The Sandakan Formation of the Segama Group is exposed across the Sandakan Peninsular in eastern Sabah. This Upper Miocene part of the Segama Group unconformably overlies the Garinono Formation and is conformably overlain by the Bongaya Formation. This formation was investigated with detailed logging of outcrops and microfossils analysis in order to map the depositional facies and sedimentary environment. This study showed the presence of seven lithofacies: Thick amalgamated sandstone; thin, lenticular interbedded HCS sandstones and mudstone; laminated mudstone with Rhizophora; trough cross-bedded sandstone; laminated mudstone; strip mudstone with thin sandstone and siltstone; and interbedded HCS sandstone and mudstone. Based on the presence of Rhizophora, Brownlowia, Florchuetia sp., Polypodium, Stenochleana palustris, Ascidian spicule low angle cross bedding, very fine grained sandstone, thin alternations of very fine sandstone, silt and clay layers showing cyclicity (muddy rhythemites), rocks in the Sandakan Formation are interpreted as mangal estuary and open marine facies. Three facies associations could be deduced from the seven lithofacies: Gradual coarsening upwards shoreface; abrupt change facies and prograding estuary facies association.
Objective: This study examined the influence of visual art therapy techniques in reducing anxiety level
among 4 to 6 years old paediatric dental patients.
Methods: Eleven subjects were selected among 4 to 6 years old paediatric dental patients. The initial
reaction towards dental procedure/treatment was evaluated using Frankl Behavior Rating Scale. The
anxiety level was assessed by using Malay-Modified Child Dental Anxiety Scale (MCDASf
) to measure
a child situational anxiety of pre- and post-treatment. Visual art making activities included free drawing,
clay moulding and collage technique. The participant reaction to dental treatment was assessed by using
Frankl Behavioural Rating Scale for two subsequent independent visits in two weeks interval. Median
and Ordinal Test ranked the variables score of behavioural reaction towards dental treatment and anxiety
level.
Results: Play-doh (PD) subjects could accept dental procedures more if compared to free drawing (FD)
and storytelling by collage (ST) subjects, which has lower post treatment-median scores in Visit 1 and
Visit 2, FD and ST subjects need more time to show positive attitude towards dental treatment.
Conclusion: These findings suggest dental anxiety level of children aged 4 to 6 years old reduced after
the art therapy and play-doh(clay-moulding technique) is the art making activity of choice among 4 to 6
years old paediatric dental patients.
Nanoparticles are defined as ultrafine particles sized between 1 and 100 nanometres in diameter. In recent decades, there has been wide scientific research on the various uses of nanoparticles in construction, electronics, manufacturing, cosmetics, and medicine. The advantages of using nanoparticles in construction are immense, promising extraordinary physical and chemical properties for modified construction materials. Among the many different types of nanoparticles, titanium dioxide, carbon nanotubes, silica, copper, clay, and aluminium oxide are the most widely used nanoparticles in the construction sector. The promise of nanoparticles as observed in construction is reflected in other adoptive industries, driving the growth in demand and production quantity at an exorbitant rate. The objective of this study was to analyse the use of nanoparticles within the construction industry to exemplify the benefits of nanoparticle applications and to address the short-term and long-term effects of nanoparticles on the environment and human health within the microcosm of industry so that the findings may be generalised. The benefits of nanoparticle utilisation are demonstrated through specific applications in common materials, particularly in normal concrete, asphalt concrete, bricks, timber, and steel. In addition, the paper addresses the potential benefits and safety barriers for using nanomaterials, with consideration given to key areas of knowledge associated with exposure to nanoparticles that may have implications for health and environmental safety. The field of nanotechnology is considered rather young compared to established industries, thus limiting the time for research and risk analysis. Nevertheless, it is pertinent that research and regulation precede the widespread adoption of potentially harmful particles to mitigate undue risk.
The sorption parameters of two heavy metals (i.e. Pb and Cu) in clay soils from Selangor were studied using batch equilibrium test. The test was conducted in two separate systems, i.e. single and mix solutions. The sorption isotherms data from this test were then used to calculate the sorption parameters, i.e. distribution coefficient (Kd) and maximum adsorption capacity (Am). Langmuir sorption equation was used to model the sorption data with the correlation coefficients (r2) higher than 0.6. The study has revealed that different soils have different sorption capacity for different heavy metals. The Kd values are proportional to the sorption capacity of the soils. The sorption of Pb and Cu in single solution is higher than in mix solution, due to the competition for sorption sites among heavy metals in mix solution. The Kd values for Pb in single solution ranging from 36.18-334.48 L/g and for Cu is 9.29-66.19 L/g. In mix solution, the Kd values for Pb and Cu are much smaller, ranging from 23.13-31.79 L/g and 3.95-18.53 L/g respectively. The Am values in single solution for both Pb and Cu are ranging from 0.48-1.09 mg/g dan 0.18-0.70 mg/g respectively. While in mix solution, the values of Am for Pb ranging from 0.20-1.11 mg/g and Cu within 0.18-0.60 mg/g.
The land area of Tanah Putih, Gua Musang, Kelantan (Malaysia) is well-known for its wealth in industrial mineral resources, especially aluminosilicate of feldspar and mica. Natural feldspar and mica were physicochemically characterized with regard to X-ray diffraction (XRD), nitrogen sorption analysis and transmission electron microscopy (TEM) techniques for qualitative and quantitative identification of feldspar and mica. They show a good crystallinity, high surface area and uniformity of mesoporous structures. For the purpose of this experiment, the aluminosilicate of feldspar was modified either by acid treatment, or grafting the silanol groups present with various functional groups including aminopropyl-, octyl-, vinyl-, mercapto- and glycidoxy-triethoxysilanes, or activation of pre-treated support with glutaraldehyde. These support derivatives were used for further utilization in the immobilization of lipase from Candida rugosa and resulted in various interaction mechanisms between enzyme and introduced supports. It seemed that the features of the functionalized feldspar surfaces provide a preferable environmental host to enable the adsorption of lipase via interfacial adsorption method. Lipase immobilization onto feldspar support were further confirmed by scanning electron microscopy (SEM) coupled with energy dispersive X-ray microanalysis (EDX), transmission electron microscopy (TEM) and infra-red spectroscopy (FTIR) techniques. Enhancement of protein loading (up to 8.22 mg protein/g support) and immobilization yield (up to 78%) were shown by modified feldspar-lipase derivatives compared to unmodified feldspar support.
Detailed geophysical investigations have been carried out using integrated geophysical methods with a view to characterising the subsurface lithologic features that might indicate suitable places for structural developments. An overview of the subsurface resistivity distribution has been achieved employing 8Vertical Electrical Soundings with the Schlumberger array and 4 2D resistivity imaging using Wenner array. In order to constrain the results of the electrical resistivity methods, we carried out a ground magnetic survey along E-W direction using the Proton precession magnetometer at 1m sampling interval. Analysis of well logs data available and VES results showed 4 to 5 geoelectric layers corresponding to sand, clayey sand, clay, silty sand and sandy clay. The 2D resistivity imaging sections showed relative decrease of apparent resistivity with depth implying a geological transition from sand with high resistivity value of about 508Ωm to clay with low resistivity value 16Ωm at depths of 0-20m and 25-50m respectively. The magnetic profiles showed that the study area was characterised by short wavelengths and amplitudes ranging from –3800 to 700 nT. The highs and lows of the magnetic responses occasioned by lithological variations and structural features were magnetically resolved. In view of the identified subsurface structures, the suggested depth to the competent layer is about 20m for low to medium structures while above 50m would be suitable for heavy or massive engineering structures. The use of integrated geophysical methods for the delineation, identification and imaging of the subsurface geological structures which could provide clues to the nature and type of foundation suitable for the development of the study area has been successfully achieved.
Radon gas has been known as one of the main factors that cause breathing complications which lead to lung cancer, second only after smoking habit. As one of the most commonly found Naturally Occurring Radioactive Materials (NORM), its contribution to background radiation is immense, and its contributors, Uranium and Thorium are widely available on Earth and have been in existence for such a long time with long half-lives. Indoor radon exposure contributed by building materials worsens the effects. The probability of inhaling radon-polluted air and being surrounded by it in any buildings is very high. This research is focused on the detection of radon emanation rate from various building materials which are commonly being used in Malaysia. Throughout this research, common building materials used in constructions in Malaysia were collected and indoor radon exposure from each material was measured individually using Tight Chamber Method coupled to a Continuous Radon Monitor, CRM 1029. It has been shown that sand brick is the biggest contributor to indoor radon compared to other samples such as sand, soil, black cement, white cement, and clay brick. From the results, materials which have high radon emanation could be reconsidered as building materials and mitigation action can be chosen, suitable to its application.
Organic photovoltaics (OPVs) die due to their interactions with environmental gases, i.e., moisture and oxygen, the latter being the most dangerous, especially under illumination, due to the fact that most of the active layers used in OPVs are extremely sensitive to oxygen. In this work we demonstrate solution-based effective barrier coatings based on composite of poly(vinyl butyral) (PVB) and mica flakes for the protection of poly (3-hexylthiophene) (P3HT)-based organic solar cells (OSCs) against photobleaching under illumination conditions. In the first step we developed a protective layer with cost effective and environmentally friendly methods and optimized its properties in terms of transparency, barrier improvement factor, and bendability. The developed protective layer maintained a high transparency in the visible region and improved oxygen and moisture barrier quality by the factor of ~7. The resultant protective layers showed ultra-flexibility, as no significant degradation in protective characteristics were observed after 10 K bending cycles. In the second step, a PVB/mica composite layer was applied on top of the P3HT film and subjected to photo-degradation. The P3HT films coated with PVB/mica composite showed improved stability under constant light irradiation and exhibited a loss of <20% of the initial optical density over the period of 150 h. Finally, optimized barrier layers were used as encapsulation for organic solar cell (OSC) devices. The lifetime results confirmed that the stability of the OSCs was extended from few hours to over 240 h in a sun test (65 °C, ambient RH%) which corresponds to an enhanced lifetime by a factor of 9 compared to devices encapsulated with pristine PVB.
Metakaolin is a manufactured pozzolan produced by thermal processing of purified kaolinitic clay using electrical furnace. This study has examined the effect of Metakaolin on the properties of cement and concrete at a replacement level of 0%, 5%, 10% and 15%. The parameters studied were divided into two groups which are chemical compositions, water requirement, setting time and soundness test were carried out for cementitous properties. Workability, compressive strength and bending strength were test for concrete properties. Hardened concrete was cured under different type of curing conditions and tested.. The result showed that the inclusions of Metakaolin as cement replacement minerals have change some of the cementitous and concrete properties. This research reveals, the optimum effect for cementitous and concrete properties for metakaolin was 10%.
The [Co(naphophen)(PPh3)(OH2)]ClO4 and [Co(naphophen)(PBu3)(OH2)]BF4 (where naphophen=bis(naphthaldehyde)1,2-phenylenediimine) complexes were synthesized and chracterized by FT-IR, UV-Vis, (1)H NMR, (13)C NMR spectroscopy and elemental analysis techniques. The coordination geometry of the synthesized complexes were determined by X-ray crystallography. Cobalt (III) complexes have six-coordinated pseudo-octahedral geometry in which the O(1), O(2), N(1) and N(2) atoms of the Schiff base forms the equatorial plane. These complexes showed a dimeric structure via hydrogen bonding between the phenolate oxygen and the hydrogens of the coordinated H2O molecule. The theoretical calculations were also performed to optimize the structure of the complexes in the gas phase to confirm the structures proposed by X-ray crystallography. In addition, UV-Visible and IR spectra of complexes were calculated and compared with the corresponding experimental spectra to complete the experimental structural identification. The synthesized complexes were incorporated onto the Montmorillonite-K10 nanoclay via simple ion-exchange reaction. The structure and morphology of the obtained nanohybrids were identified by FT-IR, XRD, TGA/DTA, SEM and TEM techniques. Based on the XRD results of the new nanohybrid materials, the Schiff base complexes were intercalated in the interlayer spaces of clay. SEM and TEM micrographs of the clay/complex shows that the resulting hybrid nanomaterials has layer structures.
Seismic surface waves are a non-destructive technique used to obtain the dynamic properties of soil by measuring the shear wave velocity and calculating the shear modulus of soil. The shear modulus is one of the parameters to measure the stiffness of materials. This study evaluates soil profiles and the position of the sensor while conducting measurements of two , soil profiles, i.e. lateral and vertical non-homogeneities, using a continuous surface wave analysis (CSW) and multi-channel analysis of surface waves (MASW). Results showed the dispersive curve demonstrated an increased shear wave velocity with increasing depth for the sensor pair measurements on the clay (between columns), and decreased shear wave velocity with increasing depth for the sensor pair measurements on the column. In both instances the surface wave velocity results influenced by the depth and size of the wavelength, indicating that depth and wavelength controlled the volume of measurement in an elliptical shape. Therefore, the shear wave velocities and thus stiffness measured from the surface wave velocity techniques are represented the volume of soil measured across the sensor length.
This study reports the use of sewage sludge generated from sewage treatment plant (STP) as raw material in a clay brick-making process. The physico-chemical and mineralogical characterization of the sewage sludge and clay were carried out in order to identify the major technological constraints and to define the sludge pretreatment requirements if necessary. Moreover, the effects on processing conditions and/or on changes of typical final characteristics are also evaluated. Bricks were produced with sewage sludge additions ranging from 10 to 40% by dry weight. The texture and finishing of the surface of sludge-amended clay bricks were rather poor. As for the physical and chemical properties, bricks with a sludge content of up to 40 wt.% were capable of meeting the relevant technical standards. However, bricks with more than 30 wt.% sludge addition are not recommended for use since they are brittle and easily broken even when handled gently. A tendency for a general degradation of brick properties with sludge additions was observed due to its refractory nature. Therefore, sludge bricks of this nature are only suitable for use as common bricks, which are normally not exposed to view, because of poor surface finishing.
A sludge lagoon has been adopted as a simple and cost effective method for dewatering of sludge. The processes occurring in a sludge lagoon include thickening, dewatering, storage and stabilization; all happening simultaneously. The objective of this study is to determine the dewatering and drying rates at pilot-scale which occur in a lagoon having different design configurations. Two types of sludge lagoons with different initial sludge depth (0.75 m and 0.375 m) were investigated to measure the drying behavior and drying efficiency. The first design is a sludge lagoon with a clay bottom where the dewatering mechanisms are decanting supernatant and evaporation. The second design is a sludge lagoon installed with a sand and underdrains system, where the dewatering mechanisms are filtration or draining and evaporation. Sludge drying kinetic models with high fitness were plotted to describe the sludge drying behavior. Drying of sludge in a sludge lagoon with a clay bottom can best be described by an exponential function. Whereas, drying of sludge in a sludge lagoon with sand and underdrains system followed a logarithmic function. A lagoon designed with sand and underdrains system and having shallower sludge depth was the most efficient. The reduction in volatile solids was lower than 4% during the study period. The drying process proceeded with an increase in dryness and decline in pH value.
Microbial content formed in bioreactors plays a significant role in the anaerobic process. Therefore, the physicochemical characteristics of microbial content in a modified anaerobic inclining-baffled reactor (MAI-BR) treating recycled paper mill effluent (RPME) were investigated using Fourier transform infrared (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric (TG), and derivative thermogravimetric (DTG) analyses, scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), Brunauer-Emmett-Teller (BET), and surface area analyzer. FTIR spectra revealed that the microbial content had stronger characteristic peaks corresponding to alcohols, water, lipids carbohydrates, proteins, and mineral compounds. Calcite, muscovite, and lepidolite were the prevalent mineral phases found by XRD analysis. The elemental of these minerals like C, Ca, N, O, and Si was confirmed by XPS results. The microbial content samples from each compartment showed similar thermal behavior. SEM images showed that straight rod-shaped and Methanosaeta-like microorganisms were predominant, whereas C, O, and Ca were noticed by EDS on the surface of granules. The BET surface areas and pores of granules are found to decline throughout the reactor's compartment, where Compartment 1 had the largest values. Thus, the findings of this study establish further understanding of the physicochemical properties of microbial content formed in MAI-BR during the RPME treatment.
Ground improvement using artificial crust composite foundation, consisting of stabilization of soft clay and composite foundation, is an effective technique for the treatment of deep soft soil layers under infrastructure embankments. In this study, the load responses and settlement performance of this improvement technique were investigated using two centrifuge model tests to compare the variations of the vertical deformation, pore water pressure, axial force of the piles and tensile stress at the bottom of the artificial crust in the crust composite foundation with those in pile-supported embankment. The results of centrifuge model tests showed that the load responses and settlement performance of artificial crust composite foundation was different from the pile-supported embankment, which displayed mainly that the final middle settlement of crust composite foundation can be reduced by about 15% compared with those of pile-supported embankment with the same length of pile and construction cost. The deformation of the crust with the characteristics of the plate was found based on the change of the tensile stress. Additionally, the excess pore water pressure in the crust composite foundation was lower owing to the stress diffusion effect of the crust during the loading period and the dissipation rate of excess pore water pressure was slower due to lower permeability of the crust at the same loading period. Eventually, the axial force of the middle piles was reduced. At the same time, the boundary stress was functioned with the crust, the axial force of the side piles was improved. The comparison of measured and calculated results was carried out using the stress reduction ratio, the result shows that the bearing capacity of the subsoil in the crust composite was improved.
The long term objective of this research is to look into the possibility of replacing soil strength parameters such as cohesion and angle of friction with electrical resistivity value for the purpose of computing among others, factor of safety in slopes or bearing capacity of soil. This paper however is limited to the investigation of correlation between electrical resistivity with some selected soil parameters. Electrical resistivity tests, using a basic multi meter, steel moulds and other related equipment, were conducted in the laboratory on soil samples with variations in soil type, compaction energy and moisture content. The samples consisted of predominantly clay, silt and sandy size particles and were compacted in a 100 x 100 mm square mould, while the corresponding electrical resistivity tests were carried out using the disc electrode method in accordance to BS 1377. The values of the electrical parameters such as voltage, current and resistance, with the corresponding value of soil parameters such as cohesion, angle of friction and moisture content, were measured and recorded. The results of the tests produced some initial crude relationships between electrical resistivity and the selected soil parameters. The strongest correlation between electrical resistivity and angle of internal friction, φ, was obtained from the clay size samples with R2 of 0.824, while the maximum correlation between electrical resistivity and moisture content again was obtained through the clay samples with R2 of 0.818. From the other results and graphs analyzed, some consistencies and specific trends of behaviour observed gave some early indications that a more detail and precise correlation between electrical resistivity and soil strength parameters could be very well possible in future.
Termites are found in various habitats, particularly diverse communities occurring in tropical forest and peatlands.
Termites are beneficial insects, which function as soil engineers, improving the soil quality. However, in peatlands
converted to commercial oil palm plantations, they are considered as pests. There is lack of studies on termite communities
in converted peatlands in Peninsular Malaysia. Thus, this study investigated termite species associated with oil palm
stands in three soil types (clay, shallow peat and deep peat) in Endau Rompin Plantation. The stand scouting method
was used to record the numbers and types of termites associated with palm trees in the individual stands on different
soil types. A total of 29 termite species associated with the palm stands were identified morphologically. All the species
belonged to the families Rhinotermitidae and Termitidae. Twenty-three of the 29 species were found in the shallow peat,
16 in clay soil and 15 in deep peat. The community structure was synthesized by two-way cluster analysis with Sorensen
(Bray Curtis) distance measure. Five termite groups associated with two soil types (clay soil and shallow/deep peat)
were generated. Moisture levels and organic content were likely to determine the presence of soil feeders identified in
the presence study. This study provides information on the status of termite species in oil palm plantation areas. Such
information may be useful in future planning strategies by the plantation management.
Waste plastics contain a substantial number of valuable chemicals. The wastes from post-consumer as well as from industrial production can be recycled to valuable chemical feedstock, which can be used in refineries and/or petrochemical industries. This chemical recycling process is an ideal approach in recycling the waste for a better environment. Polymer cracking using a laboratory fluidized bed reactor concentrated on the used highly contaminated catalyst, E-Cat 2. Even though E-Cat 2 had low activity due to fewer acid sites, the products yielded were similar with amorphous ASA and were far better than thermal cracking. The high levels of heavy metals, namely nickel and vanadium, deposited during their lifetime as an FCC catalyst, did not greatly affect on the catalyst activity. It was also shown that E-Cat 2 could be used with and without regeneration. Although there was more deactivation when there was no regeneration step, the yield of gases (C(2)-C(7)) remained fairly constant. For the first time, these results indicate that "waste" FCC catalyst (E-Cat) is a good candidate for future feedstock recycling of polymer waste. The major benefits of using E-Cat are a low market price, the ability to tolerate reuse and regeneration capacity.
Geopolymer concrete has the potential to replace ordinary Portland cement which can reduce carbon dioxide emission to the environment. The addition of different amounts of steel fibers, as well as different types of end-shape fibers, could alter the performance of geopolymer concrete. The source of aluminosilicate (fly ash) used in the production of geopolymer concrete may lead to a different result. This study focuses on the comparison between Malaysian fly ash geopolymer concrete with the addition of hooked steel fibers and geopolymer concrete with the addition of straight-end steel fibers to the physical and mechanical properties. Malaysian fly ash was first characterized by X-ray fluorescence (XRF) to identify the chemical composition. The sample of steel fiber reinforced geopolymer concrete was produced by mixing fly ash, alkali activators, aggregates, and specific amounts of hook or straight steel fibers. The steel fibers addition for both types of fibers are 0%, 0.5%, 1.0%, 1.5%, and 2.0% by volume percentage. The samples were cured at room temperature. The physical properties (slump, density, and water absorption) of reinforced geopolymer concrete were studied. Meanwhile, a mechanical performance which is compressive, as well as the flexural strength was studied. The results show that the pattern in physical properties of geopolymer concrete for both types of fibers addition is almost similar where the slump is decreased with density and water absorption is increased with the increasing amount of fibers addition. However, the addition of hook steel fiber to the geopolymer concrete produced a lower slump than the addition of straight steel fibers. Meanwhile, the addition of hook steel fiber to the geopolymer concrete shows a higher density and water absorption compared to the sample with the addition of straight steel fibers. However, the difference is not significant. Besides, samples with the addition of hook steel fibers give better performance for compressive and flexural strength compared to the samples with the addition of straight steel fibers where the highest is at 1.0% of fibers addition.