bluuebunny/crossref_metadata_2025 huggingface dataset:
A template of information needs for decision-making about delaying remediation on contaminated lands to protect human health
Authors: Burger  , Gochfeld
Published: June 2020

The contamination legacy of industrialization, militarization, and nuclear arms race poses current or future risks to populations and the environment. Responsible parties and regulators make decisions regarding which sites to clean up, how, how much, and when. This study aimed to provide
an information needs template to evaluate and reduce risks to human health when considering whether to initiate or delay remediation. This investigation focused on four aspects of timing and prioritization: 1) management, planning and implementation, 2) source terms, pathways, and exposures,
3) risks and receptors, and 4) external drivers. Within each type, issues were identified and described. Management class included personnel, health and safety data, funding, equipment, and structural integrity. Source term included contaminant sources, pathways, initiating events, and barriers
to exposure. Risk included types and exposures to workers and general public. External drivers included regulatory framework, stakeholders, Congressional mandates, and economic and social contexts. Risk may increase over time as contamination spreads, enters aquifers, and reaches receptors,
and may decline as radionuclides decay, and plumes dissipate. The overall objective was to provide a template of information that is useful to managers and regulators, and might be used by the public to understand the risks and benefits of re-prioritization cleanup.
Comprehensive palmitoyl‐proteomic analysis identifies distinct protein signatures for large and small cancer‐derived extracellular vesicles
Authors: Mariscal Javier , Vagner Tatyana , Kim Minhyung , Zhou Bo , Chin Andrew , Zandian Mandana , Freeman Michael R. , You Sungyong , Zijlstra Andries , Yang Wei , Di Vizio Dolores
Published: June 2020

Extracellular vesicles (EVs) are membrane‐enclosed particles that play an important role in cancer progression and have emerged as a promising source of circulating biomarkers. Protein S‐acylation, frequently called palmitoylation, has been proposed as a post‐translational mechanism that modulates the dynamics of EV biogenesis and protein cargo sorting. However, technical challenges have limited large‐scale profiling of the whole palmitoyl‐proteins of EVs. We successfully employed a novel approach that combines low‐background acyl‐biotinyl exchange (LB‐ABE) with label‐free proteomics to analyse the palmitoyl‐proteome of large EVs (L‐EVs) and small EVs (S‐EVs) from prostate cancer cells. Here we report the first palmitoyl‐protein signature of EVs, and demonstrate that L‐ and S‐EVs harbour proteins associated with distinct biological processes and subcellular origin. We identified STEAP1, STEAP2, and ABCC4 as prostate cancer‐specific palmitoyl‐proteins abundant in both EV populations. Importantly, localization of the above proteins in EVs was reduced upon inhibition of palmitoylation in the producing cells. Our results suggest that this post‐translational modification may play a role in the sorting of the EV‐bound secretome and possibly enable selective detection of disease biomarkers.
Homogeneous-isotropic sector of loop quantum gravity: new approach
Authors: Kisielowski Marcin
Published: June 2020

Recently, a new class of scalar constraint operators has been introduced in loop quantum gravity. They are defined on a space of solutions to the Gauss constraint and partial solutions to the vector constraint, called a vertex Hilbert space. We propose a subspace of the vertex Hilbert space formed by homogeneous-isotropic states, which is invariant under the action of the new scalar constraint operators. As a result, the operators can be reduced to our homogeneous-isotropic subspace. The (generalized) eigenstates of the reduced operator are eigenstates of the full operator. We discuss the feasibility of numerical diagonalization of the reduced scalar constraint operator.
Simulation of capillary-driven kinetics with multi-phase-field and lattice Boltzmann method
Authors: Schiedung Raphael , Tegeler Marvin , Medvedev Dmitry , Varnik Fathollah
Published: June 2020

We propose a combined computational approach based on the multi-phase-field and the lattice Boltzmann method for the motion of solid particles under the action of capillary forces. The accuracy of the method is analyzed by comparison with the analytic solutions for the motion of two parallel plates of finite extension connected by a capillary bridge. The method is then used to investigate the dynamics of multiple spherical solid bodies connected via capillary bridges. The amount of liquid connecting the spheres is varied, and the influence of the resulting liquid-morphology on their dynamics is investigated. It is shown that the method is suitable for a study of liquid-phase sintering which includes both phase transformation and capillary driven rigid body motion.
High-brightness broad-area diode lasers with enhanced self-aligned lateral structure
Authors: Elattar M , Brox O , Della Casa P , Maaßdorf A , Martin D , Wenzel H , Knigge A , Crump P
Published: June 2020

Broad-area diode lasers with increased brightness and efficiency are presented, which are fabricated using an enhanced self-aligned lateral structure by means of a two-step epitaxial growth process with an intermediate etching step. In this structure, current-blocking layers in the device edges ensure current confinement under the central stripe, which can limit the detrimental effects of current spreading and lateral carrier accumulation on beam quality. It also minimizes losses at stripe edges, thus lowering the lasing threshold and increasing conversion efficiency, while maintaining high polarization purity. In the first realization of this structure, the current block is integrated within an extreme-triple-asymmetric epitaxial design with a thin p-doped side, meaning that the distance between the current block and the active zone can be minimized without added process complexity. Using this configuration, enhanced self-aligned structure devices with 90 µm stripe width and 4 mm resonator length show up to 20% lower threshold current, 21% narrower beam waist, and slightly higher (1.03×) peak efficiency in comparison to reference devices with the same dimensions, while slope, divergence angle and polarization purity remain almost unchanged. These results correspond to an increase in brightness by up to 25%, and measurement results of devices with varying stripe widths follow the same trend.
Coherent, high repetition rate tender x-ray free-electron laser seeded by an extreme ultra-violet free-electron laser oscillator
Authors: Petrillo V , Opromolla M , Bacci A , Broggi F , Drebot I , Ghiringhelli G , Puppin E , Rossetti Conti M , Rossi A R , Ruijter M , Samsam S , Tagliaferri A , Rossi G , Serafini L
Published: June 2020

A seeded FEL driven by a linac based on super conducting cavities, generating 108–1010 coherent photons per shot at 2–5 keV with 0.2–1 MHz of repetition rate, can address the need of a source devoted to fine analysis of matter using the linear spectroscopy technique. The seeding scheme described hereafter is a multi-stage cascade upshifting the radiation frequency by a factor 20–40. The x-ray range can be achieved with a seed constituted by a coherent flash in the extreme ultraviolet range provided by an FEL oscillator operating at 12–14 nm. The whole chain of x-ray generation is described by means of start-to-end three-dimensional simulations.
Precise high-fidelity electron–nuclear spin entangling gates in NV centers via hybrid dynamical decoupling sequences
Authors: Dong Wenzheng , Calderon-Vargas F A , Economou Sophia E
Published: June 2020

Color centers in solids, such as the nitrogen-vacancy center in diamond, offer well-protected and well-controlled localized electron spins that can be employed in various quantum technologies. Moreover, the long coherence time of the surrounding spinful nuclei can enable a robust quantum register controlled through the color center. We design pulse sequence protocols that drive the electron spin to generate robust entangling gates with these nuclear memory qubits. We find that compared to using Carr-Purcell-Meiboom-Gill (CPMG) alone, Uhrig decoupling sequence and hybrid protocols composed of CPMG and Uhrig sequences improve these entangling gates in terms of fidelity, spin control range, and spin selectivity. We provide analytical expressions for the sequence protocols and also show numerically the efficacy of our method on nitrogen-vacancy centers in diamond. Our results are broadly applicable to color centers weakly coupled to a small number of nuclear spin qubits.
Hierarchy of coherent structures in turbulent channel flow
Authors: Motoori Yutaro , Goto Susumu
Published: June 2020

By analyzing a database of fully developed turbulent channel flow at the friction Reynolds number Reτ
= 4179, we investigate the sustaining mechanism of a hierarchy of coherent structures in the wall-bounded turbulence. For this purpose, we decompose the turbulent fields into different scales by a band-pass filter. Using the filtered velocity and velocity gradients, we identify the hierarchy of coherent structures to observe that the largest-scale structures at each distance from the wall are composed of quasi-streamwise vortices and low-speed streaks. Since these are similar to well-known coherent structures in the buffer layer, they are likely to be maintained by the self-sustaining process. In contrast, structures smaller than the distance from the wall distribute isotropically. These observations are also confirmed by using a conditional sampling method. Moreover, quantifying the scale-dependent contributions to the vortex stretching and energy transfer, we show that the largest-scale coherent structures are strongly affected by the mean shear, whereas smaller-scale vortices are generated by the energy cascading events. Incidentally, in large-scale ejection regions (i.e. large-scale low-speed streaks), the cascading events are stronger than in large-scale sweep regions.
Selective opposition-like control of large-scale structures in wall-bounded turbulence
Authors: Ibrahim J I , Guseva A , Garcia-Mayoral R
Published: June 2020

We investigate the effect of controlling large-scale, logarithmic-layer turbulent structures, which have a characteristic size and aspect ratio that scale with the distance from the wall. The aim is to quantify the effect of suppressing these structures while leaving the near-wall turbulent dynamics unaltered. By affecting only the logarithmic-layer structures, it might be possible to isolate their contribution to the drag from that of the other scales in the flow. We conduct direct numerical simulations of turbulent channel flows at friction Reynolds number ReT
?s 500-1000 and artificially remove certain streamwise and spanwise wavelengths of the wall-normal velocity across a range of heights. The wavelengths chosen depend on the target height (and size) of the structures that we wish to target. When these wavelengths are removed, we observe a positive, outward shift of the mean velocity profile above the target height, due to a local reduction in Reynolds shear stress, and a subsequent increase in viscous stress. Our preliminary results suggest that this shift in the mean velocity profile scales in outer units.
Active flow control for external aerodynamics: from micro air vehicles to a full aircraft in stall
Authors: Lehmkuhl Oriol , Lozano-Durán Adrián , Rodriguez Ivette
Published: June 2020

We investigate the aerodynamic performance of active flow control of airfoils and wings using synthetic jets with zero net-mass flow. The study is conducted via wall-resolved and wall-modeled large-eddy simulation using two independent CFD solvers: Alya, a finite-element-based solver; and charLES, a finite-volume-based solver. Our approach is first validated in a NACA4412, for which numerical and experimental results are already available in the literature. The performance of synthetic jets is evaluated for two flow configurations: a SD7003 airfoil at moderate Reynolds number with laminar separation bubble, which is representative of Micro Air Vehicles, and the high-lift configuration of the JAXA Standard Model at realistic Reynolds numbers for landing. In both cases, our predictions indicate that, at high angles of attack, the control successfully eliminates the laminar/turbulent recirculations located downstream the actuator, which increases the aerodynamic performance. Our efforts illustrate the technology-readiness of large-eddy simulation in the design of control strategies for real-world external aerodynamic applications.
Progress in climate change adaptation in the Arctic
Authors: Canosa I V , Ford J D , McDowell G , Jones J , Pearce T
Published: June 2020

Climate adaptation is a priority for Arctic regions which are witnessing some of the most rapid warming globally. Studies have documented examples of adaptation responses in the Arctic, but assessments evaluating if and how progress is being made over time remain scarce. We identify and examine adaptation progress in the Arctic using a systematic tracking methodology to compare adaptations documented during 2014–19 to those documented for the period 2004–2013 in a benchmark study by Ford et al (2014). Utilising the peer reviewed literature as out data source, we find no noticeable increase in reported adaptations across the two time periods, with the profile of adaptations undertaken remaining largely the same. The majority of documented adaptations continue to be reported in North America, are being undertaken most often in the subsistence-based hunting and fishing sector, are primarily developed in response to a combination of climatic and non-climatic stimuli, are reactive and behavioural in nature, and are mainly carried out at the individual/community scale. Climate change is observed, however, to have a more prominent role in motivating adaptation between 2014–19, consistent with intensifying climate-related exposures in the Arctic. There is limited evidence in the reported adaptations analysed that potential opportunities and benefits from the impacts of climate change are being targeted. The paper provides a general characterisation of adaptation across the Arctic and how it is evolving, and needs to be complimented in follow-up work by studies using alternative data sources on adaptation and research at national to regional scales.
Numerical coalescence of chaotic trajectories
Authors: Roth Bruce N , Wilkinson Michael
Published: June 2020

Pairs of numerically computed trajectories of a chaotic system may coalesce because of finite arithmetic precision. We analyse an example of this phenomenon, showing that it occurs surprisingly frequently. We argue that our model belongs to a universality class of chaotic systems where this numerical coincidence effect can be described by mapping it to a first-passage process. Our results are applicable to aggregation of small particles in random flows, as well as to numerical investigation of chaotic systems.
Cost control mechanism as procurement selection decision matrix for Malaysian infrastructure projects
Authors: Romeli N , Muhamad Halil F , Ismail F , Hasim M S
Published: June 2020

Malaysia was enumerated as the realm that retains a high quality of infrastructure facilities among the other ASEAN countries, and the number of infrastructure projects is progressively developed to offers a virtuous cordiality to the citizen. Inevitably, the infrastructure projects are barely devoted to the complex project selection decision phase where the procurement represents the suave configuration of the projects. However due to the difficulty in analyzing an assorted variety of procurement system afford by inexperienced decision maker the procurement route often unkempt the cost related dynamic. Regularly, the decision based on narrow consideration of cost and project quality overestimated in within a short period of construction. Even worst, there is partially public discourse on the cost control elements towards the disputable project procurement selection, which reflects the lesson learnt on the previous infrastructure project has mismanaged to provide a municipal cost precaution. Prior to that, the research objective is to identify the relationship in between the cost control mechanism and project procurement selection decision in infrastructure projects. The adoption of quantitative method and analysis applies in this research among the infrastructure expert settings. The output from the methods disclose that the cost control acquires a strong correlation in the project procurement selection decision equation with project risk, capital resources, alliance requirement based, changes of policy, fluctuation of inflation rates, labor cost, material cost, robust feasibility studies as a driver to an efficacious project procurement assortment verdict.
Vulnerability assessment of building material against river flood water: case study in Malaysia
Authors: Balasbaneh A T , Abidin A R Z , Ramli M Z , Khaleghi S J , Marsono A K
Published: June 2020

Flood risk is increasing in Malaysia specifically around river which influencing of climate change. The aim of this study is assessing the vulnerability of building materials by revealing the degree of loss for each structure. There are most five common materials has been assessing namely: brick, concrete block, steel wall panels, wooden wall and precast concrete framing. This research was conducted on 110 buildings, to record detailed attributes of each building in the city of Kuantan. Afterwards, the interviews were conducted with residents of 85 households along with a local authority staff expert. The lowest flood depth that effected on wall building was 25 cm and the highest depth of flood was recorded 150 cm. In general, the interview revealed that the flood lasted for 48 hours. The vulnerability of the structural type of building is determined from the percentages of damage to the wall material resulting from occurrence of the flood. Vulnerability curves were made for these five structural types, by plotting the relationships between flood depth and damage for each structural type. The result shows that by increasing the flood depth wood wall encounter by more damage, which needs more cost to repair. In other hand, Concrete block wall, which consider as one of the industrial building systems has less damage against floodwater. Although, until the depth of 75 cm both Concrete block wall and precast concrete has a same stability. The result of this research can help housemaker to choose the best material for building in flood zone area, which needs less cost in repair stage after flood hit the building.
Awareness of Building Information Modeling Implementation in Retrofitting the Existing Residential Building in Malaysia
Authors: Kermanshahi Emad Kasra , Tahir Mahmood Bin Md , Shukor Lim Nor Hasanah Abdul , Balasbaneh Ali Tighnavard , Roshanghalb Shervin
Published: June 2020

Building Information Modeling (BIM) is a new paradigm in the architecture, engineering, and construction industry in Malaysia. In the literature, there are numerous reviews of BIM implementation on new buildings, while the BIM application in retrofitting existing buildings is rather disregarded yet. Only limited research has investigated the use of the potential of BIM in residential retrofit projects. This study seeks to investigate the current status of implementation of BIM for retrofitting residential buildings practicality. The research used the questionnaire as a quantitative method to collect data in the current study. One hundred twelve professionals were chosen for this study, and the response rate was 49 percent (55 respondents). The sample of the questionnaire survey consists of the academic experts and construction engineers and architects, BIM software designers, and construction organizations in Malaysia. The data collected through the respondents are analyzed using the Statistical Package for the Social Sciences software (SPSS Version 22). The results revealed that most of the respondents (47.3%) have a low level of awareness about BIM, and the majority of the respondents (29.1%) do not use BIM in their projects. Based on the investigation, the adoption of BIM residential buildings is timely. The most common obstacles to the BIM adoption for residential retrofit are the lack of customer demand, high initial investments, and lack of standards. In conclusion, this research provides information about the feasibility of BIM adoption for retrofitting the existing residential building. It is expected that this knowledge could be useful for BIM development and tackle barriers regarding BIM adoption in the Malaysia construction sector.
Sustainable residential building retrofit for improving energy efficiency: The owners’ perspective in Malaysia
Authors: Kermanshahi Emad Kasra , Tahir Mahmood Bin Md , Shukor Lim Nor Hasanah Abdul , Balasbaneh Ali Tighnavard , Roshanghalb Shervin
Published: June 2020

Malaysia has made continuous efforts to tackle energy sustainability challenges in recent years. There are significant opportunities to cut energy consumption and greenhouse gas emission (GHG) through retrofitting of existing domestic stocks. Due to the extremely fragmented nature of retrofit practice in the construction industry, there are some challenges among project stakeholders, including home occupants and builders in retrofitting residential buildings. There is a lack of research regarding the client’s requirements for housing retrofit priorities and preferences for retrofitting measures and materials. Therefore, the aim of this research is exploring the owner’s point of view for housing retrofit and their decision-making factors for choosing retrofit measures. In this study, by using sampling techniques, 400 people staying in Kuala Lumpur and Johor Bahru were selected for the housing retrofit preference survey. Statistical Package for the Social Sciences software (SPSS Version 22) was used as a statistical software to analyze survey data. It was revealed from the questionnaire survey that window/door is the top priority for clients to improve energy efficiency. Furthermore, the most critical factors in improving energy efficiency are initial cost and thermal performance, respectively. Moreover, in decision-making factors for selecting construction materials, owners emphasized on initial cost and payback time as important factors. Therefore, all experts in the construction industry should take into account the interests of customers with technical matters at the same time. In conclusion, this research empowers professionals to know homeowner needs and preferences from the beginning of retrofit projects.
BIM and CMMS for IBS building maintenance in Malaysia
Authors: Ismail Zul-Atfi , Abdul Rahim M. , Ghazaly Z. Md.
Published: June 2020

IBS construction is gradually increasing in many building projects in Malaysia. The projects have involved modern, contemporary and innovation design for construction. The increase of demands for IBS construction every year indirectly contributes the building and infrastructure development but maintenance management however is poor, possesses low defect diagnosis and limited decision making process to repairing. These problems become more complicated in complex and high-rise building projects like Malaysia to which IBS building construction is practiced. Conventionally, the repairing maintenance method (fragmentation approach) has been criticized for serious unacceptable quality or productivity, budget and concept of the IBS building maintainability (reworks and delay). Therefore, a novel and more sophisticated technique is proposed for improving defect diagnosis and decision making process by employing BIM and CMMS integration in maintenance management on IBS buildings in Malaysia.
Modulus of rupture and surface morphology of the cement composites with the addition of quarry dust
Authors: Madzura M , Mazlee M N
Published: June 2020

Quarry dust is widely used as a substitute material in the cement composites because of its strength, and at the same time the re-use of this by-product waste from the rock mining operations has led to the environmental awareness amongst the researchers all over the world. In this research, an experimental study was undertaken to find out the effect of quarry dust for varying percentage replacement of river sand on modulus of rupture of the cement composites. Besides that, this paper also aims at the relationship of the modulus of rupture and surface morphology of the cement composites. Properties of the cement composites are investigated with partial sand replacement with the addition of quarry dust at 10 wt.%, 12.5 wt.%, 15.0 wt.% and 17.5 wt.%. Cement composites were cured, tested for modulus of rupture and characterized for surface morphology at curing period of 7 and 28 days to obtain the optimal value of quarry dust in the cement composites. The results of this research have indicated that 12.5 wt.% of quarry dust exhibits the optimal value of modulus of rupture and surface morphology in satisfactory condition.
The effectiveness of oil palm shell (OPS) as major aggregate replacement in concrete
Authors: Abdul Rahman N , Tan A S H , Waqbitu F , Roslan N H
Published: June 2020

Malaysia known as one of global leaders in production and export of palm oil. This huge production of palm oil has produced high waste product which might cause to environmental pollution. The aim of this study is to determine the effectiveness of oil palm shell (OPS) as aggregate replacement in concrete and at the same time help to reduce the environmental pollution. The workability, density, and strength performances of concrete incorporated with 80% of OPS as coarse aggregate replacement were being investigated. Through the experimental test has shown that the OPS have high potential to be used as aggregate replacement in concrete. Furthermore, the experimental test results exhibited the advantage of OPS in reducing the density of concrete within 1800kg/m3 to 2000 kg/m3. However, the compressive strength of concrete containing OPS was decreased up to 35% from normal concrete strength. Thus, by introducing steel fibres into the OPS concrete has help in improving the concrete strength. Hence the additional of steel fibre into concrete has shown good potential in improving the lightweight concrete since it shows lower in density and 35% higher than minimum lightweight concrete strength as stated by ASTM C330-89.
The effect of heat treatment to the colour of Pauh Kijang (Irvingia Malayana)
Authors: Md Noh Nur Ilya Farhana , Hashim Wardati , Jing Lin Ng , Chai Lee Jin , Razman Ruzaimah , Syamsunur Deprizon
Published: June 2020

As timber with natural durability and excellence properties is limited and high in price, there is a need to make use of the timber with low durability and properties. In order to use this kind of timber, the timber needs to be treated to improvise its properties and durability. The well-known treatment used worldwide is by using chemical preservative; however, this kind of treatment is bad to the environment. Therefore, there is a need to find an alternative way to replace this treatment with an environmentally friendly way of treatment. Heat treatment is one of the treatments which may equip the timber with new properties without using any chemical or preservative but heat where the heat is used to achieve new material properties rather than to dry the wood. Heat treatment generally causes an apparent decrease in wood mechanical properties due to the material losses in the cell wall, hemicelluloses degradation and the modification of long chain molecules. Therefore, this study investigated the effect of heat treatment on the colour of one of the Malaysian hardwood timbers; Pauh Kijang which located in Strength Group 3 of timber (SG3) after had been treated by heat. The size of the timber beam for each sample is 50mm x 90mm x 1800mm. The total numbers of the sample are 90 which 15 numbers of sample allocated for control, kiln dried and four levels of heat treatment. There are four different levels of temperatures namely 150°C, 170°C, 190°C and 210°C were applied on the timber beam samples within 1 hour. Control and kiln dried samples been used as comparisons to each test conducted to identify the changes that occur on the colour after heated. The colour turned darker as the temperatures increased for these four species of heat-treated timber which had been analysed by CIE-Lab system.
Absorption and strength properties of lightweight foamed concrete with egg shell powder as partial replacement material of cement
Authors: Tiong Hock Yong , Lim Siong Kang , Lee Yee Ling , Yew Ming Kun , Lim Jee Hock
Published: June 2020

Around 85 thousand tonnes of egg shell waste were yield in Malaysia at 2017, and when its utilization rate is low and not treated and disposed properly, it might result in environmental problem. By partially replacing cement with egg shell powder, the waste can be reduced and meanwhile reduce cement production that results in depletion of natural limestone and emission of carbon dioxide. Therefore, this study was carried out by aiming to mitigate the environmental issue by reducing eggshell wastes and pure cement production, and meanwhile, to promote the application of lightweight foamed concrete. The objective of this study is to investigate the effects on spread diameter, stability water absorption, initial surface absorption, sorptivity, and compressive strength of lightweight foamed concrete with fresh and hardened density of 1000 ± 50 kg/m3 and 1400 ± 50 kg/m3 when the cement is partially replaced by egg shell powder at replacement levels of 0%, 2.5%, 5%, 7.5%, and 10% by mass. The results showed that with incorporation of egg shell powder at all levels, the water absorption, initial surface absorption, sorptivity were improved, but spread diameter was reduced. Besides, stability of foam and compressive strength were improved in overall at replacement level of up to 7.5%. Therefore, it is feasible to use up to 7.5% egg shell powder as partial cement replacement material.
Physical behaviours of maximum loading and cracking for slurry infiltrated fibre reinforced concrete
Authors: Rahim M Abdul , Zahirah A , Shahidan S , Manaf M B H Ab , Salehuddin S , Ghazaly Z Md. , Ayob A , Bawadi N F , Anudai@Anuar S , Ahmad A N A
Published: June 2020

Concrete prisms are being test with flexural testing by different percentage volume of steel fibres. The total number of 24 prisms were made which contain 3 %, 6 % and 9 % of steel fibres respectively. This only consist experimental results. Specimens used in this study using a prism mold of 100 mm x 100 mm x 500 mm. Eighteen prisms will be added with a layer of 10 mm of steel fibre using slurry method. All of the samples were tested using flexural testing to determine the maximum loading. The highlight scope of this research is to evaluate the physical behavior of Slurry Infiltrated Fibre Reinforced Concrete in term of maximum load and cracking pattern. The results of the study were also compared with concrete without steel fibres. However, the workability of the concrete decreased as the number of steels fibre increase. The maximum load was obtained by the lowest percentage of steel fibre (3%).
Stability of man-made slopes: A numerical case study using an extreme rainfall distribution in Brunei Darussalam
Authors: Abdul Rahman E K , Ratnayake U , Tan S J , Shams S , Haji Othman D , Abdullah R R
Published: June 2020

The number of slope failure cases in Brunei Darussalam has been observed to increase during periods of intense rainfall, such as during the month with peak rainfall. Like other countries around this region, a recommended value of slope angle during earthwork and construction has been established. However, the apparent correlation between landslides and high rainfall intensity suggests that an investigation needs to be carried out to see whether the recommended value is appropriate for the current Brunei’s climate condition, especially in relation to a potential reduction in the factor of safety due to rainfall infiltration. This study investigated the effect of the peak monthly rainfall distribution on the stability of different slope angles using the continuous rainfall data from December 2013 to January 2014 as a case example. A commercial software, GeoStudio2012, was used to carry out the numerical analysis of rainfall infiltration and limit equilibrium to evaluate the factor of safety of slopes. The study revealed that the current recommendations may not be appropriate for certain soil condition under the considered critical rainfall distribution. It also revealed that the daily highest intensity of rainfall did not necessarily result in a slope failure, but rather the accumulation of rainfall was a more significant factor to trigger slope instability.
Effect of crude oil spillage on engineering properties of tropical residual soil
Authors: Abdulrahman Suleiman , Malami Salim Idris , Adedokun Timothy A , Haruna Abdulrahman , Attahiru Yusuf Babangida , Haruna Sadi Ibrahim
Published: June 2020

Oil exploration in Nigeria causes serious environmental degradation. Little is known about the effects of crude oil spillage on soils found in northern Nigeria where oil exploration started less than two years ago (2018). This research is a comparative analysis of the effect of crude oil on contaminated and uncontaminated soil typically found in northern Nigeria. Five Trial pits were dug at Bayero University Kano, two of the trial pits were filled with 20 litres of crude oil while the remaining three trial pits were left uncontaminated and used as control. The crude oil was allowed to infiltrate into the soil for about six (6) weeks before samples of soil were obtained for laboratory analysis. Maximum dry density (MDD), natural moisture content, California Bearing Ratio CBR value, cohesion, and Atterberg limits test were used to analyse the soils. Average natural moisture content was found to be 21 % for uncontaminated soil and 8% for contaminated soil, the MDD value was 1.80 g/cm3 for uncontaminated soil and 1.67g/cm3 for contaminated soil, the CBR changes from 25 % to 6 % while cohesion decreased by 48 % for the contaminated soil respectively. The results show negative consequences for road and building constructions in the simulated crude oil contaminated area.
Requirement of expansion joint for temperature load for RCC structures
Authors: Rabbani S , Gupta A , Ahmed I
Published: June 2020

Concrete is the most commonly used material in building construction. Concrete structures are subjected to seasonal and daily temperature changes due to their interaction with the surrounding environment, in addition to live and dead loads. Significant change of temperature can impose large amount of stress in a structure. These thermal stress values can even exceed the stress values induced by the live and dead loading in case of no or little thermal insulation and could lead to severe damages if not considered during the design. One way of minimizing the temperature stress is to limit lengths of building. In Bangladesh National Building Code and many other national codes, there is no specific guideline for length limits or provision for considering stresses due to temperature load. This paper is aimed to determine the maximum permissible length of a structure without providing an expansion joint so that temperature changes do not create undue stresses. Parametric study involving thermal effect on RCC structures was performed for varying dimensions, conditions and story levels. If temperature effect for structures with significant length is considered, it has been found that top deflection and rebar percentage exceeds limiting values. The finding could become useful in guiding to set the permissible building length without expansion gap.
Investigation of bamboo as concrete reinforcement in the construction for low-cost housing industry
Authors: Rahim N L , Ibrahim N M , Salehuddin S , Mohammed S A , Othman M Z
Published: June 2020

Concrete is the most consumed material, with three tonnes per year used for every person in the world. Twice as much concrete is used in construction as all other building materials combined. Concrete has excellent characteristic in compressive strength, but low in tensile strength. Steel commonly used in reinforcing material because of high tensile strength. The usage of steel as reinforcing material is limited because it is costly and also has an effect on air pollution during its manufacturing process. As an alternative to overcome this problem, bamboo material has been used as a replacement of reinforcement in concrete. Bamboo is a suitable material because it is a natural material, cheap and also available material. In this research, the performance of bamboos as an alternative material in reinforced concrete has been evaluated. Tensile strength test of bamboos has been performed to identify the yields stress of bamboos. From the test, result has shown that bamboo has a similar characteristic with steel and bamboo can be used as an alternative material for reinforcing concrete. However, the characteristic of bamboos showed high water absorption and low bonding strength between bamboo’s surface and concrete. In this research, a waterproofing agent has been used to minimize water absorption and increase the bonding strength. Flexural strength test of the bamboo singly reinforced beam with the size of 150 mm x 150 mm x 750 mm has been undertaken to determine the performance of bamboo as reinforcement. From the test, it has resulted that bamboo give good potential as an alternative material in concrete reinforcement for low-cost housing industry.
Rheological criteria assessment of a rapid setting emulsion as compared to quick set for emulsified asphalt cold mixes
Authors: Usman K R , Hainin M R , Satar M K I , Warid M Naqiuddin M , Giwangkara Grawira Ganjur
Published: June 2020

Pavement deterioration is inevitable on roads. Unlike structural failures that can only be remedied by total reconstruction, road’s functional failures are corrected through effective maintenance works. Preventive maintenance in the form of an emulsified asphalt cold slurry micro-surfacing is considered superior to corrective maintenance – which is a reactive approach. Exploring alternative(s) to the normal quick setting emulsion used for pavement preservation maintenance will make it more robust and cost-effective. This study conducted an assessment of the key parameters specified by the department of public works (Jabatan Kerja Raya) JKR-2008 and International Slurry Surfacing Association (ISSA A143) specifications for emulsified asphalts emulsions used for cold mixes, specifically, emulsified asphalt micro-surfacing mixtures used for pavement maintenance. Cationic quick set (CQS-1h) and Rapid Set (RS-1k) emulsions were tested in the Transportation laboratory of UTM under controlled laboratory conditions. Tests include settlement and storage stability, particle charge, residue by evaporation, sieve test, and Say bolt Furol viscosity, while the residue from evaporation was tested for microstructural and mechanical performance, results were compared with JKR-2008 and ISSA A143 standard specifications. The result indicated that although the desirability for opening traffic within 1hr is not guaranteed with RS-1k, yet, it gives promising similar properties with CQS whilst satisfying cold mix requirement.
Review on the potentials of natural rubber in bitumen modification
Authors: Abdulrahman Suleiman , Hainin Mohd Rosli , Mohd Satar Mohd Khairul Idham , Hassan Norhidayah Abdul , Al Saffar Zaid Hazim
Published: June 2020

In recent times both natural and synthetic rubber were blended with bitumen with the hope of producing a more durable hot mix asphalt. Although the application of natural rubber (NR) in bitumen modification have started long time ago prior to crumb rubber; only few literatures that completely characterised its performance are found today. This review aims to remind researchers and paving agencies on the benefits of NR rubberised asphalt. The study draw attention to NR production process and its unique properties, how NR was used to solve four major asphalt pavement failures namely rutting, fatigue, thermal cracking, and moisture susceptibility. It also presents barriers limiting the application of NR in bitumen modification with possible solution. Lastly, the concept of applying NR in warm mix asphalt was introduced.
A state-of-the-art review of multi-agent modelling of crowd dynamic
Authors: Mohamed Daud N A , Rahman N Abd
Published: June 2020

This paper reviews the multi-agent modelling (MAM) which applied as a platform to simulate the interaction of crowd dynamics. The research and development of MAM related to crowd dynamics can generate specific analytical evaluation, improve the safety level of the pedestrians and the quality operation of the urban space. Furthermore, crowd dynamics have become a major concern for urban space and are mainly constrained imposed by the ever-increasing populations. Consequently, these scenarios causing more attention are paid to the crowd safety in capacity assessment, especially during an emergency evacuation. This paper presents a concise review on the development of MAM over the past few years. The discussion on the state of the art of the multi-agent methods includes the history of the multi-agent method and the development of multi-agent modelling. This paper also discussed the state of the art of multi-agent methods in modelling crowd dynamic by focusing only on the microscopic approach. The advantages of multi-agent modelling approach have become one of the best methodological approaches in analysing and predicting crowd performance in the real world as a substitute for physical experimentation in a current research field.
Anaerobic digestion industries progress throughout the world
Authors: Akhiar Afifi , Ahmad Zamri Mohd Faiz Muaz , Torrijos Michel , Shamsuddin Abd Halim , Battimelli Audrey , Roslan E , Mohd Marzuki Mohamad Hanif , Carrere Helene
Published: June 2020

Anaerobic digestion is a process where microorganisms degrade organic matter in the absence of oxygen to produce biogas, mainly composed of methane and carbon dioxide. Recent years have seen a strong development of anaerobic digestion units worldwide, especially in USA, Europe and China. Countries like China, Germany, USA, Italy, UK and France are seen leading in the biogas sector in the world due to long establishment, intensive research and government incentives for renewable energy as well as waste management solution option. Asian countries have also shown their interests in the biogas technology. With more proper research and studies on-going, Asia will see the growth of biogas sector in the next few coming years. Even though African countries are in their primary phase to develop this biogas technology and there are still more hurdles to overcome, there have been interests, development and implementation work to apply this technology for its potential renewable energy production as well as its waste management solution.
Renewable energy development in Malaysia: Communication barriers towards achieving the national renewable energy target
Authors: Khairudin Noor Faezah , Bidin Rosmiza , Shamsuddin Abd Halim , Akhiar Afifi , Ideris Fazril , Rahman Adlansyah Abd
Published: June 2020

In Malaysia, the utilization of renewable energy (RE) as in “five fuel diversification policy” has been intensified since 2000 in the 8th Malaysian plan (2001-2005) as an addition to the supply from conventional energy sources. However, the RE goal in the policy was achieved minimally and later continued in the 9th Malaysian plan (2006-2010). At the end of 2010, The RE goal was again achieved minimally. Previous studies have been carried out to understand the influence of technological, economic, social and political barriers to the development of renewable energy in Malaysia, but not much on the communication barriers. Therefore, this paper will thoroughly examine the perceptions and understandings on the communication barriers towards renewable energy development in Malaysia.
Study on benefit of guide vane for vertical axis wind
Authors: Haneen S , Roslan E , Akhiar A , Zamri F , Salleh F , Isa R , Shamsuddin A H
Published: June 2020

Guide vane was introduced to overcome the problem of high turbulence intensity due to the high rise building in the urban area. The guide vane is a fixed aerofoil that directs air into the moving wind turbine. Guide vane borders the Vertical Axis Wind Turbine (VAWT) and improves the VAWT performance by increasing the wind velocity, decreasing turbulence intensity and increasing torque because it acts as wind concentrator and wind shielding to an optimum angle before it interacts with turbines. This project is based on the VAWT on the College of Engineering (COE) building in Universiti Tenaga Nasional (UNITEN). This VAWT had been fabricated in CREO software to study the benefit of guide vane onto it and the design of guide vane also was constructed by using similar software. SOLIDWORKS Flow simulation was used to analyze the performance of the VAWT. The simulation had been done by simulation of VAWT without and with guide vane to study the benefit and analyze the flow characteristic of the guide vane towards wind turbine. The simulation result shows that the presence of guide vane increase wind speed by maximum 0.0051 m/s and torque increment is about seven times from VAWT without guide vane. Other than that, decreasing of turbulence intensity value also detected in flow simulation result. To sum up, guide vane had the potential to be installed in the urban area because it improves the power output of the wind turbine.
Production of biodiesel from Jatropha curcas mixed with waste cooking oil assisted by ultrasound
Authors: Kusumo F , Shamsuddin A H , Ahmad A R , Dharma S , Milano J , Silitonga A S , Fazril I , Marzuki H , Akhiar A , Sebayang R , Tambunan B H
Published: June 2020

Jatropha curcas oil has a high amount of free fatty acid, while waste cooking oil has a low amount of free fatty acid content. The purpose of this study was to investigate the production of biodiesel from a mixture of Jatropha curcas and waste cooking. The highest biodiesel yields from the mixture of Jatropha curcas and waste cooking was obtained at 99.3%. The result shows that the physicochemical properties of mixed Jatropha curcas and waste cooking oil methyl ester met the standard requirements laid in ASTM D6751 and EN 14214.
A study of energy demand and consumption in University of Abuja, Nigeria
Authors: Evuti Abdullahi Mohammed , Baba Yusuf Mohammed , Adeyemi Kafayat
Published: June 2020

Efficient energy supply to academic institution is necessary for the successful delivery of its primary mandate of teaching, research and community service. Hence, there is need to monitor and control the energy consumption pattern in a university environment. In this study, a preliminary energy audit was conducted over 24 identified buildings at the main campus of University of Abuja, Nigeria to assess pattern of electricity consumption and efficiency in the University. The breakdown of the energy loads revealed that cooling systems (Air conditioning-33%, Central Air Conditioning-2%, Fans-13%), and Lighting 28% accounted for 76% of the total energy demand followed by office equipment (Desk top-11%, Photocopier-9%, Refrigerator-2%) and least being Lap top and Television accounting for 1% each. These on the overall gave the total energy demand of 1675.365KW and the equivalent total annual energy consumption of 1563491kWh (₦ 55,534,481.96). The senate building being the administrative building has the highest energy demand of 278.08KW (17%), followed by main library which is the second largest building in the university with energy demand of 206.615kW (12%), while among the academic buildings, the Faculty of Science has the highest energy demand of 174.285 kW (10%), followed by Faculty of Art with energy demand of 142.815 kW (9%). About 154854kWh and the sum of ₦ 5,534,481.96 would have been saved per annum if the 40W bulbs are replaced with a more energy efficient 25W bulbs in all the buildings assessed.