Applied Mechanics and Materials Vol. 749

Abstract: The purpose of this study is to determine the actual state of noise occurrence in apartment-unit households by utilizing state data to examine individual noise sources and the types of noise between floors. Among the types of noise between Floors, the top four noise sources were conversation and electrical appliance noise in the airborne noise category, and foot-stepping noise and object-dropping noise in the direct impact noise category. The result shows that in three sources (other than foot-stepping noise), the equivalent sound level was found to exceed the standard value in a specific time slot. The frequency of noise occurrence was shown to be highest between 18:00 and 21:00, after household members had come home from work. Therefore, to reduce noise between floors, a management plan should be introduced based on the actual state of the noise occurrence, considering the individual noise source and the time slot during which noise frequently occurs.

Abstract: Over the past few decades, doubts among construction researchers arise about how hospital project success is measured. However, only some general consensus of that matter was agreed upon. Therefore, the aim of this study is to identify the holistic success criteria (SC) of public hospital construction projects. This article describes the criteria, which then conceptually classified the SC into five, which are meeting client requirements; meeting for management of construction goals; meeting for production of construction goals; benefit to the project teams (D&B contractors) developments; and benefiting the community. Every SC describes a set of problem statements as well as dimensions which were based on the following issues: unsatisfactory product quality; prolong of completion period; cost overrun; unsafe site condition; clients’ dissatisfaction; and non-benefit to the community. To realise the objective, questionnaire survey was distributed to the client (Ministry of Health, Malaysia and client’s project manager) and D&B contractors throughout Malaysia. The raw data were analysed using factor analysis (FA) method reduced the variables from 93 items to only 16. Principal components analysis (PCA) procedure considered only the factor loading with a value of 0.500 and above. Each component underwent a process of reliability analysis (RA) with the overall value of Cronbach’s alpha of more than 0.700. Result was found that a set of new measure consisting 16 variables called SC measures were determined. Generally, it covered efficiency of the process and effectiveness of the product. The major limitation of the study was that the key players of the project always changed and most of projects were 95% completed. However, it is important to understand that most of the construction projects are project-basis with temporary organisation. Therefore, extra effort should be emphasised to enhance the quality of the data collected and more research should be done to overcome the issues which still grow concurrent with the development.

Abstract: A Phase Change Material (PCM) based on paraffinic wax encapsulated in polymer shell is used for improvement of the heat storage capacity of commercially produced dry plaster, originally developed for both exterior and interior hand application. The composition of PCM modified plasters is designed with respect to the workability of fresh mixtures. Characterization of applied PCM is done using the measurement of particle size distribution, powder density, and matrix density. For the newly developed composite plasters, basic physical properties, mechanical properties, and thermal properties are accessed, whereas a specific attention is paid to the Difference Scanning Calorimetry (DSC) analysis. Using DSC measurement, temperatures of phase change transitions and phase changes enthalpies are identified. The obtained results show that the temperature induced phase change can be used for the release and storage of thermal energy in buildings, which can be beneficially utilized for saving the energy spent for the achievement of the indoor thermal comfort.

Abstract: March to May at noon control area (exposed roof) temperature of 37.56°C, test below (green roofs) surface only 24.69°C, 24.79°C room temperature on the second floor, planting mean temperature of 27.6°C, effectively prevent the roof surface temperature rise, and thus reduce the interior roof of the second temperature 12.77°C . Building extensive green roofs to cooling, mainly to reduce the building room temperature of 3.76°C;reducing air conditioning electricity consumption , accomplish cooling and energy-saving benefits.March to May at noon (12:00-13:00), ANOVA analysis of cooling efficiency, the temperature difference between the building control area as the dependent variable, compare independent variables, and found that different monitoring areas of solar radiation cooling effect,2 floor indoor cooling temperature 13.9083°C, efficiency the most significant.Roofs of buildings spring will be applied as extensive green roof in spring, creating building roof thermal comfort (24.88°C) and Auliciems (1981) estimate room comfort temperature (24.55°C) are similar, significant benefits to achieve room thermal comfort.Buildings is applied for green roofs in the spring can reduce home power consumption (reducing air conditioning systems use frequency), to energy-saving (58.17%) of the economic benefits.

Abstract: Osteoarthritis is a degenerative disease of articular cartilageand meniscus that most experience in aged and obesity, always tend to grow up. Such bone surface degenerated will beirregular and has bone to grow called osteophyte. At moment making activities, the pain and the deformation of the knee joint are occurred thatcause decreasing quality of life. The deterioratedmeniscus has to encountersgradually changing the structureuntil it is not able to support the body weight. This paper proposes the preliminary studyof the knee jointbehavior, especially the meniscus during stand. Three dimensions (3-D) finite element (FE) model of the knee joint has constructed. This model consisted of femur, tibiaand meniscus without fibula.The external load were determined in each body weight and appliedon femur to evaluate maximum von-mises stress on the meniscus.The stress distribution on meniscus always occurs while exist the external load on the femur. The tendency of association between the external load and maximumstress was corresponding to that of the other author.

Abstract: With the advancement of nanotechnology and material chemistry, micelles have emerged as one of the most attractive carriers for anticancer drug delivery. In this study, a newly developed polymerization technique termed as “sequential ring-opening polymerization (SROP)“ was used to synthesize poly (ethylene glycol)-block-polylactide-block-polylactide (PEG-PLA-PLAs). Utilizing the features of SROP, well-controlled chain length of two different PLA blocks by using PEG as initiator can be achieved. Two types of PEG-PLA-PLAs, PEG-PLA₁₁-PLA₁₁ and PEG-PLA₁₈-PLA₁₈, were successfully synthesized and characterized. Having amphiphilic properties, PEG-PLA-PLAs were used to form micelles through self-assembly. The effects of PLA length on the resultant micelles were thoroughly investigated.

Abstract: This proposal aims to develop a newly, stable, excellent and environmental process of manufacturing scaffolds with virtually identical biphasic calcium phosphate compositions. Calcium phosphate cements (CPCs), which combines calcium orthophosphate powders with a liquid leading to a paste that hardens spontaneously at low temperatures, have potential to be used as a porous template for dental bone grafting substitutes [1,2]. Such newly developed sintering processes having the bone grafts with properties of bioactivity or even bioresorbability would be applied in many clinical setting. Template materials combine calcium orthophosphate powders with a liquid leading to a paste that hardens spontaneously at low temperatures. Hence, CPCs could be applied as scaffolds to support cell/tissue growth [3, 4]. This paper studies CPC scaffolds processing by foaming cement's paste state in which was added phasic stabilizer of magnesia and foaming agent of sucrose. The X-ray diffraction was performed to identify the phases of bone grafting substitutes, and we also used scanning electron microscope to observe the structure and pores of bone grafting substitutes. The cell viability about biocompatibility of developed bone grafting substitutes was examined. The results showed that our bone grafting substitutes produced steady final biphasic products consisting of hydroxyapatite (HA) and beta-tricalcium phosphates (β-TCP). We observed interconnected pores and highly porosity in microstructure of the bone grafting substitutes. The cell viability was over 70 % to make sure that the bone grafting substitutes has excellent biocompatibility. In conclusion, using the slurry of calcium phosphate cements (CPCs) and pores forming agent set into a porous template would be a useful process for manufacturing bone graft substitutes.

Abstract: This study aims to create avirulent artificial bone scaffolds. Chitosan/gelatin mixture is blended with hydroxyapatite (HA) powder, followed by being processed with a free-dry method in order to form CGH artificial bone scaffolds. A stereomicroscope, an optical microscope and an MTT assay are used to evaluate the applications of the bone scaffolds. The combination of HA powders leads to isotropic pores in the bone scaffolds, while not inflicting their biocompatibility. In addition, the cell viability increases with the increasing content of HA powder. This study successfully produces biocompatible and non-toxic bone scaffolds.

Abstract: This study proposes coronary stents in a manner of reticular tube, which are made by applying a braiding method. Polyvinyl alcohol (PVA) plied yarns are braided into hollow braids on a 16-spindle braid machine, followed by being cross-link treated to form the coronary stents. The surface observation and a compressive test are used to evaluate the resulting products. The test results show that cross-link treatment does not pertain to the reticular, tubular manner of the braids. However, a low cross-linking concentration results in a light shade and a greater compressive strength in the coronary stents. In addition, the acidification of the cross-linking solution affects the compressive modulus. The coronary stents presented by this study are proved to be biodegradable and have compressive strength and a reticular-and-tubular form.

Abstract: It is well known that titanium (Ti) has excellent properties of anticorrosion, biocompatibility and low modulus that would be applied in many clinical applications. The aim of this study wants to increase the hydrophilicity of titanium surface through silanization and then grafted with hydroxyapatite (HA) by hydrothermal synthesis method. Physiochemical analysis of grafting plate substrate was observed by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), and contact angle analysis. The surfaces with silanization were strongly interaction between SiO₂ and TiO₂, and thus Ti-O-Si-bonds formed having larger surface areas but only showed a little improved hydrophilicity. The hydrophilicity of Ti substrate was largely increased after the hydrothermal process. Compared with Ti surface without any surface treatment, the surface which modified with hydrothermal synthesis can improve the wettability of Ti surfaces. Furthermore, the Ti surface through silanized modification before hydrothermal synthesis held good calcium phosphate precipitates existing due to the better calcium ion combined ability with polar bond of aldehyde group (Ti-O-Si-CO^-).