This study examined the influence of pyrolysis temperature on biochar characteristics and evaluated its suitability for carbon capture and energy production. Biochar was produced from corn stover using slow pyrolysis at 300, 400 and 500°C and 2 hrs holding time. The experimental biochars were characterized by elemental analysis, BET, FTIR, TGA/DTA, NMR (C-13). Higher heating value (HHV) of feedstock and biochars was measured using bomb calorimeter. Results show that carbon content of corn stover biochar increased from 45.5% to 64.5%, with increasing pyrolysis temperatures. A decrease in H:C and O:C ratios as well as volatile matter, coupled with increase in the concentration of aromatic carbon in the biochar as determined by FTIR and NMR (C-13) demonstrates a higher biochar carbon stability at 500°C. It was estimated that corn stover pyrolysed at 500°C could provide of 10.12 MJ/kg thermal energy. Pyrolysis is therefore a potential technology with its carbon-negative, energy positive and soil amendment benefits thus creating win- win scenario.
Cobalt titanate-titania composite oxide films have been grown on FTO-coated glass substrates using a single-source heterometallic complex [Co2Ti4(μ-O)6(TFA)8(THF)6]·THF () which was obtained in quantitative yield from the reaction of diacetatocobalt(ii) tetrahydrate, tetraisopropoxytitanium(iv), and trifluoroacetic acid from a tetrahydrofuran solution. Physicochemical investigations of complex have been carried out by melting point, FT-IR, thermogravimetric and single-crystal X-ray diffraction analyses. CoTiO3-TiO2 films composed of spherical objects of various sizes have been grown from by aerosol-assisted chemical vapor deposition at different temperatures of 500, 550 and 600 °C. Thin films characterized by XRD, Raman and X-ray photoelectron spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis have been explored for electrochemical detection of dopamine (DA). The cyclic voltammetry with the CoTiO3-TiO2 electrode showed a DA oxidation peak at +0.215 V while linear sweep voltammetry displayed a detection limit (LoD) of 0.083 μM and a linear concentration range of 20-300 μM for DA. Thus, the CoTiO3-TiO2 electrode is a potential candidate for the sensitive and selective detection of DA.
Core-shell rutile TiO2@β-In2S3 and modified V-TiO2@β-In2S3 were synthesized to develop bilayer systems to uphold charge transport via an effective and stable interface. Morphological studies revealed that β-In2S3 was deposited homogeneously on V-TiO2 as compared to unmodified TiO2 nanorod arrays. X-ray photoelectron spectroscopy (XPS) and electron energy loss spectrometry studies verified the presence of various oxidation states of vanadium in rutile TiO2 and the vanadium surface was utilized for broadening the charge collection centers in host substrate layer and hole quencher window. Subsequently, X-ray diffraction, high-resolution transmission electron microscopy, and Raman spectra confirmed the rutile phases of TiO2 and modified V-TiO2 along with the phases of crystalline β-In2S3. XPS valence band study explored the interaction of valence band quazi Fermi levels of β-In2S3 with the conduction band quazi Fermi levels of modified V-TiO2 for enhanced charge collection at the interface. Photoelectrochemical studies show that the photocurrent density of V-TiO2@β-In2S3 is 1.42 mA/cm(2) (1.5AM illumination). Also, the frequency window for TiO2 was broadened by the vanadium modification in rutile TiO2 nanorod arrays, and the lifetime of the charge carrier and stability of the interface in V-TiO2@β-In2S3 were enhanced compared to the unmodified TiO2@β-In2S3. These findings highlight the significance of modifications in host substrates and interfaces, which have profound implications on interphase stability, photocatalysis and solar-fuel-based devices.
This article describes discovery of 29 novel bisindolylmethanes consisting of thiourea moiety, which had been synthesized through three steps. These novel bisindolylmethane derivatives evaluated for their potential inhibitory activity against carbonic anhydrase (CA) II. The results for in vitro assay of carbonic anhydrase II inhibition activity showed that some of the compounds are capable of suppressing the activity of carbonic anhydrase II. Bisindoles having halogen at fifth position showed better inhibitory activity as compared to unsubstituted bisindoles. Derivatives showing inhibition activity docked to further, understand the binding behavior of these compounds with carbonic anhydrase II. Docking studies for the active compound 3j showed that nitro substituent at para position fits into the core of the active site. The nitro substituent of compound 3j is capable of interacting with Zn ion. This interaction believed to be the main factor causing inhibition activity to take place.
In this study 36 new compounds were synthesized by condensing barbituric acid or thiobarbituric acid and respective anilines (bearing different substituents) in the presence of triethyl orthoformate in good yields. In vitro urease inhibition studies against jack bean urease revealed that barbituric acid derived compounds (1-9 and 19-27) were found to exhibit low to moderate activity however thiobarbituric acid derived compounds (10-18 and 28-36) showed significant inhibition activity at low micro-molar concentrations. Among the synthesized compounds, compounds (15), (12), (10), (36), (16) and (35) showed excellent urease inhibition with IC50 values 8.53 ± 0.027, 8.93 ± 0.027, 12.96 ± 0.13, 15 ± 0.098, 18.9 ± 0.027 and 19.7 ± 0.63 μM, respectively, even better than the reference compound thiourea (IC50 = 21 ± 0.011). The compound (11) exhibited comparable activity to the standard with IC50 value 21.83 ± 0.19 μM. In silico molecular docking studies for most active compounds (10), (12), (15), (16), (35) and (36) and two inactive compounds (3) and (6) were performed to predict the binding patterns.
Methyl esters from vegetable oils have attracted a great deal of interest as substitute for petrodiesel to reduce dependence on imported petroleum and provide an alternate and sustainable source for fuel with more benign environmental properties. In the present study biodiesel was prepared from sunflower seed oil by transesterification by alkali-catalyzed methanolysis. The fuel properties of sunflower oil biodiesel were determined and discussed in the light of ASTM D6751 standards for biodiesel. The sunflower oil biodiesel was chemically characterized with analytical techniques like FT-IR, and NMR ((1)H and (13)C). The chemical composition of sunflower oil biodiesel was determined by GC-MS. Various fatty acid methyl esters (FAMEs) were identified by retention time data and verified by mass fragmentation patterns. The percentage conversion of triglycerides to the corresponding methyl esters determined by (1)H NMR was 87.33% which was quite in good agreement with the practically observed yield of 85.1%.
Auditors play a key role in contributing to the credibility of the financial statements on which they are reporting. High quality audits s upport financial stability. The responsibility for performing quality audits of financial statements rests with the auditors. However, audit quality is best achieved in an environment where there is support from and appropriate interactions among partici pa nts in the financial reporting supply chain. Most prior studies look into audit quality from the perspective of private sector however this study focus on the quality of public sector auditing in Malaysia. There are three independent variables being inve st igated in this study that are the auditor’s independence, auditor’s competency and auditor’s workload. Data were collected through the distribution of questionnaires to 114 samples of auditors involved in public sector audit in Malaysia. The data were an al ysed using correlation test and regression test. The findings of this study show that there are positively significant relationship between auditor’s independence and auditor’s competency on audit quality. The results revealed that auditor’s competency i s the most significant factor affecting the audit quality in public sector audit. However, results show that auditor’s workload has a negative and insignificant impact on audit quality. Hence, this study recommends that the audit departments to strengthen th e audit quality and could improve the quality of the financial reporting in the public sector. In addition, auditor’s competency should be enhanced among the auditors in public sector to ensure high quality of audit work performed. Future studies should ex plore other variables such as client satisfaction, auditor switching and auditor’s turnover in public sector auditing
Introduction: Detailed information of structural and functional anatomy of thenar muscle is very significant in order to improve diagnostic and various conditions of hand surgeries so that the function of hand movement can be re-stored and to prevent further iatrogenic injuries. Methods: In this study, fifty hands were dissected to determine the variation in each of the thenar muscle. Results: Only the abductor pollicis brevis showed significant findings. Normal formation of one belly in abductor pollicis brevis represented 72.0% (18) and 84.0% (21) for the left and right hands, respectively. Variations according to the number of belly of the abductor pollicis brevis were also observed. One of the variations is the absence of the abductor pollicis brevis, 4.0% (1) in the right hand. Two belly formations of abductor pollicis brevis were observed, 28.0% (7) and 12.0% (3) for left and right sides of hand respectively. Thus, more variations were observed to occur on the left hand (7) compared to the right hand (4). Many studies describe about the variations of each thenar muscle, but few literatures were found discussing on the association of thenar muscle variation with the sides of hand. Using the Fisher Exact Test, it showed that there was no significant associa-tion of variations in the thenar muscle in relation to the sides of hand. Conclusion: This study conclude that there is no consistency between variations of the thenar muscle in relation to the sides of hand. However, clinical awareness of these variations is important in the context of compartment syndrome, use of the aberrant structures as grafting material in reconstructive surgery and proper interpretation of imaging modalities.
Medical professionals work in a constantly stressful environment. The nature of the profession requires routine extended working hours, but little is known about the effect of long working hours on selective physiological measures. A cross-sectional feasibility study was conducted from 1 October 2017 until 30 April 2018 on medical doctors in a tertiary health centre in northwest Malaysia. There was a total of 55 study participants recruited. The overall systolic blood pressure (SBP) was highest after working 24-hour stretch (p=0.006) and the overall diastolic blood pressure (DBP) were highest after working for 33 hours in a single stretch, at the end of on call rotation (p
Introduction: Oral cancer is the sixth most common malignancy in the world. It is a major concern in Southeast Asia primarily due to betel quid chewing, smoking, and alcohol consumption. In Malaysia, oral cancer related cases accounts for 1.55% of the cause of deaths. Despite recent advances in cancer diagnoses and therapies, the survival rate of oral cancer patients only reached 50% in the last few decades. Tissue engineering (TE) principles may pro-vide new technology platforms to study mechanisms of angiogenesis and tumour cell growth as well as potentially tumour cell spreading in cancer research. The use of biomaterial, appropriate cell source and proper signalling mol-ecules are vital components of TE. Collagen biomaterial are widely used scaffold or membrane in oral application. Nevertheless, no review has been performed on the its usage for the study of oral cancer. This study aimed to sys-tematically review the use of collagen scaffold in oral cancer application. Methods: Research articles were searched using Scopus, Pubmed and Web of Science (WOS) databases. The keywords were limited to “collagen membrane OR collagen scaffold” AND “oral cancer”. Results: Initial search yielded 61 papers (Scopus:37, Pubmed: 12, WOS: 12). Further scrutinization of the papers based on the inclusion criteria resulted total of 3 papers. Two of the papers used collagen membrane for regeneration of oral mucosal defect and increment of alveolar ridge height post-surgery. The remaining paper utilize collagen biomaterial as scaffold for the culture of adenoid cystic carcinoma (ACC) cells. All papers reported significant role of collagen biomaterial in terms of tissue formation, healing scaffold and cellular proliferation. Conclusion: Collagen utilization as biomaterial offers potential use for regeneration of oral related structures as well providing useful model for therapeutics anti-cancer research.
Introduction:Spilanthes acmella, also known as “subang nenek’, has been used traditionally in Malaysia to treat toothache. A previous study has shown Spilanthes acmella leaves extracts (SALE) inhibit Streptococcus mutans growth. Streptococcus mutans is commonly found in the human oral cavity and is the main contributor to tooth de-cay. There is no study on the antibacterial effects of Spilanthes acmella flower extracts (SAFE) against Streptococcus mutans reported to date. Therefore, the objective of this study is to investigate antibacterial properties of SAFE against S. mutans. Methods:S. mutans was subcultured in Muller Hinton (MH) broth and agar. Sequential extractions of S. acmella flowers were conducted using four different solvents with increasing polarity, [n- hexane, dichloromethane (DCM), acetone, methanol (MeoH)] and tested with different concentrations against S. mutans via the disc diffusion assay, minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). Sodium fluoride (NaF) was used as a positive control while DMSO was used as a negative control. Results: The disc diffusion assay shows SAFE inhibited Streptococcus mutans growth. SAFE-DCM shows the greatest inhibition properties (12.33±2.30 mm) followed by SAFE-n-hexane (11.33±0.57 mm). Meanwhile, SAFE-Meoh and SAFE-acetone show no inhibition zone (6.00±0.001 mm). MIC value for SAFE-DCM and SAFE-n-hexane is 12.5 mg/mL respectively. Whereas, MBC value SAFE-DCM and SAFE-n-hexane is 50.0 mg/mL respectively. Conclusion: It can be concluded SAFE-DCM and SAFE-n-hexane possesses bactericidal properties against Streptococcus mutans.
Tissue engineering (TE) research serves to overcome the major obstacles in organ transplantation. This paper summarizes the progress of TE in Malaysia. The online database of Elsevier’s SCOPUS was accessed. Publications related to TE from 1960 till 2017 were scrutinized. The results show an increasing trend in tissue engineering research and development in Malaysia. The search result identified and examined 264 original article publications. It is hoped that the outcomes of this study could serve as a point of reference for researchers on the status of TE research and development in Malaysia. The findings of this study could assist TE researchers in Malaysia to identify the strengths, weaknesses, opportunities and obstacles towards further enhancement in their activities. Consolidating, realigning and re-strategizing those initiatives should also be seen within the context of nurturing potential and budding researchers in TE.
Heat pipes are widely used in various industries such as automotive, electronics, and many more. Heat pipes are used as cooling devices for electronic parts in machines that emit a large amount of heat, which can damage the devices. The heat pipes used in this investigation are loop heat pipes. These pipes can transport heat over a long distance and operate against gravity. The working fluid used in this investigation is nanofluid. Nanofluid is one of the types of working fluid that is considered to have better thermal performance than conventional fluids. Nanofluid is made of nanoparticles with base-fluid. This investigation studies the thermal performance of loop heat pipes using different types of nanofluids. Nanofluid fluids used in this study are diamond nanofluid, aluminium oxide nanofluid and silica oxide nanofluid. The effect of mass concentration of nanoparticles in the base-fluid is also studied. The results showed that as the mass concentration of nanofluids increased, the thermal resistance for diamond nanofluid and aluminium oxide nanofluid decreased, but the opposite occurred for silica oxide nanofluid but still better resultsthan pure water. This shows that diamond and aluminium oxide nanofluids shows better thermal conductivity as it has lower total thermal resistance and thermal enhancement rate compared to other nanofluids. Diamond nanofluid also had higher heat capacity than aluminium oxide nanofluid as it had a lower vapour line temperature reading.
The purpose of this study is to investigate how investor's money attitudes shape their stock market participation (SMP) decisions. This study followed the theory of planned behavior (TPB), and a survey was conducted to collect the responses from active investors. Structural equation modeling (SEM) was used for the analysis of proposed relationships among the constructs, and a confirmatory factor analysis (CFA) was conducted to check the interrelation of the variables and validity of the constructs. This research has concluded that investor's money attitudes are significant to affect their stock market participation decisions. Further, it was found that risk attitudes partially mediate the relationship between money attitudes and stock market participation. Moreover, financial knowledge and financial self-efficacy positively moderated the relationship between money attitudes and stock market participation. This research is one of the early attempts at studying the money attitudes of investors and introduces financial self-efficacy as a moderating construct between money attitudes and stock market participation. The sample size for this study was 250 respondents which can be increased in future research, and the same relationships can be tested by using a larger sample. Moreover, this study has used money attitudes as predictors of stock market participation. Still, many other variables, like personal value, can also be taken to investigate their influence on stock market participation.
In order to explore the response of the soil microbial community to 1,2-dichlorobenzene exposure in Wetland soil, a short-term (7 weeks) mesocosm study was conducted at four 1,2-dichlorobenzene concentrations of (100, 400 and 800) μg g -1. Dry soil, sterile and unsterile controls were also compared. The results obtained showed a significant effect of 1,2-dichlorobenzene on the development of bacterial populations in soils contaminated with different concentrations of 1,2-dichlorobenzene at the early time after application. In general, however, the number of populations of the same soil sample treated with the same concentration of 1,2-dichlorobenzene differed significantly with the increasing incubation time within the early 5 weeks. The scale of differences in banding patterns-showed that the microbial community structures of 1,2-dichlorobenzene-treated and non-1,2-dichlorobenzene-treated soils were not significantly different after 7 weeks of incubation. DNA in application-responsive bands from the 1,2-dichlorobenzene treatments was recovered and amplified using the universal primers. PCR products were recovered and cloned into pGEM-T Easy (Promega) and two clones were obtained. The two clones were sequenced using the automated Model 3730 DNA sequencing system. The two cloned sequences had very high similarities to an uncultured bacterium reported previously in the database of NCBI.
Over many years, forested land transformation into urban, agriculture and mining areas within Tasik Chini Catchment become more intense. These activities have negatively affected the catchment through soil erosion and increased the amount of sediments that deposited into the lake. Hence, the present study aimed to estimate soil erosion risk within Tasik Chini Catchment integrating the Revised Universal Soil Loss Equation (RUSLE) model and remotely sensed geospatial data. The multispectral imagery from LANDSAT 8 was used to provide up to date information on land cover within the catchment. The result shows the majority of Tasik Chini Catchment is classified at very low class (< 10 ton ha−1 yr−1) about 4835.34 ha (92.38%), followed by the low class (10-50 ton ha−1 yr−1) with total area of 175.47 ha (3.35%), moderate high class (50-100 ton ha−1 yr−1) with total area of 65.11 ha (1.24%), high class (100-150 ton ha−1 yr−1) with total area of 38.37 ha (0.73%) and very high class (> 150 ton ha−1 yr−1) with total area of 120.04 ha (2.30%). Tasik Chini Catchment is very susceptible to soil erosion especially on northwest and southeast regions, where the main sources of soil loss come from the agricultural, new settlements and mining activities. To conclude, the estimation of soil erosion model using remotely sensed data can be used to build sustainable development strategy within Tasik Chini Catchment in the future.
Tujuan kajian ini adalah untuk mengenal pasti kesan rawatan suhu yang berbeza terhadap kebioaktifan wolastonit
yang disintesis menggunakan teknik sol gel. Abu sekam padi dan batu kapur digunakan sebagai bahan awalan untuk
menghasilkan wolastonit. Nisbah campuran kalsium oksida dan silika dioksida CaO/SiO2 ditentukan pada 55:45 dan
dimasukkan ke dalam autoklaf pada suhu 135°C dengan tekanan 0.26 MPa selama 8 jam. Campuran serbuk CaO dan
SiO2 tersebut disinter pada suhu yang berbeza (1150°C dan 1250°C) dan diuji sifat kebioaktifan secara rendaman
dalam larutan cecair badan tersimulasi (SBF) selama 1,3,5,7 dan 14 hari secara in vitro. Sifat fizikal dan kebioaktifan
wolastonit sebelum dan selepas direndam dalam larutan SBF dan beberapa pencirian telah dijalankan menggunakan
teknik analisis XRD, FESEM, EDX dan FTIR. Campuran serbuk CaO-SiO2 yang telah diautoklaf dan disinter pada suhu
1250°C menghasilkan puncak tunggal pseudowolastonit. Ujian kebioaktifan menunjukkan lapisan amorfus kalsium
fosfat (ACP) dengan julat nisbah Ca/P 1.9-1.51 terbentuk lebih pantas pada sampel wolastonit yang disinter pada suhu
1250°C berbanding pembentukan ACP pada sampel tersinter 1150°C.
A combinative effect of two or more individual material properties, such as lattice parameters and chemical properties, has been well-known to generate novel nanomaterials with special crystal growth behavior and physico-chemical performance. This paper reports unusually high catalytic performance of AgPt nanoferns in the hydrogenation reaction of acetone conversion to isopropanol, which is several orders higher compared to the performance shown by pristine Pt nanocatalysts or other metals and metal-metal oxide hybrid catalyst systems. It has been demonstrated that the combinative effect during the bimetallisation of Ag and Pt produced nanostructures with a highly anisotropic morphology, i.e., hierarchical nanofern structures, which provide high-density active sites on the catalyst surface for an efficient catalytic reaction. The extent of the effect of structural growth on the catalytic performance of hierarchical AgPt nanoferns is discussed.
Conocarpus lancifolius is a fast-growing and drought tolerant tree species with phytoremediation potential in arid environments. The present study was conducted to evaluate the phytoaccumulation potential under wastewater treatment. The experiment was performed in a greenhouse where 3-month-old seedlings were irrigated with industrial wastewater and growth, biomass and physiological parameters were measured. Concentrations of zinc (Zn), lead (Pb), and cadmium (Cd) in leaves, shoots, and roots along with translocation and tolerance index were also determined. The results showed that under wastewater treatment total biomass increased from 24.2 to 31.5 g, net CO2 assimilation rate increased from 9.93 to 13.3 μmol m-2 s-1, and water use efficiency increased from 1.7 to 2.42. Similarly, heavy metals (Zn, Pb, and Cd) accumulation in stem, leaves, and roots increased significantly under wastewater treatment where the highest concentration of Zn, Pb and Cd was found in roots followed by leaves and stem, respectively. Tolerance index was found >1, and translocation factor of all heavy metals was found >1. The study revealed that phytoaccumulation potential of C. lancifolius was mainly driven by improved net CO2 assimilation rate and water use efficiency.
A ribbed slab structure has the advantage in the reduction of concrete volume in between the ribs resulting in a lower structural self-weight. In order to overcome the drawbacks in the construction process, the application of steel fibre self-compacting concrete (SCFRC) is seen as an alternative material to be used in the slab. This preliminary investigation was carried out to investigate the flexural behaviour of steel fibre selfcompacting concrete (SCFRC) asthe main material in ribbed slab omitting the conventionalreinforcements. Two samples ofribbed slab were prepared for this preliminary study; 2-ribbed and 3-ribbed in 1 m width to identify the effect of the geometry to the slab’s flexural behaviour. The dimension of both samples is 2.5 m x 1 m with 150 mm thickness. The compressive strength of the mix is 48.6 MPa based on the cubes tested at 28 days. Load was applied to failure by using the four point bending test set-up with simple support condition. The result of the experiment recorded ultimate load carrying capacity at 30.68 kN for the 2-ribbed slab and 25.52 kN for 3-ribbed slab. From the results, the ultimate load of the 2-ribbed sample exceeds 3-ribbed by approximately 20%. This proved that even with lower concrete volume, the sample can still withstand an almost similar ultimate load. Cracks was also observed and recorded with the maximum crack width of 2 mm. It can be concluded that the steel fibres do have the potential to withstand flexural loadings. Steel fibre reduces macro-crack forming into micro-cracks and improves concrete ductility, as well as improvement in deflection. This shows that steel fibre reinforced self-compacting concrete is practical as it offers good concrete properties as well as it can be mixed, placed easier without compaction.