Understanding the factors that influence household use of clean energy in the Similipal Tiger Reserve,India

Biotic pressure in and around protected areas (PA) is the primary cause of biodiversity loss in many developing countries across the globe. The pressure comes partly from biomass energy dependency in the form of heavy extraction of fuelwood from the forests. Although biomass fuels provide easily accessible and affordable sources of domestic energy to the rural masses, their combustion results in environmental and health‐related hazards. The objectives of this paper are to assess the patterns of household energy use in a subsistence forest economy and analyze the factors that influence their energy use choice for cooking and lighting. The paper uses primary data collected randomly from 244 households located in and around the Similipal Tiger Reserve (STR), situated in the eastern Indian state of Odisha. Age of the household head, number of days in wage employment, number of adult males and females in a household, education of the household head and landholding size are found to be the major variables that determine household fuelwood collection sources inside the reserve. Considering household structure as an income indicator, the analysis clearly shows that non‐poor households prefer to use clean energy (i.e. solar) for lighting, while poor households tend to use solid fuel. Energy policies for development should be based on the realistic proposition that fuelwood will remain the major source of energy for cooking for substantial proportions of the world’s population. Promotion of public education, social forestry schemes and fuel‐efficient improved chulhas should be encouraged in order to reduce household dependence on fuelwood. Moreover, devolving sufficient property rights over forest resources to local communities may help secure their broad‐based and active participation in the decision‐making process, which may result in a positive change in the attitude of the local people towards biodiversity conservation.     

Will Musculoskeletal,Visual and Psychosocial Stress Change for Visual Display Unit (VDU) Operators When Moving From a Single-Occupancy Office to an Office Landscape?

This study investigated the effect of moving from single-occupancy offices to a landscape environment. Thirty-two visual display unit (VDU) operators reported no significant change in visual discomfort. Lighting conditions and glare reported subjectively showed no significant correlation with visual discomfort. Experience of pain was found to reduce subjectively rated work capacity during VDU tasks. The correlation between visual discomfort and reduced work capacity for single-occupancy offices was r_s = .88 (p = .000) and for office landscape r_s = .82 (p = .000). Eye blink rate during habitual VDU work was recorded for 12 operators randomly selected from the 32 participants in the office landscape. A marked drop in eye blink rate during VDU work was found compared to eye blink rate during easy conversation. There were no significant changes in pain intensity in the neck, shoulder, forearm, wrist/hand, back or headache (.24 < p < .67). Pain levels in different body areas were significantly correlated with reduced work capacity, .77 < r_s < .99 (p = .000).     

1995—2020年青海省雷电灾害时空分布及其灾害特征分析

利用1995—2020年青海省雷电灾害资料,研究该区域雷电灾害时空分布特征。结果表明：1995—2006年青海省雷电灾害呈增加趋势;2007—2015年青海省雷电灾害呈下降趋势;2016—2020年青海省雷电灾害呈平稳略有上升趋势。青海省雷电灾害空间分布呈,东多西少、南多北少分布特征,其中,雷灾密集区位于西宁市辖区、大通县、河南县、湟中县和互助县区域。1995—2020年,雷电灾害造成青海省人员伤亡282人,平均11人/a,同时对办公设备,广电、电力系统、通讯系统和住宅等方面也造成了损失,其经济损失达1 247.12万元,平均47.97万元/a。     

特种车辆雷电效应仿真分析

雷电是一种极具破坏性的自然现象,产生的电磁干扰会对电气设备造成影响,采取仿真分析的手段可提前发现车辆雷电防护设计的薄弱环节。针对某特种车辆热待机工况下,雷电击中附近避雷针时,对车辆所处的电磁环境特点进行了仿真分析,为特种车防雷设计和雷电验证试验提供支撑和参考。     

对电子设备的雷电浪涌防护

雷电浪涌是近年来由于微电子设备的不断应用而引起人们极大重视的一种雷电危害形式。分析了雷电浪涌的特性,根据雷电浪涌的入侵途径建立了3种典型的耦合模型,详细分析了雷电浪涌对于电子设备的危害,并据此提出了防护雷电浪涌的原则与措施,重点讨论了对雷电浪涌的综合防护方法。     

塔机起重作业夜间照明工效的BIM辅助优化研究

为提升塔式起重机施工作业的夜间照明工效水平,采用数学模型和BIM技术相结合的方法,以灯源的光通量及入射角为光学驱动参数,模拟眩光值、照度及其均匀度等光学变量,建立照明工效的光度学BIM辅助优化模型,优化起重作业照明灯源光学参数。研究结果表明：对塔式起重机施工作业区照明灯源光学参数进行组合优化后,夜间起重作业面照度及其均匀度显著提升,眩光值满足起重作业视觉环境条件。研究结果可为塔式起重机夜间起重作业照明方案设计提供科学依据。     

扬水造流技术控藻机制研究

围绕扬水造流技术的两个关键控藻参数Vmix(水体垂直混合速率)和Emix:Eu(混合深度与真光层深度之比),分别在实验室和现场围隔中开展模拟实验探讨藻类的时空分布.结果表明,实验开始20h后藻类垂直分布趋向动态平衡,Vmix31.08cm/min时2h内藻类未出现浮聚现象,Vmix31.35cm/min则能够长期(320h)遏制表面水华;根据20h平衡分布变异系数对光照和混合组合条件下的控藻效果进行了分类.藻类生消实验显示衰亡速率常数K与Emix:Eu呈正相关(R2=0.85,P<0.05,n=5),表明增大Emix:Eu在一定程度上有利于促进藻类衰亡.现场围隔实验结果表明,Emix:Eu对藻类生长消亡的显著影响,并认为在自然条件下,扬水造流技术要发挥控藻效用,Emix:Eu必须33:1.     

Subjective assessments of floor slipperiness before and after walk under two lighting conditions

A gait experiment was performed. The participants were tested under shoes, floors, surface and lighting conditions. They gave floor slipperiness ratings before and after a gait trial. The perceived sense of slip (PSOS) was collected. It was found that the perceived floor slipperiness (PFS) before walking was affected significantly by the lighting, floor and surface conditions. Relative low PFS values were recorded under wet and detergent-contaminated conditions in the normal daylight condition as compared with those in the dimmed condition. The PFS after the gait was significantly affected by the floor and surface conditions. The PSOS was highly correlated with the PFS after trial. The regression analyses results indicated that both the coefficient of friction (COF) of the floor and lighting were primary predictors of the PFS before a gait. The COF and walking speed were the primary predictors of the PFS after a gait.     

Safety effects of street lighting on roadway segments: Development of a crash modification function

Objective: Nighttime crashes are overrepresented on the U.S. highway system. Roadway lighting, which provides additional visibility by supplementing vehicle headlights, has been identified as an effective countermeasure to improve nighttime safety. However, the existing literature does not provide a thorough understanding of the effects of street lighting photometric characteristics on nighttime crash occurrence on roadway segments. This study aimed to investigate the relationship between lighting photometric measures and nighttime crash risk on roadway segments and develop a crash modification function/factor (CMF).

Methods: The research team collected horizontal illuminance data on 440 roadway segments between 2 successive signalized intersections in Florida for 2012–2014 and matched 4 years of nighttime and daylight crash data (2011–2014). Random parameter negative binomial models were estimated for both nighttime and daylight crash frequencies. The expected night-to-day crash odds ratio, as an equivalent of CMF, was derived from the fitted models with the correction of estimation variances. The confidence intervals (CIs) of the developed CMF were estimated using the Cox method.

Results: The coefficient of the mean of horizontal illuminance is significantly negative in the nighttime model. The coefficients of the standard deviation of horizontal illuminance are significantly positive and normally distributed in both the nighttime and daylight models. The significance of the standard deviation in the daylight model captures the confounding effects—a high standard deviation correlates with high traffic exposures, poor safety design standards, and low maintenance quality. The CMF based on the expected daylight-to-day odds ratio was developed as an exponential function of the increments and the increment squares of the mean and the standard deviation of horizontal illuminance. Its 95% CIs indicate that the CMF is almost significant over the whole range. Other significant variables contributing to nighttime crash risk include annual average daily traffic, truck percentage, segment length, access density, undivided roads, and urban/city limits.

Conclusions: Horizontal illuminance characteristics have a significant impact on nighttime crash risk on roadway segments. An increase in the mean of horizontal illuminance, indicating an improvement in average lighting level, tends to decrease nighttime crash risk; an increase in the standard deviation, representing a poor uniformity of lighting pattern on a roadway segment, is more likely to raise nighttime crash risk. Because the 2 measures are strongly correlated in a low mean range (<0.44 fc), the 2 photometric measures need to be considered together to interpret the safety effects of lighting patterns. The standard deviation shows better performance in measuring lighting uniformity on a roadway segment than the traditional ratios (max-to-min and mean-to-min). However, a new photometric measure is needed to capture the true lighting pattern influencing driver vision at night.     

Limiting the impact of light pollution on human health, environment and stellar visibility

Light pollution is one of the most rapidly increasing types of environmental degradation. Its levels have been growing exponentially over the natural nocturnal lighting levels provided by starlight and moonlight. To limit this pollution several effective practices have been defined: the use of shielding on lighting fixture to prevent direct upward light, particularly at low angles above the horizon; no over lighting, i.e. avoid using higher lighting levels than strictly needed for the task, constraining illumination to the area where it is needed and the time it will be used. Nevertheless, even after the best control of the light distribution is reached and when the proper quantity of light is used, some upward light emission remains, due to reflections from the lit surfaces and atmospheric scatter. The environmental impact of this "residual light pollution", cannot be neglected and should be limited too. Here we propose a new way to limit the effects of this residual light pollution on wildlife, human health and stellar visibility. We performed analysis of the spectra of common types of lamps for external use, including the new LEDs. We evaluated their emissions relative to the spectral response functions of human eye photoreceptors, in the photopic, scotopic and the 'meltopic' melatonin suppressing bands. We found that the amount of pollution is strongly dependent on the spectral characteristics of the lamps, with the more environmentally friendly lamps being low pressure sodium, followed by high pressure sodium. Most polluting are the lamps with a strong blue emission, like Metal Halide and white LEDs. Migration from the now widely used sodium lamps to white lamps (MH and LEDs) would produce an increase of pollution in the scotopic and melatonin suppression bands of more than five times the present levels, supposing the same photopic installed flux. This increase will exacerbate known and possible unknown effects of light pollution on human health, environment and on visual perception of the Universe by humans. We present quantitative criteria to evaluate the lamps based on their spectral emissions and we suggest regulatory limits for future lighting.