Abstract: A comprehensive thermal model for an electro-thermal-compliant (ETC) microactuator is presented in this paper. The model accounts for all modes of heat dissipation and the temperature dependence of thermophysical and heat transfer properties. The thermal modelling technique underlying the microactuator model is general and can be used for the virtual testing of any ETC device over a wide range of temperatures (300-1500 K). The influence of physical size and thermal boundary conditions at the anchors, where the device is connected to the substrate, on the behaviour of an ETC microactuator is studied by finite element simulations based on the comprehensive thermal model. Simulations show that the performance ratio of the microactuator increased by two orders of magnitude when the characteristic length of the device was increased by one order of magnitude from 0.22 to 2.2 mm. Restricting heat loss to the substrate via the device anchors increased the actuator stroke by 66% and its energy efficiency by 400%, on average, over the temperature range of 300-1500 K. An important observation made is that the size of the device and thermal boundary conditions at the device anchor primarily control the stroke, operating temperature and performance ratio of the microactuator for a given electrical conductivity.

Abstract: A barrier to the widespread application of building integrated photovoltaics (BIPV) is the lack of validated predictive performance tools Architects and building owners need these tools in order to determine if the potential energy savings realized from building integrated photovoltaics justifies the additional capital expenditure The National Institute of Standards and Technology (NIST) seeks to provide high quality experimental data that can be used to develop and validate these predictive performance tools The temperature of a photovoltaic module affects its electrical output characteristics and efficiency Traditionally, the temperature of solar cells has been characterized using the nominal operating cell temperature (NOCT), which can be used in conjunction with a calculation procedure to predict the module's temperature for various environmental conditions The NOCT procedure provides a representative prediction of the cell temperature, specifically for the ubiquitous rack-mounted installation The procedure estimates the cell temperature based on the ambient temperature and the solar irradiance It makes the approximation that the overall heat loss coefficient is constant In other words, the temperature difference between the panel and the environment is linearly related to the heat flux on the panels (solar irradiance) The heat transfer characteristics of a rack-mounted PV module and a BIPV module can be quite different The manner in which the module is installed within the building envelope influences the cell's operating temperature Unlike rack-mounted modules, the two sides of the modules may be subjected to significantly different environmental conditions This paper presents a new technique to compute the operating temperature of cells within building integrated photovoltaic modules using a one-dimensional transient heat transfer model The resulting predictions are compared to measured BIPV cell temperatures for two single crystalline BIPV panels (one insulated panel and one uninsulated panel) Finally, the results are compared to predictions using the NOCT technique

Abstract: In this paper, the drift, hysteresis and temperature effect of ISFET devices have been studied. Drift behavior exists in the whole measurement, and hysteresis behavior is affected by slow response. These two properties limit the accuracy of ISFET. Furthermore, some characteristics such as pH sensitivity and drift are affected by operating temperature. The I–V curves of a-WO3 gate ISFET was obtained at different temperatures and the pH sensitivities were calculated in the acid buffer solutions. In the measuring processes, the operating temperatures were 25, 35, 45, 55 and 65°C, respectively, and according to the experimental results, we can find that the pH sensitivity increases with increasing temperature, the hysteresis effect is dependent on measuring loop time and measuring path, and the drift increases with increasing pH value.

Abstract: A method for aligning two or more printhead modules (2) mounted to a support member (3) in a printer, the method including: positioning the printhead modules (2) on the support member (3) such that they align when the support member (3) is at its operating temperature but not necessarily at other temperatures.

Abstract: This paper describes a new generation of integrated solid-state gas-sensors embedded in SOI micro-hotplates. The micro-hotplates lie on a SOI membrane and consist of MOSFET heaters that elevate the operating temperature, through self-heating, of a gas sensitive material. These sensors are fully compatible with SOI CMOS or BiCMOS technologies, offer ultra-low power consumption (under 100 mW), high sensitivity, low noise, low unit cost, reproducibility and reliability through the use of on-chip integration. In addition, the new integrated sensors offer a nearly uniform temperature distribution over the active area at its operating temperatures at up to about 300–350°C. This makes SOI-based gas-sensing devices particularly attractive for use in handheld battery-operated gas monitors. This paper reports on the design of a chemo-resistive gas sensor and proposes for the first time an intelligent SOI membrane microcalorimeter using active micro-FET heaters and temperature sensors. A comprehensive set of numerical and analogue simulations is also presented including complex 2D and 3D electro-thermal numerical analyses.

Abstract: The O 2 , CO and NO 2 gas sensing properties of MoO 3 –TiO 2 thin films have been studied. The sol–gel process was employed to fabricate MoO 3 –TiO 2 thin films onto sapphire and alumina transducers for gas sensing measurements. It was found the MoO 3 dominated sensors have a lower optimal operating temperature of 370°C than the TiO 2 dominated sensors. The response of the sensors was stable and reproducible at operating temperatures below 400°C. However, once the films were exposed to temperatures higher than 400°C, repeatable gas sensing results could not be achieved. The low evaporation temperature of MoO 3 component of the mixed system is believed to be the cause of the sensors instability and irreversibility at high operating temperatures.

Abstract: A system and method for controlling server chassis cooling fans includes monitoring operating temperatures associated with each of a plurality of temperature sensors. The temperature sensors may be coupled with a plurality of respective server processing cards. In accordance with a particular embodiment of the present invention, the operating speed of each of a plurality of server chassis cooling fans coupled with a server chassis is increased, in response to an operating temperature exceeding a predetermined maximum operating temperature measured at any one of the plurality of temperature sensors. In accordance with another embodiment of the present invention, the operating speed of each of the plurality of server chassis cooling fans is decreased in response to an operating temperature below a predetermined minimum operating temperature measured at each of the plurality of temperature sensors. In still another embodiment, a fan shutdown timer is activated for a predetermined time period at each of the plurality of server processing cards having an operating temperature below the predetermined maximum operating temperature.

Abstract: Loop heat pipes (LHPs) are versatile two-phase heat transfer devices that have gained increasing acceptance for space and terrestrial applications The operating temperature of an LHP is a function of its operating conditions The LHP usually reaches a steady operating temperature for a given heat load and sink temperature The operating temperature will change when the heat load and/or the sink temperature changes, but eventually reaches another steady state in most cases Under certain conditions, however, the loop operating temperature never really reaches a true steady state, but instead becomes oscillatory This paper discusses the temperature oscillation phenomenon using test data from a miniature LHP

Abstract: 130 /spl mu/m VCSELs using GaAsSb quantum wells, which operate continuous-wave at and above room temperature (RT), are reported A threshold current as low as 12 mA at RT and a maximum CW operating temperature of 70/spl deg/C are demonstrated

Abstract: High-performance 1.3-/spl mu/m-emitting quantum-dot lasers were fabricated by self-organized growth of InAs dots embedded in GaInAs quantum wells. The influence of the number of quantum-dot layers on the device performance was investigated. Best device results were achieved with six-dot layers. From the length dependence; a maximum ground state gain of 17 cm/sup -1/ for six dot layers could be determined. Ridge waveguide lasers with a cavity length of 400 /spl mu/m and high-reflection coatings show threshold currents of 6 mA and output powers of more than 5 mV. Unmounted devices can be operated in continuous wave mode up to 85/spl deg/C. A maximum operating temperature of 160/spl deg/C was achieved in pulsed operation for an uncoated 2.5-mm-long ridge waveguide laser.

Abstract: In a two-stage concept for supercharging of internal combustion engines, in which the first stage is performed by an exhaust-gas turbocharger and the second stage by an electrically driven compressor, the compressor is also used to provide the secondary air used for the heating of a catalytic converter. In this manner, the catalytic converter quickly reaches an efficient operating temperature.

Abstract: A method and apparatus for operating an integrated circuit in an electronic device by controlling the supply voltage to the integrated circuit (IC). A parameter of the IC is measured and used to adjust the supply voltage of the IC. The measured parameter is indicative of the effective channel mobility of the IC. One purpose of adjusting the voltage is to modify the effective channel mobility such that the individual channel currents are substantially constant over a predetermined operating temperature range of the IC. The modification of channel mobility is chosen to set the individual channel currents at levels that either maximizes operating speed, minimizes power consumption, extends the range of operating temperature, or increases the operational reliability of the IC.

Abstract: Optoelectronic and photonic devices are formed by employing polymer materials that have a lower glass transition temperature (Tg) than the nominal operating temperature. By using such materials, the local or segmental mobility is increased so that local stress is eliminated or minimized on the polymer material, making performance more robust. The current invention involves use of a polymer in an optical device in an operating temperature range in the region above Tg, where the polymer segments between crosslinks are allowed local freedom of movement; however, large-scale movement of the material may be restricted by the crosslinked structure of the polymer material. The temperature operation point of a device constructed according to the invention is thus preferably distanced from both the viscoelastic region near Tg and from the glassy region below Tg; such that the device is operated in a region where viscoelastic effects do not significantly affect the materials system, and time-dependent responses of the polymer are minimized or eliminated. Device operation can thus achieve minimum degradation and show improved performance attributes.

Abstract: In the following, a contacting variant for solid oxide fuel cells will be presented in which the conductivity of the interconnect is ensured by contact elements made of fine silver. To this end, the interconnect has holes through which the contact elements of fine silver (99.9 wt% Ag) are introduced and then pressed. This pressing process and the thermal expansion of the silver during heating leads to a gastight joint. The silver penetrations are additionally soldered to render them capable of withstanding temperature cycling. Contact resistance measurements and corrosion studies at 800 °C in air or Ar/4 vol.% H2/3 vol.% H2O demonstrate the functionality of the contacting variant under the described conditions. The experimental results indicate that contacting by means of silver contact elements ensures long-term stability up to operating temperatures of 800 °C. Current transmission via the silver contact elements means that a large number of materials are conceivable as the interconnect material. In the following application, an FeCrAl steel (1.4767, Aluchrom Y Hf—trade name Krupp Thyssen Nirosta) with 5.7 wt.% aluminium was used. At the operating temperature, a dense aluminium oxide layer forms on its surface which prevents the vaporization, for example of chromium oxide species, during fuel cell operation.

Abstract: A method and apparatus for controlling the charge and discharge currents in a battery (2) as a function of temperature. When a battery (2) is charged or discharged in an environment that approaches its design operating temperature extreme, the currents are reduced to limit self-heating of the battery and thus extend the useful operating environment temperature range. A temperature sensor (18) is coupled to a controller (6) to sense the battery (2) temperature. The temperature information is used to set a suitable charging or discharging current (8).

Abstract: The present invention pertains to the field of methods and devices for battery (9) temperature regulation Phase change material (7; 7a, 7b) having a phase change temperature within a preferred operating temperature range is employed in order to maintain the battery temperature within the preferred operating temperature range during extreme ambient termperature conditions When the temperature of an ambient medium (21) so allows, a transfer of heat between the phase change material (7; 7a, 7b) and ambient medium (21) is effected for quickly restoring the capability of the phase change material (7; 7a, 7b) to maintain the battery temperature at the phase change temperature Otherwise, thermal insulation between the phase change material (7; 7a, 7b) and the ambient medium (21) is provided

Abstract: The invention relates to a cooling system for a motor vehicle in which a closing unit for the cooling airflow is monitored with regard to the function thereof in order to optimize the operational parameters of the internal combustion engine. Said closing unit, preferably a flap or shutter, is monitored in the function thereof for controlling the cooling airflow in order to avoid a temperature build-up or a falling short of the operating temperature. In order to monitor the position of the closing unit (1), the invention provides that the progression of the cooling water temperature is compared with a stored model progression of the temperature by using a temperature sensor which, as a rule, is present. If the cooling water temperature is within a predetermined tolerance range, the closing unit is functionally ready, and in the other case, the closing unit is blocked. In this case, the closing unit is deliberately controlled and the subsequent temperature progression is compared with a corresponding model progression. If the cooling water temperature is now outside another pre-set tolerance range (S21, S22), said range then serves as an index for blocking the closing unit (1). This shortcoming is indicated and/or stored.

Abstract: An electric power steering apparatus can correspond to high output ability, and has a power transmission mechanism of an electric driving section capable of achieving predetermined slip torque in spite of change of operating temperature. Also, a resin gear for power transmission is formed by joining a core metal and a resin with strong bonding force, and has preferable heat-dissipation property. This joining is performed by way of chemical bond according to composite molding technique or adhesive.

Abstract: The fault current limiter is a very attractive device for electric networks. Meander pattern conductors cut from bulk melt textured YBCO were studied for this application. The meanders are put in series and/or in parallel to match the required current and voltage. The YBCO materials are attractive because they show a very effective limitation with a relative low volume (high engineering current density and normal state resistivity). However, they are sensitive to hot spots. To avoid these destructive hot spots the operating temperature is chosen very close to the critical temperature (above 90 K). This temperature range is reached using a pressurised liquid nitrogen bath. Working close to Tc has two major advantages. The first is reduced values of Jc which limit the power dissipation. The Jc can be matched by changing the pressure on the nitrogen bath. The second is that the proximity of the normal state is favourable for homogeneous quenches along the whole meander as it can be experimentally recorded. Results obtained on single meanders and on the whole assembly are reported under steady state operation as well as during current limitation. Forty three meanders in series limited the current to 740 A (11 000 A unlimited value) under 1 kV.

Abstract: The present invention discloses methods and systems for generating a bias voltage during an Automatic Program Disturb Erase Verify (APDEV) operation in a memory device. During the APDEV operation, a predetermined supply voltage is generated by a regulated power supply. The predetermined supply voltage is directed to a temperature-compensated bias generator circuit (14). The temperature-compensated bias generator circuit (14) is activated to generate the bias voltage based on the operating temperature of the memory device.

Abstract: This paper presents a comprehensive experimental study of the loop operating temperature in a loop heat pipe (LHP) which has two parallel evaporators and two parallel condensers. In a single evaporator LHP, it is well known that the loop operating temperature is a function of the heat load, the sink temperature and the ambient temperature. The objective of the present study emphasizes on the stability of the loop operating temperature and parameters that affects the loop operation. Tests results show that the loop operating temperature is a function of the total system heat load, sink temperature, ambient temperature, and beat load distribution between the two evaporators. Under most conditions, only one compensation chamber (CC) contains two-phase fluid and controls the loop operating temperature, and the other CC is completely filled with liquid. Moreover, as the test condition changes, control of the loop operating temperature often shifted from one CC to another. In spite of complex interactions between various components, the test loop has demonstrated very robust operation even during fast transients.

Abstract: This application relates to a system and method for regulating the temperature of a self-contained fuel cell apparatus preferably comprising a fuel reformer. The invention maintains the various components of the fuel cell apparatus within preferred operating temperature ranges while ensuring that exhaust gases and external surfaces of the apparatus do not exceed safe temperature levels. The invention is particularly suited for self-contained hybrid power supply applications, for example for non-road electric vehicles. The various components of the apparatus are strategically configured relative to air flow paths to fully utilize the cooling capacity of the process stream and minimize parasitic loads. In some embodiments the inlet air is pre-heated to enable operation of the apparatus in low temperature environments, such as industrial freezers.

Abstract: A method of and a structure for controlling the temperature of an electrode (4). The electrode is heated prior to etching the first wafer and both a (temporally) stationary and a (spatially) homogeneous temperature of the silicon electrode are maintained. Resistive heater elements (1) are either embedded within the housing of the electrode (3) or formed as part of the electrode. The resistive heater elements form a heater of a multi-zone type in order to minimize the temperature non-uniformity. The resistive heater elements are divided into a plurality of zones, wherein the power to each zone can be adjusted individually, allowing the desirable temperature uniformity of the electrode to be achieved. Preheating the electrode to the appropriate operating temperature eliminates both the 'first wafer effect' and non-uniform etching of a semiconductor wafer.

Abstract: The importance of high fracture toughness and reliability in Si3N4, and SiC-based structural ceramics and ceramic matrix composites is reviewed. The potential of these ceramics and ceramic matrix composites for high temperature applications in defense and aerospace applications such as gas turbine engines, radomes, and other energy conversion hardware have been well recognized. Numerous investigations were pursued to improve fracture toughness and reliability by incorporating various reinforcements such as particulate-, whisker-, and continuous fiber into Si3N4 and SiC matrices. All toughening mechanisms, e.g. crack deflection, crack branching, crack bridging, etc., essentially redistribute stresses at the crack tip and increase the energy needed to propagate a crack through the composite material, thereby resulting in improved fracture toughness and reliability. Because of flaw insensitivity, continuous fiber reinforced ceramic composite (CFCC) was found to have the highest potential for higher operating temperature and longer service conditions. However, the ceramic fibers should display sufficient high temperature strength and creep resistance at service temperatures above 1000 'C. The greatest challenge to date is the development of high quality ceramic fibers with associate coatings able to maintain their high strength in oxidizing environment at high temperature. In the area of processing, critical issues are, preparation of optimum matrix precursors, precursor infiltration into fiber array, and matrix densification at a temperature, where grain crystallization and fiber degradation do not occur. A broad scope of effort is required for improved processing and properties with a better understanding of all candidate composite systems.

Abstract: A temperature compensation system for minimizing sensor offset variations includes an engine controller having stored therein a model of sensor operating behavior over temperature. In one embodiment, the sensor is a ΔP sensor for sensing a differential pressure across a flow restriction mechanism disposed between an exhaust manifold and an intake manifold of an internal combustion engine. In this embodiment, the ΔP sensor is preferably thermally coupled to a structural component of the engine whose operating temperature is readily discernable; e.g., the engine cooling system. Alternatively, the ΔP sensor may include a temperature sensor coupled thereto. In either case, the engine controller is preferably responsive to transitions of the key switch to gather “hot” and “cold” temperature data under zero ΔP conditions. This information is then used to constantly update the ΔP sensor model.