473 research outputs found
Cold Spray Coatings for Surface Enhancement of Inconel 718
No full textCold spray is an emerging additive manufacturing technology that is promising to be used for surface repair and enhancement. In this study, Inconel 713 coating was successfully deposited on Inconel 718 substrate using a high-pressure cold spray process. The microstructure and hardness of the coating were studied. The cold sprayed Inconel 713 coating had a very low porosity level due to the severe plastic deformation of the splats. Hardness of the coating is much higher than that of Inconel 718 substrate. The regions closer to the substrate-coating interface in the coating showed higher hardness value compared to those located further away from the interface. This phenomenon can be attributed to the peening effect during high-velocity impact of Inconel 713 particles with the Inconel 718 substrate. This study demonstrates that cold sprayed coatings have the potential to increase surface hardness and further improve wear resistance of the Inconel 718 substrate
Inconel 713C Coating by Cold Spray for Surface Enhancement of Inconel 718
No full textInconel 713C is a nickel-based superalloy usually considered as a material of poor weldability due to its susceptibility to hot cracking in the heat-affected zones. Cold spray, a solid-state deposition technology that does not involve melting, can be proposed as a methodology to deposit Inconel 713C for surface enhancement of other target components. In this study, Inconel 713C coating was deposited on Inconel 718 substrate with a high-pressure cold spray system. The coating was characterized in terms of microstructure, hardness, and wear properties. The cold-sprayed Inconel 713C coating has a low porosity level and refined grain structures. Microhardness of the Inconel 713C coating was much higher than the Inconel 718 substrate. The sliding wear tests showed that the wear resistance of the cold-sprayed Inconel 713C coating is three times higher than the Inconel 718 substrate, making the coating a suitable protective layer. The main wear mechanisms of the coating include oxidation, tribo-film formation, and adhesive wear
THE ELASTICITY OF CAPITAL-LABOUR SUBSTITUTION IN HONG KONG CONSTRUCTION
No full textBachelor'sBACHELOR OF SCIENCE (REAL ESTATE
sj-docx-1-tam-10.1177_17588359221087555 – Supplemental material for A phase 1 study of the safety, pharmacokinetics and pharmacodynamics of escalating doses followed by dose expansion of the selective inhibitor of nuclear export (SINE) selinexor in Asian patients with advanced or metastatic malignancies
No full textSupplemental material, sj-docx-1-tam-10.1177_17588359221087555 for A phase 1 study of the safety, pharmacokinetics and pharmacodynamics of escalating doses followed by dose expansion of the selective inhibitor of nuclear export (SINE) selinexor in Asian patients with advanced or metastatic malignancies by Jingshan Ho, Valerie Heong, Wei Peng Yong, Ross Soo, Cheng Ean Chee, Andrea Wong, Raghav Sundar, Yee Liang Thian, Anil Gopinathan, Mei Yan Pang, Priscillia Koe, Santhiay Nathan Jeraj, Phyu Pyar Soe, Mu Yar Soe, Tiffany Tang, Matthew C.H. Ng, David W.M. Tai, Tira J.Y. Tan, Hongmei Xu, Hua Chang, Yosef Landesman, Jatin Shah, Sharon Shacham, Soo Chin Lee, Daniel S.W. Tan, Boon Cher Goh and David S.P. Tan in Therapeutic Advances in Medical Oncology</p
sj-docx-2-tam-10.1177_17588359221087555 – Supplemental material for A phase 1 study of the safety, pharmacokinetics and pharmacodynamics of escalating doses followed by dose expansion of the selective inhibitor of nuclear export (SINE) selinexor in Asian patients with advanced or metastatic malignancies
No full textSupplemental material, sj-docx-2-tam-10.1177_17588359221087555 for A phase 1 study of the safety, pharmacokinetics and pharmacodynamics of escalating doses followed by dose expansion of the selective inhibitor of nuclear export (SINE) selinexor in Asian patients with advanced or metastatic malignancies by Jingshan Ho, Valerie Heong, Wei Peng Yong, Ross Soo, Cheng Ean Chee, Andrea Wong, Raghav Sundar, Yee Liang Thian, Anil Gopinathan, Mei Yan Pang, Priscillia Koe, Santhiay Nathan Jeraj, Phyu Pyar Soe, Mu Yar Soe, Tiffany Tang, Matthew C.H. Ng, David W.M. Tai, Tira J.Y. Tan, Hongmei Xu, Hua Chang, Yosef Landesman, Jatin Shah, Sharon Shacham, Soo Chin Lee, Daniel S.W. Tan, Boon Cher Goh and David S.P. Tan in Therapeutic Advances in Medical Oncology</p
Outcomes of salvage liver transplant for recurrent hepatocellular carcinoma: A comparison with primary liver transplant.
No full text10.14701/ahbps.2019.23.1.1Ann Hepatobiliary Pancreat Surg2311-
Chinese literary works translated into Baba Malay: a bibliographical study
No full textAnalyses 68 unique titles of Baba translated works published between 1889 and 1950. The titles are held in the libraries of the University of Malaya (UM), Science University Malaysia (USM), National University of Malaysia (UKM), the Dewan Bahasa dan Pustaka (DBP), National University of Singapore (NUS), National Library of Singapore (NLS) and the British Library (BL). The results reveal three periods of active publication of Baba translated works. A total of 18 works were translated before World War I, followed by 10 just after the war, 39 titles were published before the break of the World War II and 1 was identified in 1950. There were 103 persons involved in the 68 translated works, some of whom are responsible for more than one title. The most prominent translators were Chan Kim Boon, Wan Boon Seng, Seow Chin San and Lee Seng Poh. Some of the translators were also be editors, illustrators or editors. There were 31 publishers and 21 printing presses involved, all were located in Singapore. The most active publishers were Wan Boon Seng, Kim Seck Chy Press and Nanyang Romanised Malay Book Co. The translated works mainly cover historical classical Chinese stories, chivalrous stories, romances, folklore and legends. The titles were priced between 10 cents to 2 dollars in Straits currency. The University of Malaya Library held the largest number of unique title (62) out of which 15 were unique titles
Advancements in functional state estimation using sliding mode observers
No full textThis thesis explores the development of functional state estimation schemes using sliding mode observers. In many practical situations, the internal state of a system cannot be determined by direct measurement, and an observer may be use to estimate the unavailable states based on the measured outputs and control inputs. Existing work has shown that the functional observer (which estimates only a subset of the states) can be used to eliminate the redundancy possessed in full-state estimation, and also reduce computational burden. The sliding mode observer has been shown to have excellent performance in robust state estimation, and also has the extra ability of estimating the unknown input. Its use for functional state estimation is still very much in its infancy with no significant works being reported. This thesis combines the theories of functional state estimation and sliding mode observer to reduce the observer complexity as well as improve the overall performance of the observer. The first contribution of this thesis is the reformulation of the system such that the sliding mode observer can be implemented directly to achieve functional state estimation. The next contribution is the development of a two-observer scheme (which uses two observers in cascade) for functional state estimation and the investigation of its existence conditions, which were found to be weaker and more general than previous work. Following that, the work of cascading observers was extended to multiple sliding mode observers is explored, together with the investigation of its existence conditions in terms of the original system matrices; these conditions enable the user to know at the outset whether the observer scheme is applicable to their system or not, and also systematically calculates the number of observers necessary and sufficient. Following that, a new functional state estimation method is introduced, where the functional state is modeled as an unknown input, and then estimated using the ability of the sliding mode observer to estimate unknown inputs. Finally, the functional observer is implemented on the a class of descriptor systems, and the necessary and sufficient conditions are investigated. The efficiency of the functional observer schemes presented in this thesis are demonstrated by simulation examples
Evaluation of roughness, hardness, and strength of AA 6061 molds for manufacturing polymeric microdevices
No full textIn the manufacturing of polymeric microfluidic devices, micro-molds play a key role because they determine not only the manufacturing cost but also the quality of the molded parts. Recently, a high-quality aluminum alloy 6061 (AA6061) mold with fine features less than its grain size has been fabricated economically by a hot embossing technique. However, temperature cycling during hot embossing process in mold manufacturing reduces significantly the original tensile strength and hardness of the AA6061-T6 alloy substrate, which is not desirable. In this study, a tempering process is carried out to recover the tensile strength and hardness of the embossed mold. To evaluate the changes of these properties, surface roughness, tensile strength, and hardness values were measured in each stage: (1) before hot embossing, (2) after hot embossing, and (3) tempering to T4 and tempering to T6. The results obtained demonstrate that the original strengths and hardness can be fully recovered by a post-tempering process after hot embossing, but with an increase in surface roughness. Moreover, accelerated testing was carried out to evaluate the changes in hardness and roughness of AA6061-T4 and T6 molds under the typical hot embossing temperature cycles of manufacturing polymeric devices. The results obtained indicate that these temperature cycles have only a minor effect on the roughness of both T4 and T6 molds and will increase the hardness of T4 molds to T6 temper, and have negligible effect on the hardness of a T6 temper mold
Development of collagen scaffold with internal channels via indirect rapid prototyping
No full text202 p.The author would like to take this opportunity to acknowledge the contribution of anumber of people for this project. The realization of the project would not have beenpossible without the advice and assistance from them.The author wishes to express her sincere gratitude and appreciation to A/P Chua CheeKai, A/P Leong Kah Fai and Dr. Margam Chandrasekaran, for their invaluable adviceand motivation throughout the project. Appreciation is also extended to As/P AlastairCampbell Ritchie from the School of Mechanical and Aerospace Engineering, NTU,and Mr Timothy Tan and Dr Peter Lee from DNA Center, NIE, for their guidance inthe project. Heartfelt thanks to Ms Hu Quijun, from SIMTech for her guidance andsupport.DOCTOR OF PHILOSOPHY (MAE
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