A properly functioning cover over an uncontrolled landfill which is regulated under the Comprehensive Environmental Response Compensation and Liability Act (CERCLA) depends on both a well-engineered cover design and prudent construction practices.
This paper focuses on several geosynthetic construction issues which ultimately impact the performance of the final constructed cover. Preparation and placement issues related to subgrade preparation, geosynthetic placement, cover soil placement and test sections are presented. Storage and seaming of the geosynthetics are discussed. Construction quality control and quality assurance programs are emphasized. In addition, relevant design issues pertaining to settlements, interface friction, and rigid-nonrigid connections are discussed.
Although these issues apply to all landfills, this paper is based on experience gained from design, review and construction oversight of CERCLA landfill covers by the US Army Corps of Engineers. 相似文献
Matched groups of schizophrenics and neurotics (a group which also included personality disorders), were compared on their performance on the Object Sorting Test. The schizophrenics could be significantly differentiated from the neurotics (and personality disorders) by virtue of their conceptualizations involving open-private ideas (à la McGaughran and Moran, 1956), inappropriate sorting, peculiar verbalizations, and perseverative thinking. The results are related to ego impairment in schizophrenia, and add to the capacity of this test of conceptual thinking to distinguish the thinking activity of schizophrenics from that of most other psychiatric patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
Investigated the relationship of child abuse and neglect to academic achievement and discipline problems in a school-age population. A representative community sample of 420 maltreated children in kindergarten through Grade 12 were matched with 420 nonmaltreated children in the same community. Using social service and school records as the sources of data, the authors found maltreated children performed significantly below their nonmaltreated peers in standardized tests and grades and were more likely to repeat a grade. Maltreated children also had significantly more discipline referrals and suspensions. Of the maltreated children, neglected children showed the poorest outcomes on academic performance, and physically abused children showed the most discipline problems. Variations in maltreatment effects by grade level, public assistance status, and gender are also described. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
A representative sample of 796 sexual abuse, 198 physical abuse, and 880 child neglect reports in New York State in 1985 was examined to identify case factors that predict the substantiation of the reports following an investigation by child protective services. This issue has taken on added significance as the number of child maltreatment reports continues to rise, whereas the percentage of those being substantiated declines. Regression analyses revealed that reports from professionals were substantiated at a significantly higher rate than reports from nonprofessionals for all types of maltreatment. These analyses further revealed that part of the effect of source of report was due to differences between professional and nonprofessional reports in the types of actions taken after the report was received. The most important predictors of substantiation, after source of report, were the variables that reflected the case investigatory process. The data also showed that background characteristics, such as the child's ethnicity or the number of children in the household, had some impact on the outcome of the investigation and that this varied as a function of the type of maltreatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
The dimensions of discrete passives, passive integrated components (arrays, networks) and embedded integral ones should be reduced significantly in the nearest future. Therefore the relations between technological accuracy and limitations, minimal geometrical dimensions and electrical as well as stability properties become more and more important. This paper presents systematic studies of thick-film or LTCC microresistors made with the aid of laser shaping. The investigations are concerned with miniaturization of two resistor dimensions, namely length (down to 30 μm) and width (also down to 30 μm). The sheet resistance, hot temperature coefficient of resistance (HTCR) as well as long-term stability and durability of test structures to various short electrical pulses were related to geometrical properties of microresistors. Such investigations proved that combining of current materials and fabrication methods used in modern thick-film and LTCC technologies with laser shaping made possible fabrication of 30 × 30 μm2 microresistors with satisfactory electrical properties and can serve as interesting alternative for thick-film and LTCC resistors miniaturization. 相似文献
This study investigates the effectiveness of night ventilation technique for residential buildings in hot-humid climate of Malaysia. This paper firstly presents the results of a survey on usage patterns of windows and air-conditioners in typical Malaysian residential areas. Secondly, the effects of different natural ventilation strategies on indoor thermal environment for Malaysian terraced houses are evaluated based on the results of a full-scale field experiment. The results show that the majority of occupants tend to apply not night ventilation but daytime ventilation in Malaysian residential areas. It can be seen from the field experiment that night ventilation would provide better thermal comfort for occupants in Malaysian terraced houses compared with the other ventilation strategies in terms of operative temperature. However, when the evaporative heat loss of occupants is taken into account by using SET*, the night ventilation would not be the superior technique to the others in providing daytime thermal comfort mainly due to the high humidity conditions. Therefore, the indoor humidity control during the daytime such as by dehumidification would be needed when the night ventilation technique is applied to Malaysian terraced houses. Otherwise, full-day ventilation would be a better option compared with night ventilation. 相似文献