Forecasting change using an interregional homogeneity index

This study of employment change in the Allentown-Bethlehem-Easton, SMSA applies an index of interregional homogeneity to determine the extent to which the industrial structure of the region over a nine-year period has been modifiedvis-a-vis that of the rest of the nation. Indices derived from the analysis are synthesized with a modified employment shift model to forecast expected employment for twenty-two industries in the ABE, SMSA for the year 1975. It is demonstrated that an interregional homogeneity index when combined with a shift and share model can be adapted to systematically forecast regional change. The concept employed is to first stratify the allocation of change to a sub-region in total and then to each industry.This study was made possible in part by a research grant from Waynesburg College.     

ASSESSING AND MANAGING THE RISKS OF PATHOGEN TRANSFER FROM LIVESTOCK MANURES INTO THE FOOD CHAIN

A review was undertaken of (a) the levels and prevalence of Salmonella spp., Campylobacter spp., Listeria monocytogenes, Escherichia coli 0157. Cryptosporidium parvum and Giardia intestinalis in livestock manure, and (b) factors which affect their survival during storage and following land application. Pathogens are commonly present in livestock manures and can survive in soil for several months or years after spreading or excretion onto land. Temperature was identified as being the most important factor influencing pathogen survival, although pH, UV light and drying were also important. Various practical measures to minimise the risk of pathogen transfer into the food chain were identified, including treatment, extended storage and no/harvest periods following land spreading. Guidelines are being developed on managing farm manures to minimise the risks of microbiological contamination of ready-to-eat crops.     

Full scale fire tests for ship accommodation quarters

Ten full-scale test fires were conducted in a chamber simulating a three person ship accommodation quarter. The test fires used three different ventilation conditions, two types of bunks and furnishings with either polyurethane foam or chloroprene foam. The chamber was instrumented to follow the development of the fire.The furnishings with polyurethane foam were readily ignited and produced an intense fire within 2 to 4 minutes. The furnishings with chloroprene foam ignited but burned slowly with a small flame or in smoldering combustion.The ventilation conditions had a significant effect on the development and intensity of the fire as the test fires were burning under oxygen-limiting conditions.The solid pan bunks retarded the early development of the fire compared to open bunks for polyurethane furnishings. However, once the mattresses on the three bunks were ignited the intensity of the test fires was similar for both types of bunks.     

Selective removal of gallium (III) from aqueous solutions containing zinc or aluminum using sodium di-(n-octyl) phosphinate

Gallium was removed selectively from aqueous solutions containing zinc or aluminum using sodium di-(n-octyl) phosphinate as a ligand (NaL). At low pH or low mole ratios, the gallium was removed by complexation with the ligand as GaL(3(S)), while the zinc or the aluminum remained in the solution. Nearly complete separation of gallium was obtained. By increasing the amount of ligand or by increasing the pH, the zinc or aluminum remaining in the solution was then removed as a solid complex: ZnL(2(S)) or AlL(3(S)), respectively. At a pH between 1.5 and 2 and a mole ratio ligand to total metals of 0.75 for zinc solutions and 1.0 for aluminum solutions, more than 98% of the gallium was selectively removed with a high molar selectivity, alpha(Ga/Zn) and alpha(Ga/Al), respectively. Over 95% of gallium was recovered from the solid GaL(3(S)) complex by treatment of the complex with a 3M NaOH solution and diethyl ether. The gallium was concentrated in the aqueous solution to 4 times its initial concentration and the ligand was extracted into the ether phase. After evaporation of the ether, 95% of the ligand was regenerated in its sodium form as a solid.     

Compensation for extra preliminary and general (P & G) cost arising from delays, variations and disruptions: the palmiet pumped storage scheme

Underground construction is notorious for high cost and time overruns. This is probably inherent in the nature of the work, which usually involves high risks on the part of both the employer and the contractor, in view of the extent of the uncertainties with regard to such factors as geology, appropriate design and performance. The main civil works constructed for South Africa's Palmiet Pumped Storage Scheme between 1983 and 1987 have demonstrated that with early identification and proper management of the risks and costs, the value of cost and time overruns can be curtailed to a very large extent. This paper describes broadly the process adopted on the project, focusing in particular on the successful management at Palmiet of the financial risks pertaining to the cost of the contractor's overheads, establishment, supervision and plant in a contract that was known to be subject to variations, extensions and delays. This was achieved by appropriate scheduling, provisions for payment and on-site management of these cost items, usually described broadly as the Preliminary and General (P & G) Items. These items accounted for 34% of the value of the contract.     

Mercury contamination in fish from gold mining areas in Indonesia and human health risk assessment

This study investigates the effects on fish and assesses human health hazards from mercury released in two gold mining areas in Indonesia: Tatelu (North Sulawesi Province) and Galangan (Katingan District, Central Kalimatan Province). In Tatelu, 154 fish specimens of 10 freshwater species were collected, as well as five marine species from the fish market. The mean concentration of total mercury in muscles of freshwater fish from this area was 0.58+/-0.44 microg/g, with more than 45% of fish having Hg levels above the WHO guideline for human consumption of 0.5 microg/g. In Galangan, where 263 fish specimens of 25 species were collected, the total mercury in muscles averaged 0.25+/-0.69 microg/g. Excluding data from flooded open pits in sub-area P4, mean Hg levels in fish from Galangan were 2 to 4 times lower than 0.5 microg/g, while fewer than 10% of fish from Galangan exceeded WHO guidelines. The Hazard Quotient (HQ) was applied to both areas to determine the threat of MeHg exposure for communities in both areas. The HQ is a risk assessment indicator which defines the ratio of exposure level to a single substance in relation to a reference dose. Samples from Tatelu (excluding marine species) had an HQ above one, while those from Galangan resulted in values of 2.4 for the whole area and 9.9 for sub-area P4, pointing to potentially harmful fish consumption for the local population. By using the single-compartment model to estimate mercury levels in blood and hair from daily intake dose, sub-area P4 showed the highest levels, higher than the upper limit guideline for pregnant women, but still lower than threshold levels associated with observed clinical effects.     

Detection of enteric viruses, Giardia and Cryptosporidium in two different types of drinking water treatment facilities

In this study, two types of drinking water treatment facilities (two conventional drinking water treatment plants (DWTPs) and two compact units (Cus)) were compared referring to their production capacity. Water samples were collected from three main points: (a) different water treatment steps (b) washings of sand filters and (c) distribution system at different distances from the water treatment plants. Both viruses and protozoa were concentrated from each water sample by adsorption and accumulation on the same nitrocellulose membrane filters (0.45 microm pore size). Enteroviruses were detected by plaque infectivity assay in BGM cells and HAV, HEV and Norovirus were detected by RT-PCR. Giardia and Cryptosporidium were detected by conventional staining methods and PCR. The results revealed that enterovirus load at the intake ranged between 10-15 PFU/L for the two compact units and between 4.5 and 75 PFU/L for the two conventional DWTPs. The virus load in distribution system of the first type DWTPs at 1 km from the plant was the same as that of the intake. Viruses in the other type of treatment plants CUs at 1, 5 and 7 km, were much reduced. Investigation of raw water sediments of the two DWTPs showed enterovirus counts between 12 and 17.5 PFU/L. Virus count was reduced in sand of filters after washing. Giardia cysts were equally detected by microscopy and PCR in only intake samples of EL-Hawamdia CU (33.3%) and Meet Fares DWTP (50%). Cryptosporidium oocysts were equally detected by microscopy and PCR in intake samples of Abo EL-Nomros CU (100%), EL-Hawamdia CU (66.7%) and Fowa DWTP (50%). At Meet Fares DWTP three positive intake samples for Cryptosporidium were detected by PCR, compared with only two positive samples by microscopy. Giardia cysts and Cryptosporidium oocysts were detected in raw water sediment and sand of filters before washing. Only one sample from Meet Fares DWTP sand of filters after washing was positive for both Giardia and Cryptosporidium. It can be concluded that the poor microbial quality of the water may be due to improper operational skills and management of the various water treatment plants (especially at the two high capacity treatment plants).     

Limit analysis of reinforced concrete cylindrical shell roofs

Two approximate yield criteria are proposed for reinforced concrete cylindrical shell element. Three lower bound solutions are developed for cylindrical shell roofs with free longitudinal edges. Two shells with different geometric parameters are analysed. Elastic analysis is also done at working load. Graphs are presented to show the variation of stress resultants at critical sections.