bluuebunny/crossref_metadata_2025 huggingface dataset:
Two-dimensional analysis of the nonuniform quantum yields of multiple quantum wells for AlGaN-based deep-ultraviolet LEDs grown on AlN templates with dense macrosteps using cathodoluminescence spectroscopy
Authors: Nagasawa Yosuke , Sugie Ryuichi , Kojima Kazunobu , Hirano Akira , Ippommatsu Masamichi , Honda Yoshio , Amano Hiroshi , Akasaki Isamu , Chichibu Shigefusa F.
Published: December 2019

AlGaN-based deep-ultraviolet light-emitting diodes (LEDs) incorporating uneven multiple quantum wells (MQWs) with inclined and terrace zones, which were fabricated on an AlN template with dense macrosteps, have exhibited a high internal quantum efficiency (IQE). To investigate the microscopic structure of uneven MQWs, cathodoluminescence (CL) mapping characterization was carried out, and the maps of the CL intensity at 300 K relative to that at 38 K were obtained for uneven MQWs that targeted 265 and 285 nm LEDs. At an electron beam current of less than 1.0 nA, the signals from inclined and terrace zones of the uneven MQWs were confirmed to satisfy the nonsaturated excitation condition at 300 K. Nonradiative recombination (NR) was insufficiently frozen even at 38 K, specifically on the terraces in the 265 nm MQW, suggesting high concentrations of NR centers due to point defects (PDs). In contrast, NR in the 285 nm MQW at 38 K was closer to freeze-out. The concentration of PDs in the 285 nm MQW was likely to be lower than that in the 265 nm MQW. Finally, the ratios of the CL intensity at 300 K to those at 38 K were mapped, demonstrating an approach to creating an approximate map of IQE. The values in the CL intensity ratio maps are discussed by considering the analytical error factors. The results support the model of localized current injection through Ga-rich stripe zones in the n-AlGaN cladding layer.
Mutual neutralization in collisions of H+ with Cl−
Authors: Larson Åsa , Hörnquist Johan , Hedvall Patrik , Orel Ann E.
Published: December 2019

The cross section and final state distribution for mutual neutralization in collisions of H+ with Cl− have been calculated using an ab initio quantum mechanical approach. It is based on potential energy curves and nonadiabatic coupling elements for the six lowest 1Σ+ states of HCl computed with the multireference configuration interaction method. The reaction is found to be driven by nonadiabatic interactions occurring at relatively small internuclear distances (R < 6 a0). Effects on the mutual neutralization cross section with respect to the asymptotic form of the potential energy curves, inclusion of closed channels, as well as isotopic substitution are investigated. The effect of spin-orbit interaction is investigated using a semiempirical model and found to be small. A simple two-state Landau-Zener calculation fails to predict the cross section.
Equation-of-state, critical constants, and thermodynamic properties of lithium at high energy density
Authors: Zaghloul Mofreh R. , Hassanein Ahmed
Published: December 2019

High-density lithium plasmas are expected to be generated in the Inertial Confinement Fusion reactor chamber due to energy deposition of the prompt X-rays and ion debris in the first wall. These dense plasmas are encountered in many other applications as well. The design and optimization of such lithium-based applications require information about the thermodynamic properties of Li fluid over a wide range of parameters including the high-energy-density regime. A model that takes into account all essential features of strongly coupled plasmas of metal vapors is developed and used to predict the equation-of-state, critical constants, thermodynamic functions, and principal shock Hugoniot of hot dense lithium fluid. Predictions and computational results from the present model are analyzed and presented and are available in electronic form suitable for use to interested researchers and scientists.
Table-top nuclear magnetic resonance system for high-pressure studies with in situ laser heating
Authors: Meier Thomas , Dwivedi Anand Prashant , Khandarkhaeva Saiana , Fedotenko Timofey , Dubrovinskaia Natalia , Dubrovinsky Leonid
Published: December 2019

High pressure Nuclear Magnetic Resonance (NMR) is known to reveal the behavior of matter under extreme conditions. However, until now, significant maintenance demands, space requirements, and high costs of superconducting magnets render its application unfeasible for regular modern high pressure laboratories. Here, we present a table-top NMR system based on permanent Halbach magnet arrays with a diameter of 25 cm and height of 4 cm. At the highest field of 1013 mT, 1H-NMR spectra of ice VII have been recorded at 25 GPa and ambient temperature. The table-top NMR system can be used together with double sided laser heating setups. Feasibility of high-pressure high-temperature NMR was demonstrated by collecting 1H-NMR spectra of H2O at 25 GPa and 1063(50) K. The change in the signal intensity in a laser-heated NMR diamond anvil cell has been found to yield a convenient way for temperature measurements.
Effect of growth path on carcass and meat-quality traits of Hereford steers finished on pasture or in feedlot
Authors: Ferrinho Adrielle Matias , Peripolli Elisa , Banchero Georgget , Pereira Angélica Simone Cravo , Brito Gustavo , La Manna Alejandro , Fernandez Enrique , Montossi Fabio , Kluska Sabrina , Mueller Lenise Freitas , Berchielli Telma Teresinha , Baldi Fernando
Published: December 2019

The objective of this study was to evaluate the effect of nutritional management during rearing and finishing phases on beef fatty acid composition, and carcass and beef quality traits of Hereford cattle. The study used 240 castrated male calves weaned at 8 months of age, and with an average weight of 170 ± 17 kg. After weaning, the experiment was divided in to three phases in a 4 × 2 factorial design: a 93-day winter period with four treatment groups (on pasture or in feedlot and at high or low feeding levels); a 196-day compensatory-growth phase on pasture; and a finishing phase either on pasture or in feedlot. Animals were slaughtered when each group attained a mean liveweight of 500 kg. The winter growth × finishing management interaction significantly affected hot carcass weight (P = 0.0029). There was no differences observed for feedlot-finished steers, but for pasture-finished steers, those pasture-reared had higher hot carcass weight (kg) than those feedlot-reared (low pasture 256.30 ± 1.60, high pasture 253.72 ± 1.60, low feedlot 249.85 ± 1.66, high feedlot 247.60 ± 1.62). Feedlot-finished steers showed higher (P < 0.05) mean values than pasture-finished steers for ribeye area (55.61 ± 0.69 cm2 vs 53.18 cm2), backfat thickness (8.62 ± 0.32 mm vs 6.21 mm), marbling score (237.97 ± 13.06 vs 171.70) and final pH (5.53 ± 0.02 vs 5.48). Additionally, feedlot-finished steers raised in feedlot during the winter-growth period displayed the heaviest hindquarter cuts. Meat from pasture-finished steers had lower (P < 0.05) shear-force values than from feedlot-finished cattle (2.95 ± 0.18 vs 3.66 ± 0.17 kg), and when reared on either high or low pasture during winter-growth, they showed the highest (P < 0.05) conjugated linoleic acid (cis-9, trans-11) and n-3 polyunsaturated fatty acid concentrations. In conclusion, growing and finishing cattle on pasture improved the carcass yield of retail cuts because of low fat concentration, and improved the nutritional and health value of the beef fatty acid profile.
Rare earth elements as tracers of active colloidal organic matter composition
Authors: Catrouillet Charlotte , Guenet Héléne , Pierson-Wickmann Anne-Catherine , Dia Aline , LeCoz Martine Bouhnik , Deville Sarah , Lenne Quentin , Suko Yasushi , Davranche Mélanie
Published: December 2019

Environmental contextThe origin of organic matter at Earth’s continental surface can be either terrestrial or microbial, and its precise composition can influence its reactivity towards metals. We investigated the potential of rare earth elements to fingerprint the origin of various organic matters through their reactivity and composition. The rare earth element patterns can be useful tools to determine the reactivity and also pristine source of natural organic matter.
AbstractRare earth elements (REEs) have been shown to be efficient tracers of the functional sites and/or complexes formed on humic molecules. In the present study, we test the potential of REEs to be used as tracers of the sources of humic substances (HSs). Three types of organic matter (OM) of terrestrial and microbiological origin were tested. The experiments of REEs binding to the HSs were combined with size-fractionation experiments. The REE patterns were the most fractionated in the <10kDa fraction. For Leonardite humic acid (LHA) and Aldrich humic acid (AHA), the REE patterns were consistent with the REEs binding to strong but low density sites for a low REE/C loading. By contrast, for Pony Lake fulvic acid (PLFA), the REE pattern was similar to the REE pattern developed onto a bacteria cell surface and was attributed to the REEs binding to phosphate surface sites. Fluorescence and elemental analysis of PLFA showed that the <10kDa fraction was the fraction with the stronger microbiological character, which suggested the REEs were probably bound to PLFA through REE-phosphate complexes. Such results therefore provide a new possibility for the use of REEs to assess an OM source without the need to perform numerous or complex analytical methodologies.
Some observations on the biogeochemical cycling of zinc in the Australian sector of the Southern Ocean: a dedication to Keith Hunter
Authors: Ellwood Michael J. , Strzepek Robert , Chen Xiaoyu , Trull Thomas W. , Boyd Philip W.
Published: December 2019

In this study we investigated the distribution of dissolved and particulate zinc (dZn and pZn respectively) and its isotopes in the Subantarctic Zone as part of a Geotraces Process voyage. dZn and pZn depth profiles contrasted each other, with dZn showing depletion within the euphotic zone while pZn profiles showed enrichment. Fitting a power law equation to the pZn profiles produced an attenuation factor of 0.82, which contrasted values for particulate phosphorus, cadmium and copper. The results indicate that zinc has a longer regeneration length scale than phosphorus and cadmium, but shorter than copper. The differential regeneration of pZn relative to that of particulate phosphorus likely explains why dZn appears to have a deeper regeneration profile than that of phosphate. The dZn isotope (δ66Zndissolved) profiles collected across the Subantarctic Zone showed differing profile structures. For one station collected within an isolated cold-core eddy (CCE), δ66Zndissolved showed surface enrichment relative to deep waters. The corresponding pZn isotope profiles within the CCE did not show enrichment; rather, they were subtly depleted in surface waters and then converged to similar values at depth. Zinc isotope fractionation can be explained through a combination of fractionation processes associated with uptake by phytoplankton, zinc complexation by natural organic ligands and zinc regeneration from particulate matter.
Does the fungus causing white-nose syndrome pose a significant risk to Australian bats?
Authors: Holz Peter , Hufschmid Jasmin , Boardman Wayne S. J. , Cassey Phillip , Firestone Simon , Lumsden Lindy F. , Prowse Thomas A. A. , Reardon Terry , Stevenson Mark
Published: December 2019

Abstract ContextPseudogymnoascus destructans is the fungus responsible for white-nose syndrome (WNS), which has killed millions of hibernating bats in North America, but also occurs in bats in Europe and China without causing large-scale population effects. This is likely to be due to differences in species susceptibility and behaviour, and environmental factors, such as temperature and humidity. Pseudogymnoascus destructans is currently believed to be absent from Australia. AimsTo ascertain the level of risk that white-nose syndrome poses for Australian bats. Methods This risk analysis examines the likelihood that P. destructans enters Australia, the likelihood of the fungus coming in contact with native bats on successful entry, and the potential consequences should this occur. Key results This risk assessment concluded that it is very likely to almost certain that P. destructans will enter Australia, and it is likely that bats will be exposed to the fungus over the next 10 years. Eight cave-dwelling bat species from southern Australia are the ones most likely to be affected. ConclusionsThe risk was assessed as medium for the critically endangered southern bent-winged bat (Miniopterus orianae bassanii), because any increase in mortality could affect its long-term survival. The risk to other species was deemed to range from low to very low, owing to their wider distribution, which extends beyond the P. destructans risk zone. Implications Although Australia’s milder climate may preclude the large mortality events seen in North America, the fungus could still significantly affect Australian bat populations, particularly bent-winged bats. Active surveillance is required to confirm Australia’s continuing WNS-free status, and to detect the presence of P. destructans should it enter the country. Although White-nose Syndrome Response Guidelines have been developed by Wildlife Health Australia to assist response agencies in the event of an incursion of WNS into bats in Australia, these guidelines would be strengthened by further research to characterise Australian cave temperatures and hibernating bat biology, such as length of torpor bouts and movement over winter. Risk-mitigation strategies should focus on education programs that target cavers, show-cave managers and tourists, particularly those who have visited regions where WNS is known to occur.
Endogenous retroviruses are associated with hippocampus-based memory impairment
Authors: Sankowski Roman , Strohl Joshua J. , Huerta Tomás S. , Nasiri Elham , Mazzarello Andrea N. , D’Abramo Cristina , Cheng Kai Fan , Staszewski Ori , Prinz Marco , Huerta Patricio T. , Al-Abed Yousef
Published: December 2019

Retrotransposons compose a staggering 40% of the mammalian genome. Among them, endogenous retroviruses (ERV) represent sequences that closely resemble the proviruses created from exogenous retroviral infection. ERVs make up 8 to 10% of human and mouse genomes and range from evolutionarily ancient sequences to recent acquisitions. Studies inDrosophilahave provided a causal link between genomic retroviral elements and cognitive decline; however, in mammals, the role of ERVs in learning and memory remains unclear. Here we studied 2 independent murine models for ERV activation: muMT strain (lacking B cells and antibody production) and intracerebroventricular injection of streptozotocin (ICVI-STZ). We conducted behavioral assessments (contextual fear memory and spatial learning), as well as gene and protein analysis (RNA sequencing, PCR, immunohistochemistry, and western blot assays). Mice lacking mitochondrial antiviral-signaling protein (MAVS) and mice lacking stimulator of IFN genes protein (STING), 2 downstream sensors of ERV activation, provided confirmation of ERV impact. We found that muMT mice and ICVI-STZ mice induced hippocampal ERV activation, as shown by increased gene and protein expression of the Gag sequence of the transposable element intracisternal A-particle. ERV activation was accompanied by significant hippocampus-related memory impairment in both models. Notably, the deficiency of the MAVS pathway was protective against ICVI-STZ–induced cognitive pathology. Overall, our results demonstrate that ERV activation is associated with cognitive impairment in mice. Moreover, they provide a molecular target for strategies aimed at attenuating retroviral element sensing, via MAVS, to treat dementia and neuropsychiatric disorders.
The Justinianic Plague: An inconsequential pandemic?
Authors: Mordechai Lee , Eisenberg Merle , Newfield Timothy P. , Izdebski Adam , Kay Janet E. , Poinar Hendrik
Published: December 2019

Existing mortality estimates assert that the Justinianic Plague (circa 541 to 750 CE) caused tens of millions of deaths throughout the Mediterranean world and Europe, helping to end antiquity and start the Middle Ages. In this article, we argue that this paradigm does not fit the evidence. We examine a series of independent quantitative and qualitative datasets that are directly or indirectly linked to demographic and economic trends during this two-century period: Written sources, legislation, coinage, papyri, inscriptions, pollen, ancient DNA, and mortuary archaeology. Individually or together, they fail to support the maximalist paradigm: None has a clear independent link to plague outbreaks and none supports maximalist reconstructions of late antique plague. Instead of large-scale, disruptive mortality, when contextualized and examined together, the datasets suggest continuity across the plague period. Although demographic, economic, and political changes continued between the 6th and 8th centuries, the evidence does not support the now commonplace claim that the Justinianic Plague was a primary causal factor of them.
Subglacial meltwater supported aerobic marine habitats during Snowball Earth
Authors: Lechte Maxwell A. , Wallace Malcolm W. , Hood Ashleigh van Smeerdijk , Li Weiqiang , Jiang Ganqing , Halverson Galen P. , Asael Dan , McColl Stephanie L. , Planavsky Noah J.
Published: December 2019

Significance

The “Snowball Earth” ice ages featured global ice sheets for millions of years, leading to oceanic anoxia and threatening the perseverance of aerobic life on Earth. Crucially, aerobic eukaryotes survived, possibly including early animals. Iron-rich chemical sediments preserved in glacial deposits offer insights into the synglacial marine redox state. We provide evidence for oxygenated waters near ice sheet grounding lines, where oxic subglacial meltwater would be supplied to the anoxic oceans. The energy released from this mixing of oxic and anoxic waters could have fueled microbial communities and sustained localized aerobic ecosystems. This meltwater oxygen pump may therefore have been critical in the survival and evolution of aerobic eukaryotes during episodes of extreme glaciation.
Magnetoelastoresistance in WTe
2
: Exploring electronic structure and extremely large magnetoresistance under strain
Authors: Jo Na Hyun , Wang Lin-Lin , Orth Peter P. , Bud’ko Sergey L. , Canfield Paul C.
Published: December 2019

Significance

Strain is a widely employed technique to probe and control the electronic properties of quantum materials. Primary examples are studies of the elastoresistance, which describes the change of resistance due to applied strain, that have elucidated the nature of nematicity in iron-based superconductors. In this work, we introduce the measurement of magnetoelastoresistance (MER) and analyze in detail the combined effect of strain, caused by uniaxial stress, and magnetic field on the semimetal

W
T
e

2

. We show that this material exhibits a large MER that is dominated by changes of the electronic structure caused by the elastic deformation. We further demonstrate that MER provides insight into strain-induced modifications of the band structure and transport quantities that goes beyond the zero-field elastoresistance.
Treg-inducing microparticles promote donor-specific tolerance in experimental vascularized composite allotransplantation
Authors: Fisher James D. , Balmert Stephen C. , Zhang Wensheng , Schweizer Riccardo , Schnider Jonas T. , Komatsu Chiaki , Dong Liwei , Erbas Vasil E. , Unadkat Jignesh V. , Aral Ali Mübin , Acharya Abhinav P. , Kulahci Yalcin , Turnquist Heth R. , Thomson Angus W. , Solari Mario G. , Gorantla Vijay S. , Little Steven R.
Published: December 2019

Significance

Vascularized composite allotransplantation (VCA) is an emerging field that is particularly beneficial for select amputees and patients with devastating soft tissue loss that is not amenable to conventional reconstructive surgeries. As with solid organ transplantation, VCA recipients are subjected to a lifelong regimen of antirejection drugs with a well-established sequela. Herein, we report a synthetic, controlled-release microparticle system (referred to as TRI-MP) that aims to locally enrich naturally occurring, suppressive lymphocytes to prevent allograft rejection and promote tolerance. While this study exclusively focuses on VCA, this technology has implications for other conditions characterized by aberrant inflammation.
Metabolite-mediated TOR signaling regulates the circadian clock in
Arabidopsis
Authors: Zhang Nan , Meng Yanyan , Li Xu , Zhou Yu , Ma Liuyin , Fu Liwen , Schwarzländer Markus , Liu Hongtao , Xiong Yan
Published: December 2019

Circadian clocks usually run with a period close to 24 h, but are also plastic and can be entrained by external environmental conditions and internal physiological cues. Two key nutrient metabolites, glucose and vitamin B3 (nicotinamide), can influence the circadian period in both mammals and plants; however, the underlying molecular mechanism is still largely unclear. We reveal that the target of rapamycin (TOR) kinase, a conserved central growth regulator, is essential for glucose- and nicotinamide-mediated control of the circadian period in
Arabidopsis
. Nicotinamide affects the cytosolic adenosine triphosphate concentration, and blocks the effect of glucose-TOR energy signaling on period length adjustment, meristem activation, and root growth. Together, our results uncover a missing link between cellular metabolites, energy status, and circadian period adjustment, and identify TOR kinase as an essential energy sensor to coordinate circadian clock and plant growth.
A gatekeeping function of the replicative polymerase controls pathway choice in the resolution of lesion-stalled replisomes
Authors: Chang Seungwoo , Naiman Karel , Thrall Elizabeth S. , Kath James E. , Jergic Slobodan , Dixon Nicholas E. , Fuchs Robert P. , Loparo Joseph J.
Published: December 2019

Significance

DNA replication is the high-fidelity process by which cells duplicate their chromosomes prior to cell division. Cellular DNA is constantly damaged, and the resulting DNA lesions can block replication, leading to genome instability and cell death. Cells use multiple pathways to resolve stalled replication. Understanding resolution pathway choice is important because some of these pathways are more likely to introduce mutations than others. In bacterial cells, replication stresses, including antibiotic treatment, lead to mutagenesis, which may contribute to the emergence of antibiotic resistance. In this study, we describe a molecular interaction within the
Escherichia coli
replication machinery that plays a crucial role in resolution pathway choice, thereby influencing whether lesion-stalled replication is resolved in an error-prone or error-free manner.
Molecular determinants of chaperone interactions on MHC-I for folding and antigen repertoire selection
Authors: McShan Andrew C. , Devlin Christine A. , Overall Sarah A. , Park Jihye , Toor Jugmohit S. , Moschidi Danai , Flores-Solis David , Choi Hannah , Tripathi Sarvind , Procko Erik , Sgourakis Nikolaos G.
Published: December 2019

The interplay between a highly polymorphic set of MHC-I alleles and molecular chaperones shapes the repertoire of peptide antigens displayed on the cell surface for T cell surveillance. Here, we demonstrate that the molecular chaperone TAP-binding protein related (TAPBPR) associates with a broad range of partially folded MHC-I species inside the cell. Bimolecular fluorescence complementation and deep mutational scanning reveal that TAPBPR recognition is polarized toward the α
2
domain of the peptide-binding groove, and depends on the formation of a conserved MHC-I disulfide epitope in the α
2
domain. Conversely, thermodynamic measurements of TAPBPR binding for a representative set of properly conformed, peptide-loaded molecules suggest a narrower MHC-I specificity range. Using solution NMR, we find that the extent of dynamics at “hotspot” surfaces confers TAPBPR recognition of a sparsely populated MHC-I state attained through a global conformational change. Consistently, restriction of MHC-I groove plasticity through the introduction of a disulfide bond between the α
1
/α
2
helices abrogates TAPBPR binding, both in solution and on a cellular membrane, while intracellular binding is tolerant of many destabilizing MHC-I substitutions. Our data support parallel TAPBPR functions of 1) chaperoning unstable MHC-I molecules with broad allele-specificity at early stages of their folding process, and 2) editing the peptide cargo of properly conformed MHC-I molecules en route to the surface, which demonstrates a narrower specificity. Our results suggest that TAPBPR exploits localized structural adaptations, both near and distant to the peptide-binding groove, to selectively recognize discrete conformational states sampled by MHC-I alleles, toward editing the repertoire of displayed antigens.
Epstein–Barr virus EBER1 and murine gammaherpesvirus TMER4 share conserved in vivo function to promote B cell egress and dissemination
Authors: Hoffman Brett A. , Wang Yiping , Feldman Emily R. , Tibbetts Scott A.
Published: December 2019

The oncogenic gammaherpesviruses, including human Epstein–Barr virus (EBV), human Kaposi’s sarcoma-associated herpesvirus (KSHV), and murine gammaherpesvirus 68 (MHV68, γHV68, MuHV-4) establish life-long latency in circulating B cells. The precise determinants that mediate in vivo gammaherpesvirus latency and tumorigenesis remain unclear. The EBV-encoded RNAs (EBERs) are among the first noncoding RNAs ever identified and have been the subject of decades of studies; however, their biological roles during in vivo infection remain unknown. Herein, we use a series of refined virus mutants to define the active isoform of MHV68 noncoding RNA TMER4 and demonstrate that EBV EBER1 functionally conserves this activity in vivo to promote egress of infected B cells from lymph nodes into peripheral circulation.
A comparison study on mechanical properties of virgin and recycled polylactic acid (PLA)
Authors: Budin S , Maideen N C , Koay M H , Ibrahim D , Yusoff H
Published: December 2019

Huge usage of Polylactic Acid (PLA) has contributed to the high wastes which mainly come from the worn parts. Recycling of the wastes is seen to be a permissible solution to reduce the quantity of wastes in the landfills. This work aims to compare the mechanical properties of virgin and recycled PLA. The recycled material is collected from the waste produces from the injection molding process. The mechanical testing samples for both virgin and recycled materials are prepared using an injection molding process. The results show that the mechanical properties of recycled PLA lower than the virgin PLA. The tensile strength of recycled PLA decreases by 11% as compared to virgin PLA. On the other hand, TRS is also observed drop by 5% for recycled PLA compared to virgin PLA. A similar trend is found in the impact strength and hardness of properties where its impact strength drops by 50% of recycled PLA. For hardness property, it is noted that the hardness decreases by 4% of the recycled PLA. The decreasing value of the mechanical properties is due to thermal degradation of the PLA molecular chain during the injection molding process which has consequently affected the mechanical properties of the recycled PLA.
Quantitative HPLC analysis of flavonoid in three different solvent extracts in leaves of Gynura procumbens
Authors: Adeib Idris S , Markom M , Abd Rahman N , Mohd Ali J
Published: December 2019

In Malaysia, traditional folks call Gynura procumbens as Sambung nyawa or translated as longevity life. The name given might be because of the claim made by them that the leaves extracts seems to be valuable and possesses high theuraphatic potential treatment of various diseases. Extraction of the leaves have been conducted by many researchers to identify the properties for antidiabetic/antihyperglygemic, antihypertensive, antimicrobial, antioxidant, antiimflammatory, antiulcer, anticancer, antiherpes and immunomodulatory. Extracts have been obtained using different solvent. Four alcoholic extracts and one water extract were studied separately. Soxhlet extraction was conducted in the following manner: plant material (3.0 g) was placed in the Soxhlet apparatus. Extraction process was carried out for three hours using 99.9% ethanol, methanol and water as a solvent (250 mL) until the solvent discoloration (3 hours). Yield of extraction techniques was determined by evaporating the solvent under vacuum using rotary evaporator. Previous research on solvent extraction of Gynura procumbens were also compared to whereby the methanol extract obtained by other researcher was 12.2%, ethanol extract with 14.73% and 27.83%. There is also one study extracting Gynura procumbens extracts via water, however the yield is not mentioned. High performance liquid chromatography (HPLC) coupled with ultra violet (UV) detector has been used for the separation and quantification of kaempferol from the Gynura procumbens leaves extract. Reversed phase high performance liquid chromatography separation was performed, using 0.1% phosphoric acid:acetonitrile as eluent in mobile phase. Our results confirm previous reports concerning the presence of several flavonoids.
Strain Softening Prediction Using Normalized Method
Authors: Ahmad J , Md-Noor M J , Md-Jais I B , Rosli M I F , Abdul-Rahman A S , Abdul-Hadi B
Published: December 2019

This study assessed the applicability of normalized method in predicting the stress-strain curve at the strain softening phase. The methodology is based on standard test and easily replicable which is conventional triaxial test. The soil sample from Kuala Terengganu, Malaysia was taken for the test. The drained triaxial test was conducted on four samples with various effective stresses (50, 100, 200 and 300kPa). The results showed that the soil is classified as silty clay with high plasticity. Based from the results, the stress-strain curves indicate strain softening clearly. The normalized method is applied in this study. It is based from Rotational Multiple Yield Surface Framework (RMYSF). However, RMYSF is applied to predict the stress-strain curves for unsaturated soil and limited to strain hardening only. Extension work is conducted to the existing method by predicting the strain softening phase for saturated soil. It can be concluded that normalized method is successfully predicted the strain softening phase of the soil. The main advantage of this method is that it can be applied to predict the soil strength parameter for various effective stresses without having to conduct many tests. Therefore, this method will help to cut the time and cost of testing effectively.
A preliminary study of safety management practices on Pan-Borneo highway construction sites in Kuching, Malaysia
Authors: Anak Ikau R , Rashid A F A , Muhammad W M N W , Wahi N
Published: December 2019

Construction site safety is a vital issue in construction safety management. The causes of accidents in the construction industry, among others are due to individual behaviour, complicated work-site surroundings and inadequate safety supervision at the construction site. The case study, namely Pan-Borneo Highway (PBH), was initiated through the Economic Transformation Programme to transform Malaysia into a high-income nation. The PBH is an option travel mode highway alongside Borneo road linking the states of Sarawak and Sabah with Brunei. The iconic project started from Sematan, Sarawak to Tawau, Sabah. This paper aimed to evaluate the current safety management practices on PBH construction sites in Kuching, Sarawak, as well as to emphasise the significance of road construction safety supervision. Questionnaires were distributed to 30 respondents, and the survey responses were analysed using Statistical Package for Social Science (SPSS) software. The result suggested that the most important safety practices are the provision of Personal Protective Equipment (PPE), followed by accident reporting and maintenance report and provision of safety policy. Proper safety management on the construction site can minimise accidents and protect all parties involved in the construction industry.
The effect of polyethylene terephthalate (road barrier waste) in concrete for rigid pavement
Authors: Hasan D , Juhari N , Rofi M H , Albar A
Published: December 2019

Plastic have become a major problem in solid waste management due to its inability to degrade when they are disposed at landfill site. Approximately 0.80 kg/capita to 1.9 kg/capita of municipal solid waste is generated daily in Malaysia, which is expected to increase annually. Cracking of rigid pavement is the phenomenon where the pavement fails under repetitive loading by a load smaller than the load that can cause failure in single application. Other than that, decrements of the flexural strength due to the lower tensile strength can cause the joint spalling. The larger the load, the smaller will be the number of repetition to cause cracks. In this study paper presents the effect of Polyethene terephthalate (PET) road barrier waste as alternative addition in concrete grade C40 for rigid pavement. The material was obtained from Jabatan Kerja Raya(JKR) Seberang Perai Tengah and it need through cutting process to become fiber with range size about 12mm15mm length and 3mm-5mm width before to be addition into concrete. Four types of concrete mixes with different percentages of PET road barrier fibers which are 0%, 1%, 2% and 3%. Each specimen consist of six cube samples and one beam. The six cubes represent sample at 3 days, 7 days and 28 days. The beam sized 150mm x 150mm x 750mm was only tested on 28 days of curing. The result obtained on the compressive test, 2% of additive PET road barrier in concrete shows the highest result compare to the 0% and 1% additive. Compression test result shows 2% of PET road barrier waste fibers as the optimum percentage of PET road barrier additive with the maximum load of 42.13 MPa.
Investigations on power requirements for industrial compression strategies for Carbon Capture and Sequestration
Authors: Daud N K , Nasuha N , Martynov S , Mahgerefteh H
Published: December 2019

The main purpose of this study is to identify the optimum multistage compression strategies for minimising the compression and intercooler power requirements for pure CO2 stream. An analytical model based on thermodynamics principles is developed and applied to determine the power requirements for various compression strategies for pure CO2 stream. The compression options examined include conventional multistage integrally geared centrifugal compressors (option A), supersonic shockwave compressors (option B) and multistage compression combined with subcritical (option C) and supercritical liquefaction (option D) and pumping. In the case of determining the power demand for inter-stage cooling and liquefaction, a thermodynamic model based on Carnot refrigeration cycle is applied. From the previous study by [1], the power demand for inter-stage cooling duty was assumed to have been neglected. However, based on the present study, the inter-stage cooling duty is predicted to be significantly higher and contributes approximately 30% of the total power requirement for compression options A, C and D, while reaches 58% when applied to option B. It is also found that compression option C can offer higher efficiency than other compression strategies, while supercritical liquefaction efficiency is only marginally higher than that in the compression option A.
Citrus fruit peel waste as a source of natural coagulant for water turbidity removal
Authors: Dollah Z , Abdullah A R C , Hashim N M , Albar A , Badrealam S , Mohd Zaki Z Z
Published: December 2019

This research aimed to determine the suitability of citrus fruit peel waste namely as Citrus Aurantiifolia (key lime) and Citrus Microcarpa (kasturi lime) to act as a natural coagulant for water turbidity removal. The performance of these two coagulants was assessed in terms of turbidity removal using jar test experiments for synthetic low turbid water. The results indicated that the optimum dosage and turbidity removal for Citrus Microcarpa and Citrus Aurantiifolia was found at 30 mg/l with 75.6% turbidity removal and 60 mg/l with 74 % turbidity removal, respectively. Citrus Aurantiifolia showed higher removal efficiency as compared to Citrus Microcarpa. The study demonstrated that both citrus fruit peel waste has the potential to be use as a substitute for chemical based coagulant for a future alternative in water treatment.
An experimental mechanism of a tandem flapping wing for micro aerial vehicle
Authors: Ismail N.I. , Yusoff H. , Budin S. , Yamin A.F.M.
Published: December 2019

Micro Aerial Vehicles, otherwise known as MAVs, is defined as an aerial vehicle that has a 15cm or less wingspan with a take off wight of less than 200g. Its miniature size and manoeuvrability allows it to fly in confined space at low Reynolds number flight conditions (100 – 100,000). In this study, an entothopter design inspired by dragonfly wings was investigated using a subsonic wind tunnel to see the effect of tandem wing configuration on the lift generation. The study was done at different flapping frequency (5-11Hz) and at different flight speed (5m/s, 7m/s, and 9m/s). It was observed that in phase flapping configuration produces better lift for all flapping frequency and all flight speed.
Biodiversity analysis of spontaneously fermented Garcinia mangostana pericarp: From laboratory scale to pilot scale
Authors: So’aib M S , Salihon J , Ku Hamid K H
Published: December 2019

Biodiversity analysis was carried out on Garcinia mangostana pericarp (GMP) which underwent spontaneous fermentation. Population dynamic was carried out using the plating method while genotyping employed gene sequencing of 16S rDNA (bacteria) and 5.8S-Internally Transcribed Spacer (5.8S-ITS) rDNA (yeasts). Throughout 90-day fermentation in 5-L fermenter (laboratory scale) ecosystem, the prevalence of lactic acid bacteria (LAB) and yeast were indicated by their viable cell counts at 103 to 104 colony forming unit per ml (CFU/mL) on MRS medium and 103 to 107 CFU/mL on PDA medium respectively, while the prevalence of LAB and yeasts in 50-L fermenter (pilot scale) ecosystem were marked by 103 to 107 CFU/mL and 102 to 105 CFU/mL on the respective medium. Complete inhibition of enterobacteriaceae population conferred a microbiological safety of the fermented GMP. Genotyping of isolates revealed Firmicutes and Proteobacteria in 5-L fermenter ecosystem, while Firmicutes and Proteobacteria were isolated from 50-L fermenter ecosystem. Lactobacillus plantarum and Enterococcus faecalis were amongst probiotic species isolated from 5-L and 50-L ecosystems respectively, whereas Saccharomycetaceae yeasts were ubiquitous in both ecosystems.
Durability Performance of Utilising Quarry Dust as Sustainable Material in Self-Compacting Concrete
Authors: Siti Quraisyah A A Dyg. , Kartini K. , Hamidah M S
Published: December 2019

Self-compacting concrete (SCC) a latest innovation in concrete technology is being regarded as one of the most promising developments in the construction industry due to numerous advantages over conventional vibrated concrete. SCC is an innovative construction material that can be placed into forms without mechanical vibration which able to flow and consolidate under its own weight. The utilisation of quarry dust (QD) as waste and eco-friendly material in SCC was investigated in this study. Conventional vibrated concrete mix was designated as OPC while SCC mixes with different percentages of QD which are 0%, 10%, 20%, 30%, 40% and 50% that had been used to replace sand as partial fine aggregate. The high-range superplasticizer had been used as the chemical admixtures that can enhance the rheological properties of all SCC mixes. The performance of conventional vibrated concrete and QD in SCC in terms of its workability was investigated while the durability performance was investigated by conducting water absorption test and water permeability test for curing periods of 7, 28 and 60 days were considered in this study. 50% of QD is the optimum dosage that can be used in order to achieve the lowest water absorption meanwhile 40% of QD is the optimum dosage that can be used in order to achieve the lowest water permeability for QD in SCC mix. In conclusion, the innovation material by utilising QD in SCC improve the workability and durability performance of concrete.
Improvement of emissions characteristics and exhaust temperature in single cylinder diesel engine fuelled with algae oil additive
Authors: Sharudin H , Ismail N I , Pahmi A , Mahadzir M M , Rahim N A
Published: December 2019

An experimental study has been carried out to evaluate the emission characteristics and exhaust gas temperatures of algae oil additive in diesel blends. Diesel fuel (D100) and fuel blends of algae oil at 1% (A1), 2% (A2), 3% (A3) and 4% (A4) concentration were prepared and put to test on an unmodified single cylinder diesel engine. The test was conducted at a constant engine speed of 1500 rpm with varying engine load (0, 2, 4 and 6Nm). The engine performance of exhaust gas temperature and exhaust emissions of carbon monoxide (CO), carbon dioxide (CO2), and oxide of nitrogen (NOx) were measured and analyzed. The results showed that the properties of algae oil additive were comparable to diesel fuel and it was successfully used to run the diesel engine. In terms of exhaust emissions, A4 blends exhibited lowest CO and NOx emission by about 90.9% and 21% lower compared to pure diesel D100 at engine load of 6Nm, respectively. However, A4 blends also exhibited the highest CO2 percentage emission which is about 31% more than D100 and exhaust gas temperature of 1.22% higher compared to D100 at 4 Nm engine load.
Predicting the next oil change for automotive engine oil
Authors: Ibrahim D , Stapah M , Ruslan M A A , Yaakob Y , Budin S , Maideen N C , Yusoff H
Published: December 2019

The main purpose of the engine lubrication system is to supply lubricating oil to all moving parts in the engines to reduce friction rates. The failure of this can cause damage to the engine system. The aim for this project is to develop a user-friendly device to predict as accurately as possible the next oil change for an automobile. The device consisted of four main parts, the electronic part, the heating element, the main body and the cover. A 12V DC motor is used to measure the current as the shaft connected to the motor immersed in fluid which temperature is controlled at 40 Celsius. The experiment was conducted using waste oil lubricant (WLO) collected from an automobile servicing centre. The behaviour of a given fluid was analysed using data generated. A measure of viscosity was calculated. The upper limit of viscosity change is set to +15% change and -10% for lower limit. The result shows the deterioration of WLO in term of viscosity. From the sample tested with the device, all the WLO were overused as the oil was over the allowable limit of viscosity changes which could present a danger of possible damage to the engine. Therefore, this device can function as a preventive maintenance device of car as the user can predict when is the best time to change their automobile oil lubricant.
Maximum shear modulus evaluation based on continuous wavelet transform of bender element test
Authors: Ibrahim A , Noor M J Md , Ibrahim M N , Ahmad J , Ahmad A
Published: December 2019

Maximum shear modulus (Gmax) is a crucial parameter in the prediction of ground deformation and performance of seismic design. Practically, theGmaxparameter could be obtained from specific laboratory test or seismic field test. Bender element (BE) test is nondestructive laboratory test, which is simple yet reliable method in determiningGmaxof soil. This study focuses on application; processes and analysis ofGmaxvalues obtained from BE laboratory test using continuous wavelet transform (CWT) method. TheGmaxvalues were validated with results from field seismic dilatometer test (sDMT) conducted at the same site of soil sampling for BE laboratory test. BE laboratory tests were conducted on undisturbed Auckland residual clay at various effective confining pressures (ECP) under fully saturated condition. TheGmaxvalues analysis between CWT and field sDMT data were based on the overburden pressures values that matches with ECP applied in the BE laboratory test. In summary, the comparison between CWT analysis of laboratory and field sDMT data indicated good consistency ofGmaxvalues. Thus, confirmed the reliability of CWT method in estimatingGmaxparameter from BE laboratory test.
Deep convolution neural network for crack detection on asphalt pavement
Authors: Yusof N A M , Ibrahim A , Noor M H M , Tahir N M , Yusof N M , Abidin N Z , Osman M K
Published: December 2019

Asphalt cracks are one of the major road damage problems in civil field as it may potentially threaten the road and highway safety. Crack detection and classification is a challenging task because complicated pavement conditions due to the presence of shadows, oil stains and water spot will result in poor visual and low contrast between cracks and the surrounding pavement. In this paper, the network proposed a fully automated crack detection and classification using deep convolution neural network (DCNN) architecture. First, the image of pavement cracks manually prepared in RGB format with dimension of 1024x768 pixels, captured using NIKON digital camera. Next, the image will segmented into patches (32x32 pixels) as a training dataset from the original pavement cracks and trained DCNN with two different filter sizes: 3x3 and 5x5. The proposed method has successfully detected the presence of crack in the images with 98%, 99% and 99% of recall, precision and accuracy respectively. The network was also able to automatically classify the pavement cracks into no cracks, transverse, longitudinal and alligator with acceptable classification accuracy for both filter sizes. There was no significant different in classification accuracy between the two different filters. However, smaller filter size need more processing training time compared to the larger filter size. Overall, the proposed method has successfully achieved accuracy of 94.5% in classifying different types of crack.
Shear strength of food packaging plastic wastes as liner material
Authors: Abd-Aziz N H , Alias S , Bashar N A M , Ahmad A , Amir A , Abdul-Talib S , Tay C C
Published: December 2019

The demand uses of plastic are increasing day by day leading to the various outsized amount of plastic waste producees across the world. Therefore, a proper discarding of the plastic wastes without causing any environmental risk has become a real challenge. The reuse of plastic to a beneficial product is one of the sustainable options which can secure the environment and prevent the plastic discarded to the landfill or incinerated. In this study, laboratory test was conducted to analyse the potential of recycle plastic waste as liner material in engineering application. The plastic waste was fabricated as 2mm plastic sheet liner and the geotechnical behaviors namely shear strength was analysed and compared with the commercialized liner which known as the geomembrane. Results of shear analysis showed the cohesion between the fabricated plastic waste liner (FPWL) meet the reference value for cohesion ranging 10-24 kPa. However, for internal friction most of the FPWL samples did not meet the reference value for internal friction ranging between 25-35o. This shows that plastic waste has a good shear strength and meet with global factor which feasible as alternative liner material in engineering application.