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61.
The paper describes energy use in a particular heavy engineering workshop and investigates the consequences of possible improvements to lighting, to the thermal performance of the building and to the means of distribution of power. Comparisons are made with previous work done on other factories engaged in engineering. A method of describing the economic potential of energy conservation as an element of energy strategy is proposed.  相似文献   
62.
Non-propagating fatigue cracks have been observed at the roots of sharp notches in specimens of a single-phase Al-1/2% Mg alloy. The rate of fatigue crack growth, and the extent of cyclic deformation on either side of the crack, decrease with increase in length of crack. The process of formation of non-propagating cracks can be repeated in the same specimen by means of intermediate anneals. The results are discussed in terms of the cyclic strain-hardening of the material.  相似文献   
63.
Detailed information about the use of energy on industrial sites is scarce. This paper describes for a particular site how such information can be obtained from existing records together with limited measurements and approximate mathematical models of processes. an energy balance for the site is constructed. Possibilities for reducing the energy consumption by the use of readily available technologies are considered and a new energy balance calculated under these circumstances. In some instances the proposals would require further effort to provide suitable components and controls. We have indicated where this effort would be needed.  相似文献   
64.
The emission of volatile organic compounds (VOC) from nine toner powders and eleven types of processed paper from photocopying machines (6), laser (3) and matrix printers (21, and one carbonless copy fm has been measured. A total of 61 VOC from toner powders were identified by heating (185 °C) the powder for three minutes for thermal desorption and by gas chromatography followed by the use of low and high resolution EI and CI mass spectrometry. VOC from processed paper were analyzed by headspace sampling on Tenax TA from nylon bags. Thirty-one VOC with a wide range of volatility and persistency were identified from processed paper. The total VOC emission from the various types of paper differed substantially. Using the field and laboratory emission cell (FLEC), the calculated initial emission rate of styrene was 5 μg m?2h?1 from a freshly processed paper The VOC emission from machines and the processed paper can be reduced by proper choice of o m e equipment. However, an evaluation should consider all potential pollutants.  相似文献   
65.
66.
BACKGROUND: Pleomorphic xanthoastrocytoma (PXA) is an astrocytic tumor occurring primarily in childhood and adolescence with some malignant histologic features but a relatively slow clinical course. However, some tumors progress more rapidly and can undergo malignant degeneration. The authors attempted to determine whether various histologic features or tumor cell proliferative indices might help identify lesions at risk for early progression and distinguish PXAs from malignant gliomas. METHODS: In a retrospective study of 12 patients with PXA, the tumor's histologic features and DNA flow cytometric parameters were compared with their clinical course. DNA flow cytometry values for the S- and G2-phase of the PXAs also were compared with control group samples of malignant and low grade astrocytomas. RESULTS: Of the 12 tumors at initial diagnosis, 5 were considered typical PXAs whereas 7 had some atypical features (4 with paucity of reticulin fibers, 1 with focal necrosis, and 2 with both atypical reticulin and focal necrosis). During the follow-up period (range, 3.75-11 years; mean, 6.8 years), 2 patients had recurrences; 1 atypical reticulin PXA progressed to glioblastoma after 6.5 years and the 1 tumor with focal necrosis recurred at 6 months and again at 2 years with typical histologic features. DNA flow cytometry parameters of the typical PXA group were similar to values for malignant astrocytoma and significantly higher than values for control specimens of low grade astrocytomas. There were no distinctive DNA flow cytometric features that could distinguish this last tumor from others with a more benign clinical course. CONCLUSIONS: Measurements of the S-phase and G2-phase obtained from DNA flow cytometry and atypical histologic features cannot reliably identify PXA patients at risk for early progression and overall are significantly higher than values obtained for low grade gliomas. Therefore, frequent (i.e., two to three times per year) postoperative clinical and radiologic examinations are necessary to judge the appropriateness of adjuvant therapy in patients with PXA. The paradox of slow growth but DNA flow cytometry consistent with aggressive malignant lesions may represent a cell-cycle arrest mechanism in these lesions that could be verified in subsequent studies.  相似文献   
67.
The volatile organic compounds (VOCs) emitted from 12 linoleum samples were measured by use of the “Field and Laboratory Emission Cell” (FLEC) with sampling on Tenax TA followed by thermal desorbtion and GC/FID or GC/MS analysis. Major VOCs were alkanals, alkenals and fatty acids. The emissions were measured after 24 h in FLEC and again after one month's storage in a well ventilated room. The emission profiles of hexanal, nonanal and propanoic acid were modeled for four linoleum samples using a new exponential diffusion model. The time required to reach 50% of the odor threshold concentrations in a standard room was from 113 to 2296 hours. The applicability of the diffusion model for modeling long-term emission needs to be further evaluated considering possible continuous oxidative emission.  相似文献   
68.
69.
Vacuum distillation of heat-treated carobs gave an aqueous, colorless, sweet-smelling distillate which was tested over a wide range of concentrations and found to be highly attractive to adultOryzaephilus surinamensis (L.). The materials responsible for the aroma were isolated from the distillate by saturating with sodium chloride and extracting into diethyl ether as separate acidic, neutral, and basic fractions. The extraction efficiency was checked by recombining portions of the three fractions and replacing the diethyl ether with water to give a reconstituted distillate; this was almost as attractive as the original distillate. Bioassay of aqueous solutions of the three separate fractions showed that the acidic was attractive, while the neutral and basic had little effect. The five major components of the acidic fraction were found to be acetic, isobutyric,n-butyric, 2-methylbutyric, and hexanoic (caproic) acids. Bioassay of these in aqueous solution, both separately and combined, showed that hexanoic acid was the most attractive and may be responsible for both the longer-lasting attractive effect of the carob distillate and for the effectiveness of carobs themselves used in bait bags to detect stored product insects.  相似文献   
70.
A new system for measuring organizational quality on the Complex Figure Test (A. Rey, 1942; L. B. Taylor, 1969) is described. This system extends the traditional use of the test as a measure of constructional ability and figural memory. The new system is easy to learn, quick to score, and shows very good interrater reliability. Organizational quality was found to correlate moderately with copy accuracy, half-hour recall, and percentage retained. In an initial application of the system (N?=?63), organizational quality of the Rey-Osterrieth Complex Figure successfully discriminated between symptomatic (those with AIDS or AIDS-related complex) and asymptomatic Ss positive for human HIV, but organizational quality ratings of the Taylor figure did not. Results suggest that the Taylor figure is easier to organize than the Rey-Osterrieth. Thus, the Taylor figure may not be an appropriate alternative to the Rey-Osterrieth for the assessment of organizational quality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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