Performance investigation of a single-stage metal hydride heat transformer

This article presents the performance analysis of a single-stage metal hydride-based heat transformer (SS-MHHT) working with three different alloy pairs, namely LaNi_4.6Al_0.4/MmNi_4.15Fe_0.85, LaNi_4.61Mn_0.26Al_0.13/La_0.6Y_0.4Ni_4.8-Mn_0.2, and Zr_0.9Ti_0.1Cr_0.9Fe_1.1/Zr_0.9Ti_0.1Cr_0.6-Fe_1.4. The performances of the SS-MHHT are predicted by solving the conjugate heat and mass (hydrogen) transfer equations in cylindrical coordinates. The effects of various parameters such as heat output (T_H), heat input (T_M), and heat sink (T_L) temperatures on the coefficient of performance (COP_HT), specific heating power (SHP) and second law efficiency (η_E) are presented. The effects of overall heat transfer coefficient and mass ratio on the coefficient of performance (COP_HT) and specific heating power (SHP) are also presented. Numerical results are compared with the experimental data reported in the literature, and a good agreement is found between them. The maximum COP_HT of 0.436 and SHP of 54 W/kg are obtained for LaNi_4.61Mn_0.26Al_0.13/La_0.6Y_0.4Ni_4.8-Mn_0.2 pair. For a given operating temperatures of T_M = 358 K and T_L = 298 K, the maximum temperature lift of about 50 K is predicted for Zr_0.9Ti_0.1Cr_0.9Fe_1.1 /Zr_0.9Ti_0.1Cr_0.6Fe_1.4 pair.     

A comparative analysis between composite indexes of environmental performance: An analysis on the CIEP and EPI

The measurement of environmental impact through composite indexes provides information about the effects of human activities on the ecosystem. Over recent years proposals regarding the environmental composite indexes (ECI) have emerged, suggesting that they can be used to help in decisions about public policies. Due the number of these indicators, issues arise about the asymmetry of information provided, although all ECI seek to measure ecosystem quality or damage. The present paper compares the Composite Index of Environmental Performance (CIEP) (García-Sánchez et al., 2015) and the Environmental Performance Index (EPI) (Hsu et al., 2014) in order to find convergent and divergent characteristics, studying methodological aspects and empirical evidence through statistical analysis, in order to favour the decision-making by stakeholders and to improve the existing ECI in order to determine adequately the environmental impact. The results show that the indexes were developed using different methods and variables, however, they share around 20% identical variables. Despite these differences, the rate of variation in ranking countries between the indexes is 21%, on average. The EPI policy category ‘water & sanitation (effects on humans)’ has two common variables and explains part of the CIEP performance. The effect dimension of the CIEP has one more identical variable and it reduces the individual variation between rank positions.     

空中交通管制团队人误的分类及致因研究

复杂社会技术系统通常以团队方式运行,认识与预防团队人误是控制安全风险的重要途径。研究采用威胁与差错管理(TEM)的研究框架,以某空管运行自愿报告系统2004年全年数据为样本源,分析团队人误的流程与致因,统计发现团队人误占总体空管人误的31%。团队发现和指出错误后仍不能有效纠正错误的比例达到8%。根据样本统计并结合典型团队人误的案例,确认了空管团队人误的主要类型和分布情况以及团队行为促成因素(PSF)的框架及重要性排序,其中缺乏交流是团队人误的最常见PSF,报告样本量出现率达47.1%。最后,从组织文化建设、团队管理、标准操作程序、培训等方面提出了减少团队人误的建议。     

复合加筋排水褥垫软土路堤排水设计方法

复合加筋排水褥垫是针对沿海缺砂地区开发的一项可取代水平排水砂垫层、具有水平排水与加筋作用的新型专利技术。本文介绍了复合加筋排水褥垫的性能指标,给出了复合加筋排水褥垫软土路堤排水设计方法,并将复合加筋排水褥垫与水平排水砂垫层的排水性能进行了对比分析。算例结果表明,复合加筋排水褥垫能满足软土路堤排水要求,其排水性能要明显优越于水平排水砂垫层。     

腐殖质含量对填料净化污水效能的影响

掺入与腐殖垃圾级配相同的砂配置腐殖质含量分别为1.09%、0.87%、0.65%、0.44%和0.01%的5种填料，装填0.5 m厚度的试验柱，构建人工快速渗滤系统处理生活污水，并测定饱和水力渗透系数，研究腐殖质含量对填料净化污水效能的影响。结果表明，在相同的水力负荷（1 m/d）和污染负荷下，5种腐殖质填料对COD和TP的平均去除率存在明显差异，腐殖质含量为1.09%、0.87%和0.65%的3种填料对COD的去除率较腐殖质含量为0.01%的填料均高出14%以上。腐殖质含量与TP去除率呈现正相关性。腐殖质含量最高的填料（1#）其初始K值最大达3.23×10^-2 cm/s，约为腐殖质含量最低的填料（5#）的5倍，其稳定运行时间最长。     

高风险系统组织因素分类与绩效评价

在收集以组织绩效评价、人的可靠性和人误分析为目的的两类组织因素分类的基础上,结合问卷调查,并依据建立的概念上的组织因素分类框架,从组织的目标和战略、组织结构、资源、规程、管理功能、培训、交流、组织文化等方面确立组织因素分类指标,基本克服了传统的组织因素分类缺陷。同时,依据组织因素的分类,考虑到组织绩效评价的复杂性和不确定性,采用模糊决策方法对某组织的绩效进行评价,识别出该组织现存的主要缺陷:组织管理方面的问题以及组织的结构设计不太合理等问题。     

能源消费与环境污染的边限协整分析

能源的使用是导致环境恶化的主要原因之一,所以研究能源消费与不同污染物之间的关系就很有必要。本文以1985-2007年的年度数据为样本,建立了自回归分布滞后—误差修正模型,并运用边限检验对我国的能源消费与环境污染之间的关系进行了实证研究。研究结果表明:长期来看能源消费总量、煤炭占能源消费总量的比重和水电、核电、风电占能源消费总量的比重对SO2的排放有重要影响,但是对工业烟尘排放量来说只有水电、核电、风电占能源消费总量的比重的影响是显著的;短期来看煤炭占能源消费总量的比重对SO2排放的影响是显著的,能源消费总量和水电、核电、风电占能源消费总量的比重对工业烟尘的排放有显著影响。由于能源消费总量和结构对不同污染物的长期和短期影响存在较大差异,所以在治理时应区别对待。     

Piggery waste treatment by using down-flow anaerobic fixed bed reactors

A study of the role of the depth in the performance of laboratory-scale down-flow anaerobic fixed-bed reactors (DFAFBR) was carried out at different nominal hydraulic retention times (HRT _N ) using piggery waste as substrate at different influent concentrations (2, 4, 6 and 8 g COD/L). The profiles of soluble chemical oxygen demand (COD) (SCOD), organic nitrogen (O.N.), ammonia nitrogen (A.N.), pH and electrical conductivity (E.C.) through the reactor depths showed an initial highly active zone, which was located around the first half of the reactor depth, and a second zone with a lower biological activity. It was found that the depth of the active zone decreased as the HRT _N increased and that the slopes of the profiles obtained increased with the rise in the influent concentration. A hydraulic test showed an increase in the dispersion number when the HRT _N increased. The reactors showed a hydraulic pattern between plug-flow and back-mix. The real values of HRT (Θ) also defined as real contact times were determined to be 0.7, 2.1, 3.4, 4.7, 6.4 and 8 days for values of HRT _N of 1, 2, 3, 4, 5 and 6 days, respectively. It was found that the concentration of SCOD within the reactor decreased exponentially with the increase in the value of θ. Additionally, the influent concentration had a strong influence on the SCOD variation concentration, mainly at values of θ under 1.5 days, which corresponded to the first part of the reactors.     

Application of indoxacarb for managing shoot and fruit borer of eggplant (Solanum melongena L.) and its decontamination

Indoxacarb was applied at 75 and 150 g a.i. ha^{? 1} for two years to an eggplant (Solanum melongena L.) crop grown in the field plots in order to evaluate its efficacy for management of the lepidopteron pest, shoot and fruit borer. The residues of the insecticide were quantified by high-pressure liquid chromatography (HPLC). The mean initial deposits of indoxacarb on eggplant fruits were found to be 2.60–2.634 mg kg^{? 1} and 3.64–3.68 mg kg^{? 1} from the two rates of applications, respectively. They declined with time and reached to non-detectable (< 0.02 mg kg^{? 1}) after 15–20 d. Residues dissipated with a half-life of 3.0–3.8 d from both first and second-year application. A 3 d waiting period for harvest of fruits after insecticide application and processing resulted in the residue levels that were below the Codex maximum residue limit (MRL) of 0.5 mg kg^{? 1} thereby achieving a maximum safety and minimum risk to consumers. The best combination of chemicals for decontamination of indoxacarb was found to be by washing with a mixture of alkali and potassium permanganate (KMnO₄) thereby resulting in the removal of 67.5% and 59.2 % residues for 5 and 10 μ g g^{? 1} spiking doses, respectively. Major products formed on reaction of indoxacarb with alkali were identified by electron spray ionization chromatography/mass spectrometry (ESI/MS). The per cent reduction on the weight and number basis of treated eggplant plots were compared to those observed in control plots to demonstrate the effectiveness of indoxacarb treatment on shoot and fruit borer population.