Highly weathered basaltic rock was exposed at PSK profile of Kuantan, Segamat Highway. The weathering profile from fresh rock soil can be observed at PKJ profile at Kg. Jabi Quarry. Twelve rock and soil samples from PSK profile and thirteen samples from PKJ profile have been collected for geochemical analysis. The objective of the analysis is to establish the behaviour of several major and trace elements in the weathering profile of the basaltic rock. The samples were analysed by XRF and XRD techniques. Petrographic study was done on fresh rock samples and concretions. The concentration of major elements (TiO2, Al2O3 and Fe2O3) appear to be increased with the increasing of the degree of weathering whereas the concentration of SiO2 and CaO are decreased. There is a clear correlation between Fe2O3 + Al2O3 with L.O.I as well as between Fe2O3 with Al2O3. Behaviour of the trace elements (Ni, Co, Cr and Zn) against the weathering process are totally different. The secondary minerals (kaolinite, nactire, geothite, hematite and gibbsite) appear to control the behaviour of the major and trace elements.
Batuan basalt yang terluluhawa sepenuhnya telah dicerap di lokaliti PSK Lebuhraya Segamat-Kuantan. Profil luluhawa yang boleh dilihat perubahan daripada batuan segar hingga tanih didapati di lokaliti PKJ Kuari Kg. Jabi. Dua contoh profil dengan masing-masing 12 sampel dan 13 sample tanih telah dikaji untuk menentukan perlakuan beberapa unsur major dan unsur surih batuan basalt yang terluluhawa. Kaedah analisis yang digunakan ialah pendarflour sinar-X (XRF) dan pembelauan sinar-X (XRF). Kajian petrografi pula dibuat pada sampel batuan segar dan sampel konkresi. Nilai unsur major TiO2, Al2O3 dan Fe2O3 bertambah dengan bertambahnya darjah luluhawa manakala SiO2 dan CaO menyusut. Hubungan korelasi Fe2O3 + Al2O3 dengan L.O.I dan Fe2O3 denagn Al2O3 adalah jelas. Unsur surih nikel (Ni) kobalt (Co), kromium (Cr) dan zink (Zn) mempunyai perlakuan yang berbeza-beza dengan luluhawa. Perlakuan yang ditunjukkan oleh unsur major dan surih tersebut dikawal oleh mineral sekunder (koalinit, nakrit, geotit, hematit dan gibsit).
A survey to characterize seismic and ultrasonic properties of a granite weathering profile have been carried out at a roadcut slope exposure along Kuala Lumpur-Karak highway at kilometres 39.9. The terraced cut slope shows a complete weathering profile beginning from fresh grade I rock to grade VI residual soil. Together with in situ seismic measurement, rock samples have been collected for ultrasonic tests in laboratory. The range of velocities representing grades and indices of weathered rocks and soils are determined from the in situ seismic surveys. The range of ultrasonic velocities and elastic moduli are obtained from the laboratory measurements.
Satu survei untuk mencirikan sifat seismos dan ultrasonik profil luluhawa granit telah dilakukan di singkapan potongan jalan, cerun utara lebuhraya Kuala Lumpur-Karak pada lokaliti 39.9 km. Potongan berteres ini mempamirkan satu profil luluhawa lengkap iaitu mulai batuan gred 1 yang segar hingga ke tanah baki bergred VI. Di samping pengukuran seismos secara in situ, sampel batuan juga diambil untuk dibuat pengukuran halaju ultrasonik di makmal. Julat halaju yang mewakili gred dan indeks luluhawa bagi tanah dan batuan diperolehi daripada survei seismos in situ. Julat halaju trasonik dan modulus kenyal diperolehi hasil pengukuran di makmal.
This study aimed to document the fish diversity and water quality at Semariang mangrove area, Kuching, Sarawak, which is located at the eastern part of Kuching Wetland National Park. Field samplings were carried out in 2009 during the construction of the flood mitigation channel at the eastern part of the park. A total of 21 families represented by 37 species of fish were caught from the area. The six dominant families in terms of the number of individuals caught were Mugilidae (16%), Leiognathidae (16%), Ambassidae (11%), Ariidae (9%), Lutjanidae (8%) and Plotosidae (6%). In terms of the percentage of six dominant genera based on the number of individuals caught, 16% was represented by Valamugil, 11% by Ambassis, 10% by Gazza, 9% by Arius, 8% by Lutjanus and 6% by Plotosus. The values of diversity and richness indices were lower at stations located close to the flood mitigation channel. Similarly, the concentrations of dissolved oxygen were lower and total suspended solids were significantly higher at stations close to the channel and sand mining area. Therefore, fish fauna and water quality at Semariang mangrove area were affected during the construction of the flood mitigation channel.
The presence of pores plays an important role for many membrane processes especially in ultrafiltration and microfiltration. Epoxidised natural rubber (ENR)/polyvinyl chloride (PVC) membranes filled with two types of silica fillers were prepared via simultaneous solvent exchange and evaporation of solvent technique. Two types of silica, i.e. microsilica (microcrystalline
silica powder) and nanosilica (generated from tetraethoxysilane (TEOS)) were used. The chemical composition, morphology and mechanical stability of the membranes were studied. Both types of silica showed good interaction with the membrane matrix. The formation of pores depended on the size of silica particles added. Microsilica produced large pores while insitu generated nanosilica produced nanosized pores. The mechanical properties of membrane improved with the addition
of silica. The tensile strength increased from 10.6 MPa to 17.8 MPa and 14.5 MPa for nanosilica and microsilica filled membrane while the tensile modulus increased from 1.6 MPa to 3.8 MPa and 3.4 MPa, respectively. Thus, both types of silica acted as a filler as well as pore forming agent for the ENR/PVC membrane.
Catalytic esterification of glycerol with oleic acid (OA) was optimized over hydrophobic mesoporous zirconia-silica heterogeneous acid catalyst (ZrO2-SiO2-Me&Et-PhSO3H) and benchmarked with commercial catalysts (Aquivion and Amberlyst 15) in order to examine the effect of catalyst acidity on conversion, yield and product selectivity. The process optimisation results showed an 80% conversion with a 59.4% glycerol mono-oleate (GMO) and 34.6% glycerol dioleate (GDO) selectivities corresponding to a combined GMO and GDO selectivity of 94.8% at equimolar OA-to-glycerol ratio, 160°C reaction temperature, 5 wt% catalyst concentration with respect to the OA weight and 4 h reaction time. This work reveals that the hydrophobic and mild acidic ZrO2-SiO2-Me&Et-PhSO3H catalyst outperformed Amberlyst 15 and Aquivion with a yield of 82% and GMO selectivity of 60%. It is found that catalyst acidity is a key parameter for catalytic activity and conversion rate. Nevertheless, high acidity/acid strength reduced the product yield in the glycerol esterification of OA.
This study was conducted to study the morphological features of species under the genus Chaetoceros isolated from the coastal waters of Pahang, Malaysia. The species were isolated, cultivated and viewed under light microscope (LM) and scanning electron microscope (SEM). Four taxa were successfully isolated and cultivated in pure culture, namely Chaetoceros affinis var. affinis, Chaetoceros affinis var. willei, Chaetoceros anastomosans and Chaetoceros baculites. Both varieties of C. affinis were considered as distinct taxa where both strains can be distinguished based on morphological characteristics. C. affinis var. affinis has a thick cell wall compared with C. affinis var. willei. C. anastomosans has special features including a silica bar on the intersection of setae and the production of mucous. The length of the aperture opening is a new record from this study. The new record obtained for C. baculites includes the size of the aperture, the terminal setae, spinal arrangement, the thinness of the cell wall and the location of the species in tropical waters. Detailed data on each species will be added to the taxonomic information for future studies.
Nanocrystalline aluminosilicate F-type zeolite (K-F, EDI-type structure) was synthesized in an organic template-free system
using rice husk ash (RHA) silica source and microwave energy. The morphology, crystallite size, chemical composition,
crystallographic and basicity properties of the nanocrystals were studied by using various characterization techniques.
The results showed that fully crystalline K-F zeolite (Si/Al ratio = 1.26) with flattened cuboid-like shaped could be
obtained within 2 min of crystallization which was considerably very fast. In addition, K-F zeolite nanocrystals was also
tested as a solid base catalyst in the microwave-enhanced Aldol condensation reaction of heptanal with benzaldehyde
and the six catalytic parameters were studied and optimized. The nanosized K-F zeolite crystals showed good catalytic
performance in the studied reaction with 77.1% heptanal conversion and 69.5% jasminaldehyde selectivity under optimum
reaction condition. The nanocatalyst was reusable and no significant loss in its catalytic reactivity was observed even
after five consecutive reaction cycles.
In this paper, with debris flow in Zhouqu as the research object, combined with experiments such as cation exchange capacity (CEC), mineral chemical composition and water quality analysis, relation between water and salt in solid source forming debris flow was studied via soil column leaching test and soluble salt analysis, and internal characteristics of debris flow was accordingly showed. It was found that, the soil was loose, and the content of gravel and sand was high, and the content of fine particle was low. The soluble contents at the slope of the accumulation body were described as, collapsed accumulation body > landslide accumulation body, slope toe > slope top, gentle slope > steep slope, also related to length of the slope. The results indicated that accumulations released a large number of base ion after intense weathering, which migrated with water, concentrated and enriched at the slope toe. Saline soil with high salt content collapsed when encountering water and then formed mudflow, thus becoming the internal power to trigger and initiate debris flow to some extent.
A well-known planting medium in soilless culture is a coconut based material famously known in Malaysia as cocopeat.
It is a viable ecologically friendly peat soil substitute for containerized crop production. The multipurpose growing media
had received much interest particularly in commercial applications. This study focused on the physical and hydraulic
characteristics of cocopeat perlite mixture as a growing media in containerized plant production. Perlite was added to
cocopeat at a ratio of 3 cocopeat: 1 perlite. Bulk density, particle density, porosity, particle size distribution, water holding
capacity, wettability and hydraulic conductivity of the media were evaluated. About 82.93% of the total particles were
in the range between 0.425 and 4 mm in diameter at a bulk density of 0.09 g/cm3
. Total porosity (79%) and wettability
improved with the incorporation of perlite to cocopeat. This study showed that water holding capacity was very high at
912.54% whereas the saturated hydraulic conductivity was low at 0.1 cm/s. The results showed that adding perlite to
cocopeat had improved the physical and hydraulic characteristics of the media.
The present study investigated the use of modified titanium dioxide (TiO2) based photocatalytic degradation (PCD) process for the removal of some critical charged aqueous phase pollutants. First of all, the use of Nafion TiO2 (Nf-TiO2) and silica TiO2 (Si-TiO2) for the removal of aqueous phase ammonia (NH4+/NH3) species employing near UV lamp as energy source was studied. The use of Nf-TiO2 enhanced NH4+/NH3 PCD with optimum removal noted for 1 mL of Nafion solution coating per g of TiO2 and respective overall NH4+/NH3 removal was about 1.7 times higher compared to plain TiO2 at 6 h reaction time. Similarly the 0.5 mL silica solution coating per g TiO2 sample, also enhanced NH4+/NH3 removal with optimum efficiency similar to Nf-TiO2. The results from effect of ammonia concentration on to its PCD using Nf-TiO2 indicated that overall mass based NH4+/NH3 removal was higher at greater NH4+/NH3 amounts indicating high efficiency of Nf-TiO2. Similar trends were noted for Si-TiO2 as well. Furthermore, the results from modified TiO2 and mixed NH4+/NH3 and cyanide (CN-) systems indicated successful removal of co-pollutant CN- along with simultaneous degradation of NH4+/NH3 species at rates that were still higher than plain TiO2. Nevertheless application of Nf-TiO2 for the treatment of cationic dye methylene blue (MB) indicated slower MB removal compared to plain TiO2 though significant MB degradation using Nf-TiO2 could still be achieved at pH3. Additionally the results from solar radiation energized PCD process indicated positive role of solar radiation for the removal of NH4+/NH3 species under a varying set of conditions.
Levulinic acid (LA) is one of biomass derived building block chemicals with various applications. Catalytic esterification
of LA with alkyl alcohol produces levulinate ester which can be applied as fragrance, flavouring agents, as well as fuel
additives. In this study, a series of sulfated silica (SiO2
) catalyst was prepared by modification of SiO2
with sulfuric acid
(H2
SO4
) at different concentrations; 0.5 M to 5 M H2
SO4
. The catalysts were characterized, and tested for esterification
of LA with ethanol to ethyl levulinate (EL). The effect of various reaction parameters including reaction time, catalyst
loading and molar ratio of LA to ethanol on esterification of LA to EL were inspected. The catalyst with high concentration
of acid sites seemed suitable for LA esterification to EL. Among the sulfated SiO2
catalysts tested (0.5 M-SiO2
, 1 M-SiO2
,
3 M-SiO2
and 5 M-SiO2
), 3 M-SiO2
exhibited the highest performance with the optimum EL yield of 54% for reaction
conducted at reflux temperature for 4 h, 30% 3 M-SiO2
loading and LA to ethanol molar ratio of 1:20. Besides, the
reusability of 3 M-SiO2
catalyst for LA esterification with ethanol was examined for five cycles. Esterification of LA with
methanol and 1-butanol were also carried out for methyl levulinate (ML) and butyl levulinate (BL) productions with 69%
and 40% of ML and BL yields, respectively. This study demonstrates the potential of sulfated SiO2
catalyst for levulinate
ester production from LA at mild process condition.
This study attempts to assess the impact of various types of land use along Sungai Langat and describes hydrological
change and water quality variation along this river. This study also determines water quality of Sungai Langat based on
low flow dry period Q100,7 using the application of QUAL2K. Dissolved oxygen (DO), pH, temperature and conductivity
were measured in situ. Biochemical oxygen demand (BOD5
), ammonia nitrogen (NH3
-N) and total suspended solid (TSS)
were analysed according to the standard methods (APHA). Water quality data was referred to National Water Quality
Standards for Malaysia (NWQS) proposed by Malaysian Department of Environment (DOE) to estimate Sungai Langat
water quality status. Four important water quality parameters namely DO, BOD5, NH3
-N and TSS were simulated with
QUAL2K version 2.07 for 83.67 km. As regard to individual parameter, DO classified this river into class III, BOD5 in
Class II, NH3
-N in Class IV and TSS in Class I. Based on QUAL2K simulation for low flow scenario, the results clearly
demonstrates a gradually reduction of DO and BOD5 whereas NH3
-N and TSS display opposite. Only NH3
-N was found
significantly increase which cause low water quality class towards the downstream. Three parameters namely DO, BOD5
and NH3
-N show effects of industrial which approximately located at the middle of river stretch. The TSS was contributed
to the river system at the upstream and downstream of the river stretch which most likely from sand mining activity which
located at Sungai Long, Cheras (near R5) and Sungai Semenyih (R11).
The contribution of palm oil fuel ash (POFA), an agricultural waste as a low cost adsorbent for the removal of arsenite (As(III)) and arsenate (As(V)) was explored. Investigation on the adsorbency characteristics of POFA suspension revealed that the surface area, particle size, composition, and crystallinity of the SiO2 rich mullite structure were the crucial factors in ensuring a high adsorption capacity of the ions. Maximum adsorption capacities of As(III) and As(V) at 91.2 and 99.4 mg g-1, respectively, were obtained when POFA of 30 μm particle size was employed at pH 3 with the highest calcination temperature at 1150 °C. An optimum dosage of 1.0 g of dried POFA powder successfully removed 48.7% and 50.2% of As(III) and As(V), respectively. Molecular modeling using the density functional theory consequently identified the energy for the proposed reaction routes between the SiO- and As+ species. The high stability of the POFA suspension in water in conjunction with good adsorption capacity of As(III) and As(V) seen in this study, thus envisages its feasibility as a potential alternative absorbent for the remediation of water polluted with heavy metals.
Fission tracks are linear trails of intense radiation damage in the crystal structure of a mineral, produced by spontaneous fissioning of uranium-238 (238U) atoms. Detail information on the low-temperature thermal histories of rocks, below∼120 °C for tracks in apatite and below∼350 °C for zircon, can be provided by Fission-track (FT) analysis. The purpose of this article is to present apatite and zircon fission-track data, and U-Pb granite ages that provide information about the cooling histories of a rock which can be crucial in comprehending the exhumation episodes of the study area, in particular, and the region, in general. Granite samples were collected along the same vertical profile at different elevation, 178-944 m.a.s.l. These samples were used to determine Fission-Track and crystallization ages. HeFTy software was employed to interpret the cooling histories of the samples using forward and inverse models. The inverse model was an approach of reproducing the observed data, and it was carried out only for fission-track data from the apatite grains. And it was constructed after generating a number of forward models, where in each of these models the predicted apatite fission-track parameters were compared to the measured values. The apatite fission track (AFT) and zircon fission track (ZFT) data indicated expected age trends, i.e. the older ages at higher elevations and the younger ages at lower elevations. Similarly, the data shows that the apatite and zircon FT ages appear younger than the age of the rock crystallization. The U-Pb age in zircon consistently suggest the age of the granite is Late Triassic.
This paper discussed the effects of modified metakaolin (MK) with nano-silica (NS) on the mechanical properties and durability of concrete. In the first phase, trial mixes of concrete were prepared for achieving the desired value of the 28 days compressive strength, and the charge passed in rapid chloride permeability test (RCPT). In the second phase, statistical analysis was performed on the experimental results using the response surface method (RSM). The RSM was applied for optimizing the mix proportions for the required performance by exploiting the relationship between the mix characteristics and the corresponding test results. A blend of 10% MK + 1% NS as part of cement replacement exhibited the highest mechanical properties and durability characteristics of concrete; concrete mix showed that the 28-days compressive strength (CS) was 103 MPa, which was 15% greater than the CS of the control mix without MK or NS. The same mix showed more than 40% higher flexural and split-tensile strength than the control mix; also it resulted in a reduction of 73% in the rapid chloride permeability value. ANOVA technique was used for optimizing the nano-silica and metakaolin content for achieving maximum compressive strength and minimum RCPT value. Statistical analysis using ANOVA technique showed that the maximum compressive strength and lowest RCPT value could be achieved with a blend of 10% MK and 1.55% NS.
Three fluorescent organic compounds-furocoumarin (FC), dansyl aniline (DA), and 7-hydroxycoumarin-3-carboxylic acid (CC)-are mixed to produce almost pure white light emission (WLE). This novel mixture is immobilised in silica aerogel and applied as a coating to a UV LED to demonstrate its applicability as a low-cost, organic coating for WLE via simultaneous emission. In ethanol solution and when immobilised in silica aerogel, the mixture exhibits a Commission Internationale d'Eclairage (CIE) chromaticity index of (0.27, 0.33). It was observed that a broadband and simultaneous emission involving coumarin carboxylic acid, furocoumarin and dansyl aniline played a vital role in obtaining a CIE index close to that of pure white light.
Catalysts prepared from industrial wastes rich in Fe, Ca, Si, and Al were used in catalytic upgrading of pyrolysis vapour derived from durian shell and their effect on product yield and properties were compared. With same silica-to-alumina ratio, catalyst prepared from oil palm ash (AS-OPA) with lower Fe and Ca contents gave higher liquid yield (8.32 wt%) with alcohols (28.90%), hydrocarbons (46.00%), and nitrogen-containing compounds (21.46%) while catalyst prepared from electric arc furnace slag (AS-EAF) with higher Fe and Ca contents produced lower liquid yield (50.21 wt%) with high amount of esters (25.80%) and hydrocarbons (72.82%). The presence of AS-OPA and AS-EAF catalysts enhanced deoxygenation degree of bio-oil to 81.13% and 85.49%, respectively. The catalytic performance of AS-EAF at different temperatures (400-600 °C) and AS-EAF/durian shell ratios (1:30, 2:30, 3:30) was investigated. Increasing catalytic temperature enhanced production of bio-oil, reduced oxygenates and enhanced formation of esters. The liquid yield and yield of esters decreased with increasing catalyst loading. Hydrocarbons (mainly neopentane) were the major chemical compounds found in bio-oil produced over AS-EAF. Besides that, AS-EAF showed good deoxygenation performance with highest selectivity of hydrocarbons at 500 °C and AS-EAF/durian shell ratio of 2:30. Catalytic fast pyrolysis of durian shell using waste-derived catalysts is an effective waste management strategy as the bio-oil produced can be a potential alternative source of energy or chemical feedstocks.
Multiple contaminants including heavy metals and phenolic compounds are normally co-exist in wastewater, which caused the treatment process is rather complicated. Herein, the synergistic photoredox of Cr(VI) and p-cresol (pC) by innovative fibrous silica zirconia (FSZr) photocatalyst was reported. The high surface area of FSZr comprised of microspheres with a bicontinuous concentric lamella structure morphology consisted of silica, while its core consisted of ZrO2 structure. The rearrangement of FSZr framework increased the crystallinity, formed Si-O-Zr bonds and narrowed the band gap of ZrO2 for enhanced of photoredox of Cr(VI) and pC. Compared to the reaction, the photoredox efficiency of FSZr for removing Cr(VI) and pC in simultaneous system was found to be 96 % and 59 %, respectively which are higher than that in its single system owing to the efficient electron-hole charge separation. Phenolic compound with high degree of electron donating group gave beneficial effect to photoreduction of Cr(VI). Consequently, a proposed mechanism involving multi-photoredox pathway were proposed based on photoredox reaction and scavengers studies. FSZr sustained the simultaneous photoredox activities after five runs demonstrating its possibility to be use in the wastewater treatment of various pollutants.
Kaempferia parviflora is an ethnomedicinally important plant. Conventional propagation of K. parviflora is hindered by slow growth rate, long dormancy periods and dual use of rhizomes for seeds as well as marketable produce. In our study, we developed a promising dual-phase micropropagation protocol to increase number of plantlets, survivability, biomass and quality plantlets for mass production. Multiple shoot regeneration was found most successful on Murashige and Skoog (MS) media supplemented with 35.52 μM N6-benzyladenine (BA) in terms of highest number of shoots (22.4 ± 1.84), leaves (29.27 ± 1.30), and roots (17.8 ± 1.72) per explant. High survivability was observed with an acclimatisation percentage of 100% in sterile perlite medium. This method was shown to be preferable compared to conventional propagation in terms of propagation time and number of plantlets. Regenerated in vitro plantlets were then successfully induced to form microrhizomes in MS media with an optimal concentration of 6% (w/v) sucrose. Increase in microrhizome biomass (35.7 ± 2.59 g per flask), number of microrhizomes (5.2 ± 0.78), shoots (8.5 ± 1.58) and roots (8.5 ± 1.58) were observed for this treatment. This investigation successfully highlights the manipulation of single factors in short time frame to produce a simple and efficient alternative propagation method for K. parviflora.
The reinforcing silica filler, which can be more than 40% of an elastomer composite, plays a key role to achieve the desired mechanical properties in elastomer vulcanizates. However, the highly hydrophilic nature of silica surface causes silica particle aggregation. It remained a challenge for many tire manufacturers when using silica-filled elastomer compounds. Here, the silica surface energy changes when the surface is modified with coupling or noncoupling silanes; coupling silanes can covalently bond the silica to the elastomers. The surface energy of silica was determined using inverse gas chromatography (IGC) at finite dilution (FD-IGC) and found to be reduced by up to 50% when the silica surface was silanized. The spatial distribution of silica aggregates within the tire matrix is determined by transmission electron microscopy (TEM) and a direct correlation between aggregate size (silica microdispersion) and work of cohesion from IGC is reported, highlighting surface energy and work of cohesion being excellent indicators of the degree of dispersion of silica aggregates.