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Heteroatom-doped photoreduced graphene oxide photocatalysts for removal of volatile organic compounds / Tai Xin Hong
No full textIndoor air quality (IAQ) has become a great concern as people today spend most of their time indoors, particularly during the Covid-19 pandemic era. Indoor air pollutants such as volatile organic compounds (VOCs) significantly deteriorate air quality and endanger human health. Photocatalytic oxidation (PCO) is a promising method for air remediation because of its ability to operate under ambient conditions to degrade and mineralise VOCs into harmless compounds such as carbon dioxide (CO2). Recently, the use of metal-free photocatalyst has emerged as a cost-effective, sustainable, lightweight, and earth abundance approach for various photocatalytic applications. Graphene oxide (GO) is a promising metal-free carbon-based photocatalyst that showed photocatalytic activities for dye degradation, water splitting, and CO2 reduction. Nevertheless, the application of GO and heteroatom (e.g, boron (B), nitrogen (N), and fluorine (F)) doped GO in the PCO of air pollutants have not been explored yet. There are two common strategies to enhance the photoactivity and properties of GO, namely reduction and heteroatom-doping. Therefore, an effective, green, and scalable method to simultaneously reduce and dope GO was developed. In this study, GO was transformed into photoreduced graphene oxide (PRGO) and doped with heteroatom via a facile photoirradiation technique. The photoactivity of the PRGO was 2.4 times better than GO due to the narrower band gap and slower charge carrier recombination rate. Besides that, GO was simultaneously reduced and doped via photoirradiation with B, N, and F heteroatoms as BPRGO, NPRGO, and FPRGO, respectively. The VOCs photodegradation efficiencies of the photocatalysts followed the pseudo-first-order kinetic (k) as according to this sequence: NPRGO (100%, k = 0.38 h-1) > FPRGO (80.4%, k = 0.26 h-1) > BPRGO (67.7%, k = 0.19 h-1) > PRGO (27.0%, k = 0.06 h-1) > GO (13.7%, k = 0.03 h-1). Additionally, VOCs were successfully mineralised into CO2 by the heteroatom-doped PRGO photocatalysts with mineralisation efficiency up to 100% for NPRGO-0.5. The improved photocatalytic activities of the heteroatoms-doped PRGO were attributed to their increment of charge carrier densities after doping, which resulted in slower charge carrier recombination rates. Among the heteroatom-doped PRGO, the NPRGO had the slowest charge carrier recombination rate because of its n-type conductivity. As an n-type semiconductor, the N dopants formed a shallow donor level near the conduction band of NPRGO. During photocatalysis, if a photoexcited electron falls from the conduction band of NPRGO, the shallow dopant level could trap the electron and reemit it back to the conduction band easily, therefore preventing the electron from recombining with a hole at the valence band. Moreover, the NPRGO could be reused for five PCO cycles without any significant loss in photoactivity. Through mechanism studies, it was determined that the photogenerated hole was the most significant reactive species in the PCO processes. This study provides new insights into a scalable photoirradiation method for producing effective metal-free PRGO-based photocatalysts for air purification
Investigations on heavy-duty gearboxes temperature and the viscosity of the lubricant through simulation and experiment method / Navin Kumar Ganesan
No full textThe development of gear transmissions nowadays is focusing on four main reasons which
are noise, vibration, and harshness to reduce the surrounding sound pollution, load
capacity, wear and tear which will lessen friction and productivity. Gearboxes are as often
as possible outlined conservatively with a supply of oil to ensure operational unwavering
quality. The present study will focus on the viscosity of plastic extruder line gearbox oil
and how the oil temperature is maintained. In this study, two types of lubricants will be
used to demonstrate which lubricant performs well. use a calculation method to prove the
efficiency of the heat exchanger before and after the gear oil temperature. An earlier
investigation focused more on oil temperature and did not show what would happen due
to high oil temperature and didn’t demonstrate simulation results with gear oils of actual
viscosity. This study aims to collect actual data and prove it by simulation and
experimental methods. This research is more effective for high voltage cable industry
production because normally the extrusion line will be run for two or three weeks nonstop
to reach the target of the order. The data also show an exponential trend between the
average wear rates and the surface fatigue lives. Lubricants with similar viscosities but
differing additives and compositions had somewhat differing gear surface fatigue lives
and wear rates. It determined the way to reduce gearbox portion temperature and maintain
the lubricant additive and also the viscosity index number. The method to eliminate water
and acid contained in the plastic extruder gearbox during the machine operating at high
temperature
Safety culture in construction industry / Edwin Tan Ai Yang
No full textThe construction industry is top contributor of accidents in workplace in Malaysia. This industry had recorded 143 deaths and 8,191 accidents in 2018 alone. Therefore, change of safety culture in the industry is necessary for improved safety performance. Before any change can take place, assessing the existing safety culture is a must to determine the current situation. This study aimed to assess the safety culture of the local construction industry. A self-administered questionnaire was developed on Google Form and disseminated through SiswaMail and social medias. Targeted respondents are management-level construction personnel. The survey included demographic questions, safety-culture scale, and questions related to safety-culture factors. The safety-culture scale comprised 40 five-points Likert items under various dimensions and was analyzed by descriptive statistics to gauge the current level of safety culture of the industry. The mean value of the safety-culture assessment was “high” (N = 54, x̄ = 3.82) and more agreement than disagreement was generated indicating that respondents were satisfied with safety culture at their organizations. Besides that, relative importance index was performed to rank safety-culture factors by their perceived importance. The top 5 safety-culture factors are: 1) management commitment, 2) site management, 3) communication, 4) supportive environment, and 5) safety alignment. Furthermore, safety-culture assessment also identified two main areas for safety culture improvement: reporting culture and safety behaviour. Based on the literature and survey findings, a framework for improvement was developed to solve those issues
To determine the customer satisfaction factor to architecture design of Malaysia high rise residential building projects during the design and planning stage / Lo Jia Woei
Get PDFCustomer satisfaction in high-rise residential buildings has evolved as an influential
framework in psychology, personal life satisfaction, community lifestyle, health, and
well-being. Architectural design has played a vital part in influencing the state and is the
main aspect that will directly influence house buyer decisions in Malaysia. This study
aims to determine the significant customer satisfaction element in high-rise residential
architectural design based on the unit layout plan and project design. Furthermore, this
study has specified the function of a professional architect in supervising and ensuring
the quality of high-rise residential architectural design. This study employed a mixedmethod
approach, with quantitative data serving as the primary source of information.
Structured interviews were conducted to validate the customer satisfaction factor in
Malaysian high-rise residential buildings based on questionnaire findings. The results of
the interviews were utilized to determine if the customer satisfaction factor was
equivalent to a professional architect's high-rise residential building design requirements.
A total of 189 questionnaires were sent to the intended house buyer at one of Malaysia's
high-rise residential complexes. Seventy people responded, and their responses were
determined to be beneficial for data analysis. Three of the project architects mentioned
above were interviewed for the construction project. The data were analyzed using the Statistical Package for the Social Sciences (SPSS). From the data analysis, thirteen (13) primary factors in architectural design significantly affect customer satisfaction. They are House floor plan design; Quality of finishes IV workmanship; Quality of materials used for floor and wall; Unit scale and proportion;
Size of the rooms in the unit; Brightness or light in the unit during daytime; Location of
different rooms; Safety and security; Building accessibility; Building durability and life
span; Building orientation; Facility plan design and usage; Building performance
requirements. While four (4) primary roles in terms of professional architect services to
significantly affect customer satisfaction are Managing defects on architectural work;
Project design control; Supervision skill on construction work, and Quality assurance on
building work. According to the interview results, there is some disagreement between
the customer satisfaction factor and the architect's point of view. Based on the data, it is
possible to infer that the architectural design and services supplied by the architect in the
high-rise residential impact customer satisfaction. As a result, greater emphasis is likely
to be placed on those characteristics to increase consumer satisfaction with Malaysia's
high-rise residential building architectural design
The implementation of project management processes and its relationship with project success in the Malaysian interior design sector / Kashini Mahenthiran
Get PDFThe work of an interior designer revolves around the design, construction and management of the project. Therefore, the knowledge and understanding with regards to project management, technicality and system of work is required in order to deliver projects successfully. However, existing literature shows insufficient documented knowledge and information with relation to the implementation of project management processes in interior design projects. The basic attention of available literature on this topic is mostly directed towards specific issues faced in the lifetime of interior design projects with studies on its possible solutions, but very little information has been found on the overall management of these projects to curb those issues. The review of literature also exposed a lack of information and research with relation to project management in the interior design sector and its relationship with project success. Thus, the aim of this research is to study the implementation of project management processes in interior design projects and its relationship to project success. The research approach adopted in this study is the deductive approach whereby the theory is established first through an extensive literature review before empirical research and analysis is based on quantitative data collected from 86 interior design professionals using an online questionnaire survey. It is anticipated that this study will establish the implementation of project management processes in interior design projects in Malaysia as well as assist in proving the importance and contribution of project management in influencing interior design project success, and later, identifying potential opportunities of interior design management
Waste biomass assisted synthesis of silicon nanostructures for photoelectrochemical water splitting / Farah Nadiah Nordin
No full textThis work reports on the growth of Si nanostructures (nanorods and nanowires) by a
chemical vapor deposition technique. The main interest of this work is to utilize the wastebiomass
sources for the application of photoelectrochemical water splitting. This work is
initiated to transform the biomass into a value-added product as well as to investigate the
optimization conditions of Si nanostructures as photocatalyst for the water splitting
application. In this work, the effect of variation of SiO2 source masses (15 to 150 mg) on
the growth, structural and optical properties of the nanostructures are studied at a fixed
deposition temperature of 1410 oC. Si nanorods were prepared at low SiO2 source masses
of 15, 25 and 50 mg with an average diameter of about (247 �} 22), (55.1 �} 5.5) and (221
�} 28) nm, respectively. An increase in SiO2 source masses of 100, 125 and 150 mg
resulted in the formation of high-density Si nanowires with relatively smaller in average
diameter of (31.8 �} 3.0), (48 �} 4) and (82 �} 17) nm, respectively. The microstructure
studies of these nanostructures have revealed the perfect single crystal structure of a
highly crystalline Si nanowires with a very thin amorphous SiOx layer. Therefore, this
resulted in the band gap energies of the Si nanowires and nanorods been tailored within
the UV and visible light region showing an excellent visible light absorption capability.
Apart from that, this work also highlights on the photoelectrochemical behaviour of asgrown
Si nanowires with a better photocurrent density of 0.5 mA cm-2 as compared to asgrown
Si nanorods at a potential of 0.6 V in Ag/AgCl aqueous solution. This is attributed
to the extremely large surface area and large number of active sites of Si nanowires, which
enhancing the water splitting oxidation and reduction reaction processes. The role of silica
in facilitating the growth mechanism of these nanostructures were also discussed
Ergonomic intervention program of computer workstation for school community during Covid-19 pandemic / Muhammad Azri Syafiq Mohamed Ariff
No full textDuring the pandemic, there have been multiple reports from the education sector that home
schooling is not practical. This is worrying because the pandemic is expected not to end within a
short of period of time. Thus, this study was undertaken to observe the ergonomics of teachers'
and students' home computer workstations while home schooling and tutoring. By doing a three-part survey questionnaire on ergonomics practices on home computer workstation was sent toward
respondents through social media platform. The respondents involved employees from education
sector and also students ranging from primary to secondary schools, who were forced to adapt into
home schooling session due to the COVID-19 pandemic. The data is collected in the form of
musculoskeletal disease symptoms and also computer vision syndrome symptoms. From there, it
is then analyzed to identify incorrect postures and discomfort level faced by the subjects. An
ergonomic intervention program is introduced as a part of the questionnaire and subjects are
required to give their opinion on the program. The results obtained showed that there is indeed a
symptom such as back aches and dry eyes which may develop into musculoskeletal disease and
computer vision syndrome. The ergonomic intervention introduced received a good review from
the subjects
Assessment of musculoskeletal disorders among nurses at private hospitals / Vanitha Chantiran
No full textErgonomics is the study of making workplaces and work, tasks more compatible with
the physical and mental capabilities of the people there. The goal of ergonomics is to
decrease stress and prevent injuries and illnesses caused by muscle fatigue, poor posture,
and repetitive job tasks. This research aims to assess the prevalence of musculoskeletal
disorders (MSDs) among nurses at private hospitals. A descriptive cross-sectional design
utilized for carrying out this study. The study addressed nurses within selected private
hospitals (N=169). The tool used to collect data was a set of questionnaires including
persistent of job risk factors, factors that affect the level of awareness and Nordic
Musculoskeletal Questionnaire (NMQ). According to the study's findings, nurses are
increasingly vulnerable to MSDs. Furthermore, there was a highly statistically significant
positive link (p-value 0.05) between employment risk factors, factors influencing MSD
awareness, and prevalence of MSDs among nurses working in private hospitals. The
study recommended that the hospitals’ organization as they devise strategies for reducing
MSDs health risks in the workplace. It is important to make sure that the workplace
(hospital) has an ergonomic work environment, educate, and communicate the risk factors
of MSDs as well as to provide workshop on application of ergonomic principles at
workplace. Combining interventions aimed at the organization and the individual to
combat MSDs in the healthcare industry. Though the nurse should embed physical
exercise in their daily tasks. Physical exercise is strong therapeutic modality to reduce
musculoskeletal pain or discomfort and enhance the quality of life. Besides that, the
nurses also should show their commitment towards the organization’s every endeavor and
attempt on reducing MSDs. Nurses should strongly prepare themselves room for
improvements. MSDs in the healthcare industry may be prevented or minimized with clear policies, strategies, and safety culture based on the management support, nurses’
involvement, and rigorous change procedures. MSDs on the rise, and more study is
needed to find ways to minimize their frequency, incidence, and long-term impact. Also,
the future studies should be performed to investigate the relationship between MSDs and
other variables such as demographic background, job performance and job satisfaction
Effects of online teaching and learning on mental health of students, teachers and parents: Case study in an international school / Kanaheswaree Rajendran
No full textThere has been a rapid disruption of the education system since the Covid Pandemic hit
the world, affecting more than 200 nations. Learning institutions were closed indefinitely,
leading to more than ninety-five per cent of students facing the impact. For this reason,
there have been some changes in different spheres of life due to distance in movement,
which came as a policy to control the spread of the virus. When re-opening the school
came after a long period of staying at home, it came with many challenges because there
were many standard rules. There is a feeling of dilemma, insecurity and uncertainty about
learning at large. There have been different ways of learning introduced, one of them
being online learning. Some factors have intervened in the experience, and many students
and teachers have been affected. Prolonged lockdown and fatigue have brought mental
health concerns for students, teachers, and parents.
There has been a challenge of emotions from students' connection to their fellow students
and teachers. Their academic results have been greatly affected due to this drastic
unexpected change. This case study examines on determining the factors that causes
mental health disturbance for teachers, students and parents while online teaching and
learning process is being conducted during pandemic period. This study was conducted
through survey and interview session. SPSS software was used to analyse the data from
the survey question. Subsequently, this study is to identify the mitigation methods that
can be implemented to eliminate or to reduce the occurrence of mental health in hope that
online studies will be executed in the future as there is the hope of improvement in
communication between the people involved. Thus, the introduction of digital learning
will have its way which will improve the internet exploration
Deep learning-based colorectal cancer classification using augmented and normalised gut microbiome data / Mwenge Mulenga
No full textColorectal cancer is the third most deadly cancer worldwide. The use of gut microbiome in early detection of the disease has attracted much attention from the research community due to its non-invasive nature. Recent achievements in next generation sequencing technology that have resulted in an increased availability of sequence data have also created an enabling environment for the growth of the gut microbiome research area. At the same time, there has been growing interest from the research community in machine learning based detection of diseases using sequence based on gut microbiome data. The detection of colorectal cancer using this approach offers a non-invasive alternative in colorectal cancer research where data can be obtained from stool samples. Considering the limitations of existing methods for colorectal cancer detection, such as colonoscopy and faecal occult blood test, the medical research community has adopted the use of sequence data to identify the disease. While the complex relations that exist between the microbiome and host phenotypes make machine learning algorithms suitable for analysing the microbiome data, deep learning methods are becoming more popular due to their outstanding performance in related fields. However, the performance of deep learning methods is also affected by limitations such as dimensionality, sparsity, and feature dominance inherent in microbiome data. Therefore, to address the above-mentioned limitations in deep learning classification of colorectal cancer based on gut microbiome data, three objectives were formulated. First, to investigate the methods used to address limitations associated with microbiome-based datasets in colorectal cancer identification using deep neural network algorithms. Second, to develop novel techniques that combine the strengths of normalisation, feature engineering and data augmentation to address the problem of dimensionality, feature dominance and sparsity in colorectal cancer identification based on gut microbiome data, using deep neural network algorithms. Third, to evaluate the proposed techniques using the benchmark datasets and compare the results with the baseline methods. Consequently, the techniques for combining existing normalisation methods, namely feature extension, chaining and stacking were proposed in the research. Based on the results, the proposed techniques significantly outperform baseline methods. The research shows that a model that addresses dimensionality, feature dominance and sparsity produce outstanding prediction results in colorectal cancer identification using high sequence-based gut microbiome data. The improved results due to the proposed techniques could aid the growth of the research field and beyond