EFFECTS OF GLYCEROL IMPREGNATION ON COMPRESSIVE STRENGTH PARALLEL TO GRAIN OF ACACIA AURICULIFORMIS UPON DRYING

ABSTRACT. This study deals with the chemical treatment of the Acacia Auriculiformis species with a 99.5% glycerol solution with the aim of demonstrating the possibility of producing better ultimate compressive strength parallel to the grain upon drying. The vacuum pressure method was used to impregnate the glycerol solution into the cell wall of the wood. The results indicate a significant improvement (about 30% higher) of the properties investigated; specifically the compressive strength of wood perpendicular to the grain, however, the non-impregnated sample still has superiority when it comes to toughness.

KEYWORDS: AcaciaAuriculiformis, compression test, drying defect, glycerol

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COMMERCIAL SILICATE GLASS-CERAMICS: CHARACTERIZATION BY XRD AND TEM ON CRYSTALLIZATION

ABSTRACT.Crystallization in commercial spodumene glass-ceramic, Corningware® and commercial fluosilicate glass-ceramic, Macor® were characterized by comparing with the quench studies of in-house melted glasses using XRD and advanced microscopy techniques (TEM). XRD, Energy Dispersive X-Ray Analysis (EDAX) and Selected Area Diffraction Pattern (SADP) by TEM confirmed the crystallization of the β-spodumene s.s. with minor needle-like rutile and also precipitation of cuboidal spinel in in-house spodumene glass-ceramics. The techniques were also used in confirming crystallization in the in-house fluosilicate glass-ceramics where different microstructure based on the early-formed fluorophlogopite crystals were observed with minor cuboidal mullite present as compared to the commercial fluosilicate glass-ceramics.

KEYWORDS. Glass-ceramics, fluosilicate, spodumene, EDAX, TEM

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HARVESTING ELECTRICAL CHARGE FROM AMBIENT VIBRATION USING PIEZOELECTRIC MATERIALS

ABSTRACT. Nowadays the energy source for portable electronic devices heavily depends on battery which has limited lifetime and contributes to environmental pollution after discarding it. This has created an environment impact to the soil and water. A green solution to reduce excessive pollution from battery usage is suggested in this paper with the use of piezoelectric materials to convert ambient vibration into the required electrical energy. The piezoelectric material is adhered to a cantilever beam to form a piezoelectric bender and its analytical model with base excitation is first established to study the effect of the structural and connecting configurations of the constructed benders on the harvested electric charge. The model predicts that the single-active layer piezoelectric bender harvests about 1.6 times of electric charge and two-active layer piezoelectric bender in parallel connection harvests two times, than that harvested by two-active layer piezoelectric benders in series connection. The experimental results comply with the theoretical predications. Among all the combinations, the two-active layer piezoelectric bender in parallel connection is concluded the optimum configuration for electrical charges harvesting. It is also shown in this paper the application of piezoelectric charge harvester to light up LED. This shows the potential application of piezoelectric charge harvester to replace battery usage that may reduce heavy mental pollution to the environment.

KEYWORDS. Electric charge generation, piezoelectric materials, single-active layer bender, two-active layer bender.

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SURVEY OF SLOPE FAILURES (SFS) ALONG THE BUNDU TUHAN KUNDASANG HIGHWAY, SABAH, MALAYSIA

ABSTRACT. This study focused on the slope failures survey (SFS) along the Bundu Tuhan – Kundasang highway, which is one of the most vulnerable areas to slope failures in west coast of Sabah. The area is underlain the Trusmadi Formation (Palaeocene to Eocene age), the Crocker Formation (Late Eocene to Early Miocene age) and Quaternary Alluvium Deposits. These geologic units are dissected by numerous lineaments and structural styles produced by complex tectonic history of multi phase deformations. The tectonic complexity reduces the physical and mechanical properties of the rocks and soils; and produced intensive displacements in substrata, resulting in intensive high degree of weathering processes and instability. In this study, a total of 50 selected critical slopes were studied. This study classified the slope failures into three main groups: soil slope failures, rock slope failures and erosional failures. Failures in soil slopes (including embankments) total 34 (68 %) with 10 failures (20 %) of rock slopes and 6 failures (12 %) caused by erosion. Soil slope failures normally involved large volume of failed material compared to rock slopes, where most failures are small to large size. Of the 34 failures in soil slopes, 31 (91 %) are embankment failures making them 62 % of all types of failures. Engineering geological evaluation of the study area indicates that the slope failures took place when slope materials are no longer able to resist the force of gravity. These decrease the shear strength and increase the shear stress resulting slope failures, which is due to internal and external factors. Internal factors involve some factors change in either physical or chemical properties of the rock or soil such as topographic setting, climate, geologic setting and processes, groundwater condition and engineering characteristics. External factors involve increase of shear stress on slopes, which usually involves a form of disturbance that is induced by man includes removal of vegetation cover, vehicles loading and artificial changes or natural phenomenon. Development planning has to consider this disaster in order to mitigate their effect. An landslide risk management program should be implemented to prevent these losses. This engineering geological study will play a vital role in slope stability assessment to ensure the public safety.

KEYWORDS: Slope failures survey (SFS), failure probability, physical and mechanical properties

5- Survey Of Slope Failures (Sfs) Along The Bundu Tuhan-Kundasang Highway, Sabah, Malaysia

LANDSLIDE HAZARD FACTORS (LHF) BY COMMUNITY PERCEPTION SURVEY IN KOTA KINABALU, SABAH

ABSTRACT. This study aims to investigate disaster perception of factors causing landslides for the people of Kota Kinabalu city area, Sabah, Malaysia. Five hundred and seven adult respondent residents from the local government and private agencies exposed to landslide hazard participated in this study using structured questionnaires. Perception of landslide hazard factors (LHF) was assessed by statistical analysis such as Descriptive Analysis, Factor Analysis, Independent Samples T-Tests and Analysis of Variance (ANOVA). Major information in this survey relates to the factors likelihood to cause landslides. Socio-demographic and experiential information of respondents was also collected. Exploratory study on descriptive analysis indicates that the slope gradient factor fell in the highest rank with highest frequency (474) for events causing landslides, followed by water (469), supervision (425), negligence (415), geology (390), design (385) and geomorphology (365). Factor analysis results show that there are two factors that cause landslides: Engineering Geological Characteristics (EGC) and Human Factors (HF). After performing Varimax Rotation Method with Kaiser Normalisation, Factor EGC comprises four items: geology, geomorphology, water and slope gradient; while Factor HF comprises three items: negligence, supervision and design. Independent samples t-test for equality of mean results showed there were no significant mean differences in community perception of EGC or HF for both gender with professions and gender with educational background categories for all respondent items (p>0.05). ANOVA results showed there were significant mean differences in community perceptions of EGC among educational background at 10% level of significance (p<0.1) but no significant mean differences among other variables such as professions, home location and living area (p>0.05). In a different situation, the ANOVA results showed there was significant mean differences in community perceptions of HF among professions at 5% level of significance (p<0.0.5) but no significant mean differences among other variables such as educational background, home location and living area (p>0.05).

KEYWORDS:
Landslide hazard factors (LHF), community perception survey (CPS), statistical analysis

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