Assessment of in situ properties of municipal solid waste with a large-diameter borehole method.

A Municipal Solid Waste Borehole Assessment (MBA) was developed to assess in situ geotechnical properties of municipal solid waste (MSW) during the boring of gas extraction well construction. A Large-Diameter Borehole Caliper (LDBC) was lowered into the borehole to measure the diameter and record the condition of the wall by time-lapse video photography. The results indicated that the borehole experienced significant radial compression with depth following completion. Radial compressions amounted to approximately 7.5% at 9.14 m, 10% at 21.3 m and 11% at 27.4 m below ground surface. The bulk modulus was estimated by using the captured volumetric strains and reported lateral earth coefficients, and the results showed that it increases with increasing depth. For MSW, the bulk modulus increased up to 13.4 MPa in a linear trend with depth. The unit weights of MSW were obtained using three diameter readings from LDBC, auger barrel outside diameter and outer cutting bit outside diameter. The results showed that the diameter based on outer cutting bit yielded realistic unit weights (5.08-9.68 kN m-3) due to unrealistic calculated saturations by other two assumed diameters. The borehole assessment with LDBC was shown to be an efficient and valuable means for characterising MSW and effectively designing gas extraction wells. The research provided a means to assess the waste mass with accuracy at great depths by directly observing and measuring borehole condition.

Evaluation of depth-dependent properties of municipal solid waste using a large diameter-borehole sampling method.

This study is to analyze geotechnical properties and biological status of undisturbed municipal solid waste (MSW) associated with depth by using a large-diameter borehole sampling method. Through the method, a 28 m-borehole with 0.8 m of the diameter was drilled into the MSW body consisting of ten-lift layers of waste placed over 4000 days in an operating landfill. MSW sample cuttings were collected from the field site, weighted, and transferred to a laboratory for additional experiments to measure various properties such as moisture content, constituent characterization, unit weights, specific gravity, decomposition state, saturation, and compression rates with regard to waste depth. Also, the methane production obtained from MSW decomposition tests indicated that waste mass was relatively consistent throughout the depth of borehole and had not reached the accelerated production phase of methane. The wet and dry unit weights of the MSW sample with different depths produced excellent trends of the first-order rate with vertical stress. First Oder Rate Equation (FORE) analysis indicated that the maximum total and dry unit weight of MSW (γMSWw and γMSWd) achieved at depth in the waste mass were 12.9 kN/m3 and 10.6 kN/m3, respectively. Based on the waste shrinkage ratio (WSR) defined as the initial dry unit weight divided by succeeding dry unit weight, the height of the original MSW pile was estimated to be 40.5 m. Different compression parameters, including aggregated MSW compression index (Cc), modified compression index (CCE), and compression ratio parameter (Cc'), were comparably evaluated, which can be beneficial to understand compressibility and settlement processes in a landfill.Implications: Geotechnical properties and biological status of undisturbed municipal solid waste (MSW) associated with depth were analyzed by using a large-diameter borehole sampling method. The wet and dry unit weights of the MSW sample with different depths produced excellent trends of the first-order rate with vertical stress. Based on the waste shrinkage ratio (WSR) defined as the initial dry unit weight divided by succeeding dry unit weight, the height of the original MSW pile was estimated to be 40.5 m. Different compression parameters, including aggregated MSW compression index (Cc), modified compression index (CCE), and compression ratio parameter (Cc'), were comparably evaluated, which can be beneficial to understand compressibility and settlement processes in a landfill.

A comparison of the high count-rate performance of three commercially available digital signal processors.

Three commercial gamma-ray digital signal processors, a Canberra InSpector 2000, an ORTEC DigiDART, and an X-ray Instrumentation Associates Polaris system, coupled to a Canberra 2002C resistive-feedback preamplifier-equipped high-purity germanium detector, were performance tested to input rates of 440 kHz. The spectrometers were evaluated on their throughput, stability and peak shape performance. The accuracy of their quantitative corrections for dead time and pile-up were also tested. All three of the tested units performed well at input rates that strain most analog spectroscopy systems.

Efeitos da buspirona e diazepam, puros ou em combinaçäo com álcool, no desempenho de habilidades e potencias evocados / Buspirone and diazepam effects alone or in association with the alcohol in abilities and e vocated menpowers

Os efeitos da buspirona 10 e 20 mg e diazepam 10 mg no desempenho de habilidades e me respostas evocadas, bem como suas interaçöes com álcool - 0.8 g/Kg, foram pesquisados em 24 homens saudáveis. O álcool causou o maior dano a atividade normal, seguido de perto pelo diazepam. Ambas as doses de buspirona causaram menores efeitos. A buspirona apresenta pricipalmente efeitos sedativos de menor duraçäo, ao passo que o diazepam prejudicou o senso de direçäo e o equilíbrio do corpo, além de ser sedativo. Ambos os ansiolíticos mostraram apenas leves interaçöes adicionais na presença da dose de álcool. Foram observados nos potenciais evocados um forte efeito das drogas, um menor, mas significativo efeito do álcool e de interaçäo droga/álcool. Os efeitos do dizepam nos potenciais evocados foram similares aos do álcool, ao passo que a buspirona em algumas circunstância pareceu reverter o efeito do álcool. A farmacocinética tanto buspirona quanto do diazepam näo foi significativamente afetada pela administraçäo de álcool. O perfil de efeitos colaterais psicomotores de uma dose ansiolítica única é preferivel ao de uma dose única de 10 mg de dizepam