bluuebunny/crossref_metadata_2025_split huggingface dataset:
Glucomannan–Beeswax–Chitosan Antimicrobial Edible Coating to Maintain the Storage Quality of Salak Fruit (Salacca zalacca)
Authors: Meindrawan Bayu , Ofe Ofe , Susanto Clarissa Sarah , Ayman Azzadin , Mangindaan Dave , Kasih Tota Pirdo 
Published: June 2020

AbstractIn this study, the possibility to improve the quality and shelf life of salak (snake fruit, Salacca zalacca) via application of glucomannan–beeswax–chitosan polymer edible film coating is investigated. The formulated glucomannan–beeswax–chitosan edible coating is applied to minimally processed salak, and the characteristics of the edible coating are evaluated. The glucomannan–beeswax–chitosan edible coating not just successfully reduces the growth of Staphylococcus aureus and Escherichia coli (10%, compared to control, that is, the salak fruit coated with glucomannan only), but also decreases the water vapor transfer rate that penetrates salak fruit (by 27% vs control), and lowers the weight loss of salak fruit (<4%, compared to that of control (10% weight loss)). Peeled salak fruit coated with glucomannan–beeswax–chitosan maintains its quality at room temperature in 3 days, without any indication of mold growth. Based on the results in this study, glucomannan–beeswax–chitosan edible coating is a promising antimicrobial edible polymer coating for minimally processed salak fruit, and possibly for other varieties of fruits.
Effect of Carbon Black/Bi2O3 Ratio on the Vulcanization Characteristic and Mechanical Properties of Rubber Compound
Authors: Nurhajati Dwi W. , Lestari Umi R. , Setyorini Ike , Mayasari Hesty E. 
Published: June 2020

AbstractThis study aims to determine the effect of Bi2O3 as a substitute for carbon black (CB) fillers on the characteristics of vulcanization and mechanical properties of rubber compounds. The comparison of CB/Bi2O3 used are 50/0, 45/5, 40/10, and 35/15. Rubber compounds are prepared using two‐rolls mill. The rubber vulcanizates are prepared using hydraulic press at 150 °C. Vulcanization characteristics are determined by the moving die rheometer. Rubber vulcanizates are evaluated from aspects of physical and mechanical properties (tensile strength, elongation, density, hardness), morphology (SEM), and heat aging. It is found that rubber compounds containing high amounts of Bi2O3 show higher torque and higher optimum vulcanization time. In addition, rubber compounds with high Bi2O3 content show higher density, tensile strength, and elongation.
Mastication Process of Natural Rubber/Butadiene Rubber Blending: Validation Method on Influence of Peptizer
Authors: Arti Dewi K. , Hidayat Ade S. , Ulfah Ika M. , Susanto Herri , Wisojodharmo Lies A. , Dandi Ahmad 
Published: June 2020

AbstractThe performance of tire tread is measured by the combination of “magic triangle properties.” They are rolling resistance, traction, and wear. To obtain high quality of tire tread, good quality of rubber compound is necessary to be prepared. Natural rubber (NR) has a wide application especially in tire tread. Cured Butadiene Rubber (BR) impacts excellent abrasion resistance and low rolling resistance due to its low glass transition temperature (Tg). Mastication process is a very important step in compounding preparation. To obtain homogeneous compounding, mastication has to be prepared well. Recently, the effect of peptizer in the mastication process of natural rubber/butadiene rubber has been investigated by using Vestenamer, Aktiplast 8, and Rhenosin 145. To validate to method and formulation, the experiment is repeated three times to find out the type of peptizer that provide the highest compatibility to masticate natural rubber and butadiene rubber as well. The experimental design is done to collect the data and repeatability of each peptizer effect is analyzed by calculating the variance (ANOVA test). As expected, the addition of Vestenamer significantly increases the mechanical properties, and it has better repeatability than others. However, the value of tensile strength and tear strength are still lower than Aktiplast, but it has already fulfilled the requirement, 20 N/mm2 and 200 N, for tensile strength and tear strength, respectively. It is proved that Vestenamer can optimize the mastication process.
Optimization of Fiber Content and Alkali Treatment on Sound Damping Performances of Kenaf Core/Unsaturated Polyester Composites
Authors: Vicarneltor David Natanael , Ujianto Onny , Setijotomo Hendro Sat , Nurindah  
Published: June 2020

AbstractKenaf core/unsaturated polyester (KC/UP) composites are prepared by mechanical stirrer followed by compression molding. Effect of fiber percentage as well as alkali treatment (NaOH concentration and immersion time) on sound damping performance are analyzed and optimized using three factors and three levels of Box–Behnken experimental design. Flexural properties, heat deflection temperature (HDT), density, lignin content, and morphology are investigated on selected samples. The results show that the optimum condition to produce KC/UP composites is predicted at 54.5% of fiber, 8.1% of NaOH used on alkali treatment, and 2 h fiber immersion on NaOH, giving 5.6% of sound damping/mm. Verifying the model results in 5.1% of sound damping/mm. Despite lower value of verification sample than predicted, this is still between 95% of predicting interval (4.1–7.1%), which is still higher than control sample (3.8%), suggesting model capability to predict the result. Further analysis on selected samples with the highest, mid and lowest sound damping property results in the change of flexural modulus at 38%, −9%, and 28%, respectively, and improvement in HDT (23%, 12%, and 22%). However, the flexural strengths of all selected samples are lower than that of control (−37%, −67%, and −44%). Morphology analysis shows that sample with 45% fiber content is more compact than 30% fiber content, which improves sound damping.
The Crystallinity of Arenga pinnata “Ijuk” Fiber Cellulose through KMnO4 Addition on NaClO Bleaching Process
Authors: Yuanita Evana , Pudjiastuti Wiwik , Chalid Mochamad 
Published: June 2020

AbstractArenga pinnata “ijuk” fiber is one of the lignocellulosic sources that is abundant in Indonesia. At present, this fiber is only for brush, shiever, mat, and rope. Delignified “ijuk” fiber is a potential source of cheap crystalline cellulose, a material that can be used for composite. This paper presents chemical treatment of A. pinnata “ijuk” fiber to get cellulose with high crystallinity. The fiber is treated by alkalization with 2% sodium hydroxide (NaOH) for 1 h, 0.01 n KMnO4 as NaClO activator for 10 min and bleaching with 5% NaClO at varying time of treatment 3, 5, 7 h, respectively. For comparison, the fiber is treated with 2% sodium hydroxide (NaOH) for 1 h and then with 5% NaClO without KMnO4 for 3 h (N3). Addition of KMnO4 as NaClO activator will control ClO gas released and then the bleaching process becomes more effective because the ClO gas will bleach the fiber, not releasing fast to the air. Furthermore, NaClO leads an oxidative fragmentation from the remaining lignin and then the lignin dissolves out from the fiber. The result shows that the highest crystallinity of the cellulose is the fiber which is treated by alkalization with 2% sodium hydroxide (NaOH) for 1 h, 0.01 n KMnO4 for 10 min, and oxidation with 5% NaClO for 5 h (KN5). Fourier transform infrared confirms the removal of some lignocellulosic components such as lignin, wax, and hemicelluloses; X‐ray diffraction reveals an increase of crystalline parts in the fiber via cellulose through crystallinity index value. Field emission scanning electron microscopy displays dimension and surface morphology of fiber. So the treatment can remove some amorphous part of the lignocellulose namely, lignin and hemicellulose to obtain cellulose with high crystallinity.
Quantification of internal dosimetry in PET patients: individualized Monte Carlo vs generic phantom‐based calculations
Authors: Neira Sara , Guiu‐Souto Jacobo , Díaz‐Botana Pablo , Pais Paulino , Fernández Carlos , Pubul Virginia , Ruibal Álvaro , Candela‐Juan Cristian , Gago‐Arias Araceli , Pombar Miguel , Pardo‐Montero Juan 
Published: June 2020

PurposeThe purpose of this work is to calculate individualized dose distributions in patients undergoing 18F‐FDG PET/CT studies through a methodology based on full Monte Carlo (MC) simulations and PET/CT patient images, and to compare such values with those obtained by employing nonindividualized phantom‐based methods.MethodsWe developed a MC‐based methodology for individualized internal dose calculations, which relies on CT images (for organ segmentation and dose deposition), PET images (for organ segmentation and distributions of activities), and a biokinetic model (which works with information provided by PET and CT images) to obtain cumulated activities. The software vGATE version 8.1. was employed to carry out the Monte Carlo calculations. We also calculated deposited doses with nonindividualized phantom‐based methods (Cristy–Eckerman, Stabin, and ICRP‐133).ResultsMedian MC‐calculated dose/activity values are within 0.01–0.03 mGy/MBq for most organs, with higher doses delivered especially to the bladder wall, major vessels, and brain (medians of 0.058, 0.060, 0.066 mGy/MBq, respectively). Comparison with values obtained with nonindividualized phantom‐based methods has shown important differences in many cases (ranging from −80% to + 260%). These differences are significant (p < 0.05) for several organs/tissues, namely, remaining tissues, adrenals, bladder wall, bones, upper large intestine, heart, pancreas, skin, and stomach wall.ConclusionsThe methodology presented in this work is a viable and useful method to calculate internal dose distributions in patients undergoing medical procedures involving radiopharmaceuticals, individually, with higher accuracy than phantom‐based methods, fulfilling the guidelines provided by the European Council directive 2013/59/Euratom.
The effect of adding online homework assignments to a small introductory physical geology class
Authors: Brevik Eric C. 
Published: June 2020

AbstractOnline homework (OLH) assignments were added to the Introduction to Physical Geology class at Dickinson State University in the fall semester of 2014. Anticipated advantages included timely feedback and opportunities for students to correct mistakes made during homework completion. The same instructor taught all lecture and laboratory sections over the course of the study, and student performance was compared for the 3 years prior to adopting the OLH and the 3 years after. Following adoption of the OLH, the average grade in the class increased by 7.5% and average test scores increased by 6.2%. The OLH did not significantly improve the performance of the top students (those who received an A), but it did improve the performance of the other students. Test grades showed a similar trend. The average test scores for those who received an A in the class were 88.0% before and 88.6% after adopting the OLH, whereas test averages for students who received less than an A were 63.9% before and 71.4% (7.5% improvement) after adopting the OLH. There was no statistical difference in scores in the Introduction to Physical Geology laboratory over the same period. Students are required to take the lecture and laboratory at the same time, so the student populations were virtually identical. The OLH applied to the lecture, where grades improved, but not to the laboratory, where grades remained consistent. Therefore, it was concluded that the OLH improved student performance.
Fabrication of polystyrene/carbon nanocomposites with superior mechanical properties
Authors: Yeh Shu‐Kai , Su Chi‐Chun , Huang Jian‐Ming , Ke Ming‐Qing , Bogale Dawit , Anbarasan Ramasamy , Tung Kuo‐Lun , Wang Sea‐Fue 
Published: June 2020

AbstractAdding fillers reinforces the modulus of the polymer, but the ductility is sacrificed. Such a phenomenon is especially true for brittle polymers like polystyrene (PS). Nanofillers are known to solve the problem because the high aspect ratio and surface area may improve the stiffness at a much lower loading level, and thus significantly reduce the ductility. However, the dispersion of nanofillers is always challenging. In the current investigation, PS nanocomposites were prepared by melt compounding, ultrasonication, and solution compounding to investigate the effect of the addition of the following carbon nanomaterial to the mechanical properties: nanographite (H25), multiwalled carbon nanotube, carbon nanofiber, and thermally reduced graphene (TRG). Among them, TRG exhibited the best reinforcing effect. Young's modulus of PS increased by 27% with only 0.1 wt% loading of TRG, and the ductility remained unchanged. Such an improvement has rarely been reported in thermoplastic polymer nanocomposites. The results were carefully analyzed and compared with those reported in the available literature. In this study, the solution compounding method offered the best modulus value. The aspect ratio of carbon nanomaterials in the composite was estimated by the Halpin‐Tsai equation. These estimations agree well with the transmission electron microscopy microstructure results.
High‐performance HTL‐free perovskite solar cell: An efficient composition of ZnO NRs, RGO, and CuInS2 QDs, as electron‐transporting layer matrix
Authors: Taheri‐Ledari Reza , Valadi Kobra , Maleki Ali 
Published: June 2020

AbstractA hole‐transporting layer (HTL)‐free perovskite solar cell (PSC) with fluorine‐doped tin oxide (FTO)/nanocomposite electron‐transporting layer (ETL)/perovskite/Au structure is presented that takes advantage of a novel ternary nanocomposite constructed of zinc oxide (ZnO) nanorods, reduced graphene oxide (RGO), and copper indium sulfide quantum dots (CuInS2 QDs), as ETL. Concisely, the photoelectric and photovoltaic properties of all the individual, binary, and ternary composites were monitored by using of the photoluminescence (PL) spectroscopy, UV‐visible (vis) spectroscopy, J‐V curves, and incident photon‐to‐current conversion efficiency (IPCE) spectra studies. The comparative values exhibited a noticeable benefit for the ZnO‐RGO5%‐CuInS220% ternary nanocomposite as an appropriate ETL for PCS. Also, the comparative structural studies on the individual nanoscale components, binary, and ternary nanocomposite (with different percentages of CuInS2 QDs) were precisely performed by Fourier transform infrared (FT‐IR), energy‐dispersive X‐ray (EDX), X‐ray diffraction (XRD), Raman spectroscopy, and field emission scanning electron microscopy (FESEM), as well. Overall, after careful optimization of the ETL, a15.74% efficiency was resulted through applying the prepared ZnO‐RGO5%‐CuInS220% composite in a HTL‐free PCS with 0.33 cm2 active area.
Rock glaciers automatic mapping using optical imagery and convolutional neural networks
Authors: Marcer Marco 
Published: June 2020

AbstractDespite their relevance in alpine environments, rock glaciers remain uncharted in several regions of the globe due to the considerable efforts required in the mapping process. To develop a support tool for rock glacier mapping, this study investigates the feasibility using artificial intelligence to recognize these landforms on satellite optical imagery. The results of this exploratory analysis indicate that convolutional neural networks can accurately classify unshadowed and snow‐free rock glaciers images (88% true positives and 79% true negatives on the test set). A simple detection algorithm is also tested, achieving inferior, but still promising, performances. The algorithm works on large orthoimages and is capable of spotting large rock glaciers characterized by a ridge–furrow structure, although the detection results in several false positives. Overall, the results suggest that further developments of this methodology can produce useful tools to facilitate efforts in mapping rock glaciers for large uncharted regions.
Comparative analysis of dose verification between computed tomography scan phantom and virtual digital phantom of Delta4
Authors: Liu Ting‐Ting , Dai Zhi‐Tao , Kang Kai‐Lian , Gao Li‐Ying , Liu Rui‐Feng , Ou‐Yang Shui‐Gen 
Published: June 2020

AbstractObjectiveThis study compared the dose verification results between plans created based on computed tomography (CT) scan and digital virtual phantom.MethodsWe retrospectively analyzed the treatment plan of 10 patients with head and neck cancer. CT scanned phantom and digital virtual phantom measured using Delta4 3‐D matrix were used to generate verification plans for each patient. The doses based on the effective measurement volume of the two phantoms were compared, and the verification results were analyzed using gamma index analysis.ResultsFor the body, the minimum dose, the maximum dose, the average dose, and the total dose were 0.72 ± 0.46 cGy, 251.86 ± 49.83 cGy, 58.10 ± 10.93 cGy, and 154.67 ± 20.28 cGy, respectively, in the CT‐scan group, and 0.62 ± 0.36 cGy, 248.34 ± 48.59 cGy, 57.20 ± 10.77 cGy, and 151.57 ± 19.73 cGy, respectively in the Uniform group. The difference between the groups was significant (P < 0.05). In the Delta4 analysis software, the dose deviation, distance to agreement, and gamma passing rates were 73.39 ± 10.75%, 95.25 ± 1.00%, and 96.67 ± 1.415%, respectively in the CT‐scan group, and 83.36 ± 10.15%, 98.61 ± 0.810%, and 99.38 ± 0.452%, respectively, in the Uniform group. The two plans were significantly different (P < 0.05), and there was a 3% difference in the gamma passing rate. Therefore, the conclusions relating to the examined dose applied, the groups were significantly higher than those of CT‐scan groups. (both P‐values were <0.05). As the parameter value increases, the difference decreases. In the 3 mm/3% standard, both groups met the clinical requirement of gamma passing rate of >95%, but the Uniform group had a higher passing rate than the CT‐scan group.ConclusionsBecause the passing rate was higher in the Uniform group than in the CT‐scan group, it is recommended to use digital virtual phantom modules to generate verification plans in clinical practice.
Endothelium‐derived dopamine modulates EFS‐induced contractions of human umbilical vessels
Authors: Britto‐Júnior José , Pinheiro David H. A. , Justo Alberto F. O. , Figueiredo Murari Guilherme M. , Campos Rafael , Mariano Fernanda V. , de Souza Valéria B. , Schenka André A. , Mónica Fabiola Z. , Antunes Edson , De Nucci Gilberto 
Published: June 2020

AbstractElectrical field stimulation (EFS) induces contractions of both snake aorta and human umbilical cord vessels (HUCV) which were dependent on the presence of the endothelium. This study aimed to establish the nature of the mediator(s) responsible for EFS‐induced contractions in HUCV. Rings with or without endothelium from human umbilical artery (HUA) or vein (HUV) were mounted in organ bath chambers containing oxygenated, heated Krebs‐Henseleit's solution. Basal release of dopamine (DA), noradrenaline, and adrenaline was measured by LC‐MS‐MS. Cumulative concentration‐response curves were performed with dopamine in the absence and in the presence of L‐NAME or of dopamine antagonists. EFS studies were performed in the presence and absence of L‐NAME, the α‐adrenergic blockers prazosin and idazoxan, and the dopamine antagonists SCH‐23390 and haloperidol. Tyrosine hydroxylase (TH) and dopa‐decarboxylase (DDC) were studied by immunohistochemistry and fluorescence in situ hybridizations. Basal release of dopamine requires an intact endothelium in both HUA and HUV. TH and DDC are present only in the endothelium of both HUA and HUV as determined by immunohistochemistry. Dopamine induced contractions in HUA only in the presence of L‐NAME. Dopamine‐induced contractions in HUV were strongly potentiated by L‐NAME. The EFS‐induced contractions in both HUA and HUV were potentiated by L‐NAME and inhibited by the D2‐like receptor antagonist haloperidol. The α‐adrenergic antagonists prazosin and idazoxan and the D1‐like receptor antagonist SCH‐23390 had no effect on the EFS‐induced contractions of HUA and HUV. Endothelium‐derived dopamine is a major modulator of HUCV reactivity in vitro.
Experimental removal of invasive Africanized honey bees increased breeding population size of the endangered Lear's macaw
Authors: Pacífico Erica C , Efstathion Caroline A , Filadelfo Thiago , Horsburgh Robert , Cunha Roberta A , Paschotto Fernanda R , Denes Francisco V , Gilardi James , Tella José L 
Published: June 2020

AbstractBACKGROUNDInvasive Africanized honey bees potentially compete with cavity‐nesting birds in South America. However, the impacts of this competition and its conservation consequences to threatened species are poorly known. We quantified the presence of these bees and assessed their competition for cliff cavities used by nesting Lear's macaws Anodorhynchus leari, a globally endangered parrot endemic to the Caatinga biome of Brazil. We treated beehives with permethrin by shooting them with a crossbow bolt that distributed the compound upon impact. When feasible, we removed the comb and applied an insecticide (fipronil) to deter bee recolonization. We subsequently surveyed the macaw breeding population to verify whether our treatment allowed for nest recruitment in cavities previously occupied by bees.RESULTSWe recorded > 100 beehives in the nesting cliffs. Hives outnumbered macaw nests tenfold in two areas recently recolonized by macaws. Cavities occupied by bees were significantly higher than those occupied by macaws, suggesting that macaws may be forced to breed in lower cavities. None of the untreated cavities (n = 50) were occupied by nesting macaws, whereas 15% of treated cavities (n = 52) were occupied within 2 years post treatment. Treated cavities occupied by macaws were significantly higher than those not occupied. Hive management increased macaw breeding population by 71% of the macaw breeding population increase.CONCLUSIONExperimental hive treatments were effective in restoring nesting resources lost due to bee infestation. An intensive and continued eradication program is recommended to enhance macaw habitat restoration, facilitating its expansion into historical areas. © 2020 Society of Chemical Industry
Postgraduate migration behaviour of international university students supported from the Czech Development Cooperation scholarships
Authors: Novotný Josef , Feřtrová Marie , Jungwiertová Lucie 
Published: June 2020

AbstractThe development impacts of international scholarships for students from the Global South are most commonly understood through the expansion of human capital in the students' home countries for which the scholars' return analysed in this paper represents a key prerequisite. Utilising the theory of planned behaviour, this paper examines factors influencing the plans to return and actual postgraduation migration behaviour of 430 grantees of the Czech scholarship programme financed from the official development aid. One half of the current grantees reported plan to return, and only the 31% of alumni respondents actually returned suggesting a risk of brain drain. We found that economic integration rather than perceived sociocultural integration influences migration decision making of international students. We show how the propensity to return to scholars' home countries can be estimated from cross‐sectional data. A graphical path model was developed, which helps to understand drivers of postgraduate migration behaviour of international students.