bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on control scheme of on-line measurement system for key dimension of spinning head
Authors: Jin Mingzhi , Min Min , Lin Xuehui , Liu Hongjiao
Published: July 2020

According to the basic principles of roller measurement and displacement measurement, the on-line measurement system of the outer circumference and roundness tolerance and its control scheme are discussed. To implement automatic and real time measurement of circumference and roundness tolerance, the S7-200 PLC is selected as the controller, the STEP7-Microwin V4.0 is used for programming, the ladder diagram is used as the programming language. The motion simulation test of the measurement system is carried out, and the results show that the control scheme is feasible.
Preliminary of finite element analysis (FEA) investigation on the stent expansion
Authors: Lazim Zulfaqih , Ismail Al Emran , Taib Ishkrizat
Published: July 2020

The requirement of stent expansion is important to stent deployment on the inner of the defected blood vessel. This defected blood vessel decreases in lumen diameter size because of accumulation of fat or plaque and caused the reduction of blood flow and oxygen supply to overall body. According to clinical guidelines, blood vessel that blockage by 70% need to be stenting. Stent expand past it elastic limit and plastically deform until the targeted diameter is achieved. Explicit dynamics Finite Element Analysis (FEA) was used in this paper to analyse the stent expansion process. The knowledge of stent radial displacement could prevent the injury of inner surface of artery while understanding on longitudinal foreshortening that aided the stent placement on targeted artery location. The controlled variable was geometry, material and boundary condition of stent. The manipulated variable was the speed of pressure application. The outcomes of this stent expansion simulation are maximum radial expansion, the uniform of radial displacement and longitudinal foreshortening. This simulation results help to improve stent installation on human body for balloon expandable stent and increase the understanding of explicit dynamics structure simulation of finite element in biomedical application.
Physical Properties and Hardness of Treated Amorphous Silica as Reinforcement of AA7075 Recycled Aluminum Chip
Authors: Mohd Joharudin Nurul Farahin , Latif Noradila Abdul , Mustapa Mohammad Sukri , Badarulzaman Nur Azam , Mahmod Muhammad Faisal
Published: July 2020

Solid state recycling techniques of waste aluminum materials without melting the material is a process that consumed less energy consumption. The reuses of waste materials such as aluminum scrap and rice husk ash lead to the friendly environmentally and low cost of production. Physical properties and hardness of treated amorphous silica as reinforcement of AA7075 recycled aluminum chip were investigated. Recycled aluminum sample AA7075 reinforced treated amorphous silica by rice husk ash was prepared by the technique of powder metallurgy (PM) owing of reduced energy consumption and operating cost in comparison with conventional cast-recycling. The presence of silica exists in rice husk ash obtained after through chemical treatment and burning process of rice husk at temperatures of 700°C for 2 hours. The effect of aluminum recycled chip with rice husk ash composite with composition of 2.5 wt.%, 5 wt.%, 7.5 wt.%, 10 wt.% and 12.5 wt.%, on physical properties and hardness were investigated. Based on investigation to AA7075 recycled aluminum chip reinforced treated amorphous silica by rice husk ash, the porosity and water absorption of composite of metal matrix is increase with increasing of composition of treated rice husk ash as the density shows decrease when the treated rice husk ash is added up to 5 wt.%. The addition of treated rice husk ash has improve the hardness of composite of metal matrix from 53.49 Hv of 100 wt.% of AA7075 recycled aluminum chip to 69.53 Hv of composite of metal matrix at 10 wt.% of composition of treated rice husk ash. Based on this research, treated amorphous silica as reinforcement has enhance the physical properties and hardness of recycled aluminum chip sample in composition up to 10 wt.% of treated amorphous silica.
Optimization of Acoustical Properties Polyurethane (PU) Wood Fibres Foam Composites
Authors: Wahab Hanani Abdul , Rus Anika Zafiah M. , Moen Ahmad Tajuddin , Ngadimon Khairul Nizam , Noor Fazimah Mat
Published: July 2020

In this study, an optimization approach was proposed to improve acoustical behaviours of PU foams. The important parameters of PU foams: content of the combination of renewable monomer and epoxy as polyol, methylene diphenyl diisocyanate (MDI) as crosslinker. Their effects on sound absorption coefficient of PU foams were studied by using Taguchi methods. In addition, wood fibres were incorporated into PU foams as fillers to improve the acoustical properties of PU foams. Three controlled factors: the monomers, wood fibres and sample thickness with three levels for each factor were chosen and Taguchi method based on orthogonal array L9 (33) was employed to conduct the experiments. Based on the results of Taguchi’s orthogonal array L9 (33), signal-to noise (S/N) analysis was used and developed to determine an optimal formulation of PU wood fibres foam composites. The results showed that the noise reduction coefficient (NRC) had showed an increased value from 0.4850 to 0.5550 positively improved the acoustic property and the best combination values of variables were monomer mixture of 25 gram, filler ratio of 3% wt and sample thickness of 30mm.
Characterization of Continuous Gradient Functionally Graded Natural Fiber Reinforced Polymer Composites
Authors: Jamaludin M I H , Jamian S , Awang M K , Kamarudin K A , Nor M K Mohd , Ismail A E
Published: July 2020

In this study, cylindrical tubes of functionally graded natural fibre reinforced polymer (FGNF/epoxy) composite are fabricated using horizontal centrifugal casting method. Natural fibres (NF) used in this research are coconut coir and oil palm empty fruit bunch (OPEFB). Natural fibres are mixed with epoxy at four different compositions which is at 0%, 5%, 10% and 15%. The study aims to determine the mechanical properties and microstructure of the FGNF/Epoxy composites. In this method, a homogenous mixture of epoxy liquid and natural fibres is inserted into mould simultaneously. Then, the mould is rotated at a constant speed for 4 hours. Effect of this process, the natural fibres particles in epoxy liquid move radial during mould rotation. Hardness and compression test are carried out to characterize the FGNF/epoxy cylindrical tubes. The microstructures of the composites are observed using optical microscope (OM) and scanning electron microscope (SEM). From the microstructural observation, it is found that the natural fibres particles can be graded from inner to outer surfaces of the FGNF/epoxy cylindrical tubes. The hardness value of the outer part of the FGNF/epoxy fabricated is higher than the middle and inner parts. Besides, from the compression test it shows that epoxy reinforced NF give a better result in strength compared to specimen without reinforced NF. However, the strength value decrease when the fibres percentage increase more than 5%. FGNF/epoxy with 5% NF content gives a balanced composition to have high hardness value and strength.
Synthesis and molecular docking study of 6-chloropyrazine-2-carboxylic acid derivatives
Authors: Aijijiyah Nur Pasca , Ghulam Fahmi Muhammad Riza , Fatmawati Sri , Santoso Mardi
Published: July 2020

One of the most lethal and frequent infectious diseases worldwide is tuberculosis. Multi and extensively tuberculosis drug-resistant constitutes a serious problem and emphasizes the need for novel anti-tubercular agents. Accordingly, various pyrazine-2-carboxamides were synthesized and evaluated as potential anti-tuberculosis agents. The synthesis involved reaction of pyrazinoic acids with thionyl chloride to yield acyl chlorides which on treatment with various anilines gave various pyrazine-2-carboxamides. Based on structure-activity relationships extracted from previously published, this paper reported the synthesis and molecular docking study of 6-chloropyrazine-2-carboxamides. Synthesis involved reaction of 6-chloropyrazinoic acid with 2,4,6-trichlorobenzoyl chloride instead of thionyl chloride which listed under the Chemical Weapons Convention as it may use for the production of chemical weapons. Structure identification of 6-chloropyrazine-2-carboxamides was carried out by 1H NMR, 13C NMR, FTIR, and high-resolution mass spectroscopy. It is predicted that 6-chloro-N-octylpyrazine-2-carboxamide has better bioactivity against Mycobacterium tuberculosis, based on molecular docking study.
The Potency of Antioxidant Perfume of Essential Oils to Reduce Free Radical Content in Air
Authors: Deshinta Selena B , Cahyo F A D , Aggreini G D , Utomo Edi P , Tazi I
Published: July 2020

Free radical contamination is very dangerous for health. Perfume contains essential oils whose components are potential as antiradical. Antioxidant perfume is a perfume made from essential oil with a certain concentration which is very effective to reduce free radicals in the air. This study aims to determine the effectiveness of essential oils as antiradical compounds using laboratory experiments in the reduction of free radical concentration of DPPH with various concentrations of fruit extract which containing terpenoid component. DPPH concentration changes in the air followed by using electronic nose (E-Nose) equipped with multisensory gas. The experimental results showed that the critical concentration of fruit extract which effectively decreased free radical i.e. apple, orange, grape, melon, and lemon were 7.47%, 6.21%, 15.61%, 7.58%, and 6.22%. The greater concentration of these critical concentrations of fruit extracts is potentially as prooxidants.
Physicochemical Properties and Antibacterial Activity of Castor Oil and Its Derivatives
Authors: Fitranda M I , Sutrisno  , Marfu’ah S
Published: July 2020

Castor oil is vegetable oil sourced from castor seeds (Ricinus communis Linn). The main content of fatty acids in castor oil are ricinoleic acid (92%), oleic acid (3.53%), linoleic acid (2.90%), stearic acid (1.02%), and myristic acid (0.55%). Research on the antibacterial activity of castor oil and ricinoleic fatty acid has been carried out but for the K-soap and fatty acids methyl esters of castor oil have not been conducted. This research aims to produce castor oil derivatives, namely K-soap, free fatty acids (FFAs) and fatty acids methyl esters of (FAMEs) and evaluate their antibacterial activity. The results of the study included (1) K-soap (solid, white, melting point 168–175°C), (2) free fatty acids (liquid, yellow, boiling point 210°C, density 0.98 g.mL−1, refractive index 1.46, viscosity 693.22 cSt, and the value of acids, saponification, and esters are 145.88, 294.52, 148.64), (3) fatty acids methyl esters (liquid, yellow, boiling point 170°C, density 0.98 g.mL−1, refractive index 1.46, viscosity 27.31 cSt, and the value of acids, saponification and esters are 0.33, 392.7, 392.37). K-soap, free fatty acids, and methyl esters from castor oil have antibacterial activity against Escherichia coli and Staphylococcus aureus bacteria.
Antibacterial activity of Achromobacter sp. and Bacillus sp., bacterial endophytes derived from Mangrove Ceriops tagal (Perr.) C.B.Robb
Authors: Haryani Yuli , Hilma Rahmiwati , Delfira Noviza , Martalinda Tetty , Puspita Fifi , Friska Amelia , Juwita Dita , Farniga Analdi , Ardi Fri
Published: July 2020

A total of 95 bacterial endophytes have been isolated from mangroves plant in Bengkalis coastal area, Riau Province, Indonesia. Mangrove plant samples were identified as Bruguiera sp. and Ceriops tagal (Perr.) C.B.Robb. Antagonism study showed that 4 out of 95 isolates were possessed antibacterial activity based on their ability to inhibit the growth of Vibrio alginolyticus and Staphylococcus aureus; while none of them was able to inhibit Escherichia coli. According to the results of 16s rRNA genes amplification, the closest species relative of the 4 active isolates was Achromobacter insolitus (isolate no. 34), Bacillus siamensis (isolate no. 39), and Bacillus subtilis (isolate no. 88 and 89). This is the first report on bacterial endophytes associated with Mangrove in Riau Province, Indonesia.
Antifungal Activity of Red Dragon Peel (Hylocereus polyrhizus)
Authors: Hendra Rudi , Masdeatresa Lidya , Almurdani Muhammad , Abdulah Rizky , Haryani Yuli
Published: July 2020

Red dragon fruit (Hylocereus polyrhizus) is a species of plant that provides natural pigment which is betalain. Betalain is one of the pigments that give a natural color to flowers and fruits. Moreover, of betalain in red dragon fruit peel, there is a bioactive compound such as polyphenol and flavonoid with antioxidant and antifungal activities. This research was objected to extract pigments and other secondary metabolites from red dragon fruit peel using ethanol, methanol, dichloromethane, and ethyl acetate solvents, continued with determined potential activity againstCandida albicansby using Resazurin Microtiter Assay (REMA) method. Furthermore, total phenolics compounds (TPC) and total flavonoid compounds (TFC) were determined from all the extracts. The results of antifungal activity showed various inhibition percentage against the fungal at 500 ppm. The ethyl acetate showed the highest activity among the extracts with 74.27% inhibition followed by pigment extracts (60.88%). Furthermore, from test TPC and TFC determination, the ethyl acetate possessed the highest amount with the value of 34.38 mg gallic acid equivalent/g fresh weight and 28.62 mg quercetin/g fresh weight, respectively. Therefore, to find the active compounds, multiple analysis is needed.
Phytochemistry and Antibacterial Activity Evaluation of Genitri (Elaeocarpus ganitrus)
Authors: Indriatie Retno , Mudaliana Siti , Hapsari Febriyana Rizky , Masruri Masruri
Published: July 2020

TheElaeocarpus ganitrushas local name as genitri. It has been used traditionally as traditional medicine. This paper reported the phytochemistry and their antibacterial activity onStaphylococcus aureusandEscherichia coli. Several extracts have been afforded using high speed extraction technique using methanol, ethyl acetate and n-hexane as solvents. The extract is composed of alkaloid, tannin, and flavonoid. The negative result is afforded for saponin test. The MIC of all extracts in both bacteria are above 10 mg/mL. Moreover, the quantitative analysis using spiking method using liquid chromatography found a quercetin and rutin in minor quantity of some sample extract.
The Carbazole Compounds Endowed with Phosphonic Anchoring Group for Sensitizer in Dye-Sensitized Solar Cells
Authors: Kusumawati Y , Pamungkas B S
Published: July 2020

The sensitizer dye contacts onto the TiO2 surface through an anchoring group in a Dye-Sensitized Solar Cells (DSSC). The thermal stability of the anchoring group and TiO2 binding contact is important to be considered in order to obtain the cell stability. Phosphonic acid is an anchoring group that has a good binding-contact thermal stability with TiO2 surface. In this research we investigated through the computational study the electronic properties of carbazole derivative compounds endowed with the phosphonic anchoring-groups (CP). A series of 10 CP derivatives was studied which has a different functional donor group. The electronic properties were investigated using the TD-DFT method with the CAM-B3LYP basis set. The substitution of carboxyl group with the phosphonic one showed the absorption spectrum to the blue shift (5-70 nm) which gave a less beneficial effect to the DSSC performance. The addition of donor functional group aniline into the CP (aniline-CP) could shift back the absorption spectrum to the red-shift. The DSSC parameter also has been calculated including the electron injection driving force ΔGinject and the open circuit votage (eVOC). Overall the aniline-CP has the best performance among the observed compounds which showed the highest ΔGinject (-0.84872 eV) and eVOC (2.763 V).
A Potency of Microcellulose from Pineapple Leave Isolated by Hydrolysis-Assisted Sonication
Authors: Latif Luqi Khoiriyah , Masruri Masruri , Rumhayati Barlah
Published: July 2020

Cellulose has been reported have many functions for separation and adsorption of heavy metals and organic materials waste or pollutants. This paper reported the preparation of micro size cellulose from the waste of pineapple leaves. The strategy involves delignification, bleaching, and hydrolysis process. The hydrolysis step plays an important role for cutting of the cellulose chain, and ultrasonication assisted hydrolytic procedure was applied. In addition, the isolated product was characterized by means of FTIR spectrometry to identify functional group, Scanning Electron Microscopy to inform morphology features, and Particle Size Analyzer to inform the size of cellulose particle. The yield of initial isolated cellulose was 62.07%. Then, through the ultrasonication process using 30% of sulphuric acid for 1 hour at room temperature resulted about 3.497% yield of microcellulose. The FTIR show O-H, C-O-specific band for cellulose in 3402 cm−1, 1385 and 1200-1300 cm−1, respectively. This finding lead for further application of this micro/nano-cellulose for heavy-metals-and dye pollutants adsorbent.
Emulsifier and antimicrobial activity against Propionibacterium acnes and Staphylococcus epidermidis of oxidized fatty acid esters from hydrolyzed castor oil
Authors: Nabilah A , Handayani S , Setiasih S , Rahayu D U C , Hudiyono S
Published: July 2020

This study aimed to synthesize esters from oxidized fatty acids produced by castor oil hydrolysis as emulsifiers and antimicrobial compounds. Castor oil was hydrolyzed using KOH and the fatty acids were then oxidized using KMnO4. The success of oxidation proven by determined the iodine number. Esterification was conducted with varied alcohols, namely methanol, ethanol, isopropanol, and 1-butanol using ZnCl2 as catalyst and mole ratio was 1:2. The conversion percentage of esterification was determined using titrimetric method and products were characterized using FTIR. From the hydrolysis of castor oil, 84% of fatty acids were produced. Decreasing iodine number from 43.38 mg/g to 13.11 mg/g and increasing intensity of the -OH group absorption in the FTIR spectrum showed the success of fatty acids oxidation. Emulsifier test showed all products have emulsifier ability and emulsions were stable up to 24 hours with a water-in-oil (w/o) emulsion type. The best ability as an emulsifier demonstrated by methyl ester. Antimicrobial assay against Propionibacterium acnes and Staphylococcus epidermidis showed all ester products could inhibit the growth of both bacteria. Largest inhibition zone obtained from isopropyl ester for P. acnes by 16 mm and butyl ester for S. epidermidis by 17 mm.
Electron transfer study between hydrogen molecules and graphene surface
Authors: Nasri  , Subagyono R R D J N , Gunawan R
Published: July 2020

Electron transfer studies on the interaction of graphene surface and hydrogen (H2) molecules have been carried out. The calculations were based on the Density Functional Theory (DFT) with a basis set of Generalized-Gradient-Corrected PBE method approach (Perdew-Burke-Ernzerhof). The results showed that the optimum distance (lowest potential energy) between hydrogen molecules on the surface of the graphene was 3.2 Å, and the partial density of state (PDOS) calculation showed that the hydrogen-graphene system band gap was 2.51 eV. The electron transfer shown by the isosurface value indicates that the electron transfer from the p sub orbitals from the surface of the graphene to the hydrogen molecular orbitals was +0.3603 e/Å.
Acetylacetone as A Potential Chemosensor for Rapid Detection of Cu(II) in Aqueous Media
Authors: Nugroho Antonius Agung , Kurniawan Yehezkiel Steven , Yuliati Leny
Published: July 2020

Monitoring of Cu(II) ions is one of the most critical issues in wastewater treatment. Since the application of diketone-derived compounds as the Cu(II) chemosensor has not been addressed yet, in this present work, acetylacetone (penta-2,4-dione) was employed as the chemosensor to detect Cu(II) ions in the aqueous media. Ultraviolet (UV)-visible spectra showed that the blue colored-Cu(II) solution gave absorption at 811 nm, while the acetylacetone only gave absorption at UV region of 272 nm. Interestingly, the blue Cu(II) solution immediately turned to green solution after the addition of Cu(II) solution into the ligand solution, giving a new peak at 748 nm due to formation of Cu(II)-acetylacetone complex. This large blue shifting suggested the potential application of the acetylacetone as a colorimetric sensor of Cu(II), which gives benefit in the rapid detection. The limit of detection (LoD) and limit of quantification (LoQ) were found to be 0.15 and 0.51 mM, respectively. Furthermore, the presence of other metal ions, such as Na(I), K(I), Mg(II), Mn(II), Ni(II), Al(III), Au(III) and La(III), could be neglected since they gave low extents of interferences up to less than 10%. These results demonstrated that the acetylacetone is a potential chemosensor for Cu(II) detection in the aquatic environment.
Oxalic Acid from Corn Stalk for Photocatalytic Reduction of Cr(VI)
Authors: Nurjanah Ana , Rumhayati Barlah , Wiryawan Adam
Published: July 2020

Cr(VI) is toxic species of chromium in the aquatic environment. The reduced species, Cr (III), has lower toxicity than Cr(VI). The change of Cr(VI) species to Cr(III) can be conducted by photocatalytic reduction using oxalic acid as an oxidant with the aid of Fe(III) as a catalyst. Oxalic acid can be isolated from the biomass waste of corn stalk. This research aimed to isolate oxalic acid from corn stalk biomass as an oxidator for Cr(VI) photocatalytic reduction. The oxalic acid was isolated from corn stalks powder using NaOH, precipitated with the addition of CaCl2, acidified with H2SO4, and then crystalized to form the oxalic acid crystals. The photocatalytic reduction was carried out in a closed reactor equipped with two of 30-watt UV lights. About 30 mg of oxalic acid was used to reduce 300 mg/L Cr(VI) with the presence of 4 ml Fe(III) 100 mg/L as a catalyst. The process was conducted for 120 minutes while stirring. The reduction efficiency was calculated from the differentiation of the initial Cr(VI) concentration to the final ones. Cr(VI) concentrations were measured as Cr(VI)-diphenylcarbazide complex compound at pH 2 that could be detected at 540 nm. The results showed that the isolated oxalic acid has hydroxyl and carbonyl groups at 3441 cm−1and 1627 cm−1respectively identical with the oxalic acid standard. The crystals have melting point at 103°C. It could be used effectively to reduced Cr(VI) up to 45.9 %.
Mechanical Properties of Alginate Based Biopolymers as Wound Dressing Material
Authors: Nurjanah Ane , Amran Muhammad Bachri , Rusnadi
Published: July 2020

The utilization of biopolymers has been widely accepted in many areas due to its eco-friendly. Especially in medical care, biopolymers are receiving great attention and are considered as a potential for wound healing. Wound dressing material is one of medical needs and the demand continue to raise. One of the most widely used biopolymers for wound dressing is alginate. To improve alginate properties as wound dressing material, various alginate modifications with nanoparticles or synthetic polymers have been developed. In this paper alginate biopolymer will be modified with ZnO nanoparticles and synthetic polymer, such as poly (ethylene glycol) dimethacrylate (PEGDMA) as one of the candidates of wound dressing material. Alginate can go through swelling and because of its crystallinity is low so that it affects its mechanical properties. In order to increase the compatibility, ZnO needs to be modified with PEGDMA which is crosslink with alginate to strengthen the bonding network of materials. Characterization of alginate-based wound dressing material was performed using FTIR, XRD and SEM. In addition, optimization tests of mechanical and antibacterial resistance properties were performed to meet detailed studies of the effect of ZnO nanoparticles and PEGDMA interpenetrated into alginate to the properties of the wound dressing material.
Antifungal Activity from Co-Culture of a Local Fungus of Tropical Peat Swamp Soil, Penicillium sp. LBKURCC34 with Gram-Negative and Gram-Positive Bacteria
Authors: Nurulita Yuana , Yuharmen  , Dahliati Andy , Eryanti Yum , Supridianto  , Khairulinas  , Haryani Yuli , Nugroho Titania Tjandrawati
Published: July 2020

Microorganism is important producer of novel bioactive natural products, particularly in the field of drug discovery. Co-culture methods is one of powerful emerging tools for enhancing the chemical diversity of microorganisms. This research used the local culture collection of Penicillium sp. LBKURCC34, the fungus isolated from peat soil of primary forest at Giam Siak Kecil Bukit Batu (GSKBB) - Biosphere Reserve in Riau Province, to produce secondary metabolites secreted to their growth media that was cultivated by two different Gram of bacterial pathogen, Escherichia coli and Staphylococcus aureus. The 14 days fermentation was carried out and the media was extracted with ethyl acetate. The ethyl acetate crude extract was evaporated, then the concentrate dissolved in methanol. Antifungal, Candida albicans test was performed by the disc diffusion and the resazurin-based turbidimetric method. This study found that the crude extract of the co-culture with S. aureus could inhibit C. albicans growth, while that extract of the co-culture with E.coli could not do. The value of minimum inhibitory concentration (MIC) of the potential extract was less than the positive control, Ketoconazole. It only has potency as bacteriostatic extract.
Consistency of Spectra and Antibacterial Activity of The Extract Mixture of Curcuma longa, Zingiber officinale, and Syzigium aromaticum
Authors: Pangesti Dwika Putri , Masruri Masruri
Published: July 2020

Finding new antibiotic based on local resources is always a challenging effort, since Indonesia almost totally import the antibiotics. Then, antibiotic based jamu is an alternative. Jamu is a traditional herb prepared from local plants and some rhizomes, such as Curcuma longa, Zingiber officinale, and Syzigium aromaticum. These plants have been reported for their antibacterial capability. This paper is focused on the evaluation of antibacterial of these mixtures and their spectral consistency. The method was initiated by extraction of each plants/rhizome using ethanol and water. Each extract was mixed with equal ratio, and further evaluation for growth inhibiting activity in Staphylococcus aureus and Escherichia coli. Meanwhile, the spectral analysis was determined using FTIR and UV-Vis spectrophotometry. The result showed that the mixture of ethanol extract gives a slightly better activity than that using water extract. Furthermore, the UV-Vis spectra of the mixture from ethanol extracts indicates different band absorption in 439 and 417 nm, but no absorption observed in water extract in this range. In addition, the ethanol mixture extract also gives new band (FTIR spectra) in between 1010-1045 cm−1, that these are not observed in water extract. In short, it can be summarized that ethanol extraction process give better extraction procedure and provide better antibacterial activity.
Carbon dioxide occupancies inside ice XVII structure from grand-canonical Monte Carlo simulation
Authors: Pradana Irwansyah Putra , Mardiana Diah , Hakim Lukman
Published: July 2020

Clathrate hydrate is a promising material that can be used to trap the carbon dioxide (CO2) as a mean for the greenhouse-gas emission control. A compromise between experimental findings and density functional theory calculations was recently made to determine the occupancy of the newly reported CO2 clathrate hydrate of ice XVII structure. In this work, a hybrid isobaric Grand-Canonical Monte Carlo simulation is performed as a direct approach to determine CO2 occupancy inside ice XVII structure. The simulation results show that the CO2-to-water ratio starts at about 1:3.55 under lower pressure and ends at about 1:4 under high pressure. The potential energy of CO2-water interaction as a function of CO2 molecule displacement inside the voids shows a cage-like character, and the orientation of CO2 molecules inside the spiral void is shown to be well-ordered. The simulation results support the experimental observation and provide molecular insight into the structure of CO2 molecules inside the ice XVII structure.
Toxicity and Radical Scavenger Properties of Various Extracts of Sponge Clionidae sp. Kangean Islands
Authors: Rahman Moh. Farid , Masruri Masruri , Dibha Alyaa Farrah
Published: July 2020

Sponge Clionidae sp. is a multicellular animal that has active secondary metabolites that are used for survival. Sponge has cytotoxic, anticancer and antitumor properties and can be used in the pharmaceutical field, but the toxicity and antioxidant levels must be done to determine the uses level. Toxicity levels of sponge Clionidae sp. against Artemia salina L. and the IC50 value of the antioxidant was tested against DPPH radicals. Extraction of sponge Clionidae sp. was carried out with sonication using methanol, n-butanol, ethyl acetate and n-hexane as solvents. Then, the crude extract was tested for toxicity levels by the BSLT method and the antioxidant test by the DPPH method. Sponge extracts with ethyl acetate has the highest LC50 at 62.50 ppm and n-butanol has the highest IC50 values of 77.34 ppm. Identification of extract sponge with ethyl acetate was carried out using a UV-Vis spectrophotometer, resulting a maximum wavelength at 407.5 nm, ethyl acetate sponge extract showed the presence of O-H stretch groups 3327 cm−1, C-H stretch 2922 cm−1, C=C aromatic 1462 cm−1, and C=O 1711 cm−1 by FT-IR. The dominant compound in ethyl acetate extract that identified in LC-HRMS are chlorhexidine, 1,3,7-octanetriol, tobramycin, stigmatellin Y and maraniol.
Evaluation of The Stability and In Vitro Anti-inflammatory Activity of Partially Purified Bromelain Nanoemulsion
Authors: Randy Fransiskus , Setiasih Siswati , Jufri Mahdi , Handayani Sri , Hudiyono Sumi
Published: July 2020

Bromelain is an enzyme belonging to cysteine protease. It is known for topical use as debridement for inflammation treatment. Nanoemulsion of bromelain (NEB) aims to solve this problem and also improve its stability. NEB was made by high emulsification method using homogenizer and sonicator. Nanoemulsion physicochemical stabilities were evaluated. The bromelain as an active compound was isolated from the core of pineapple (Ananas comosus [L.] Merr) which was purified by ammonium sulphate fractionation and then dialysis followed. Nanoemulsion formula 2 was found to be the most suitable formula for encapsulating bromelain with good physicochemical stability after 30 days of storage. This formula showed clear visual appearance with globule diameter of 37.42 nm with polydispersity index of 0.40. The result showed that the fraction of bromelain obtained from each purification step showed an increase in specific activity. The specific activities of fractionation using 20-50% ammonium sulphate and dialysis were 152.05 and 266.58 U/mg, respectively. The purest bromelain fraction was encapsulated into nanoemulsion formula 2. The bromelain fraction’s anti-inflammatory activity was tested based on HRBC membrane stabilization method. The result showed that bromelain dialysis fraction shows the ability as anti-inflammatory agent with stability percentage of 79.76%.
The Potency of Plant Dye Extracts for Halal Detection on Consumed Animal Fats
Authors: Retnowati Rurini , Sulistyarti Hermin , Suratmo
Published: July 2020

One point of the halal concepts is the food does not contain any lard or any pigs derivatives. UV-vis spectrophotometry using natural dyes, among other methods, can be developed for animal fat analysis. One factor that influence the analysis is the solubility of animal fats and natural dyes in organic solvents. This research was conducted to study the differences of UV-vis spectrum profile in animal fats (chicken, beef, lamb, pork) using various natural dyes (namely Curcuma longa Linn., Curcuma zanthorriza, Curcuma heyneana, Zingiber montanum, Uncaria, Caesalpinia sappan, and Areca catechu) in different type of solvents. The research consists of four main steps: 1) screening of plant dyes in several solvents with different polarity, 2) screening of animal fat in several solvents with different polarity, 3) screening of animal fats mixed with plant dyes in selected solvents, and 4) analysis of animal fats mixed with plant dyes in selected solvents by UV-Vis spectrophotometry. The results showed that plant dyes from C. longa Linn., C. zanthorrhiza, A. catechu, and Uncaria, well as all animal fats used in this work, were soluble in ethyl-acetate and isopropanol. UV-vis spectrum profile of the animal fats with turmeric dyes in ethyl-acetate for chicken, beef, pork, and lamb fats, shows peaks at λ of 484, 792, 488.5, and 741 nm with absorbance of 3.913, 0.816, 3.524, and 0.175 respectively. Meanwhile in isopropanol, the profile for chicken, beef, pork, and lamb fats have λ of 751, 787, 712, 499 nm with absorbance of 0.007, 1.012, 0.479, and 3.913, respectively. Therefore, the UV-vis spectrum profile of animal fat with C. longa Linn dyes in ethyl-acetate can distinguish lard from the beef and lamb fats. In isopropanol, the lard cannot be distinguished from the chicken and beef fats, but it can differentiate lard from the lamb fats. The C. zanthorrhiza dyes in ethyl-acetate cannot distinguish lard from the chicken, beef, and lamb fats, but C. zanthorrhiza dyes can distinguish lard from the beef fat using isopropanol as the solvent. For A. catechu and Uncaria dyes in ethyl-acetate and isopropanol, they all cannot distinguish lard from the chicken, beef and lamb fats.
Sulphate Removal from Wastewater in Constructed Wetland Ecotechnology Using Pumice Amended in the Sand Media
Authors: Rozari Philiphi de , Dua Monang Maria Agusta , Krisnayanti Denik Sri , Tawa Bibiana Dho
Published: July 2020

Sulphate is a part of sulphur compounds which potentially inhibit plant growth and microbial activities in receiving surface water. Thus, it is important to remove concentration of sulphate from wastewater to acceptable concentration before the water is released into aquatic system. Constructed wetlands (CWs) are good option of wastewater treatments due to their low-cost and eco-technology. This research aimed to investigate the removal of sulphate from domestic wastewater using sand media amendment with pumice in CWs. In this experiment, six variations of CWs consisting sand and pumice planted with lemongrass (Cymbopogon citratus) were established. Domestic wastewater was loaded into CWs with loading rate 2 L/day. Sulphate concentrations were determined in inflows and outflows. The results showed that all treatment significantly remove sulphate concentrations from the inflow. The highest removal efficiency was in the media with 100% of pumice.
Analysis of Fe in Coral Reefs for Monitoring Environmental Areas of Prigi Coast Waters Using the Tessier-Microwave Method
Authors: Suci Cahyanti Wulan , Wijaya Anugrah Ricky
Published: July 2020

This study revealed the analysis of Fe content in the coral reef of Prigi Coast to monitor its waters as an environmental biomonitoring agent. Fe can accumulate into the coral structure through food, the mucous tissue, the mesenterium filament, and calcium element substitution that built-in the each of Fe coral fractions. Fe can be leached in the coral reef fractions using the Tessier-microwave method. Tessier microwave method divided of Fe in the ion exchange (fraction 1), carbonate bound (fraction 2), reduction (fraction 3), oxidation (fraction 4) and residual (fraction 5), respectively. The Tessier-microwave method results detected of Fe in the fraction 3 only, indicated that all of the Fe in the coral reefs was bound to the reduction fraction. The Fe content in the fraction 3 at 6 selected locations of Prigi Coast was 127.10 ppm, 39.12 ppm, 56.64 ppm, 78.10 ppm, 11.46 ppm, and 47.62 ppm, respectively. According to several calculations of CF, PLI and Igeo indexes, it indicated the contaminated of Fe in the coral reefs, especially at reduction fraction.
Development of Indirect Spectrophotometric Method for Mercury Determination Based on The Formation of Iron(III)-Thiocyanate Complex
Authors: Sulistyarti Hermin , Retnowati Rurini , Sulistyo Erwin , Wulandari Eka Ratri , Nashukha Hikmanita Lisan
Published: July 2020

A new spectrophotometric method for mercury determination has been developed based on the complexation of mercury(II) in ascertained excess of thiocyanate. The remaining thiocyanate is reacted with iron(III) to form a red iron(III)-thiocyanate complex which gave maximum absorbance at 460 nm. The concentration of mercury(II) is inversely proportional to the decrease absorbance of the complex. The method was optimized to the concentrations of thiocyanate and iron(III). Selectivity of the method has also studied based on percent recovery of mercury(II) in the presence of common metal ions in the tailing waters of gold mine. Under the optimum conditions, the method showed linear correlation to mercury(II) concentration from 1-30 mg L−1 with detection limit of 0.58 mg L−1. The method was not interfered in the presence of all metal ions studied up to 50 mg L−1, except of silver which was tolerated at 10 mg L−1. The developed method has been satisfactorily applied for mercury(II) determination in synthetic and tailing waters of gold mine samples.
Potency of Modified Cassava Flour as Binder and Thickener in Formulation of Instant Infant Porridge using Fortificant of Natural Folic Acid
Authors: Susilowati Agustine , Maryati Yati , Aspiyanto
Published: July 2020

A dry mixing process in preparation instant and pour infant porridges fortified by natural folic acid of A and B, and added by modified cassava (mocav) flour as thickener and binder had been conducted. Fortificant of natural folic acid of A and B are a mixture of soy bean tempeh, nixtamalized yellow corn and fermented broccoli, and a mixture of mung bean tempeh, nixtamalized yellow corn, and fermented broccoli. This experiment aims to optimize by adding mocav flour and the best type of natural folic acid in preparing instant and pour infant porridges for complementary breastfeeding (CBF) and its characteristic on the whole composition, particularly folic acid, characteristic of folic acid monomer, volatile compounds, particle size, and particle size distribution on instant and pour infant porridges. The experiment were done on mocav flour with concentrations of 0, 6, 12, 18, 24, and 30% (w/w of base formula of infant porridge) with fortificant of natural folic acid of A and B, and pouring to produce instant and pour infant porridges A and B. The result of experiment showed that based on folic acid, process optimization was achieved on fortificant A at mocav concentration 18% (w/w, based formula of porridge) and increase folic acid 532.26% (5.30-folds), dissolved protein 226.62% (2.27-folds), total sugars 120.44% (1.20-fold), however drop total solids 4.61% and reducing sugars 14.94% in instant infant porridge compared to each components concentration in base formula of infant porridge. In this condition, volatile compounds of instant infant porridge and pour infant porridge dominated by acetic acid and its derivatives (44.21%), and furan and its derivatives (29.812%).
Computational study of Cu2+, Fe2+, Fe3+, Mn2+ and Mn3+ binding sites identification on HSA 4K2C
Authors: Wibowo Syahputra , Sumitro Sutiman B , Widyarti Sri
Published: July 2020

This research aims to computationally characterize HSA 4K2C protein and describe as well as its ability to bind transition metal ions. Data mining is performed to obtain HSA 4K2C from PDB and transition metal ions such as Cu2+ (ID: 27099), Fe2+ (ID: 27284), Mn2+ (ID: 27854), Mn3+ (ID: 105130) and Fe3+ (ID: 29936) from PubChem. The analysis consists of ProtParam, Motif Search, CFSSP, DLP-SVM, and docking. Docking used PyRx Autodock Vina. Analysis of receptor-ligand interactions used DS 2016. The results of the ProtParam analysis provide some information on HAS 4K2C, which is it has 585 amino acids with an isoelectric point (pI) of 5.67, an index of protein instability of 38.85, then total amino acids (aa) residues of negatively charged (Asp + Glu) are 98 while the positively charged ones (Arg + Lys) are 83. Motive Search shows that there are three HSA motifs namely motif 1 (aa. 551-575), motif 2 (aa. 353-377), and motif 3 (aa. 61-185). CFSP shows α -helix structure is the dominant structure compared to β-sheet, turn and coil in 4K2C. DLP-SVM shows two domain linkers where DL-1 (aa. 410-451) and DL-2 (aa. 96-122). Docking shows the ability of HSA 4K2C in binding metal ions such as Cu2+, Fe2+, Mn2+, Mn3+ and Fe3+.
Purification of Keratinase from Bacillus sp. MD24 using Ammonium Sulfate Fractionation
Authors: Zuhriyah U F , Susanti E , Suharti
Published: July 2020

A keratin degrading bacterium, Bacillus sp MD24, was isolated from soil. The crude keratinase produced by the bacterium has been reported to dehair goat skin. However, the dehairing process took 72 hours. In order to shorten the dehairing time it is necessary to increase the keratinase concentration. This could be done by optimizing keratinase production either finding the best fermentation media or optimizing fermentation condition. Another way to increase the concentration could be done by partially purifying the enzyme. Keratinase from Bacillus sp MD24 had been produced under submerged fermentation, however, it produced a relatively low amount of enzyme. Although an effort to increase enzyme production had been reported by solid state fermentation, the enzyme concentration was not enough for industrial purposes. This work aimed to increase enzyme concentration by partial purification through enzyme precipitation using ammonium sulphate. The research was conducted in three stages: (1) regeneration the bacterium, (2) production of keratinase, and (3) purification of keratinase with ammonium sulfate fractionation. Keratinase activity was measured by Anson method and protein concentration was measured by Lowry method. Enzyme purity was clarified using a combination of specific activity, purity level, and SDS-PAGE analysis. Based on the analysis result, ammonium sulphate did not act as a good precipitation agent for the keratinase. Two major bands were suggested as keratinase with an estimated molecular weight of 25 and 66 kDa as monomer and dimer form, respectively.
Synthesis of 5-(4-bromobutyl)-2,3-dimethyl-1,4-benzoquinone and the Solubility Test in n-Octanol/Water Partition System
Authors: Zuhroh Nadiyah , Ulfa Siti Mariyah
Published: July 2020

The modification structure of 1,4-benzoquinone is fascinating in the frame of drug design. The solubility properties of a new drug are important, especially for oral drug administration. The 2-isopropyl-5-methyl-1,4-benzoquinone (known as thymoquinone) which is the major constituent in Nigella sativa seed extract is known as an active compound with poor lipophilicity. Here, we reported the synthesis of 5-(4-bromobutyl)-2,3-dimethyl-1,4-benzoquinone which analog with thymoquinone having higher lipophilicity. The synthesis proposed by oxidation reaction of 2,3-dimethyl-1,4-hydroquinone (1) with H2SO4 followed by bromoalkylation reaction using bromopentanoic acid in the presence of AgNO3 and (NH4)2S2O8. The oxidation product 2,3-dimethyl-1,4-benzoquinone (2) and alkylated-quinone 5-(4-bromobutyl)-2,3-dimethyl-1,4-benzoquinone (3) were obtained in 52.64% and 5.85%, respectively. The FTIR analysis of 3 showed the additional C-Br stretching at 562 cm−1. The solubility test in n-octanol/water system using HPLC gave the log P value of 5-(4-bromobutyl)-2,3-dimethyl-1,4-benzoquinone (3) is 2.99, higher than thymoquinone. By this result, it is suggested that the modification of 1,4-benzoquinone by bromo alkylating agent increased the solubility of the compound.
Electrochemical Behavior of Nickel Laterite Ores Dissolution in Sulphuric Acid Solutions
Authors: Abidin Faizinal , Gunawan Wibowo Abdul Hatta , Ambari Arya An , Harjanto Sri
Published: July 2020

Hydrometallurgical process of laterite nickel ore is carried out by leaching techniques at high temperatures. At atmospheric temperatures, the acquisition of nickel is low. Therefore, this study aims to characterize the electrochemical laterite nickel ore using a solution of sulfuric acid and hydrochloric acid at atmospheric temperature. Sulfuric and chloride acid solutions were used with solution concentrations of 1 M, 2 M, 4 M and 6 M. The study was carried out by sample and solution preparation, characterization by SEM-EDAX and Petrography method, and electrochemical characterization using the OCP, EIS method and LSV. The characterization results showed that the highest dissolution rate in both solutions was obtained at a concentration of 6 M solution. Increased concentrations of sulfuric acid reduced the value of OCP testing, while an increase in the concentration of hydrochloric acid increased the value of OCP. The EIS test results showed that the lowest R2 or Rct value in sulfuric acid solution was obtained at 2M concentration of 269.59 Ω while in hydrochloric acid solution it was obtained at a concentration of 6M of 523.07 Ω. The results of the second LP acid solution showed the formation of a passive layer at each concentration. The highest dissolution rate occurred at a concentration of 6M in each solution where the corrosion rate of sulfuric acid was 1.00 mm / year, while in hydrochloric acid it was 9.55 mm / year. Increasing the concentration of the two solutions led to the breakdown of the passive layer on the surface which can be seen from the Nyquist curve, the value of R2 is lower, the value of Q1 is higher and the value of N is lower, but in the sulfuric acid solution the formation of passive layers returns to increasing concentration starting from 4M. The three electrochemical tests show an increase in concentration to the optimum concentration increasing the dissolution rate and breaking the passive layer on the surface.
The Effect of Aging and Crystallization Time on the Synthesis and Characteristics of Zeolite-Y from Malang-Quartzite Silica
Authors: Arni Sukrawati , Sumari Sumari , Santoso Aman , Tamara Tasya
Published: July 2020

The purpose of this study is to determine the effect of aging and crystallization time on the synthesis and characteristics of zeolite-Y. The raw material of silica used was obtained from the silica extraction of Malang quartzite by leaching and sol-gel methods. The extracted silica was analyzed using XRF and XRD. Synthesis of zeolite-Y was carried out using hydrothermal method by mixing NaOH, Al(OH)3, SiO2, and H2O according to the molar ratio of the elements in zeolite-Y. The aging process was carried out with time variations of 12, 24, 48 hours and the crystallization process were carried out with time variations of 6, 9, 12 hours at a 150 °C. The synthesized zeolite-Y was analyzed using XRF, XRD, FTIR, and SEM. The results showed that quartzite silica could be extracted by leaching and sol-gel methods with a yield of 99.1 wt%. The optimum condition of synthesis zeolite-Y was obtained at the aging time of 12 hours and the crystallization time of 12 hours.