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Performance evaluation of geopolymer mortar with sustainable palm oil clinker sand using a volume based approach / Pouya Darvish
No full textExcessive sand exploitation is believed to be one of the main factors for lowering groundwater and flooding, resulting in erosion. This research focused on replacing the conventional sand with a local industrial by-product, palm oil clinker (POC), to incorporate in mortar and concrete. The physical properties, chemical composition, and microscopic images of POC sand and conventional sand were compared. Due to POC’s porous nature and irregular shape, a volume-based approach was applied for replacements and to design mixes based on ASTM codes of practice. Fresh and hardened characteristics such as mechanical properties, durability, and microstructural investigations were performed in order to study the effect of POC in cement and geopolymer mortars and concrete. In addition, the effect of different gradings of POC sand was studied in both cases of cement and geopolymer mortars to have a better understanding of this by-product. To promote the sustainability of the geopolymer products, the mixes were cured at ambient condition to eliminate the unnecessary oven-curing method. This was possible with the incorporation of ground granulated blast-furnace slag (GGBS), which is a by-product of the iron mill. POC sand showed a comparable result in cement and geopolymer mortars to those of mining sand mortars. However, a slight decrease in the compressive strength was reported while benefiting from a lower density. It was found that the use of finer particles of POCS decreased the flowability while it increased the compressive strength. Furthermore, the sodium silicate present in the geopolymer was replaced with an identified batik waste generated from the batik factories with different percentages. With up to 60% replacement of commercial sodium silicate with batik waste, the 28-day compressive strength experienced a negligible reduction of less than 5% to achieve 65 MPa. The utilization of batik waste as the replacement for conventional commercial silicate demonstrated acceptable performance in geopolymer mortar and concrete. The incorporation of these waste materials in concrete could improve sustainability, reduce the cost, and mitigate the environmental impacts. To address the application of the findings, the materials and the concept were further deployed in concrete and the production of hollow blocks
Heat transfer to nanofluids flow in variable circular and annular passage configuration / Arrul Jagindar
No full textThe invention of the heat exchanger is widely regarded as one of the most significant
inventions of all time. Heat exchangers are critical pieces of equipment used in a variety of
industrial settings, including power plants, the HVAC sector, and the chemical industry. In heat
exchangers, numerous fluids are employed as working fluids. Water, oil, and ethylene glycol are
three of the most often utilized working fluids.A minor alteration in the operating principle of a
heat exchanger can produce a significantly larger result at a lower cost. This concept has always
piqued the interest of scholars. As a result, researchers have done several studies to improve the
heat exchanger, whether from a material or heat transfer standpoint.
In terms of heat transfer, they discovered that traditional working fluids have limited thermal
conductivity and characteristics. There have been attempts to make a combination of solid
particles suspended in water. This invention suffered a setback when the pressure drop was
impaired, sedimentation developed, or even erosion happened, resulting in higher maintenance
costs.
Gago and TioSio nanofluids were synthesized in this study investigated their performance in
heat exchanger applications. Thermophysical characteristics, thermal conductivity, specific heat
capacity were measured.The heat transfer coefficients were investigated at fully developed
turbulent flow regime in an annular tube heat exchanger .
The experimental data of all the synthesized nanofluids showed a considerable increase in
thermal conductivity and heat transfer coefficient when compared with the results obtained
from the base fluid. Based on the experimental results, several improved empirical correlations
for calculating the Nusselt number and friction factor were proposed in this study
Potential saving and return of investment of solar panel system installation for residential in Malaysia / Tan Kian Hwa
No full textNowadays, electrical demand is getting to increase in residential area. Annually, there
are 3% of electrical consumption increase in residential. Therefore, the electrical price is
followed to increase. Besides that, non-renewable energy source is gradually depleting.
Hence, renewable energy had been introduced to replace the non-renewable energy
source. Due to Malaysia is in a strategical location, solar photovoltaic (PV) system is the
renewable energy to promote to implement in Malaysia. In addition, solar PV system is a
suitable solution to reduce the household electricity bill by selling back the solar energy
back to the electrical grid. Along the year, Malaysia government implemented several
policies to expand the usage of renewable energy in Malaysia such as Feed In Tariff (FiT)
scheme and Net Energy Metering (NEM). However, people still did not convince on the
performance of the solar PV system. This research study provides the analysis of solar
energy production in three different locations to illustrate the potential saving. The
potential saving based on three different location is up to 50% from the initial electricity
bill with assumption of 2% increment on the electrical tariff. The return of investment for
the solar panel system is fall in between 33% to 38% based on three different locations
Women’s labour force participation and exit decisions in Malaysia / Sharifah Nabilah Syed Salleh
No full textAlmost one out of every two Malaysian women of working age are not in the labour force. Despite significant improvements in schooling, women’s participation rate is still low in comparison to men, particularly in the Malay heartland states. Moreover, a large proportion of the currently out-of-the-labour-force female population are dropouts. These patterns have motivated our research. The probable reasons for non-participation (including quitting the labour force) are varied and range from social norms and traditional gender roles within marriage to that of the gender wage differential. All of these factors shaping women’s economic status vary considerably by geography. This research utilised a nationally representative survey data, the Malaysian Population and Family Survey (MPFS) 2014, to investigate some of these explanations for limited labour force participation of women. The first objective of this research is to study the size of the gender gap in labour market participation and the role of place of childhood residence, in explaining the labour market participation gap. The probit regression estimation, which includes detailed controls for individual and household characteristics, current location, indirect proxies of care-related factors and place of childhood residence, found a large gender gap in labour market participation, both in rural and urban Malaysia. We also document a large regional variation in conditional estimates of the gender gap. Female labour force participation in economically advanced states are higher compared to Kelantan and Terengganu, the Malay heartland states. However, this gap can also reflect differences in place-specific norms and traditions. But the influence of childhood residence in historically Malay majority states is shown to proxy indirectly for traditional social customs. More specifically, childhood spent in Kelantan and Terengganu was found to be significant and negatively related to women’s participation, whereas it is insignificant for men. At the same time, we show that the influence of childhood residence cannot be explained away by differences in the poverty rate, local labour market wage differentials and other state-specific factors such as share of women in teaching jobs, and Bumiputera population share. The second objective is to estimate the size of the gender gap in wages and to investigate whether the gender wage discrimination explains the participation decisions. The analysis found that women are paid significantly less compared to men of comparable characteristics. The wages gap are significant throughout age groups and schooling levels. Additionally, alongside low participation of women in the labour market, there is also an issue of exits among women from the labour market – which are not well studied. The final objective is to estimate the size of the gender gap in the labour market exit decisions and identify the determinants of women’s labour market exit decisions. Heckman-probit regression was applied to circumvent the problem of sample selection bias. The analysis found a sizeable gender gap in exit decisions from the labour market where women are more likely to exit the labour market. Being married decreased the probability of participation in the labour market for women and increased the likelihood of exits. Furthermore, the number of children also increased the possibility of exit among women. This shows that the priority of the mother changed with the presence of children
Diversity of marine fungi isolated from selected scleractinian corals and their secondary metabolites / Lee Li Chuen
No full textScleractinian corals (also known as hard corals) are organisms comprised of colonies polyps that harbor assemblage of microbes, known collectively as coral holobionts which comprises of algae, bacteria, virus, fungi and archaea. Despite the prevalence of coral fungi, not much is known regarding their role and interaction with its host, especially their secondary metabolites aspect. The marine environment hosts fungal community with a contrasting metabolic profile as compared to its terrestrial counterparts. In current study, a total of 31 marine fungi has been isolated from eight scleractinian corals. Penicillium and Neodevriesia both frequently occurred in the collected scleractinian
corals. Using multigene phylogeny approaches, selected strains were identified as
Colletotrichum siamense (from Porites sp2) and Neodevriesia sp. 4 (from Galaxea
astreata) for studies of their secondary metabolites. Fungal strains were cultured in potato
dextrose broth for 30 days and mycelium were filtered and macerated in methanol.
Methanol extract were further partitioned with ethyl acetate and water. Ethyl acetate
extract were undergone further purification using column chromatography and
preparative thin-layered chromatography to isolate secondary metabolites. Partially
purified isolates were evaluated using NMR and methylated lipid layers were analysed
for fatty acid composition. Investigated strains of fungus showed contrasting FAME
profiles making it potential identification markers to fungus. Crude extracts and fractions
of C. siamense were inactive against bacterial strains. 1H- NMR results showed that
majority of the fatty acids isolated are variation of very-long-chained fatty acids
The antecedents and consequences of electronic invoice in China from a tax perspective / Qi Yu Lan
Get PDFThe purpose of this study is to examine the factors that affect the adoption of electronic invoice and in return the consequences of these factors on tax compliance process efficiency of companies in China. A questionnaire survey was distributed to 276 users who adopted electronic invoice and partial least squares regression was used to analyze the data. This study found that perceived benefits and trust in e-government had a positive influence on the adoption of electronic invoice. Furthermore, we also found that the adoption of electronic invoice have a positive impact on the efficiency of the tax compliance process. Moreover, the factors affecting adoption of electronic invoice can have a mediating effect between adoption and tax compliance process efficiency. This study has some limitations because it only explores these influencing factors on companies that has adopted electronic invoice. Future research will be carried out to distinguish between adopters and non-adopters. The results of this study can guide tax authorities and other electronic invoice suppliers to promote the adoption of electronic invoice. This study contributes to the electronic adoption literature by examining antecedents that have consequences on tax compliance processes efficiency
The influence of religion and state ownership on CSR disclosure quality: A case of the pharmaceutical industry in China / Tian Tian
Get PDFA growing amount of research has identified the importance of the institutional environment in determining the companies’ CSR disclosure (CSRD). This perspective suggests that companies in any society facing both formal and informal institutional constraints that they must follow to gain legitimacy. Hence, this research provides insights into the CSRD quality by considering the vital role of institutional constraints. Specifically, the primary purpose of this research is to investigate the influence of religion, representing an informal institution, on the CSRD quality. Additionally, the study identifies the effect of different religions on the CSRD quality. Further, the study also examines how state ownership, representing a formal institution, moderates the relationship between religion and the CSRD quality. The investigation focuses on the pharmaceutical industry in China, an ancient country where religion has an impact on the life of the society. The country is also the leading producer and consumer in pharmaceutical products. Thus, the decisions (including CSRD) of the pharmaceutical companies have a significant impact on both domestic and international stakeholders. This research is conducted by employing the panel data regression method. The results demonstrate that pharmaceutical companies with the higher CSRD quality are positively correlated with religion, which weakens when the state owns these companies, indicating that state ownership moderates the relationship between religion and the CSRD quality. Further, the findings suggest that Buddhism, Taoism, and Catholicism are found to be positively related to the CSRD quality, whereas Islam and Protestantism are not associated with the CSRD quality. The findings of this research contribute theoretically to understanding the influence of religion and state ownership on the CSRD quality in the pharmaceutical industry in China. Practically, the findings established in this study provide evidence on determinants of the CSRD quality in China’s pharmaceutical companies that can assist various stakeholders (managers of pharmaceutical companies, investors, regulators, and the public) in making relevant economic decisions
High quality single-crystalline aluminum nitride grown using pulsed atomic-layer Epitaxy technique by MOCVD on sapphire substrate / Mohd Nazri Abd Rahman
Get PDFThe unique structural properties and engineering characteristics of nitride-based materials have given them a special position in semiconductor applications. Alloys with a tuned energy bandgap from ultraviolet to infrared wavelengths are possible to be deposited in maintaining the wurtzite crystal structure. However, the aluminum nitride / aluminum gallium nitride (AlN/AlGaN) based hetero-structures for deep-ultraviolet (DUV) emitters as well as AlN-based actuators and piezoelectric sensors are highly inefficient owing to the excessive mismatch in thermal and lattice features between these epilayers with flat c-plane sapphire substrates, resulting in crack formation and high dislocation densities. This thesis mainly focuses on the development of high-quality single-crystalline AlN epilayer at relatively low growth temperature and at standard pressure on c-plane sapphire substrate by metal organic chemical vapor deposition (MOCVD).
This thesis mainly covers the examinations of as-deposited AlN films on c-plane sapphire substrates at relatively low growth temperature and standard pressure using pulsed atomic-layer epitaxy (PALE) techniques and evaluates the effects of growth conditions towards the as-deposited PALE AlN films. The results are based on atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM), Raman spectroscopy, photoluminescence (PL) spectroscopy, high-resolution X-ray diffractometer (HR-XRD) and X-ray photoelectron spectroscopy (XPS). For the deposition of AlN films at relatively low growth temperature using PALE growth techniques, it was demonstrated that the optimization of PALE AlN deposition temperature, AlN nucleation layer (NL) growth temperature, number of pulse cycle, and the flow of ammonia (NH3) flux density during deposition have an immense effect towards the growth mechanism and its physical properties.
Defects were examined morphologically, structurally and optically in the as-deposited PALE AlN films which then been described in detail. The initial growth conditions were delineated to be crucial for the final quality of the PALE AlN film. A 2-micrometer thick with a near-atomically flat of 0.87 nm root mean square surface roughness and crack-free surface of as-deposited PALE AlN films has well been obtained in the end of this thesis. Additionally, a high crystal quality of as-deposited PALE AlN films was recorded with the lowest threading dislocation density of 1.50 x 107 cm-2 for screw dislocation and 3.70 x 109 cm-2 for mixed-edge dislocation. The mechanism of strain relief was described using the in-plane strain analysis with Raman spectroscopy and correlated with each type of defect that was found in the PALE AlN films. The lowest in-plane stress and strain was recorded at 0.195 GPa and 0.042%, respectively. Moreover, the PL and XPS survey scan revealed the low incorporation of oxygen impurity in the as-deposited PALE AlN films surface. Finally, a crack-free with high crystal quality and atomically-flat surface of AlN template was achieved on c-plane sapphire substrate at relatively low growth temperature and standard pressure using PALE growth techniques via MOCVD. This thesis enclosed the possibility to perform a high quality single-crystalline AlN epilayer grown at relatively low temperature and at standard pressure without the needs of additional ex-situ high-technology instrument as per compared to other research group
Determinants of user satisfaction and usage intention of e-Filing system in Malaysia / Ashameena Nagaratnam
Get PDFPurpose – The purpose of this paper is to investigate on the factors that affect the user to filing corporate tax returns using the e-filing system in Malaysia.
Design/methodology/approach – The study uses quantitative research approach where questionnaires with close-ended questions were used. In total, 200 questionnaires were distributed and 187 were found usable for data analysis. Analysis of data was done through two types of statistical analysis software which are SPSS and Smart PLS. Structural equation modelling is used to analyse the hypotheses. 11 hypotheses were formulated and tested.
Findings – The results shows that service quality and user satisfaction have significant impact on usage intention while trust in technology significantly influenced perceived risk among users.Meanwhile, information quality and trust in government significantly influenced user satisfaction.Based on the three dimensions of IS success model, service quality and information quality were found to have the most consistent and significant influence over user satisfaction and usage intention in adopting the system. The implications are further discussed.
Originality/value – This study proposes a framework which constitutes the combination of Information System Success Model (ISSM) theory and Trust theory. This framework is useful since it is able to identify factors that affect users’ adoption of e-filing system
Assessment of carbon footprint/emissions for solid waste added clay bricks productions / Aeshwini Singarajan
Get PDFCarbon footprint is an important component of ecological footprint because it quantifies the impact of specific products, activities, or industries in the form of carbon emissions. The higher the carbon footprint, the more greenhouse gases are emitted and contribute to climate change and global warming. The correlation between carbon footprint and waste recovery contributes towards combating environmental, social and economic issues through research and consistent applications. This comparative study was conducted based on three processes which are commercial, recovered clay bricks production and (S/S: stabilization and solidification) of SW204 sludge. The functional unit of 1kg is used throughout the study. The main aim of the study is to define the system boundary of the involved processes and access the carbon footprint. All the information used in this study for evaluation purpose is obtained from secondary data. The evaluation remarks that contributing factors to carbon dioxide emissions in the involved processes are electricity, water, fuel, raw material consumption, including solid waste and scheduled waste generation. The highest carbon footprint released is from process 3: (S/S) of SW204 sludge, which is 65 kg CO2 where it is rooted in high raw material consumption, solid waste generation and electricity usage: 63 kg CO2 ,1 kg CO2 ,0.73 kg CO2 (respective carbon emission). The disposal cost per kg of SW204 sludge is RM6.50, which is 70% higher than the other production costs discussed. Therefore, among several processes discussed, the best suggestion is the production of recovered clay bricks, which emit 21 kg CO2 with a production cost of RM1.15 per kg. The findings generated from this study will show the outline of circular economy benefits and how cost effective it is in the clay brick industry as well as carbon footprint contribution