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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

An investigation into ways of economic empowerment of rural in Dr Ruth's Mompati district municipality / E.M Moncho

Moncho, E M January 2010 (has links)
The study was designed to identify rural women's constraints in economic empowerment, regarding their participation in LED activities and mainly how the rural women can be empowered for sustainable agricultural development in the district of Dr Ruth S Mompati, North West Province, South Africa. A large proportion of the respondents reported that they have problems and constraints in accessing information regarding Local Economic Development Activities and they don't even know the organisations that are providing LED Services in their respective municipal areas. However, by addressing these constraints effectively the situation of women empowerment can be improved in rural areas. / Thesis (MBA) North-West University, Mafikeng Campus, 2010
2

Topological conditions for positive Lyapunov exponent in unimodal maps

Sands, Duncan James January 1993 (has links)
No description available.
3

The application of dual channel analysis techniques for on-line vibration monitoring of mining processes

Sihra, Tarsem Singh January 1993 (has links)
No description available.
4

Signal processing techniques for on-line partial discharge monitoring of high voltage electrical machines

Jamieson, John W. January 1994 (has links)
No description available.
5

The ageing and breakdown characteristics of electrical machine insulation materials

Kouadria, Djilali January 1998 (has links)
No description available.
6

The use of high frequency stress waves for monitoring gears

Al-Balushi, Khamis Rajab Nasser January 1995 (has links)
The aim of this research is to investigate the feasibility of using stress waves for condition monitoring of gears. The project involved setting up an experimental rig, carrying out experimental work, acquiring stress waves signatures, and processing the signals. It has been shown that stress waves can successfully be employed for early detection of incipient gear failure. A experimental gearbox was employed during the experiments. Miniature ultrasound transducers, both sensitive and sufficiently small, were manufactured and installed on the stationary outer race of the rolling element bearing of the gearbox to detect stress waves from the meshing gears. The stress waves signals from the transducers were digitised and digitally processed to extract relevant information. The signatures were high-pass filtered at a cut-off frequency of 200 kHz, thus representing exclusive ultrasonic frequencies. A new statistical parameter, Energy Index, was developed and performed on the stress wave signatures which were segmented to represent individual gear teeth. Along with this new parameter, the classical statistical parameters, (Peaks, RMS, Standard Deviation, Kurtosis, etc.) were also performed. Conclusive results are presented in graphical form in terms of Cumulative Energy Indices' and Energy Indices in polar form for individual gear teeth. A new algorithrn was also developed and presented for the envelope detection of signal by iterative peak detection. Although no direct comparison was made between condition monitoring of gears using stress waves and methods such as low frequency vibration analysis and wear debris analysis, it is apparent that stress waves monitoring offers a much earlier warning of incipient gear failure because the technique can detect material defonnations which are precursors to changes in the dynamic properties of gears and the occurrence of wear debris. The technique, therefore, can predict incipient failure much earlier, extending the lead-time before failure, and as a result, minimising sudden failures which may have catastrophic consequences.
7

Validation of the no slip boundary condition at solid-liquid interfaces

Honig, Christopher David Frederick January 2008 (has links)
This thesis describes the study of the hydrodynamic boundary condition at the solid-liquid interface using the colloidal probe Atomic Force Microscope. Quantitative comparison between measured lubrication forces and theoretical lubrication forces show that the measured forces agree with theory when the no slip boundary condition is employed. We measure an effective slip length of 0 ± 2 nm at shear rates up to 250,000 sec-1. Our results are consistent with the Taylor lubrication equation without the need to invoke a slip length fitting parameter. Our results are also consistent with molecular dynamic simulations that predict no slip at the shear rates that are currently experimentally accessible.
8

Validation of the no slip boundary condition at solid-liquid interfaces

Honig, Christopher David Frederick January 2008 (has links)
This thesis describes the study of the hydrodynamic boundary condition at the solid-liquid interface using the colloidal probe Atomic Force Microscope. Quantitative comparison between measured lubrication forces and theoretical lubrication forces show that the measured forces agree with theory when the no slip boundary condition is employed. We measure an effective slip length of 0 ± 2 nm at shear rates up to 250,000 sec-1. Our results are consistent with the Taylor lubrication equation without the need to invoke a slip length fitting parameter. Our results are also consistent with molecular dynamic simulations that predict no slip at the shear rates that are currently experimentally accessible.
9

Reproductive and endocrine parameters of fat versus moderately conditioned mares following parturition

Cavinder, Clay Alan 02 June 2009 (has links)
An increase in time to ovulation following parturition could result in economic loss if the mare cannot successfully conceive within a short time after foaling. To evaluate if a difference exists in reproductive efficiency of fat- (body condition score of 7 to 8) versus moderately-conditioned (body condition score of 5 to 6), 24 mares were allotted to and maintained in their respective group from late gestation until pregnancy was confirmed following breeding on the second post-partum estrus. Days to ovulation, interovulatory intervals, conception rates, and endocrine profiles were analyzed. Serum concentrations of thyroxine (T4), insulin-like growth factor-1 (IGF-1) and leptin were assayed in order to characterize normal circulating blood concentrations. There were no differences (P>0.05) in mean interval from parturition to first ovulation (14.41 ± 1.07 and 16.18 ± 1.06 d), first to second postpartum ovulation (22.91 ± 1.07 and 24.33 ± 0.93 d), or in conception rates (91.67% and 83.33%) between the 2 groups. However, mares in moderate conditioning did lose a greater percentage of body fat upon foaling as compared to fleshier mares (0.82% versus 0.35%). Leptin concentrations were not different between the groups (P>0.05). Nevertheless, serum concentrations of T4 were higher (P<0.01) and IGF-1 concentrations lower (P<0.01) in moderate- as compared to fat-conditioned mares during times of ovulation and the interovulatory period. Results indicate that mares maintained in a fleshy body condition are not prone to reproductive dysfunction or lowered levels of fertility. The significance of the current results is important as it reassures the breeder that mares in a fatter body condition score (BCS of 7-8) should not demonstrate sub-fertility related to level of body fat. Additionally, results indicate that mares may need to be kept in a BCS of 6 in order to avoid losing enough weight upon parturition and early lactation to bring the BCS below 5. It suggests that varying amounts of circulating T4 and IGF-1 do not affect reproductive capabilities of mares in a BCS of greater than 5 following parturition.
10

Reproductive and endocrine parameters of fat versus moderately conditioned mares following parturition

Cavinder, Clay Alan 02 June 2009 (has links)
An increase in time to ovulation following parturition could result in economic loss if the mare cannot successfully conceive within a short time after foaling. To evaluate if a difference exists in reproductive efficiency of fat- (body condition score of 7 to 8) versus moderately-conditioned (body condition score of 5 to 6), 24 mares were allotted to and maintained in their respective group from late gestation until pregnancy was confirmed following breeding on the second post-partum estrus. Days to ovulation, interovulatory intervals, conception rates, and endocrine profiles were analyzed. Serum concentrations of thyroxine (T4), insulin-like growth factor-1 (IGF-1) and leptin were assayed in order to characterize normal circulating blood concentrations. There were no differences (P>0.05) in mean interval from parturition to first ovulation (14.41 ± 1.07 and 16.18 ± 1.06 d), first to second postpartum ovulation (22.91 ± 1.07 and 24.33 ± 0.93 d), or in conception rates (91.67% and 83.33%) between the 2 groups. However, mares in moderate conditioning did lose a greater percentage of body fat upon foaling as compared to fleshier mares (0.82% versus 0.35%). Leptin concentrations were not different between the groups (P>0.05). Nevertheless, serum concentrations of T4 were higher (P<0.01) and IGF-1 concentrations lower (P<0.01) in moderate- as compared to fat-conditioned mares during times of ovulation and the interovulatory period. Results indicate that mares maintained in a fleshy body condition are not prone to reproductive dysfunction or lowered levels of fertility. The significance of the current results is important as it reassures the breeder that mares in a fatter body condition score (BCS of 7-8) should not demonstrate sub-fertility related to level of body fat. Additionally, results indicate that mares may need to be kept in a BCS of 6 in order to avoid losing enough weight upon parturition and early lactation to bring the BCS below 5. It suggests that varying amounts of circulating T4 and IGF-1 do not affect reproductive capabilities of mares in a BCS of greater than 5 following parturition.

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