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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.
71

Near Real-Time Exercise Machine Power Statistics Reporting

Asche, Brendan C 01 March 2010 (has links) (PDF)
Cal Poly’s Recreation Center expansion project provides an opportunity to implement Energy Harvesting From Exercise Machines (EHFEM). Part of this implementation is a system that reports the exercise machines’ energy production. Although products capable of reporting exercise machine energy harvesting statistics exist, they have limited capabilities. This thesis project defends a system capable of reporting exercise machine power statistics in near real-time. The system consists of display, database, and power measurement modules. The display module presents statistics in an interactive, graphical, and widely-accessible way. The database module provides an efficient way of organizing and accessing stored statistics. Multiple power measurement module types gather power and energy generation measurements from multiple exercise machine types and transmit those measurements to the database module over the computer network.
72

Development of a whole-stalk sweet sorghum harvester

Rains, Glen Christopher 29 November 2012 (has links)
Sweet sorghum produces more carbohydrates and more biomass per unit land area than com in the Eastern U. S. Piedmont. An equipment system for harvesting and processing whole-stalk sweet sorghum is being developed, with the expectation that sweet sorghum can be commercialized as an ethanol feedstock. A whole-stalk harvester was designed, constructed, and tested during the 1988 harvest season. The harvester captured a row of stalks between two counter rotating gathering belts, cut them at the base with a disk cutter (basecutter), and, at the rear of the machine, rotated the stalks 90° by capturing the stalk butts between to spring-loaded disks, called the stalk flipper. At a field speed of 6.7 km/h, the machine worked best when the flipper tangential velocity was 24 percent higher than the gathering belt Linear velocity, which was approximately (within six percent) equal to ground speed. The harvester was pulled behind a tractor and powered with a universal joint drive line. Two computer software packages, Computer-Graphic Augmented Design and Manufacturing (CADAM) and Integrated Mechanisms Program (IMP), were used to design the hitch and drive line. Calculated angular accelerations in the 3-joint drive line were excessive during a right or left turn; consequently a constant velocity joint was used at the tractor PTO. The hitch was designed with three position settings. With the hitch in the Field 1 position, the harvester was offset sufficiently to capture a row with the gathering belts. In the travel position, the harvester trailed behind the tractor within the 2.4 m legal road width. / Master of Science
73

Logging in the Streamside Management Zone: Effects of Harvesting System and Intensity on Visual Soil Disturbance

Hodges, Christine Lamb 14 December 2006 (has links)
Streamside management zones (SMZs) are a common and effective mechanism used to protect and maintain water quality during timber harvesting operations. In the southeastern United States timber harvesting is typically allowed inside the SMZ, but there is little information regarding suitable types of harvesting systems and the acceptable amount of canopy cover. The effects of two harvesting systems and harvesting intensities on visual soil disturbance were evaluated throughout Virginia and eastern West Virginia. The harvesting systems were a chainsaw/cable-skidder system (manual) and a feller-buncher/grapple-skidder system (mechanized). A total of 118 unique SMZ plots were measured at 50 different harvest sites, split evenly between manual and mechanized operations. Analyses of variance (ANOVA) at the p < 0.10 significance level indicated that there was no significant difference in visual indices of soil disturbance levels between the two systems. However, the manual system had significantly more "rutted" disturbed area and slash cover than the mechanized system. Harvesting intensity was found to be a significant factor in the occurrence of total visual soil disturbance (slight, deep, rutted classes). Slope gradient was evaluated and revealed that slope percentages had no significant effect on percent soil disturbance for this study. Based on the parameters measured, the general occurrence and frequency of soil disturbance generally depends on the specific site conditions. / Master of Science
74

A Comparison of Chipper Productivity, Chip Characteristics, and Nutrient Removals from Two Woody Biomass Harvesting Treatments

Groover, Miles Clark 17 January 2012 (has links)
Increased costs of fossil fuels, regulatory policies, and investments by federal and state governments have caused increased interest and incentive for the use of wood as a renewable form of energy. As a result, landowners and forest managers are considering chipping whole trees and harvesting residues as a means to meet increased demand of wood chips as a renewable source of energy. However, the profitability, productivity gains, and sustainability of these alternative harvesting methods continue to be an area of research. The objective of this study was to compare two biomass harvesting treatments with regard to the characteristics of the chips they produced, chipper productivity, nutrient removals, and site disturbance. The first biomass harvesting treatment was an integrated harvest where roundwood was merchandized and hauled to the appropriate mill and limbs, tops, and small stems (residues) were chipped for hog fuel. The second biomass harvesting treatment simulated a scenario where biomass markets were competing with pulpwood markets and landowners could choose to sell wood for energy or pulp wood. In this treatment whole trees and small stems were chipped for hog fuel. A third harvesting treatment was a conventional roundwood harvest where no wood was chipped, and this treatment was used as a control for comparison of nutrient removals and site disturbance. The chips produced from both harvesting treatments were very similar, but those produced from whole trees tended to be slightly smaller than those produced from residues. Chipper productivity was significantly higher when chipping whole trees and it was also much more efficient in terms of fuel use. Estimations of nutrient removals showed that there was very little difference in the amount of nutrient removed from the biomass harvesting treatments, but both treatments removed significantly more N and Ca than the conventional roundwood harvesting treatment. There was significantly more downed and standing material left on the site after harvesting in the conventional treatment, but this did not translate into a large amount of additional nutrients left on the site. There was little difference in soil disturbance between all three treatments, and due to the dry soil conditions during harvesting, there was very little visual soil disturbance at all during harvesting. / Master of Science
75

The influence of some physical properties of carrots on their damage characteristics

Millington, Susan January 1985 (has links)
No description available.
76

Harvesting Rainwater for Landscape Use

Waterfall, Patricia January 2006 (has links)
56 pp. / Second Edition, October 2004 / In the arid Southwest, rainfall is scarce and evapotranspiration rates are high. Only natives and some desert-adapted plants can live on 10 or 11 inches of annual rainfall. Other plants require some supplemental irrigation and harvesting rainwater can reduce the use of drinking water for landscape irrigation. This publication discusses the water requirements for some plants and the way to collect rainwater. Its topics include: - Water Harvesting System Components - Simple Water Harvesting System Design and Construction - Complex Water Harvesting Systems
77

Simulation of micro catchment water harvesting systems

Namde, Noubassem Nanas,1955- January 1987 (has links)
A mathematical model for personal computers was prepared as a planning tool for development of micro catchment water harvesting systems. It computes runoff from natural or treated catchments, using estimated or actual parameters. The model also computes the water balance of the soil zone in the cultivated area and the water balance of the reservoir system which serves it. The model was calibrated with hydrolologic data and site characteristics for a location near Tucson, Arizona. Its prediction of cotton and grain sorghum yields was comparable to that of Morin (1977). An attempt was made to use weekly or monthly rainfall data for areas where daily data are unavailable. Lack of direct rainfall and runoff durations and infiltration characteristics made this attempt unsuccessful. This option cannot be used with the model in its current form.
78

Current Developments in the Exploitation of the Sea as a Source of Food

Goodman, Lonnie E. 06 1900 (has links)
The chronic problem of protein deficiency that prevails in many parts of the world today poses a great challenge to modern technology. Current production of protein food of animal origin is insufficient to meet the needs of an increasing world population. From this fact arises the possibility of a world in which the majority of people will never have enough to eat,
79

The promotion of rainwater harvesting as a supplementary source of domestic water in Kigali, Rwanda- A feasibility study

Sully, Robert Peter 14 February 2007 (has links)
Student Number : 7336898 - MSc (Eng) research report - School of Civil and Environmental Engineering - Faculty of Engineering and the Built Environment / Theme and Context Despite being the source of two of Africa’s greatest rivers, the Nile and the Congo, Rwanda is a water scarce country and 50% of the citizens of the capital, Kigali, do not have access to safe drinking water. Rwanda’s tragic history of violent social upheaval combined with regional macro-economic factors and the effects of globalization have made this tiny country one of the poorest on the African continent. Aim and Objectives of this Study The aim of this report is to establish the value that Rainwater Harvesting holds as a supplementary water source for the city of. To evaluate this potential intervention, the suitability of the climate for the harvesting of rainwater is reviewed as well as the availability of the required resources and the effect that the prevailing social environment may have on an implementation program. The current developments in the practice of Rainwater Harvesting are researched and ways in which Rainwater Harvesting could be utilized are explored as well as the possible impediments that might be encountered. Scope and Methodology Adopted The scope of the report includes: 1. Providing an overview of the country both geographically as well as socially. 2. Establishing the need for alternative water sources by: a. Reviewing the present water supplies for the city particularly with regard to their vulnerability to the rapid environmental degradation being experienced within the country, b. Reviewing the prevailing water/health nexus. 3. Investigating metrological records, specifically rainfall patterns, and the quality of the statistics. 4. Review international trends and research in rainwater harvesting specifically in poor countries. 5. Considering obstacles to implementing a wide-ranging scheme to harvest rainwater. The methodology adopted includes: 1. Reviewing published research on the subject of Rainwater Harvesting techniques and implementation. 2. Attending symposia on the subject. 3. Meeting with water practitioners both in the public sector as well as in NGOs to establish the current status of water availability, quality and consumption. 4. Conducting on-site research into water sourcing problems in and around Kigali. 5. Designing, sizing and costing hypothetical installations suitable for local conditions. Summary of Main Findings, Conclusions and Recommendations Although the climate and topography are very favorable to the use of Rainwater Harvesting, this report finds that the promotion of Rainwater harvesting is just one of a number of possible interventions which should be pursued in order to improve the availability of water to the citizens of Kigali The cost and sophistication of Rainwater Harvesting schemes vary considerably but at the lower end of the scale the technology would be affordable to most Kigali residents and the community has the potential human resource to be trained to execute the work. Obstacles to this approach include ignorance about the safety of storing water, the comparative low cost of municipal water the perception that water collection is the responsibility of a family’s women and children. This report also found that a household using a Rainwater Harvesting scheme is likely to require some supplementary water on occasions. Furthermore, as the potential to catch sufficient water is a function of the ratio of a dwelling’s roof area to the number of inhabitants, its efficacy is limited in densely inhabited poor communities. Strong leadership and coordination would be necessary for a successful wideranging Rainwater Harvesting implementation project. In addition a coordinated educational programme will have to be conducted to dispel myths about stored water and to create the required skills base. The statutes and bylaws regarding water would also have to be reviewed to avoid legal impediments. This report concludes that rainwater harvesting cannot be relied upon to fulfill all the communities’ water needs but it can go a long way to improving the general access to safe water and in so doing reduce the time and labour presently demanded, mainly of women and children, in the carrying of heavy loads of water.
80

Contour ridge modelling using fuzzy logic and process based approaches for improved rainwater harvesting

Mhizha, Alexander January 2017 (has links)
A thesis submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements of the degree of Doctor of Philosophy. Johannesburg, February 2017 / Rainwater harvesting is used as a way of improving crop yields in rain fed agriculture by capturing excess rainfall and storing it in-situ or in reservoirs for use during dry spells. Contour ridges are one of the many rainwater harvesting technologies that are used although little is known about their effectiveness. Contour ridges harvest runoff generated in the cropped field upstream of the ridges. The traditional contour ridge type in Zimbabwe was introduced by the government in the 1950s to control soil erosion through safely draining away runoff from cropped fields and is commonly referred to as graded contour (GC) ridges. In the 1990s the country experienced severe and more frequent droughts leading stakeholders to experiment on contour ridges that retain the runoff instead of draining it away which are known as dead level contour (DLC) ridges. There was therefore the need to find out if there are benefits derived from this change and assess conditions under which benefits would be experienced. Previous studies have shown that rainwater harvested by contour ridges can improve water availability in downstream fields. However these studies did not investigate the conditions under which such benefits are realised. In addition no attempt to model water harvesting by contour ridges have been made in Zimbabwe while the contour ridges are widely being used for soil and water conservation. This research investigated the effect of contour ridges by comparing soil moisture between plots with DLC and GC ridges using plots with no contours as a control. Experimental work was carried out in Zhulube, in Matebeleland South Province of Zimbabwe. Matebeleland South Province falls within the semi-arid area in which rainfall is characterised by mid-season dry spells leading to frequent crop failure. In addition, the area often receives high rainfall intensities leading to soil erosion and sedimentation of rivers. DLC and GC ridges were constructed in farmers’ fields where maize crops were planted. Soil moisture measurements were done using a micro gopher soil moisture profiler while runoff plots were used to measure runoff generation. A fuzzy model was developed using data from this experiment and a previous study in Masvingo Province of Zimbabwe to simulate runoff generation at field scale while a process based water balance model was also developed to simulate soil moisture changes within the root zone of the cropped area. The results from this study indicate that DLC are effective in clay and loamy soils where runoff generation is significant and not in sandy soils due to insignificant generation of runoff under the rainfall regimes of semi-arid areas. Fuzzy logic was found to be a useful method of incorporating uncertainty in modelling runoff at field scale. A mass water balance model developed on process based principles was able to model soil moisture in the root zone reasonably well (NSE =0.55 to 0.66 and PBIAS=-1.3% to 6.1%) and could help to predict the water dynamics in contour ridged areas as would be required in determining the suitable dimensions and spacing of contour ridges. Further research is required to improve the fuzzy component of the model for estimation of runoff when more data becomes available. In addition experiments to validate methods of estimating macro pore fluxes and lateral transfer of water from the contour ridge channel to the downslope field are also recommended. The model structure can be improved by adopting the representative elementary watershed approaches to include momentum and energy balances in addition to mass balance that was used in this study. / MT2017

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