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High quality greenhouse control requires accurate modeling of the greenhouse as a thermal system along with all the influences affecting it. A decomposed model is the only way to tackle the complexity of such a system. A very important module of the decomposition is the heating system, due to its high impact on the overall financial cost of the greenhouse. This paper inspects the theoretical limits...
Here we present the design and implementation of a 130-MHz on-chip reference oscillator in a 0.18-μm 1-ploy 6-metal digital CMOS process. To compensate for the influences on the oscillation frequency by process, supply voltage and temperature (PVT) variations, the oscillator uses a bias adjustment technique without BJT devices, on-chip inductors or external components. Measurements of 8 samples in...
The greenhouse micro-climate has many characteristics such as strongly nonlinear, large time delay, strong coupling, strong interference, time-varying. Studying on the modeling and simulation of greenhouse micro-climate is the foundation to establish the ability to automatically control the greenhouse micro-climate and characteristics for our climate of controlled environment agriculture. In this...
Strained engineering in nano process technology is considered to be a promising enhancements on the electric characteristics of MOSFET devices. Both tensile and compressive strains are applied to NMOS and PMOS individually using silicon nitride as contact etching stop layer (CESL). As appeared in this study, the electrical characteristics are to be compared with or without strain on 10μm/10μm (channel...
The oil temperature is the significant factor to ensure the safe operation of crude oil storage tank. The final temperature formula for both received and delivered oil were deduced according to energy conservation law and heat transfer principle on the basis of the one in static state. The practical production data of some oil depot in Daqing Oilfield was taken for example to calculate the final temperature...
Hydration parameters adopt in numerical analysis of temperature and stress of mass concrete are different between hydraulic engineering and building construction engineering. The affection of the hydration parameters, such as quantity of hydration heat, hydration rate and the hear transfer coefficient between concrete and air surface, to the temperature of the mass concrete are investigated. Some...
Deep mining will definitely cause high temperature mining face. This paper induces the primary and secondary importance of different factors that affect the thermal environment of high temperature working face by field data analysis and heat transmission mechanism analysis. It also shows the technical economical comparison and the effect analysis of different regulation technology and cooling methods...
Trend of the high speed and high efficiency machining has pushed the continuous demand of higher spindle speed and power for the machining center application. However, the extremely high speed will produce significant centrifugal force. Conventional steel spindles are not appropriate for high speed operation because of their high rotational inertia and low damping ratio. Moreover, heat generation...
To research maximum smoke temperature under the ceiling in slope tunnel with longitudinal ventilation and enhance fire protection of the Shiziyang long-sized underwater railway tunnel structure, a series of fire tests were conducted. The tests were conducted in a 1:9 scale model. The model tunnel has a circular cross-section with an inner diameter of 1.1 m and 52.5 m in length. Twenty-one different...
The killing of Microcystis aeruginosa by strong ionization discharge was studied experimentally. The relation of aeration amount, initial content of bacterium, treatment time, PH value and temperature to the killing rate of Microcystis aeruginosa was studied. The experiment has show that in a certain degree, the killing rate of Microcystis aeruginosa was raised with the increasing of aeration amount,...
A low-power complementary metal oxide semiconductor (CMOS) bandgap current reference is proposed under the 1.8V supply voltage. The temperature compensation current generator was used in order to obtain an accurate 5μA current with lower temperature coefficient. Sub-threshold technology and advanced startup circuit were adopted to decrease the circuit power consumption. The current reference has been...
Since the design of integral abutment bridge are basically depended on experience. In this paper, the three dimensional FEM model of integral abutment bridge is built . The effect on the loaded property of integral abutment bridge with different stiffness of main beam, abutment and pier are analyzed under temperature load and differential settlement. Some reference conclusion offer a theoretical basis...
As an example of semi-arid region in western part of Jilin Province, the hydro-chemical data of 48 shallow wells for more than 20 years were collected to study. The results showed that TDS increased continually which illustrated deterioration of groundwater quality. With the aim to protect groundwater resources, the influence factors of groundwater quality changes are the key points to be studied...
When the water environment around is relatively stable, carbon dioxide and temperature become the two major factors affecting the strength of oilwell cement. In order to understand the affecting extents, the compressive strength of corroded cement samples were examined under different corrosion conditions by carbon dioxide and temperature. The corrosion mechanism of oilwell cement by carbon dioxide...
Abstract-Sanitary landfill leachate disposal is one of the most necessary tasks in refuse landfill management. The most widely applied biological technology is usual the secondary stage in a combined process with additional physical-chemical pretreatment process. A novel coagulant, Poly-ferric(III)-magnesium(II)-sulfate (PFMS) was introduced to pre-treat landfill leachate and the effects of coagulation...
To master the heat transfer rule of phase change material(PCM) wall, two kinds of hollow boxes was made with different material, one was made of pure EPS granule, the other one was made of EPS and PCM, temperature of cavum was measured during thermal translation process experiment. The hollow boxes was separated into 4 nodes finite element, the experiment time was divided into finite time point, the...
In order to study the effect of chlorine (Cl2) inactivating Giardia in water, different factors as Cl2 concentration, contact time, pH, temperature, turbidity and organic content which might influence the inactivation were studied by using fluorescence staining method. With the Giardia was 1×106 cysts/mL, turbidity 1.0NTU, temperature 22°C, pH 7.0, and after 240 min reaction, under the condition that...
Thermophysical parameters of cohesive soil are important properties in the design of the ground source heat pump system and the ventilation system of subway. In this paper, the more precise measurements are taken to study the thermophysical parameters of cohesive soil based on the transient heat flow probe method by KD2 pro. The results show that the thermal conductivity and capacity increase obviously...
Consider heat conduction, convection, heat source, pipe cooler in the process of cement hydration; consider the elastic modulus of concrete, creep and shrinkage; study properties of concrete under the action of the water-reducing and set-retarding admixture and the expansive agent. Midas/Civil, one finite element analysis soft-ware, analyses mass concrete construction of the whole process of the temperature...
Intensive aquaculture releases large amount of nutrients into aquatic ecosystems and can lead to eutrophication of coastal waters. The effect of salinity and temperature on absorption of ammonium by S. muticum were discussed in this paper. This study was conducted in laboratory to evaluate whether S. muticum could be cultivated efficiently for removing the ammonium from water. The results showed that,...
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