bluuebunny/crossref_metadata_2025 huggingface dataset:
Separation angle for flow past a circular cylinder in the subcritical regime
Authors: Jiang Hongyi
Published: January 2020

Instantaneous and time-averaged flow separation locations for the canonical case of flow past a circular cylinder are investigated through direct numerical simulations. It is found that the instantaneous movement of the upper/lower separation point on the cylinder surface is governed by a dynamic balance between the upper/lower separating shear layer and a shear layer generated at the back of the cylinder due to wake recirculation. It is also found that flow three-dimensionality contributes to an upstream movement of the time-averaged separation point through the effect of the separating shear layer. For the three-dimensional flow, the disordered mode B flow structures developed in the separating shear layer (which is directly responsible for the flow three-dimensionality) would result in turbulent energy dissipation and, therefore, the separating shear layer is less rolled-up in the cross-flow direction, which weakens the effect of the separating shear layer in pushing the separation point downstream. The time-averaged separation angle vs the Reynolds number (θs¯−Re) relationship is not monotonic over the three-dimensional wake transition regimes of Re = 190–270 since there is a transition sequence of different wake flow patterns with different levels of flow three-dimensionality. For Re ≥ 270, on the physical basis that the increasingly disordered mode B flow becomes the sole wake flow pattern, an empirical formula is proposed for the θs¯−Re relationship, i.e., θs¯=78.8+505Re−1/2 (270 ≤ Re ≲ 105).
Molecular beam epitaxy of InAlN alloys in the whole compositional range
Authors: Bhuiyan Ashraful G. , Islam Md. Sherajul , Hashimoto Akihiro
Published: January 2020

The fabrication of high-quality InxAl1−xN alloys over the whole composition is very challenging. Controlling the In/(In + Al) beam flux ratio and the growth temperature, this paper reports the fabrication of single crystalline InxAl1−xN alloys over the whole In composition by radio-frequency plasma-assisted molecular beam epitaxy. A comprehensive systematic study on the structural and vibrational properties of the InxAl1−xN alloys for the whole In composition has been carried out experimentally by Raman spectroscopy and theoretically by the forced vibrational method. The InxAl1−xN alloys show broad Raman peaks in the intermediate range of In composition. The appearance of Raman inactive B1 (High) mode has been confirmed by the experimental and theoretical results. The B1 (High) and A1 (LO) modes show one-mode behavior, whereas the E2 (High) mode shows the two-mode behavior in the whole In composition range. The observed Raman modes from the grown InxAl1−xN alloys well match with the calculated phonon modes of the InxAl1−xN alloys. These results provide an in-depth understanding of the growth of whole compositional InxAl1−xN alloys and the fabrication of optoelectronic devices using these promising materials.
Model of buoyancy-driven motion of a liquid shows role of surface tension in droplet dynamics
Authors: Liebendorfer Adam
Published: January 2020

Numerical study finds dispersion occurs on short hydrodynamic time scales in which surface tension plays a major role.
Membrane conductances of mouse cone photoreceptors
Authors: Ingram Norianne T. , Sampath Alapakkam P. , Fain Gordon L.
Published: January 2020

Vertebrate photoreceptor cells respond to light through a closure of CNG channels located in the outer segment. Multiple voltage-sensitive channels in the photoreceptor inner segment serve to transform and transmit the light-induced outer-segment current response. Despite extensive studies in lower vertebrates, we do not know how these channels produce the photoresponse of mammalian photoreceptors. Here we examined these ionic conductances recorded from single mouse cones in unlabeled, dark-adapted retinal slices. First, we show measurements of the voltage dependence of the light response. After block of voltage-gated Ca2+ channels, the light-dependent current was nearly linear within the physiological range of voltages with constant chord conductance and a reversal potential similar to that previously determined in lower vertebrate photoreceptors. At a dark resting membrane potential of −45 mV, cones maintain a standing Ca2+ current (iCa) between 15 and 20 pA. We characterized the time and voltage dependence of iCa and a calcium-activated anion channel. After constitutive closure of the CNG channels by the nonhydrolysable analogue GTP-γ-S, we observed a light-dependent increase in iCa followed by a Ca2+-activated K+ current, both probably the result of feedback from horizontal cells. We also recorded the hyperpolarization-activated cyclic nucleotide-gated (HCN) conductance (ih) and measured its current-voltage relationship and reversal potential. With small hyperpolarizations, ih activated with a time constant of 25 ms; activation was speeded with larger hyperpolarizations. Finally, we characterized two voltage-gated K+-conductances (iK). Depolarizing steps beginning at −10 mV activated a transient, outwardly rectifying iK blocked by 4-AP and insensitive to TEA. A sustained iK isolated through subtraction was blocked by TEA but was insensitive to 4-AP. The sustained iK had a nearly linear voltage dependence throughout the physiological voltage range of the cone. Together these data constitute the first comprehensive study of the channel conductances of mouse photoreceptors.
How patchiness controls the properties of chain-like assemblies of colloidal platelets
Authors: Karner Carina , Dellago Christoph , Bianchi Emanuela
Published: January 2020

Patchy colloidal platelets with non-spherical shapes have been realized with different materials at length scales ranging from nanometers to microns. While the assembly of these hard shapes tends to maximize edge-to-edge contacts, as soon as a directional attraction is added—by means of, e.g. specific ligands along the particle edges—a competition between shape and bonding anisotropy sets in, giving rise to a complex assembly scenario. Here we focus on a two-dimensional system of patchy rhombi, i.e. colloidal platelets with a regular rhombic shape decorated with bonding sites along their perimeter. Specifically, we consider rhombi with two patches, placed on either opposite or adjacent edges. While for the first particle class only chains can form, for the latter we observe the emergence of either chains or loops, depending on the system parameters. According to the patch positioning—classified in terms of different configurations, topologies and distances from the edge center—we are able to characterize the emerging chain-like assemblies in terms of length, packing abilities, flexibility properties and nematic ordering.
Widespread non-modular overlapping codes in the coding regions*
Authors: Bergman Shaked , Tuller Tamir
Published: January 2020

Messenger RNAs (mRNAs) consist of a coding region (open reading frame (ORF)) and two untranslated regions (UTRs), 5′UTR and 3′UTR. Ribosomes travel along the coding region, translating nucleotide triplets (called codons) to a chain of amino acids. The coding region was long believed to mainly encode the amino acid content of proteins, whereas regulatory signals reside in the UTRs and in other genomic regions. However, in recent years we have learned that the ORF is expansively populated with various regulatory signals, or codes, which are related to all gene expression steps and additional intracellular aspects. In this paper, we review the current knowledge related to overlapping codes inside the coding regions, such as the influence of synonymous codon usage on translation speed (and, in turn, the effect of translation speed on protein folding), ribosomal frameshifting, mRNA stability, methylation, splicing, transcription and more. All these codes come together and overlap in the ORF sequence, ensuring production of the right protein at the right time.
Penetration Depth of Free Falling Intruder into a Particles Bed in Fluid-Immersed Two-Dimension Spherical Particle System
Authors: Viridi S , Sanny T A
Published: January 2020

In a system of spherical particles which is entirely immersed in fluid, an intruder is let free fall into the particles bed consisted of 220 particles with height about 13 particles diameter and width about 15 particles diameter, both are in average. The system is placed in a container with height of 40 cm and width of 15 cm. Bed particles have the same diameter of 1 cm, while the intruder has 4 cm. Water is the fluid with density of 1 g/cm3 and viscosity of 8.90×10−4 Pa·s, which is assumed to constant during the simulation. Intruder initial height is always the same and bed particles are let to be relaxed for about 2 s from its initial random configuration of 20×11 in height and width of bed particle diameter, before the intruder is dropped into the system. Bed particles has always the same density about 2 g/cm3, while intruder density ρ
int is varied from 2 to 4.5 g/cm3 with increment of 0.5 g/cm3. It is observed that higher ρ
int gives higher penetration depth after the density of 2.5 g/cm3. Density of 4.5 g/cm3 and beyond will give similar final result, since the intruder already reached bottom of the container. An empirical model for penetration depth as function of ρ
int is proposed.
Ultraviolet (UV) Activation Effect on Antibacterial Agents of Red Betel (Piper Crocatum) Extract to Streptococcus mutans
Authors: Dyah Astuti Suryani , Dysan Tirtana Rio , Fitriana Mahmud Amalia , Mawaddah Amiliyatul , Abdurachman  , Yasin Moh.
Published: January 2020

Ultraviolet (UV) radiation has caused negative effect on biological environment. As non–moving living things, plants have their own response to reduce the negative effect by increasing flavonoid accumulation, such as red betel (Piper crocatum), which help the plant’s protection from bacteria. In Indonesia, red betel has been used as a herb treatment, especially in oral treatment. This study aims to optimise the antibacterial effect of red betel extract on oral bacteria, Streptococcus mutans, by irradiating UV. Kirby-Bauer method of disk diffusion test was used on this study by showing the bacteria’s diameter of inhibition zone. The samples distribution was devided into two groups, group (L–R+), control group, only used red betel extract without UV irradiation and group (L+R+) treatment combination of UV irradiation and red betel extract. The results showed that group L+R+ had better antibacterial effect on Streptococcus mutans, proven by the bigger inhibition zone, than group L–R+. UV irradiation for 12 hours showed the best result on each treatment with diameter of inhibition zone (15.00 ± 0.05) mm for 10 watt and (15.96 ± 0.05) mm for 15 watt. So, it is proven that UV irradiation can increase the antibacterial effect of red betel extract.
Theoretical Study on Radiationless Decay in Butadiene Isomerization Case using First-principles Calculation
Authors: Fadilla R N , Jannah A N , Febriana F N , Munir S , Zaidan A H
Published: January 2020

This study is to learn the radiation-less decay in butadiene isomerization from skew- to trans- conformation based on energy level diagram. We construct energy level diagram to determine the energy difference of butadiene in transition geometry between ground state and excited state with the basis of first-principles calculations. We use density functional theory for ground state butadiene while configuration interaction and complete active space for the excited state. The result is that the energy difference is 0.005 eV. It implies that there is degeneration occurred at the transition state of butadiene between its ground state and excited state. We conclude that conical intersection may occurs in the butadiene isomerization reaction.
Approximation Rectangular Function as Potential Barrier
Authors: Wardani I , Aisyah N D , Supardi A
Published: January 2020

Quantum tunneling occurs in the isomerization of hydroxymethylene into formaldehyde. Experiments and theory have proven the occurrence of it but both of them have a different result of the half-life of 0.7 hours. The differences the result is the motivation in this study. In theoretical, the probability of quantum tunneling calculates by Wentzel, Kreamer, Berlioun (WKB) approximation. This study calculates probability quantum tunneling use WKB and rectangular function approximation. The calculation of quantum tunneling probability with rectangular function approximation started at 1, 3, 5, 7 until 59 rectangular functions potential barrier use transfer matrix method to simplify the calculation. We use Gaussian function as the potential barrier that the height and width of the potential barrier satisfy the character of the potential barrier in isomerization hydroxymethylene barrier to formaldehyde. And the result, we get the minimum number of rectangular potential barrier to obtain a stable quantum tunneling probability value of 35 potential.
D-band Center Theory for the Case of Hydrogen Atom Adsorption on Fe(100) and Al(100) Surfaces: A Density Functional Study
Authors: Aji Eko Prabowo Wahyu , Khoiroh Nikmatul , Wibisono Satriyaji , Supardi Adri
Published: January 2020

The adsorption process occurs in technology that involves the surface. This study aims at investigating the adsorption of hydrogen atom on iron (Fe) and aluminium (Al) surfaces by using d-band center theory based-on density functional theory (DFT) method. DBC theory has proven very useful to understand the formation bond and the tendency of reactivity of transition metal which can learn by electronic structure system. This study obtained electronic structure system which is described by projected density of states (PDOS) using a system that consist of hydrogen atom adsorbed on Fe and Al surfaces. The result of PDOS used to explain the results of adsorption energy. The antibonding states on Fe surface were unfilled, meanwhile on Al surface were filled. Those results was suitable with the adsorption energy calculation results which showed that the bond between hydrogen and Fe surface was stronger than the bond between hydrogen and Al surface.
Temperature Effect of Chemical Bath Deposition (CBD) to Fabrication and Characterization of Zinc Oxide Nanorods Thin Films Based Gas Sensing: Ethanol
Authors: Ramadhan Adimas , Wulan Septiani Ni Luh , Aji Eko Prabowo Wahyu , Melati Asih
Published: January 2020

Fabrication of zinc oxide (ZnO) nanorods thin films based gas sensing ethanol have been done. Ethanol belongs to volatile organic compound (VOC) that are dangerous if inhaled by humans in high concentrations, so that its detection is necessary. Temperature as kinetic controller of chemical bath deposition (CBD) process take effect to ZnO fabrication and characterization. ZnO nanorods thin films was synthesized onto glass substrate by dip-coating technique. ZnO nanorods was grown using Zn(NO3)2.4H2O and HMTA with ratio 1:1 under CBD condition at temperature 75°C, 83°C, and 87°C. Result of SEM showing ZnO CBD 83°C has nanorods shape with diameter size is 95.56 nm, furthermore at 75°C the formation of the nanorods was not completed yet while at nanorods became deconstructed. XRD result showed all of ZnO sample have hexagonal wurzite which are match well with ICDS-094004 card. Ethanol gas sensing tested at 100°C, 150°C, 200°C showed high sensitivity of the sensor up to 77.31% for ZnO CBD 75°C at 100°C. ZnO CDB 83°C sample at test 200°C have highest response on 2.22 min (tres) and 0.45 min (trec). Time respond and recovery will increase along with increasing of test temperature.
Determination of Infrared Laser Energy Dose for Cancer Cells Inactivation as a Candidate of Photodynamic Therapy
Authors: Kholimatussa’diah Septia , Dyah Astuti Suryani , Apsari Retna
Published: January 2020

The aim of this research is to find out the effect of GaAlAs diode laser 808 nm exposure on MCF-7 breast cancer cells in vitro with and without the addition of a photosensitizer. Methylene blue (C16H18N3SCl) with concentration of 2 µM is used as the photosensitizer based on the preliminary results of cytotoxicity assay. Energy dose is set in the range of 23, 043 to 322, 062 J/cm2. Laser exposure with the addition of the photosensitizer generates the highest percentage of cell death of 20.80% at energy dose of 184, 344 J/cm2 and cell death begin to decrease at energy dose above this value. This behavior is likely caused by photodegradation and photobleaching effect of the photosensitizer due to the longer exposure time. However, the percentage of cell death without the addition of photosensitizer is increased proportionally to the increase of energy dose and achieved 32, 45% cell mortality at 299, 559 J/cm2. This study not only shows that the exposure of infrared laser can be used to inactivate cancer cells but also determines its optimum energy dose, makes it a possible candidate for photodynamic therapy in the future.
Electrospun Collagen-based Scaffold as Therapeutic Agent for Ocular Chemical Injury
Authors: Hasbiyani N A F , Hikmawati D , Siswanto
Published: January 2020

Ocular chemical injury hit on cornea and conjunctiva due to chemical contact. This injury damages to the epithelial surface of the eye, cornea, anterior segment and permanent unilateral or bilateral permanent viscous damage). Nowadays, human amniotic membrane, allograft biomaterials is used as the treatment for the injury. However, this method has many obstacles. Collagen-based Scaffold is a new study of electrospinning membrane made of collagen, hyaluronic acid, and polyethylene oxide. This research is aimed to obtain the optimum concentration of polymer solution that produces the best morphology in the formation of electrospun collagen-based scaffold. The result show that the fiber had mean diameter of 212, 63 nm to 500, 8 nm and mean pore diameter 498, 56 until 2788 nm. FTIR test shows the loss of functional groups Amide A and Amide II indicate successful crosslinking process with glutaraldehyde. The cytotoxicity test showed electrospun collagen-based scaffold was nontoxic.
Expert System for Stroke Classification Using Naive Bayes Classifier and Certainty Factor as Diagnosis Supporting Device
Authors: Ain Khusnul , Hidayati Hanik B. , Aulia Nastiti Olivia
Published: January 2020

Stroke is a disease that has high mortality rate in Indonesia and worldwide. This disease is dangerous if not immediately treated because the brain circulatory disorder can cause a permanent disability or death. Diagnosis process of stroke disease can be assisted by an expert system using Naive Bayes Classifier and Certainty Factor. Decision making by Naive Bayes Classifier uses total probability value of all the diagnostic criteria on the existing database. Certainty Factor uses a weight value combination from measure of believe provided by expert. This expert system research aims to assist in the early diagnosis of a neurologist in diagnosing potential stroke patient from several diagnostic criteria as well as determine the accuracy of the expert system program created. The sample used in this study are the hospital medical records of 130 patients from Dr. Soetomo Hospital of Surabaya consists of 80 stroke patients data and 50 non-stroke patients data. Expert system program uses 12 category for diagnosis as an input and two statement outputs between stroke or non-stroke. Based on the analysis from the 25 testing data of 105 training data we obtained the accuracy of the method Naive Bayes classifier by 96% and of the method of Certainty Factor of 84%. Expert system program using Naive Bayes Classifier and Certainty Factor can be a device for stroke diagnosis.
The nitrogen footprint of organic food in the United States
Authors: Cattell Noll Laura , Leach Allison M , Seufert Verena , Galloway James N , Atwell Brooke , Erisman Jan Willem , Shade Jessica
Published: January 2020

We estimated the reactive nitrogen (Nr) lost per unit food Nr consumed for organic food production in the United States and compared it to conventional production. We used a nitrogen footprint model approach, which accounts for both differences in Nr losses as well as differences in productivity of the two systems. Additionally, we quantified the types of Nr inputs (new versus recycled) that are used in both production systems. We estimated Nr losses from organic crop and animal production to be of comparable magnitude to conventional production losses, with the exception of beef. While Nr losses from organic vegetables are possibly higher (+37%), Nr losses from organic grains, starchy roots, legumes are likely of similar magnitude to conventional production (+7%, +6%, −12%, respectively). Nr losses from organic poultry, pigmeat, and dairy production are also likely comparable to conventional production (+9%, +10%, +12%, respectively), while Nr losses from organic beef production were estimated to be higher (+124%). Due to the high variability and high uncertainty in Nr efficiency in both systems we cannot make conclusions yet on the statistical significance of these potential differences. Conventional production relies heavily on the creation of new Nr (70%–90% of inputs are from new Nr sources like synthetic fertilizer), whereas organic production primarily utilizes already existing Nr (0%–50% of organic inputs are from new Nr sources like leguminous N fixation). Consuming organically produced foods has little impact on an individual’s food N footprint but changes the percentage of new versus recycled Nr in the footprint. With the exception of beef, Nr losses from organic production per unit N in product are comparable to conventional production. However, organic production requires the creation of less new Nr, which could reduce global Nr pollution.
Exploring China’s energy situation through One Belt And One Road
Authors: Gholizadeh Ali , Gong Yilin , Huang Qiang
Published: January 2020

Energy refers to various resources that can be directly obtained or be obtained through processing or conversion, including coal, crude oil, natural gas, coal-bed methane, water energy, nuclear energy, wind energy, solar energy, geothermal energy, biomass energy and other primary energy, electricity, thermal energy, refined oil and other secondary energy, as well as other new and renewable energy. Energy is an important material basis of national economy, and the future national destiny depends on the control of energy. The development and efficient use of energy and per capita consumption are important indicators of production technology and living standards. This paper analyzes the relationship between China’s energy status and One Belt And One Road security from the aspects of China’s energy status, China’s energy consumption in the next 30 years, China’s various energy basic conditions and important energy policies related to countries along the silk road. It is found that “The Belt And Road” strategy provides support and conditions for China’s energy development.
Challenges for product development of wind turbines from the current market situation in Germany
Authors: Wiener Philipp , Nicoleit Thomas
Published: January 2020

The qualitative results of this empirical thesis are the four superior challenges “reduced time for development”, “integration of the value chain”, “reduction of complexity” and “digital transformation”, which apply to the product development of wind turbines. It is assumed that these superior challenges apply to a variety of business areas rather than only for the product development. Recommendations for actions to reduce the time for development are “customized integration of agile approaches”, “break down silo mentality” and “optimization of the innovation culture”. For the integration of the value chain in the product development process, an “establishment of a common basis of trust”, “establishment of multi-company development networks” and an “increase of compatibility of different tools and process automation” are recommended. A reduction of complexity can be achieved with an “expansion of the available capacities in predevelopment” and “development of long-term multi-platform strategies”. The challenges and possible solution approaches for “digital transformation” need further investigation, but it is clear to advise to “ensure access to operational data through digital business models or service contracts”.
Greenhouse gas emissions comparison of solid waste transportation system: a case study in Thailand
Authors: Koiwanit J , Hamontree C
Published: January 2020

During the early periods of civilization, solid waste was conveniently collected transported and disposed because of the low number of population. However, waste generation is expected to increase becasue of rapid population growth and consequently shows an increase in solid waste collection, transportation, and disposal. Waste transportation planning is a difficult task due to the issues of the increasing numbers of garbage vehicles and the fluctuation of fuel prices as well as the cost-effectiveness and health and environmental impacts. An unsustainable waste collection and transportation is heading towards a variety of indirect human health impacts. Accordingly, the vehicle routing problem (VRP) plays a significant role in the field of waste collection and transportation system. This study compares three different Life Cycle Assessment (LCA approaches for the waste transport in Ladkrabang, Bangkok, Thailand. The three scenarios are modelled using GaBi 7 software tool and results are presented based on the CML 2001. The assessment outcomes indicated that the routing optimization with diesel and electric garbage trucks could significantly reduce the GWP impact by 8.51% and 66.44% compared to the baseline scenario, respectively.
Simplified methods of monitoring airborne bacteria for quality and environmental management in the Japanese food industry
Authors: Liu Ze , Tanaka Takehiro , Fujii Shuji
Published: January 2020

Airborne microbes are examined generally by sampling them on culture media and counting the number of their colonies formed. However, because it takes at least two days for bacteria and five days for fungi to be cultivated, reliable data may not be obtained in a time of need. Therefore, the development of simple and quick detection methods is required. In this study, rapid detection methods of indoor airborne bacteria for the improvement of quality and environmental management were reviewed, and a basic study on simplified monitoring techniques of airborne bacteria applicable to food factories was carried out.
Effectiveness of conventional wastewater treatment processes in removing pharmaceutically active compounds
Authors: Maraqa M A , Meetani M , Alhalabi A M
Published: January 2020

Limited work has been done to assess the types and levels of PACs in domestic and treated wastewater in arid and semi-arid countries. In these countries, reuse or artificial recharge of treated sewage effluent is commonly practiced. Thus, the objectives of this study were to quantify the levels of selected PACs in domestic wastewater in the United Arab Emirates (UAE) and to assess the effectiveness of domestic wastewater treatment plants in their removal. An analytical protocol was developed for the analysis of 15 PACs using a UPLC-MS/MS system. Four batches of water and sludge samples were collected from different locations at Al Saad Wastewater Treatment Plant in Al Ain, UAE. Aliquots of each sample were enriched by solid phase extraction. Results show that phenylephrine, dapsone, noscapine, propyl gallate, genistein, and ketoconazole were present in the raw wastewater at low levels (<0.1 μg/L), while acetaminophen and caffeine were present at high levels (>10 μg/L). The overall removal efficiency of the tested PACs from the water stream exceeded 99% for cotinine, acetaminophen, caffeine, naproxen, and ibuprofen, but significantly drops (<50%) for phenylephrine, amoxicillin, dapsone, noscapine, spiramycin, noscapine, genistein and ketoconazole. Analysis of the results indicate that, for highly removed PACs, the main mechanism of removal is possibly aerobic biodegradation. However, for tyramine, dapsone, 9-aminoacridine, noscapine, propyl gallate, and ketoconazole sorption onto the mixed liquor suspended solids first occurs followed by removal by anaerobic digestion. Results of the study should be useful for properly managing treated sewage effluent and sewage sludge.
Characteristics of Cellulose Acetate/Polyethylene Glycol membrane with the addition of Graphene Oxide by using surface coating method
Authors: Nurkhamidah S , Devi B C , Febriansyah B A , Ramadhani A , Nyamiati R D , Rahmawati Y , Chafidz A
Published: January 2020

Fabrication of membrane for desalination process with high performance is the objective of this study. The addition of Graphene Oxide (GO) in cellulose acetate/polyethylene glycol (CA/PEG) with a ratio of 80:20 was prepared by a surface coating method. In this study, the composition of GO was compared, with composition ranging from 0.0025 to 0.0125 wt% to the mass of the solvent. The characteristics of membranes were observed by using Scanning Electron Microscopy (SEM), Fourier-Transformed Infra-Red (FTIR), contact angle analysis and Dynamic Mechanical Analysis (DMA). While its performance was observed by analyzing salt rejection, flux permeate and permeability of the membranes. SEM analysis shows that membrane exhibits asymmetric membrane with sponge-like structure. FTIR results show that the peak area of –OH bonding decreases with the addition of GO. This result is in agreement with the contact angle analysis. The experiment results shows that membrane with the best performance is CA/PEG membrane with the addition of 0.01 wt% GO with salt rejection (%R) of 37%, flux permeate (F) of 1356 L/m2.h, and permeability (P) of 0.0013 L/m2.h.kPa.
Process development for the enrichment of curcuminoids in the extract of ionic type of NADES
Authors: Rachmaniah O , Muhsin M R , Widya A P , Rachimoellah M
Published: January 2020

Curcuminoids were successfully extracted from Curcuma zeodaria powder with Natural Deep Eutectic Solvents (NADES) as solvent. Ionic types of NADES such choline chloride-citric acid-water (CCCA-H2O = 1:1:18, mole ratio) and choline chloride-malic acid-water (CCMA-H2O = 1:1:18, mole ratio) gave the highest yield of extracted curcuminoids, ca. 0.270±0.025 and 0.355±0.055 mg/g respectively for CCCA and CCMA. However, the final product of the extracted curcuminoids was mixed in the NADES matrix. Hence, a separation process by means a solidification was mandatory. Isopropanol-n-hexane in both volume and molar ratio, i.e. 1:1, 1:1.5, 1:2, 2:1, and 2.5:1, were observed as a solvent in the solidification process as well as the solubility of curcuminoids in both isopropanol and n-hexane. Unfortunately, both of CCCA-H2O (1:1:18) or CCMA-H2O (1:1:18) and curcuminoids form a homogenous mixture with isopropanol. Therefore, all NADES constituents, i.e. choline chloride, citric acid/malic acid, and water, should be first removed before solidification process. Solubility of curcuminoids in isopropanol and n-hexane was, respectively, 3.2 mg/mL and 0.4 mg/mL at 40 °C. Isopropanol-hexane (1:1.5, v/v) give the highest recovery of curcuminoids, ca. 74.29%, by solidification process.
Recovery bitumen from asbuton with sodium tripolyphospate and SDBS surfactant as wetting agent
Authors: Irfin Z , Susianto S , Suprapto S , Altway A , Hardjono H , Nurmahdi H
Published: January 2020

The objective of this research is to develop a more-environmental friendly method of bitumen extraction from Asbuton, which also has high rate of percentage recovery, by using a mixture of sodium tripolyphosphate (Na5P3O10/NTP) and sodium dodecyl benzene sulfonate (SDBS) surfactant in several temperatures process. The extraction process itself has three steps of reactions, first is premixing, second is digesting and third is separating. Separated layer of bitumen after separation process will be analyzed to obtain bitumen percentage recovery during extraction. The purpose of premixing step is reducing viscosity of Asbuton by adding DEX up to 60 percent (w/w) of the total mass and then mixing it for 30 minutes. The digesting step is carried out by adding a mixture of DEX Asbuton with wetting agent. Wetting agent is a mixture solution of sodium dodecyl benzene sulfonate surfactant (SDBS) and Na5P3O10 (NTP) in various concentration. This mixture is being stirred at 1500 rpm using controlled temperature at 60, 70, 80 0C for 30 minutes. We use various surfactant ratio of SDBS from 0.125%; 0.25%; 0.37%, 0.5% (w/w) to the total mass ratio, and for NTP ratio is 0.125%; 0.25%; 0.37%; 0.5% (w/w). Separation process is done by adding water to form three layers of solution, the top layer, DEX-bitumen solution, will be weighed and measured for its weight and density to obtain the percentage recovery of bitumen. It can be concluded that the combination of SDBS and NTP mixture as wetting agent, can bring better result on bitumen extraction from Asbuton asphalt. The highest percentage of bitumen recovery is 74.63% at 80°C of temperature, and with SDBS concentration of 0.125% and Na5P3O10 concentration of 0.25%.
A new form of steel base isolation system for seismic high-rise building
Authors: Rochman T , Rasidi N , Sumardi S , Purnomo F
Published: January 2020

The higher story of a building then it will be more vulnerable to its earthquake or seismic responses. The use of seismic devices will reduce earthquake force. In this study, the steel base isolation material has been proposed. This paper aims to design a new steel base isolation system that have good resistance in both of seismic vibration and axial pull out. The building data are 3D mini three-story, six-story, nine-story steel frame structures. The shaking table is used to test with two types of vibration, medium and maximum. FEM analysis was implemented to find the seismic responses. From the calculation results, a reduced response was obtained in conditions of moderate damage to a three-story frame with an average acceleration of 88% reduction, a maximum acceleration of 22% reduction and a six-story frame in heavy damage with an average acceleration of 73%, the maximum acceleration is reduced into 43%.
Optimizing agricultural land area to increase productivity for anticipating decreasing irrigation water supply
Authors: Azis S
Published: January 2020

In order to maintain food security in Indonesia it is very necessary to organize the provision of irrigation water as well as possible. Current surface water discharge conditions have decreased compared to 10 years ago so that there really must be efficiency and wise efforts in the provision of irrigation water in paddy fields. Many efforts to increase the productivity of paddy fields and one of them is by optimizing the area of paddy fields and regulating cropping patterns in the paddy fields. In the initial stage of this study an analysis of the availability of surface water discharge was then analyzed for irrigation water requirements that could be given to each paddy field in accordance with a predetermined cropping pattern. Then a land area simulation is carried out to obtain the most optimal land area. This simulation is carried out in the conditions of the wet season, the normal season and the dry season. Simulations are carried out with various cropping patterns including rice, secondary crops and sugar cane. Simulation results show that the most optimal land area is in the wet season, then the normal season and the dry season.
Performance of Ashpalt Concrete Wearing Course on the effect of duration of water immersion
Authors: Purwono G A , Sulaiman S , Nursyafril N
Published: January 2020

Asphalt concrete as a wear layer, known as the Asphalt Concrete-Wearing Course (AC-WC) with a minimum nominal thickness of 4.0 cm. However, the use of AC-WC layers in the pavement structure is often faced with problems of performance degradation due to the development of various types of damage during the service life one of them is a result of the effect of water. In general, water has a negative effect on road pavement construction. Standing water can be caused by high rainfall, poor drainage systems, high groundwater levels, and water runoff. This research aims to look at the performance of the physical and mechanical properties of testing Marshall characteristics on a mixture of asphalt pen 60/70 wear layer (AC-WC) on the duration of water immersion from three different types of water. The specimen was carried out immersion testing from three types of water, namely clean water, brown flood water and black air with 30 minute immersion standards with variations of 1 day, 7 days, 14 days, 21 days and 30 days. The study outcomes shows several conclusions: (1) From the Marshall test results the physical properties obtained showed that the longer the immersion time the greater the VIM value obtained, the increase occurred in the type of brown flood water with the lowest Ph. Whereas the value of VFB in brown flood water immersion decreased the most as the duration of the immersion; (2) The mechanical properties of the Marshall test results are stability values still meet the standards, while for the value of melt and MQ black flood water immersion is the most influential on the asphalt mixture.
The effect of using crumb rubber on fatigue and rutting lives in flexible pavement
Authors: Balqis T A , Suherman S
Published: January 2020

This research is performed to analyze effect of using crumb rubber (CR) on the overlay design of Palembang City – Betung roads. Analysis of existing road conditions using the AASHTO 1993. This analysis based on deflection data using the Falling Weight Deflectometer (FWD). While, the overlay design analysis using CIRCLY 7.0 software to determine horizontal tensile strain (εh) for fatigue live and vertical compressive strain (εv) for rutting live parameters. The result showed that using CR can increase fatigue live into 66 % and rutting lives into 22 % for contribute pavement performance. To ensure the effect of CR in pavement’s performance, further research must be taken to find out if there are other effects that support.
The performance of composite steel in the elements of a post-fire steel bridge
Authors: Utami A , Gunadi R
Published: January 2020

The steel structure is commonly acknowledged able to return to its original strength condition. It is yet unknown whether composite structure may return to its initial condition. Test specimen on the present study consists of 8 units, each of them divided into four stud-connector bold (SP) composites beams and four UNP connector (SF) composite beams. Each of the specimen has control value by SP/020 and SF/020, and other six specimens with combustion of SP/400, SP/550, SP/700 and SF/400, SF/500, SF/700, within condition of point load for about 12 kN. The study intends to investigate composite girder of post-fire bridge element towards duration and heat temperature factors and effect of beam performance towards stud-connector and UNP connector composites. The results draw several conclusions; The process of composite combustion shows that the failure on composite steel beam specimen is due to the load, burning duration and temperature which results in residual deflection. Deflection test reveals the effect of temperature, load, and duration do not give significant impact to load capacity of post-combustion beam structure.
Design load controller and load shedding mechanism at DC house prototype
Authors: Hidayat M N , Hermawan S L , Ronilaya F
Published: January 2020

The DC house project is a pure DC electricity system to enable optimal use of renewable and alternative energy, DC House promotes a more sustainable solution by not using fossil-based fuels. DC sources are mainly from renewable generation, such as PV and wind turbines, the output from PV and Wind turbine produced is not stable, so there is a need for a regulatory system, arrangements can be made on the generation side and on the load side. Because the output of the generator is not constant, a setting on the load side is needed to adjust the generation capacity. If one of the offsets is to be released, a load shedding must be carried out to meet the load requirements. The release of the load is carried out when the supply is reduced because one of the generators is off, then the lower priority load will be released automatically. In this study simulated DC loads using PID control on the buck converter and load release using switching four loads with priority scale. The DC current sensor is used to determine the amount of current when determining the load released due to limited supply from the source.
Design and analysis of a portable spiral vortex hydro turbine for a Pico Hydro Power Plant
Authors: Hidayat M N , Ronilaya F , Eryk I H , Joelianto G
Published: January 2020

Pico Hydro Power Plant (PHPP) is a hydroelectric power plant with a scale below 5 kW. This technology is suitable to be applied to areas that have many rivers with sloping slopes. The PHPP applied in this research utilized the river flow and then flowing the water through a water channel with a slope angle around 10 degrees. Due to this sloping angle, it is necessary to modify the turbine intake to produce a more rapid water flow so that the turbine can rotate faster. The modification is made by designing and making a spiral vortex hydro turbine, where the intake is designed to resemble a snail house or a whistle to produce a spiral vortex to drive a turbine. The results show that the spiral vortex hydro turbine can produce faster turbine rotation, compared with a conventional water intake. The speed of the portable spiral vortex hydro turbine in this research can reach 90 rpm. Then, the turbine is coupled with a generator to produce electricity, through a pulley system. The faster the turbine rotation, the higher the generator output voltage. The highest output voltage of the generator is 27.5 Vdc at the speed of 293 rpm. In addition, the device is easy to move and maintain due to its portable design with a weight of 22 kg.
Design of Energy Database Management System (EDBMS) on the unit 2 outgoing transformer at the State Polytechnic of Malang
Authors: Syamsiana I N , Setiawan A , Saputra M
Published: January 2020

Recently, the efficiency of electrical energy is one of big challenges in the world. The needed energy is very huge; meanwhile the sources of energy are limited. Many researchers have been trying to find solutions for increasing the energy efficiency. One of ways is to monitor the use of the energy easily so we can reduce the energy usage. This paper proposes a system for monitoring energy usage by using Internet of Thing. Such system is called as Energy Internet of Things (IoT) based Database Management System (EDBMS). All buildings are supplied by Unit 2 Outgoing Transformer in the State Polytechnic of Malang which collects data of the used energy by using smart energy meter. It uses router LAN in UPT PP for sending the data from all buildings to the cloud, and displaying the received data on a web page. The collected data will be used for the analysis of power quality. Based on the result of the harmonic monitoring that shown the value are still in the standard range because the limitation of allowable THD current is 15%. And based on IEEE STD 446-1995, the standard for three-phase load imbalance is as much as 5-20% maximum for each phase. Meaning, Unit 2 Outgoing Transformer is out of standard or it does not comply with the standard.
Dynamic VAWT Darrieus by changing angle of attack to reach maximum efficiency
Authors: Setiawan B , Habibi I I A , Parastiwi A , Damayanti A M , Wakidah R N
Published: January 2020

Vertical Axis Wind Turbine is one of the most widely developed Renewable Energy. Many experiments and research are conducted to obtain maximum power efficiency. To get the maximum energy conversion efficiency required TSR (Tip Speed Ratio) is constant. To have the efficiency controller to change the Angle of Attack is required to maintain maximum efficiency at any wind speed. The method is applying controlled blades (aileron), the blades represent the value of Angle of Attack. In accordance with the changing of wind speed. In the VAWT Darrieus TSR reference value of 6, this value becomes the reference to obtain maximum efficiency against changes of wind speed. PID method is used to control the blades to form an Angle of Attack corresponding to the dynamic changes in wind speed. So that the VAWT speed is used as feedback into control. The shape of the blade affects the efficiency of the resulting spin, therefore the most efficient blade of the blades is the thin airfoil family in order to obtain the maximum flow of wind to rotate the generator. From the simulation done by using VAWT, it can be shown that the power efficiency obtained up to 28% in any wind speed.
Implementation of Programmable Logic Controller in multi machine operations with product sorting and packaging based on colour detection
Authors: Fathahillah F , Siswanto M , Fauziyah M , Parlindungan R , Putri R I , Roh Y-G
Published: January 2020

Automation is widely used in various industries to increase the speed, accuracy and effectiveness of production and reduce the risk of hazards. In general, the manufacturing industry has a product packaging and sorting process based on size, weight, shape, height and color. Currently, the sorting process in the industry is still mostly done manually which causes human error problems, so the development of industrial automation that is low cost, easy to maintain, efficient, user friendly and more accurate needs to be done. Programmable Logic Controller (PLC) is one of the most widely used for automation equipment in the industry and can be programmed to control machine operations. In this paper, the Mitsubishi Melsec PLC with ladder diagram programming using GX work2 has been developed to control multi-machine operation by product sorting and packaging based on product color. Multi-machine operation consists of three DC motors used for conveyors, two single solenoids, proximity sensors, inductive sensors and limit switches. The proximity sensors are used to detect the products based on color. The system is equipped with an emergency button and alarm system to facilitate the implementation of troubleshooting. To facilitate communication with operators and user-friendly systems, the human machine interface (HMI) is used as an interface for system monitoring and controlling. HMI uses Pro-face from Schneider which is programmed using GP-Pro EX4.0. The ladder diagram has been implemented in the PLC and tested on hardware to simulate the system. Based on test results, MELSEC PLC can communicate with HMI and control multi-operation machines with product sorting and packaging. The machine can separate and package metal products by colour and the packaging system can be monitored and controlled remotely automatically with HMI.