Geotechnical properties of tire-cohesive clayey soil mixtures as a fill material

Geotechnical properties of pure fine and coarse grained tire-chips and their mixtures (10, 20, 30, 40 and 50%) with a cohesive clayey soil were investigated through a series of soil mechanical tests in order to investigate possibilities of their usage as a lightweight fill material. Grain size and Atterberg limits analysis, permeability, direct shear and compaction tests were performed on the clayey soil, tire chips (both fine and coarse) alone and their mixtures. The results indicate that the use of used tire-chips mixed with clayey soils as a fill material is possible. The mixtures up to 20% coarse grained tire-chips and 30% fine grained tire-chips can be used above ground water tables where low weight, low permeability and high strength are needed in fills such as highway embankments, bridge abutments and backfills behind retaining structures especially when they are to be built on weak foundation soils with low bearing capacity and high settlement problems. They should not be used where drainage is needed to prevent the development of pore pressures during loading of fills under saturated conditions. In these cases, they may, however, be used by mixing with high permeability material such as sand and gravel. © 2006 Elsevier B.V. All rights reserved.FBE.97YL.96Part of this study was financially supported by the Çukurova University Research Foundation (Project No: FBE.97YL.96). The authors thank two anonymous Engineering Geology reviewers for their critical review of the manuscript. Their invaluable comments improved the manuscript considerably. We would also like to thank Aysun Serin and Hikmet Senbayrak for their help in soil mechanics tests and Mustafa Laman for providing unlimited access to the soil mechanics laboratory of the Civil Engineering Deparment at Çukurova University

Soil structure changes during compaction of a cohesive soil

Orientations of particles, pores and other constituents during compaction of an artificially made clayey soil were studied in order to investigate how soil structure, and in turn, engineering parameters such as dry unit weight, porosity, void ratio and compaction characteristics, change during compaction of a cohesive soil at different moisture contents on both the dry and wet sides of the optimum moisture content. The results show that the orientation pattern at the very dry stage of the compaction curve is nearly random. The overall degree of preferred orientation increases as the moisture content increases until the optimum moisture content is reached. Edge-edge contacts between the particles and/or domains at the very dry stage of the compaction curve first become mainly edge-face and then become face-face contacts near the optimum moisture content. Around the optimum moisture content, the overall degree of preferred orientation becomes the highest. From this point on, however, the overall degree of preferred orientation starts to decrease again indicating that further moisture content increase does not cause additional overall preferred orientation. The structure beyond the optimum moisture content is mainly characterised by long strings of differently oriented packets in the form of curved trajectories and mainly face-to-face contacts between the particles and/or domains in the packets. Though there is a high degree of preferred fabric orientation in each individual packet, the overall degree of preferred orientation decreases because the packets are themselves oriented in different directions. The results agree with previous studies showing that the soil fabric dry of optimum is randomly oriented but becomes increasingly oriented towards the optimum. However, as the moisture content increases on the wet side of optimum, the overall degree of preferred orientation decreases as opposed to the generally accepted view. © 2007 Elsevier B.V. All rights reserved.FBE2002D47, MMF2003BAP17, MMF200043This study was financially supported in part by the Çukurova University Research Foundation (Project Nos: FBE2002D47, MMF2003BAP17 and MMF200043). The authors thank two anonymous Engineering Geology reviewers for their critical review of the manuscript

Sawability prediction of carbonate rocks from shear strength parameters using artificial neural networks

[No abstract available]Fundamental Research Fund of Shandong UniversityThe authors are deeply grateful to Nigde University Research Fund for the financial support. The authors wish to acknowledge Kamer Mermer, Derinkok Mermer, Toros Mermer, Akmeras Mermer, Kombassan Mermer, Antalya Mermer, Model Mermer, Derinoglu Mermer and Detay Mermer for providing facilities for the machine performance measurements

Effects of a monthly injectable steroidal contraceptive, Mesigyna, on menstrual pattern, lipoproteins, and coagulation parameters

WOS: 000168767700007PubMed: 11368988The objective of this study was to determine the effects of a once-monthly injectable contraceptive (Mesigyna) on menstrual pattern, lipoproteins, and coagulation parameters. Thirty-six women aged 18-35 years requesting monthly injectable contraception were included. Before injecting estradiol valerate 5 mg and norethisterone enanthate 50 mg, coagulation, lipoprotein, and liver function parameters were determined. After the 3- and 6-month injections, the same coagulation and serum lipid measurements and liver function tests were repeated, and women were questioned about their menstrual patterns and side effects. Thirty women who completed 6 months were evaluated. At the end of 3 months, two-thirds of the 30 women had normal menstrual patterns; at the end of 6 months, 80% of the women had normal menses. Serum LDL, total cholesterol, and triglyceride levels did not change significantly, while HDL and VLDL decreased significantly (p = 0.032 and p = 0.039, respectively) at 6 months. PT and aPTT measures did not change at the end of 6 months, while fibrinogen levels were significantly lower (p = 0.013). Serum total bilirubin levels increased (p = 0.022) and albumin levels decreased (p = 0.022) at the end of 6 months. Mesigyna was well tolerated and side effects and menstrual abnormalities were acceptable. There were no clinically significant changes in lipoprotein, coagulation, or hepatic parameters. (C) 2001 Elsevier Science Inc. All rights reserved

Life History and Ecology of Coyotes in the Mid-Atlantic States: A Summary of the Scientifi c Literature

Relatively little information has been published on Coyotes in the eastern United States, particularly in the mid-Atlantic region, the last area of the contiguous US to be colonized by Coyotes. Increases in eastern Coyote distribution and abundance have been documented, and concerns about their impact on wildlife and livestock are growing. Information from published and unpublished manuscripts, theses, dissertations, and state wildlife agency records in the mid-Atlantic region were examined and synthesized. This review provides a comprehensive summary of Coyote ecology in the mid-Atlantic for natural resource managers and researchers

Controle de plantas daninhas através da palha de cana-de-açúcar associada à mistura dos herbicidas trifloxysulfuron sodium + ametrina Weed control through green cane harvesting residue combined with the herbicide mixture trifloxysulfuron sodium + ametryne

O objetivo deste trabalho foi avaliar os efeitos da palha de cana-de-açúcar resultante da colheita sem queima e da mistura comercial dos herbicidas trifloxysulfuron sodium + ametrina, na emergência e no acúmulo de biomassa seca de nove espécies de plantas daninhas. Os tratamentos foram distribuídos em esquema fatorial 3 x 3, sendo três quantidades de palha resultantes da colheita da cana-de-açúcar sem queima (0, 10 e 15 t ha-1), e três doses da mistura formulada dos herbicidas trifloxysulfuron sodium + ametrina (0, 1,75 e 2,00 kg ha-1), aplicados em condições de pós-emergência das plantas daninhas. As densidades das plantas daninhas foram avaliadas aos 15, 60 e 90 dias após a aplicação (DAA) da mistura dos herbicidas, e a biomassa seca das plantas daninhas, aos 90 DAA. A presença de palha sobre o solo suprimiu as densidades das populações de Brachiaria plantaginea, Digitaria horizontalis, Panicum maximum, Sida glaziovii e Amaranthus hybridus a níveis de infestação considerados satisfatórios de controle. A palhada também reduziu as populações de Senna obtusifolia, Ipomoea hederifolia, I. grandifolia e I. nil, porém em níveis insatisfatórios de controle. A mistura de herbicidas nas doses estudadas controlou todas as espécies de plantas daninhas avaliadas. Na presença da palha, o controle das plantas de S. obtusifolia, I. nil, I. hederifolia e I. grandifolia somente foi satisfatório quando foi aplicada a mistura de herbicidas. Para o controle de P. maximum, houve vantagem na integração dos dois métodos de controle, em relação à aplicação isolada da menor quantidade de palha estudada ou à aplicação da mistura de herbicidas.<br>This work aimed to evaluate the effects of green cane harvesting residue and of the herbicide mixture trifloxysulfuron sodium + ametryne on the emergence and dry biomass accumulation of nine weed species. The treatments were arranged in a 3 x 3 factorial design, with three green cane harvesting residue amounts (0, 10 and 15 t ha-1) and three rates of the commercial formulation of the herbicide mixture trifloxysulfuron sodium + ametryne (0, 1.75 and 2.00 kg ha-1), applied under weed post-emergence conditions. Weed density was evaluated at 15, 60 and 90 days after herbicide application (DAA) and weed dry biomass at 90 DAA. The presence of the green cane harvesting residue on the soil suppressed the density of the populations of Brachiaria plantaginea, Digitaria horizontalis, Panicum maximum, Sida glaziovii and Amaranthus hybridus. The green cane harvesting residue reduced the populations of Senna obtusifolia, Ipomoea hederifolia, I. grandifolia and I. nil, even though the control was not satisfactory. The herbicide mixture studied controlled all the weed species evaluated. In the presence of green cane harvesting residue, the control of S. obtusifolia, I. nil, I. hederifolia and I. grandifolia was satisfactory only when the herbicide mixture was applied.Green cane harvesting residue combined with the herbicide mixture was advantageous for P. maximum control, compared with applying the smallest amount of green cane harvesting residue or the herbicide mixture alone on the soil surface