bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Mechanical Properties Under Temperature influence and sucrose composition on cockleshell structure.
Authors: Anpalagan Ranjhini , Kamarudin Kamarul-Azhar , Mohamed Hatta Mohamed Nasrul , Hussin Rosniza , Mohamad Zaleha 
Published: July 2020

Abstract
Cockle shell is one of the marine organisms that easily found in Malaysia. This invertebrate type of animal lived by depending on their shell that contains of high calcium carbonate which makes it so tough and can be explore for further application. In this study, a ceramic material was fabricated from cockle shell and sucrose as a binder. The cockle shell was crushed and milled into small size at around 160 μm -200 μm. The cockle shell powder then was mixed and compacted with sucrose binder by ratio of 10, 20, and 30 wt%. The drying process was carried out in 2 methods which are heating at 150°C for one hour and normal drying at room temperature for 1 day. The effect of binder percentage and drying method on flexural properties, density and porosity of ceramic were investigated. Flexural test result shows that the samples with oven drying produced better resistance compared with samples dried at room temperature and the highest strength was obtained by sample with 20wt% sucrose dried in oven. The sample with 20wt% sucrose dried in oven also has the highest values of density. 20 wt% sucrose binder has higher ultimate strength and higher maximum force. The comparisons of sample morphology were determined by scanning electron morphology (SEM).
Verification of the hydrostatic weighing system with existing gold purity instruments
Authors: Nor Fazrul Mohd , Tamuri Abd Rahman , Ismail Abd Khamim , Mazuki A.A.M. 
Published: July 2020

Abstract
Determination of gold bar purity remains one of the most challenging tasks in gold industry. Currently, the existing instruments have a limitation to determine the purity, which in turn have produced inaccurate gold purity measurement. For example, X-ray fluorescence (XRF) technique has a limitation to penetrate the gold bar and XRF was only used to determine the surface purity. Therefore, an improved non-destructive method and precise technique has been developed to determine the gold purity. Gold density measurement can verify the purity of the gold and in this study, the density of gold bar was calculated using a custom made hydrostatic weighing system (HWS). Several measurements of density were carried out for gold bar and tungsten bar. Using HWS, the density of gold bar and tungsten bar were 19.268 g/ml and 19.206 g/ml respectively. The expanded uncertainty was also evaluated and the value was 0.006 g/ml. The new developed HWS method was also verified with existing density measurement instruments where the same density results has been obtained but the existing instruments have produced bigger uncertainty of 0.2 g/ml. Thus, this study demonstrates that the developed HWS is appropriate to be used to measure the density of gold bar accurately. Furthermore, the new developed system of HWS have shown better measurement with smaller uncertainty and hence the improvement in gold bar purity measurement.
Verification of Mathematical Model for Upper Limb Spasticity with Clinical Data
Authors: Yee J , Low C Y , Ong P , Soh W S , Hanapiah F A , Zakaria N A Che , Enzberg S von , Asmar L , Dumitrescu R 
Published: July 2020

Abstract
Healthcare providers in the field of physical and rehabilitation medicine play a vital role to help patients suffering spasticity readapting themselves to their normal daily activities. Mathematical modeling of spasticity has the potential to avoid the issue of variability in the assessment of spasticity using the Modified Ashworth scale (MAS). In this work, an existing mathematical model for upper limb spasticity is verified using clinical data sets of upper limb spasticity collected in Malaysia at the level of MAS 1+. The data set consists of torque values measured at each elbow angle as the elbow extends from a full flexion position to a full extension position during slow and fast stretch of the forearm. The aim is to find out the capability of the mathematical model and lay a foundation for the future work on data-driven modeling of upper limb spasticity based on the Modified Ashworth Scale.
Bottleneck-Based Heuristic for Permutation Flowshop Scheduling
Authors: Isa N.A. , Bareduan S.A. , Zainudin A.S. 
Published: July 2020

Abstract
This paper addresses the permutation flowshop scheduling problem with objective of makespan minimization. It proposes a heuristic that apply bottleneck-based identification technique and Nawaz, Enscore and Ham (NEH) insertion technique. This experiment was carried out using measurement of four-machines and six-jobs simulated in Microsoft Excel Simple Programming. The computational result show that bottleneck-based (BNB) achieved 60 % and more of optimum solution and heuristic validation result prove that the proposed heuristic resulting to be much better than existing heuristic by achieving more best solution of 6 sets out of 10 sets replication.
Crystallinity of nanocellulose isolated from the flower waste of pine tree (Pinus merkusii)
Authors: Aisiyah Mahrullina Mahirotul , Masruri Masruri , Srihardyastutie Arie 
Published: July 2020

Abstract
Pine flower is an agricultural waste that has high cellulose content. Cellulose is a major material for making nanocellulose. Nanocellulose has been isolated from the flower waste of the pine tree (Pinus merkusii). The process was initiated by delignification and bleaching process with sodium hydroxide 6% and sodium hypochlorite 6% followed by hydrolysis with acetic acid under stirring at 45°C for 1 hour. Three different concentrations of acetic acid (10%, 30%, and 60%) were studied toward nanocellulose crystallinity. Nanocellulose was characterized by FTIR, XRD spectroscopy, and TEM analysis. The result shows that the % yield of nanocellulose was 87.4%, 94.2%, and 91.8% respectively. Nanocellulose has high crystallinity as indicated by the crystallinity index. Besides, the nanocellulose width is 12.82 – 21.36 nm and the length is 267.12 – 326.87 nm.
Experimental and Theoretical Study of Pinostrobin as Copper Corrosion Inhibitor at 1 M H2SO4 Medium
Authors: Hadisaputra Saprizal , Purwoko Agus Abhi , Hakim Aliefman , Wati Rosita , Asnawati Dina , Prananto Yuniar Ponco 
Published: July 2020

Abstract
The effect of variations in concentration and temperature on the efficiency of pinostrobin corrosion inhibition of copper in 1M H2SO4 was studied using an experimental and theoretical approach. Pinostrobin was isolated from the Boesenbergia rotunda L rhizome and was tested for corrosion inhibition of copper in acidic medium. Variations in the concentration of 300 ppm, 400 ppm, and 500 ppm and temperature (308 K, 318 K, and 328 K) were carried out in the weight loss method of corrosion inhibition test. Pinostrobin crystals were isolated with a yield of 57.65 %, a melting point of 98.5 °C and with a purity of 100 %. The optimum corrosion inhibition efficiency of pinostrobin is 65.71 % at a concentration of 500 ppm and a temperature of 328 K. The activation energy value of Ea < 80 kJ.mol−1 indicates the adsorption of pinostrobin on copper surfaces is physical and spontaneously ΔG°ads < -20 kJ.mol−1. The effect of substituent on the efficiency of corrosion inhibition from pinostrobin was studied using density functional theory. The addition of NH2 increased the efficiency of corrosion inhibition to 73.07 %, whereas the addition of NO2 substituents decreased the efficiency of inhibition to 60.97 %. Experimental and theoretical studies have a good correlation in explaining the efficiency of corrosion inhibition from pinostrobin.
Antioxidant and Xanthine Oxidase Inhibitory Activities of Kecapi (Sandoricum koetjape (Burm.f) Merr.) Leaf Extract
Authors: Hamzah Fajar Nur , Subandi  , Sujarwo Wawan , Septama Abdi Wira , Mozef Tjandrawati 
Published: July 2020

AbstractSandoricum koetjapehas been used as folk medicine for the treatment of several diseases. The study was undertaken to determine antioxidant property ofS. koetjapeextract. The xanthine oxidase inhibitory effect was also evaluated. The dried powder ofS. koetjapeleaves was extracted with methanol. The extract was then successively partitioned with different solvents: n-hexane, ethyl acetate, buthanol and water. Phytochemical, total phenolic contents (TPC) and total flavonoid compounds (TFC) were analysed. DPPH scavenging assay was conducted to evaluate antioxidant activity. Xanthine oxidase inhibitor were determined using spectrophotometer. The results showed that amongst of tested extract, methanol extract contained high amount of phenolic and flavonoid compounds. For antioxidant and XO inhibitor, ethyl acetate fraction revealed strong activity with IC50values of 3.70 and 50.18 µg/mL, respectively. XO inhibition by ethyl acetate extract was found to be a competitive inhibition that mimics inhibition mechanism of allopuriol. LC-MS/MS chromatogram exhibited that the extract contains dehydrotumulosic acid, methyl ophiopogonanone A, quercetin-4′-glucoside, luteolin-7-β-D-glucopyranosid and neokurarinol. The result of this study indicated that the potency ofS. koetjapeextract as antioxidant and XO inhibitor.
Synthesis of ZnO/rGO/TiO2 Composite and Its Photocatalytic Activity for Rhodamine B Degradation
Authors: Nurdiansah Haniffudin , Firlyana Rena Eka , Susanti Diah , Purwaningsih Hariyati 
Published: July 2020

Abstract
Nowadays the growth of the textile industry in Indonesia is increasing. An example of dangerous textile waste is Rhodamine-B. Therefore, a method to treat Rhodamine B waste is needed. One method that can be used is photocatalysis. ZnO and TiO2 semiconductors are known as good photocatalyst material because they have a small band gap energy. In addition, reduced graphene oxide (rGO) has a potential due to its good conductivity and large surface area. This study aims to synthesize ZnO/rGO/TiO2 composite. Analysis of the composite shows peaks correspond to diffraction pattern of ZnO, TiO2, and rGO. Based on scanning electron microscope analysis, the surface morphology of the composite was in the form of sheets (rGO), agglomerates (TiO2), and hexagonal nanorod (ZnO). Further confirmation by EDX analysis shows elemental compositions of Zn, Ti, O, C (18.44, 7.44, 46.01, 28.11, respectively). FTIR analysis resulting in bands of C-O at 998 cm−1, Ti-O-Ti at 506 cm−1, and Zn-O at 497 cm−1. Photocatalysis test using the composite gave the optimum value of Rhodamine-B degradation of 94.72 % under UV light irradiation for 5 hours.
Preparation of Cyperus diffusus Vahl cellulose–polyanniline composite for dye removal
Authors: Burhan Ricky Jenihansen , Falahudin Aswin , Salprima Yudha S. , Gustian Irfan 
Published: July 2020

Abstract

C. diffusus Vahl cellulose was used as an alternative in the preparation of cellulose-polyaniline composites. This involved the use of sodium hydroxide, hydrogen peroxide, and sulfuric acid as reagents for the isolation of C. diffusus Vahl cellulose. The isolated material was analysed using Fourier Transforms Infrared (FTIR) and the results showed the it has similar peaks pattern with the original cellulose as observed with 3333 cm−1 for OH stretching, 2889 cm−1 for C-H vibration, and several other indicators. The powder produced was used as a reaction partner for in-situ synthesis of C. diffusus Vahl cellulose-Polyaniline (C. diffusus Vahl cellulose-PANI) in dimethyl sulfoxide (DMSO) using ammonium persulfate (NH4)2S2O8) as the oxidator. The solid material product was effective in metanil yellow adsorption from the corresponding solution up to 99%.
The Effect of Zr Addition on Microstructures and Hardness Properties of Zn-Zr Alloys for Biodegradable Orthopaedic Implant Applications
Authors: Ghani Fahmi Moh Waqyan , Trinanda Achmad Fauzi , Pratiwi Rizki Yuni , Astutiningtyas Sotya , Zakiyuddin Ahmad 
Published: July 2020

Abstract
The development of Mg and Fe based biomaterials in the past decade has been extensively studied as biodegradable material for medical applications. The development of this material is limited in terms of its suitability for clinical applications. Zn-based alloys began to be an alternative to be studied as a substitute for Mg and Fe based biomaterials. Zn-based alloys have a moderate degradation rate but have low mechanical properties, so other elements need to be added to improve their mechanical properties. In this study, the added element is zirconium (Zr) with a composition variation of 0.5%, 1%, and 2%. The alloying method used was casting with a temperature of 550°C. The results of the microstructure analysis, the addition of Zr to Zn alloys will form precipitates in the side of the grain boundaries and more addition of Zr composition, the smaller grain size formed. The grain size from pure Zn until the addition of 2% Zr in the sequence are 266.40 µm, 20.16 µm, 16.70 µm, and 15.85 µm. The XRD analysis, from the addition of Zr, will form the Zn phase and the intermetallic phase Zn22 Zr. The hardness value obtained from pure Zn until 2% Zr in the sequence are 35.162 HV, 41.988 HV, 42.324 HV, 57.112 HV.
Blending Polymer Cellulose Acetate/Polysulfone For Resistance of Protein Fouling
Authors: Indarti Dwi , Putra Dana Iswara , Piluharto Bambang , Setyawan D. 
Published: July 2020

Abstract
Blending polymer CA/PSf was prepared using N.N-dimethylacetamide (DMAc) as solvent and PEG400 as an additive in membrane fabrication. The phase inversion method using immersion precipitation process was carried out to make the membrane CA/PSf. Membrane CA/PSf characterized by measuring the contact angle of the membrane to determine the membrane hydrophilicity. Performance of membrane is measured using water flux and rejection of dextran 70 kDa and Bovine Serum Albumin (BSA) 67 kDa. The contact angle of the membrane CA/PSf which amounted to 50° until 63°, so it can be categorized as hydrophilic membranes, because the value of the contact angle is lower than 90°. The resulting water flux membranes CA/PSf from 3.8708 L.m−2.h−1 to 10.462 L.m−2.h−1. Dextran rejection generated which is equal from 40.24% to 89.53%, while the BSA rejection of membrane from 36.21% to 81.68%. Increasing the composition of PSf produces contact angle and water flux increased, but the rejection of dextran and BSA decreased. Resilience fouling membranes CA/PSf is measured by Relative water Flux Reduction (RFR) and Fouling Resistance. RFR membranes CA/PSf which amounted from 9.445% to 32.75%, while the membrane fouling resistant CA/PSf ranged from 0.6725 to 0.9055. RFR is higher when the amount of PSf increased and indicating that their membranes are prone to fouling, it also can be evidenced by the decreased value of resistance fouling when the composition of PSf increase.
Swelling Effect Observation of The Copper Phthalocyanine Layer on QCM and Its Effect on Surface Roughness and Morphology Changes
Authors: Oktafiansyah Rahmad , Herry Santjojo D J Djoko , Sakti Setyawan P , Zafirah Tyas N , Ghufron Muhammad , Khusnah N F , Masruroh  
Published: July 2020

Abstract
Copper Phthalocyanine (CuPc) is one material often used for the active layer on Quartz Crystal Microbalance (QCM) sensor. One important mechanism which can shorten the recovery time in the sensor is the swelling effect. The swelling effect is studied by observing the morphology of the layer and subsequent changes in QCM frequency during surface contact with three kinds of solution. The solutions used in this study were distilled water, phosphate-buffered saline (PBS) and Tris-HCl. The results of frequency measurements indicate a swelling effect which was shown by the decrease of the frequency change after the injection process. The most significant change in frequency occurs in PBS solutions. This change occurs as PBS has a higher molecular weight and ionic strength than distilled water and Tris-HCl. SEM results show that the swelling of the CuPc layer changes the microstructure layer. A decrease in the roughness of the CuPc layer was also observed due to the presence of buffer solution molecules that diffuse through the layer. Upon diffusion of the solution molecules into the CuPc layer, a continuous decrease in the QCM frequency occurs. Further, the diffusion caused the CuPc microstructure to become more tenuous.
Accelerating cosmologies in an integrable model with noncommutative minisuperspace variables
Authors: Kan Nahomi , Kuniyasu Masashi , Shiraishi Kiyoshi , Takimoto Kohjiroh 
Published: July 2020

Abstract
We study classical and quantum noncommutative cosmology with a Liouville-type scalar degree of freedom. The noncommutativity is imposed on the minisuperspace variables through a deformation of the Poisson algebra. In this paper, we investigate the effects of noncommutativity of minisuperspace variables on the accelerating behavior of the cosmic scale factor. The probability distribution in noncommutative quantum cosmology is also studied and we propose a novel candidate for interpretation of the probability distribution in terms of noncommutative arguments.
Flexoelectric-like radial polarization of single-walled nanotubes from first-principles
Authors: Bennett Daniel 
Published: July 2020

Abstract
Flexoelectricity is the polar response of an insulator to strain gradients such as bending. While the size dependence makes it weak in bulk systems in comparison to piezoelectricity, it can play a bigger role in nanoscale systems such as thin films and nanotubes (NTs). In this paper we demonstrate using first-principles calculations that the walls of carbon nanotubes (CNTs) and transition metal dichalcogenide nanotubes (TMD NTs) are polarized in the radial direction, the strength of the polarization increasing as the size of the NT decreases. This is reminiscent of a flexoelectric response in bulk insulators, the strain gradient being achieved by bending the 2D monolayers into NTs. For CNTs and TMD NTs with chiral indices (n, m), the radial polarization of the walls P
R diverges below

C

(

n
,
m

)

/
a
=

n

2

+
n
m
+

m

2

∼
10

, where C(n, m) is the circumference and a is the monolayer lattice constant. For CNTs, P
R drops to zero above this value but for TMD NTs there is a non-zero polarization, which is ionic rather than electronic. The size dependence of P
R in the TMD NTs is interesting: it increases gradually and reaches a maximum of P
R ∼ 100  C  cm−2 at C(n, m)/a ∼ 15, then decreases until C(n, m)/a ∼ 10 where it starts to diverge. Measurements of the radial strain on the bonds with respect to the monolayers shows that this polarization is the result of a larger strain on the outer bonds than the inner bonds, but did not explain the peculiar size dependence. These results suggest that while the walls of smaller CNTs and TMD NTs are polarized, the walls of larger TMD NTs are also polarized due to a difference in strain on the inner and outer bonds.
Burnout, Mental Health, and Quality of Life Among Employees of a Malaysian Hospital: A Cross-sectional Study
Authors: Woon Luke Sy-Cherng , Tiong Chea Ping 
Published: July 2020

Abstract
Burnout and mental health issues are common among healthcare workers. Burnout and mental ill-health may also adversely affect quality of life (QOL). This study aimed to determine the prevalence of burnout, mental ill-health, and QOL among employees of Hospital Bentong in Pahang state, Malaysia. This was a 2-week, cross-sectional online survey for Hospital Bentong employees. It consisted of (i) sociodemographic data, (ii) respondents’ perceptions, (iii) Malay-version Copenhagen Burnout Inventory (CBI), (iv) 21-item Depression, Anxiety and Stress scale (DASS-21), and (v) WHO Quality of Life-BREF (WHOQOL-BREF) instrument. In total, 52.4% of hospital employees (N = 251) participated in the study. The burnout rates were 17.5% (personal burnout), 13.9% (work burnout), and 6.0% (client burnout). The prevalence rates of depression, anxiety, and stress were 18.7, 38.6, and 12.0%, respectively. In multivariate regression analysis, personal burnout was associated with Malay ethnicity [odds ratio (OR) = 4.54, 95% confidence interval (CI) = 1.41–18.17], management and professional position (OR = 3.89, 95% CI = 1.34–11.29), and having financial problem (OR = 3.29, 95% CI = 1.53–7.06). Work burnout was associated with management and professional position (OR = 7.26, 95% CI = 1.84–28.59), having problem with colleagues (OR = 2.85, 95% CI = 1.08–7.50), and having financial problem (OR = 4.41, 95% CI = 1.82–10.72), while age (OR = 1.12, 95% CI = 1.00–1.25) and male gender (OR = 7.14, 95% CI = 2.00–25.55) were significant factors for client burnout. There were moderate-to-strong correlations between CBI, DASS-21, and WHOQOL-BREF scores (P values &lt;0.01). In mediation analysis, mental ill-health was shown to have significant mediating effect in the relationship between burnout and poor QOL. Such findings need to be replicated across different hospital settings. Studies on effectiveness strategies to manage identified issues will be required.
Associations between phytohormones and cellulose biosynthesis in land plants
Authors: Wang Liu , Hart Bret E , Khan Ghazanfar Abbas , Cruz Edward R , Persson Staffan , Wallace Ian S 
Published: July 2020

AbstractBackgroundPhytohormones are small molecules that regulate virtually every aspect of plant growth and development, from basic cellular processes, such as cell expansion and division, to whole plant environmental responses. While the phytohormone levels and distribution thus tell the plant how to adjust itself, the corresponding growth alterations are actuated by cell wall modification/synthesis and internal turgor. Plant cell walls are complex polysaccharide-rich extracellular matrixes that surround all plant cells. Among the cell wall components, cellulose is typically the major polysaccharide, and is the load-bearing structure of the walls. Hence, the cell wall distribution of cellulose, which is synthesized by large Cellulose Synthase protein complexes at the cell surface, directs plant growth.ScopeHere, we review the relationships between key phytohormone classes and cellulose deposition in plant systems. We present the core signalling pathways associated with each phytohormone and discuss the current understanding of how these signalling pathways impact cellulose biosynthesis with a particular focus on transcriptional and post-translational regulation. Because cortical microtubules underlying the plasma membrane significantly impact the trajectories of Cellulose Synthase Complexes, we also discuss the current understanding of how phytohormone signalling impacts the cortical microtubule array.ConclusionGiven the importance of cellulose deposition and phytohormone signalling in plant growth and development, one would expect that there is substantial cross-talk between these processes; however, mechanisms for many of these relationships remain unclear and should be considered as the target of future studies.