Usability of non-standard lower anchor configurations for child restraint system (CRS) installation

Abstract

Objectives: The objective of this study was to determine whether the amount of tension required for proper child restraint system (CRS) installation varies with lower anchor spacing and to determine whether nonexperts can produce adequate tension on wider-than-standard lower anchor configurations.

Methods: CRSs were installed by certified child passenger safety technicians (CPSTs; n?=?6 subjects, n?=?72 installations) and nonexperts (n?=?30 subjects, n?=?120 installations) on a mock-up vehicle seat fixture with lower anchors set at 11 (standard), 15, 19, and 23 in. apart from one another. Each CPST installed a rear-facing (RF) infant base, RF convertible, and forward-facing (FF) convertible into each of the 4 spacing configurations in random order. The CPSTs were instructed to tighten the lower connector strap until the tension was exactly at the threshold between passing and failing the 1-in. test. Each nonexpert installed one CRS model into all 4 spacing conditions in random order. Nonexperts were instructed to install the CRS to the best of their ability. The tension produced on the lower connector strap was recorded via load cell in the lower anchor assembly of the vehicle seat. Resultant tension magnitudes were compared across spacing conditions using matched pair t-tests. The CPSTs’ mean 1-in. test threshold values were compared to tensions produced by nonexperts. Installations were visually evaluated for errors and qualitative usability feedback was collected via survey.

Results: CPSTs installed the infant base with higher tensions in the 15-, 19-, and 23-in. configurations compared to the standard 11-in. configuration (P = .034, .032, and .003, respectively). The nonexperts installed the infant base with higher tension in the 15- and 23-in. configurations compared to the 11-in. configuration (P = .004 and .026, respectively). The RF convertible and FF convertible installations showed no significant differences in tension among any of the spacing configurations for either group. Only 19% of the nonexperts’ installations were tight enough to pass CPST thresholds, and the pass rate did not vary with respect to lower anchor spacing. In feedback surveys, the nonexpert group did not show a consistent preference for either standard or wider-than-standard lower anchor configurations.

Conclusions: The amount of tension required to pass the 1-in. rule did not vary with lower anchor spacing configurations for the RF and FF convertible CRS, but the infant base required more tension in wider anchor configurations. Nonexperts tended to produce less than ideal tension in all configurations, although their tension magnitudes increased for the infant base in wider configurations.     

H∞ loop-shaping controller design for a grid-connected single-phase photovoltaic system

This paper presents a H_∞ loop-shaping controller for controlling dc-link voltage by regulating the switching signal of the inverter associated with a grid-connected single-phase photovoltaic system. To facilitate a robust control design, state-space realisation of the system model is made with uncertainties represented by linear fractional transformation. The controller is achieved through H_∞ synthesis followed by obtaining desired loop shapes through the choice of the proper weighting functions. The controller order is reduced by Henkel-norm method for facilitating its practical implementation. Controller performance is evaluated through carrying out simulations on MATLAB/Simulink platform under standard and changing atmospheric conditions, and fault condition.     

Development of a fuel cell propulsion system for the existing Mercedes B-Class 160 of petrol driven car

This paper presents a theoretical comparison between fuel cell (FC) power train and conventional petrol driven propulsion system. FC has potential to reduce the CO₂-emissions from road. However, FC power trains require energy storing device, to meet the peak power during extreme drive situations and also able to recover the kinetic energy of the vehicle during break operation. The proposed system includes a polymer electrolyte membrane fuel cell (PEMFC) based drive train and a super capacitor connected in parallel. The system is designed and dimensioned for a conventional petrol driven propulsion system of the Mercedes B-Class160. The feasibility study also includes comparison between the existing conventional systems. It is shown that although FC power train is heavier compared to existing system, urban performance is better and produces no CO₂ and other harmful emissions.     

公众生态文明素养及其科普教育研究

本文对国家文明城市芜湖市进行实地问卷调查发现:公众具有一定生态意识,但生态文明素养整体状况不佳。公众对生态文明概念比较了解和很了解的只占17.7%;各类人群对周围环境关注度较高,均在65%左右;有相关生态知识或行为的公众占92%;有76.7%的人表示没有破坏环境的行为;64.8%的受访者表示他们有保护环境的行为。通过生态科普教育现状调查发现:受访者对目前生态科普教育满意度只有25.9%,政府在生态科普教育方面还存在活动流于形式、创新性不强、投入不足、制度不完善、不能及时回应公众关切热点、专项科普匮乏、媒体不给力、内容不接地气、无区域特色、平台手段落后等问题。提出了提升公众生态文明素养需构建四个相互联动的科普教育体系:高度重视生态科普教育的思想体系、支撑生态科普教育的技术能力体系、生态科普教育的长效机制体系和具有区域特色生态科普教育内容体系。     

生态文明制度体系研究——以江苏省为例

生态文明制度体系是由制度构成的一个相互配合、有机联系的整体。本文基于文献统计分析与实地调研咨询,从广义和狭义层面,分别对生态文明制度进行梳理。根据国家生态文明建设需求与省级层面实际情况,本文将广义的生态文明制度体系分为源头保护制度体系、损害赔偿与激励体系、追责考评制度体系和污染治理制度体系四大板块,并针对国家与省级重点生态文明制度,构建生态资源保护制度链与污染防治制度链。同时,对制度地位、制度衔接、相互关系及其优化选择进行分析,以提高环境管理效能,推进生态文明研究纵深发展。     

于GRI体系的机场企业环境信息披露研究

机场作为民航运输的关键节点和重要枢纽,肩负着服务区域经济的重要使命,同时也面临环境保护与可持续发展的巨大挑战。作为公共基础设施和城市形象窗口,机场上市公司具有披露环境信息的义务与责任。在充分研究国内机场上市公司环境信息披露制度背景的基础上,本研究借鉴全球报告倡议组织（GRI）发布的《可持续发展报告指南》（第四版）及机场运营者行业补充（GRI-AOSS）构建了适用于我国机场的环境信息披露评价指标体系,并利用公开数据对国内6家机场上市公司的环境信息披露情况进行了实际测评。结果表明：我国机场环境信息披露程度较低,存在内容简单、量化不足、质量下降等问题。机场上市公司环境信息披露亟待在法律法规层面进行系统规范。建议借鉴GRI等相关国际标准及成功经验,制定适用于我国的科学可行的环境信息披露标准和制度体系。     

Future implications of urban intensification on residential water demand

Over recent decades Auckland, New Zealand, metropolitan area has vastly expanded as a result of rapid population growth and low-density housing developments. In order to manage the uncontrolled low-density urban sprawl, Auckland Council proposed a compact city model through promoting higher density housing developments. In order to understand the implications of this transition on future residential water demand, this study first evaluated water consumption in three major housing types in Auckland including single houses, low-rise and high-rise apartments. Using the geographic information system, the water consumption information, estimated from a large sample of 60,000 dwellings across Auckland, was subsequently integrated with the Proposed Auckland Unitary Plan outlining the future housing composition over different areas in Auckland. Through developing different growth scenarios, the study showed that the housing transition from single houses to more intensified multi-unit houses cannot considerably affect the average per capita water consumption in Auckland.     

1961~2015年西南地区降水及洪涝指数空间分布特征

利用西南地区98个气象站连续完整的日降水序列数据,整合降水强度、持续性指数及等级指数形成降水指数体系并研究该区域降水及洪涝指数的空间分布特征,得到以下主要结论：（1） 1961~2015年,西南地区年降水量（PRCPTOT）与极端降水量（R95PTOT）都呈现出“东多西少、南多北少”的分布形态;持续降水日数（CWD）则表现为“南高北低、西高东低”的分布格局。区域多年平 均PRCPTOT、R95PTOT、CWD分别以-13.12 mm/10 a、1.34 mm/10 a、-0.29 d/10 a的速率变化。（2）西南地区不同等级降水日数具有相似的空间分布特征,均呈现出“南高北低、东高西低”的分布形态。（3）西南地区洪涝强度指数呈由东北向西南递减的分布特征;降水总量越多的地区,洪涝强度反而越低,主要由于单站洪涝强度表征的是降水的波动情况,降水量越多波动越不明显。21世纪以来,该 地区洪涝等级以重级为主,2010年以来连续多年出现特重级洪涝。此外,洪涝强度越大,区域性年度灾害等级越高。该研究对于掌握西南地区极端气候变化规律,从而服务于防灾减灾具有一定的理论意义。     

Quantity and biochemical composition of sedimentary organic matter around offshore gas extraction platforms of the Adriatic Sea

Gas platforms can exert relevant effects on various ecosystem properties of the hosting area, modifying patterns of productivity and particle sedimentation. We hypothesised that the presence of gas platforms is associated with higher organic matter (OM) contents and we tested the null hypothesis by which benthic trophic conditions do not vary significantly among gas structures with different architectural characteristics. To test these hypotheses, we investigated sedimentary OM contents and biochemical composition at increasing distance from two distinct structures: one subsea well-site and one four-leg platform (FLP). We found that sediments surrounding the structures were characterised by similar OM contents, but different biochemical compositions, and that sedimentary OM compositional change with increasing distance from the structure is confirmed only at the FLP. These results suggest that: (i) benthic eutrophication is not consistent among different structures; (ii) OM biochemical composition changes are more evident than those in OM quantity; and (iii) the effect, wherever present, disappears at a very narrow distance from the platform. As biochemical composition of OM reflects food availability for benthic organisms, our results suggest that the enrichment of macrozoobenthic communities around these structures could be the consequence of increased nutritional quality of resources.     

Accounting for monogastric livestock as a driver in global land use and cover change assessments

Land systems are described based on various characteristics, including land cover composition and agricultural production. However, it is uncertain to what extent livestock, particularly monogastric livestock, determines land systems. We included monogastrics in a land system classification, and statistically analyzed the land cover composition and agricultural production of otherwise similar land systems with and without monogastric livestock. The results indicate that land systems with monogastrics are statistically different from their counterparts in the classification without monogastrics in terms of grassland area and crop yields, but are less different in terms of tree area, crop area, and ruminant livestock production. We then used a land systems map that includes monogastrics in the classification and a similar map that does not include monogastrics to project future changes in a novel manner that integrates livestock as a determinant of land systems. The results show that including monogastrics in otherwise similar projections yields less cropland intensification and more cropland expansion in several world regions, including Northern Africa and the Middle East. Other regions, such as Europe and Australia, were characterized by less decrease or more increase in tree area in the application with monogastrics, mainly due to the occurrence of open forests with monogastrics. This study prompts a call for improved characterization of land systems for land use and cover change (LUCC) assessments in order to better represent LUCC driven by monogastric livestock.