• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 98
  • 35
  • 18
  • 6
  • 5
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 214
  • 98
  • 51
  • 31
  • 29
  • 24
  • 21
  • 19
  • 19
  • 19
  • 18
  • 18
  • 17
  • 17
  • 16
  • 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.
101

'n Staatkundige ontleding van geselekteerde standpunte tydens die grondwetlike onderhandelingsprosesse in die Republiek van Suid-Afrika : 1992-1996 (Afrikaans)

Du Plessis, Hendrik Christoffel 26 July 2006 (has links)
AFRIKAANS: In Suid-Afrika het 'n onderhandelde oorgang na demokrasie van 1992 af tot 1996 voorgekom waartydens twee grondwette deur die betrokke politieke partye onderhandel is. Die eerste bydrae in die studie is dat aangetoon word dat die Suid¬-Afrikaanse voorbeeld van die onderhandelde oorgang die siening in die literatuur ondersteun dat politieke partye 'n belangrike rol in die uitvoering van oorgangstake kan vervul indien hul oor die vermoë beskik. Die hoof vakkundige probleem wat in die studie gestel is, is of die grondwetlike onderhandelingsprosesse daarop dui of daar 'n noodwendige verhouding is tussen die verwesenliking van 'n party se standpunte in 'n grondwet, en die politieke mag waaroor 'n party beskik. 'n Analise van die standpunte van die drie grootste partye in vergelyking met die onderhandelingsresultate het getoon dat daar wel 'n verhouding bestaan tussen die verwesenliking van die hoeveelheid standpunte in 'n grondwet en die politieke mag waaroor 'n party beskik. Waar die twee hoofpartye (die ANC en die NP) ten opsigte van die 1993-Grondwet in 'n relatiewe magsewewig tot mekaar was, is 'n kompromie tussen die NP se hoofdoelwit van magsdeling en die ANC se hoofdoelwit van meerderheidsregering basies getref deurdat kernaspekte van beide hierdie hoofdoelwitte verwesenlik is. Met die 1996-Grondwet, waar die ANC oor die groter politieke mag beskik het, is die grondwetlike resultaat nader aan die hoofdoelwit van meerderheidsregering as aan magsdeling. Die IVP het aan beide onderhandelingsprosesse onttrek, maar sodoende is die invloed van die magsbalans tussen die partye op die grondwetlike resultaat nie ontduik nie. Die rede is dat dié party nie daarin geslaag het om die oorhoofse beleidsdoelwit van 'n opvallende federale bedeling wat baie gedesentraliseerd is te realiseer nie. 'n Verdere bydrae in die studie is dat aangetoon is hoe suksesvol partye tot die bereiking van 'n demokratiese ooreenkoms in Suid-Afrika bygedra het. In hierdie verband is 'n oorhoofse onderhandelingsingesteldheid met behulp van 'n raamwerk geïdentifiseer wat elke party met onderhandelinge gevolg het. 'n Party dra hiervolgens suksesvol tot die bereiking van 'n demokratiese ooreenkoms by deur 'n basiese balans te handhaaf tussen 'n samewerkende onderhandelingsingesteldheid (waardeur die onderhandelingsverhouding bevorder word) en 'n handhawende onderhandelingsingesteldheid (waardeur ondersteuners se belange bevorder word). Die ANC het ten opsigte van die 1993-Grondwet min of meer sodanige balans gehandhaaf ('n effens meer samewerkende as handhawende ingesteldheid), terwyl die klem van die Party na die verwesenliking van die belange van ondersteuners verskuif het ('n meestal handhawende ingesteldheid) met die onderhandeling van die 1996¬Grondwet. Die NP het ook ten opsigte van die 1993-Grondwet sodanige basiese balans gehandhaaf (effens meer handhawend as samewerkend), terwyl 'n ingesteldheid van meer samewerkend as handhawend ten opsigte van die daarstelling van die 1996-Grondwet openbaar is. Die IVP se onderhandelingstyl van vermyding, deurdat aan beide grondwetskrywende prosesse onttrek is, het beteken dat die Party nie 'n bewussyn openbaar het dat dit noodsaaklik is om ook toegewings te doen ten einde 'n wedersyds aanvaarbare oplossing te vind wat tot die vestiging van die demokrasie lei nie. ENGLISH: A negotiated transfer to democracy took place in South Africa from 1992 to 1996. In this period two constitutions were negotiated by the political parties concerned. The study shows, as a first contribution, that the South African example of the negotiated transfer supports the view in the literature that political parties can play an important role in the execution of tasks related to a transition, if they have the necessary capability. The main problem stated in the study is whether an analysis of the constitutional negotiation processes will show whether an inevitable relation exists between the realisation of the standpoints of a party in a constitution, and the political power of such a party. The standpoints of the three major parties compared with the negotiation results showed that there was indeed such a relation (between the realisation of the number of standpoints in a constitution and the political power of a party). The two major parties (the ANC and the NP) were in a relative balance of power with the negotiation of the 1993 Constitution, and a compromise was therefore reached between the NP's general policy goal of power sharing and the ANC's general policy goal of majority government. Core aspects of both these policy goals were realised. The ANC had the greater political power with the negotiation of the 1996 Constitution and the negotiation result was therefore closer to the policy goal of majority government than to power sharing. The IFP withdrew from both negotiation processes, but did not escape the influence of the balance of power between the parties so doing, because the general policy goal (of a strongly federal, decentralised system) were not achieved. The study further shows to what extent parties contributed successfully to the democratic agreement in South Africa. In this regard, a negotiation disposition that each party followed in negotiations was identified by means of a framework. A party contributes successfully to the realisation of a democratic agreement by achieving a basic balance between a cooperative disposition (through which the negotiation agreement is promoted) and an assertive disposition (through which the interests of supporters are promoted). The ANC managed to achieve such a basic balance regarding the 1993 Constitution (a disposition of being slightly more cooperative than assertive was identified), while the focus shifted to the realisation of the interests of supporters (a mostly assertive disposition) with the negotiation of the 1996 Constitution. The NP also achieved such a basic balance in regard to the 1993 Constitution (slightly more assertive than cooperative), while a disposition of more cooperative than assertive was shown in the realisation of the 1996 Constitution. The IFP's negotiation style of avoidance (in withdrawing from both constitution writing processes), meant that it did not reveal the consciousness that it is also necessary to make concessions in order to find a mutually acceptable solution that would lead to the establishment of democracy. / Thesis (PhD (Political Science))--University of Pretoria, 2007. / Political Sciences / unrestricted
102

Characterizing the Impact of Stress Exposure on Survival of Foodborne Pathogens

Shah, Manoj Kumar January 2019 (has links)
Bacterial pathogens transmitted by the fecal-oral route endure several stresses during survival/growth in host and non-host environments. For foodborne pathogens, understanding the range of phenotypic responses to stressors and the environmental factors that impact survival can provide insights for the development of control measures. For example, the gastrointestinal system presents acidic, osmotic, and cell-envelope stresses and low oxygen levels, but Listeria monocytogenes can withstand these stresses, causing illnesses in humans. Survival/growth characteristics may differ among L. monocytogenes strains under these stressors due to their genetic diversities. Our knowledge of such phenotypic characteristics under bile and salt stresses are inadequate. In this dissertation, variation in growth characteristics was observed among L. monocytogenes strains under bile and osmotic stresses with no evidence of cross-protection, but rather an antagonistic effect was observed with the formation of filaments when pre-exposed to 1% bile and treated with 6% NaCl. This shows that variation in stress adaptability exists among L. monocytogenes strains with the ability to form filaments under these conditions. Similarly, Salmonella survival in soil is dependent on several factors, such as soil, amendment types, moisture, irrigation, and desiccation stress. In this study, the use of HTPP (heat-treated poultry pellets) was investigated as a soil amendment in the survival/growth of Salmonella in soil extracts mimicking runoff events, and in soil cultivated with spinach plants to assess its safety for use for an organic fertilizer. The presence of HTPP in soil increased S. Newport survival with a greater likelihood of its transfer to and survival on spinach plants. Increased microbial loads and rpoS mutant showed decreased growth/survival in soil extracts, however, rpoS was not important for survival in soil under the tested conditions showing possible lack of desiccation stress. These results show that HTPP provided nutrients to the Salmonella for increased growth and survival in soil extracts and soil, respectively, which show that the use of treated BSAAO to soils may still require appropriate mitigation to minimize Salmonella Newport contamination of leafy greens in the pre-harvest environment. Overall, the results in this study increased our understanding of L. monocytogenes and Salmonella phenotypic adaptation to stressful environments.
103

Using Organic Amendments to Stabilize Sand-based Athletic Fields During Turfgrass Establishment Period

Drietz, Thomas January 2019 (has links)
Athletic field rootzones are often sand-based for improved drainage. Sand-based rootzones may have stability issues if turfgrass is not fully established. Our objective was to use organic amendments to improve the stability of sand-based fields during the turfgrass establishment period and avoid overuse of inorganic materials, which have negative effects. We tested coconut coir, peat and wheat straw at 1% organic material, peat at 2% organic material, and an inorganic stabilizing fiber, StaLok, in the top 10 cm of the rootzone. Surface hardness, volumetric water content, traction, penetration resistance and visual quality were measured 2 to 4 months after construction of the plots. Surface hardness was greatest in the inorganic stabilizer and the wheat straw treatments. The kinetic penetration had no differences between the wheat straw (33.78-51.10 kPa) and the StaLok fibers (34.99-56.23 kPa). Wheat straw could be used to stabilize sand-based fields as an organic alternative to inorganic fibers.
104

Growth, yield and quality of tomatoes (Lycopersicon Esculentum Mill.)and lettuce (Lactuca Sativa L.) as affected by gel-polymer soil amendment and irrigation management

Maboko, Martin Makgose 20 February 2007 (has links)
Tomato and lettuce are amongst the most important fresh vegetables used in South Africa. However, growth, yield and quality of tomato and lettuce are constrained by water shortage and poor productivity of sandy soil. In South Africa, large parts of the agricultural land are in a semi-arid region and water is becoming scarcer and more costly. Recognizing the fundamental importance of water-holding amendments like gel-polymers to enhance water use efficiency and soil physical properties, this study was carried out to investigate the effects of pure gel-polymer and fertiliser-fused gel-polymer soil amendments across five irrigation intervals on growth, yield and quality of tomato (Lycopersicon esculentum Mill.) and lettuce (Lactuca sativa L.). The response of tomato growth, yield and quality to irrigation interval and gel-polymer soil amendments (pure gel-polymer and fertiliser fused gel-polymer) was conducted in a tunnel. The gel-polymer treatments were: control (sandy soil), two pure gel-polymer levels (8 and 16 g-20 L-1 sandy soil, equivalent to 400 g and 800 g-m-3) and two fertiliser fused gel-polymer levels (20 and 40 g-20 L-1 sandy soil, equivalent to 1 kg and 2 kg-m-3). Irrigation was either applied once daily or every second, third, fourth or fifth day, equivalent to 0.8, 1.25, 1.45, 1.88 and 2.29 L of water per 20 L bag of sand. Fruit mass, fruit diameter, fruit number, plant height, stem diameter, number of trusses, root fresh and dry mass, total soluble solids, fruit juice pH and titratable acidity were determined. Neither irrigation interval nor gel-polymer amendments had an influence on tomato quality (total soluble solids, pH and titratable acidity). Generally, plant yield, height, stem diameter, number of trusses, and root fresh and dry mass were increased with gel-polymer amendments compared to pure sandy soil. Regardless of irrigation interval, both fertilizer-fused gel-polymer levels appeared to be effective in improving plant growth and yield compared to pure gel-polymer, which gave good results only at the higher level of application. The study revealed that gel-polymer amendments increased productivity of tomato on a sandy soil. Similarly, the response of lettuce growth, yield and quality to gel-polymers and irrigation intervals was investigated under a tunnel conditions. The gel-polymer treatments were: control, two pure gel-polymer levels (4 and 8 g-10 L-1 sandy soil, equivalent to 400 g and 800 g-m-3) and two fertilizer-fused gel-polymer levels (10 and 20 g-20 L-1 sandy soil, equivalent to 1 kg and 2 kg-m-3). Irrigation was either applied daily or every second, third, fourth or fifth day, equivalent to 0.63, 0.83, 1.04, 1.25 and 1.46 L per 10 L plastic bags. Measurements were made of fresh head mass, head height, head circumference, head diameter, stem diameter, fresh root mass, dry root mass and dry head mass. The dried head samples were analysed for percentage tissue calcium and nitrogen. Lettuce grown on sandy soil amended with higher level of pure gel-polymer (Stock 8) and both fertiliser fused gel-polymer levels (Aqua 10 and 20) resulted in significantly higher fresh and dry head mass, head circumference, head diameter, head height, stem diameter, and fresh and dry root mass as compared to low level of pure gel-polymer (Stock 4) and sandy soil without gel-polymer (control). All irrigation intervals did not have an effect on growth, yield and quality of lettuce except at irrigation interval of every third day, which significantly lowered head circumference. Gel-polymer did not have a significant effect on percentage calcium and nitrogen concentration in the leaf tissue. Growing lettuce in soil amended with higher pure gel-polymer (Stock 8) level and both fertiliser-fused gel-polymer (Aqua 20 and Aqua 40) would likely be economically advantageous for a grower due to improved growth and higher yield of good quality lettuce. / Dissertation (MSc (Horticulture))--University of Pretoria, 2005. / Plant Production and Soil Science / unrestricted
105

Background to the Second amendment, : "A well regulated militia being necessary to the security of a free state, the right of the people to keep and bear arms shall not be infringed."

Nichols, John Thomas 01 January 1977 (has links)
Research into the background of the Second Amendment is hampered by its relationship to the current highly emotional debate over gun control. Many otherwise useful secondary sources either ignore the issue completely or give accounts which reflect the controversies of the twentieth century rather than those of the eighteenth. Fortunately, however, the Americans of the revolutionary era wrote extensively about the subject. With independence, the Americans were faced with the problem of organizing and controlling a defense establishment. The new nation was virtually defenseless: the Continental Army was disbanded and the militia, after years of neglect, emasculated. During the decade following the War for Independence, many unsuccessful attempts were made to revitalize the militia and thus prevent the establishment of a professional army. With the adoption of the Constitution in 1787, military affairs reached a turning point. The central government was granted almost unlimited power to rise a standing army without any firm mandate to reform the militia. In an attempt to prevent this and assure that the people would continue to control the military power of the nation, the Second Amendment was adopted as a part of the Bill of Rights.
106

Evaluation of composts for production of sod and groundcover crops /

O'Brien, Tara A. 01 January 1995 (has links) (PDF)
No description available.
107

Physio-Chemical Evaluation and Functional Assessment of Native Wetland Soils and Organic Amendments for Freshwater Mitigation Wetlands

Stockman, Emily K.D. 01 January 2007 (has links) (PDF)
ABSTRACT PHYSIO-CHEMICAL EVALUATION AND FUNCTIONAL ASSESSMENT OF NATIVE WETLAND SOILS AND ORGANIC AMENDMENTS FOR FRESHWATER MITIGATION WETLANDS MAY 2007 EMILY K.D. STOCKMAN, B.S., UNIVERSITY OF MASSACHUSETTS AMHERST M.S., UNIVERSITY OF MASSACHUSETTS AMHERST Directed by: Dr. Peter Veneman Due to the history of wetland loss within the United States a National “No Net Loss” policy was adopted in 1988. This policy requires the creation of mitigation wetlands to replace lost and/or damaged natural wetlands. The role of soil in natural wetland systems is key in providing a number of ecology functions, such as the supply of wetland plant nutrients and the retention of nonpoint source pollutants. Nonetheless, Federal and Massachusetts guidelines regarding the creation of soil and the utilization of organic amendments in mitigation wetlands lack specific parameters and thresholds. This research compares the chemical and physical properties of two commercially available composts and two natural wetland soils and evaluates these materials as possible pollutant sources and sinks. The results of the characterization study demonstrate significant differences between the compost samples and the wetland soils in regards to the following properties: organic matter content, pH, polarity, total nutrients (P, K, B, Zn, Fe, Al, Cd, Ni, Cr) and extractable nutrients (P, K, Ca, B, Mn). These physio-chemical properties influence the functions of supplying plant nutrients and retaining nonpoint source pollutants such as excessive nutrients and herbicides. The results of the nutrient release studies indicate that the compost samples behave as potential sources of excessive levels of phosphorus and nitrate. In addition, the pollutant retention studies concluded that the compost samples sorbed lower amounts of phosphorus under aerobic conditions and lower amounts of the commonly-used herbicide, 2,4-D, as compared to the wetland soils. Overall, the differences in both physio-chemical properties and the behavior of the composts as compared with the wetlands soils as well as each other, substantiate the necessity to re-evaluate Federal and Massachusetts guidelines pertaining to mitigation wetland soil and amendments. Based on the results of this study the following minimal analyses are recommended: organic matter content, pH, total nutrients and extractable nutrients. In addition, based on the phosphorus release and retention studies the following thresholds are recommended to prohibit the release of excessive levels of phosphorus into the mitigation wetland and adjacent aquatic systems: Morgan’s extractable P content ≤ 25 mg kg-1 and/or the total P content ≤ 1286 mg kg-1.
108

Development Of Hydraulic And Soil Properties For Soil Amendments And Native Soils For Retention Ponds In Marion County, Florida

Naujock, Lisa 01 January 2008 (has links)
The vadose zone plays an important role in managing stormwater. Predicting the water balance and water movement is crucial in ground water remediation to keep water suitable for use. To aid in understanding soils ability to transmit and store water, soil and hydraulic properties were analyzed for soils in Marion County, Florida, and potential soil amendments. Soil and hydraulic properties were examined for two soil amendments and for the soils in Marion County, Florida, at the South Oak and the Hunter's Trace locations. The hydraulic properties measured were the soil moisture retention curve (SMRC) and saturated hydraulic conductivity (Ks). The soil properties measured were the particle-size distribution (PSD) and the specific gravity. From these, the bulk density and porosity were calculated. The SMRC corresponds to the water holding capacities, while the Ks corresponds to the soils ability to transmit water. Both are dependent on the soil properties. The SMRC for the soil amendments and native soils were developed in the laboratory using a Tempe Cell apparatus. In addition, the SMRC was measured in the field at the Hunter's Trace location with time domain reflectometry (TDR) and tensiometer equipment at three depths of 1-ft, 2-ft, and 3-ft over approximate a two month period. The SMRC obtained in the laboratory was compared to two analytical models, Brooks and Corey and van Genuchten, and to the field data. There is a strong correlation between the laboratory, analytical, and field SMRC for both South Oak and Hunter's Trace. In addition, there is a strong correlation between the laboratory SMRC and analytical models for the soil amendments. The Arya and Paris (AP) model, a pedotransfer function, was examined for its accuracy in predicting the SMRC for the soils at South Oak and Hunter's Trace, in addition to the soil amendments. Measuring the SMRC in the lab is a time consuming process; therefore, inferring the SMRC from textural and structural soil properties which are easier measured characteristics would be advantageous.
109

Evaluation of novel litter amendments for use in the commercial broiler industry

Urrutia, Jorge A 09 December 2022 (has links) (PDF)
Poultry litter amendments (LA) are commonly used to maintain good litter quality; the most common ones; are acidifiers. However, concern over the lifespan of LA acidifiers (d) and corrosive nature revealed a need for alternative LA. Products of interest include biochar (BC), superabsorbent polymers (SAPs), and alum mud (AM). Experiment 1 was a screening study (n=17 treatments, no birds) conducted to determine the optimal application rate/method of BC, SAPs, and AM vs.commercial LA and a control. Most SAPs treatments measured metrics may be similar (i.e., bacteria, water activity) or better (pH) vs. commercial LA (PLT). High inclusions of novel LA elicited the most litter quality benefit; therefore, were chosen for experiment 2 to determine their effects on 60 d litter quality and broiler performance and processing. Overall, novel LA improved litter quality parameters (i.e., moisture content, pH water activity) without negatively affecting live performance and processing parameters vs. control
110

An integrated subterranean termite management system coupling soil amendments with insect repellent plant tissues

Kitchens, Shane Clinton 03 May 2008 (has links)
Currently, soil termiticides are the primary termite defense mechanism used under and around living spaces in the continental United States. While this form of treatment has been effective for many years, the creation of a new, more environmentally friendly termite management system could reduce the amount of termiticides introduced annually into the environment around structures. A natural barrier containing soil amendments and mulches amended with insect-repellent plant tissues discourages termite foraging and directs the termites away from the structure. The proposed integrated management system developed during this project, divides a structure into three zones. Each zone has particular responsibilities to the overall biological durability of the structure. This study concentrates on the inner-detritus zone, which extends 24” (0.61m) from the outer wall of the structure, an area that can harbor potential hazards such as moisture traps, conducive termite food, water and protection sources, and other factors that could put undue biological pressures on the structure. Altering this zone, more specifically the pH of the soil and the mixture of products used as mulch, creates an environment unsuitable for termite foraging. This integration of several termite repelling strategies should obviate or significantly reduce the need for termiticidal soil barriers under and around houses.

Page generated in 0.063 seconds