Extended Range of a Gun Launched Smart Projectile Using Controllable Canards

Directory of Open Access Journals (Sweden)

Mark Costello

2001-01-01

Full Text Available This effort investigates the extent to which moveable canards can extend the range of indirect fire munitions using both projectile body and canard lift. Implications on terminal velocity and time of flight using this mechanism to extend range are examined for various canard configurations. Performance predictions are conducted using a six-degree-of-freedom simulation model that has previously been validated against range data. The projectile dynamic equations are formed in the body frame and aerodynamic loads from the body and canards are Mach number and angle of attack dependent. The projectile body aerodynamic moments include unsteady aerodynamic damping. The focus of the study is directed toward low cost competent munitions that extend range and as such a simple flight control system is considered which utilizes only timer, roll rate, and roll attitude inputs.

Flow Range of Centrifugal Compressor Being Extended

Science.gov (United States)

Skoch, Gary J.

2001-01-01

General Aviation will benefit from turbine engines that are both fuel-efficient and reliable. Current engines fall short of their potential to achieve these attributes. The reason is compressor surge, which is a flow stability problem that develops when the compressor is subjected to conditions that are outside of its operating range. Compressor surge can occur when fuel flow to the engine is increased, temporarily back pressuring the compressor and pushing it past its stability limit, or when the compressor is subjected to inlet flow-field distortions that may occur during takeoff and landing. Compressor surge can result in the loss of an aircraft. As a result, engine designers include a margin of safety between the operating line of the engine and the stability limit line of the compressor. Unfortunately, the most efficient operating line for the compressor is usually closer to its stability limit line than it is to the line that provides an adequate margin of safety. A wider stable flow range will permit operation along the most efficient operating line of the compressor, improving the specific fuel consumption of the engine and reducing emissions. The NASA Glenn Research Center is working to extend the stable flow range of the compressor. Significant extension has been achieved in axial compressors by injecting air upstream of the compressor blade rows. Recently, the technique was successfully applied to a 4:1 pressure ratio centrifugal compressor by injecting streams of air into the diffuser. Both steady and controlled unsteady injection were used to inject air through the diffuser shroud surface and extend the range. Future work will evaluate the effect of air injection through the diffuser hub surface and diffuser vanes with the goal of maximizing the range extension while minimizing the amount of injected air that is required.

NOAA Extended Reconstructed Sea Surface Temperature (ERSST), Version 5

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Extended Reconstructed Sea Surface Temperature (ERSST) dataset is a global monthly sea surface temperature dataset derived from the International...

Extending the Dynamic Range of a Time Projection Chamber

Science.gov (United States)

Estee, Justin; S πRIT Collaboration

2017-09-01

The use of Time Projection Chambers (TPCs) in intermediate heavy ion reactions faces some challenges in addressing the energy losses that range from the small energy loss of relativistic pions to the large energy loss of slow moving heavy ions. A typical trade-off can be to set the smallest desired signals to be well within the lower limits of the dynamic range of the electronics while allowing for some larger signals to saturate the electronics. With wire plane anodes, signals from readout pads further away from the track remain unsaturated and allow signals from tracks with saturated pads to be accurately recovered. We illustrate this technique using data from the SAMURAI Pion-Reconstruction and Ion-Tracker (S πRIT) TPC , which recently measured pions and light charged particles in collisions of Sn+Sn isotopes. Our method exploits knowledge of how the induced charge distribution depends on the distance from the track to smoothly extend dynamic range even when some of the pads in the track are saturated. To accommodate the analysis of slow moving heavy ions, we have extended the Bichsel energy loss distributions to handle slower moving ions as well. In this talk, I will discuss a combined approach which successfully extends the dynamic range of the TPC electronics. This work is supported by the U.S. DOE under Grant Nos. DE-SC0014530, DE-NA0002923, US NSF Grant No. PHY-1565546 and the Japan MEXT KAKENHI Grant No. 24105004.

Design considerations of a linear generator for a range extender application

Directory of Open Access Journals (Sweden)

Seo Un-Jae

2015-12-01

Full Text Available The free piston linear generator is a new range extender concept for the application in a full electric vehicle. The free piston engine driven linear generators can achieve high efficiency at part and full load which is suitable for the range extender application. This paper presents requirements for designing a linear generator deduced from a basic analysis of a free piston linear generator.

Wide-range vortex shedding flowmeter for high-temperature helium gas

Energy Technology Data Exchange (ETDEWEB)

Baker, S.P.; Herndon, P.G.; Ennis, R.M. Jr.

1983-01-01

The existing design of a commercially available vortex shedding flowmeter (VSFM) was modified and optimized to produce three 4-in. and one 6-in. high-performance VSFMs for measuring helium flow in a gas-cooled fast reactor (GCFR) test loop. The project was undertaken because of the significant economic and performance advantages to be realized by using a single flowmeter capable of covering the 166:1 flow range (at 350/sup 0/C and 45:1 pressure range) of the tests. A detailed calibration in air and helium at the Colorado Engineering Experiment Station showed an accuracy of +-1% of reading for a 100:1 helium flow range and +-1.75% of reading for a 288:1 flow range in both helium and air. At an extended gas temperature of 450/sup 0/C, water cooling was necessary for reliable flowmeter operation.

In-Situ Extended Lateral Range Surface Metrology, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — We propose to develop an extended lateral range capability for a dynamic optical profiling system to enable non-contact, surface roughness measurement of large and...

Temperature dependence of charge-transfer fluorescence from extended and U-shaped donor-bridge-acceptor systems in glass-forming solvents.

NARCIS (Netherlands)

Goes, M.; de Groot, M.; Koeberg, M.; Verhoeven, J.W.; Lokan, N.R.; Shephard, M.J.; Paddon-Row, M.N.

2001-01-01

Abstract: The behavior is reported of three fluorescent D-bridge-A systems that display a fascinating temperature dependence in glass forming solvents over the temperature range between 77 and 293 K. In two of these systems, a rigid, saturated alkane bridge maintains an extended conformation, and as

High temperature creep behavior in the (α + β) phase temperature range of M5 alloy

International Nuclear Information System (INIS)

Trego, G.

2011-01-01

The isothermal steady-state creep behavior of a M5 thin sheet alloy in a vacuum environment was investigated in the (α + β) temperature, low-stress (1-10 MPa) range. To this aim, the simplest approach consists in identifying α and β creep flow rules in their respective single-phase temperature ranges and extrapolating them in the two-phase domain. However, the (α + β) experimental behavior may fall outside any bounds calculated using such creep flow data. Here, the model was improved for each phase by considering two microstructural effects: (i) Grain size: Thermo-mechanical treatments applied on the material yielded various controlled grain size distributions. Creep tests in near-α and near-β ranges evidenced a strong grain-size effect, especially in the diffusional creep regime. (ii) Chemical contrast between the two phases in the (α + β) range: From thermodynamic calculations and microstructural investigations, the β phase is enriched in Nb and depleted in O (the reverse being true for the α phase). Thus, creep tests were performed on model Zr-Nb-O thin sheets with Nb and O concentrations representative of each phase in the considered temperature range. New α and β creep flow equations were developed from this extended experimental database and used to compute, via a finite element model, the creep rates of the two-phase material. The 3D morphology of phases (β grains nucleated at α grain boundaries) was explicitly introduced in the computations. The effect of phase morphology on the macroscopic creep flow was shown using this specific morphology, compared to other typical morphologies and to experimental data. (author) [fr

A Novel Range-Extended Strategy for Fuel Cell/Battery Electric Vehicles.

Science.gov (United States)

Hwang, Jenn-Jiang; Hu, Jia-Sheng; Lin, Chih-Hong

2015-01-01

The range-extended electric vehicle is proposed to improve the range anxiety drivers have of electric vehicles. Conventionally, a gasoline/diesel generator increases the range of an electric vehicle. Due to the zero-CO2 emission stipulations, utilizing fuel cells as generators raises concerns in society. This paper presents a novel charging strategy for fuel cell/battery electric vehicles. In comparison to the conventional switch control, a fuzzy control approach is employed to enhance the battery's state of charge (SOC). This approach improves the quick loss problem of the system's SOC and thus can achieve an extended driving range. Smooth steering experience and range extension are the main indexes for development of fuzzy rules, which are mainly based on the energy management in the urban driving model. Evaluation of the entire control system is performed by simulation, which demonstrates its effectiveness and feasibility.

Range-extending Zinc-air battery for electric vehicle

Directory of Open Access Journals (Sweden)

Steven B. Sherman

2018-01-01

Full Text Available A vehicle model is used to evaluate a novel powertrain that is comprised of a dual energy storage system (Dual ESS. The system includes two battery packs with different chemistries and the necessary electronic controls to facilitate their coordination and optimization. Here, a lithium-ion battery pack is used as the primary pack and a Zinc-air battery as the secondary or range-extending pack. Zinc-air batteries are usually considered unsuitable for use in vehicles due to their poor cycle life, but the model demonstrates the feasibility of this technology with an appropriate control strategy, with limited cycling of the range extender pack. The battery pack sizes and the battery control strategy are configured to optimize range, cost and longevity. In simulation the vehicle performance compares favourably to a similar vehicle with a single energy storage system (Single ESS powertrain, travelling up to 75 km further under test conditions. The simulation demonstrates that the Zinc-air battery pack need only cycle 100 times to enjoy a ten-year lifespan. The Zinc-air battery model is based on leading Zinc-air battery research from literature, with some assumptions regarding achievable improvements. Having such a model clarifies the performance requirements of Zinc-air cells and improves the research community's ability to set performance targets for Zinc-air cells.

Error sensitivity analysis in 10-30-day extended range forecasting by using a nonlinear cross-prediction error model

Science.gov (United States)

Xia, Zhiye; Xu, Lisheng; Chen, Hongbin; Wang, Yongqian; Liu, Jinbao; Feng, Wenlan

2017-06-01

Extended range forecasting of 10-30 days, which lies between medium-term and climate prediction in terms of timescale, plays a significant role in decision-making processes for the prevention and mitigation of disastrous meteorological events. The sensitivity of initial error, model parameter error, and random error in a nonlinear crossprediction error (NCPE) model, and their stability in the prediction validity period in 10-30-day extended range forecasting, are analyzed quantitatively. The associated sensitivity of precipitable water, temperature, and geopotential height during cases of heavy rain and hurricane is also discussed. The results are summarized as follows. First, the initial error and random error interact. When the ratio of random error to initial error is small (10-6-10-2), minor variation in random error cannot significantly change the dynamic features of a chaotic system, and therefore random error has minimal effect on the prediction. When the ratio is in the range of 10-1-2 (i.e., random error dominates), attention should be paid to the random error instead of only the initial error. When the ratio is around 10-2-10-1, both influences must be considered. Their mutual effects may bring considerable uncertainty to extended range forecasting, and de-noising is therefore necessary. Second, in terms of model parameter error, the embedding dimension m should be determined by the factual nonlinear time series. The dynamic features of a chaotic system cannot be depicted because of the incomplete structure of the attractor when m is small. When m is large, prediction indicators can vanish because of the scarcity of phase points in phase space. A method for overcoming the cut-off effect ( m > 4) is proposed. Third, for heavy rains, precipitable water is more sensitive to the prediction validity period than temperature or geopotential height; however, for hurricanes, geopotential height is most sensitive, followed by precipitable water.

A Novel Range-Extended Strategy for Fuel Cell/Battery Electric Vehicles

Directory of Open Access Journals (Sweden)

Jenn-Jiang Hwang

2015-01-01

Full Text Available The range-extended electric vehicle is proposed to improve the range anxiety drivers have of electric vehicles. Conventionally, a gasoline/diesel generator increases the range of an electric vehicle. Due to the zero-CO2 emission stipulations, utilizing fuel cells as generators raises concerns in society. This paper presents a novel charging strategy for fuel cell/battery electric vehicles. In comparison to the conventional switch control, a fuzzy control approach is employed to enhance the battery’s state of charge (SOC. This approach improves the quick loss problem of the system’s SOC and thus can achieve an extended driving range. Smooth steering experience and range extension are the main indexes for development of fuzzy rules, which are mainly based on the energy management in the urban driving model. Evaluation of the entire control system is performed by simulation, which demonstrates its effectiveness and feasibility.

Variability of Diurnal Temperature Range During Winter Over Western Himalaya: Range- and Altitude-Wise Study

Science.gov (United States)

Shekhar, M. S.; Devi, Usha; Dash, S. K.; Singh, G. P.; Singh, Amreek

2018-04-01

The current trends in diurnal temperature range, maximum temperature, minimum temperature, mean temperature, and sun shine hours over different ranges and altitudes of Western Himalaya during winter have been studied. Analysis of 25 years of data shows an increasing trend in diurnal temperature range over all the ranges and altitudes of Western Himalaya during winter, thereby confirming regional warming of the region due to present climate change and global warming. Statistical studies show significant increasing trend in maximum temperature over all the ranges and altitudes of Western Himalaya. Minimum temperature shows significant decreasing trend over Pir Panjal and Shamshawari range and significant increasing trend over higher altitude of Western Himalaya. Similarly, sunshine hours show significant decreasing trend over Karakoram range. There exists strong positive correlation between diurnal temperature range and maximum temperature for all the ranges and altitudes of Western Himalaya. Strong negative correlation exists between diurnal temperature range and minimum temperature over Shamshawari and Great Himalaya range and lower altitude of Western Himalaya. Sunshine hours show strong positive correlation with diurnal temperature range over Pir Panjal and Great Himalaya range and lower and higher altitudes.

Temperature dependence of muonium spin exchange with O2 in the range 88 K to 478 K

International Nuclear Information System (INIS)

Senba, M.; Garner, D.M.; Arseneau, D.J.; Fleming, D.G.

1984-01-01

The authors have extended an earlier study of the spin exchange reactions of Mu with O 2 in the range 295 K to 478 K, to a low temperature region down to 88 K. From 135 K to 296 K, the spin depolarization rate constant was found to vary according to the relative velocity of the colliding species, which indicates that the spin exchange cross section of Mu-O 2 is temperature independent in this range. However, it was found that below 105 K and above 400 K, the spin depolarization rate constant tends to have stronger temperature dependences. (Auth.)

Extended irreversible thermodynamics and non-equilibrium temperature

Directory of Open Access Journals (Sweden)

Casas-Vazquez, Jose'

2008-02-01

Full Text Available We briefly review the concept of non-equilibrium temperature from the perspectives of extended irreversible thermodynamics, fluctuation theory, and statistical mechanics. The relations between different proposals are explicitly examined in two especially simple systems: an ideal gas in steady shear flow and a forced harmonic oscillator in a thermal bath. We examine with special detail temperatures related to the average molecular kinetic energy along different spatial directions, to the average configurational energy, to the derivative of the entropy with respect to internal energy, to fluctuation-dissipation relation and discuss their measurement.

Performance and driveline analyses of engine capacity in range extender engine hybrid vehicle

Science.gov (United States)

Praptijanto, Achmad; Santoso, Widodo Budi; Nur, Arifin; Wahono, Bambang; Putrasari, Yanuandri

2017-01-01

In this study, range extender engine designed should be able to meet the power needs of a power generator of hybrid electrical vehicle that has a minimum of 18 kW. Using this baseline model, the following range extenders will be compared between conventional SI piston engine (Baseline, BsL), engine capacity 1998 cm3, and efficiency-oriented SI piston with engine capacity 999 cm3 and 499 cm3 with 86 mm bore and stroke square gasoline engine in the performance, emission prediction of range extender engine, standard of charge by using engine and vehicle simulation software tools. In AVL Boost simulation software, range extender engine simulated from 1000 to 6000 rpm engine loads. The highest peak engine power brake reached up to 38 kW at 4500 rpm. On the other hand the highest torque achieved in 100 Nm at 3500 rpm. After that using AVL cruise simulation software, the model of range extended electric vehicle in series configuration with main components such as internal combustion engine, generator, electric motor, battery and the arthemis model rural road cycle was used to simulate the vehicle model. The simulation results show that engine with engine capacity 999 cm3 reported the economical performances of the engine and the emission and the control of engine cycle parameters.

Modelling of thermoelectric generator with heat pipe assist for range extender application

OpenAIRE

Brito, F. P.; Martins, Jorge; Gonçalves, L. M.; Sousa, R.

2011-01-01

Recent trends towards electrification of vehicles favour the adoption of waste energy recovery into electricity. Battery-only Electric Vehicles (BEV) need a very large energy storage system so the use of a Range Extender (RE) may allow a significant downsizing of these bulky components. The Internal Combustion Engines (ICE) have two major discarded energy fluxes, engine cooling and exhaust gas. In Extended Range Electric Vehicles (EREV) and hybrids the potential for heat conversion into elect...

Dual voltage source inverter topology extending machine operating range

NARCIS (Netherlands)

Gerrits, T.; Wijnands, C.G.E.; Paulides, J.J.H.; Duarte, J.L.

2012-01-01

Field weakening operation of an electrical machine is a conventional method to extend the angular velocity range of a system above the peak output voltage of the inverter. A downside, however, is that an increased reactive current is required that creates losses but no output torque. A dual voltage

Extending the range of compounds amenable for gas chromatography-mass spectrometric analysis.

Science.gov (United States)

Fialkov, Alexander B; Gordin, Alexander; Amirav, Aviv

2003-04-04

Gas chromatography-mass spectrometry (GC-MS) suffers from a major limitation in that an expanding number of thermally labile or low volatility compounds of interest are not amenable for analysis. We found that the elution temperatures of compounds from GC can be significantly lowered by reducing the column length, increasing the carrier gas flow rate, reducing the capillary column film thickness and lowering the temperature programming rate. Pyrene is eluted at 287 degrees C in standard GC-MS with a 30 m x 0.25 mm I.D. column with 1-microm DB5ms film and 1-ml/min He column flow rate. In contrast, pyrene is eluted at 79 degrees C in our "Supersonic GC-MS" system using a 1 m x 0.25 mm I.D. column with 0.1-microm DB5ms film and 100-ml/min He column flow rate. A simple model has been invoked to explain the significantly (up to 208 degrees C) lower elution temperatures observed. According to this model, every halving of the temperature programming rate, or number of separation plates (either through increased flow rate or due to reduced column length), results in approximately 20 degrees C lower elution temperature. These considerably lower elution temperatures enable the analysis of an extended range of thermally labile and low volatility compounds, that otherwise could not be analyzed by standard GC-MS. We demonstrate the analysis of large polycyclic aromatic hydrocarbons (PAHs) such as decacyclene with ten fused rings, well above the current GC limit of PAHs with six rings. Even a metalloporphirin such as magnesiumoctaethylporphin was easily analyzed with elution temperatures below 300 degrees C. Furthermore, a range of thermally labile compounds were analyzed including carbamates such as methomyl, aldicarb, aldicarbsulfone and oxamyl, explosives such as pentaerythritol tetranitrate, Tetryl and HMX, and drugs such as reserpine (608 a.m.u.). Supersonic GC-MS was used, based on the coupling of a supersonic molecular beam (SMB) inlet and ion sources with a bench

Primary Paralleled Isolated Boost Converter with Extended Operating Voltage Range

DEFF Research Database (Denmark)

Hernandez Botella, Juan Carlos; Sen, Gökhan; Mira Albert, Maria del Carmen

2012-01-01

Applications requiring wide input and output voltage range cannot often be satisfied by using buck or boost derived topologies. Primary paralleled isolated boost converter (PPIBC) [1]-[2] is a high efficiency boost derived topology. This paper proposes a new operation mode for extending the input...

Effect of semen extender and storage temperature on ram sperm motility over time

Science.gov (United States)

Storage of ram semen for long period of time depends on a number of factors, including type of extender and storage temperature. A study compared the effect of semen extender and storage temperature on motility of ram semen stored for 72 h. Semen collected via electroejaculator from 5 mature Katahd...

Density Measurements of Waste Cooking Oil Biodiesel and Diesel Blends Over Extended Pressure and Temperature Ranges

Directory of Open Access Journals (Sweden)

Thanh Xuan NguyenThi

2018-05-01

Full Text Available Density and compressibility are primordial parameters for the optimization of diesel engine operation. With this objective, these properties were reported for waste cooking oil biodiesel and its blends (5% and 10% by volume mixed with diesel. The density measurements were performed over expanded ranges of pressure (0.1 to 140 MPa and temperature (293.15 to 353.15 K compatible with engine applications. The isothermal compressibility was estimated within the same experimental range by density differentiation. The Fatty Acid Methyl Esters (FAMEs profile of the biodiesel was determined using a Gas Chromatography–Mass Spectrometry (GC-MS technique. The storage stability of the biodiesel was assessed in terms of the reproducibility of the measured properties. The transferability of this biodiesel fuel was discussed on the basis of the standards specifications that support their use in fuel engines. Additionally, this original set of data represents meaningful information to develop new approaches or to evaluate the predictive capability of models previously developed.

The influence of interstitial impurities on temperature ranges of deuterium retention in austenitic stainless steel 18Cr10NiTi

International Nuclear Information System (INIS)

Neklyudov, I.M.; Morozov, O.M.; Kulish, V.G.; Zhurba, V.I.; Galytsky, A.G.; Piatenko, E.V.

2009-01-01

The influence of nitrogen, oxygen and helium on the temperature range of deuterium retention in 18Cr10NiTi stainless steel (of AISI304L type) has been investigated. It is demonstrated that the introduction of oxygen, nitrogen or helium into 18Cr10NiTi steel extends the upper limit in the high-temperature range of deuterium retention. It has been found that for 18Cr10NiTi stainless steel, pre-irradiated with helium ions, the increase in the temperature range of deuterium retention occurs in steps: on attainment of helium concentration of ∼0.5 at.% He the temperature range increases by ∼100 K, and on attainment of helium concentration of ∼2.5 at.% He the temperature range increases by ∼350 K. The introduction of oxygen into 18Cr10NiTi stainless steel results in the increase of the temperature range of deuterium retention in the direction of rise in temperature. In the deuterium thermodesorption spectrum, this manifests itself by the occurrence of an additional low-amplitude peak with the maximum temperature T m ∼ 560 K. The introduction of nitric impurity into 18Cr10NiTi stainless steel results in the extension of the temperature range of deuterium retention towards higher temperatures.

Attenuation and immunogenicity of host-range extended modified vaccinia virus Ankara recombinants.

Science.gov (United States)

Melamed, Sharon; Wyatt, Linda S; Kastenmayer, Robin J; Moss, Bernard

2013-09-23

Modified vaccinia virus Ankara (MVA) is being widely investigated as a safe smallpox vaccine and as an expression vector to produce vaccines against other infectious diseases and cancer. MVA was isolated following more than 500 passages in chick embryo fibroblasts and suffered several major deletions and numerous small mutations resulting in replication defects in human and most other mammalian cells as well as severe attenuation of pathogenicity. Due to the host range restriction, primary chick embryo fibroblasts are routinely used for production of MVA-based vaccines. While a replication defect undoubtedly contributes to safety of MVA, it is worth considering whether host range and attenuation are partially separable properties. Marker rescue transfection experiments resulted in the creation of recombinant MVAs with extended mammalian cell host range. Here, we characterize two host-range extended rMVAs and show that they (i) have acquired the ability to stably replicate in Vero cells, which are frequently used as a cell substrate for vaccine manufacture, (ii) are severely attenuated in immunocompetent and immunodeficient mouse strains following intranasal infection, (iii) are more pathogenic than MVA but less pathogenic than the ACAM2000 vaccine strain at high intracranial doses, (iv) do not form lesions upon tail scratch in mice in contrast to ACAM2000 and (v) induce protective humoral and cell-mediated immune responses similar to MVA. The extended host range of rMVAs may be useful for vaccine production. Published by Elsevier Ltd.

Long-range analysis of density fitting in extended systems

Science.gov (United States)

Varga, Scarontefan

Density fitting scheme is analyzed for the Coulomb problem in extended systems from the correctness of long-range behavior point of view. We show that for the correct cancellation of divergent long-range Coulomb terms it is crucial for the density fitting scheme to reproduce the overlap matrix exactly. It is demonstrated that from all possible fitting metric choices the Coulomb metric is the only one which inherently preserves the overlap matrix for infinite systems with translational periodicity. Moreover, we show that by a small additional effort any non-Coulomb metric fit can be made overlap-preserving as well. The problem is analyzed for both ordinary and Poisson basis set choices.

A Proportional Resonant Control Strategy for Efficiency Improvement in Extended Range Electric Vehicles

Directory of Open Access Journals (Sweden)

Xiaoyuan Wang

2017-02-01

Full Text Available The key to control the range extender generation system is to improve the efficiency and reduce the emissions of the electric vehicle (EV. In this paper, based on the purpose of efficiency optimization, both engine and generator are matched to get a public high efficiency region, and a partial power following control strategy was presented. The engine speed is constant in the defined power range, so the output power regulation of the range extender is only realized by the adjustment of the torque of the generator. Engine speed and generator torque were decoupled. An improved proportional resonant (PR controller is adopted to achieve fast output power regulation. In order to ensure the response characteristics of the control system and to improve the robustness, the impacts on system’s characteristics and stability caused by PR controller and parameters in the inner-current loop were analyzed via frequency response characteristics. A pre-Tustin with deviation compensation is proposed for PR controller’s discretization. A stable and robust power following control method is obtained for the range extender control system. Finally, simulation and experiment of the proposed control strategy illustrated its feasibility and correctness.

Nickel-titanium alloys: stress-related temperature transitional range.

Science.gov (United States)

Santoro, M; Beshers, D N

2000-12-01

The inducement of mechanical stress within nickel-titanium wires can influence the transitional temperature range of the alloy and therefore the expression of the superelastic properties. An analogous variation of the transitional temperature range may be expected during orthodontic therapy, when the archwires are engaged into the brackets. To investigate this possibility, samples of currently used orthodontic nickel-titanium wires (Sentalloy, GAC; Copper Ni-Ti superelastic at 27 degrees C, 35 degrees C, 40 degrees C, Ormco; Nitinol Heat-Activated, 3M-Unitek) were subjected to temperature cycles ranging between 4 degrees C and 60 degrees C. The wires were mounted in a plexiglass loading device designed to simulate clinical situations of minimum and severe dental crowding. Electrical resistivity was used to monitor the phase transformations. The data were analyzed with paired t tests. The results confirmed the presence of displacements of the transitional temperature ranges toward higher temperatures when stress was induced. Because nickel-titanium wires are most commonly used during the aligning stage in cases of severe dental crowding, particular attention was given to the performance of the orthodontic wires under maximum loading. An alloy with a stress-related transitional temperature range corresponding to the fluctuations of the oral temperature should express superelastic properties more consistently than others. According to our results, Copper Ni-Ti 27 degrees C and Nitinol Heat-Activated wires may be considered suitable alloys for the alignment stage.

Similarities and differences among fluid milk products: traditionally produced, extended shelf life and ultrahigh-temperature processed.

Science.gov (United States)

Grabowski, N T; Ahlfeld, B; Brix, A; Hagemann, A; von Münchhausen, C; Klein, G

2013-06-01

Extended shelf life milk is a relatively new kind of fluid milk, generally manufactured by high-temperature treatment and/or micro-filtration. Being advertised as 'pasteurized milk with an extended shelf life', its flavour, compositional quality and labelling was questioned. Extended shelf life (high-temperature treatment), pasteurized ('traditionally produced') and ultrahigh-temperature milk were, therefore, compared at the beginning and end of shelf life. In triangle tests, panellists distinguished clearly between all products. High-temperature treatment milk's flavour was closer to ultrahigh-temperature and traditionally produced milk in the beginning and at the end of shelf life, respectively. Physicochemically and bacteriologically, all three types could be distinguished. Since 'extended shelf life' comprises many process varieties (each affecting flavour differently), consumer information and appropriate package labelling beyond 'long-lasting' is necessary, e.g. by mentioning the heat treatment applied.

Technique to extend ozonesonde temperature data to the mesopause

International Nuclear Information System (INIS)

Weichel, R.L.

1983-10-01

An analysis of global Multichannel Filter Radiometer radiances and ozone retrieval results revealed that the simulated radiances were not always representative of the measurements for the CO 2 channels sensing the temperatures in the middle and upper stratosphere. This problem was particularly pronounced, but not limited to, higher latitude winter conditions. Because of the special importance of the middle stratosphere and high latitudes for ozone analyses, a research effort was undertaken to develop an improved method (described below) of extending the temperatures from the ozonesondes used in the simulation procedure. An overview of the radiative transfer theory is provided to show the importance of the temperature profile in the calculation of simulated radiances

Extended-range high-resolution dynamical downscaling over a continental-scale spatial domain with atmospheric and surface nudging

Science.gov (United States)

Husain, S. Z.; Separovic, L.; Yu, W.; Fernig, D.

2014-12-01

Extended-range high-resolution mesoscale simulations with limited-area atmospheric models when applied to downscale regional analysis fields over large spatial domains can provide valuable information for many applications including the weather-dependent renewable energy industry. Long-term simulations over a continental-scale spatial domain, however, require mechanisms to control the large-scale deviations in the high-resolution simulated fields from the coarse-resolution driving fields. As enforcement of the lateral boundary conditions is insufficient to restrict such deviations, large scales in the simulated high-resolution meteorological fields are therefore spectrally nudged toward the driving fields. Different spectral nudging approaches, including the appropriate nudging length scales as well as the vertical profiles and temporal relaxations for nudging, have been investigated to propose an optimal nudging strategy. Impacts of time-varying nudging and generation of hourly analysis estimates are explored to circumvent problems arising from the coarse temporal resolution of the regional analysis fields. Although controlling the evolution of the atmospheric large scales generally improves the outputs of high-resolution mesoscale simulations within the surface layer, the prognostically evolving surface fields can nevertheless deviate from their expected values leading to significant inaccuracies in the predicted surface layer meteorology. A forcing strategy based on grid nudging of the different surface fields, including surface temperature, soil moisture, and snow conditions, toward their expected values obtained from a high-resolution offline surface scheme is therefore proposed to limit any considerable deviation. Finally, wind speed and temperature at wind turbine hub height predicted by different spectrally nudged extended-range simulations are compared against observations to demonstrate possible improvements achievable using higher spatiotemporal

Salinity/temperature ranges for application of seawater SA-T-P models

Science.gov (United States)

Marion, G. M.; Millero, F. J.; Feistel, R.

2009-01-01

At the present time, little is known about how broad salinity and temperature ranges are for seawater thermodynamic models that are functions of absolute salinity (SA), temperature (T) and pressure (P). Such models rely on fixed compositional ratios of the major components (e.g. Na/Cl, Mg/Cl, Ca/Cl, SO4/Cl, etc.). As seawater evaporates or freezes, solid phases (e.g. CaCO3(s) or CaSO42H2O(s)) will eventually precipitate. This will change the compositional ratios, and these salinity models will no longer be applicable. A future complicating factor is the lowering of seawater pH as the atmospheric concentrations of CO2 increase. A geochemical model (FREZCHEM) was used to quantify the SA-T boundaries at P=0.1 MPa and the range of these boundaries for future atmospheric CO2 increases. An omega supersaturation model for CaCO3 minerals based on homogeneous nucleation was extended from 25-40°C to 3°C. CaCO3 minerals were the boundary defining minerals (first to precipitate) between 3°C (at SA=104 g kg-1 and 40°C (at SA=66 g kg-1. At 2.82°C, calcite(CaCO3) transitioned to ikaite(CaCO36H2O) as the dominant boundary defining mineral for colder temperatures, which culminated in a low temperature boundary of -4.93°C. Increasing atmospheric CO2 from 385 μatm (in Year 2008) to 550 μatm (in Year 2100) would increase the SA and t boundaries as much as 11 g kg-1 and 0.66°C, respectively. The model-calculated calcite-ikaite transition temperature of 2.82°C is in excellent agreement with ikaite formation in natural environments that occurs at temperatures of 3°C or lower. Furthermore, these results provide a quantitative theoretical explanation (FREZCHEM model calculations) for why ikaite is the solid phase CaCO3 mineral that precipitates during seawater freezing.

A combined stochastic analysis of mean daily temperature and diurnal temperature range

Science.gov (United States)

Sirangelo, B.; Caloiero, T.; Coscarelli, R.; Ferrari, E.

2018-03-01

In this paper, a stochastic model, previously proposed for the maximum daily temperature, has been improved for the combined analysis of mean daily temperature and diurnal temperature range. In particular, the procedure applied to each variable sequentially performs the deseasonalization, by means of truncated Fourier series expansions, and the normalization of the temperature data, with the use of proper transformation functions. Then, a joint stochastic analysis of both the climatic variables has been performed by means of a FARIMA model, taking into account the stochastic dependency between the variables, namely introducing a cross-correlation between the standardized noises. The model has been applied to five daily temperature series of southern Italy. After the application of a Monte Carlo simulation procedure, the return periods of the joint behavior of the mean daily temperature and the diurnal temperature range have been evaluated. Moreover, the annual maxima of the temperature excursions in consecutive days have been analyzed for the synthetic series. The results obtained showed different behaviors probably linked to the distance from the sea and to the latitude of the station.

Peculiarities of austenitic state in premartensitic temperature range

International Nuclear Information System (INIS)

Sarrak, V.I.; Suvorova, S.O.

1982-01-01

A review of works on the study of austenite behaviour in premartensitic temperature range carried out using the investigation methods of resistance to microplastic deformation, mechanical properties and internal friction, is presented. The investigation is carried out using carbon-free iron-nickel alloy N31, alloy 40N24 and alloy 50Kh20N10. It is established that in premartensitic temperature range at a certain temperature Msub(elast.) exceeding by approximately 35 deg C the starting temperature of martensitic transformation, austenite state changes sharply: mechanical instability as to microplastic deformation appears. It manifests itself in an anomalous decrease of resistance to microplastic deformation at the temperature approaching the beginning of martensitic transformation. Martensitic transformation develops under tension in an elastic region. At the temperature above Msub(elast.) martensitic transformation develops only under the effect of plastic deformation. Decrease of temperature of martensitic transformation start as a result of microplastic deformation and subsequent ageing is connected with blocking of possible places of martensite initiation

Peculiarities of austenitic state in premartensitic temperature range

Energy Technology Data Exchange (ETDEWEB)

Sarrak, V.I.; Suvorova, S.O.

A review of works on the study of austenite behaviour in premartensitic temperature range carried out using the investigation methods of resistance to microplastic deformation, mechanical properties and internal friction, is presented. The investigation is carried out using carbon-free iron-nickel alloy N31, alloy 40N24 and alloy 50Kh20N10. It is established that in premartensitic temperature range at a certain temperature Msub(elast.) exceeding by approximately 35 deg C the starting temperature of martensitic transformation austenite state changes sharply: mechanical instability as to microplastic deformation appears. It manifests itself in an anomalous decrease of resistance to microplastic deformation at the temperature approaching the beginning of martensitic transformation. Martensitic transformation develops under tension in an elastic region. At the temperature above Msub(elast.) martensitic transformation develops only under the effect of plastic deformation. Decrease of temperature of martensitic transformation start as a result of microplastic deformation and subsequent ageing is connected with blocking of possible places of martensite initiation.

Performance of a 100V Half-Bridge MOSFET Driver, Type MIC4103, Over a Wide Temperature Range

Science.gov (United States)

Patterson, Richard L.; Hammoud, Ahmad

2011-01-01

The operation of a high frequency, high voltage MOSFET (metal-oxide semiconductor field-effect transistors) driver was investigated over a wide temperature regime that extended beyond its specified range. The Micrel MIC4103 is a 100V, non-inverting, dual driver that is designed to independently drive both high-side and low-side N-channel MOSFETs. It features fast propagation delay times and can drive 1000 pF load with 10ns rise times and 6 ns fall times [1]. The device consumes very little power, has supply under-voltage protection, and is rated for a -40 C to +125 C junction temperature range. The floating high-side driver of the chip can sustain boost voltages up to 100 V. Table I shows some of the device manufacturer s specification.

Sorting method to extend the dynamic range of the Shack-Hartmann wave-front sensor

International Nuclear Information System (INIS)

Lee, Junwon; Shack, Roland V.; Descour, Michael R.

2005-01-01

We propose a simple and powerful algorithm to extend the dynamic range of a Shack-Hartmann wave-front sensor. In a conventional Shack-Hartmann wave-front sensor the dynamic range is limited by the f-number of a lenslet, because the focal spot is required to remain in the area confined by the single lenslet. The sorting method proposed here eliminates such a limitation and extends the dynamic range by tagging each spot in a special sequence. Since the sorting method is a simple algorithm that does not change the measurement configuration, there is no requirement for extra hardware, multiple measurements, or complicated algorithms. We not only present the theory and a calculation example of the sorting method but also actually implement measurement of a highly aberrated wave front from nonrotational symmetric optics

Temperature profile retrievals with extended Kalman-Bucy filters

Science.gov (United States)

Ledsham, W. H.; Staelin, D. H.

1979-01-01

The Extended Kalman-Bucy Filter is a powerful technique for estimating non-stationary random parameters in situations where the received signal is a noisy non-linear function of those parameters. A practical causal filter for retrieving atmospheric temperature profiles from radiances observed at a single scan angle by the Scanning Microwave Spectrometer (SCAMS) carried on the Nimbus 6 satellite typically shows approximately a 10-30% reduction in rms error about the mean at almost all levels below 70 mb when compared with a regression inversion.

Extended Reconstructed Sea Surface Temperature (ERSST) Monthly Analysis, Version 3b

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Version 3b (v3b) of the Extended Reconstructed Sea Surface Temperature (ERSST) dataset is a monthly SST analysis on a 2-degree global grid based on the International...

A multifluid model extended for strong temperature nonequilibrium

Energy Technology Data Exchange (ETDEWEB)

Chang, Chong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-08-08

We present a multifluid model in which the material temperature is strongly affected by the degree of segregation of each material. In order to track temperatures of segregated form and mixed form of the same material, they are defined as different materials with their own energy. This extension makes it necessary to extend multifluid models to the case in which each form is defined as a separate material. Statistical variations associated with the morphology of the mixture have to be simplified. Simplifications introduced include combining all molecularly mixed species into a single composite material, which is treated as another segregated material. Relative motion within the composite material, diffusion, is represented by material velocity of each component in the composite material. Compression work, momentum and energy exchange, virtual mass forces, and dissipation of the unresolved kinetic energy have been generalized to the heterogeneous mixture in temperature nonequilibrium. The present model can be further simplified by combining all mixed forms of materials into a composite material. Molecular diffusion in this case is modeled by the Stefan-Maxwell equations.

A sub-circuit MOSFET model with a wide temperature range including cryogenic temperature

Energy Technology Data Exchange (ETDEWEB)

Jia Kan; Sun Weifeng; Shi Longxing, E-mail: jiakan.01@gmail.com [National ASIC System Engineering Research Center, Southeast University, Nanjing 210096 (China)

2011-06-15

A sub-circuit SPICE model of a MOSFET for low temperature operation is presented. Two resistors are introduced for the freeze-out effect, and the explicit behavioral models are developed for them. The model can be used in a wide temperature range covering both cryogenic temperature and regular temperatures. (semiconductor devices)

Evaluation of high temperature structural adhesives for extended service

Science.gov (United States)

Hendricks, C. L.; Hill, S. G.

1984-01-01

High temperature stable adhesive systems were evaluated for potential Supersonic Cruise Research (SCR) vehicle applications. The program was divided into two major phases: Phase I 'Adhesive Screening' evaluated eleven selected polyimide (PI) and polyphenylquinoxaline (PPQ) adhesive resins using eight different titanium (6Al-4V) adherend surface preparations; Phase II 'Adhesive Optimization and Characterization' extensively evaluated two adhesive systems, selected from Phase I studies, for chemical characterization and environmental durability. The adhesive systems which exhibited superior thermal and environmental bond properties were LARC-TPI polyimide and polyphenylquinoxaline both developed at NASA Langley. The latter adhesive system did develop bond failures at extended thermal aging due primarily to incompatibility between the surface preparation and the polymer. However, this study did demonstrate that suitable adhesive systems are available for extended supersonic cruise vehicle design applications.

USE OF ALTERNATIVE EXTENDERS AND TEMPERATURES IN LONG TERM STORAGE OF BOAR SEMEN

OpenAIRE

Lina Raquel Santos Araújo; Tatyane Bandeira Barros; Daianny Barboza Guimarães; Ludymila Furtado Cantanhêde; Aline Viana Dias; Ricardo Toniolli

2016-01-01

The use of appropriate extenders is important for the success of an artificial insemination program. The objective of this study was to evaluate the efficiency of alternative extenders for swine semen at different temperatures (17 to 10 °C). The following extenders were used: Beltsville Thawing Solution (BTS), powdered coconut water (ACP-103®), and skimmed milk powder (LPD). The 50 ejaculates were analyzed daily, in natura and after dilution, during the 5-day period of semen preservation  (D0...

USE OF ALTERNATIVE EXTENDERS AND TEMPERATURES IN LONG TERM STORAGE OF BOAR SEMEN

Directory of Open Access Journals (Sweden)

Lina Raquel Santos Araújo

2016-01-01

Full Text Available The use of appropriate extenders is important for the success of an artificial insemination program. The objective of this study was to evaluate the efficiency of alternative extenders for swine semen at different temperatures (17 to 10 °C. The following extenders were used: Beltsville Thawing Solution (BTS, powdered coconut water (ACP-103®, and skimmed milk powder (LPD. The 50 ejaculates were analyzed daily, in natura and after dilution, during the 5-day period of semen preservation  (D0 to D4, regarding spermatic vigor and motility. Acrosome integrity and sperm viability were evaluated on D0 and D4. Data were analyzed using Mann-Whitney, Students, Tukey and chi-square tests (p<0.05. The LPD extender at 10 °C presented higher motility and sperm vigor compared to BTS and ACP until D2, and to treatments stored at 17 °C. Acrosome vitality and integrity remained higher (p<0.001 with LPD at 10 °C on D0 and D4. LPD showed to be a good extender for the swine semen at lower temperature (10 °C. Furthermore, it provided better protection to sperm cells, by allowing greater integrity and vitality of the acrosome. Keywords: coconut water; conservation; skimmed milk; semen boar.

Measuring Systems for Thermometer Calibration in Low-Temperature Range

Science.gov (United States)

Szmyrka-Grzebyk, A.; Lipiński, L.; Manuszkiewicz, H.; Kowal, A.; Grykałowska, A.; Jancewicz, D.

2011-12-01

The national temperature standard for the low-temperature range between 13.8033 K and 273.16 K has been established in Poland at the Institute of Low Temperature and Structure Research (INTiBS). The standard consists of sealed cells for realization of six fixed points of the International Temperature Scale of 1990 (ITS-90) in the low-temperature range, an adiabatic cryostat and Isotech water and mercury triple-point baths, capsule standard resistance thermometers (CSPRT), and AC and DC bridges with standard resistors for thermometers resistance measurements. INTiBS calibrates CSPRTs at the low-temperature fixed points with uncertainties less than 1 mK. In lower temperature range—between 2.5 K and about 25 K — rhodium-iron (RhFe) resistance thermometers are calibrated by comparison with a standard which participated in the EURAMET.T-K1.1 comparison. INTiBS offers a calibration service for industrial platinum resistance thermometers and for digital thermometers between 77 K and 273 K. These types of thermometers may be calibrated at INTiBS also in a higher temperature range up to 550°C. The Laboratory of Temperature Standard at INTiBS acquired an accreditation from the Polish Centre for Accreditation. A management system according to EN ISO/IEC 17025:2005 was established at the Laboratory and presented on EURAMET QSM Forum.

A highly sensitive RF-to-DC power converter with an extended dynamic range

KAUST Repository

Almansouri, Abdullah Saud Mohammed; Ouda, Mahmoud H.; Salama, Khaled N.

2017-01-01

This paper proposes a highly sensitive RF-to-DC power converter with an extended dynamic range that is designed to operate at the medical band 433 MHz and simulated using 0.18 μm CMOS technology. Compared to the conventional fully cross

Spacecraft Trajectory Estimation Using a Sampled-Data Extended Kalman Filter with Range-Only Measurements

National Research Council Canada - National Science Library

Erwin, R. S; Bernstein, Dennis S

2005-01-01

.... In this paper we use a sampled-data extended Kalman Filter to estimate the trajectory or a target satellite when only range measurements are available from a constellation or orbiting spacecraft...

Study on The Extended Range Weather Forecast of Low Frequency Signal Based on Period Analysis Method

Science.gov (United States)

Li, X.

2016-12-01

Although many studies have explored the MJO and its application for weather forecasting, low-frequency oscillation has been insufficiently studied for the extend range weather forecasting over middle and high latitudes. In China, low-frequency synoptic map is a useful tool for meteorological operation department to forecast extend range weather. It is therefore necessary to develop objective methods to serve the need for finding low-frequency signal, interpretation and application of this signal in the extend range weather forecasting. In this paper, method of Butterworth band pass filter was applied to get low-frequency height field at 500hPa from 1980 to 2014 by using NCEP/NCAR daily grid data. Then period analysis and optimal subset regression methods were used to process the low frequency data of 150 days before the first forecast day and extend the low frequency signal of 500hPa low-frequency high field to future 30 days in the global from June to August during 2011-2014. Finally, the results were test. The main results are as follows: (1) In general, the fitting effect of low frequency signals of 500hPa low-frequency height field by period analysis in the northern hemisphere was better than that in the southern hemisphere, and was better in the low latitudes than that in the high latitudes. The fitting accuracy gradually reduced with the increase of forecast time length, which tended to be stable during the late forecasting period. (2) The fitting effects over the 6 key regions in China showed that except filtering result over Xinjiang area in the first 10 days and 30 days, filtering results over the other 5 key regions throughout the whole period have passed reliability test with level more than 95%. (3) The center and scope of low and high low frequency systems can be fitted well by using the methods mentioned above, which is consist with the corresponding use of the low-frequency synoptic map for the prediction of the extended period. Application of the

Note: A wide temperature range MOKE system with annealing capability.

Science.gov (United States)

Chahil, Narpinder Singh; Mankey, G J

2017-07-01

A novel sample stage integrated with a longitudinal MOKE system has been developed for wide temperature range measurements and annealing capabilities in the temperature range 65 K temperatures without adversely affecting the cryostat and minimizes thermal drift in position. In this system the hysteresis loops of magnetic samples can be measured simultaneously while annealing the sample in a magnetic field.

An extended Kalman-Bucy filter for atmospheric temperature profile retrieval with a passive microwave sounder

Science.gov (United States)

Ledsham, W. H.; Staelin, D. H.

1978-01-01

An extended Kalman-Bucy filter has been implemented for atmospheric temperature profile retrievals from observations made using the Scanned Microwave Spectrometer (SCAMS) instrument carried on the Nimbus 6 satellite. This filter has the advantage that it requires neither stationary statistics in the underlying processes nor linear production of the observed variables from the variables to be estimated. This extended Kalman-Bucy filter has yielded significant performance improvement relative to multiple regression retrieval methods. A multi-spot extended Kalman-Bucy filter has also been developed in which the temperature profiles at a number of scan angles in a scanning instrument are retrieved simultaneously. These multi-spot retrievals are shown to outperform the single-spot Kalman retrievals.

Deeply trapped electrons in imaging plates and their utilization for extending the dynamic range

International Nuclear Information System (INIS)

Ohuchi, Hiroko; Kondo, Yasuhiro

2010-01-01

The absorption spectra of deep centers in an imaging plate (IP) made of BaFBr 0:85 I 0:15 :Eu 2+ have been studied in the ultraviolet region. Electrons trapped in deep centers are considered to be the cause of unerasable and reappearing latent images in IPs over-irradiated with X-rays. Deep centers showed a dominant peak at around 320 nm, followed by two small peaks at around 345 and 380 nm. By utilizing deeply trapped electrons, we have attempted to extend the dynamic range of an IP. The IP was irradiated by 150-kV X-rays with doses from 8.07 mGy to 80.7 Gy. Reading out the latent image by the stimulation of Eu 2+ luminescence with a 633-nm He-Ne laser light from a conventional Fuji reader showed a linear relationship with irradiated dose up to 0.8 Gy, but then becoming non-linear. After fully erasing with visible light, unerasable latent images were read out using 635-nm semi-conductor laser light combined with a photon-counting detection system. The dose-response curve so obtained gave a further two orders of magnitude extending the dynamic range up to 80.7 Gy. Comprehensive results indicate that electrons supplied from deep centers to the F centers provided the extended dynamic range after the F centers became saturated. Based on these facts, a model of the excitation of deeply trapped electrons and PSL processes is proposed.

Characterization of advanced piezoelectric materials in the wide temperature range

Energy Technology Data Exchange (ETDEWEB)

Burianova, L.; Kopal, A.; Nosek, J

2003-05-25

We report about methods and results of our measurements of piezoelectric, dielectric and elastic properties of piezoelectric materials like crystals, ceramics, composites, polymers and thin layer composites. Among the methods, used in our laboratories are: the resonance method working in the temperature range 208-358 K, hydrostatic methods, both static and dynamic in the range 273-333 K, laser interferometric methods, using single and double-beam interferometer, working at room temperature, single and double-beam micro-interferometers, working inside of optical cryostat in the range 150-330 K, and pulse echo method for measurements of elastic coefficients, using ultrasonic set, working at room temperature. In our earlier papers we reported about some of our results of piezoelectric measurements of PZT ceramics using resonance method and laser interferometric method. The results of both methods were in good agreement. Now, the measurements are realized on 0-3 ceramic-polymer composites and thin layer composites. It is well known, that both intrinsic (material) and extrinsic (domain structure) contributions to properties of ferroelectric samples have characteristic, sometimes rather strong, temperature dependence. Therefore, any extension of temperature range of the above mentioned methods is welcomed.

Heart rate, multiple body temperature, long-range and long-life telemetry system for free-ranging animals

Science.gov (United States)

Lund, G. F.; Westbrook, R. M.; Fryer, T. B.

1980-01-01

The design details and rationale for a versatile, long-range, long-life telemetry data acquisition system for heart rates and body temperatures at multiple locations from free-ranging animals are presented. The design comprises an implantable transmitter for short to medium range transmission, a receiver retransmitter collar to be worn for long-range transmission, and a signal conditioner interface circuit to assist in signal discrimination and demodulation of receiver or tape-recorded audio outputs. Implanted electrodes are used to obtain an ECG, from which R-wave characteristics are selected to trigger a short RF pulse. Pulses carrying heart rate information are interrupted periodically by a series of pulse interval modulated RF pulses conveying temperature information sensed at desired locations by thermistors. Pulse duration and pulse sequencing are used to discriminate between heart rate and temperature pulses as well as radio frequency interference. The implanted transmitter may be used alone for medium and short-range tracking, or with a receiver-transmitter collar that employs commercial tracking equipment for transmissions of up to 12 km. A system prototype has been tested on a dog.

The extended range neutron rem counter LINUS: overview and latest developments

International Nuclear Information System (INIS)

Birattari, C.; Rancati, T.; Esposito, A.; Pelliccioni, M.; Ferrari, A.; Silari, M.

1997-01-01

The 'history' of the extended range neutron rem counter LINUS, since its first conception in 1990 is reviewed, along with the latest developments. These include the calibration of the initially cylindrical version with nearly monoenergetic neutrons in the energy range 34-66 MeV, a detailed evaluation of the anisotropy of its response function, the construction and calibration of an improved spherical version, and recent measurements in reference high energy stray radiation fields. The instrument can now be considered as being fully characterized. Similar monitors built by other laboratories following the present design have confirmed its performances. The instrument is now in semi-routine use at a number of particle accelerator facilities and is one of several devices used on-board of aircrafts for assessing the exposure to cosmic rays at commercial flight altitudes. (author)

Development of parallel-plate-based MEMS tunable capacitors with linearized capacitance–voltage response and extended tuning range

International Nuclear Information System (INIS)

Shavezipur, M; Nieva, P; Khajepour, A; Hashemi, S M

2010-01-01

This paper presents a design technique that can be used to linearize the capacitance–voltage (C–V) response and extend the tuning range of parallel-plate-based MEMS tunable capacitors beyond that of conventional designs. The proposed technique exploits the curvature of the capacitor's moving electrode which could be induced by either manipulating the stress gradients in the plate's material or using bi-layer structures. The change in curvature generates a nonlinear structural stiffness as the moving electrode undergoes out-of-plane deformation due to the actuation voltage. If the moving plate curvature is tailored such that the capacitance increment is proportional to the voltage increment, then a linear C–V response is obtained. The larger structural resistive force at higher bias voltage also delays the pull-in and increases the maximum tunability of the capacitor. Moreover, for capacitors containing an insulation layer between the two electrodes, the proposed technique completely eliminates the pull-in effect. The experimental data obtained from different capacitors fabricated using PolyMUMPs demonstrate the advantages of this design approach where highly linear C–V responses and tunabilities as high as 1050% were recorded. The design methodology introduced in this paper could be easily extended to for example, capacitive pressure and temperature sensors or infrared detectors to enhance their response characteristics.

Using subseasonal-to-seasonal (S2S) extreme rainfall forecasts for extended-range flood prediction in Australia

Science.gov (United States)

White, C. J.; Franks, S. W.; McEvoy, D.

2015-06-01

Meteorological and hydrological centres around the world are looking at ways to improve their capacity to be able to produce and deliver skilful and reliable forecasts of high-impact extreme rainfall and flooding events on a range of prediction timescales (e.g. sub-daily, daily, multi-week, seasonal). Making improvements to extended-range rainfall and flood forecast models, assessing forecast skill and uncertainty, and exploring how to apply flood forecasts and communicate their benefits to decision-makers are significant challenges facing the forecasting and water resources management communities. This paper presents some of the latest science and initiatives from Australia on the development, application and communication of extreme rainfall and flood forecasts on the extended-range "subseasonal-to-seasonal" (S2S) forecasting timescale, with a focus on risk-based decision-making, increasing flood risk awareness and preparedness, capturing uncertainty, understanding human responses to flood forecasts and warnings, and the growing adoption of "climate services". The paper also demonstrates how forecasts of flood events across a range of prediction timescales could be beneficial to a range of sectors and society, most notably for disaster risk reduction (DRR) activities, emergency management and response, and strengthening community resilience. Extended-range S2S extreme flood forecasts, if presented as easily accessible, timely and relevant information are a valuable resource to help society better prepare for, and subsequently cope with, extreme flood events.

A numerical investigation on the efficiency of range extending systems using Advanced Vehicle Simulator

Science.gov (United States)

Varnhagen, Scott; Same, Adam; Remillard, Jesse; Park, Jae Wan

2011-03-01

Series plug-in hybrid electric vehicles of varying engine configuration and battery capacity are modeled using Advanced Vehicle Simulator (ADVISOR). The performance of these vehicles is analyzed on the bases of energy consumption and greenhouse gas emissions on the tank-to-wheel and well-to-wheel paths. Both city and highway driving conditions are considered during the simulation. When simulated on the well-to-wheel path, it is shown that the range extender with a Wankel rotary engine consumes less energy and emits fewer greenhouse gases compared to the other systems with reciprocating engines during many driving cycles. The rotary engine has a higher power-to-weight ratio and lower noise, vibration and harshness compared to conventional reciprocating engines, although performs less efficiently. The benefits of a Wankel engine make it an attractive option for use as a range extender in a plug-in hybrid electric vehicle.

A Voltage Doubler Circuit to Extend the Soft-switching Range of Dual Active Bridge Converters

DEFF Research Database (Denmark)

Qin, Zian; Shen, Yanfeng; Wang, Huai

2017-01-01

A voltage doubler circuit is realized to extend the soft-switching range of Dual Active Bridge (DAB) converters. No extra hardware is added to the DAB to form this circuit, since it is composed of the dc blocking capacitor and the low side full bridge converter, which already exist in DAB....... With the voltage doubler, the DAB converter can achieve soft switching and high efficiency when the low side dc voltage is close to 2 pu (1 pu is the high side dc voltage divided by the transformer turn ratio), which can be realized only when the low side dc voltage is close to 1 pu by using the conventional phase...... shift modulation in DAB. Thus the soft switching range is extended. The soft switching boundary conditions are derived. A map to show the soft switching or hard switching in the full load and voltage range is obtained. The feasibility and effectiveness of the proposed method is finally verified...

High-temperature absorbed dose measurements in the megagray range

International Nuclear Information System (INIS)

Balian, P.; Ardonceau, J.; Zuppiroli, L.

1988-01-01

Organic conductors of the tetraselenotetracene family have been tested as ''high-temperature'' absorbed dose dosimeters. They were heated up to 120 0 C and irradiated at this temperature with 1-MeV electrons in order to simulate, in a short time, a much longer γ-ray irradiation. The electric resistance increase of the crystal can be considered a good measurement of the absorbed dose in the range 10 6 Gy to a few 10 8 Gy and presumably one order of magnitude more. This dosimeter also permits on-line (in-situ) measurements of the absorbed dose without removing the sensor from the irradiation site. The respective advantages of organic and inorganic dosimeters at these temperature and dose ranges are also discussed. In this connection, we outline new, but negative, results concerning the possible use of silica as a high-temperature, high-dose dosimeter. (author)

Using subseasonal-to-seasonal (S2S extreme rainfall forecasts for extended-range flood prediction in Australia

Directory of Open Access Journals (Sweden)

C. J. White

2015-06-01

Full Text Available Meteorological and hydrological centres around the world are looking at ways to improve their capacity to be able to produce and deliver skilful and reliable forecasts of high-impact extreme rainfall and flooding events on a range of prediction timescales (e.g. sub-daily, daily, multi-week, seasonal. Making improvements to extended-range rainfall and flood forecast models, assessing forecast skill and uncertainty, and exploring how to apply flood forecasts and communicate their benefits to decision-makers are significant challenges facing the forecasting and water resources management communities. This paper presents some of the latest science and initiatives from Australia on the development, application and communication of extreme rainfall and flood forecasts on the extended-range "subseasonal-to-seasonal" (S2S forecasting timescale, with a focus on risk-based decision-making, increasing flood risk awareness and preparedness, capturing uncertainty, understanding human responses to flood forecasts and warnings, and the growing adoption of "climate services". The paper also demonstrates how forecasts of flood events across a range of prediction timescales could be beneficial to a range of sectors and society, most notably for disaster risk reduction (DRR activities, emergency management and response, and strengthening community resilience. Extended-range S2S extreme flood forecasts, if presented as easily accessible, timely and relevant information are a valuable resource to help society better prepare for, and subsequently cope with, extreme flood events.

Anomalous X-ray scattering studies of short-, intermediate- and extended-range order in glasses

International Nuclear Information System (INIS)

Price, D.L.; Saboungi, M.L.; Armand, P.; Cox, D.E.

1998-01-01

The authors present the formalism of anomalous x-ray scattering as applied to partial structure analysis of disordered materials, and give an example of how the technique has been applied, together with that of neutron diffraction, to investigate short-, intermediate- and extended-range order in vitreous germania and rubidium germanate

A highly sensitive RF-to-DC power converter with an extended dynamic range

KAUST Repository

Almansouri, Abdullah Saud Mohammed

2017-10-24

This paper proposes a highly sensitive RF-to-DC power converter with an extended dynamic range that is designed to operate at the medical band 433 MHz and simulated using 0.18 μm CMOS technology. Compared to the conventional fully cross-coupled rectifier, the proposed design offers 3.2× the dynamic range. It is also highly sensitive and requires −18 dBm of input power to produce a 1 V-output voltage when operating with a 100 kΩ load. Furthermore, the proposed design offers an open circuit sensitivity of −23.4 dBm and a peak power conversion efficiency of 67%.

Design, calibration and tests of an extended-range Bonner sphere spectrometer

CERN Document Server

Mitaroff, Angela; Silari, Marco

2001-01-01

Stray radiation fields outside the shielding of hadron accelerators are of complex nature. They consist of a multiplicity of radiation components (neutrons, photons, electrons, pions, muons, ...) which extend over a wide range of energies. Since the dose equivalent in these mixed fields is mainly due to neutrons, neutron dosimetry is a particularly important task. The neutron energy in these fields ranges from thermal up to several hundreds of MeV, thus making dosimetry difficult. A well known instrument for measuring neutron energy distributions from thermal energies up to about E=10 MeV is the Bonner sphere spectrometer (BSS). It consists of a set of moderating spheres of different radii made of polyethylene, with a thermal neutron counter in the centre. Each detector (sphere plus counter) has a maximum response at a certain energy value depending on its size, but the overall response of the conventional BSS drops sharply between E=10-20 MeV. This thesis focuses on the development, the calibration and tests...

Methanol adsorption by amorphous silica alumina in the critical temperature range

NARCIS (Netherlands)

Kuczynski, M.; van Ooteghem, A.; Westerterp, K.R.

1986-01-01

The methanol adsorption capacity of an amorphous silica-alumina was measured using an equilibrium technique. The experimental temperature range was of 140 to 260°C and the pure methanol pressure range was 0.1 to 1.2 MPa. A multilayer adsorption was found, also for temperatures above the critical

Calibration and experiment of an extended range Bonner sphere spectrometer

Energy Technology Data Exchange (ETDEWEB)

Mitaroff, A.; Mayer, S. [CERN, Geneva (Switzerland)]|[Atominstitut der TU-Wien, Vienna (Austria); Dimovasili, E.; Silari, M. [CERN, Geneva (Switzerland); Birattari, C. [Univ. of Milan, LASA, Segrate (Italy); Wiegel, B. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Aiginger, H. [Atominstitut der TU-Wien, Vienna (Austria)

2001-07-01

High-energy neutrons dominate the dose equivalent outside the shielding of hadron accelerators (protons, heavy ions). Nowadays these accelerators are not only used or foreseen in high- and intermediate energy physics but in other fields like medicine or waste transmutation, too. In addition it was shown that at commercial flight altitudes a large fraction of the exposure of aircraft personnel is due to neutrons with a comparable energy spectrum to that along hadron accelerators. For this reason in radiation protection the exact knowledge of the neutron spectrum and the relevant dose quantities is very important. The neutrons of these radiation fields extend over more than 14 orders of magnitude up to 1 GeV, thus making the measurement of the spectrum difficult. A newly developed Bonner sphere spectrometer with extended range shall evaluate spectra with a high-energy neutron component. This contribution shows the FLUKA simulated response functions of the two new spheres - Stanlio and Ollio - dedicated for high energies. These simulations should be verified by calibration with quasi monoenergetic neutrons. These took place at PTB with neutron beams of 144 keV, 1.2 MeV, 5 MeV and 14.8 MeV. Additionally experiments at the CERF (CERN-EU Reference Field) facility, which provides a broad neutron spectrum with two pronounced maxima at around 1 MeV and 70 MeV, are shown and compared to the Monte Carlo simulations. (orig.)

Calibration and experiment of an extended range Bonner sphere spectrometer

International Nuclear Information System (INIS)

Mitaroff, A.; Mayer, S.; Dimovasili, E.; Silari, M.; Birattari, C.; Wiegel, B.; Aiginger, H.

2001-01-01

High-energy neutrons dominate the dose equivalent outside the shielding of hadron accelerators (protons, heavy ions). Nowadays these accelerators are not only used or foreseen in high- and intermediate energy physics but in other fields like medicine or waste transmutation, too. In addition it was shown that at commercial flight altitudes a large fraction of the exposure of aircraft personnel is due to neutrons with a comparable energy spectrum to that along hadron accelerators. For this reason in radiation protection the exact knowledge of the neutron spectrum and the relevant dose quantities is very important. The neutrons of these radiation fields extend over more than 14 orders of magnitude up to 1 GeV, thus making the measurement of the spectrum difficult. A newly developed Bonner sphere spectrometer with extended range shall evaluate spectra with a high-energy neutron component. This contribution shows the FLUKA simulated response functions of the two new spheres - Stanlio and Ollio - dedicated for high energies. These simulations should be verified by calibration with quasi monoenergetic neutrons. These took place at PTB with neutron beams of 144 keV, 1.2 MeV, 5 MeV and 14.8 MeV. Additionally experiments at the CERF (CERN-EU Reference Field) facility, which provides a broad neutron spectrum with two pronounced maxima at around 1 MeV and 70 MeV, are shown and compared to the Monte Carlo simulations. (orig.)

Semiconductor resistance thermometer for the temperature range 300-0.3 K

International Nuclear Information System (INIS)

Zinov'eva, K.N.; Zarubin, L.I.; Nemish, I.Yu.; Vorobkalo, F.M.; Boldarev, S.T.; AN Ukrainskoj SSR, Kiev. Inst. Poluprovodnikov)

1979-01-01

Thermometric characteristics of semiconductor resistor thermometers for the temperature range from 300 to 0.3 K and from 77 to 0.3 K are given. Temperature dependence of thermometer resistances in the 300-1.3 K range was measured in cryostats with pumping-out of N 2 , H 2 and 4 He. For measurements below 1.3 K use was made of a 3 H- 4 He dissolving cryostat. The accuracy of measuring temperatures in the 1.3-0.3 K range is not below +-0.003 K, the error in determining thermometer resistances does not exceed 1%. The analysis of obtained thermometric characteristics of several series of semiconductor resistance thermometers showed that observed insignificant spread of resistances of thermometers in one series and identity of characteristics allows them to be used without preliminary calibration for relatively coarse measurements in the range from 3O0 to 0.3 K. Besides, it has been found that in the 4.2-0.3 K range the thermometric characteristics represent a straight line in the lgR-Tsup(-n) coordinates, where R is the thermometer resistance, T is the temperature and n=0.5. Thus, the thermometers of the same series can be calibrated only in 2 or 3 reference point measurements

LysM domains mediate lipochitin-oligosaccharide recognition and Nfr genes extend the symbiotic host range

DEFF Research Database (Denmark)

Radutoiu, Simona; Madsen, Lene H; Madsen, Esben B

2007-01-01

and Nfr5 Nod-factor receptor genes in Medicago truncatula and L. filicaulis, extends their host range to include bacterial strains, Mesorhizobium loti or DZL, normally infecting L. japonicus. As a result, the symbiotic program is induced, nodules develop and infection threads are formed. Using L...

Charging up for the future of plug-in hybrids and range extenders. An exploration of options for increased battery utilisation; Opladen voor de toekomst van plug-in hybrides en range extenders. Een verkenning naar mogelijkheden voor vergroten van het elektrische gebruik

Energy Technology Data Exchange (ETDEWEB)

Van Essen, H.; Schroten, A.; Aarnink, S.

2013-05-15

If the full potential of plug-in hybrids and electric cars with a range extender is to be usefully exploited, it is important that these vehicles be used in battery mode as much as possible. This means that users' charging and driving behaviour needs to be positively influenced. This can be achieved through suitably designed financial incentives on the part of employers and government, further expansion of battery-charging infrastructure, and transferring knowledge on driving style. Improved driving and charging behaviour will lead to lower effective fuel consumption, reduced CO2 emissions and improved air quality. These are some of the results of this study in which it is examined how the performance of plug-in hybrids and cars with a range extender can be improved. It is the first study to look into the factors governing practical usage of such vehicles and the options available to the various parties to improve that usage. To this end a literature study was carried out and interviews were held with employers, leasing companies, trade associations, government agencies and other parties [Dutch] Om het potentieel van plug-in hybrides en elektrische auto's met een range extender te benutten is het van belang dat deze auto's zoveel mogelijk elektrisch worden gereden. Hiervoor is het nodig om het oplaad- en rijgedrag van de gebruikers positief te beïnvloeden. Dit kan door het geven van slimme financiële prikkels door werkgevers en overheid, het verder uitbreiden van de laadinfrastructuur en kennisoverdracht over rijgedrag. Een verbeterd rij- en laadgedrag zorgt voor een lager brandstofpraktijkverbruik, minder CO2-uitstoot en een betere luchtkwaliteit. Dit staat onder meer in de studie 'Opladen voor de toekomst van plug-in hybrides en range extenders' van CE Delft, waarin op verzoek van de Nederlandse importeurs van Toyota en Opel is onderzocht hoe het elektrisch gebruik kan worden verbeterd. Hierin is voor het eerst gekeken naar de factoren

True coincidence summing corrections for an extended energy range HPGe detector

Energy Technology Data Exchange (ETDEWEB)

Venegas-Argumedo, Y. [Centro de Investigación en Materiales Avanzados (CIMAV), Miguel de Cervantes 120, Chihuahua, Chih 31109 (Mexico); M.S. Student at CIMAV (Mexico); Montero-Cabrera, M. E., E-mail: elena.montero@cimav.edu.mx [Centro de Investigación en Materiales Avanzados (CIMAV), Miguel de Cervantes 120, Chihuahua, Chih 31109 (Mexico)

2015-07-23

True coincidence summing (TCS) effect for natural radioactive families of U-238 and Th-232 represents a problem when an environmental sample with a close source-detector geometry measurement is performed. By using a certified multi-nuclide standard source to calibrate an energy extended range (XtRa) HPGe detector, it is possible to obtain an intensity spectrum slightly affected by the TCS effect with energies from 46 to 1836 keV. In this work, the equations and some other considerations required to calculate the TCS correction factor for isotopes of natural radioactive chains are described. It is projected a validation of the calibration, performed with the IAEA-CU-2006-03 samples (soil and water)

Spatial filtering velocimeter for vehicle navigation with extended measurement range

Science.gov (United States)

He, Xin; Zhou, Jian; Nie, Xiaoming; Long, Xingwu

2015-05-01

The idea of using spatial filtering velocimeter is proposed to provide accurate velocity information for vehicle autonomous navigation system. The presented spatial filtering velocimeter is based on a CMOS linear image sensor. The limited frame rate restricts high speed measurement of the vehicle. To extend measurement range of the velocimeter, a method of frequency shifting is put forward. Theoretical analysis shows that the frequency of output signal can be reduced and the measurement range can be doubled by this method when the shifting direction is set the same with that of image velocity. The approach of fast Fourier transform (FFT) is employed to obtain the power spectra of the spatially filtered signals. Because of limited frequency resolution of FFT, a frequency spectrum correction algorithm, called energy centrobaric correction, is used to improve the frequency resolution. The correction accuracy energy centrobaric correction is analyzed. Experiments are carried out to measure the moving surface of a conveyor belt. The experimental results show that the maximum measurable velocity is about 800deg/s without frequency shifting, 1600deg/s with frequency shifting, when the frame rate of the image is about 8117 Hz. Therefore, the measurement range is doubled by the method of frequency shifting. Furthermore, experiments were carried out to measure the vehicle velocity simultaneously using both the designed SFV and a laser Doppler velocimeter (LDV). The measurement results of the presented SFV are coincident with that of the LDV, but with bigger fluctuation. Therefore, it has the potential of application to vehicular autonomous navigation.

An extended set-value observer for position estimation using single range measurements

DEFF Research Database (Denmark)

Marcal, Jose; Jouffroy, Jerome; Fossen, Thor I.

the observability of the system is briefly discussed and an extended set-valued observer is presented, with some discussion about the effect of the measurements noise on the final solution. This observer estimates bounds in the errors assuming that the exogenous signals are bounded, providing a safe region......The ability of estimating the position of an underwater vehicle from single range measurements is important in applications where one transducer marks an important geographical point, when there is a limitation in the size or cost of the vehicle, or when there is a failure in a system...... of transponders. The knowledge of the bearing of the vehicle and the range measurements from a single location can provide a solution which is sensitive to the trajectory that the vehicle is following, since there is no complete constraint on the position estimate with a single beacon. In this paper...

Operation of a New Half-Bridge Gate Driver for Enhancement - Mode GaN FETs, Type LM5113, Over a Wide Temperature Range

Science.gov (United States)

Patterson, Richard; Hammoud, Ahmad

2011-01-01

A new commercial-off-the-shelf (COTS) gate driver designed to drive both the high-side and the low-side enhancement-mode GaN FETs, National Semiconductor's type LM5113, was evaluated for operation at temperatures beyond its recommended specified limits of -40 C to +125 C. The effects of limited thermal cycling under the extended test temperature, which ranged from -194 C to +150 C, on the operation of this chip as well as restart capability at the extreme cryogenic and hot temperatures were also investigated. The driver circuit was able to maintain good operation throughout the entire test regime between -194 C and +150 C without undergoing any major changes in its outputs signals and characteristics. The limited thermal cycling performed on the device also had no effect on its performance, and the driver chip was able to successfully restart at each of the extreme temperatures of -194 C and +150 C. The plastic packaging of this device was also not affected by either the short extreme temperature exposure or the limited thermal cycling. These preliminary results indicate that this new commercial-off-the-shelf (COTS) halfbridge eGaN FET driver integrated circuit has the potential for use in space exploration missions under extreme temperature environments. Further testing is planned under long-term cycling to assess the reliability of these parts and to determine their suitability for extended use in the harsh environments of space.

Extended two-temperature model for ultrafast thermal response of band gap materials upon impulsive optical excitation

Energy Technology Data Exchange (ETDEWEB)

Shin, Taeho [Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307 (United States); Samsung Advanced Institute of Technology, Suwon 443-803 (Korea, Republic of); Teitelbaum, Samuel W.; Wolfson, Johanna; Nelson, Keith A., E-mail: kanelson@mit.edu [Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307 (United States); Kandyla, Maria [Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307 (United States); Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, Athens 116-35 (Greece)

2015-11-21

Thermal modeling and numerical simulations have been performed to describe the ultrafast thermal response of band gap materials upon optical excitation. A model was established by extending the conventional two-temperature model that is adequate for metals, but not for semiconductors. It considers the time- and space-dependent density of electrons photoexcited to the conduction band and accordingly allows a more accurate description of the transient thermal equilibration between the hot electrons and lattice. Ultrafast thermal behaviors of bismuth, as a model system, were demonstrated using the extended two-temperature model with a view to elucidating the thermal effects of excitation laser pulse fluence, electron diffusivity, electron-hole recombination kinetics, and electron-phonon interactions, focusing on high-density excitation.

Extended Range Intercept Technology

Science.gov (United States)

1991-09-01

1988). Desert bighorn ewes with lambs show a stronger response than do groups of only rams, only ewes, or mixed groups of adults (Miller and Smith...1985). While all startle events may affect desert bighorns, those occurring during the lambing period (February-April) would represent the highest...35807 U.S. Army Pueblo Depot Activity SDSTE-PU-EE Pueblo, CO 81001-5000 U.S. Army White Sands Missile Range STEWS -EL-N White Sands, NM 88002-5076

Temperature dependence of thermal expansion of cadmium sulfide in the temperature range 20 - 820 K

International Nuclear Information System (INIS)

Oskotskij, V.S.; Kobyakov, I.B.; Solodukhin, A.V.

1980-01-01

The linear thermal expansion of cadmium sulfide is measured perpendicularly (α 1 ) and parallelly (α 2 ) to the hexagonal axis in the temperature range from 20 to 820 K. Anisotropy is low at up to 80 K; rises at higher temperatures; at 3OO K α 1 /α 3 ratio is 1.8; at 820 K, 2.4. Heat expansion is negative at temperatures lower than 104.5 K(α 1 ) and 126.0 K(α 2 ). It achieves the minimum at 43.6 K (α 1 ) and 52.5K (α 3 ). The theory of heat expansion is plotted in the Debue, approximation and cadmium sulfide is considered as an isotope crystal with average elastic constants. Two parameters of the theory are determined by the position and value of the minimum of volumetric thermal expansion of the model isotope crystal. The theoretic curve agrees well with the experimental one at temperatures up to 160 K, i.e in the range of applicability of the Debue approximation and the isotropic model

Finite temperature CPN-1 model and long range Neel order

International Nuclear Information System (INIS)

Ichinose, Ikuo; Yamamoto, Hisashi.

1989-09-01

We study in d space-dimensions the finite temperature behavior of long range Neel order (LRNO) in CP N-1 model as a low energy effective field theory of the antiferromagnetic Heisenberg model. For d≤1, or d≤2 at any nonzero temperature, LRNO disappears, in agreement with Mermin-Wagner-Coleman's theorem. For d=3 in the weak coupling region, LRNO exists below the critical temperature T N (Neel temperature). T N decreases as the interlayer coupling becomes relatively weak compared with that within Cu-O layers. (author)

Lattice Parameter of Polycrystalline Diamond in the Low-Temperature Range

International Nuclear Information System (INIS)

Paszkowicz, W.; Piszora, P.; Lasocha, W.; Margiolaki, I.; Brunelli, M.; Fitch, A.

2010-01-01

The lattice parameter for polycrystalline diamond is determined as a function of temperature in the 4-300 K temperature range. In the range studied, the lattice parameter, expressed in angstrom units, of the studied sample increases according to the equation a = 3.566810(12) + 6.37(41) x 10 -14 T 4 (approximately, from 3.5668 to 3.5673 A). This increase is larger than that earlier reported for pure single crystals. The observed dependence and the resulting thermal expansion coefficient are discussed on the basis of literature data reported for diamond single crystals and polycrystals. (authors)

Histogram Matching Extends Acceptable Signal Strength Range on Optical Coherence Tomography Images

Science.gov (United States)

Chen, Chieh-Li; Ishikawa, Hiroshi; Wollstein, Gadi; Bilonick, Richard A.; Sigal, Ian A.; Kagemann, Larry; Schuman, Joel S.

2015-01-01

Purpose. We minimized the influence of image quality variability, as measured by signal strength (SS), on optical coherence tomography (OCT) thickness measurements using the histogram matching (HM) method. Methods. We scanned 12 eyes from 12 healthy subjects with the Cirrus HD-OCT device to obtain a series of OCT images with a wide range of SS (maximal range, 1–10) at the same visit. For each eye, the histogram of an image with the highest SS (best image quality) was set as the reference. We applied HM to the images with lower SS by shaping the input histogram into the reference histogram. Retinal nerve fiber layer (RNFL) thickness was automatically measured before and after HM processing (defined as original and HM measurements), and compared to the device output (device measurements). Nonlinear mixed effects models were used to analyze the relationship between RNFL thickness and SS. In addition, the lowest tolerable SSs, which gave the RNFL thickness within the variability margin of manufacturer recommended SS range (6–10), were determined for device, original, and HM measurements. Results. The HM measurements showed less variability across a wide range of image quality than the original and device measurements (slope = 1.17 vs. 4.89 and 1.72 μm/SS, respectively). The lowest tolerable SS was successfully reduced to 4.5 after HM processing. Conclusions. The HM method successfully extended the acceptable SS range on OCT images. This would qualify more OCT images with low SS for clinical assessment, broadening the OCT application to a wider range of subjects. PMID:26066749

Extended-bandwidth frequency sweeps of a distributed feedback laser using combined injection current and temperature modulation.

Science.gov (United States)

Hefferman, Gerald; Chen, Zhen; Wei, Tao

2017-07-01

This article details the generation of an extended-bandwidth frequency sweep using a single, communication grade distributed feedback (DFB) laser. The frequency sweep is generated using a two-step technique. In the first step, injection current modulation is employed as a means of varying the output frequency of a DFB laser over a bandwidth of 99.26 GHz. A digital optical phase lock loop is used to lock the frequency sweep speed during current modulation, resulting in a linear frequency chirp. In the second step, the temperature of the DFB laser is modulated, resulting in a shifted starting laser output frequency. A laser frequency chirp is again generated beginning at this shifted starting frequency, resulting in a frequency-shifted spectrum relative to the first recorded data. This process is then repeated across a range of starting temperatures, resulting in a series of partially overlapping, frequency-shifted spectra. These spectra are then aligned using cross-correlation and combined using averaging to form a single, broadband spectrum with a total bandwidth of 510.9 GHz. In order to investigate the utility of this technique, experimental testing was performed in which the approach was used as the swept-frequency source of a coherent optical frequency domain reflectometry system. This system was used to interrogate an optical fiber containing a 20 point, 1-mm pitch length fiber Bragg grating, corresponding to a period of 100 GHz. Using this technique, both the periodicity of the grating in the frequency domain and the individual reflector elements of the structure in the time domain were resolved, demonstrating the technique's potential as a method of extending the sweeping bandwidth of semiconductor lasers for frequency-based sensing applications.

Extended-bandwidth frequency sweeps of a distributed feedback laser using combined injection current and temperature modulation

Science.gov (United States)

Hefferman, Gerald; Chen, Zhen; Wei, Tao

2017-07-01

This article details the generation of an extended-bandwidth frequency sweep using a single, communication grade distributed feedback (DFB) laser. The frequency sweep is generated using a two-step technique. In the first step, injection current modulation is employed as a means of varying the output frequency of a DFB laser over a bandwidth of 99.26 GHz. A digital optical phase lock loop is used to lock the frequency sweep speed during current modulation, resulting in a linear frequency chirp. In the second step, the temperature of the DFB laser is modulated, resulting in a shifted starting laser output frequency. A laser frequency chirp is again generated beginning at this shifted starting frequency, resulting in a frequency-shifted spectrum relative to the first recorded data. This process is then repeated across a range of starting temperatures, resulting in a series of partially overlapping, frequency-shifted spectra. These spectra are then aligned using cross-correlation and combined using averaging to form a single, broadband spectrum with a total bandwidth of 510.9 GHz. In order to investigate the utility of this technique, experimental testing was performed in which the approach was used as the swept-frequency source of a coherent optical frequency domain reflectometry system. This system was used to interrogate an optical fiber containing a 20 point, 1-mm pitch length fiber Bragg grating, corresponding to a period of 100 GHz. Using this technique, both the periodicity of the grating in the frequency domain and the individual reflector elements of the structure in the time domain were resolved, demonstrating the technique's potential as a method of extending the sweeping bandwidth of semiconductor lasers for frequency-based sensing applications.

Extended-Range Ultrarefractive 1D Photonic Crystal Prisms

Science.gov (United States)

Ting, David Z.

2007-01-01

A proposal has been made to exploit the special wavelength-dispersive characteristics of devices of the type described in One-Dimensional Photonic Crystal Superprisms (NPO-30232) NASA Tech Briefs, Vol. 29, No. 4 (April 2005), page 10a. A photonic crystal is an optical component that has a periodic structure comprising two dielectric materials with high dielectric contrast (e.g., a semiconductor and air), with geometrical feature sizes comparable to or smaller than light wavelengths of interest. Experimental superprisms have been realized as photonic crystals having three-dimensional (3D) structures comprising regions of amorphous Si alternating with regions of SiO2, fabricated in a complex process that included sputtering. A photonic crystal of the type to be exploited according to the present proposal is said to be one-dimensional (1D) because its contrasting dielectric materials would be stacked in parallel planar layers; in other words, there would be spatial periodicity in one dimension only. The processes of designing and fabricating 1D photonic crystal superprisms would be simpler and, hence, would cost less than do those for 3D photonic crystal superprisms. As in 3D structures, 1D photonic crystals may be used in applications such as wavelength-division multiplexing. In the extended-range configuration, it is also suitable for spectrometry applications. As an engineered structure or artificially engineered material, a photonic crystal can exhibit optical properties not commonly found in natural substances. Prior research had revealed several classes of photonic crystal structures for which the propagation of electromagnetic radiation is forbidden in certain frequency ranges, denoted photonic bandgaps. It had also been found that in narrow frequency bands just outside the photonic bandgaps, the angular wavelength dispersion of electromagnetic waves propagating in photonic crystal superprisms is much stronger than is the angular wavelength dispersion obtained

Disentangling neighbors and extended range density oscillations in monatomic amorphous semiconductors.

Science.gov (United States)

Roorda, S; Martin, C; Droui, M; Chicoine, M; Kazimirov, A; Kycia, S

2012-06-22

High energy x-ray diffraction measurements of pure amorphous Ge were made and its radial distribution function (RDF) was determined at high resolution, revealing new information on the atomic structure of amorphous semiconductors. Fine structure in the second peak in the RDF provides evidence that a fraction of third neighbors are closer than some second neighbors; taking this into account leads to a narrow distribution of tetrahedral bond angles, (8.5 ± 0.1)°. A small peak which appears near 5 Å upon thermal annealing shows that some ordering in the dihedral bond-angle distribution takes place during structural relaxation. Extended range order is detected (in both a-Ge and a-Si) which persists to beyond 20 Å, and both the periodicity and its decay length increase upon thermal annealing. Previously, the effect of structural relaxation was only detected at intermediate range, involving reduced tetrahedral bond-angle distortions. These results enhance our understanding of the atomic order in continuous random networks and place significantly more stringent requirements on computer models intending to describe these networks, or their alternatives which attempt to describe the structure in terms of an arrangement of paracrystals.

Extended Kalman filtering for continuous volumetric MR-temperature imaging.

Science.gov (United States)

Denis de Senneville, Baudouin; Roujol, Sébastien; Hey, Silke; Moonen, Chrit; Ries, Mario

2013-04-01

Real time magnetic resonance (MR) thermometry has evolved into the method of choice for the guidance of high-intensity focused ultrasound (HIFU) interventions. For this role, MR-thermometry should preferably have a high temporal and spatial resolution and allow observing the temperature over the entire targeted area and its vicinity with a high accuracy. In addition, the precision of real time MR-thermometry for therapy guidance is generally limited by the available signal-to-noise ratio (SNR) and the influence of physiological noise. MR-guided HIFU would benefit of the large coverage volumetric temperature maps, including characterization of volumetric heating trajectories as well as near- and far-field heating. In this paper, continuous volumetric MR-temperature monitoring was obtained as follows. The targeted area was continuously scanned during the heating process by a multi-slice sequence. Measured data and a priori knowledge of 3-D data derived from a forecast based on a physical model were combined using an extended Kalman filter (EKF). The proposed reconstruction improved the temperature measurement resolution and precision while maintaining guaranteed output accuracy. The method was evaluated experimentally ex vivo on a phantom, and in vivo on a porcine kidney, using HIFU heating. On the in vivo experiment, it allowed the reconstruction from a spatio-temporally under-sampled data set (with an update rate for each voxel of 1.143 s) to a 3-D dataset covering a field of view of 142.5×285×54 mm(3) with a voxel size of 3×3×6 mm(3) and a temporal resolution of 0.127 s. The method also provided noise reduction, while having a minimal impact on accuracy and latency.

Long-range correlations in rectal temperature fluctuations of healthy infants during maturation.

Directory of Open Access Journals (Sweden)

Georgette Stern

Full Text Available BACKGROUND: Control of breathing, heart rate, and body temperature are interdependent in infants, where instabilities in thermoregulation can contribute to apneas or even life-threatening events. Identifying abnormalities in thermoregulation is particularly important in the first 6 months of life, where autonomic regulation undergoes critical development. Fluctuations in body temperature have been shown to be sensitive to maturational stage as well as system failure in critically ill patients. We thus aimed to investigate the existence of fractal-like long-range correlations, indicative of temperature control, in night time rectal temperature (T(rec patterns in maturing infants. METHODOLOGY/PRINCIPAL FINDINGS: We measured T(rec fluctuations in infants every 4 weeks from 4 to 20 weeks of age and before and after immunization. Long-range correlations in the temperature series were quantified by the correlation exponent, alpha using detrended fluctuation analysis. The effects of maturation, room temperature, and immunization on the strength of correlation were investigated. We found that T(rec fluctuations exhibit fractal long-range correlations with a mean (SD alpha of 1.51 (0.11, indicating that T(rec is regulated in a highly correlated and hence deterministic manner. A significant increase in alpha with age from 1.42 (0.07 at 4 weeks to 1.58 (0.04 at 20 weeks reflects a change in long-range correlation behavior with maturation towards a smoother and more deterministic temperature regulation, potentially due to the decrease in surface area to body weight ratio in the maturing infant. alpha was not associated with mean room temperature or influenced by immunization CONCLUSIONS: This study shows that the quantification of long-range correlations using alpha derived from detrended fluctuation analysis is an observer-independent tool which can distinguish developmental stages of night time T(rec pattern in young infants, reflective of maturation of

Thermotaxis of human sperm cells in extraordinarily shallow temperature gradients over a wide range.

Directory of Open Access Journals (Sweden)

Anat Bahat

Full Text Available On the basis of the finding that capacitated (ready to fertilize rabbit and human spermatozoa swim towards warmer temperatures by directing their movement along a temperature gradient, sperm thermotaxis has been proposed to be one of the processes guiding these spermatozoa to the fertilization site. Although the molecular mechanism underlying sperm thermotaxis is gradually being revealed, basic questions related to this process are still open. Here, employing human spermatozoa, we addressed the questions of how wide the temperature range of thermotaxis is, whether this range includes an optimal temperature or whether spermatozoa generally prefer swimming towards warmer temperatures, whether or not they can sense and respond to descending temperature gradients, and what the minimal temperature gradient is to which they can thermotactically respond. We found that human spermatozoa can respond thermotactically within a wide temperature range (at least 29-41°C, that within this range they preferentially accumulate in warmer temperatures rather than at a single specific, preferred temperature, that they can respond to both ascending and descending temperature gradients, and that they can sense and thermotactically respond to temperature gradients as low as <0.014°C/mm. This temperature gradient is astonishingly low because it means that as a spermatozoon swims through its entire body length (46 µm it can sense and respond to a temperature difference of <0.0006°C. The significance of this surprisingly high temperature sensitivity is discussed.

Extending the Effective Ranging Depth of Spectral Domain Optical Coherence Tomography by Spatial Frequency Domain Multiplexing

Directory of Open Access Journals (Sweden)

Tong Wu

2016-11-01

Full Text Available We present a spatial frequency domain multiplexing method for extending the imaging depth range of a spectral domain optical coherence tomography (SDOCT system without any expensive device. This method uses two galvo scanners with different pivot-offset distances in two independent reference arms for spatial frequency modulation and multiplexing. The spatial frequency contents corresponding to different depth regions of the sample can be shifted to different frequency bands. The spatial frequency domain multiplexing SDOCT system provides an approximately 1.9-fold increase in the effective ranging depth compared with that of a conventional full-range SDOCT system. The reconstructed images of phantom and biological tissue demonstrate the expected increase in ranging depth. The parameters choice criterion for this method is discussed.

Scattering from extended targets in range-dependent fluctuating ocean-waveguides with clutter from theory and experiments.

Science.gov (United States)

Jagannathan, Srinivasan; Küsel, Elizabeth T; Ratilal, Purnima; Makris, Nicholas C

2012-08-01

Bistatic, long-range measurements of acoustic scattered returns from vertically extended, air-filled tubular targets were made during three distinct field experiments in fluctuating continental shelf waveguides. It is shown that Sonar Equation estimates of mean target-scattered intensity lead to large errors, differing by an order of magnitude from both the measurements and waveguide scattering theory. The use of the Ingenito scattering model is also shown to lead to significant errors in estimating mean target-scattered intensity in the field experiments because they were conducted in range-dependent ocean environments with large variations in sound speed structure over the depth of the targets, scenarios that violate basic assumptions of the Ingenito model. Green's theorem based full-field modeling that describes scattering from vertically extended tubular targets in range-dependent ocean waveguides by taking into account nonuniform sound speed structure over the target's depth extent is shown to accurately describe the statistics of the targets' scattered field in all three field experiments. Returns from the man-made targets are also shown to have a very different spectral dependence from the natural target-like clutter of the dominant fish schools observed, suggesting that judicious multi-frequency sensing may often provide a useful means of distinguishing fish from man-made targets.

Design of an extended range long counter using super Monte Carlo simulation

International Nuclear Information System (INIS)

Mazunga, Mohamed; Li, Taosheng; Li, Yanan; Hong, Bing; Wang, Yongfeng; Ji, Xiang

2017-01-01

We have designed an extended range neutron long counter on the basis of work optimized using SuperMC code. The problem of the existing traditional long counters is that their response function falls rapidly above 5 MeV. We proposed a new designed by adding two layers of converter material inside the polyethylene moderator. The relatively low density chromium and high density lead metals convert high energy neutron by (n, xn) spallation reaction. This produces more neutrons of lower energies, which have higher probability of being detected by thermal 3 He-counter. The response function at lower neutron energies was improved by inserting small polyethylene cylinder in front of 3 He counter. In this design we achieved to extent the flat response function of the long counter from few keV up to 150 MeV. The total fluctuation of response curve is less than ±9% over the entire energy range. The designed long counter is suitable to be used as neutron monitor for monitoring neutron fluence at high-energy neutron source. (authors)

Tuning thermal conduction via extended defects in graphene

Science.gov (United States)

Huang, Huaqing; Xu, Yong; Zou, Xiaolong; Wu, Jian; Duan, Wenhui

2013-05-01

Designing materials for desired thermal conduction can be achieved via extended defects. We theoretically demonstrate the concept by investigating thermal transport in graphene nanoribbons (GNRs) with the extended line defects observed by recent experiments. Our nonequilibrium Green's function study excluding phonon-phonon interactions finds that thermal conductance can be tuned over wide ranges (more than 50% at room temperature), by controlling the orientation and the bond configuration of the embedded extended defect. Further transmission analysis reveals that the thermal-conduction tuning is attributed to two fundamentally different mechanisms, via modifying the phonon dispersion and/or tailoring the strength of defect scattering. The finding, applicable to other materials, provides useful guidance for designing materials with desired thermal conduction.

Extended-range forecast for the temporal distribution of clustering tropical cyclogenesis over the western North Pacific

Science.gov (United States)

Zhu, Zhiwei; Li, Tim; Bai, Long; Gao, Jianyun

2017-11-01

Based on outgoing longwave radiation (OLR), an index for clustering tropical cyclogenesis (CTC) over the western North Pacific (WNP) was defined. Around 76 % of total CTC events were generated during the active phase of the CTC index, and 38 % of the total active phase was concurrent with CTC events. For its continuous property, the CTC index was used as the representative predictand for extended-range forecasting the temporal distribution of CTC events. The predictability sources for CTC events were detected via correlation analyses of the previous 35-5-day lead atmospheric fields against the CTC index. The results showed that the geopotential height at different levels and the 200 hPa zonal wind over the global tropics possessed large predictability sources, whereas the predictability sources of other variables, e.g., OLR, zonal wind, and relatively vorticity at 850 hPa and relatively humility at 700 hPa, were mainly confined to the tropical Indian Ocean and western Pacific Ocean. Several spatial-temporal projection model (STPM) sets were constructed to carry out the extended-range forecast for the CTC index. By combining the output of STPMs separately conducted for the two dominant modes of intraseasonal variability, e.g., the 10-30 and the 30-80 day mode, useful forecast skill could be achieved for a 30-day lead time. The combined output successfully captured both the 10-30 and 30-80 day mode at least 10 days in advance. With a relatively low rate of false alarm, the STPM achieved hits for 80 % (69 %) of 54 CTC events during 2003-2014 at the 10-day (20-day) lead time, suggesting a practical value of the STPM for real-time forecasting WNP CTC events at an extended range.

Transducer-based fiber Bragg grating high-temperature sensor with enhanced range and stability

Science.gov (United States)

Mamidi, Venkata Reddy; Kamineni, Srimannarayana; Ravinuthala, Lakshmi Narayana Sai Prasad; Tumu, Venkatappa Rao

2017-09-01

Fiber Bragg grating (FBG)-based high-temperature sensor with enhanced-temperature range and stability has been developed and tested. The sensor consists of an FBG and a mechanical transducer, which furnishes a linear temperature-dependent tensile strain on FBG by means of differential linear thermal expansion of two different ceramic materials. The designed sensor is tested over a range: 20°C to 1160°C and is expected to measure up to 1500°C.

The influence of diurnal temperature range on the incidence of respiratory syncytial virus in Japan.

Science.gov (United States)

Onozuka, D

2015-03-01

The incidence of respiratory syncytial virus (RSV) has been reported to exhibit seasonal variation. However, the impact of diurnal temperature range (DTR) on RSV has not been investigated. After acquiring data related to cases of RSV and weather parameters of DTR in Fukuoka, Japan, between 2006 and 2012, we used negative binomial generalized linear models and distributed lag nonlinear models to assess the possible relationship between DTR and RSV cases, adjusting for confounding factors. Our analysis revealed that the weekly number of RSV cases increased with a relative risk of 3·30 (95% confidence interval 1·65-6·60) for every 1°C increase in DTR. Our study provides quantitative evidence that the number of RSV cases increased significantly with increasing DTR. We suggest that preventive measures for limiting the spread of RSV should be considered during extended periods of high DTR.

Analysis of stable components in the extended-range forecast for the coming 10–30 days in winter 2010 and 2011

International Nuclear Information System (INIS)

Wang Kuo; Zeng Yu-Xing; Wang Xu-Jia; Feng Guo-Lin

2013-01-01

In this paper we try to extract stable components in the extended-range forecast for the coming 10–30 days by using empirical orthogonal function (EOF) analysis, similarity coefficient, and some other methods based on the National Center for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR) reanalysis daily data. The comparisons of the coefficient of variance of climatological background field and truth data in winter between 2010 and 2011 are made. The method of extracting stable components and climatological background field can be helpful to increase forecasting skill. The forecasting skill improvement of air temperature is better than geopotential height at 500 hPa. Moreover, this method improves the predictability better in the Pacific Ocean. In China, the forecast in winter in Northeast China is more uncertain than in the other parts. (geophysics, astronomy, and astrophysics)

Improvement of Surface Temperature Prediction Using SVR with MOGREPS Data for Short and Medium range over South Korea

Science.gov (United States)

Lim, S. J.; Choi, R. K.; Ahn, K. D.; Ha, J. C.; Cho, C. H.

2014-12-01

As the Korea Meteorology Administration (KMA) has operated Met Office Global and Regional Ensemble Prediction System (MOGREPS) with introduction of Unified Model (UM), many attempts have been made to improve predictability in temperature forecast in last years. In this study, post-processing method of MOGREPS for surface temperature prediction is developed with machine learning over 52 locations in South Korea. Past 60-day lag time was used as a training phase of Support Vector Regression (SVR) method for surface temperature forecast model. The selected inputs for SVR are followings: date and surface temperatures from Numerical Weather prediction (NWP), such as GDAPS, individual 24 ensemble members, mean and median of ensemble members for every 3hours for 12 days.To verify the reliability of SVR-based ensemble prediction (SVR-EP), 93 days are used (from March 1 to May 31, 2014). The result yielded improvement of SVR-EP by RMSE value of 16 % throughout entire prediction period against conventional ensemble prediction (EP). In particular, short range predictability of SVR-EP resulted in 18.7% better RMSE for 1~3 day forecast. The mean temperature bias between SVR-EP and EP at all test locations showed around 0.36°C and 1.36°C, respectively. SVR-EP is currently extending for more vigorous sensitivity test, such as increasing training phase and optimizing machine learning model.

Comparison of different extenders and storage temperature on the ...

African Journals Online (AJOL)

Semen was pooled and randomly allocated to four groups and diluted at a ratio of 1:1 (v/v) with Beltsville thawing solution (BTS), Kobidil+, egg yolk citrate (EYC) and non-extended semen (Control). Each extender had two similar semen samples, making a total of eight samples. Extended and non-extended semen were ...

Validation of Core Temperature Estimation Algorithm

Science.gov (United States)

2016-01-20

based on an extended Kalman filter , which was developed using field data from 17 young male U.S. Army soldiers with core temperatures ranging from...CTstart, v) %KFMODEL estimate core temperature from heart rate with Kalman filter % This version supports both batch mode (operate on entire HR time...CTstart = 37.1; % degrees Celsius end if nargin < 3 v = 0; end %Extended Kalman Filter Parameters a = 1; gamma = 0.022^2; b_0 = -7887.1; b_1

Extended exposure to elevated temperature affects escape response behaviour in coral reef fishes

Directory of Open Access Journals (Sweden)

Donald T. Warren

2017-08-01

Full Text Available The threat of predation, and the prey’s response, are important drivers of community dynamics. Yet environmental temperature can have a significant effect on predation avoidance techniques such as fast-start performance observed in marine fishes. While it is known that temperature increases can influence performance and behaviour in the short-term, little is known about how species respond to extended exposure during development. We produced a startle response in two species of damselfish, the lemon damsel Pomacentrus moluccensis, and the Ambon damselfish Pomacentrus amboinensis, by the repeated use of a drop stimulus. We show that the length of thermal exposure of juveniles to elevated temperature significantly affects this escape responses. Short-term (4d exposure to warmer temperature affected directionality and responsiveness for both species. After long-term (90d exposure, only P. moluccensis showed beneficial plasticity, with directionality returning to control levels. Responsiveness also decreased in both species, possibly to compensate for higher temperatures. There was no effect of temperature or length of exposure on latency to react, maximum swimming speed, or escape distance suggesting that the physical ability to escape was maintained. Evidence suggests that elevated temperature may impact some fish species through its effect on the behavioural responses while under threat rather than having a direct influence on their physical ability to perform an effective escape response.

Extending the range and performance of non-line-of-sight ultraviolet communication links

Science.gov (United States)

Shaw, Gary A.; Siegel, Andrew M.; Model, Joshua

2006-05-01

This paper describes recent advances in the technology for, and implementation of, short-range non-line-of-sight (NLOS) optical communication links. The approach relies on molecular scattering of ultraviolet wavelengths by the atmosphere to achieve NLOS, omni-directional communication Links. The implementation employs commercially produced semiconductor sources emitting in the solar-blind region of the UV spectrum, around 275nm. This paper extends previously reported field measurements to longer ranges (100+m) and to a wider variety of application scenarios, including an outdoor demonstration of real-time speech at 2.4kbps in full sunlight. The paper also addresses the design trades associated with replacing photomultiplier detectors with semiconductor detectors for reasons of cost and ruggedness. Even with improvements in semiconductor materials and commensurate reduction in dark currents, the use of semiconductor detectors will require the introduction of imaging arrays. Incorporation of imaging arrays opens the possibility of adaptive links in which bandwidth and transmit power are adapted to best exploit the channel constraints.

The long-range correlation and evolution law of centennial-scale temperatures in Northeast China.

Science.gov (United States)

Zheng, Xiaohui; Lian, Yi; Wang, Qiguang

2018-01-01

This paper applies the detrended fluctuation analysis (DFA) method to investigate the long-range correlation of monthly mean temperatures from three typical measurement stations at Harbin, Changchun, and Shenyang in Northeast China from 1909 to 2014. The results reveal the memory characteristics of the climate system in this region. By comparing the temperatures from different time periods and investigating the variations of its scaling exponents at the three stations during these different time periods, we found that the monthly mean temperature has long-range correlation, which indicates that the temperature in Northeast China has long-term memory and good predictability. The monthly time series of temperatures over the past 106 years also shows good long-range correlation characteristics. These characteristics are also obviously observed in the annual mean temperature time series. Finally, we separated the centennial-length temperature time series into two time periods. These results reveal that the long-range correlations at the Harbin station over these two time periods have large variations, whereas no obvious variations are observed at the other two stations. This indicates that warming affects the regional climate system's predictability differently at different time periods. The research results can provide a quantitative reference point for regional climate predictability assessment and future climate model evaluation.

HEPS4Power - Extended-range Hydrometeorological Ensemble Predictions for Improved Hydropower Operations and Revenues

Science.gov (United States)

Bogner, Konrad; Monhart, Samuel; Liniger, Mark; Spririg, Christoph; Jordan, Fred; Zappa, Massimiliano

2015-04-01

In recent years large progresses have been achieved in the operational prediction of floods and hydrological drought with up to ten days lead time. Both the public and the private sectors are currently using probabilistic runoff forecast in order to monitoring water resources and take actions when critical conditions are to be expected. The use of extended-range predictions with lead times exceeding 10 days is not yet established. The hydropower sector in particular might have large benefits from using hydro meteorological forecasts for the next 15 to 60 days in order to optimize the operations and the revenues from their watersheds, dams, captions, turbines and pumps. The new Swiss Competence Centers in Energy Research (SCCER) targets at boosting research related to energy issues in Switzerland. The objective of HEPS4POWER is to demonstrate that operational extended-range hydro meteorological forecasts have the potential to become very valuable tools for fine tuning the production of energy from hydropower systems. The project team covers a specific system-oriented value chain starting from the collection and forecast of meteorological data (MeteoSwiss), leading to the operational application of state-of-the-art hydrological models (WSL) and terminating with the experience in data presentation and power production forecasts for end-users (e-dric.ch). The first task of the HEPS4POWER will be the downscaling and post-processing of ensemble extended-range meteorological forecasts (EPS). The goal is to provide well-tailored forecasts of probabilistic nature that should be reliable in statistical and localized at catchment or even station level. The hydrology related task will consist in feeding the post-processed meteorological forecasts into a HEPS using a multi-model approach by implementing models with different complexity. Also in the case of the hydrological ensemble predictions, post-processing techniques need to be tested in order to improve the quality of the

Measurements of short-range ordering in Ni3Al

International Nuclear Information System (INIS)

Okamoto, J.K.; Ahn, C.C.

1992-01-01

This paper reports on extended electron energy-loss fine structure (EXELFS) that has been used to measure short-range ordering in Ni 3 Al. Films of fcc Ni 3 Al with suppressed short-range order synthesized by vacuum evaporation of Ni 3 Al onto room temperature substrates. EXELFS data were taken from both Al K and Ni L 23 edges. The development of short-range order was observed after the samples were annealed for various times at temperatures below 350 degrees C. Upon comparison with ab initio planewave EXELFS calculations, it was found that the Warren-Cowley short-range order parameter a(1nn) changed by about -0.1 after 210 minutes of annealing at 150 degrees C

Low Friction and Wear Surface for Application over a Wide Range of Temperature

National Research Council Canada - National Science Library

Bhattacharya, Rabi

1997-01-01

...) and Transmission electron microscopy (TEM), both before and after exposure to high temperatures (up to 700 deg C) in air. Friction measurements were performed at temperatures in the range of room temperature to 700 deg C in air...

First operation of an extended range grasshopper monochromator on the Aladdin storage ring

International Nuclear Information System (INIS)

Brown, F.C.

1986-01-01

First operation of a new extended range monochromator on the 1 GeV storage ring Aladdin is described. Curves are given of output flux as a function of photon energy for the 2 m and for the 5 m gratings as measured with an NBS diode. Relatively low background and flux up to 1500 eV is obtained using a 1200 line/mm 5 m holographic grating. Highly reproducible scans were obtained of the transmission of thin films including the carbon K and titanium L edges. This reproducibility and high throughput is in large part due to the small beam size and excellent stability of Aladdin. (orig.)

Extended Holstein-Primakoff mapping for the next-to-leading order of the 1/N expansion at finite temperature

International Nuclear Information System (INIS)

Dzhioev, Alan; Storozhenko, A.; Vdovin, A.; Aouissat, Z.; Wambach, J.

2004-01-01

An extended Holstein-Primakoff mapping which incorporates both single- and double-fermion mappings is used in the context of thermofield dynamics to study the next-to-leading order of the 1/N expansion at finite temperature. For the Lipkin-Meshkov-Glick model it is shown that the extended mapping naturally leads to the correct Fermi statistics both in leading and next-to-leading order

Extended storage of gamma-irradiated mango at tropical ambient temperature by film wrap packaging

International Nuclear Information System (INIS)

Janave, Machhindra T.; Sharma, A.

2005-01-01

Low dose gamma-irradiation of pre-climacteric mango (Mangifera indica L var.'Alphonso') fruits at 100 Gy extended the shelf-life at ambient temperature (28-32 degC) by 5-6 days. The extension of shelf-life was dose dependent, maximum being at 200 Gy by about 8-10 days. Wrapping the fruits in food grade Klin Wrap film resulted in more number of fruits remaining in semiripe condition after 21 days of storage as revealed by colour of the fruits, texture, TSS, pH, acidity and vitamin C content. The fruits retained about 40% of chlorophyll however, unwrapped fruits were complete yellow. Physiological weight loss (PWL) was reduced by 50% in Klin film wrapped fruits as compared to that in unwrapped fruits. More than 70-80% fruits remained as marketable fruits at the end of experiment when control fruits were slightly overripe. The shelf-life in Klin film wrapped irradiated mangoes was extended by about 10-15 days over irradiated unwrapped fruits resulting in total shelf-life of about 25-30 days at room temperature. In mangoes of variety 'Dasheri', gamma-irradiation extended the shelf-life by 4-5 days, which could be increased further, by another 7-10 days by Klin wrap packaging. These fruits also remained green at the end of experiment, confirming the observations with 'Alphonso' mango. These results show that low dose gamma-irradiation in combination with Klin film packaging delayed ripening as indicated by higher retention of fruit colour and reduction of PWL. (author)

Reliable Multicast MAC Protocol for IEEE 802.11 Wireless LANs with Extended Service Range

Science.gov (United States)

Choi, Woo-Yong

2011-11-01

In this paper, we propose the efficient reliable multicast MAC protocol by which the AP (Access Point) can transmit reliably its multicast data frames to the recipients in the AP's one-hop or two-hop transmission range. The AP uses the STAs (Stations) that are directly associated with itself as the relays for the data delivery to the remote recipients that cannot be reached directly from itself. Based on the connectivity information among the recipients, the reliable multicast MAC protocol optimizes the number of the RAK (Request for ACK) frame transmissions in a reasonable computational time. Numerical examples show that our proposed MAC protocol significantly enhances the MAC performance compared with the BMMM (Batch Mode Multicast MAC) protocol that is extended to support the recipients that are in the AP's one-hop or two-hop transmission range in IEEE 802.11 wireless LANs.

Dielectric relaxation in solid collagen over a wide temperature range

International Nuclear Information System (INIS)

Khan, Muhammad Abdullah; Rizvi, Tasneem Zahra; Janjua, Khalid Mehmood; Zaheer, Muhammad Yar

2001-07-01

Dielectric constant ε' and loss factor ε'' have been measured in bovine tendon collagen in the frequency range 30 Hz - 3 MHz and temperature range 30 deg. C to 200 deg. C. Frequency dependence curve of ε'' shows a low frequency strong α-dispersion attributed to phonon assisted proton hopping between localized sites and a weak high frequency. α 2 - dispersion attributed to reorientation of polar components of collagen molecules. Temperature dependence of the dielectric data show release of bound moisture as a three step process with discrete peaks at 50 deg. C, 90 deg. C and 125 deg. C. These peaks have been attributed to release of adsorbed surface water, water bound to exposed polar sites and strongly bound internal moisture respectively. A peak observed at 160 deg. C has been attributed to thermally induced helix-coil transition of collagen molecules. (author)

Associations of day-to-day temperature change and diurnal temperature range with out-of-hospital cardiac arrest.

Science.gov (United States)

Onozuka, Daisuke; Hagihara, Akihito

2017-01-01

Background Although the impacts of temperature on mortality and morbidity have been documented, few studies have investigated whether day-to-day temperature change and diurnal temperature range (DTR) are independent risk factors for out-of-hospital cardiac arrest (OHCA). Design This was a prospective, population-based, observational study. Methods We obtained all OHCA data from 2005-2013 from six major prefectures in Japan: Hokkaido, Tokyo, Kanagawa, Aichi, Kyoto, and Osaka. We used a quasi-Poisson regression analysis with a distributed-lag non-linear model to assess the associations of day-to-day temperature change and DTR with OHCA for each prefecture. Results In total, 271,698 OHCAs of presumed cardiac origin were reported during the study period. There was a significant increase in the risk of OHCA associated with cold temperature in five prefectures, with relative risks (RRs) ranging from 1.298 (95% confidence interval (CI) 1.022-1.649) in Hokkaido to 3.893 (95% CI 1.713-8.845) in Kyoto. DTR was adversely associated with OHCA on hot days in Aichi (RR 1.158; 95% CI 1.028-1.304) and on cold days in Tokyo (RR 1.030; 95% CI 1.000-1.060), Kanagawa (RR 1.042; 95% CI 1.005-1.082), Kyoto (RR 1.060; 95% CI 1.001-1.122), and Osaka (RR 1.050; 95% CI 1.014-1.088), whereas there was no significant association between day-to-day temperature change and OHCA. Conclusion We found that associations between day-to-day temperature change and DTR and OHCA were generally small compared with the association with mean temperature. Our findings suggest that preventative measures for temperature-related OHCA may be more effective when focused on mean temperature and DTR.

Changes in diurnal temperature range and national cereal yields

Energy Technology Data Exchange (ETDEWEB)

Lobell, D

2007-04-26

Models of yield responses to temperature change have often considered only changes in average temperature (Tavg), with the implicit assumption that changes in the diurnal temperature range (DTR) can safely be ignored. The goal of this study was to evaluate this assumption using a combination of historical datasets and climate model projections. Data on national crop yields for 1961-2002 in the 10 leading producers of wheat, rice, and maize were combined with datasets on climate and crop locations to evaluate the empirical relationships between Tavg, DTR, and crop yields. In several rice and maize growing regions, including the two major nations for each crop, there was a clear negative response of yields to increased DTR. This finding reflects a nonlinear response of yields to temperature, which likely results from greater water and heat stress during hot days. In many other cases, the effects of DTR were not statistically significant, in part because correlations of DTR with other climate variables and the relatively short length of the time series resulted in wide confidence intervals for the estimates. To evaluate whether future changes in DTR are relevant to crop impact assessments, yield responses to projected changes in Tavg and DTR by 2046-2065 from 11 climate models were estimated. The mean climate model projections indicated an increase in DTR in most seasons and locations where wheat is grown, mixed projections for maize, and a general decrease in DTR for rice. These mean projections were associated with wide ranges that included zero in nearly all cases. The estimated impacts of DTR changes on yields were generally small (<5% change in yields) relative to the consistently negative impact of projected warming of Tavg. However, DTR changes did significantly affect yield responses in several cases, such as in reducing US maize yields and increasing India rice yields. Because DTR projections tend to be positively correlated with Tavg, estimates of yields

Extending the range of real time density matrix renormalization group simulations

Science.gov (United States)

Kennes, D. M.; Karrasch, C.

2016-03-01

We discuss a few simple modifications to time-dependent density matrix renormalization group (DMRG) algorithms which allow to access larger time scales. We specifically aim at beginners and present practical aspects of how to implement these modifications within any standard matrix product state (MPS) based formulation of the method. Most importantly, we show how to 'combine' the Schrödinger and Heisenberg time evolutions of arbitrary pure states | ψ 〉 and operators A in the evaluation of 〈A〉ψ(t) = 〈 ψ | A(t) | ψ 〉 . This includes quantum quenches. The generalization to (non-)thermal mixed state dynamics 〈A〉ρ(t) =Tr [ ρA(t) ] induced by an initial density matrix ρ is straightforward. In the context of linear response (ground state or finite temperature T > 0) correlation functions, one can extend the simulation time by a factor of two by 'exploiting time translation invariance', which is efficiently implementable within MPS DMRG. We present a simple analytic argument for why a recently-introduced disentangler succeeds in reducing the effort of time-dependent simulations at T > 0. Finally, we advocate the python programming language as an elegant option for beginners to set up a DMRG code.

Relationship between Magnetic Anisotropy below Pseudogap Temperature and Short-Range Antiferromagnetic Order in High-Temperature Cuprate Superconductor

Science.gov (United States)

Morinari, Takao

2018-06-01

The central issue in high-temperature cuprate superconductors is the pseudogap state appearing below the pseudogap temperature T*, which is well above the superconducting transition temperature. In this study, we theoretically investigate the rapid increase of the magnetic anisotropy below the pseudogap temperature detected by the recent torque-magnetometry measurements on YBa2Cu3Oy [Y. Sato et al., 10.1038/nphys4205" xlink:type="simple">Nat. Phys. 13, 1074 (2017)]. Applying the spin Green's function formalism including the Dzyaloshinskii-Moriya interaction arising from the buckling of the CuO2 plane, we obtain results that are in good agreement with the experiment and find a scaling relationship. Our analysis suggests that the characteristic temperature associated with the magnetic anisotropy, which coincides with T*, is not a phase transition temperature but a crossover temperature associated with the short-range antiferromagnetic order.

Extended Kalman Filtering to estimate temperature and irradiation for maximum power point tracking of a photovoltaic module

International Nuclear Information System (INIS)

Docimo, D.J.; Ghanaatpishe, M.; Mamun, A.

2017-01-01

This paper develops an algorithm for estimating photovoltaic (PV) module temperature and effective irradiation level. The power output of a PV system depends directly on both of these states. Estimating the temperature and irradiation allows for improved state-based control methods while eliminating the need of additional sensors. Thermal models and irradiation estimators have been developed in the literature, but none incorporate feedback for estimation. This paper outlines an Extended Kalman Filter for temperature and irradiation estimation. These estimates are, in turn, used within a novel state-based controller that tracks the maximum power point of the PV system. Simulation results indicate this state-based controller provides up to an 8.5% increase in energy produced per day as compared to an impedance matching controller. A sensitivity analysis is provided to examine the impact state estimate errors have on the ability to find the optimal operating point of the PV system. - Highlights: • Developed a temperature and irradiation estimator for photovoltaic systems. • Designed an Extended Kalman Filter to handle model and measurement uncertainty. • Developed a state-based controller for maximum power point tracking (MPPT). • Validated combined estimator/controller algorithm for different weather conditions. • Algorithm increases energy captured up to 8.5% over traditional MPPT algorithms.

Long-term temperature trends and variability on Spitsbergen: the extended Svalbard Airport temperature series, 1898–2012

Directory of Open Access Journals (Sweden)

Øyvind Nordli

2014-01-01

Full Text Available One of the few long instrumental records available for the Arctic is the Svalbard Airport composite series that hitherto began in 1911, with observations made on Spitsbergen, the largest island in the Svalbard Archipelago. This record has now been extended to 1898 with the inclusion of observations made by hunting and scientific expeditions. Temperature has been observed almost continuously in Svalbard since 1898, although at different sites. It has therefore been possible to create one composite series for Svalbard Airport covering the period 1898–2012, and this valuable new record is presented here. The series reveals large temperature variability on Spitsbergen, with the early 20th century warming as one striking feature: an abrupt change from the cold 1910s to the local maxima of the 1930s and 1950s. With the inclusion of the new data it is possible to show that the 1910s were colder than the years at the start of the series. From the 1960s, temperatures have increased, so the present temperature level is significantly higher than at any earlier period in the instrumental history. For the entire period, and for all seasons, there are positive, statistically significant trends. Regarding the annual mean, the total trend is 2.6°C/century, whereas the largest trend is in spring, at 3.9°C/century. In Europe, it is the Svalbard Archipelago that has experienced the greatest temperature increase during the latest three decades. The composite series may be downloaded from the home page of the Norwegian Meteorological Institute and should be used with reference to the present article.

Passive Wireless Temperature Sensors with Enhanced Sensitivity and Range, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — This proposal describes the development of passive surface acoustic wave (SAW) temperature sensors with enhanced sensitivity and detection range for NASA application...

Determination of plant growth rate and growth temperature range from measurement of physiological parameters

Science.gov (United States)

R. S. Criddle; B. N. Smith; L. D. Hansen; J. N. Church

2001-01-01

Many factors influence species range and diversity, but temperature and temperature variability are always major global determinants, irrespective of local constraints. On a global scale, the ranges of many taxa have been observed to increase and their diversity decrease with increasing latitude. On a local scale, gradients in species distribution are observable with...

A wide temperature range irradiation cryostat for reasearch on solid state targets

Energy Technology Data Exchange (ETDEWEB)

Reeve, Scott; Dutz, Hartmut; Goertz, Stefan; Runkel, Stefan; Voge, Thomas [Physikalisches Institut, Universitaet Bonn (Germany)

2012-07-01

To qualitatively improve the data obtained in asymmetry measurements of scattering experiments the figure of merit (FOM) plays a major role and can reduce the data acquisition time when a certain precision in the measurement is needed. One of the defining factors for the improvement of the polarised experiment lies in the target choice and preparation, in particular the method employed to introduce the paramagnetic defects for the use of dynamic nuclear polarisation (DNP). To this end the Polarized Target Group in Bonn has developed a wide range temperature cryostat for the irradiation of potential target materials in which materials can be irradiated to varying doses at specified temperatures. The stable irradiation temperature of the materials can be controlled to within {+-}1 K over a range of 90 K

Extending the upper temperature range of gas chromatography with all-silicon microchip columns using a heater/clamp assembly.

Science.gov (United States)

Ghosh, Abhijit; Johnson, Jacob E; Nuss, Johnathan G; Stark, Brittany A; Hawkins, Aaron R; Tolley, Luke T; Iverson, Brian D; Tolley, H Dennis; Lee, Milton L

2017-09-29

Miniaturization of gas chromatography (GC) instrumentation is of interest because it addresses current and future issues relating to compactness, portability and field application. While incremental advancements continue to be reported in GC with columns fabricated in microchips (referred to in this paper as "microchip columns"), the current performance is far from acceptable. This lower performance compared to conventional GC is due to factors such as pooling of the stationary phase in corners of non-cylindrical channels, adsorption of sensitive compounds on incompletely deactivated surfaces, shorter column lengths and less than optimum interfacing to injector and detector. In this work, a GC system utilizing microchip columns was developed that solves the latter challenge, i.e., microchip interfacing to injector and detector. A microchip compression clamp was constructed to heat the microchip (i.e., primary heater), and seal the injector and detector fused silica interface tubing to the inlet and outlet ports of the microchip channels with minimum extra-column dead volume. This clamp allowed occasional operation up to 375°C and routine operation up to 300°C. The compression clamp was constructed of a low expansion alloy, Kovar™, to minimize leaking due to thermal expansion mismatch at the interface during repeated thermal cycling, and it was tested over several months for more than one hundred injections without forming leaks. A 5.9m long microcolumn with rectangular cross section of 158μm×80μm, which approximately matches a 100μm i.d. cylindrical fused silica column, was fabricated in a silicon wafer using deep reactive ion etching (DRIE) and high temperature fusion bonding; finally, the channel was coated statically with a 1% vinyl, 5% phenyl, 94% methylpolysiloxane stationary phase. High temperature separations of C10-C40 n-alkanes and a commercial diesel sample were demonstrated using the system under both temperature programmed GC (TPGC) and thermal

Effects of air-sea interaction on extended-range prediction of geopotential height at 500 hPa over the northern extratropical region

Science.gov (United States)

Wang, Xujia; Zheng, Zhihai; Feng, Guolin

2018-04-01

The contribution of air-sea interaction on the extended-range prediction of geopotential height at 500 hPa in the northern extratropical region has been analyzed with a coupled model form Beijing Climate Center and its atmospheric components. Under the assumption of the perfect model, the extended-range prediction skill was evaluated by anomaly correlation coefficient (ACC), root mean square error (RMSE), and signal-to-noise ratio (SNR). The coupled model has a better prediction skill than its atmospheric model, especially, the air-sea interaction in July made a greater contribution for the improvement of prediction skill than other months. The prediction skill of the extratropical region in the coupled model reaches 16-18 days in all months, while the atmospheric model reaches 10-11 days in January, April, and July and only 7-8 days in October, indicating that the air-sea interaction can extend the prediction skill of the atmospheric model by about 1 week. The errors of both the coupled model and the atmospheric model reach saturation in about 20 days, suggesting that the predictable range is less than 3 weeks.

Responses of conventional and extended-range neutron detectors in mixed radiation fields around a 150-MeV electron LINAC

International Nuclear Information System (INIS)

Lin, Yu-Chi; Sheu, Rong-Jiun; Chen, Ang-Yu

2015-01-01

This study analyzed the responses of two types of neutron detector in mixed gamma-ray and neutron radiation fields around a 150-MeV electron linear accelerator (LINAC). The detectors were self-assembled, high efficiency, and designed in two configurations: (1) a conventional moderated-type neutron detector based on a large cylindrical He-3 proportional counter; and (2) an extended-range version with an embedded layer of lead in the moderator to increase the detector’s sensitivity to high-energy neutrons. Two sets of the detectors were used to measure neutrons at the downstream and lateral locations simultaneously, where the radiation fields differed considerably in intensities and spectra of gamma rays and neutrons. Analyzing the detector responses through a comparison between calculations and measurements indicated that not only neutrons but also high-energy gamma rays (>5 MeV) triggered the detectors because of photoneutrons produced in the detector materials. In the lateral direction, the contribution of photoneutrons to both detectors was negligible. Downstream of the LINAC, where high-energy photons were abundant, photoneutrons contributed approximately 6% of the response of the conventional neutron detector; however, almost 50% of the registered counts of the extended-range neutron detector were from photoneutrons because of the presence of the detector rather than the effect of the neutron field. Dose readings delivered by extended-range neutron detectors should be interpreted cautiously when used in radiation fields containing a mixture of neutrons and high-energy gamma rays

Increasing sea surface temperature and range shifts of intertidal gastropods along the Iberian Peninsula

Science.gov (United States)

Rubal, Marcos; Veiga, Puri; Cacabelos, Eva; Moreira, Juan; Sousa-Pinto, Isabel

2013-03-01

There are well-documented changes in abundance and geographical range of intertidal invertebrates related to climate change at north Europe. However, the effect of sea surface warming on intertidal invertebrates has been poorly studied at lower latitudes. Here we analyze potential changes in the abundance patterns and distribution range of rocky intertidal gastropods related to climate change along the Iberian Peninsula. To achieve this aim, the spatial distribution and range of sub-tropical, warm- and cold-water species of intertidal gastropods was explored by a fully hierarchical sampling design considering four different spatial scales, i.e. from region (100 s of km apart) to quadrats (ms apart). Variability on their patterns of abundance was explored by analysis of variance, changes on their distribution ranges were detected by comparing with previous records and their relationship with sea water temperature was explored by rank correlation analyses. Mean values of sea surface temperature along the Iberian coast, between 1949 and 2010, were obtained from in situ data compiled for three different grid squares: south Portugal, north Portugal, and Galicia. Lusitanian species did not show significant correlation with sea water temperature or changes on their distributional range or abundance, along the temperature gradient considered. The sub-tropical species Siphonaria pectinata has, however, increased its distribution range while boreal cold-water species showed the opposite pattern. The latter was more evident for Littorina littorea that was almost absent from the studied rocky shores of the Iberian Peninsula. Sub-tropical and boreal species showed significant but opposite correlation with sea water temperature. We hypothesized that the energetic cost of frequent exposures to sub-lethal temperatures might be responsible for these shifts. Therefore, intertidal gastropods at the Atlantic Iberian Peninsula coast are responding to the effect of global warming as it

Recent progress in low-temperature silicon detectors

International Nuclear Information System (INIS)

Abreu, M.; D'Ambrosio, N.; Bell, W.; Berglund, P.; Borchi, E.; Boer, W. de; Borer, K.; Bruzzi, M.; Buontempo, S.; Casagrande, L.; Chapuy, S.; Cindro, V.; Devine, S.R.H.; Dezillie, B.; Dierlamm, A.; Dimcovski, Z.; Eremin, V.; Esposito, A.; Granata, V.; Grigoriev, E.; Grohmann, S.; Hauler, F.; Heijne, E.; Heising, S.; Hempel, O.; Herzog, R.; Haerkoenen, J.; Janos, S.; Jungermann, L.; Konorov, I.; Li, Z.; Lourenco, C.; De Masi, R.; Menichelli, D.; Mikuz, M.; Niinikoski, T.O.; O'Shea, V.; Pagano, S.; Palmieri, V.G.; Paul, S.; Pretzl, K.; Smith, K.; Solano, B. Pere; Sousa, P.; Pirollo, S.; Rato Mendes, P.; Ruggiero, G.; Sonderegger, P.; Tuominen, E.; Verbitskaya, E.; Da Via, C.; Watts, S.; Wobst, E.; Zavrtanik, M.

2003-01-01

The CERN RD39 Collaboration studies the possibility to extend the detector lifetime in a hostile radiation environment by operating them at low temperatures. The outstanding illustration is the Lazarus effect, which showed a broad operational temperature range around 130 K for neutron irradiated silicon detectors

Extended Range Prediction of Indian Summer Monsoon: Current status

Science.gov (United States)

Sahai, A. K.; Abhilash, S.; Borah, N.; Joseph, S.; Chattopadhyay, R.; S, S.; Rajeevan, M.; Mandal, R.; Dey, A.

2014-12-01

The main focus of this study is to develop forecast consensus in the extended range prediction (ERP) of monsoon Intraseasonal oscillations using a suit of different variants of Climate Forecast system (CFS) model. In this CFS based Grand MME prediction system (CGMME), the ensemble members are generated by perturbing the initial condition and using different configurations of CFSv2. This is to address the role of different physical mechanisms known to have control on the error growth in the ERP in the 15-20 day time scale. The final formulation of CGMME is based on 21 ensembles of the standalone Global Forecast System (GFS) forced with bias corrected forecasted SST from CFS, 11 low resolution CFST126 and 11 high resolution CFST382. Thus, we develop the multi-model consensus forecast for the ERP of Indian summer monsoon (ISM) using a suite of different variants of CFS model. This coordinated international effort lead towards the development of specific tailor made regional forecast products over Indian region. Skill of deterministic and probabilistic categorical rainfall forecast as well the verification of large-scale low frequency monsoon intraseasonal oscillations has been carried out using hindcast from 2001-2012 during the monsoon season in which all models are initialized at every five days starting from 16May to 28 September. The skill of deterministic forecast from CGMME is better than the best participating single model ensemble configuration (SME). The CGMME approach is believed to quantify the uncertainty in both initial conditions and model formulation. Main improvement is attained in probabilistic forecast which is because of an increase in the ensemble spread, thereby reducing the error due to over-confident ensembles in a single model configuration. For probabilistic forecast, three tercile ranges are determined by ranking method based on the percentage of ensemble members from all the participating models falls in those three categories. CGMME further

MTF measurement of IR optics in different temperature ranges

Science.gov (United States)

Bai, Alexander; Duncker, Hannes; Dumitrescu, Eugen

2017-10-01

Infrared (IR) optical systems are at the core of many military, civilian and manufacturing applications and perform mission critical functions. To reliably fulfill the demanding requirements imposed on today's high performance IR optics, highly accurate, reproducible and fast lens testing is of crucial importance. Testing the optical performance within different temperature ranges becomes key in many military applications. Due to highly complex IR-Applications in the fields of aerospace, military and automotive industries, MTF Measurement under realistic environmental conditions become more and more relevant. A Modulation Transfer Function (MTF) test bench with an integrated thermal chamber allows measuring several sample sizes in a temperature range from -40 °C to +120°C. To reach reliable measurement results under these difficult conditions, a specially developed temperature stable design including an insulating vacuum are used. The main function of this instrument is the measurement of the MTF both on- and off-axis at up to +/-70° field angle, as well as measurement of effective focal length, flange focal length and distortion. The vertical configuration of the system guarantees a small overall footprint. By integrating a high-resolution IR camera with focal plane array (FPA) in the detection unit, time consuming measurement procedures such as scanning slit with liquid nitrogen cooled detectors can be avoided. The specified absolute accuracy of +/- 3% MTF is validated using internationally traceable reference optics. Together with a complete and intuitive software solution, this makes the instrument a turn-key device for today's state-of- the-art optical testing.

Extending EV Range with Direct Methanol Fuel Cells

OpenAIRE

Steckmann, Kai

2009-01-01

Electric cars are the vehicles of the future, and there is a proven hybrid system for extending their mileage. Direct methanol fuel cells (DMFCs) provide safe, lightweight, onboard battery charging that can free car owners from worry about running out of power. The hybrid system includes a DMFC fuel cell, fuel cell cartridge and electric vehicle batteries. The fuel cell operates almost silently with virtually no exhaust, it is immune to extreme weather and the convenient fuel cartridges featu...

Extended capture range for focus-diverse phase retrieval in segmented aperture systems using geometrical optics.

Science.gov (United States)

Jurling, Alden S; Fienup, James R

2014-03-01

Extending previous work by Thurman on wavefront sensing for segmented-aperture systems, we developed an algorithm for estimating segment tips and tilts from multiple point spread functions in different defocused planes. We also developed methods for overcoming two common modes for stagnation in nonlinear optimization-based phase retrieval algorithms for segmented systems. We showed that when used together, these methods largely solve the capture range problem in focus-diverse phase retrieval for segmented systems with large tips and tilts. Monte Carlo simulations produced a rate of success better than 98% for the combined approach.

Density of Liquid Steel over Temperature Range of 1 803-1 873 K

Institute of Scientific and Technical Information of China (English)

XIAO Feng; FANG Liang

2004-01-01

The density of three kinds of liquid steel was measured by a modified sessile drop method over the temperature range of 1 803-1 873 K. It is found that the density of liquid steels decreases with increasing temperature and carbon content in steel. Both of the density and its absolute temperature coefficient of studied steels are smaller than the literature values of pure iron. The molar volume of the steels increases with increasing temperature.

Germanium thermometers in the temperature range .1000K to 4.20K

International Nuclear Information System (INIS)

Hsieh, S.Y.; Sanchez, D.H.

1974-01-01

The sensitivity characteristics of two germanium thermometers that proved to be convenient sensors in the temperature range from .100 0 K to 4.2 0 K, are described. Their resistances change from about 8 x 10 5 ohms at .100 0 K to about 100 ohms at 4.2 0 K. The calibration curves were fitted to natural spline functions of order 3 in the whole range of temperatures. These functions give less than half millidegree standard dispersion against 15 millidegree standard dispersion when usual polynomial interpolations are used. It is discussed what spline functions are, and compare the goodness of spline interpolation with polynomial methods [pt

Development and validation of a 5 stroke engine for range extenders application

International Nuclear Information System (INIS)

Kéromnès, A.; Delaporte, B.; Schmitz, G.; Le Moyne, L.

2014-01-01

Highlights: • We have designed and built an innovative five stroke internal combustion engine. • The design includes an innovative exhaust gas management system, the smart waste gate. • The turbocharged port-injection spark ignition engine has a fuel conversion efficiency of 36%. - Abstract: A 5-stroke turbo-charged port-injection spark-ignition engine has been developed in the present study for use as a range extender or series-hybrid main power source. The development and the design of the engine are based on 0D/1D model and experimental results have been compared with the engine model. The 5-stroke engine is a three-cylinder in which two cylinders perform a four-stroke cycle and alternatively a second expansion of the burnt gases is performed in the third cylinder. The boost pressure delivered by the turbocharger is controlled by a particular innovative system called “smart wastegate”, different from a conventional wastegate, consisting in a variable valve timing of the two exhaust valves of the low pressure cylinder. The engine develops up to 40 kW for a speed range of 3500–4500 rpm. BSFC is 226 g/kW.h which corresponds to a fuel conversion efficiency of 36.1%. This efficiency can be achieved for an engine speed of 4000 rpm and a brake power of 32.5 kW, which are notable scores for an MPI two-valve per cylinder engine. Expected optimum should be below 217 g/kW.h BSFC and over 90 N.m torque. The engine has been tested over a wide range of conditions; model predictions and experimental results are compared and combustion efficiency increase discussed

Modeling of carbon dioxide absorption by aqueous ammonia solutions using the Extended UNIQUAC model

DEFF Research Database (Denmark)

Darde, Victor Camille Alfred; van Well, Willy J. M.; Stenby, Erling Halfdan

2010-01-01

An upgraded version of the Extended UNIQUAC thermodynamic model for the carbon dioxide-ammonia-water system has been developed, based on the original version proposed by Thomsen and Rasmussen. The original model was valid in the temperature range 0-110°C, the pressure range 0-10 MPa...... properties of carbon dioxide and ammonia to supercritical conditions....

Visual performance after bilateral implantation of 2 new presbyopia-correcting intraocular lenses: Trifocal versus extended range of vision.

Science.gov (United States)

Monaco, Gaspare; Gari, Mariangela; Di Censo, Fabio; Poscia, Andrea; Ruggi, Giada; Scialdone, Antonio

2017-06-01

To compare the visual outcomes and quality of vision of 2 new diffractive multifocal intraocular lenses (IOLs) with those of a monofocal IOL. Fatebenefratelli e Oftalmico Hospital, Milan, Italy. Prospective case series. Patients had bilateral cataract surgery with implantation of a trifocal IOL (Panoptix), an extended-range-of-vision IOL (Symfony), or a monofocal IOL (SN60WF). Postoperative examinations included assessing distance, intermediate, and near visual acuity; binocular defocus; intraocular and total aberrations; point-spread function (PSF); modulation transfer function (MTF); retinal straylight; and quality-of-vision (QoV) and spectacle-dependence questionnaires. Seventy-six patients (152 eyes) were assessed for study eligibility. Twenty patients (40 eyes) in each arm of the study (60 patients, 120 eyes) completed the outcome assessment. At the 4-month follow-up, the trifocal group had significantly better near visual acuity than the extended-range-of-vision group (P = .005). The defocus curve showed the trifocal IOL had better intermediate/near performance than the extended-range-of-vision IOL and both multifocal IOLs performed better than the monofocal IOL. Intragroup comparison of the total higher-order aberrations, PSF, MTF, and retinal straylight were not statistically different. The QoV questionnaire results showed no differences in dysphotopsia between the multifocal IOL groups; however, the results were significantly higher than in the monofocal IOL group. Both multifocal IOLs seemed to be good options for patients with intermediate-vision requirements, whereas the trifocal IOL might be better for patients with near-vision requirements. The significant perception of visual side effects indicates that patients still must be counseled about these effects before a multifocal IOL is implanted. Copyright © 2017 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Standardization of radiation protection measurements in mixed fields of an extended energy range

International Nuclear Information System (INIS)

Hoefert, M.; Stevenson, G.R.

1977-01-01

The improved ICRU concept of dose equivalent index aims at standardizing both area and personnel dose measurements so that the results on the dosimetry of external irradiations in radiation protection become compatible. It seems that for photon and neutron energies up to 3 and 20 MeV respectively the realization of dose-equivalent index is straightforward, but the inclusion of higher energies and/or other types of radiation will lead both to conceptual and practical difficulties. It will be shown that practical measurements in mixed radiation fields of an extended energy range for protection purposes will overestimate the standardized quantity. While area measurements can be performed to represent a good approximation, greater uncertainties have to be accepted in personnel dosimetry for stray radiation fields around GeV proton accelerators

An Investigation on Attributes of Ambient Temperature and Diurnal Temperature Range on Mortality in Five East-Asian Countries.

Science.gov (United States)

Lee, Whan-Hee; Lim, Youn-Hee; Dang, Tran Ngoc; Seposo, Xerxes; Honda, Yasushi; Guo, Yue-Liang Leon; Jang, Hye-Min; Kim, Ho

2017-08-31

Interest in the health effects of extremely low/high ambient temperature and the diurnal temperature range (DTR) on mortality as representative indices of temperature variability is growing. Although numerous studies have reported on these indices independently, few studies have provided the attributes of ambient temperature and DTR related to mortality, concurrently. In this study, we aimed to investigate and compare the mortality risk attributable to ambient temperature and DTR. The study included data of 63 cities in five East-Asian countries/regions during various periods between 1972 and 2013. The attributable risk of non-accidental death to ambient temperature was 9.36% (95% confidence interval [CI]: 8.98-9.69%) and to DTR was 0.59% (95% CI: 0.53-0.65%). The attributable cardiovascular mortality risks to ambient temperature (15.63%) and DTR (0.75%) are higher than the risks to non-accidental/respiratory-related mortality. We verified that ambient temperature plays a larger role in temperature-associated mortality, and cardiovascular mortality is susceptible to ambient temperature and DTR.

TLD personnel monitoring dose estimation- extending the upper limit of the dose range

International Nuclear Information System (INIS)

Popli, K.L.; Sathian, Deepa; Divakaran, T.; Massand, O.P.

2001-01-01

TLD personnel monitoring was introduced in the year 1975 in India and at present nearly 41,000 radiation workers are being monitored by 13 monitoring laboratories all over India. The BARC- TLD being used for personnel monitoring is based on CaSO 4 :Dy embedded in PTFE and semi-automatic TL reader using hot N 2 Gas for heating the dosimeters. This reader has the range to measure γ dose from ten μSv to 3 μSv and x-ray dose form 1 μ Sv to 0.3 Sv due to the higher sensitivity of CaSO 4 : Dy to lower energy photons (20keV-50 keV) generated by diagnostic x-ray units. The x-ray radiation workers are at present nearly 35% of the total radiation workers monitored and this number is expected to grow as more and more number of x-ray workers are covered under this service. The upper limit of the x-ray dose range of the instrument is 0.3 Sv, whereas in the past one year it has been observed that at least 25% of the total overexposures reported in case of x-ray workers have recorded the dose more than 0.3 Sv. This paper presents the technique developed to extend the upper limit of the range from 0.3 Sv to 1 Sv for x-rays and 10 Sv for γ rays

An extended range soft X-ray beam line for the 1 GeV storage ring Aladdin

International Nuclear Information System (INIS)

Hulbert, S.L.; Stott, J.P.; Brown, F.C.

1983-01-01

The design and implementation of a soft X-ray beam line on the new 1 GeV storage ring Aladdin in Stoughton, Wisconsin is discussed. The beam line consists of a long horizontally focussing collection mirror, an extended range (50-1500 eV) grasshopper monochromator, an ellipsoidal refocussing mirror, and a photoemission chamber. Also discussed are the factors considered in matching the monochromator to the storage ring, flux and performance expectations, and the results of a ray tracing analysis. (orig.)

Chandra Observations of Extended X-Ray Emission in ARP 220

Science.gov (United States)

McDowell, J. C.; Clements, D. L.; Lamb, S. A.; Shaked, S.; Hearn, N. C.; Colina, L.; Mundell, C.; Borne, K.; Baker, A. C.; Arribas, S.

2003-01-01

We resolve the extended X-ray emission from the prototypical ultraluminous infrared galaxy Arp 220. Extended, faint, edge-brightened, soft X-ray lobes outside the optical galaxy are observed to a distance of 1CL 15 kpc on each side of the nuclear region. Bright plumes inside the optical isophotes coincide with the optical line emission and extend 1 1 kpc from end to end across the nucleus. The data for the plumes cannot be fitted by a single-temperature plasma and display a range of temperatures from 0.2 to 1 keV. The plumes emerge from bright, diffuse circumnuclear emission in the inner 3 kpc centered on the Ha peak, which is displaced from the radio nuclei. There is a close morphological correspondence between the Ha and soft X-ray emission on all spatial scales. We interpret the plumes as a starburst-driven superwind and discuss two interpretations of the emission from the lobes in the context of simulations of the merger dynamics of Arp 220.

Temperature dependence of the Schottky-barrier heights of n-type semiconductors in the temperature range of 7 to 300 K

International Nuclear Information System (INIS)

Chen, T.P.; Lee, T.C.; Fung, S.; Beling, C.D.

1994-01-01

In this note we present the results of the temperature dependence of the SBH in Au/n-Si, Ag/n-GaAs, and Au/n-GaAs in the temperature range of 7 to 300 K from our internal photoemission measurements. (orig.)

Locality of Temperature

Science.gov (United States)

Kliesch, M.; Gogolin, C.; Kastoryano, M. J.; Riera, A.; Eisert, J.

2014-07-01

This work is concerned with thermal quantum states of Hamiltonians on spin- and fermionic-lattice systems with short-range interactions. We provide results leading to a local definition of temperature, thereby extending the notion of "intensivity of temperature" to interacting quantum models. More precisely, we derive a perturbation formula for thermal states. The influence of the perturbation is exactly given in terms of a generalized covariance. For this covariance, we prove exponential clustering of correlations above a universal critical temperature that upper bounds physical critical temperatures such as the Curie temperature. As a corollary, we obtain that above the critical temperature, thermal states are stable against distant Hamiltonian perturbations. Moreover, our results imply that above the critical temperature, local expectation values can be approximated efficiently in the error and the system size.

Modelling of monovacancy diffusion in W over wide temperature range

International Nuclear Information System (INIS)

Bukonte, L.; Ahlgren, T.; Heinola, K.

2014-01-01

The diffusion of monovacancies in tungsten is studied computationally over a wide temperature range from 1300 K until the melting point of the material. Our modelling is based on Molecular Dynamics technique and Density Functional Theory. The monovacancy migration barriers are calculated using nudged elastic band method for nearest and next-nearest neighbour monovacancy jumps. The diffusion pre-exponential factor for monovacancy diffusion is found to be two to three orders of magnitude higher than commonly used in computational studies, resulting in attempt frequency of the order 10 15 Hz. Multiple nearest neighbour jumps of monovacancy are found to play an important role in the contribution to the total diffusion coefficient, especially at temperatures above 2/3 of T m , resulting in an upward curvature of the Arrhenius diagram. The probabilities for different nearest neighbour jumps for monovacancy in W are calculated at different temperatures

New England observed and predicted August stream/river temperature daily range points

Data.gov (United States)

U.S. Environmental Protection Agency — The shapefile contains points with associated observed and predicted August stream/river temperature daily ranges in New England based on a spatial statistical...

New England observed and predicted July stream/river temperature daily range points

Data.gov (United States)

U.S. Environmental Protection Agency — The shapefile contains points with associated observed and predicted July stream/river temperature daily ranges in New England based on a spatial statistical network...

Extending the accredited low flow liquid calibration range

NARCIS (Netherlands)

Platenkamp, Tom; Lötters, Joost Conrad

2017-01-01

There is an increasing demand for ISO/IEC 17025:2005 accredited liquid flow calibrations in the range of 1 g/h to 30 kg/h. The accredited Low Flow liquid Calibration Setup [1] (LFCS) at Bronkhorst® covers a flow range of 1 to 200 g/h, leaving a traceability gap in the flow range of 0.2 to 30 kg/h.

Design, Fabrication and Prototype testing of a Chip Integrated Micro PEM Fuel Cell Accumulator combined On-Board Range Extender

International Nuclear Information System (INIS)

Balakrishnan, A; Mueller, C; Reinecke, H

2014-01-01

In this work we present the design, fabrication and prototype testing of Chip Integrated Micro PEM Fuel Cell Accumulator (CIμ-PFCA) combined On-Board Range Extender (O-BRE). CIμ-PFCA is silicon based micro-PEM fuel cell system with an integrated hydrogen storage feature (palladium metal hydride), the run time of CIμ-PFCA is dependent on the stored hydrogen, and in order to extend its run time an O-BRE is realized (catalytic hydrolysis of chemical hydride, NaBH 4 . Combining the CIμ-PFCA and O-BRE on a system level have few important design requirements to be considered; hydrogen regulation, gas -liquid separator between the CIμ-PFCA and the O-RE. The usage of traditional techniques to regulate hydrogen (tubes), gas-liquid phase membranes (porous membrane separators) are less desirable in the micro domain, due to its space constraint. Our approach is to use a passive hydrogen regulation and gas-liquid phase separation concept; to use palladium membrane. Palladium regulates hydrogen by concentration diffusion, and its property to selectively adsorb only hydrogen is used as a passive gas-liquid phase separator. Proof of concept is shown by realizing a prototype system. The system is an assembly of CIμ-PFCA, palladium membrane and the O-BRE. The CIμ-PFCA consist of 2 individually processed silicon chips, copper supported palladium membrane realized by electroplating followed by high temperature annealing process under inter atmosphere and the O-BRE is realized out of a polymer substrate by micromilling process with platinum coated structures, which functions as a catalyst for the hydrolysis of NaBH 4 . The functionality of the assembled prototype system is demonstrated by the measuring a unit cell (area 1 mm 2 ) when driven by the catalytic hydrolysis of chemical hydride (NaBH 4 and the prototype system shows run time more than 15 hours

Reaction rate constants of HO2 + O3 in the temperature range 233-400 K

Science.gov (United States)

Wang, Xiuyan; Suto, Masako; Lee, L. C.

1988-01-01

The reaction rate constants of HO2 + O3 were measured in the temperature range 233-400 K using a discharge flow system with photofragment emission detection. In the range 233-253 K, the constants are approximately a constant value, and then increase with increasing temperature. This result suggests that the reaction may have two different channels. An expression representing the reaction rate constants is presented.

Effect of cutoff radius, long range interaction and temperature controller on thermodynamic properties of fluids: Methanol as an example

Science.gov (United States)

Obeidat, Abdalla; Jaradat, Adnan; Hamdan, Bushra; Abu-Ghazleh, Hind

2018-04-01

The best spherical cutoff radius, long range interaction and temperature controller were determined using surface tension, density, and diffusion coefficients of van Leeuwen and Smit methanol. A quite good range of cutoff radii from 0.75 to 1.45 nm has been studied on Coulomb cut-off and particle mesh Ewald (PME) long range interaction to determine the best cutoff radius and best long range interaction as well for four sets of temperature: 200, 230, 270 and 300 K. To determine the best temperature controller, the cutoff radius of 1.25 nm was fixed using PME long range interaction on calculating the above properties at low temperature range: 200-300 K.

Piezoelectricity above the Curie temperature? Combining flexoelectricity and functional grading to enable high-temperature electromechanical coupling

Energy Technology Data Exchange (ETDEWEB)

Mbarki, R. [Department of Mechanical Engineering, University of Houston, Houston, Texas 77204 (United States); Baccam, N. [Department of Mathematics, Southwestern University, Georgetown, Texas 78626 (United States); Dayal, Kaushik [Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Sharma, P. [Department of Mechanical Engineering and Department of Physics, University of Houston, Houston, Texas 77204 (United States)

2014-03-24

Most technologically relevant ferroelectrics typically lose piezoelectricity above the Curie temperature. This limits their use to relatively low temperatures. In this Letter, exploiting a combination of flexoelectricity and simple functional grading, we propose a strategy for high-temperature electromechanical coupling in a standard thin film configuration. We use continuum modeling to quantitatively demonstrate the possibility of achieving apparent piezoelectric materials with large and temperature-stable electromechanical coupling across a wide temperature range that extends significantly above the Curie temperature. With Barium and Strontium Titanate, as example materials, a significant electromechanical coupling that is potentially temperature-stable up to 900 °C is possible.

Dem Generation from Close-Range Photogrammetry Using Extended Python Photogrammetry Toolbox

Science.gov (United States)

Belmonte, A. A.; Biong, M. M. P.; Macatulad, E. G.

2017-10-01

Digital elevation models (DEMs) are widely used raster data for different applications concerning terrain, such as for flood modelling, viewshed analysis, mining, land development, engineering design projects, to name a few. DEMs can be obtained through various methods, including topographic survey, LiDAR or photogrammetry, and internet sources. Terrestrial close-range photogrammetry is one of the alternative methods to produce DEMs through the processing of images using photogrammetry software. There are already powerful photogrammetry software that are commercially-available and can produce high-accuracy DEMs. However, this entails corresponding cost. Although, some of these software have free or demo trials, these trials have limits in their usable features and usage time. One alternative is the use of free and open-source software (FOSS), such as the Python Photogrammetry Toolbox (PPT), which provides an interface for performing photogrammetric processes implemented through python script. For relatively small areas such as in mining or construction excavation, a relatively inexpensive, fast and accurate method would be advantageous. In this study, PPT was used to generate 3D point cloud data from images of an open pit excavation. The PPT was extended to add an algorithm converting the generated point cloud data into a usable DEM.

Temperature dependence of three-body ion-molecule reactions

International Nuclear Information System (INIS)

Boehringer, H.; Arnold, F.

1983-01-01

The temperature dependence of the ion-molecule association reactions (i) N 2 + + N 2 + M → N 4 + + M (M=N 2 , He), (ii) O 2 + + O 2 + M → O 4 + + M (M=O 2 , He) and (iii) He + + 2He → He 2 + + He have been studied over an extended temperature range to temperatures as low as 30K with a recently constructed liquid helium-cooled ion drift tube. Over most of the temperature range the threebody reaction rate coefficients show an inverse temperature dependence proportional to Tsup(-n) with n in the range 0.6 to 2.9. This temperature dependence is quite consistent with current theories of ion molecule association. At low temperatures, however, a deviation from the Tsup(-n) dependence was observed for the association reactions (ii). For reactions (i) different temperature dependences were obtained for N 2 and He third bodies indicating an additional temperature dependence of the collisional stabilisation process. (Authors)

Viability of Timor deer stag (Cervus timorensis spermatozoa extended in tris egg yolk diluent with different sources of carbohydrate and storage at room temperature

Directory of Open Access Journals (Sweden)

W. Marlene Mesang-Nalley

2007-12-01

Full Text Available The successful sperm preservation, influenced by the capability of its extender on the maintenance the sperm quality during storage. The carbohydrate such as glucose and fructose were the common sugar added on the mammalian sperm extender to support their live and motility. The sucrose was the main carbohydrate in Timor deer stag seminal plasma. The experiment was conducted to evaluate the effect of carbohydrates in Tris egg yolk (TEY extender on the motility and viability of stag sperm, stored in room temperature (27-28 oC. The semen was collected using electro ejaculator from five Timor deer stags at hard antler stage, 3-5 years old, body weight of 64-102 kg with normal testes. The semen was than evaluated macro-and microscopically and divided into 3 aliquots. Each of them was diluted with TEY-glucose (TEYG, TEY-fructose (TEYF and TEY-Sucrose (TEYS with the concentration of spermatozoa 100 x 106 ml-1. The extended semen was than stored at room temperature. The sperm motility and viability were evaluated every 3 hours. Result of the experiment showed that the semen volume was 2.06 ± 0.63 ml, pH 7.03±0.13, yellow white until creamy in color and the consistency ranged from normal to thick. The mass movement between ++ to +++ and the sperm motility was 68.67 ± 7.4%. The average of sperm concentration was 842.35 ± 258.14x106 ml-1, the viable sperm was 78.11 ± 3.61%, the sperm abnormality was 7.31 ± 2.98%. The percentages of sperm motility on TEYG (18.00 ± 17.63% and TEYS (21.83 ± 15.92% were higher compare to TEYF (4,00 ± 0,00% extender in 24 hours observation. The percentage of sperm viability showed the same pattern. The sperm viability in TEYG (28.17 ± 20.06 and TEYS (24.00 ± 22.59% (P<0.05 were significantly higher compare to TEYF (4.00 ± 0.00%. It is concluded that the deer stag sperm can use the three sugars for their nutrition source. The diluted sperm still can be used for artificial insemination after 12 hour storage.

Electrolytes for Use in High Energy Lithium-ion Batteries with Wide Operating Temperature Range

Science.gov (United States)

Smart, Marshall C.; Ratnakumar, B. V.; West, W. C.; Whitcanack, L. D.; Huang, C.; Soler, J.; Krause, F. C.

2012-01-01

Met programmatic milestones for program. Demonstrated improved performance with wide operating temperature electrolytes containing ester co-solvents (i.e., methyl butyrate) containing electrolyte additives in A123 prototype cells: Previously demonstrated excellent low temperature performance, including 11C rates at -30 C and the ability to perform well down to -60 C. Excellent cycle life at room temperature has been displayed, with over 5,000 cycles being demonstrated. Good high temperature cycle life performance has also been achieved. Demonstrated improved performance with methyl propionate-containing electrolytes in large capacity prototype cells: Demonstrated the wide operating temperature range capability in large cells (12 Ah), successfully scaling up technology from 0.25 Ah size cells. Demonstrated improved performance at low temperature and good cycle life at 40 C with methyl propionate-based electrolyte containing increasing FEC content and the use of LiBOB as an additive. Utilized three-electrode cells to investigate the electrochemical characteristics of high voltage systems coupled with wide operating temperature range electrolytes: From Tafel polarization measurements on each electrode, it is evident the NMC-based cathode displays poor lithium kinetics (being the limiting electrode). The MB-based formulations containing LiBOB delivered the best rate capability at low temperature, which is attributed to improved cathode kinetics. Whereas, the use of lithium oxalate as an additive lead to the highest reversible capacity and lower irreversible losses.

Thermal Stability of Austempered Ductile Iron Evaluated in a Temperature Range of 20-300K

Directory of Open Access Journals (Sweden)

Dawid MYSZKA

2016-05-01

Full Text Available The aim of this article was to determine through changes in magnetic properties the stability of the austempered ductile iron (ADI microstructure during temperature changes in a range of 20 – 300 K. The measurements were taken in a vibrating sample magnetometer (VSM using Fe27Ni2TiMoAlNb austenitic stainless steel and four types of austempered ductile iron obtained under various heat treatment conditions. The plotted curves showing changes in the magnetisation degree as a function of temperature had a number of characteristic points illustrating changes taking place in the microstructure. For each of the materials examined, the martensite start temperature Ms and the temperature range within which the martensitic transformation takes place were identified.

A systematic Monte Carlo simulation study of the primitive model planar electrical double layer over an extended range of concentrations, electrode charges, cation diameters and valences

Science.gov (United States)

Valiskó, Mónika; Kristóf, Tamás; Gillespie, Dirk; Boda, Dezső

2018-02-01

The purpose of this study is to provide data for the primitive model of the planar electrical double layer, where ions are modeled as charged hard spheres, the solvent as an implicit dielectric background (with dielectric constant ɛ = 78.5), and the electrode as a smooth, uniformly charged, hard wall. We use canonical and grand canonical Monte Carlo simulations to compute the concentration profiles, from which the electric field and electrostatic potential profiles are obtained by solving Poisson's equation. We report data for an extended range of parameters including 1:1, 2:1, and 3:1 electrolytes at concentrations c = 0.0001 - 1 M near electrodes carrying surface charges up to σ = ±0.5 Cm-2. The anions are monovalent with a fixed diameter d- = 3 Å, while the charge and diameter of cations are varied in the range z+ = 1, 2, 3 and d+ = 1.5, 3, 6, and 9 Å (the temperature is 298.15 K). We provide all the raw data in the supplementary material (ftp://ftp.aip.org/epaps/aip_advances/E-AAIDBI-8-084802">supplementary material).

A systematic Monte Carlo simulation study of the primitive model planar electrical double layer over an extended range of concentrations, electrode charges, cation diameters and valences

Directory of Open Access Journals (Sweden)

Mónika Valiskó

2018-02-01

Full Text Available The purpose of this study is to provide data for the primitive model of the planar electrical double layer, where ions are modeled as charged hard spheres, the solvent as an implicit dielectric background (with dielectric constant ϵ = 78.5, and the electrode as a smooth, uniformly charged, hard wall. We use canonical and grand canonical Monte Carlo simulations to compute the concentration profiles, from which the electric field and electrostatic potential profiles are obtained by solving Poisson’s equation. We report data for an extended range of parameters including 1:1, 2:1, and 3:1 electrolytes at concentrations c = 0.0001 − 1 M near electrodes carrying surface charges up to σ = ±0.5 Cm−2. The anions are monovalent with a fixed diameter d− = 3 Å, while the charge and diameter of cations are varied in the range z+ = 1, 2, 3 and d+ = 1.5, 3, 6, and 9 Å (the temperature is 298.15 K. We provide all the raw data in the supplementary material.

Intercomparison of the Dew-Point Temperature Realizations at LPM and MIKES in the Range from -70 °C to + 20 ° C

Science.gov (United States)

Heinonen, Martti; Zvizdic, Davor; Sestan, Danijel

2012-09-01

The first European humidity key comparison EURAMET-T.K6 was completed in 2008, and it covered the dew-point temperature range from -50 °C to + 20 °C. Both LPM and MIKES participated in the comparison, but a new low dew-point generator was introduced at LPM as a result of progress in the EUROMET P912 project. To extend the range of available comparison evidence down to -70 °C and to study the validity of improved uncertainties of LPM, a bilateral comparison was carried out between LPM and MIKES in 2009-2010. The applied comparison procedure was similar to that applied in EURAMET-T.K6. However, only one transfer standard was used instead of two units and the measurement point -70 °C was added in the measurement scheme. The results show that the bilateral equivalence between LPM and MIKES is between (0.00 ± 0.06) °C and (0.02 ± 0.08) °C in the range from -50 °C to + 20 °C and (0.01 ± 0.10) °C at -70 °C. Using MIKES results as the link to the EURAMET.T-K6, it is shown that the difference between the results obtained with the new LPM dew-point temperature standard and the EURAMET Comparison Reference Values is between (-0.02 ± 0.08) °C at 20 °C and (+ 0.02 ± 0.07) ° C at -50 °C.

Extending the molecular application range of gas chromatography

NARCIS (Netherlands)

Kaal, E.; Janssen, H.-G.

2008-01-01

Gas chromatography is an important analytical technique for qualitative and quantitative analysis in a wide range of application areas. It is fast, provides a high peak capacity, is sensitive and allows combination with a wide range of selective detection methods including mass spectrometry.

Critical current measurements of high-temperature superconducting short samples at a wide range of temperatures and magnetic fields

Science.gov (United States)

Ma, Hongjun; Liu, Huajun; Liu, Fang; Zhang, Huahui; Ci, Lu; Shi, Yi; Lei, Lei

2018-01-01

High-Temperature Superconductors (HTS) are potential materials for high-field magnets, low-loss transmission cables, and Superconducting Magnetic Energy Storage (SMES) due to their high upper critical magnetic field (Hc2) and critical temperature (Tc). The critical current (Ic) of HTS, which is one of the most important parameters for superconductor application, depends strongly on the magnetic fields and temperatures. A new Ic measurement system that can carry out accurate Ic measurement for HTS short samples with various temperatures (4.2-80 K), magnetic fields (0-14 T), and angles of the magnetic field (0°-90°) has been developed. The Ic measurement system mainly consists of a measurement holder, temperature-control system, background magnet, test cryostat, data acquisition system, and DC power supply. The accuracy of temperature control is better than ±0.1 K over the 20-80 K range and ±0.05 K when measured below 20 K. The maximum current is over 1000 A with a measurement uncertainty of 1%. The system had been successfully used for YBa2Cu3O7-x(YBCO) tapes Ic determination with different temperatures and magnetic fields.

Critical current measurements of high-temperature superconducting short samples at a wide range of temperatures and magnetic fields.

Science.gov (United States)

Ma, Hongjun; Liu, Huajun; Liu, Fang; Zhang, Huahui; Ci, Lu; Shi, Yi; Lei, Lei

2018-01-01

High-Temperature Superconductors (HTS) are potential materials for high-field magnets, low-loss transmission cables, and Superconducting Magnetic Energy Storage (SMES) due to their high upper critical magnetic field (H c2 ) and critical temperature (T c ). The critical current (I c ) of HTS, which is one of the most important parameters for superconductor application, depends strongly on the magnetic fields and temperatures. A new I c measurement system that can carry out accurate I c measurement for HTS short samples with various temperatures (4.2-80 K), magnetic fields (0-14 T), and angles of the magnetic field (0°-90°) has been developed. The I c measurement system mainly consists of a measurement holder, temperature-control system, background magnet, test cryostat, data acquisition system, and DC power supply. The accuracy of temperature control is better than ±0.1 K over the 20-80 K range and ±0.05 K when measured below 20 K. The maximum current is over 1000 A with a measurement uncertainty of 1%. The system had been successfully used for YBa 2 Cu 3 O 7-x (YBCO) tapes I c determination with different temperatures and magnetic fields.

Range Extension Opportunities While Heating a Battery Electric Vehicle

Energy Technology Data Exchange (ETDEWEB)

Lustbader, Jason A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rugh, John P [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Titov, Eugene V [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Meyer, John [Hanon Systems; Agathocleous, Nicos [Hanon Systems; Vespa, Antonio [Hyundai-Kia America Technical Center Inc.

2018-04-03

The Kia Soul battery electric vehicle (BEV) is available with either a positive temperature coefficient (PTC) heater or an R134a heat pump (HP) with PTC heater combination (1). The HP uses both ambient air and waste heat from the motor, inverter, and on-board-charger (OBC) for its heat source. Hanon Systems, Hyundai America Technical Center, Inc. (HATCI) and the National Renewable Energy Laboratory jointly, with financial support from the U.S. Department of Energy, developed and proved-out technologies that extend the driving range of a Kia Soul BEV while maintaining thermal comfort in cold climates. Improved system configuration concepts that use thermal storage and waste heat more effectively were developed and evaluated. Range extensions of 5%-22% at ambient temperatures ranging from 5 degrees C to -18 degrees C were demonstrated. This paper reviews the three-year effort, including test data of the baseline and modified vehicles, resulting range extension, and recommendations for future actions.

The temperature dependence of intermediate range oxygen-oxygen correlations in liquid water

International Nuclear Information System (INIS)

Schlesinger, Daniel; Pettersson, Lars G. M.; Wikfeldt, K. Thor; Skinner, Lawrie B.; Benmore, Chris J.; Nilsson, Anders

2016-01-01

We analyze the recent temperature dependent oxygen-oxygen pair-distribution functions from experimental high-precision x-ray diffraction data of bulk water by Skinner et al. [J. Chem. Phys. 141, 214507 (2014)] with particular focus on the intermediate range where small, but significant, correlations are found out to 17 Å. The second peak in the pair-distribution function at 4.5 Å is connected to tetrahedral coordination and was shown by Skinner et al. to change behavior with temperature below the temperature of minimum isothermal compressibility. Here we show that this is associated also with a peak growing at 11 Å which strongly indicates a collective character of fluctuations leading to the enhanced compressibility at lower temperatures. We note that the peak at ∼13.2 Å exhibits a temperature dependence similar to that of the density with a maximum close to 277 K or 4 °C. We analyze simulations of the TIP4P/2005 water model in the same manner and find excellent agreement between simulations and experiment albeit with a temperature shift of ∼20 K.

The temperature dependence of intermediate range oxygen-oxygen correlations in liquid water

Energy Technology Data Exchange (ETDEWEB)

Schlesinger, Daniel; Pettersson, Lars G. M., E-mail: Lars.Pettersson@fysik.su.se [Department of Physics, AlbaNova University Center, Stockholm University, SE-106 91 Stockholm (Sweden); Wikfeldt, K. Thor [Department of Physics, AlbaNova University Center, Stockholm University, SE-106 91 Stockholm (Sweden); Science Institute, University of Iceland, VR-III, 107 Reykjavik (Iceland); Skinner, Lawrie B.; Benmore, Chris J. [X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Nilsson, Anders [Department of Physics, AlbaNova University Center, Stockholm University, SE-106 91 Stockholm (Sweden); Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States)

2016-08-28

We analyze the recent temperature dependent oxygen-oxygen pair-distribution functions from experimental high-precision x-ray diffraction data of bulk water by Skinner et al. [J. Chem. Phys. 141, 214507 (2014)] with particular focus on the intermediate range where small, but significant, correlations are found out to 17 Å. The second peak in the pair-distribution function at 4.5 Å is connected to tetrahedral coordination and was shown by Skinner et al. to change behavior with temperature below the temperature of minimum isothermal compressibility. Here we show that this is associated also with a peak growing at 11 Å which strongly indicates a collective character of fluctuations leading to the enhanced compressibility at lower temperatures. We note that the peak at ∼13.2 Å exhibits a temperature dependence similar to that of the density with a maximum close to 277 K or 4 °C. We analyze simulations of the TIP4P/2005 water model in the same manner and find excellent agreement between simulations and experiment albeit with a temperature shift of ∼20 K.

Laser parameters of a Fe : ZnSe crystal in the 85-255-K temperature range

NARCIS (Netherlands)

Voronov, AA; Kozlovskii, [No Value; Korostelin, YV; Podmar'kov, YP; Frolov, MP

The temperature dependence of the efficiency of a laser based on a Fe:ZnSe crystal grown from the vapour phase by the free-growth method is studied in the 85-255-K temperature range. As the temperature was increased, the slope efficiency of the laser with respect to absorbed energy decreased from

INVESTIGATION OF THE FREQUENCY-TEMPERATURE RELATIONSHIP OF THE DIELECTRIC PERMITTIVITY OF THE PZT PIEZOCERAMICS IN THE LOW FREQUENCY RANGE

Directory of Open Access Journals (Sweden)

A. I. ZOLOTAREVSKIY

2018-05-01

Full Text Available Purpose. To investigate the frequency-temperature relationship of the dielectric permittivity of PZT piezoceramics in the low frequency range. Methodology. To obtain the frequency-temperature relationship of the dielectric permittivity of the PZT piezoceramics, a technique was used to determine the capacitance of the capacitor, between which plates the sample was placed. The value of the dielectric permittivity of the sample was calculated from the capacitor capacitance obtained. Findings. The frequency-temperature relationship of the dielectric permittivity of the PZT piezoceramics in the low frequency range has been obtained by the authors. The dielectric permittivity is not practically related to the frequency of the alternating voltage at a low temperature, with increasing in temperature its value increases and frequency relationship is observed. The temperature relationship of the dielectric permittivity of the PZT piezoceramics is satisfactorily described by the exponential functional dependence in the low-temperature range. The activation energy of the PZT piezoceramics polarization is determined from the graph of the dependence of the logarithm of the dielectric permittivity upon the inverse temperature. Different values of the activation energy for the two temperature regions prove on the existence of different mechanisms of the PZT piezoceramics polarization in the temperature range being investigated. Originality. The authors investigated the frequency-temperature relationship of the dielectric permittivity of the PZT piezoceramics in the low-frequency range. It is established that the temperature relationship of the dielectric permittivity of the PZT piezoceramics is satisfactorily described by an exponential functional relationship in the lowtemperature range. The activation energy of polarization is determined for two temperature sections. Practical value. The research results can be used to study the mechanism of polarization of

Dislocation mechanisms for plastic flow of nickel in the temperature range 4.2-1200K

International Nuclear Information System (INIS)

Sastry, D.H.; Tangri, K.

1975-01-01

The temperature ranges of thermal and athermal deformation behaviour of nickel are identified by employing the temperature-dependence of flow-stress and strain-rate cycling data. The results are used to present a unified view of dislocation mechanisms of glide encompassing the two thermally activated and the intermediate athermal regimes of plastic flow. In the low-temperature thermally activated region (<250K) the strain rate is found to be controlled by the repulsive intersection of glide and forest dislocations, in accordance with current ideas. The athermal stress in this region can be attributed mainly to the presence of strong attractive junctions which are overcome by means of Orowan bowing, a small contribution also coming from the elastic interactions between dislocations. The values of activation area and activation energy obtained in the high-temperature region (<750K) negate the operation of a diffusion-controlled mechanism. Instead, the data support a thermal activation model involving unzipping of the attractive junctions. The internal (long-range) stress contribution here results solely from the elastic interactions between dislocations. This view concerning the high-temperature plastic flow is further supported by the observation that the Cottrell-Stokes law is obeyed over large strains in the range 750-1200K. (author)

Deformability of 12MKh steel within the temperature range of polymorphous transformations

International Nuclear Information System (INIS)

Surovtsev, A.P.; Sukhanov, V.E.

1987-01-01

Deformability and the structure of 12 MKh steel under tension, upsetting and torsion within the temperature range of polymorphous transformations have been investigated. Tests for tension showed the presence of two plasticity maxima, which correspond to the temperatures of P-A and F-A structural transformation beginning. Loss of strength during deformation is connected with dynamic polygonization and the initial stage of dynamic recrystallization as well as the state preceding ferrite transformation. Loss of plasticity is observed at the temperature accompanying the end of F-A transformation; it is explained by the formation of more strength martensite and by increase of material porosity as a result of the transformation with volume decrease

Deformability of 12MKh steel within the temperature range of polymorphous transformations

Energy Technology Data Exchange (ETDEWEB)

Surovtsev, A P; Sukhanov, V E

1987-01-01

Deformability and the structure of 12 MKh steel under tension, upsetting and torsion within the temperature range of polymorphous transformations have been investigated. Tests for tension showed the presence of two plasticity maxima, which correspond to the temperatures of P-A and F-A structural transformation beginning. Loss of strength during deformation is connected with dynamic polygonization and the initial stage of dynamic recrystallization as well as the state preceding ferrite transformation. Loss of plasticity is observed at the temperature accompanying the end of F-A transformation; it is explained by the formation of more strength martensite and by increase of material porosity as a result of the transformation with volume decrease.

Assimilation of lake water surface temperature observations using an extended Kalman filter

Directory of Open Access Journals (Sweden)

Ekaterina Kourzeneva

2014-10-01

Full Text Available A new extended Kalman filter (EKF-based algorithm to assimilate lake water surface temperature (LWST observations into the lake model/parameterisation scheme Freshwater Lake (FLake has been developed. The data assimilation algorithm has been implemented into the stand-alone offline version of FLake. The mixed and non-mixed regimes in lakes are treated separately by the EKF algorithm. The timing of the ice period is indicated implicitly: no ice if water surface temperature is measured. Numerical experiments are performed using operational in-situ observations for 27 lakes and merged observations (in-situ plus satellite for 4 lakes in Finland. Experiments are analysed, potential problems are discussed, and the role of early spring observations is studied. In general, results of experiments are promising: (1 the impact of observations (calculated as the normalised reduction of the LWST root mean square error comparing to the free model run is more than 90% and (2 in cross-validation (when observations are partly assimilated, partly used for validation the normalised reduction of the LWST error standard deviation is more than 65%. The new data assimilation algorithm will allow prognostic variables in the lake parameterisation scheme to be initialised in operational numerical weather prediction models and the effects of model errors to be corrected by using LWST observations.

Temperature-dependent dielectric function of germanium in the UV–vis spectral range: A first-principles study

International Nuclear Information System (INIS)

Yang, J.Y.; Liu, L.H.; Tan, J.Y.

2014-01-01

The study of temperature dependence of thermophysical parameter dielectric function is key to understanding thermal radiative transfer in high-temperature environments. Limited by self-radiation and thermal oxidation, however, it is difficult to directly measure the high-temperature dielectric function of solids with present experimental technologies. In this work, we implement two first-principles methods, the ab initio molecular dynamics (AIMD) and density functional perturbation theory (DFPT), to study the temperature dependence of dielectric function of germanium (Ge) in the UV–vis spectral range in order to provide data of high-temperature dielectric function for radiative transfer study in high-temperature environments. Both the two methods successfully predict the temperature dependence of dielectric function of Ge. Moreover, the good agreement between the calculated results of the AIMD approach and experimental data at 825 K enables us to predict the high-temperature dielectric function of Ge with the AIMD method in the UV–vis spectral range. - Highlights: • The temperature dependence of dielectric function of germanium (Ge) is investigated with two first-principles methods. • The temperature effect on dielectric function of Ge is discussed. • The high-temperature dielectric function of Ge is predicted

Natural circulation studies in a LBE loop for a wide range of temperature

International Nuclear Information System (INIS)

Borgohain, A.; Srivastava, A.K.; Jana, S.S.; Maheshwari, N.K.; Kulkarni, R.D.; Vijayan, P.K.; Tewari, R.; Ram, A. Maruthi; Jha, S.K.

2016-01-01

Highlights: • A high temperature Lead Bismuth Eutectic loop named as Kilo Temperature Loop (KTL) has been made. • Natural circulation experimental studies were carried out and reported in the range of 200–780 °C. • The experiments at high temperature were carried in inert atmosphere to avoid oxidation of the loop material. • Theoretical studies are carried out to simulate the loop with natural circulation in primary as well as in the secondary side. • The predictions of the code LeBENC used to simulate the natural circulation in the loop are compared with the experimental results. - Abstract: Lead–Bismuth Eutectic (LBE) is increasingly getting more attention as a coolant for advanced reactor systems. It is also the primary coolant of the Compact High Temperature Reactor (CHTR) being designed at Bhabha Atomic Research Centre (BARC). A high temperature liquid metal loop named as Kilo Temperature Loop (KTL) has been installed at BARC for thermal hydraulics, instrument development and material related studies. Natural circulation experimental studies were carried out for the power range of 200–1200 W in the loop. The corresponding LBE flow rate is calculated to be in the range of 0.075–0.12 kg/s. Transient studies for start-up of natural circulation in the loop, loss of heat sink and step power change have also been carried out. The maximum temperature of the loop operated so far is 1100 °C. A computer code named LeBENC has been developed at BARC to simulate the natural circulation characteristics in closed loops. The salient features of the code include ability to handle non-uniform diameter components, axial thermal conduction in fluid and heat losses from the piping to the environment. The code has been modified to take into account of two natural circulation loops in series so that the natural cooling by argon gas in the secondary side of the loop can be simulated. This paper deals with the description of the loop and its operation. The various

Dusty plasma in a glow discharge in helium in temperature range of 5–300 K

Energy Technology Data Exchange (ETDEWEB)

Samoilov, I. S.; Baev, V. P.; Timofeev, A. V., E-mail: timofeevalvl@gmail.com; Amirov, R. Kh.; Kirillin, A. V.; Nikolaev, V. S.; Bedran, Z. V. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

2017-03-15

Dusty plasma structures in glow discharge in helium in the temperature range of 5–300 K are investigated experimentally. We have described the experimental setup that makes it possible to continuously vary the temperature regime. The method for experimental data processing has been described. We have measured interparticle distances in the temperature range of 9–295 K and compared them with the Debye radius. We indicate the ranges of variations in experimental parameters in which plasma–dust structures are formed and various types of their behavior are manifested (rotation, vibrations of structures, formation of vertical linear chains, etc.). The applicability of the Yukawa potential to the description of the structural properties of a dusty plasma in the experimental conditions is discussed.

Innovative use of Distributed Temperature Sensing and Meteorological Data to Understand Thermoregulation of Free-Ranging Howling Monkeys

Science.gov (United States)

Suarez, F. I.; Vinyard, C. J.; Williams, S. H.; Hausner, M. B.; Tyler, S. W.; Glander, K.

2011-12-01

Temperature fluctuations are a major driver of change in natural habitats and influence the lifestyle of all organisms because temperature impacts molecular, physiological, and behavioral processes. However, there is a lack of understanding on how temperature affects metabolism, behavior, and ecology at the organismal level. Even though physiological responses to temperature fluctuations have been well documented in laboratory conditions, it has been challenging to collect the required environmental data to study thermoregulation of free-ranging mammals such as mantled howling monkeys (Alouatta palliata). Fortunately, recent advances in fiber-optic distributed temperature sensing (DTS) now permit the observation of temperature fields in the environment at scales ranging from millimeters to kilometers. This has opened an exciting opportunity for temperature monitoring at scales that were previously not feasible. This study addresses the main limitations of previous studies of primate behavior by integrating real-time environmental data with the behavior and physiological response of free-ranging primates. In this work, we present preliminary DTS data collected in a natural habitat of howling monkeys. Fiber-optic cables were hung between the ground and an elevation of approximately 15 m within the forest canopy, providing continuous profiles of temperature without any disturbance due to the animals and habitat. These measurements were integrated with conventional meteorological data and with the ambient temperature at the location of the animal, as well as with measurements of primate's subcutaneous and core body temperatures. These data will be utilized to determine how environmental conditions relate to primate behavioral and physiological responses in time and space. The methodologies used in this study provide tools to test theories of physiological thermoregulation of other free-ranging animals.

Temperature sensor realized by inkjet printing process on flexible substrate

International Nuclear Information System (INIS)

Dankoco, M.D.; Tesfay, G.Y.; Benevent, E.; Bendahan, M.

2016-01-01

Highlights: • Flexible temperature sensor was realized by inkjet printing process on Kapton substrate. • The jetting parameters were optimized to obtain evenly distributed silver coating layers and a large meander forming the sensor. • The Temperature sensor studied offers a good sensitivity, a good linearity and less than 5% hysteresis in extended measurement in the range of 20–60 °C. - Abstract: The objective of this study is to realize a printed and flexible temperature sensor to achieve surface temperature measurement of the human body. The sensor is a thermistor composed silver (Ag) deposited on a Polyimide substrate (Kapton HN). The meander was patterned by inkjet printing with a drop-on-demand Jetlab4 (Microfab Technologies Inc.). The resistance temperature coefficients have been studied in the temperature range of 20–60 °C with a range of voltage between 0 and 1 V. The stability versus time has also been measured without a sensor layer protection. The sensitive area of the sensor, silver lines width and the gap between the electrical conductors were, respectively 6.2 cm 2 , 300 μm, 60 μm. The mean temperature sensor sensitivity found was 2.23 × 10 −3 °C −1 . The results show a good linearity and less than 5% hysteresis in the extended measurement.

Combining 2-m temperature nowcasting and short range ensemble forecasting

Directory of Open Access Journals (Sweden)

A. Kann

2011-12-01

Full Text Available During recent years, numerical ensemble prediction systems have become an important tool for estimating the uncertainties of dynamical and physical processes as represented in numerical weather models. The latest generation of limited area ensemble prediction systems (LAM-EPSs allows for probabilistic forecasts at high resolution in both space and time. However, these systems still suffer from systematic deficiencies. Especially for nowcasting (0–6 h applications the ensemble spread is smaller than the actual forecast error. This paper tries to generate probabilistic short range 2-m temperature forecasts by combining a state-of-the-art nowcasting method and a limited area ensemble system, and compares the results with statistical methods. The Integrated Nowcasting Through Comprehensive Analysis (INCA system, which has been in operation at the Central Institute for Meteorology and Geodynamics (ZAMG since 2006 (Haiden et al., 2011, provides short range deterministic forecasts at high temporal (15 min–60 min and spatial (1 km resolution. An INCA Ensemble (INCA-EPS of 2-m temperature forecasts is constructed by applying a dynamical approach, a statistical approach, and a combined dynamic-statistical method. The dynamical method takes uncertainty information (i.e. ensemble variance from the operational limited area ensemble system ALADIN-LAEF (Aire Limitée Adaptation Dynamique Développement InterNational Limited Area Ensemble Forecasting which is running operationally at ZAMG (Wang et al., 2011. The purely statistical method assumes a well-calibrated spread-skill relation and applies ensemble spread according to the skill of the INCA forecast of the most recent past. The combined dynamic-statistical approach adapts the ensemble variance gained from ALADIN-LAEF with non-homogeneous Gaussian regression (NGR which yields a statistical mbox{correction} of the first and second moment (mean bias and dispersion for Gaussian distributed continuous

Effect of temperature and water activity on heat transfer in parsley leaves in the  range of temperatures 10–30 °C

Directory of Open Access Journals (Sweden)

Jiří Štencl

2007-01-01

Full Text Available The equilibrium moisture contents of parsley leaves were measured by the gravimetric dynamic method with continuous recording of changes in sample weight. Consequently water activity values were determined. Henderson equation was found to be a good model both for moisture adsorption and desorption. Isosteric heat of sorption was defined and determined in the temperature range of 10–30 °C. Clausius-Clapeyron equation was used to calculate the isosteric heat of sorption since no dependence on temperature in the analysed range was observed. The isosteric heats of sorption (qnst were indicated graphic in the form qnst versus moisture content. Values for isosteric heat of sorption ranged from 54.41 to 46.85 kJ/mol.

Thermophysical and thermodynamic properties of ionic liquids over an extended pressure range: [bmim][NTf2] and [hmim][NTf2

International Nuclear Information System (INIS)

Gomes de Azevedo, R.; Esperanca, J.M.S.S.; Szydlowski, J.; Visak, Z.P.; Pires, P.F.; Guedes, H.J.R.; Rebelo, L.P.N.

2005-01-01

The current study focuses on 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide, [bmim][NTf 2 ], and 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide, [hmim][NTf 2 ]. The objective is to study the influence of pressure as well as that of the cation's alkyl chain length on several properties of this type of ionic liquids. Speed of propagation of ultrasound waves and densities in pure ionic liquids (ILs) as a function of temperature and pressure have been determined. Several other thermodynamic properties such as compressibilities, expansivities and heat capacities have been obtained. Speed of sound measurements have been carried out in broad ranges of temperature (283 < T/K < 323) and pressure (0.1 < p/MPa < 150), using a non-intrusive microcell. Density measurements have been performed at broad ranges of temperature (298 < T/K < 333) and pressure (0.1 < p/MPa < 60) using a vibrating tube densimeter. The pressure dependence of heat capacities, which is generally mild, is highly dependent on the curvature of the temperature dependence of density

Electric resistance of nickel and niobium in the temperature range of 300-1300 K

International Nuclear Information System (INIS)

Novikov, I.I.; Roshchupkin, V.V.; Mozgovoj, A.G.; Semashko, N.A.

1982-01-01

The results of experimental investigation of nickel and niobium electric resistance on the wire samples by the potentiometric method in the temperature range of 300-1300 K are presented. Experimental data processing by the least square method is carried out; approximating equations of temperature dependence of the nickel and niobium electric resistance are prepared

Influence of temperature on the spectral characteristics of semiconductor lasers in the visible range

Science.gov (United States)

Adamov, A. A.; Baranov, M. S.; Khramov, V. N.

2018-04-01

The results of studies on the effect of temperature on the output spectral characteristics of continuous semiconductor lasers of the visible range are presented. The paper presents the results of studying the spectral-optical radiation parameters of semiconductor lasers, their coherence lengths, and the dependence of the position of the spectral peak of the wavelength on temperature. This is necessary for the selection of the most optimal laser in order to use it for medical ophthalmologic diagnosis. The experiment was carried out using semiconductor laser modules based on a laser diode. The spectra were recorded by using a two-channel automated spectral complex based on the MDR-23 monochromator. Spectral dependences on the temperature of semiconductor lasers are obtained, in the range from 300 to 370 K. The possibility of determining the internal damage to the stabilization of laser modules without opening the case is shown, but only with the use of their spectral characteristics. The obtained data allow taking into account temperature characteristics and further optimization of parameters of such lasers when used in medical practice, in particular, in ophthalmologic diagnostics.

Interaction processes between vacancies and dislocations in molybdenum in the temperature range around 0.3 of the melting temperature

International Nuclear Information System (INIS)

Zelada-Lambri, G.I.; Lambri, O.A.; Bozzano, P.B.; Garcia, J.A.; Celauro, C.A.

2008-01-01

Mechanical spectroscopy, electrical resistivity and transmission electron microscopy studies have been performed on pre-strained neutron irradiated single crystalline molybdenum in order to check the interaction processes between vacancies and dislocations in the temperature range between room temperature and 1273 K. The anelastic relaxation in molybdenum which appears between 800 K and 1273 K has been separated in two different physical mechanisms depending on the temperature of appearance of the relaxation peak. The physical mechanism which controls the damping peak appearing at around 800 K was related with the dragging of jogs by the dislocation under movement assisted by vacancy diffusion. The damping peak which appears at higher temperatures of about 1000 K was more consistent with the formation and diffusion of vacancies assisted by the dislocation movement

Interaction processes between vacancies and dislocations in molybdenum in the temperature range around 0.3 of the melting temperature

Energy Technology Data Exchange (ETDEWEB)

Zelada-Lambri, G.I. [Facultad de Ciencias Exactas, Ingenieria y Agrimensura, Universidad Nacional de Rosario, Laboratorio de Materiales, Escuela de Ingenieria Electrica, Avenida Pellegrini 250, 2000 Rosario (Argentina); Lambri, O.A. [Facultad de Ciencias Exactas, Ingenieria y Agrimensura, Universidad Nacional de Rosario, Laboratorio de Materiales, Escuela de Ingenieria Electrica, Avenida Pellegrini 250, 2000 Rosario (Argentina); Instituto de Fisica Rosario, Member of the CONICET' s Research Staff (Argentina)], E-mail: olambri@fceia.unr.edu.ar; Bozzano, P.B. [Laboratorio de Microscopia Electronica, Unidad de Actividad Materiales, Centro Atomico Constituyentes, Comision Nacional de Energia Atomica, Avenida General Paz 1499, 1650 San Martin (Argentina); Garcia, J.A. [Departamento de Fisica Aplicada II, Facultad de Ciencias y Tecnologia, Universidad del Pais Vasco, Apartado 644, 48080 Bilbao, Pais Vasco (Spain); Celauro, C.A. [Reactor Nuclear RA-4, Facultad de Ciencias Exactas, Ingenieria y Agrimensura, Universidad Nacional de Rosario, Riobamba y Berruti, 2000 Rosario (Argentina)

2008-10-15

Mechanical spectroscopy, electrical resistivity and transmission electron microscopy studies have been performed on pre-strained neutron irradiated single crystalline molybdenum in order to check the interaction processes between vacancies and dislocations in the temperature range between room temperature and 1273 K. The anelastic relaxation in molybdenum which appears between 800 K and 1273 K has been separated in two different physical mechanisms depending on the temperature of appearance of the relaxation peak. The physical mechanism which controls the damping peak appearing at around 800 K was related with the dragging of jogs by the dislocation under movement assisted by vacancy diffusion. The damping peak which appears at higher temperatures of about 1000 K was more consistent with the formation and diffusion of vacancies assisted by the dislocation movement.

Tribological behavior and self-healing functionality of TiNbCN-Ag coatings in wide temperature range

Energy Technology Data Exchange (ETDEWEB)

Bondarev, A.V., E-mail: abondarev88@gmail.com; Kiryukhantsev-Korneev, Ph.V.; Levashov, E.A.; Shtansky, D.V., E-mail: shtansky@shs.misis.ru

2017-02-28

Highlights: • TiNbCN–Ag coatings for wide temperature range tribological applications. • Alloying with Nb and Ag improve tribological properties and oxidation resistance. • Ag-rich TiNbCN coatings show friction coefficient below 0.45 in range of 25–700 °C. • Ag-doped coatings show active oxidation protection and self-healing functionality. - Abstract: Ag- and Nb-doped TiCN coatings with about 2 at.% of Nb and Ag contents varied between 4.0 and 15.1 at.% were designed as promising materials for tribological applications in a wide temperature range. We report on the structure, mechanical, and tribological properties of TiNbCN-Ag coatings fabricated by simultaneous co-sputtering of TiC{sub 0.5} + 10%Nb{sub 2}C and Ag targets in comparison with those of Ag-free coating. The tribological characteristics were evaluated during constant-temperature tests both at room temperature and 300 °C, as well as during dynamic temperature ramp tests in the range of 25–700 °C. The coating structure and elemental composition were studied by means of X-ray diffraction, scanning and transmission electron microscopy, and glow discharge optical emission spectroscopy. The coating microstructures and elemental compositions inside wear tracks, as well as the wear products, were examined by scanning electron microscopy, energy-dispersive spectroscopy, and Raman spectroscopy. We demonstrate that simultaneous alloying with Nb and Ag permits to overcome the main drawbacks of TiCN coatings such as their relatively high values of friction coefficient at elevated temperatures and low oxidation resistance. It is shown that a relatively high amount of Ag (15 at.%) is required to provide enhanced tribological behavior in a wide temperature range of 25–700 °C. In addition, the prepared Ag-doped coatings demonstrated active oxidation protection and self-healing functionality due to the segregation of Ag metallic particles in damage areas such as cracks, pin-holes, or oxidation sites.

Formation of Medium Carbon TRIP Steel Microstructure During Annealing in the Intercritical Temperature Range

Directory of Open Access Journals (Sweden)

Kokosza A.

2014-10-01

Full Text Available The paper presents the results of research conducted on austenite formation in the microstructure of 41MnSi6-5 TRIP steel during annealing in the intercritical temperature range. The influence of the annealing temperature on the volume fraction of retained austenite in the microstructure of the investigated steel after water quenching was also determined.

Communication: Anomalous temperature dependence of the intermediate range order in phosphonium ionic liquids

International Nuclear Information System (INIS)

Hettige, Jeevapani J.; Kashyap, Hemant K.; Margulis, Claudio J.

2014-01-01

In a recent article by the Castner and Margulis groups [Faraday Discuss. 154, 133 (2012)], we described in detail the structure of the tetradecyltrihexylphosphonium bis(trifluoromethylsulfonyl)-amide ionic liquid as a function of temperature using X-ray scattering, and theoretical partitions of the computationally derived structure function. Interestingly, and as opposed to the case in most other ionic-liquids, the first sharp diffraction peak or prepeak appears to increase in intensity as temperature is increased. This phenomenon is counter intuitive as one would expect that intermediate range order fades as temperature increases. This Communication shows that a loss of hydrophobic tail organization at higher temperatures is counterbalanced by better organization of polar components giving rise to the increase in intensity of the prepeak

Temperature-sensitive host range mutants of herpes simplex virus type 2

International Nuclear Information System (INIS)

Koment, R.W.; Rapp, F.

1975-01-01

Herpesviruses are capable of several types of infection of a host cell. To investigate the early events which ultimately determine the nature of the virus-host cell interaction, a system was established utilizing temperature-sensitive mutants of herpes simplex virus type 2. Four mutants have been isolated which fail to induce cytopathic effects and do not replicate at 39 C in hamster embryo fibroblast cells. At least one mutant is virus DNA negative. Since intracellular complementation is detectable between pairs of mutants, a virus function is known to be temperature sensitive. However, all four mutants induce cytopathic effects and replicate to parental virus levels in rabbit kidney cells at 39 C. This suggests that a host cell function, lacking or nonfunctional in HEF cells but present in rabbit kidney cells at 39 C, is required for the replication of these mutants in hamster embryo fibroblast cells at 39 C. Therefore, we conclude that these mutants are both temperature sensitive and exhibit host range properties

NOAA's Strategy to Improve Operational Weather Prediction Outlooks at Subseasonal Time Range

Science.gov (United States)

Schneider, T.; Toepfer, F.; Stajner, I.; DeWitt, D.

2017-12-01

NOAA is planning to extend operational global numerical weather prediction to sub-seasonal time range under the auspices of its Next Generation Global Prediction System (NGGPS) and Extended Range Outlook Programs. A unification of numerical prediction capabilities for weather and subseasonal to seasonal (S2S) timescales is underway at NOAA using the Finite Volume Cubed Sphere (FV3) dynamical core as the basis for the emerging unified system. This presentation will overview NOAA's strategic planning and current activities to improve prediction at S2S time-scales that are ongoing in response to the Weather Research and Forecasting Innovation Act of 2017, Section 201. Over the short-term, NOAA seeks to improve the operational capability through improvements to its ensemble forecast system to extend its range to 30 days using the new FV3 Global Forecast System model, and by using this system to provide reforecast and re-analyses. In parallel, work is ongoing to improve NOAA's operational product suite for 30 day outlooks for temperature, precipitation and extreme weather phenomena.

Wide-Temperature Electrolytes for Lithium-Ion Batteries.

Science.gov (United States)

Li, Qiuyan; Jiao, Shuhong; Luo, Langli; Ding, Michael S; Zheng, Jianming; Cartmell, Samuel S; Wang, Chong-Min; Xu, Kang; Zhang, Ji-Guang; Xu, Wu

2017-06-07

Formulating electrolytes with solvents of low freezing points and high dielectric constants is a direct approach to extend the service-temperature range of lithium (Li)-ion batteries (LIBs). In this study, we report such wide-temperature electrolyte formulations by optimizing the ethylene carbonate (EC) content in the ternary solvent system of EC, propylene carbonate (PC), and ethyl methyl carbonate (EMC) with LiPF 6 salt and CsPF 6 additive. An extended service-temperature range from -40 to 60 °C was obtained in LIBs with lithium nickel cobalt aluminum oxide (LiNi 0.80 Co 0.15 Al 0.05 O 2 , NCA) as cathode and graphite as anode. The discharge capacities at low temperatures and the cycle life at room temperature and elevated temperatures were systematically investigated together with the ionic conductivity and phase-transition behaviors. The most promising electrolyte formulation was identified as 1.0 M LiPF 6 in EC-PC-EMC (1:1:8 by wt) with 0.05 M CsPF 6 , which was demonstrated in both coin cells of graphite∥NCA and 1 Ah pouch cells of graphite∥LiNi 1/3 Mn 1/3 Co 1/3 O 2 . This optimized electrolyte enables excellent wide-temperature performances, as evidenced by the high capacity retention (68%) at -40 °C and C/5 rate, significantly higher than that (20%) of the conventional LIB electrolyte, and the nearly identical stable cycle life as the conventional LIB electrolyte at room temperature and elevated temperatures up to 60 °C.

Species-specific physiological response by the cold-water corals Lophelia pertusa and Madrepora oculata to variations within their natural temperature range

Science.gov (United States)

Naumann, Malik S.; Orejas, Covadonga; Ferrier-Pagès, Christine

2014-01-01

The scleractinian cold-water corals (CWC) Lophelia pertusa and Madrepora oculata represent two major deep-sea reef-forming species that act as key ecosystem engineers over a wide temperature range, extending from the northern Atlantic (ca. 5-9 °C) to the Mediterranean Sea (ca. 11-13 °C). Recent research suggests that environmental parameters, such as food supply, settling substrate availability or aragonite saturation state may represent important precursors controlling habitat suitability for CWC. However, the effect of one principal environmental factor, temperature, on CWC key physiological processes is still unknown. In order to evaluate this effect on calcification, respiration, and dissolved organic carbon (DOC) net flux, colonies of Mediterranean L. pertusa and M. oculata were acclimated in aquaria to three temperatures (12, 9 and 6 °C), by consecutive decrements of 1 month duration. L. pertusa and M. oculata maintained at Mediterranean control conditions (i.e. 12 °C) displayed constant rates, on average respiring 4.8 and 4.0 μmol O2 cm-2 coral surface area d-1, calcifying 22.3 and 12.3 μmol CaCO3 g-1 skeletal dry weight d-1 and net releasing 2.6 and 3.1 μmol DOC cm-2 coral surface area d-1, respectively. Respiration of L. pertusa was not affected by lowered temperatures, while M. oculata respiration declined significantly (by 48%) when temperature decreased to 9 °C and 6 °C relative to controls. L. pertusa calcification at 9 °C was similar to controls, but decreased significantly (by 58%) at 6 °C. For M. oculata, calcification declined by 41% at 9 °C and by 69% at 6 °C. DOC net flux was similar throughout the experiment for both CWC. These findings reveal species-specific physiological responses by CWC within their natural temperature range. L. pertusa shows thermal acclimation in respiration and calcification, while these mechanisms appear largely absent in M. oculata. Conclusively, species-specific thermal acclimation may significantly affect

Plastic behaviour of Zircaloy-4 in the temperature range 77-1000 K

International Nuclear Information System (INIS)

Derep, J.L.; Ibrahim, S.; Rouby, D.; Fantozzi, G.; Gobin, P.

1979-01-01

Tensile tests were carried out on Zircaloy-4 over a temperature range 77-1000 K. So, we have determined the flow stress variations as a function of temperature and strain rate. Two thermally activated zones were observed between about 77 and 600 K, a plateau stress between 600 and 700 K and an other thermally activated zone above 700 K. The various mechanisms which can be responsible for the thermally activated and athermal zones are discussed in the light of experimental results. The mechanical behaviour of Zircaloy-4 appears similar to the zirconium-oxygen alloys one. (orig.) [de

A luminescent Lanthanide-free MOF nanohybrid for highly sensitive ratiometric temperature sensing in physiological range.

Science.gov (United States)

Zhou, You; Zhang, Denan; Zeng, Jin; Gan, Ning; Cuan, Jing

2018-05-01

Luminescent MOF materials with tunable emissions and energy/charge transfer processes have been extensively explored as ratiometric temperature sensors. However, most of the ratiometric MOF thermometers reported thus far are based on the MOFs containing photoactive lanthanides, which are potentially facing cost issue and serious supply shortage. Here, we present a ratiometric luminescent thermometer based on a dual-emitting lanthanide-free MOF hybrid, which is developed by encapsulation of a fluorescent dye into a robust nanocrystalline zirconium-based MOF through a one-pot synthesis approach. The structure and morphology of the hybrid product was characterized by Powder X-ray diffraction (PXRD), N 2 adsorption-desorption measurement and Scanning electron microscopy (SEM). The pore confinement effect well isolates the guest dye molecules and therefore suppresses the nonradiative energy transfer process between dye molecules. The incorporated dye emission is mainly sensitized by the organic linkers within MOF through fluorescence resonance energy transfer. The ratiometric luminescence of the MOF hybrid shows a significant response to temperature due to the thermal-related back energy transfer process from dye molecules and organic linkers, thus can be exploited for self-calibrated temperature sensing. The maximum thermometric sensitivity is 1.19% °C -1 in the physiological temperature range, which is among the highest for the ratiomtric MOF thermometers that operating in 25-45°C. The temperature resolution is better than 0.1°C over the entire operative range (20-60°C). By integrating the advantages of excellent stability, nanoscale nature, and high sensitivity and precision in the physiological temperature range, this dye@MOF hybrid might have potential application in biomedical diagnosis. What' more, this work has expanded the possibility of non-lanthanide luminescent MOF materials for the development of ratiometric temperature sensors. Copyright © 2018

Asymetric change of daily temperature range: Proceedings

Energy Technology Data Exchange (ETDEWEB)

Kukla, G. [ed.] [Columbia Univ., Palisades, NY (United States). Lamont-Doherty Earth Observatory; Karl, T.R. [ed.] [National Climatic Data Center, Asheville, NC (United States); Riches, M.R. [ed.] [USDOE, Washington, DC (United States)

1994-04-01

This report is a compilation of abstracts of papers presented at the MINIMAX workshop. Topics include; temperature fluxes, influence of clouds on temperature, anthropogenic influences on temperature flux, and carbon dioxide and aerosol induced greenhouse effect.

Asymetric change of daily temperature range: Proceedings

International Nuclear Information System (INIS)

Kukla, G.; Riches, M.R.

1994-04-01

This report is a compilation of abstracts of papers presented at the MINIMAX workshop. Topics include; temperature fluxes, influence of clouds on temperature, anthropogenic influences on temperature flux, and carbon dioxide and aerosol induced greenhouse effect

TOPLAR: Time of Flight with Larmor Precessions - or - How to extend the dynamic range of NSE spectrometers

International Nuclear Information System (INIS)

Van Well, A.A.; Bleuel, M.; Pappas, C.

2011-01-01

Neutron Spin Echo (NSE) spectrometers typically cover a dynamic range of three orders of magnitude at a given wavelength. At long Fourier times the limits are given by the homogeneity of precession fields. At short Fourier times, the quasi-elastic approximation and the NSE formalism mark a methodological limit. We propose to overcome this limitation and by combining Time Of Flight with Larmor precession to extend the capabilities of Neutron Spin Echo spectrometers towards short Fourier times. TOFLAR should be easily implemented on NSE spectrometers equipped with a chopper system such as IN15 or the planned WASP. (authors)

Brightness temperature of the ''quiet'' Sun in the millimeter wavelength range

International Nuclear Information System (INIS)

Pelyushenko, S.A.

1982-01-01

Results are presented of recalibration of the data available for measurements of the solar brightness temperature Tsub(s) made by comparison with the lunar radio emission. A spectrum has been obtained of the ''quiet'' Sun radio emission in the range of 1-20 mm. The mean square spread of data does not exceed +-(from 3 to 4)%. The ''quiet'' Sun spectrum has a form of: Tsub(c)=(6150+-70)lambdasup(01+-0.01)[mm]K in the wavelength interval of lambda=(1-6) mm and Tsub(c)=(3470+-80)lambdasup(0.42+-0.01) [mm]K in the wavelength interval of lambda=(7-20) mm on approximation of recalibrated values of Tsub(c) with a linear dependence using the mean-square-root method. The obtained spectral characteristics of the ''quiet'' Sun radio frequency emission in the mullimeter wavelength range testify on the spectrum flatteming in the (1-6) mm wavelength range

Effect of thermal cycling on the transformation temperature ranges of a Ni-Ti shape memory alloy

International Nuclear Information System (INIS)

Paula, A.S.; Canejo, J.P.H.G.; Martins, R.M.S.; Braz Fernandes, F.M.

2003-01-01

Shape memory alloys (SMA) represents a class of metallic materials that has the capability of recovering a previously defined initial shape when subject to an adequate thermomechanical treatment. The present work aims to study the influence of thermal cycles on the transition temperatures of a Ni-Ti alloy. In this system, small variations around the equiatomic composition give rise to significant transformation temperature variations ranging from 173 to 373 K. SMA usually presents the shape memory effect after an annealing treatment at ca. 973 K. The optimisation of the thermomechanical treatment will allow to 'tune' the material to different transformation temperature ranges from the same starting material, just by changing the processing conditions. Differential scanning calorimeter (DSC) and in situ high-temperature X-ray diffraction (XRD) have been used to identify the transformation temperatures and the phases that are present after different thermal cycles. The results concerning a series of thermal cycles with different heating and cooling rates (from 1.67x10 -2 to 1.25x10 -1 K/s) and different holding temperatures (from 473 to 1033 K) are presented

Extended-Range Passive RFID and Sensor Tags

Science.gov (United States)

Fink, Patrick W.; Kennedy, Timothy F.; Lin, Gregory Y.; Barton, Richard

2012-01-01

Extended-range passive radio-frequency identification (RFID) tags and related sensor tags are undergoing development. A tag of this type incorporates a retroreflective antenna array, so that it reflects significantly more signal power back toward an interrogating radio transceiver than does a comparable passive RFID tag of prior design, which does not incorporate a retroreflective antenna array. Therefore, for a given amount of power radiated by the transmitter in the interrogating transceiver, a tag of this type can be interrogated at a distance greater than that of the comparable passive RFID or sensor tag of prior design. The retroreflective antenna array is, more specifically, a Van Atta array, named after its inventor and first published in a patent issued in 1959. In its simplest form, a Van Atta array comprises two antenna elements connected by a transmission line so that the signal received by each antenna element is reradiated by the other antenna element (see Figure 1). The phase relationships among the received and reradiated signals are such as to produce constructive interference of the reradiated signals; that is, to concentrate the reradiated signal power in a direction back toward the source. Hence, an RFID tag equipped with a Van Atta antenna array automatically tracks the interrogating transceiver. The effective gain of a Van Atta array is the same as that of a traditional phased antenna array having the same number of antenna elements. Additional pairs of antenna elements connected by equal-length transmission lines can be incorporated into a Van Atta array to increase its directionality. Like some RFID tags here-to-fore commercially available, an RFID or sensor tag of the present developmental type includes one-port surface-acoustic-wave (SAW) devices. In simplified terms, the mode of operation of a basic one-port SAW device as used heretofore in an RFID device is the following: An interrogating radio signal is converted, at an input end, from

Investigation of Kodak extended dose range (EDR) film for megavoltage photon beam dosimetry

International Nuclear Information System (INIS)

Chetty, Indrin J.; Charland, Paule M.

2002-01-01

We have investigated the dependence of the measured optical density on the incident beam energy, field size and depth for a new type of film, Kodak extended dose range (Kodak EDR). Film measurements have been conducted over a range of field sizes (3x3 cm 2 to 25x25 cm 2 ) and depths (d max to 15 cm), for 6 MV and 15 MV photons within a solid water phantom, and the variation in sensitometric response (net optical density versus dose) has been reported. Kodak EDR film is found to have a linear response with dose, from 0 to 350 cGy, which is much higher than that typically seen for Kodak XV film (0-50 cGy). The variation in sensitometric response for Kodak EDR film as a function of field size and depth is observed to be similar to that of Kodak XV film; the optical density varied in the order of 2-3% for field sizes of 3x3 cm 2 and 10x10 cm 2 at depths of d max , 5 cm and 15 cm in the phantom. Measurements for a 25x25 cm 2 field size showed consistently higher optical densities at depths of d max , 5 cm and 15 cm, relative to a 10x10 cm 2 field size at 5 cm depth, with 4-5% differences noted at a depth of 15 cm. Fractional depth dose and profiles conducted with Kodak EDR film showed good agreement (2%/2 mm) with ion chamber measurements for all field sizes except for the 25x25 cm 2 at depths greater than 15 cm, where differences in the order of 3-5% were observed. In addition, Kodak EDR film measurements were found to be consistent with those of Kodak XV film for all fractional depth doses and profiles. The results of this study indicate that Kodak EDR film may be a useful tool for relative dosimetry at higher dose ranges. (author)

Investigation of Kodak extended dose range (EDR) film for megavoltage photon beam dosimetry.

Science.gov (United States)

Chetty, Indrin J; Charland, Paule M

2002-10-21

We have investigated the dependence of the measured optical density on the incident beam energy, field size and depth for a new type of film, Kodak extended dose range (Kodak EDR). Film measurements have been conducted over a range of field sizes (3 x 3 cm2 to 25 x 25 cm2) and depths (d(max) to 15 cm), for 6 MV and 15 MV photons within a solid water phantom, and the variation in sensitometric response (net optical density versus dose) has been reported. Kodak EDR film is found to have a linear response with dose, from 0 to 350 cGy, which is much higher than that typically seen for Kodak XV film (0-50 cGy). The variation in sensitometric response for Kodak EDR film as a function of field size and depth is observed to be similar to that of Kodak XV film; the optical density varied in the order of 2-3% for field sizes of 3 x 3 cm2 and 10 x 10 cm2 at depths of d(max), 5 cm and 15 cm in the phantom. Measurements for a 25 x 25 cm2 field size showed consistently higher optical densities at depths of d(max), 5 cm and 15 cm, relative to a 10 x 10 cm2 field size at 5 cm depth, with 4-5% differences noted at a depth of 15 cm. Fractional depth dose and profiles conducted with Kodak EDR film showed good agreement (2%/2 mm) with ion chamber measurements for all field sizes except for the 25 x 25 cm2 at depths greater than 15 cm, where differences in the order of 3-5% were observed. In addition, Kodak EDR film measurements were found to be consistent with those of Kodak XV film for all fractional depth doses and profiles. The results of this study indicate that Kodak EDR film may be a useful tool for relative dosimetry at higher dose ranges.

Wide-range nuclear reactor temperature control using automatically tuned fuzzy logic controller

International Nuclear Information System (INIS)

Ramaswamy, P.; Edwards, R.M.; Lee, K.Y.

1992-01-01

In this paper, a fuzzy logic controller design for optimal reactor temperature control is presented. Since fuzzy logic controllers rely on an expert's knowledge of the process, they are hard to optimize. An optimal controller is used in this paper as a reference model, and a Kalman filter is used to automatically determine the rules for the fuzzy logic controller. To demonstrate the robustness of this design, a nonlinear six-delayed-neutron-group plant is controlled using a fuzzy logic controller that utilizes estimated reactor temperatures from a one-delayed-neutron-group observer. The fuzzy logic controller displayed good stability and performance robustness characteristics for a wide range of operation

Single-ion polymer electrolyte membranes enable lithium-ion batteries with a broad operating temperature range.

Science.gov (United States)

Cai, Weiwei; Zhang, Yunfeng; Li, Jing; Sun, Yubao; Cheng, Hansong

2014-04-01

Conductive processes involving lithium ions are analyzed in detail from a mechanistic perspective, and demonstrate that single ion polymeric electrolyte (SIPE) membranes can be used in lithium-ion batteries with a wide operating temperature range (25-80 °C) through systematic optimization of electrodes and electrode/electrolyte interfaces, in sharp contrast to other batteries equipped with SIPE membranes that display appreciable operability only at elevated temperatures (>60 °C). The performance is comparable to that of batteries using liquid electrolyte of inorganic salt, and the batteries exhibit excellent cycle life and rate performance. This significant widening of battery operation temperatures coupled with the inherent flexibility and robustness of the SIPE membranes makes it possible to develop thin and flexible Li-ion batteries for a broad range of applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The sighting of Howarth’s Hairstreak (Lepidoptera: Lycaenidae: Theclinae: Chrysozephyrus disparatus interpositus Howarth, 1957 from Tenga Valley, Arunachal Pradesh, India, extending its known range

Directory of Open Access Journals (Sweden)

Rachit Pratap Singh

2016-12-01

Full Text Available The butterfly subspecies, Chrysozephyrus disparatus interpositus is sighted at Tenga Valley, Western Arunachal Pradesh, 58 years after its original description, extending its known range eastwards by 350 km. 

Wide Temperature Range DC-DC Boost Converters for Command/Control/Drive Electronics, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — We shall develop wide temperature range DC-DC boost converters that can be fabricated using commercial CMOS foundries. The boost converters will increase the low...

Analysis of the device characteristics of AlGaN/GaN HEMTs over a wide temperature range

International Nuclear Information System (INIS)

Zhao, M.; Liu, X.Y.; Zheng, Y.K.; Li, Yankui; Ouyang, Sihua

2013-01-01

Highlights: ► We report the behavior of the current–voltage characteristics of AlGaN/GaN HEMT in the temperature range of 223–398 K. ► The origin of the leakage current and the current transport behaviors are reported. ► There is a linear relationship between the barrier height and the ideality factor, which is attributed to barrier height in homogeneities. -- Abstract: In this study, we investigate the behavior of the current–voltage (I–V) characteristics of AlGaN/GaN HEMT in the temperature range of 223–398 K. Temperature dependent device characteristics and the current transport mechanism are reported. It is observed that the Schottky barrier height Φ increases and the ideality factor n decreases with temperature. There is a linear relationship between the barrier height and the ideality factor, which is attributed to barrier height inhomogeneities of AlGaN/GaN HEMT. The estimated values of the series resistances (R s ) are in the range of 144.2 Ω at 223 K to 74.3 Ω at 398 K. The Φ, n, R s , G m and Schottky leakage current values are seen to be strongly temperature dependent

Wide-Temperature Electrolytes for Lithium-Ion Batteries

Energy Technology Data Exchange (ETDEWEB)

Li, Qiuyan; Jiao, Shuhong; Luo, Langli; Ding, Michael S.; Zheng, Jianming; Cartmell, Samuel S.; Wang, Chong-Min; Xu, Kang; Zhang, Ji-Guang; Xu, Wu

2017-05-26

Formulating electrolytes with solvents of low freezing points and high dielectric constants is a direct approach to extend the service temperature range of lithium (Li)-ion batteries (LIBs), for which propylene carbonate (PC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), methyl butyrate (MB) are excellent candidates. In this work, we report such low temperature electrolyte formulations by optimizing the content of ethylene carbonate (EC) in the EC-PC-EMC ternary solvent system with LiPF6 salt and CsPF6 additive. An extended service temperature range from 40°C to 60°C was obtained in LIBs with lithium nickel cobalt aluminum mixed oxide (LiNi0.80Co0.15Al0.05O2, NCA) as cathode and graphite as anode. The discharge capacities at low temperatures and the cycle life at room and elevated temperatures were systematically investigated in association with the ionic conductivity and phase transition behaviors. The most promising electrolyte formulation was identified as 1.0 M LiPF6 in EC-PC-EMC (1:1:8 by wt.) with 0.05 M CsPF6, which was demonstrated in both coin cells of graphite||NCA and 1 Ah pouch cells of graphite||LiNi1/3Mn1/3Co1/3O2. This optimized electrolyte enables excellent wide-temperature performances, as evidenced by the 68% capacity retention at 40C and C/5 rate, and nearly identical stable cycle life at room and elevated temperatures up to 60C.

Accurate dew-point measurement over a wide temperature range using a quartz crystal microbalance dew-point sensor

Science.gov (United States)

Kwon, Su-Yong; Kim, Jong-Chul; Choi, Buyng-Il

2008-11-01

Quartz crystal microbalance (QCM) dew-point sensors are based on frequency measurement, and so have fast response time, high sensitivity and high accuracy. Recently, we have reported that they have the very convenient attribute of being able to distinguish between supercooled dew and frost from a single scan through the resonant frequency of the quartz resonator as a function of the temperature. In addition to these advantages, by using three different types of heat sinks, we have developed a QCM dew/frost-point sensor with a very wide working temperature range (-90 °C to 15 °C). The temperature of the quartz surface can be obtained effectively by measuring the temperature of the quartz crystal holder and using temperature compensation curves (which showed a high level of repeatability and reproducibility). The measured dew/frost points showed very good agreement with reference values and were within ±0.1 °C over the whole temperature range.

Accurate dew-point measurement over a wide temperature range using a quartz crystal microbalance dew-point sensor

International Nuclear Information System (INIS)

Kwon, Su-Yong; Kim, Jong-Chul; Choi, Buyng-Il

2008-01-01

Quartz crystal microbalance (QCM) dew-point sensors are based on frequency measurement, and so have fast response time, high sensitivity and high accuracy. Recently, we have reported that they have the very convenient attribute of being able to distinguish between supercooled dew and frost from a single scan through the resonant frequency of the quartz resonator as a function of the temperature. In addition to these advantages, by using three different types of heat sinks, we have developed a QCM dew/frost-point sensor with a very wide working temperature range (−90 °C to 15 °C). The temperature of the quartz surface can be obtained effectively by measuring the temperature of the quartz crystal holder and using temperature compensation curves (which showed a high level of repeatability and reproducibility). The measured dew/frost points showed very good agreement with reference values and were within ±0.1 °C over the whole temperature range

Tensile properties and fracture mechanism of IN-100 superalloy in high temperature range

Directory of Open Access Journals (Sweden)

Milan T. Jovanović

2017-06-01

Full Text Available Tensile properties and fracture mechanism of a polycrystalline IN-100 superalloy have been investigated in the range from room temperature to 900°C. Optical microscopy (OM and transmission electron microscopy (TEM applying replica technique were used for microstructural investigation, whereas scanning electron microscopy (SEM was utilized for fracture study. High temperature tensile tests were carried out in vacuumed chamber. Results show that strength increases up to 700°C, and then sharply decreases with further increase in temperature. Elongation increases very slowly (6-7.5% till 500°C, then decreases to 4.5% at 900°C. Change in elongation may be ascribed to a change of fracture mechanism. Appearance of a great number of microvoids prevails up to 500°C resulting in a slow increase of elongation, whereas above this temperature elongation decrease is correlated with intergranular crystallographic fracture and fracture of carbides.

Evaluations of Extended-Range tropical Cyclone Forecasts in the Western North Pacific by using the Ensemble Reforecasts: Preliminary Results

Science.gov (United States)

Tsai, Hsiao-Chung; Chen, Pang-Cheng; Elsberry, Russell L.

2017-04-01

The objective of this study is to evaluate the predictability of the extended-range forecasts of tropical cyclone (TC) in the western North Pacific using reforecasts from National Centers for Environmental Prediction (NCEP) Global Ensemble Forecast System (GEFS) during 1996-2015, and from the Climate Forecast System (CFS) during 1999-2010. Tsai and Elsberry have demonstrated that an opportunity exists to support hydrological operations by using the extended-range TC formation and track forecasts in the western North Pacific from the ECMWF 32-day ensemble. To demonstrate this potential for the decision-making processes regarding water resource management and hydrological operation in Taiwan reservoir watershed areas, special attention is given to the skill of the NCEP GEFS and CFS models in predicting the TCs affecting the Taiwan area. The first objective of this study is to analyze the skill of NCEP GEFS and CFS TC forecasts and quantify the forecast uncertainties via verifications of categorical binary forecasts and probabilistic forecasts. The second objective is to investigate the relationships among the large-scale environmental factors [e.g., El Niño Southern Oscillation (ENSO), Madden-Julian Oscillation (MJO), etc.] and the model forecast errors by using the reforecasts. Preliminary results are indicating that the skill of the TC activity forecasts based on the raw forecasts can be further improved if the model biases are minimized by utilizing these reforecasts.

Relation of extended Van Hove singularities to high-temperature superconductivity within strong-coupling theory

International Nuclear Information System (INIS)

Radtke, R.J.; Norman, M.R.

1994-01-01

Recent angle-resolved photoemission (ARPES) experiments have indicated that the electronic dispersion in some of the cuprates possesses an extended saddle point near the Fermi level which gives rise to a density of states that diverges like a power law instead of the weaker logarithmic divergence usually considered. We investigate whether this strong singularity can give rise to high transition temperatures by computing the critical temperature T c and isotope effect coefficient α within a strong-coupling Eliashberg theory which accounts for the full energy variation of the density of states. Using band structures extracted from ARPES measurements, we demonstrate that, while the weak-coupling solutions suggest a strong influence of the strength of the Van Hove singularity on T c and α, strong-coupling solutions show less sensitivity to the singularity strength and do not support the hypothesis that band-structure effects alone can account for either the large T c 's or the different T c 's within the copper oxide family. This conclusion is supported when our results are plotted as a function of the physically relevant self-consistent coupling constant, which shows universal behavior at very strong coupling

Tribological behavior and self-healing functionality of TiNbCN-Ag coatings in wide temperature range

Science.gov (United States)

Bondarev, A. V.; Kiryukhantsev-Korneev, Ph. V.; Levashov, E. A.; Shtansky, D. V.

2017-02-01

Ag- and Nb-doped TiCN coatings with about 2 at.% of Nb and Ag contents varied between 4.0 and 15.1 at.% were designed as promising materials for tribological applications in a wide temperature range. We report on the structure, mechanical, and tribological properties of TiNbCN-Ag coatings fabricated by simultaneous co-sputtering of TiC0.5 + 10%Nb2C and Ag targets in comparison with those of Ag-free coating. The tribological characteristics were evaluated during constant-temperature tests both at room temperature and 300 °C, as well as during dynamic temperature ramp tests in the range of 25-700 °C. The coating structure and elemental composition were studied by means of X-ray diffraction, scanning and transmission electron microscopy, and glow discharge optical emission spectroscopy. The coating microstructures and elemental compositions inside wear tracks, as well as the wear products, were examined by scanning electron microscopy, energy-dispersive spectroscopy, and Raman spectroscopy. We demonstrate that simultaneous alloying with Nb and Ag permits to overcome the main drawbacks of TiCN coatings such as their relatively high values of friction coefficient at elevated temperatures and low oxidation resistance. It is shown that a relatively high amount of Ag (15 at.%) is required to provide enhanced tribological behavior in a wide temperature range of 25-700 °C. In addition, the prepared Ag-doped coatings demonstrated active oxidation protection and self-healing functionality due to the segregation of Ag metallic particles in damage areas such as cracks, pin-holes, or oxidation sites.

A broadening temperature sensitivity range with a core-shell YbEr@YbNd double ratiometric optical nanothermometer

Science.gov (United States)

Marciniak, L.; Prorok, K.; Francés-Soriano, L.; Pérez-Prieto, J.; Bednarkiewicz, A.

2016-02-01

The chemical architecture of lanthanide doped core-shell up-converting nanoparticles can be engineered to purposely design the properties of luminescent nanomaterials, which are typically inaccessible to their homogeneous counterparts. Such an approach allowed to shift the up-conversion excitation wavelength from ~980 to the more relevant ~808 nm or enable Tb or Eu up-conversion emission, which was previously impossible to obtain or inefficient. Here, we address the issue of limited temperature sensitivity range of optical lanthanide based nano-thermometers. By covering Yb-Er co-doped core nanoparticles with the Yb-Nd co-doped shell, we have intentionally combined temperature dependent Er up-conversion together with temperature dependent Nd --> Yb energy transfer, and thus have expanded the temperature response range ΔT of a single nanoparticle based optical nano-thermometer under single ~808 nm wavelength photo-excitation from around ΔT = 150 K to over ΔT = 300 K (150-450 K). Such engineered nanocrystals are suitable for remote optical temperature measurements in technology and biotechnology at the sub-micron scale.The chemical architecture of lanthanide doped core-shell up-converting nanoparticles can be engineered to purposely design the properties of luminescent nanomaterials, which are typically inaccessible to their homogeneous counterparts. Such an approach allowed to shift the up-conversion excitation wavelength from ~980 to the more relevant ~808 nm or enable Tb or Eu up-conversion emission, which was previously impossible to obtain or inefficient. Here, we address the issue of limited temperature sensitivity range of optical lanthanide based nano-thermometers. By covering Yb-Er co-doped core nanoparticles with the Yb-Nd co-doped shell, we have intentionally combined temperature dependent Er up-conversion together with temperature dependent Nd --> Yb energy transfer, and thus have expanded the temperature response range ΔT of a single nanoparticle

Effect of processor temperature on film dosimetry

International Nuclear Information System (INIS)

Srivastava, Shiv P.; Das, Indra J.

2012-01-01

Optical density (OD) of a radiographic film plays an important role in radiation dosimetry, which depends on various parameters, including beam energy, depth, field size, film batch, dose, dose rate, air film interface, postexposure processing time, and temperature of the processor. Most of these parameters have been studied for Kodak XV and extended dose range (EDR) films used in radiation oncology. There is very limited information on processor temperature, which is investigated in this study. Multiple XV and EDR films were exposed in the reference condition (d max. , 10 × 10 cm 2 , 100 cm) to a given dose. An automatic film processor (X-Omat 5000) was used for processing films. The temperature of the processor was adjusted manually with increasing temperature. At each temperature, a set of films was processed to evaluate OD at a given dose. For both films, OD is a linear function of processor temperature in the range of 29.4–40.6°C (85–105°F) for various dose ranges. The changes in processor temperature are directly related to the dose by a quadratic function. A simple linear equation is provided for the changes in OD vs. processor temperature, which could be used for correcting dose in radiation dosimetry when film is used.

The dynamical mechanical properties of tungsten under compression at working temperature range of divertors

International Nuclear Information System (INIS)

Zhu, C.C.; Song, Y.T.; Peng, X.B.; Wei, Y.P.; Mao, X.; Li, W.X.; Qian, X.Y.

2016-01-01

In the divertor structure of ITER and EAST with mono-block module, tungsten plays not only a role of armor material but also a role of structural material, because electromagnetic (EM) impact will be exerted on tungsten components in VDEs or CQ. The EM loads can reach to 100 MN, which would cause high strain rates. In addition, directly exposed to high-temperature plasma, the temperature regime of divertor components is complex. Aiming at studying dynamical response of tungsten divertors under EM loads, an experiment on tungsten employed in EAST divertors was performed using a Kolsky bar system. The testing strain rates and temperatures is derived from actual working conditions, which makes the constitutive equation concluded by using John-Cook model and testing data very accurate and practical. The work would give a guidance to estimate the dynamical response, fatigue life and damage evolution of tungsten divertor components under EM impact loads. - Graphical abstract: From the comparison between the experimental curves and the predicted curves calculated by adopting the corrected m, it is very clear that the new model is of great capability to explain the deformation behavior of the tungsten material under dynamic compression at high temperatures. (EC, PC and PCM refers to experimental curve, predicted curve and predicted curve with a corrected m. Different colors represent different scenarios.). - Highlights: • Test research on dynamic properties of tungsten at working temperature range and strain rate range of divertors. • Constitutive equation descrbing strain hardening, strain rate hardening and temperature softening. • A guidance to estimate dynamical response and damage evolution of tungsten divertor components under impact.

Glassy aerosols with a range of compositions nucleate ice heterogeneously at cirrus temperatures

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T. W. Wilson

2012-09-01

Full Text Available Atmospheric secondary organic aerosol (SOA is likely to exist in a semi-solid or glassy state, particularly at low temperatures and humidities. Previously, it has been shown that glassy aqueous citric acid aerosol is able to nucleate ice heterogeneously under conditions relevant to cirrus in the tropical tropopause layer (TTL. In this study we test if glassy aerosol distributions with a range of chemical compositions heterogeneously nucleate ice under cirrus conditions. Three single component aqueous solution aerosols (raffinose, 4-hydroxy-3-methoxy-DL-mandelic acid (HMMA and levoglucosan and one multi component aqueous solution aerosol (raffinose mixed with five dicarboxylic acids and ammonium sulphate were studied in both the liquid and glassy states at a large cloud simulation chamber. The investigated organic compounds have similar functionality to oxidised organic material found in atmospheric aerosol and have estimated temperature/humidity induced glass transition thresholds that fall within the range predicted for atmospheric SOA. A small fraction of aerosol particles of all compositions were found to nucleate ice heterogeneously in the deposition mode at temperatures relevant to the TTL (<200 K. Raffinose and HMMA, which form glasses at higher temperatures, nucleated ice heterogeneously at temperatures as high as 214.6 and 218.5 K respectively. We present the calculated ice active surface site density, n_s, of the aerosols tested here and also of glassy citric acid aerosol as a function of relative humidity with respect to ice (RH_i. We also propose a parameterisation which can be used to estimate heterogeneous ice nucleation by glassy aerosol for use in cirrus cloud models up to ~220 K. Finally, we show that heterogeneous nucleation by glassy aerosol may compete with ice nucleation on mineral dust particles in mid-latitudes cirrus.

The relationship between brightness temperature and soil moisture. Selection of frequency range for microwave remote sensing

International Nuclear Information System (INIS)

Rao, K.S.; Chandra, G.; Rao, P.V.N.

1987-01-01

The analysis of brightness temperature data acquired from field and aircraft experiments demonstrates a linear relationship between soil moisture and brightness temperature. However, the analysis of brightness temperature data acquired by the Skylab radiometer demonstrates a non-linear relationship between soil moisture and brightness temperature. In view of the above and also because of recent theoretical developments for the calculation of the dielectric constant and brightness temperature under varying soil moisture profile conditions, an attempt is made to study the theoretical relationship between brightness temperature and soil moisture as a function of frequency. Through the above analysis, the appropriate microwave frequency range for soil moisture studies is recommended

Computer calculation of heat capacity of natural gases over a wide range of pressure and temperature

Energy Technology Data Exchange (ETDEWEB)

Dranchuk, P.M. (Alberta Univ., Edmonton, AB (Canada)); Abou-Kassem, J.H. (Pennsylvania State Univ., University Park, PA (USA))

1992-04-01

A method is presented whereby specific heats or heat capacities of natural gases, both sweet and sour, at elevated pressures and temperatures may be made suitable to modern-day machine calculation. The method involves developing a correlation for ideal isobaric heat capacity as a function of gas gravity and pseudo reduced temperature over the temperature range of 300 to 1500 K, and a mathematical equation for the isobaric heat capacity departure based on accepted thermodynamic principles applied to an equation of state that adequately describes the behavior of gases to which the Standing and Katz Z factor correlation applies. The heat capacity departure equation is applicable over the range of 0.2 {le} Pr {le} 15 and 1.05 {le} Tr {le} 3, where Pr and Tr refer to the reduced pressure and temperature respectively. The significance of the method presented lies in its utility and adaptability to computer applications. 25 refs., 2 figs., 4 tabs.

Micromechanical properties of C70 single crystals in the temperature range 77-350 K

International Nuclear Information System (INIS)

Lubenets, S.V.; Natsik, V.D.; Fomenko, L.S.; Rusakova, A.V.; Natsik, V.D.; Osip'yan, Yu.A.; Orlov, V.I.; Sidorov, N.S.; Izotov, A.N.

2012-01-01

Hexagonal single crystals of C 70 up to a size down to 1-2 mm were grown which allowed for the first time to investigate their low-temperature mechanical properties. Morphology, microplasticity anisotropy and the temperature dependence of Vickers microhardness HV (T) of the C 70 crystals in the temperature range 77-350 K involving all known phase transitions have been studied with the aid of optical microscopy and microindentation. The association of the features of HV (T) dependence with orientation phase transformations has been analyzed. It is suggested that anisotropy of microplasticity in the C 70 crystals correlates with the active slip systems.

Evolution of extended defects in polycrystalline Au-irradiated UO{sub 2} using in situ TEM: Temperature and fluence effects

Energy Technology Data Exchange (ETDEWEB)

Onofri, C., E-mail: claire.onofri@cea.fr [CEA, DEN, DEC, F-13108 Saint Paul Lez Durance Cedex (France); Sabathier, C. [CEA, DEN, DEC, F-13108 Saint Paul Lez Durance Cedex (France); Baumier, C.; Bachelet, C. [CSNSM/CNRS, PARIS-SUD University, F-91400 Orsay (France); Palancher, H. [CEA, DEN, DEC, F-13108 Saint Paul Lez Durance Cedex (France); Legros, M. [CEMES/CNRS, F-31055 Toulouse Cedex 4 (France)

2016-12-15

In situ Transmission Electron Microscopy irradiations were performed on polycrystalline UO{sub 2} thin foils with 4 MeV gold ions at three different temperatures: 600 °C, room and liquid nitrogen temperature. In order to study the dislocation evolution and to determine the growth mechanisms, the dislocation loop and line densities and the loop size repartition were monitored as a function of fluence, and irradiation temperature. We show that dislocation loops, with Burgers vectors along the <110> directions, evolve into dislocation lines with increasing fluence by a loop overlapping mechanism. Furthermore, a fluence offset is highlighted between the irradiations performed at high and low temperature due to an increase of the defect mobility. Indeed, a growth by Oswald ripening is probably activated at room temperature and 600 °C and changes the kinetic evolution of loops into lines. After this transformation, and for all the irradiation temperatures, a steady state equilibrium is reached where both extended defects (dislocation lines and small dislocations loops -around 5 nm in size-) are observed simultaneously. A continuous nucleation of small dislocation loops and of nanometer-sized cavities formed directly by irradiation is also highlighted.

The temperature dependence of the BK channel activity - kinetics, thermodynamics, and long-range correlations.

Science.gov (United States)

Wawrzkiewicz-Jałowiecka, Agata; Dworakowska, Beata; Grzywna, Zbigniew J

2017-10-01

Large-conductance, voltage dependent, Ca 2+ -activated potassium channels (BK) are transmembrane proteins that regulate many biological processes by controlling potassium flow across cell membranes. Here, we investigate to what extent temperature (in the range of 17-37°C with ΔT=5°C step) is a regulating parameter of kinetic properties of the channel gating and memory effect in the series of dwell-time series of subsequent channel's states, at membrane depolarization and hyperpolarization. The obtained results indicate that temperature affects strongly the BK channels' gating, but, counterintuitively, it exerts no effect on the long-range correlations, as measured by the Hurst coefficient. Quantitative differences between dependencies of appropriate channel's characteristics on temperature are evident for different regimes of voltage. Examining the characteristics of BK channel activity as a function of temperature allows to estimate the net activation energy (E act ) and changes of thermodynamic parameters (ΔH, ΔS, ΔG) by channel opening. Larger E act corresponds to the channel activity at membrane hyperpolarization. The analysis of entropy and enthalpy changes of closed to open channel's transition suggest the entropy-driven nature of the increase of open state probability during voltage activation and supports the hypothesis about the voltage-dependent geometry of the channel vestibule. Copyright © 2017 Elsevier B.V. All rights reserved.

The extending lithosphere (Arthur Holmes Medal Lecture)

Science.gov (United States)

Brun, Jean-Pierre

2017-04-01

Extension of the lithosphere gives birth to a wide range of structures, with characteristic widths between 10 and 1000 km, which includes continental rifts, passive margins, oceanic rifts, core complexes, or back-arc basins. Because the rheology of rocks strongly depends on temperature, this variety of extensional structures falls in two broad categories of extending lithospheres according to the initial Moho temperature TM. "Cold extending systems", with TM 750°C and crustal-dominated strength, lead, depending on strain rate, to either wide rifts or metamorphic core complexes. A much less quoted product of extension is the exhumation of high-pressure (HP ) metamorphic rocks occurring in domains of back-arc extension driven by slab rollback (e.g. Aegean; Appennines-Calabrian) or when the subduction upper plate undergoes extension for plate kinematics reasons (e.g. Norwegian Caledonides; Papua New Guinea). In these tectonic environments, well-documented pressure-temperature-time (P - T - t) paths of HP rocks show a two-stage retrogression path whose the first part corresponds to an isothermal large pressure drop ΔP proportional to the maximum pressure Pmax recorded by the rocks. This linear relation between ΔP and Pmax, which likely results from a stress switch between compression and extension at the onset of exhumation, is in fact observed in all HP metamorphism provinces worldwide, suggesting that the exhumation of HP rocks in extension is a general process rather than an uncommon case. In summary, the modes and products of extension are so diverse that, taken all together, they constitute a very versatile natural laboratory to decipher the rheological complexities of the continental lithosphere and their mechanical implications.

Scale-invariant extended inflation

International Nuclear Information System (INIS)

Holman, R.; Kolb, E.W.; Vadas, S.L.; Wang, Y.

1991-01-01

We propose a model of extended inflation which makes use of the nonlinear realization of scale invariance involving the dilaton coupled to an inflaton field whose potential admits a metastable ground state. The resulting theory resembles the Jordan-Brans-Dicke version of extended inflation. However, quantum effects, in the form of the conformal anomaly, generate a mass for the dilaton, thus allowing our model to evade the problems of the original version of extended inflation. We show that extended inflation can occur for a wide range of inflaton potentials with no fine-tuning of dimensionless parameters required. Furthermore, we also find that it is quite natural for the extended-inflation period to be followed by an epoch of slow-rollover inflation as the dilaton settles down to the minimum of its induced potential

Defining the temperature range for cooking with extra virgin olive oil using Raman spectroscopy

Science.gov (United States)

Ahmad, Naveed; Saleem, M.; Ali, H.; Bilal, M.; Khan, Saranjam; Ullah, Rahat; Ahmed, M.; Mahmood, S.

2017-09-01

Using the potential of Raman spectroscopy, new findings regarding the effects of heating on extra virgin olive oil (EVOO) during frying/cooking are presented. A temperature range from 140 to 150 °C has been defined within which EVOO can be used for cooking/frying without much loss of its natural molecular composition. Raman spectra from the EVOO samples were recorded using an excitation laser at 785 nm in the range from 540 to 1800 cm-1. Due to heating, prominent variations in intensity are observed at Raman bands from 540 to 770 cm-1, 790 to 1170 cm-1 and 1267 and 1302 cm-1. The Raman bands at 1267 and 1302 cm-1 represent cis unsaturated fats and their ratio is used to investigate the effects of temperature on the molecular composition of EVOO. In addition, principal component analysis has been applied on all the groups of data to classify the heated EVOO samples at different temperatures and for different times. In addition, it has been found that use of EVOO for frying twice does not have any prominent effect on its molecular composition.

Low temperature resistivity studies of SmB6: Observation of two-dimensional variable-range hopping conductivity

Science.gov (United States)

Batkova, Marianna; Batko, Ivan; Gabáni, Slavomír; Gažo, Emil; Konovalova, Elena; Filippov, Vladimir

2018-05-01

We studied electrical resistance of a single-crystalline SmB6 sample with a focus on the region of the "low-temperature resistivity plateau". Our observations did not show any true saturation of the electrical resistance at temperatures below 3 K down to 70 mK. According to our findings, temperature dependence of the electrical conduction in a certain temperature interval above 70 mK can be decomposed into a temperature-independent term and a temperature-activated term that can be described by variable-range hopping formula for two-dimensional systems, exp [ -(T0 / T) 1 / 3 ]. Thus, our results indicate importance of hopping type of electrical transport in the near-surface region of SmB6.

Dynamic mechanical behaviour and dislocation substructure evolution of Inconel 718 over wide temperature range

Energy Technology Data Exchange (ETDEWEB)

Lee, Woei-Shyan, E-mail: wslee@mail.ncku.edu.tw [Department of Mechanical Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Lin, Chi-Feng [National Center for High-Performance Computing, Hsin-Shi Tainan County 744, Taiwan (China); Chen, Tao-Hsing [Department of Mechanical Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 807, Taiwan (China); Chen, Hong-Wei [Department of Mechanical Engineering, National Cheng Kung University, Tainan 701, Taiwan (China)

2011-07-25

A compressive split-Hopkinson pressure bar and transmission electron microscope (TEM) are used to investigate the mechanical behaviour and microstructural evolution of Inconel 718 at strain rates ranging from 1000 to 5000 s{sup -1} and temperatures between -150 and 550 deg. C. The results show that the flow stress increases with an increasing strain rate or a reducing temperature. The strain rate effect is particularly pronounced at strain rates greater than 3000 s{sup -1} and a deformation temperature of -150 deg. C. A significant thermal softening effect occurs at temperatures between -150 and 25 deg. C. The microstructural observations reveal that the strengthening effect in deformed Inconel 718 alloy is a result primarily of dislocation multiplication. The dislocation density increases with increasing strain rate, but decreases with increasing temperature. By contrast, the dislocation cell size decreases with increasing strain rate, but increases with increasing temperature. It is shown that the correlation between the flow stress, the dislocation density and the dislocation cell size is well described by the Bailey-Hirsch constitutive equations.

Raman spectroscopic characterization of CH4 density over a wide range of temperature and pressure

Science.gov (United States)

Shang, Linbo; Chou, I-Ming; Burruss, Robert; Hu, Ruizhong; Bi, Xianwu

2014-01-01

The positions of the CH4 Raman ν1 symmetric stretching bands were measured in a wide range of temperature (from −180 °C to 350 °C) and density (up to 0.45 g/cm3) using high-pressure optical cell and fused silica capillary capsule. The results show that the Raman band shift is a function of both methane density and temperature; the band shifts to lower wavenumbers as the density increases and the temperature decreases. An equation representing the observed relationship among the CH4 ν1 band position, temperature, and density can be used to calculate the density in natural or synthetic CH4-bearing inclusions.

Range-wide latitudinal and elevational temperature gradients for the world's terrestrial birds: implications under global climate change.

Directory of Open Access Journals (Sweden)

Frank A La Sorte

Full Text Available Species' geographical distributions are tracking latitudinal and elevational surface temperature gradients under global climate change. To evaluate the opportunities to track these gradients across space, we provide a first baseline assessment of the steepness of these gradients for the world's terrestrial birds. Within the breeding ranges of 9,014 bird species, we characterized the spatial gradients in temperature along latitude and elevation for all and a subset of bird species, respectively. We summarized these temperature gradients globally for threatened and non-threatened species and determined how their steepness varied based on species' geography (range size, shape, and orientation and projected changes in temperature under climate change. Elevational temperature gradients were steepest for species in Africa, western North and South America, and central Asia and shallowest in Australasia, insular IndoMalaya, and the Neotropical lowlands. Latitudinal temperature gradients were steepest for extratropical species, especially in the Northern Hemisphere. Threatened species had shallower elevational gradients whereas latitudinal gradients differed little between threatened and non-threatened species. The strength of elevational gradients was positively correlated with projected changes in temperature. For latitudinal gradients, this relationship only held for extratropical species. The strength of latitudinal gradients was better predicted by species' geography, but primarily for extratropical species. Our findings suggest threatened species are associated with shallower elevational temperature gradients, whereas steep latitudinal gradients are most prevalent outside the tropics where fewer bird species occur year-round. Future modeling and mitigation efforts would benefit from the development of finer grain distributional data to ascertain how these gradients are structured within species' ranges, how and why these gradients vary among

Measurements on the extended range of the wake

International Nuclear Information System (INIS)

Kumbartzki, G.J.; Kroesing, G; Neuburger, H.

1981-01-01

The Coulomb explosion of H 2 + -ions at 28 MeV is used to probe the wake over a range of about 400 A in Al. Preliminary results give food agreement with the wavelength prediction of the simple plasma oscillation wake model. (author)

Intelligent Energy Management Control for Extended Range Electric Vehicles Based on Dynamic Programming and Neural Network

Directory of Open Access Journals (Sweden)

Lihe Xi

2017-11-01

Full Text Available The extended range electric vehicle (EREV can store much clean energy from the electric grid when it arrives at the charging station with lower battery energy. Consuming minimum gasoline during the trip is a common goal for most energy management controllers. To achieve these objectives, an intelligent energy management controller for EREV based on dynamic programming and neural networks (IEMC_NN is proposed. The power demand split ratio between the extender and battery are optimized by DP, and the control objectives are presented as a cost function. The online controller is trained by neural networks. Three trained controllers, constructing the controller library in IEMC_NN, are obtained from training three typical lengths of the driving cycle. To determine an appropriate NN controller for different driving distance purposes, the selection module in IEMC_NN is developed based on the remaining battery energy and the driving distance to the charging station. Three simulation conditions are adopted to validate the performance of IEMC_NN. They are target driving distance information, known and unknown, changing the destination during the trip. Simulation results using these simulation conditions show that the IEMC_NN had better fuel economy than the charging deplete/charging sustain (CD/CS algorithm. More significantly, with known driving distance information, the battery SOC controlled by IEMC_NN can just reach the lower bound as the EREV arrives at the charging station, which was also feasible when the driver changed the destination during the trip.

Research of resonant losses of ultrasonic sound in the deformed single crystals in temperature range 77...300 K

International Nuclear Information System (INIS)

Petchenko, A.M.; Petchenko, G.A.

2007-01-01

The damped dislocation resonance in preliminary deformed up to 1 % single crystals KBr was investigated. The measurements of a frequency dependence of a dislocation damping decrement of ultrasonic sound were conducted in range of frequencies 7,5...217,5 MHz and temperature range 77...300 K. From the analysis of frequency spectrums the temperature course of a coefficient of phonon viscosity B was determined, which is agreed both with the theory and experimental literary data. The influencing temperature changes of length of a dislocation segment on parameters of a resonant maximum and dynamic drag of dislocations by phonons was revealed and analyzed

Modeling and Simulation of - and Silicon Germanium-Base Bipolar Transistors Operating at a Wide Range of Temperatures.

Science.gov (United States)

Shaheed, M. Reaz

1995-01-01

Higher speed at lower cost and at low power consumption is a driving force for today's semiconductor technology. Despite a substantial effort toward achieving this goal via alternative technologies such as III-V compounds, silicon technology still dominates mainstream electronics. Progress in silicon technology will continue for some time with continual scaling of device geometry. However, there are foreseeable limits on achievable device performance, reliability and scaling for room temperature technologies. Thus, reduced temperature operation is commonly viewed as a means for continuing the progress towards higher performance. Although silicon CMOS will be the first candidate for low temperature applications, bipolar devices will be used in a hybrid fashion, as line drivers or in limited critical path elements. Silicon -germanium-base bipolar transistors look especially attractive for low-temperature bipolar applications. At low temperatures, various new physical phenomena become important in determining device behavior. Carrier freeze-out effects which are negligible at room temperature, become of crucial importance for analyzing the low temperature device characteristics. The conventional Pearson-Bardeen model of activation energy, used for calculation of carrier freeze-out, is based on an incomplete picture of the physics that takes place and hence, leads to inaccurate results at low temperatures. Plasma -induced bandgap narrowing becomes more pronounced in device characteristics at low temperatures. Even with modern numerical simulators, this effect is not well modeled or simulated. In this dissertation, improved models for such physical phenomena are presented. For accurate simulation of carrier freeze-out, the Pearson-Bardeen model has been extended to include the temperature dependence of the activation energy. The extraction of the model is based on the rigorous, first-principle theoretical calculations available in the literature. The new model is shown

Investigation of Breakpoint and Trend of Daily Air Temperature Range for Mashhad, Iran

Directory of Open Access Journals (Sweden)

shideh shams

2017-01-01

Full Text Available Introduction: Air temperature as an important climatic factor can influence variability and distribution of other climatic parameters. Therefore, tracking the changes in air temperature is a popular procedure in climate change studies.. According to the national academy in the last decade, global temperature has raised 0.4 to 0.8⁰C. Instrumental records show that, with the exception of 1998, the 10 warmest year (during the last 150 years, occurred since 2000, and 2014 was the warmest year. Investigation of maximum and minimum air temperature temporal trend indicates that these two parameters behave differently over time. It has been shown that the minimum air temperature raises noticeably more than the maximum air temperature, which causes a reduction in the difference of maximum and minimum daily air temperature (daily temperature range, DTR. There are several factors that have an influence on reducing DTR such as: Urban development, farms’ irrigation and desertification. It has been shown that DTR reduction occurs mostly during winter and is less frequent during summer, which shows the season’s effect on the temperature trend. Considering the significant effects of the climatological factors on economic and agricultural management issues, the aim of this study is to investigate daily air temperature range for yearly, seasonal and monthly time scales, using available statistical methods. Materials and Methods: Daily maximum and minimum air temperature records (from 1950 to 2010 were obtained from Mashhad Meteorological Organization. In order to control the quality of daily Tmax and Tmin data, four different types of quality controls were applied. First of all, gross errors were checked. In this step maximum and minimum air temperature data exceeding unlikely air temperature values, were eliminated from data series. Second, data tolerance was checked by searching for periods longer than a certain number of consecutive days with exactly the

Calibration and assessment of channel-specific biases in microarray data with extended dynamical range.

Science.gov (United States)

Bengtsson, Henrik; Jönsson, Göran; Vallon-Christersson, Johan

2004-11-12

Non-linearities in observed log-ratios of gene expressions, also known as intensity dependent log-ratios, can often be accounted for by global biases in the two channels being compared. Any step in a microarray process may introduce such offsets and in this article we study the biases introduced by the microarray scanner and the image analysis software. By scanning the same spotted oligonucleotide microarray at different photomultiplier tube (PMT) gains, we have identified a channel-specific bias present in two-channel microarray data. For the scanners analyzed it was in the range of 15-25 (out of 65,535). The observed bias was very stable between subsequent scans of the same array although the PMT gain was greatly adjusted. This indicates that the bias does not originate from a step preceding the scanner detector parts. The bias varies slightly between arrays. When comparing estimates based on data from the same array, but from different scanners, we have found that different scanners introduce different amounts of bias. So do various image analysis methods. We propose a scanning protocol and a constrained affine model that allows us to identify and estimate the bias in each channel. Backward transformation removes the bias and brings the channels to the same scale. The result is that systematic effects such as intensity dependent log-ratios are removed, but also that signal densities become much more similar. The average scan, which has a larger dynamical range and greater signal-to-noise ratio than individual scans, can then be obtained. The study shows that microarray scanners may introduce a significant bias in each channel. Such biases have to be calibrated for, otherwise systematic effects such as intensity dependent log-ratios will be observed. The proposed scanning protocol and calibration method is simple to use and is useful for evaluating scanner biases or for obtaining calibrated measurements with extended dynamical range and better precision. The

Long-term strength of claddings made of E110 in the temperature range of 400-570 degrees C

International Nuclear Information System (INIS)

Kobylyansky, G.; Shamardin, V.; Eremin, S.

2003-01-01

This paper presents the data on the initial stage of the in-sight into the mechanism of long-term strength of spent fuel rod claddings in the temperature range 400-570 0 C and also their comparison with corresponding mechanism of irradiated in the inert environment specimens and unirradiated ones. A set of test results in the temperature range 400-570 0 C of non-irradiated and irradiated in BOR-60 specimens and also of the WWER-1000 fuel element claddings irradiated up to a burnup of 29-47 MWd/kgU is approximated by Larson-Miller parametric dependence in the first approximation that allows the long-term strength data to be extrapolated and interpolated onto the unknown value regions of stress, temperature and time. The time before damage of the fuel element claddings irradiated up to ∼ 29MWd/kgU in the temperature range 540-570 0 C is higher than that of non-irradiated tubular specimens and irradiated ones up to fast neutron fluence (1-2)x10 22 cm -2 (E >0.1 MeV). With temperature decreasing to 673 K, the long-term strength of the claddings irradiated up to ∼ 47 MWd/kgU is lower than it can be expected from the extrapolation of high-temperature data obtained with the irradiated specimens. Now, the bulk of experimental data on the long-term strength of the claddings made of E110 alloy makes it possible to provide only preliminary estimation for the validation of parameters typical of the deviation from the normal operation conditions; emergencies and accidental situations; dry and wet storage and also transportation. The experiments should be continued to accumulate missing data, in particular, tests of fuel element claddings irradiated up to high burnup at temperatures ranging 300-400 0 C and stresses, which are significantly lower than the yield stress

The enthalpy of solid scandium in the temperature range 406 - 1812 K

International Nuclear Information System (INIS)

Lyapunov, K.M.; Baginskij, A.V.; Stankus, S.V.

2001-01-01

Enthalpy of pure scandium was measured on massive calorimeter in the range from 406 to 1812 K by mixing method. The enthalpy of face centered close cubic lattice - body centered cubic lattice transformation is equal to ΔH t 4068 J/mol. Obtained value within the limits of error is compatible with the results given earlier (4009 J/mol). The dependence of the middle specific heat of scandium C p (T) on the temperature was shown in correlation with the results of other works. The results of the conducted experiments reinforce the conclusion made earlier about an absence (or a little) in the decomposition of an anharmonic component of the oscillation specific heat of scandium C p a (T) members proportional to the first or the second degrees of temperature [ru

High Voltage Gain Dual Active Bridge Converter with an Extended Operation Range for Renewable Energy Systems

DEFF Research Database (Denmark)

Zhang, Zhe; Tomas Manez, Kevin; Yudi, Xiao

2018-01-01

Bridge (P2DAB) converter, i.e. low-voltage (LV) side parallel and high-voltage (HV) side series, is proposed to achieve high voltage gain and low current stress over switching devices and transformer windings. Given the unmodified P2DAB power stage, by regulating the phase-shift angle between......Developing bidirectional dc-dc converters has become a critical research topic and gains more and more attention in recent years due to the extensive applications of smart grids with energy storages, hybrid and electrical vehicles and dc microgrids. In this paper, a Partial Parallel Dual Active...... the paralleled active bridges, the power equations and voltage gain are then modified, and therefore the operation range can be extended effectively. The operating principles of the proposed converter and its power characteristics under various operation modes are studied, and the design constraints...

110 °C range athermalization of wavefront coding infrared imaging systems

Science.gov (United States)

Feng, Bin; Shi, Zelin; Chang, Zheng; Liu, Haizheng; Zhao, Yaohong

2017-09-01

110 °C range athermalization is significant but difficult for designing infrared imaging systems. Our wavefront coding athermalized infrared imaging system adopts an optical phase mask with less manufacturing errors and a decoding method based on shrinkage function. The qualitative experiments prove that our wavefront coding athermalized infrared imaging system has three prominent merits: (1) working well over a temperature range of 110 °C; (2) extending the focal depth up to 15.2 times; (3) achieving a decoded image being approximate to its corresponding in-focus infrared image, with a mean structural similarity index (MSSIM) value greater than 0.85.

Finite-range-scaling analysis of metastability in an Ising model with long-range interactions

International Nuclear Information System (INIS)

Gorman, B.M.; Rikvold, P.A.; Novotny, M.A.

1994-01-01

We apply both a scalar field theory and a recently developed transfer-matrix method to study the stationary properties of metastability in a two-state model with weak, long-range interactions: the Nx∞ quasi-one-dimensional Ising model. Using the field theory, we find the analytic continuation f of the free energy across the first-order transition, assuming that the system escapes the metastable state by the nucleation of noninteracting droplets. We find that corrections to the field dependence are substantial, and, by solving the Euler-Lagrange equation for the model numerically, we have verified the form of the free-energy cost of nucleation, including the first correction. In the transfer-matrix method, we associate with the subdominant eigenvectors of the transfer matrix a complex-valued ''constrained'' free-energy density f α computed directly from the matrix. For the eigenvector with an associated magnetization most strongly opposed to the applied magnetic field, f α exhibits finite-range scaling behavior in agreement with f over a wide range of temperatures and fields, extending nearly to the classical spinodal. Some implications of these results for numerical studies of metastability are discussed

Compact extended model for doppler broadening of neutron absorption resonances in solids

International Nuclear Information System (INIS)

Villanueva, A. J; Granada, J.R

2009-01-01

We present a simplified compact model for calculating Doppler broadening of neutron absorption resonances in an incoherent Debye solid. Our model extends the effective temperature gas model to cover the whole range of energies and temperatures, and reduces the information of the dynamical system to a minimum content compatible with a much better accuracy of the calculation. This model is thus capable of replacing the existing algorithm in standard codes for resonance cross sections preparation aimed at neutron and reactor physics calculations. The model is applied to the 238 U 6.671 eV effective broadened cross section. We also show how this model can be used for thermometry in an improved fashion compared to the effective temperature gas model. Experimental data of the same resonance at low and high temperatures are also shown and the performances of each model are put to the test on this basis. [es

Response matrix of an extended range Bonner sphere spectrometer for the characterization of collimated neutron beams

International Nuclear Information System (INIS)

Bedogni, R.; Esposito, A.; Gomez-Ros, J.M.

2010-01-01

Accelerator-based neutron beams are becoming popular tools for material testing, radiation hardness and soft errors studies. The characterization of these beams in terms of dosimetric and spectrometric quantities is a challenging task, mainly due to their wide energy interval (from thermal up to hundreds MeV) and, in certain facilities like VESUVIO - ISIS (RAL, UK), to their small dimension (few cm in radius). Extended Range Bonner Sphere Spectrometers (ERBSS) would be a valuable tool, due to their wide energy range, good photon discrimination and possibility to choose among different central detectors according to the intensity, photon component and time structure of the field. Nevertheless, the non-uniform irradiation of the spheres could lead to important systematic errors. With the aim of bringing the advantages of ERBSS into the characterization of collimated beams, a dedicated study was performed using the VESUVIO spallation-based collimated beam at ISIS (Rutherford Appleton Laboratory, Oxford). Here a 3.21 cm radius collimated beam was characterized using a Dysprosium activation foil-based ERBSS whose response matrix was recalculated for this specific beam diameter. Besides the results of the experimental campaign, this paper presents the calculation of the response matrix and its dependence on the beam dimension.

Range of monthly mean hourly land surface air temperature diurnal cycle over high northern latitudes

Science.gov (United States)

Wang, Aihui; Zeng, Xubin

2014-05-01

Daily maximum and minimum temperatures over global land are fundamental climate variables, and their difference represents the diurnal temperature range (DTR). While the differences between the monthly averaged DTR (MDTR) and the range of monthly averaged hourly temperature diurnal cycle (RMDT) are easy to understand qualitatively, their differences have not been quantified over global land areas. Based on our newly developed in situ data (Climatic Research Unit) reanalysis (Modern-Era Retrospective analysis for Research and Applications) merged hourly temperature data from 1979 to 2009, RMDT in January is found to be much smaller than that in July over high northern latitudes, as it is much more affected by the diurnal radiative forcing than by the horizontal advection of temperature. In contrast, MDTR in January is comparable to that in July over high northern latitudes, but it is much larger than January RMDT, as it primarily reflects the movement of lower frequency synoptic weather systems. The area-averaged RMDT trends north of 40°N are near zero in November, December, and January, while the trends of MDTR are negative. These results suggest the need to use both the traditional MDTR and RMDT suggested here in future observational and modeling studies. Furthermore, MDTR and its trend are more sensitive to the starting hour of a 24 h day used in the calculations than those for RMDT, and this factor also needs to be considered in model evaluations using observational data.

A Comprehensive Prediction Model of Hydraulic Extended-Reach Limit Considering the Allowable Range of Drilling Fluid Flow Rate in Horizontal Drilling.

Science.gov (United States)

Li, Xin; Gao, Deli; Chen, Xuyue

2017-06-08

Hydraulic extended-reach limit (HERL) model of horizontal extended-reach well (ERW) can predict the maximum measured depth (MMD) of the horizontal ERW. The HERL refers to the well's MMD when drilling fluid cannot be normally circulated by drilling pump. Previous model analyzed the following two constraint conditions, drilling pump rated pressure and rated power. However, effects of the allowable range of drilling fluid flow rate (Q min  ≤ Q ≤ Q max ) were not considered. In this study, three cases of HERL model are proposed according to the relationship between allowable range of drilling fluid flow rate and rated flow rate of drilling pump (Q r ). A horizontal ERW is analyzed to predict its HERL, especially its horizontal-section limit (L h ). Results show that when Q min  ≤ Q r  ≤ Q max (Case I), L h depends both on horizontal-section limit based on rated pump pressure (L h1 ) and horizontal-section limit based on rated pump power (L h2 ); when Q min  drilling fluid flow rate, while L h2 keeps decreasing as the drilling fluid flow rate increases. The comprehensive model provides a more accurate prediction on HERL.

Study of plastic deformation peculiarities in CdS single crystals within the temperature range of 25 to 300 deg C

International Nuclear Information System (INIS)

Bulatova, T.M.

1990-01-01

By the method of stress relaxation dependences of platic deformation rate on effective strain in CdS monocrystals for the temperatures of 25-300 deg C both in the darkness and in the light are obtained. In the range of the temperatures up to 150 deg C deformation activation energy is determined, which correlates with the value of point defect diffusion activation energy in the crystal. Anomalous temperature dependence of plastic deformation rate, i.e. its decrease with the temperature increase in the range of 150-300 deg C is detected

Extending Database Integration Technology

National Research Council Canada - National Science Library

Buneman, Peter

1999-01-01

Formal approaches to the semantics of databases and database languages can have immediate and practical consequences in extending database integration technologies to include a vastly greater range...

Infinite-range Heisenberg model and high-temperature superconductivity

Science.gov (United States)

Tahir-Kheli, Jamil; Goddard, William A., III

1993-11-01

A strongly coupled variational wave function, the doublet spin-projected Néel state (DSPN), is proposed for oxygen holes in three-band models of high-temperature superconductors. This wave function has the three-spin system of the oxygen hole plus the two neighboring copper atoms coupled in a spin-1/2 doublet. The copper spins in the neighborhood of a hole are in an eigenstate of the infinite-range Heisenberg antiferromagnet (SPN state). The doublet three-spin magnetic polaron or hopping polaron (HP) is stabilized by the hopping terms tσ and tτ, rather than by the copper-oxygen antiferromagnetic coupling Jpd. Although, the HP has a large projection onto the Emery (Dg) polaron, a non-negligible amount of doublet-u (Du) character is required for optimal hopping stabilization. This is due to Jdd, the copper-copper antiferromagnetic coupling. For the copper spins near an oxygen hole, the copper-copper antiferromagnetic coupling can be considered to be almost infinite ranged, since the copper-spin-correlation length in the superconducting phase (0.06-0.25 holes per in-plane copper) is approximately equal to the mean separation of the holes (between 2 and 4 lattice spacings). The general DSPN wave function is constructed for the motion of a single quasiparticle in an antiferromagnetic background. The SPN state allows simple calculations of various couplings of the oxygen hole with the copper spins. The energy minimum is found at symmetry (π/2,π/2) and the bandwidth scales with Jdd. These results are in agreement with exact computations on a lattice. The coupling of the quasiparticles leads to an attraction of holes and its magnitude is estimated.

Electric vehicle with or without range extender. Who is the driver - technology, customer or legislation?; Elektrofahrzeuge mit oder ohne Range Extender. Wer bestimmt den Weg - die Technik, der Kunde oder die Gesetzgebung?

Energy Technology Data Exchange (ETDEWEB)

Beidl, Christian; Kluin, Matthias [Technische Univ. Darmstadt (Germany); Hohenberg, Guenter; Bacher, Christian [IVD Prof. Hohenberg GmbH, Graz (Austria)

2011-07-01

Let us begin with an analysis of the technical context of E-mobility. The starting point of any such investigation is the restricted range of this technology. Greater car sizes bring ever-greater problems, especially in terms of the growing influence of driving speed and surrounding conditions. The combination of an E-motor and combustion engine thus represents an expedient ''enabler'' of E-mobility. This combination enables a drive system solution which overcomes the restrictions of a purely electric vehicle in terms of flexibility of use and availability of mobility. This paper discusses the difference between parallel and serial drives using already realized concepts. It also seeks to present a new concept for a compact, cost-efficient solution (ICE Assist). The second section will compare the current legal framework, customer expectations and technical solutions. Of critical importance is the concept for which the government will opt and the ''incentives'' which it sets to achieve this end. OEMs are currently beset by a significant level of insecurity regarding the concept with the best future and as a result, those involved are currently seeking solutions which cover all possible variants. This invariably results in compromises, which further add to the time and effort involved and increases costs. Customers generally have a positive attitude towards electric driving, but at the same time, their expectations follow their prior experience. Range extender / plug-in / ICE-assist solutions thus have the potential to bring a significant increase in the amount of electric driving / the number of kilometers driven by electrical means. To achieve a breakthrough in E-mobility, it is first necessary to establish a clear definition of an ''electric vehicle''. This requires a clear response from the government. 32. Internationales (orig.)

Individual shrink wrapping extends the storage life and maintains the quality of pomegranates (cvs. 'Mridula' and 'Bhagwa') at ambient and low temperature.

Science.gov (United States)

Sudhakar Rao, D V

2018-01-01

The present investigation was carried out to study the response of two commercial pomegranate cultivars to individual shrink wrapping in extending the storage life and quality maintenance. Pomegranate fruits ('Mridula' and 'Bhagwa') were individually shrink wrapped using three semi-permeable films (Cryovac ® BDF-2001, D-955 and normal LDPE) and stored at ambient (25-32 °C and 49-67% RH) and low temperature (8 °C and 75-80% RH). Shrink wrapping greatly reduced weight loss in both cultivars irrespective of the film used and storage temperature. Weight loss in shrink wrapped (D-955 film) 'Mridula' and 'Bhagwa' after 1 month storage at ambient temperature was respectively 1.40 and 1.05%, when compared to 22.92 and 22.53% in non-wrapped fruits. After 3 months at 8 °C, shrink wrapped 'Mridula' and 'Bhagwa' fruits lost only 0.43 and 0.68% weight respectively, compared to 17.23 and 21.67% in non-wrapped ones. Shrink wrapping significantly reduced the respiration rate at ambient temperature and the response varied with variety and film used. Shrink wrapped fruits of both cultivars retained the original peel colour (Hunter h∘ and C* values) to a maximum extent during 3 months storage at 8 °C and shelf-life period at ambient temperature. Irrespective of variety and film, shrink wrapping maintained the peel thickness and peel moisture content, significantly much higher than non-wrapped fruits at both temperatures. Compared to 'Mridula' cultivar, 'Bhagwa' responded well to shrink wrapping during prolonged storage at both temperatures with better maintenance of quality in terms of appearance, colour, juice content, TSS, acidity, sugars and sensory attributes. At ambient temperature, shrink wrapping with D-955 or LDPE film extended the storage life of 'Mridula' and 'Bhagwa' for 3 weeks and 1 month respectively, whereas at 8 °C both could be stored for 3 months with 3 days of shelf life.

Structure and tribological properties of MoCN-Ag coatings in the temperature range of 25–700 °C

Energy Technology Data Exchange (ETDEWEB)

Shtansky, D.V., E-mail: shtansky@shs.misis.ru [National University of Science and Technology “MISIS”, Leninsky Prospect 4, Moscow (Russian Federation); Bondarev, A.V.; Kiryukhantsev-Korneev, Ph.V. [National University of Science and Technology “MISIS”, Leninsky Prospect 4, Moscow (Russian Federation); Rojas, T.C.; Godinho, V.; Fernández, A. [Instituto de Ciencia de Materiales de Sevilla CSIC-US, Avda. Américo Vespucio 49, 41092 Sevilla (Spain)

2013-05-15

The preparation of hard coatings with low friction coefficient over a wide temperature range is still a challenge for the tribological community. The development of new nanocomposite materials consisting of different metal-ceramic phases, each of which exhibiting self-lubricating characteristics at different temperatures, may help to solve this problem. We report on the structure and tribological properties of MoCN-Ag coatings deposited by magnetron co-sputtering of Mo and C (graphite) targets and simultaneous sputtering of an Ag target either in pure nitrogen or in a gaseous mixture of Ar + N{sub 2}. The structure and elemental composition of the coatings were studied by means of X-ray diffraction, scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, energy dispersive spectroscopy, Raman spectroscopy, and glow discharge optical emission spectroscopy. The tribological properties of the coatings against an Al{sub 2}O{sub 3} ball were investigated first at discrete temperatures of 25, 500, and 700 °C, and then during continuous heating in the temperature range of 25–700 °C. The coating structure and their respective wear tracks were also examined to elucidate their phase transformations during heat treatments. The lowest friction coefficients (<0.4) were observed in the temperature ranges of 25–100 °C and 400–700 °C and can be explained by the presence of a free amorphous carbon phase, which served as a lubricant at low temperatures, and by a positive role of silver and two phases forming at elevated temperatures, molybdenum oxide and silver molybdate, which provided lubrication above 400 °C. In the temperature range between 100 and 400 °C, the friction coefficient was relatively high. This problem is to be addressed in future works.

Structure and tribological properties of MoCN-Ag coatings in the temperature range of 25–700 °C

International Nuclear Information System (INIS)

Shtansky, D.V.; Bondarev, A.V.; Kiryukhantsev-Korneev, Ph.V.; Rojas, T.C.; Godinho, V.; Fernández, A.

2013-01-01

The preparation of hard coatings with low friction coefficient over a wide temperature range is still a challenge for the tribological community. The development of new nanocomposite materials consisting of different metal-ceramic phases, each of which exhibiting self-lubricating characteristics at different temperatures, may help to solve this problem. We report on the structure and tribological properties of MoCN-Ag coatings deposited by magnetron co-sputtering of Mo and C (graphite) targets and simultaneous sputtering of an Ag target either in pure nitrogen or in a gaseous mixture of Ar + N 2 . The structure and elemental composition of the coatings were studied by means of X-ray diffraction, scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, energy dispersive spectroscopy, Raman spectroscopy, and glow discharge optical emission spectroscopy. The tribological properties of the coatings against an Al 2 O 3 ball were investigated first at discrete temperatures of 25, 500, and 700 °C, and then during continuous heating in the temperature range of 25–700 °C. The coating structure and their respective wear tracks were also examined to elucidate their phase transformations during heat treatments. The lowest friction coefficients (<0.4) were observed in the temperature ranges of 25–100 °C and 400–700 °C and can be explained by the presence of a free amorphous carbon phase, which served as a lubricant at low temperatures, and by a positive role of silver and two phases forming at elevated temperatures, molybdenum oxide and silver molybdate, which provided lubrication above 400 °C. In the temperature range between 100 and 400 °C, the friction coefficient was relatively high. This problem is to be addressed in future works.

Development of an experimental variable temperature set-up for a temperature range from 2.2 K to 325 K for cost-effective temperature sensor calibration

Science.gov (United States)

Pal, Sandip; Kar, Ranjan; Mandal, Anupam; Das, Ananda; Saha, Subrata

2017-05-01

A prototype of a variable temperature insert has been developed in-house as a cryogenic thermometer calibration facility. It was commissioned in fulfilment of the very stringent requirements of the temperature control of the cryogenic system. The calibration facility is designed for calibrating industrial cryogenic thermometers that include a temperature sensor and the wires heat-intercept in the 2.2 K-325 K temperature range. The isothermal section of the calibration block onto which the thermometers are mounted is weakly linked with the temperature control zone mounted with cooling capillary coil and cryogenic heater. The connecting wires of the thermometer are thermally anchored with the support of the temperature insert. The calibration procedure begins once the temperature of the support is stabilized. Homogeneity of the calibration block’s temperature is established both by simulation and by cross-comparison of two calibrated sensors. The absolute uncertainty present in temperature measurement is calculated and found comparable with the measured uncertainty at different temperature points. Measured data is presented in comparison to the standard thermometers at fixed points and it is possible to infer that the absolute accuracy achieved is better than  ±0.5% of the reading in comparison to the fixed point temperature. The design and development of simpler, low cost equipment, and approach to analysis of the calibration results are discussed further in this paper, so that it can be easily devised by other researchers.

Drying Temperature Dependence of Sol-gel Spin Coated Bilayer Composite ZnO/TiO2 Thin Films for Extended Gate Field Effect Transistor pH Sensor

Science.gov (United States)

Rahman, R. A.; Zulkefle, M. A.; Yusoff, K. A.; Abdullah, W. F. H.; Rusop, M.; Herman, S. H.

2018-03-01

This study presents an investigation on zinc oxide (ZnO) and titanium dioxide (TiO2) bilayer film applied as the sensing membrane for extended-gate field effect transistor (EGFET) for pH sensing application. The influences of the drying temperatures on the pH sensing capability of ZnO/TiO2 were investigated. The sensing performance of the thin films were measured by connecting the thin film to a commercial MOSFET to form the extended gates. By varying the drying temperature, we found that the ZnO/TiO2 thin film dried at 150°C gave the highest sensitivity compared to other drying conditions, with the sensitivity value of 48.80 mV/pH.

High energy storage density over a broad temperature range in sodium bismuth titanate-based lead-free ceramics.

Science.gov (United States)

Yang, Haibo; Yan, Fei; Lin, Ying; Wang, Tong; Wang, Fen

2017-08-18

A series of (1-x)Bi 0.48 La 0.02 Na 0.48 Li 0.02 Ti 0.98 Zr 0.02 O 3 -xNa 0.73 Bi 0.09 NbO 3 ((1-x)LLBNTZ-xNBN) (x = 0-0.14) ceramics were designed and fabricated using the conventional solid-state sintering method. The phase structure, microstructure, dielectric, ferroelectric and energy storage properties of the ceramics were systematically investigated. The results indicate that the addition of Na 0.73 Bi 0.09 NbO 3 (NBN) could decrease the remnant polarization (P r ) and improve the temperature stability of dielectric constant obviously. The working temperature range satisfying TCC 150  °C  ≤±15% of this work spans over 400 °C with the compositions of x ≥ 0.06. The maximum energy storage density can be obtained for the sample with x = 0.10 at room temperature, with an energy storage density of 2.04 J/cm 3 at 178 kV/cm. In addition, the (1-x)LLBNTZ-xNBN ceramics exhibit excellent energy storage properties over a wide temperature range from room temperature to 90 °C. The values of energy storage density and energy storage efficiency is 0.91 J/cm 3 and 79.51%, respectively, for the 0.90LLBNTZ-0.10NBN ceramic at the condition of 100 kV/cm and 90 °C. It can be concluded that the (1-x)LLBNTZ-xNBN ceramics are promising lead-free candidate materials for energy storage devices over a broad temperature range.

Temperature Range for Metasomatism at the Bakalskoe Siderite Deposits with Use of Geochemical Data

Directory of Open Access Journals (Sweden)

M. T. Krupenin

2017-06-01

Full Text Available The data obtained with the quantitative microprobe ankerite–siderite composition analysis of seven samples from the different parts of Bakalskoe field showed that the wallrock ankerites in the western and central parts of the ore field differ in average concentrations of FeCO 3 (respectively 14.21 and 20.84 wt.%. However, there is no significant difference in composition of siderites. The calculation of the Mg-Fe metasomatism temperatures based on ankerite-siderite and ankerite-breinerite geothermometers showed the close agreement of the values of both methods at temperatures of 250 °C and above. The average temperatures of siderite metasomatism in the central part of the Bakalskoe ore field are in range 250-270 ° C, and, in the peripheral part, the determined temperature does not exceed 190-220 ° C. These values do not depend on the position of the siderite deposits in stratigraphic level of the Bakalskaya Suite.

Mechanical response of AA7075 aluminum alloy over a wide range of temperatures and strain rates

Energy Technology Data Exchange (ETDEWEB)

Jin, Z.; Cassada, W.A. [Reynolds Metals Co., Chester, VA (United States). Corp. Res. and Dev.; Cady, C.M.; Gray, G.T. III

2000-07-01

The influence of temperature and strain rate on the flow stress and work hardening rate of a 7075 aluminum alloy was studied under compressive loading over the temperature range from 23 C to 470 C, and strain rates from 0.001 s{sup -1} and 2100 s{sup -1}. While the temperature dependence of the flow stress was found to be most significant at temperatures below 300 C, the strain rate dependence of the flow stress was found to be pronounced at temperatures above 23 C. Concurrently, the work hardening rate decreases significantly with increasing temperature between 23 C and 300 C and increases slightly at higher temperatures. The minimum work hardening rate is observed to occur at temperatures between 200 C and 300 C and shift to higher temperatures with increasing strain rate. A negative strain rate dependence of work hardening rate was observed at 23 C, although a positive strain rate dependence of work hardening rate occurs at higher temperatures. Analysis of the experimental data revealed three deformation regimes. (orig.)

Managing Temperature Effects in Nanoscale Adaptive Systems

CERN Document Server

Wolpert, David

2012-01-01

This book discusses new techniques for detecting, controlling, and exploiting the impacts of temperature variations on nanoscale circuits and systems.  It provides a holistic discussion of temperature management, including physical phenomena (reversal of the MOSFET temperature dependence) that have recently become problematic, along with circuit techniques for detecting, controlling, and adapting to these phenomena. A detailed discussion is also included of the general aspects of thermal-aware system design and management of temperature-induced faults. A new sensor system is described that can determine the temperature dependence as well as the operating temperature to improve system reliability.  A new method is presented to control a circuit’s temperature dependence by individually tuning pull-up and pull-down networks to their temperature-insensitive operating points. This method extends the range of supply voltages that can be made temperature-insensitive, achieving insensitivity at nominal voltage fo...

Effects of diurnal temperature range and drought on wheat yield in Spain

Science.gov (United States)

Hernandez-Barrera, S.; Rodriguez-Puebla, C.; Challinor, A. J.

2017-07-01

This study aims to provide new insight on the wheat yield historical response to climate processes throughout Spain by using statistical methods. Our data includes observed wheat yield, pseudo-observations E-OBS for the period 1979 to 2014, and outputs of general circulation models in phase 5 of the Coupled Models Inter-comparison Project (CMIP5) for the period 1901 to 2099. In investigating the relationship between climate and wheat variability, we have applied the approach known as the partial least-square regression, which captures the relevant climate drivers accounting for variations in wheat yield. We found that drought occurring in autumn and spring and the diurnal range of temperature experienced during the winter are major processes to characterize the wheat yield variability in Spain. These observable climate processes are used for an empirical model that is utilized in assessing the wheat yield trends in Spain under different climate conditions. To isolate the trend within the wheat time series, we implemented the adaptive approach known as Ensemble Empirical Mode Decomposition. Wheat yields in the twenty-first century are experiencing a downward trend that we claim is a consequence of widespread drought over the Iberian Peninsula and an increase in the diurnal range of temperature. These results are important to inform about the wheat vulnerability in this region to coming changes and to develop adaptation strategies.

Long-lived Control of Sierras Pampeanas Ranges on Andean Foreland Basin Evolution Revealed by Coupled Low-temperature Thermochronology and Sedimentology

Science.gov (United States)

Stevens Goddard, A.; Carrapa, B.; Larrovere, M.; Aciar, R. H.

2017-12-01

The Sierras Pampeanas ranges of west-central Argentina (28º- 31ºS) are a classic example of thick-skinned style basement block uplifts. The style and timing of uplift in these mountain ranges has widely been attributed to the onset of flat-slab subduction in the middle to late Miocene. However, the majority of low-temperature thermochronometers in the Sierras Pampeanas have much older cooling dates. Thermal modeling derived from new low-temperature thermochronometers in Sierra de Velasco, one of the highest relief (> 4 km) mountains in the Sierras Pampeanas, suggest that the rocks in these ranges have been at near-surface temperatures (history of long-lived topography illustrated in Sierra de Velasco can be expanded to other ranges in the Sierras Pampeanas by integrating multiple data sets.

Downstream changes in spring-fed stream invertebrate communities: the effect of increased temperature range?

Directory of Open Access Journals (Sweden)

Russell G. DEATH

2011-09-01

Full Text Available Reduced thermal amplitude has been highlighted as a limiting factor for aquatic invertebrate diversity in springs. Moving downstream water temperature range increases and invertebrate richness is expected to change accordingly. In the present study temperature patterns were investigated in seven spring-fed streams, between April 2001 and November 2002, and compared to five run-off-fed streams to assess the degree of crenic temperature constancy. Temperature and physico-chemical characteristics of the water, and food resource levels were measured, and the invertebrate fauna collected at 4 distances (0, 100, 500 m and 1 km from seven springs in the North and South Islands of New Zealand. Temperature variability was greater for run-off-fed streams than for springs, and increased in the spring-fed streams with distance from the source. Periphyton and physico-chemical characteristics of the water did not change markedly over the 1 km studied, with the exception of water velocity and organic matter biomass, which increased and decreased, respectively. The rate of increase in temperature amplitude differed greatly for the studied springs, probably being affected by flow, altitude, and the number and type of tributaries (i.e., spring- or run-off-fed joining the spring-fed stream channel. Longitudinal changes in the number and evenness of invertebrate taxa were positively correlated to thermal amplitude (rs = 0.8. Moving downstream, invertebrate communities progressively incorporated taxa with higher mobility and taxa more common in nearby run-off-fed streams. Chironomids and non-insect taxa were denser at the sources. Chironomid larvae also numerically dominated communities 100 and 500 m downstream from the sources, together with Pycnocentria spp. and Zelolessica spp., while taxa such as Hydora sp. and Hydraenidae beetles, the mayflies Deleatidium spp. and Coloburiscus humeralis, and the Trichoptera Pycnocentrodes spp., all had greater abundances 1 km

Detection of irradiated foods by the thermoluminescence. Relationships between the temperature ranges of integrating TL glow curves and TL glow ratios

International Nuclear Information System (INIS)

Sekiguchi, Masayuki; Yamazaki, Masao; Goto, Michiko; Todoriki, Setsuko; Hagiwara, Shoji

2007-01-01

Our study demonstrated that the effects of the several temperature ranges for integrating TL glow intensity on the TL glow ratios by using spice-set purchased at a Turkish air port. The spice set had no labeling of irradiation feeds, but nine of 12 spices were judged as irradiated food in this study. Those temperature ranges were defined by evaluating the glow curves of irradiated TLD-100 chip (167-230degC), TLD-100 disc (177-238degC) and Dolomite element (145-258degC). Those are relatively stable and the difference of typical glow peak temperatures of TLD-100 disc in two institutes was less than 2%. On the other hand, those of TLD-100 tip was shift to higher temperature side at about 4degC because of declining of thermal conductance. The temperature ranges defined by TLD-100 were showed that discriminate more clearly between irradiated and nonirradiated spices compared with the full temperature range of TL measurement (70-400degC). With the exception of low glow intensity, background measurement for estimating net glow intensity was not necessary because TL glow ratio was hardly influenced whether the background measured or not. (author)

Hot ductility of a microalloyed steel in the intermediate temperature range

International Nuclear Information System (INIS)

Darsouni, A.; Bouzabata, B.; Montheillet, F.

1995-01-01

In this study hot ductility has been determined from tensile tests for two states of a microalloyed steel: after casting and after rolling processes. Hot deformations were carried out at speeds varying from 10 -4 s -1 to 10 -2 s -1 and temperatures from 750 C to 1100 C. Two heat treatments were chosen before hot deformation. A ferrite precipitation is observed at austenitic grain boundaries in the intercritical temperature range, causing intergranular embrittlement. Ductility trough is deeper in the as-cast samples due to the growth of large grain size. Also, precipitation makes the hot ductility curve wider and deeper around 900 C. The results show a decrease in hot ductility. Minimum values of hot ductility are determined for (ITC) treatment at 900 C and for (DTC) treatment at 800 C. For this second treatment another decrease in hot ductility was observed at 900 C. We can explain hot ductility losses by the presence of precipitates in the austenitic region and the presence of the two-phase structure in the intercritical region. (orig.)

Extending the Linear Modulation Range to the Full Base Speed Using a Single DC-Link Multilevel Inverter With Capacitor-Fed H-Bridges for IM Drives

DEFF Research Database (Denmark)

Rahul, Arun; Pramanick, Sumit; Kaarthik, R. Sudharshan

2017-01-01

In this paper, a new space vector pulse width modulation method to extend the linear modulation range of a cascaded five level inverter topology with a single dc supply is presented. Using this method, the inverter can be controlled linearly and the peak phase fundamental output voltage of the in......In this paper, a new space vector pulse width modulation method to extend the linear modulation range of a cascaded five level inverter topology with a single dc supply is presented. Using this method, the inverter can be controlled linearly and the peak phase fundamental output voltage...... of the inverter can be increased from 0.577 to 0.637Vdc without increasing the dc bus voltage and without exceeding the induction motor voltage rating. This new technique makes use of cascaded inverter pole voltage redundancy and property of the space vector structure for its operation. Using this, the induction...

Heat transfer effect of an extended surface in downward-facing subcooled flow boiling

Energy Technology Data Exchange (ETDEWEB)

Khan, Abdul R., E-mail: khan@vis.t.u-tokyo.ac.jp [Department of Nuclear Engineering and Management, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Erkan, Nejdet, E-mail: erkan@vis.t.u-tokyo.ac.jp [Nuclear Professional School, School of Engineering, The University of Tokyo, 2-22 Shirakata, Tokai-mura, Ibaraki, 319-1188 (Japan); Okamoto, Koji, E-mail: okamoto@n.t.u-tokyo.ac.jp [Nuclear Professional School, School of Engineering, The University of Tokyo, 2-22 Shirakata, Tokai-mura, Ibaraki, 319-1188 (Japan)

2015-12-15

Highlights: • Compare downward-facing flow boiling results from bare and extended surfaces. • Upstream and downstream temperatures were measured on the extended surface. • Downstream temperatures exceed upstream temperatures for all flow rates. • Bubble accumulation occurs downstream on extended surface. • Extended surface heat transfer lower than bare surface as flow rate reduced. - Abstract: New BWR containment designs are considering cavity flooding as an accident management strategy. Unlike the PWR, the BWR has many Control Rod Guide Tube (CRGT) penetrations in the lower head. During a severe accident scenario with core melt in the lower plenum along with cavity flooding, the penetrations may affect the heat transfer on the ex-vessel surface and disrupt fluid flow during the boiling process. A small-scale experiment was performed to investigate the issues existing in downward-facing boiling phenomenon with an extended surface. The results were compared with a bare (flat) surface. The mass flux of 244 kg/m{sup 2} s, 215 kg/m{sup 2} s, and 177 kg/m{sup 2} s were applied in this study. CHF conditions were observed only for the 177 kg/m{sup 2} s case. The boiling curves for both types of surfaces and all flow rates were obtained. The boiling curves for the highest flow rate showed lower surface temperatures for the extended surface experiments when compared to the bare surface. The downstream location on the extended surface yielded the highest surface temperatures as the flow rate was reduced. The bubble accumulation and low velocity in the wake produced by flow around the extended surface was believed to have caused the elevated temperatures in the downstream location. Although an extended surface may enhance the overall heat transfer, a reduction in the local heat transfer was observed in the current experiments.

The behavior of plastic deformation in a duplex Cu-Zn alloy, in the temperature range 24-3000C

International Nuclear Information System (INIS)

Andrade, A.H.P. de.

1978-01-01

The mechanical behavior of Muntz Metal (Cu-40%Zn) containing duplex microstructure with a coarse grain size approximately 40μm) has been investigated at the temperature range 2 0 -300 0 C, and at strain rat e of epsilon=2.6x10 -4 S -1 , as a function of the second phase volume fraction(v(subβ)). Whereas at room temperature yielding increases with v(subβ) for v(subβ)>0.35, it remains virtually independent of v(subβ in the range 0.26 0 C. At low temperature (RT) and strains (epsilon approximately 0.01 the work hardening rate increases strongly with v subβ up to v subβ approximately 0.45. At higher temperatures and strains work hardening rate decreases for all volume fractions due to the thermal and dynamic recovery respectively. Then ultimate tensile strength (UTS) at room temperature increases with v subβ up to v subβ = 0.45, thus resulting in overall increase in U.T.S. The Portevin - Le Chatelier Effect (PLE)in Muntz Metal, at the temperature range 24 0 -300 0 C manifests itself in essentially two different forms. At RT, irregular serrations are observed, where amplitude decreases with increases in v subβ. At higher temperatures (100 0 C), serrations become regular, with increase in amplitude. At 200 0 C or over the serrations amplitude decrease at almost disappearing completely. These observations have been explained on the basis of collective behavior of mobile dislocations, influenced by the internal stress fields created during deformation by the presence of phase β. The Voce equation fits well with the experimental stress-strain data for temperatures up to 200 0 C. The method of Hollomon requires the use of stages in sigma-epsilon curve, curve, which does not have a physical significance. (Author) [pt

Host range of Phytophthora parsiana: a new high temperature pathogen of woody plants

Directory of Open Access Journals (Sweden)

Somieh HAJEBRAHIMI

2011-05-01

Full Text Available Normal 0 14 false false false IT ZH-TW X-NONE MicrosoftInternetExplorer4 Among several Phytophthora spp. reported previously from Pistacia vera in Iran, a high temperature species recently identified as P. parsiana (formerly known as high temperature P. cryptogea is becoming important in woody plants, including P. vera. The host range of this newly recognised species, including both annual and perennial plants, is reported here. The pathogen infected 4–5 month-old glasshouse grown seedlings of P. vera, Ficus carica, Malus pumila and Prunus dulcis, and detached stems of 23 woody plants collected during dormant and growing seasons. Nineteen field and vegetable crops and 17 weed species were not infected by  P. parsiana in these pathogenicity assays.

Instrument for Radiation Testing/Screening Electronic Devices over an Extended Temperature Range.

Science.gov (United States)

1986-12-19

CENTER ATTN: STEWS -TE-AN A DE LA PAZ ATTN: CODE 6054 D PLATTETER ATTN: STEWS -TE-AN J MEASON OFC OF THE DEP ASST SEC OF THE NAVY USAG ATTN: L J ABELLA...MAURER ATTN: D LAMB ATTN: D NIELSEN JOHNS HOPKINS UNIVERSITY ATTN: R BELT ATTN: G MASSON/DEPT OF ELEC ENGR ATTN: R GUMM KAMAN SCIENCES CORP HONEYWELL

Extending the fungal host range of a partitivirus and a mycoreovirus from Rosellinia necatrix by inoculation of protoplasts with virus particles.

Science.gov (United States)

Kanematsu, Satoko; Sasaki, Atsuko; Onoue, Mari; Oikawa, Yuri; Ito, Tsutae

2010-09-01

The potential host range of mycoviruses is poorly understood because of the lack of suitable inoculation methods. Recently, successful transfection has been reported for somatically incompatible fungal isolates with purified virus particles of two mycoviruses, the partitivirus RnPV1-W8 (RnPV1) and the mycoreovirus RnMyRV3/W370 (MyRV3), from the white root rot fungus Rosellinia necatrix (class Sordariomycetes, subclass Xylariomycetidae). These studies examined and revealed the effect of the mycoviruses on growth and pathogenicity of R. necatrix. Here, we extended the experimental host range of these two mycoviruses using a transfection approach. Protoplasts of other phytopathogenic Sordariomycetous fungi-Diaporthe sp., Cryphonectria parasitica, Valsa ceratosperma (Sordariomycetidae), and Glomerella cingulata (Hypocreomycetidae)-were inoculated with RnPV1 and MyRV3 viral particles. The presence of double-stranded RNA viral genomes in regenerated mycelia of Diaporthe sp., C. parasitica, and V. ceratosperma confirmed both types of viral infections in these three novel host species. An established RnPV1 infection was confirmed in G. cingulata but MyRV3 did not infect this host. Horizontal transmission of both viruses from newly infected strains to virus-free, wild-type strains through hyphal anastomosis was readily achieved by dual culture; however, vertical transmission through conidia was rarely observed. The virulence of Diaporthe sp., C. parasitica, and V. ceratosperma strains harboring MyRV3 was reduced compared with their virus-free counterpart. In summary, our protoplast inoculation method extended the experimental host range of RnPV1-W8 and MyRV3 within the class Sordariomycetes and revealed that MyRV3 confers hypovirulence to the new hosts, as it does to R. necatrix.

Temperature Dependence of Short-Range Order in β-Brass

DEFF Research Database (Denmark)

Dietrich, O.W.; Als-Nielsen, Jens Aage

1967-01-01

Critical scattering of neutrons around the superlattice reflections (1, 0, 0) and (1, 1, 1) from a single crystal of beta-brass has been measured at temperatures from 2 to 25deg C above the transition temperature. The temperature dependence of the critical peak intensity, proportional to the susc......Critical scattering of neutrons around the superlattice reflections (1, 0, 0) and (1, 1, 1) from a single crystal of beta-brass has been measured at temperatures from 2 to 25deg C above the transition temperature. The temperature dependence of the critical peak intensity, proportional...

Bentonite Permeability at Elevated Temperature

Directory of Open Access Journals (Sweden)

Katherine A. Daniels

2017-01-01

Full Text Available Repository designs frequently favour geological disposal of radioactive waste with a backfill material occupying void space around the waste. The backfill material must tolerate the high temperatures produced by decaying radioactive waste to prevent its failure or degradation, leading to increased hydraulic conductivity and reduced sealing performance. The results of four experiments investigating the effect of temperature on the permeability of a bentonite backfill are presented. Bentonite is a clay commonly proposed as the backfill in repository designs because of its high swelling capacity and very low permeability. The experiments were conducted in two sets of purpose-built, temperature controlled apparatus, designed to simulate isotropic pressure and constant volume conditions within the testing range of 4–6 MPa average effective stress. The response of bentonite during thermal loading at temperatures up to 200 °C was investigated, extending the previously considered temperature range. The results provide details of bentonite’s intrinsic permeability, total stress, swelling pressure and porewater pressure during thermal cycles. We find that bentonite’s hydraulic properties are sensitive to thermal loading and the type of imposed boundary condition. However, the permeability change is not large and can mostly be accounted for by water viscosity changes. Thus, under 150 °C, temperature has a minimal impact on bentonite’s hydraulic permeability.

Thermal decomposition of agardites (REE) - relationship between dehydroxylation temperature and electronegativity

International Nuclear Information System (INIS)

Frost, Ray L.; Erickson, Kristy L.; Weier, Matt L.; McKinnon, Adam R.; Williams, Peter A.; Leverett, Peter

2005-01-01

The thermal decomposition of a suite of synthetic agardites of formula ACu 6 (AsO 4 ) 2 (OH) 6 ·3H 2 O where A is given by a rare earth element has been studied using thermogravimetric analysis techniques. Dehydration of the agardites occurs at low temperatures and over an extended temperature range from ambient to around 60 deg. C. This loss of water is attributed to the loss of zeolitic water. The mass loss of water indicates 3 mol of zeolitic water in the structure. Dehydroxylation occurs in steps over a wide range of temperatures from 235 to 456 deg. C. The mass loss during dehydroxylation shows the number of moles of hydroxyl units is six. There is a linear relationship between the first dehydroxylation temperature and the electronegativity of the agardites (REE)

Constitutive behaviour of an as-cast AA7050 alloy in the sub-solidus temperature range

International Nuclear Information System (INIS)

Subroto, T A S; Miroux, A G; Eskin, D G; Katgerman, L

2012-01-01

Aluminum alloy 7050 is of interest for aerospace industries due to its superior mechanical properties. However, its inherent solidification behaviour may augment the accumulation of residual stresses due to uneven cooling conditions upon direct-chill (DC) casting. This can increase the propensity of cold cracking (CC), which is a potentially catastrophic phenomenon in casting ingots. To predict the outcome of the aluminum casting process, ALSIM software is utilised. This software has the capability to predict CC susceptibility during the casting process. However, at the moment, ALSIM lacks the information regarding material constitutive behaviour in the sub-solidus temperature range, which is considered important for studying CC phenomenon. At the moment, ALSIM only has a partial constitutive database for AA7050 and misses data, especially in the vicinity of non-equilibrium solidus (NES) point. The present work presents measurements of tensile constitutive parameters in the temperature range between 400 °C and NES, which is for this alloy defined as 465 °C. The mechanical behaviour is tested in a Gleeble 3800 thermo-mechanical simulator. Constitutive parameters such as stress-strain curves, strain-rate sensitivity and ductility of the alloy have been measured at different test temperatures. With these constitutive data, we expect to improve the accuracy of ALSIM simulations in terms of CC prediction, and gain more insight into the evolution of mechanical properties of AA7050 in the temperature nearby the NES.

A liquid crystalline medium for measuring residual dipolar couplings over a wide range of temperatures

Energy Technology Data Exchange (ETDEWEB)

Wang Hong; Eberstadt, Matthias; Olejniczak, Edward T.; Meadows, Robert P.; Fesik, Stephen W. [Abbott Laboratories (United States)

1998-10-15

A mixture of dilauroyl phosphatidylcholine (DLPC) and 3-(cholamidopropyl)dimethylammonio-2-hydroxyl-1-propane sulfonate (CHAPSO) in water forms disc shaped bicelles that become ordered at high magnetic fields over a wide range of temperatures. As illustrated for the FK506 binding protein (FKBP), large residual dipolar couplings can be measured for proteins dissolved in low concentrations (5% w/v) of a DLPC/CHAPSO medium at a molar ratio of 4.2:1. This system is especially useful for measuring residual dipolar couplings for molecules that are only stable at low temperatures.

Memory effects, two color percolation, and the temperature dependence of Mott variable-range hopping

Science.gov (United States)

Agam, Oded; Aleiner, Igor L.

2014-06-01

There are three basic processes that determine hopping transport: (a) hopping between normally empty sites (i.e., having exponentially small occupation numbers at equilibrium), (b) hopping between normally occupied sites, and (c) transitions between normally occupied and unoccupied sites. In conventional theories all these processes are considered Markovian and the correlations of occupation numbers of different sites are believed to be small (i.e., not exponential in temperature). We show that, contrary to this belief, memory effects suppress the processes of type (c) and manifest themselves in a subleading exponential temperature dependence of the variable-range hopping conductivity. This temperature dependence originates from the property that sites of type (a) and (b) form two independent resistor networks that are weakly coupled to each other by processes of type (c). This leads to a two-color percolation problem which we solve in the critical region.

ATMOSPHERIC DYNAMICS OF TERRESTRIAL EXOPLANETS OVER A WIDE RANGE OF ORBITAL AND ATMOSPHERIC PARAMETERS

Energy Technology Data Exchange (ETDEWEB)

Kaspi, Yohai [Department of Earth and Planetary Sciences, Weizmann Institute of Science, 234 Herzl st., 76100, Rehovot (Israel); Showman, Adam P., E-mail: yohai.kaspi@weizmann.ac.il [Department of Planetary Sciences and Lunar and Planetary Laboratory, The University of Arizona, 1629 University Blvd., Tucson, AZ 85721 (United States)

2015-05-01

The recent discoveries of terrestrial exoplanets and super-Earths extending over a broad range of orbital and physical parameters suggest that these planets will span a wide range of climatic regimes. Characterization of the atmospheres of warm super-Earths has already begun and will be extended to smaller and more distant planets over the coming decade. The habitability of these worlds may be strongly affected by their three-dimensional atmospheric circulation regimes, since the global climate feedbacks that control the inner and outer edges of the habitable zone—including transitions to Snowball-like states and runaway-greenhouse feedbacks—depend on the equator-to-pole temperature differences, patterns of relative humidity, and other aspects of the dynamics. Here, using an idealized moist atmospheric general circulation model including a hydrological cycle, we study the dynamical principles governing the atmospheric dynamics on such planets. We show how the planetary rotation rate, stellar flux, atmospheric mass, surface gravity, optical thickness, and planetary radius affect the atmospheric circulation and temperature distribution on such planets. Our simulations demonstrate that equator-to-pole temperature differences, meridional heat transport rates, structure and strength of the winds, and the hydrological cycle vary strongly with these parameters, implying that the sensitivity of the planet to global climate feedbacks will depend significantly on the atmospheric circulation. We elucidate the possible climatic regimes and diagnose the mechanisms controlling the formation of atmospheric jet streams, Hadley and Ferrel cells, and latitudinal temperature differences. Finally, we discuss the implications for understanding how the atmospheric circulation influences the global climate.

ATMOSPHERIC DYNAMICS OF TERRESTRIAL EXOPLANETS OVER A WIDE RANGE OF ORBITAL AND ATMOSPHERIC PARAMETERS

International Nuclear Information System (INIS)

Kaspi, Yohai; Showman, Adam P.

2015-01-01

The recent discoveries of terrestrial exoplanets and super-Earths extending over a broad range of orbital and physical parameters suggest that these planets will span a wide range of climatic regimes. Characterization of the atmospheres of warm super-Earths has already begun and will be extended to smaller and more distant planets over the coming decade. The habitability of these worlds may be strongly affected by their three-dimensional atmospheric circulation regimes, since the global climate feedbacks that control the inner and outer edges of the habitable zone—including transitions to Snowball-like states and runaway-greenhouse feedbacks—depend on the equator-to-pole temperature differences, patterns of relative humidity, and other aspects of the dynamics. Here, using an idealized moist atmospheric general circulation model including a hydrological cycle, we study the dynamical principles governing the atmospheric dynamics on such planets. We show how the planetary rotation rate, stellar flux, atmospheric mass, surface gravity, optical thickness, and planetary radius affect the atmospheric circulation and temperature distribution on such planets. Our simulations demonstrate that equator-to-pole temperature differences, meridional heat transport rates, structure and strength of the winds, and the hydrological cycle vary strongly with these parameters, implying that the sensitivity of the planet to global climate feedbacks will depend significantly on the atmospheric circulation. We elucidate the possible climatic regimes and diagnose the mechanisms controlling the formation of atmospheric jet streams, Hadley and Ferrel cells, and latitudinal temperature differences. Finally, we discuss the implications for understanding how the atmospheric circulation influences the global climate

DC Algorithm for Extended Robust Support Vector Machine.

Science.gov (United States)

Fujiwara, Shuhei; Takeda, Akiko; Kanamori, Takafumi

2017-05-01

Nonconvex variants of support vector machines (SVMs) have been developed for various purposes. For example, robust SVMs attain robustness to outliers by using a nonconvex loss function, while extended [Formula: see text]-SVM (E[Formula: see text]-SVM) extends the range of the hyperparameter by introducing a nonconvex constraint. Here, we consider an extended robust support vector machine (ER-SVM), a robust variant of E[Formula: see text]-SVM. ER-SVM combines two types of nonconvexity from robust SVMs and E[Formula: see text]-SVM. Because of the two nonconvexities, the existing algorithm we proposed needs to be divided into two parts depending on whether the hyperparameter value is in the extended range or not. The algorithm also heuristically solves the nonconvex problem in the extended range. In this letter, we propose a new, efficient algorithm for ER-SVM. The algorithm deals with two types of nonconvexity while never entailing more computations than either E[Formula: see text]-SVM or robust SVM, and it finds a critical point of ER-SVM. Furthermore, we show that ER-SVM includes the existing robust SVMs as special cases. Numerical experiments confirm the effectiveness of integrating the two nonconvexities.

X-ray extended-range technique for precision measurement of the x-ray mass attenuation coefficient and IM(F) for copper using synchrotron radiation

International Nuclear Information System (INIS)

Tran, C.Q.; Paterson, D.; Barnea, Z.; Cookson, D.J.; Chantler, C.T.

2000-01-01

Full text: Complex X-ray form factors are used in crystallography, material science, medical diagnosis refractive index studies and XAFS. We introduce the X-ray Extended-Range Technique for measurements of the imaginary component of the atomic form factor. We achieve accuracies of 0.27%-0.5% for copper from 8.84 keV to 20 keV. Discrepancies between measurements using earlier experimental techniques are 10%. We achieve reproducibility of 0.02%. New methods of computation are required to approach the accuracy of our data. Results probe the transform of atomic orbital wavefunctions and long-range order. Discrepancies of order 10% between current theory and experiments can be addressed

Oxidation Kinetics of Ferritic Alloys in High-Temperature Steam Environments

Science.gov (United States)

Parker, Stephen S.; White, Josh; Hosemann, Peter; Nelson, Andrew

2018-02-01

High-temperature isothermal steam oxidation kinetic parameters of several ferritic alloys were determined by thermogravimetric analysis. The oxidation kinetic constant ( k) was measured as a function of temperature from 900°C to 1200°C. The results show a marked increase in oxidation resistance compared to reference Zircaloy-2, with kinetic constants 3-5 orders of magnitude lower across the experimental temperature range. The results of this investigation supplement previous findings on the properties of ferritic alloys for use as candidate cladding materials and extend kinetic parameter measurements to high-temperature steam environments suitable for assessing accident tolerance for light water reactor applications.

An Efficiency-Optimized Isolated Bidirectional DC-DC Converter with Extended Power Range for Energy Storage Systems in Microgrids

Directory of Open Access Journals (Sweden)

Xiaolong Shi

2012-12-01

Full Text Available This paper proposes a novel extended-single-phase shift (ESPS control strategy of isolated bidirectional full-bridge DC-DC converters (IBDCs which are a promising alternative as a power electronic interface in microgrids with an additional function of galvanic isolation. Based on the mathematical models of ESPS control under steady-state conditions, detailed theoretical and experimental analyses of IBDC under ESPS control are presented. Compared with conventional single-phase-shift (CSPS control, ESPS control can greatly improve the efficiency of IBDCs in microgrids through decreasing current stress and backflow power considerably over a wide input and output voltage range under light and medium loads. In addition, ESPS control only needs to adjust one single phase-shift angel to control transmission power, thus it retains implementation simplicity in comparison with dual-phase-shift (DPS control for microgrid applications. Furthermore, an efficiency-optimized modulation scheme based on ESPS and CSPS control is developed in the whole power range of IBDC for power distribution in microgrids. A 10 kW IBDC prototype is constructed and the experimental results validate the effectiveness of the proposed control strategy, showing that the proposed strategy can enhance the overall efficiency up to 30%.

Temperature dependence of the electrical resistivity of amorphous Co80-xErxB20 alloys

International Nuclear Information System (INIS)

Touraghe, O.; Khatami, M.; Menny, A.; Lassri, H.; Nouneh, K.

2008-01-01

The temperature dependence of the electrical resistivity of amorphous Co 80-x Er x B 20 alloys with x=0, 3.9, 7.5 and 8.6 prepared by melt spinning in pure argon atmosphere was studied. All amorphous alloys investigated here are found to exhibit a resistivity minimum at low temperature. The electrical resistivity exhibits logarithmic temperature dependence below the temperature of resistivity minimum T min . In addition, the resistivity shows quadratic temperature behavior in the interval T min < T<77 K. At high temperature, the electrical resistivity was discussed by the extended Ziman theory. For the whole series of alloys, the composition dependence of the temperature coefficient of electrical resistivity α shows a change in structural short range occurring in the composition range 8-9 at%

Interspecific Differences in Metabolic Rate and Metabolic Temperature Sensitivity Create Distinct Thermal Ecological Niches in Lizards (Plestiodon).

Science.gov (United States)

Watson, Charles M; Burggren, Warren W

2016-01-01

Three congeneric lizards from the southeastern United States (Plestiodon fasciatus, P. inexpectatus, and P. laticeps) exhibit a unique nested distribution. All three skink species inhabit the US Southeast, but two extend northward to central Ohio (P. fasciatus and P. laticeps) and P. fasciatus extends well into Canada. Distinct interspecific differences in microhabitat selection and behavior are associated with the cooler temperatures of the more Northern ranges. We hypothesized that interspecific differences in metabolic temperature sensitivity locally segregates them across their total range. Resting oxygen consumption was measured at 20°, 25° and 30°C. Plestiodon fasciatus, from the coolest habitats, exhibited greatly elevated oxygen consumption compared to the other species at high ecologically-relevant temperatures (0.10, 0.17 and 0.83 ml O2. g-1. h-1 at 20°, 25° and 30°C, respectively). Yet, P. inexpectatus, from the warmest habitats, exhibited sharply decreased oxygen consumption compared to the other species at lower ecologically-relevant temperatures (0.09, 0.27 and 0.42 ml O2. g-1. h-1 at 20°, 25° and 30°C, respectively). Plestiodon laticeps, from both open and closed microhabitats and intermediate latitudinal range, exhibited oxygen consumptions significantly lower than the other two species (0.057, 0.104 and 0.172 ml O2. g-1. h-1 at 20°, 25° and 30°C, respectively). Overall, Plestiodon showed metabolic temperature sensitivities (Q10s) in the range of 2-3 over the middle of each species' normal temperature range. However, especially P. fasciatus and P. inexpectatus showed highly elevated Q10s (9 to 25) at the extreme ends of their temperature range. While morphologically similar, these skinks are metabolically distinct across the genus' habitat, likely having contributed to their current distribution.

Red-light-emitting laser diodes operating CW at room temperature

Science.gov (United States)

Kressel, H.; Hawrylo, F. Z.

1976-01-01

Heterojunction laser diodes of AlGaAs have been prepared with threshold current densities substantially below those previously achieved at room temperature in the 7200-8000-A spectral range. These devices operate continuously with simple oxide-isolated stripe contacts to 7400 A, which extends CW operation into the visible (red) portion of the spectrum.

Temperature dependence on mutual solubility of binary (methanol + limonene) mixture and (liquid + liquid) equilibria of ternary (methanol + ethanol + limonene) mixture

International Nuclear Information System (INIS)

Tamura, Kazuhiro; Li Xiaoli; Li Hengde

2009-01-01

Mutual solubility data of the binary (methanol + limonene) mixture at the temperatures ranging from 288.15 K close to upper critical solution temperature, and ternary (liquid + liquid) equilibrium (tie-lines) of the (methanol + ethanol + limonene) mixture at the temperatures (288.15, 298.15, and 308.15) K have been obtained. The experimental results have been represented accurately in terms of the extended and modified UNIQUAC models with binary parameters, compared with the UNIQUAC model. The temperature dependence of binary and ternary (liquid + liquid) equilibrium for the binary (methanol + limonene) and ternary (methanol + ethanol + limonene) mixtures could be calculated successfully using the extended and modified UNIQUAC model

Stable solid state reference electrodes for high temperature water chemistry

International Nuclear Information System (INIS)

Jayaweera, P.; Millett, P.J.

1995-01-01

A solid state electrode capable of providing a stable reference potential under a wide range of temperatures and chemical conditions has been demonstrated. The electrode consists of a zirconia or yttria-stabilized zirconia tube packed with an inorganic polymer electrolyte and a silver/silver chloride sensing element. The sensing element is maintained near room temperature by a passive cooling heat sink. The electrode stability was demonstrated by testing it in high temperature (280 C) aqueous solutions over extended periods of time. This reference electrode is useful in many applications, particularly for monitoring the chemistry in nuclear and fossil power plants

Reconfigurable Resonant Regulating Rectifier With Primary Equalization for Extended Coupling- and Loading-Range in Bio-Implant Wireless Power Transfer.

Science.gov (United States)

Li, Xing; Meng, Xiaodong; Tsui, Chi-Ying; Ki, Wing-Hung

2015-12-01

Wireless power transfer using reconfigurable resonant regulating (R(3)) rectification suffers from limited range in accommodating varying coupling and loading conditions. A primary-assisted regulation principle is proposed to mitigate these limitations, of which the amplitude of the rectifier input voltage on the secondary side is regulated by accordingly adjusting the voltage amplitude Veq on the primary side. A novel current-sensing method and calibration scheme track Veq on the primary side. A ramp generator simultaneously provides three clock signals for different modules. Both the primary equalizer and the R(3) rectifier are implemented as custom integrated circuits fabricated in a 0.35 μm CMOS process, with the global control implemented in FPGA. Measurements show that with the primary equalizer, the workable coupling and loading ranges are extended by 250% at 120 mW load and 300% at 1.2 cm coil distance compared to the same system without the primary equalizer. A maximum rectifier efficiency of 92.5% and a total system efficiency of 62.4% are demonstrated.

Artificial neural network model to predict slag viscosity over a broad range of temperatures and slag compositions

Energy Technology Data Exchange (ETDEWEB)

Duchesne, Marc A. [Chemical and Biological Engineering Department, University of Ottawa, 161 Louis Pasteur, Ottawa, Ont. (Canada); CanmetENERGY, 1 Haanel Drive, Ottawa, Ontario (Canada); Macchi, Arturo [Chemical and Biological Engineering Department, University of Ottawa, 161 Louis Pasteur, Ottawa, Ont. (Canada); Lu, Dennis Y.; Hughes, Robin W.; McCalden, David; Anthony, Edward J. [CanmetENERGY, 1 Haanel Drive, Ottawa, Ontario (Canada)

2010-08-15

Threshold slag viscosity heuristics are often used for the initial assessment of coal gasification projects. Slag viscosity predictions are also required for advanced combustion and gasification models. Due to unsatisfactory performance of theoretical equations, an artificial neural network model was developed to predict slag viscosity over a broad range of temperatures and slag compositions. This model outperforms other slag viscosity models, resulting in an average error factor of 5.05 which is lower than the best obtained with other available models. Genesee coal ash viscosity predictions were made to investigate the effect of adding Canadian limestone and dolomite. The results indicate that magnesium in the fluxing agent provides a greater viscosity reduction than calcium for the threshold slag tapping temperature range. (author)

Parametrization of the average ionization and radiative cooling rates of carbon plasmas in a wide range of density and temperature

OpenAIRE

Gil de la Fe, Juan Miguel; Rodriguez Perez, Rafael; Florido, Ricardo; Garcia Rubiano, Jesus; Mendoza, M.A.; Nuez, A. de la; Espinosa, G.; Martel Escobar, Carlos; Mínguez Torres, Emilio

2013-01-01

In this work we present an analysis of the influence of the thermodynamic regime on the monochromatic emissivity, the radiative power loss and the radiative cooling rate for optically thin carbon plasmas over a wide range of electron temperature and density assuming steady state situations. Furthermore, we propose analytical expressions depending on the electron density and temperature for the average ionization and cooling rate based on polynomial fittings which are valid for the whole range...

PMR Extended Shelf Life Technology Given 2000 R and D 100 Award

Science.gov (United States)

Meador, Michael A.

2001-01-01

An approach developed at the NASA Glenn Research Center for extending the shelf life of PMR polyimide solutions and prepregs received an R&D 100 Award this year. PMR polyimides, in particular PMR-15, have become attractive materials for a variety of aerospace applications because of their outstanding high-temperature stability and performance. PMR-15 can be used in components with exposures to temperatures as high as 290 C, which leads to substantial reductions in weight, as much as 30 percent over metal components. PMR-15 composites are used widely in aerospace applications ranging from ducts and external components in aircraft engines to an engine access door for the Space Shuttle Main Engine. A major barrier to more widespread use of these materials is high component costs. Recent efforts at Glenn have addressed the various factors that contribute to these costs in an attempt to more fully utilize these lightweight, high-temperature materials.

Red-light-emitting laser diodes operating cw at room temperature

International Nuclear Information System (INIS)

Kressel, H.; Hawrylo, F.Z.

1976-01-01

Heterojunction laser diodes of AlGaAs have been prepared with threshold current densities substantially below those previously achieved at room temperature in the 7200 to 8000-A spectral range. These devices operate cw with simple oxide-isolated stripe contacts to 7400 A, which extends cw operation for the first time into the visible (red) portion of the spectrum

Definition by modelling, optimization and characterization of a neutron spectrometry system based on Bonner spheres extended to the high-energy range

International Nuclear Information System (INIS)

Serre, S.

2010-01-01

This research thesis first describes the problematic of the effects of natural radiation on micro- and nano-electronic components, and the atmospheric-radiative stress of atmospheric neutrons from cosmic origin: issue of 'Single event upsets', present knowledge of the atmospheric radiative environment induced by cosmic rays. The author then presents the neutron-based detection and spectrometry by using the Bonner sphere technique: principle of moderating spheres, definition and mathematical formulation of neutron spectrometry using Bonner spheres, active sensors of thermal neutrons, response of a system to conventional Bonner spheres, extension to the range of high energies. Then, he reports the development of a Bonner sphere system extended to the high-energy range for the spectrometry of atmospheric neutrons: definition of a conventional system, Monte Carlo calculation of response functions, development of the response matrix, representation and semi-empirical verification of fluence response, uncertainty analysis, extension to high energies, and measurement tests of the spectrometer. He reports the use of a Monte Carlo simulation to characterize the spectrometer response in the high-energy range

Reproductive output of a non-zooxanthellate temperate coral is unaffected by temperature along an extended latitudinal gradient.

Directory of Open Access Journals (Sweden)

Valentina Airi

Full Text Available Global environmental change, in marine ecosystems, is associated with concurrent shifts in water temperature, circulation, stratification, and nutrient input, with potentially wide-ranging biological effects. Variations in seawater temperature might alter physiological functioning, reproductive efficiency, and demographic traits of marine organisms, leading to shifts in population size and abundance. Differences in temperature tolerances between organisms can identify individual and ecological characteristics, which make corals able to persist and adapt in a climate change context. Here we investigated the possible effect of temperature on the reproductive output of the solitary non-zooxanthellate temperate coral Leptopsammia pruvoti, along an 8° latitudinal gradient. Samples have been collected in six populations along the gradient and each polyp was examined using histological and cyto-histometric analyses. We coupled our results with previous studies on the growth, demography, and calcification of L. pruvoti along the same temperature gradient, and compared them with those of another sympatric zooxanthellate coral Balanophyllia europaea to understand which trophic strategy makes the coral more tolerant to increasing temperature. The non-zooxanthellate species seemed to be quite tolerant to temperature increases, probably due to the lack of the symbiosis with zooxanthellae. To our knowledge, this is the first field investigation of the relationship between reproductive output and temperature increase of a temperate asymbiotic coral, providing novel insights into the poorly studied non-zooxanthellate scleractinians.

Reproductive output of a non-zooxanthellate temperate coral is unaffected by temperature along an extended latitudinal gradient.

Science.gov (United States)

Airi, Valentina; Prantoni, Selena; Calegari, Marco; Lisini Baldi, Veronica; Gizzi, Francesca; Marchini, Chiara; Levy, Oren; Falini, Giuseppe; Dubinsky, Zvy; Goffredo, Stefano

2017-01-01

Global environmental change, in marine ecosystems, is associated with concurrent shifts in water temperature, circulation, stratification, and nutrient input, with potentially wide-ranging biological effects. Variations in seawater temperature might alter physiological functioning, reproductive efficiency, and demographic traits of marine organisms, leading to shifts in population size and abundance. Differences in temperature tolerances between organisms can identify individual and ecological characteristics, which make corals able to persist and adapt in a climate change context. Here we investigated the possible effect of temperature on the reproductive output of the solitary non-zooxanthellate temperate coral Leptopsammia pruvoti, along an 8° latitudinal gradient. Samples have been collected in six populations along the gradient and each polyp was examined using histological and cyto-histometric analyses. We coupled our results with previous studies on the growth, demography, and calcification of L. pruvoti along the same temperature gradient, and compared them with those of another sympatric zooxanthellate coral Balanophyllia europaea to understand which trophic strategy makes the coral more tolerant to increasing temperature. The non-zooxanthellate species seemed to be quite tolerant to temperature increases, probably due to the lack of the symbiosis with zooxanthellae. To our knowledge, this is the first field investigation of the relationship between reproductive output and temperature increase of a temperate asymbiotic coral, providing novel insights into the poorly studied non-zooxanthellate scleractinians.

Phonon Anharmonicity of Germanium in the Temperature Range 80-880 K

Energy Technology Data Exchange (ETDEWEB)

Nelin, G; Nilsson, G

1974-06-15

Phonon frequency shifts and line widths in germanium have been studied in the temperature range 80 - 880 K by means of thermal neutron spectrometry. The results cannot be described in terms of the quasiharmonic approximation in which phonon frequencies are solely volume dependent. Theoretical calculations are found to be more satisfactory for the Raman frequency than for most other modes. A good account of the observed shifts is given by a proposal due to Barron according to which the relative frequency renormalization of a crystal is proportional to the total harmonic vibrational energy. An analysis of the gradients of measured dispersion relations in the principal symmetry directions at 80 K is presented. It is shown that accidental degeneracies may influence the dispersion

Impact of Prolonged Blood Incubation and Extended Serum Storage at Room Temperature on the Human Serum Metabolome

Directory of Open Access Journals (Sweden)

Beate Kamlage

2018-01-01

Full Text Available Metabolomics is a powerful technology with broad applications in life science that, like other -omics approaches, requires high-quality samples to achieve reliable results and ensure reproducibility. Therefore, along with quality assurance, methods to assess sample quality regarding pre-analytical confounders are urgently needed. In this study, we analyzed the response of the human serum metabolome to pre-analytical variations comprising prolonged blood incubation and extended serum storage at room temperature by using gas chromatography-mass spectrometry (GC-MS and liquid chromatography-tandem mass spectrometry (LC-MS/MS -based metabolomics. We found that the prolonged incubation of blood results in a statistically significant 20% increase and 4% decrease of 225 tested serum metabolites. Extended serum storage affected 21% of the analyzed metabolites (14% increased, 7% decreased. Amino acids and nucleobases showed the highest percentage of changed metabolites in both confounding conditions, whereas lipids were remarkably stable. Interestingly, the amounts of taurine and O-phosphoethanolamine, which have both been discussed as biomarkers for various diseases, were 1.8- and 2.9-fold increased after 6 h of blood incubation. Since we found that both are more stable in ethylenediaminetetraacetic acid (EDTA blood, EDTA plasma should be the preferred metabolomics matrix.

Room-temperature heteroepitaxy of single-phase Al1−xInxN films with full composition range on isostructural wurtzite templates

International Nuclear Information System (INIS)

Hsiao, Ching-Lien; Palisaitis, Justinas; Junaid, Muhammad; Persson, Per O.Å.; Jensen, Jens; Zhao, Qing-Xiang; Hultman, Lars; Chen, Li-Chyong; Chen, Kuei-Hsien; Birch, Jens

2012-01-01

Al 1−x In x N heteroepitaxial layers covering the full composition range have been realized by magnetron sputter epitaxy on basal-plane AlN, GaN, and ZnO templates at room temperature (RT). Both Al 1−x In x N single layers and multilayers grown on these isostructural templates show single phase, single crystal wurtzite structure. Even at large lattice mismatch between the film and the template, for instance InN/AlN (∼ 13% mismatch), heteroepitaxy is achieved. However, RT-grown Al 1−x In x N films directly deposited on non-isostructural c-plane sapphire substrate exhibit a polycrystalline structure for all compositions, suggesting that substrate surface structure is important for guiding the initial nucleation. Degradation of Al 1−x In x N structural quality with increasing indium content is attributed to the formation of more point- and structural defects. The defects result in a prominent hydrostatic tensile stress component, in addition to the biaxial stress component introduced by lattice mismatch, in all RT-grown Al 1−x In x N films. These effects are reflected in the measured in-plane and out-of-plane strains. The effect of hydrostatic stress is negligible compared to the effects of lattice mismatch in high-temperature grown AlN layers thanks to their low amount of defects. We found that Vegard’s rule is applicable to determine x in the RT-grown Al 1−x In x N epilayers if the lattice constants of RT-sputtered AlN and InN films are used instead of those of the strain-free bulk materials. - Highlights: ► Magnetron sputter epitaxy of single-phase Al 1−x In x N(0001) at room temperature ► Growing Al 1−x In x N onto temperature sensitive substrates is desirable. ► Substrate surface structure plays a vital role at nucleation stage. ► Point and extended defects produce hydrostatic tensile stress. ► The applicability of Vegard's rule for these compounds is confirmed.

Temperature-dependent deliquescence relative humidities and water activities using humidity controlled thermogravimetric analysis with application to malonic acid.

Science.gov (United States)

Beyer, Keith D; Schroeder, Jason R; Kissinger, Jared A

2014-04-03

We utilize a new experimental technique, humidity-controlled thermogravimetric analysis (HTGA), to determine temperature-dependent deliquescence relative humidities (DRH) and to determine the equilibrium concentration of a solution at a given temperature and relative humidity. To that end, we have investigated the malonic acid/water system determining the DRH and concentration/RH relationship in the temperature range 303-278 K. Excellent agreement is found with literature values for the DRH of malonic acid as a function of temperature and for the concentration/RH relationship at several temperatures. Thus, we extend the DRH and concentration/RH relationship to a broader temperature range and are using the HTGA experiments to investigate other organic acids.

Production of jet fuel range paraffins by low temperature polymerization of gaseous light olefins using ionic liquid

International Nuclear Information System (INIS)

Jiang, Peiwen; Wu, Xiaoping; Zhu, Lijuan; Jin, Feng; Liu, Junxu; Xia, Tongyan; Wang, Tiejun; Li, Quanxin

2016-01-01

Graphical abstract: A novel catalytic transformation of light olefins into jet fuel range iso-paraffins by the low-temperature olefin polymerizations under atmospheric conditions. - Highlights: • A novel transformation of light olefins to jet fuel range paraffins was demonstrated. • The synthetic fuels can be produced by atmospheric olefin polymerizations. • C 8 –C 15 iso-paraffins from light olefins was achieved with a selectivity of 80.6%. - Abstract: This work demonstrated a novel catalytic transformation of gaseous olefins into jet fuel range iso-paraffins by the low-temperature olefin polymerizations under atmospheric conditions. The production of the desired C 8 –C 15 iso-paraffins with the selectivity of 80.6 C mol% was achieved by the room-temperature polymerizations of gaseous light olefins using the [BMIM] Al 2 Cl 7 ionic liquid. The influences of the reaction conditions on the olefinic polymerizations were investigated in detail. The properties of hydrocarbons in the synthetic fuels were determined by the GC–MS analyses combined with 1 H NMR, and 13 C NMR analyses. The formation of C 8 –C 15 hydrocarbons from gaseous light olefins was illustrated by the identified products and the functional groups. This transformation potentially provides a useful avenue for the production of the most important components of iso-paraffins required in jet fuels.

Measurements and Monte Carlo calculations with the extended-range Bonner sphere spectrometer at high-energy mixed fields

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00406842; Bay, Aurelio; Silari, Marco; Aroua, Abbas

The use of spectrometry to provide information for neutron radiation protection has become an increasingly important activity over recent years. The need for spectral data arises because neither area survey instruments nor personal dosimeters give the correct dose equivalent results at all neutron energies. It is important therefore to know the spectra of the fields in which these devices are used. One of the systems most commonly employed in neutron spectrometry and dosimetry is the Bonner Sphere Spectrometers (BSS). The extended- range BSS that was used for this work, consists of 7 spheres with an overall response to neutrons up to 2 GeV. A 3He detector is used as a thermal counter in the centre of each sphere. In the context of this thesis the BSS was calibrated in monoenergetic neutron fields at low and intermediate energies. It was also used for measurements in several high energy mixed fields. These measurements have led to the calculation of neutron yields and spectral fluences from unshielded targets....

Temperature dependence of residual electrical resistivity of Cu-Au in pseudopotential approximation

International Nuclear Information System (INIS)

Khwaja, F.A.; Ahmed, I.; Shaukat, A.

1986-08-01

The problem of temperature dependence of residual electrical resistivity of Cu-Au system is re-examined in the light of static distortion and thermal vibration of the lattice along with the short-range-order of atoms above critical temperature. The extended version of Ziman's formula for resistivity obtained yields a unified version for the calculation of resistivity in pseudopotential approximation. The temperature dependence of the quantity Δρ/ρ in this framework for Cu-Au system is found to be in better agreement with the experimental data as compared to previous calculation. (author)

Phase diagram of Ti-B-C system in the temperature range of 300-3500 K

International Nuclear Information System (INIS)

Gusev, A.I.

1996-01-01

Calculation of phase equilibrium in the ternary system Ti-B-C in the areas of the TiC y -TiB 2 and B 4 C y -TiB 2 cross sections as well as partial construction of three-dimensional (spatial)diagram of the Ti-B-C system within the temperature range of 300-3500 K is carried out. The form of the isothermal cross section of the ternary system remains almost unchanged up to 1900 K. The most essential change is related to disordering of the low-temperature ordered phases Ti 2 C, Ti 3 C and Ti 6 C 5 of the titanium carbide at T > 950 K [ru

Theory of the transition temperature of superconducting amorphous transition metals

International Nuclear Information System (INIS)

Zwicknagel, G.

1979-11-01

In the present paper first the transition temperature Tsub(c) is shown to be a local quantity, which depends on the (average) short range order, and second it is demonstrated how to calculate local electronic properties in the framework of a short range order model and the transition temperature of amorphous systems based on accepted structure models of the amorphous state. In chapter I the theoretical basis of this work is presented in brief. The model used to study the role of short range order (in periodically ordered as well as in disordered system) is described in chapter II. The results of this model for the periodically ordered case are compared in chapter III with band structure calculations. In chapter IV it is shown how to establish short range order models for disordered systems and what kind of information can be obtained with respect to the electronic properties. Finally in chapter V it is discussed to what extend the interpretation of the transition temperature Tsub(c) as being determined by short range order effects can be supported by the electronic properties, which are calculated in the chapters III and IV. (orig.) [de

Effect of a temperature increase in the non-noxious range on proton-evoked ASIC and TRPV1 activity.

Science.gov (United States)

Blanchard, Maxime G; Kellenberger, Stephan

2011-01-01

Acid-sensing ion channels (ASICs) are neuronal H(+)-gated cation channels, and the transient receptor potential vanilloid 1 channel (TRPV1) is a multimodal cation channel activated by low pH, noxious heat, capsaicin, and voltage. ASICs and TRPV1 are present in sensory neurons. It has been shown that raising the temperature increases TRPV1 and decreases ASIC H(+)-gated current amplitudes. To understand the underlying mechanisms, we have analyzed ASIC and TRPV1 function in a recombinant expression system and in dorsal root ganglion (DRG) neurons at room and physiological temperature. We show that temperature in the range studied does not affect the pH dependence of ASIC and TRPV1 activation. A temperature increase induces, however, a small alkaline shift of the pH dependence of steady-state inactivation of ASIC1a, ASIC1b, and ASIC2a. The decrease in ASIC peak current amplitudes at higher temperatures is likely in part due to the observed accelerated open channel inactivation kinetics and for some ASIC types to the changed pH dependence of steady-state inactivation. The increase in H(+)-activated TRPV1 current at the higher temperature is at least in part due to a hyperpolarizing shift in its voltage dependence. The contribution of TRPV1 relative to ASICs to H(+)-gated currents in DRG neurons increases with higher temperature and acidity. Still, ASICs remain the principal pH sensors of DRG neurons at 35°C in the pH range ≥6.

Application of zirconia membranes as high-temperature PH sensors

International Nuclear Information System (INIS)

Neidrach, L.W.

1983-01-01

The zirconia pH sensor behaves much like the classical glass electrode, but it extends the range of measurement to much higher temperatures - about 300 0 vs 120 0 C. It also has virtues over the glass electrode at lower temperatures because of the absence of an ''alkaline error.'' Like the glass electrode, it is insensitive to changes in the redox potential of the environment and, in turn, it exerts no influence on the environment. Such sensors have been finding application in the direct measurement of the pH of geothermal brines, of water in nuclear reactors, and in high-temperature corrosion studies. The sensors can also be used as ''pseudoreference'' electrodes for the measurement of redox and corrosion potentials in high-temperature media

Modeling of extended defects in silicon

International Nuclear Information System (INIS)

Law, M.E.; Jones, K.S.; Earles, S.K.; Lilak, A.D.; Xu, J.W.

1997-01-01

Transient Enhanced Diffusion (TED) is one of the biggest modeling challenges present in predicting scaled technologies. Damage from implantation of dopant ions changes the diffusivities of the dopants and precipitates to form complex extended defects. Developing a quantitative model for the extended defect behavior during short time, low temperature anneals is a key to explaining TED. This paper reviews some of the modeling developments over the last several years, and discusses some of the challenges that remain to be addressed. Two examples of models compared to experimental work are presented and discussed

Thermal conductivity and electrical resistivity of cadmium arsenide (Cd3As2) in the temperature range 4.2-40K1

International Nuclear Information System (INIS)

Bartkowski, K.; Ratalowicz, J.; Zdanowicz, W.

1986-01-01

Results on electrical resistivity and thermal conductivity measured in the temperature range 4.2-40 K are presented for single-crystal and polycrystalline samples of Cd 3 As 2 . Hall effect has been studied at temperatures of 4.2, 77, and 300K. The calculated value of the conduction electron concentration was in the range 1.87-1.95 10 24 m -3 . Electrical resistivity of all investigated samples was independent of temperature up to about 10K and increased slowsly at higher temperatures. The thermal conductivity shows a maximum in the region in which the lattice component of thermal conductivity dominates. The strong anistropy of the lattice component determines the anisotropy of the total thermal conductivity. The electronic component of thermal conductivity does not exhibit any anisotropy and shows a maximum at a temperature of about 300 K

Application of a vortex shedding flowmeter to the wide range measurement of high temperature gas flow

International Nuclear Information System (INIS)

Baker, S.P.; Ennis, R.M. Jr.; Herndon, P.G.

1981-01-01

A single flowmeter was required for helium gas measurement in a Gas Cooled Fast Breeder Reactor loss of coolant simulator. Volumetric flow accuracy of +-1.0% of reading was required over the Reynolds Number range 6 x 10 3 to 1 x 10 6 at flowing pressures from 0.2 to 9 MPa (29 to 1305 psia) at 350 0 C (660 0 F) flowing temperature. Because of its inherent accuracy and rangeability, a vortex shedding flowmeter was selected and specially modified to provide for a remoted thermal sensor. Experiments were conducted to determine the relationship between signal attenuation and sensor remoting geometry, as well as the relationship between gas flow parameters and remoted thermal sensor signal for both compressed air and helium gas. Based upon the results of these experiments, the sensor remoting geometry was optimized for this application. The resultant volumetric flow rangeability was 155:1. The associated temperature increase at the sensor position was 9 0 C above ambient (25 0 F) at a flowing temperature of 350 0 C. The volumetric flow accuracy was measured over the entire 155:1 flow range at parametric values of flowing density. A volumetric flow accuracy of +- % of reading was demonstrated

Temperature behaviour of photoluminescence and electron-beam-induced current recombination behaviour of extended defects in solar grade silicon

CERN Document Server

Arguirov, T; Kittler, M; Reif, J

2002-01-01

The temperature dependence of D-band and band-to-band (BB) luminescence was measured in EFG samples between 80 K and room temperature for defects/dislocations presenting different amounts of contamination. The contamination density was estimated from the temperature behaviour of the electron-beam-induced current contrast, ranging between about 10 sup 4 and 10 sup 6 impurities cm sup - sup 1 dislocation length. The D1 line became already visible at room temperature but its intensity was found to exhibit a maximum at about 150 K. D2, D3 and D4 start to show up at about 250, 190 and 170 K, respectively, and increase their intensities upon lowering temperature. At room temperature the width of the D1 line is broad and becomes narrower upon lowering the temperature. D2 shows the opposite behaviour. The intensities of D1 and D2 were observed to show strong variations across the sample, whereas this was not observed for the pair D4/D3. In particular, the origin of the lines D1 and D2 is still far from being understo...

Conductance of partially disordered graphene: crossover from temperature-dependent to field-dependent variable-range hopping

International Nuclear Information System (INIS)

Cheah, C Y; Jaurigue, L C; Kaiser, A B; Gómez-Navarro, C

2013-01-01

We report an analysis of low-temperature measurements of the conductance of partially disordered reduced graphene oxide, finding that the data follow a simple crossover scenario. At room temperature, the conductance is dominated by two-dimensional (2D) electric field-assisted, thermally driven (Pollak–Riess) variable-range hopping (VRH) through highly disordered regions. However, at lower temperatures T, we find a smooth crossover to follow the exp(−E 0 /E) 1/3 field-driven (Shklovskii) 2D VRH conductance behaviour when the electric field E exceeds a specific crossover value E C (T) 2D =(E a E 0 1/3 /3) 3/4 determined by the scale factors E 0 and E a for the high-field and intermediate-field regimes respectively. Our crossover scenario also accounts well for experimental data reported by other authors for three-dimensional disordered carbon networks, suggesting wide applicability. (paper)

Ductile long range ordered alloys with high critical ordering temperature and wrought articles fabricated therefrom

Science.gov (United States)

Liu, Chain T.; Inouye, Henry

1979-01-01

Malleable long range ordered alloys having high critical ordering temperatures exist in the V(Fe, Co).sub.3 and V(Fe, Co, Ni).sub.3 systems. These alloys have the following compositions comprising by weight: 22-23% V, 14-30% Fe, and the remainder Co or Co and Ni with an electron density no more than 7.85. The maximum combination of high temperature strength, ductility and creep resistance are manifested in the alloy comprising by weight 22-23% V, 14-20% Fe and the remainder Co and having an atomic composition of V(Fe .sub.0.20-0.26 C Co.sub.0.74-0.80).sub.3. The alloy comprising by weight 22-23% V, 16-17% Fe and 60-62% Co has excellent high temperature properties. The alloys are fabricable into wrought articles by casting, deforming, and annealing for sufficient time to provide ordered structure.

Global climate change: impact of diurnal temperature range on mortality in Guangzhou, China.

Science.gov (United States)

Yang, Jun; Liu, Hua-Zhang; Ou, Chun-Quan; Lin, Guo-Zhen; Zhou, Qin; Shen, Gi-Chuan; Chen, Ping-Yan; Guo, Yuming

2013-04-01

Diurnal temperature range (DTR) is an important meteorological indicator associated with global climate change, but little is known about the effects of DTR on mortality. We examined the effects of DTR on cause-/age-/education-specific mortality in Guangzhou, a subtropical city in China during 2003-2010. A quasi-Poisson regression model combined with distributed lag non-linear model was used to examine the effects of DTR, after controlling for daily mean temperature, air pollutants, season and day of the week. A 1 °C increase in DTR at lag 0-4 days was associated with a 0.47% (95% confidence interval: 0.01%-0.93%) increase in non-accidental mortality. Stroke mortality was most sensitive to DTR. Female, the elderly and those with low education were more susceptible to DTR than male, the youth and those with high education, respectively. Our findings suggest that vulnerable subpopulations should pay more attention to protect themselves from unstable daily weather. Copyright © 2012 Elsevier Ltd. All rights reserved.

Outgassing tests on graphites in temperature range 100-1600 degrees C

International Nuclear Information System (INIS)

Alessandrini, C.; Apicella, M.L.; Verdini, L.

1993-01-01

Graphite is a an interesting material for plasma-facing components in fusion experiments, mainly because of its low atomic number and excellent thermal properties. Nevertheless, it contains a large amount of gaseous impurities, which can be released by plasma-surface interactions and affect the purity of the deuterium-tritium plasma. To investigate the outgassing behaviour of graphites, CFC's and doped C composites, a facility was set up to perform outgassing tests on samples, as a function of temperature in the range between 100 and 1600 degrees C. The experimental apparatus, designed to work in UHV conditions, allows outgassing measurements by a quadrupole mass spectrometer (1-200 AMU) using two different methods. The test facility, the quadrupole calibration and preliminary quantitative outgassing measurements on SEP CARB N112 samples are described

Influence of the atomic structure of crystal surfaces on the surface diffusion in medium temperature range

International Nuclear Information System (INIS)

Cousty, J.P.

1981-12-01

In this work, we have studied the influence of atomic structure of crystal surface on surface self-diffusion in the medium temperature range. Two ways are followed. First, we have measured, using a radiotracer method, the self-diffusion coefficient at 820 K (0.6 T melting) on copper surfaces both the structure and the cleanliness of which were stable during the experiment. We have shown that the interaction between mobile surface defects and steps can be studied through measurements of the anisotropy of surface self diffusion. Second, the behavior of an adatom and a surface vacancy is simulated via a molecular dynamics method, on several surfaces of a Lennard Jones crystal. An inventory of possible migration mechanisms of these surface defects has been drawn between 0.35 and 0.45 Tsub(m). The results obtained with both the methods point out the influence of the surface atomic structure in surface self-diffusion in the medium temperature range [fr

Biaxial creep deformation of Zircaloy-4 in the high alpha phase temperature range

International Nuclear Information System (INIS)

Donaldson, A.T.; Horwood, R.A.; Healey, T.

1983-01-01

The ballooning response of Zircaloy-4 fuel tubes during a postulated loss-of-coolant accident may be calculated from a knowledge of the thermal environment of the rods and the creep deformation characteristics of the cladding. In support of such calculations biaxial creep studies have been performed on fuel tubes supplied by Westinghouse, Wolverine and Sandvik of temperatures in the alpha phase range. This paper presents the results of an investigation of their respective creep behaviour which has resulted in the formulation of equations for use in LOCA fuel ballooning codes. (author)

The potential for extending the spectral range accessible to the european X-ray free electron laser in the direction of longer wavelengths

CERN Document Server

Saldin, E L; Yurkov, M V

2004-01-01

The baseline specifications of European XFEL give a range of wavelengths between 0.1 nm and 2 nm. This wavelength range at fixed electron beam energy 17.5 GeV can be covered by operating the SASE FEL with three undulators which have different period and tunable gap. A study of the potential for the extending the spectral range accessible to the XFEL in the direction of longer wavelengths is presented. The extension of the wavelength range to 6 nm would be cover the water window in the VUV region, opening the facility to a new class of experiments. There are at least two possible sources of VUV radiation associated with the X-ray FEL; the "low (2.5 GeV) energy electron beam dedicated" and the " 17.5 GeV spent beam parasitic" (or "after-burner") source modes. The second alternative, "after-burner undulator" is the one we regard as most favorable. It is possible to place an undulator as long as 80 meters after 2 nm undulator. Ultimately, VUV undulator would be able to deliver output power approaching 100 GW. A b...

Temperature measurement in the liquid helium range at pressure

International Nuclear Information System (INIS)

Itskevich, E.S.; Krajdenov, V.F.

1978-01-01

The use of bronze and germanium resistance thermometers and the use of a (Au + 0.07 % Fe)-Cu thermocouple for temperature measurements from 1.5 to 4.2 K in the hydrostatic compression of up to 10 kbar are considered. To this aim, the thermometer resistance as a function of temperature and pressure is measured. It is revealed that pressure does not change the thermometric response of the bronze resistance thermometer but only shifts it to the region of lower temperatures. The identical investigations of the germanium resistance thermometer shows that strong temperature dependence and the shift of its thermometric response under the influence of pressure make the use of germanium resistance thermometers in high-pressure chambers very inconvenient. The results of the analysis of the (Au + 0.07 % Fe) - Cu thermocouple shows that with a 2 per cent accuracy the thermocouple Seebeck coefficient does not depend on pressure. It permits to use this thermocouple for temperature measurements at high pressures

Bacteriospermia in extended porcine semen.

Science.gov (United States)

Althouse, Gary C; Lu, Kristina G

2005-01-15

Bacteriospermia is a frequent finding in freshly extended porcine semen and can result in detrimental effects on semen quality and longevity if left uncontrolled. The primary source of bacterial contamination is the boar. Other sources that have been identified include environment, personnel, and the water used for extender preparation. A 1-year retrospective study was performed on submissions of extended porcine semen for routine quality control bacteriological screening at the University of Pennsylvania. Out of 250 sample submissions, 78 (31.2%) tested positive for bacterial contamination. The most popular contaminants included Enterococcus spp. (20.5%), Stenotrophomonas maltophilia (15.4%), Alcaligenes xylosoxidans (10.3%), Serratia marcescens (10.3%), Acinetobacter lwoffi (7.7%), Escherichia coli (6.4%), Pseudomonas spp. (6.4%), and others (23.0%). Prudent individual hygiene, good overall sanitation, and regular monitoring can contribute greatly in controlling bacterial load. Strategies that incorporate temperature-dependent bacterial growth and hyperthermic augmentation of antimicrobial activity are valuable for effective control of susceptible bacterial loads. Aminoglycosides remain the most popular antimicrobial class used in porcine semen extenders, with beta-lactam and lincosamide use increasing. With the advent of more novel antimicrobial selection and semen extender compositions in swine, prudent application and understanding of in vitro pharmacodynamics are becoming paramount to industry success in the use of this breeding modality.

Nuclear collective vibrations in extended mean-field theory

Energy Technology Data Exchange (ETDEWEB)

Lacroix, D. [Lab. de Physique Corpusculaire/ ENSICAEN, 14 - Caen (France); Ayik, S. [Tennessee Technological Univ., Cookeville, TN (United States); Chomaz, Ph. [Grand Accelerateur National d' Ions Lourds (GANIL), 14 - Caen (France)

2003-07-01

The extended mean-field theory, which includes both the incoherent dissipation mechanism due to nucleon-nucleon collisions and the coherent dissipation mechanism due to coupling to low-lying surface vibrations, is briefly reviewed. Expressions of the strength functions for the collective excitations are presented in the small amplitude limit of this approach. This fully microscopic theory is applied by employing effective Skyrme forces to various giant resonance excitations at zero and finite temperature. The theory is able to describe the gross properties of giant resonance excitations, the fragmentation of the strength distributions as well as their fine structure. At finite temperature, the success and limitations of this extended mean-field description are discussed. (authors)

Effect of daily temperature range on respiratory health in Argentina and its modification by impaired socio-economic conditions and PM_1_0 exposures

International Nuclear Information System (INIS)

Carreras, Hebe; Zanobetti, Antonella; Koutrakis, Petros

2015-01-01

Epidemiological investigations regarding temperature influence on human health have focused on mortality rather than morbidity. In addition, most information comes from developed countries despite the increasing evidence that climate change will have devastating impacts on disadvantaged populations living in developing countries. In the present study, we assessed the impact of daily temperature range on upper and lower respiratory infections in Cordoba, Argentina, and explored the effect modification of socio-economic factors and influence of airborne particles We found that temperature range is a strong risk factor for admissions due to both upper and lower respiratory infections, particularly in elderly individuals, and that these effects are more pronounced in sub-populations with low education level or in poor living conditions. These results indicate that socio-economic factors are strong modifiers of the association between temperature variability and respiratory morbidity, thus they should be considered in risk assessments. - Highlights: • Daily temperature range is a strong risk factor for respiratory infections. • Low education level and poor living conditions are strong modifiers of this relationship. • In Cordoba city higher risk for respiratory infections were observed during summertime. - Daily temperature range is a strong risk factor for respiratory infections, particularly for populations with low educational level or poor living conditions.

A high-stability non-contact dilatometer for low-amplitude temperature-modulated measurements

Energy Technology Data Exchange (ETDEWEB)

Luckabauer, Martin; Sprengel, Wolfgang; Würschum, Roland [Institute of Materials Physics, Graz University of Technology, A-8010 Graz (Austria)

2016-07-15

Temperature modulated thermophysical measurements can deliver valuable insights into the phase transformation behavior of many different materials. While especially for non-metallic systems at low temperatures numerous powerful methods exist, no high-temperature device suitable for modulated measurements of bulk metallic alloy samples is available for routine use. In this work a dilatometer for temperature modulated isothermal and non-isothermal measurements in the temperature range from room temperature to 1300 K is presented. The length measuring system is based on a two-beam Michelson laser interferometer with an incremental resolution of 20 pm. The non-contact measurement principle allows for resolving sinusoidal length change signals with amplitudes in the sub-500 nm range and physically decouples the length measuring system from the temperature modulation and heating control. To demonstrate the low-amplitude capabilities, results for the thermal expansion of nickel for two different modulation frequencies are presented. These results prove that the novel method can be used to routinely resolve length-change signals of metallic samples with temperature amplitudes well below 1 K. This high resolution in combination with the non-contact measurement principle significantly extends the application range of modulated dilatometry towards high-stability phase transformation measurements on complex alloys.

Long-term creep behavior of high-temperature gas turbine materials under constant and variable stress

International Nuclear Information System (INIS)

Granacher, J.; Preussler, T.

1987-01-01

Within the framework of the documented research project, extensive creep rupture tests were carried out with characteristic, high-temperature gas turbine materials for establishment of improved design data. In the range of the main application temperatures and in stress ranges down to application-relevant values the tests extended over a period of about 40,000 hours. In addition, long-term annealing tests were carried out in the most important temperature ranges for the measurement of the density-dependent straim, which almost always manifested itself as a material contraction. Furthermore, hot tensile tests were carried out for the description of the elastoplastic short-term behavior. Several creep curves were derived from the results of the different tests with a differentiated evaluation method. On the basis of these creep curves, creep equations were set up for a series of materials which are valid in the entire examined temperature range and stress range and up to the end of the secondary creep range. Also, equations for the time-temperature-dependent description of the material contraction behavior were derived. With these equations, the high-temperature deformation behavior of the examined materials under constant creep stress can be described simply and application-oriented. (orig.) With 109 figs., 19 tabs., 77 refs [de

The one-dimensional extended Bose–Hubbard model

Indian Academy of Sciences (India)

Unknown

method to obtain the zero-temperature phase diagram of the one-dimensional, extended ... Progress in this field has been driven by an interplay between ... superconductor-insulator transition in thin films of superconducting materials like bis-.

Physical activity profile of 2014 FIFA World Cup players, with regard to different ranges of air temperature and relative humidity

Science.gov (United States)

Chmura, Paweł; Konefał, Marek; Andrzejewski, Marcin; Kosowski, Jakub; Rokita, Andrzej; Chmura, Jan

2017-04-01

The present study attempts to assess changes in soccer players' physical activity profiles under the simultaneous influence of the different combinations of ambient temperature and relative humidity characterising matches of the 2014 FIFA World Cup hosted by Brazil. The study material consisted of observations of 340 players representing 32 national teams taking part in the tournament. The measured indices included total distances covered; distances covered with low, moderate, or high intensity; numbers of sprints performed, and peak running speeds achieved. The analysis was carried out using FIFA official match data from the Castrol Performance Index system. Ultimately, consideration was given to a combination of three air temperature ranges, i.e. below 22 °C, 22-28 °C, and above 28 °C; and two relative humidity ranges below 60 % and above 60 %. The greatest average distance recorded (10.54 ± 0.91 km) covered by players at an air temperature below 22 °C and a relative humidity below 60 %, while the shortest (9.83 ± 1.08 km) characterised the same air temperature range, but conditions of relative humidity above 60 % ( p ≤ 0.001). Two-way ANOVA revealed significant differences ( p ≤ 0.001) in numbers of sprints performed by players, depending on whether the air temperature range was below 22 °C (40.48 ± 11.17) or above 28 °C (30.72 ± 9.40), but only where the relative humidity was at the same time below 60 %. Results presented indicate that the conditions most comfortable for physical activity on the part of players occur at 22 °C, and with relative humidity under 60 %.

The interrelationship between dengue incidence and diurnal ranges of temperature and humidity in a Sri Lankan city and its potential applications.

Science.gov (United States)

Ehelepola, N D B; Ariyaratne, Kusalika

2015-01-01

Temperature, humidity, and other weather variables influence dengue transmission. Published studies show how the diurnal fluctuations of temperature around different mean temperatures influence dengue transmission. There are no published studies about the correlation between diurnal range of humidity and dengue transmission. The goals of this study were to determine the correlation between dengue incidence and diurnal fluctuations of temperature and humidity in the Sri Lankan city of Kandy and to explore the possibilities of using that information for better control of dengue. We calculated the weekly dengue incidence in Kandy during the period 2003-2012, after collecting data on all of the reported dengue patients and estimated midyear populations. Data on daily maximum and minimum temperatures and night-time and daytime humidity were obtained from two weather stations, averaged, and converted into weekly data. The number of days per week with a diurnal temperature range (DTR) of >10°C and humidity range (DHR) of >20 and humidity. There were negative correlations between dengue incidence and a DTR >10°C and a DHR >20% with 3.3-week and 4-week lag periods, respectively. Additionally, positive correlations between dengue incidence and a DTR humidity in the future. We suggest ways and means to use this information for local dengue control and to mitigate the potential effects of the ongoing global reduction of DTR on dengue incidence.

Yield and strength properties of the Ti-6-22-22S alloy over a wide strain rate and temperature range

International Nuclear Information System (INIS)

Krueger, L.; Kanel, G.I.; Razorenov, S.V.; Bezrouchko, G.S.; Meyer, L.

2002-01-01

A mechanical behavior of the Ti-6-22-22S alloy was studied under uniaxial strain conditions at shock-wave loading and under uniaxial compressive stress conditions over a strain rate range of 10-4 s-1 to 103 s-1. The test temperature was varied from -175 deg. C to 620 deg. C. The strain-rate and the temperature dependencies of the yield stress obtained from the uniaxial stress tests and from the shock-wave experiments are in a good agreement and demonstrate a significant decrease in the yield strength as the temperature increases. This indicates the thermal activation mechanism of plastic deformation of the alloy is maintained at strain rates up to 106 s-1. Variation of sample thickness from 2.24 to 10 mm results in relatively small variations in the dynamic yield strength and the spall strength over the whole temperature range

Reassessing changes in diurnal temperature range: A new data set and characterization of data biases

Science.gov (United States)

Thorne, P. W.; Menne, M. J.; Williams, C. N.; Rennie, J. J.; Lawrimore, J. H.; Vose, R. S.; Peterson, T. C.; Durre, I.; Davy, R.; Esau, I.; Klein-Tank, A. M. G.; Merlone, A.

2016-05-01

It has been a decade since changes in diurnal temperature range (DTR) globally have been assessed in a stand-alone data analysis. The present study takes advantage of substantively improved basic data holdings arising from the International Surface Temperature Initiative's databank effort and applies the National Centers for Environmental Information's automated pairwise homogeneity assessment algorithm to reassess DTR records. It is found that breakpoints are more prevalent in DTR than other temperature elements and that the resulting adjustments have a broader distribution. This strongly implies that there is an overarching tendency, across the global meteorological networks, for nonclimatic artifacts to impart either random or anticorrelated rather than correlated biases in maximum and minimum temperature series. Future homogenization efforts would likely benefit from simultaneous consideration of DTR and maximum and minimum temperatures, in addition to average temperatures. Estimates of change in DTR are relatively insensitive to whether adjustments are calculated directly or inferred from adjustments returned for the maximum and minimum temperature series. The homogenized series exhibit a reduction in DTR since the midtwentieth century globally (-0.044 K/decade). Adjustments serve to approximately halve the long-term global reduction in DTR in the basic "raw" data. Most of the estimated DTR reduction occurred over 1960-1980. In several regions DTR has apparently increased over 1979-2012, while globally it has exhibited very little change (-0.016 K/decade). Estimated changes in DTR are an order of magnitude smaller than in maximum and minimum temperatures, which have both been increasing rapidly on multidecadal timescales (0.186 K/decade and 0.236 K/decade, respectively, since the midtwentieth century).

Finite temperature effects on monopole and dipole excitations

International Nuclear Information System (INIS)

Niu, Y F; Paar, N; Vretenar, D; Meng, J

2011-01-01

The relativistic random phase approximation based on effective Lagrangian with density dependent meson-nucleon couplings has been extended to finite temperature and employed in studies of multipole excitations within the temperature range T = 1 - 2 MeV. The model calculations showed that isoscalar giant monopole and isovector giant dipole resonances are only slightly modified with temperature, but additional transition strength appears at low energies because of thermal unblocking of single-particle orbitals close to the Fermi level. The analysis of low-lying states shows that isoscalar monopole response in 132 Sn results from single particle transitions, while the isovector dipole strength for 60 Ni, located around 10 MeV, is composed of several single particle transitions, accumulating a small degree of collectivity.

Thermodynamic modeling of CO2 absorption in aqueous N-Methyldiethanolamine using Extended UNIQUAC model

DEFF Research Database (Denmark)

Sadegh, Negar; Stenby, Erling Halfdan; Thomsen, Kaj

2015-01-01

A Thermodynamic model that can predict the behavior of the gas sweetening process over the applicable conditions is of vital importance in industry. In this work, Extended UNIQUAC model parameters optimized for the CO2-MDEA-H2O system are presented. Different types of experimental data consisting...... model accurately represents thermodynamic and thermal properties of the studied systems. The model parameters are valid in the temperature range from -15 to 200 °C, MDEA mass% of 5-75 and CO2 partial pressure of 0-6161.5 kPa....

New records of Lophoproctuscoecus Pocock, 1894 (Diplopoda, Polyxenida, Lophoproctidae) extend the range of the genus Lophoproctus.

Science.gov (United States)

Short, Megan

2015-01-01

The geographic distribution of the genus Lophoproctus Pocock, 1894 has greatly expanded with new records of the species Lophoproctuscoecus Pocock, 1894, together with the reassignment of a number of millipedes formerly identified as Lophoproctuslucidus (Chalande, 1888). Lophoproctuscoecus was found to be the sole representative of the family Lophoproctidae in collections examined from Crimea and the Caucasian region. The species was also identified from Iran and Kyrgyzstan. Lophoproctus specimens collected in Italy by Verhoeff were reassigned as Lophoproctuscoecus with the exception of one specimen of Lophoproctusjeanneli (Brölemann, 1910) from Capri. These data were combined with all available information from the literature to look at the pattern of distribution of the four species in the genus. The range of the genus Lophoproctus extends from Portugal to Central Asia. Lophoproctuscoecus is widespread from Italy eastward, while the morphologically very similar species Lophoproctuslucidus is confined to France and northern Africa. The two species have a narrow overlap in the Alpes Maritimes region of France. Lophoproctusjeanneli has a scattered coastal distribution around the Mediterranean Sea. The troglobitic species Lophoproctuspagesi (Condé, 1982) has only been recorded from a cave on Majorca, Spain.

Extended family medicine training

Science.gov (United States)

Slade, Steve; Ross, Shelley; Lawrence, Kathrine; Archibald, Douglas; Mackay, Maria Palacios; Oandasan, Ivy F.

2016-01-01

Abstract Objective To examine trends in family medicine training at a time when substantial pedagogic change is under way, focusing on factors that relate to extended family medicine training. Design Aggregate-level secondary data analysis based on the Canadian Post-MD Education Registry. Setting Canada. Participants All Canadian citizens and permanent residents who were registered in postgraduate family medicine training programs within Canadian faculties of medicine from 1995 to 2013. Main outcome measures Number and proportion of family medicine residents exiting 2-year and extended (third-year and above) family medicine training programs, as well as the types and numbers of extended training programs offered in 2015. Results The proportion of family medicine trainees pursuing extended training almost doubled during the study period, going from 10.9% in 1995 to 21.1% in 2013. Men and Canadian medical graduates were more likely to take extended family medicine training. Among the 5 most recent family medicine exit cohorts (from 2009 to 2013), 25.9% of men completed extended training programs compared with 18.3% of women, and 23.1% of Canadian medical graduates completed extended training compared with 13.6% of international medical graduates. Family medicine programs vary substantially with respect to the proportion of their trainees who undertake extended training, ranging from a low of 12.3% to a high of 35.1% among trainees exiting from 2011 to 2013. Conclusion New initiatives, such as the Triple C Competency-based Curriculum, CanMEDS–Family Medicine, and Certificates of Added Competence, have emerged as part of family medicine education and credentialing. In acknowledgment of the potential effect of these initiatives, it is important that future research examine how pedagogic change and, in particular, extended training shapes the care family physicians offer their patients. As part of that research it will be important to measure the breadth and uptake of

Preliminary Performance Evaluation of MEMS-based Piezoelectric Energy Harvesters in Extended Temperature Range

DEFF Research Database (Denmark)

Xu, R.; Borregaard, L.M.; Lei, A.

2012-01-01

In this work a batch of MEMS-based vibration energy harvesters consisting of a silicon/PZT thick film ntilever with integrated proof mass is characterized. The purpose of a vibration energy harvester is to convert low grade vibrations to useful electrical power. Optimally, the natural frequency...

Analysis of four-stroke, Wankel, and microturbine based range extenders for electric vehicles

International Nuclear Information System (INIS)

Ribau, João; Silva, Carla; Brito, Francisco P.; Martins, Jorge

2012-01-01

Highlights: ► VSP correlates well with the engine use, regenerative braking and boost setting. ► Wankel engine vehicle is the most efficient in urban driving. ► Over-expanded engine vehicle is the most efficient in annual combined use. ► The higher the annual urban commuting driving the lower is energy consumption. ► Over-expanded solution has 5.7% WTW less energy usage and 8.8% less CO 2 emissions. - Abstract: This paper aims to compare the energy efficiency and CO 2 emissions of four different range extender engine solutions deployed in the same baseline series hybrid vehicle, under a combination of driving scenarios aiming to be representative of typical driving instead of standard cycles. Baseline vehicle is roughly based on Chevy VOLT/Opel Ampera. The baseline internal combustion engine is replaced by an over-expanded cycle engine, Wankel engine and microturbine, with respective generator and exhaust after treatment. Weight savings are compensated by introducing additional battery modules, maintaining the original baseline vehicle curb weight. Vehicle Specific Power (VSP) is used for driving cycle analysis and as explanatory variable for energy consumption and CO 2 emissions variations. Upstream fuel energy and CO 2 emissions of gasoline/diesel and electricity are regarded. Average VSP correlates with variation of the percentage of engine off, potential regenerative braking energy and eco/boost operation. Positive wheel energy correlates with energy consumption and electric autonomy adequately. The vehicle with the lightest engine (Wankel) and largest battery shows to be the most efficient in urban driving (when the engine does not have to work), while the vehicle with the highest efficient engine (over-expanded) and with dual eco/boost setting is the most efficient during the charge sustaining operation and in annual combined use.

Dissipation range turbulent cascades in plasmas

International Nuclear Information System (INIS)

Terry, P. W.; Almagri, A. F.; Forest, C. B.; Nornberg, M. D.; Rahbarnia, K.; Sarff, J. S.; Fiksel, G.; Hatch, D. R.; Jenko, F.; Prager, S. C.; Ren, Y.

2012-01-01

Dissipation range cascades in plasma turbulence are described and spectra are formulated from the scaled attenuation in wavenumber space of the spectral energy transfer rate. This yields spectra characterized by the product of a power law and exponential fall-off, applicable to all scales. Spectral indices of the power law and exponential fall-off depend on the scaling of the dissipation, the strength of the nonlinearity, and nonlocal effects when dissipation rates of multiple fluctuation fields are different. The theory is used to derive spectra for MHD turbulence with magnetic Prandtl number greater than unity, extending previous work. The theory is also applied to generic plasma turbulence by considering the spectrum from damping with arbitrary wavenumber scaling. The latter is relevant to ion temperature gradient turbulence modeled by gyrokinetics. The spectrum in this case has an exponential component that becomes weaker at small scale, giving a power law asymptotically. Results from the theory are compared to three very different types of turbulence. These include the magnetic plasma turbulence of the Madison Symmetric Torus, the MHD turbulence of liquid metal in the Madison Dynamo Experiment, and gyrokinetic simulation of ion temperature gradient turbulence.

Compressive laser ranging.

Science.gov (United States)

Babbitt, Wm Randall; Barber, Zeb W; Renner, Christoffer

2011-12-15

Compressive sampling has been previously proposed as a technique for sampling radar returns and determining sparse range profiles with a reduced number of measurements compared to conventional techniques. By employing modulation on both transmission and reception, compressive sensing in ranging is extended to the direct measurement of range profiles without intermediate measurement of the return waveform. This compressive ranging approach enables the use of pseudorandom binary transmit waveforms and return modulation, along with low-bandwidth optical detectors to yield high-resolution ranging information. A proof-of-concept experiment is presented. With currently available compact, off-the-shelf electronics and photonics, such as high data rate binary pattern generators and high-bandwidth digital optical modulators, compressive laser ranging can readily achieve subcentimeter resolution in a compact, lightweight package.

Partial molar volumes of (acetonitrile + water) mixtures over the temperature range (273.15 to 318.15) K

International Nuclear Information System (INIS)

Yeow, Y. Leong; Leong, Yee-Kwong

2007-01-01

Isothermal molar volume data of (acetonitrile + water) mixtures, between T = 273.15 K and T = 318.15 K, extracted from different sources are combined and treated as a single set to even out minor differences between sources and to increase the number of data points for each temperature. Tikhonov regularization is applied to compute the isothermal first and second derivatives of these data with respect to molar composition. For the reference temperature of 298.15 K, this computation is extended to the third derivative. Generalized Cross Validation is used to guide the selection of the regularization parameter that keeps noise amplification under control. The resulting first derivatives are used to construct the partial molar volume curves which are then checked against published results. Properties of the partial molar volumes are analysed by examining their derivatives. Finally the general shape of the second derivative curve of molar volume is explained qualitatively in terms of tripartite segmentation of the molar composition interval but quantitative comparisons are required to confirm this explanation

Verification of High Temperature Free Atom Thermal Scattering in MERCURY Compared to TART

International Nuclear Information System (INIS)

Cullen, D E; McKinley, S; Hagmann, C

2006-01-01

This is part of a series of reports verifying the accuracy of the relatively new MERCURY [1] Monte Carlo particle transport code by comparing its results to those of the older TART [2] Monte Carlo particle transport code. In the future we hope to extend these comparisons to include deterministic (Sn) codes [3]. Here we verify the accuracy of the free atom thermal scattering model [4] by using it over a very large temperature range. We would like to be able to use these Monte Carlo codes for astrophysical applications, where the temperature of the medium can be extremely high compared to the temperatures we normally encounter in our terrestrial applications [5]. The temperature is so high that is it often defined in eV rather than Kelvin. For a correspondence between the two scale 293.6 Kelvin (room temperature) corresponds to 0.0253 eV ∼ 1/40 eV. So that 1 eV temperature is about 12,000 Kelvin, and 1 keV temperature is about 12 million Kelvin. Here we use a relatively small system measured in cm, but by using ρR scaling [6] our results are equally applicable to systems measured in Km or thousands of Km or any size that we need for astrophysical applications. The emphasis here is not on modeling any given real system, but rather in verifying the accuracy of the free atom model to represent theoretical results over a large temperature range. There are two primary objectives of this report: (1) Verify agreement between MERCURY and TART results, both using continuous energy cross sections. In particular we want to verify the free atom scattering treatment in MERCURY as used over an extended temperature range; by comparison to many other codes for TART this has already been verified over many years [4, 7]. (2) Demonstrate that this agreement depends on using continuous energy cross sections. To demonstrate this we also present TART using the Multi-Band method [8, 9], which accounts for resonance self-shielding, and Multi-Group method, without self-shielding [9

Improved Models and Tools for Prediction of Radiation Effects on Space Electronics in Wide Temperature Range, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — All NASA exploration systems operate in the extreme environments of space and require reliable electronics capable of handling a wide temperature range (-180ºC to...

Exclusion Bounds for Extended Anyons

Science.gov (United States)

Larson, Simon; Lundholm, Douglas

2018-01-01

We introduce a rigorous approach to the many-body spectral theory of extended anyons, that is quantum particles confined to two dimensions that interact via attached magnetic fluxes of finite extent. Our main results are many-body magnetic Hardy inequalities and local exclusion principles for these particles, leading to estimates for the ground-state energy of the anyon gas over the full range of the parameters. This brings out further non-trivial aspects in the dependence on the anyonic statistics parameter, and also gives improvements in the ideal (non-extended) case.

Temperature jump boundary conditions in radiation diffusion

International Nuclear Information System (INIS)

Alonso, C.T.

1976-12-01

The radiation diffusion approximation greatly simplifies radiation transport problems. Yet the application of this method has often been unnecessarily restricted to optically thick regions, or has been extended through the use of such ad hoc devices as flux limiters. The purpose of this paper is to review and draw attention to the use of the more physically appropriate temperature jump boundary conditions for extending the range of validity of the diffusion approximation. Pioneering work has shown that temperature jump boundary conditions remove the singularity in flux that occurs in ordinary diffusion at small optical thicknesses. In this review paper Deissler's equations for frequency-dependent jump boundary conditions are presented and specific geometric examples are calculated analytically for steady state radiation transfer. When jump boundary conditions are applied to radiation diffusion, they yield exact solutions which are naturally flux- limited and geometry-corrected. We believe that the presence of temperature jumps on source boundaries is probably responsible in some cases for the past need for imposing ad hoc flux-limiting constraints on pure diffusion solutions. The solution for transfer between plane slabs, which is exact to all orders of optical thickness, also provides a useful tool for studying the accuracy of computer codes

Intermediate Temperature Fuel Cell Using CsH₂PO₄/ZrO₂-Based Composite Electrolytes

DEFF Research Database (Denmark)

Jensen, Annemette Hindhede; Li, Qingfeng; Christensen, Erik

2014-01-01

Proton conductors operating at intermediate temperatures are receiving significant attention due to their advantages over conventionally used materials in proton exchange membrane fuel cells. CsH2PO4 has proven to be proton conducting above 230°C, however within a narrow temperature range of the ...... to 280°C under low atmospheric humidification. Higher open circuit voltage and stability in the extended temperature range were achieved with composite electrolytes with a CsH2PO4 to ZrO2 molar ratio of 2....

Standard test method for determination of reference temperature, to, for ferritic steels in the transition range

CERN Document Server

American Society for Testing and Materials. Philadelphia

2011-01-01

1.1 This test method covers the determination of a reference temperature, To, which characterizes the fracture toughness of ferritic steels that experience onset of cleavage cracking at elastic, or elastic-plastic KJc instabilities, or both. The specific types of ferritic steels (3.2.1) covered are those with yield strengths ranging from 275 to 825 MPa (40 to 120 ksi) and weld metals, after stress-relief annealing, that have 10 % or less strength mismatch relative to that of the base metal. 1.2 The specimens covered are fatigue precracked single-edge notched bend bars, SE(B), and standard or disk-shaped compact tension specimens, C(T) or DC(T). A range of specimen sizes with proportional dimensions is recommended. The dimension on which the proportionality is based is specimen thickness. 1.3 Median KJc values tend to vary with the specimen type at a given test temperature, presumably due to constraint differences among the allowable test specimens in 1.2. The degree of KJc variability among specimen types i...

Calorie restriction extends the chronological lifespan of Saccharomyces cerevisiae independently of the Sirtuins.

Science.gov (United States)

Smith, Daniel L; McClure, Julie M; Matecic, Mirela; Smith, Jeffrey S

2007-10-01

Calorie restriction (CR) extends the mean and maximum lifespan of a wide variety of organisms ranging from yeast to mammals, although the molecular mechanisms of action remain unclear. For the budding yeast Saccharomyces cerevisiae reducing glucose in the growth medium extends both the replicative and chronological lifespans (CLS). The conserved NAD(+)-dependent histone deacetylase, Sir2p, promotes replicative longevity in S. cerevisiae by suppressing recombination within the ribosomal DNA locus and has been proposed to mediate the effects of CR on aging. In this study, we investigated the functional relationships of the yeast Sirtuins (Sir2p, Hst1p, Hst2p, Hst3p and Hst4p) with CLS and CR. SIR2, HST2, and HST4 were not major regulators of CLS and were not required for the lifespan extension caused by shifting the glucose concentration from 2 to 0.5% (CR). Deleting HST1 or HST3 moderately shortened CLS, but did not prevent CR from extending lifespan. CR therefore works through a Sirtuin-independent mechanism in the chronological aging system. We also show that low temperature or high osmolarity additively extends CLS when combined with CR, suggesting that these stresses and CR act through separate pathways. The CR effect on CLS was not specific to glucose. Restricting other simple sugars such as galactose or fructose also extended lifespan. Importantly, growth on nonfermentable carbon sources that force yeast to exclusively utilize respiration extended lifespan at nonrestricted concentrations and provided no additional benefit when restricted, suggesting that elevated respiration capacity is an important determinant of chronological longevity.

Two-phase CFD PTS validation in an extended range of thermohydraulics conditions covered by the COSI experiment

International Nuclear Information System (INIS)

Coste, P.; Ortolan, A.

2014-01-01

Highlights: • Models for large interfaces in two-phase CFD were developed for PTS. • The COSI experiment is used for NEPTUNE C FD integral validation. • COSI is a PWR cold leg scaled 1/100 for volume. • Fifty runs are calculated, covering a large range of flow configurations. • The CFD predicting capability is analysed using global and local measurements. - Abstract: In the context of the Pressurized Water Reactors (PWR) life duration safety studies, some models were developed to address the Pressurized Thermal Shock (PTS) from the two-phase CFD angle, dealing with interfaces much larger than cells size and with direct contact condensation. Such models were implemented in NEPTUNE C FD, a 3D transient Eulerian two-fluid model. The COSI experiment is used for its integral validation. It represents a cold leg scaled 1/100 for volume and power from a 900 MW PWR under a large range of LOCA PTS conditions. In this study, the CFD is evaluated in the whole range of parameters and flow configurations covered by the experiment. In a first step, a single choice of mesh and CFD models parameters is fixed and justified. In a second step, fifty runs are calculated. The CFD predicting capability is analysed, comparing the liquid temperature and the total condensation rate with the experiment, discussing their dependency on the inlet cold liquid rate, on the liquid level in the cold leg and on the difference between co-current and counter-current runs. It is shown that NEPTUNE C FD 1.0.8 calculates with a fair agreement a large range of flow configurations related to ECCS injection and steam condensation

Thermal quantum coherence and correlation in the extended XY spin chain

Science.gov (United States)

Sha, Ya-Ting; Wang, Yue; Sun, Zheng-Hang; Hou, Xi-Wen

2018-05-01

Quantum coherence and correlation of thermal states in the extended XY spin chain are studied in terms of the recently proposed l1 norm, skew information, and Bures distance of geometry discord (BGD), respectively. The entanglement measured via concurrence is calculated for reference. A two-dimensional susceptibility is introduced to explore their capability in highlighting the critical lines associated with quantum phase transitions in the model. It is shown that the susceptibility of the skew information and BGD is a genuine indicator of quantum phase transitions, and characterizes the factorization. However, the l1 norm is trivial for the factorization. An explicit scaling law of BGD is captured at low temperature in the XY model. In contrast to the entanglement, quantum coherence reveals a kind of long-range nonclassical correlation. Moreover, the obvious relation among model parameters is extracted for the factorized line in the extended model. Those are instructive for the understanding of quantum coherence and correlation in the theory of quantum information, and quantum phase transitions and factorization in condensed-matter physics.

Ion Exchange Temperature Testing with SRF Resin - 12088

Energy Technology Data Exchange (ETDEWEB)

Russell, R.L.; Rinehart, D.E.; Brown, G.N.; Peterson, R.A. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States)

2012-07-01

Ion exchange using the Spherical Resorcinol-Formaldehyde (SRF) resin has been selected by the U.S. Department of Energy's Office of River Protection for use in the Pretreatment Facility of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) and for potential application in an at-tank deployment for removing Cs-137. Recent proposed changes to the WTP ion exchange process baseline indicate that higher temperatures (50 deg. C) to alleviate post-filtration precipitation issues prior to reaching the ion exchange columns may be required. Therefore, it is important to understand the behavior of SRF resin performance under the conditions expected with the new equipment and process changes. This research examined the impact of elevated temperature on resin loading and resin degradation during extended solution flow at elevated temperature (45 deg., 50 deg., 55 deg., 60 deg., 65 deg., 75 deg. C). Testing for extended times at elevated temperatures showed that the resin does degrade and loading capacity is reduced at and above 45 deg. C. Above 60 deg. C the resin appears to not load at all. It was observed that the resin disintegrated at 75 deg. C until not much was left and partially disintegrated at 65 deg. C, which caused the column to plug in both tests after ∼336 hours. The results indicate that WTP will lose resin loading capacity if the ion exchange process is performed above 25 deg. C, and the resin will disintegrate above 65 deg. C. Therefore, WTP will have a restricted operating range of temperatures to perform the ion exchange process with this resin. PNNL and WTP are currently evaluating the operating limits of the resin in further detail. Aging in 0.5 M HNO{sub 3} also caused the resin to lose capacity above 25 deg. C and to completely dissolve at 55 deg. C. Again, WTP will have a restricted operating range of temperatures when eluting the resin with nitric acid in order to maintain resin loading capacity and avoid disintegration of the resin

Determination of Germination Response to Temperature and Water Potential for a Wide Range of Cover Crop Species and Related Functional Groups.

Science.gov (United States)

Tribouillois, Hélène; Dürr, Carolyne; Demilly, Didier; Wagner, Marie-Hélène; Justes, Eric

2016-01-01

A wide range of species can be sown as cover crops during fallow periods to provide various ecosystem services. Plant establishment is a key stage, especially when sowing occurs in summer with high soil temperatures and low water availability. The aim of this study was to determine the response of germination to temperature and water potential for diverse cover crop species. Based on these characteristics, we developed contrasting functional groups that group species with the same germination ability, which may be useful to adapt species choice to climatic sowing conditions. Germination of 36 different species from six botanical families was measured in the laboratory at eight temperatures ranging from 4.5-43°C and at four water potentials. Final germination percentages, germination rate, cardinal temperatures, base temperature and base water potential were calculated for each species. Optimal temperatures varied from 21.3-37.2°C, maximum temperatures at which the species could germinate varied from 27.7-43.0°C and base water potentials varied from -0.1 to -2.6 MPa. Most cover crops were adapted to summer sowing with a relatively high mean optimal temperature for germination, but some Fabaceae species were more sensitive to high temperatures. Species mainly from Poaceae and Brassicaceae were the most resistant to water deficit and germinated under a low base water potential. Species were classified, independent of family, according to their ability to germinate under a range of temperatures and according to their base water potential in order to group species by functional germination groups. These groups may help in choosing the most adapted cover crop species to sow based on climatic conditions in order to favor plant establishment and the services provided by cover crops during fallow periods. Our data can also be useful as germination parameters in crop models to simulate the emergence of cover crops under different pedoclimatic conditions and crop

Pyroelectric Properties of Potassium and Rubidium Titanyl-Arsenate Single Crystals in the Temperature Range of 4.2-300 K

International Nuclear Information System (INIS)

Shaldin, Yu. V.; Matyjasik, S.; Novikova, N. E.; Tseitlin, M.; Mozhaev, E.; Roth, M.

2010-01-01

The temperature dependences of the pyroelectric coefficients of KTiOAsO 4 and RbTiOAsO 4 single crystals grown by flux crystallization have been investigated in the temperature range of 4.2-300 K. With an increase in temperature, superionic conductivity first arises in KTiOAsO4 (at T > 200 K) and then (at T > 270 K) in RbTiOAsO 4 . This conductivity is much higher in the samples polarized at T = 4.2 K. An exponential change in the crystal resistivity along the polar direction is simultaneously observed. The results of measurements in the range of 4.2-200 K indicate larger values of pyroelectric coefficients when compared with potassium and rubidium titanyl-phosphate crystals. A correlation between the pyroelectric coefficients and a change in the lattice constants at isomorphic substitutions of K atoms for Rb and P atoms for As has been revealed within the symmetry approach.

Pyroelectric Properties of Potassium and Rubidium Titanyl-Arsenate Single Crystals in the Temperature Range of 4.2-300 K

Energy Technology Data Exchange (ETDEWEB)

Shaldin, Yu. V., E-mail: yuri1999@rambler.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Matyjasik, S. [International Laboratory of Strong Magnetic Fields and Low Temperatures (Poland); Novikova, N. E. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Tseitlin, M.; Mozhaev, E. [Ariel University Center of Samaria (Israel); Roth, M. [Hebrew University, School of Applied Sciences (Israel)

2010-11-15

The temperature dependences of the pyroelectric coefficients of KTiOAsO{sub 4} and RbTiOAsO{sub 4} single crystals grown by flux crystallization have been investigated in the temperature range of 4.2-300 K. With an increase in temperature, superionic conductivity first arises in KTiOAsO4 (at T > 200 K) and then (at T > 270 K) in RbTiOAsO{sub 4}. This conductivity is much higher in the samples polarized at T = 4.2 K. An exponential change in the crystal resistivity along the polar direction is simultaneously observed. The results of measurements in the range of 4.2-200 K indicate larger values of pyroelectric coefficients when compared with potassium and rubidium titanyl-phosphate crystals. A correlation between the pyroelectric coefficients and a change in the lattice constants at isomorphic substitutions of K atoms for Rb and P atoms for As has been revealed within the symmetry approach.

Ranges of diurnal variation and the pattern of body temperature, blood pressure and heart rate in laboratory beagle dogs.

Science.gov (United States)

Miyazaki, Hiroyasu; Yoshida, Mutsumi; Samura, Keiji; Matsumoto, Hiroyoshi; Ikemoto, Fumihiko; Tagawa, Masahiro

2002-01-01

Ranges in diurnal variation and the patterns of body temperature (T), blood pressure (BP), heart rate (HR) and locomotor activity (LA) in 61 laboratory beagle dogs were analyzed using a telemetry system. Body temperature, BP, HR and LA increased remarkably at feeding time. Locomotor activity increased sporadically during the other periods. Body temperature was maintained at the higher value after feeding but had decreased by 0.2 C by early the next morning. Blood pressure fell to a lower value after feeding but had increased by 2.8% by early the next morning. Heart rate decreased progressively after feeding and was 14.5% lower the next morning. This study determined that in laboratory beagles the ranges of diurnal variation and patterns of T, BP and HR are significantly different from those reported in humans and rodents, and that over 24 hr these physiological changes were associated with their sporadic wake-sleep cycles of the dogs.

Water sorption isotherms of skimmed milk powder within the temperature range of 5–20 °C

Directory of Open Access Journals (Sweden)

Jitka Langová

2012-01-01

Full Text Available Moisture sorption isotherms (MSI’s of skimmed milk powder in the temperature range of 5–20 °C were determined using manometric method. MSI’s, which show the water content versus water activity (Aw at a constant temperature, are used to describe relationships between water content and equilibrium state relative vapour pressure (RVP. The equilibrium moisture content (EMC of skimmed milk powder samples is growing with an increase of Aw at a constant temperature both for water adsorption and desorption. Isotherms were found to be type II of Brunauer-Emmett-Teller classification. It is the type most common for foods. The shape of created isotherms was sigmoid. Structural modifications of crystals were observed during adsorption in the microscope, too. Critical value of EMC of tested samples corresponding to the Aw equal to 0.6 for adsorption was 6.50% MC (w.b. at temperature 5 °C, 9.15% MC (w.b. at temperature 10 °C, and 7.71% MC (w.b. at temperature 20 °C. These values determine optimal conditions for storage from the point of view microorganisms grow, Aw<0.6.

Reaction CH3 + OH studied over the 294-714 K temperature and 1-100 bar pressure ranges.

Science.gov (United States)

Sangwan, Manuvesh; Chesnokov, Evgeni N; Krasnoperov, Lev N

2012-08-30

Reaction of methyl radicals with hydroxyl radicals, CH(3) + OH → products (1) was studied using pulsed laser photolysis coupled to transient UV-vis absorption spectroscopy over the 294-714 K temperature and 1-100 bar pressure ranges (bath gas He). Methyl radicals were produced by photolysis of acetone at 193.3 nm. Hydroxyl radicals were generated in reaction of electronically excited oxygen atoms O((1)D), produced in the photolysis of N(2)O at 193.3 nm, with H(2)O. Temporal profiles of CH(3) were recorded via absorption at 216.4 nm using xenon arc lamp and a spectrograph; OH radicals were monitored via transient absorption of light from a dc discharge H(2)O/Ar low pressure resonance lamp at ca. 308 nm. The absolute intensity of the photolysis light inside the reactor was determined by an accurate in situ actinometry based on the ozone formation in the presence of molecular oxygen. The results of this study indicate that the rate constant of reaction 1 is pressure independent within the studied pressure and temperature ranges and has slight negative temperature dependence, k(1) = (1.20 ± 0.20) × 10(-10)(T/300)(-0.49) cm(3) molecule(-1) s(-1).

PEM fuel cells operated at 0% relative humidity in the temperature range of 23-120 oC

International Nuclear Information System (INIS)

Zhang, Jianlu; Tang, Yanghua; Song, Chaojie; Cheng, Xuan; Zhang, Jiujun; Wang, Haijiang

2007-01-01

Operation of a proton exchange membrane (PEM) fuel cell without external humidification (or 0% relative humidity, abbreviated as 0% RH) of the reactant gases is highly desirable, because it can eliminate the gas humidification system and thus decrease the complexity of the PEM fuel cell system and increase the system volume power density (W/l) and weight power density (W/kg). In this investigation, a PEM fuel cell was operated in the temperature range of 23-120 o C, in particular in a high temperature PEM fuel cell operation range of 80-120 o C, with dry reactant gases, and the cell performance was examined according to varying operation parameters. An ac impedance method was used to compare the performance at 0% RH with that at 100% RH; the results suggested that the limited proton transfer process to the Pt catalysts, mainly in the inonomer within the membrane electrode assembly (MEA) could be responsible for the performance drop. It was demonstrated that operating a fuel cell using a commercially available membrane (Nafion (registered) 112) is feasible under certain conditions without external humidification. However, the cell performance at 0% RH decreased with increasing operation temperature and reactant gas flow rate and decreasing operation pressure

A pressurized ion chamber monitoring system for environmental radiation measurements utilizing a wide-range temperature-compensated electrometer

International Nuclear Information System (INIS)

Stevenick, W. Van

1994-01-01

The performance of a complete pressurized ion chamber (PIC) radiation monitoring system is described. The design incorporates an improved temperature-compensated electrometer which is stable to ±3 · 10 -16 A over the environmental range of temperature (-40 to +40 C). Using a single 10 11 Ω feed-back resistor, the electrometer accurately measures currents over a range from 3 · 10 -15 A to 3 · 10 -11 A. While retaining the sensitivity of the original PIC system (the instrument responds readily to small background fluctuations on the order of 0.1 μR h -1 ), the new system measures radiation levels up to the point where the collection efficiency of the ion chamber begins to drop off, typically ∼27 pA at 1 mR h -1 . A data recorder and system controller was designed using the Tattletale trademark Model 4A computer. Digital data is stored on removable solid-state, credit-card style memory cards

Structural mechanisms of high-temperature shape changes in titanium-nickel alloys after low-temperature thermomechanical treatment

International Nuclear Information System (INIS)

Prokoshkin, S.D.; Turenne, S.; Khmelevskaya, I.Yu.; Brailovski, V.; Trochu, F.

2000-01-01

High-Temperature Shape Memory Effect (HTSME) in Ti-Ni alloys and corresponding structural and internal stress changes were studied using dilatometry, in situ electron microscope and X-ray diffractometry. The HTSME induced by the Low Temperature Thermomechanical Treatment (LTMT) consists of two stages. The temperature range of the first stage is limited to 250 o C, while the second stage extends to 400-500 o C. The first stage is caused by the oriented reverse martensite transformation. The heterogeneous residual stress field causes a different thermal stability for the different martensite orientations. During the reverse transformation an anisotropic shift of martensite and austenite X-ray lines is observed that can be due to a relaxation of the orientated stresses and to changes in the martensite lattice. The second stage of HTSME is caused by internal stress relaxation during recovery and polygonization of austenite that are not typical shape memory mechanisms. The possible reasons for the martensite stabilization induced by LTMT will be discussed. (author)

Thermodynamic investigation of methyl salicylate/1-pentanol binary system in the temperature range from 278.15K to 303.15K

International Nuclear Information System (INIS)

Tsierkezos, Nikos G.; Molinou, Ioanna E.

2007-01-01

Densities (ρ), speeds of sound (u), isentropic compressibilities (k s ), refractive indices (n D ), and surface tensions (σ) of binary mixtures of methyl salicylate (MSL) with 1-pentanol (PEN) have been measured over the entire composition range at the temperatures of 278.15K, 288.15K, and 303.15K. The excess molar volumes (V E ), excess surface tensions (σ E ), deviations in speed of sound (Δu), deviations in isentropic compressibility (Δk s ), and deviations in molar refraction (ΔR) have been calculated. The excess thermodynamic properties V E , σ E , Δu, Δk s , and ΔR were fitted to the Redlich-Kister polynomial equation and the A k coefficients as well as the standard deviations (d) between the calculated and experimental values have been derived. The surface tension (σ) values have been further used for the calculation of the surface entropy (S S ) and the surface enthalpy (H S ) per unit surface area. The lyophobicity (β) and the surface mole fraction (x 2 S ) of the surfactant component PEN have been also derived using the extended Langmuir model. The results provide information on the molecular interactions between the unlike molecules that take place at the surface and the bulk

Neural network for adapting nuclear power plant control for wide-range operation

International Nuclear Information System (INIS)

Ku, C.C.; Lee, K.Y.; Edwards, R.M.

1991-01-01

A new concept of using neural networks has been evaluated for optimal control of a nuclear reactor. The neural network uses the architecture of a standard backpropagation network; however, a new dynamic learning algorithm has been developed to capture the underlying system dynamics. The learning algorithm is based on parameter estimation for dynamic systems. The approach is demonstrated on an optimal reactor temperature controller by adjusting the feedback gains for wide-range operation. Application of optimal control to a reactor has been considered for improving temperature response using a robust fifth-order reactor power controller. Conventional gain scheduling can be employed to extend the range of good performance to accommodate large changes in power where nonlinear characteristics significantly modify the dynamics of the power plant. Gain scheduling is developed based on expected parameter variations, and it may be advantageous to further adapt feedback gains on-line to better match actual plant performance. A neural network approach is used here to adapt the gains to better accommodate plant uncertainties and thereby achieve improved robustness characteristics

Comparison of thermal properties of fish collagen and bovine collagen in the temperature range 298-670K.

Science.gov (United States)

Gauza-Włodarczyk, Marlena; Kubisz, Leszek; Mielcarek, Sławomir; Włodarczyk, Dariusz

2017-11-01

The increased interest in fish collagen is a consequence of the risk of exposure to Creutzfeld-Jacob disease (CJD) and the bovine spongiform encephalopathy (BSE), whose occurrence is associated with prions carried by bovine collagen. Collagen is the main biopolymer in living organisms and the main component of the skin and bones. Until the discovery of the BSE, bovine collagen had been widely used. The BSE epidemic increased the interest in new sources of collagen such as fish skin collagen (FSC) and its properties. Although the thermal properties of collagen originating from mammals have been well described, less attention has been paid to the thermal properties of FSC. Denaturation temperature is a particularly important parameter, depending on the collagen origin and hydration level. In the reported experiment, the free water and bound water release processes along with thermal denaturation process were studied by means of the differential scanning calorimetry (DSC). Measurements were carried out using a DSC 7 instrument (Elmer-Perkin), in the temperature range 298-670K. The study material was FSC derived by acidic hydration method. The bovine Achilles tendon (BAT) collagen type I was used as the control material. The thermograms recorded revealed both, exothermic and endothermic peaks. For both materials, the peaks in the temperature range of 330-360K were assigned to the release of free water and bound water. The denaturation temperatures of FSC and BAT collagen were determined as 420K and 493K, respectively. Thermal decomposition process was observed at about 500K for FSC and at about 510K for BAT collagen. These results show that FSC is less resistant to high temperature than BAT collagen. Copyright © 2017 Elsevier B.V. All rights reserved.

Screening of Metarhizium and Beauveria spp. conidia with exposure to simulated sunlight and a range of temperatures

International Nuclear Information System (INIS)

Morley-Davies, J.; Moore, D.; Prior, C.

1996-01-01

Conidia of 14 isolates of the entomopathogenic fungi Beauveria bassiana, Metarhizium flavoviride and M. anisopliae were formulated by suspending in paraffinic oil or as dry powder. Non-indicating silica gel was added to both formulations which were stored at 13 °C for at least 2 wk before exposure to a range of temperatures: −10°, 10°, 20°, 30°, 40° and 50° to determine the effects of temperature of storage on viability. At 50° the isolate studied in most detail (M. flavoviride, IMI 330189) initially showed a gradual decline in viability with 73% germination for oil samples after 60 d from an initial level of 93%, whereas the dry samples typically showed higher germination rates (initially 96% germination, dropping to 80% after 60 d). Subsequently there was a rapid decline and both oil formulated and dry conidia had lost almost all viability by 90 d. Samples of IMI 330189 stored dry or in oil, at 40° and below showed > 79% germination after 90 d. M. flavoviride 191–660 exhibited the highest temperature tolerance with >40% germination of the dry stored conidia after 90 d at 50°. Some isolates of both B. bassiana and Metarhizium spp. showed markedly lower tolerance of high temperatures. Samples stored dry usually showed greater percentage germination than samples in oil for all isolates, at all temperatures. The isolates were also exposed to 4, 8, 16 and 24 h uv light from a sunlight simulator at 40°. Conidial viability decreased markedly in all isolates with increasing uv exposure. Germination ranged between 10 and 50% after 24 h exposure to uv, 191–660 retaining highest viability. (author)

Genetic hitch-hiking extends the range of coast live oak

Science.gov (United States)

Richard S. Dodd; Zara Afzal-Rafii; Wasima Mayer

2006-01-01

The northernmost range of coast live oak (Quercus agrifolia) is reported from the Ukiah Valley (Mendocino County, California). Here, field observations suggest that hybridization with interior live oak (Q. wislizeni) is important. Elsewhere in northern California, morphology of coast live oak can be highly variable (particularly...

The exotic invasive plant Vincetoxicum rossicum is a strong competitor even outside its current realized climatic temperature range

Directory of Open Access Journals (Sweden)

Laurа Sanderson

2013-03-01

Full Text Available Dog-strangling vine (Vincetoxicum rossicum is an exotic plant originating from Central and Eastern Europe that is becoming increasingly invasive in southern Ontario, Canada. Once established, it successfully displaces local native plant species but mechanisms behind this plant’s high competitive ability are not fully understood. It is unknown whether cooler temperatures will limit the range expansion of V. rossicum, which has demonstrated high tolerance for other environmental variables such as light and soil moisture. Furthermore, if V. rossicum can establish outside its current climatic limit it is unknown whether competition with native species can significantly contribute to reduce fitness and slow down invasion. We conducted an experiment to test the potential of V. rossicum to spread into northern areas of Ontario using a set of growth chambers to simulate southern and northern Ontario climatic temperature regimes. We also tested plant-plant competition by growing V. rossicum in pots with a highly abundant native species, Solidago canadensis, and comparing growth responses to plants grown alone. We found that the fitness of V. rossicum was not affected by the cooler climate despite a delay in reproductive phenology. Growing V. rossicum with S. canadensis caused a significant reduction in seedpod biomass of V. rossicum. However, we did not detect a temperature x competition interaction in spite of evidence for adaptation of S. canadensis to cooler temperature conditions. We conclude that the spread of V. rossicum north within the tested range is unlikely to be limited by climatic temperature but competition with an abundant native species may contribute to slow it down.

Thermal effects of an ICL-based mid-infrared CH4 sensor within a wide atmospheric temperature range

Science.gov (United States)

Ye, Weilin; Zheng, Chuantao; Sanchez, Nancy P.; Girija, Aswathy V.; He, Qixin; Zheng, Huadan; Griffin, Robert J.; Tittel, Frank K.

2018-03-01

The thermal effects of an interband cascade laser (ICL) based mid-infrared methane (CH4) sensor that uses long-path absorption spectroscopy were studied. The sensor performance in the laboratory at a constant temperature of ∼25 °C was measured for 5 h and its Allan deviation was ∼2 ppbv with a 1 s averaging time. A LabVIEW-based simulation program was developed to study thermal effects on infrared absorption and a temperature compensation technique was developed to minimize these effects. An environmental test chamber was employed to investigate the thermal effects that occur in the sensor system with variation of the test chamber temperature between 10 and 30 °C. The thermal response of the sensor in a laboratory setting was observed using a 2.1 ppm CH4 standard gas sample. Indoor/outdoor CH4 measurements were conducted to evaluate the sensor performance within a wide atmospheric temperature range.

Extended vapor-liquid-solid growth of silicon carbide nanowires.

Science.gov (United States)

Rajesh, John Anthuvan; Pandurangan, Arumugam

2014-04-01

We developed an alloy catalytic method to explain extended vapor-liquid-solid (VLS) growth of silicon carbide nanowires (SiC NWs) by a simple thermal evaporation of silicon and activated carbon mixture using lanthanum nickel (LaNi5) alloy as catalyst in a chemical vapor deposition process. The LaNi5 alloy binary phase diagram and the phase relationships in the La-Ni-Si ternary system were play a key role to determine the growth parameters in this VLS mechanism. Different reaction temperatures (1300, 1350 and 1400 degrees C) were applied to prove the established growth process by experimentally. Scanning electron microscopy and transmission electron microscopy studies show that the crystalline quality of the SiC NWs increases with the temperature at which they have been synthesized. La-Ni alloyed catalyst particles observed on the top of the SiC NWs confirms that the growth process follows this extended VLS mechanism. The X-ray diffraction and confocal Raman spectroscopy analyses demonstrate that the crystalline structure of the SiC NWs was zinc blende 3C-SiC. Optical property of the SiC NWs was investigated by photoluminescence technique at room temperature. Such a new alloy catalytic method may be extended to synthesis other one-dimensional nanostructures.

Recrystallization kinetics of warm-rolled tungsten in the temperature range 1150-1350 °C

Science.gov (United States)

Alfonso, A.; Juul Jensen, D.; Luo, G.-N.; Pantleon, W.

2014-12-01

Pure tungsten is a potential candidate material for the plasma-facing first wall and the divertor of fusion reactors. Both parts have to withstand high temperatures during service. This will alter the microstructure of the material by recovery, recrystallization and grain growth and will cause degradation in material properties as a loss in mechanical strength and embrittlement. The thermal stability of a pure tungsten plate warm-rolled to 67% thickness reduction was investigated by long-term isothermal annealing in the temperature range between 1150 °C and 1350 °C up to 2200 h. Changes in the mechanical properties during annealing are quantified by Vickers hardness measurements. They are described concisely by classical kinetic models for recovery and recrystallization. The observed time spans for recrystallization and the obtained value for the activation energy of the recrystallization process indicate a sufficient thermal stability of the tungsten plate during operation below 1075 °C.

Short-range order structures of self-assembled Ge quantum dots probed by multiple-scattering extended x-ray absorption fine structure

International Nuclear Information System (INIS)

Sun Zhihu; Wei Shiqiang; Kolobov, A.V.; Oyanagi, H.; Brunner, K.

2005-01-01

Multiple-scattering extended x-ray absorption fine structure (MS-EXAFS) has been used to investigate the local structures around Ge atoms in self-assembled Ge-Si quantum dots (QDs) grown on Si(001) substrate. The MS effect of Ge QDs is dominated by the scattering path Ge 0 →B 1 →B 2 →Ge 0 (DS2), which contributes a signal destructively interfering with that of the second shell single-scattering path (SS2). MS-EXAFS analysis reveals that the degree of Ge-Si intermixing for Ge-Si QDs strongly depends on the temperature at which the silicon cap layer is overgrown. It is found that the interatomic distances (R Ge-Ge and R Ge-Si ) within the third nearest-neighbor shells in Ge-Si QDs indicate the compressively strained nature of QDs. The present study demonstrates that the MS-EXAFS provides detailed information on the QDs strain and the Ge-Si mixing beyond the nearest neighbors

The mechanical behavior and reliability prediction of the HTR graphite component at various temperature and neutron dose ranges

International Nuclear Information System (INIS)

Fang, Xiang; Yu, Suyuan; Wang, Haitao; Li, Chenfeng

2014-01-01

Highlights: • The mechanical behavior of graphite component in HTRs under high temperature and neutron irradiation conditions is simulated. • The computational process of mechanical analysis is introduced. • Deformation, stresses and failure probability of the graphite component are obtained and discussed. • Various temperature and neutron dose ranges are selected in order to investigate the effect of in-core conditions on the results. - Abstract: In a pebble-bed high temperature gas-cooled reactor (HTR), nuclear graphite serves as the main structural material of the side reflectors. The reactor core is made up of a large number of graphite bricks. In the normal operation case of the reactor, the maximum temperature of the helium coolant commonly reaches about 750 °C. After around 30 years’ full power operation, the peak value of in-core fast neutron cumulative dose reaches to 1 × 10 22 n cm −2 (EDN). Such high temperature and neutron irradiation strongly impact the behavior of graphite component, causing obvious deformation. The temperature and neutron dose are unevenly distributed inside a graphite brick, resulting in stress concentrations. The deformation and stress concentration can both greatly affect safety and reliability of the graphite component. In addition, most of the graphite properties (such as Young's modulus and coefficient of thermal expansion) change remarkably under high temperature and neutron irradiations. The irradiation-induced creep also plays a very important role during the whole process, and provides a significant impact on the stress accumulation. In order to simulate the behavior of graphite component under various in-core conditions, all of the above factors must be considered carefully. In this paper, the deformation, stress distribution and failure probability of a side graphite component are studied at various temperature points and neutron dose levels. 400 °C, 500 °C, 600 °C and 750 °C are selected as the

Thermal annealing of radiation damage in CMOS ICs in the temperature range -140 C to +375 C

Science.gov (United States)

Danchenko, V.; Fang, P. H.; Brashears, S. S.

1982-01-01

Annealing of radiation damage was investigated in the commercial, Z- and J-processes of the RCA CD4007A ICs in the temperature range from -140 C to +375 C. Tempering curves were analyzed for activation energies of thermal annealing, following irradiation at -140 C. It was found that at -140 C, the radiation-induced shifts in the threshold potentials were similar for all three processes. The radiation hardness of the Z- and J-process is primarily due to rapid annealing of radiation damage at room temperature. In the region -140 to 20 C, no dopant-dependent charge trapping is seen, similar to that observed at higher temperatures. In the unbiased Z-process n-channels, after 1 MeV electron irradiation, considerable negative charge remains in the gate oxide.

Parametrization of the average ionization and radiative cooling rates of carbon plasmas in a wide range of density and temperature

International Nuclear Information System (INIS)

Gil, J.M.; Rodriguez, R.; Florido, R.; Rubiano, J.G.; Mendoza, M.A.; Nuez, A. de la; Espinosa, G.; Martel, P.; Minguez, E.

2013-01-01

In this work we present an analysis of the influence of the thermodynamic regime on the monochromatic emissivity, the radiative power loss and the radiative cooling rate for optically thin carbon plasmas over a wide range of electron temperature and density assuming steady state situations. Furthermore, we propose analytical expressions depending on the electron density and temperature for the average ionization and cooling rate based on polynomial fittings which are valid for the whole range of plasma conditions considered in this work. -- Highlights: ► We compute the average ionization, cooling rates and emissivities of carbon plasmas. ► We compare LTE and NLTE calculations of these magnitudes. ► We perform a parametrization of these magnitudes in a wide range of plasma conditions. ► We provide information about where LTE regime assumption is accurate

A 7 μW Offset- and Temperature-Compensated pH-to-Digital Converter

Directory of Open Access Journals (Sweden)

Saleh Heidary Shalmany

2017-01-01

Full Text Available This paper demonstrates a micropower offset- and temperature-compensated smart pH sensor, intended for use in battery-powered RFID systems that monitor the quality of perishable products. Low operation power is essential in such systems to enable autonomous logging of environmental parameters, such as the pH level, over extended periods of time using only a small, low-cost battery. The pH-sensing element in this work is an ion-sensitive extended-gate field-effect transistor (EGFET, which is incorporated in a low-power sensor front-end. The front-end outputs a pH-dependent voltage, which is then digitized by means of a co-integrated incremental delta-sigma ADC. To compensate for the offset and temperature cross-sensitivity of the EGFET, a compensation scheme using a calibration process and a temperature sensor has been devised. A prototype chip has been realized in a 0.16 μm CMOS process. It occupies 0.35 × 3.9 mm2 of die area and draws only 4 μA from a 1.8 V supply. Two different types of custom packaging have been used for measurement purposes. The pH sensor achieves a linearity of better than ±0.1 for pH values ranging from 4 to 10. The calibration and compensation scheme reduces errors due to temperature cross-sensitivity to less than ±0.1 in the temperature range of 6°C to 25°C.

Diffusion and agglomeration of helium in stainless steel in the temperature range from RT to 600 deg. C

International Nuclear Information System (INIS)

Zhang, C.H.; Chen, K.Q.; Zhu, Z.Y.

2000-01-01

Diffusion of helium and formation of helium bubbles in stainless steel in conditions of atomic displacement in the temperature range from RT to 600 deg. C are studied theoretically using standard rate equations. The dissociative mechanism via self-interstitial/He replacement is assumed to control helium diffusion and bubble formation. The numerical analysis shows that the temperature dependence of the effective diffusion coefficient of helium, the number density and the mean radius of bubbles has two distinctly different regimes with the transition occurring around 300 deg. C. The effective diffusion coefficient of helium, the number density and the mean radius of bubbles show weak temperature dependence in the low temperature regime, while they change abruptly with temperature in the high temperature regime. The results are qualitatively in agreement with the results of our experimental study on helium diffusion and bubble formation in helium-implanted 316L stainless steel. However, the discrepancy in the absolute values of number density and mean radius of bubbles between theoretical and experimental studies indicates that helium diffusion and bubble formation may be controlled by some athermal mechanisms in the low temperature regime

SHOVAV-JUEL. A one dimensional space-time kinetic code for pebble-bed high-temperature reactors with temperature and Xenon feedback

International Nuclear Information System (INIS)

Nabbi, R.; Meister, G.; Finken, R.; Haben, M.

1982-09-01

The present report describes the modelling basis and the structure of the neutron kinetics-code SHOVAV-Juel. Information for users is given regarding the application of the code and the generation of the input data. SHOVAV-Juel is a one-dimensional space-time-code based on a multigroup diffusion approach for four energy groups and six groups of delayed neutrons. It has been developed for the analysis of the transient behaviour of high temperature reactors with pebble-bed core. The reactor core is modelled by horizontal segments to which different materials compositions can be assigned. The temperature dependence of the reactivity is taken into account by using temperature dependent neutron cross sections. For the simulation of transients in an extended time range the time dependence of the reactivity absorption by Xenon-135 is taken into account. (orig./RW)

Thermal degradation of concrete in the temperature range from ambient to 315 degree C (600 degree F). Revision 10/96

International Nuclear Information System (INIS)

Kassir, M.K.; Bandyopadhyay, K.K.; Reich, M.

1996-10-01

This report is concerned with determining the effect of elevated temperatures on the behavior of concrete. Emphasis is placed on quantifying the degree of potential degradation of the physical properties of concrete in high-level waste storage tanks. The temperature elevation range of interest is from ambient to 315 C (600 F). The literature has been reviewed to examine the applicable experimental data and quantify the degradation in the concrete and reinforcing steel. Since many variables and test conditions control the results in the data base, upper and lower bounds of the degraded properties at temperatures applicable to the environments of the storage tanks are summarized and presented in explicit forms. For properties with large data bases, a normal logarithmic distribution of the data is assumed and a statistical analysis is carried out to find the mean and 84% values of the degraded property in the temperature range of interest. Such results are useful in assessing the effect of elevated temperatures on the structural behavior of the tanks. In addition, the results provide the technical basis for a parametric study that may be necessary to investigate the thermal aspects of the structural integrity of the tanks. 50 refs., 23 figs

Accurate solid solution range of BiMnxFe3-xO6 and low temperature magnetism

Science.gov (United States)

Jiang, Pengfei; Yue, Mufei; Cong, Rihong; Gao, Wenliang; Yang, Tao

2017-11-01

BiMnxFe3-xO6 (x = 1) represents a new type of oxide structure containing Bi3+ and competing magnetic super-exchanges. In literature, multiple magnetic states were realized at low temperatures in BiMnFe2O6, and the hypothetical parent compounds (BiMn3O6, BiFe3O6) were predicted to be different in magnetism. Herein, we performed a careful study on the syntheses of BiMnxFe3-xO6 at ambient pressure, and the solid solution range was determined to be 0.9 ≤ x ≤ 1.3 by Rietveld refinements on high-quality powder X-ray diffraction data. Due to the very similar cationic size of Mn3+ and Fe3+, and possibly the structural rigidity, there was no significant structure change in the whole range of solid solution. The magnetic behavior of BiMnxFe3-xO6 (x = 1.2, 1.22, 1.26, 1.28 and 1.3) was generally similar to BiMnFe2O6, while the relative higher concentration of Mn3+ led to the decreasing of the antiferromagnetic ordering temperature.

Extending the dynamic range of silicon photomultipliers without increasing pixel count

International Nuclear Information System (INIS)

Johnson, Kurtis F.

2010-01-01

A silicon photomultiplier, sometimes called 'multipixel photon counter', which we here refer to as a 'SiPM', is a photo-sensitive device built from an avalanche photodiode array of pixels on a common silicon substrate, such that it can detect single photon events. The dimensions of a pixel may vary from 20 to 100 μm and their density can be greater than 1000 per square millimeter. Each pixel in a SiPM operates in Geiger mode and is coupled to the output by a quenching resistor. Although each pixel operates in digital mode, the SiPM is an analog device because all the pixels are read in parallel, making it possible to generate signals within a dynamic range from a single photon to a large number of photons, ultimately limited by the number of pixels on the chip. In this note we describe a simple and general method of increasing the dynamic range of a SiPM beyond that one may naively assume from the shape of the cumulative distribution function of the SiPM response to the average number of photons per pixel. We show that by rendering the incoming flux of photons to be non-uniform in a prescribed manner, a significant increase in dynamic range is achievable. Such re-distribution of the incoming flux may be accomplished with simple, non-focusing lenses, prisms, interference films, mirrors or attenuating films. Almost any optically non-inert interceding device can increase the dynamic range of the SiPM.

The influence of environment, sex, and innate timing mechanisms on body temperature patterns of free-ranging black-tailed prairie dogs (Cynomys ludovicianus).

Science.gov (United States)

Lehmer, Erin M; Bossenbroek, Jonathan M; Van Horne, Beatrice

2003-01-01

Mechanisms that influence body temperature patterns in black-tailed prairie dogs are not well understood. Previous research on both free-ranging and laboratory populations of black-tailed prairie dogs (Cynomys ludovicianus) has suggested that reductions in ambient temperature and food and water deprivation are the primary factors that stimulate torpor in this species. In other species, however, torpor has been shown to be influenced by a multitude of factors, including innate circadian and circannual timing mechanisms, energy status, and reproductive behaviors. Our objective was to clarify the influence of weather, sex, and intrinsic timing mechanisms on the body temperature patterns of free-ranging black-tailed prairie dogs. We monitored body temperatures of eight adult (>1 yr) prairie dogs from November 1999 to June 2000. Prairie dogs showed distinct daily and seasonal body temperature patterns, which reflected changes in ambient temperatures that occurred during these periods. These patterns of daily and seasonal heterothermy suggest that body temperature patterns of black-tailed prairie dogs may be driven by an innate timing mechanism. All prairie dogs entered torpor intermittently throughout winter and spring. Torpor bouts appeared to be influenced by precipitation and reductions in ambient temperature. Our results also suggest that reproductive behaviors and circadian timing may influence torpor in this species.

Temperature range extension of an organically crosslinked polymer system and its successful field application for water and gas shutoff

Energy Technology Data Exchange (ETDEWEB)

Vasquez, Julio; Eoff, Larry; Dalrymple, Dwyann [Halliburton, Rio de Janeiro. RJ (Brazil)

2008-07-01

Excessive water production from hydrocarbon reservoirs is one of the most serious problems in the oil industry. Water production greatly affects the economic life of producing wells and brings along secondary problems such as sand production, corrosion, and tubular scale. Remediation techniques for controlling water production, generally referred to as conformance control, include the use of polymer systems to reduce or plug permeability to water. This paper presents the laboratory evaluation of an organically crosslinked polymer (OCP) system used as a sealant for water control problems in hydrocarbon wells. Originally, the OCP system had a limited working temperature range (140 deg to 260 deg F). Recently, an alternative base polymer (for low temperatures) and a retarder (for high temperatures) have been introduced to expand the temperature range of applicability of the OCP system from 70 deg F to 350 deg F without compromising its effectiveness or thermal stability. More than 400 jobs have been performed with the OCP system around the world to address conformance problems such as water coning/cresting, high-permeability streaks, gravel pack isolation, fracture shutoff, and casing leak repairs. This paper presents an overview of case histories that used the OCP system in various regions of the world for a wide variety of applications. (author)

Biaxial creep deformation of Zircaloy-4 PWR fuel cladding in the alpha,(alpha + beta) and beta phase temperature ranges

International Nuclear Information System (INIS)

Donaldson, A.T.; Healey, T.; Horwood, R.A.L.

1985-01-01

The biaxial creep behaviour of Zircaloy-4 fuel cladding has been determined at temperatures between 973 - 1073 K in the alpha phase range, in the duplex (alpha + beta) region between 1098 - 1223 K and in the beta phase range between 1323 - 1473 K. This paper presents the creep data together with empirical equations which describe the creep deformation response within each phase region. (author)

Solubility of hydrogen in water in a broad temperature and pressure range

International Nuclear Information System (INIS)

Baranenko, V.I.; Kirov, V.S.

1989-01-01

In the coolant of water-water reactors, as a result of radiolytic decomposition of water and chemical additives (hydrazine and ammonia) and saturation of the make-up water of the first loop with free hydrogen in order to suppress radiolysis, 30-60 ml/kg of hydrogen is present in normal conditions. On being released from the water, it is free to accumulate in micropores of the metals, resulting in hydrogen embrittlement; gas accumulates in stagnant zones, with deterioration in heat transfer in the first loop and corresponding difficulty in the use of the reactor and the whole reactor loop. To determine the amount of free hydrogen and hydrogen dissolved in water in different elements of the first loop, it is necessary to know the limiting solubility of hydrogen in water at different temperatures and pressures, and also to have the corresponding theoretical dependences. The experimental data on the solubility of hydrogen in water are nonsystematic and do not cover the parameter ranges of modern nuclear power plants (P = 10-30 MPa, T = 260-370C). Therefore, the aim of the present work is to establish a well-founded method of calculating the limiting solubility of hydrogen in water and, on this basis, to compile tables of the limiting solubility of hydrogen in water at pressures 0.1-50 MPa and temperatures 0-370C

Modelled temperature-dependent excitability behaviour of a generalised human peripheral sensory nerve fibre.

Science.gov (United States)

Smit, Jacoba E; Hanekom, Tania; Hanekom, Johan J

2009-08-01

The objective of this study was to determine if a recently developed human Ranvier node model, which is based on a modified version of the Hodgkin-Huxley model, could predict the excitability behaviour in human peripheral sensory nerve fibres with diameters ranging from 5.0 to 15.0 microm. The Ranvier node model was extended to include a persistent sodium current and was incorporated into a generalised single cable nerve fibre model. Parameter temperature dependence was included. All calculations were performed in Matlab. Sensory nerve fibre excitability behaviour characteristics predicted by the new nerve fibre model at different temperatures and fibre diameters compared well with measured data. Absolute refractory periods deviated from measured data, while relative refractory periods were similar to measured data. Conduction velocities showed both fibre diameter and temperature dependence and were underestimated in fibres thinner than 12.5 microm. Calculated strength-duration time constants ranged from 128.5 to 183.0 micros at 37 degrees C over the studied nerve fibre diameter range, with chronaxie times about 30% shorter than strength-duration time constants. Chronaxie times exhibited temperature dependence, with values overestimated by a factor 5 at temperatures lower than body temperature. Possible explanations include the deviated absolute refractory period trend and inclusion of a nodal strangulation relationship.

Reaction OH + OH studied over the 298-834 K temperature and 1-100 bar pressure ranges.

Science.gov (United States)

Sangwan, Manuvesh; Chesnokov, Evgeni N; Krasnoperov, Lev N

2012-06-21

Self-reaction of hydroxyl radicals, OH + OH → H(2)O + O (1a) and OH + OH → H(2)O(2) (1b), was studied using pulsed laser photolysis coupled to transient UV-vis absorption spectroscopy over the 298-834 K temperature and 1-100 bar pressure ranges (bath gas He). A heatable high-pressure flow reactor was employed. Hydroxyl radicals were prepared using reaction of electronically excited oxygen atoms, O((1)D), produced in photolysis of N(2)O at 193 nm, with H(2)O. The temporal behavior of OH radicals was monitored via transient absorption of light from a dc discharge in H(2)O/Ar low-pressure resonance lamp at ca. 308 nm. The absolute intensity of the photolysis light was determined by accurate in situ actinometry based on the ozone formation in the presence of molecular oxygen. The results of this study combined with the literature data indicate that the rate constant of reaction 1a, associated with the pressure independent component, decreases with temperature within the temperature range 298-414 K and increases above 555 K. The pressure dependent rate constant for (1b) was parametrized using the Troe expression as k(1b,inf) = (2.4 ± 0.6) × 10(-11)(T/300)(-0.5) cm(3) molecule(-1) s(-1), k(1b,0) = [He] (9.0 ± 2.2) × 10(-31)(T/300)(-3.5±0.5) cm(3) molecule(-1) s(-1), F(c) = 0.37.

The correlation between dengue incidence and diurnal ranges of temperature of Colombo district, Sri Lanka 2005–2014

Directory of Open Access Journals (Sweden)

N. D. B. Ehelepola

2016-08-01

Full Text Available Background: Meteorological factors affect dengue transmission. Mechanisms of the way in which different diurnal temperatures, ranging around different mean temperatures, influence dengue transmission were published after 2011. Objective: We endeavored to determine the correlation between dengue incidence and diurnal temperature ranges (DTRs in Colombo district, Sri Lanka, and to explore the possibilities of using our findings to improve control of dengue. Design: We calculated the weekly dengue incidence in Colombo during 2005–2014, after data on all of the reported dengue patients and estimated mid-year populations were collected. We obtained daily maximum and minimum temperatures from two Colombo weather stations, averaged, and converted them into weekly data. Weekly averages of DTR versus dengue incidence graphs were plotted and correlations observed. The count of days per week with a DTR of >7.5°C and 7.5°C with an 8-week lag period, and a positive correlation between dengue incidence and a DTR<7.5°C, also with an 8-week lag. Conclusions: Large DTRs were negatively correlated with dengue transmission in Colombo district. We propose to take advantage of that in local dengue control efforts. Our results agree with previous studies on the topic and with a mathematical model of relative vectorial capacity of Aedes aegypti. Global warming and declining DTR are likely to favor a rise of dengue, and we suggest a simple method to mitigate this.

Oxidation kinetics of zircaloy-4 in the temperature range correspondent to alpha phase

International Nuclear Information System (INIS)

Medeiros, L.F.

1975-12-01

Oxidation kinetics of Zry-4 in the alpha phase is isothermally studied in the temperature range from 600 0 C to 800 0 C, by continuous and discontinuous gravimetric methods. The total mass gain during the oxidation takes place by two distinct ways: oxide formation and solid solution formation. The first one has been studied by microscopy: the latter by microhardness. The oxygen diffusion coefficients in the zirconium are experimentally determined by microhardness measurements and are compared with those obtained by the oxide layer thickness and by oxygen mass in the oxide. The oxygen diffusion coefficients in the oxide are obtained too by oxide layer thickness and by oxygen diffusivities in the alpha phase and compared with literature. (author)

Oxidation limited lifetime of Ni-Base metal foams in the temperature range 700-900 C

Energy Technology Data Exchange (ETDEWEB)

Chyrkin, Anton; Singheiser, Lorenz; Quadakkers, Willem Joseph [Forschungszentrum Juelich GmbH, IEF-2, Juelich (Germany); Schulze, Sebastian Leif; Bleck, Wolfgang [Department of Ferrous Metallurgy, RWTH Aachen University, Aachen (Germany); Piron-Abellan, Javier [Vallourec Mannesmann Tubes, Duesseldorf (Germany)

2010-09-15

INCONEL 625 metal foams produced from alloy powder by the slip-reaction-foam-sinter-process are tested in respect to cyclic oxidation behavior in air in the temperature range 700-900 C. The structure of the oxide scales formed on the foam particles is characterized using optical microscopy and SEM/EDX analysis. Main emphasis is put on studying the oxidation limited lifetimes of the foams as function of temperature and foam microstructure. It is shown that mechanical disintegration during long term oxidation at the highest test temperatures is caused by a critical depletion of the Cr content in the alloy as a result of the growth of the initially formed surface chromia layer. This results in chemical breakaway due to accelerated oxide growth of voluminous Ni-rich oxide on chromium exhausted alloy particles. Lifetime modeling based on calculation of Cr-depletion in the alloy at the oxide/metal interface of each individual foam particle using the DICTRA software is in good agreement with the experimentally determined values of the time to breakaway. (Copyright copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Integrated modeling for the cyclic behavior of high power Li-ion batteries under extended operating conditions

International Nuclear Information System (INIS)

Miranda, Á.G.; Hong, C.W.

2013-01-01

Highlights: • Redefine the traditional concepts of state of charge modeling. • Accurate non-intrusive extraction method of an integrated battery model. • Indexes of performance can be employed to compare different types of batteries. • High power electrical battery model dependent on current and temperature effects. - Abstract: The dynamic thermal and electrical behavior of high power LiFePO 4 cathode-type Li-ion batteries is studied with extended considerations such as demanded current ranging from 12 to 30 A, battery temperatures ranging from 283 to 313 K and a redefinition of the concept of state of charge during cycling conditions. The equivalent electrical model, consisting of a series resistance, a parallel resistance–capacitor, a voltage source and state of charge calculators, can be improved with the addition of current and temperature gains for each element. In addition, a non-intrusively-obtained alternative thermal model extraction is proposed to uncouple from the experimental battery temperature based on electrochemical research found in the literature. This improved model extraction for high power cylindrical batteries can achieve a temperature and voltage relative runtime error in the range of 1% and 5% in average, respectively. The effects of lithium concentration in the anode and cathode are accurately predicted with state of charge accelerators, which vary linearly with temperature. Aiming for a power systems environment, the integrated battery model is built and validated experimentally to demonstrate its accurate prediction. This improved integrated battery model can be employed for battery stack simulations, improved state of charge algorithm testing and optimization of hybrid systems - with a light computational demand. Finally, a performance index radar plot is proposed to conveniently compare electrical and thermal properties of different types of batteries

Bi-Directional Brillouin Optical Time Domain Analyzer System for Long Range Distributed Sensing

Science.gov (United States)

Guo, Nan; Wang, Liang; Wang, Jie; Jin, Chao; Tam, Hwa-Yaw; Zhang, A. Ping; Lu, Chao

2016-01-01

We propose and experimentally demonstrate a novel scheme of bi-directional Brillouin time domain analyzer (BD-BOTDA) to extend the sensing range. By deploying two pump-probe pairs at two different wavelengths, the Brillouin frequency shift (BFS) distribution over each half of the whole fiber can be obtained with the simultaneous detection of Brillouin signals in both channels. Compared to the conventional unidirectional BOTDA system of the same sensing range, the proposed BD-BOTDA scheme enables distributed sensing with a performance level comparable to the conventional one with half of the sensing range and a spatial resolution of 2 m, while maintaining the Brillouin signal-to-noise ratio (SNR) and the BFS uncertainty. Based on this technique, we have achieved distributed temperature sensing with a measurement range of 81.9 km fiber at a spatial resolution of 2 m and BFS uncertainty of ~0.44 MHz without introducing any complicated components or schemes. PMID:27999250

Bi-Directional Brillouin Optical Time Domain Analyzer System for Long Range Distributed Sensing.

Science.gov (United States)

Guo, Nan; Wang, Liang; Wang, Jie; Jin, Chao; Tam, Hwa-Yaw; Zhang, A Ping; Lu, Chao

2016-12-16

We propose and experimentally demonstrate a novel scheme of bi-directional Brillouin time domain analyzer (BD-BOTDA) to extend the sensing range. By deploying two pump-probe pairs at two different wavelengths, the Brillouin frequency shift (BFS) distribution over each half of the whole fiber can be obtained with the simultaneous detection of Brillouin signals in both channels. Compared to the conventional unidirectional BOTDA system of the same sensing range, the proposed BD-BOTDA scheme enables distributed sensing with a performance level comparable to the conventional one with half of the sensing range and a spatial resolution of 2 m, while maintaining the Brillouin signal-to-noise ratio (SNR) and the BFS uncertainty. Based on this technique, we have achieved distributed temperature sensing with a measurement range of 81.9 km fiber at a spatial resolution of 2 m and BFS uncertainty of ~0.44 MHz without introducing any complicated components or schemes.

Experimental determination of the temperature range of AlO molecular emission in laser-induced aluminum plasma in air

Energy Technology Data Exchange (ETDEWEB)

Bai, Xueshi; Motto-Ros, Vincent [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon Villeurbanne (France); Lei, Wenqi [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon Villeurbanne (France); State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062 (China); Zheng, Lijuan [State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062 (China); Yu, Jin, E-mail: jin.yu@univ-lyon1.fr [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon Villeurbanne (France); Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astrophysics, Shanghai Jiao Tong University, Shanghai 200240 (China)

2014-09-01

Measurements with laser-induced breakdown spectroscopy (LIBS) usually take place in the atmospheric air. For quantitative analysis of metallic elements, oxidation may represent an important issue which can significantly modify the stoichiometry of the plasma. Molecule formation in plasma should be therefore studied and taken into account in the LIBS practice. In this work, we experimentally investigated the temporal evolution and transformation of the plasma induced on an aluminum target by a nanosecond infrared (1064 nm) laser in the atmospheric air, in terms of its temperatures over a large interval of time from hundreds of nanoseconds to tens of microseconds. Such evolution was then correlated to the temporal evolution of the emission intensity from AlO molecules in the ablation plume. In particular, for a given ablation laser pulse energy, the appearance of the molecular emission while the plume cools down allows determining a minimal delay, τ{sub min}, which corresponds to a maximal value of the temperature, T{sub max}, below which the molecular emission begins to be clearly observed and to grow as a function of the delay. Such delay or such temperature indicates the longest delay or the lowest temperature for laser-induced plasma to be suitable for a correct analysis of metallic elements without significant influence of the alternation of the stoichiometry by oxidation. In our experiment, the values of τ{sub min} and T{sub max} have been determined for a range of ablation laser pulse energies from 5 mJ to 50 mJ. These values lie respectively in the range of 3 to 15 μs for τ{sub min}, and 4500 K to 6600 K in terms of the molecule temperature for T{sub max}. Beyond the practical interest for LIBS, our results provide also insights to the kinetics of the AlO molecule formation in laser-induced plasma. - Highlights: • Determination of the temperatures in laser-induced plasma up to tens of microseconds • Determination of the molecule temperature by fitting

Thermodynamic Properties, Hysteresis Behavior and Stress-Strain Analysis of MgH2 Thin Films, Studied over a Wide Temperature Range

Directory of Open Access Journals (Sweden)

Yevheniy Pivak

2012-06-01

Full Text Available Using hydrogenography, we investigate the thermodynamic parameters and hysteresis behavior in Mg thin films capped by Ta/Pd, in a temperature range from 333 K to 545 K. The enthalpy and entropy of hydride decomposition, ∆Hdes = −78.3 kJ/molH2, ∆Sdes = −136.1 J/K molH2, estimated from the Van't Hoff analysis, are in good agreement with bulk results, while the absorption thermodynamics, ∆Habs = −61.6 kJ/molH2, ∆Sabs = −110.9 J/K molH2, appear to be substantially affected by the clamping of the film to the substrate. The clamping is negligible at high temperatures, T > 523 K, while at lower temperatures, T < 393 K, it is considerable. The hysteresis at room temperature in Mg/Ta/Pd films increases by a factor of 16 as compared to MgH2 bulk. The hysteresis increases even further in Mg/Pd films, most likely due to the formation of a Mg-Pd alloy at the Mg/Pd interface. The stress–strain analysis of the Mg/Ta/Pd films at 300–333 K proves that the increase of the hysteresis occurs due to additional mechanical work during the (de-hydrogenation cycle. With a proper temperature correction, our stress–strain analysis quantitatively and qualitatively explains the hysteresis behavior in thin films, as compared to bulk, over the whole temperature range.

On the nature of anomalies in temperature dependence of the OKh18N1OT steel yield strength after thermal cycling in the low temperature range

International Nuclear Information System (INIS)

Medvedev, E.M.; Lavrent'ev, F.F.; Kurmanova, T.N.

1978-01-01

Investigated were structural transformations in 0Kh18N10T steel as a result of heating and cooling and of deformation within the range of temperatures between 300 and 77 K, the quantity relationships between the said transformations and the variation of the yield limit with the temperature. The studies were conducted by metallography and mechanical test methods. It was shown that an increase in the number of heating and cooling cycles correlates with a loss in strength of the steel while deformation at 77 K. This anomaly in the temperature relationship of the yield limit is related to the appearance in the course of deformation of α-martensite with a BCC lattice. Deformation at 300 K increases the amount ea of epsilon-martensite, a decrses the effectve size of grain and, in consequence, increases the yield limit. The relationship between the yield limit and the grain size at the temperature of 300 K is described adequately by the Hall-Petch equation

Discriminating low frequency components from long range persistent fluctuations in daily atmospheric temperature variability

Directory of Open Access Journals (Sweden)

V. Cuomo

2009-07-01

Full Text Available This study originated from recent results reported in literature, which support the existence of long-range (power-law persistence in atmospheric temperature fluctuations on monthly and inter-annual scales. We investigated the results of Detrended Fluctuation Analysis (DFA carried out on twenty-two historical daily time series recorded in Europe in order to evaluate the reliability of such findings in depth. More detailed inspections emphasized systematic deviations from power-law and high statistical confidence for functional form misspecification. Rigorous analyses did not support scale-free correlation as an operative concept for Climate modelling, as instead suggested in literature. In order to understand the physical implications of our results better, we designed a bivariate Markov process, parameterised on the basis of the atmospheric observational data by introducing a slow dummy variable. The time series generated by this model, analysed both in time and frequency domains, tallied with the real ones very well. They accounted for both the deceptive scaling found in literature and the correlation details enhanced by our analysis. Our results seem to evidence the presence of slow fluctuations from another climatic sub-system such as ocean, which inflates temperature variance up to several months. They advise more precise re-analyses of temperature time series before suggesting dynamical paradigms useful for Climate modelling and for the assessment of Climate Change.

Effect of chain extender on properties of silicone rubber sealant

Science.gov (United States)

Liu, Jiesheng; Wu, Shaopeng; Mi, Yixuan; Zhu, Guojun; Zheng, Shaoping

2010-03-01

The room-temperature vulcanizing silicone rubber sealant was prepared with chain extender. The effect of chain extender on the properties of silicone rubber sealant was discussed. The composite samples with chain extender were investigated from the aspects of tack-free time, cross-linkage density, hardness (penetration number) and adhesive strength with the concrete slab. It was found that the adding of the chain extender effectively makes the molecular chain length increase and causes the mechanical properties improvement. In addition, the increase in the amount of the chain extender reduces the cross-linkage density and hardness of silicone rubber sealant, which is accompanied with a decrease in the tack-free time. Adhesive strength is one of the most important requirements for sealant. The effect of chain extender on the adhesive strength was also investigated in this study. It was found that the increase in the amount of the chain extender makes the adhesive strength between the sealant and the concrete slab decrease.

Influence of temperature on the critical in-plane field range for VBLs in the walls of hard domains

International Nuclear Information System (INIS)

Nie, X.F.; Guo, G.X.; Xu, J.P.; Liu, S.P.; Wang, L.N.; Huo, S.G.

2006-01-01

The influence of temperature on the critical in-plane field range for vertical Bloch lines in the walls of three kinds of hard domains is investigated experimentally. It is found that for each kind of three hard domains, there exists a critical in-plane field range, i. e. [H ip (1) (T),H ip (2) (T)], which depends on temperatures and in which vertical Bloch lines are unstable. Here, H ip (1) (T) is the initial critical in-plane field where VBLs in the walls of three kinds of hard domains are annihilated, and H ip (2) (T) is the lowest in-plane field where VBLs in their corresponding hard domains are annihilated completely. H ip (1) (T), H ip (2) (T) and [H ip (1) (T),H ip (2) (T)], all decrease as the temperature increase. Furthermore, H ip (1) (T) and H ip (2) (T) reach zero at T 0 1 and T 0 , respectively. In addition, there exists a relationship among them, when T is unchanged, H ip (1) (T) of the three kinds of hard domains (ordinary hard bubbles (OHB), first kind of dumbbell domain (ID) and second kind of dumbbell domains (IID)) decrease successively, and theirH ip (2) (T) are the same

Black holes from extended inflation

International Nuclear Information System (INIS)

Hsu, S.D.H.; Lawrence Berkeley Lab., CA

1990-01-01

It is argued that models of extended inflation, in which modified Einstein gravity allows a graceful exit from the false vacuum, lead to copious production of black holes. The critical temperature of the inflationary phase transition must be >10 8 GeV in order to avoid severe cosmological problems in a universe dominated by black holes. We speculate on the possibility that the interiors of false vacuum regions evolve into baby universes. (orig.)

Thermal expansivity and bulk modulus of ZnO with NaCl-type cubic structure at high pressures and temperatures

International Nuclear Information System (INIS)

Sun Xiaowei; Liu Zijiang; Chen Qifeng; Chu Yandong; Wang Chengwei

2006-01-01

The thermal expansivity and bulk modulus of ZnO with NaCl-type cubic structure were estimated by using the constant temperature and pressure molecular dynamics technique with effective pair potentials which consist of the Coulomb, dispersion, and repulsion interaction at high pressures and temperatures. It is shown that the calculated thermodynamic parameters including linear thermal expansion coefficient, isothermal bulk modulus and its pressure derivative are in good agreement with the available experimental data and the latest theoretical results. At an extended pressure and temperature ranges, linear thermal expansion coefficient and isothermal bulk modus have also been predicted. The thermodynamic properties of ZnO with NaCl-type cubic structure are summarized in the pressure 0-150 GPa ranges and the temperature up to 3000 K

Predicting Long-Range Traversability from Short-Range Stereo-Derived Geometry

Science.gov (United States)

Turmon, Michael; Tang, Benyang; Howard, Andrew; Brjaracharya, Max

2010-01-01

Based only on its appearance in imagery, this program uses close-range 3D terrain analysis to produce training data sufficient to estimate the traversability of terrain beyond 3D sensing range. This approach is called learning from stereo (LFS). In effect, the software transfers knowledge from middle distances, where 3D geometry provides training cues, into the far field where only appearance is available. This is a viable approach because the same obstacle classes, and sometimes the same obstacles, are typically present in the mid-field and the farfield. Learning thus extends the effective look-ahead distance of the sensors.

Adaptive and freeze-tolerant heteronetwork organohydrogels with enhanced mechanical stability over a wide temperature range

Science.gov (United States)

Gao, Hainan; Zhao, Ziguang; Cai, Yudong; Zhou, Jiajia; Hua, Wenda; Chen, Lie; Wang, Li; Zhang, Jianqi; Han, Dong; Liu, Mingjie; Jiang, Lei

2017-06-01

Many biological organisms with exceptional freezing tolerance can resist the damages to cells from extra-/intracellular ice crystals and thus maintain their mechanical stability at subzero temperatures. Inspired by the freezing tolerance mechanisms found in nature, here we report a strategy of combining hydrophilic/oleophilic heteronetworks to produce self-adaptive, freeze-tolerant and mechanically stable organohydrogels. The organohydrogels can simultaneously use water and oil as a dispersion medium, and quickly switch between hydrogel- and organogel-like behaviours in response to the nature of the surrounding phase. Accordingly, their surfaces display unusual adaptive dual superlyophobic in oil/water system (that is, they are superhydrophobic under oil and superoleophobic under water). Moreover, the organogel component can inhibit the ice crystallization of the hydrogel component, thus enhancing the mechanical stability of organohydrogel over a wide temperature range (-78 to 80 °C). The organohydrogels may have promising applications in complex and harsh environments.

Temperature variations of average o-Ps lifetime in porous media

CERN Document Server

Goworek, T; Jasinska, B; Wawryszczuk, J

2000-01-01

Modification of the Tao-Eldrup model is proposed in order to extend its usefulness to the case of porous media. The modification consists in the transition from spherical to capillary geometry and in inclusion of pick-off annihilation from the excited states of a particle in the well. Approximated equations for pick-off constant in these states are given. The model was tested by observing the temperature dependences of o-Ps lifetime in various media. In the case of silica gels and Vycor glass with narrow pores, the model seems to work well, while for larger pores in Vycor unexpectedly long lifetimes appear in the range of lowest temperatures.

Performance of room temperature mercuric iodide (HgI2) detectors in the ultra low energy x-ray region

International Nuclear Information System (INIS)

Dabrowski, A.J.; Iwanczyk, J.S.; Barton, J.B.; Huth, G.C.; Whited, R.; Ortale, C.; Economou, T.E.; Turkevich, A.L.

1980-01-01

Performance of room temperature mercuric iodide x-ray spectrometers has been recently improved through new fabrication techniques and further development of low noise associated electronic systems. This progress has extended the range of measurements to the ultra low energy x-ray region at room temperature. This paper reports the study of the effect of contact material on the performance of HgI 2 detectors in the low energy x-ray region

Thermostating extended Lagrangian Born-Oppenheimer molecular dynamics.

Science.gov (United States)

Martínez, Enrique; Cawkwell, Marc J; Voter, Arthur F; Niklasson, Anders M N

2015-04-21

Extended Lagrangian Born-Oppenheimer molecular dynamics is developed and analyzed for applications in canonical (NVT) simulations. Three different approaches are considered: the Nosé and Andersen thermostats and Langevin dynamics. We have tested the temperature distribution under different conditions of self-consistent field (SCF) convergence and time step and compared the results to analytical predictions. We find that the simulations based on the extended Lagrangian Born-Oppenheimer framework provide accurate canonical distributions even under approximate SCF convergence, often requiring only a single diagonalization per time step, whereas regular Born-Oppenheimer formulations exhibit unphysical fluctuations unless a sufficiently high degree of convergence is reached at each time step. The thermostated extended Lagrangian framework thus offers an accurate approach to sample processes in the canonical ensemble at a fraction of the computational cost of regular Born-Oppenheimer molecular dynamics simulations.

Test plan for long-term, low-temperature oxidation of spent fuel, Series 1

International Nuclear Information System (INIS)

Einziger, R.E.

1986-06-01

Preliminary studies indicated the need for more spent fuel oxidation data in order to determine the probable behavior of spent fuel in a tuff repository. Long-term, low-temperature testing was recommended in a comprehensive technical approach to: (1) confirm the findings of the short-term thermogravimetric analyses scoping experiments; (2) evaluate the effects of variables such as burnup, atmospheric moisture and fuel type on the oxidation rate; and (3) extend the oxidation data base ot representative repository temperatures and better define the temperature dependence of the operative oxidation mechanisms. This document presents the Series 1 test plan to study, on a large number of samples, the effects of atmospheric moisture and temperature on oxidation rate and phase formation. Tests will run for up to two years, use characterized fragmented, and pulverized fuel samples, cover a temperature range of 110 0 C to 175 0 C and be conducted with an atmospheric moisture content rangeing from 0 C to approx. 80 0 C dew point. After testing, the samples will be examined and made available for leaching testing

Intercomparison of the Extended Reconstructed Sea Surface Temperature v4 and v3b Datasets

Science.gov (United States)

Wang, Jinping; Chen, Xianyao

2018-04-01

Version 4 (v4) of the Extended Reconstructed Sea Surface Temperature (ERSST) dataset is compared with its precedent, the widely used version 3b (v3b). The essential upgrades applied to v4 lead to remarkable differences in the characteristics of the sea surface temperature (SST) anomaly (SSTa) in both the temporal and spatial domains. First, the largest discrepancy of the global mean SSTa values around the 1940s is due to ship-observation corrections made to reconcile observations from buckets and engine intake thermometers. Second, differences in global and regional mean SSTa values between v4 and v3b exhibit a downward trend (around -0.032°C per decade) before the 1940s, an upward trend (around 0.014°C per decade) during the period of 1950-2015, interdecadal oscillation with one peak around the 1980s, and two troughs during the 1960s and 2000s, respectively. This does not derive from treatments of the polar or the other data-void regions, since the difference of the SSTa does not share the common features. Third, the spatial pattern of the ENSO-related variability of v4 exhibits a wider but weaker cold tongue in the tropical region of the Pacific Ocean compared with that of v3b, which could be attributed to differences in gap-filling assumptions since the latter features satellite observations whereas the former features in situ ones. This intercomparison confirms that the structural uncertainty arising from underlying assumptions on the treatment of diverse SST observations even in the same SST product family is the main source of significant SST differences in the temporal domain. Why this uncertainty introduces artificial decadal oscillations remains unknown.

Thermo-economic optimization of heat recovery steam generator for a range of gas turbine exhaust temperatures

International Nuclear Information System (INIS)

Nadir, Mahmoud; Ghenaiet, Adel; Carcasci, Carlo

2016-01-01

Highlights: • Thermo-economic optimization of HRSG configurations. • The maximum value of the net present value was targeted for the economic optimization. • Three level HRSG is the best option in respect of power output and high priced medium. • Two level HRSG is the best for net benefit in low and intermediate priced mediums. - Abstract: This paper illustrates the effect of selling price on the optimum design parameters of a heat recovery steam generator (HRSG) and the selection of its ideal configuration for an outlet temperature range of 350–650 °C. The Particle Swarm Optimization (PSO) method was used, considering the steam cycle specific work as an objective to be maximized, the net present value as another objective to be maximized for the economic optimization and a combination of both. Three configurations of heat recovery steam generators are considered with one, two and three pressure levels and a reheat. The results show that, the three pressure level system is the best configuration from a thermodynamic point of view, but with respect to the economical aspect the two pressure levels is the best configuration for the low and medium selling prices (0.04 $/kW h, 0.08 $/kW h and 0.2 $/kW h), whereas the three pressure level configuration would only be interesting for a high selling price of 0.3 $/kW h and a temperature range 450–600 °C. For a temperature of 650 °C, the high cost of the three level system leads to a decrease in the net present value. As the selling price increases the optimized design parameters of the three pressure level HRSG based on economic or thermodynamic optimization are similar. The obtained results are used to elaborate a new correlation relating the net present value with the gas turbine outlet temperature, gas mass flow rate, number of levels of HRSG and selling price.

Short-range correlations in an extended time-dependent mean-field theory

International Nuclear Information System (INIS)

Madler, P.

1982-01-01

A generalization is performed of the time-dependent mean-field theory by an explicit inclusion of strong short-range correlations on a level of microscopic reversibility relating them to realistic nucleon-nucleon forces. Invoking a least action principle for correlated trial wave functions, equations of motion for the correlation functions and the single-particle model wave function are derived in lowest order of the FAHT cluster expansion. Higher order effects as well as long-range correlations are consider only to the extent to which they contribute to the mean field via a readjusted phenomenological effective two-body interaction. The corresponding correlated stationary problem is investigated and appropriate initial conditions to describe a heavy ion reaction are proposed. The singleparticle density matrix is evaluated

Stokes profile analysis and vector magnetic fields. III. Extended temperature minima of sunspot umbrae as inferred from Stokes profiles of Mg I 4571 A

International Nuclear Information System (INIS)

Lites, B.W.; Skumanich, A.; Rees, D.E.; Murphy, G.A.; Carlsson, M.; Sydney Univ., Australia; Oslo Universitetet, Norway)

1987-01-01

Observed Stokes profiles of Mg I 4571 A are analyzed as a diagnostic of the magnetic field and thermal structure at the temperature minimum of sunspot umbrae. Multilevel non-LTE transfer calculations of the Mg I-II-III excitation and ionization balance in model umbral atmospheres show: (1) Mg I to be far less ionized in sunspot umbrae than in the quiet sun, leading to greatly enhanced opacity in 4571 A, and (2) LTE excitation of 4571 A. Existing umbral models predict emission cores of the Stokes I profile due to the chromospheric temperature rise. This feature is not present in observed umbral profiles. Moreover, such an emission reversal causes similar anomalous features in the Stokes Q, U, V profiles, which are also not observed. Umbral atmospheres with extended temperature minima are suggested. Implications for chromospheric heating mechanisms and the utility of this line for solar vector magnetic field measurements are discussed. 35 references

Diurnal temperature range trend over North Carolina and the associated mechanisms

Science.gov (United States)

Sayemuzzaman, Mohammad; Mekonnen, Ademe; Jha, Manoj K.

2015-06-01

This study seeks to investigate the variability and presence of trend in the diurnal surface air temperature range (DTR) over North Carolina (NC) for the period 1950-2009. The significance trend test and the magnitude of trends were determined using the non-parametric Mann-Kendall test and the Theil-Sen approach, respectively. Statewide significant trends (p < 0.05) of decreasing DTR were found in all seasons and annually during the analysis period. Highest (lowest) temporal DTR trends of magnitude - 0.19 (- 0.031) °C/decade were found in summer (winter). Potential mechanisms for the presence/absence of trend in DTR have been highlighted. Historical data sets of the three main moisture components (precipitation, total cloud cover (TCC), and soil moisture) and the two major atmospheric circulation modes (North Atlantic Oscillation and Southern Oscillation) were used for correlation analysis. The DTRs were found to be negatively correlated with the precipitation, TCC and soil moisture across the state for all the seasons and annual basis. It appears that the moisture components related better to the DTR than to the atmospheric circulation modes.

Low temperature electrical transport in modified carbon nanotube fibres

International Nuclear Information System (INIS)

Lekawa-Raus, Agnieszka; Walczak, Kamil; Kozlowski, Gregory; Hopkins, Simon C.; Wozniak, Mariusz; Glowacki, Bartek A.; Koziol, Krzysztof

2015-01-01

Carbon nanotube fibres are a new class of materials highly promising for many electrical/electronic applications. The range of applications could be extended through the modification of their electrical transport properties by inclusions of foreign materials. However, the changes in electrical transport are often difficult to assess. Here, we propose that the analysis of resistance–temperature dependencies of modified fibres supported by a recently developed theoretical model may aid research in this area and accelerate real life applications of the fibres

Thermodynamic investigation of methyl salicylate/1-pentanol binary system in the temperature range from 278.15K to 303.15K

Energy Technology Data Exchange (ETDEWEB)

Tsierkezos, Nikos G. [Institut fuer Chemie, Humboldt-Universitaet zu Berlin, Brook-Taylor-Strasse 2, D-12489 Berlin (Germany)]. E-mail: tsierkezos@chemie.hu-berlin.de; Molinou, Ioanna E. [Physical Chemistry Laboratory, Department of Chemistry, University of Athens, Panepistimiopolis, Athens 15771 (Greece)]. E-mail: imolinou@chem.uoa.gr

2007-08-15

Densities ({rho}), speeds of sound (u), isentropic compressibilities (k{sub s}), refractive indices (n{sub D}), and surface tensions ({sigma}) of binary mixtures of methyl salicylate (MSL) with 1-pentanol (PEN) have been measured over the entire composition range at the temperatures of 278.15K, 288.15K, and 303.15K. The excess molar volumes (V{sup E}), excess surface tensions ({sigma}{sup E}), deviations in speed of sound ({delta}u), deviations in isentropic compressibility ({delta}k{sub s}), and deviations in molar refraction ({delta}R) have been calculated. The excess thermodynamic properties V{sup E}, {sigma}{sup E}, {delta}u, {delta}k{sub s}, and {delta}R were fitted to the Redlich-Kister polynomial equation and the A{sub k} coefficients as well as the standard deviations (d) between the calculated and experimental values have been derived. The surface tension ({sigma}) values have been further used for the calculation of the surface entropy (S{sup S}) and the surface enthalpy (H{sup S}) per unit surface area. The lyophobicity ({beta}) and the surface mole fraction (x{sub 2}{sup S}) of the surfactant component PEN have been also derived using the extended Langmuir model. The results provide information on the molecular interactions between the unlike molecules that take place at the surface and the bulk.

Reconstructing Interlaced High-Dynamic-Range Video Using Joint Learning.

Science.gov (United States)

Inchang Choi; Seung-Hwan Baek; Kim, Min H

2017-11-01

For extending the dynamic range of video, it is a common practice to capture multiple frames sequentially with different exposures and combine them to extend the dynamic range of each video frame. However, this approach results in typical ghosting artifacts due to fast and complex motion in nature. As an alternative, video imaging with interlaced exposures has been introduced to extend the dynamic range. However, the interlaced approach has been hindered by jaggy artifacts and sensor noise, leading to concerns over image quality. In this paper, we propose a data-driven approach for jointly solving two specific problems of deinterlacing and denoising that arise in interlaced video imaging with different exposures. First, we solve the deinterlacing problem using joint dictionary learning via sparse coding. Since partial information of detail in differently exposed rows is often available via interlacing, we make use of the information to reconstruct details of the extended dynamic range from the interlaced video input. Second, we jointly solve the denoising problem by tailoring sparse coding to better handle additive noise in low-/high-exposure rows, and also adopt multiscale homography flow to temporal sequences for denoising. We anticipate that the proposed method will allow for concurrent capture of higher dynamic range video frames without suffering from ghosting artifacts. We demonstrate the advantages of our interlaced video imaging compared with the state-of-the-art high-dynamic-range video methods.

An evaluation of the transition temperature range of super-elastic orthodontic NiTi springs using differential scanning calorimetry.

Science.gov (United States)

Barwart, O; Rollinger, J M; Burger, A

1999-10-01

Differential scanning calorimetry (DSC) was used to determine the transition temperature ranges (TTR) of four types of super-elastic orthodontic nickel-titanium coil springs (Sentalloy). A knowledge of the TTR provides information on the temperature at which a NiTi wire or spring can assume superelastic properties and when this quality disappears. The spring types in this study can be distinguished from each other by their characteristic TTR during cooling and heating. For each tested spring type a characteristic TTR during heating (austenite transformation) and cooling (martensite transformation) was evaluated. The hysteresis of the transition temperature, found between cooling and heating, was 3.4-5.2 K. Depending on the spring type the austenite transformation started (As) at 9.7-17.1 degrees C and finished (Af) at 29.2-37 degrees C. The martensite transformation starting temperature (Ms) was evaluated at 32.6-25.4 degrees C, while Mf (martensite transformation finishing temperature) was 12.7-6.5 degrees C. The results show that the springs become super-elastic when the temperature increases and As is reached. They undergo a loss of super-elastic properties and a rapid decrease in force delivery when they are cooled to Mf. For the tested springs, Mf and As were found to be below room temperature. Thus, at room temperature and some degrees lower, all the tested springs exert super-elastic properties. For orthodontic treatment this means the maintenance of super-elastic behaviour, even when mouth temperature decreases to about room temperature as can occur, for example, during meals.

Viscoplastic behavior of zirconium alloys in the temperatures range 20 deg C - 400 deg C: characterization and modeling of strain ageing phenomena

International Nuclear Information System (INIS)

Graff, St.

2006-10-01

The anomalous strain rate sensitivity of zirconium alloys over the temperatures range 20-600 C has been widely reported in the literature. This unconventional behavior is related to the existence of strain ageing phenomenon which results from the combined action of thermally activated diffusion of foreign atoms to and along dislocation cores and the long range of dislocations interactions. The important role of interstitial and substitutional atoms in zirconium alloys, responsible for strain ageing and the lack of information about the domain where strain ageing is active have not been yet adequately characterized because of the multiplicity of alloying elements and chemical impurities. The aim of this work is to characterize experimentally the range of temperatures and strain rates where strain ageing is active on the macroscopic and mesoscopic scales. We propose also a predictive approach of the strain ageing effects, using the macroscopic strain ageing model suggested by McCormick (McCormick, 1988; Zhang et al., 2000). Specific zirconium alloys were elaborated starting from a crystal bar of zirconium with 2.2 wt% hafnium and very low oxygen content (80 wt ppm), called ZrHf. Another substitutional atom was added to the solid solution under the form of 1 wt% niobium. Some zirconium alloys were doped with oxygen, others were not. All of them were characterized by various mechanical tests (standard tensile tests, tensile tests with strain rate changes, relaxation tests with unloading). The experimental results were compared with those for the standard oxygen doped zirconium alloy (1300 wt ppm) studied by Pujol (Pujol, 1994) and called Zr702. The following experimental evidences of the age-hardening phenomena were collected and then modeled: 1) low and/or negative strain rate sensitivity around 200-300 C, 2) creep arrest at 200 C, 3) relaxation arrest at 200 C and 300 C, 4) plastic strain heterogeneities observed in laser extensometry on the millimeter scale

Viscoplastic behavior of zirconium alloys in the temperatures range 20 deg C - 400 deg C: characterization and modeling of strain ageing phenomena

Energy Technology Data Exchange (ETDEWEB)

Graff, St

2006-10-15

The anomalous strain rate sensitivity of zirconium alloys over the temperatures range 20-600 C has been widely reported in the literature. This unconventional behavior is related to the existence of strain ageing phenomenon which results from the combined action of thermally activated diffusion of foreign atoms to and along dislocation cores and the long range of dislocations interactions. The important role of interstitial and substitutional atoms in zirconium alloys, responsible for strain ageing and the lack of information about the domain where strain ageing is active have not been yet adequately characterized because of the multiplicity of alloying elements and chemical impurities. The aim of this work is to characterize experimentally the range of temperatures and strain rates where strain ageing is active on the macroscopic and mesoscopic scales. We propose also a predictive approach of the strain ageing effects, using the macroscopic strain ageing model suggested by McCormick (McCormick, 1988; Zhang et al., 2000). Specific zirconium alloys were elaborated starting from a crystal bar of zirconium with 2.2 wt% hafnium and very low oxygen content (80 wt ppm), called ZrHf. Another substitutional atom was added to the solid solution under the form of 1 wt% niobium. Some zirconium alloys were doped with oxygen, others were not. All of them were characterized by various mechanical tests (standard tensile tests, tensile tests with strain rate changes, relaxation tests with unloading). The experimental results were compared with those for the standard oxygen doped zirconium alloy (1300 wt ppm) studied by Pujol (Pujol, 1994) and called Zr702. The following experimental evidences of the age-hardening phenomena were collected and then modeled: 1) low and/or negative strain rate sensitivity around 200-300 C, 2) creep arrest at 200 C, 3) relaxation arrest at 200 C and 300 C, 4) plastic strain heterogeneities observed in laser extensometry on the millimeter scale

Radiation-Hardening of Best-In-Class SiGe Mixed-Signal and RF Electronics for Ultra-Wide Temperature Range, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Innovative, reliable, low-power, and low-noise electronics that can operate over a wide temperature range and high radiation are critical for future NASA missions....

Extended-range prediction trials using the global cloud/cloud-system resolving model NICAM and its new ocean-coupled version NICOCO

Science.gov (United States)

Miyakawa, Tomoki

2017-04-01

The global cloud/cloud-system resolving model NICAM and its new fully-coupled version NICOCO is run on one of the worlds top-tier supercomputers, the K computer. NICOCO couples the full-3D ocean component COCO of the general circulation model MIROC using a general-purpose coupler Jcup. We carried out multiple MJO simulations using NICAM and the new ocean-coupled version NICOCO to examine their extended-range MJO prediction skills and the impact of ocean coupling. NICAM performs excellently in terms of MJO prediction, maintaining a valid skill up to 27 days after the model is initialized (Miyakawa et al 2014). As is the case in most global models, ocean coupling frees the model from being anchored by the observed SST and allows the model climate to drift away further from reality compared to the atmospheric version of the model. Thus, it is important to evaluate the model bias, and in an initial value problem such as the seasonal extended-range prediction, it is essential to be able to distinguish the actual signal from the early transition of the model from the observed state to its own climatology. Since NICAM is a highly resource-demanding model, evaluation and tuning of the model climatology (order of years) is challenging. Here we focus on the initial 100 days to estimate the early drift of the model, and subsequently evaluate MJO prediction skills of NICOCO. Results show that in the initial 100 days, NICOCO forms a La-Nina like SST bias compared to observation, with a warmer Maritime Continent warm pool and a cooler equatorial central Pacific. The enhanced convection over the Maritime Continent associated with this bias project on to the real-time multi-variate MJO indices (RMM, Wheeler and Hendon 2004), and contaminates the MJO skill score. However, the bias does not appear to demolish the MJO signal severely. The model maintains a valid MJO prediction skill up to nearly 4 weeks when evaluated after linearly removing the early drift component estimated from

New records of Lophoproctus coecus Pocock, 1894 (Diplopoda, Polyxenida, Lophoproctidae extend the range of the genus Lophoproctus

Directory of Open Access Journals (Sweden)

Megan Short

2015-06-01

Full Text Available The geographic distribution of the genus Lophoproctus Pocock, 1894 has greatly expanded with new records of the species Lophoproctus coecus Pocock, 1894, together with the reassignment of a number of millipedes formerly identified as Lophoproctus lucidus (Chalande, 1888. L. coecus was found to be the sole representative of the family Lophoproctidae in collections examined from Crimea and the Caucasian region. The species was also identified from Iran and Kyrgyzstan. Lophoproctus specimens collected in Italy by Verhoeff were reassigned as L. coecus with the exception of one specimen of L. jeanneli (Brölemann, 1910 from Capri. These data were combined with all available information from the literature to look at the pattern of distribution of the four species in the genus. The range of the genus Lophoproctus extends from Portugal to Central Asia. Lophoproctus coecus is widespread from Italy eastward, while the morphologically very similar species L. lucidus is confined to France and northern Africa. The two species have a narrow overlap in the Alpes Maritimes region of France. L. jeanneli has a scattered coastal distribution around the Mediterranean Sea. The troglobitic species L. pagesi (Condé, 1982 has only been recorded from a cave on Majorca, Spain.

Vapor pressures, osmotic and activity coefficients for (LiBr + acetonitrile) between the temperatures (298.15 and 343.15) K

Energy Technology Data Exchange (ETDEWEB)

Nasirzadeh, Karamat E-mail: karamat.nasirzadeh@chemie.uni-regensburg.de; Neueder, Roland; Kunz, Werner

2004-06-01

Precise vapor pressure data for pure acetonitrile and (LiBr + acetonitrile) are given for temperatures ranging from T=(298.15 to 343.15) K. The molality range is from m=(0.0579 to 0.8298) mol {center_dot} kg{sup -1}. The osmotic coefficients are calculated by taking into account the second virial coefficient of acetonitrile. The parameters of the extended Pitzer ion interaction model of Archer and the mole fraction-based thermodynamic model of Clegg-Pitzer are evaluated. These models accurately reproduce the available osmotic coefficients. The parameters of the extended Pitzer ion interaction model of Archer are used to calculate the mean molal activity coefficients.

Neutron scattering near the order-disorder transition in Cu3Au: evidence for a lower spinodal temperature

International Nuclear Information System (INIS)

Rogge, R.B.; Gaulin, B.D.; Svensson, E.C.; Hallman, E.D.; Wei, W.

1995-01-01

The binary alloy Cu 3 Au undergoes a first-order phase transition at 667 ± 3 K Within the context of the Landau theory of phase transitions, there exist, in addition to the order-disorder temperature, T c , upper and lower spinodal temperatures, T su and T si . These mark the first temperatures, upon approaching the phase transition from above and below, respectively, at which metastable droplets of the second phase can fluctuate out of the first phase. Until recently, there has, however, been little physical evidence supporting the existence of the spinodal temperatures. Elastic and inelastic neutron-scattering measurements have been carried out on Cu 3 Au over an extended temperature range with particular emphasis on temperatures near T c . The lattice constant data, order-parameter data, and phonon data provided by these measurements all indicate that there are two temperature regimes just below T c with a crossover between these regimes in the range of (T c - 35) to (T c - 25) K. This crossover temperature is interpreted as the lower spinodal temperature of Cu 3 Au. (author)

Extended shelf life of random donor platelets stored for 7 days in platelet additive solution at different temperatures

Directory of Open Access Journals (Sweden)

Tulika Chandra

2014-08-01

Full Text Available Background: Platelets are routinely stored in plasma for 5 days at an average temperature of 22°C. In the present study, the shelf life of random donor platelets was extended by storing for 7 days with and without additive solution at temperatures of 22°C, 18°C, and 16°C. Methods: Random donor platelets were stored in 100% plasma and 20%/80% platelet additive solution. The data were compared using paired "t"- test. The confidence limit was kept at 95%, hence a "p" < 0.05 was considered to be statistically significant. Results: Out of total 150 samples, 148 samples were analyzed and 2 were discarded due to the bacterial contamination on day 7 at 22°C without platelet additive solution. A significant difference in platelet count, platelet factor 3 (PF 3, glucose, lactate dehydrogenase (LDH, and platelet aggregation was observed on day 7 (p < 0.001 at 16°C in without platelet additive solution. In platelet additive solution, the mean values of platelet count, platelet distribution width (PDW, LDH, and pH showed no significant difference on day 7 at 22°C, 18°C, and 16°C. Only significant differences were observed in the levels of mean platelet volume (MPV, PF 3, glucose, and platelet aggregation on day 7 (p < 0.001 at 16°C of the storage period. Conclusion: Random donor platelets functions are better maintained in platelet additive solution as compared to plasma at a lower temperature of 18°C but not at 16°C, on the 7 th day.

Effects of Temperature on the Performance and Stability of Recent COTS Silicon Oscillators

Science.gov (United States)

Patterson, Richard L.; Hammoud, Ahmad

2010-01-01

Silicon oscillators have lately emerged to serve as potential replacement for crystal and ceramic resonators to provide timing and clock signals in electronic systems. These semiconductor-based devices, including those that are based on MEMS technology, are reported to be resistant to vibration and shock (an important criteria for systems to be deployed in space), immune to EMI, consume very low current, require few or no external components, and cover a wide range of frequency for analog and digital circuits. In this work, the performance of five recently-developed COTS silicon oscillator chips from different manufacturers was determined within a temperature range that extended beyond the individual specified range of operation. In addition, restart capability at extreme temperatures, i.e. power switched on while the device was soaking at extreme (hot or cold) temperature, and the effects of thermal cycling under a wide temperature range on the operation of these silicon oscillators were also investigated. Performance characterization of each oscillator was obtained in terms of its output frequency, duty cycle, rise and fall times, and supply current at specific test temperatures. The five different oscillators tested operated beyond their specified temperature region, with some displaying excellent stability throughout the whole test temperature range. Others experienced some instability at certain temperature test points as evidenced by fluctuation in the output frequency. Recovery from temperature-induced changes took place when excessive temperatures were removed. It should also be pointed out that all oscillators were able to restart at the extreme test temperatures and to withstand the limited thermal cycling without undergoing any significant changes in their characteristics. In addition, no physical damage was observed in the packaging material of any of these silicon oscillators due to extreme temperature exposure and thermal cycling. It is recommended

Case study: beverage temperature at aid stations in ironman triathlon.