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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Estimation of total and active microbial biomass in soils subjected to long-term storage and restoration

Williamson, J. C. January 1988 (has links)
No description available.
2

Assessment of stockpiling methods to increase late summer and early fall forage biomass

Hickman, Amber Leanna 06 May 2013 (has links)
As one of the major forage crops of the United States management programs to optimize stockpiled tall fescue (Festuca arundinacea Schreb.) can potentially increase livestock profitability.  This study consists of two experiments designed to assess different aspects of summer stockpiling.  Experiment 1 evaluated the effects of summer stockpiling endophyte infected Kentucky 31 tall fescue on biomass and nutritive value of tall fescue forage.  Treatments included four whole plot treatments (two nitrogen (N) application timing, legume inclusion, and control) each divided into sub-plot cut and no cut treatments.  The cut treatment consisted of a single cutting taken in May.  Nitrogen in the form of urea was applied at a rate of 56 kg/ha for the March N treatment and for the June N treatment.  Yield and quality of summer stockpiled fescue was adequate to support dry beef cows.  Experiment 2 evaluated the effects of summer stockpiling on the biomass yield and nutritive value of three types of tall fescue with N fertilization (endophyte infected (E+), endophyte-free (E-), and novel endophyte (MaxQ)) and four species of native warm-season grasses without N fertilization (switchgrass (Panicum virgatum L.), big bluestem (Andropogon gerardii Vitman), indiangrass (Sorghastrum nutans (L.) Nash), and little bluestem (Schizachyrium scoparium (Michx.) Nash)).  Native warm-season grasses produced much higher yields than all tall fescue types but the nutritive value was not adequate to support the nutrient requirements of livestock.  Summer stockpiled tall fescue is a viable resource to provide low requirement animals with quality forage during late summer and early fall. / Master of Science
3

Forage Utilization and Nitrogen Management of Tall Fescue Stockpiled for Winter Grazing

Shireman, Nathan Todd 30 June 2015 (has links)
The Southeastern United States offers a beneficial environment for stocker and cow-calf production. Abundant tall fescue grass offers a feed source that has been underutilized. These studies evaluated how nitrogen rate and source can affect yield and nutritional quality of fall stockpiled tall fescue, and how grazing methods impact weight gains, forage utilization, and forage nutritive value. The first study evaluated the impact of N rate and source on the yield tall fescue stockpiled for winter grazing. In mid-September, seven N sources (ammonium sulfate (AS), ammonium nitrate (AN), urea + Agrotain @ 2.1 l/Mg (AG2), urea + Agrotain @ 4.2 l/Mg (AG4), urea + Agrotain @ 6.3 l/Mg (AG6), Nutrisphere (NuS), and urea) were applied at 0, 45, 90, and 135 kg N/ha. Ammonium sulfate produced the highest nutritive values of all N sources. Only yield in 2012 was found to be influenced by N volatilization inhibitors; said products had no effect on nutritive value. The second study evaluated how grazing methods impact nutritive value, ADG, and utilization of tall fescue stockpiled for winter grazing. Three treatments (continuous grazing, moved once per week, and moved twice per week) were used. In year one, cattle moved once and twice per week showed significantly higher ADG (P < 0.05) than the continuous treatment. In year two, cattle that continuously grazed had higher ADG (P <0.05), than cattle moved once and twice per week. Cattle moved once and twice per week showed greater forage utilization (P < 0.05) than cattle that continuously grazed. / Master of Science
4

An analysis of the tax implications of ore stockpiling in the mining industry

Faber, Pieter Coenraad 27 February 2009 (has links)
The purpose of this study was to examine whether unmined ore stockpiles fall within the ambit of the definition of trading stock in section 1 of the Income Tax Act (58/1962) and therefore needs to be considered for the purposes of section 22 in the determination of taxable income. Furthermore the judgement in Richards Bay Iron&Titanium (Pty) Ltd and Another v CIR (1996:55) would be analysed to determine whether a distinction could be made between the stockpiled material held in that case as opposed to unmined ore. The research object would be determined by analysing the nature of ore stockpiles, the accounting treatment ore stockpiles and its effect on the tax treatment as well as the taxation of stockpiles in terms of case law. As to the first part, a distinction in the legal sense was examined between movable and immovable property. It was concluded that stockpiles could by its nature in certain circumstances, be considered immovable property even though they became movable by its separation from the soil. Intention was furthermore identified as one of the most important criteria in a three tier test for the determination of the legal nature of stockpiles. As to its tax nature, it was concluded that even though case law suggests that the intention to realise through mining activities could make such stockpiles floating capital, it was submitted that intention remains the conclusive criteria and therefore only once an intention exist, to utilise mining property in a mining process that is a scheme of profit making, does the intention change and does the fixed capital (both immovable property and movable stockpiles) become floating capital. In the second chapter an analysis was done of the financial reporting requirements for stockpiles and whether the accounting treatment thereof would influence the tax treatment. It was concluded that the accounting treatment would influence the tax treatment as the definition of trading stock in section 1 of the ITA (58/1962) is actually an extension of the normal grammatical meaning, the latter for which the accounting treatment is critical. In terms of IAS1 it was found that an essential criterion for a current asset was that it must be expected to be realised in the 12 months after the reporting date. It was found that even though mined ore and crushed ore could be seen as work in progress and thus inventories, such ore still had to comply with the requirements of IAS1 and IAS2 to be classified as inventory. The valuation of the ore would be in terms of IAS2 if at historical cost and in terms of SANREC if at net realisable value. It was concluded that stockpiles that did not meet the trading stock criteria due to various uncertain circumstances could be disclosed as non-current assets at historical cost, but not in terms of IAS16. However, if no reasonable expectation of future benefits existed, then no disclosure would be required. In examining the taxation of stockpiles the definition of trading stock was analysed. It was concluded that to the extent that the normal grammatical meaning did not apply, the extension to the definition still had to be considered. It was held that the extension to the definition had two parts of which the first required that the object must be acquired, produced or manufactured for the purpose of use in a manufacturing process, irrespective of whether the object was saleable in its current condition. The second part required no intention but was an objective enquiry of whether a saleable object was disposed of and which the proceeds would be revenue in nature It was also found that a distinction between a mining process and a manufacturing process exists in the South African tax law and that objects intended for use in the different processes could be treated differently from a tax perspective. Finally the analysis of the Richards Bay case (1996:55) revealed that even though the court considered that stockpiles are raw materials or work-in-progress, it was the taxpayer’s admission of a manufacturing process and his lack of distinction of the mining process that was critical in the decision against him. The court accepted the taxpayer’s contentions and withheld opinion on these two critical matters. It was concluded that stockpiles of unmined ore did not constitute trading stock in the extended definition and only under very specific circumstances could it be considered trading stock under the normal grammatical meaning when inferred from accounting disclosure and valuation requirements. Copyright / Dissertation (MCom)--University of Pretoria, 2009. / Taxation / unrestricted
5

Stockpiling and resource allocation for influenza preparedness and manufacturing assembly

Huang, Hsin-Chan 06 November 2014 (has links)
Stockpiling resources is a pervasive way to handle demand uncertainty and future demand surges. However, stockpiling is subject to costs, including warehousing costs, inventory holding costs, and wastage of expired resources. Hence, how to stockpile in an economically efficient manner is an important topic to study. Furthermore, if the inventoried supply is insufficient for a surge in demand, how to best allocate available resources becomes a natural question to ask. In this dissertation, we consider three applications of stockpiling and resource allocation: (i) we stockpile ventilators both centrally and regionally for an influenza pandemic; (ii) we allocate limited vaccine doses of various types to target populations for an influenza pandemic; and, (iii) we investigate inventory needs for low cost, high usage (class C) parts in an engine assembly plant. First, we describe and analyze a model for estimating the number of ventilators that the Texas Department of State Health Services (DSHS), and eight health service regions in Texas, should stockpile for an influenza pandemic. Using a probability distribution governing peak-week demand for ventilators across the eight health service regions, an optimization model allows investigation of the tradeoff between the cost of the total stockpile and the expected shortfall of ventilators under mild, moderate, and severe pandemic scenarios. Our analysis yields the surprising result that there is little benefit to DSHS holding a significant stockpile, even when those centrally held ventilators can be dispatched to regions after observing the peak-week demand realization. Three factors contribute to this result: positively correlated regional demands, a relatively low coefficient of variation, and wastage of the central stockpile once it is dispatched to the regions. Second, we formulate an optimization model for allocating various types of vaccines to multiple priority groups in 254 counties in the state of Texas that DSHS can use to distribute its vaccines for an influenza pandemic. For reaching the public, vaccines are allocated to the state’s Registered Providers (RPs), Local Health Departments (LHDs), and Health Service Regions (HSRs). The first two allocations are driven by requests from RPs and LHDs while HSR allocation is at DSHS’s discretion. The optimization model aims to achieve proportionally fair coverage of priority groups across the 254 counties, as informed by user-specified weights on those priority groups, using the HSR doses. With proportional fairness as our primary goal, the optimal allocation also counts policy simplicity and regional equity. Sensitivity analysis on the portion of the state’s vaccines reserved for HSRs shows that a small portion can effectively shrink the gap of vaccination coverage between urban and rural counties. Finally, we derive short-cut formulae for estimating the extra inventory needed for managing class C parts in units of bins that an engine assembly plant can use to achieve a desired fill rate at workstations. The plant orders a class C part from its supplier based on the part’s aggregated next-day demand across all workstations. After receiving the part, the plant first stores the supply in the warehouse and delivers the part to workstations in bins whenever the line-side inventory at a workstation is empty. We study four cases of various information availability in the order quantity calculation and derive associated formulae for estimating the extra inventory needed due to demand aggregation and bin delivery. We demonstrate the performance of our short-cut formulae, showing the tradeoff between extra inventory needed and the associated risk of not satisfying all workstation requests. Our sensitivity analysis shows that workstation demand variation and bin size have little or no influence on the performance of our short-cut formulae. / text
6

ENHANCED EFFICIENCY NITROGEN FORMULATION EFFECT ON GRASS-LEGUME PASTURE PRODUCTIVITY

Payne, Kathryn Marie 01 January 2019 (has links)
The use of nitrogen (N) fertilizer is generally restricted on mixed species forage systems due to its stimulatory effect on grasses which increases competition with legume species. Reduced legume growth from this competition can compromise forage nutritive value and prospective yields. The controlled-release nature of several enhanced efficiency fertilizer N products holds the potential to improve legume persistence in mixed species pastures while providing supplemental N required by the grass component. The studies contained in this dissertation evaluated the effect of different enhanced efficiency N formulations (ATU, ESN, methylene urea, SuperU, and a 75% ESN: 25% urea blend) and untreated urea on yield, nutritive value, and legume persistence in a ‘Wrangler’ bermudagrass and ‘Durana’ white clover mixture (2014-2016 growing seasons), ‘KY-31’tall fescue and ‘Kenland’ red clover mixture (2015-2016 growing seasons), and ‘KY-31’ stockpiled tall fescue (2015-2017). The three studies were conducted at the University of Kentucky Spindletop Research Farm in Lexington, KY in a randomized complete block design. In the bermudagrass-white clover study, all enhanced efficiency N sources maintained white clover populations similar to the unfertilized grass/clover control, but only ESN caused greater clover composition than standard urea. Total forage yields increased linearly with N rate in all years, but dry weather conditions in the second and third years resulted in lower total yield. Forage nutritive value followed general trends throughout each growing season, but ESN’s ability to maintain clover resulted in higher nutritive value. In the tall fescue-red clover, total forage yields curvilinearly increased with N rate in 2015 but did not vary in 2016. ESN and ESN+urea blend treatments retained clover composition similar to that of the unfertilized control. Stockpiled forage yield increased with higher N rates. Enhanced efficiency N fertilizers with the ability to control N release can enhance forage yield while maintaining clover in mixed species swards.
7

Oil Sands Mine Reclamation Using Boreal Forest Surface Soil (LFH) in Northern Alberta

MacKenzie, Dean D Unknown Date
No description available.
8

Stockpiling Behavior Impacted by Social Media Use Among Middle-aged Women Consumers in Sweden Amid Coronavirus Pandemic Outbreak

Lin, Biqiong January 2020 (has links)
The research paper presents qualitative research and aims to examine the impact of social media on consumers’ stockpiling behavior under the situation of the coronavirus disease (COVID-19) outbreak in Sweden since week 11, 2020. Data is collected by interviewing five middle-aged women in Sweden who are either native Swedes or permanent immigrants and who had experienced stockpiling behavior. The interpretation of collected data is discussed based on the two-step flow theory, risk communication and the theory of planned behavior, and the social contagion theory. The qualitative content analysis is used to analyze the data with the results of three themes: being inclined to reach information, realizing why and when to hoard things, and behavior changes and showing confidence. The five women interviewed all use various social media ways to get information about COVID-19. There is a significant correlation between social media use, risk perception formulation, and stockpiling behavior. Participants have their judgment to look into the authenticity and reliability of related news. They trust the official social media reports, underwent the influence of social media reports, two-way online interaction, and other stockpiling consumers. They also experience the decreasing level of risk perception and thus changes in stockpiling behavior.
9

The psychology behind stockpiling behaviour during critical situations : A study of the change in consumer behaviour with special regards to the phenomenon stockpiling among Swedish residents during the Covid-19 outbreak

Hanser, Anna, Bereilh, David January 2020 (has links)
Background: The novel coronavirus (Covid-19) spread globally from its outbreak in China in the beginning of 2020, causing numerous deaths and strained on the health care systems all over the world. Most countries gave answer to this pandemic by implementing national lockdowns, which often evoked panic among citizens and therefore lead to stockpiling or sometimes panic buying behaviours. However, Sweden decided to take another approach in handling the crisis and refrained from implementing a forced lockdown and mainly focused on the responsibility of individuals. Given the lack of research in the field of stockpiling behaviour among Swedish residents and the magnitude of difference in the “Swedish approach”, compared to other countries, this situation provides the perfect ground to research stockpiling behaviour in Sweden. Purpose: This research aims to identify patterns and drivers within stockpiling behaviour among Swedish residents during the Covid-19 outbreak. Method: The paper is based on a qualitative study. A frame of reference to support findings and provide important links to existing literature regarding the psychology behind consumer behaviour, in particular stockpiling during critical situations, has been presented. To create in-depth insight into the reasonings behind stockpiling behaviour in Sweden during the Covid-19 outbreak, six semi-structured interviews have been conducted. Conclusion: Two patterns, rational stockpiling and the absence of irrational stockpiling, along with five drivers, namely, governmental restrictions and recommendations, fear from the disease or transmission, risk mitigation, convenience, and level of trust in the government, have been observed.
10

The impact of demand uncertainty on stockpile and distribution decisions during influenza pandemic

Waldman, Andrew M. January 1900 (has links)
Master of Science / Department of Industrial & Manufacturing Systems Engineering / Jessica L. Heier Stamm / The main goal of public health emergency preparedness efforts is to mitigate the impact of events on the health of the population. However, decision-makers must also remain conscientious of the costs associated with these efforts. Planning is further complicated by uncertainty about the location and volume of demand that will need to be met in an emergency, the speed with which demand must be met, and the potential scarcity of needed items once an emergency occurs. To address these challenges, public health emergency planners often keep inventory stockpiles that are distributed when an event happens. Managing these stockpiles is a difficult task, and inefficient stockpile location and equipment distribution strategies can be costly both in terms of cost and public health impact. This research is motivated by challenges faced by state public health departments in creating stockpile location and equipment distribution strategies. The primary emphasis is on facemasks and respirators used by health workers during an influenza pandemic, but the approach is generalizable to other scenarios. The model proposed here uses a two-stage approach to generate a holistic solution to the problem. The first stage uses a pull distribution strategy to make stockpile location decisions. Additionally, it determines how counties should be assigned to stockpiles to minimize both storage and distribution costs. The second stage adopts a push distribution strategy to determine optimal delivery routes based on the county assignments made in stage one. This stage offers guidance for public health planners who have made location-allocation decisions but who then face a different distribution scenario than what was anticipated in the original planning phase. Recourse methods for managing demand uncertainty are also proposed. A case study of the state of Kansas is conducted using the methods introduced in the thesis. The computational results yield several significant insights into the tradeoffs and costs of various facility location-allocation and vehicle routing decisions: • For the tested range of storage and distribution cost parameters, multiple stockpile locations are preferred over a single location. • In a pull distribution system, storage costs play a greater role in location-allocation decisions than distribution costs. • In the push distribution system, finding an optimal vehicle routing plan is computationally intensive for stockpiles with a large number of assigned counties. • Efficient heuristics perform well to design recourse routing plans when realized demand is greater than expected. • In the event that planners wish to specify routes well in advance, the results of this research suggest adopting a robust routing plan based on higher-than-expected demand levels. This thesis makes three important contributions. The first is an optimization approach that considers multiple distribution strategies. This is especially relevant when stockpiling for an influenza pandemic where stockpiles need to be located significantly before the material is needed, during which time the distribution strategy may change. Second, the case study demonstrates that the proposed methods are applicable to a large-scale problem arising in practice. Finally, this research illustrates for decision-makers the tradeoffs between different stockpile management strategies and between optimal and heuristic methods.

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