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The optical and photoelectrochemical (PEC) properties of semiconductors can be manipulated by varying the deposition time and the solvent used. In this work, the study investigates the influence of organic solvent (methanol and ethanol) on accelerating deposition time for the efficient optical and photoelectrochemical performance of the fabricated α-Fe2O3 thin film photoanode below 10 minutes. The α-Fe2O3 film was fabricated via aerosol-assisted chemical vapor deposition (AACVD). The study discovered that the solvent with high polarity enhanced the crystal growth direction of α-Fe2O3 on the (110) orientation. The UV-vis showed that all deposited α-Fe2O3 films exhibit the absorption band in the visible-light region with the estimated energy bandgap of 2.10 eV. Furthermore, the PEC performance exhibited good photoanodic responses with excellent charge transfer behavior and photostability. These findings show that the choice of solvent could influence the rapid deposition time, thus, would be reliable to accelerate the fabrication process of photoelectrochemical water-splitting photoanode.

The urban population in Malaysia has increased to 77.7% in 2021, from 66% two decades ago, of which the current percentage shows Malaysia has more than 25 million city dwellers out of the 32.7 million total population. This statistic resulted in 80% of carbon emissions, roughly 200 million tCO2e, being produced by the urban cities in Malaysia. To balance out the high number of carbon emissions from urban settings, our government has aimed to reduce 33% of carbon by 2030, aligning with the COP commitment by Malaysia in 2021, and later aiming for carbon neutrality by 2050. Carbon neutrality can be achieved by using digital twin technology, which can virtually represent any physical system, including a whole city to its real-world counterpart. Bertam, a city in Pulau Pinang is used as a case study in this study. A baseline simulation has been made of the digital twin city, resulting in 253 kWh/m2 of total energy consumption in 2021, and 1.75 tonnes of carbon per capita. The recent applications of active and passive design strategies will be applied to the virtual city, to obtain its potential energy savings and carbon reduction data. At the end of the study, the digital twin technology will discover the city’s potential energy savings and carbon reduction after the optimization.

This paper demonstrates the field performance of Ground Penetrating Radar (GPR) as a non-destructive testing tool to predict in situ asphalt pavement. In previous study, GPR has been used successfully in a variety of pavements application such as determining layer thickness, detecting subsurface distresses, and others. Nuclear Density Gauge (NDG) is specifically designed to measure the moisture and density of soils, aggregates, cement, and lime treated materials, and also to measure the density of asphalt concrete. Alternative analysis approaches by correlating the GPR and NDG data had been performed for density prediction of asphalt pavement. A density model name Al-Qadi, Lahouar, and Leng (ALL model) was used to predict the density of the asphalt pavement from the GPR data correlate with NDG database. This study shows that density for asphalt pavement from GPR data provide reasonably accurate density prediction when ALL model approach was used.

Prior research has shown viable methods towards identifying sources of pollution in rivers by utilizing Unmanned Aerial Vehicles (UAVs) combined with proper image classification techniques. This research attempts to develop and implement a novel approach to monitor the IIUM River whereby a Parrot Bebop 2 drone is utilized for data collection, while the Quantum Geographic Information System (QGIS) software is used for the supervised classification of the collected data. The image processing techniques of stitching or mosaicking, georeferencing and supervised classification are done using Adobe Photoshop, QGIS Georeferencing plugin, and QGIS Semi-Automatic Supervised Classification Toolbox, respectively. Results show that the classification process successfully recognized target objects, however, differing sun locations in datasets along with insufficient training data have led to some minor flaws. Despite these flaws, this research successfully achieved its objectives and will be vital for further investigations in the future.

Most radiology departments utilize ordinary concrete and lead for radiation shielding as the primary radiation can be reduced through photon absorption. There are many studies done focusing on the transmitted photons that penetrate the shielding materials for radiation shielding. However, the scattering from the shielding materials would be ignored. When high-energy photons impinge on thick shields, most of the incident energy is absorbed in the shielding materials, but some of it can also be deflected sideways or in a backward direction. This is important as the backscatter radiation can contribute to unnecessary additional radiation dose to healthcare workers. Hence, this study evaluates several shielding materials namely aluminium, iron, copper, lead, ordinary concrete, and heavy concrete particularly for its attenuated and scattered photons for radiation shielding. The shielding materials were evaluated using the Monte Carlo simulation, specifically PHITS code. In the simulation, all shielding materials were modelled as a fixed 30 x 30 cm rectangular shape with a fixed thickness of 10 cm. Mono-energy and pencil beam photon energies ranging from 100 keV until 1 MeV were directed to the shielding materials. As a result, at 100 keV, lead shielding showed the least amount of transmitted dose compared to other shielding materials. However, lead shielding also showed the highest reflected dose at the same incident photon energy. As copper showed the least amount of reflected dose at this incident energy, hence applying a thin layer of this material to lead shielding can tolerate the compromise between low transmitted dose and high reflected dose. Therefore, this can improve the radiation shielding at various irradiation facilities. In conclusion, the reflected dose for all materials studied will increase or higher when the incident photon energy increase, except for lead as well as for low-Z element materials rather than high-Z element materials.

Mixed neutron and gamma radiations are common in many nuclear applications. Several materials can be combined to obtain a composite material that is better for mixed radiation than the individual component materials. The aim of this paper is to investigate the shielding effectiveness of a polyethylene (PE)-based composite with boron and tungsten additives. Several compositions are tested to shield against a 252Cf fission neutron source using an attenuation experiment. The composite is also manufactured using the melt-mixing method of component raw materials. Comparisons are made between the different compositions and the experimental results. Results suggest that the PE composite with 16%wt boron and 16%wt tungsten show the best mixed radiation attenuation as compared to pure PE, PE composite with 25%wt boron, and PE composite with 25%wt tungsten.

For an X-ray room, there is a special window for radiation workers to monitor the patient during an irradiation procedure. Lead glass commonly used as protective window materials for diagnostic X-rays even it is known for its toxicity due to the lead oxide in the air which could be inhaled either during manufacturing or recycled process. Monte Carlo simulation (EGS5 code) was used to study several other types of available protective windows for its radiation shielding efficiency. In this study, the practicability of acrylic glass, plate glass and Pyrex glass systems with respect to lead glass were studied for protective window materials. The photon attenuation coefficients (μ), the percentage of transmitted and reflected photon energy spectra and half-value layer (HVL) were investigated by using simulation. Three photon source energies of 59.5 keV, 150 keV, and X-ray 150 kVp were calculated via EGS5 code to study the capability of these four glass systems as low energy photons radiation shielding materials. A thickness of 7 cm plate glass, 8 cm pyrex glass and more than 10 cm acrylic glass are adequate as a non-lead shielding material for 150 kVp X-ray to have a similar lead-glass equivalency. The use of plate glass as radiation protecting material to replace lead glass can reduce expenses as plate is way cheaper than lead but the increase thickness of plate will need special framing and concerns of its increased weight needs to be considered. However, given that the X-ray primary beam will not be directed towards the protective windows, therefore the findings are appropriate, with less thickness of plate glass could be used.

A nuclear security system is often developed based on a particular framework. In our case, a nuclear security system is developed based on the big data analytics framework with the purpose of integrating all nuclear security systems within a nuclear facility. Nuclear security can be defined as the prevention and detection of, and response to, theft, sabotage, unauthorized access, illegal transfer, or other malicious acts involving nuclear material, other radioactive substances, or their associated facilities. Whereas, big data analytics is denoted as a new way of collecting, analyzing large amounts of data, finding the appropriate patterns to support decision making, hence improving the action taken in solving the problems. The system-based evaluations methodology is widely used to measure the performance metrics of nuclear security systems. However, the system-based evaluation methodology consumes time and demands a lot of effort because in applying the methodology, a complete nuclear security system that is based on the particular framework needs to be designed, developed, and implemented in the nuclear facilities environment before the performance metrics could be measured. In this paper, we present an empirical method of measuring the performance metrics by utilizing the Rasch Measurement Model. The methodology is formulated to reduce the time and efforts in measuring the performance metrics of a nuclear system that is developed based on a framework…

Precast Self-Compacting Concrete (PSCC) is one of many types of approach in Industrialised Building System (IBS) that were used to speed up construction to meet consumer’s demand. The usage of Self-Compacting Concrete (SCC) will profit in many ways such as faster construction, reduction in manpower, easier placing, uniform and complete consolidation, better surface finishes, improved durability, increased strength, and safer working environment. The addition coir fibre in PSCC can improve the tensile strength and flexural strength in the concrete mixture.by combining the two elements of SCC and CF in PSCC slab panel, the desired structural behaviour can be achieved. The four-point bending test was conducted on the all 4 type of PSCC slab panel that is solid control, solid CF, hollow control, and hollow CF. The solid PSCC-CF slab panel has the best structural performance compared to the other 3 other PSCC slab panel. The crack and ultimate load of the solid PSCC-CF slab panel recorded are 24.5 kN and 35 kN respectively compared to the reading collected from the other 3 slab panels. The crack propagation on the solid PSCC-CF slab panel also less propagated due to the addiction of CF that build concrete bridges. The load-deflection profile of solid PSCC-CF slab panel also shown the best result compared to the other slab panel. The load-strain profile recorded also shown the highest values of 105 micro strain on top and 53.14 micro strain on side of solid PSCC-CF slab panel.

As issues on sustainable construction material gains prominence in Malaysia, experimental work to investigate the combination of agricultural and construction waste material into a single concrete mixture was conducted. These waste materials will partially replace cement and aggregate content with added Palm Oil Fibre (POF) involving twenty-four cube specimen and six stretcher units of Green Concrete Hollow (GCH) block samples. The optimum replacement percentage of the green concrete material is 10% Palm Oil Fuel Ash (POFA), 15% Rice Hush Ash (RHA), 20% Recycled Concrete Aggregate (RCA) and 0.25% Palm Oil Fibre (POF) resulting a cube compressive strength of 40.4 MPa at 28 days and an average compressive strength for GCH stretcher block unit at 16.31 MPa. From the results obtained, the innovative green concrete mix with added POF and the GCH stretcher block units show its potential as a building material with the ability to be sustainable, eco-friendly and a possibility to meet the reduction in carbon emissions and low carbon footprints.