bluuebunny/crossref_metadata_2025 huggingface dataset:
Ethylene: Its adsorption, reaction, and coking on Pt/h-BN/Rh(111) nanocluster arrays
Authors: Düll Fabian , Steinhauer Johann , Späth Florian , Bauer Udo , Bachmann Philipp , Steinrück Hans-Peter , Wickert Sandra , Denecke Reinhard , Papp Christian
Published: June 2020

We present well-ordered Pt nanocluster arrays supported on the h-BN/Rh(111) Moiré as a model system for an ethylene dehydrogenation catalyst. Thereby, the h-BN nanomesh serves as a chemically inert eggbox-like template for clusters with a narrow size distribution. The thermal evolution of ethylene is investigated by synchrotron-based high-resolution in situ x-ray photoelectron spectroscopy on the Pt nanoclusters. We compare our results with data on Pt(111) and Pt(355). Interestingly, the Pt nanoclusters and Pt(355) behave very similarly. Both open a new reaction pathway via vinylidene in addition to the route via ethylidyne known for Pt(111). Due to the importance of coking in ethylene dehydrogenation on Pt catalysts, we also studied C2H4 adsorption and decomposition on carbon precovered Pt nanoclusters. While the amount of adsorbed ethylene decreases linearly with the carbon coverage, we found that edge sites are more affected than facet sites and that the vinylidene reaction pathway is effectively suppressed by carbon residues.
Experimental cell with a Fabry–Pérot resonator tuned in situ for magnetic resonance studies of matrix-isolated radicals at temperatures below 1 K
Authors: Sheludiakov S. , Lee D. M. , Khmelenko V. V. , Järvinen J. , Ahokas J. , Vasiliev S.
Published: June 2020

We describe the design and construction of an experimental cell for the study of free radicals in macroscopically thick films of solidified molecular and rare gases by 128 GHz Electron Spin Resonance (ESR) at temperatures below 1 K. The ESR resonator has an open Fabry–Pérot design, and its frequency can be tuned in situ by adjusting the spacing between the mirrors. The tuning mechanism consists of a piezo positioner and a stainless-steel edge-welded bellows, which can change the resonator frequency by at least 6 GHz. The films of solidified gases can be deposited either directly from a room temperature reservoir or by recondensing from a specially arranged chamber. The free radicals can be created in the solid films by dissociating matrix species by running an rf discharge in a helium vapor. We suggest that such a sample cell design can also be used for a broad range of low-temperature ESR experiments where sample cooling needs to be enhanced by the presence of superfluid helium.
Suspended two-dimensional electron gases in In0.75Ga0.25As quantum wells
Authors: Chen C. , Holmes S. N. , Farrer I. , Beere H. E. , Ritchie D. A.
Published: June 2020

We demonstrate that In0.75Ga0.25As quantum wells can be freely suspended without losing electrical quality when the epitaxial strain-relieving buffer layer is removed. In applied magnetic fields, non-dissipative behavior is observed in the conductivity, and a current induced breakdown of the quantum Hall effect shows a lower critical current in the suspended layers due to efficient thermal isolation compared to the non-suspended-control device. Beyond the critical current, background impurity scattering in the suspended two-dimensional channel regions dominates with stochastic, resonant-like features in the conductivity. This device fabrication scheme offers the potential for thermally isolated devices containing suspension-asymmetry-induced, high spin–orbit coupling strengths with reduced electron–phonon interaction behavior but without introducing high levels of disorder in the processing.
Effect of Flemingia macrophylla silage on in vitro fermentation characteristics and reduced methane production
Authors: Viennasay Bounnaxay , Wanapat Metha , Totakul Pajaree , Phesatcha Burarat , Ampapon Thiwakorn , Cherdthong Anusorn
Published: June 2020

Fodder shrub, Flemingia macrophylla silage (FMS), was nutritionally evaluated for rumen fermentation characteristics using an in vitro gas production technique. Dietary treatments were imposed in a 2 × 7 factorial arrangement in a completely randomised design. The first factor was two ratios of roughage:concentrate (R:C at 60:40 and 40:60), and the second factor was seven levels of FMS supplementation at 0, 20, 40, 60, 80, 100 and 120 g/kg of dietary substrate. The results revealed that a R:C ratio at 40:60 increased the kinetics of gas production (P < 0.001). Moreover, supplementation of FMS increased in vitro degradability and the concentration of propionic acid (P < 0.001), whereas acetic acid concentration, protozoal population and methane production were reduced (P < 0.001). In conclusion, supplementation of FMS at 120 g/kg of dietary substrate improved rumen fermentation and subsequently reduced methane production. However, in vivo feeding trials using FMS should be conducted to gain more information for further implementations.
Translational research in agriculture. Can we do it better?
Authors: Passioura John B.
Published: June 2020

‘Translational research’ became an increasingly common term when it was realised that much agriculturally inspired basic research failed to contribute to the improvement of crops. Most of the failure has come from laboratory-based attempts to ameliorate abiotic stresses. Dealing with biotic stress has been much more successful; the control of pests and weeds is often enabled by transforming crops with single genes, for such genes have little or no influence on a crop’s metabolism. By contrast, abiotic stress varies with the weather; i.e. crops respond systemically, over a range of levels of organisation (e.g. cells, tissues, organs), with many feedbacks and feedforwards. Drought is the most pervasive form of abiotic stress. There are 4600 papers that have searched, ineffectively, for ‘drought resistance’, a term that usually defies useful definition. By contrast, dealing with a measured, limited water supply (e.g. seasonal rainfall), rather than with ‘drought’, has effectively increased water-limited yield through agronomic innovation based on improving water-use efficiency. ‘Salt tolerance’ has similar difficulties; nevertheless, physiological knowledge has revealed effective single genes, in contrast to the failures of empirical gene prospecting. Another important goal has been to increase potential crop yield by exploring mechanistic opportunities to improve photosynthetic efficiency. These attempts have not, so far, succeeded, perhaps because they have rarely broached physiological responses beyond carbon balance, such as metabolic responses to environmental challenges that may affect meristematic development. A major reason for the predominant failure of translational research from laboratory to field is that the peer-review system is too narrow; i.e. reviewers have the same backgrounds as the authors. Effective translation will require the addition of reviewers who can assess the pathway from laboratory to field.
The role of NO in plant response to salt stress: interactions with polyamines
Authors: Napieraj Natalia , Reda Małgorzata , Janicka Małgorzata
Published: June 2020

Soil salinity is a major abiotic stress that limits plant growth and productivity. High concentrations of sodium chloride can cause osmotic and ionic effects. This stress minimises a plant’s ability to uptake water and minerals, and increases Na+ accumulation in the cytosol, thereby disturbing metabolic processes. Prolonged plant exposure to salt stress can lead to oxidative stress and increased production of reactive oxygen species (ROS). Higher plants developed some strategies to cope with salt stress. Among these, mechanisms involving nitric oxide (NO) and polyamines (PAs) are particularly important. NO is a key signalling molecule that mediates a variety of physiological functions and defence responses against abiotic stresses in plants. Under salinity conditions, NO donors increase growth parameters, reduce Na+ toxicity, maintain ionic homeostasis, stimulate osmolyte accumulation and prevent damages caused by ROS. NO enhances salt tolerance of plants via post-translational protein modifications through S-nitrosylation of thiol groups, nitration of tyrosine residues and modulation of multiple gene expression. Several reviews have reported on the role of polyamines in modulating salt stress plant response and the capacity to enhance PA synthesis upon salt stress exposure, and it is known that NO and PAs interact under salinity. In this review, we focus on the role of NO in plant response to salt stress, paying particular attention to the interaction between NO and PAs.
Sea catfishes (Ariidae) feeding on freshwater floodplains of northern Australia
Authors: Pusey Bradley J. , Jardine Timothy D. , Bunn Stuart E. , Douglas Michael M.
Published: June 2020

Flooding of the terminal floodplains of northern Australian rivers provides a greatly expanded, productive habitat accessed by both freshwater and estuarine fishes. This study aimed to determine the extent to which sea catfishes (Ariidae) make use of floodplains and the reasons for doing so (i.e. spawning, feeding). Nine species were collected from floodplains and adjacent distributaries of the Mitchell and Flinders rivers; floodplain use was largely restricted to freshwater species. Evidence of prior wet season spawning was recorded for some species, and mesenteric lipid deposits indicated that fish were in good condition. However, little evidence of spawning on floodplains was found. Stomach content analysis and stable isotope analysis indicated dietary partitioning, particularly between freshwater and estuarine species, but also within freshwater species, and indicated that some species were responsive to variations in food availability. Isotope analyses suggest extensive movement between freshwater, estuarine and marine habitats at different life history stages for the catfish assemblage studied. Terminal floodplains of northern Australian rivers provide important temporary habitat for adult sea catfishes to feed upon, but do not appear to be used as spawning grounds.
A comparison of an environmental impact assessment (EIA) vertebrate fauna survey with a post-approval fauna salvage program: consequences of not adhering to EIA survey guidelines, a Western Australian example
Authors: Thompson Graham G. , Thompson Scott A.
Published: June 2020

The Western Australian Environmental Protection Authority (EPA) has issued written guidance on its expectations for terrestrial vertebrate fauna surveys to support environmental impact assessments (EIA). We report on one of the few circumstances where a direct comparison of the results from an EIA vertebrate fauna survey, that did not, in our opinion, appear to conform with the EPA’s guidance statement expectations but was seemingly accepted by the EPA, and a comprehensive terrestrial vertebrate fauna salvage program were undertaken at the same site. This has enabled us to comment on the consequences of not undertaking a survey that complies with the EPA’s expectations. Excluding incursions by non-local species, bats and avian fauna, ~33% of terrestrial vertebrate fauna species recorded during the fauna salvage program were not reported as being present in the EIA survey. The relative abundance of various species differed appreciably between the fauna salvage program and the EIA survey, and an endangered species present in the project area was not identified as likely to occur. We believe these differences occurred because of a single-season EIA survey, insufficient trapping effort, a failure to survey an important fauna habitat, the presumption that a threatened species would be absent due to a lack of local records and records in the available habitat types. A comprehensive review and rewrite of the outdated Western Australian EPA vertebrate fauna survey guidelines and a requirement for proponents and environmental practitioners to meet (or exceed) the revised guidelines are the recommended outcomes.
Three-dimensional structural interrelations between cells, extracellular matrix, and mineral in normally mineralizing avian leg tendon
Authors: Zou Zhaoyong , Tang Tengteng , Macías-Sánchez Elena , Sviben Sanja , Landis William J. , Bertinetti Luca , Fratzl Peter
Published: June 2020

The spatial-temporal relationship between cells, extracellular matrices, and mineral deposits is fundamental for an improved understanding of mineralization mechanisms in vertebrate tissues. By utilizing focused ion beam-scanning electron microscopy with serial surface imaging, normally mineralizing avian tendons have been studied with nanometer resolution in three dimensions with volumes exceeding tens of micrometers in range. These parameters are necessary to yield sufficiently fine ultrastructural details while providing a comprehensive overview of the interrelationships between the tissue structural constituents. Investigation reveals a complex lacuno-canalicular network in highly mineralized tendon regions, where ∼100 nm diameter canaliculi emanating from cell (tenocyte) lacunae surround extracellular collagen fibril bundles. Canaliculi are linked to smaller channels of ∼40 nm diameter, occupying spaces between fibrils. Close to the tendon mineralization front, calcium-rich deposits appear between the fibrils and, with time, mineral propagates along and within them. These close associations between tenocytes, tenocyte lacunae, canaliculi, small channels, collagen, and mineral suggest a concept for the mineralization process, where ions and/or mineral precursors may be transported through spaces between fibrils before they crystallize along the surface of and within the fibrils.
Large enhancement of thermoelectric performance in MoS
2
/
h
-BN heterostructure due to vacancy-induced band hybridization
Authors: Wu Jing , Liu Yanpeng , Liu Yi , Cai Yongqing , Zhao Yunshan , Ng Hong Kuan , Watanabe Kenji , Taniguchi Takashi , Zhang Gang , Qiu Cheng-Wei , Chi Dongzhi , Neto A. H. Castro , Thong John T. L. , Loh Kian Ping , Hippalgaonkar Kedar
Published: June 2020

Significance

The study of correlated phenomena in 2D semiconductors opens up new pathways toward understanding and engineering material functionalities (such as thermoelectrics) in easily accessible van der Waals solids. Local structural defects such as vacancies inevitably exist in natural as well as synthetic TMD crystals and have been predicted to serve as magnetic impurities capable of enhancing the strongly correlated effect. Herein we discover unusual thermoelectric behavior in sulfur vacancy-enriched MoS
2
by rationally selecting
h
-BN as the substrate. We demonstrate that the thermoelectric transport properties can be strongly manipulated by vacancy-induced Kondo hybridization. A significant enhancement of thermoelectric power factor by two orders of magnitude is achieved in the MoS
2
/
h
-BN device.
Writing and language learning
Authors: Manchón Rosa M.
Published: June 2020

This introductory chapter serves two main purposes. One is to contextualize the book within the
larger professional discussion, which entails a look back approach in order to provide a synthetic review of key
milestones and developments in the study of writing as a site for language learning. The second aim is to introduce
readers to the aims, structure, and contents of the book. To this end, I (a) outline the key elements of the various
contributions to the book and the way in which they are framed in a common research agenda; (b) describe the
interconnection among contributions and the internal coherence of the volume; and (c) advance the way in which the
book attempts to move theory and research forward.
Effects of task repetition with the aid of direct and indirect written corrective feedback
Authors: Amelohina Victoria , Nicolás-Conesa Florentina , Manchón Rosa M.
Published: June 2020

This study sheds light on the learning affordances of task repetition in writing by analyzing the
effects of exact task repetition (2 iterations of the same task) and procedural task repetition (2 task types, each
one performed twice over 6 months) aided with written corrective feedback (WCF). The participants were 19 EFL students
enrolled in an out-of-school instructional program. Two sequences of direct and indirect WCF were implemented and
potential differences in terms of CAF measures of the texts produced in a new iteration of the task and across tasks
and time were examined. Results showed linear and non-linear effects of task repetition with WCF on diverse components
of CAF, as well as a differential appropriation of indirect WCF across time. Theoretical and methodological
implications for the learning affordances of task repetition in the environment of writing are drawn.
A mixed-methods approach to exploring the L2 learning potential of writing versus speaking
Authors: Zalbidea Janire
Published: June 2020

The study reported in this chapter investigated the extent to which task modality can impact L2
learners’ (a) noticing of the target form, (b) target form incorporation, and (c) perceptions of task-induced demands
in a grammar-focused task. Using a mixed-methods approach, three sources of information were examined: (a) stimulated
recall protocols, (b) learners’ task performance, and (c) subjective post-task questionnaires. Although both task
modality conditions led to substantial noticing and form incorporation, along with similar ratings of task demands,
participants in the writing condition were more accurate in incorporating the target form into their own output.
Findings are discussed in terms of their implications for the L2 learning potential of writing versus speaking and the
contributions of mixed-methods approaches to the study of task modality in SLA.
Writing on history in a Content and Language Integrated Learning (CLIL) context
Authors: Whittaker Rachel , McCabe Anne
Published: June 2020

In this chapter we attempt to answer Manchón and Williams’ (2016, p. 580) question as to “how language and writing develop in content-based instruction and CLIL
programs” as a key concern in the study of writing as a site for language learning. Our longitudinal study from a CLIL
context traces students’ development in writing in English by analyzing a key feature of disciplinary literacy,
grammatical metaphor (GM), created through nominalizations and abstract nouns. Data for this study consists of 64
texts by the same 16 students, on a topic from the history syllabus, collected yearly over the four years of
obligatory secondary education. In the data we identified and analyzed just under 1,500 instances of GM. Results
showed a significantly higher use and greater accuracy of GM in second cycle texts. Given the role of writing in
learning subject discourses, the chapter closes by reflecting on the implications of these findings for practice and
for research directions for writing in CLIL contexts.
Elucidation of colon-protective efficacy of diosgenin in experimental TNBS-induced colitis: inhibition of NF-κB/IkB-α and Bax/Caspase-1 signaling pathways
Authors: Tang Xiaobo , Huang Gengzhen , Zhang Tao , Li Shiqing
Published: June 2020

The aim of present investigation was to elucidate the unrevealed beneficial role of diosgenin against an experimental model of TNBS (2,4,6-trinitrobenzenesufonic acid)-induced ulcerative colitis (UC). Colitis was induced in Sprague-Dawley rats by intrarectal administration of TNBS (in 50% ethanol). Then animals were treated with diosgenin (50, 100, and 200 mg/kg) for 14 days. Various biochemical, behavioral, molecular, and histological analysis was performed. Diosgenin significantly decreased (p < 0.05) TNBS-induced elevated colonic oxido-nitrosative damage, myeloperoxidase, hydroxyproline, mRNA expressions of proinflammatory cytokines (TNF-α, IL-1β, IL-6, and IFN-γ) and inflammatory markers (iNOs and COX-2) induced by TNBS. Western blot analysis relevated that TNBS-induced up-regulated protein expressions of NF-κB, IκBα, Bax, and Caspase-1 were markedly decreased (p < 0.05) by diosgenin treatment. It also markedly ameliorated the histological insults induced in the colon by TNBS. In conclusion, diosgenin exerts its colon-protective efficacy probably through the inhibition of NF-κB/IkB-α and Bax/Caspase-1 signaling pathways to experimental TNBS-induced ulcerative colitis.

Abbreviations

ANOVA: Analysis of variance; 5-ASA: 5-aminosalicylic acid; Bax: Bcl-2-associated X protein; COX-2: Cyclooxygenase-2; DAI: Disease Activity Index; DMSO: Dimethyl sulfoxide; GAPDH: Glyceraldehyde 3-phosphate dehydrogenase; GSH: Glutathione; HP: Hydroxyproline; IAEC: International Animal Ethics Committee; IBD: Inflammatory Bowel Disease; IBS: Inflammatory Bowel Syndrome; IL’s: Interleukin’s; IFN-γ: Interferon-gamma; IκBα: nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor-alpha; iNOs: Inducible nitric oxide synthase; LTB4: Leukotriene B4; MDA: Malondialdehyde; MPO: Myeloperoxidase; NO: Nitric Oxide; NF-κB: Nuclear Factor-κB; ROS: Reactive Oxygen Species; SOD: Superoxide Dismutase; TNBS: Trinitrobenzene Sulfonic Acid; TNF-α: Tumor necrosis factor-α
A comparison of the time constant of the cerebral arterial bed using invasive and non-invasive arterial blood pressure measurements
Authors: Uryga Agnieszka , Kaczmarska Katarzyna , Burzyńska Małgorzata , Czosnyka Marek , Kasprowicz Magdalena
Published: June 2020

Objective: The time constant of the cerebral arterial bed (τ), which is an index of brain haemodynamics, can be estimated in patients using continuous monitoring of arterial blood pressure (ABP), transcranial Doppler cerebral blood flow velocity (CBFV) and intracranial pressure (ICP) if these measures are available. But, in some clinical scenarios invasive measurement of ABP is not feasible. Therefore, in this study we aimed to investigate whether invasive ABP can be replaced with non-invasive ABP, monitored using the Finapres photoplethysmograph (fABP). Approach: Forty-six recordings of ICP, ABP, fABP, and CBFV in the right and left middle cerebral arteries were performed daily for approximately 30 min in 10 head injury patients. Two modelling approaches (constant flow forward [CFF, pulsatile blood inflow and steady blood outflow] and pulsatile flow forward [PFF, where both blood inflow and outflow are pulsatile]) were applied to estimate τ using either invasive ABP (τCFF, τPFF) or non-invasive ABP (fτCFF, fτPFF). Main results: Bland–Altman analysis showed quite poor agreement between the fτ and τ methods of estimation. The fτ method produced significantly higher values than the τ method when calculated using both the CFF and PFF models (p < .001 for both). The correlation between fτCFF and τCFF was moderately high (r
s = 0.63; p < .001), whereas that between fτPFF and τPFF was weaker (r
s = 0.40; p = .009). Significance: Our results suggest that using non-invasive ABP for estimation of τ is inaccurate in head injury patients.
The role and importance of standards in cost optimization and increased productivity and quality in constructing health centers
Authors: Balasbaneh A T , Khaleghi S J , Abidin A R Z , Ramli M Z , Marsono A K
Published: June 2020

Standardization of building process in medical sectors has provided the ground for specialization levels, ensuring the future buildings will have better quality. The life span of Health Centers in Iran is only one quarter of same building in other countries, which leads to extra cost for both structure and non-structure (hospital facilities & equipment) and So far, there are no approved regulations to make health care spaces. The aims of this research are reducing the cost of building, facilities and equipment and increasing productivity implies the provision of standard spaces in which the facilities are optimized by proposing Quality management model. This research has discussed the deficiency of building regulations in healthcare sector. The interviews accomplished for collecting data about defects in construction of health center and hospital. The primarily result shows that the budget estimates are not correct, design is done poorly, and studies are not accurate, so long construction time can cause a depreciation of structures. Due to the increasing need of society for healthcare spaces and their high level of construction, standard regulations should be regarded in cost optimization and increasing productivity and quality in order to maintain national assets for future generations. Finally, based on requirement a model is suggested for improving current practice definition and revision of existing laws for medical spaces. The model has been divided into ten categories namely: planning, organize, communicate, substructure, education, leading the process, control, predict variation, accessory measures and finally documentation.
Implementation of Building Information Modeling for Construction Clash Detection Process in the Design Stage: A Case Study of Malaysian Police Headquarter Building
Authors: Kermanshahi Emad Kasra , Tahir Mahmood Bin Md , Shukor Lim Nor Hasanah Abdul , Balasbaneh Ali Tighnavard , Roshanghalb Shervin
Published: June 2020

The Malaysian government motivates constructor companies to use Building Information Modeling (BIM) on their projects because it can dominate problems such as design error, delay, and construction-overrun costs. This research also assesses the effect of BIM in the design phase of the construction process and how this technology can detect all existing clash in construction plans during the design phase. The research was carried out through a case study that contains an architectural, structural, and Mechanical, Electrical and Plumbing (MEP) BIM models and their following clash detection. The current study implemented Autodesk Revit and Autodesk Navisworks Manage as BIM tools to develop features to simplify and automatically clash detection process. The result from the case study analysis revealed that BIM is an appropriate tool for detecting clashes among the building elements. Therefore, constructability issues can be determined earlier during the design phase before the construction phase begins, controlling project cost, time, and having a seamless design to produce a better building.
Influence of Worker’s Attitude and Communication Skill towards Safety Performance in Construction Site
Authors: Zainol N Z , Mohd Zahid M Z A , Ahmad M M , Zailani Z N , Ab Manaf M B H
Published: June 2020

The construction site is one of the most hazardous working places with numerous sources of hazards and potentially high risk to deals with. Typically, the main sources of hazards are unsafe condition and unsafe act by the human. Eventually, both sources related to human errors which potentially have an effect on the performance of the site. To reveals the underlying, this study aims to determine the influential factors that governed the success of safety performance of a construction site. The study involved a self-administered three-part questionnaire among the construction personnel. Part A measures the workers’ attitude and safety performance while Part B on communication skills. The respondents randomly selected from construction sites range from school building and infrastructure renovation. The sample size was 113. From the survey, it was found that the most influential factor was the worker’s attitude and followed closely by communication skills. Suggestion and recommendations on equipment design and improved work practices and procedures to improve efficiency and productivity of construction workers were proposed. Management was urged to get their workers better informed about safety matters.
Durability Property of Oil-Palm-Boiler Clinker Lightweight Concrete Based on Water Absorption Test
Authors: Lee Jin Chai , Shafigh Payam , Lee See Kim
Published: June 2020

Utilizing waste material in the construction industry is an effective way to protect the environment and minimize construction cost. Oil-palm-boiler clinker (OPBC) is a waste material obtained by the burning off solid wastes of the palm oil industry during the process of palm oil extraction. This study presents an investigation on the use of OPBC as coarse aggregate in a grade 40 conventional concrete when normal coarse aggregate was fully substituted (by volume) with this porous and lightweight aggregate. Workability of concrete was assessed based on slump test. The development of compressive strength up to 56 days as well as initial and final water absorption were measured. Test results showed that full substitution of normal coarse aggregate with OPBC reduced workability, compressive strength and density of the concrete. However, OPBC concrete has still good workability for casting and also practical favorable 28-day compressive strength. Water absorption test results revealed that OPBC concrete could be considered as good quality concrete in term of durability property.
Mechanical performance of engineered cementitious composite containing crumb rubber at elevated temperature
Authors: Adamu Musa , Mohammed Bashar S , Woen Ean Lee , Yen Lee Yin , Bala Nura
Published: June 2020

The growing amount of waste tires has raised ever-increasing environmental concern with the development of the automobile industries. Therefore, utilization of crumb rubber in Engineered Cementitious Composite (ECC) has attracted attention in the construction industry. During elevated temperature, the crumb rubber (CR) melts and creates escape routes for build-up pressure due to moisture in the matrix. This research reports the influence of crumb rubber on the residual compressive strength of ECC after exposure to elevated temperature up to 1000°C. The CR-ECC mixes were developed for utilizing crumb rubber in the percentage of 0%, 1%, 3% and 5%. The CR-ECC fresh mixtures were cast into 50 mm cube moulds and cured for 28 days. The samples were preconditioned and exposed to elevated temperature (23°C, 100°C, 200°C, 300°C, 400°C, 500°C, 600°C, 700°C, 800°C, 900°C, 1000°C) for 1-hour duration. Afterward, the samples were evaluated for residual compressive strength. However, there was no explosive spalling recorded in all the specimens used for the experiment.
Sound absorption of lightweight brick containing expanded polystyrene beads and palm oil fuel ash
Authors: Adnan S H , Kamarulzaman N A , Mohd Sari K A , Osman M H , Jamellodin Z , Abdul Hamid N A , Alisibramulisi A , Abdul Roni N , Mohd Yassin N I , Wahee Anuar M N A
Published: June 2020

Bricks are considered as important and strongest materials being used over the years. Commonly, bricks are made of clay mineral and usually used in construction of building wall. The purpose of this study is to assess the effectiveness of palm oil fuel ash (POFA) and expanded polystyrene beads (EPS) as a brick and its suitability as sound absorption material. POFA is used as partial replacement of cement while EPS as partial replacement of sand in the mortar mixture. Various percentages of EPS and POFA have been used which include 0%, 20%, 30%, 40% and 50% as sand replacement and from 0%, 5%, 10%, 15%, 20% and 25% as cement replacement respectively. Sound absorption tests were conducted using impedance tube. From this study, it has been identified that for sound absorption test, lowest result recorded is at maximum 25% POFA replacement with 50% EPS replacement with 0.011 sound absorption coefficient at frequency of 3500 Hz. The best sound absorption coefficient recorded is 0.998 at frequency of 250 Hz for sample with 0% EPS and 20% POFA replacement. It can be recognized that the brick produced have the excellent sound absorption.
Development of lightweight fire resistant sandwich panel
Authors: Beh J H , Yew M C , Saw L H
Published: June 2020

Fire resistant panel is one of the crucial element used to construct building components such as fire partition wall, fire door and ceiling. These fire resistant building components function as passive fire protection method to prevent the spread of smoke and fire, and to allow emergency escape of dwellers. Current challenges associated with existing fire resistant panels are heavy, labor and time inefficient. In this research fire resistant sandwich panels which are lighter in density were invented without compromising the fire resistant performance. Three fire resistant sandwich panels with various thickness were produced for two hours fire rated testing. Fire resistant sandwich panels were fabricated using respective mix proportion of vermiculite and consolidated with intumescent binder via molding techniques. Temperature profiles of fire resistant panels were recorded, plotted and analyzed. Fire resistant sandwich panel with optimum outcomes was determined by density, fire resistant performance, heat transmission rate, adhesion strength and flexural strength. Fire resistant sandwich panel Z obtained the best results in overall. Fire panel Z achieved a maximum temperature at only 83.2 ºC in the Bunsen burner test, indicating a higher fire resistivity with lower heat transmission rate. Panel Z had the highest flexural strength and better fire endurance and yet with the lowest density of 578.98 kg/m3. This research revealed formulation of fire-resistant sandwich panel was the key manipulating factor to density and fire resistivity.
Effect of Effective Microorganisms (EM) on concrete performance
Authors: Mohammed S A , Rahim N L , Roslan M A
Published: June 2020

Concrete technology is life-long research, that strives to discover the best additives or admixtures that are able to produce good concrete in terms of physical, chemical and mechanical properties in a more economical, sustainable, environmental friendly and obtainable. This study focuses the effect of different percentages of EM toward strength of concrete. The compressive strength test was carried out to analyse these properties by using the concrete cubes with size 100 mm x 100 mm x 100 mm. These concrete mixes were tested at different ages which are 7, 14 and 28 days. Effective microorganism (EM) replacement percentages are 5%, 10% and 15% and the strength of concrete with EM replacement will be compared with the control sample. All the cubes were cured by immersed in the water for curing process before the compressive strength tests were conducted. The finding shows that the workability degree of EM mixture is similar with the conventional mixture. The compressive strength increase with the increment of EM content. The results shows that 10% of EM could be the optimum value of water replacement in concrete production to improve strength and durability.
Potential use of foam in the production of lightweight aggregate (LWA) and its performance in foamed concrete
Authors: Mohamad Ibrahim N , Ismail K N , Che Amat R , Rahim N L , Nazmi N
Published: June 2020

This paper discusses about the production and characteristic of lightweight bubble aggregate and foamed concrete. Lightweight aggregates (LWA) are produced by mixing an appropriate amount of foam and ordinary Portland cement and pelletized into assigned size and shape. Then, the characteristics of LWA are identified to ensure that aggregate produced can be categorized into LWA with acceptable qualities. For the foamed concrete, its performances are tested and studied by selecting five different percentages for partial substitution of LWA as coarse aggregate. Main aim of the research is to identify the characteristic of lightweight foamed concrete such as density, water absorption, aggregate impact value (AIV), compressive strength after using LWA as an alternative material for construction industry. This aim also in parallel to main idea of reducing the usage of natural coarse aggregate which is granite that is facing serious depletion. Three different percentages of concrete mixtures using LWA have been prepared that consist of 25% and 50% of LWA together with control sample that contained 100% natural coarse aggregate. These three different mixes are produced manually where the mortars, foam, granite and LWA were mixed together in mixer. The samples have undergone several testing including density test, water absorption test and compression test. Microstructure of the samples also was examined using SEM. From the results obtained, foamed concrete that were produced with 25% substitution of LWA showed the highest compressive strength of 10.74 MPa with density of 1735 kg/m3. In conclusion, LWA have shown promising potential to be used in the foamed concrete production.
Uniaxial compression test of rocks: Review of strain measuring instruments
Authors: Isah B W , Mohamad H , Ahmad N R , Harahap I S H , Al-Bared M A M
Published: June 2020

The importance of uniaxial compression test (UCT) of rocks will never be overemphasized as it plays a vital role in understanding the mechanical properties of rocks for use in civil, mining, and petroleum engineering. Strain response of rocks to external loading is small; it requires a precise instrument to capture the strain with reasonable accuracy. The conventional method is associated with system compliance error, limited precision, and bedding error. Several methods were devised to alleviate these errors. This study embodies the existing strain measuring instruments during UCT of rocks, their principles, features, accuracy, merits, and demerits are correctly scrutinized. The paper serves as a powerful tool that enables the selection of a suitable instrument accordingly. It is hoped that the study will encourage more exploration in the area.
Estimation of Unconfined Compression Test (UCT) parameters using digital image analysis
Authors: Ismail Badrul Nizam , Osman Muhammad Hafeez , Mohd Padzil Muhammad Shafiq
Published: June 2020

Digital image analysis is a method of studying digital image for obtaining significant information and has been widely used in engineering field. In this research, digital image analysis is used to estimate related parameters from unconfined compression test. Soil sample is prepared and tested until failure. During testing, vertical deformation are recorded manually, and video are captured. Static images are extracted from the video and analysis on those images are performed. The measurement from digital images are compared with manual measurement. It was found that, digital image analysis on sample produce close result when compared with manual measurement. This suggest that this method might be suitable as an alternative for manual measurement. Method for determining Poisson’s ratio using digital image is also proposed.
The effect of coal bottom ash as a replacement on subgrade strength
Authors: Ahmad M M , Zainol N Z
Published: June 2020

Coal Bottom Ash (CBA) which is one of coal combustion product (CCPs) obtained from thermal power plant will negatively affect the ecological system which human health ultimately depends on. The increase in demands for landfill requirements and the limitations natural aggregates is quite disturbing unless the new alternative to cut the usage of natural aggregates is found. Therefore, this paper present the laboratory investigation work to improve the strength of subgrade by the replacement of CBA with different percentage varies (0%, 15%, 30% & 40%) by weight. California Bearing Ratio (CBR) test is carried out to obtain the optimum percentage replacement CBA and then some physical which are particle size distribution, Atterberg limit test, specific gravity test and compaction test also carried out to observe the mechanical properties of optimum sample. The optimum percentage of CBA replacement obtained is 40.65% at 30% CBA replacement compared to 17.99% of subgrade soil alone. The moisture dry-density of unmodified soil sample is higher (1.99Mg/m3, 15.34%) than optimum sample (1.95Mg/m3, 10.2%). Moreover, 30% CBA replacement resulted in intermediate plasticity than the subgrade soil which is highly plastic. In conclusion, strength of subgrade soil is highest at 20-30% of CBA replacement.
Punching shear behavior of rubberized concrete slab
Authors: Safiee Nor Azizi , Alosta Moad Mohamed , Mohd Nasir Noor Azline , Bakar Nabilah Abu
Published: June 2020

Punching shear of flat slabs made from normal concrete is a local, brittle failure that may occur before the ductile flexural failure. Since the concrete technology introduced alternative materials into concrete to promote the sustainability by using recycle material such as agriculture waste and industrial by product, the quality of this concrete need to be investigate further in all aspect. Therefore, this study is initiated to investigate the performance of concrete containing rubber to be used as structural element. This study is investigated the behavior of rubberized concrete flat slab subjected to the punching load. The effect of rubberized concrete and different slab thickness to the punching shear strength is main consideration in this investigation. The study is started by evaluating the mechanical properties of rubberized concrete such as compressive strength, flexural strength and splitting tensile strength. In comparison to normal concrete, the mechanical properties of rubberized concrete shown a reduction in compressive strength and increase in flexural strengths and split tensile strength. The performance of rubberized flat slab is observed in term of punching shear strength, critical perimeter and displacement by using experimental approach. Punching shear strength and development of crack within critical perimeter are observed during experimental test. Punching shear strength produced by experiment test is compared to values obtained by established equations from EC2 and ACI 813. From this comparison, it is indicated that the equations are over predicted the punching shear strength in the range of 12 – 72 %. Rubberized concrete slab exhibited ductile failure and underwent significant displacement before reaching punching fracture. Critical perimeter produced by rubberized concrete slab also extended more than produced in the normal concrete in the range of 34 - 75%. The punching shear strength of rubberized concrete slab also exhibited a significant reduction in punching shear resistance compared to normal concrete for the similar slab thickness. As conclusion, the rubberized concrete produced better critical perimeter at the lower punching shear resistance.
Seismic vulnerability assessment in Kota Kinabalu, Sabah
Authors: Jainih V , Harith N S H
Published: June 2020

Sabah has witnessed an increasingly low to moderate number of seismic activities throughout the years due to active Mensaban and Lobou-Lobou faults lines. Vulnerability level of older buildings in Sabah, designed and built on the basis of older codes of practice poses a significant threat to life safety and structural capacities of the existing buildings. This paper presents a framework of preliminary seismic vulnerability assessment of existing buildings in Kota Kinabalu. Building stocks include major government buildings and facilities, residential, educational, institutional, business as well as public buildings. The objective of this study is to evaluate and determine the vulnerability of existing buildings in seven major areas near Kota Kinabalu district using Rapid Visual Screening (RVS) scoring method based on FEMA154 (2002). The rapid visual score indicates that from the total two-hundredth-fifty (250) buildings assessed, (60.4%) are categorized as unsafe buildings and are strongly recommended for further evaluation and detailed analysis whereby modelling of structure is necessary.
Assessment on the performance of flat slab under service load and ultimate load using ABAQUS
Authors: Salehuddin S , Zaini S S , Nik Azizan N Z , Rahim N L , Mohamad Ibrahim N , Abdul Rahim M , Mamat Ghani A
Published: June 2020

The research carried out to study on the performance of the flat slab under the design load. The design loads consist of service load, 14.68 kN/m2 and the ultimate load, 21.31 kN/m2. The justification on the design load was from the car park. The Three-Dimensional (3D) Finite Element Analysis (FEA) were conducted to investigate their failures modes with the appropriate modelling of element, mesh and concrete parameter. The size of flat slab was 1200 mm x 1200 mm x 175 mm while the material parameters were the Grade 25 for concrete and S275 for steel. It is found that the improvements more than 20% to the strength of model flat slab with shear reinforcement. Another outcome of the study indicated that the punching shear location using the FEA was less than 250 mm from column perimeter which is within the two times the depth (2d) from column face as proposed by the Eurocode 2: Design of Concrete Structures.
Economic feasibility of smart city power generation from biogas produced by food waste in Malaysia via techno-economic analysis
Authors: Hanif M , Hesam N M , Akhiar A , Fazril I , Zamri M F M A , Shamsuddin A H
Published: June 2020

Malaysia is one of the fastest growing country towards modernization and technological advancement. The country population increased along with that with estimated population of 32.45 million in 2019 with annual growth rate of 1.6%. Rapid industrialization and urbanization lead to adverse effect on the environment from the increasing of waste generated. It is projected that Malaysia is expected to generate 49,670 tons of waste per day with annual increment of 5.19%. Current method of waste management is being dumped daily in unsanitary landfill. In Malaysia, 50% of waste generated is organic waste where disposal in landfill will generate methane gas emission. Total of 310,220 tons of methane gas was generated in peninsular in year 2010 and projected to reach 370,000 tons in 2020, an increase of 19.3% in 10 years. The government has planned to phase out landfills as waste-management method and to substitute with more energy efficient and environmental friendly method such as waste-to-energy and bio-digestion. To realize the government plan, economic analysis will be conducted on biogas production for electricity generation to be utilized in Malaysia smart city where one of the main criteria is sustainability and environmental friendly. This paper will give insight on economic feasibility of biogas production from municipal food waste for electricity generation to be utilized in existing and new township. This will include the estimation of capital cost required, unit production cost and payback period.
Biogas as alternative SOFC fuel: Research and implementation
Authors: Arifin N A , Steinberger-Wilckens R , Shamsuddin A H
Published: June 2020

With the current environment situation and the inclining demand of energy globally, SOFC fits as the perfect solution with up to 90% efficiency and ultra-low emission. Adaptation of this advanced green technology with biogas is still limited despite of the availability of the fuel. The main aim of this paper is to bring into attention the possibility of this technology implementation in agriculture-based country utilising the readily available biogas and as reliable renewable energy option. This paper briefly reports on the possible reaction in the SOFC fuelled by biogas compared to the operation with hydrogen, the material suitability and modification to tolerate biogas fuel; and finally, the demonstration of biogas fuelled SOFC with brief review on economic studies. This paper concludes that SOFC fuelled by biogas is technology and economically feasible with payback period as short as 7.7 years when paired with micro gas turbine.