigid...
Ever-present water vapor and dust distort or block incoming radiations. ... were among the first scientific sensors to be attached to the earliest space rockets. ...
Earlier studies had concluded that the preferred direction of the rocket nozzle should ..... Center had to redesign the sensor canisters, brackets and cable supports. ... depending on inspection of the quality of the incoming pictures in real-time. ...
A highly sensitive and stable tris(2,2prime-bipyridyl)ruthenium(II) (Ru(bpy)32+) electrogenerated chemiluminescence (ECL) sensor was developed based on carbon nanotube (CNT) dispersed in mesoporous composite films of sol-gel titania and perfluorosulfonated ionomer (Nafion). Single-wall (SWCNT) and multi-wall carbon nanotubes (MWCNT) can be easily dispersed in the titania-Nafion composite solution. The hydrophobic CNT in the titania-Nafion composite films coated on a glassy carbon electrode certainly increased the amount of Ru(bpy)32+ immobilized in the ECL sensor by adsorption of Ru(bpy)32+ onto CNT surface, the electrocatalytic activity towards the oxidation of hydrophobic analytes, and the electronic conductivity of the composite films. Therefore, the present ECL sensor based on the CNT-...
indications of the formation of palladium silicides. 2, 4. It has been reported .... At room temperature, palladium silicides formed in a relatively narrow interface ...
Canada will provide telescope baffles and fine error sensor assemblies. ..... ( Ongoing) Flight tests aboard sounding rockets and balloon planned for FY 1995. .... the effects of incoming energetic particles and solar radiation on the ...
... in Taylor and Williamson.* Most satellite sensors cannot be ... The coordinates of the rocket Ii ... I - Incoming Global Radiant Flux between 0.285 and ...
The potentials of the spherical sensor and nearby conductors are controlled by ... Incoming data are continuously monitored by algorithms in the software to ... launched together with FM5 (Rumba) by a Soyuz-Fregat rocket from Baikonur. ...
instrument is shown in Figure 4-9 The incoming radiation is focused onto ...... An early rocket-borne ultraviolet spectrometer of the Ebert type by ...
The first space photographs were obtained from V-2 rockets fired upwards from the ..... Some fraction of the incoming solar radiation is reflected towards a sensor ...
of the Intelligent Control System (ICS) for reusable rocket engines. .... the incoming measurements with corresponding estimates, a sensor failure can be ...
NO{sub x} compounds, specifically NO and NO{sub 2}, are pollutants and potent greenhouse gases. Compact and inexpensive NO{sub x} sensors are necessary in the next generation of diesel (CIDI) automobiles to meet government emission requirements and enable the more rapid introduction of more efficient, higher fuel economy CIDI vehicles. Because the need for a NO{sub x} sensor is recent and the performance requirements are extremely challenging, most are still in the development phase. Currently, there is only one type of NO{sub x} sensor that is sold commercially, and it seems unlikely to meet more stringent future emission requirements. Automotive exhaust sensor development has focused on solid-state electrochemical technology, which has proven to be robust for in-situ operation in harsh, high-temperature environments (e.g., the oxygen stoichiometric sensor). Solid-state ...
... the open source OpenMap Java toolkit from BBN ... 2001), Handbook of Multisensor Data Fusion ... Oxenham (2002), Sensor Registration Using Airlanes ...
... The three meteorological rocket systems, in order of ... IC3 and IC4 divides the incoming clock pulses f ... at the junction of the temperature sensor and R ...
The detection and characterization of deeply buried fatigue damage in thick, multi-layer airframe components pose significant technical challenges to the aviation safety community. Currently, no nondestructive evaluation technique is available to reliably detect such potential damage from the exterior of the airframe, which is highly desirable in light of inspection cost as well as avoidance of structure damage. Recent technological advances in high-sensitivity magnetic sensors, i.e., spin-dependent tunneling (SDT) sensors, make it feasible to employ electromagnetic inspection techniques for deep fatigue crack inspection. In this work, we report on the development and fabrication of a low frequency eddy current probe based on a magnetically shielded SDT pickup sensor concentrically located...
Sep 18, 2009 ... It is proposed to develop desensitized optimal filtering ... in robust and/or adaptive generalized Kalman and Sigma-Point filters for ...
Briefly, 48 MOS microparticle sensors (essentially the same as those flown on .... at the Naval Research Lab to interpret the polarization of the incoming radio .... Adapter Satellite, to be published in Journal of Spacecraft and Rockets, 1994. ...
Nov 5, 2010 ... PEM. The Particle Environment Monitor measures the type, amount, energy, ... info, Daily PEM HEPS and MEPS data at the original sensor ...
Feb 23, 2011 ... The potentials of the spherical sensor and nearby conductors are ... Incoming data are continuously monitored by algorithms in the software to ..... together with FM6 (Salsa) by a Soyuz-Fregat rocket from Baikonur. ...
... Using a weighted linear regression on randomly selected coincident SSM/I-buoy pairs from each of the climate m codes, it was possible to produce ...
This paper will provide an overview of the Common Aperture Multispectral Sensor (CAMS) Hardware Demonstrator. CAMS is a linescanning sensor that simultaneously collected digital imagery over the Far-IR (8 to 12 {mu}m) and visible spectral (0.55 to 1.1 PM) spectral bands, correlated at the pixel level. CAMS was initially sponsored by the U.S. Naval Air System Commands F/A-18 program office (PMA-265). The current CAMS field tests are under the direction of Northrop-Grumman for the Defense Nuclear Agency (DNA) in support of the Follow-On Open Skies Sensor Evaluation Program (FOSEP) and are scheduled to be conducted in April 1996. 8 figs., 4 tabs.
... a Networked Embedded Sensing Toolkit (MSR Sense ... edging due to mis-registration than the ... Langrebe, Signal theory in multisensor remote sensing ...
Nov 13, 2006 ... Indicator Experiment (TIE) consists of a wideband sensor to gather radar, ... November 10 at Shore Memorial. Hospital in Nassawadox, Va. ...
Wasaga Distribution Inc. is located on Georgian Bay in one of the fastest growing communities in Ontario. It has a customer base of 10,400 residential customers in a service territory of 61 square kilometres. This presentation outlined Wasaga's experience with the Itron fixed network 2.0 RF Centron IDM meter. It outlined the dataflow features and capabilities of the meter in terms electricity endpoints, repeaters, and neighbourhood collectors. The repeater is designed to capture ERT IDM reads and retransmit at a higher power. The meter is also designed to reduce the number of cell control units (CCU) necessary to cover an area. The meter sleeve design allows for simple and cost effective installation, and has a bandwidth capable of over 3000 reads per second. The Itron CCU4 is a listening receiver that captures ERT reads and transmits the data to the utilities. It has a battery back up that lasts 4 hours in case of a power outage. It can be mounted on a ...
We developed prototype chemistry for nucleic acid hybridization on our bead-based diagnostics platform and we established an automatable bead handling protocol capable of 50 part-per-billion (ppb) sensitivity. We are working towards a platform capable of parallel, rapid (10 minute), raw sample testing for orthogonal (in this case nucleic acid and immunoassays) identification of biological (and other) threats in a single sensor microsystem. In this LDRD we developed the nucleic acid chemistry required for nucleic acid hybridization. Our goal is to place a non-cell associated RNA virus (Bovine Viral Diarrhea, BVD) on the beads for raw sample testing. This key pre-requisite to showing orthogonality (nucleic acid measurements can be performed in parallel with immunoassay measurements). Orthogonal detection dramatically reduces false positives. We chose BVD because our collaborators (UC-Davis) can supply samples from persistently infected animals; ...
The production and characterisation of thin films made from molybdenum sulphide, molybdenum selenide, tungsten sulphide and tungsten selenide are described. The electronic properties of the thin films were examined by Hall measurements and by thermal sensors. For the MoSe[sub 2] films, the majority of the samples were n-conducting and p-conduction was only found for a few examples. All the other films (MoS[sub 2], WS[sub 2], WSe[sub 2]) were p-conducting. The electrical transport properties of the thin films are comparable to those of single crystals. With these thin films as absorber materials, it was possible for the first time to produce the polycrystalline solid n-ZnO/p-MoSe[sub 2], n-ZnO/WSe[sub 2], n-ZnO/WS[sub 2]- and n-ITO/WS[sub 2] solar cells. In spite of not yet optimized diode geometry (lateral build-up), a maximum short circuit current of I[sub SC] = 18 mA/cm[sup 2] was achieved for the MoSe[sub 2] diode. (orig.)
Thin film solar cells and solar cell testing - photovoltaic cells, radiation damage to cadmium sulfide solar cells, and airplane testing of solar cells
A highly sensitive and stable tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)_3 "2"+) electrogenerated chemiluminescence (ECL) sensor was developed based on carbon nanotube (CNT) dispersed in mesoporous composite films of sol-gel titania and perfluorosulfonated ionomer (Nafion). Single-wall (SWCNT) and multi-wall carbon nanotubes (MWCNT) can be easily dispersed in the titania-Nafion composite solution. The hydrophobic CNT in the titania-Nafion composite films coated on a glassy carbon electrode certainly increased the amount of Ru(bpy)_3 "2"+ immobilized in the ECL sensor by adsorption of Ru(bpy)_3 "2"+ onto CNT surface, the electrocatalytic activity towards the oxidation of hydrophobic analytes, and the electronic conductivity of the composite films. Therefore, the present ECL sensor based on the CNT-titania-Nafion showed improved ECL sensitivity for tripropylamine (TPA) compared to the ECL sensors based on ...
A highly sensitive and stable tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy){sub 3} {sup 2+}) electrogenerated chemiluminescence (ECL) sensor was developed based on carbon nanotube (CNT) dispersed in mesoporous composite films of sol-gel titania and perfluorosulfonated ionomer (Nafion). Single-wall (SWCNT) and multi-wall carbon nanotubes (MWCNT) can be easily dispersed in the titania-Nafion composite solution. The hydrophobic CNT in the titania-Nafion composite films coated on a glassy carbon electrode certainly increased the amount of Ru(bpy){sub 3} {sup 2+} immobilized in the ECL sensor by adsorption of Ru(bpy){sub 3} {sup 2+} onto CNT surface, the electrocatalytic activity towards the oxidation of hydrophobic analytes, and the electronic conductivity of the composite films. Therefore, the present ECL sensor based on the CNT-titania-Nafion showed improved ECL sensitivity for tripropylamine (TPA) compared to the ECL ...
The proposed device incorporates an axle which has a roller bearing support mounted upon it. This support uses a cylindrical sleeve that comes in contact with the housing, the sensors, and the bearing support component. Metering accuracy is improved by placing roller bearing supports into grooves running through the protruding center sections of the sensor elements. These roller bearing supports interface with the cylindrical sleeve.
The application of various signal processing methods to extract energy storage information from plasma diamagnetism sensors occurring during physics experiments on the Tandom Mirror Experiment-Upgrade (TMX-U) is discussed. We show how these processing techniques can be used to decrease the uncertainty in the corresponding sensor measurements. The algorithms suggested are implemented using SIG, an interactive signal processing package developed at LLNL.
A piezoelectric biosensor substrate useful for immobilizing biomolecules in an oriented manner on the surface of a piezoelectric sensor has a ladder polymer of polyacrylonitrile. To make the substrate, a solution of an organic polymer, preferably polyacrylonitrile, is applied to the surface of a piezoelectric sensor. The organic polymer is modifying by heating the polymer in a controlled fashion in air such that a ladder polymer is produced which, in turn, forms the attachment point for the biomolecules comprising the piezoelectric biosensor. 3 figs.
Fiber optic metrology developed at the CEA LIST laboratories involves fiber Bragg grating sensors, distributed Brillouin optical time domain reflectometry and optically stimulated luminescence dosimetry. Recent activities in optical fiber sensing are reviewed from laboratory experiments to field trials.
This comprehensive, critical review summarizes the use of nanoparticles in enhanced and amplified chemiluminescence detection, illustrated by different reaction strategies, electrogenerated chemiluminescence sensors, immunoassay or hybridization labels and electrogenerated chemiluminescence immunoassay or hybridization sensors. We discuss the analytical applications on the basis of validity, range and sensitivity, and draw some useful conclusions about the most sensitive approach in each type of application.
University research group with research areas: * Land based and submersible autonomous robots, (UUVs: AUVs and ROVs); * Controllers, electronics, sensor design and fusion, motion control; * Guidance and navigation of underwater vehicles; * AI, neural networks, fuzzy logic, subsumption control, behaviour based control; * Optical fibre and ultrasonic sensors for proximal object detection; * Robot arm control, visual servoing; * Imaging sonar applications; * Simulator development: UUV simulator; imaging sonar simulator; Aircraft/flight simulator.
In order to examine the state of technology of all areas of magnetic suspension and to review related recent developments in sensors and controls approaches, superconducting magnet technology, and design/implementation practices, a symposium was held. The proceedings are presented. The sessions covered the areas of bearings, sensors and controls, microgravity and vibration isolation, superconductivity, manufacturing applications, wind tunnel magnetic suspension systems, magnetically levitated trains (MAGLEV), space applications, and large gap magnetic suspension systems.
Real-time horizon sensing on continuous mining machines is becoming an industry tool. Installation and testing of production-grade Horizon Sensor (HS) systems continued this quarter at Monterey Coal Company (ExxonMobil), Mountain Coal Company West Elk Mine (Arch), and Ohio Valley Coal Company (OVC). Monitoring of system function, user experience, and mining benefits is ongoing. All horizon sensor components have finished MSHA (U.S.) and IEC (International) certification.
Biofuels will have more intense impact on the energetic grid of the planet, because known fossil fuels reserves are being exhausted. The biofuel production relies on the transformation process of some organic material in the desired hydrocarbon product. Because of the natural characteristics of the related processes, fibre optic sensors appear to be adequate candidates to be used.
The application of airborne sensors for providing environmental assessment and monitoring of a test site in an open cast mining area that is part of a lignite deposit in central Germany is described. Hyperspectral remote sensing data from three different sensors were tested. The hyperspectral scanner data was suitable for classification of different sediments and vegetation types and the water chemistry of residual mining lakes. Summary form only. 1 tab.
Topics addressed include future trends in IR sensors, IR observer performance modeling ... steer a sensor platform with a thermal camera or an air-to-air missile system. .... Skyship and Sentinel series airships. It also outlines the current .... A layout schematic of the UPS is given. AIAA. A93-55494 ...
Abstract The term -stem cell- most commonly refers to embryonic stem cells, particularly in the lay media; however, it also describes other cell types. A stem cell represents a cell of multi-lineage potential with the ability for self-renewal. It is now clear that the plasticity and immortality of a given stem cell will depend on what type of stem cell it is, whether an embryonic stem cell, a fetal-placental stem cell or an adult stem cell. Stem cells offer great promise as cell-based therapies for the future. With evolving technology, much of the socio-political debate regarding stem cells can now be avoided.
Sandia National Laboratories has recently developed two major field test capabilities for unattended ground sensor systems at the Department of energy`s Nevada Test Site (NTS). The first capability utilizes the NTS large area, varied terrain, and intrasite communications systems for testing sensors for detecting and tracking vehicular traffic. Sensor and ground truth data can be collected at either of two secure control centers. This system also includes an automated ground truth capability that consists of differential Global Positioning Satellite (GPS) receivers on test vehicles and live TV coverage of critical road sections. Finally there is a high-speed, secure computer network link between the control centers and the Air Force`s Theater Air Command and Control Simulation Facility in Albuquerque NM. The second capability is Bunker 2-300. It is a facility for evaluating advanced sensor systems for ...
The present investigation deals with the fabrication of liquid petroleum gas (LPG) sensor based on semiconducting oxide SnO{sub 2}. The gas sensor elements have been prepared by conventional solid state route. Addition of noble metal sensitizer, palladium and grain growth inhibitor, aluminum silicate to the base material SnO{sub 2}, not only improved the sensitivity towards LPG but also the selectivity in the presence of CO and CH{sub 4} gases. Out of various sensor compositions, SnO{sub 2}:Al{sub 2}Si{sub 2}O{sub 7} (35 wt.%):Pd (1.5 wt.%) sintered at 800 C for 5 h has shown high sensitivity (0.97) towards LPG at an operating temperature of 350 C. Different characterization techniques have been employed, such as differential thermal analysis (DTA), surface area analyzer, X-ray diffraction (XRD), to study the formation of SnO{sub 2}, surface area and crystallite size, respectively. The results suggested the possibility of ...
The objectives of this study are to make a biosensor on a trial basis which can instantaneously measure the nitrogen in wastewater, and to develop a wastewater treatment system which is capable of on-line measurement and controlling. The system provides easier operational control relating to such a high efficient treatment as the removal of nitrogen content in wastewater, serving as a solution to the eutrophication problem. It can be applied also to the analysis of fertilizer components for agriculture. Ammonia oxidizing bacteria were immobilized with cellulose acetate film, which is mounted on a diaphragm type oxygen electrode to make a sensor, and its responsibility was studied. The gradient is slow in high concentration but sharp in low concentration, and it seems possible to use it for the measurement for less than 20 ppm nitrogen concentration. The dependence of the sensor including electrodes and activity of bacteria on temperature is ...
This is the final report of a three year DOE funded project titled ''A real-time coal content/ore grade (C{sub 2}OG) sensor''. The sensor, which is based on hyperspectral imaging technology, was designed to give a machine vision assay of ore or coal. Sensors were designed and built at Resonon, Inc., and then deployed at the Stillwater Mining Company core room in southcentral Montana for analyzing platinum/palladium ore and at the Montana Tech Spectroscopy Lab for analyzing coal and other materials. The Stillwater sensor imaged 91' of core and analyzed this data for surface sulfides which are considered to be pathfinder minerals for platinum/palladium at this mine. Our results indicate that the sensor could deliver a relative ore grade provided tool markings and iron oxidation were kept to a minimum. Coal, talc, and titanium sponge samples ...
Human bone marrow mesenchymal stem cells (BM-MSC) are multipotent progenitor cells that have transient immunomodulatory properties on Natural Killer (NK) cells, Dendritic Cells (DC), and T cells. This...Full Text Available
The urine test strip is the most common test used to detect ketones in veterinary patients, but it can underestimate the degree of ketonuria and hence, ketonemia. Additionally, adequate urine samples for analysis may be difficult to obtain from dehydrated animals. The standard method used to detect and monitor ketonemia in human medicine is measurement of serum or whole blood beta-hydroxybutyrate (?HOB). A point-of-care (POC) analyzer has been validated for this purpose in humans. This study compared the accuracy of the POC device to an enzymatic reaction laboratory method for measurement of ?HOB in dogs. Although the POC sensor tended to overestimate ?HOB concentrations, there was good correlation (R(2) = 0.96) and good agreement between the 2 methods with a bias +/- precision of 0.0860 +/- 0.3410 mmol/L ?HOB. The POC ?HOB sensor can be useful for assessing ketonemia in dogs. PMID:21119867
Mesoporous films of platinized carbon nanotube-zirconia-Nafion composite have been used for the immobilization of tris(2,2prime-bipyridyl)ruthenium (II) (Ru(bpy)32+) on an electrode surface to yield a solid-state electrogenerated chemiluminescence (ECL) sensor. The composite films of Pt-CNT-zirconia-Nafion exhibit much larger pore diameter (3.55 nm) than that of Nafion (2.82 nm) and thus leading to much larger ECL response for tripropylamine (TPA) because of the fast diffusion of the analyte within the films. Due to the conducting and electrocatalytic features of CNTs and Pt nanoparticles, their incorporation into the zirconia-Nafion composite films resulted in the decreased electron transfer resistance within the films. The present ECL sensor based on the Pt-CNT-zirconia-Nafion gave a lin...
The authors report the fabrication and characterization of a low temperature (200--400 C) thin film gas sensor constructed from a MOCVD-grown yttria-stabilized zirconia (YSZ) layer sandwiched between two platinum thin film electrodes. A reproducible gas-sensing response is produced by applying a cyclic voltage which generates voltammograms with gas-specific current peaks and shapes. Growth conditions are optimized for preparing YSZ films having dense microstructures, low leakage currents, and maximum ion conductivities. In particular, the effect of growth temperature on film morphology and texture is discussed and related to the electrical and gas-sensing properties of the thin film sensor device.
In this work, we have investigated the capability of different bimetallic nanoparticle alloy combinations to be used in fibre optic sensors based on the technique of surface plasmon resonance. The metals considered for this analysis are silver, gold, copper and aluminium. The performance of the sensor with different bimetallic nanoparticle alloy combinations is evaluated and compared numerically. The performance is analysed in terms of three parameters: sensitivity, signal-to-noise ratio (SNR) and operating range for the sensing layer refractive index values. On the basis of the comparison and some logistic criteria, the best possible bimetallic alloy combinations along with a requisite alloy composition ratio are predicted. The bimetallic nanoparticle alloy combination is capable of simultaneously providing larger values of sensitivity, SNR and operating range, which is not possible with any single metallic nanoparticle layer.
We described the use of silica nanoparticles as building blocks for the immobilization of electrogenerated chemiluminescence (ECL) reagent Ru(bpy){sub 3}{sup 2+} and the fabrication of layer-by-layer assembly film by alternating the deposition of the Ru(bpy){sub 3}{sup 2+}-doped silica nanoparticles and Au nanoparticles. UV-vis absorption spectroscopy, scanning electron microscopy (SEM), cyclic voltammetry and ECL were used to characterize the uniform growth of the multilayer film. Since Ru(bpy){sub 3}{sup 2+} could still maintain its ECL property when doped into the silica nanoparticles, the as-prepared multilayer film could be used as an effective ECL sensor, and the sensor showed high sensitivity and good stability.
We described the use of silica nanoparticles as building blocks for the immobilization of electrogenerated chemiluminescence (ECL) reagent Ru(bpy)_3"2"+ and the fabrication of layer-by-layer assembly film by alternating the deposition of the Ru(bpy)_3"2"+-doped silica nanoparticles and Au nanoparticles. UV-vis absorption spectroscopy, scanning electron microscopy (SEM), cyclic voltammetry and ECL were used to characterize the uniform growth of the multilayer film. Since Ru(bpy)_3"2"+ could still maintain its ECL property when doped into the silica nanoparticles, the as-prepared multilayer film could be used as an effective ECL sensor, and the sensor showed high sensitivity and good stability.
We described the use of silica nanoparticles as building blocks for the immobilization of electrogenerated chemiluminescence (ECL) reagent Ru(bpy)32+ and the fabrication of layer-by-layer assembly film by alternating the deposition of the Ru(bpy)32+-doped silica nanoparticles and Au nanoparticles. UV-vis absorption spectroscopy, scanning electron microscopy (SEM), cyclic voltammetry and ECL were used to characterize the uniform growth of the multilayer film. Since Ru(bpy)32+ could still maintain its ECL property when doped into the silica nanoparticles, the as-prepared multilayer film could be used as an effective ECL sensor, and the sensor showed high sensitivity and good stability.
The Multiconjugate Adaptive optics Demonstrator (MAD) has successfully demonstrated on sky both Star Oriented (SO) and Layer Oriented (LO) multiconjugate adaptive optics techniques. While SO has been realized using 3 Shack-Hartmann wavefront sensors (WFS), we designed a multi-pyramid WFS for the LO. The MAD bench accommodates both WFSs and a selecting mirror allows choosing which sensor to use. In the LO approach up to 8 pyramids can be placed on as many reference stars and their light is co-added optically on two different CCDs conjugated at ground and to an high layer. In this paper we discuss LO commissioning phase and on sky operations.
Passive microwave soil moisture datasets can be used as an input to provide an integrated assessment of climate variability as it relates to agricultural production. The objective of this research was to examine three passive microwave derived soil moisture datasets over multiple growing seasons in contrasting Canadian agricultural environments. Absolute and relative soil moisture was evaluated from two globally available datasets from the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) sensor using different retrieval algorithms, as well as relative soil wetness at a weekly scale from the Special Sensor Microwave/Imager (SSM/I) sensor. At a daily scale, the Land Parameter Retrieval Model (LPRM) provides a better estimate of surface soil moisture conditions than the National Snow a...
A electrogenerated chemiluminescence (ECL) sensor for itopride was developed based on tris(2,2-bipyridyl)ruthenium(II) (Ru(bpy)32+)-doped silica (RuDS) nanoparticles/biopolymer chitosan composites membrane modified glassy carbon electrode (GCE). The RuDS nanoparticles (52+-5nm) were prepared by a modified Stber synthesis method and were characterized by electrochemical, fluorometric and transmission electron microscopy technology. The Ru(bpy)32+ encapsulation interior of the silica nanoparticle maintains its electrochemical activities and also reduces Ru(bpy)32+ leaching from the silica matrix when immersed in water due to the electrostatic interaction. The ECL analytical performances of this ECL sensor for itopride based on its enhancement ECL emission of Ru(bpy)32+ were investigated in d...
Energy consumption is a perennial issue in the design of wireless sensor networks (WSNs) which typically rely on portable sources like batteries for power. Recent advances in ambient energy harvesting technology have made it a potential and promising alternative source of energy for powering WSNs. By using energy harvesters with supercapacitors, WSNs are able to operate perpetually until hardware failure and in places where batteries are hard or impossible to replace. In this paper, we study the performance of different medium access control (MAC) schemes based on CSMA and polling techniques for WSNs which are solely powered by ambient energy harvesting using energy harvesters. We base the study on (i) network throughput (S), which is the rate of sensor data received by the sink, (ii) fair...
Silicon sensors have about ten times improved radiation hardness around 130 K temperature, compared with the state-of-art sensors close to room temperature. This is based on the Lazarus effect studied by the RD39 Collaboration of CERN. Other benefits of low temperatures will also be discussed. We shall describe the conceptual design of low-mass detector modules cooled using two-phase flow of argon in miniature cooling pipes integrated in the module structure between the sensors and the readout hybrid circuit. The main engineering features of the cooling system and mechanical support structures are discussed, as well as the benefits arising from the operation of the tracker under cryogenic vacuum. 4 Refs.
A calorimetric sensor with several novel design features has been developed. These sensors will provide an accurate sampling of thermal power density and energy deposition from proton beams incident on target components of accelerator-based systems, such as the Accelerator Production of Tritium Project (APT) and the Spallation Neutron Source (SNS). A small, solid slug (volume = 0.347 cc) of target material is suspended by kevlar fibers and surrounded by an adiabatic enclosure in an insulating vacuum canister of stainless steel construction. The slug is in thermal contact with a low-mass, calibrated, 100-k{Omega} thermistor. Power deposition caused by the passage of radiation through the slug is calculated from the rate of temperature rise of the slug. The authors have chosen slugs composed of Pb, Al, and LiAl.
This paper describes the design, fabrication and application of a micro-fabricated salinity sensor system. The theoretical electrochemical behaviour is described using electrical equivalent diagrams and simple scaling properties are investigated analytically and numerically using finite element method (FEM). The chip design and fabrication is described and measurement results of two different electrode designs are presented. The 4mm Formula Not Shown 4mm multi-sensor allows for salinity determination with an accuracy of Formula Not Shown 0.5psu through determination of the electrical conductivity, temperature and pressure with accuracies of Formula Not Shown 0.6mS, Formula Not Shown 0.065 Formula Not Shown C and Formula Not Shown 0.05bar, respectively.
At Super-LHC luminosity it is expected that the standard suite of L1 triggers for CMS will saturate. Information from the tracker will be needed to reduce trigger rates to satisfy the L1 bandwidth. Tracking trigger modules which correlate information from closely-spaced sensor layers to form an on-detector momentum filter are being developed by several groups. We report on a trigger module design which utilizes three dimensional IC technology to incorporate chips which are connected both to the top and bottom sensor, providing the ability to filter information locally. A demonstration chip, the VICTR, has been submitted to the Chartered/Tezzaron two-tier 3D run coordinated by Fermilab. We report on the 3D design concept, the status of the VICTR chip and associated sensor integration utilizing oxide bonding.
The problem of passively tracking a moving signal source has importance in a variety of applications such as radar, sonar, seismology, and radio astronomy. In many applications, only limited information is available about the signal source. It will be assumed here that only the signals which are detected by the sensors and the velocity of the source signal are known. The objective of this document is to present a program which passively tracks a target using an array of sensors. This program is available in MATLAB, version 3.5. The algorithm which is implemented consists of three main parts: time delay estimation, passive localization, and data post processing. Each of these parts are discussed, and the mathematical foundation for their solution given. Following, this the organization of the program is presented, and an example of its usage is given.
The core-shell luminol-doped SiO2 nanoparticles were synthesized and immobilized on the surface of chitosan film coating graphite electrode by the self-assembled technique. Then, a novel electrogenerated chemiluminescence (ECL) sensor for pyrogallol was developed based on its ECL enhancing effect for the core-shell luminol-doped silica nanoparticles. The ECL analytical performances and the sensing mechanism of this ECL sensor for pyrogallol were investigated in detail. The corresponding results showed that: compared with the conventional ECL reaction procedures by luminol ECL reaction system, the electrochemical (EC) reaction of pyrogallol and its subsequent chemiluminescence (CL) reaction occurred in the different spatial region whilst offering a high efficiency to couple the EC with the ...
The Lawrence Livermore National Laboratory has developed a mobile field laboratory for remote measurement of atmospheric processes and observables that are important in global climate change, dispersal of hazardous materials, and atmospheric pollution. Specific observables of interest are water vapor, trace gases, aerosol size and density, wind, and temperature. The goal is to study atmospheric processes continuously for extended periods in remote field locations. This laboratory has just reached field ready status with sensors for aerosol and trace gas measurement based on established techniques. A development program is underway to enhance the sensor suite with several new techniques and instruments that are expected to significantly extend the state of the art in remote trace gas analysis. The new sensors will be incorporated into the lab during the next two years.
Abstract In this paper, a Cognitive Radio Based Medium Access Control (CR-MAC) protocol for Wireless Sensor Body Area Networks (WSBAN) that utilizes cognitive radio transmission is proposed. In this proposal, the sensor nodes are classified into nodes of life-critical health information and nodes of non-critical health information. The CR-MAC protocol prioritizes the critical packets access to the transmission medium by transmitting them with higher power while transmitting lower priority packets using lower transmission power. At the receiver, a higher priority packet experiences collision only when there are more than one critical packet transmission at the same transmission slot while non critical packets experience collision when there are more than one transmission at the same transmi...
Motivation: Automatic recognition of cell identities is critical for quantitative measurement, targeting and manipulation of cells of model animals at single-cell resolution. It has been...Full Text Available
vehicles including the H2-A rocket and the space shuttle. .... The vacuum can's main function is to provide a high vacuum so that the science experiment and its sensors ... EMI-shielded power conversion from the incoming ISS power supply. 4. ...
Incoming solar energy had to be assimilated to sustain it. .... Roll stability was achieved with an Earth sensor mounted on the directional antenna. .... Once more a rocket becomes the means of producing a vector change in velocity. ...
Introduction and hypothesisThis study seeks to evaluate axial variation, comparisons with current technology, performance during dynamic conditions, and patient tolerability of the...Full Text Available
Lists of reportable conditions and case definitions are important tools for epidemiologic surveillance. As part of an initiative to encourage occupational disease surveillance systems linked to intervention...Full Text Available
Oct 2, 2007 ... The Payload combines some of the most sensitive particle sensors .... provide state-of-the-art measurements of incoming x-ray, ultraviolet, .... It will be launched into a low-Earth orbit on a Delta 7320 rocket in September 2004. ...
The plant hormone cytokinin is perceived by membrane-located sensor histidine kinases. Arabidopsis (Arabidopsis thaliana) possesses three cytokinin receptors: ARABIDOPSIS HISTIDINE...Full Text Available
Trace gas molecules absorb specific wavelengths of incoming solar ... These data(with information collected from similar experiments carried on balloons, rockets, ... The ATMOS sensor instrumentis a state-of-the-art version of a 19th century ...
Peptide toxins with high affinity, divergent pharmacological functions, and isoform-specific selectivity are powerful tools for investigating the structure-function relationships of voltage-gated...Full Text Available
Feb 23, 2011 ... THEMIS-D: The Solid State Telescope (SST) measures the incoming ... Each single sensor covers an angle of 36 degrees. .... The five small satellites were launched together on a Delta II rocket and they carry identical ...
Aerosol Polarimetry Sensor (APS) + Continuous along-track scanning ... side of the spacecraft and faces outward, measures the intensity of incoming solar ... on a larger rocket, and faced slightly different conditions in spaceinto Glory wasn't ...
Mar 1, 2011 ... Bending moments recorded by sensors on the aluminum tube. ... the escape rocket motor, tests also were made with the escape tower and rocket .... Incoming photographic data will be electronically converted and processed ...
BackgroundThe Streptococcus pyogenes (group A streptococci, GAS) two-component signal transduction system CovRS has been described to be important for pathogenesis...Full Text Available
An overview of the operations of Sandia`s Microelectronics Development Lab (MDL) is to develop radiation hardened IC, but techniques used for IC processing have been applied to a variety of related technologies such as micromechanics, smart sensors, and packaging.
THEMIS-A: The Solid State Telescope (SST) measures the incoming intensity ... units (heads), each SST unit has two pairs of opposing ion and electron sensors. .... The five small satellites were launched together on a Delta II rocket and they ...
The author describes the layout of the environmental monitoring scheme at Devco's No. 26 Colliery in Canada, which includes wall face ventilation, fan performance, and methane drainage monitoring. He gives details of the sensors, outstations, and the surface control room.
Most palladium thin film based hydrogen gas sensors have response and recovery times that are too long to make them useful in vehicular and stationary gas leak detection applications. In contrast, a palladium-silver thin film based microcantilever (MC) hydrogen gas microsensor is reported herein with near ideal response characteristics for use in these hydrogen economy related applications. Specifically, 3-10 second response and recovery times have been measured for these sensors in contrast to previous sensor response measurements of several to tens of minutes using Pd thin film and MC based sensing techniques. The much reduced response times observed in the present study are attributed to a wet chemical Pd-Ag thin film deposition technique and a gas conditioning protocol that produces a highly nanostructured, porous film that rapidly adsorbs and desorbs H2, allowing rapid equilibration with the H2 concentration in the ...
This document concerns the proposal to negotiate an amendment to an existing contract for the supply of thick 6 inch silicon micro-strip sensors for the CMS tracker. For the reasons explained in this document, the Finance Committee is invited to approve an amendment to an existing contract with HAMAMATSU PHOTONICS (CH) for the supply of 7 000 thick 6 inch silicon micro-strip sensors for the CMS tracker, for an amount of 3 248 000 euros (5 131 840 Swiss francs), not subject to revision, with an option for up to 11 000 additional sensors, for a maximum amount of 4 708 000 euros (7 438 640 Swiss francs), not subject to revision, bringing the total maximum amount of the amendment to 7 956 000 euros (12 570 480 Swiss francs) not subject to revision. This total maximum amount will be added to the initial contract amount of 415 835 000 Japanese yen (4 879 824 Swiss francs), not subject to revision. The amounts in Swiss francs have ...
Mar 2, 2011 ... CCT's software is capable of simultaneously handling incoming ... has been using CCTK to automate its remote control rocket cryogenic fueling systems. ... seismic, infrared, and proximity sensor data with auto-tracking ...
SummaryPAS domains sense oxygen, redox potential and light, and are implicated in behavior, circadian rhythmicity, development and metabolic regulation. Although PAS domains are...Full Text Available
Feb 7, 2011 ... The potentials of the spherical sensor and nearby conductors are controlled ... Incoming data are continuously monitored by algorithms in the software ... together with FM8 (Tango) by a Soyuz-Fregat rocket from Baikonur. ...
Advanced aerospace vehicles and system components tend to be slim and elastic, ...... In the manufacturing sector, semiconductor manufacturing requires ... The energy generation and storage for modern-day sensor networks, ...... Current NASA roadmaps point towards development of new hydrocarbon fueled engines. ...
Eddy current inspection methods are widely used for the nondestructive evaluation (NDE) of tubular products. Specifically, the sensors and instrumentation are designed to detect and characterize changes in a material's electrical and magnetic properties produced by the presence of discontinuities. A recent major enhancement in eddy current inspection technology has been the development of computer interfacing for data collection, analysis, and display. This breakthrough has led to multiple-frequency testing, eddy current imaging, and automated data interpretation systems that significantly enhance both capabilities and reliability of the eddy current inspection. In addition to the clear advantages in data processing, computer interfacing also permits the design and creation of unique sensors that further enhance eddy current inspection capabilities. Perhaps the most promising area of computer interactive probe design is multiple ...
Integration of solid-state biosensors and lipid bilayer membranes is important for membrane protein research and drug discovery. In these sensors, it is critical that the solid-state sensing...Full Text Available
Equipped with terahertz sensors, the Aura mission will see far more ... We introduce you to a few amazing individuals, all sharing the dubious title of rocket scientist . And a ..... similar thing happens with incoming light. Astronomers call it the ...
The NS together with a gamma ray sensor make up the Gamma- Ray and ... A simplified view of the interactions between incoming cosmic rays and the .... held in Huntsville, Alabama, at the U.S. Space and Rocket Center on January 2830. ...
Study of cloud pictures taken from rockets, such as figure 1, indicates that it is .... One might visualize a "Satellite Weather Data Center" where incoming data would ... about 300 miles; satellite packaging, containing the sensors, storage, power, ...
AMP-activated-protein-kinase (AMPK) is a key sensor and regulator of cellular and whole-body energy metabolism and plays a key role in regulation of lipid metabolism. Since lipid metabolism...Full Text Available
It was thus actually the fourth stage of the rocket assembly. ... package, and several temperature sensors - was mounted in the cross-lattice frame. ... Earth's geomagnetic field and incoming charged particles from the Sun and extra-solar space. ...
Sep 9, 2009... a French Ariane rocket successfully launched a new Earth-observing satellite ... The payload is a pair of identical sensors known as "high-resolution ... the resulting image) are activated simultaneously by incoming radiation; ...
funded these sensors as the first Discovery Mission of. Opportunity, part of the ... aboard a Russian Soyuz rocket. .... the Swedes on other projects, mainly sounding rocket projects. ..... incoming applications for the Fellowship Program, fielding ...
In voltage-gated Na+, K+, and Ca2+ channels, four voltage-sensor domains operate on a central pore domain in response to membrane voltage. In contrast, the voltage-gated...Full Text Available
A silicon capacitive accelerometer was fabricated to detect subsurface elastic waves by using micromachining technology. Characteristics required for it call for capability of detecting acceleration with amplitudes from 0.1 to 1 gal and flat amplitude characteristics in frequency bands of 10 Hz to several kHz. For the purpose of measuring transition phenomena, linear phase characteristics in the required bands must be guaranteed, cross sensitivity must be small, and resistance to water, pressure and heat is demanded. Sensitivity of the sensor is determined finally by noise level in a detection circuit. The sensor`s minimum detection capability was 40 mgal in the case of the distance between a weight and an electrode being 3 {mu}m. This specification value is a value realizable by the current micromachining technology. Dimensions for the weight and other members were decided with the natural frequency to make band width 2 kHz set to 4 kHz. ...
Aug 15, 2002 ... In Section II, we describe the routing and transceiver power model used ... In our power model, we assume a certain non-zero minimum level of ...
The goal of this LDRD was to demonstrate the use of robotic vehicles for deploying and autonomously reconfiguring seismic and acoustic sensor arrays with high (centimeter) accuracy to obtain enhancement of our capability to locate and characterize remote targets. The capability to accurately place sensors and then retrieve and reconfigure them allows sensors to be placed in phased arrays in an initial monitoring configuration and then to be reconfigured in an array tuned to the specific frequencies and directions of the selected target. This report reviews the findings and accomplishments achieved during this three-year project. This project successfully demonstrated autonomous deployment and retrieval of a payload package with an accuracy of a few centimeters using differential global positioning system (GPS) signals. It developed an autonomous, multisensor, temporally aligned, radio-frequency communication and signal ...
AMP-activated protein kinase (AMPK) was initially viewed as energy sensor and activated by increased intracellular concentrations of AMP following nutrient deprivation. Physiological or pathological...Full Text Available
BackgroundObesity is one of the principal causative factors involved in the development of metabolic syndrome. AMP-activated protein kinase (AMPK) is an energy sensor that regulates...Full Text Available
... Rep. ISIS-04-504, Institute for Software Integrated Systems (2004). [59] G. Simon, M. Maroti, A. Ledeczi, G. Balogh, B. Kusy, A. Nadas, G. Pap, J ...
The mission includes a reflected solar instrument retrieving at-sensor .... incoming solar radiation. This direct aerosol radiative forcing (DARF) ... examining the behavior of geosynchronous rocket bodies and non-stabilized payloads as ...
Ventilation of blind drifts in the Karaganda Basin because of the high release of methane is a very important task. As indicated by measurements in 116 blind drifts, on the average the magnitude of air velocity in the pipelines VPM is in limits of 15-25 m/sec. The DPV-1 sensor encompasses almost the entire range of velocities of air motion. Operation of the DPV-1 sensors at mines of the production association ''Karaganda-ugol''' confirmed their high reliability and convenience for operation.
Aggregation of fine-resolution land-cover maps to coarser scales indicates that estimates of the proportions of land-cover types vary as a function of spatial resolution. The magnitude of these proportional errors in a forested area in northern California increase significantly as resolution exceeds a 90-m threshold. These errors could pose difficulties for the use of land-cover products generated from coarse-resolution sensors such as the NOAA-AVHRR and the MODIS sensor planned for the EOS program. The magnitude of the errors appears to be a function of the spatial resolution of the map, the original size of the land-cover classes, and the spatial patterns of the classes.
The repeated use and limited lifetime of a composite tiring vessel compel a need to survey techniques for monitoring the structural integrity of the vessel in order to determine when it should be retired. Various nondestructive techniques were researched and evaluated based on their applicability to the vessel. The methods were visual inspection, liquid penetrant testing, magnetic particle testing, surface mounted strain gauges, thermal inspection, acoustic emission, ultrasonic testing, radiography, eddy current testing, and embedded fiber optic sensors. It was determined that embedded fiber optic sensor is the most promising technique due to their ability to be embedded within layers of composites and their immunity to electromagnetic interference.
A new coumarin-based sensor molecule (L1) has been synthesized and this was found to bind calcium and magnesium ions more effectively as compared to other alkali/alkaline earth/lanthanide and certain transition metal ions. A significant enhancement in fluorescence intensity was observed on binding to Ca2+ and Mg2+ ions; while a minor quenching was observed for weakly bound Hg2+, Ni2+, Fe3+, and Co2+ ions. PET process, coupled with the ICT process, is proposed to explain the observed spectral response.
The term biological motion is often used by researchers studying the patterns of movement generated by living forms and in sports. We studied a pattern recognition system of motion in sport using biological motion data. Biological motion data are acquired using a 3D motion capture system. However, 3D motion capture systems are very expensive. In this article, a biological motion capture system was built using acceleration sensors. Our proposed system uses the technique of Gaussian fitting and regression analysis. We tested our proposed system in pattern recognition of outdoor tennis and its evaluations.
In one of the first uses of high Tc superconductors in an end-use product, Lake Shore Cryotronics and a Swiss lab have developed a liquid nitrogen level sensor using a high Tc thin film. The probe is manufactured using a seamless stainless steel tube with an yttrium-based zirconium oxide flame-sprayed on the tube. A plasma-sprayed superconductor compound is deposited on top of that. The probe is coated with a sealant that protects the superconducting film from the atmosphere. This manufacturing method has yielded an extremely durable product. Unaffected by ice formation and related mechanical problems, the superconducting level sensor can be kept in the dewar for long periods of time.
We studied telomeric DNA in leukemic cells as well as in normal T cells, B cells, monocytes, polymorphonuclear leukocytes, and bone marrow hematopoietic progenitor cells. No marked differences were...Full Text Available
We have investigated the properties of nerve cell precursors in hydra by analyzing the differentiation and proliferation capacity of interstitial cells in the peduncle of Hydra oligactis, which is a region of active nerve cell differentiation. Our results indicate that about 50% of the interstitial cells in the peduncle can grow rapidly and also give rise to nematocyte precursors when transplanted into a gastric environment. If these cells were committed nerve cell precursors, one would not expect them to differentiate into nematocytes nor to proliferate apparently without limit. Therefore we conclude that cycling interstitial cells in peduncles are not intermediates in the nerve cell differentiation pathway but are stem cells. The remaining interstitial cells in the peduncle are ...
A silicon solar cell assembly comprising a large, thin silicon solar cell bonded to a metal mount for use when there exists a mismatch in the thermal expansivities of the device and the mount.
Experiments were designed to elucidate whether or not the irradiated bone marrow cells receive any stimulation for the self-replication and differentiation from normal 'stromal' cell colonies in the bone marrow cell culture in vitro. When irradiated or unirradiated bone marrow cells were overlaid on the normal adherent cell colonies, the proliferation of haemopoietic stem cells was supported, the degree of the stimulation depending on the starting cellular concentration. There was, however, no significant changes in the concentration of either CFUs or CFUc regardless of the dose of irradiation on the bone marrow cells overlaid. This was a great contrast to the dose-dependent decrease of CFUs or CFUc within the culture in which both the stem cells and stromal cells were ...
Ethane oxidation was studied in ethane-grown resting cells (mycelia) of an Acremonium sp. and in cell-free preparations of such mycelia. From resting cell experiments evidence was found for a pathway...Full Text Available
In most adult tissues there reside pools of stem and progenitor cells inside specialized microenvironments referred to as niches. The niche protects the stem cells from inappropriate expansion...Full Text Available
... Fuel Cell Technologies Equipment on Environmental Expert Find and compare a variety of fuel cell technologies equipment on the world's largest environmental industry portal. View ...
Purpose.There is a paucity of neuron replacement studies for retinal ganglion cells. Given the complex phenotype of these neurons, replacement of ganglion cells may be impossible....Full Text Available
Cell cultures were prepared from lung tumors occurring in beagles following exposure to inhaled plutonium. Morphologic and growth characteristics of two of these cell lines are described.
We report the isolation of adherent, clonogenic, fibroblast-like cells with osteogenic and adipogenic potential from the blood of four mammalian species. These cells phenotypically resemble but are...Full Text Available
Effects of cell concentrations on the survival and repopulation of haemopoietic stem cells after irradiation were studied in the long-term culture of mouse bone marrow cells in vitro. No difference was observed in the survival of the stem cells among cultures in which 0 - 10/sup 7/ cells were re-inoculated on the adherent cell colonies in the culture flask. Stem cells showed a significant proliferation within 1 week and the number of the stem cells exceeded the control in 3 weeks after irradiation in the cultures with less than 10/sup 6/ re-inoculated cells per flask. In contrast, there was a considerable delay in the onset of stem cell proliferation after irradiation in the culture with 10/sup 7/ cells per flask. Based on these results, a possibility that a ...
We have studied the correlation between the chemical state and the oxygen-sensing properties of an iron oxide thin film using a setup that allows simultaneous sensor resistance measurements and X-ray photoelectron spectroscopy (XPS) data acquisition. The gas exposures were performed at the highest operating pressure of the XPS spectrometer at a controlled sample temperature which allows direct comparison between the sensor response and the chemical state of the surface. The iron oxide film was modified by a sequence of argon ion sputtering steps and the induced changes in the chemical state, resistance, and sensitivity to oxygen were investigated. The sputtering was found to reduce the iron from the Fe"3"+ to the Fe"2"+ state and to decrease the sensor resistance. The measured sensitivity to oxygen first increased by a factor of two but then collapsed to its original level. The mechanism for oxygen sensing was found to be ...
Mesoporous V2O5/Nafion composite films have been used for the immobilization of tris(2,2prime-bipyridyl)ruthenium (II) (Ru(bpy)$\\rm{ {_{3}^{2+}}}$) on an electrode surface to yield a solid-state electrogenerated chemiluminescence (ECL) sensor. The electrochemical and ECL behavior of Ru(bpy)$\\rm{ {_{3}^{2+}}}$ ion-exchanged into the composite films has been characterized as a function of the amount of Nafion incorporated into the V2O5/Nafion composite. The composite film with 80% Nafion content has the largest pore diameter (4.19 nm) and yields the maximum ECL response for tripropylamine (TPA) because of the fast diffusion of analyte into the film with large pores. Due to the enlarged pore size and enhanced conductivity of the V2O5/Nafion composite, the present ECL sensor based on the compo...
In this article we describe an optoelectronic sensor for assessing the level of light petrochemical products in technological tanks at the oil refineries. This sensor employs the multi-element vertical array of discrete micro- optical refractometric transducers. The transducers are made of silica glass and have the conical shape. In the air, each transducer operates as a tiny retro-reflector that optically couple together two multimode optical fibers. The optical coupling in the transducer is due to the internal reflection at the conical surface. The amount of the coupling depends on the refractive index of the surrounding media. In a fluid, the total internal reflection vanishes and the coupling becomes negligibly small. The number of immersed transducers is a measure of the fluid level in the reservoir. Because of the significance of the transducer transmission function, it is evaluated in detail under various combinations of the geometrical ...
We demonstrate detection of a single core-shell magnetite-silica nanoparticle (outer diameter #approx#120 nm, moment #approx#10"4#mu#_B) using an Nb dc superconducting quantum interference device (SQUID) with the loop size of 350 nm operational at T < 10 K. The system noise was minimized down to 0.2 #mu##PHI#_0 Hz"-"1"/"2 using a cryogenic SQUID series array pre-amplifier. Initial measurements of an individual magnetic nanoparticle were performed and a clear change of the noise spectra of the nano-SQUID was detected at low frequencies in the presence of the nanoparticle. Similar behaviour was confirmed with an FePt nanoparticle with a larger magnetic moment (diameter #approx#150 nm, moment #approx#10"6#mu#_B). Thus, we demonstrate a magnetic sensor based on a dc nano-SQUID and enabling detection of small moments (potentially down to a few electron spins). Such a sensor is of considerable significance for nanomagnetic metrology and quantum ...
Eaton, in partnership with Oak Ridge National Laboratory and the Electric Power Research Institute (EPRI) has completed a project that applies a combination of wireless sensor network (WSN) technology, anticipatory theory, and a near-term value proposition based on diagnostics and process uptime to ensure the security and reliability of critical electrical power infrastructure. Representatives of several Eaton business units have been engaged to ensure a viable commercialization plan. Tennessee Valley Authority (TVA), American Electric Power (AEP), PEPCO, and Commonwealth Edison were recruited as partners to confirm and refine the requirements definition from the perspective of the utilities that actually operate the facilities to be protected. Those utilities have cooperated with on-site field tests as the project proceeds. Accomplishments of this project included: (1) the design, modeling, and simulation of the anticipatory wireless sensor ...
This patent describes a solar heater freeze protection valve apparatus comprising in combination: a valve housing; a remote sensor operatively connected to the valve housing from a remote position, the remote sensor including a bulb containing a liquid adapted to compress and expand with the temperature adjacent the bulb; a piston located in the valve body and slidable responsive to expansion and contraction of the liquid in the remote sensor; a first valve element located in the valve housing and attached to the valve piston for movement; a second valve element located in the valve housing and attached to the housing; a first valve seat in the second valve element forming an opening; a second valve seat positioned in a water passageway to allow the flow of fluid when the second valve element is in an open position and to cut off the flow of fluid when the second valve element is in a closed position. Liquid in a solar ...
The report details the results of a series of large-scale experiments where small coal fires were used to ignite conveyor belting at air velocities ranging from 0.76 m/s to 6.1 m/s. In the tests, electrical strip heaters imbedded within a pile of coal were used to heat the coal to a point of flaming ignition. The flaming coal subsequently ignited conveyor belting located approximately 5 to 10 cm above the coal pile. During the tests, temperature, CO, and smoke levels were continuously measured in order to determine both alarm time and level as the fire intensity progressed through the stages of smoldering coal, flame coal, and flaming coal plus flaming belt. Analysis of the data leads to certain conditions of air velocity and sensor alarm levels that are required for early detection of conveyor belt entry fires. Two nomographs are presented which define sensor alarm levels and sensor spacings as a function of belt entry ...
A study was conducted under the auspices of the Coordinating Research Council, Inc. (CRC) to assess the potential effects of gasoline octane quality on vehicle acceleration performance. Twelve participating laboratories, representing both the oil and the automotive industries, tested a total of 182 vehicles as part of the 1989 CRC Octane Number Requirement Survey. The vehicles consisted of 78 with electronic knock control systems and 104 without. All testing was performed using the 1989/1990 CRC FBRU fuel series. The results showed that acceleration performance of vehicles with knock sensors was significantly affected by gasoline octane quality. Octane effects on acceleration performance were most pronounced at maximum-throttle (detent) conditions and at octane levels below the vehicles' octane requirements; however, some knock-sensor vehicles did show improved acceleration performance with fuels at octane levels above the octane ...
SummaryIn vivo tumor cell migration through integrin-dependent pathways is key to the metastatic behavior of malignant cells. Using quantitative in vivo...Full Text Available
Terminal differentiation of many vascular cells involves cell wall changes. Cells first elongate their primary wall, then lay down a lignified secondary wall, which is often followed by digestion of...Full Text Available
For proper tissue morphogenesis, cell divisions and cell fate decisions must be tightly and coordinately regulated. One elegant way to accomplish this is to couple them with asymmetric cell divisions....Full Text Available
Totipotent stem cells have the potential to differentiate into every cell type. Renewal of totipotent stem cells in the germline and cellular differentiation during early embryogenesis rely upon posttranscriptional...Full Text Available
We have established a cartilaginous fish cell line [Squalus acanthias embryo cell line (SAE)], a mesenchymal stem cell line derived from the embryo of an elasmobranch, the spiny dogfish...Full Text Available
AIM: To isolate and identify the biological characteristics of human colon cancer stem cells (SW1116 cells) and further study their proteome.METHODS: SW1116 cells were isolated and cultured with...Full Text Available
Interleukin 2 (IL-2) and B-cell growth factors I and II (BCGF I and BCGF II) are lymphokines produced by T cells that play a major role in T- and B-cell cooperation. Peripheral blood lymphocytes from...Full Text Available
Normal cells, both in vivo and in vitro, become quiescent after serial cell proliferation. During this process, cells can develop immortality with genomic instability,...Full Text Available
BackgroundStem cell characteristics are an important feature of human cancer cells and play a major role in the therapy resistance of tumours. Strategies to target cancer stem cells...Full Text Available
Endothelial cells and mural cells (smooth muscle cells, pericytes, or fibroblasts) are known to communicate with one another. Their interactions not only serve to support fully functional blood...Full Text Available
BackgroundAs the resident stem cells of skeletal muscle, satellite cells are activated by extracellular cues associated with local damage. Once activated, satellite cells will re-enter...Full Text Available
Craniofacial injuries require a variety of different cell types to repopulate areas of bone, cartilage, tendon, and fat. Mesenchymal stem cells (MSCs) provide a multipotent cell source for tissue...Full Text Available
We describe the lethal, recessive accelerated-cell-death11 Arabidopsis mutant (acd11). Cell death in acd11 exhibits characteristics of animal apoptosis...Full Text Available
Somatic cell nuclear transfer or therapeutic cloning has provided great hope for stem cell-based therapies. However therapeutic cloning has been experiencing both ethical and technical difficulties....Full Text Available
Background:Stem cells can differentiate into multiple cell types, and therefore can be used for cellular therapies, including tissue repair. However, the participation of stem cells...Full Text Available
It has been postulated that thrombin binds to endothelial cells through, at least in part, cell surface glycosaminoglycans such as heparan sulfate, which could serve as antithrombin cofactor on the...Full Text Available
Hematopoietic stem cells replenish all the cells of the blood throughout the lifetime of an animal. Although thousands of stem cells reside in the bone marrow, only a few contribute to blood production...Full Text Available
In the growing chloronema cell suspension cultures of the moss Funaria hygrometrica Hedw., activities of several enzymes have been found to be cell-density-dependent. Cyclic nucleotide...Full Text Available
In preimplantation mouse development, the first cell lineages to be established are the trophectoderm (TE) and inner cell mass. TE possesses epithelial features, including apical-basal cell polarity...Full Text Available
...false Guidelines for Human Stem Cell Research Presidential Documents ...2009 Guidelines for Human Stem Cell Research Memorandum for the Heads...scientifically worthy human stem cell research, including human...
The Defense Advanced Research Projects Agency (DARPA) inaugurated a program addressing research and development for an Exoskeleton for Human Performance Augmentation in FY!2001. A team consisting of Oak Ridge National Laboratory, the prime contractor, AeroVironment, Inc., the Army Research Laboratory, the University of Minnesota, and the Virginia Polytechnic Institute has recently completed an 18-month Phase I effort in support of this DARPA program. The Phase I effort focused on the development and proof-of-concept demonstrations for key enabling technologies, laying the foundation for subsequently building and demonstrating a prototype exoskeleton. The overall approach was driven by the need to optimize energy efficiency while providing a system that augmented the operator in as transparent manner as possible (non-impeding). These needs led to the evolution of two key distinguishing features of this team's approach. The first is the ''no knee ...
We have developed a cell-mediated mutagenesis assay in which cells with the appropriate markers for mutagenesis are co-cultivated with either lethally irradiated rodent embryonic cells that can metabolize carcinogenic hydrocarbons or with primary rat liver cells that can metabolize chemicals carcinogenic to the liver. During co-cultivation, the reactive metabolites of the procarcinogen appear to be transmitted to the mutable cells and induce mutations in them. Assays of this type make it possible to demonstrate a relationship between carcinogenic potency of the chemicals and their ability to induce mutations in mammalian cells. In addition, by simultaneously comparing the frequencies of transformation and mutation induced in normal diploid hamster cells by benzo(a)pyrene (BP) and one of its metabolites, it is possible to estimate the genetic ...
...Basic Information | Fuel Cells & Vehicles | US EPA This web page provides basic information on EPA's Fuel Cells & Vehicles web site ...including the chemical composition of fuel cell technology, how it works, descriptions of the various types of fuel cells , their availability and ... background,electrochemical,hydrogen,fuel cell,fuel cell vehicle,fuel reformer,performace,improved fuel economy,increased engine efficiency,lower emissions,zero emissions,availablity,fuel cell types,diagram,Proton ...Exchange Membrane,PEM Basic Information | Fuel Cells & Vehicles | US EPA background,electrochemical,hydrogen,fuel cell,fuel cell vehicle,fuel reformer,performace,improved fuel economy,...
Laser-assisted processing techniques for producing high-quality solar cell metallization patterns are investigated, developed, and characterized. The tasks comprising these investigations are outlined. A new batch of solar cells was processed using the laser decomposition of spun-on silver neodecanoate to metallize cells. Decomposition of silver neodecanoate was carried out at different laser powers on different cells on a given wafer to determine whether this would have any effect on cell performance. Solar cells which were written with laser powers of 5 to 8 watts, gave excellent results with cell efficiencies in the range of 14 to 16%.
... nent to the design and construction of metal-semiconductor solar cells, in that both the photovoltage and the efficiency of metal-semiconductor cells ...
Reactor Power Measurement is an essential part of the Reactor Power Control Loop in PHWRs. None of the available power measuring sensor offers characteristics which allow their direct use in the Reactor Power Control Loop. Thermal power, which is considered as relatively accurate, suffers from measurement delays and is used only as reference. Neutronic power sensors like Ion Chambers and Self Powered Neutron Detectors (SPNDs) which sense instantaneous power suffer from inaccuracies. A technique is required which makes use of both types-reference power and instantaneous power to extract real power information from the signals. This paper describes techniques to calibrate (correct) neutronic power that with the thermal reference power signals. The paper also brings out limitation of the calibration technique. (author)
The Authenticated Tracking and Monitoring System (ATMS) has been designed to address the need for global monitoring of the status and location of proliferation-sensitive items. Conceived to utilize the proposed Global Verification and Location System (GVLS) satellite link, ATMS could use the existing International Maritime Satellite commercial communication system until GVLS is operational. The ATMS concept uses sensor packs to monitor items and environmental conditions, collects a variety of events data through a sensor processing unit, and transmits the data to a satellite, which then sends data to ground stations. Authentication and encryption algorithms will be used to secure the data. A typical ATMS application would be to track and monitor the safety and security of a number of items in transit along a scheduled shipping route. This paper also discusses a possible proof-of-concept system demonstration.
We describe a position sensitive photon counting microchannel plate based detector with an improved quadrant anode (QA) readout system. The technique relies on a combination of the four planar elements pattern and an additional fifth electrode. The charge cloud induced by single particle detection is split between the electrodes. The measured charge values uniquely define the position of the initial event. QA has been first published in 1976 by Lampton and Malina. This anode configuration was undeservedly forgotten and its potential has been hardly underestimated. The presented approach extends the operating spatial range to the whole sensitive area of the microchannel plate surface and demonstrates good linearity over the field of view. Therefore, the novel image sensor results in spatial resolution better then 50?m and count rates up to one million events per second.
We describe a position sensitive photon counting microchannel plate based detector with an improved quadrant anode (QA) readout system. The technique relies on a combination of the four planar elements pattern and an additional fifth electrode. The charge cloud induced by single particle detection is split between the electrodes. The measured charge values uniquely define the position of the initial event. QA has been first published in 1976 by Lampton and Malina. This anode configuration was undeservedly forgotten and its potential has been hardly underestimated. The presented approach extends the operating spatial range to the whole sensitive area of the microchannel plate surface and demonstrates good linearity over the field of view. Therefore, the novel image sensor results in spatial...
Retaining an appropriate level of moisture at the interface between a healing wound and an applied dressing is considered to be critical for effective wound healing. Failure to control exudate at this interface can result in maceration or drying out of the wound surface. The ability to control moisture balance at the wound interface is therefore a key aspect of wound dressing performance. To date it has not been possible to monitor in any effective manner the distribution of moisture within dressings or how this varies with time.A new measurement system is presented based on sensors placed at the wound/dressing interface which are capable of monitoring moisture levels in real time. The system comprises a model wound bed and sensor array complete with fluid injection path to mimic exudate f...
An automotive powertrain includes a conventional piston engine, a continuously variable ratio transmission, an engine speed sensor and a feedback control system. The control system adjusts both the transmission ratio and the throttle valve in the engine carburetor or fuel metering system in response to the position of the accelerator pedal and in response to the crankshaft speed as measured by the engine sensor. The transmission provides extreme overdrive gear ratios which allow the engine to be operated at wide open throttle even during moderate cruising, and, in addition, the engine carburetor or fuel metering system is calibrated to deliver to the engine a stoichiometric air-fuel mixture which is combined, before combustion, with a special proportion of recirculated exhaust gas. As a result of extensive wide open throttle engine operation with the above mentioned intake charge composition, combustion variables are optimized to produce ...
A new surveillance system for Oil-Filled cable, which can provide continuous monitoring, using a newly developed optical gas sensor that can detect the concentration of the gas dissolved in the oil with extremely high sensitivity has been developed. It was proved that the degree of deterioration of the insulating oil can be detected by measuring C{sub 2}H{sub 2} and CH{sub 4} by investigating the relation between the degree of deterioration and amount of combustible gas generated. In order to detect extremely small amounts of gas, a new gas detecting method using absorption line of the gas using a frequency modulated technique has been developed. The gas detection ability was also confirmed by examination using a 66 kV of cable and the possibility of detection at an early stage is expected.
Many nondestructive beam position monitors are known. However, these devices can not be used for DC particle beam diagnostics. We investigated a method of beam diagnostics applicable for the operative control of DC high power e-beam inside closed waveguide. A design of the detector for determination of{open_quote} center of mass {close_quote} position of DC particle beam was developed. It was shown that the monitor can be used as a nondestructive method for the beam position control in resonators. Magnetic field of the particle beam outside a resonator is used. The detector consists of the steel yokes and magnetic field sensors. The sensors measure magnetic fluxes in the steel yokes fixed outside the resonator. When the particle beam changes its position, these magnetic fluxes also change. Beam displacement sensitivity of the monitor depends on the steel yoke dimensions. The detector sensitivity is equal to 1 Gauss/mm for the conditions ...
The high-frequency data from 12 sensors at the ITCE 1976 are analyzed to determine the Kolmogoroff constants for velocity, temperature and humidity fluctuations, ..cap alpha../sub u/, ..cap alpha../sub T/, and ..cap alpha../sub q/. The occurrence of aliasing in the spectral analysis in some cases together with the limited response of some sensors at the higher frequencies introduces some uncertainties into the analysis. The Soviet sonic anemometer, fine-wire thermometer and infrared hygrometer and the Australian infrared hygrometer provide the best information, namely that: ..cap alpha../sub u/ = 0.59 +/- 0.01, ..cap alpha../sub T/ = 0.68 +/- 0.02, ..cap alpha../sub q/ = 0.76 +/- 0.03, where the errors quoted refer solely to statistical errors. The other instruments provide general support to these values. The technique of using spectral density measurements to determine eddy fluxes is illustrated.
Eddy current testing is one of the most widely used methods in non-destructive testing for the inspection of conductive materials. Numerical modelling of eddy current testing has emerged as an important approach alongside experimental studies. This paper investigates an application of numerical modelling and experimental study as a means of the quantitative non-destructive evaluation (QNDE) of defects in conductive samples. There are two methods of measuring eddy current response, more commonly by measuring the change in impedance of the eddy current probe coil, or as used in this work, by measuring the change in magnetic field directly using magnetic field sensors such as superconducting quantum interference devices, giant magneto resistance, or as in this case Hall sensors. Specifically,...
The ultrasonic inspection pig system was described as being under development. This system was said to adopt the unique wheel type ultrasonic sensor which does not need couplant. This pig was designed to detect external corrosion in long-distance pipelines without interruption of the gas service. The wall-thickness measurement performance test and the travel performance test of the inspection pig in the test line confirmed that these performances satisfied the development specifications. However, the effect induced by the inner surface properties of the pipe and the influence of the pipe`s performance over long distances and for a long period of time still needed to be verified in an actual gas pipeline, and while the pipeline was actually in service. Improvements to the prototype model of the inspection pig were expected to include combinations of inspection pigs, with increases in battery and memory capacities to permit them to cope with in increased number of ...
Polymer-coated magnetic nanoparticles (MNPs) have been prepared and used as an immobilization matrix for the fabrication of solid-state tris(2,2prime-bipyridyl)ruthenium(II) (Ru(bpy)32+) electrogenerated chemiluminescence (ECL) sensor. The pre-synthesized maghemite (g-Fe2O3) MNPs were coated with poly(3-thiopheneacetic acid) based on an oxidative polymerization method using KMnO4. The poly(3-thiopheneacetic acid)-coated MNPs have formed the clusters with average diameter of 200-500nm. The multilayer films of poly(3-thiopheneacetic acid)-coated MNPs were uniformly formed on the surface of a Pt electrode by an external magnet. The Ru(bpy)32+ was rapidly incorporated into the multilayer films within 5min through the electrostatic interaction between the Ru(bpy)32+ and the negatively charged c...
The methods of superconducting device fabrication by lithography and multilevel processing usually require a number of processing steps with lithographic resolution and alignment adequate for the scale of the device be fabricated. As an alternative, the focused ion beam (FIB) microscope is increasingly being used directly to fabricate devices. A major advantage of using a FIB compared to other lithography methods is its flexibility and high resolution. It allows in-situ, milling (#propor to#5 nm at a beam current of 1 pA) to a variety of depths, and imaging (2 nm) of the sample. In this paper we describe our development of junction fabrication techniques using the FIB and their application in creating a range of potential sensor devices and quantum electronics applications. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
The exposure and subsequent undermining of pier/abutment foundations through the scouring action of a flood can result in the structural failure of a bridge. Bridge scour is one of the leading causes of bridge failure. Bridges subject to periods of flood/high flow require monitoring during those times in order to protect the traveling public. In this study, an innovative scour monitoring system using button-like fiber Bragg grating (FBG) sensors was developed and applied successfully in the field during the Aere typhoon period in 2004. The in situ FBG scour monitoring system has been demonstrated to be robust and reliable for real-time scour-depth measurements, and to be valid for indicating depositional depth at the Dadu Bridge. The field results show that this system can function well and survive a typhoon flood.
A stable chlorobenzene dispersion of conducting polyaniline (PANI) has been obtained by doping emeraldine base with dodecylbenzene sulfonic acid (DBSA) and studied by spectrophotometric measurements in the UV-vis-IR range. The electrical properties of PANI: DBSA films obtained from the above dispersion have been investigated under different temperature and relative humidity conditions. All-organic chemoresistive devices have been developed by spin-coating the PANI: DBSA dispersion on flexible substrates, and then by depositing electrodes on the top, from a carbon nanotube conducting ink. Sensing tests performed under exposition to calibrated amounts of ammonia reveal that these simple and inexpensive sensors are able to detect ammonia at room temperature in a reliable way, with a sensitivity linearly related to concentration in the range between 5 ppm and 70 ppm.
A compact and supersensitive device that can rapidly detect minute trace vapors from concealed explosives has been developed by scientists at Oak Ridge National Laboratory (ORNL). The new explosives sensor can detect and chemically identify organic nitrogen-oxygen compounds which are the building blocks of explosives such as TNT, plastiques, and nitroglycerine. The device could be used to scan persons entering airport terminals, nuclear power plants, defense installations, or other sensitive locations, providing greater security against potential terrorism. This device works on a glow discharge principle, and is more specifically called an ''Atmospheric Sampling Glow Discharge Ionization'' (ASGDI) source. The new detector is a highly automated, miniaturized version of research mass spectrometers widely used to trace constituents of chemical mixtures. Detail of this device's construction and advantages are discussed in ...
This paper reviews various techniques to harden Charged Coupled Device (CCD) sensors and the results after irradiation of three Thomson n buried channel CCDs having a different degree of hardening. It describes the major irradiation effects on CCD performances and it makes a comparison of the results between the different hardening levels. It shows good results on dark voltage after ionizing radiation for TH 7863M device hardened both by design and by operating conditions (MPP mode) with respect to the standard device TH 7863A. The irradiations were performed with "6"0Co or X-ray (10 keV) sources on devices in operating mode. (author). 3 refs., 8 figs.
The results of a study on the application of remote sensing and geophysical methods for the detection and monitoring of acid mine drainage (AMD) are summarized, with emphasis on those that appear most suitable. The study consisted of a literature review, an information survey of users and suppliers, and discussions with various experts. Space-borne sensors, airborne sensors, airborne videography and digital frame cameras, spectroradiometers, radar, and photographic data are considered. Geophysical methods are effective for measurement of sulphides, areas of active chemical oxidation, acid mine drainage, and contaminated ground water movement. The popularity and effectiveness of various geophysical methods are rated for AMD applications. 25 refs., 1 fig., 3 tabs.
... and pathogen transmission. Because the ultimate object of stem cell research is cell-based clinical therapy, hES cells should ... 4%) Supported by grants (SC12021 and SC11012) from Stem Cell Research...
Abstract Epstein-Barr virus (EBV), which infects not only B cells, but also T cells and natural killer (NK) cells, is associated with multiple lymphoid malignancies. Recently, the proteasome inhibitor bortezomib was reported to induce apoptosis of EBV-transformed B cells. We evaluated the killing effect of this proteasome inhibitor on EBV-associated T lymphoma cells and NK lymphoma cells. First, we found that bortezomib treatment decreased the viability of multiple T and NK cell lines. No significant difference was observed between EBV-positive and EBV-negative cell lines. The decreased viability in response to bortezomib treatment was abrogated by a pan-caspase inhibitor. The induction of apoptosis was confirmed by flow cytometric assessment of annexin V staining. Additionally, cleavage o...
A system and method for enabling human beings to communicate by way of their monitored brain activity. The brain activity of an individual is monitored and transmitted to a remote location (e.g. by satellite). At the remote location, the monitored brain activity is compared with pre-recorded normalized brain activity curves, waveforms, or patterns to determine if a match or substantial match is found. If such a match is found, then the computer at the remote location determines that the individual was attempting to communicate the word, phrase, or thought corresponding to the matched stored normalized signal.
During its jubilee, the French building technical and scientific centre (CSTB) has organized a colloquium about the future tendencies of buildings evolution in the 20 forthcoming years: autonomy in energy production and wastes or effluents management, reduction of water consumption and management of water, hot water production and space heating, bio-sensors for the management of indoor air-quality, control of noise environment using active acoustic systems etc.. (J.S.)
DescriptionAbstract of Research Proposal The root environment has a major effect on crop growth, both directly through the supply of water and nutrients to the shoot, and indirectly through root to shoot signalling. Better management of crop root systems through agronomic and genetic means has the potential to improve the efficiency of water and nutrient uptake, and limit root restrictions to crop growth. However, progress in this area is currently limited by the lack of sensors for in situ estimates of [continued...
Practical procedures were developed for large-scale microbial decontamination of dry egg powder and gelatine with gamma radiation ("6"0Co). The formation and lifes of free organic radicals in these materials were examined by ESR measurements of powder samples. The concentration of these radicals was studied in dependence on the time of storage. Secondary oxidation of egg fats by air oxygen was investigated. Sensoric tests of irradiated gelatine, both in powder and hydrogel form, were performed. (author). 4 figs., 2 tabs., 2 refs.
We discuss the use of active control to reduce mirror position fluctuations at the quantum level. We have shown in a recent experiment that it is possible to reduce the thermal noise of a mirror by measuring and controlling its motion with an optomechanical sensor based on a high-finesse optical cavity. This approach can be extended to lock the mirror motion at the quantum level, and to suppress the quantum effects of radiation pressure in interferometric measurements such as gravitational-wave detectors. The sensitivity improvement is furthermore independent of losses in the interferometer.
It is maintained that special features of FFTF make it an ideal system to test sodium boiling detection techniques by acoustic/neutronic methods and to test the response of acoustic/neutronic sensors to vibrations. It is shown that accumulated research results indicate that such tests in FFTF are feasible, predictable, promising and safe. (author).
Measurement-While-Drilling (MWD) sensors can supply much of the critical downhole information needed in a systems approach to improving drilling efficiency. The author looks at some areas where MWD information has helped to improve drilling efficiency. To date, most use of MWD has been for directional survey, pressure prediction, and formation evaluation. As MWD systems become more reliable and cost effective, their applications will expand.
Remotely-fielded unattended sensor networks generally must operate at very low power--in the milliwatt or microwatt range--and thus have extremely limited communications bandwidth. Such sensors might be asleep most of the time to conserve power, waking only occasionally to transmit a few bits. RFID tags for tracking or material control have similarly tight bandwidth constraints, and emerging nanotechnology devices will be even more limited. Since transmitted data is subject to spoofing, and since sensors might be located in uncontrolled environments vulnerable to physical tampering, the high-consequence data generated by such systems must be protected by cryptographically sound authentication mechanisms; but such mechanisms are often lacking in current sensor networks. One reason for this undesirable situation is that standard authentication methods become impractical or impossible when bandwidth is ...
A length of metal sheathed metal oxide cable is perforated to permit liquid access to the insulation about a pair of conductors spaced close to one another. Changes in resistance across the conductors will be a function of liquid level, since the wetted insulation will have greater electrical conductivity than that of the dry insulation above the liquid elevation.
A short synopsis of each project is given covering the following main areas of research and development: Atmospheric sciences; Biotechnology; Chemical and instrumentation analysis; Computer and information science; Design and manufacture engineering; Ecological science; Electronics and sensors; Experimental technology; Health protection and dosimetry; Hydrologic and geologic science; Marine sciences; Materials science; Nuclear science and engineering; Process science and engineering; Sociotechnical systems analysis; Statistics and applied mathematics; and Thermal and energy systems.
The results show that the SQUID device eddy current testing system is a suitable tool for NDE. Due to the high low-frequency sensitivity of the SQUID sensor, the SQUID device eddy current testing system permits lower examination frequencies than the conventional eddy current probe system. The SQUID system enhances fault detection in even deeper materials layers. (orig./MM).
The effect of the moisture content in amorphous polymers (PS, PVC, PMMA) on their electro-physical properties is considered. Analytical relationships describing the inflence of the external-field frequency and environmental relative humidity on the conductivity of the polymers are given. For the use of these polymers as active elements of moisture sensors, the moisture-resistive effect is estimated.
We apply two variations of the principle of Minimum Cross Entropy (the Kullback information measure) to fit parameterized probability density models to observed data densities. For an array beamforming problem with P incident narrowband point sources, N > P sensors, and colored noise, both approaches yield eigenvector fitting methods similar to that of the MUSIC algorithm[1]. Furthermore, the corresponding cross-entropies are related to the MDL model order selection criterion[2].
Coatings and sensors having both steric and chemical selectivity. Controlled porosity provides the steric selectivity, whereas chemically tailored film properties, using controlled composition or modification by coupling agents, chemical species replacement, or chemical species within pores, provide the chemical selectivity. Single or multiple layers may be provided.
We propose a system for the on-line monitoring of short and medium term radioactive waste repositories. Such a system is distributed, fine-grained, robust, reliable, and must be based on low-cost components. It could, in principle, open new perspectives on the modality of waste packaging and storage. In particular we propose to employ a new family of cheap and powerful micro sensors to be placed in shape of a fine grid around each single drum. (authors)
In order to identify cells of maternal origin in CVS cultures, tissue from 1st trimester abortions were cultivated and the cultures stained in situ for X-chromatin. Convoluted cells and maternal fibroblasts were found to be positive. By chromosome analysis of cultures from 105 diagnostic placenta biopsies, obtained by the transabdominal route, metaphases of maternal origin were found in nine cases. In eight of these cases colonies of convoluted cells were observed. We conclude that convoluted cells are of maternal origin and are a reliable marker for maternal cell contamination in CVS cultures.
An assay system for the stem cell that colonizes the thymus and differentiates into T cells was developed, and by using this assay system the existence of two subpopulations of stem cells for T cell lineage was clarified. Part-body-shielded and 900-R-irradiated C57BL/6 (H-2b, Thy-1.2) recipient mice, which do not require the transfer of pluripotent stem cells for their survival, were transferred with cells from B10 X Thy-1.1 (H-2b, Thy-1.1) donor mice. The reconstitution of the recipient's thymus lymphocytes was accomplished by stem cells in the donor cells and those spared in the shielded portion of the recipient that competitively colonize the thymus. Thus, the stem cell activity of donor cells can be evaluated by determining the proportion of donor-type (Thy-1.1+) ...
Understanding prostate stem cells may provide insight into the origin of prostate cancer. Primary cells have been cultured from human prostate tissue but they usually survive only 15-20 population doublings before undergoing senescence. We report here that RC-170N/h/clone 7 cells, a clonal cell line from hTERT-immortalized primary non-malignant tissue-derived human prostate epithelial cell line (RC170N/h), retain multipotent stem cell properties. The RC-170N/h/clone 7 cells expressed a human embryonic stem cell marker, Oct-4, and potential prostate epithelial stem cell markers, CD133, integrin #alpha#2#beta#1"h"i and CD44. The RC-170N/h/clone 7 cells proliferated in KGM and Dulbecco's Modified Eagle Medium with 10% fetal bovine serum and 5 #mu#g/ml insulin (DMEM + 10% FBS + Ins.) ...
The herbicide atrazine is a known immunotoxicant and an inhibitor of human natural killer (NK) cell lytic function. The precise changes in NK cell lytic function following atrazine exposure have not been fully elucidated. The current study identifies the point at which atrazine exerts its affect on the stepwise process of human NK cell-mediated lyses of the K562 target cell line. Using intracellular staining of human peripheral blood lymphocytes, it was determined that a 24-h in vitro exposure to atrazine did not decrease the level of NK cell lytic proteins granzyme A, granzyme B or perforin. Thus, it was hypothesized that atrazine exposure was inhibiting the ability of the NK cells to bind to the target cell and subsequently inhibit the release of lytic protein from the NK cell. To test t...
Introduction: Haploidentical transplantation, with extensive T cell depletion to prevent GvHD, is associated with a high incidence of infection-related deaths. The key challenge is to improve immune recovery with allogeneic donor T cells without triggering GvHD. As T regulatory cells (Tregs) controlled GvHD in pre-clinical studies, the present study evaluated the impact of an infusion of donor CD4/CD25 + Tregs, followed by an inoculum of donor mature T cells (Tcons) and positively immunoselected CD34 + cells in the setting of haploidentical stem cell transplantation. Patients and methods: Twenty-eight patients were enrolled in this study (22 AML; 5 ALL; 1 NHL). All received immunoselected Tregs (CliniMACS, Miltenyi Biotec) followed by positively immunoselected CD34 + cells together with Tc...
The presence of a high number of activated T cells in the bloodstream and spontaneous proliferation of peripheral blood mononuclear cells in vitro are striking characteristics of human T-cell leukemia...Full Text Available
The article is the second part of a review dealing with latest developments in the area of solar cell technologies and application. Physical principles, design and efficiency as well as advantages and disadvantages of GaAs- and CdS-solar cells are described. Power generation solar cell systems with voltage converters, combined solar cell/solar collector systems and thermoelectric solar systems are presented in the second part of the article.
The herbicide atrazine is a known immunotoxicant and an inhibitor of human natural killer (NK) cell lytic function. The precise changes in NK cell lytic function following atrazine exposure have not been fully elucidated. The current study identifies the point at which atrazine exerts its affect on the stepwise process of human NK cell-mediated lyses of the K562 target cell line. Using intracellular staining of human peripheral blood lymphocytes, it was determined that a 24-h in vitro exposure to atrazine did not decrease the level of NK cell lytic proteins granzyme A, granzyme B or perforin. Thus, it was hypothesized that atrazine exposure was inhibiting the ability of the NK cells to bind to the target cell and subsequently inhibit the release of lytic protein from the NK cell. To test this hypothesis, flow cytometry ...
Cell therapy is a promising novel option for treatment of cardiovascular disease. Because the role of bone marrow-derived circulating progenitor cells (BM-CPCs) after cell therapy is less clear, we...Full Text Available
PCD (programmed cell death) in plants presents important morphological and biochemical differences compared with apoptosis in animal cells. This raises the question of whether PCD arose independently...Full Text Available
Although human T-cell lymphotropic virus type I (HTLV-I) is the etiologic agent of adult T-cell leukemia/lymphoma (ATL), the role of viral gene expression in the progression to and maintenance of the...Full Text Available
Bovine leukemia virus (BLV), a retrovirus related to human T-cell leukemia virus types 1 and 2, can induce persistent nonneoplastic expansion of the CD5+ B-cell population, termed...Full Text Available
Solid Oxide Fuel Cell (SOFC) is expected as a new power generation source. The development of SOFC is being conducted by CRIEPI, and so far several reports of the reults were presented. This report examines materials of SOFC. For the purpose, cells were made using some of typical materials and manufacturing processes, and cell performance tests were carried out.
The PVSCAN is an instrument designed to characterize silicon solar cell materials and devices. It performs a host of measurements that yield spatial maps of dislocation density, grain distribution, reflectance, and photoresponses from near-junction and the bulk of a solar cell.
The penetration by moxifloxacin of human neutrophils (polymorphonuclear leukocytes [PMN]) and tissue-cultured epithelial cells (McCoy cells) was evaluated by a fluorometric assay. At...Full Text Available
There is ample evidence suggesting that superantigens may act as a triggering factor in the pathogenesis of rheumatoid arthritis (RA). We investigated whether superantigen could activate T cells in...Full Text Available
SUMMARYThe cytolytic activity of natural killer (NK) cells is regulated by inhibitory receptors that detect the absence of self molecules on target cells. Structural studies of...Full Text Available
The proliferation of stem cell research, conflated with its ethical and moral implications, has led governments to attempt regulation of both the science and funding of stem cells. Due to a diversity...Full Text Available
Embryonic stem cells have the ability to develop into virtually any cell in the body, and may have the potential to treat medical conditions such as diabetes and Parkinsons disease. On August 9, 2001, President Bush announced that for the first time feder...
Background: In North America and Europe, 80% of invasive skin cancers are basal cell carcinoma while 20% are squamous cell carcinoma (SCC). In contrast, African studies reveal a preponderance...Full Text Available
BackgroundSpindle cell carcinoma (SpCC) is a rare microscopic type of cancer of the mouth and oropharynx. Although SpCC is thought to arise from squamous cell carcinoma (SCC), it...Full Text Available
This paper describes a radiation shield verification survey of a large hot cell at the Fast Flux Test Facility (FFTF). The following aspects of the shield test are discussed: description of the FFTF; description of the hot cell; the test procedures; radiation protection, and the test results.
... from Dr. Austin Smith of the Institute for Stem Cell Research, University of Edinburgh) was modified from the CGR8 ... to thank Dr. Austin Smith, the Institute for Stem Cell Research, University of Edinbu...
Human myeloid-lineage cells are refractory to HIV-1 infection. The Vpx proteins from HIV-2 and sooty mangabey SIV render these cells permissive to HIV-1 infection through proteasomal degradation of...Full Text Available
Most genetic changes that promote tumorigenesis involve dysregulation of G1 cell cycle progression. A key regulatory site in G1 is a growth factor–dependent restriction point (R) where cells...Full Text Available
Target of rapamycin (TOR) kinases control cell growth through two functionally distinct multiprotein complexes. TOR complex 1 (TORC1) controls temporal cell growth and is sensitive to rapamycin, whereas...Full Text Available
... based, disease treatment remains promising, the emphasis for stem cell research from the biomedical research community is clear, and ... diagnosis as a novel source of embryos for stem cell research. Repr...
The cells of the endosperm of castor bean seeds (Ricinus communis) undergo programmed cell death during germination, after their oil and protein reserves have been mobilized. Nuclear...Full Text Available
Placental and placental-like alkaline phosphatase (PLAP) levels in the culture media of 87 cell lines of neoplastic and 'normal' origin were measured by a conventional immunosorbent enzymatic assay...Full Text Available
The rate and capacity for chloroform (CF) and trichloroethylene (TCE) transformation by a mixed methanotrophic culture of resting cells (no exogenous energy source) and formate-fed cells were measured....Full Text Available
A new method is described for continuously measuring cell turgor pressure (P), hydraulic conductivity (Lp), and volumetric elastic modulus (ε) in higher plant cells, using a pressure...Full Text Available
PURPOSE: To determine the frequency of ophthalmic abnormalities in patients with cutaneous T-cell lymphoma (mycosis fungoides and Sézary syndrome) and T-cell lymphoma involving the skin and...Full Text Available
Neutral endopeptidase 24.11 (NEP, CD10) is a cell-surface enzyme expressed by prostatic epithelial cells that cleaves and inactivates neuropeptides implicated in the growth of androgen-independent prostate...Full Text Available
The primary aim of this study was to develop a model system that uses epidermal cells (keratinocytes and accessory pigmented cells) cultured on a reconstituted basement membrane biomatrix for use in...Full Text Available
Amorphous silicon solar cells have been shown to have efficiencies which degrade as a result of long exposure to light. Annealing such cells in air at a temperature of about 200.degree. C. for at least 30 minutes restores their efficiency.
Special red cells were found on the adaxial surface of tertiary pulvini of Mimosa pudica and experiments performed to determine the origin and function of these cells. Using anatomical...Full Text Available
Red cell transfusions are associated with the development of acute lung injury in the critically ill. Recent evidence suggests that storage induced alterations of the red blood cell (RBC) collectively...Full Text Available
Adhesion of Spirogyra (tentatively, Spirogyra fluviatilis) cells to glass is described. The cells of an algal filament can adhere to a substrate only when they are...Full Text Available
Many patients who undergo hematopoietic cell transplantation (HCT) present with anemia and have received red blood cell transfusions before HCT. As a result, iron overload is frequent and appears...Full Text Available
Understanding the interactions between herpesviruses and their host cells and also the interactions between neoplastically transformed cells and the host immune system is fundamental to understanding...Full Text Available
Stem cells of the human prostate gland have not yet been identified utilizing a structural biomarker. We have discovered a new prostatic epithelial cell phenotype-expressing cytokeratin 6a (Ck6a+...Full Text Available
BackgroundStem cells divide to reproduce themselves and produce differentiated progeny. A fundamental problem in human biology has been the inability to measure how often stem cells...Full Text Available
... is known as "reproductive cloning." The Link to Stem Cell Research Stem cell research and research cloning are closely linked. Scientists in ... to arrive at a position on cloning and stem cell research. Many nations, including the UK, China, and South ...
Although most self-reactive T cells are eliminated in the thymus, mechanisms to inactivate or control T cells specific for extrathymic antigens are required and exist in the periphery. By investigating...Full Text Available
The glycolipid content of human non-seminomatous germ cell tumour cell lines correlates with their differentiation lineage. To analyse whether this reflects the situation in primary tumours, we studied...Full Text Available
One of the major decisions that germ cells make during their development is whether to differentiate into oocytes or sperm. In mice, the germ cells’ decision to develop as male or female depends...Full Text Available
DNA from the peripheral blood mononuclear cells of 17 different individuals infected with human T-cell lymphoma/leukemia virus type II (HTLV-II) was successfully amplified by the polymerase chain reaction...Full Text Available
It Peripheral blood progenitor enriched CD34+ cells (PBPC) are rather often used as stem cell background in cancer patients following high dose therapy. Keeping in mind that precursor dendritic cells (DCs) originate from haematopoietic progenitor cells, purified CD34+ cells might also serve as starting cells for ex-vivo production of DC. The aim of the present study is to develop a clinical grade procedure for ex-vivo production of DC derived from enriched CD34+ cells. Various concentrations of CD34+ cells were grown in gas-permeable Teflon bags with different serum-free and serum-containing media supplemented with GM-CSF, IL-4, TNF-a, SCF, Flt-3L and INF-a. Serum-free CellGroSCGM medium for 7 days followed by CellGroDC medium in 7 days gave equal results as serum-containing ...
Metastatic testicular germ cell tumours are cured in approximately 85% of patients using cisplatin-based combination chemotherapy. Patients who fail to respond have a poor prognosis, and there is a...Full Text Available
The first cell lineage specification in mouse embryo development is the formation of trophectoderm (TE) and inner cell mass (ICM) of the blastocyst. This article is to review and discuss the...Full Text Available
Zygotes of fucoid algae have long been studied as a paradigm for cell polarity. Polarity is established early in the first cell cycle and is then expressed as localized growth and invariant cell division....Full Text Available
Naturally occurring and contaminant ferromagnetic and ferrimagnetic particles have been found within or near cells, and might allow pulsed magnetic fields to create transient cell membrane opening ("pores")....Full Text Available
BackgroundClara cell protein (CC16), the main secretory product of bronchiolar Clara cells, plays an important protective role in the respiratory tract against oxidative stress and...Full Text Available
... ions. MATERIALS AND METHODS Cell Culture Culture of NT2/D1 cells was carried out as described previously (18, 19). NT2 cells were plated at a density of 2. ... ...
BackgroundPerfluorocarbons (PFC) are used to improve gas exchange in diseased lungs. PFC have been shown to affect various cell types. Thus, effects on alveolar type II (ATII) cells...Full Text Available
1. Paired or single recordings of paraventricular and/or supraoptic oxytocin cells at the beginning of suckling in urethane-anaesthetized rats enabled us to study cell recruitment and compare the characteristics...Full Text Available
Reaggregated cells from 6- to 8-day-old mouse cerebella have been used to raise antibodies in rabbits. The interaction of these antibodies with cerebellar cell surface components was assessed by cytotoxicity...Full Text Available
Cells have an internal compass that enables them to move along shallow chemical gradients. As amoeboid cells migrate, signaling events such as Ras and PI3K activation occur spontaneously on pseudopodia....Full Text Available
The cell types involved in the cellular immune response were studied with the GVH in vitro as a test system. Comparison of the activities of cells of different lymphoid organs in the...Full Text Available
Species differences in lifespan have been attributed to cellular survival during various stressors, designated here as ‘cell resilience’. In primary fibroblast cultures, cell...Full Text Available
Stem cell therapies for neurodegenerative disorders require accurate delivery of the transplanted cells to the sites of damage. Numerous studies have established that fluid injections to the hippocampus...Full Text Available
We review the application of C. elegans as a model system to understand key aspects of stem cell biology. The only bona fide stem cells in C. elegans...Full Text Available
One of the main obstacles encountered when trying to culture human seminoma (SE) cells in vitro is massive degeneration of the tumour cells. We investigated whether dissociation of tumour tissue, to...Full Text Available
SummaryFor mammalian somatic cells the importance of microtubule cytoskeleton integrity in interphase cell cycle progression is uncertain. The loss, diminishment, or stabilization...Full Text Available
BACKGROUND--Interstitial lung diseases are characterised by the recruitment of mononuclear cells to disease sites where maturation occurs and activation products, including lysozyme (LZM), are released....Full Text Available
BackgroundA fundamental requirement for the exploitation of embryonic stem (ES) cells in regenerative medicine is the ability to reproducibly derive sufficient numbers of cells of...Full Text Available
Cultured mouse or human embryonic stem (ES) cells provide access to all of the genes required to elaborate the fundamental components and physiological systems of a mammalian cell. Chemical or insertional...Full Text Available
ObjectiveThe goal of the study was to investigate the genetic and molecular basis of a novel syndrome of marked hyperglucagonemia and pancreatic α cell hyperplasia...Full Text Available
Fate maps are generated by marking and tracking cells in vivo to determine how progenitors contribute to specific structures and cell types in developing and adult tissue. An advance in this...Full Text Available
It may result in acute radiation syndrome after body is exposed to ionizing radiation. The one of long-term effects of irradiation injury is leukemia. The bone marrow cells (BMC) transplantation including stem cells is the only effective therapy for acute radiation syndrome patients. Recently, with the advancement of stem cell research that the stem cells have multipotential and can convert each other, it may supply the new stem source for the irradiation injury patients. At the same time with the further research of radioprotective reagents, the hematopoietic stem cells proliferation after irradiation injury is promoted
In the last two years, rapid progress has been made in the energy conversion efficiencies of GaAs solar cells fabricated from molecular beam epitaxy (MBE) material. The efficiencies of cells fabricated from MBE material are now comparable with those fabricated from metal-organic chemical vapor deposition material, even for cells of dimension 2 cmx4 cm. This paper reviews the progress in MBE cell efficiencies. Also discussed is the role oval defects play in GaAs diode and solar cell performance. (orig.).
As concern regarding global environmental problems such as the greenhouse effect and acid rain has increased, so too has the demand for commercially viable solar cells as a clean energy source. Interest in amorphous silicon (a-Si) solar cells has been particularly high, due to their low cost. Technological developments in the field of a-Si solar cells are discussed from the viewpoints of fabrication process, materials, and cell structures. Various applications and systems that take advantage of the a-Si solar cell are then introduced. Finally, future prospects are mentioned
Transdifferentiation of an individual's own cells into functional differentiated cells to replace an organ's lost function would be a personalized approach to therapeutics. In this two part series, we will describe the progress toward establishing functional transdifferentiated adrenal cortical cells. In this article (Part 2), we describe the disorders of the adrenal cortex, therefore establishing why there is the need for personalized cell-based therapy for individuals with these disorders. We then present our pilot studies of cell transdifferentiation toward an adrenal cortical fate using genes described in the first article of this pair (Part 1).
In this contract, Laser-assisted processing techniques for producing high-quality solar cell metallization patterns are being investigated, developed, and characterized. The tasks comprising these investigations are outlined. Four new batches of solar cells were processed, in addition to several test runs on wafers, using the laser decomposition of spun-on silver neodecanoate to metallize cells. Decomposition of silver neodecanoate was carried out at different laser powers on different cells on a given wafer to determine whether this would have any effect on cell performance. A one watt laser power gave an electroplated linewidth of 50 microns , while at 8 watts the line width was 90 microns.
We report on multijunction GaInP/GaAs photovoltaic cells with total-area efficiencies of 29.5% at one-sun concentration and air mass (AM) 1.5 global and 25.7% one-sun, AM0. These values represent the highest efficiencies achieved by any solar cell under these illumination conditions. Three key areas in this technology are identified and discussed: the grid design, front surface passivation of the top cell, and bottom surface passivation of both cells. Aspects of cell design related to its operation under different solar spectra and under concentration are also discussed.
The theory for the general case of solar cells operating inside integrating cavity receivers is established. This is applied to the particular case of different configurations of silicon and GaAs cells. The results of the analysis show that a composite system of silicon and GaAs cells manufactured using relatively simple technology could reach an efficiency of 34%. The optimal configuration is that in which the GaAs cells are placed in the directly illuminated area of the receiver and the silicon cells are placed in the indirectly illuminated area of the receiver. (orig.).
With the aid of a DOE grant (No. DE-FC26-01NT41050), Stolar Research Corporation (Stolar) developed the Horizon Sensor (HS) to distinguish between the different layers of a coal seam. Mounted on mining machine cutter drums, HS units can detect or sense the horizon between the coal seam and the roof and floor rock, providing the opportunity to accurately mine the section of the seam most desired. HS also enables accurate cutting of minimum height if that is the operator's objective. Often when cutting is done out-of-seam, the head-positioning function facilitates a fixed mining height to minimize dilution. With this technology, miners can still be at a remote location, yet cut only the clean coal, resulting in a much more efficient overall process. The objectives of this project were to demonstrate the feasibility of horizon sensing on mining machines and demonstrate that Horizon Sensing can allow coal to be cut cleaner and more efficiently. ...
pletely new PW fuel cell model had to be developed for CINDA. Several ...... following linear equation, which is used in the SINDA fuel cell model: ...
ObjectiveTo achieve osteochondral regeneration utilizing transplantation of cartilage-lineage cells and adequate scaffolds, it is essential to characterize the behavior of transplanted...Full Text Available
BackgroundThe evolution of eukaryotic cells is widely agreed to have proceeded through a series of endosymbiotic events between larger cells and proteobacteria or cyanobacteria,...Full Text Available
The molecular structure, chemical properties, and biological function of the xyloglucan polysaccharide isolated from cell walls of suspension-cultured sycamore (Acer pseudoplatanus)...Full Text Available
... Program: Quallion Matrix Design (small cells) - Investigate the feasibly of a hybrid battery matrix composed of small D-sized cells for use in HEVs ...
The most advanced frontier of allogeneic hematopoietic stem cell transplantation (allo-HSCT) is represented by the use of an HLA-partially matched relative as donor. In this type of transplantation, donor-derived natural killer (NK) cells, which are alloreactive towardtoward recipient cells, significantly contribute to the eradication of leukemia blasts. Alloreactive NK cells may also kill host dendritic cells and T lymphocytes, thus preventing graft-versus-host disease and graft rejection, respectively. Sophisticated strategies of adoptive infusion of T-cell lines/clones specific for the most life-threatening pathogens (namely cytomegalovirus, Epstein-Barr virus, Aspergillus and Adenovirus) have been envisaged, and successfully tested in a few pilot trials, to protect the recipient in the...
Gene expression is a fundamentally stochastic process, with randomness in transcription and translation leading to significant cell-to-cell variations in mRNA and protein levels. This variation...Full Text Available
Conditions were found in which Chlamydomonas reinhardi exhibits a circadian alteration of its cell surface, measured as ability to stick to glass. Under these same conditions the cells...Full Text Available
To examine the possibility that mast cells have a central role in the pathogenesis of hypersensitivity pneumonitis, 20 patients with this disease were studied with the aim of seeking evidence for mast...Full Text Available
Regulatory T cells are proposed to play a central role in the maintenance of immunological tolerance in the periphery, and studies in many animal models demonstrate their capacity to inhibit inflammatory...Full Text Available
There is a requirement for a noninvasive technique to monitor stem cell differentiation. Several candidates based on optical spectroscopy are discussed in this review: Fourier transform infrared (FTIR)...Full Text Available
Diverse cell polarity networks require positive feedback for locally amplifying distributions of signalling molecules at the plasma membrane1. Additional...Full Text Available
Morphological, Electrophysiological and Behavioral Investigations of the Nervous Tissue Developed from the Embryonic Matrix Zone Cells of the Dorsolateral Walls of Lateral Ventricles, Implanted into the Lesioned Regions of the Adult Rat's Brain
Jun 10, 2011 ... The PSSC is a picosatellite designed to test the space environment by providing a testbed to gather data on new solar cell technologies.
The present volume on modeling of batteries and fuel cells discusses the significance of the effectiveness factor for flooded porous electrodes, active pore distribution spectroscopy for characterizing porous battery electrodes, the agglomerate model for porous electrodes, and dynamic-performance measurements of battery cells for electric vehicles and other applications. Attention is given to mathematical modeling of a primary zinc/air battery, mathematical modeling of Grace Li-TiS2 cells, modeling of electrocrystallization processes in battery systems, and rotating disk electrode studies in molten Li/K carbonate eutectic. Topics addressed include the variability of nickel oxide cathode dissolution in molten carbonate fuel cells, water transport properties of fuel cell ionomers, modeling water content effects in polymer electrolyte fuel cells, and computer ...
Many mutations associated with retinal degeneration lead to the production of misfolded proteins by cells of the retina. Emerging evidence suggests that these abnormal proteins cause cell death...Full Text Available
Methods for improving the sensitivity of scintillation cells for radon concentration measurements were studied with emphasis on improving light collection efficiency. This allows the length and hence the volume of the cell to be increased. Variables studied were choice of scintillator material, its method of application and thickness, length of cell, cell material, type and configuration of reflectors, choice of photomultipliers, and factors affecting background. Response from various areas of the cell surface was studied with an alpha source and with radon filling. Coating the window with phosphor was found to be counter-productive. The optimum results obtained were with the inside of the cell (other than the window) covered with a thick layer of ZnS(Ag), or with a thick layer of reflective material coated with a thin layer of phosphor. With it, a 10 cm ...
Methods for improving the sensitivity of scintillation cells for radon concentration measurements were studied with emphasis on improving light collection efficiency. This allows the length and hence the volume of the cell to be increased. Variables studied were choice of scintillator material, its method of application and thickness, length of cell, cell material, type and configuration of reflectors, choice of photomultipliers, and factors affecting background. Response from various areas of the cell surface was studied with an alphy source and with radon filling. Coating the window with phosphor was found to be counter-productive. The optimum results obtained were with the inside of the cell (other than the window) covered with a thick layer of ZnS(Ag), or with a thick layer of reflective material coated with a thin layer of phosphor. With it, a 10 cm ...
Proliferating cells have been immunophenotypically characterized in lymph node and bronchoalveolar lavage (BAL) samples obtained from patients with active and inactive sarcoidosis with the cell-cycle-related...Full Text Available
Erythrocytes serve as reservoirs for cis- and trans-epoxyeicosatrienoic acids (EETs). Incubation of rat red blood cells (RBCs) with cis- and...Full Text Available
PASTICCINO (PAS) genes are required for coordinated cell division and differentiation during plant development. In loss-of-function pas mutants,...Full Text Available
PurposeTo analyze the expression of apoptosis and cell proliferation molecules in pterygium tissues of Chinese patients.MethodsThirty-three pterygia...Full Text Available
Proton exchange membrane (PEM) fuel cells are energy sources that have the ... for H2 /02 PEM fuel cells because their catalysts have properties suitable for 0 ...
Substantially genetically stable continuous human cell lines derived from normal human mammary epithelial cells (HMEC) and processes for making and using the same. In a preferred embodiment, the cell lines are derived by treating normal human mammary epithelial tissue with a chemical carcinogen such as benzo(a)pyrene. The novel cell lines serve as useful substrates for elucidating the potential effects of a number of toxins, carcinogens and mutagens as well as of the addition of exogenous genetic material. The autogenic parent cells from which the cell lines are derived serve as convenient control samples for testing. The cell lines are not neoplastically transformed, although they have acquired several properties which distinguish them from their normal progenitors. 2 tabs.
... with the loosening of Bush-era restrictions on stem cell research, a move that was widely hailed by the ... The first two explore the contentious debate over stem cell research. Using a series of intervie...
The existence of stem cells committed to the T lymphoid lineage was deduced from studying how rat T and B stem cells differ in their expression of membrane W3/13 antigen and in their susceptibility in vivo to gamma irradiation. Stem cell activity of rat bone marrow and fetal liver was measured in long-term radiation chimeras using B and T cell alloantigenic surface markers to identify the progeny of donor cells. Monoclonal mouse anti-rat thymocyte antibody W3/13 labeled approximately 40% of fetal liver cells and 60-70% of young rat bone marrow cells (40% brightly, 25% dimly). Bright, dim, and negative cells were separated on a fluorescence-activated cell sorter. All B and T lymphoid stem cells in fetal liver were W3/13 bright, as were B lymphoid stem cells in ...
Cancer, by definition, is a proliferative disease. The fundamental scientific issue explored at the international symposium "Cell Proliferation and Chemical Carcinogenesis" was the impact of chemically...Full Text Available
Cells of the mononuclear phagocyte lineage have the capability to adhere to and fuse with each other and to differentiate into osteoclasts and giant cells. To investigate the macrophage adhesion/fusion...Full Text Available
Abstract: In many biological processes heterogeneity within clonal cell populations is an important issue. One of the most striking examples is a population of cancer cells in which after a common, identical death signal some cells die whereas others survive. The reason for this heterogeneity is intrinsic and extrinsic noise. In this paper we present a mechanistic multi-scale modeling framework for cell populations, in which the dynamics of every individual cell is captured by a parameter dependent stochastic differential equation (SDE). Heterogeneity among individual cells is accounted for by differences in parameter values, modeling extrinsic influences. Based on the statistical properties of the extrinsic noise and the SDE model for the individual cell, a partial differential equation (...
We present a sample preparation method for measuring magnesium in individual whole lymphocytes by electron probe X-ray microanalysis. We use Burkitt's lymphoma cells in culture as the test sample and compare X-ray microanalysis of individual cells with atomic absorption analysis of pooled cell populations. We determine the magnesium peak-to-local continuum X-ray intensity ratio by electron probe X-ray microanalysis and calculate a mean cell magnesium concentration of 39 +/- 19 mmol/kg dry weight from analysis of 100 cells. We determine a mean cell magnesium concentration of 34 +/- 4 mmol/kg dry weight by atomic absorption analysis of pooled cells in three cell cultures. The mean cell magnesium concentrations determined by the two methods are not significantly different. We find a 10% coefficient of ...
May 31, 2011 ... A Theoretical Solid Oxide Fuel Cell Model for System Controls and Stability Design AUTHOR(S): Kopasakis, George; Brinson, Thomas; Credle, ...
The purpose of this review is to consider the hypothesis that cancer frequently originates from stem cells. Using the spleen transplantation assay where stem cells were transplanted in the spleen of mice lethally irradiated by ionizing radiation, the author undertook a study aimed at defining the risk of radiogenic cancer per susceptible cells with use of rat radiogenic mammary and thyroid cancers because of the high incidences of these cancers in a-bomb survivors. Measured were the number of cancer-susceptible cells initially present in the tissue, the number of such cells that survived at a given dose and the number of cancers that developed per surviving cell. Thyroid cell differentiation and proliferation in rats transplanted with thyroid cells were enhanced by thyroidectomy and low iodine diet. Further, the ...
Physiological functions are carried out by differentiated cells, with finite lifespans, which age and need to be replaced. In young individuals, tissue functions are sustained at optimal levels because cellular dysfunction and cell loss are balanced by the emergence of newly differentiated cells as stem cells and their partially differentiated descendants replicate. However, with the passage of time the mitotic rates of these cells diminish. Eventually, replications occur too infrequently to offset the loss. It is at this point that the tissue begins to show structural changes and declining function which, as they become pervasive, are identified as ageing. In this paper the theory is set forth that: (1) Diminishing mitotic activity in older tissues results from limited stem cell replicative capacity. (2) All stem cells, regardless of ...
Bone marrow is one of the most radiosensitive organs. Irradiation causes a marked decrease in the total number of hematopoietic cells in the bone marrow. The reticular meshwork structure of marrow stromal cells, however, is relatively resistant to irradiation. Unimpaired stromal cell structure has been thought to be a prerequisite for the repopulation of hematopoietic cells during recovery from the effects of irradiation. The reticular framework is maintained by cell adhesion apparatuses such as gap junctions. The in vitro radiobiologic survival values of a cloned stromal cell line, H-1/A, were studied (n = 1.8, D0 = 138 cGy). Radiation doses of up to 4000 cGy had no detectable effects on the production of colony-stimulating factor 1. H-1/A cells communicate with each other via gap junctions as determined by the sensitive dye-transfer ...
Bone marrow is one of the most radiosensitive organs. Irradiation causes a marked decrease in the total number of hematopoietic cells in the bone marrow. The reticular meshwork structure of marrow stromal cells, however, is relatively resistant to irradiation. Unimpaired stromal cell structure has been thought to be a prerequisite for the repopulation of hematopoietic cells during recovery from the effects of irradiation. The reticular framework is maintained by cell adhesion apparatuses such as gap junctions. The in vitro radiobiologic survival values of a cloned stromal cell line, H-1/A, were studied (n = 1.8, D0 = 138 cGy). Radiation doses of up to 4000 cGy had no detectable effects on the production of colony-stimulating factor 1. H-1/A cells communicate with each other via gap junctions as determined by the sensitive dye-transfer ...
The cell is modeled as an ellipsoid with shell and the surface stress distribution calculated by means of the Maxwell Stress Tensor. The cell membrane is treated as incompressible material having both bending and shear energies of deformation. Employing the principle of virtual work, cell volume (and hence shape) is computed as a function of the external field strength and orientation with respect to the field. The following results were obtained: (1) The surface stresses that develop or the cell membrane are distributed having both normal and tangential components that act together to produce a rounding of the cell. (2) If the tangential component of the stress is ignored, then higher field strengths are needed to produce similar deformation (shape change) of cells. (3) The threshold value of the applied field, i.e, the field strength at which the volume ...
The field of stem cell research was revolutionized with the advent of induced pluripotent stem cells. By reprogramming somatic cells to pluripotent stem cells, most ethical concerns associated with the use of embryonic stem cells are overcome, such that many hopes from the stem cell field now seem a step closer to reality. Several methods and cell sources have been described to create induced pluripotent stem cells and we discuss their characteristics in terms of feasibility and efficiency. From these cells, cardiac progenitors and cardiomyocytes can be derived by several protocols and most recent advances as well as remaining limitations are being discussed. However in the short time period this technology has been around, evidence emerges that induced pluripotent stem cells may ...
One approach to validate nuclear power plant (NPP) signals makes use of pattern recognition techniques. This approach often assumes that there is a set of signal prototypes that are continuously compared with the actual sensor signals. These signal prototypes are often computed based on empirical models with little or no knowledge about physical processes. A common problem of all data-based models is their limited ability to make predictions on the basis of available training data. Another problem is related to suboptimal training algorithms. Both of these potential shortcomings with conventional approaches to signal validation and sensor operability validation are successfully resolved by adopting a recently proposed learning paradigm called the support vector machine (SVM). The work presented here is a novel application of SVM for data-based modeling of system state variables in an NPP, integrated with a nonlinear, nonparametric technique ...
The two-phase flow regime transition in a large diameter (I.D.=200mm) vertical pipe was experimentally investigated using a dual-sensor optical probe. The flow transitions from bubbly to chum without an intermediate slug flow regime as the air flow rate is increased. The transition boundaries developed for bubbly to slug flow in small diameter pipes are compared to the bubbly to chum flow transition of the present experiment. The bubbly to chum transition occurs at a void fraction of about 0.15 compared to 0.25 for bubbly to slug transition in small diameter pipes. The radial distribution of bubble diameter, bubble frequency, bubble velocity and local void fraction were obtained using a dual-sensor optical probe at different flow conditions. The Probability Density Function (PDF) and Cumulative Distribution Function (CDF) of the bubble velocity and size are used to study the flow regime transition in the large diameter pipe. (author)
The two-phase flow regime transition in a large diameter (I.D.=200mm) vertical pipe was experimentally investigated using a dual-sensor optical probe. The flow transitions from bubbly to chum without an intermediate slug flow regime as the air flow rate is increased. The transition boundaries developed for bubbly to slug flow in small diameter pipes are compared to the bubbly to chum flow transition of the present experiment. The bubbly to chum transition occurs at a void fraction of about 0.15 compared to 0.25 for bubbly to slug transition in small diameter pipes. The radial distribution of bubble diameter, bubble frequency, bubble velocity and local void fraction were obtained using a dual-sensor optical probe at different flow conditions. The Probability Density Function (PDF) and Cumulative Distribution Function (CDF) of the bubble velocity and size are used to study the flow regime transition in the large diameter pipe. (author)
Protecting sensitive items from undetected tampering in an unattended environment is crucial to the success of non-proliferation efforts relying on the verification of critical activities. Tamper Indicating Packaging (TIP) technologies are applied to containers, packages, and equipment that require an indication of a tamper attempt. Examples include: the transportation and storage of nuclear material, the operation and shipment of surveillance equipment and monitoring sensors, and the retail storage of medicine and food products. The spectrum of adversarial tampering ranges from attempted concealment of a pin-hole sized penetration to the complete container replacement, which would involve counterfeiting efforts of various degrees. Sandia National Laboratories (SNL) has developed a technology base for advanced TIP materials, sensors, designs, and processes which can be adapted to various future monitoring systems. The purpose of this technology ...
This work describes the theoretical basis for a new concept rotating magnetic tensor gradiometer. The rotating gradiometer consists of an approximately axial or transverse gradiometer which is made to rotate about a perpendicular axis so that the direction of sensitivity is continually changing. It is demonstrated for the first time that the rotation separates gradient components of progressively higher-order in the frequency domain and enables absolute-value measurements of all components of the first-order magnetic gradient tensor, even if the magnetic sensors comprising the gradiometer are intrinsically incapable of absolute-value detection. In addition, the rotating gradiometer concept has a number of other advantages: the gradiometer imbalance is no longer directly determined by the engineering precision, the DC and low-frequency performance of the instrument is not limited by the performance of the detectors in these respects, rotation at frequencies above ...
Stripping Voltammetry (SV) at microelectrodes has gained increased interest in the analysis of aqueous solutions due to its ability to analyze low concentrations (ppb) of electroactive metallic species in solution. Existing integrated circuit (IC) technology allows the inexpensive fabrication of microelectrodes with dimensions on the order of microns and with a high degree of uniformity and reproducibility. Additional circuitry, both multiplexing and signal conditioning, can be placed directly onto the sensor offering increased sensitivity and flexibility. Multi-element electrochemical sensors containing arrays of Pt, Au, and Ag electrodes and capable of individual measurement through built-in multiplexing or simultaneous measurement at the appropriate potential ranges for each individual electrode were fabricated using existing 2 micron IC technology. Results of simultaneous measurements of low concentrations of Cd, Pb, Cu, As, and Hg in ...
Size-selected SnO{sub 1.8}:Ag mixed nanoparticle films have been prepared using a gas phase condensation method. Transmission electron microscopy showed that the applied size-selection technique yields well-defined, monodisperse and spherical SnO{sub 1.8} and Ag nanoparticles, both with a fixed diameter of 20 nm. The technique allows an independent variation of the particle size of both materials as well as the concentration of Ag. It allows to assess the influence of these parameters on the gas-sensing properties of the films, here for ethanol vapor in synthetic air. SnO{sub 1.8}:Ag nanoparticle films show optimal values of the sensor signal and response time at a Ag nanoparticle concentration of 5%. Due to the fact that the Ag nanoparticles are clearly distinct from the SnO{sub 1.8} nanoparticles in the film, the most probable mechanism leading to improved sensor properties is chemical sensitization via a spill-over effect.
The video documents the results of a Small Business Innovative Research (SBIR-Phase II) project conducted for DARPA focusing on the use of all-source overhead remote sensor imagery for monitoring underground nuclear tests and related activities. The documentation includes: (1) the main unclassified body of the report; (2) a separate ground truth Annex; and (3) a separate classified Annex. Autometric's approach was to investigate the exploitation potential of the various sensors, especially the fusion of products from them in combination with each other and other available collateral data. This approach featured empirical analyses of multisensor/multispectral imagery and collateral data collected before, during, and after an actual underground nuclear test (named 'BEXAR'). Advanced softcopy digital image processing and hardcopy image interpretation techniques were investigated for the research. These included ...
A 19.1 metre wind turbine blade was subjected to static tests. The purpose of the test series was to verify the abilities of different types of sensors to detect damage in wind turbine blades. Prior to each of the static test-series an artificial damage was made on the blade. The damage made for each test-series was surveyed during each series by acoustic emission, fiber optic micro bend displacement transducers and strain gauges. The propagation of the damage was determined by use of ultra sonic and X-ray surveillance during stops in the test series. By use of acoustic emission it was possible to measure damage propagation before the propagation was of visible size. By use of fiber optic micro bend displacement transducers and strain gauges it was possible to measure minor damage propagation. By use of both ultra sonic, and X-ray NDT-equipment it were possible to determine the size of propagated damage. (au)
High precision, fast computation speed, as well as a good capability of fault tolerant and reconstruction are required more and more for spacecraft attitude determination system. To realize the above requirement, an approach was presented to the synthesis of federated filters using sigma point technique. In this algorithm, the sigma point technique brought the algorithm a high precision, while the federated structure significantly enhanced the filters' capability of multi-rate information fusion, fault tolerance, and system modularity. Within consideration of computation consumption, a simple information-sharing formulation was derived to adapt to the special property of sigma point distribution, and a dynamical information sharing strategy for multi-rate fusion was developed. A numerical simulation example was employed to give the algorithm a test, where the simulated system contained a suit of gyroscopes; a three-axis magnetometer and a sun sensor each had a ...
A novel method for the determination of metoclopramide (MCP) using electrogenerated chemiluminescence (ECL) is presented. A tris(2,2prime-bipyridyl)dichlororuthenium(II) (Ru(bpy)32+)-doped silica (RuDS) nanoparticle/perfluoinated ion-exchange resin (Nafion) with nanocomposite membrane modified glassy carbon electrode (GCE) is used. The Ru(bpy)32+ encapsulation interior of the silica nanoparticle maintains its electrochemical activities and also reduces Ru(bpy)32+ leaching from the silica matrix when immersed in water due to the electrostatic interaction. The analytical performance of this ECL sensor for MCP is shown in detail. Under optimal experimental conditions, it has good linearity in the concentration range from 2x10-8mol/L to 1x10-5mol/L (R=0.9989) with a detection limit of 7x10-9mo...
The personal neutron dosimetry becomes more important with the increasing use of nuclear and accelerator facilities. The solid state track detector, film badge and thermo-luminescent dosimeter have widely been used as passive-type personal neutron dosimeters, but the real-time neutron dosimeter is strongly needed. A real time personal dosimeter which could give neutron dose equivalent over wide energy range from thermal to 10 odd MeV by using two neutron sensors has been developed by our group. For practical commercial product, some changes from these prototype sensors have recently been done by Fuji Electric Co. Ltd. The purpose of this work is the final performance test of the dosimeter just before sale. We checked again about the sensitivity in the monoenergetic neutron field from 8 keV to 15 MeV and in the neutron fields around a few accelerator facilities. (author)
A new monolithic semi-insulating (SI) GaAs sensor design for X-ray imaging applications between 10-100keV has been proposed. Monolithic pixel detectors offer a number of advantages over hybrid bump-bonded detectors, such as high device yield, low costs and are easier to produce large scale arrays. In this thesis, an investigation is made of the use of a SI GaAs wafer as both a detector element and substrate for the epitaxially grown High Electron Mobility Transistors (HEMTs). The design of the HEMT transistors, optimised for this application, were produced with the aid of the Silvaco 'Virtual Wafer Fab' simulation package. It was determined that the device characteristics would consist of a small positive threshold voltage, a low off-state drain current and high transconductance. The final HEMT transistor design, that would be integrated to a pixel detector, had a threshold voltage of 0.17V, an off-state leakage current of approx 1nA and a transconductance of ...
Laser devices are currently in widespread use in particular by armed forces for different tasks. Electro-optical sensors as well as unprotected human eyes are extremely sensitive to laser radiation and can be permanently damaged from direct or reflected beams. Laser damage depends on the interaction between the laser beam and the atmosphere in which it traverses. The atmospheric conditions, including the range, terrain features, turbulence, and atmospheric particulates, may alter the laser's effect on different electro-optical devices and systems. When a laser beam passes through the atmosphere the optical turbulence affects the beam. As a result, temporal intensity fluctuations (scintillations) or spatial variations in intensity within a beam cross-section occur. Atmospheric scintillations pose a safety problem because an observer or sensor can be subjected to the risk of a localized irradiance (local focusing effect) much greater than that ...
The Loose Parts Monitoring System (LPMS) provides information on the location of a loosened or detached metal impacted onto the inner surface of a primary pressure boundary and on a mass or energy of the impact signal. For the conventional system, it is popular to employ the group delay among the sensors installed within 3 ft range from the impact source in a collection zone as stated in the Reg. Guide 1.133. However, there exist inherent errors for the estimation of the true location of the impact since it is highly dependent on the plant personnel's decision to determine the arrival time differences of the generated wave group among the neighbouring sensors. To overcome this problem in this study, the two-dimensional approach has been proposed and applied to effectively estimate the arrival time differences of the impact signal by using continuous wavelet transform which is one of the linear time-frequency analysis methods. The experiment has ...
Design of energy efficient schemes for data gathering is an important concern for lifetime enhancement of wireless sensor networks. Variation in the distances of nodes from the Base Station and differences in inter-nodal distances are primary factors causing unequal energy dissipation among the nodes. Thus energy difference between the various nodes increases with time resulting in degraded network performance. The LEACH and PEGASIS schemes which provided elegant solutions to the problem suffer basic drawbacks due to randomization of cluster heads and greedy chain formation respectively. In this paper, we propose an Optimized Lifetime Enhancement (OLE) Scheme which shows enhanced performance over these schemes. OLE increases the network performance by ensuring a sub-optimal energy dissipation of the individual nodes despite their random deployment. It employs modern heuristics like particle swarm optimization instead of the greedy algorithm as in PEGASIS to ...
We report for the first time about a micromachined mass flow sensor directly integrated between the double guidance and the needle seat into the body of a Common Rail (CR) injection nozzle. The thermal measurement principle was chosen because gaseous as well as liquid mass flows can be determined fast and precisely. Additionally, with glass-ceramic materials fabricated in a low cost batch process, a high temperature and especially pressure stable substrate can be used. The flow sensitive thin film is realized by an e-beam evaporated 110 nm thick molybdenum (Mo) layer. The latter is electrically characterized by the resistivity of {rho} = 8.2 x 10{sup -7} {omega} m ({+-}2%) at room temperature as well as by the first {alpha}=4.5 x 10{sup -4} K{sup -1} ({+-}5%) and second {beta}=3.0 x 10{sup -6} K{sup -2} ({+-}12%) temperature coefficients of resistance up to 300 C. The static temperature field at and around the thin film sensor on the ...
A centralized, automatic monitoring system for coal mines has been developed. The system consists of newly-developed and improved sensors, transmission equipment, a minicomputer designed for scientific and technical calculations, and accompanying software (MOLES). MOLES performs six functions: input, computation, decision, memory, output and correction. Previously, centralized monitoring has been limited to single dimensional monitoring of the 'time and point' type. The present system carries out data analysis and processing with respect to time, space and item. It is also capable of simple automatic diagnosis of abnormalities. (In Japanese)
This report addresses remote monitoring of coal waste impoundments for stability. Existing automated geotechnical monitoring systems are described and reviewed along with details of instruments suitable for such systems. An impoundment in West Virginia, which was in the construction stage, was instrumented and monitored between July 1979 and May 1981. Sensors that measure surface and subsurface parameters including settlement, horizontal deflection, surface tilt, pore water pressure, seepage, pond level, and meteorlogical parameters were installed. Recommendations for improving and expanding the capabilities of the monitoring system are given.
For reliable operation and the optimization of production, industrial fermentation processes require appropriate tools for monitoring the process in real time. This work presents the structure and operation of a soft sensor for the on-line monitoring of biomass and product concentration during salinomycin and bacitracin fermentation in an industrial, 80-m^3 batch reactor; moreover it provides a tool for evaluation of batch production verified in industrial application. The process estimation algorithm consists of decoupled growth and product models, which ensures an unbiased convergence of the estimator and the robustness of the model. The production of secondary metabolites is described with a non-structured model upgraded with a variable forgetting factor that demonstrated a successful e...
The theme of the conference was recent developments in airborne remote sensing and their applications. The proceedings contain the papers presented at 14 general sessions and 13 interactive sessions covering airborne platforms, sensor systems, airborne/spaceborne synergy, atmospheric and oceanic measurements, land cover/land use, emergency response and reconnaissance, data handling, forestry, agriculture, water resources, geospatial reference, system calibration, environmental monitoring and planning, and information product advancements. Two papers are abstracted separately.
The fission fragments from spontaneous fission of 252Cf have been measured with the spectrometric and position-sensitive semiconductor pixel detector Medipix2. Fragments are identified by pattern recognition of clusters generated in the Medipix2 pixel matrix sensor upon heavy particle hit. From analysis of cluster area, the distribution of kinetic energy of fission fragments is obtained. Together with a novel USB readout interface, the Medipix2/USB system operates as active nuclear emulsion in single-quantum and on-line tracking mode.
The design and material characteristics of garter spring were summarized and Nondestructive detection techniques of garter spring were also described. In particular, Eddy current testing of loose type garter spring was used in Wolsung unit 1 and was described in detail. The inspection technique of tight type garter spring has not been established and all candidated techniques were investigated in order to choose the possible detection technique. Candidated nondestructive techniques including RFEC, PEC, Magnetic technique using GMR sensor, AE, Guided Wave technique, and high frequency ultrasonic technique, are summarized for evaluating the detectability of tight garter spring.
The Meteorological Information System (MIS) comprising the meteorological instruments, the computers, and the software for data processing and recording, is part of the KfK safety and control system. In 1982 is was equipped with an independent data processing system. The report explains the arrangement and the operation of the sensors and thw two process computers. For selected meteorological situations the ability of the system is demonstrated, i.e., the presentation of the vertical profiles of wind, temperature and turbulence in the lower atmospheric boundary layer as well as the calculation and graphical representation of the transport and dispersion into the KfK environment of radioactive pollutants being released by the nuclear installations of the KfK into the atmosphere.
We report on the single-particle properties of lanthanide-ion doped oxide nanoparticles. We have demonstrated that their size can be accurately determined from their luminosity. The optically determined size distribution is in very good agreement with the distribution obtained from transmission electron microscopy (TEM). We also showed that the photobleaching of these nanoparticles is related to a reduction process and that we can use it to sense in a concentration-dependent manner the presence of an oxidant like H2O2. Finally, we propose a way to perform nanoparticle-protein coupling and to determine the protein-nanoparticle ratio at the single-particle level.
A Si array neutron detector is proposed based on commercial CCD and CMOS sensor technology coupled with a thin film neutron conversion coating. System sensitivity is estimated for a baseline device containing a single array and various schemes to increase detection probability by simple area scaling and stacking are discussed. Some possible use scenarios are discussed involving static and moving sources. Likely neutron source fluxes for weapons grade and commercial grade nuclear material are estimated along with expected intensities of cosmic background neutrons which would establish a noise floor to detection limits.
We have developed a novel laser ray-tracing method to measure aberrations in optical systems. It consists of delivering narrow laser pencils (by a laser scanner), recording the spots that are formed on the image plane (with a CCD camera), and computing the position of each centroid. This approach could be considered an experimental (approximate) implementation of standard numerical ray tracing. Several tests and experiments, including a direct comparison with a Hartmann-Shack wave-front sensor, provided highly satisfactory results that confirmed the validity of the method and revealed potential advantages. PMID:18073906
We describe a position-sensitive event-counting microchannel plate detector with a quadrant anode readout system that combines the advantages of several centroid-finding readout techniques. The relative amount of charge collected by each quadrant of the anode mounted behind the output side of the microchannel plate is used to localize each event. The position-sensitive area is about 80% of the active microchannel plate surface. By changing a single voltage a remote-controlled image magnification can be achieved. Due to a correction function that minimizes image distortions the imaging characteristics of this low-cost readout system are similar to those of expensive resistive anodes.
This article deals with the need for control strategies and control systems in buildings with hybrid ventilation. In this respect, control strategies are methods of keeping certain parameters like temperature, air quality etc within specified limits. A control system is automatic and includes sensors, motors, dampers etc. The article also discusses consequences with respect to thermal comfort, air quality and energy use following selection of control parameters for controlling air masses.
Initial clinical experience in gastrointestinal radiography using Fuji Computed Radiography(FCR) system was reported. Image quality of conventional film/screen radiography and FCR system on upper GI series and barium enema was compared. Reflecting wide dynamic range of the system, improved image quality was confirmed, particularity in visibility of fine mucosal pattern(area gastricae), folds and overall contour. High sensor sensitivity of the system could reduce radiation dose requirement significantly. Diagnostically acceptable images were obtained with approximately 1/5 of routine dose for conventional radiography except in cases of lateral view of the rectum. (author).
The present invention is a device for a solar heating system having a solar collector, a storage tank connected to the solar collector, a pump for circulating liquid from the tank to the solar collector, a supply of liquid at a temperature above freezing and a connection from the supply of liquid to the solar collector for replacing any liquid lost from said solar collector. The device comprises a sensor for sensing the temperature of liquid in the solar collector, and a valve for bleeding liquid from the solar collector when the sensed temperature falls below a predetermined minimum whereby cool liquid in the solar collector is automatically replaced by liquid at a temperature above freezing.
Plans, engineering parameters, and some test results for several FFTF core and primary sodium circuit instrument systems are presented. The systems discussed include temperature, flow, pressure, leak detectors, level sensors, fuel failure monitoring, sodium impurity analysis and cover gas monitors. Since many of these instruments are similar to those used in other fast reactors around the world, only a brief description is presented for these systems. Results of recent demonstration tests of the FFTF Under-Sodium Viewing and Ranging system are also presented. (U.K.).
The development of new electro-optical instrumentation for studying the annular dispersed two-phase flow regime is described. The system measures the thickness of the water film and droplet size and velocity distributions which would be encountered in such a flow regime. The water film thickness is measured by an improved capacitance method with a short time constant using newly developed sensor electrodes. The electrodes are made flush with the inner wall of a cylindrical tube and do not disturb the flow. In the test equipment, steady, laminar flow of water along the inner wall of the tube is controlled by appropriate valves and a porous jacket while droplets are introduced by means of a special spray nozzle.
A hyperbolic Stefan problem based on the linearized Gurtin-Pipkin heat conduction law is considered. The temperature and free boundary are controlled by a thermostat acting on the boundary. This feedback control is based on temperature measurements performed by real thermal sensors located within the domain containing the two-phase system and/or at its boundary. Three different types of thermostats are analyzed: simple switch, relay switch, and a Preisach hysteresis operator. The resulting models lead to integrodifferential hyperbolic Stefan problems with nonlinear and nonlocal boundary conditions. Existence results are proved in all the cases. Uniqueness is also shown, except in the situation corresponding to the ideal switch.
In this article, several applications of nanomaterials in food packaging and food safety are reviewed, including: polymer/clay nanocomposites as high barrier packaging materials, silver nanoparticles as potent antimicrobial agents, and nanosensors and nanomaterial-based assays for the detection of food-relevant analytes (gasses, small organic molecules and food-borne pathogens). In addition to covering the technical aspects of these topics, the current commercial status and understanding of health implications of these technologies are also discussed. These applications were chosen because they do not involve direct addition of nanoparticles to consumed foods, and thus are more likely to be marketed to the public in the short term.
We describe a position-sensitive event-counting microchannel plate detector with a quadrant anode readout system that combines the advantages of several centroid-finding readout techniques. The relative amount of charge collected by each quadrant of the anode mounted behind the output side of the microchannel plate is used to localize each event. The position-sensitive area is about 80% of the active microchannel plate surface. By changing a single voltage a remote-controlled image magnification can be achieved. Due to a correction function that minimizes image distortions the imaging characteristics of this low-cost readout system are similar to those of expensive resistive anodes. (orig.).
We describe a position-sensitive event-counting microchannel plate detector with a quadrant anode readout system that combines the advantages of several centroid-finding readout techniques. The relative amount of charge collected by each quadrant of the anode mounted behind the output side of the microchannel plate is used to localize each event. The position-sensitive area is about 80% of the active microchannel plate surface. By changing a single voltage a remote-controlled image magnification can be achieved. Due to a correction function that minimizes image distortions the imaging characteristics of this low-cost readout system are similar to those of expensive resistive anodes.
Solid-state acoustic sensors for monitoring conditions at a surface immersed in a liquid and for monitoring concentrations of species in a liquid and for monitoring electrical properties of a liquid are formed by placing interdigital input and output transducers on a piezoelectric substrate and propagating acoustic plate modes therebetween. The deposition or removal of material on or from, respectively, a thin film in contact with the surface, or changes in the mechanical properties of a thin film in contact with the surface, or changes in the electrical characteristics of the solution, create perturbations in the velocity and attenuation of the acoustic plate modes as a function of these properties or changes in them.
The cupola furnace is used to melt scrap steel, pig iron, foundry returns, and alloying additives to a prescribed tapping chemistry and temperature for iron casting applications. The melting process within the cupola is highly complex and not well quantified. The American Foundrymen's Society is developing a mathematical model to aid in the understanding of these processes. This model is reaching maturity, and has been successful in estimating a number of melting parameters. This paper details the results of efforts to verify the model in a controlled system, equipped wit the appropriate sensors, for model verification. The work was performed on a research-scale cupola furnace located at the Department of Energy's Albany Research Center.
This document is a Final Technical Report that describes the results of the Geophex Airborne Unmanned Survey System (GAUSS) research project. The objectives were to construct a geophysical data acquisition system that uses a remotely operated unmanned aerial vehicle (UAV) and to evaluate its effectiveness for characterization of hazardous environmental sites. The GAUSS is a data acquisition system that mitigates the potential risk to personnel during geophysical characterization of hazardous or radioactive sites. The fundamental basis of the GAUSS is as follows: (1) an unmanned survey vehicle carries geophysical sensors into a hazardous location, (2) the pilot remains outside the hazardous site and operates the vehicle using radio control, (3) geophysical measurements and their spatial locations are processed by an automated data-acquisition system which displays data on an off-site monitor in real-time, and (4) the pilot uses the display to direct the survey ...
A small-sized inexpensive carbon dioxide gassensor was prepared using LiTi2 (PO4)3 +0.2Li3PO4 as lithium-ion conductive, solid electrolyte and its detectability and the effects of co-existing gases were examined. The above compound was obtained by the method where a powdery mixture of Li2CO3, TiO2, (NH4)H2PO4 and Li3PO3 was molded in the presence of a sintering assistant, subjected to hydrostatic press, and sintered. Measurements were made on the relation between CO2 concentration and the electromotive force of the CO2 sensor made of the compound and the influence of concentration of coexisting NO2, SO2 or CH4 on the electromotive force. The results are summarized as follows. A linear relation exists between the electromotive force and the CO2 concentration in the range from 80ppm to 1% to show a good agreement between theoretical and experimental results. Coexistence of NO2 the range of 100-4500ppm has no influence on the electromotive force. Coexistence of ...
In order to study the neurobiological basis of seasonal changes in hippocampal structure and function, the rate of cell proliferation was examined in male and female wild meadow voles captured during different seasons. We found that the number of [3H]thymidine-labeled cells varied across the seasons and across sex in the meadow vole. Non-breeding female meadow voles had a higher rate of cell proliferation and cell death than males captured during either season or breeding females. These seasonal changes in the female meadow vole were associated with both fluctuating levels of adrenal steroids and gonadal steroids. Estradiol level was highly correlated with both the number of [3H]thymidine-labeled cells and the number of pyknotic cells in female meadow voles, with high levels of estradiol being associated with low levels of cell proliferation ...
The authors describe an effect of suppression of invasion of the guinea pig eye conjunctiva and the HEp-2 epithelial cells by virulent Sh. flexneri bacilli, with a simultaneous administration of the same dose of avirulent shigella mutants, genetically connected with them. The data of morphological study and experiments with 3H-glucose labeled shigellae carried out on the cell species model indicated that the bacterial competition for the specific sites for absorption on the epithelial cells underlay the observed phenomenon. PMID:331774
Regulatory T (T reg) cells exert powerful down-modulatory effects on immune responses, but it is not known how they act in vivo. Using intravital two-photon laser scanning microscopy we determined that,...Full Text Available
Microfluidic systems and methods are disclosed which are adapted to transport and lyse cellular components of a test sample for analysis. The disclosed microfluidic systems and methods, which employ an electric field to rupture the cell membrane, cause unusually rapid lysis, thereby minimizing continued cellular activity and resulting in greater accuracy of analysis of cell processes.
IntroductionThe phenotypic and functional differences between cells that initiate human breast tumors (cancer stem cells) and those that comprise the tumor bulk are difficult to...Full Text Available
BackgroundAberrant CD40 ligand (CD154) expression occurs on both T cells and B cells in human lupus patients, which is suggested to enhance B cell CD40 signaling and play a role...Full Text Available