bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship between the common brushtail possum (Trichosurus vulpecula) and tuart (Eucalyptus gomphocephala) tree decline in Western Australia
Authors: Anderson Hannah , Valentine Leonie E. , Hardy Giles E. St. J. , Fleming Patricia A.
Published: July 2019

Forest canopy loss due to plant pathogens, insect or abiotic factors significantly alters habitat and resource availability for animals, which has flow-on effects for whole ecosystems. The tuart (Eucalyptus gomphocephala) has been in decline throughout its geographic range; this is likely associated with watertable and salinity changes, although a plant pathogen (Phytophthora multivora) has also been implicated. We examined the relative abundance of common brushtail possums (Trichosurus vulpecula) across 12 sites (each 0.72 ha) selected on the basis of the health of dominant tuart trees (six ‘healthy’ and six ‘declining’ sites). Habitat variables (understorey, tuart dimensions and density, tree hollows, tree-to-trap distance) and tuart tree health (crown loss, epicormic regrowth) were compared with possum abundance. Possums were detected at most sites. There was no significant difference between brushtail possum numbers at ‘healthy’ or ‘declining’ sites, although marginally more possums were recorded at declining sites (5.7 ± 1.5 (s.e.), n = 6 sites) compared with healthy sites (3.3 ± 0.7; Cohen’s effect size d = 0.80). Slightly higher abundance of possums was associated with sites that had a greater density of smaller-diameter but taller tuart trees. ‘Declining’ sites, with more epicormic regrowth and greater tree densities, may provide more palatable food resources for possums.
PdII Immobilized on Ferromagnetic Multi-Walled Carbon Nanotubes Functionalized by Aminated 2-Chloroethylphosphonic Acid with S-Methylisothiourea (FMMWCNTs@CPA@SMTU@PdII NPs) Applied as a Highly Efficient and Recyclable Nanostructured Catalyst for Suzuki–Miyaura and Mizoroki–Heck Cross-Coupling Reactions in Solvent-Free Conditions
Authors: Ghasemzadeh Maryam Sadat , Akhlaghinia Batool
Published: July 2019

The new ferromagnetic nanostructured FMMWCNTs@CPA@SMTU@PdII NPs (IV) as an eco-friendly heterogeneous nanocatalyst with a particle size of ~20–30nm reported earlier by our group has been found to be very effective for Suzuki–Miyaura and Mizoroki–Heck cross-coupling reactions at ambient temperature. The procedure has been applied for a wide range of aryl halides, arylboronic acids, and alkenes. The magnetic separation by an external magnetic field, mild reaction conditions, and catalyst reusability up to four times without significant decrease in catalytic activity (reduced catalytic activity from 11 to 18% in the fifth, sixth, and seventh cycles) made the present method sustainable and economically viable for C–C cross-coupling reactions.
Disentangling lattice and electronic contributions to the metal–insulator transition from bulk vs. layer confined RNiO
3
Authors: Georgescu Alexandru B. , Peil Oleg E. , Disa Ankit S. , Georges Antoine , Millis Andrew J.
Published: July 2019

Significance

Our combined theoretical and experimental study of bulk and heterostructured forms of a correlated electron material leads to insights into the metal–insulator transition. Comparison of single-layer, bilayer, and very thick samples validates a combined ab-initio/many-body theoretical approach and enables a clear disentangling of electronic and lattice contributions to the transition by independently changing each. Analysis of the lattice relaxations associated with the metal–insulator transition highlights the importance of the elastic properties of and propagation of distortions into the electronically inert counterlayer, defining a control parameter for tuning electronic properties. Counterlayer-induced bond-angle changes and electronic confinement provide separate tuning parameters, with bond-angle changes found to be a much less effective tuning parameter.
Redox control on nitrogen isotope fractionation during planetary core formation
Authors: Dalou Celia , Füri Evelyn , Deligny Cécile , Piani Laurette , Caumon Marie-Camille , Laumonier Mickael , Boulliung Julien , Edén Mattias
Published: July 2019

Significance

The origin and evolution of Earth’s nitrogen is often discussed by comparing the large variation of N-isotopic compositions among Earth’s building blocks (chondrites) to the signatures of various terrestrial reservoirs. Here, we demonstrate that planetary differentiation processes, such as core formation, may have significantly modified the N-isotopic composition of the proto-Earth. During core–mantle differentiation, a significant amount of isotopically light N entered Earth’s core, producing an isotopic fractionation much larger than has been observed for other geochemical tracers of core formation. The magnitude of N-isotopic fractionation varies significantly as a function of the redox history of the early Earth. Therefore, distinct N-isotopic ratios among Earth’s reservoirs or between planetary bodies may reflect different planetary evolution processes as opposed to different N sources.
Interspecies analysis of MYC targets identifies tRNA synthetases as mediators of growth and survival in MYC-overexpressing cells
Authors: Zirin Jonathan , Ni Xiaochun , Sack Laura M. , Yang-Zhou Donghui , Hu Yanhui , Brathwaite Roderick , Bulyk Martha L. , Elledge Stephen J. , Perrimon Norbert
Published: July 2019

Aberrant MYC oncogene activation is one of the most prevalent characteristics of cancer. By overlapping datasets of
Drosophila
genes that are insulin-responsive and also regulate nucleolus size, we enriched for Myc target genes required for cellular biosynthesis. Among these, we identified the aminoacyl tRNA synthetases (aaRSs) as essential mediators of Myc growth control in
Drosophila
and found that their pharmacologic inhibition is sufficient to kill MYC-overexpressing human cells, indicating that aaRS inhibitors might be used to selectively target MYC-driven cancers. We suggest a general principle in which oncogenic increases in cellular biosynthesis sensitize cells to disruption of protein homeostasis.
Mapping the native organization of the yeast nuclear pore complex using nuclear radial intensity measurements
Authors: Vallotton Pascal , Rajoo Sasikumar , Wojtynek Matthias , Onischenko Evgeny , Kralt Annemarie , Derrer Carina Patrizia , Weis Karsten
Published: July 2019

Significance

The nuclear pore complex (NPC) is a huge protein assembly that selectively transports macromolecules across the nuclear envelope (NE) of eukaryotes. Determining the precise organization of that machinery has been a long-standing goal of structural biology. Here, we introduce a methodology called NuRIM that can map the average position of NE proteins in vivo based on the analysis of intensity patterns in fluorescence micrographs. This generally applicable technique delivers a precise positional map of the native yeast NPC and associated factors. Further, it allows us to investigate the structural consequences of NPC compositional perturbations, and to orient specific protein segments that play an essential role in NPC transport and assembly.
Encoding counterfactuality in Chinese, syntactically
Authors: Liu Haiyong
Published: July 2019

In this article, I demonstrate how past time-reference, modality, negation, conditional, and the causal relationship between the protasis and the apodosis work together to generate counterfactuality in Chinese, syntactically. I study two syntactic means that can help construe counterfactuality in Chinese. First, I study the case of the specialized complementizeryaobushi‘if not for’ based onIppolito and Su (2009)by arguing that the causal clausal relationship and the overt or covert modality are obligatory inyaobushicounterfactual; in particular, I resort to the inherent negative entailment of the modal adverbcai‘not until’ that satisfies the exhaustive operator to account for the needed negation incaiapodosis. Second, I propose that a hypothetical conditional clause with a past time-reference guarantees past counterfactuality in Chinese. I extend the morphological past-tense exclusion operator for counterfactuality (Iatridou 2000) to a more general and more pragmatic past time-reference to include tenseless languages like Chinese. I also show the special typological status of past tense and past counterfactual.
Soldiers in business: the pitfalls of METEC’s projects in the context of Ethiopia’s civil–military relations
Authors: Gebregziabher Tefera Negash
Published: July 2019

This article critically chronicles the ascendancy and apparent decline of a business conglomerate, Metals and Engineering Corporation (METEC), in post-1991 Ethiopia. Informed by ‘developmental state’ ideology, the political elites managed to create METEC, entrusting it to the military for their use in leading the industrialisation of the country. With a sober analysis of the conglomerate’s engagement in mega-projects in the context of civil–military relations, this article shows that the ‘developmental role’ of METEC has been characterised by extreme delays in projects, with symptoms of financial embezzlement which have led the party-state to reconsider the military’s role in the economy. The article relies primarily on documents, informal discussions and media content analysis.
Near-field imaging of locally perturbed periodic surfaces
Authors: Liu Xiaoli , Zhang Ruming
Published: July 2019

This paper concerns the inverse scattering problem to reconstruct a locally perturbed periodic surface. Different from scattering problems with quasi-periodic incident fields and periodic surfaces, the scattered fields are no longer quasi-periodic. Thus the classical method for quasi-periodic scattering problems no longer works. The method based on the Floquet–Bloch transform provides an efficient numerical algorithm to solve the direct scattering problem, and a possibility to reconstruct both the unknown periodic part and the unknown local perturbation from the near-field data.

By transforming the original scattering problem into one defined in an infinite rectangle, the information of the surface is included in the coefficients. The numerical scheme contains two steps. The first step is to obtain an initial guess from a sampling method. The second step is to reconstruct the surface. As is proved in the paper, for some incident fields, the corresponding scattered fields carry little information of the perturbation. In this case, we use these scattered fields to reconstruct the periodic surface. Then we could apply the data that carries more information of the perturbation to reconstruct the local perturbation. The Newton-CG method is applied to solve the associated optimization problems. Numerical examples are given at the end of this paper to show the efficiency of our numerical method.
Effect of ionizing radiation towards human health: A review
Authors: Abu Bakar Nurul Fathihah , Amira Othman Siti , Amirah Nor Azman Nor Farah , Saqinah Jasrin Nurin
Published: July 2019

This paper reviews the properties, process and effect of ionizing radiation towards human health. The fetus and human embryo are much sensitive to ionizing radiation. The health consequences of exposure can be vary even at low radiation and as a result it will affect the mother. Such consequences can include cancer, malformations, growth retardation and impaired brain function. There are two types of biological effects which is deterministic and stochastic effect. Biological effect of radiation results from both direct and indirect action of radiation. Radiation exposure may be external or internal and can be acquired through various exposure pathways. Different organs have different sensitivity to ionizing radiation. Ionizing radiation is a radiation that carries enough energy to liberate electrons from atoms or molecules, thereby ionizing them. Ionizing radiation is made up of energetic subatomic particles, ions or atoms moving at high speeds such as alpha, beta, gamma, neutron particles and X-rays. The spontaneous disintegration of atoms is known as radioactivity and the excess energy emitted is a form of ionizing radiation. As the use of ionizing radiation increases, so does the potential for health hazards.
Implementation of green building materials in construction industry in Johor Bahru, Malaysia
Authors: Kuppusamy S , Chew H Y , Mari T S , Chai C S
Published: July 2019

The research paper is to investigate the implementation of green building materials by construction industry stakeholders in Johor Bahru. Several features and the main types of green building material used in construction industry in Johor Bahru is determined. Barriers and solutions is identified in adopting the green building materials and questionaire is used to gauge response from targetted respondends. The design structure of the questionnaire is to achieve the three objectives of the research. The first objective of the study intends to investigate the importance level for features of green building and the types of green building materials. The second objective of the research is to investigate importance level of the core barriers for the usage of green building materials and the third objective is to investigate importance level of the solutions for the barriers in adopting green building materials.

The data collected is analysed using SPSS software, descrptive statistics eg. mean score and standard deviation interpretations. In conclusion, the GBM features preferred are energy efficiency, low carbon emission and raw material and waste is recyclable. Preferred GBM types are “sustainable brick”, “lightweight reinforced concrete” and “wood flooring” are the top three ranked GBM in Johor Bahru. The research also found that, “Higher cost”, “Lack of awareness” and “Lack of rules and regulations” are the top three ranked core barriers. Finally, the research concluded that, “Reduce green building material cost”, “Education” and “Training campaign” are the top three ranked solutions importance level in adopting GBM in Johor Bahru.
Experimental study on heat transfer characteristics of annular flow between vertical concentric pipe
Authors: Tao Z.Y. , Jia G.S. , Meng X.Z. , Zhang L.Y. , Chai J.C. , Jin L.W.
Published: July 2019

Concentric pipe heat exchangers have been utilized extensively in practical project, such as petroleum, chemical, geothermal energy utilization and other fields. The study of annular flow between vertical concentric pipes is dominated by boiling heat transfer, while the study of forced convection heat transfer for single-phase flow is scarce. In this paper, an experimental investigation is carried out to study of the flow and heat transfer characteristics of the annular flow between vertical concentric pipes. The annular in a vertical concentric pipe heat exchanger with 25mm ring gap is tested with different volume flow rates and different constant heat flow densities. The results show that the Nusselt number of annular flow between vertical concentric pipes increases with Reynolds number. The local convective heat transfer coefficients reduce with the distance from the top to the bottom, which lead to a gradually increased trend in the fluid temperature along the flow direction. Based on the experimental data, an empirical equation of the Nusselt number is obtained to evaluate the overall heat transfer performance of vertically concentric pipe heat exchangers.
Low Cost Light Fidelity (Li-Fi) System Employing On-Off Keying Data Modulation in Half-Duplex Asynchronous Transmission Mode
Authors: Gheng Tuck Yong , Chee Yong Lau
Published: July 2019

In recent years, Light Fidelity (LiFi) technology has gained more and more attention due to its ability to transmit large data in a short time, and prevents interference and radiation compared to conventional WiFi communication. Therefore, it is more preferable to be employed in health care related sector. In this paper, a low cost wireless data communication using Li-Fi Technology is presented. This project employed On-Off Keying (OOK) Modulation Technique to encode and decode messages. A pair of prototype transceivers were developed and adapting Half-Duplex Asynchronous Transmission Mode. The overall hardware is employing Arduino Nano and LEDs and hence the price was kept around USD 25. The entire system was being tested on four different aspects and they were data transmission duration, distance between transceivers, the transmission angle of the transceivers and the message capacity. These tests were being evaluated by Word Error Rate (WER) to acquire the accuracy. In short, the transceivers were able to transmit and receive all the alphabets, numbers and symbols on the ASCII computer keyboard. It works optimally with the transceiver angle of ±10° in a distance of 20cm with the minimum delay of 102ms. The data modulation techniques and the hardware selection were believed as the factors to improve the system performance.
Mechanical and Structural Comparison of AZ31 and AZ61 Magnesium Alloys Along with Deep Drawing Capabilities
Authors: Akhtar Maaz , Saeed Atif , Mehdi Murtuza
Published: July 2019

In the world of advance development, rapid growth for any nation, country or individual is a must thing to have. There are several studies and researches that have put forward to us, not only revolutionized the human society but also helped us to live a better life in a better way. This study focusses on a similar track to analyze the characteristics of magnesium alloys; known for its high weight to strength ratio, so that it could replace; at time; extensively used materials i.e. steel and aluminum. The magnesium alloy has several advantages over steel and aluminum i.e. due to its low density, its weight is quite low, which is the reason that it is extensively used in aerospace and outer space application. Studies suggests that Low weight allows system to consume lesser fuel as compare to the normal ones. Along with it, inspite of having lesser density it doesn’t compromises its mechanical strength and provide high weight to strength ratio; which makes it more suitable for structural and automotive applications. However, inspite of having such tremendous advantages, there are some drawbacks which leads to its minimum usage as compare to both the materials. Magnesium alloys have low ductility, however, it can be enhanced to certain level by several methods to make it cope with real world industrial, commercial and residential applications. This study focusses on analyzing the mechanical and structural characteristics of two grades of magnesium alloy i.e. AZ31 and AZ61. The conclusion has been made by carrying out different mechanical tests i.e. tensile testing, Brinell hardness testing, torsion testing and cupping testing. After conducting these tests this was concluded that AZ31 and AZ61 are a good replacement for aluminium as it has a poison’s ration of 0.4 and 0.24 respectively.
Development of analytical solution for thermo-mechanical stresses of multi-layered hollow cylinder for the application of underground hydrogen storage
Authors: Sim L C , Yeo W H , Pubolaksono J , Saw L H , Tey J Y , Ting C H
Published: July 2019

Hydrogen fuel has been playing an important role nowadays, it is considered as clean fuel and the hydrogen element is highly abundant. Storage of hydrogen in geological formations has been widely applied particularly for large-scale energy storage that required to meet high energy demand. There are different types of underground hydrogen storage methods, one of the most popular and reliable method is to store the hydrogen in depleted oil and gas wells. The structure of the depleted oil and gas well usually constructed by several layers of different materials such as formations, cement and casing. To ensure the well integrity is maintained, a reliable analytical solution to estimate the development of stress under pressure and thermal loading is required. In this paper, a more effective method to estimate the thermo-mechanical stresses of multi-layered hollow cylinder well is developed. The analytical solution is established by considering the well as generalized plane strain problem. The derivation of the equations and the algorithm to obtain results for four layered gas well were demonstrated. In general, the results obtained from the proposed analytical solution are well in agreement with the numerical results. The variations of results obtained from analytical solution and numerical solution are only less than 0.1%.
Solar Distillation Thermoelectric Power Generation
Authors: Remeli M F , Singh B , Amirah N , Meon M S , Fadilla W N
Published: July 2019

In this paper, a phase change material (PCM) heat storage and thermoelectric cells were integrated into a solar still. This project aim is to store the available solar heat using the PCM for generating power and increasing freshwater production. An experimental test rig of the solar still was designed, built and tested. The solar still consists of a single slope basin container with a PCM storage located at the bottom. The thermoelectric cells were installed beneath the PCM storage. The natural convection cooling method was used to cool the thermoelectric cells. The study showed that the solar still thermoelectric power generation (SSTEG) was able to produce 9.6 ml/m2 of fresh water and at the same time generated peak open circuit voltage of 44mV. The study is hopefully could provide a simple and cheap solar still system that can solve the water and electricity problem in rural areas.
Performance Analysis of a Solar Desalination System with Concentrated Solar Power (CSP)
Authors: Yong Ho Zhi , Bahar Rubina
Published: July 2019

Malaysia, being located around the tropical belt, enjoys ample solar exposure throughout the year. Harnessing solar energy for different application is making progress nationwide. Besides extending research on photovoltaic cells; the solar water heating for different purposes is progressing through the past decades. In this paper, performance of a solar still associated with concentrated solar power facilities is presented. In a typical solar still, the solar heat is used to evaporate waste/brackish/saline water (generally termed as feedwater). A basin of the feedwater covered by an inclined transparent cover is placed under the sun to trap the solar heat. The solar heat evaporates the feedwater and the condensate is collected from the inner surface of the transparent cover. In this study, the incident solar irradiation is optimized to produce freshwater from saline/brackish water in a portable solar collector with concentrated solar power (CSP). Fresnel lens has been used as the CSP apparatus. A flat Fresnel lens of size 400 mm x 300 mm with a focal length of 510 mm and light intensity of 92% was attached to concentrate the incident solar irradiation on the inclined transparent cover. Preliminary experiments showed that addition of the Fresnel lens with an optimum tilt of 45° created a “hotspot” in the basin in a particular time of the day and the average condensate production rate increased by 92% compared to that from a bare transparent cover. The distillate from the solar still had a conductivity of 39 μS (25 ppm) which is well below the range of drinking water standard (500 ppm) of the World Health Organization. This study has been conducted in Kajang, Malaysia during the month of August 2018 with an average daytime temperature of 32°C.
Development of Rainwater Harvesting System for Sekolah Menengah Kebangsaan Iskandar Syah Melaka
Authors: Halim ZA , Din AT , Tokit EM , Rosli MAM
Published: July 2019

This paper presents the development of rainwater harvesting (RWH) system at Sekolah Menengah Kebangsaan Iskandar Syah (SMKIS), Melaka to promote landscape sustainability. The proposed RWH system deployed an elevated tank, a sequential filter, and a storage tank. A fertigation pond and a turbine were installed as part of the RWH system in Taman Herba to promote an ecosystem for freshwater habitat and to generate energy. The RWH system was used as an alternative water supply to the Taman Herba and the fertigation pond as well as water supply for power generation. It was found that the RWH system has successfully reduced the rainwater flowrate in the existing drainage system by 50.9% and effectively reduced the utility bills for the landscape irrigation and the fertigation pond. The turbine generated 26.6 W power which is adequate to light up a scrolling message board at Taman Herba. Both the fertigation pond and the turbine embellished the Taman Herba landscape and are a good platform for experiential learning for the secondary students in SMKIS.
Cleaner production and sustainability: stakeholder pressure and the adoption of pollution prevention measures of industrial hazardous waste in Malaysia
Authors: AuYong HN , Chin YH
Published: July 2019

In Malaysia, related environment laws to comply is mainly Environmental Quality Act 1974. The Cradle to Cradle concept is practiced, where recycling and recovery are considered useful resources. The scheduled waste recycling companies are mostly located in Selangor, Pulau Pinang and Johor. Majority of the license issued is of the type of electronics waste. Regulated industries are expected to implement the environmental safety and health management programme to maintain their competitive edge. Hazard control actions are such as scheduled waste control and emission control. Safety management programmes must be integrated into the company daily activities. Workplace hazard is mandatory to be communicated to those who work with the risk. The employees must be trained to handle hazardous waste. Companies have to prepare emergency and crisis management against potential hazardous waste emergencies. Consequently, the benefits gained through improvement with technological investment offset are the main drivers for environmental management programme. In other words, this programme can improve the environmental aspects and performance using industrial engineering, improve natural resource efficiency, reduce energy costs as well as the costs of handling and disposing of hazardous waste, reuse alternative materials and reduce release of pollutants by recycling of waste. This study looks into the quantity of hazardous waste generated, as well as DOE court cases. The study shows the increasing trend of environmental protection expenditure especially on waste management, even though the chemical industry is generating lesser scheduled waste. DOE court cases are mainly related to licensing and water pollution. Many companies engage the services of scheduled waste facilities are located in Selangor, Johor and Pulau Pinang, though Cenviro operates the first integrated hazardous waste management centre in Malaysia. With the positive relationship between environmental performance and environmental care, the higher level of environmental performance achieved, the better will become the environmental quality. Environment performance of the manufacturing sector could be further improved by promoting environmental management programmes.
Utilization of bottom ash for degraded soil improvement for sustainable technology
Authors: Trung Phan Nghia , Sengsingkham Thidphavanh , Tiyayon Pimsiri , Maneeintr Kreangkrai
Published: July 2019

Bottom ash is one of the main products from coal combustion in coal-fired power plants. It has been applied in many applications such as landfill, cement industry or raw feed for clinker, concrete, etc. Furthermore, it can be used in agriculture to improve soil quality. However, the utilization rate of bottom ash in agriculture is still very low only 0.1% of bottom ash. The properties of bottom ash can adjust the pH in soil and provide some nutrients to improve soil quality. Moreover, the soil degradation is a major problem in agricultural countries. The soil degradation is the decline in soil quality due to the improper land use, agriculture with misuse or excess use of fertilizers and so on. In Thailand, the soil degradation is a serious problem in agriculture in the northern mountainous areas. The mainly causes of soil degradation are from human activities such as overuse of pesticide, herbicide, and fertilizer, deforestation, expansion of cultivated areas. Therefore, the objective of this research is to apply the bottom ash from Mae-Moh power plant to improve soil quality of degraded soil in Nan province, Thailand and to investigate the effects of amount of bottom ash from 0-30% by weight on some parameters such as pH, electrical conductivity (EC), bulk density and soil texture. From the result, it is clear that with higher amount of bottom ash, the quality of degraded soil has been improved especially pH and soil texture. The pH can increase from 5.664 up to 7.408. Soil texture can change from clay to loam or sandy loam. The bulk density of soil decreases at all rates of bottom ash which is favorable for plant growth. This research can be applied for soil amendment and is expected to improve the yield for plant growing. Furthermore, the practical combinations of 10% and 20% of bottom ash are considered to apply in the real field to evaluate the improvement on soil properties in the future.
Synthesis and Evaluation of Novel TiO2-based Self-cleaning Coating Layer for Buildings
Authors: Appasamy J S , Kurnia J C
Published: July 2019

This research was carried out in order to analyse the potential of novel nitrogen-doped TiO2/SWCNT (N-doped TiO2/SWCNT) photocatalyst nanocomposites for pollutant removal that deposits on surfaces of buildings. In the present work, the procedure to fabricate this nanocomposite follows a simple method which is sol-gel synthesis method using titanium tetraisopropoxide (TTIP) and ammonia as the precursor. Different composition of TiO2 and SWCNT were used to achieve the optimum composition suitable for building surfaces as a self-cleaning coating. The fabricated dried sols were characterized by XRD to ensure TiO2’s anatase nanocrystalline structure was maintained even after doping. The morphology of these novel coatings was observed by FESEM. FESEM showed that uniform dispersion between TiO2 and SWCNT is present which exhibited a vine-like structure. Methylene blue degradation test was conducted to measure the photocatalytic efficiency of each coating. The highest degradation efficiency achieved was 72.43 %. Spin-coating method was used to deposit a thin layer of this coating on the glass substrate to inspect the water contact angle (WCA) of the as-prepared coatings. The coatings displayed a contact angle of 21.3 °proving that the wetting characteristic falls under hydrophilic category in which any sprinkled water is able to remove the dirt that deposits on the surface. Self-cleaning testing was carried out on glass substrates to further evaluate the coating layers. The coated substrates cleaned about 99 % of the dirt that deposited on its surface. These coatings could be utilized in various applications be it indoors or outdoors, for water remediation, energy saving panels and many potential fields.
Wave velocity selection for leakage localization of water pipeline by Variational Mode Decomposition
Authors: Lee W T , Tan A C , Tey J Y , Rahman F A
Published: July 2019

Water pipelines are susceptible to leakage due to deterioration over time, pipe corrosion, water hammer and soil movement. Water leakage results in losses of revenue and can cause devastating consequence to the environment. Water leakage often happens below ground and remains undetected until a sizable crack has been developed on the pipeline. In the event of a leak, water from the pressurized pipeline expels through the crack at high velocity and generates acoustic waves which propagate along the pipeline. These waves can be picked up by acoustic emission (AE) sensors attached on the surface of the pipe without interfering with the operation of the pipeline. To pinpoint the location of a leak, it requires at least two sensors to be placed on each side of the leak along the pipe. The location of the leak can be located by knowing the time delay of arrival (TDOA) of the acoustic waves at both sensors by employing cross-correlation technique. Leak location is commonly calculated using a constant wave velocity which corresponds to the pipe material. However, the localization error is often large because acoustic wave does not travel along the pipeline at a fixed velocity due to wave dispersion phenomena. The velocity of the acoustic wave is dependent on the frequency and mode of the wave. This paper proposes a leak localization method with an innovative wave velocity selection method based on mode separation by Variational Mode Decomposition (VMD). The proposed method is validated by a leak simulation experiment and it achieves an accuracy of within 7.72% in leak localization.
Phosphoric Acid Doped Polybenzimidazole and Sulfonated Polyether Ether Ketone Composite Membrane for Hydrogen Production in High-Temperature Copper Chloride Electrolysis
Authors: Kamaroddin M F A , Sabli N , Abdullah T A T , Abdullah L C , Izhar S , Ripin A , Ahmad A
Published: July 2019

A composite membrane of polybenzimidazole (PBI) and sulfonated polyether ether ketone (SPEEK) based electrolyzer that operates at higher working temperature above 80 °C is advantageous for faster electrochemical kinetics, higher current exchange density and more resistance to fuel impurities. A high-temperature copper chloride-based composite membrane electrolysis is proposed to overcome the issue of fuel diffusivity, membrane’s thermal and mechanical stability in hydrogen production. The phosphoric acid (PA) functionalized composite PBI and SPEEK membranes were synthesized by a standard method followed with immersion in 85 wt% phosphoric acid at different temperatures for 80 minutes. The composite membranes have been characterized for water uptake, tensile strength, thermal stability by thermogravimetric (TGA) analysis, permeability by Cu diffusion cell and ionic exchange capacity (IEC). From the result, the PA doped PBI membrane (100 °C, 80 min) shows significant improvement in tensile strength (92.23 MPa) with PA doped PBI membrane (40 °C, 80 min) exhibited the lowest Cu diffusion at 5.56 x 10−8 cm2 s−1. The composite PBI/ZrP has the advantage of the most thermally stable membrane and excellent ionic exchange capacity at 3.20 x 10−3 mol g−1.
Mechanical and Fatigue Properties of Gravity Die-Cast A356 Aluminium Alloy with Addition of Scandium
Authors: Masita A , Yeo W H , Saw L H , Lim Y P , Lee J W , Ng T C
Published: July 2019

A356 is widely used for the casting of high strength components in automotive, aerospace and other industrial applications. This is due to its high achievable strength, castability, light weight, good thermal and electrical conductivity. However, the as-cast A356 exhibits relative poor mechanical properties due to the presence of coarse acicular eutectic silicon morphology. In this study, Sc-modified-A356 and the effect of heat treatment have been studied and compared with unmodified A356. Various amounts of Sc ranging from 0.2 wt% to 0.6 wt% were added into the mixture of A356 aluminium alloy and the specimens were produced by using gravity die-casting. Next, the ultimate tensile strength, Vickers hardness and fatigue behaviour of the cast samples are examined. The results revealed that by adding 0.4 wt.% of Sc, the heat treated sample is able to achieve ultimate tensile strength of above 300 MPa and Vicker’s hardness of 118 HV. Furthermore, the fatigue properties of the 0.4 wt% Sc-A356 with T6 heat treatment was found to be improved as compared to the unmodified A365 samples.
Experimental Study on the Performance of a Savonius-Darrius Counter-Rotating Vertical Axis Wind Turbine
Authors: Didane D H , Maksud S M , Zulkafli M F , Rosly N , Shamsudin S S , Khalid A
Published: July 2019

This paper describes the study of a small vertical axis wind turbine (VAWT) with a combined design of Darrius and Savonius counter-rotating rotors. The main purpose of this study is to improve the extraction capabilities of a single-rotor VAWT by using two distinct rotor designs while adopting the counter-rotating technique. Given that the conversion capabilities and operational speed of the existing wind turbines are still limited, the current technique is used to enhance the efficiency and expand the operating speed range of the VAWT. The Darrius and Savonius counter-rotating rotors were exposed to a similar upstream wind speed using a centrifugal blower. It was found that the Savonius-Darrius counter-rotating rotor was able to operate effectively particularly at the low-speed wind. By looking at the individual performance of the rotors, it was observed that the conversion efficiency of the H-type rotor increases as the wind speed increases. However, in the case of the S-type rotor, it is higher at lower wind speed and tends to decreases as the operating speed increases. Thus, the maximum efficiency of the S-type rotor was achieved at low-speed, whereas the H-type rotor has achieved its maximum efficiency at the highest operating wind speed. The average efficiency of the present Savonius-Darrius counter-rotating rotor has been improved to reach almost 42% more efficiency in terms of torque.
Implementation of smart monitoring system in vertical farming
Authors: Chuah Y D , Lee J V , Tan S S , Ng C K
Published: July 2019

The agriculture industry is facing labour shortage problem due to the difficulty to employ workers for “3D” (dangerous, dirty and difficult) jobs. This will reduce the number of labours needed and minimize the threats associated with the traditional agricultural system. Cyber-physical system (CPS) can provide farmers with a framework to remotely monitor and control the various factors that affect plant growth. The aim of this project is to implement CPS into a vertical farming system in which an Android-based remote monitoring and control (M&C) system is developed based on CPS for optimal production of the plantation system using Arduino ESP32 and sensors through the Internet. Experiments were carried to evaluate the practicality of implementing CPS in vertical farming process. Growth factors that were monitored and controlled in the experiments include ambient temperature, water temperature, humidity, pH level, light and carbon dioxide. In this study, an android application was developed and evaluated. The controlled parameters were display on the phone. The evaluation results shown that, the CPS system is practical to be used in plant growth monitoring (sensors and feedback system) and plant growth optimisation (sensors, feedback system and actuators). In addition, the automation of plant growth monitoring process can overcome the shortage of manpower in agriculture industry.
The effect of pH in the synthesis of carbon quantum dots from rice husk on their photoluminescence properties
Authors: Wongso V , Sambudi N S , Sufian S , Isnaeni  , Abdullah B
Published: July 2019

The dependence of photoluminescence properties to pH solution of carbon quantum dots (CQDs) has been widely investigated. However, the influence of pH condition in synthesis process of CQDs was rarely explored, especially in synthesis by using natural precursor. Herein, this report established the synthesis of CQDs from rice husk by using hydrothermal method in varying pH condition (pH 0-14). The oxidation treatment during synthesis process leads to the initiation of surface defect on carbon precursor. Since surface defect plays crucial role in tuning photoluminescence properties, controlling the amount of oxidant agents was suggested to tune distinct photoluminescence properties. According to High-Resolution Transmission Electron Microscope (HRTEM), pH condition during synthesis affects the size of CQDs which has diameter in the range of 3-20 nm. X-ray Diffractometer (XRD) spectra revealed that the obtained CQDs were amorphous with (002) plane of graphite, while the presence of silica on CQDs was revealed by Energy Dispersive X-ray Spectroscopy (EDX) and Fourier Transform Infrared Spectroscopy (FTIR) findings. Photoluminescence spectroscopy showed that the variation of pH in synthesis process broadens the photoluminescence properties of CQDs from green region wavelength to cyan – orange region wavelength (510-632 nm). Therefore, this study suggests that the variation of pH is able to tune photoluminescence properties of CQDs that will be beneficial for its application.
Research on the efficacy of integrated fuel cell and distribution static synchronous compensator in improving power quality on distribution networks with photovoltaic systems
Authors: Lam D H C , Wong J , Lim Y S , Thiam H S
Published: July 2019

The increased penetration of intermittent energy sources has the potential to cause voltage fluctuation and flicker. Static synchronous compensator has been proven to be one of the solutions to solve this issue. Integrating an energy storage system with a static synchronous compensator can increase its performance for real power compensation. While batteries are the preferred solution for photovoltaic power fluctuation mitigation, fuel cells have several advantages over batteries. Based on literature review, integrating a static synchronous compensator with fuel cells can compensate for the fuel cell’s slow response time for transient stability improvement. Hence, this paper presents a model and control scheme of an integrated distribution static synchronous compensator with fuel cell on a distribution network with a grid-connected photovoltaic system. A proportional-integral controller is developed to manipulate the real and reactive power flow for power and voltage regulation. The distribution network is modelled in MATLAB Simulink and the performance of the proposed system for voltage fluctuation and flicker mitigation is evaluated. Results show that the proposed system can reduce flicker levels by more than 80% as well as regulate the voltage on the network at 1.0 p.u.
Energy optimization of sustainable Internet of Things (IoT) systems using an energy harvesting medium access protocol
Authors: Shabana Anjum Shaik , Md Noor Rafidah , Ahmedy Ismail , Hossein Anisi Mohammad
Published: July 2019

The process of modelling the energy expenditure for IoT systems is distinct when compared to Wireless Sensor Networks (WSN), due to a number of factors and metrics. Few of such factors to mention are the IoT layers being different from the Open System Interconnection (OSI) with communication protocols like IPv6 Low power Wireless Personal Area Networks (6LoWPAN), Routing for Low Power and Lossy networks (RPL) and Constrained Application Protocol (CoAP). This leads to the demand for designing efficient Medium Access Control (MAC) protocols to serve the purpose of balance between the performance of the system and minimum energy consumption. The challenge of compatibility of MAC protocols for IoT deployment needs to be addressed. The proposed work is aimed at developing energy efficient framework for optimal balance between energy consumed by connected devices (sensor networks) in a complex and time-critical IoT system through performance monitoring of underlying communication technologies. It also focuses to address the trade-off between energy expenditure and performance of the network for the communicating nodes. An Energy Harvesting MAC protocol is designed and developed after modelling of the nodes using Reinforcement Learning (RL) for time critical IoT systems. The results have shown that the energy expenditure of the IoT devices is considerably minimized and the performance is increased by nearly 80% when compared to the state-of-art energy harvesting solutions for sustainable IoT systems. This research also plays a significant role in matching the energy predictions and the experimentations that validate the IoT systems in a real-world scenario.
Investigation on effective thermal conductivities of porous electrodes for the commercial Li-ion battery
Authors: Lu Z , Yu X L , Xie Y F , Gao S , Zhang L Y , Yang X , Meng X Z , Jin L W
Published: July 2019

The effective thermal conductivities (ETCs) of porous electrodes in electrolyte are of rather significance for determining the thermal conductivity of Li-ion battery which is an important factor in designing battery thermal management system and predicting battery thermal behaviour. In this study, the representative Li-ion battery consisting of a Li(NiCoMn)O2 positive electrode and a graphite negative electrode was chosen to explore the ETCs of porous electrodes. The effects of ETCs of porous electrodes on the Li-ion battery’s thermal conductivity were firstly discussed, and the ETCs were analysed based on its internal configuration and basic assumptions. Most importantly, the ETCs bounds of porous electrodes were acquired using basic thermal conductivity models and the limits of ETCs were obtained based on Maxwell 2 model combined with volume fractions of electrolyte. The results show that the ETCs of porous electrodes in electrolyte are obviously lower than the thermal conductivities of active materials, namely Li(NiCoMn)O2 and graphite. In addition, the ETCs of porous electrodes are not constant but variable values caused by the variation of volume fractions of electrolyte in porous electrodes which indicates that the volume fractions of electrolyte should be considered for accurately estimate the thermal conductivity of commercial Li-ion battery.
A porous medium based heat transfer and fluid flow model for thermal energy storage in packed rock beds
Authors: Amiri L , Ghoreishi-Madiseh S A , Sasmito A P , Hassani F P
Published: July 2019

Thermal energy storage in packed rock beds helps to reduce energy costs and carbon footprint’s on an industrial, commercial and residential scale. Fluid flow and heat transfer in large-size packed rock beds used in mining applications such as heating/cooling of mine intake air or ventilation of block-caved mines have recently received significant attention. Understanding the porous structure of such packed rock beds is a necessity in the design of such systems. The pressure drop across a rock bed directly affects its heat exchange performance, as it requires additional fan power to circulate air during periods of storage/extraction. In this study, the fluid flow behavior inside a packed rock bed thermal energy storage system is investigated by developing a computational fluid dynamics model and a heat transfer model. The model offers useful information for evaluating the performance of rock beds packed with large rocks or in caved zones. Finally, the main goal of this study is to perform a practical energy saving analysis for porous media composed of large particles by changing the physical properties of the porous medium, such as porosity and permeability. The findings of this study also show that while the total thermal energy storage capacity of the system is not significantly affected by the mass flow rate, a lower mass flow rate can provide a longer working period for thermal energy storage systems.