The Danish Twin Apartment Study – Part II: Mathematical modeling of the relative strength of sources of indoor air pollution

Abstract This study deals with the modeling of air pollution in apartments from laboratory measurements of source strengths, using formaldehyde and Total Volatile Organic Compounds (TVOCs) as model pollutants. The sources in two test apartments were grouped into two: building-related sources and occupant-related sources. The measured source strengths and ventilation rates were used for the prediction of concentrations expected in the apartments. These predictions were compared to measurements in the apartment over 12 months. The conclusions were that the model predictions based on emission rates measured in the laboratory can be used to predict the long-term concentration of the two model pollutants in the apartments. Considering the measured differences in ventilation between the apartments, an occupant emission rate of between 0.2 and 0.3 mg/h/kg body weight could be estimated. Based on previous suggested limits of acceptable exposures of humans to VOCs, an acceptable average emission rate of VOCs from building materials in general was estimated to be about 30 (μ/m²/h. The modeling showed that during the first 200 days, building materials dominated the emissions. After this, sources relating to the occupants dominated. On average about half of the VOC pollution originated from the building materials.     

Effect of igneous activity on hydrocarbon source rocks in Jiyang sub-basin, eastern China

A 50 m thick diabase sill was found in the Paleogene black mudstone hydrocarbon source rocks in Xia38 well. Within heating aureola of the sill, optical changes of kerogen and signatures of extractable bitumens in the mudstones were investigated. Under effects of high heating rate associated with sill intrusion, the vitrinite reflectance (Ro) has an increasing tendency with decreasing distance to the sill both below and above the sill. However, only within a zone of about 15 m to the diabase sill, the vitrinite reflectance shows significant increase. Above the sill, the Ro values increase gradually from 0.6% to 1.0%, whereas below the sill, the Ro values increase dramatically from 0.8% to 3.8%. The contrasting Ro increasing patterns are attributed to the different heat transferring conditions, the relatively open system above the sill and the relatively close system below. The more mature signatures below the sill are also demonstrated by the n-alkane distribution, carbon predominance index and odd-to-even carbon number predominance of the extracted bitumens. Below the sill, the proportion of the saturated hydrocarbons in the extracted bitumens increases from 34% to 79% towards the sill contact. The bitumens in the two highest rank samples which are closest to the sill are dominated by saturated or saturated + aromatic hydrocarbons.The %20S, %αββ and %Ts biomarker parameters of the extracted bitumens are 46%, 58% and 54%, respectively, at Ro = 1.5%. At Ro = 2.6% or 3.0%, they reach to 52%, 71%, and 71%, respectively, still under or close to their corresponding equilibrium end-points. These samples of high rank, established on the basis of optical assessment (vitrinite reflectance), have less mature biomarker signatures. The remarkable disparities between optical and biomarker parameters can be ascribed to that the aromatization of kerogen to increase Ro was more favored than the isomerization of biomarker in the rapid heating scenario.     

Coding distributive lattices with Edge Firing Games

In this note, we show that any distributive lattice is isomorphic to the set of reachable configurations of an Edge Firing Game. Together with the result of James Propp, saying that the set of reachable configurations of any Edge Firing Game is always a distributive lattice, this shows that the two concepts are equivalent.     

堆底熔穿事故的场外后果及其对策

在压水堆核电站应急计划和应急响应中，堆底熔穿事故占有重要位置。本文用法国核电厂事故源项Ｓ３（对应于堆底熔穿事故）计算了在典型气象条件下的场外放射学的后果，根据一般防护决策原则和我国颁布的干预水平，提出了保护公众的应急防护措施的建议。     

微机控制多功能晶闸管逆变弧焊电源研究

本文介绍了微机控制多功能晶闸管逆变弧焊电源的主要功能硬件及软件程序设计,微机主芯片采用了单片机 MCS—51,焊机能输出四种静特性,实现一机多用。     

铸件型腔气体和铸件品质

全面分析铸件浇注成型过程中气体的气源后，指出正确认识气孔的形成，从气孔的大小，位置、分布、形态反过程分析形成气孔的气源，有针对性地采取措施解决铸件中的气孔弊病问题。     

Applying storm water management in Greek cities: learning from the European experience

This paper is based on the studies forming part of the European research project DayWater, which aims at the promotion of stormwater source control (participating countries: UK, France, Sweden, Denmark, Germany, The Netherlands and Greece). Source control techniques include all techniques (e.g. retention, infiltration, reuse) of stormwater treatment near its source, in contrast to end-of-pipe. In this paper we present: the different stormwater management issues across Europe; the specific stormwater management issues in Greece; source control techniques applied in European cities; Public policies for promoting source control techniques; Strategies of application of the aforementioned techniques and policies in Greek cities. In Greece, the question of stormwater treatment has not yet attracted a lot of attention. Wastewater management, flood prevention and fresh water scarcity issues are given priority instead. However source control stormwater management can contribute to the solution of all these problems. In many European cities source control techniques have been chosen for stormwater treatment because: a) they are less expensive than massive end-of-pipe treatment installations, b) they are more compatible with the natural water cycle, c) they reduce the overall stormwater flow and thus permit the expansion of cities without requesting reconstruction of the existing sewer networks. Different policy instruments (taxes, specific regulations and controls, information campaigns) have been applied in order to promote source control techniques. The main objective of this work is to discuss the possibility of applying similar techniques and policies in Greek cities.     

Electrical properties of (Bi3.5La0.5)Ti3O12 thin-films prepared by liquid source misted chemical deposition

The ((Bi_3.5La_0.5)Ti₃O₁₂(BLT) thin-films used in this study were fabricated on a Pt(111)/SiO₂/Si(100) substrate by a Liquid Source Misted Chemical Deposition (LSMCD) technique. X-ray diffraction patterns showed that the BLT films were crystallized and no other phases were observed when annealed above 650 ‡C. Grain size and remnant polarizations increased with increase in the annealing temperature, while leakage current densities decreased. The remnant polarizations (Pr) increased from 2.0 to 4.8 and 19.0 μC/cm2 with increase in the annealing temperature from 650 to 700 and 750 ‡C, respectively. The BLT films annealed at 700 ‡C in O₂ showed a good fatigue resistance of reduced polarization by 10% after 10⁹ switching cycles when 9 V of bipolar voltage was applied at a frequency of 40 kHz.     

网站构建中开源软件许可分析

本文对开源软件许可最著名的版权协议之一——GNUGPL的本质和规则进行了探讨,并分析了OSI开源软件发布规制及开放源代码价值体现。最后,论文介绍了GPL的发展,并分析了开源软件面临的障碍及发展经验的汲取。     

基于OpenStack的数字校园体系架构研究

当前,云计算技术的广泛应用已成为不可阻挡的趋势,随之而来的开源云计算也迅速崛起。开源云计算以其开源性、低成本等优点吸引越来越多的用户。对开源云计算OpenStack的功能和架构进行介绍,并针对高校数字校园存在的问题,从数字校园的实际需求出发,利用先进的OpenStack平台,采用分层设计的方法设计、实现一个可对云资源进行综合管理的数字校园体系架构。并重点研究该架构中的资源调度,提出了一种基于任务调度和负载均衡的方案,通过实践,验证了该调度方案能够均衡服务器的资源负载,使基于OpenStack的数字校园处于相对稳定的状态。