Computational fluid dynamics simulation of formaldehyde emission characteristics and its experimental validation in environment chamber

We investigated the effect of supply air rate and temperature on formaldehyde emission characteristics in an environment chamber.A three-dimensional computational fluid dynamics(CFD) chamber model for simulating formaldehyde emission in twelve different cases was developed for obtaining formaldehyde concentration by the area-weighted average method.Laboratory experiments were conducted in an environment chamber to validate the simulation results of twelve different cases and the formaldehyde concentration was measured by continuous sampling.The results show that there was good agreement between the model prediction and the experimental values within 4.3 difference for each case.The CFD simulation results varied in the range from 0.21 mg/m3 to 0.94 mg/m3,and the measuring results in the range from 0.17 mg/m3 to 0.87 mg/m3.The variation trend of formaldehyde concentration with supply air rate and temperature variation for CFD simulation and experiment measuring was consistent.With the existence of steady formaldehyde emission sources,formaldehyde concentration generally increased with the increase of temperature,and it decreased with the increase of air supply rate.We also provided some reasonable suggestions to reduce formaldehyde concentration and to improve indoor air quality for newly decorated rooms.

Micro-vibration response analysis and its application of electronic workshop raw land based on whale optimization algorithm

Environmental micro-vibration is one of the key factors impacting the running of electronic workshop.Low frequency micro-vibration has a significant influence on the normal operation of high precision machining and testing equipment,and even causes irreversible damage to the equipment.Micro-vibration testing and response analysis are important to guide the vibration isolation design and ensure the stable operation of various precision equipment in the workshop.Parameters of Davidenkov model are fitted based on whale swarm optimization algorithm,and its applicability is verified.At the same time,taking the testing project of an electronic workshop raw land as an example,the micro-vibration response is analyzed.The results show that the nonlinear constitutive model constructed by whale optimization algorithm can simulate the dynamic nonlinear behavior of soil under the action of micro-vibration better.Compared with the traditional equivalent linearization method,the nonlinear constitutive model based on the whale optimization algorithm has a smaller acceleration response value.It can effectively suppress the“virtual resonance effect”produced by the equivalent linearization method.

清光绪《营造算例》抄本校勘

以近期发现的清光绪时期匠师抄本为核心,通过与内务府销算房《大木做法》、《营造算例》等材料的综合校勘,全面比较分析了各本所载大木作、装修作、石作、瓦作、土作、搭材作的内容异同与技术特征。通过分析可知,该抄本在主要内容上与《大木做法》、《营造算例》可以相互补正,同时亦有部分内容属诸本所未载,对清代晚期官式营造技艺研究具有重要的参考价值。

Effects of using a computer-lab on oral English fluency amongst all Chinese students at WOU

The purpose of this study is to assess the effectiveness of using a computer-lab on oral English fluency amongst all Chinese students at Western Oregon University （WOU）. The participants are oversea Chinese graduate students who take undergraduate courses at WOU, and some of them regard English as their Second Language. The study adopts the experimental design, There are total of 60 Chinese students participating in the study. The results indicate that the use of a Computer-Lab significantly improved students＇ English oral expression ability.

Work Boilers in the Real Heat Loads

Analysis was performed on the boiler for solid fuels in a corresponding real-thermal load. The tests were conducted with the use of a low-temperature top-loading KWSM water boiler. For control of the burning process, three control algorithms were used as implemented in microprocessor temperature controls. The analysis aimed at determination of influence of the control algorithm upon quality of the buming process in conditions of actual demand for thermal energy. The detailed analysis of operating parameters in relation to the variable thermal load of the boiler provided necessary information and made it possible to state that control algorithms do influence quality of the controlled process. Particular attention was paid to a situation, in which demand for thermal energy is decreased.

The Impact of Occupant Behavior on Daylight Performance of an Office Room in a Tropical Climate

This work explores three patterns of occupants’ control of window blinds and the potential influence on daylight performance of an office room in a tropical climate. In this climate, windows are frequently obstructed by curtains to avoid glare, despite the daylighting and the exterior view. The consequences are obstructed outside view, poor daylight quality and dependency on artificial lighting. This paper assesses the impact on available daylight using parametric analysis based on daylighting dynamic computer simulations using Grasshopper and Daysim software, combining WWR （window-to-wall ratio） （40% and 80%）, SVF （sky view factor） （small and large） and occupant behavior （active, intermediate and passive users）. The user patterns are based in an office buildings survey that identifies preferences concerning daylight use and control of shading devices. The daylight performance criteria combine UDI （useful daylight illuminance） （500-5,000 lux） and illuminance uniformity distribution. Results confirm the impact of occupant behavior on daylighting performance. The optimum combination of external shading devices, high SVF and high window size results in a useful daylighting for 1/3 of the time for passive users and 2/3 for active users.

Guidelines for Low-Cost, Energy-Efficient House in Iraq

The goal of this study is to determine specific guidelines for Iraqi architects to contribute to the design and composition of energy-efficient housing units within the limits of a normal budget, locally available materials and technologies. These units can provide comfort despite the current energy situation in Iraq. The study is based on a computer simulation for a reference building in Baghdad, which has been selected according to the urban conditions, building legislations, housing market and statistics. The final results displayed the main recommendations and the possibility to achieve up to 50% energy reduction with a pay-back period not exceeding two years in some cases. There are some measures that have big energy saving potential. Yet, some of the measures may require big investment or have some bad environmental impacts. Some other good measures are already being implemented.

Energy-saving performance investigation on sustainable architecture design of open-plan housing in temperate region

With the increasing requirement of a higher living quality and the growing awareness of energy saving, how to improve the indoor comfort level and to reduce the expenditure of energy and slow down the rate of natural resource consumption is becoming increasingly important. The theory of open-plan housing is able to provide a more flexible and adaptive space for the users and bring sustainable and economic benefit in the way of making full use of construction materials. Sustainable architecture design, as a method to respond the phenomenon, is able to low down the building＇ s energy consumption and has enormous potentials in creation of sustainable living environment and a high-quality dwelling condition. The primary aim of this research is to create a new sustainable architecture design method for occupancy by integrating openplan housing theory and application of sustainable technologies. Numerical simulation by computer program is applied in order to investigate and evaluate the possibility of this method in teruas of improving indoor comfort level and energy-saving capacity.

Right atrial angiosarcoma and electrocardiogram-gated cardiac computed tomography:a case report

Primary cardiac tumors are quite rare and most of these tumors are benign.In this report,a patient presented with chest distress and shortness of breath after activity.Echocardiography of other hospital showed a hyperechoic right atrial mass.Electrocardiogram-gated cardiac computed tomography(ECG-Gated CT) of our hospital provided accurate information about the site and extent of the tumor,and the involvement of neighboring structures,even about the malignant nature of the lesion.The pathological study indicated angiosarcoma.The role of ECG-Gated CT in the assessment of cardiac masses and tumors was discussed.Cardiac tumors are extremely rare and can be divided into benign and malignant lesions.Myxomas are the most common type of cardiac benign tumor,while angiosarcomas are the most common type of cardiac malignant tumor.Imaging studies play an important role in the diagnosis of cardiac angiosarcomas.Echocardiogram,computed tomography(CT) and magnetic resonance imaging(MRI) are the most common imaging studies for tumors evaluation.However,the precise tumor location is often difficult to evaluate precisely on the basis of two-dimensional source images.We conducted ECG-gated cardiac CT examination with 3D reconstruction for preoperative assessment in a patient with a angiosarcoma arising in the right atrium.

Biomedical X-ray Imaging Enabled by Carbon Nanotube X-ray Sources

Although discovered more than 100 years ago, X-ray source technology has evolved rather slowly. The recent invention of the carbon nanotube （CNT） X-ray source technology holds great promise to revolutionize the field of biomedical X-ray imaging. CNT X-ray sources have been successfully adapted to several biomedical imaging applications including dynamic rnicro-CT of small animals and stationary breast tomosynthesis of breast cancers. Yet their more irnportant biomedical imaging applications still lie ahead in the future, with the devel- oprnent of stationary rnulti-source CT as a noteworthy exarnple.

樣式雷圖檔中衙署著者考辨

凡是樣式房繪、製的圖文檔案,以及混雜在其間的相關衙署、工程部門製作的圖文檔案統稱為樣式雷圖檔。這樣的話,樣式雷圖檔的作者也就更為寬泛,不僅是雷家,還有可能是高家,還有可能是木廠,也有可能是造辦處、宗人府、檔房等這些衙署機關。儘管所存衙署機關繪製的圖檔數量較少,本文擬通過對這些少量圖檔內容進行分析,從而找出皇家建築工程從選址至施工的全過程中,這些衙署機關的功能、作用及其相互之間、與樣式雷家族之間的關係。

Classification of breast lesions based on a dual S-shaped logistic model in dynamic contrast enhanced magnetic resonance imaging

This study proposes a novel dual S-shaped logistic model for automatically quantifying the characteristic kinetic curves of breast lesions and for distinguishing malignant from benign breast tumors on dynamic contrast enhanced (DCE) magnetic resonance (MR) images.D(,) is the diagnostic parameter derived from the logistic model.Significant differences were found in D(,) between the malignant benign groups.Fisher's Linear Discriminant analysis correctly classified more than 90% of the benign and malignant kinetic breast data using the derived diagnostic parameter (D(,)).Receiver operating characteristic curve analysis of the derived diagnostic parameter (D(,)) indicated high sensitivity and specificity to differentiate malignancy from benignancy.The dual S-shaped logistic model was effectively used to fit the kinetic curves of breast lesions in DCE-MR.Separation between benign and malignant breast lesions was achieved with sufficient accuracy by using the derived diagnostic parameter D(,) as the lesion's feature.The proposed method therefore has the potential for computer-aided diagnosis in breast tumors.

Calculation of fire extinguishment time with water mist in an enclosed room

The fire extinguishment time is a major factor to evaluate the efficiency of fire extinguishment with water mist. In this paper the fire extinguishment time with water mist in an enclosed room is calculated. Before adding water mist, the chemical kinetics plays the role in combustion, where a dimensionless math model is established by us-ing the Semenov theory. After adding water mist, the diffusion plays the role instead. Then another math model containing water mist and dominated by oxygen concentration is established. The fire temperature is integrated from Tm to extinguishment temperature TB and the extinguishment time can be obtained. The calculated values are compared with the experimental data under different conditions. The results show that this model can predict the fire extinguishment time accurately. Besides, this model also can be used to determine the critical water mist flux and evaluate which fire extinguishment mechanisms dominate the extinguishment.

Bio-inspired computational heuristics to study models of HIV infection of CD4＋ T-cell

In this work, biologically-inspired computing framework is developed for HIV infection of CD4＋ T-cell model using feed-forward artificial neural networks （ANNs）, genetic algorithms （GAs）, sequential quadratic programming （SQP） and hybrid approach based on GA-SQP. The mathematical model for HIV infection of CD4＋ T-cells is represented with the help of initial value problems （IVPs） based on the system of ordinary differential equations （ODEs）. The ANN model for the system is constructed by exploiting its strength of universal approximation. An objective function is developed for the system through unsupervised error using ANNs in the mean square sense. Training with weights of ANNs is carried out with GAs for effective global search supported with SQP for efficient local search. The proposed scheme is evaluated on a number of scenarios for the HIV infection model by taking the different levels for infected cells, natural substitution rates of uninfected cells, and virus particles. Comparisons of the approximate solutions are made with results of Adams numerical solver to establish the correctness of the proposed scheme. Accuracy and convergence of the approach are validated through the results of statistical analysis based on the sufficient large number of independent runs.

A Robot Cooked My Goose!

It’s lunch hour on a weekday and a small restaurant in central Beijing is packed to the gil s.Harried-looking waiters run from table to table to cope with the stream of orders,and the manager’s fingers fly like lightning over the calculator as she tallies up bills.In sharp contrast to the hectic activity,the little kitchen,visible through the long narrow glass window that partitions it from the dining hal,is a calm oasis.A lean but efficient army composed of three cooks is dishing out the orders,working in perfect coordination and harmony.

The Social Welfare Housing Project and Its Effects in China

It was planned to build 36 million units of social welfare housing during the twelve-five2011-2015 in China.This paper introduces the estimation of owner occupied dwelling sector and develops a dynamic computable general equilibrium model for China's real estate and macro-economy,to simulate the policy effects.The simulation results show that this policy can meet the increased requirements of housing demand due to fast urbanization and improvement of living conditions,therefore it will effectively cool down the price boom of housing market.Meanwhile,although the investment on social welfare housing will reduce the investment on other sectors,it will still stimulate GDP growth.

Analysis of a System Describing Proliferative-Quiescent Cell Dynamics

Systems describing the dynamics of proliferative and quiescent cells are commonly used as computational models, for instance for tumor growth and hematopoiesis.Focusing on the very earliest stages of hematopoiesis, stem cells and early progenitors, the authors introduce a new method, based on an energy/Lyapunov functional to analyze the long time behavior of solutions. Compared to existing works, the method in this paper has the advantage that it can be extended to more complex situations. The authors treat a system with space variable and diffusion, and then adapt the energy functional to models with three equations.