bluuebunny/crossref_metadata_2025 huggingface dataset:
Bilevel Integer Programs with Stochastic Right-Hand Sides
Authors: Zhang Junlong , Özaltın Osman Y.
Published: March 2021

We develop an exact value function-based approach to solve a class of bilevel integer programs with stochastic right-hand sides. We first study structural properties and design two methods to efficiently construct the value function of a bilevel integer program. Most notably, we generalize the integer complementary slackness theorem to bilevel integer programs. We also show that the value function of a bilevel integer program can be characterized by its values on a set of so-called bilevel minimal vectors. We then solve the value function reformulation of the original bilevel integer program with stochastic right-hand sides using a branch-and-bound algorithm. We demonstrate the performance of our solution methods on a set of randomly generated instances. We also apply the proposed approach to a bilevel facility interdiction problem. Our computational experiments show that the proposed solution methods can efficiently optimize large-scale instances. The performance of our value function-based approach is relatively insensitive to the number of scenarios, but it is sensitive to the number of constraints with stochastic right-hand sides.

Summary of Contribution: Bilevel integer programs arise in many different application areas of operations research including supply chain, energy, defense, and revenue management. This paper derives structural properties of the value functions of bilevel integer programs. Furthermore, it proposes exact solution algorithms for a class of bilevel integer programs with stochastic right-hand sides. These algorithms extend the applicability of bilevel integer programs to a larger set of decision-making problems under uncertainty.
Workforce Scheduling with Order-Picking Assignments in Distribution Facilities
Authors: Rijal Arpan , Bijvank Marco , Goel Asvin , de Koster René
Published: March 2021

Scheduling the availability of order pickers is crucial for effective operations in a distribution facility with manual order pickers. When order-picking activities can only be performed in specific time windows, it is essential to jointly solve the order picker shift scheduling problem and the order picker planning problem of assigning and sequencing individual orders to order pickers. This requires decisions regarding the number of order pickers to schedule, shift start and end times, break times, as well as the assignment and timing of order-picking activities. We call this the order picker scheduling problem and present two formulations. A branch-and-price algorithm and a metaheuristic are developed to solve the problem. Numerical experiments illustrate that the metaheuristic finds near-optimal solutions at 80% shorter computation times. A case study at the largest supermarket chain in The Netherlands shows the applicability of the solution approach in a real-life business application. In particular, different shift structures are analyzed, and it is concluded that the retailer can increase the minimum compensated duration for employed workers from six hours to seven or eight hours while reducing the average labor cost with up to 5% savings when a 15-minute flexibility is implemented in the scheduling of break times.
Stability Analysis of Spools with Imperfect Sealing Gap Geometries
Authors: Rituraj Rituraj , Scheidl Rudolf
Published: March 2021

Spools in hydraulic valves are prone to sticking caused by unbalanced lateral forces due to geometric imperfections of their sealing lands. This sticking problem can be related to the stability of the coaxial spool position. Numerical methods are commonly used to study this behaviour. However, since several parameters can influence the spool stability, parametric studies become significantly computationally expensive and graphical analysis of the numerical results in multidimensional parameter space becomes difficult.

To overcome this difficulty, in this work, an analytical approach for studying the stability characteristics of the spool valve is presented. A Rayleigh-Ritz method is used for solving the Reynolds equation in an approximate way in order to determine an analytical expression for the lateral force on the sealing lands. This analytical expression allows stability analysis of the spool via analytical means which finally results in the expression of critical axial velocity which demarcates the regions of stable behaviour. Simplicity of the expression allows an immediate insight into the role of design parameters in the stability of the spool. To verify the analytical model, a numerical model for spool dynamics is developed in this work and the numerical results are found to match the analytical model in terms of the stability behaviour of the spool.
Coiling of internal carotid through ‘eye of the needle’ internal jugular vein: a dual great vessel anomaly
Authors: Iftikhar H , Ikram M
Published: March 2021

A variation in the usual course of great vessels during neck dissection can predispose them to inadvertent iatrogenic injury, which can lead to massive bleeding. We present a case of a male patient with oral squamous cell carcinoma who underwent inferior maxillectomy and supra-omohyoid neck dissection. Lateral coiling of the extracranial internal carotid artery was seen through fenestration of the internal jugular vein. Anomalies of great vessels in the neck are rare. Variation in the course of any of these vessels can prove to be catastrophic if control is not achieved. Careful study of radiographic imaging with special consideration given to the course of great vessels in the neck should be undertaken prior to neck surgeries.
Observations of human muscle response during daily life activities of biped kinematics using a musculoskeletal simulator
Authors: KUNCHALA Balakrishna Reddy , GAMINI Suresh , MAGULURI Nagarjuna
Published: March 2021

Research in biomechanics has numerous applications including rehabilitation which helps in the fabrication of assistive devices. The Assistive devices or exoskeletons are used to serve the patients affected by stroke and spinal cord malfunctioning. These devices are programmed to follow a fixed redundant gait cycle and are lacking in producing natural movement of the gait. To overcome this limitation and make the device more user comfortable during usage of their daily life activities, a thorough study was done using an open source software that contributed to the design of exoskeleton device for the subject. In the current study, a simulation of various daily life activities are thoroughly studied using a musculoskeletal simulator package like OpenSim. The paper presents the observations of muscle responses from ground reaction forces with minimized metabolic cost function in various activities of daily living such as sitting to standing, standing to sitting, jumping, twisting suddenly while walking and turning suddenly. The study deliberates the inputs for developing more comfortable exoskeletons in performing tasks in a more sophisticated manner.
Synthesis and Characterization of Nano Cerium Oxide Using Hydrothermal Technique
Authors: SANKAR J. , SURESH KUMAR S.
Published: March 2021

Cerium oxide rice grain like nanoparticles have been synthesized using wet chemical hydrothermal synthesis method. Hydrothermal synthesis method provides nanoparticles with unique dimension and shape due to supercritical synthesis conditions than conventional precipitation techniques. The hydrothermal synthesis of Cerium salt in the presence of urea produces Cerium carbonate hydroxide nanoparticles with rice-grain morphology, which are reduced into Cerium oxide by heat-treating at 600°C, for 4 hours, without changing its morphology. The formation of Cerium carbonate hydroxide with orthorhombic crystal structure and Cerium oxide with cubic crystal structure were confirmed by X-Ray Diffraction [XRD] spectroscopy studies. Thermo-gravimetric analysis [TGA] in inert nitrogen atmosphere and ambient air provides the reduction temperature of hydroxide and carbonate is about 600°C. Scanning electron microscope [SEM] studies show the uniform rice grain like morphology of as-prepared Cerium carbonate hydroxide and Cerium oxide, due to the reduction at elevated temperature and crystalline structural deformation Cerium oxide shows cracks and porous on its surfaces.
‘A mirror to the room’: Pyer Moss, specular strategy and Black Lives Matter
Authors: Desjardins Molly
Published: March 2021

Drawing on Walter Benjamin’s version of historical materialism and with reference to the concept of despecularization from psychoanalytic film theory, this article looks at the historical and cultural significance of Pyer Moss’s Spring/Summer 2015 fashion show, where Kerby Jean-Raymond, the artist and designer behind the label, used the runway to bring attention to state-enforced violence against Black men and women.
Hivatás- és pályamotivációs tényezők első éves óvodapedagógus hallgatók körében
Authors: Dr. Szontagh Pál
Published: March 2021

Napjainkban a pedagógus pálya (beleértve annak egzisztenciális, szervezeti és infrastrukturális feltételeit is) iránti motiváció eltér a nevelés-oktatás hivatása iránti elkötelezettség mértékétől (amely megélhető informális, vagy a köznevelési intézményrendszeren kívüli formában is). A pedagógusjelöltek körében végzett hivatás-és pályamotivációi kutatásunk első lépéseként 2019/20-ban és 2020/21-ben felmérést végeztünk a Károli Gáspár Református Egyetem Tanítóképző Főiskolai Karának első éves óvodapedagógus hallgatói között. A hallgatók szabadon szerkesztett motivációs esszéinek strukturált tartalmi elemzésével igyekeztünk feltárni azokat a hivatás- és pályamotivációs jellemzőket, amelyek a hallgatókat a képzésre való jelentkezésben befolyásolták. Kiemelt szempontként kezeltük a nappalis és levelezős hallgatók közötti különbségeket, azt vizsgálva, hogy utóbbiak élet- és munkatapasztalatuk révén mennyiben más motivációs bázissal rendelkeznek. A kutatás eredményei igazolják, hogy az óvodapedagógus szak választásakor a vonzó tényezők többsége a hivatásmotiváció körébe sorolható. Igazolódott továbbá. hogy a levelező munkarendben tanuló hallgatók motivációja sokoldalúbb és kiérleltebb a nappalisoknál, utóbbiak között több a nem kiforrott, naiv elképzelés a pedagógus pályáról, valamint a pálya családbarát időbeosztása és változatossága a levelező munkarendű hallgatók számára nagyobb motiváló erővel bír.
Üzleti kapcsolatok beágyazottsága a magyar gazdaságban (Heaviness of the Hungarian business relationships)
Authors: Gelei Andrea , Dobos Imre , Nagy Judit
Published: March 2021

A cikk a hazai ellátási láncok alapegységének, az üzleti kapcsolatoknak a beágyazottságát vizsgálja. A vállalatok közötti üzleti kapcsolatok sokféle jellemzője közül kiemelt jelentőségű azok stabilitása, ami közvetlenül függ a kapcsolatok beágyazottságának fokától. Az üzleti kapcsolat beágyazottságára hatást gyakorol az együttműködő felek közötti kötelékek három típusa (Håkansson – Snehota [szerk.], 1995): a megrendelő-beszállító közötti (i) tevékenység, (ii) szociális és (iii) erőforrás-kötelékek erőssége, intenzitása. A szerzők kutatásának hipotézise szerint e kötelékek erősségét, és ezen keresztül a kapcsolat beágyazottságának mértékét befolyásolja az, hogy milyen a felek közötti csere tárgyát képező termék- és szolgáltatáscsomag komplexitása. Tanulmányuk a Budapesti Corvinus Egyetem Versenyképesség Kutató Központjának „Kis- és középvállalatok beszállítói pozíciói” című kutatási programja (2007–2008) keretében készült kérdőíves felmérés kiemelt eredményeit mutatja be. Az elemzés magában foglalja az üzleti kapcsolatok számára releváns különböző köteléktípusok jellemzőinek bemutatását, a csere tárgyát meghatározó vevői elváráscsomagok, illetve azok leképeződéseként kialakuló tipikus termék- és szolgáltatáscsomagok ismertetését, végül annak bemutatását, hogy azok miképpen hatnak az üzleti kapcsolatok beágyazottságára. ________________ The focal question of this research is how heavy Hungarian business relationships are, and what specific characteristics this relationships have. Business relationship heaviness is one of the most important relationship features because substantially influences the stability of the relationship itself. The authors argue that the level of buyer-supplier relationship heaviness is determined by activity ties, social bonds and resource links (Håkansson – Snehota ed., 1995) and influenced by the complexity of the exchange object relevant for a specific relationship. The paper presents the results of an online survey carried out among Hungarian companies at the Competitive Research Centre of the Corvinus University of Budapest. The authors’ analysis examines the effect of the exchanged product and service package on relational ties and relationship heaviness.
Effects of Paclobutrazol on Growth and Antioxidant Content of Brassica Rapa Var. Oleifera
Authors: Yusop Z , Y Tsan F , M Jusoh J , S Sahmat S
Published: March 2021

The experiment was conducted with the main objective was to study the effects of Paclobutrazol (PBZ) on growth and antioxidant content of Brassica rapa var. oleifera. The PBZ was applied at various concentrations (0, 5, 10, 15 and 20 mg /L) through seed soaking and seedling as soil drenching. The growth performance data collection was conducted on weekly basis starting from week 3 until week 6 of planting while antioxidant content analyses were conducted on day 38. It was found that PBZ affected the growth and antioxidant content of Brassica rapa var. oleifera. The soil drenching techniques was found significantly affect the plant height, number of leaves and internode length. Similarly, both ascorbic acid and phenolic content were significantly affected by the technique. It was found that application of 10mg/L and 5mg/L of PBZ has recorded highest amount of ascorbic acid and phenolic content, respectively. This study has proven that the application of PBZ using soil drenching technique on Brassica rapa var. oleifera has contributed to enhancement of its antioxidant content which is also one of the important component in healthy diet intake.Â Â
Isolation and Molecular Identification of Biosurfactant Producing Soil Bacteria
Authors: A N Zamani N , E Tengku Zainal Mulok T , Mat Nor R , . .
Published: March 2021

Biosurfactants are amphiphilic compound, having hydrophilic and hydrophobic moieties enabling them to reduce surface and interfacial tension at the surface. Their unique properties are applied in various industries such as foaming and wetting agents, emulsifiers, detergents and bioremediation. A total of 98 isolates showed biosurfactant activity using hemolytic activity, drop collapse test and oil spreading assay. All isolates were rod-shaped, Gram positive and majority of them were non-endospore former. Only the isolates showing the highest percentage of emulsification index (E24) and ability to reduce tension were used for species identification using 16S rDNA gene sequencing which were isolates A1(6) and A2(1). Both isolates were identified as Bacillus sp. cp-h50 and Bacillus sp. XT-24 respectively, rod-shaped, endospore former and Gram positive. The biosurfactant produced by both species showed high emulsification index (E24) (A1(6), 63.3% and A2(1), 46.7%) and good surfactant capacity. The size of amplified gene of 16S rDNA gene was approximately 1.5 kb. These features provide evidence that both species could be a potential biosurfactant producer with proper optimization for the production of biosurfactant. The biosurfactant produced by both bacterial species were identified as surfactin using Fourier Transform Infrared Spectroscopy (FTIR).Â Â
Diversity and Distribution of the Mangrove Gastropods of Kuala Selangor Nature Park, Selangor
Authors: Jahid A , R Singh H
Published: March 2021

This study reports on the diversity and distribution of mangrove gastropods from Kuala Selangor Nature Park sampled from August to November 2017. The line transect with quadrat method was employed to sample gastropods which were handpicked from the various mangrove structures (root, stem, branch) and mangrove floor within 5m x 5m quadrats. Nineteen gastropod taxa were recorded from the Bruguiera, mixed (Bruguiera, Avicennia & Rhizophora), and Avicennia & Rhizophora zones. The Ellobiidae (Elobium aurisjudae and Cassidula aurisfelis), Potamidae (Cerithedia obtusa, Cerithidea cingulata and Telescopium telescopium), Muricidae (Chicoreus capucinus) and Naticidae (Nerita balteata) were the most distributed gastropod families at the study site. Gastropod horizontal distribution varied between tree zones (Bruguiera; Bruguiera-Avicennia-Rhizophora; and Avicennia-Rhizophora) and tree type (Brugueira, Rhizophora and Avicennia), while gastropod vertical distribution varied based on height on tree (0 â€“ 120cm) and sub-habitats (roots, floor and trunk) as shown by the principle components analysis (PCA) biplots. The Margalefâ€™s species richness (D=2.90) and Shannon-Weiner diversity (Hâ€™=2.32) was low which is typical of mangroves that are mature while Pielouâ€™s evenness (J=0.77) was high implying lack of dominance by specific gastropod taxa.Â Â
Anti-Acetylcholinesterase, Anti-Inflammatory and Anti-Oxidant Activities of Raw-Extract Centella Asiatica (RECA) on Lipopolysaccharide (LPS)-Induced Neuroinflammation Sprague Dawley Rats
Authors: Hafiz Z , Shamsuddin N , M Mukhtar S , J James R , I Adenan M
Published: March 2021

The present study was designed to investigate the potential of raw-extract of Centella asiatica (RECA) in suppressing acetylcholinesterase (AChE), inflammations and oxidative stress via induction of lipopolysaccharide (LPS) on animal model of Sprague Dawley rats. Centella asiatica is a plant thatÂ has been used as a traditional herbal remedy for the management of several diseases, including memory improvement, treatment of mental fatigue and wound healing. Pre-treatment with RECA in vitro significantly reduced the AChE activity in a concentration-dependent manner with IC50 value of 57.47 Â± 13.55 Âµg/ml. Interestingly, this result was parallel with in vivo studies. Moreover, the level of pro-inflammatory cytokines and oxidative stress were significantly reduced by RECA in dose-dependent manner. Overall, our findings clearly dictate the potential of RECA as AChE inhibitor as well anti-inflammatory and anti-oxidant agents.Â
Isolation of Dihydrostilbenes from Macaranga Heynei and their Bioactivities
Authors: S. Kamarozaman A , Ahmat1 N , L. Muhammad Low A , F. Rajab N , Zamkhuri Z , Shaameri Z , Jaafar Sidik N , D. A. Kamaruzzaman N
Published: March 2021

Macaranga is known to contain abundant sources of prenylated flavonoids and stilbenoids which possessed broad spectrum of biological activities including anti-inflammatory, antimicrobial, antioxidant and cytotoxicity. These species are widely distributed in New Guinea, Borneo and from West Africa to the south Pacific islands. Although Macaranga comprises a large number of species, this genus has not been widely investigated which prompted us to conduct a study on Macaranga heynei. This research is conducted to isolate and characterise the compounds from M. heynei as well as to access the antibacterial and cytotoxicity of the isolates. The purification from the leaves of M. heynei has successfully yielded three dihydrostilbenes which were analysed by means of NMR, UV-Vis, FTIR, MS and comparison with the literature data. These compounds were characterised as laevifolins A (1) and B (2) as well as macarubiginosin C (3). Laevifolin A (1) exhibited good activity against S.cohnii subsp. urealyticum and moderate activity against S.aureus ATCC 25923 with the IC50 values of 11.65 and 27.13 ï­M respectively. It also displayed pronounced inhibition against HT-29 cells with an IC50 value of 21.20 ï­M. Meanwhile, laevifolin B (2) displayed moderate activity on S.cohnii subsp. urealyticum but strong inhibition against S.aureus ATCC 25923 with the IC50 values of 20.71 and 1.64 ï­M respectively.Â
Potential Use of Jackfruit (Artocarpus Heterophyllus) and Breadfruit (Artocarpus Altilis) as Fat Replacer to Produce Low-Fat Chicken Patties
Authors: Rashedi Ismail-Fitry Mohammad , Farihah Azwa Abas Nur
Published: March 2021

Commercial chicken patties contain high fat, which could affect consumersâ€™ health. Jackfruit (Artocarpus heterophyllus) and breadfruit (Artocarpus altilis) may have the potential to be used as the fat replacer in the chicken patties.Â  This study aimed to evaluate the low-fat chicken patties produced by replacing the fat with jackfruit (JF) or breadfruit (BF) at 0% (control), 50% and 100%. The samples were analysed in terms of water holding capacity (WHC), cooking yield (CY), proximate analysis, colour, texture properties, and sensory parameters. Both BF and JF showed higher value (p<0.05) for WHC, moisture content and protein compared to the control. BF (100%) and JF (100%) were recorded of having significantly reduced fat (p<0.05) at 1.80% and 2.23%, respectively. BF showed higher L*(lightness) and b*(yellowness) values significantly (p<0.05) compared to the control. Not many significant differences (p>0.05) between the control and newly formulated chicken patties texture based on the hardness, cohesiveness, and chewiness recorded, proving that BF and JF did not affect the patties texture. Overall, the sensory evaluation of BF (100%) was preferred by the consumer in terms of appearance, texture, flavour, juiciness, and aroma. Thus, BF (100%) can be considered as the best fat replacer in this study.Â Â
Effect of Pre-Treatment on the Morphology and Chemical Properties of Polyethylene Terephthalate (PET)/Pineapple Leaf Fiber (PALF) Electrospun Mat
Authors: N Surip S , M A Aziz F , H Yuwono A , Sofyan N
Published: March 2021

In the past decades, conventional petroleum-based plastics have resulted in environmental and sustainability issues. Thus, there has been significant interest in the utilization of natural materials for nanofibers product such as for filtration media.Â  However, poor compatibility exists between polymers and natural fibers due to natural fibers hydrophilic properties leading to poor nanofibers formation. In this study, Pineapple Leaf Fiber (PALF) remarkable properties were explored. PALF undergo alkaline treatment and bleaching treatment in order to improve its compatibility. Thermal, morphology and structural properties of PALF raw (PR), PALF after alkali treatments (PA) and PALF after alkali + bleaching treatment (PB) were studied. Further, all the samples were diluted using Trifluoroacetic Acid (TFA) as the solvent and Polyethylene Terephthalate (PET) as the polymer carrier and proceed to electrospinning to produce a nanofibers electrospun mats. The electrospun mats were then characterized in terms of its chemical properties using Fourier transform infrared spectroscopy (FTIR) as well as the morphology which using Fields Emission Scanning Electron Microscopy (FESEM).Â  FTIR result shows the electrospun PET does not produce any peak at ~3400cm-1 due to its hydrophobic properties. Nevertheless, with addition of PALF, the peak was significantly increased. FESEM results indicated that the present of fibers led to a tendency of lower average fiber diameter compared to the neat PET. Unconnected and thin fibers were coexited from single fiber of PALF raw electrospun indicated that new fibers were ejected however the bond were collapsed during ejection thus did not produce a complete single fiber. Despite that, more uniform fibers of electrospun mat were produced by pre-treatment of PALF.Â
Mechanical Characterization of Aluminium-Silicon-Titanium Diboride (Al-Si-TiB2) Reinforced by Scandium (Sc) and Strontium (Sr)
Authors: N.A. Basir N. , H. Mustafa N. , E. Ibrahim R. , Rosmamuhamadani R. , M. Mahat M. , M. Yahaya Sabrina , K. Talari M.
Published: March 2021

Aluminium based metal matrix composites (MMCs) have better properties and performance. They are commonly used in transport applications which require combinations of high strength and ductility. They are quite attractive due to their low density, capability to be strengthened by precipitation, good corrosion resistance, high thermal and electrical conductivity. Grain refinement plays a crucial role in improving characteristics and properties of aluminium-silicon (Al-Si) alloy. In this investigation, scandium (Sc) and strontium (Sr) elements were added to aluminium-silicon-titanium diboride (Al-Si-TiB2) alloy for refinement of grains. The compositions of 93 wt.% Al-Si, 6 wt.% TiB2, 0.5 wt.% Sc and 0.5 wt.% Sr were melted into induction furnace. Then the composites have been characterized on the mechanical properties and microstructure characterization. Instron tensile machine and vickers hardness tester were used to characterize the mechanical properties of the composite alloy. Microstructure and phase composition were characterized by Field Emission Scanning Electron Microscope (FESEM) and X-ray Diffraction (XRD). From the results obtained, addition of Sc and Sr, into Al-S-TiB2 improved the tensile strength and hardness of composite alloy. Results also showed that the inoculants addition able to enhance the refinement of grains and escalate the values of hardness and tensile strength of Al-Si-TiB2 composite. Mechanical properties related much on the microstructure as it can be seen that the addition of grain refiners produced much higher value of mechanical properties.Â Â
Dyeability of Red Cabbage Colorant on Silk Fabric Treated With Entada Spiralis Extracts
Authors: Mat Shom N. , I.A. Kadir M. , R. Ahmad M.
Published: March 2021

Of late, dyeing fabrics with natural colorants have been the attention of the industry. Natural colorants especially from plants have the advantage of being friendly towards the environment as the extraction, processing and dyeing procedures are considered green and safe. However, most natural dyes have poor colourfastness and needed mordants to improve their dyeability. In this study, the addition of Entada spiralis was utilized as a surface modifier to improve dyeability on 100% silk fabrics using extracts from red cabbage. The plant serves as a surface-active agent to reduce the surface tension of the fabrics. The surfactant is also a natural resource and therefore is not harmful to the environment. The Entada spiralis was extracted through boiling for 30 minutes on a hot plate before treating the extracts on the fabrics. During dyeing, lime was used as the mordant simultaneously with dyeing. The dyed fabrics were evaluated for colorfastness to washing, rubbing/crocking and perspiration using the Gray Scale Standard. In addition, the dyed fabrics were also measured for their colour strength, colour coordinates and % reflectance. The results showed that dyed fabrics with Entada spiralis have darker shades in comparisons with the untreated fabric.Â Â
Uniaxial Tensile Stress-Strain Response on the 3D Angle Interlock Woven Fabric Composite
Authors: M.Z. Nasrun F. , F. Yahya M. , R. Ahmad M. , A. Ghani S.
Published: March 2021

An experimental study have been performed to investigate the uniaxial tensile stress-strain response on the 3D angle interlock (3DAI) woven fabric composite. The tensile analysis were examined based on different woven fabric set-up parameter of draw-in plan ; pointed (DRW 1), broken (DRW 2), broken mirror (DRW 3), and straight (DRW 4). Meanwhile, the woven fabric composite were produced based on 22 and 25 pick.cm-1 of weft densities. The outcomes produced shown that woven composite sample with 25 pick.cm-1 on DRW 4 projected the highest stress response, 113 MPa. Extensive review indicated that DRW 1 and 4 gave better tensile stress-strain response than the other counterpart.Â
Effect of Deposition Time of Mn on Photoelectrochemical Properties of Mn/TiO2 Nanotubes
Authors: Kadim Ayal Asmaa , Mohammed Farhan Ahlam , Lim Ying-Chin
Published: March 2021

Coupling of TiO2 nanotube arrays (NTAs) with narrow band gap materials has been a promising strategy to extend the absorption of TiO2 into visible light region. In this work, the fabrication of manganese doped TiO2 nanotube arrays (Mn/TiO2 NTAs) was carried out by an electrodeposition method. The deposition time of Mn onto TiO2 NTAs which was varied in the range of 1-5 minutes was found to play an important role in controlling the formation and distribution of Mn nanoparticles onto TiO2 NTAs. The films were characterized by field emission scanning electron microscopy (FESEM), X-ray diffractometry (XRD), energy dispersive X-ray spectroscopy (EDX) and UVâ€“vis diffuse reflectance spectroscopy to determine their morphology, crystalline structure, and optical properties of the samples. The results from FESEM showed that Mn nanoparticles were found to grow larger and cause blockage to the mouth of the nanotubes with prolongs deposition time. On the other hand, Mn/TiO2 NTAs synthesized with shorter deposition time exhibits significant enhancements in the optical absorption and photocurrent density. In particular, the Mn/TiO2 NTAs produced at 1minute deposition time exhibited the highest photocurrent density compared to the others. The uniform distribution and quantity of the Mn could be the reason for this performance, therefore, more light was absorbed and generating more electron-hole pairs then giving the highest photocurrent.Â
Crude Glycerol for Monoolein Production using Nanotubes Supported Lipase
Authors: Artikah Muhammad Shahrin Nur , Aziah Serri Noor , Hana Hanif Abu Bakar Noor , . .
Published: March 2021

A growing demand for biofuels as the alternative for fossil fuelsâ€™ extinction has produced abundance amount of crude glycerol as by-product in biofuel industries. Utilization of crude glycerol into a value-added product such as monoolein has been the focus for this present work. Instead of using free catalyst, the enzyme (lipase) used for this study was immobilized onto the halloysite nanotubes. The immobilized enzyme was characterized using TEM, BET and FTIR analysis. Further, the effect of time, temperature, agitation rate, and substrate molar ratio on monoolein production and fatty acid conversion were studied between free lipase and immobilized lipase using GC analysis. The best working conditions for immobilized lipase to produce monoolein was at 50oC, with 8 to 1 ratio of glycerol to oleic acid, agitated at 250 rpm for 18h. The amount of monoolein produced using immobilized lipase was highly comparable with free lipase, with ability to be reused and thermally stable at higher temperature.Â
Influence of Additives on Thermal Properties and Morphological of Magnetorheological Elastomer
Authors: Zarina Ku Ahmad Ku , Khairi MHA , Mazlan SA
Published: March 2021

Magnetorheological elastomers (MREs) are categorized as part of the smart materials class whose rheological properties can be altered under the influence of a magnetic field. MREs are fabricated by embedding soft magnetic particles such as carbonyl iron particles (CIPs) in a rubber matrix such as silicone and natural rubber. In this project, epoxidized natural rubber (ENR-50) is used as a base material with carbonyl iron particles. Sucrose Acetate Isobutyrate (SAIB) ester is added to the formulation to improve the viscosity and enhance the MRE properties. The isotropic MRE is fabricated using two roll mill and a compression mould. Various tests comprise mechanical, morphology, thermal and magnetic tests were conducted for MRE characterization purpose. The results showed that the addition of SAIB on the MRE had reduced 53% of viscosity in the rubber matrix compared to non-ester based MRE. Dispersion of magnetic particles is improved by the addition of ester as observed through Field Emission Scanning Electron Microscope (FESEM). Additionally, the thermal stability was also improved. Tensile strength of MRE consisting SAIB ester achieved maximum strength of 12.3 MPa and an elongation of 620% compared to non-ester based MRE.Â Â
Magnetic Properties of Magnetite Nanoparticles (Fe3O4-NPs) Coated with Mesoporous Silica by Surfactant Templated Sol-Gel Method
Authors: Izza Taib Nurul , G. St. Pierre Timothy , C. Woodward Robert , J. House Michael
Published: March 2021

Here, we present the magnetic properties of silica-coated magnetite nanoparticles. We have coated 7 nm of Fe3O4 with cetyltrimethylammonium bromide (CTAB) for phase transformation from hydrophobic to hydrophilic. Core-shell structure of silica-coated magnetite nanoparticles have been obtained using surfactant templated sol-gel method. The obtained silica-coated magnetite nanoparticles were characterized by transmission electron microscopy (TEM), fourier transform infrared (FTIR) spectroscopy and superconducting quantum interference device (SQuID). The hysteresis loops of the coated particles were measured using SQuID and the results showed a superparamagnetic behavior at room temperature. The saturation magnetization (Ms) of the coated particles indicate the presence of non-magnetic surface layers resulting from the strong chemical attachment of the silica to the Fe3O4â€™s surface, also observed by FTIR spectroscopy.Â Â Â
Effects of Boron and Carbon Added Titanium Filler on Microstructure and Mechanical Properties of Ti-15-3 Alloy Weldments
Authors: Adli Bin Mohd Arif Izzul , Kumar Talari Mahesh , Kishore Babu N , Lutfi Bin Anis Ahmad , Hussain Ismail Muhammad , Bin Ramli Rosmamuhamadani
Published: March 2021

Microstructural and mechanical properties beta Titanium (Î²-Ti) weldments can be improved by grain refinement and formation of insoluble precipitates in the weld. This paper reports the effect of Boron (B) and Carbon (C) addition to Ti-15V-3Cr-3Sn-3Al (Ti-15-3) fillers on the microstructural and mechanical properties of Ti-15-3 gas tungsten arc weldments. X-ray diffraction and scanning electron microscopic analysis revealed the presence of Î²-Ti phase in the weldments prepared without the filler modification, while additional TiB and TiC phases are observed in the weldments prepared with fillers modified with B and C, respectively. B and C addition to the fillers has resulted in the grain refinement of the weldments and the grain size reduction is seen to be higher with the increasing B and C addition. The formation of TiB, TiC and growth restriction effect due to the presence of B and C in the filler resulted in the decreased grain size of the Î²-Ti weldments. Mechanical properties such as hardness and tensile strength improved as the amount of B and C addition increased. The improvement of mechanical properties is contributed by the grain refinement and the formation of TiB and TiC precipitates in weldments.Â
Influence of Different Atomic Percentage of Silver Doped Nano Zinc Oxide on Titanium Dioxide Seeded Substrate
Authors: Zulaikha Umbaidilah Siti , Amierah M. Asib Nur , Afaah Abdullah Nurul , Rusop Mohamad , Khusaimi Zuraidah
Published: March 2021

Non-doped ZnO/TiO2 and Silver (Ag) doped ZnO/TiO2 nanostructures thin film were successfully synthesized on glass substrate by using sol-gel spin coating technique for deposition of TiO2 seed layer and solution immersion method for growth of Ag-doped ZnO/TiO2 nanostructure. Different atomic percentage (at%) which is 0.5, 1.0, 1.5, 2.0 and 2.5 at% of Ag doped were added in 0.4 M of Zn2+ solution. The EDX result revealed that the sample was composed of Zn, O and Ag elements which confirmed the existence of Ag element in the sample. The XRD spectra shows that the intensity of the (002) peak of 0.5 at % Ag-doped ZnO/TiO2 was the highest compared to other samples and all the samples revealed polycrystalline structure belonging to the ZnO hexagonal wurtzite type. The UV-vis absorbance also indicates that 0.5 at% Ag-doped ZnO/TiO2 has the highest absorbance and non-doped ZnO/TiO2 displayed the lowest absorbance compared to the other sample. Thus, 0.5 at% of Ag-doped ZnO/TiO2 is the best candidate for optical application due to the higher intensity and greater absorbance.Â Â
Effects of EC Plastisizer and SiO2 Nano-Filler on Electrical and Thermal Properties of Chitosan-G-PMMA based Solid Polymer Electrolytes
Authors: Kartini. Jaafar Nor , Malik Marwan Ali Ab , Zu Azhan Yahya Muhamad , Zakaria Rosnah , Zafirah Zainal Abidin Siti
Published: March 2021

Composite grafted polymer electrolyte based on chitosan grafted poly(methyl methacrylate) (Ch-g-PMMA) have been prepared and investigated. The lithium triflouromethanesulfate salt (LiCF3SO3 or LiTf), ethylene carbonate (EC) and SiO2 are applied as a salt, plasticizer and ceramic filler, to the polymer host system. Impedance spectroscopy was performed at room temperature. The highest conductivity of 1.63 x 10-4 Scm-1 was obtained for the grafted polymer with 50 wt. % of LiCF3SO3 and enhanced to 2.23 x 10-4 Scm-1 with the addition of 30 wt. % EC. The conductivity is further enhanced to 4.21 x 10-4 Scmâˆ’1 with the addition of 6 wt. % SiO2. Both additives caused a reduction of the Ch-g-PMMA crystalline phase content and increased segmental flexibility leading to conductivity enhancement.Â Â
Personal Injury Claims (PIC) Database Modeling in Malaysia
Authors: Ruslawati Nik Mustapa Nik , Awang Ali Najihan , Husna Jamian Nurul , Abdul Hamid Hussin , Syaeda Mat Saleh Syadatul , Baharain Roziana
Published: March 2021

Road accident often leads to claims for personal injury by aggrieved parties. In Malaysia, courts have been using multiplier-multiplicand approach. This approach seems to be outdated and unfair to the claimant. Presently, the approach excludes the claimant's personal condition in the calculation of quantum of damages. Hence, this study uses the Ogden Table as introduced in the United Kingdom as benchmarking guidelines, by taking into account of all aspect of claimant's personal condition for the purpose of such calculation. This study aim is to build upon a proposed data modeling system known as Entity Relationship Diagram (ERD) and the created process modeling known as data flow diagram (DFD). In so doing, the claimants will insert his input data, run it through the first process, and store the information in the claim injury part database. They can also edit and store to claim injury part database on their own. This will generate a report with the information in claim injury part database and can be viewed by claimant, court and lawyer as target users. It is hoped that it will facilitate the calculation of injury claim which would serve justice and accuracy of personal injury in road accidents.Â Â
Retinal Fundus Image Blood Vessels Segmentation via Object-Oriented Metadata Structures
Authors: Firdaus Ahmad Fadzil Ahmad , Ahmad Zaaba , Elaiza Abd Khalid Noor , Ibrahim Shafaf
Published: March 2021

Retinal fundus image is a crucial tool for ophthalmologists to diagnose eye-related diseases. These images provide visual information of the interior layer of the retina structures such as optic disc, optic cup, blood vessels and macula that can assist ophthalmologist in determining the health of an eye. Segmentation of blood vessels in fundus images is one of the most fundamental phase in detecting diseases such as diabetic retinopathy. However, the ambiguity of the retina structures in the retinal fundus images presents a challenge for researcher to segment the blood vessels. Extensive pre-processing and training of the images is necessary for precise segmentation, which is very intricate and laborious. This paper proposes the implementation of object-oriented-based metadata (OOM) structures of each pixel in the retinal fundus images. These structures comprise of additional metadata towards the conventional red, green, and blue data for each pixel within the images. The segmentation of the blood vessels in the retinal fundus images are performed by considering these additional metadata that enunciates the location, color spaces, and neighboring pixels of each individual pixel. From the results, it is shown that accurate segmentation of retinal fundus blood vessels can be achieved by purely employing straightforward thresholding method via the OOM structures without extensive pre-processing image processing technique or data training.Â Â Â Â Â Â
Literature Review: Some of TVET Area Will Be Eliminated Due to Industrial Revolution 4.0, is That True?
Authors: Syahril Chairani Vici , Bruri Mochamad , Minghat Dahar
Published: March 2021

The 4.0 industrial revolution that began to be known since 2011 in Germany had a significant influence on several aspects of the world. Automation and digitilization that comes through Industrial Revolution 4.0, forecasted will brought many impact to demand and skillset of occupation and industry. Even that change is expected to have a lot of impact on Technical Vocational Education and Training (TVET). As a vocational education that has the main objective to prepare graduates to be able to work and be accepted in the industrial world. The aim of this study firstly is to provide a view of the issue about job lost due to the industrial revolution 4.0, is true or not. Secondly is to give an overview about the TVET area that have most possibility impact to be eliminated due to industry 4.0. To overcome this, this paper will explain a literature study from journal articles, opinion papers, conceptual papers, research study, etc. were analyzed for content related to Industrial Revolution 4.0 and TVET. It was concluded that (1) Occupation will be transformed by automation due to Industrial Revolution 4.0, not eliminated; (2) There is no certainty about which areas on TVET will be lost, but the areas that have the risk of being automated in TVET high school in Indonesia are administration, tourism and health.Â  Â
Technology-based Business Incubator Model as Efforts to Improve the Learning Process
Authors: Hurriyati Ratih , A Ana , Hassan R. , C.S Lai
Published: March 2021

This paper tries to identify technology-based business incubator models as an effort to improve the right learning process. The method used is an experimental method, where in the early stages the criteria for learning technology-based business incubator learning criteria are developed by integrating pedagogical aspects and technological aspects that will be used as experiments through need assessment, then proceed with making a model design. Model design based on the teaching model that will be applied. In the next stage, the implementation of the trial was carried out by using the teaching model and the entrepreneurship courses that were set, and then conducted a trial on the technology-based business incubator learning system with the same teaching model and courses and the same students. The results of this study produce a learning system that is able to create individuation, acceleration, enrichment, expansion, effectiveness and productivity of learning which in turn will improve the quality of education as an overall human-resource development infrastructure.Â
Evaluation of Blended Learning Implementation which is Conditioned to Optimize the Mastery of Student Knowledge and Skills
Authors: Rozahi Istambul Muhammad , Supriadi Hari , . .
Published: March 2021

Learning process is part of the E-Procurement courses curriculum in Information Systems Study Program at Widyatama University. All this time, in the face-to-face method of learning process, students have not been able to optimize the mastery of knowledge and skills as expected. One of the things that the Information Systems Study Program did to optimize said mastery is applying the blended learning program in e-Procurement courses. This study uses mixed method evaluation approach in evaluating various stages of the process to implement a blended learning program. Meanwhile, the evaluation method used consists of 2 parts of the model namely 1) CIPP, an evaluation carried out on context, input, process, and product, 2) The Flashlight Triad, an evaluation of activities that utilize information technology online. As the final result of evaluating the implementation of blended learning based on observations and research that has been done, there is an optimization of the increase in mastery of students' knowledge and skills, after conducting various activities that are conditioned on face-to-face activities combined with online ones. The results of this evaluation mean that a well-conditioned blended learning program can influence students in terms of motivation, therefore mastering the knowledge and skills of a course can be optimized through the student learning experience.Â Â
The Heat Treatment effect of Nickel-coated Steel Plate Substrate by Electroless Plating on Hardness Test
Authors: Hirary Marisa , Ramelan Aditianto , . .
Published: March 2021

The present study was aimed to analyze the effect of heat treatment on phase change of thin layer of nickel on steel plate substrate. The coating process was electroless plated using chemical solution. This work requires nickel solution as the main component of coating. Substrate was coated by electroless nickel plating at pH 7.5 and temperature was 85 â„ƒ for 100 minutes with heat treatment for 30 minutes at temperature are 320 â„ƒ and 340 â„ƒ. Furthermore, the substrate will be analyzed with metallography method to obtain visualization of thickness on plate surface. The result show that the layer on steel surface has a uniform thickness. Based on the hardness test, the heated plated resulting the better performance compared with the non-heated one. Surface hardness increased from 134VHN to 646VHN with a coating thickness of 17.49Î¼m and a XRD characterization showed a broadened Ni peak. After heat treatment at temperature are 320â„ƒ and 340â„ƒ, the surface hardness increased up to 851VHN and 1020VHN.Â Â
Low Complexity Interference Alignment for Distributed Large-Scale MIMO Hardware Architecture and Implementation for 5G Communication
Authors: Galih Savitri , . . , . .
Published: March 2021

Massive MIMO or Large Scale MIMO is a promising solution for achieving superior data rates in 5G communication systems. However, it has limitation in term of scalability and coverage for users that has highly spatial separation. Distributed massive MIMO is expected to enhance these drawbacks. One main problem arises in this scheme is the MIMO interference channel condition that can be copied by interference alignment algorithm. The main consideration for interference alignment algorithm in distributed Massive MIMO is to achieve low complexity precoding to eliminate interference channel condition and to design efficient hardware architecture for its implementation. Previous research regarding IA for Distributed Massive MIMO indicate that the complexity issues is still not widely discussed. This paper proposed the low complexity IA scheme for large scale MIMO system based on limited interferer and the implementation of low cost interference alignment and wireless synchronization for distributed MIMO using software defined radio hardware. From the simulation result, it shows that limited interferer IA algorithm achieve acceptable BER performance, i.e. in order of 10-3. The hardware implementation of the IA precoding matrix computation is also discussed. Based on the experiment, it is show that the proposed algorithm and architecture achieved higher hardware performance compared to the linear IA.Â Â
Improvement Branch Line Coupler Isolation in S Band Frequency
Authors: Barnadi Yudi , Agustian Yanyan , Hasan Fuad
Published: March 2021

In this paper, the research was conducted to investigate the effects of optimization dimension to the isolation value of the Branch line coupler. The isolation is very important because it affects to the performance of the duplexer. The smaller value the better isolation performance of the duplexer. This research is carried out by modifying the length and width of the channels of the impedance of the Coupler. In this experiment, Branch-Line coupler is designed in the form of microstrip and fabricated using the FR-4 substrate that has a dielectric constant of 4.6, thickness of 1.3 mm, and 3 GHz operating frequency. To get the optimization value of the isolation characteristic, impedance channel must be modified, which are the length and width of the arms series (Z0 = 50 Î©), the length and width of the arms series (Z0 = 35.35 Î©), and the length and width of the arms shunt (Z0 = 50 Î©). The optimized result of the isolation is -67,786 B