bluuebunny/crossref_metadata_2025 huggingface dataset:
Designing phenylalanine-based hybrid biological materials: controlling morphology via molecular composition
Authors: Mushnoori Srinivas , Schmidt Kassandra , Nanda Vikas , Dutt Meenakshi
Published: March 2018

Harnessing the self-assembly of peptide sequences has demonstrated great promise in the domain of creating high precision shape-tunable biomaterials.
Synthesis and properties of geometrical 4-diarylmethylene analogs of the green fluorescent protein chromophore
Authors: Ikejiri Masahiro , Kojima Haruka , Fugono Yuumi , Fujisaka Aki , Chihara Yoshiko , Miyashita Kazuyuki
Published: March 2018

The E- and Z-isomers of E/Z-photoisomerizable diarylmethylene analogs of the GFP chromophore (geo-DAIN) produce different colors of aggregation-induced emission (AIE).
Peroxoniobium inhibits leukemia cell growth
Authors: Pereira-Maia Elene C. , Souza Ivina P. , Nunes Kelen J. R. C. , Castro Alexandre A. , Ramalho Teodorico C. , Steffler Fernando , Duarte Helio A. , Pacheli Ana , Chagas Poliana , Oliveira Luiz C. A.
Published: March 2018

A new class of polyoxoniobate complex has been synthesized and characterized as a novel anticancer agent for photodynamic therapy.
Generalized nano-thermodynamic model for capturing size-dependent surface segregation in multi-metal alloy nanoparticles
Authors: Divi Srikanth , Chatterjee Abhijit
Published: March 2018

Nano-thermodynamic model captures thermodynamic preference of metal species for different regions of a nanoparticle while accounting for size effects.
A supramolecular approach towards strong and tough polymer nanocomposite fibers
Authors: Zhao Xiaojuan , Zheng Hongzhi , Qu Dan , Jiang Haijing , Fan Wei , Sun Yuyuan , Xu Yan
Published: March 2018

Strong, tough and flexible polymer nanocomposite fibers can be approached by electrospinning of supramolecular ensemble of CNT–AIE–CNC/PVA in an aqueous system, which could be used for sensing.
Coordination effect of network NiO nanosheet and a carbon layer on the cathode side in constructing a high-performance lithium–sulfur battery
Authors: Wang Jie , Liang Jianing , Wu Jianzhong , Xuan Cuijuan , Wu Zexing , Guo Xuyun , Lai Chenglong , Zhu Ye , Wang Deli
Published: March 2018

Network structured NiO sheets served as a mediator for lithium-sulfur battery coupled with a carbon layer on the cathode side in combination prevented the dissolution of polysulfides, enhanced the rate capability and long-term stability.
Flurbiprofen axetil attenuates cerebral ischemia/reperfusion injury by reducing inflammation in a rat model of transient global cerebral ischemia/reperfusion
Authors: Wu Huisheng , Tang Chaoliang , Tai Lydia Wai , Yao Weifeng , Guo Peipei , Hong Junmou , Yang Xin , Li Xinyi , Jin Zhao , Ke Jianjuan , Wang Yanlin
Published: March 2018

Ischemic stroke has been ranked as the second cause of death in patients worldwide. Inflammation which is activated during cerebral ischemia/reperfusion (I/R) is an important mechanism leading to brain injury. The present study aimed to investigate the effect of flurbiprofen axetil on cerebral I/R injury and the role of inflammation in this process. Rats were subjected to sham operation or global cerebral I/R with or without flurbiprofen axetil (5 or 10 mg/kg). Global cerebral ischemia was achieved by occlusion of bilateral common carotid arteries combined with hypotension for 20 min followed by reperfusion for 72 h. Then the neurological deficit score, hippocampal cell apoptosis, levels of aquaporin (AQP) 4, AQP9, intercellular cell adhesion molecule-1 (ICAM-1), nuclear factor-κB (NF-κB), tumor necrosis factor (TNF-α), interleukin-1 β (IL-1β), thromboxane B2 (TXB2), and 6-keto-PGI1α were assessed. After reperfusion, neurological deficit score was significantly increased accompanied by severe neuronal damage (exacerbated morphological deficit, increased terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay (TUNEL)-positive cells and cleaved caspase-3 protein expression in hippocampal CA1 region). Cerebral I/R injury also enhanced expressions of TNF-α, IL-1β, NF-κB, AQP4 and AQP9 as well as TXB2 and TXB2/6-keto-PGI1α. All these changes were reversed by pretreatment with flurbiprofen axetil. Flurbiprofen axetil protects the brain from cerebral I/R injury through reducing inflammation and brain edema.
Spatial signature for secure MISO‐OFDM systems
Authors: Ozbek B. , Kurt G.K.
Published: March 2018

Physical layer security is a promising approach to establish secure communications based on the characteristics of wireless channels. A spatial signature based secure multiple‐input single‐output (MISO) orthogonal frequency division multiplexing (OFDM) system is proposed to disrupt the reception of a passive eavesdropper by holding two practically relevant assumptions: a limited feedback link for legitimate node and the unavailability of channel state information of eavesdropper. The proposed algorithm achieves a higher average secrecy rate than the conventional secure MISO‐OFDM systems in presence of a limited feedback link.
Homing in on Polaris: A 7 M⊙ first-overtone Cepheid entering the instability strip for the first time
Authors: Anderson Richard I.
Published: March 2018

A recently presented HST/FGS parallax measurement of the Polaris system has been interpreted as evidence for the Cepheid Polaris Aa to be pulsating in the second overtone. An age discrepancy between components A and B has been noted and discussed in terms of a stellar merger. Here I show that the new parallax of Polaris is consistent with a simpler interpretation of Polaris as a 7 M⊙, first-overtone, classical Cepheid near the hot boundary of the first instability strip crossing. This picture is anchored to rates of period change, the period-luminosity relation, the location in color-magnitude space, the interferometrically determined radius, spectroscopic N/C and N/O enhancements, and a dynamical mass measurement. The detailed agreement between models and data corroborates the physical association between the Cepheid and its visual companion as well as the accuracy of the HST parallax. The age discrepancy between components A and B is confirmed and requires further analysis, for example to investigate the possibility of stellar mergers in an evaporating birth cluster of which the Polaris triple system would be the remaining core.
Chromospheric counterparts of solar transition region unresolved fine structure loops
Authors: Pereira Tiago M. D. , van der Voort Luc Rouppe , Hansteen Viggo H. , De Pontieu Bart
Published: March 2018

Low-lying loops have been discovered at the solar limb in transition region temperatures by the Interface Region Imaging Spectrograph (IRIS). They do not appear to reach coronal temperatures, and it has been suggested that they are the long-predicted unresolved fine structures (UFS). These loops are dynamic and believed to be visible during both heating and cooling phases. Making use of coordinated observations between IRIS and the Swedish 1-m Solar Telescope, we study how these loops impact the solar chromosphere. We show for the first time that there is indeed a chromospheric signal of these loops, seen mostly in the form of strong Doppler shifts and a conspicuous lack of chromospheric heating. In addition, we find that several instances have a inverse Y-shaped jet just above the loop, suggesting that magnetic reconnection is driving these events. Our observations add several puzzling details to the current knowledge of these newly discovered structures; this new information must be considered in theoretical models.
A FE-ADMM algorithm for Lavrentiev-regularized state-constrained elliptic control problem
Authors: Chen Zixuan , Song Xiaoliang , Zhang Xuping , Yu Bo
Published: March 2018

In this paper, Elliptic control problems with pointwise box constraints on the state is considered, where the corresponding Lagrange multipliers in general only represent regular Borel measure functions. To tackle this difficulty, the Lavrentiev regularization is employed to deal with the state constraints. To numerically discretize the resulted problem, full piecewise linear finite element discretization is employed. Estimation of the error produced by regularization and discretization is done. The error order of full discretization is not inferior to that of variational discretization because of the Lavrentiev-regularization. Taking the discretization error into account, algorithms of high precision do not make much sense. Utilizing efficient first-order algorithms to solve discretized problems to moderate accuracy is sufficient. Then a heterogeneous alternating direction method of multipliers (hADMM) is proposed. Different from the classical ADMM, our hADMM adopts two different weighted norms in two subproblems respectively. Additionally, to get more accurate solution, a two-phase strategy is presented, in which the primal-dual active set (PDAS) method is used as a postprocessor of the hADMM. Numerical results not only verify error estimates but also show the efficiency of the hADMM and the two-phase strategy.
Optimization of the fermentation time and bacteria cell concentration in the starter culture for cyanide acid removal from wild cassava (Manihot glaziovii)
Authors: Hawashi Mohamed , Surya Ningsih Tika , Bias Tri Cahyani Sekar , Tri Widjaja Kuswandi , Gunawan Setiyo
Published: March 2018

Cassava is one of the most widespread starchy tuberous roots in Indonesia, being one of the typical plants used in the starch market. However, due to the high cyanide content (338.41 ppm), these roots become a poison if they are unsuitably processed. Therefore, a detoxification process is needed to reduce the cyanide level to the safe level for human consumption (10 ppm). This study was focused on (i) the investigation of the detoxification potential of fermentation with Lactobacillus plantarum (L. plantarum) on the cyanide level of wild cassava tubers (Manihot glaziovii) and (ii) the optimization of the fermentation time and bacteria cell number in the starter culture. The fermentation was performed for different periods of time (12, 24 and 36 h) and various initial bacteria cell number (7x1010, 7x1011, 1.05x1012, and 3.5x1012 L. plantarum cells). The results showed a significant decrease of the cyanide level, 97 % of cyanide degradation being noticed after 36 h of fermentation for an initial bacterial cell number of 3.5x1012 cells. Hence, the strong point of the study consists of a noteworthy reduction of the cyanide content in wild cassava in short periods, whereas the protein content was increased (from 1.5% to 3.5%) in Modified Cassava Flour (MOCAF).
The Effect of Alcohol on Bead Performance of Encapsulated Iron Using Deacetylated Glucomannan
Authors: Wardhani Dyah H. , Cahyono Heri
Published: March 2018

The success of encapsulation to protect iron from inhibitor degradation or oxidation depends on many factors including the excipient characteritics. Glucomannan, a neutral heterosaccharide, has a potential for the excipient. To improve the excipient performances, glucomannan is deacetylated to remove the acetyl groups by reacted with Na2CO3. This deacylated glucomannan is subject to bead formation after iron loading. The alcohol solution is commonly used in bead forming as dehydration medium during the encapsulation process. The objective of this work was to study the effect of alcohol on the bead performance of encapsulated iron using deacetylated glucomannan. The bead forming was conducted by dropping the excipient into ethanol and isopropyl alcohol (IPA) solution at various concentrations (50, 60, 70, 80 and 90%) and two condition temperatures (27-30° and 7-10°C). The encapsulation samples were subject to yield (YE) and efficiency of encapsulation (EE). The concentration of alcohol showed a positive impact on the yield and efficiency of encapsulation. Ethanol has a better performance compared with that of IPA regarding yield and efficiency of encapsulation. The optimum of yield bead formation (69.67%) and highest EE (66.80%) were obtained at 90% ethanol. Temperature of dehydration did not affect the YE and EE significantly.
Preliminary study for acetylation of cassava bagasse starch and microfibrillated cellulose of bamboo
Authors: Silviana Silviana , Susanti Siti , Subagio Agus
Published: March 2018

Bio composite matrixes have been developed from several biomaterials, such as starch. One of potential resources is starch isolated from cassava bagasse still consisting 30-50% of starch. Reinforcement material may be inserted into bio composite to tough and reduce the drawback of the starch-based bio composite or bio plastic. Microfibrillated cellulose of bamboo (MFC) can be used as toughening filler for composite matrix. However, surface modification of material could be employed to alter its properties, such as acetylation of starch-based bio composite and microfibrillated cellulose. The acetylation was executed by using glacial acetic acid (GAA) catalyzed with sodium hydroxide. This paper investigates optimum condition of acetylation for bagasse starch (BS) and bamboo MFC in different weight ratio of GAA to BS or MFC (1:1, 2:1, 3:1, 1:2, 1:3), temperature range of 30°C to 70°C, and pH range of 7 to 11. Data were resulted from degree of susbtitution for each running. The optimum condition of acetylation of BS was obtained at temperature of 50°C (for BS) and 30°C (for MFC), pH of 9, and 2:1 ratio. This acetylation was confirmed by fourier transform infrared spectroscopy and scanning electron microscope.
Kinetic of Biomass Growth and Protein Formation on Rice Bran Fermentation Using Rhizopus oryzae
Authors: Sukma Andhika , Jos Bakti , Sumardiono Siswo
Published: March 2018

Rice bran is the outermost part of the rice grain wrapped in rice husks. Rice bran contains macro and micro nutrients that are bound to fibers that affect psychochemical properties when used in food products. The purpose of this study was to increase the nutritional value of rice bran with solid state fermentation using Rhizopus oryzae FNCC 6011 in tray bioreactor at 30°C for 120 h. The results showed an increase in protein, fat and ash content by 58.5%, 124.5%, and 18.6%, respectively, while carbohydrate and fiber content decreased respectively by 25.6% and 51.2%. The deceleration model successfully depicts the profile of biomass growth and improved protein. The kinetic parameters obtained k, A, and YPX were 0.0536/h, 5.2537, and 0.1821 g/g, respectively.
Conversion of Cassava Starch to Produce Glucose and Fructose by Enzymatic Process Using Microwave Heating
Authors: Sumardiono Siswo , Budiarti Gita , Kusmiyati
Published: March 2018

In this study, variation of glycosidase enzyme concentration and saccharification time on enzymatic hydrolysis using microwave have been investigated. Concentration and kinetic parameters rate of glucose and fructose were analyzed. Cassava starch was liquefied and gelatinized by microwave at 80°C. The gelatinized starch was saccharified at 60°C using (0.2;0.4;0.6;0.8;1% (w/v)) glycosidase enzyme for 24, 48 and 72 hours. The glucose which has been saccharified with 1% glycosidase enzyme for 72 hours gave highest conversion 66.23 %. The optimization process by multilevel reaction gave the highest conversion at enzyme concentrations 0.88 %and saccharification time 29 hours that 68.82%. The highest conversion of glucose was isomerized to fructose. The fructose which has been isomerized for 180 minutes gave highest conversion 20.05 %. The kinetics enzymatic reaction was approached and determined by Michaelis - Menten equation, Km and Vmax of reaction for glucose 22.94 g/L; 2.70 g/L hours and for fructose 3.39 g/L; 0.38 g/L. min respectively.
Improvement the Chemical Properties of Cassava Through Microbial Fermentation Using Rhizopus Oligosporus
Authors: Prasetyo Totok , Ardhianto Ferry , Pawitra Mayang , Sumardiono Siswo
Published: March 2018

Indonesia is the world’s largest importer of wheat. Because of high wheat imported, Indonesia’s researchers has seek an alternative to wheat-based local materials that having equivalent physicochemical properties. Potential alternative replacement of wheat flour is cassava. Cassava can be modified its rheology and physicochemical properties in order to be wheat equivalents. Cyanide contained in the cassava flour cannot be removed immediately by physical treatment. Several efforts have been made, such as soaking with saline solution, the addition of citric acid, and heating, showed a reduction in levels of cyanide in the flour. In this study, reduced levels of cyanide bound by converting it into protein using of Rhizopus oligosporus. While cyanide dissolved with the help of soaking with saline solution and buffer solution. In this case, use a buffer solution such as sodium sulphites which serves to change the form of cyanide dissolved into a form that is less toxic. In addition, a buffer solution pH also controls a range of 6, because in this range of cyanide bound to be easier to dissolve. With the combination treatment is expected to be a reduction in the levels of cyanide and exhibited significantly increased levels of protein in cassava flour. Flour has a protein content of best nutritional protein at 3.68 % dry basis. Cyanide reduction was highest in samples with high levels of Rhizopus oligosporus grated 1.5% (w/w) as 72 hours, with a lag of 0.09 (mg/kg) cyanide. Flour with the best nutritional quality is obtained from fermentation with conditions: grated, 12 hours of fermentation as well as using Rhizopus oligosporus 3.5% (w/w).
Effect of Soaking Time in Sodium Metabisulfite Solution on the Physicochemical and Functional Properties of Durian Seed Flour
Authors: Kumoro Andri , Hidayat Jefri
Published: March 2018

With regard to its high carbohydrate and gum contents, durian seed flour has been used as a substitute to wheat flour in butter cake and cookies manufactures. Unfortunately, processing of fruit seeds into flour may be hampered by discoloration, which may affect the nutrition and sensory quality of the food products. The objective of this study is to investigate the effect of soaking time on the physicochemical and functional properties of durian seed flour. Durian seed chips were soaked in 0.6% w/v sodium metabisulfite solution as anti-browning agent at 30°C for desired periods (40, 60, 80, 100, 120 minutes), followed by drying at 50°C for 17 hours, milling and sieving to obtain flour. The flour was analyzed for its moisture, ash, protein, fat and carbohydrate contents, sulfite residue, yield, gelatinization temperature, and water and oil absorption capacities (WAC and OAC). The results showed that longer soaking time reduced the moisture and ash content of durian seed flour, but increased most of the other studied parameters. The WAC, OAC and fat content were less affected by soaking time. It can be concluded that soaking of durian seed chips in sodium metabisulfite solution can improve the nutrition and functional properties of flour. Based on the residual sulfite content, durian seed flour obtained in this work is safe for consumption.
Optimization of Supercritical Carbon Dioxide and Co-solvent Ethanol Extraction of Wasted Peanut Skin Using Response Surface Methodology
Authors: Rahmana Putra Nicky , Hazim Abdul Aziz Ahmad , Nian Yian Lee , Diyana Ramli Wan , Azizi Che Yunus Mohd
Published: March 2018

Peanut skin is a waste of peanut industries especially peanut butter industries. Peanut skin contain high antioxidant and high nutritional values. The objective of this study was to optimize the effect of parameters to obtain high extract yield and high antioxidant activity by using supercritical carbon dioxide and co-solvent ethanol. A Box-Behnken design (BBD) was used to optimize the extraction process at the condition temperature (40, 55 and 70 ºC), rate of co-solvent ethanol (2.5, 5, and 7.5 % Vethanol/Vtotal), and extraction pressure (10, 20 and 30 MPa). The extraction time was 3 hours. The optimum condition to obtain yield of extraction and antioxidant activity 22.05 MPa, 62.76 °C and 6.03 %(Vethanol/Vsolvent) with 15.404 % yield extract and 94.040 % antioxidant activity.
Reuse of Newspaper As An Adsorbent For Cu (II) Removal By Citric Acid Modification
Authors: Mardiah  , Fathoni Rif’an , Pudyaningtyas Pratiwi , Gamu Hamdania , Rinaldy
Published: March 2018

High Consumption of paper, bring the impact of the waste paper itself. And the utilization of the paper is limited to recycled products and crafts, whereas paper such as newspaper still contains cellulose that can be potential to be used as a heavy metal adsorbent. In this study, newspaper was dissolved in sodium bicarbonate to reduce various impurities and then was reacted with citric acid (CA). The modified adsorbent was characterized by FTIR and was tested for adsorb Cu(II) in artificial solution. After adsorption process, the solution was filtered and analysed using Atomic Absorption Spectrophotometer (AAS). The adsorption experimental data was fitted to Langmuir, Freundlich, Tempkin, and Dubinin-Radushkevich for equilibrium model and was fitted to pseudo first order reaction and pseudo second order reaction for kinetic studies. The result showed that CA-modification newspaper able to remove heavy metals Cu(II) in solution.
Palm H-FAME Production through Partially Hydrogenation using Nickel/Carbon Catalyst to Increase Oxidation Stability
Authors: Ramayeni Elsa , Susanto Bambang Heru , Pratama Dimas Firlyansyah
Published: March 2018

One of the methods to improve the oxidation stability of palm biodiesel is through partially hydrogenation. The production using Nickel/Carbon catalyst to speed up the reaction rate. Product is called Palm H-FAME (Hydrogenated FAME). Partial hydrogenation breaks the unsaturated bond on FAME (Fatty Acid Methyl Ester), which is a key component of the determination of oxidative properties. Changes in FAME composition by partial hydrogenation are predicted to change the oxidation stability so it does not cause deposits that can damage the injection system of diesel engine, pump system, and storage tank. Partial hydrogenation is carried out under operating conditions of 120 °C and 6 bar with 100:1, 100:3, 100:5, 100:10 % wt catalyst in the stirred batch autoclave reactor. H-FAME synthesis with 100:5 % wt Ni/C catalyst can decrease the iodine number which is the empirical measure of the number of unsaturated bonds from 91.78 to 82.38 (g-I2/100 g) with an increase of oxidation stability from 585 to 602 minutes.
Adsorption of Nickel and Chromium Ions by Amine-Functionalized Silica Aerogel
Authors: Sertsing Sudarat , Chukeaw Thanaphat , Pengpanich Sitthiphong , Pornchuti Bawornpong
Published: March 2018

In this study, silica aerogel was synthesized by drying at atmospheric pressure and modified further with aminopropyl triethoxysilane (APTES). The amine-functionalized silica aerogel was investigated as an adsorbent for removal of nickel and chromium ions. The effect of contact time, solution pH, and initial solution concentration were studied. The equilibrium was achieved within 60 min. The optimum pH was found to be 4. Adsorption equilibrium data were agreed fairly well with Langmuir isotherm model. Adsorption capacities for nickel and chromium ions were found to be 40.32 mg/g and 46.08 mg/g, respectively.
Solvent Development for Post-Combustion CO2 Capture: Recent Development and Opportunities
Authors: Raksajati Anggit , Ho Minh , Wiley Dianne
Published: March 2018

Chemical absorption is widely regarded as the most promising technology for post-combustion CO2 capture from large industrial emission sources with CO2 separation from natural gas using aqueous amine solvent system having been applied since the 1930s. The use of monoethanolamine (MEA) in CO2 absorption system possesses several drawbacks, such as high regeneration energy, high solvent loss, and high corrosion tendency. Various solvents have been developed for post-combustion CO2 capture application including the development of aqueous solvents and phase-change solvents. Some of these alternate solvents have been reported to have better solvent properties, which could improve the CO2 absorption system performance. This paper reviews key parameters involved in the design improvement of several chemical absorption process systems. In addition, some novel solvent systems are also discussed, for example encapsulated solvents systems. Some of the key solvent parameters that affect the capture performance, such as heat of reaction, absorption rate, solvent working capacity, solvent concentration, and solvent stability, are discussed in this paper, particularly in relation to the economic viability of the capture process. In addition, some guidelines for the future solvent development are discussed.
Synthesis Study Of Surfactants Sodium Ligno Sulphonate (SLS) From Biomass Waste Using Fourier Transform Infra Red (FTIR)
Authors: Priyanto Slamet , Pramudono Bambang , Kusworo Tutuk Djoko , Suherman  , Aji Hapsoro Aruno , Untoro Edi , Ratu Puspa
Published: March 2018

Lignin from biomass waste (Black Liquor) was isolated by using sulfuric acid 25% and sodium hydroxide solutions 2N. The obtained lignin was reacted with Sodium Bisulfite to Sodium Ligno Sulfonate (SLS). The best result was achieved at 80 ° C, pH 9, ratio of lignin and bisulfite 4: 1, for 2 hours, and 290 rpm stirring rate. The result of lignin formed was sulfonated using Sodium Bisulfite (NaHSO3) to Sodium Ligno Sulfonate (SLS) whose results were tested by the role of groups in peak formation by FTIR and compared to the spectrum of Sodium Ligno Sulfonate made from pure Lignin (commercial) reacted with the commercial Sodium Bisulfite. The result can be seen by the typical functional groups present in the SLS.
Synthesis of Rice Straw as Biosorbent for Colour Removal in Batik Industrial Waste which is Represented by Methylene Blue
Authors: Putut Prilininta Nakesamas , Oktrianto
Published: March 2018

Use of rice straw as a biosorbent for water treatment in batik industry is not fully developed. Liquid waste for the colour’s adsorption using rice straw biosorbent represented by methylene blue solution. Rice straw biosorbent has been activated by HNO3 1 M and NaOH 0,75 M. Then characterized using Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM EDS) dan Fourier Transform Infrared (FTIR) Spectroscopy. The variation of dosage and drying temperature applied to know the optimum dosage for utilization of biosorbent and optimum drying temperature for biosorbent synthesis. The equilibrium were fitted to Langmuir isotherm and Pseudo Order 2 kinetics. The optimum adsorption obtained in 1,67 gr/L biosorbent with 100ºC drying temperature in 4 ppm methylene blue waste simulation solution with 95.27% adsorption capacities and 4 ppm batik industrial waste solution with 30.59% adsorption capacities.
Characterization and acid resistance test of one-part geopolymer from fly ash and water treatment sludge
Authors: Orbecido Aileen , Ho Vuong , Hinode Hirofumi , Kurniawan Winarto , Nguyen Long , Promentilla Michael Angelo
Published: March 2018

Development of geopolymers from wastes or by-products introduces a sustainable approach to replace ordinary Portland cement (OPC)-based concrete with an eco-material of lower green-house gases emissions. However, safety concerns related to the conventional two-part geopolymer has limited large-scale applications of the product. In this context, a novel one-part geopolymer from coal fly ash and water treatment sludge has been presented. The transformation of raw materials to geopolymer was observed by FTIR, SEM and XRD analyses. Acid resistance test has proved that the new binder had great durability against sulphuric acid attack. After 28 days immersion in 5% H2SO4 solution, weight of all samples was hardly changed. Compressive strength, on the other hand, has not decreased but significantly increased as curing time increased. The properties were also compared to those of control samples cured in water. It was demonstrated that strong acid immersion did not create any noticeable effect on the weight and strength of one-part geopolymer system developed from coal fly ash and water treatment sludge.
Performance Analysis of Solar Tray Dryer for Cassava Starch
Authors: Suherman Suherman , Djaeni Mohammad , Wardhani Dyah H. , Dzaki R Mukhtar , N. Bagas F Muhammad
Published: March 2018

The main objective of this study is to analyze the performance of solar tray dryyer for cassava starch. The solar tray dryer is made of glass and iron shaped dryer and box, where the solar collector is made of black painted iron plate. The initial moisture content of cassava starch is 50% wet bases. The experimental result show the moisture content of starch decrease rapidly in 8 hours of drying the first day until 14% moisture content. Further drying able to dry starch to 8% water content. The water temperature in solar dryer can reach 60°C was higher than the ambient of 32°C. Furthermore, the air humidity relative in the solar dryer can drop dramatically to 30% is lower than the ambient 80%. Maximum drying rate can reach up to 0.2 g/h. Thermal efficiency of the dryer can reach 40%. The performance of this solar dryer is much better than the sun dryer which veing piloted in this study
Investigation on mixture design of one-part geopolymer from fly ash and water treatment sludge
Authors: Ho Vuong , Orbecido Aileen , Promentilla Michael A.
Published: March 2018

This study presents a one-part geopolymer system from coal fly ash and water treatment sludge. Geopolymer is typically produced from two parts namely the aluminosilicate solids, which is typically sourced out from industrial by-product, and an alkali activator solution which reacts with aluminosilicate solids to form an inorganic polymeric network. For a one-part geopolymer system, the solid binder with activators will just be added with water to address the drawback of corrosive and viscous alkali activator solution. Formulation of the proportion of geopolymer precursors with the two solid alkali activators namely sodium hydroxide and sodium aluminate was conducted using statistical mixture design. Effects of each components as well as interactions between them were evaluated by step-wise regression analysis. It was found that high alkali content decreased the compressive strength of binder. Meanwhile, the incorporation of sludge in this system helps reduce the unit weight of samples. Multiple response surface analysis that maximized compressive strength and minimized unit weight resulted in the optimal combination of 18.9% sludge, 76.1% fly ash and 5.0% NaOH.
Thermal, Morphological and Physic-Mechanical Properties of Natural Rubber - CaCO3 Composites Using Jatropha Oil as Softener.
Authors: Nasruddin  , Susanto Tri
Published: March 2018

The urgency of green technology in rubber compounding has become a critical issue recently. In this research, the effect of using renewable resources in rubber compounding has been studied. Commercial Calcium Carbonate, Silica and Jatropha Oil were used in natural rubber composite. The research was designed by varying the types of commercial filler namely CaCO3 (47-51) phr, silica (47-51) phr and Jatropha Oil (4-6) phr in natural rubber composites (SIR-20). The formulas were intentionally designed for rubber tips vulcanizates. The samples were characterized by the determination of physic-mechanical, thermal (TGA) and morphological (SEM) properties. From the measured results, there is no significant effect on the tensile strength, specific gravity, and hardness on the loading of commercial CaCO3 and Silica in natural rubber composites using Jatropha Oil. However, a slight difference in elongation at break and abrasion resistance could be detected. Compared to the commercial rubber tips, the rubber tips produced in this research have higher tensile strength, elongation at break and abrasion resistance. Due to the usage of commercial CaCO3 and Silica, the SEM micrographs show rough surface because of the agglomeration. The thermogram shows clearly the compositional analysis of the rubber tips vulcanizates consist of Jatropha Oil and natural rubber, CaCO3, ash and other filler residues such as Silica.
Biodiesel Production from Dry Microalga Biomass by Microwave-Assisted In-Situ Transesterification
Authors: Qadariyah Lailatul , Panjaitan Mahfud Renova , Mujaddid Fatkhulloh , Kalsum Ummu
Published: March 2018

Microalga is one of the potential feedstocks in the manufacture of biodiesel because it contains high oil content. In this study, Chlorella sp. was selected because its high oil content about 28-32% of oil (based on its dry weight) and its presence is abundant among other green algae. In situ transesterification was carried out in round neck flask under microwave irradiation. Microwave irradiation can facilitate the in situ transesterification by extracted the lipid of microalga and simultaneous convert to FAME. The purposes of this study are to investigate the effect of acid catalyst concentration, microwave power, reaction time and the addition of co-solvent (n-hexane) on the yield of biodiesel, to get optimum operating conditions and to know the fatty acid compounds of biodiesel from Chlorella sp. The results of oil extraction and biodiesel were analyzed by GC-MS analysis. Based on the experiment, the yield of microalga oil was 11.37%. The optimum yield of biodiesel by in-situ transesterification was 75.68%. It was obtained at the microwave power of 450 watts, the reaction time of 60 minutes, an acid catalyst concentration of 0,2M of H2SO4, and the co-solvent addition of 10 ml.
Optimization of Preparation of Zeolite Y Dealuminate Catalysts for Glycerol Conversion to Glycerol Mono Laurate
Authors: Dwi Anggoro Didi , Buchori Luqman , Istadi Istadi , Fadhil R. P. , Antonio G.
Published: March 2018

This Research has been done to analyze Zeolite Y CBV 712 as a catalyst. Zeolite Y CBV 712 was dealuminated by treating it with H2SO4 solution, with 3 – 8 M concentration at 40 – 60 oC. The dealumination treatment runs for 4 hours. Then, dealuminated zeolite was calcinated with a furnace for 3 hours with temperature range between 500 – 600 oC. Dealuminated zeolit Y then tested to synthesize Glycerol Mono Laurate (GML). By Analysis of Variance (ANOVA) analyze, indicated that the higher Glycerol Monolaurate yield, X2 factor is the most significance factor, indicating with high F-value (29.60768) and low P-value (0.001600). Objective function from this tests, is used to determine the optimum value between dealumination temperature (X1), acid concentration used (X2) and calcinating temperature (X3). The relation between each operating variables and the responses is shown in mathematical equation below :

[see formula in PDF]

The optimum condition obtained is 43.25oC for dealumination temperature, 5.45 M for acid concentration and 614oC for calcination temperature. According to the optimum condition obtained, the glycerol monolaurate yield obtained is 59.470%.
Improving the Student Competency of the “Modeling and Computation Process” Course by Using Open Source Application.
Authors: Sasongko Setia Budi , Buchori Luqman
Published: March 2018

One of the student outcome based on ABET is the ability to use the techniques, skills, and modern engineering tools (in this case is engineering software) necessary for engineering practice. The problem is how the process of student centered learning so that the learning outcome of the “Modeling and computation process” subject can be achieved especially analysis process using modern engineering software. The first problem is commercial software applications have limitations due to high prices and limited amounts and usage time. The second problem is pasive student caused of one-way learning. The first problem is solve by utilisation of the open source software, that is “scilab” and “COCO”. The blended learning method is used to minimize the second problem, that is combination of face-to-face learning in the class, distance learning which use the “edmodo”, and accompaniment learning by senior student in the computation laboratory. The results of the active learning are increasing the ability of the student to apply equipment design and process system, improving soft skill outcome such as team work, communication, time management, thinking criticaly and analysing effectively.
Oilfield Produced Water Reuse and Reinjection with Membrane
Authors: Siagian Utjok W.R. , Widodo Setyo , Khoiruddin  , Wardani Anita K. , Wenten I Gede
Published: March 2018

Produced water has become a global environmental issue due to its huge volume and toxicity that may pose detrimental effects on receiving environment. Several approaches have been proposed to provide a strategy for produced water handling such as reinjection, reuse, or discharge. With various advantages, membrane technology has been increasingly used in produced water treatment replacing the conventional technologies. However, fouling is a major drawback of membrane processes in this application which needs to be controlled. This paper gives an overview and comparison of different produced water management. Special attention is given to produced water treatment for reuse purpose. Furthermore, the use of membrane processes in produced water reuse including performance, challenges, and future outlook are discussed.
SO2 Removal from the flue gas by hollow fibre membrane contactor
Authors: Ariono Danu , Siagian Utjok W. R. , Wardani Anita K. , Hakim Ahmad N. , Wenten I Gede
Published: March 2018

The combustion of fossils fuels is the main source of the environmental problems, such as acid rain, photochemical smog, and ozone depletion. To solve these problems, the appropriate technology to remove acid gasses such as SO2 is urgently required. In this work, SO2 removal was conducted using polypropylene and polysulfone-based hollow fiber membrane contactors. Water and sodium sulfite were used as sorbents. The results showed that the use of sodium sulfite as a sorbent provided 2 times higher SO2 permeation than water. Moreover, permeate flux of polypropylene membrane was higher than polysulfone membrane since the hydrophobic membrane is more suitable as membrane contactor for flue gas cleaning. In addition, a comparison between membrane contactor and conventional scrubber showed that membrane contactor can reduce the contact volume up to 27 times smaller than those used in the conventional scrubber.
Innovative Design of Solar-Powered Desalination (SPD) System using Vacuum-Multi Effect Membrane Distillation (V-MEMD) Process
Authors: Chafidz Achmad , RM Faisal , Kerme Esa D. , Wazeer Irfan , AlZahrani Saeed M.
Published: March 2018

This research focused on the development of an innovative design of solar-powered desalination (SPD) system which was expected to solve the water and energy problem simultaneously. We have developed a portable and hybrid solar-powered desalination (SPD) system for producing potable water from saline water. It is a self-contained and integrated system which combines solar-thermal collector and solar-photovoltaic for its operation, and thus the system can operate to produce water by only using solar energy. Therefore, the system is highly suitable to be implemented in remote arid and coastal areas without infrastructures or connection to the grid (water and power), but blessed with abundant solar irradiation, like in Saudi Arabia. A Memsys Vacuum Multi-Effect Membrane Distillation (V-MEMD) unit was used as the core of the SPD system. A heat pump was also integrated into the SPD system for energy recovery and to improve the performance of the system. The system could be considered as sustainable and “green” desalination technology, which will be very useful for the Kingdom of Saudi Arabia. To study the performance of the system, small-scale tests have been carried out at the Engineering College - King Saud University, Saudi Arabia. Based on the experimental results, the system has run successfully by only utilizing solar energy.
Diagnosis of machine tool with using Renishaw ball-bar system
Authors: Čep Robert , Malotová Šárka , Kratochvíl Jiří , Stančeková Dana , Czán Andrej , Jakab Tomáš
Published: March 2018

The article deals with accuracy of machine tools. The aim was to determine the accuracy with which already operates used machine – HAAS CNC Milling machine MiniMill. For evaluation of accuracy of the machine tool was used Renishaw QC20-W Ballbar system, which has the Department of Machining, Assembly and Engineering Metrology of VŠB – TUO. The theoretical part describes the measurement principle using a telescopic Ballbar system. The principle of measurement is the comparison of the actual deviation from the ideal circle which is programmed. Experimental part is focused on the diagnosis of the whole process by the direct method of measurement during changing feed rate. Specifically, the determination of circularity deviation at machine tool was in accordance with international standards, e.g. ISO 230-4.
Analysis of motion of the three wheeled mobile platform
Authors: Jaskot Anna , Posiadała Bogdan
Published: March 2018

The work is dedicated to the designing motion of the three wheeled mobile platform under the unsteady conditions. In this paper the results of the analysis based on the dynamics model of the three wheeled mobile robot, with two rear wheels and one front wheel has been included The prototype has been developed by the author's construction assumptions that is useful to realize the motion of the platform in a various configurations of wheel drives, including control of the active forces and the direction of their settings while driving. Friction forces, in longitudinal and in the transverse directions, are considered in the proposed model. Relation between friction and active forces are also included. The motion parameters of the mobile platform has been determined by adopting classical approach of mechanics. The formulated initial problem of platform motion has been solved numerically using the Runge-Kutta method of the fourth order. Results of motion analysis with motion parameters values are determined and sample results are presented.
The characteristics analysis of torque and rotation speed of working unit of branch grinder - introductory research
Authors: Warguła Łukasz , Adamiec Jarosław M. , Waluś Konrad J. , Krawiec Piotr
Published: March 2018

Carrying out a realistic research on working units of machines that grinder waste coming from tree and bush trimming requires designing machines that would be more efficient. It is neccesary both to introduce the analysis of already existing solutions as well as searching for innovative ones that would result in the increase of efficiency, lowering the costs and time needed as well as lower exhaust emission into the atmosphere. The results presented below will be used for the following purposes: the analysis of grinding process that supplies data to cunstruct simulating models that reflect the real working conditions of grinding machines. The results of the experiments will allow to estimate the influence of construction featrures, including the ones connected with automatisation. The importance of the carried out research is also applicable to the analisys of influence of grinding process on the form of flakes that result from the process, energy consumption. It also allows to make conclusions leading to the improvement of the processes that use grinded mass.The construction specifity of ths kind of machines and their working principles results from the fact, that the cutting process they perform concerns orthotropic plant material that has inhomogenic structure and physical-chemical properties requires further analysis. The article presents the construcion of a research stand designed to record the characteristisc of changes of the torque and rotation speed of working unit of mill chopper type MQS2800 Macalister. The introductory research results presented below point out that depending on the position of the sample (along the grain) against the mill chopper significantly influences on the form of generated changes of the torque. The research stand that has been designed and constructed allows the analysis of both construction features of the chopper as well via the assessment of grinding process also separte paremeters of processed wood.
Flap casting of turbine engine optimization by numerical simulation
Authors: Brůna Marek , Remišová Anna
Published: March 2018

Submitted article focuses on possibilities of increasing internal quality of flap casting of turbine engine produced by investment casting technology. Material porosity will be eliminated by altering the gate system. ProCast software has been used to evaluate and analyse the design of the flap. The aim of the research was to evaluate the porosity of the cast after its solidification, the flow velocity of the melted material and visualise the turbulence of the flow during casting. Main aim will be to observe and analyse velocity, flow, turbulences, solidification and internal porosity for nickel based alloy.
The space distribution and transfer of positioning errors from actuators to the TCP point of parallel mechanism
Authors: Bulej Vladimír , Stanček Ján , Kuric Ivan , Zajacko Ivan
Published: March 2018

The article deals with the analysis of the transfer and distribution of inaccuracies from actuators to the position of the point TCP on one of these machines. The real functional model of the mechanism was developed at the authors’ workplace. The analyses of the workspace were carried out on CAD model. The results should be used for simulation of mechanism’s behaviour, structural optimization as well as for generating of control algorithms for real functional prototype.
Design of a computational model for multi-body contact of deformable bodies in the flowing fluid
Authors: Handrik Marián , Vaško Milan
Published: March 2018

The article deals with the design and testing of a computational model for multi-body contact of deformable bodies in the flowing fluid. The computational model will be designed to allow easy modify the impact area of deformable bodies and their shape. The computational model must allow the application of an endless cycle of bodies impact with the possibility of restarting and calculating the following time intervals for collision of bodies.
Analysis of deformation and microstructure evolution during the hot deformation of titanium alloy
Authors: Kukuryk Marcin , Winczek Jerzy
Published: March 2018

The paper presents theoretical and experimental analysis of deformations and microstructural evolutions in the hot cogging process of Ti-6Al-4V alloy. A three–dimensional thermal – plastic coupled finite element model is employed to study the mechanical and thermal interaction between the forging anvils and the workpiece. To explore the distributions of effective strain, effective stress, mean stress and temperature of the specimens have been systematically studied. Attention has been paid to deformation, temperature, stress and strain inside the specimens and these parameters have been used to determine the evolution of the microstructure in deformed samples during hot cogging process. A comparison of theoretical with experimental results shows that the developed model may be used to accurately predict deformations and microstructural parameters.
Application of analytical methods for determination of hardness distribution in welded joint made of S1100QL steel
Authors: Piekarska Wiesława , Sága Milan , Goszczyńska-Króliszewska Dorota , Domański Tomasz , Kopas Peter
Published: March 2018

The prediction of hardness distribution in the cross section of welded join made of S1100QL steel is performed in this study on the basis of analytical methods. Analytical CCT diagram and volume fraction of each phases of S1100QL steel as a function of cooling time t8/5 are determined. A numerical simulation of welding process is performed in ABAQUS. Thermal cycles and temperature field in welded joints are determined. Prediction of hardness distribution in the cross section of the joint is performed on the basis of obtained cooling times t8/5. Results of numerical simulations are compared with experimentally obtained results.