994 resultados para Terrestrial Impact
Resumo:
Derailments due to lateral collisions between heavy road vehicles and passenger trains at level crossings (LCs) are serious safety issues. A variety of countermeasures in terms of traffic laws, communication technology and warning devices are used for minimising LC accidents; however, innovative civil infrastructure solution is rare. This paper presents a study of the efficacy of guard rail system (GRS) to minimise the derailment potential of trains laterally collided by heavy road vehicles at LCs. For this purpose, a three-dimensional dynamic model of a passenger train running on a ballasted track fitted with guard rail subject to lateral impact caused by a road truck is formulated. This model is capable of predicting the lateral collision-induced derailments with and without GRS. Based on dynamic simulations, derailment prevention mechanism of the GRS is illustrated. Sensitivities of key parameters of the GRS, such as the flange way width, the installation height and contact friction, to the efficacy of GRS are reported. It is shown that guard rails can enhance derailment safety against lateral impacts at LCs.
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Open biomass burning from wildfires and the prescribed burning of forests and farmland is a frequent occurrence in South-East Queensland (SEQ), Australia. This work reports on data collected from 10-30 September 2011, which covers the days before (10-14 September), during (15-20 September) and after (21-30 September) a period of biomass burning in SEQ. The aim of this project was to comprehensively quantify the impact of the biomass burning on air quality in Brisbane, the capital city of Queensland. A multi-parameter field measurement campaign was conducted and ambient air quality data from 13 monitoring stations across SEQ were analysed. During the burning period, the average concentrations of all measured pollutants increased (from 20% to 430%) compared to the non-burning period (both before and after burning), except for total xylenes. The average concentration of O3, NO2, SO2, benzene, formaldehyde, PM10, PM2.5 and visibility-reducing particles reached their highest levels for the year, which were up to 10 times higher than annual average levels, while PM10, PM2.5 and SO2 concentrations exceeded the WHO 24-hour guidelines and O3 concentration exceeded the WHO maximum 8-hour average threshold during the burning period. Overall spatial variations showed that all measured pollutants, with the exception of O3, were closer to spatial homogeneity during the burning compared to the non-burning period. In addition to the above, elevated concentrations of three biomass burning organic tracers (levoglucosan, mannosan and galactosan), together with the amount of non-refractory organic particles (PM1) and the average value of f60 (attributed to levoglucosan), reinforce that elevated pollutant concentration levels were due to emissions from open biomass burning events, 70% of which were prescribed burning events. This study, which is the first and most comprehensive of its kind in Australia, provides quantitative evidence of the significant impact of open biomass burning events, especially prescribed burning, on urban air quality. The current results provide a solid platform for more detailed health and modelling investigations in the future.
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This book provides an overview of state of the art assessments of water quality; with an understanding how water quality is affected, and improving water quality for irrigation, drinking and recreation activities.
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This paper deals with the development of simplified semi-empirical relations for the prediction of residual velocities of small calibre projectiles impacting on mild steel target plates, normally or at an angle, and the ballistic limits for such plates. It has been shown, for several impact cases for which test results on perforation of mild steel plates are available, that most of the existing semi-empirical relations which are applicable only to normal projectile impact do not yield satisfactory estimations of residual velocity. Furthermore, it is difficult to quantify some of the empirical parameters present in these relations for a given problem. With an eye towards simplicity and ease of use, two new regression-based relations employing standard material parameters have been discussed here for predicting residual velocity and ballistic limit for both normal and oblique impact. The latter expressions differ in terms of usage of quasi-static or strain rate-dependent average plate material strength. Residual velocities yielded by the present semi-empirical models compare well with the experimental results. Additionally, ballistic limits from these relations show close correlation with the corresponding finite element-based predictions.
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Child sexual abuse is widespread and difficult to detect. To enhance case identification, many societies have enacted mandatory reporting laws requiring designated professionals, most often police, teachers, doctors and nurses, to report suspected cases to government child welfare agencies. Little research has explored the effects of introducing a reporting law on the number of reports made, and the outcomes of those reports. This study explored the impact of a new legislative mandatory reporting duty for child sexual abuse in the State of Western Australia over seven years. We analysed data about numbers and outcomes of reports by mandated reporters, for periods before the law (2006-08) and after the law (2009-12). Results indicate that the number of reports by mandated reporters of suspected child sexual abuse increased by a factor of 3.7, from an annual mean of 662 in the three year pre-law period to 2448 in the four year post-law period. The increase in the first two post-law years was contextually and statistically significant. Report numbers stabilised in 2010-12, at one report per 210 children. The number of investigated reports increased threefold, from an annual mean of 451 in the pre-law period to 1363 in the post-law period. Significant decline in the proportion of mandated reports that were investigated in the first two post-law years suggested the new level of reporting and investigative need exceeded what was anticipated. However, a subsequent significant increase restored the pre-law proportion, suggesting systemic adaptive capacity. The number of substantiated investigations doubled, from an annual mean of 160 in the pre-law period to 327 in the post-law period, indicating twice as many sexually abused children were being identified.
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The aim of this study was to estimate the development of fertility in North-Central Namibia, former Ovamboland, from 1960 to 2001. Special attention was given to the onset of fertility decline and to the impact of the HIV epidemic on fertility. An additional aim was to introduce parish registers as a source of data for fertility research in Africa. Data used consisted of parish registers from Evangelical Lutheran congregations, the 1991 and 2001 Population and Housing Censuses, the 1992 and 2000 Namibia Demographic and Health Surveys, and the HIV sentinel surveillances of 1992-2004. Both period and cohort fertility were analysed. The P/F ratio method was used when analysing census data. The impact of HIV infection on fertility was estimated indirectly by comparing the fertility histories of women who died at an age of less than 50 years with the fertility of other women. The impact of the HIV epidemic on fertility was assessed both among infected women and in the general population. Fertility in the study population began to decline in 1980. The decline was rapid during the 1980s, levelled off in the early 1990s at the end of war of independence and then continued to decline until the end of the study period. According to parish registers, total fertility was 6.4 in the 1960s and 6.5 in the 1970s, and declined to 5.1 in the 1980s and 4.2 in the 1990s. Adjustment of these total fertility rates to correspond to levels of fertility based on data from the 1991 and 2001 censuses resulted in total fertility declining from 7.6 in 1960-79 to 6.0 in 1980-89, and to 4.9 in 1990-99. The decline was associated with increased age at first marriage, declining marital fertility and increasing premarital fertility. Fertility among adolescents increased, whereas the fertility of women in all other age groups declined. During the 1980s, the war of independence contributed to declining fertility through spousal separation and delayed marriages. Contraception has been employed in the study region since the 1980s, but in the early 1990s, use of contraceptives was still so limited that fertility was higher in North-Central Namibia than in other regions of the country. In the 1990s, fertility decline was largely a result of the increased prevalence of contraception. HIV prevalence among pregnant women increased from 4% in 1992 to 25% in 2001. In 2001, total fertility among HIV-infected women (3.7) was lower than that among other women (4.8), resulting in total fertility of 4.4 among the general population in 2001. The HIV epidemic explained more than a quarter of the decline in total fertility at population level during most of the 1990s. The HIV epidemic also reduced the number of children born by reducing the number of potential mothers. In the future, HIV will have an extensive influence on both the size and age structure of the Namibian population. Although HIV influences demographic development through both fertility and mortality, the effect through changes in fertility will be smaller than the effect through mortality. In the study region, as in some other regions of southern Africa, a new type of demographic transition is under way, one in which population growth stagnates or even reverses because of the combined effects of declining fertility and increasing mortality, both of which are consequences of the HIV pandemic.
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The objective of this study is to examine the social impacts of the integrated conservation and development project (ICDP) aimed at biodiversity conservation and local socio-economic development in the Ranomafana National Park (RNP), Madagascar. Furthermore, the study explores social sustainability and justice of the ICDP in Ranomafana. This ethnographically informed impact study uses of various field methods. The research material used consists of observation, interviews (key-person and focus group), school children's writings, official statistics and project documents. Fieldwork was conducted in three phases in 2001, 2002 and 2004 in twelve villages around the park, as well as in neighbouring areas of Ranomafana. However, four of those twelve villages were chosen for closer study. This study consists of five independent articles and a concluding chapter. Social impacts were studied through reproductive health indicators as well as a life security approach. Equity and distribution of benefits and drawbacks of ICDP were analysed and the actors related to the conservation in Ranomafana were identified. The children and adolescents' environmental views were also examined. The reproductive health indicators studied showed a poor state of reproductive health in the park area. Moreover, the existing social capital in the villages seemed to be fragmented due to economic difficulties that were partly caused by the conservation regulations. The ICDP in Ranomafana did not pay attention to the heterogeneity of the affected communities even though the local beneficiaries of the ICDP varied according to their ethnicity, living place, wealth, social position and gender. In addition, various conservation actors (local people in various groups, local authorities, tourist business owners, conservation NGOs and scientists) contest their interests over the forest, conservation and its related activities. This study corroborates the same type of evidence and conclusions discussed in other similar cases elsewhere: so called social conservation programmes still cannot meet the needs of the people living near the protected areas; on the contrary, they even have a reverse impact on the people's lives. A fundamental misunderstood assumption in the conservation process in Ranomafana was to consider the local people as a problem for biodiversity conservation. Major reasons for the failure of the ICDP in Ranomafana include a lack of local institutions that would have been able to communicate as equals with the conservation NGOs as well as to transfer the tradition of the authoritarian governance in conservation management together with the over-appreciation of scientific biodiversity, and lack of will to understand the local people's rights to use the forest for their livelihoods.
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While significant research has been undertaken exploring the pedagogical benefits of undertaking lengthy social work and human services field placements, there has been very little consideration regarding the potential financial stress involved for students. This study has addressed this knowledge gap. Research was conducted in 2014 using quantitative and qualitative methods with students, academic and professional staff from six Queensland Universities. The findings show a significant relationship between unpaid placements and financial hardship creating considerable stress for students and at times a compromised learning experience whilst on placement. The limited flexibility in the requirements of professional bodies and universities for how placements are undertaken has been identified as a key contributor to financial hardship. Addressing the complexities inherent in this issue requires a collaborative effort from multiple stakeholders and should not be regarded as a problem for students to endure and manage.
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The impact of riparian land use on the stream insect communities was studied at Kudremukh National Park located within Western Ghats, a tropical biodiversity hotspot in India. The diversity and community composition of stream insects varied across streams with different riparian land use types. The rarefied family and generic richness was highest in streams with natural semi evergreen forests as riparian vegetation. However, when the streams had human habitations and areca nut plantations as riparian land use type, the rarefied richness was higher than that of streams with natural evergreen forests and grasslands. The streams with scrub lands and iron ore mining as the riparian land use had the lowest rarefied richness. Within a landscape, the streams with the natural riparian vegetation had similar community composition. However, streams with natural grasslands as the riparian vegetation, had low diversity and the community composition was similar to those of paddy fields. We discuss how stream insect assemblages differ due to varied riparian land use patterns, reflecting fundamental alterations in the functioning of stream ecosystems. This understanding is vital to conserve, manage and restore tropical riverine ecosystems.
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Uracil DNA glycosylase (Ung)initiates the uracil excision repair pathway. We have earlier characterized the Y66W and Y66H mutants of Ung and shown that they are compromised by similar to 7- and similar to 170-fold, respectively in their uracil excision activities. In this study, fluorescence anisotropy measurements show that compared with the wild-type, the Y66W protein is moderately compromised and attenuated in binding to AP-DNA. Allelic exchange of ung in Escherichia coli with ung::kan, ungY66H:amp or ungY66W:amp alleles showed similar to 5-, similar to 3.0- and similar to 2.0-fold, respectively increase in mutation frequencies. Analysis of mutations in the rifampicin resistance determining region of rpoB revealed that the Y66W allele resulted in an increase in A to G (or T to C) mutations. However, the increase in A to G mutations was mitigated upon expression of wild-type Ung from a plasmid borne gene. Biochemical and computational analyses showed that the Y66W mutant maintains strict specificity for uracil excision from DNA. Interestingly, a strain deficient in AP-endonucleases also showed an increase in A to G mutations. We discuss these findings in the context of a proposal that the residency of DNA glycosylase(s) onto the AP-sites they generate shields them until recruitment of AP-endonucleases for further repair.
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Nowadays any analysis of Russian economy is incomplete without taking into account the phenomenon of oligarchy. Russian oligarchs appeared after the fall of the Soviet Union and are represented by wealthy businessmen who control a huge part of natural resources enterprises and have a big political influence. Oligarchs’ shares in some natural resources industries reach even 70-80%. Their role in Russian economy is big without any doubts, however there has been very little economic analysis done. The aim of this work is to examine Russian oligarchy on micro and macro levels, its role in Russia’s transition and the possible positive and negative outcomes from this phenomenon. For this purpose the work presents two theoretical models. The first part of this thesis work examines the role of oligarchs on micro level, concentrating on the question whether the oligarchs can be more productive owners than other types of owners. To answer the question this part presents a model based on the article “Are oligarchs productive? Theory and evidence” by Y. Gorodnichenko and Y. Grygorenko. It is followed by empirical test based on the works of S. Guriev and A. Rachinsky. The model predicts oligarchs to invest more in the productivity of their enterprises and have higher returns on capital, therefore be more productive owners. According to the empirical test, oligarchs were found to outperform other types of owners, however it is not defined whether the productivity gains offset losses in tax revenue. The second part of the work concentrates on the role of oligarchy on macro level. More precisely, it examines the assumption that the depression after 1998 crises in Russia was caused by the oligarchs’ behavior. This part presents a theoretical model based on the article “A macroeconomic model of Russian transition: The role of oligarchic property rights” by S. Braguinsky and R. Myerson, where the special type of property rights is introduced. After the 1998 crises oligarchs started to invest all their resources abroad to protect themselves from political risks, which resulted in the long depression phase. The macroeconomic model shows, that better protection of property rights (smaller political risk) or/and higher outside investing could reduce the depression. Taking into account this result, the government policy can change the oligarchs’ behavior to be more beneficial for the Russian economy and make the transition faster.
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We study the impact of cosmic inhomogeneities on the interpretation of SNe observations. We build an inhomogeneous universe model that can confront supernova data and yet is reasonably well compatible with the Copernican Principle. Our model combines a relatively small local void, that gives apparent acceleration at low redshifts, with a meatball model that gives sizeable lensing (dimming) at high redshifts. Together these two elements, which focus on different effects of voids on the data, allow the model to mimic the concordance model.
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Impacts of climate change on hydrology are assessed by downscaling large scale general circulation model (GCM) outputs of climate variables to local scale hydrologic variables. This modelling approach is characterized by uncertainties resulting from the use of different models, different scenarios, etc. Modelling uncertainty in climate change impact assessment includes assigning weights to GCMs and scenarios, based on their performances, and providing weighted mean projection for the future. This projection is further used for water resources planning and adaptation to combat the adverse impacts of climate change. The present article summarizes the recent published work of the authors on uncertainty modelling and development of adaptation strategies to climate change for the Mahanadi river in India.