On-Chip Micro Temperature Controllers Based on Freestanding Thermoelectric Nano Films for Low-Power Electronics

Multidimensional integration and multifunctional com-ponent assembly have been greatly explored in recent years to extend Moore’s Law of modern microelectronics.However,this inevitably exac-erbates the inhomogeneity of temperature distribution in microsystems,making precise temperature control for electronic components extremely challenging.Herein,we report an on-chip micro temperature controller including a pair of thermoelectric legs with a total area of 50×50μm^(2),which are fabricated from dense and flat freestanding Bi2Te3-based ther-moelectric nano films deposited on a newly developed nano graphene oxide membrane substrate.Its tunable equivalent thermal resistance is controlled by electrical currents to achieve energy-efficient temperature control for low-power electronics.A large cooling temperature difference of 44.5 K at 380 K is achieved with a power consumption of only 445μW,resulting in an ultrahigh temperature control capability over 100 K mW^(-1).Moreover,an ultra-fast cooling rate exceeding 2000 K s^(-1) and excellent reliability of up to 1 million cycles are observed.Our proposed on-chip temperature controller is expected to enable further miniaturization and multifunctional integration on a single chip for microelectronics.

Gypsum-based Silica Gel Humidity-controlling Composite Materials:Preparation,Characterization,and Performance

Gypsum was used as substrate,and silica gel was mixed into substrate at a certain mass ratio to prepare humidity-controlling composites;moreover,the moisture absorption and desorption properties of gypsum-based composites were compared with adding different silica gel particle size and proportion.The morphological characteristics,the isothermal equilibrium moisture content curve,moisture absorption and desorption rate,moisture absorption and desorption stability,and humidity-conditioning performance were tested and analyzed.The experimental results show that,compared with pure-gypsum,the surface structure of the gypsum-based composites is relatively loose,the quantity,density and aperture of the pores in the structure increase.The absorption and desorption capacity increase along with the increase of silica gel particle size and silica gel proportion.When 3 mm silica gel particle size is added with a mass ratio of 40%,the maximum equilibrium moisture content of humidity-controlling composites is 0.161 g/g at 98% relative humidity(RH),3.22 times that of pure-gypsum.The moisture absorption and desorption rates are increased,the equilibrium moisture absorption and desorption rates are 2.68 times and 1.61 times that of pure-gypsum at 58.5% RH,respectively.The gypsum-based composites have a good stability,which has better timely response to dynamic humidity changes and can effectively regulate indoor humidity under natural conditions.

A strength model for cement-stabilized mud subjected to various curing temperatures and its early-stage quality control

The influence of curing temperature on the strength development of cement-stabilized mud has been well documented in terms of strength-increase rate and ultimate strength.However,the strength development model is not mature for the extremely early stages.In addition,there is a lack of studies on quality control methods based on early-stage strength development.This paper presents a strength model for cement-stabilized mud to address these gaps,considering various curing temperatures and early-stage behaviors.In this study,a series of laboratory experiments was conducted on two types of muds treated with Portland blast furnace cement and ordinary Portland cement under four different temperatures.The results indicate that elevated temperatures expedite strength development and lead to higher long-term strength.The proposed model,which combines a three-step conversion process and a hyperbolic model at the reference temperature,enables accurate estimate of the strength development for cement-treated mud with any proportions cured under various temperatures.With this model,a practical early quality control method is introduced for applying cement-stabilized mud in field projects.The back-analysis parameters obtained from a 36-h investigation at temperature of 60C demonstrated a sufficient accuracy in predicting strength levels in practical applications.

Control system design for a pressure-tube-type supercritical water-cooled nuclear reactor via a higher order sliding mode method

Nuclear power plants exhibit non-linear and time-variable dynamics.Therefore,designing a control system that sets the reactor power and forces it to follow the desired load is complicated.A supercritical water reactor(SCWR)is a fourth-generation conceptual reactor.In an SCWR,the non-linear dynamics of the reactor require a controller capable of control-ling the nonlinearities.In this study,a pressure-tube-type SCWR was controlled during reactor power maneuvering with a higher order sliding mode,and the reactor outgoing steam temperature and pressure were controlled simultaneously.In an SCWR,the temperature,pressure,and power must be maintained at a setpoint(desired value)during power maneuvering.Reactor point kinetics equations with three groups of delayed neutrons were used in the simulation.Higher-order and classic sliding mode controllers were separately manufactured to control the plant and were compared with the PI controllers speci-fied in previous studies.The controlled parameters were reactor power,steam temperature,and pressure.Notably,for these parameters,the PI controller had certain instabilities in the presence of disturbances.The classic sliding mode controller had a higher accuracy and stability;however its main drawback was the chattering phenomenon.HOSMC was highly accurate and stable and had a small computational cost.In reality,it followed the desired values without oscillations and chattering.

Design of greenhouse temperature and humidity wireless control system based on CC3200

Referring to the shortages that the process of traditional greenhouse measurement by using thermometer and hygrometer is complex,the measurement result is not accurate,and the control system operation is cumbersome,a greenhouse temperature and humidity(TH)control system based on CC3200 is designed.The system uses FPGA as the main controller,sends the TH signals to the wireless module CC3200 by controlling DHT22.The proposed system realizes the remote transmission of data and the automatic control of system.

Studies on the Economical and Practical Temperature Control Facility of Deep-Litter Systems for Swine Production

Deep-Litter System is a high yield approach to raise swine with pollution free in a lower cost. In the research, based on the heat stress in summer caused by fermentation, three temperature-control systems were designed, including natural ventilation through transoms, forced ventilation via fans, and cooling by hyperbaric spray system. Specifically, the latter intermittent auto-pressurized spray system developed in our lab, which could spray successively via pressure from storage tubes without wetting the fermentation bed, is suitable for the promotion with the deep-litter technology in rural regions , since the power consumption is only 1 kwh per day.

Experimental study on temperature stress calculation and temperature control optimization of concrete based on early age parameters

Temperature control curve is the key to achieving temperature control and crack prevention of high concrete dam during construction,and its rationality depends on the accurate measurement of temperature stress.With the simulation testing machine for the temperature stress,in the present study,we carried out the deformation process tests of concrete under three temperature curves:convex,straight and concave.Besides,we not only measured the early-age elastic modulus,creep parameters and stress process,but also proposed the preferred type.The results show that at early age,higher temperature always leads to greater elastic modulus and smaller creep.However,the traditional indoor experiments have underestimated the elastic modulus and creep development at early age,which makes the calculated value of temperature stress too small,thus increasing the cracking risk.In this study,the stress values of the three curves calculated based on the strain and early-age parameters are in good agreement with the temperature stress measured by the temperature stress testing machine,which verifies the method accuracy.When the temperature changes along the concave curve,the law of stress development is in consistent with that of strength.Under this condition,the stress fluctuation is small and the crack prevention safety of the concave type is higher,so the concave type is better.The test results provide a reliable basis and support for temperature control curve design and optimization of concrete dams.

Multivariable temperature measurement and control system of large-scaled vertical quench furnace based on temperature field

A temperature control system of 31m vertical forced air-circulation quench furnace is proposed, which is a kind of equipment critical for thermal treatment of aluminum alloy components that are widely used in aerospace industry. For the effective operation of the furnace, it is essential to analyze the radial temperature distribution of the furnace. A set of thermodynamic balance equations modeling is established firsdy. By utilizing the numerical analysis result to modify the temperature measurements, the control accuracy and precision of the temperature are truly guaranteed. Furthermore, the multivariable decoupling self-learning PID control algorithm based on the characteristics of strong coupling between the multi-zones in the large-scaled furnace is implemented to ensure the true homogeneity of the axial temperature distribution. Finally, the redundant structure composed of industrial control computers and touch panels leads to great improvement of system reliability.

Temperature Control and Simulation of Temperature-Altitude Test System

The temperature-Altitude Test System(TATS) supplies various testing environments.The traditional PID method controls the temperature in TATS Temperature-Pressure Cabin(TPC) over a long adjusting time and with a large overshoot.In order to solve this problem simply,a temperature control strategy with temperature difference corresponding factors is presented through a dynamic analysis and modeling of TPC temperature change.The TPC temperature descending process is simulated,and the results show that this control strategy can allot the proportion of PID heating controller and PID cooling controller in the whole control process and TPC temperature can be controlled at a set point quickly and effectively.

COMPUTER DECOUPLE CONTROL OF TEMPERATURE AND HUMIDITY IN PREPROCESSING CHAMBER OF AIR-CONDITIONING TEST EQUIPMENT

This paper deals with the application of decouple Control theory to temperature and humidi-ty control in air-conditioning system. The decouple control algorithm for bivariable systems isderived applicablly for air-conditioning system. The algorithm is used to design a temperatureand humidity computer control system for the preprocessing chamber of air-conditioning testequipment. The results of the real-time control experiments indicate that the decouple controlalgorithm is feasible, the control quality is improved and high control precision is achieved.

Temperature Intelligent Control System of Large-Scale Standing Quench Furnace

Considering some characteristics of large-scale standing quench furnace, such as great heat inertia, evident time lag, strong coupling influence, hard to establish exact mathematical models of plant and etc, an artificial intelligent fuzzy control algorithm is put forward in this paper. Through adjusting the on-off ratio of electric heating elements, the temperature in furnace is controlled accurately. This paper describes structure and qualities of the large-scale standing quench furnace briefly, introduces constitution of control system, and expounds principle and implementation of intelligent control algorithm. The applied results prove that the intelligent control system can completely satisfy the technological requirements. Namely, it can realize fast increasing temperature with a little overshoot, exact holding temperature, and well-distributed temperature in quench furnace. It has raised the output and quality of aluminum material, and brought the outstanding economic and social benefits.

Temperature and Humidity Control in Greenhouses in Desert Areas

Water consumption can be reduced by using a greenhouse for agriculture in desert areas. We analyzed the effect of control of ventilation, sprinkler water, and solar radiation?shielding on changes of temperature and humidity in a greenhouse under various desert area conditions. We calculated the changes in temperature and humidity in a greenhouse for a whole day in four seasons, and the calculation results of water consumption with and without a greenhouse were compared. When ventilation, shielding, and sprinkler water were controlled under suitable conditions to grow orchids in a desert area, water consumption in July was only 7% of that without a greenhouse.

Study and Application of a New Association Polymer System for Profile Control

A new polymer system, referred to simply as the AP-P4 polymer system, aims at solving the problems of high temperature, high salinity and the poor shearing resistance, all of which are encountered by conventional polymers (such as polyacrylamide) used in profile control, profile performance improvement and EOR operations in the Zhongyuan Oilfield, Sinopec. This system has been developed on the basis of the specific molecular structure and the better properties of high temperature resistance, high salinity resistance and strong shearing resistance of the new type of AP-P4 association polymer. Acidity modifying agents and cross-linking agents (MZ-YL, MZ-BE, MZ-XS), compatible with the new polymer system, are selected. Results of performance tests have shown that the new polymer system has excellent thickening, high temperature, high salinity and shearing resistance and anti-dehydrating properties. In 2003, it underwent its first pilot test in 26 wells in China, with remarkable effects in increasing oil production and decreasing water production. The newly developed polymer system and its application technology described in this paper may play a guiding role in polymer profile control operations in the oil reservoirs of high temperature and high salinity.

Design and Research on New Intelligent Temperature Control System for Stove

A new intelligent temperature control system for stove was introduced. It could accomplish A/D conversion, data processing, output displaying and alarming while the temperature exceeds the given threshold. The temperature adjusting devices were bi direction SCR and heating resistor. The hardware and software were discussed in the paper.

Single-Stage Wide-Range CMOS VGA with Temperature Compensation and Linear-in-dB Gain Control

A novel wide-range CMOS variable gain amplifier （VGA） topology is presented. The proposed VGA is composed of a variable transconductor and a novel variable output resistor and can offer a high gain variation range of 80dB while using a single variable-gain stage. Temperature-compensation and decibel-linear gain characteristic are achieved by using a control circuit that provides a gain error lower than ±1.5dB over the full temperature and gain ranges. Realized in 0.25μm CMOS technology, a prototype of the proposed VGA provides a total gain range of 64.5dB with 55.6dB-linear range,a P-1dB varying from - 17.5 to 11.5dBm,and a 3dB-bandwith varying from 65 to 860MHz while dissipating 16.5mW from a 2.5V supply voltage.

Development and application of the standard for infrared intelligent body temperature measurement system in the normalized COVID-19 prevention and control

In the phase of the normalized COVID-19 prevention and control,non-contact temperature measurement is one of the most efficient and convenient methods for initial screening of suspected cases.In the year of 2020 in Wuhan,such non-contact equipment was urgently demanded,standards development in the traditional way cannot satisfy the market needs.So,the research and development of this standard for infrared intelligent body temperature measurement system was carried out in a rapid way.

TK7 High-Temperature Tunnel Kiln Computer Control System of SRIC Thailand

Based on the TK7 high-temperature tunnel kiln computer control system, this article describes the control line system, the automatic loop control which has been realized in firing zone temperature, inner and bottom pressure and flow, and logic control of kiln doors and pusher, etc. In addition, this system integrates the product information management system of magnesite brick and efficiently ensures the important process parameters. During three months performance of the control system, all parameters and energy consumption have turned out a good result.

TEMPERATURE FIELD CONTROL PRINCIPLE AND CONTROL MODELS FOR CRYOGENIC MACHINING SYSTEM

Cryogenic machining is a new technology which makes use of the special mechanicalprcperties of niaterials in a cryogenic or a 'super cold' state for machining. The control of acryogenic machining system(CMS)is one of the key problems which need to be solved for practi-cal cryogenic machining A temperature field control principle is presented which calculates theheat source temperature in the light of the tool temperature field information, and a control mod-el of three-dimensional dynamic temperature field for CMS is established, and the boundary con-ditions and the heat source of temperature field in orthogonal cutting are discussed. Based on theinvestigation of the control feature and technique. a prototype system for controlling CMS is crea-ted.

Reinforced temperature control of a reactive double dividing-wall distillation column

The mass and thermal coupling makes the control of the reactive double dividing-wall distillation column(R-DDWDC) an especially challenging issue with a highly interactive nature. With reference to the separation of an ideal endothermic quaternary reversible reaction with the most unfavorable ranking of relative volatilities(A + B ■ C + D with α_(A)>α_(C)>α_(D)>α_(B)), the operation rationality of the R-DDWDC is studied in this contribution. The four-point single temperature control system leads to great steady-state discrepancies in the compositions of products C and D and the reason stems essentially from the failure in keeping strictly the stoichiometric ratio between reactants A and B. A temperature plus temperature cascade control scheme is then employed to reinforce the stoichiometric ratio control and helps to secure a substantial abatement in the steady-state discrepancies. A temperature difference plus temperature cascade control scheme is finally synthesized and leads even to better performance than the most effective double temperature difference control scheme. These outcomes reveal not only the operation feasibility of the R-DDWDC but also the general significance of the proposed temperature difference plus temperature cascade control scheme to the inferential control of any other complicated distillation columns.

Feasibility Assessment of Fast Numerical Simulations for Real-Time Monitoring and Control of PEM Fuel Cells

Computational models that ensure accurate and fast responses to the variations in operating conditions,such as the cell tem-perature and relative humidity(RH),are essential monitoring tools for the real-time control of proton exchange membrane(PEM)fuel cells.To this end,fast cell-area-averaged numerical simulations are developed and verifi ed against the present experiments under various RH levels.The present simulations and measurements are found to agree well based on the cell voltage(polarization curve)and power density under variable RH conditions(RH=40%,RH=70%,and RH=100%),which verifi es the model accuracy in predicting PEM fuel cell performance.In addition,computationally feasible reduced-order models are found to deliver a fast output dataset to evaluate the charge/heat/mass transfer phenomena as well as water production and two-phase fl ow transport.Such fast and accurate evaluations of the overall fuel cell operation can be used to inform the real-time control systems that allow for the improved optimization of PEM fuel cell performance.