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Fulltext Microstructure characterization of mechanically activated nanocrystalline quartz using XRD line broadening

Palaniandy, Samayamutthirian, Khairun Azizi Mohd Azizli, Hashim Hussin, Syed Fuad Saiyid Hashim

Journal of Nuclear and Related Technologies, 2007;2007(1):101-108.
MyJurnal

Mechanical activation of quartz was carried out in jet mill at various specific kinetic energy level and classifier speed. The characterization of the particle size, crystallite size, amorphism rate and lattice strain was conducted on the feed and mechanically activated particles. The area under the prominent quartz peak was used to calculate the amorphism rate of the mechanically activated particles. Scherer equation was used to determine the crystallite size of the feed and mechanically activated particles. Mean particle size less than 5μm was obtained when the specific kinetic energy is ranging between 500 kWh/ton and 1000 kWh/ton. Amorphism of the mechanically activated particles up to 18% was observed at 500 kWh/ton. The crystallite size and lattice strain is influence by the intensity of the specific kinetic energy and classifier speed. The reduction in the crystallite size up to 39% was observed where the minimum crystallite is 23nm. The lattice strain is ranging from 0.024 to 0.038 respective to the specific kinetic energy and classifier speed.

Matched MeSH terms: Quartz
Potential alkali-reactivity of granite aggregates in the Bukit Lagong area, Selangor, peninsular Malaysia

Ng TF, Raj JK, Ghani AA

Sains Malaysiana, 2013;42:773-781.

The Bukit Lagong area is the most important aggregate supply centre in Selangor. Geological studies were carried out in four quarries in the Bukit Lagong area and samples were subjected to petrographic examination and accelerated expansion tests to assess the potential alkali-aggregate reactivity of granite aggregates. The granitic rocks comprise mainly of coarse grained megacrystic granite, minor medium grained megacrystic granite and microgranite. Petrographic examination showed that the primary minerals in these undeformed granitic rocks are not alkali reactive. Faulting and related alteration and mineralization have produced potentially alkali reactive minerals including microcrystalline and strained quartz and fine phyllosilicates. Marginally deleterious and deleterious expansion is shown by the accelerated mortar bar tests. Although alkali reactive rocks are present in some quarries in Bukit Lagong, their volume is small. When blended with the undeformed granitic rocks, the aggregates produced are not expected to cause alkali-aggregate reaction in concrete.

Matched MeSH terms: Quartz
Effect of grain size and grain content on the hardness and drillability of rock

Mou Y, Yingfeng-Meng, Gao L, Lin H, Yufei-Li

Sains Malaysiana, 2014;43:81-87.

It is well-known that the characteristics of hardness and drillability are influenced by microstructure of rock. In this study, rock properties were analyzed on grain size and grain content. Coarse-grain and fine-grain sandstones were tested under successive indentation condition. Eighteen groups of sandstone and shale were employed for the drillability test. Indentation tests results showed that grain size influenced the low point of residual hardness, the crushing depth and volume and grain content influenced the peak point of hardness. The drillability values of shale increased with increasing contents of clay and quartz. Meanwhile, drillability values of sandstone increased with increasing content of quartz, but decreased with increasing content of clay. Therefore, these preliminary studies show great potential applications for selecting suitable bit type and formulating drilling program as a function of rock microstructure and crushing rock method for bit in the oil drilling.

Matched MeSH terms: Quartz
Fulltext Sequence data describing the fungal community in a tropical quartzite soil

Brearley FQ

Data Brief, 2020 Apr;29:105112.
PMID: 31993470 DOI: 10.1016/j.dib.2020.105112

The soil fungal community of the Klang Gates quartz ridge in Malaysia was determined by ITS amplicon sequencing using the Illumina HiSeq platform. The community contained 2767 OTUs, 47% of which could not be assigned to a phylum, likely representing new lineages. Those that could be assigned were found within 5 phyla, 16 classes, 49 orders and 98 families with over 85% of these within the Ascomycota. Sequence data is available from the NCBI's Sequence Read Archive (PRJNA542066). This data illustrates the microbial diversity in a particularly nutrient poor tropical soil and can be used for broader-scale comparisons of microbial distributions.

Matched MeSH terms: Quartz
Peptide Cross-Linked Poly(2-oxazoline) as a Sensor Material for the Detection of Proteases with a Quartz Crystal Microbalance

Ahmad N, Colak B, Gibbs MJ, Zhang DW, Gautrot JE, Watkinson M, et al.

Biomacromolecules, 2019 07 08;20(7):2506-2514.
PMID: 31244015 DOI: 10.1021/acs.biomac.9b00245

Inflammatory conditions are frequently accompanied by increased levels of active proteases, and there is rising interest in methods for their detection to monitor inflammation in a point of care setting. In this work, new sensor materials for disposable single-step protease biosensors based on poly(2-oxazoline) hydrogels cross-linked with a protease-specific cleavable peptide are described. The performance of the sensor material was assessed targeting the detection of matrix metalloproteinase-9 (MMP-9), a protease that has been shown to be an indicator of inflammation in multiple sclerosis and other inflammatory conditions. Films of the hydrogel were formed on gold-coated quartz crystals using thiol-ene click chemistry, and the cross-link density was optimized. The degradation rate of the hydrogel was monitored using a quartz crystal microbalance (QCM) and showed a strong dependence on the MMP-9 concentration. A concentration range of 0-160 nM of MMP-9 was investigated, and a lower limit of detection of 10 nM MMP-9 was determined.

Matched MeSH terms: Quartz Crystal Microbalance Techniques*
Fulltext The effect of effective diameter on fluidization quality in compartmented fluidized bed gasifier

Wee, Siaw Khur, Chok, Vui Soon, Gorin, Alexander, Chua, Han Bing, Yan, Hong Ming

Pertanika Journal of Science & Technology, 2009;17(2):-.
MyJurnal

Compartmented Fluidized Bed Gasifier (CFBG), consisting of two compartments - the combustorand gasifier, uses air blown instead of pure oxygen for syngas production in bubbling fluidization mode, eliminating the need of air separation unit, and reducing the capital cost, thus distinguishes it from other traditional ones. Fluidization quality is a determining factor in the CFBG to guarantee its well-lifted behaviour. Previous study, without solid circulation at ambient conditions, brought to the fore the necessity of considering the effect of the minimum allowable effective diameter. The study was then performed in the CFBG cold physical model of 0.66m overall diameter (effective diameter for combustor and gasifier is 0.413m and 0.257m) to investigate the fluidization quality and compare it with the results obtained from the previous cold model of about 1.36 times smaller, but with the same compartmented ratio of 65:35. Different inert particles (river sand, quartz sand and alumina) were used, over a range of aspect ratios, for the aforementioned objective. The results showed that the fluidization quality in the gasifier has not been achieved and the degradation of fluidization quality in the combustor is still observed, notwithstanding the fact that the condition of the minimum allowable effective diameter has been met. The reduction of distributor free area, to increase the distributor pressure drop, showed a marginal effect on the quality. The effect of the minimum allowable effective diameter on fluidization quality in CFBG as well as the interplay of geometric and operational parameters require further studies be carried out. The fluidization quality of the binary mixture is also currently under investigation.

Matched MeSH terms: Quartz
Fulltext Quartz crystal microbalance-based biosensors as rapid diagnostic devices for infectious diseases

Lim HJ, Saha T, Tey BT, Tan WS, Ooi CW

Biosens Bioelectron, 2020 Nov 15;168:112513.
PMID: 32889395 DOI: 10.1016/j.bios.2020.112513

Infectious diseases are the ever-present threats to public health and the global economy. Accurate and timely diagnosis is crucial to impede the progression of a disease and break the chain of transmission. Conventional diagnostic techniques are typically time-consuming and costly, making them inefficient for early diagnosis of infections and inconvenient for use at the point of care. Developments of sensitive, rapid, and affordable diagnostic methods are necessary to improve the clinical management of infectious diseases. Quartz crystal microbalance (QCM) systems have emerged as a robust biosensing platform due to their label-free mechanism, which allows the detection and quantification of a wide range of biomolecules. The high sensitivity and short detection time offered by QCM-based biosensors are attractive for the early detection of infections and the routine monitoring of disease progression. Herein, the strategies employed in QCM-based biosensors for the detection of infectious diseases are extensively reviewed, with a focus on prevalent diseases for which improved diagnostic techniques are in high demand. The challenges to the clinical application of QCM-based biosensors are highlighted, along with an outline of the future scope of research in QCM-based diagnostics.

Matched MeSH terms: Quartz Crystal Microbalance Techniques
Fulltext Transport and retention of engineered Al2O3, TiO2, and SiO2 nanoparticles through various sedimentary rocks

Bayat AE, Junin R, Shamshirband S, Chong WT

Sci Rep, 2015;5:14264.
PMID: 26373598 DOI: 10.1038/srep14264

Engineered aluminum oxide (Al2O3), titanium dioxide (TiO2), and silicon dioxide (SiO2) nanoparticles (NPs) are utilized in a broad range of applications; causing noticeable quantities of these materials to be released into the environment. Issues of how and where these particles are distributed into the subsurface aquatic environment remain as major challenges for those in environmental engineering. In this study, transport and retention of Al2O3, TiO2, and SiO2 NPs through various saturated porous media were investigated. Vertical columns were packed with quartz-sand, limestone, and dolomite grains. The NPs were introduced as a pulse suspended in aqueous solutions and breakthrough curves in the column outlet were generated using an ultraviolet-visible spectrophotometer. It was found that Al2O3 and TiO2 NPs are easily transported through limestone and dolomite porous media whereas NPs recoveries were achieved two times higher than those found in the quartz-sand. The highest and lowest SiO2-NPs recoveries were also achieved from the quartz-sand and limestone columns, respectively. The experimental results closely replicated the general trends predicted by the filtration and DLVO calculations. Overall, NPs mobility through a porous medium was found to be strongly dependent on NP surface charge, NP suspension stability against deposition, and porous medium surface charge and roughness.

Matched MeSH terms: Quartz
Fulltext Comparison of the Effect for Fracture Resistance of Different Coronally Extended Post Length with Two Different Post Materials

Chauhan NS, Saraswat N, Parashar A, Sandu KS, Jhajharia K, Rabadiya N

J Int Soc Prev Community Dent, 2019 04 12;9(2):144-151.
PMID: 31058064 DOI: 10.4103/jispcd.JISPCD_334_18

Aims and Objectives: To compare the effect for fracture resistance of different coronally extended post length with two different post materials.
Materials and Methods: One hundred and sixty endodontically treated maxillary central incisors embedded in acrylic resin with decoronated root portion were taken for the study. The postspaces were prepared according to standard protocol. The samples were divided into two groups according to the post material: glass-fiber post and Quartz fiber post. These groups were further subdivided on the basis of coronal extension of 4 and 6 mm for glass fiber and Quartz fiber posts, respectively. The posts were then luted with dual-polymerizing resin cement followed by core buildup. Samples were subjected to increasing compressive oblique load until fracture occurred in a universal testing machine. Data were analyzed with one-way ANOVA and independent Student's t-test. Analysis was done using SPSS version 15 (SPSS Inc., Chicago, IL, USA) Windows software program.
Results: Glass fiber post with coronal extension of 4 mm (182.8 N) showed better results than with 6-mm length (124.1 N). Similarly, in quartz fiber posts group, 4-mm postlength (314 N) was better when compared with 6 mm (160 N). The 4-mm coronal extension of quartz fiber post displayed superior fracture resistance.
Conclusions: Glass fiber posts showed better fracture resistance than Quartz fiber posts. 4-mm coronal length showed more fracture resistance than 6 mm.

Matched MeSH terms: Quartz
Electrical and optical properties of nanostructured zinc oxide thin films influenced by annealing temperature

Shariffudin SS, Mamat MH, Rusop M

J Nanosci Nanotechnol, 2012 Oct;12(10):8165-8.
PMID: 23421195

Transparent nanostructured ZnO thin films were successfully deposited using sol-gel spin coating method on a quartz substrate. The 0.4 M ZnO solution gel was prepared using zinc acetate dihydrate (Zn(CH3COO)22H2O) as the precursor, 2-methoxyethanol as the solvent and monoethanolamine (MEA) as the stabilizer. The electrical and optical properties dependencies on the annealing temperature of the nanostructured ZnO thin films were investigated. It was found that as the annealing temperature increased, the particle size, conductivity and the peak of the UV emission also increased.

Matched MeSH terms: Quartz
Fulltext Depth of polymerization of a new nanocomposite according to different exposure times and shades

Lui, J.L., Chan, C.L., Yap, K.T.

Ann Dent, 2006;13(1):6-11.
MyJurnal

The aim of the study was to determine the depth of cure of a new nanocomposite when exposed to different curing times and also when different shades were polymerized. The nanocomposite, Filtek Supreme (3M ESPE), was packed into 96 plastic cylindrical moulds measuring 4 mm in internal diameter and 8 mm in length and then polymerized using a conventional quartz-tungsten-halogen light curing unit. The first part of the study involved curing 16 samples each of A2 shade of the nanocomposite at exposure times of 20s, 40s, 60s and 120s. For the second part, a similar number of samples of the dentinal opacity shades of A2, B3 and A4 of the nanocomposite were polymerized at a constant exposure time of 40s. The depth of polymerization of the nanocomposite in each sample was measured using a digimatic indicator. Curing depths were found to increase significantly (P < 0.05) with longer exposure time (20s < 40s < 60s < 120s) and decrease significantly with darker shades (A2 > B3 > A4).

Matched MeSH terms: Quartz
Fulltext A survey on light intensity outputs of QTH, cabled and cordless LED light curing units

Athirah Ab Rahman, Adam Husein, Hany Mohamed Aly Ahmed, Dasmawati Mohamad, Wan Zaripah Wan Bakar, Manal Farea, et al.

Archives of Orofacial Sciences, 2014;9(2):85-90.
MyJurnal

Light intensity output is one of the determinants for adequate curing of visible light-cured materials. The aim of this survey was to evaluate the light intensity outputs (LIOs) of light curing units (LCUs) in dental clinics of Hospital Universiti Sains Malaysia (HUSM) and School of Dental Sciences, Universiti Sains Malaysia (USM). The respective LIOs of all functioning Quartz Tungsten Halogen (QTH) and Light Emitting Diode (LED) LCUs were tested using two light radiometers. For cordless LED LCUs, the testing procedure was done in situ and after being fully charged. Statistical analysis using Kruskal Wallis and Wilcoxon signed ranks tests were performed to compare the LIOs between groups and between the LIOs of in situ and post-charged cordless LED LCUs, respectively. The level of significance was set at 0.05 (p

Matched MeSH terms: Quartz
Fulltext X-ray diffraction study of clay from north-west Peninsular Malaysia

Ahmad Saat, Zaini Hamzah

Journal of Nuclear and Related Technologies, 2008;2008(1):1-9.
MyJurnal

Clay has been regarded as very important natural industrial materials. All these industries exploit the properties that clay can be molded into any shape and fired to dry without losing its form. A study was carried out on clay samples from eight sites in the north-eastern part of Peninsular Malaysia. The study was accomplished by using X-ray diffraction (XRD) technique. The x-ray diffraction spectra obtained enable the determination of the lattice spacing associated with the types of clay and nonclay minerals present in the samples. Results of the study shows that the major components of clay minerals present in all samples studied are kaolinite and illite. The presence of kaolinite is confirmed by firing test in which the kaolinite diffraction peaks disappeared upon heating the samples at 600 o C. The presence of non-clay minerals such as quartz, mica, feldspar and chlorite are also observed.

Matched MeSH terms: Quartz
Tio2 nanoparticles coated with porphyrin dye thin film as fluorescence gas sensor

Nurul Huda Yusoff, Muhamad Mat Salleh, Muhammad Yahaya

Sains Malaysiana, 2008;37:233-237.

This research explores the possibility of using fluorescence technique to detect the presence of volatile organic compounds based on a single sensing material. The material used was TiO2 nanoparticles coated with porphyrin dye. The TiO2 nanoparticles colloid is in a sol-gel form synthesized from titanium (IV) ethoxide in ethanol with addition of kalium chloride (KCl) as stabilizer. TiO2 nanoparticles were then coated with porphyrin dye, Manganase (III) 5,10,15,20 tetra (4-pyridyl)-21H, 23H porphine chloride tetrakis (metachloride). The coated nanoparticles were deposited on quartz substrate using self-assembly through dip coating technique. The sensing properties of the thin film toward volatile organic compounds; ethanol, acetone, cyclohexane and 2-propanol were studied using luminescence spectrometer. It was found that the thin film produced different emission spectra peaks for different volatile organic compounds (VOCs). Hence, it eases chemical identification process and potentially be use as fluorescence gas sensor.

Matched MeSH terms: Quartz
Tuning the optical band gap of DH6T by Alq3 dopant

Fahmi Fariq Muhammad, Khaulah Sulaiman

Sains Malaysiana, 2011;40.

Dihexyl-sexithiophene (DH6T) was doped with tris (8-hydroxyquinolinate) aluminum (Alq3) to prepare blends of DH6T/ Alq3 by dissolving the mixture in the chloroform/hexane co-solvent. Solid films with different thickness deposited on quartz substrates were obtained from the blends via casting process. Optical absorption spectroscopy has been performed to measure the optical band gap of pure and doped DH6T as well as variations in the band gap with dopant concentration (weight %). This variation in optical band gap with dopant concentration was determined quantitatively with fitted and extrapolated techniques and observed qualitatively from the red shift appeared along the optical absorption spectra. The results showed that within a specific dopant content, the optical energy gap, Eg of DH6T decreases from 2.69 eV to 1.8 eV with increasing dopant concentration to 23.1%.

Matched MeSH terms: Quartz
Performance of quartz crystal microbalance gas sensors using thin films of titanium dioxide, porphyrin and titanium dioxide coated with dye porphyrin

Syariena Arshad, Salleh M, Yahaya M

Sains Malaysiana, 2008;37:233-237.

Titanium dioxide (TiO2), porphyrin and TiO2 coated with dye porphyrin thin films were prepared on Quartz Crystal Microbalance (QCM) using sol-gel dip coating method and were tested for sensing of volatile organic compounds (VOCs). The porphyrin used was 5,10,15,20-tetraphenyl-21H,23H-porphine manganese (III) chloride (MnTPPCl). The sensing sensitivity was based on the change in the fundamental frequency of the QCM upon exposure towards six vapor samples, namely ethanol, acetone, cyclohexane, toluene, o-xylene and 2-propanol. It was found that all the thin films were sensitive towards all the vapors. However, the TiO2 coated MnTPPCl thin film exhibit the most sensitive and has good selectivity property.

Matched MeSH terms: Quartz Crystal Microbalance Techniques
MEMS biosensor for monitoring water toxicity based on quartz crystal microbalance

Lee KL, Ng S, Li F, Nordin AN, Voiculescu I

Biointerphases, 2020 03 26;15(2):021006.
PMID: 32216379 DOI: 10.1116/1.5142722

This paper presents the use of a commercial quartz crystal microbalance (QCM) to investigate live-cell activity in water-based toxic solutions. The QCM used in this research has a resonant frequency of 10 MHz and consists of an AT-cut quartz crystal with gold electrodes on both sides. This QCM was transformed into a functional biosensor by integrating with polydimethylsiloxane culturing chambers. Rainbow trout gill epithelial cells were cultured on the resonators as a sensorial layer. The fluctuation of the resonant frequency, due to the change of cell morphology and adhesion, is an indicator of water toxicity. The shift in the resonant frequency provides information about the viability of the cells after exposure to toxicants. The toxicity result shows distinct responses after exposing cells to 0.526 μM of pentachlorophenol (PCP) solution, which is the Military Exposure Guidelines concentration. This research demonstrated that the QCM is sensitive to a low concentration of PCP and no further modification of the QCM surface was required.

Matched MeSH terms: Quartz Crystal Microbalance Techniques*
Checklist of vascular plants of Klang Gates Quartz Ridge, Malaysia, a 14-km long quartz dyke

Kiew R, Chung-Lu L

PhytoKeys, 2020;166:57-77.
PMID: 33199961 DOI: 10.3897/phytokeys.166.55778

The Klang Gates Quartz Ridge (KGQR) is proposed for protection as National Heritage and as a UNESCO World Heritage Site because of its spectacular size, exceptional beauty and significant biodiversity. The checklist of vascular plants documents 314 species that comprise a unique combination that grows on lowland quartz and that is distinct from the surrounding lowland equatorial rain forest by the absence of orchids, palms, gingers and tree canopy families. The Rubiaceae, Gramineae, Moraceae, Apocynaceae, Melastomataceae and Polypodiaceae are the most speciose families. The summit vegetation at 200-400 m elevation is dominated by Baeckea frutescens (Myrtaceae) and Rhodoleia championii (Hamamelidaceae) and shows similarities to the plant community on rocky mountain peaks above 1500 m. About 11% of its species are endemic in Peninsular Malaysia and four are endemic to KGQR: Aleisanthia rupestris (Rubiaceae), Codonoboea primulina (Gesneriaceae), Spermacoce pilulifera (Rubiaceae), and Ilex praetermissa (Aquifoliaceae). All four are provisionally assessed as Critically Endangered. Two, Eulalia milsumi (Gramineae) and Sonerila prostrata (Melastomataceae), are endemic to KGQR and a few neighbouring smaller quartz dykes. They are assessed as Endangered. The KGQR is a fragile habitat and conservation management is urgently required to halt the spread of the aggressive alien grass, Pennisetum polystachion and to prevent further habitat degradation from visitors. Based on KGQR being a threatened habitat, its biodiverse flora, and endangered species, it qualifies as an Important Plant Area.

Matched MeSH terms: Quartz
Fulltext Characterization study of oil sludge solid sediment

Meor Yusoff, M.S., Hishamuddin, H., Choo, Thye Foo

Journal of Nuclear and Related Technologies, 2007;2005(1):25-28.
MyJurnal

The storage of oil sludge at refineries is a major problem to the petroleum industry. Oil sludge treatments such as by using sludge farming, incineration, physical and chemical techniques have been applied to separate the hydrocarbon from the solid sediment. The paper relates a characteristic study performed on solid sediment from a local oil sludge sample for making sintered brick. The study includes the used of XRD, XRF, digital microscopy and particle size analyzer. The result shows that the sample highly contains quartz minerals with particle size ranging from 0.5 – 200 ȝm. The chemical phosphorous from the surfactant can be removed by washing to make this solid sediment to be used as a material in the brick making.

Matched MeSH terms: Quartz
Engineering geological properties of oil-contaminated granitic and metasedimentary soils

Zulfahmi Ali Rahman, Umar Hamzah, Noorulakma Ahmad

Sains Malaysiana, 2011;40.

Hydrocarbon is a light-non aqueous phase liquid or known as LNAPL. It poses environmental hazard if accidentally spilled out into the soil and water systems as a result of its insoluble nature in water. LNAPL component infiltrates into soil through pore spaces and afloat at the top of groundwater level. Some of this hydrocarbon would trap and clog within the voids, difficult to remove and costly to clean. The occurence of hydrocarbon in the soil definitely degraded the behaviour of soils in terms of engineering properties. This study aimed to investigate the engineering properties of oil-contaminated soil for two different residual soils originally developed from in-situ weathering of granitic and metasedimentary rocks. The physical characterisations of the soil were determined including particle size distribution, specific gravity test and x-ray diffraction (XRD). The engineering parameters for the contaminated and uncontaminated soils were Atterberg limits, compaction and soil shear strength (UU tests). The amounts of hydrocarbon added to soil were varied at 0%, 4%, 8%, 12% and 16% of dried weigth of soil samples. The results from the particle size distribution analysis showed that residual soil from granitic rock comprises of 38% sand, 33% silt and 4% clay while metasedimentary soil consists of 4% sand, 43% silt dan 29% clay. The mean values of specific gravity for the granitic and metasedimentary soils were 2.56 and 2.61, respectively. The types of minerals present in granitic soil sample were quartz, kaolinite and gibbsite while metasedimentary soil consists of quartz and kaolinite. The Atterberg limits value decreased as a result of increasing amount of added hydrocarbon into the soil. A similar behaviouir was observed with the values of maximum dry density and optimum water content with increasing hydrocarbon content. The overall unconsolidated undrained shear strength, Cu showed a decreasing trend with the increase in hydrocarbon content.

Matched MeSH terms: Quartz

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