bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparing Lexical Cues in Listener Processing of Dysarthria and Speech in Noise
Authors: Fletcher Annalise , McAuliffe Megan
Published: February 2021

Purpose

The frequency of a word and its number of phonologically similar neighbors can dramatically affect how likely it is to be accurately identified in adverse listening conditions. This study compares how these two cues affect listeners' processing of speech in noise and dysarthric speech.

Method

Seven speakers with moderate hypokinetic dysarthria and eight healthy control speakers were recorded producing the same set of phrases. Statements from control speakers were mixed with noise at a level selected to match the intelligibility range of the speakers with dysarthria. A binomial mixed-effects model quantified the effects of word frequency and phonological density on word identification.

Results

The model revealed significant effects of word frequency (
b
= 0.37,
SE
= 0.12,
p
= .002) and phonological neighborhood density (
b
= 0.40,
SE
= 0.12,
p
= .001). There was no effect of speaking condition (i.e., dysarthric speech vs. speech in noise). However, a significant interaction was observed between speaking condition and word frequency (
b
= 0.26,
SE
= 0.04,
p
< .001).

Conclusions

The model's interactions indicated that listeners were more strongly influenced by the effects of word frequency when decoding moderate hypokinetic dysarthria as compared to speech in noise. Differences in listener reliance on lexical cues may have important implications for the selection of communication-based treatment strategies for speakers with dysarthria.
Formant Trajectory Patterns of American English /l/ Produced by Adults and Children
Authors: Chung Hyunju , Weismer Gary
Published: February 2021

Purpose

Most acoustic and articulatory studies on /l/ have focused on either duration, formant frequencies, or tongue shape during the constriction interval. Only a limited set of data exists for the transition characteristics of /l/ to and from surrounding vowels. The aim of this study was to examine second formant (F2) transition characteristics of /l/ produced by young children and adults. This was to better understand articulatory behaviors in the production of /l/ and potential clinical applications of these data to typical and delayed /l/ development.

Method

Participants included 17 children with typically developing speech between the ages of 2 and 5 years, and 10 female adult speakers of Southern American English. Each subject produced single words containing pre- and postvocalic /l/ in two vowel contexts (/i, ɪ/ and /ɔ, ɑ/). F2 transitions, out of and into /l/ constriction intervals from the adjacent vowels, were analyzed for perceptually acceptable /l/ productions. The F2 transition extent, duration, and rate, as well as F2 loci data, were compared across age groups by vowel context for both pre- and postvocalic /l/.

Results

F2 transitions of adults' /l/ showed a great similarity across and within speakers. Those of young children showed greater variability, but became increasingly similar to those of adults with age. The F2 loci data seemed consistent with greater coarticulation among children than adults. This conclusion, however, must be regarded as preliminary due to the possible influence of different vocal tract size across ages and variability in the data.

Conclusions

The results suggest that adult patterns can serve as a reliable reference to which children's /l/ productions can be evaluated. The articulatory configurations associated with the /l/ constriction interval and the vocal tract movements into and out of that interval may provide insight into the underlying difficulties related to misarticulated /l/.
Physical properties of brightest cluster galaxies up to redshift 1.80 based on HST data
Authors: Chu A. , Durret F. , Márquez I.
Published: February 2021

Context. Brightest cluster galaxies (BCGs) grow by accreting numerous smaller galaxies, and can be used as tracers of cluster formation and evolution in the cosmic web. However, there is still controversy regarding the main epoch of formation of BCGs; some authors believe they already formed before redshift z = 2, while others find that they are still evolving at more recent epochs.

Aims. We study the physical properties of a large sample of BCGs covering a wide redshift range up to z = 1.8 and analyzed in a homogeneous way, to see if their characteristics vary with redshift. As a first step we also present a new tool to determine for each cluster which galaxy is the BCG.

Methods. For a sample of 137 clusters with HST images in the optical and/or infrared, we analyzed the BCG properties by applying GALFIT with one or two Sérsic components. For each BCG we thus computed the Sérsic index, effective radius, major axis position angle, and surface brightness. We then searched for correlations of these quantities with redshift.

Results. We find that the BCGs follow the Kormendy relation (between the effective radius and the mean surface brightness), with a slope that remains constant with redshift, but with a variation with redshift of the ordinate at the origin. Although the trends are faint, we find that the absolute magnitudes and the effective radii tend to become respectively brighter and bigger with decreasing redshift. On the other hand, we find no significant correlation of the mean surface brightnesses or Sérsic indices with redshift. The major axes of the cluster elongations and of the BCGs agree within 30° for 73% of our clusters at redshift z ≤ 0.9.

Conclusions. Our results agree with the BCGs being mainly formed before redshift z = 2. The alignment of the major axes of BCGs with their clusters agree with the general idea that BCGs form at the same time as clusters by accreting matter along the filaments of the cosmic web.
2D mineral substrate leads to more sensitive flexible magnetosensors
Authors: Fore Meredith
Published: February 2021

By using a layered mica substrate, magnetosensors can be made extremely flexible without sacrificing sensitivity.
Instability of mixed convection in a differentially heated channel filled with porous medium: A finite amplitude analysis
Authors: Khandelwal Manish K. , Sharma Abhishek K. , Bera P.
Published: February 2021

This paper reports the instability mechanism of parallel mixed convection flow in a differentially heated vertical channel filled with a highly permeable porous medium. Linear and weakly nonlinear stability analysis involving the finite-amplitude expansion method is considered to investigate the instability mechanism of the flow. Darcy–Brinkman's model is considered. The results are presented for both water-saturated and oil-saturated porous medium flows. The linear stability results show that the stability of the flow decreases on increasing the Reynolds number as well as the Darcy number, and the contribution of viscous dissipation in the kinetic energy balance is not negligible for highly permeable porous medium flows. The results from the weakly nonlinear analysis show only supercritical bifurcation in the vicinity of the critical or bifurcation point for both the fluids; however, for water, the parallel flow may experience subcritical bifurcation away from the critical point, which depends on the value of the Darcy number. The variation of neutral stability curves of the parallel flow of water reveals that a bifurcation that is supercritical for some wavenumber may be subcritical at other nearby wavenumbers. The nonlinear interaction of different harmonics enhances the heat transfer rate as well as the friction coefficient in the linearly unstable regime. A comparison with the results using a model based on volume averaged Navier–Stokes equation reveals the possibility of subcritical bifurcation even in the vicinity of the critical point.
Progress in blade-coating method for perovskite solar cells toward commercialization
Authors: Wu Runsheng , Wang Chunhua , Jiang Minhua , Liu Chengyu , Liu Dongyang , Li Shuigen , Kong Qingrong , He Wei , Zhan Changjun , Zhang Fayun , Liu Xiaohong , Yang Bingchu , Hu Wei
Published: February 2021

The hybrid organic–inorganic halide perovskite solar cells (PSCs) have attracted considerable attention in the photovoltaic community during the last decade due to unique properties, such as high absorption coefficient, solutionable fabrication, and compatibility with roll-to-roll technology. A certified power conversion efficiency of PSCs as high as 25.2% has been obtained, approaching the levels of silicon solar cells, copper indium gallium selenide (CIGS), and cadmium telluride (CdTe) thin-film solar cells. However, the device area of a PSC is one of the biggest challenges for the commercialize applications. To fabricate large-area PSCs, various fabrication methods have been proposed, including spray coating, slot-die coating, vacuum deposition, and blade coating. Here, the blade-coating technique progress for the PSC fabrication has been reviewed. Moreover, the optimized ways during the solution fabrication process, the efficient strategy for improving the perovskite films' morphology, have also been summarized in this work. In the last part, the challenges and opportunities of PSC commercialization have also been proposed.
Pulsed-field nuclear magnetic resonance: Status and prospects
Authors: Liu Qinying , Liu Shiyu , Luo Yongkang , Han Xiaotao
Published: February 2021

High-magnetic-field nuclear magnetic resonance (NMR) has manifested itself as an indispensable tool in modern scientific research in the fields of physics, chemistry, materials science, biology, and medicine, among others, owing to its great advantages in both measurement sensitivity and quantum controllability. At present, the use of pulsed fields is the only controllable and nondestructive way to generate high magnetic fields of up to 100 T. NMR combined with pulsed fields is therefore considered to have immense potential for application in multiple scientific and technical disciplines. Irrespective of the paramount technical challenges, including short duration of the pulsed fields, unstable plateaus, and poor field homogeneity and reproducibility, great progress has been made in a number of pulsed-field laboratories in Germany, France, and Japan. In this paper, we briefly review the status of the pulsed-field NMR technique, as well as its applications in multiple disciplines. We also discuss future trends with regard to the upgrading of pulsed-field NMR.
East Asia has delinked – can Ethiopia delink too?
Authors: Pérez Francisco
Published: February 2021

The possible emergence of a developmental state in Ethiopia has renewed the debate among African activists, scholars and policymakers over how to explain the remarkable success of the ‘East Asian model’. Rapid industrialisation in South Korea, Taiwan and China supposedly invalidates dependency theory, yet Samir Amin’s framework of delinking can better explain the success of these countries than can competing theories of the developmental state, since it highlights the role of international and domestic political alliances. Delinking means submitting international trade and financial relations to domestic priorities and is necessary for capitalist or socialist development.
From surface data to bulk properties: a case study for antiphase boundaries in GaP on Si(001)
Authors: Farin P , Eisele H , Dähne M , Lenz A
Published: February 2021

The orientation, atomic structure, and charge state of defects in crystals have a large influence on the functionality of resultant semiconductor devices. Two-dimensional defects are especially challenging to analyze, as they are embedded within the bulk. We developed a data analysis procedure using information from atomically resolved cross-sectional surface data from two non-parallel surfaces, enabling us to draw conclusions about two-dimensional defects within the bulk. Using antiphase boundaries (APBs) in GaP on Si

001

as a model system, we show that this approach can be applied to any material and microscopy method. For the GaP/Si

001

system and for two-side cross-sectional scanning tunneling microscopy as the experimental tool, the procedure shows that the commonly discussed

111

and

112

APBs do not arise in the investigated sample, whereas the data strongly indicates that previously not recognized

123

APBs are present. Furthermore, a statistical analysis allows a calculation of the net excess charge carrier density introduced into the crystal by the APBs. Its value is negligible compared to the density of wrong bonds that characterize the APBs, since negative and positive excess charges compensate each other almost completely. Moreover, we suggest that controlled enhancement of the formation of APBs may also lead to applications in thermoelectric devices.
Tunable and polarization-sensitive graphene-based terahertz absorber with eight absorption bands
Authors: Cai Yijun , Guo Yongbo , Zhang Hongyi , Wang Yi , Chen Chengying , Lin Feng , Zuo Shikai , Zhou Yuanguo
Published: February 2021

A metamaterial absorber consisting of stacked and orthogonal elliptical graphene layers is proposed to achieve eight absorption bands in the terahertz (THz) frequency range. By adjusting the length of the short or long axis for each graphene ellipse, the corresponding absorption peak can be tuned independently. Electric field distributions are present to reveal the physical mechanism. The absorption spectrum can also be tuned by varying the chemical potential of each graphene ellipse and the manipulation for the polarization angle of the incidence. Moreover, the absorber can work properly under oblique incidences. Our work paves a way for designing tunable THz absorbers with numerous absorption bands.
Hierarchical porous carbon materials obtained by Cu–Al double hydroxide templates with high gravimetric and volumetric capacitance
Authors: Zhang Mingyang , Sun Yue , Song Rongjun
Published: February 2021

The hard-template method belongs to an effective route for preparing porous carbon materials with ideal hierarchical pores. In this work, a kind of hierarchical porous carbon (HPC) with high gravimetric and volumetric capacitance is fabricated by the use of Al–Cu double hydroxides (Al–Cu DHs) as hard templates and polyethylene glycol-200 as carbon precursors. It is found that the Al/Cu molar ratio has a profound influence on the morphology and composition of Al–Cu DHs and the obtained hierarchical porous architecture of HPCs owing to the template and catalyst functions of both Cu and Al2O3. For Al/Cu molar ratios of 5:1 and 7:1, the prepared HPC-05 and HPC-07 display a large specific surface area and appropriate hierarchical porous architecture. They can be used as the electrode materials of supercapacitors without any activation. The HPC-05 exhibits gravimetric capacitance (296.9 F g−1) and high volumetric capacitance (183.3 F cm−3). Moreover, the capacitance retention is 105% in 1 M Na2SO4 electrolyte with an ultrahigh gravimetric energy density of 16.32 W h kg−1 and a volumetric energy density of 10.09 W h l−1. This paper provides a tunable double-hydroxide-template way to construct HPC materials with high gravimetric and volume capacitance.
IPEM Topical Report: an international IPEM survey of MRI use for external beam radiotherapy treatment planning
Authors: Speight Richard , Tyyger Marcus , Schmidt Maria A , Liney Gary , Johnstone Robert , Eccles Cynthia L , Dubec Michael , George Ben , Henry Ann , Herbert Trina , Nyholm Tufve , Mahmood Faisal , Korhonen Juha , Sims Rick , Tijssen Rob H N , Vanhoutte Frederik , Busoni Simone , Lacornerie Thomas , McCallum Hazel
Published: February 2021

Introduction/Background. Despite growing interest in magnetic resonance imaging (MRI), integration in external beam radiotherapy (EBRT) treatment planning uptake varies globally. In order to understand the current international landscape of MRI in EBRT a survey has been performed in 11 countries. This work reports on differences and common themes identified. Methods. A multi-disciplinary Institute of Physics and Engineering in Medicine working party modified a survey previously used in the UK to understand current practice using MRI for EBRT treatment planning, investigate how MRI is currently used and managed as well as identify knowledge gaps. It was distributed electronically within 11 countries: Australia, Belgium, Denmark, Finland, France, Italy, the Netherlands, New Zealand, Sweden, the UK and the USA. Results. The survey response rate within the USA was <1% and hence these results omitted from the analysis. In the other 10 countries the survey had a median response rate of 77% per country. Direct MRI access, defined as either having a dedicated MRI scanner for radiotherapy (RT) or access to a radiology MRI scanner, varied between countries. France, Italy and the UK reported the lowest direct MRI access rates and all other countries reported direct access in ≥82% of centres. Whilst ≥83% of centres in Denmark and Sweden reported having dedicated MRI scanners for EBRT, all other countries reported ≤29%. Anatomical sites receiving MRI for EBRT varied between countries with brain, prostate, head and neck being most common. Commissioning and QA of image registration and MRI scanners varied greatly, as did MRI sequences performed, staffing models and training given to different staff groups. The lack of financial reimbursement for MR was a consistent barrier for MRI implementation for RT for all countries and MR access was a reported important barrier for all countries except Sweden and Denmark. Conclusion. No country has a comprehensive approach for MR in EBRT adoption and financial barriers are present worldwide. Variations between countries in practice, equipment, staffing models, training, QA and MRI sequences have been identified, and are likely to be due to differences in funding as well as a lack of consensus or guidelines in the literature. Access to dedicated MR for EBRT is limited in all but Sweden and Denmark, but in all countries there are financial challenges with ongoing per patient costs. Despite these challenges, significant interest exists in increasing MR guided EBRT planning over the next 5 years.
Color-electric conductivity in a viscous quark-gluon plasma *
Authors: Jiang Bing-feng , Shi Shao-wu , Hou De-fu , Li Jia-rong
Published: February 2021

Several different transport processes, such as heat, momentum, and charge transports, may occur simultaneously in a thermal plasma system. The corresponding transport coefficients are heat conductivity, shear viscosity, and electric conductivity. In the present study, we investigate the color-electric conductivity of the quark-gluon plasma (QGP) in the presence of shear viscosity, focusing on the connection between the charge transport and momentum transport. To achieve this goal, we solve the viscous chromohydrodynamic equations obtained from the QGP kinetic theory associated with the distribution function modified by shear viscosity. According to the solved color fluctuations of hydrodynamic quantities, we obtain the induced color current through which the color-electric conductivity is derived. Numerical analysis shows that the conductivity properties of the QGP are mainly demonstrated by the longitudinal part of the color-electric conductivity. Shear viscosity has an appreciable impact on real and imaginary parts of the color-electric conductivity in some frequency regions.
Immobilization of activated carbon in fractionated clay from East Kalimantan as wastewater adsorption material
Authors: Sasria N , Patandean S W , Awali J , Lubis M P D
Published: February 2021

The aim of this research is to make immobilization of activated carbon in fractionated clay from East Kalimantan as wastewater adsorption material. Fractionated clay and activated carbon were made from the lai shell, then the adsorbents were immobilized using a ratio of 2.5:5 (g activated carbon: g clay) to increase their adsorption ability to wastewater. Furthermore, the adsorbents were characterized using X-Ray Diffraction (XRD) to analyze the phase, composition, and crystal structure and Scanning electron microscopy (SEM) to analyze the morphology of adsorbent and Fourier Transform Infrared (FTIR) to analyze the functional group. The results of adsorbent characterization by XRD showed that the sample contains 70% SiO2 phase which is shown at the highest and sharpest peak, namely at 26.47°. The results of SEM analysis on immobilized adsorbents indicates the presence of silica nanoparticles that appear as white aggregates, where this silica is a compound contained in the clay. Whereas the results of the adsorbent characterization using FTIR showed that the functional groups in fractionated clay were Si-OH (silanol), Al-O-Al, Si-C and Si-O-Si (siloxane). In activated carbon found several functional groups namely C-H (alkyne), C=C (aromatics) and alkylhalide. Whereas the immobilized adsorbents with a ratio of 2.5:5 are Si-OH, Si-O-Si, Al-O-Al, alkylhalide and C-H. This shows that immobilized adsorbents have formed quite well.
The influence of cocamide DEA towards the characteristics of transparent soap
Authors: Cholifah U , Nafiunisa A , Aryanti N , Wardhani D H
Published: February 2021

Soap is a mixture of fatty acid compounds used as body cleansers so it must not caused irritation to the skin. The quality of sugar, alcohol, and glycerin is crucial for the clarity and clearness of soap. Replacement of hazardous chemicals are neccessary because chemical surfactants contain lots of carcinogenic substances, skin irritants, eyes and respiratory disorders. This research was conducted as natural surfactants applied on transparent soap including cocamide DEA. Cocamide DEA concentration varies at 0%, 2.5%, 5.0%, 7.5%, and 10.0%. The surfactant properties of cocamide DEA will characterized based on Critical Micell Consentration (CMC), Hydrophile Lipophile Balance (HLB), and foaming properties. After the characteristics of cocamide DEA are investigated, hereinafter it applied to produce transparent soap. The process of making soap uses the hot method with a hotplate as the medium. The addition of surfactant cocamide DEA was able to reduce the surface tension up to 31.27x10−3 N/m implied the surface tension reduction for 56.56% to water. The transparent soap with the addition of 10% cocamide DEA had the best formulation with the properties of has 8% moisture content, 69.38% foaming ability, 0.146% free fatty acid, 0.0938% free alkali, unsaponified fat 2.376%, pH 8.9 and hardness 569.6 mm/g/s, has highest brightness level, and still in accordance with indonesian standard.
The Effect of Addition of F3O4 and Sintering Temperature on Properties of the Magnetite/Hydroxyapatite Particles Produced through the Coprecipitation Technique
Authors: Fadli Ahmad , Iskandar Dion Julio , Pane Khobar Bahari
Published: February 2021

Nowadays, the composite of magnetite/hydroxyapatite has become one of the main topics in biomedical field especially as drug delivery system. In this paper, the effect of sintering temperature and Fe3O4addition on the properties of coprecipitation produced by magnetite/hydroxyapatite composite is investigated. The magnetite was first dispersed into 100 mL aquadest and mixed with 33.7 mmol Ca(NO3)2.4H2O while stiring for 15 minutes. Subsequently, the mixture was reacted with 20 mmol (NH4)2HPO4for 120 minutes at 90ºC. The mixture pH of 11 during process was controlled by adding NH4OH 25%. The mixture was left to stand for 1 day, washed and then the precipitate was separated from the mixture. The precipitate was dried at 90ºC for 1 day and it ended with sintering for 2 hours. The composite powder was characterized by field emission scanning election microscopy (FESEM), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). The result showed that increase in the amount of of Fe3O4in the composite, it produced the larger crystalline Fe3O4size of 15.59 nm, a decrease in crystallinity to 14.22%, and a higher saturation magnetization was 17.2 emu/g. The higher sintering temperature causes an increase in the size of a hydroxyapatite crystal to 22.94 nm, an increase in crystallinity to 22.55%, and a lower saturation magnetization was 4.0 emu/g.
Synthesis and characterization of targeted superparamagnetic MRI contrast agent MnFe2O4-chitosan-folate
Authors: Gunawan A.H. , Sugiharto Y. , Yulianto S. , Fikri A.
Published: February 2021

Superparamagnetic materials MnFe2O4 in nanosized form, is useful for some applications such as magnetic storage, electronic devices, biosensing and MRI contrast agent. Efficiency of the contrast agent (CA) delivery to cellular targets generally depends on the rate of vascular extravasation and pharmacokinetics in the plasma. Contrast agents with longer circulation time could show better kinetics at the target site. In this research, strategies to prolong the plasma life is conjugatingMnFe2O4 NPs with chitosan-folate. MnFe2O4 NPs were synthesized from MnCl2 with FeCl3 using a reducing agent NaOH. In other side, chitosan was conjugated with folic acid to produce chitosan-folate compounds. Then chitosan-folate was reacted with MnFe2O4 nanoparticles to produce MnFe2O4 -chitosan-folate.MnFe2O4 nanoparticles was characterized using UV Vis, FTIR, PSA and SEM EDX. The characterization of MnFe2O4 -chitosan-folate is also carried out using radioactive agent by labeling with 99mTc radionuclide which will produce the MnFe2O4 - (99m Tc) Chitosan-folate complex. The characterization tests using 99m Tc radionuclides showed yields and radiochemical purity ofmore than 95%. It indicates that the compound of MnFe2O4-chitosan-folate has been successfully synthesized. MnFe2O4-chitosan-folate nanoparticles as finished product will be used for targeted MRI Contrast agent.
Effect of iron fortification on gummy candies properties: basic nutrient, microstructure, and texture during the storage period
Authors: Handayani Noer Abyor , Krisanti Elsa , Kartohardjono Sutrasno , Mulia Kamarza
Published: February 2021

Iron fortification program relates to iron delivery through daily foods, which have a potential impact on many people. In this study, chitosan microparticle loaded with ferrous gluconate was used as fortificant, while gummy candies were selected as food vehicles. This work aimed to assess the effect of iron microparticles addition on basic nutrient composition, textural, and microstructural characteristics. The properties of iron microparticles obtained from the spray drying method were also discussed in this article. The iron fortification was carried out by adding the iron microparticles into the candies solution. This solution was then molded and cooled at room temperature before the analysis. The yield, iron loading, efficiency encapsulation, mean diameter, and SPAN factor of iron microparticles were 49%, 3.5 mg Fe/100 mg dried microparticles, 48%, 17 µm, and 1.7. The iron microparticle had a spherical shape with the wrinkles structure on the surface. Therefore, the fortified gummy candies had wavy structures with the prominent spheres. The protein and fat content of our gummy candies were higher than the commercial gummy candies. However, gummy candies’ hardness and gumminess value had changed significantly, while the cohesiveness and springiness properties were not significantly different during the storage.
Synthesis and characterization of mesoporous silica from beach sands as silica source
Authors: Salamah S , Trisunaryanti W , Kartini I , Purwono S
Published: February 2021

The amorphous mesoporous silica was successfully synthesized from beach sand sources. Dodecyl amine, DDA, was used as a mesoporous template under a sol-gel reaction. The synthesized mesoporous silica has a high specific surface area 766.40 m2/g, pore volume 0.51 cc/g, average pore diameter in mesoporous range 3.04 nm, and relatively high acidity value 0.88 mmol/g. It was found that rotation speed during the addition of DDA affects greatly the porosity formation, with higher rotation speed favors porosity formation.
Enhancement of strength and flexibility of high-density polyethylene using rubber leaves
Authors: Shaari Norin Zamiah Kassim , Rahman Nurfatheen Abd , Taha Ahmad Redha , Alauddin Sakinah Mohd , Akhbar Suffiyana
Published: February 2021

High density polyethylene (HDPE) polymer suffers with lack of strength and flexibility that result in fracture of vessels and leakage of piping system. One way to overcome the brittleness problem of the polymer is by reinforcement of fillers such as fibers into the polymer matrix to form a polymer composite. In this study, the effect of incorporating rubber leaves as the filler into high density polyethylene (HDPE) polymer matrix on the tensile properties and morphology of the polymer composite was investigated. The composites were prepared with or without addition of glycerol as plasticizer and citric acid as cross linker. Despite using a common size of the filler, the sieve sizes of the rubber leaves were varied at 200µm, 300µm and 500µm respectively. Results show that the presence of 200 µm rubber leaves with glycerol and citric acid increased the strength of the polymer composites, where the tensile strength achieves 22.1 MPa without jeopardizing the elongation of the composite. The image from SEM reveals that rubber leaves fibers and plasticizers are dispersed homogeneously in the polymer matrix HDPE. This potential used of rubber leaves in the manufacturing of HDPE polymer composites will help to utilize the abundant amount of rubber leaves.
Scanning Electron Microscopy Observation of Coir Fibre with Alkali and Drying Method Treatment
Authors: Windyandari A , Kurdi O , Sulardjaka  , Tauviqirrahman M
Published: February 2021

The natural fiber, such as bamboo, hemp, ramie, jute, and coir, has been proposed as an alternative fiber to replace the synthetic fibers. Coir fiber, which is physically recognized as coarse and stiff fiber with red-brown colored, comprises lignin, cellulose, hemicellulose, and other plant substance. Coir fibers capability can stretch beyond the elastic limit with no rupture and excellent resistance to microbiological and salt degradation. Therefore coir fiber can be applied as an alternative material for a marine structure such as boat and small crafts. In this paper, the scanning electron microscopy (SEM) observation was made to evaluate the influence of alkali treatment (2% and 6% NaOH) and the drying method, including sun drying, oven, and air drying. Progressive changes in surface morphology due to the two kinds of coir fibre treatments were presented.
Comparison of Identified Compounds from Extracted Pelargonium Radula Leaves by Supercritical Fluid Extraction and Commercial Geranium Essential Oil
Authors: Gaaffar I F , Zainuddin N A M , Zainal S
Published: February 2021

Supercritical fluid extraction (SFE) is a green technology that is convenient to extract Pelargonium radula (P. radula) leaves without leaving any negative impacts on the environment. It is an alternative approach to reduce the solvent residual problem during the extraction process. Therefore, this research was performed to compare the active ingredients extracted by SFE technique with the commercialized geranium essential oil in the market. Extraction of powdered P. radula leaves by supercritical carbon dioxide (SC-CO2) was operated at constant pressure, temperature, and solvent flowrate which were 100 bar, 40 °C, and 24 mL/min, respectively. SC- CO2 extraction on P. radula leaves result in 0.19 % of oil yield. By comparing extracted P. radula oil with the commercialized geranium essential oil, both oil consists of benzyl acetate, citronellol, geraniol, e-amyl cinnamaldehyde, isopropyl tetradecanoate, and isopropyl hexadecanoate.
Copper Removal by Enterobacter cloacae strain IrSuk1, Enterobacter cloacae strain IrSuk4a, and Serratia nematodiphila strain IrSuk13 Isolated from Sukolilo River-Indonesia
Authors: Irawati Wahyu , Tahya Candra Yulius
Published: February 2021

Copper is one of the pollutants found in Sukolilo river due to industrial activities surrounding this area. The concentration of copper in this river has exceeded the threshold causing the death of organisms in the sea and various diseases. The presence of copper in the environment continually causes bacteria to develop copper removal mechanism by accumulation and biosorption so that copper removal occurs. Waste treatment by using indigenous bacteria is an effective and economical way to remove copper from the environment. This study aims to isolate and characterize bacteria from the Sukolilo River. Selected bacterial isolates were tested for copper accumulation and biosorption potential. The growth medium used was Luria Bertani with the addition of CuSO4. Bacterial identification was carried out based on the 16S rDNA gene. Bacterial resistance was tested by determining the Minimum Inhibitory Concentration (MIC) value. The ability of copper accumulation and biosorption is measured using atomic absorption spectrophotometer. The results of bacterial isolation from Sukolilo River have obtained three bacterial isolates with the MIC values of 9 mM CuSO4 and coded by strains IrSuk1, IrSuk4a, and IrSuk13. Each bacterial strain has high similarities with Enterobacter cloacae, Enterobacter cloacae strain subsp. dissolvens, and Serratia nematodiphila strain LMG 2683 respectively with a value of 96.68%, 98.31%, and 99.03%. Copper quantities accumulated by that three bacterial strain are of 0.96 mg, 0.85 mg,1.89 mg per gram dry weight of cells, respectively. The efficiency of copper biosorption by strains IrSuk1, IrSuk4a, and IrSuk13 was 68.78%, 68.34%, and 68.47%, respectively.
Characterization of polyethylene-starch based film at a different percentage of crude palm oil and Aloe vera gel
Authors: Karim S F A , Jai J , Hamid K H K , Irfan M A
Published: February 2021

Combination of polytethylene (PE) and starch is an alternative to enhance the capability of plastic film to degrade faster. However, the compatibility between each material was unsatisfied due to the hydrophobic nature of PE and hydrophilic nature of starch. Therefore, this paper was introducing crude palm oil (CPO) to act as plasticizer whileAloe vera(AV) as the compatibilizer. The objective of this paper was to study the changes caused by CPO and AV towards thermal degradation, thermal properties, and mechanical performance of PE/starch-based film. Melt-blending and hot press technique were applied to prepare the samples. Film 0.15C/1.08Av performed highest thermal degradation rate occurred with the lowest residue left. An increasing amount of CPO had caused decrement of percent crystallinity of the film while an increasing amount of AV shows an inconsistent value of percent crystallinity. The best tensile strength occurred at the formulation of 0.15C/1.08Av while highest elongation obtained by 2.7C/0.06Av. As a conclusion, CPO and AV affect the properties of the film. However, only AV has the potential to proceed with the next stage in improving the tensile strength of the film while CPO did not show good improvement.
Comparing the Performance of Lactobacillus delbrueckii and Lactobacillus rhamnosus on The Formation of Lactic Acid from Glucose
Authors: maryanty Yanty , Hadiantoro Sigit , Widjajanti Kristina , Kinasih Ruri Hapsari , Natalia Vicky Meritha Nanda
Published: February 2021

For producing lactic acid, it may use pure glucose. Lactic acid is a category in organic compounds, and it has a high sales value since being used in the food processing industry is quite diverse. Lactic acid has also has used in numerous manufacturing fields and that same food industry, including pharmaceuticals, cosmetics, chemicals, and textiles. We can make lactic acid from refined starch and cellulose fermentation materials; lactic acid is a monomer of poly-lactic acid (PLA), the primary ingredient manufacturer of environmentally friendly biodegradable plastic. Variables used in this research include up to 10-60 percent for medium BHM (Bushnell Haas Medium), 40-60 percent for medium MRS (de Man Rogosa and Sharpe), and Lactobacillus delbrueckii and Lactobacillus rhamnosus for glucose concentration. After the fermentation process, we took lactic acid, and absorbance, lactic acid, and glucose levels have measured. The study shows that best-operating conditions are 21 hours of fermentation time. Lactobacillus delbrueckii develops more vital lactic acid from both the media used, BHM, and MRS media.
Antimicrobial properties colorimetric film of Damask Rose and freshness monitoring: A review
Authors: Suzihaque M.U.H. , Mohammad Nurul Aida Binti
Published: February 2021

This work aims to investigate the antimicrobial properties of colorimetric film using different types of anthocyanins on different types of microorganisms such as Escherichia coli, Staphylococcus aureus, Bacillus cereus, Listeria innocua, Pseudomonas aeruginosa and other types of microorganisms. Most of colorimetric film with addition of anthocyanins exhibits the antimicrobial properties which could prolong the shelf life of food products. Moreover, the methods to extract anthocyanins using different kinds solvent such as ethanol, methanol, tetrahydrofuran and others solvent also been studied. Finally, the effect of colorimetric films such as colour changes to monitor the freshness on different kinds of food products also been reported.
Preparation of Solid Acid – Activated Carbon as Catalyst in Aspirin Synthesis
Authors: Kurniawansyah Firman , Syifa Sarah , Pakpahan Ronal Marada , Ni’mah Hikmatun , Roesyadi Achmad
Published: February 2021

Pharmaceutical synthesis commonly relies on a homogeneous acid catalyst, which is relatively simple in application yet problematic in product purification procedures. This study was an effort to investigate an alternative replacement for homogeneous acid catalysts with an acidified solid catalyst, developed from activated carbon. The activated carbon catalyst had been treated with sulfuric acid before it was applied to produce aspirin (acetylsalicylic acid) through catalytic acetylation route. Using atmospheric pressure reaction, conducted at 353 K, aspirin was successfully synthesized. When salicylic acid and acetic acid glacial were used as reactants, approximately 9-10 % reaction yield could be obtained. Replacement of acetic acid with acetic anhydride in the acetylation reaction produced an overall yield as high as 28 %.
Ultrasound-assisted Esterification of Glycerol for Triacetin Production
Authors: Raemas A F A , Cahyonugroho J , Wicaksono A D , Dewi R L , Hadiyanto
Published: February 2021

Glycerol is a by-product of biodiesel production. So far, glycerol has not been used optimally. An alternative product that can be produced from glycerol is triacetin through the esterification process. Research on the review of reaction kinetics to determine the optimum conditions of the reaction still limited. Previous study also reported that the esterification process requires quite a long reaction time. Therefore, in this study ultrasonic technology will be used to accelerate the reaction of glycerol esterification with acetic acid using sulfuric acid catalyst. The purpose of this study is to study the effect of ultrasonic technology on the conversion of esterification of glycerol/acetic acid, and to observe the kinetic study of triacetin production. To answer this goal, this study uses a set of ultrasonic devices as a substitute for the esterification of conventional models. The greatest conversion results are obtained when the reaction temperature is 1000C with a mole ratio of glycerol/mole of acetic acid 1/8. The use of ultrasonic technology in theory should have a greater impact on conversion results. The reaction order obtained is order 2 with the largest k value in the mole ratio of glycerol: acetic acid 1: 8 which is 0.0006 (l.mol−1menit−1). Due to the variation of moles ratio, the ratio at 1/6 and 1/4 did not show significant changes of reaction rate, the changes are constant for both first and second order reaction. But at the mole ratio of 1/8, the reaction rate constant shows a significant different for temperature changes.
Glycerol Steam Reforming to Biohydrogen over Zeolite Catalyst from Geothermal Solid Waste
Authors: Widayat  , Philia J , Dwilaksana M I , Luthfi A
Published: February 2021

Glycerol (C3H8O3) is a polyhydric alcohol compound with three hydroxyl groups in one molecule, polar and viscous in nature. Glycerol can be obtained through the transesterification process in the biodiesel industry, the saponification process in the soap industry and the hydrolysis process in the fatty acid industry. The research method follows two partss, which is catalyst synthesis and steam reforming process. The zeolite catalyst was characterized using X-Ray Diffraction (XRD) to determine crystal characteristic, Scanning Electron Microscopy (SEM) to identify the morphology of the catalyst, and surface area by using BET method. Zeolite catalyst have analcime diffraction pattern Performance of zeolite catalyst was evaluated trough glycerol steam reforming process. The biohydrogen yield increased up to 47% by using zeolite catalyst. Reaction temperature is a parameter that affected to the biohydrogen yield.
PALM KERNEL SHELL BIOCHAR CATALYST FOR BIODIESEL PRODUCTION FROM WASTE COOKING OIL
Authors: Widayat  , Fernanda A A A , Silvie E S
Published: February 2021

Biodiesel is an alternative fuel and have properties similar to conventional diesel. The process of making biodiesel requires two stages of the process, namely esterification then proceed with the transesterification. But to keep the process efficient, the esterification and transesterification are carried out simultaneously. A new type of catalyst is being developed that comes from carbonization of incomplete natural products called biochar. Biochar has better catalyst performance for FFA esterification, and higher stability than other solid acid catalysts. The research procedure consist of stages: Pretreatment Palm Kernel Shell (PKS), Increasing Surface Size and Porosity, catalyst impregnation with H2SO4 and (NH4)2Fe(SO4)2.6H2O, and the biodiesel manufacture. Weight variations of the catalyst (1% wt; 1.5 wt%; 2% wt, 2.5% wt; and 3% wt) and variations of temperature (50°C; 55°C; 60°C; 65°C; 65°C and 70°C) to the %FAME biodiesel produced, is used in this research.
Production of biodegradable plastics using aking rice starch and chitosan from crab shells as a substitute for conventional plastic
Authors: Sasria N , Hernando R , Lubis M P D , Zulfikar A
Published: February 2021

The aim of this research is to make biodegradable plastics using starch and chitosan from crab shells as a substitute for conventional plastic. Biodegradable plastic synthesis can utilize organic materials such as crab shell waste and Aking rice as the basic ingredients. Crab shells are used as basic ingredients because they contain chitosan which has several beneficial properties namely biocompability, biodegradability, hydrophilicity and antibacterial. Meanwhile, aking rice waste which is a household waste can also be used as a biodegradable plastic base material because it contains starch consisting of two types of polymers namely amylose and amylopectin which can form a thin layer. In the manufacture of bioplastics, a transparent and strong enough sample was obtained, namely 1 g of chitosan, 3% glycerol and bioplastic which had sufficient flexibility but had an uneven surface, namely 2 gr chitosan, 5% glycerol samples. Plastics with the highest percentage of biodegradation, 33.3%, were found in samples with 1 g of chitosan, 3% glycerol, while the lowest percentage of biodegradation was 2% which was obtained in samples with 2 gr chitosan, 5% glycerol.
Competitiveness in removing copper, zinc and chromium trivalent in plating industrial effluent by using hydroxide precipitation versus sulphide precipitation
Authors: Yatim Siti Rohana Mohd , Zainuddin N A , Mokhtar Nurul Shahirazni , Syahjidan Hanin Nazhifah , Kamsuri Siti Nor Hazliyana
Published: February 2021

Plating industry wastewater is one of the processes that may contain various types of heavy metals. The most common heavy metals that mostly found are copper, nickel, cadmium, chromium, silver, zinc, and lead. In this study, three types of metals which are copper, zinc and chromium trivalent were removed using hydroxide precipitation and sulphide precipitation. Both performances of the method were observed and compared. A jar test was used to determine the optimum pH, coagulant dosage and precipitant dosage. The coagulant and precipitant used in this experiment was ferric chloride (FeCl3), poly aluminium chloride (PAC), sodium hydroxide (hydroxide precipitant) and sodium sulphide (sulphide precipitation) respectively. In order to remove chromium trivalent, sodium metabisulfite was used to reduce chromium hexavalent to chromium trivalent. Based on the result, hydroxide precipitation can remove 86.61% of copper, 99.81% of zinc and 99.99% of chromium trivalent. While, for sulphide precipitation, 93.91% of copper, 99.37% of zinc and 99.99% of chromium trivalent were removed. Therefore, sulphide precipitation can remove better mixed heavy metals, thus it also produces less total suspended solid compared to hydroxide precipitation.
Fuel Grade Bioetanol Production from Suweg Starch Through Distilation-Adsorption Process Using Natural Zeolite
Authors: Hargono H , Jos B , Purwanto P , Sumardiono S , Zakaria M F
Published: February 2021

Suweg (Amorphophallus campanulatus B) is a sweet tuber which has starch content around 77%, it is suitable as raw material for fuel grade bioethanol production. Bioethanol is ethanol derived from biomass. Fuel grade bioethanol must have a minimum concentration 99.5%. This research will study the effect of zeolite adsorbent concentration on the ethanol purification. The manufacture of fuel grade bioethanol through hydrolysis, fermentation, and purification via distillation and adsorption. Hydrolysis and fermentation (SSF) were carried out on Suweg starch at concentration of 250 g/L using StargenTM 002 at a concentration of 1.5% (w/w) and a concentration of 5 g/L Saccharomyces cerevisiae for 78 hours, producing maximum crude ethanol at a concentration of 14.09% for 54 hours. Furthermore, this crude ethanol is purified using two-stage distillation for 105 minutes and adsorption using natural zeolite with various concentration of 30-90% (w/v) for 120 minutes. The best results of distillation purification produce ethanol concentration of 94.78% (v/v) for 90 minutes, while the adsorption process stage produces 99.62% bioethanol using 90% (w/v) zeolite for 90 minutes.
Simultaneous Biogas Upgrade and Production of Precipitated Calcium Carbonate
Authors: Madhania S , Abdurrahman F M , Naufal M , Kusidanto K , Machmudah S , Winardi S
Published: February 2021

Biogas upgrading is a necessary step to remove impurities and increase a calorific value of biogas before it can be used as a proper energy source. The most significant impurity in raw biogas is typically carbon dioxide, composing up to 50% of biogas volume. Carbon dioxide capture is therefore an important part of the upgrading process which in turn raises the question of the availability of final carbon storage. This problem can be addressed by using calcium hydroxide solution or other lime-based solvents as scrubber in carbon dioxide capture via carbonation where precipitated calcium carbonate (PCC) is formed as a by-product. This paper reviews the viability of packed column, bubble column, and spray column for simultaneous biogas purification by CO2 capture and PCC synthesis, as well as examining various parameters that affect both carbon dioxide capture and the production of PCC. Among the three reviewed types of contactors, only packed column is deemed unsuitable for the simultaneous process. The optimal condition for both carbon dioxide scrubbing efficiency and PCC yield can be obtained by using a high liquid flow rate, low gas flow rate, and high solvent concentration. However, the desired characteristics of PCC should be considered in determining the operating parameters as the said characteristics such as crystal phase, morphology, and particle size are affected by several operating parameters, namely gas flow rate, solvent concentration, temperature, size of bubbles, and concentration of additives.