Analysis of radiation hazards to personnel on marine platforms

The large number of radio frequency (RF) transmitters employed in modern marine platforms requires that they operate in mutual coexistence while posing no danger to operators and equipment despite the limited available physical space. A key to the successful system integration is the control of the electromagnetic environment on the ships’ topsides, which might pose radiation hazards (RADHAZ) to personnel (HERP). HERP are caused by transmitter antenna installations that generate intentional EM radiation in excess of the safe levels in zones of personnel activity. Radiation safety to personnel is achieved when the average radiation power density is below the permissible exposure limits (PEL) for HERP at locations of personnel activity and medical equipment operation. This paper describes the analysis tools and techniques for the evaluation of HERP on marine platforms. The same approaches could be employed in the analysis of land site antenna deployment scenarios.     

The use of incubation behavior to adjust avian reproductive costs after egg laying

Reproduction in birds requires the input of time and energy during discrete breeding phases leading to investment trade-offs between laying date, clutch size, body mass, and incubation constancy. We investigated costs during incubation by experimentally enlarging 25 clutches of white-tailed ptarmigan Lagopus leucurus. The experiment was conducted in 2 years, one with harsh weather that forced a natural delay in reproduction. When forced to delay egg-laying, females began incubation with poorer body condition and foraged more during incubation. Rates of mass loss during incubation were not affected by clutch enlargement, and did not differ between harsh and benign years; however, females that were heavier at the start of incubation lost more mass than lighter females. Clutch-enlarged females had reduced nest attendance compared to control birds in both years and incubation periods increased by up to 2 days relative to controls. In the harsh year, there was a trend for clutch-enlarged females to have lower nest success, but there was no effect on overwinter survival. Different behavioral responses by females in the 2 years showed that incubation costs may depend on other factors such as female quality, food supply, or weather conditions. Incubation is a dynamic period during which birds may adjust energy balances by varying body condition and food intake. Received: 28 March 2000 / Received in revised form: 18 August 2000 / Accepted: 2 July 2000     

灰霾天气条件下天津市环境空气中颗粒物污染特征分析

针对天津地区灰霾天气条件下环境空气中颗粒物的污染程度及变化特征进行分析。指出出现灰霾天气是污染加重的直观反映,将其发展成为一项环保指标,将对大气污染控制起到一定的积极作用。     

Assessment of Changes in Stream and Riparian Conditions of the Marys River Basin,Nevada1

Abstract: Stream and riparian managers must effectively allocate limited financial and personnel resources to monitor and manage riparian ecosystems. They need to use management strategies and monitoring methods that are compatible with their objectives and the response potential of each stream reach. Our objective is to help others set realistic management objectives by comparing results from different methods used to document riparian recovery across a diversity of stream types. The Bureau of Land Management Elko Field Office, Nevada, used stream survey, riparian proper functioning condition (PFC) assessment, repeat photographic analysis, and stream and ecological classification to study 10 streams within the Marys River watershed of northeast Nevada during all or parts of 20 years. Most riparian areas improved significantly from 1979 to 1992‐1993 and then additionally by 1997‐2000. Improvements were observed in riparian and habitat condition indices, bank cover, and stability, pool quality, bank angle, and depth of undercut bank. Interpretation of repeat photography generally confirmed results from stream survey and should be part of long‐term riparian monitoring. More attributes of Rosgen stream types C and E improved than of types B and F. A and Gc streams did not show significant improvement. Alluvial draws and alluvial valleys improved in more ways than V‐erosional canyons and especially V‐depositional canyons. Stream survey data could not be substituted for riparian PFC assessment. Riparian PFC assessments help interpret other data.     

蒽醌染料及其中间体絮凝菌的特性

本文研究所分离到的真菌ＮＸ１对蒽醌染料ＫＮＲ及其中间体溴氨酸的作用,并考察营养条件、体系ＰＨ等对ＮＸ１的生长及絮凝作用的影响,结果表明,ＮＺ１及溴氨酸有很好的絮絮凝效果,对ＰＨ的适应范围广,最佳碳、氮源分别为蔗粮主尿素。     

餐饮业废油脂皂化工艺的探索

研究了废油脂的皂化方法和皂化机理。通过红外光谱分析废油脂皂化样品 ,对皂化度的影响因素进行了讨论。摸索出最佳皂化工艺条件 :皂化时间 4h ,皂化温度 10 0℃ ,碱液用量 (NaOH与废油脂的质量比 ) 1∶2 ,皂化用NaOH碱液浓度为 30 %。     

Material cycle, waste disposal, and recycling in a Leontief–Sraffa–von Neumann economy

The purpose of this paper is to analyze problems concerning household waste disposal and material flow by means of a Leontief–Sraffa–von Neumann framework. We treat household residuals as if they were traded and valued in a daily market transaction. Thus, we can calculate the shadow price of waste, making a value system compatible with a quantity system. We show the theoretical existence of an equilibrium solution between a value system and a quantity system. This means that if there is a well-organized market for waste treatment, the flow of waste is smoothly regulated by a price adjustment mechanism. Household residuals are shown to be negatively valued if a certain constraint is satisfied. Thus, those residuals are bads instead of goods. Interestingly enough, household waste treatment in the market does not affect the price formation of normal commodities, since waste treatment services or recycling services are nonbasics in Sraffa's sense. Partly due to this character, the Hawkins–Simon condition is required only for normal production sectors, and not for recycling sectors. In the final section, we have dropped the assumption that household residuals are always treated as waste, since some residuals may be traded as normal commodities. Applying the Gale–Nikaido–Debreu lemma to a newly defined excess demand function, we have proved that our model can accommodate such a situation. By this analysis, we have shown that the goods/bads (waste) relationship is a relative matter, being dependent upon economic conditions. The changes in demand for, or supply of, residuals may turn some goods into bads, and vice versa. Received: October 5, 1999 / Accepted: October 18, 1999     

挥发性卤代烃地表水环境样品保存方法研究

针对国内外监测技术规范对挥发性卤代烃样品保存条件不一致的问题,开展不同因素对挥发性卤代烃样品保存的影响研究。结果表明,调节pH≤2可使水样中挥发性卤代烃的损失率减少2%~25%;在水样中加入抗坏血酸或硫代硫酸钠可减少目标物的损失率约10%。挥发性卤代烃样品的最佳保存条件:加盐酸调节水样pH≤2,加10%硫代硫酸钠或抗坏血酸除余氯(有余氯时),冷藏,14 d内完成测试。在实际工作中,对未受余氯影响的集中式饮用水源地水样,特别是水库水样,若能在2 d内完成测试,在冷藏保存的条件下,可以考虑不调节pH,不添加固定剂。     

型号研制中实验室环境试验条件剪裁方法浅析

目的分析某导弹环境条件的制定和试验流程,总结在型号中如何制定环境试验条件和方法。方法从环境工程的角度出发,对产品的特性及服役环境进行分析。结果根据项目自身的特点和需要制定相应的环境试验要求。结论将环境条件和试验方法在某型武器装备产品中得到了成功应用。     

Resilience-based approach to safety barrier performance assessment in process facilities

The performance assessment of safety barriers is essential to find vulnerable elements in a safety barrier system. Traditional performance assessment approaches mainly focus on using several static indicators for quantifying the performance of safety barriers. However, with the increasing complexity of the system, emerging hazards are highly uncertain, making it challenging for the static indicators to assess the performance of safety barriers. This paper proposes a resilience−based performance assessment method for safety barriers to overcome this problem. Safety barriers are classified according to their functions first. The dynamic Bayesian network (DBN) is then introduced to calculate the availability function under normal and disruption conditions. The ratio of the system's availability, when affected by the disruption, to the initial availability, is used to determine the absorption capacity of the system. The ratio of the quantity of availability recovery to the total quantity of system represents the adaptation and restoration capacity of the system. The system's resilience is represented by the sum of absorption, adaptation, and restoration capacities. The wax oil hydrogenation process is used to demonstrate the applicability of the proposed methodology.