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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.
181

none

Liu, Chuan-Tsung 13 August 2009 (has links)
When we open the history book of Human Sea Power, there is always an entangled relationship between the scale of navy force and the state of economy within a country. Since 1978, three decades reforming on its economic policy, China has . Eye-witting the First Gulf War, the Kosovo War, the September 11th terrorist attack on America territory, the Second Gulf War, and, most recently, the piracy in Gulf of Aden, China authority is now reconsidering its role on both international and regional security and then amending its navy strategy based on evaluations. Although the ultimate goal is to protect its own profit, yet aggressively expanding its navy force might generate instability status and will break the Strait balance and its peace progress in Asia Pacific. No doubt, due to the modernized strategic of China Navy which has created tension in its neighborhood area, and, particularly, it is obvious that the force gap between China and Taiwan has yawned by steadily economy boom in China. By the end of Taiwan President Election in 2008, the stalemate prevailed under Chen era is now melting and quickly treading toward peace, yet national security couldn¡¦t merely rely on jubilant atmosphere of diplomacy but on staid force. Facing problems between the Strait, China has adopted both peace and war strategies simultaneously and never give up its intention to invade Taiwan. Frankly, it is undoubtedly best to solve political conundrum under peaceful diplomatic progress, but facing the threat of China¡¦s invasion, we still need to grasp the status of its development of navy, to forecast the pattern of its navy expanding, and to mull best way to defiance, to ensure the national security of Taiwan.
182

Assessment of ceramic raw materials in Uganda for electrical porcelain

Olupot, Peter Wilberforce January 2006 (has links)
<p>Clay, quartz and feldspar are widely available in Uganda. The location and properties of various clay deposits are reported in the literature, but little is reported on feldspar and quartz deposits. In this work an extended literature on ceramics and porcelains in particular, is documented. Samples from two deposits of feldspar and two deposits of quartz are characterised and found to possess requisite properties for making porcelain insulators. Sample porcelain bodies are made from materials collected from selected deposits using different mixing proportions of clay, feldspar and quartz. Their properties in relation to workability, firing temperature, dielectric and bending strengths are studied. It is found that a mixture consisting of 30% Mutaka kaolin, 15% Mukono ball clay, 30% Mutaka feldspar and 25% Lido beach flint yields a body with highest mechanical strength (72MPa) and dielectric strength (19kV/mm) when fired at 1250°C. The strength (both mechanical and dielectric) is found to decrease with increasing firing temperature. At high firing temperatures, the undissolved quartz in the body decreased, the glass content increases and pores are formed. Mullite content on the other hand does not change at temperatures above 1200°C but there are significant differences in the morphologies of the mullite crystals in the samples. Optimum mechanical and electrical properties are found at maximum virtification and a microstructure showing small closely packed mullite needles.</p>
183

Development length equation for high-strength materials

Kim, Najung, 1977- 24 July 2015 (has links)
The goal of this study was to revise the development length equation of ACI 318- 05 and to better reflect test results for high-strength concrete. The revision of the equation was accomplished using test results tabulated in the Database 10-2001maintained by ACI committee 408. Equations for development length in ACI 318-05 and ACI 408.3 examined to understand the issues to be considered for revision on the variability of test data. The development length equation in ACI 318-05 was very conservative for [compressive strength of concrete][less than or equal to]14,000 psi based on the experimental data in Database 10-2001 of ACI Committee 408. On the contrary, the ACI 318-05 may be less conservative for high-strength concrete, [compressive strength of concrete] [greater than or equal to]14,000 psi . Thus, modified design equations were proposed to provide realistic values for normal strength concrete and conservatively for high-strength concrete. The ACI 318-05 equation was modified for 1) compressive strength of concrete and 2) confinement as expressed by the term [minimum side cover, cover over the bar or wire, or one-half the center-to-center spacing of the bars or wires] + [contribution of confining reinforcement across potential splitting planes] / [normal diameter of bar] in ACI 318-05. The basic assumption is that bar stress is a linear function of development length, and development length is the length required for bar stresses to reach the yield. / text
184

MUSCULOSKELETAL STRENGTH, FALL AND FRACTURE RISK IN EARLY POSTMENOPAUSAL WOMEN

2015 September 1900 (has links)
Purpose: To evaluate the course of recovery in fall-risk and functional status over the first year following a distal radius fracture (DRF), and evaluate differences in fall and fracture risk factors in women over the age of 50 years with a DRF compared to their non-fractured peers. Methods: Two cohorts of participants volunteered in two sub-studies of the thesis. The first was seventy-eight women recruited from a DRF Clinic within the first week after their fracture, and followed up in concert with standard clinic appointments at week three, nine, 12, 26, and 52 post-fracture. The second cohort consisted of women aged 50 years or older, with and without a recent distal radius fracture, being at least 6 months post-DRF, but no more than 2 years post-fracture. Seventy-seven women age 50-78 with (Fx, n = 32) and without (NFx = 45) a history of DRF were assessed on two occasions within 4 weeks apart using a battery of fall and fracture risk tools, including balance, mobility, gait speed, fracture risk assessment, as well as bone quality assessment using peripheral quantitative computer tomography (pQCT) and dual x-ray absorptiometry (DXA). Results: Fall-risk status (strength, balance, mobility) gradually improved over the first year post-fracture, with balance confidence remaining high even immediately post-fracture. In the second study, women with a recent DRF, compared to women without, demonstrated higher fall and fracture risk. Women with a recent DRF had lower bone and muscle strength in both the upper and lower extremities compared to the non-fractured controls, with no differences in DXA derived aBMD at the femoral neck or spine. Significance of findings: The results of these studies will help clinicians understand the normal course of functional recovery post-fracture, and assist in determining appropriate fall risk assessment and interventions for post-menopausal women at risk of fragility fracture. Results demonstrate the importance of studying women at risk of DRF as an important first indicator of bone fragility and risk of future fracture. These findings also strengthen the notion that DXA alone may not be the best predictor for fracture risk.
185

海洋環境における鋼管杭の圧縮強度の経年変化予測法

NAKAMURA, Hideharu, NAGATA, Kazutoshi, NOGAMI, Ikuei, SUGIURA, Kunitomo, ITOH, Yoshito, WATANABE, Eiichi, HASHIMOTO, Kazuaki, FUJII, Katashi, 中村, 秀治, 永田, 和寿, 野上, 邦栄, 杉浦, 邦征, 伊藤, 義人, 渡邊, 英一, 橋本, 和朗, 藤井, 堅 19 March 2010 (has links)
No description available.
186

Determination of strength imbalance of the lower extremities

Gerber, Aimee January 2002 (has links)
Fourteen college softball players were recruited to participate in this study to determine if a strength imbalance between the lower extremities, how significant this difference this may be and of any correlations existed among all the functional tests. Subjects took part in isokinetic flexion and extension at 60 and 240 deg/sec, parallel squats, 2-legged vertical jump, single leg vertical jump, and a five-hop test. Peak and average torque was recorded for isokinetic testing and revealed significant differences between the dominant and non-dominant limbs (13.00%- 16.00%). Peak and average force was analyzed for squats and all vertical jumps. Significance was found among all activities between dominant and non-dominant legs, other than average force for single leg vertical jump. A significant difference was also exhibited for the five-hop test between the lower extremities. Significant correlations were also found at the 0.05 and 0.01 levels amongst the various functional tests. Overall findings revealed a significant strength imbalance between the dominant and non-dominant limbs. Further research needs to be conducted in determining how detrimental these differences could be in daily performance for athletes. / School of Physical Education
187

Effect of microstructure on static and dynamic mechanical properties of high strength steels

Qu, Jinbo, 1971- January 2007 (has links)
The high speed deformation behavior of a commercially available dual phase (DP) steel was studied by means of split Hopkinson bar apparatus in shear punch (25m/s) and tension (1000s-1) modes with an emphasis on the influence of microstructure. The cold rolled sheet material was subjected to a variety of heat treatment conditions to produce several different microstructures, namely ferrite plus pearlite, ferrite plus bainite and/or acicular ferrite, ferrite plus bainite and martensite, and ferrite plus different fractions of martensite. Static properties (0.01mm/s for shear punch and 0.001s -1 for tension) of all the microstructures were also measured by an MTS hydraulic machine and compared to the dynamic properties. The effects of low temperature tempering and bake hardening were investigated for some ferrite plus martensite microstructures. In addition, two other materials, composition designed as high strength low alloy (HSLA) steel and transformation induced plasticity (TRIP) steel, were heat treated and tested to study the effect of alloy chemistry on the microstructure and property relationship. / A strong effect of microstructure on both static and dynamic properties and on the relationship between static and dynamic properties was observed. According to the variation of dynamic factor with static strength, three groups of microstructures with three distinct behaviors were identified, i.e. classic dual phase (ferrite plus less than 50% martensite), martensite-matrix dual phase (ferrite plus more than 50% martensite), and non-dual phase (ferrite plus non-martensite). Under the same static strength level, the dual phase microstructure was found to absorb more dynamic energy than other microstructures. It was also observed that the general dependence of microstructure on static and dynamic property relationship was not strongly influenced by chemical composition, except the ferrite plus martensite microstructures generated by the TRIP chemistry, which exhibited much better dynamic factor values. This may suggest that solid solution strengthening should be more utilized in the design of crashworthy dual phase steels.
188

On-the-go soil strength profile sensor

Chung, Sun-Ok, January 2004 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2004. / Typescript. Vita. Includes bibliographical references (leaves 243-253). Also available on the Internet.
189

On-the-go soil strength profile sensor /

Chung, Sun-Ok, January 2004 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2004. / Typescript. Vita. Includes bibliographical references (leaves 243-253). Also available on the Internet.
190

The effects of grip force and mental processing during isometric shoulder exertions /

MacDonell, Christopher W. January 2003 (has links)
Thesis (M.Sc.)--York University, 2003. Graduate Programme in Kinesiology & Health Science. / Typescript. Includes bibliographical references. Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pMQ86295

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