937 resultados para Hazardous waste disposal in the ground
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Rangelands store about 30% of the world’s carbon and support over 120 million pastoralists globally. Adjusting the management of remote alpine pastures bears a substantial climate change mitigation potential that can provide livelihood support for marginalized pastoralists through carbon payment. Landless pastoralists in Northern Pakistan seek higher income by cropping potatoes and peas over alpine pastures. However, tilling steep slopes without terracing exposes soil to erosion. Moreover, yields decline rapidly requiring increasing fertilizer inputs. Under these conditions, carbon payment could be a feasible option to compensate pastoralists for renouncing hazardous cropping while favoring pastoral activities. The study quantifies and compares C on cropped and grazed land. The hypothesis was that cropping on alpine pastures reduces former carbon storage. The study area located in the Naran valley of the Pakistani Himalayas receives an annual average of 819 mm of rain and 764 mm of snow. Average temperatures remain below 0°C from November to March while frost may occur all year round. A total of 72 soil core samples were collected discriminating land use (cropping, pasture), aspect (North, South), elevation (low 3000, middle 3100, and high 3200 m a.s.l.), and soil depth (shallow 0-10, deep 10-30 cm). Thirty six biomass samples were collected over the same independent variables (except for soil depth) using a 10x10x20 cm steal box inserted in the ground for each sample. Aboveground biomass and coarse roots were separated from the soil aggregate and oven-dried. Soil organic carbon (SOC) and biomass carbon (BC) were estimated through a potassium dichromate oxidation treatment. The samples were collected during the second week of October 2010 at the end of the grazing and cropping season and before the first snowfall. The data was statistically analyzed by means of a one-way analysis of variance. Results show that all variables taken separately have a significant effect on mean SOC [%]: crop/pasture 1.33/1.6, North/South 1.61/1.32, low/middle/high 1.09/1.62/1.68, shallow/deep 1.4/1.53. However, for BC, only land use has a significant effect with more than twice the amount of carbon in pastures [g m-2]: crop/pasture 127/318. These preliminary findings suggest that preventing the conversion of pastures into cropping fields in the Naran valley avoids an average loss of 12.2 t C ha-1 or 44.8 t CO2eq ha-1 representing a foreseeable compensation of 672 € ha-1 for the Naran landless pastoralists who would renounce cropping. The ongoing study shall provide a complete picture for carbon payment integrating key aspects such as the rate of cropping encroachment over pastures per year, the methane leakage from the system due to livestock enteric fermentation, the expected cropping income vs. livestock income and the transaction costs of implementing the mitigation project, certifying it, and verifying carbon credits. A net present value over an infinite time horizon for the mitigation scenario shall be estimated on an iterative simulation to consider weather and price uncertainties. The study will also provide an estimate of the minimum price of carbon at which pastoralists would consider engaging in the mitigation activity.
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The Measurements of Humidity in the Atmosphere and Validation Experiment (MOHAVE) 2009 campaign took place on 11–27 October 2009 at the JPL Table Mountain Facility in California (TMF). The main objectives of the campaign were to (1) validate the water vapor measurements of several instruments, including, three Raman lidars, two microwave radiometers, two Fourier-Transform spectrometers, and two GPS receivers (column water), (2) cover water vapor measurements from the ground to the mesopause without gaps, and (3) study upper tropospheric humidity variability at timescales varying from a few minutes to several days. A total of 58 radiosondes and 20 Frost-Point hygrometer sondes were launched. Two types of radiosondes were used during the campaign. Non negligible differences in the readings between the two radiosonde types used (Vaisala RS92 and InterMet iMet-1) made a small, but measurable impact on the derivation of water vapor mixing ratio by the Frost-Point hygrometers. As observed in previous campaigns, the RS92 humidity measurements remained within 5% of the Frost-point in the lower and mid-troposphere, but were too dry in the upper troposphere. Over 270 h of water vapor measurements from three Raman lidars (JPL and GSFC) were compared to RS92, CFH, and NOAA-FPH. The JPL lidar profiles reached 20 km when integrated all night, and 15 km when integrated for 1 h. Excellent agreement between this lidar and the frost-point hygrometers was found throughout the measurement range, with only a 3% (0.3 ppmv) mean wet bias for the lidar in the upper troposphere and lower stratosphere (UTLS). The other two lidars provided satisfactory results in the lower and mid-troposphere (2–5% wet bias over the range 3–10 km), but suffered from contamination by fluorescence (wet bias ranging from 5 to 50% between 10 km and 15 km), preventing their use as an independent measurement in the UTLS. The comparison between all available stratospheric sounders allowed to identify only the largest biases, in particular a 10% dry bias of the Water Vapor Millimeter-wave Spectrometer compared to the Aura-Microwave Limb Sounder. No other large, or at least statistically significant, biases could be observed. Total Precipitable Water (TPW) measurements from six different co-located instruments were available. Several retrieval groups provided their own TPW retrievals, resulting in the comparison of 10 different datasets. Agreement within 7% (0.7 mm) was found between all datasets. Such good agreement illustrates the maturity of these measurements and raises confidence levels for their use as an alternate or complementary source of calibration for the Raman lidars. Tropospheric and stratospheric ozone and temperature measurements were also available during the campaign. The water vapor and ozone lidar measurements, together with the advected potential vorticity results from the high-resolution transport model MIMOSA, allowed the identification and study of a deep stratospheric intrusion over TMF. These observations demonstrated the lidar strong potential for future long-term monitoring of water vapor in the UTLS.
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The development of the Marcellus Shale gas play in Pennsylvania and the northeastern United States has resulted in significant amounts of water and wastes transported by truck over roadways. This study used geographic information systems (GIS) to quantify truck travel distances via both the preferred routes (minimum distance while also favoring higher-order roads) as well as, where available, the likely actual distances for freshwater and waste transport between pertinent locations (e. g., gas wells, treatment facilities, freshwater sources). Results show that truck travel distances in the Susquehanna River Basin are greater than those used in prior life-cycle assessments of tight shale gas. When compared to likely actual transport distances, if policies were instituted to constrain truck travel to the closest destination and higher-order roads, transport mileage reductions of 40-80% could be realized. Using reasonable assumptions of current practices, greenhouse gas (GHG) emissions associated with water and waste hauling were calculated to be 70-157 MT CO2 eq per gas well. Furthermore, empty so-called backhaul trips, such as to freshwater withdrawal sites or returning from deep well injection sites, were found to increase emissions by an additional 30%, underscoring the importance of including return trips in the analysis. The results should inform future life-cycle assessments of tight shale gases in managed watersheds and help local and regional governments plan for impacts of transportation on local infrastructure. (C) 2013 American Society of Civil Engineers.
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The transition in Central and Eastern Europe since the late 1980s has provided a testing ground for classic propositions. This project looked at the impact of privatisation on private consumption, using the Czech experiment of voucher privatisation to test the permanent income hypothesis. This form of privatisation moved state assets to individuals and represented an unexpected windfall gain for participants in the scheme. Whether the windfall was consumed or saved offers a clear test of the permanent income hypothesis. Of a total population of 10 million, 6 million Czechs, i.e. virtually every household, participated in the scheme,. In a January 1996 survey, 1263 individuals were interviewed , 75% of whom had taken part. The data obtained suggests that only a small quantity of transferred assets were cashed in and spent on consumption, providing support for the permanent income hypothesis. The fraction of the windfall consumed grows with age, as would be predicted from the lower life expectancy of older consumers. The most interesting deviation was for people aged 26 to 35, who apparently consumed more that they would if the windfall were annuitised. As these people are at the stage in their lives when they would otherwise be borrowing to cover consumption related to establishing a family, etc., this is however consistent with the permanent income hypothesis, which predicts that individuals who would otherwise borrow money would use the windfall to avoid doing so.
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The relative abundance of the heavy water isotopologue HDO provides a deeper insight into the atmospheric hydrological cycle. The SCanning Imaging Absorption spectroMeter for Atmospheric CartograpHY (SCIAMACHY) allows for global retrievals of the ratio HDO/H2O in the 2.3 micron wavelength range. However, the spectroscopy of water lines in this region remains a large source of uncertainty for these retrievals. We therefore evaluate and improve the water spectroscopy in the range 4174–4300 cm−1 and test if this reduces systematic uncertainties in the SCIAMACHY retrievals of HDO/H2O. We use a laboratory spectrum of water vapour to fit line intensity, air broadening and wavelength shift parameters. The improved spectroscopy is tested on a series of ground-based high resolution FTS spectra as well as on SCIAMACHY retrievals of H2O and the ratio HDO/H2O. We find that the improved spectroscopy leads to lower residuals in the FTS spectra compared to HITRAN 2008 and Jenouvrier et al. (2007) spectroscopy, and the retrievals become more robust against changes in the retrieval window. For both the FTS and SCIAMACHY measurements, the retrieved total H2O columns decrease by 2–4% and we find a negative shift of the HDO/H2O ratio, which for SCIAMACHY is partly compensated by changes in the retrieval setup and calibration software. The updated SCIAMACHY HDO/H2O product shows somewhat steeper latitudinal and temporal gradients and a steeper Rayleigh distillation curve, strengthening previous conclusions that current isotope-enabled general circulation models underestimate the variability in the near-surface HDO/H2O ratio.
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OBJECTIVES: This study was designed to evaluate the effect of gap width and graft placement on bone healing around implants placed in simulated extraction sockets of various widths in four Labrador dogs. MATERIALS AND METHODS: Five Osseotite implants per dog were placed in the mandible of four dogs. Two implants were inserted into sites with a 2.37 mm and two with a 1 mm gap present between the implants and bone around the coronal 6 mm of the implants in each dog. For one of each gap sizes, the gap was filled with Bio-Oss, and the other two with blood alone. A fifth implant was inserted without a gap and used as a control. Ground sections were prepared from biopsies taken at 4 months and histometric measurements of osseointegration and bone between the threads made for the coronal 6 mm. RESULTS: The medians for osseointegration ranged from 5.2 mm for control to 1-2.6 mm for the test modalities. There were significant differences for linear measurements of osseointegration (chi(2) 18.27; df 4; P=0.0011) and bone area within threads (chi(2) 23.4; df 4; P=0.0001) between test modalities. CONCLUSIONS: The results suggest that the wider the gap around the implants, the less favourable the histological outcome at short time intervals following treatment. They also infer that bone grafting with an organic bovine bone xenograft seems to lead to a more favourable histological outcome for wider circumferential defects but not for narrower defects.
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The role of colostrum and milk in the neonate has been chiefly recognized as a comprehensive nutrient foodstuff. In addition, the provision of colostrum-the first milk-for early immune capacity has been well documented for several species. Colostrum is additionally a rich and concentrated source of various factors that demonstrate biological activity in vitro. Three hypotheses have been proposed for the phenotypic function of these secreted bioactive components: (1) only mammary disposal, (2) mammary cell regulation, and (3) neonatal function [gastrointestinal tract (GIT) or systemic]. Traditionally, it was assumed that the development of the GIT is preprogrammed and not influenced by events occurring in the intestinal lumen. However, a large volume of research has demonstrated that colostrum (or milk-borne) bioactive components can basically contribute to the regulation of GIT growth and differentiation, while their role in postnatal development at physiological concentrations has remained elusive. Much of our current understanding is derived from cell culture and laboratory animals, but experimentation with agriculturally important species is taking place. This chapter provides an overview of work conducted primarily in neonatal calves and secondarily in other species on the effects on neonates of selected peptide endocrine factors (hormones, growth factors, in part cytokines) in colostrum. The primary focus will be on insulin-like growth factors (IGFs) and IGF binding proteins (IGFBPs) and other bioactive peptides, but new interest and concern about steroids (especially estrogens) in milk are considered as well.
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Efficient planning of soil conservation measures requires, first, to understand the impact of soil erosion on soil fertility with regard to local land cover classes; and second, to identify hot spots of soil erosion and bright spots of soil conservation in a spatially explicit manner. Soil organic carbon (SOC) is an important indicator of soil fertility. The aim of this study was to conduct a spatial assessment of erosion and its impact on SOC for specific land cover classes. Input data consisted of extensive ground truth, a digital elevation model and Landsat 7 imagery from two different seasons. Soil spectral reflectance readings were taken from soil samples in the laboratory and calibrated with results of SOC chemical analysis using regression tree modelling. The resulting model statistics for soil degradation assessments are promising (R2=0.71, RMSEV=0.32). Since the area includes rugged terrain and small agricultural plots, the decision tree models allowed mapping of land cover classes, soil erosion incidence and SOC content classes at an acceptable level of accuracy for preliminary studies. The various datasets were linked in the hot-bright spot matrix, which was developed to combine soil erosion incidence information and SOC content levels (for uniform land cover classes) in a scatter plot. The quarters of the plot show different stages of degradation, from well conserved land to hot spots of soil degradation. The approach helps to gain a better understanding of the impact of soil erosion on soil fertility and to identify hot and bright spots in a spatially explicit manner. The results show distinctly lower SOC content levels on large parts of the test areas, where annual crop cultivation was dominant in the 1990s and where cultivation has now been abandoned. On the other hand, there are strong indications that afforestations and fruit orchards established in the 1980s have been successful in conserving soil resources.
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Small clusters of gallium oxide, technologically important high temperature ceramic, together with interaction of nucleic acid bases with graphene and small-diameter carbon nanotube are focus of first principles calculations in this work. A high performance parallel computing platform is also developed to perform these calculations at Michigan Tech. First principles calculations are based on density functional theory employing either local density or gradient-corrected approximation together with plane wave and gaussian basis sets. The bulk Ga2O3 is known to be a very good candidate for fabricating electronic devices that operate at high temperatures. To explore the properties of Ga2O3 at nonoscale, we have performed a systematic theoretical study on the small polyatomic gallium oxide clusters. The calculated results find that all lowest energy isomers of GamOn clusters are dominated by the Ga-O bonds over the metal-metal or the oxygen-oxygen bonds. Analysis of atomic charges suggest the clusters to be highly ionic similar to the case of bulk Ga2O3. In the study of sequential oxidation of these slusters starting from Ga2O, it is found that the most stable isomers display up to four different backbones of constituent atoms. Furthermore, the predicted configuration of the ground state of Ga2O is recently confirmed by the experimental result of Neumark's group. Guided by the results of calculations the study of gallium oxide clusters, performance related challenge of computational simulations, of producing high performance computers/platforms, has been addressed. Several engineering aspects were thoroughly studied during the design, development and implementation of the high performance parallel computing platform, rama, at Michigan Tech. In an attempt to stay true to the principles of Beowulf revolutioni, the rama cluster was extensively customized to make it easy to understand, and use - for administrators as well as end-users. Following the results of benchmark calculations and to keep up with the complexity of systems under study, rama has been expanded to a total of sixty four processors. Interest in the non-covalent intereaction of DNA with carbon nanotubes has steadily increased during past several years. This hybrid system, at the junction of the biological regime and the nanomaterials world, possesses features which make it very attractive for a wide range of applicatioins. Using the in-house computational power available, we have studied details of the interaction between nucleic acid bases with graphene sheet as well as high-curvature small-diameter carbon nanotube. The calculated trend in the binding energies strongly suggests that the polarizability of the base molecules determines the interaction strength of the nucleic acid bases with graphene. When comparing the results obtained here for physisorption on the small diameter nanotube considered with those from the study on graphene, it is observed that the interaction strength of nucleic acid bases is smaller for the tube. Thus, these results show that the effect of introducing curvature is to reduce the binding energy. The binding energies for the two extreme cases of negligible curvature (i.e. flat graphene sheet) and of very high curvature (i.e. small diameter nanotube) may be considered as upper and lower bounds. This finding represents an important step towards a better understanding of experimentally observed sequence-dependent interaction of DNA with Carbon nanotubes.
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This study investigates the compressive properties of concrete incorporating Mature Fine Tailings (MFTs) waste stream from a tar sands mining operation. The objectives of this study are to investigate material properties of the MFT material itself, as well as establish general feasibility of the utilization of MFT material in concrete mixtures through empirical data and visual observations. Investigations undertaken in this study consist of moisture content, materials finer than No. 200 sieve, Atterburg Limits as well as visual observations performed on MFT material as obtained. Control concrete mixtures as well as MFT replacement mixture designs (% by wt. of water) were guided by properties of the MFT material that were experimentally established. The experimental design consists of compression testing of 4”-diameter concrete cylinders of a control mixture, 30% MFT, 50% MFT and 70% MFT replacement mixtures with air-entrainer additive, as well as a control mixture and 30% MFT replacement mixture with no air-entrainer. A total of 6 mixtures (2 control mixtures, 4 replacement mixtures) moist-cured in lime water after 24 hours initial curing were tested for ultimate compressive strength at 7 days and 28 days in accordance to ASTM C39. The test results of fresh concrete material show that the addition of air-entrainer to the control mixture increases slump from 4” to 5.5”. However, the use of MFT material in concrete mixtures significantly decreases slump as compared to controls. All MFT replacement mixtures (30%, 50%, and 70%) with air-entrainer present slumps of 1”. 30% MFT with no air-entrainer presents a slump of 1.5”. It was found that 7-day ultimate compressive stress was not a good predictor of 28-day ultimate compressive stress. 28-day results indicate that the use of MFT material in concrete with air-entrainer decreases ultimate compressive stress for 30%, 50% and 70% MFT replacement amounts by 14.2%, 17.3% and 25.1% respectively.
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High concentrations of fluoride naturally occurring in the ground water in the Arusha region of Tanzania cause dental, skeletal and non-skeletal fluorosis in up to 90% of the region’s population [1]. Symptoms of this incurable but completely preventable disease include brittle, discolored teeth, malformed bones and stiff and swollen joints. The consumption of high fluoride water has also been proven to cause headaches and insomnia [2] and adversely affect the development of children’s intelligence [3, 4]. Despite the fact that this array of symptoms may significantly impact a society’s development and the citizens’ ability to perform work and enjoy a reasonable quality of life, little is offered in the Arusha region in the form of solutions for the poor, those hardest hit by the problem. Multiple defluoridation technologies do exist, yet none are successfully reaching the Tanzanian public. This report takes a closer look at the efforts of one local organization, the Defluoridation Technology Project (DTP), to address the region’s fluorosis problem through the production and dissemination of bone char defluoridation filters, an appropriate technology solution that is proven to work. The goal of this research is to improve the sustainability of DTP’s operations and help them reach a wider range of clients so that they may reduce the occurrence of fluorosis more effectively. This was done first through laboratory testing of current products. Results of this testing show a wide range in uptake capacity across batches of bone char emphasizing the need to modify kiln design in order to produce a more consistent and high quality product. The issue of filter dissemination was addressed through the development of a multi-level, customerfunded business model promoting the availability of filters to Tanzanians of all socioeconomic levels. Central to this model is the recommendation to focus on community managed, institutional sized filters in order to make fluoride free water available to lower income clients and to increase Tanzanian involvement at the management level.
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Direction-of-arrival (DOA) estimation is susceptible to errors introduced by the presence of real-ground and resonant size scatterers in the vicinity of the antenna array. To compensate for these errors pre-calibration and auto-calibration techniques are presented. The effects of real-ground constituent parameters on the mutual coupling (MC) of wire type antenna arrays for DOA estimation are investigated. This is accomplished by pre-calibration of the antenna array over the real-ground using the finite element method (FEM). The mutual impedance matrix is pre-estimated and used to remove the perturbations in the received terminal voltage. The unperturbed terminal voltage is incorporated in MUSIC algorithm to estimate DOAs. First, MC of quarter wave monopole antenna arrays is investigated. This work augments an existing MC compensation technique for ground-based antennas and proposes reduction in MC for antennas over finite ground as compared to the perfect ground. A factor of 4 decrease in both the real and imaginary parts of the MC is observed when considering a poor ground versus a perfectly conducting one for quarter wave monopoles in the receiving mode. A simulated result to show the compensation of errors direction of arrival (DOA) estimation with actual realization of the environment is also presented. Secondly, investigations for the effects on received MC of λ/2 dipole arrays placed near real-earth are carried out. As a rule of thumb, estimation of mutual coupling can be divided in two regions of antenna height that is very near ground 0
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The Koyukuk Mining District was one of several northern, turn of the century, gold rush regions. Miners focused their efforts in this region on the Middle Fork of the Koyukuk River and on several of its tributaries. Mining in the Koyukuk began in the 1880s and the first rush occurred in 1898. Continued mining throughout the early decades of the 1900s has resulted in an historic mining landscape consisting of structures, equipment, mining shafts, waste rock, trash scatters, and prospect pits. Modern work continues in the region alongside these historic resources. An archaeological survey was completed in 2012 as part of an Abandoned Mine Lands survey undergone with the Bureau of Land Management, Michigan Technological University, and the University of Alaska Anchorage. This thesis examines the discrepancy between the size of mining operations and their respective successes in the region while also providing an historical background on the region and reports on the historical resources present.
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Acer saccharum Marsh., is one of the most valuable trees in the northern hardwood forests. Severe dieback was recently reported by area foresters in the western Upper Great Lakes Region. Sugar Maple has had a history of dieback over the last 100 years throughout its range and different variables have been identified as being the predisposing and inciting factors in different regions at different times. Some of the most common factors attributed to previous maple dieback episodes were insect defoliation outbreaks, inadequate precipitation, poor soils, atmospheric deposition, fungal pathogens, poor management, or a combination of these. The current sugar maple dieback was evaluated to determine the etiology, severity, and change in dieback on both industry and public lands. A network of 120 sugar maple health evaluation plots was established in the Upper Peninsula, Michigan, northern Wisconsin, and eastern Minnesota and evaluated annually from 2009-2012. Mean sugar maple crown dieback between 2009-2012 was 12.4% (ranging from 0.8-75.5%) across the region. Overall, during the sampling period, mean dieback decreased by 5% but individual plots and trees continued to decline. Relationships were examined between sugar maple dieback and growth, habitat conditions, ownership, climate, soil, foliage nutrients, and the maple pathogen sapstreak. The only statistically significant factor was found to be a high level of forest floor impacts due to exotic earthworm activity. Sugar maple on soils with lower pH had less earthworm impacts, less dieback, and higher growth rates than those on soils more favorable to earthworms. Nutritional status of foliage and soil was correlated with dieback and growth suggesting perturbation of nutrient cycling may be predisposing or contributing to dieback. The previous winter's snowfall totals, length of stay on the ground, and number of days with freezing temperatures had a significant positive relationship to sugar maple growth rates. Sapstreak disease, Ceratocystis virescens, may be contributing to dieback in some stands but was not related to the amount of dieback in the region. The ultimate goal of this research is to help forest managers in the Great Lakes Region prevent, anticipate, reduce, and/or salvage stands with dieback and loss in the future. An improved understanding of the complex etiology associated with sugar maple dieback in the Upper Great Lakes Region is necessary to make appropriate silvicultural decisions. Forest Health education helps increase awareness and proactive forest management in the face of changing forest ecosystems. Lessons are included to assist educators in incorporating forest health into standard biological disciplines at the secondary school curricula.