bluuebunny/crossref_metadata_2025 huggingface dataset:
QCD chiral phase transition and critical exponents within the nonextensive Polyakov-Nambu-Jona-Lasinio model *
Authors: Zhao Ya-Peng , Zuo Shu-Yu , Li Cheng-Ming
Published: April 2021

We present a nonextensive version of the Polyakov-Nambu-Jona-Lasinio model that is based on nonextentive statistical mechanics. This new statistics model is characterized by a dimensionless nonextensivity parameter q that accounts for all possible effects violating the assumptions of the Boltzmann-Gibbs (BG) statistics (for

, it returns to the BG case). Based on the nonextensive Polyakov-Nambu-Jona-Lasinio model, we discussed the influence of nonextensive effects on the curvature of the phase diagram at

and especially on the location of the critical end point (CEP). A new and interesting phenomenon we found is that with an increase in q, the CEP position initially shifts toward the direction of larger chemical potential and lower temperature. However, when q is larger than a critical value

, the CEP position moves in the opposite direction. In other words, as q increases, the CEP position moves in the direction of smaller chemical potential and higher temperature. This U-turn phenomenon may be important for the search of CEP in relativistic heavy-ion collisions, in which the validity of BG statistics is questionable due to strong fluctuations and long-range correlations, and nonextensive effects begin to manifest themselves. In addition, we calculated the influence of the nonextensive effects on the critical exponents and found that they remain almost constant with q.
Modelling the visual response to an OUReP retinal prosthesis with photoelectric dye coupled to polyethylene film
Authors: Yamashita Koichiro , Sundaram Prathima , Uchida Tetsuya , Matsuo Toshihiko , Wong Willy
Published: April 2021

Objective. Retinal prostheses have been developed to restore vision in blind patients suffering from diseases like retinitis pigmentosa. Approach. A new type of retinal prosthesis called the Okayama University-type retinal prosthesis (OUReP) was developed by chemically coupling photoelectric dyes to a polyethylene film surface. The prosthesis works by passively generating an electric potential when stimulated by light. However, the neurophysiological mechanism of how OUReP stimulates the degenerated retina is unknown. Main results. Here, we explore how the OUReP affects retinal tissues using a finite element model to solve for the potential inside the tissue and an active Hodgkin–Huxley model based on rat vision to predict the corresponding retinal bipolar response. Significance. We show that the OUReP is likely capable of eliciting responses in retinal bipolar cells necessary to generate vision under most ambient conditions.
Random matrix ensembles in hyperchaotic classical dissipative dynamic systems
Authors: Odavić J , Mali P
Published: April 2021

We study the statistical fluctuations of Lyapunov exponents in the discrete version of the non-integrable perturbed sine-Gordon equation, the dissipative AC- and DC-driven Frenkel–Kontorova model. Our analysis shows that the fluctuations of the exponent spacings in the strictly overdamped limit, which is nonchaotic, conform to an uncorrelated Poisson distribution. By studying the spatiotemporal dynamics, we relate the emergence of the Poissonian statistics to Middleton’s no-passing rule. Next, by scanning values of the DC drive and the particle mass, we identify several parameter regions for which this one-dimensional model exhibits hyperchaotic behavior. Furthermore, in the hyperchaotic regime where roughly fifty percent of the exponents are positive, the fluctuations exhibit features of the correlated universal statistics of the Gaussian orthogonal ensemble (GOE). Due to the dissipative nature of the dynamics, we find that the match between the Lyapunov spectrum statistics and the universal statistics of GOE is not complete. Finally, we present evidence supporting the existence of the Tracy–Widom distribution in the fluctuation statistics of the largest Lyapunov exponent.
AOUP in the presence of Brownian noise: a perturbative approach
Authors: Martin David , Arnoulx de Pirey Thibaut
Published: April 2021

By working in the small persistence time limit, we determine the steady-state distribution of an active Ornstein Uhlenbeck particle (AOUP) experiencing, in addition to self-propulsion, a Gaussian white noise modeling a bath at temperature T. This allows us to derive analytical formulas for three quantities: the spatial density of a confined particle, the current induced by an asymmetric periodic potential and the entropy production rate. These formulas disentangle the respective roles of the passive and active noises on the steady state of AOUPs, showing that signatures of non-equilibrium can display surprising behaviors as the temperature is varied. Indeed, depending on the potential in which the particle evolves, both the current and the entropy production rate can be non-monotonic functions of T. The latter can even diverge at high temperature for steep enough confining potentials. Thus, depending on context, switching on translational diffusion may drive the particle closer to or further away from equilibrium. We then probe the range of validity of our quantitative derivations by numerical simulations. Finally, we explain how the method presented here to tackle perturbatively an Ornstein Uhlenbeck noise could be further generalized beyond the Brownian case.
Free energy fluxes and the Kubo–Martin–Schwinger relation
Authors: Doyon Benjamin , Durnin Joseph
Published: April 2021

A general, multi-component Eulerian fluid theory is a set of nonlinear, hyperbolic partial differential equations. However, if the fluid is to be the large-scale description of a short-range many-body system, further constraints arise on the structure of these equations. Here we derive one such constraint, pertaining to the free energy fluxes. The free energy fluxes generate expectation values of currents, akin to the specific free energy generating conserved densities. They fix the equations of state and the Euler-scale hydrodynamics, and are simply related to the entropy currents. Using the Kubo–Martin–Schwinger relations associated to many conserved quantities, in quantum and classical systems, we show that the associated free energy fluxes are perpendicular to the vector of inverse temperatures characterising the state. This implies that all entropy currents can be expressed as averages of local observables. In few-component fluids, it implies that the averages of currents follow from the specific free energy alone, without the use of Galilean or relativistic invariance. In integrable models, in implies that the thermodynamic Bethe ansatz must satisfy a unitarity condition. The relation also guarantees physical consistency of the Euler hydrodynamics in spatially-inhomogeneous, macroscopic external fields, as it implies conservation of entropy, and the local-density approximated Gibbs form of stationarity states. The main result on free energy fluxes is based on general properties such as clustering, and we show that it is mathematically rigorous in quantum spin chains.
Coherent spin states and stochastic hybrid path integrals
Authors: Bressloff Paul C
Published: April 2021

Stochastic hybrid systems involve a coupling between a discrete Markov chain and a continuous stochastic process. If the latter evolves deterministically between jumps in the discrete state, then the system reduces to a piecewise deterministic Markov process. Well known examples include stochastic gene expression, voltage fluctuations in neurons, and motor-driven intracellular transport. In this paper we use coherent spin states to construct a new path integral representation of the probability density functional for stochastic hybrid systems, which holds outside the weak noise regime. We use the path integral to derive a system of Langevin equations in the semi-classical limit, which extends previous diffusion approximations based on a quasi-steady-state reduction. We then show how in the weak noise limit the path integral is equivalent to an alternative representation that was previously derived using Doi–Peliti operators. The action functional of the latter is related to a large deviation principle for stochastic hybrid systems.
Numerical study of savonius wind turbines performance at Demak coastal area, Indonesia: a comparative study of savonius wind turbines without fin and with fin
Authors: Saputro H , Purdiatama M E , Wijayanto D S , Muslim R , Munir F A
Published: April 2021

The coastline of Demak city shows an increase in the need for electrical energy every year, in line with an increase in pond production. Currently, electricity needs are supplied from diesel generators. However, the use of diesel generators as electricity generators causes pond production costs to increase. On the other hand, the coastal location of Demak has wind potential, which can be used as a power plant. In this study, a numerical study was carried out using the savonius wind turbine as a power plant in the coastal area of Demak city. This research’s initial stage was to collect data on wind characteristics during the day and night conditions. Wind speed data are then used as input parameters in the numerical simulation using the ANSYS R.15 software. This study compares simulations between Savonius wind turbines without using fins and using fins for placement on the coast of Demak. The simulation results show that the wind speed on the coast of Demak ranges from 2 to 3.5 m / s. In these wind conditions, the savonius wind turbine with one fin has a power coefficient (Cp) better than without the fin. The relationship between wind speed and the electric power produced has been simulated and discussed in depth in this paper.
Influence of GaAs substrate misorientation on gallium and arsenic evaporation rates
Authors: Spirina A A , Shwartz N L
Published: April 2021

The dependence of the Ga and As evaporation rates on GaAs(111)A substrate misorientation was analyzed using Monte Carlo simulation. The gallium and arsenic desorption rates are proportional to the step density of vicinal substrates at congruent (layer-by-layer) evaporation. With incongruent evaporation (gallium droplet formation on the surface), the arsenic desorption rate weakly depends on the substrate misorientation and the gallium desorption rate is independent of it.
Resonant activation of resistive switching in ZrO2(Y) films
Authors: Ryabova M A , Filatov D O , Koriazhkina M N , Antonov D A , Antonov I N , Gorshkov O N , Kharcherva A A , Dubkov A A
Published: April 2021

Local resistive switching (RS) in ZrO2(Y) films on conductive substrates has been studied using Conductive Atomic Force Microscopy (CAFM). Switching was performed by triangle voltage pulses with superimposed a high-frequency (HF) sinusoidal signal applied to the contact of the CAFM probe to the ZrO2(Y) film (together constituting a nanometer-sized virtual memristor). Earlier, the enhancement of the RS performance has been observed when the HF signal was superimposed onto the switching pulses. The effect was attributed to the resonant activation of the migration of oxygen ions via oxygen vacancies by an external alternating electric field. In the present study, this assumption was confirmed by measuring the frequency dependence of the difference between the probe currents in the low-resistance and high-resistance states with a maximum at about 5 kHz. This frequency corresponds to the characteristic one of the jumps of oxygen ions onto adjacent oxygen vacancies in ZrO2(Y) at 300 K. The experimental results were compared with the results of simulation based on the Chua model of an ideal memristor.
A study of the GaN/Si(111) epitaxial structures grown by PA MBE via coalescence overgrowth of GaN nanocolumns
Authors: Shubina K Yu , Mokhov D V , Berezovskaya T N , Nikitina E V , Mizerov A M
Published: April 2021

The GaN/Si(111) epitaxial structures were synthesized by coalescence overgrowth of GaN nanocolumns using the plasma-assisted molecular beam epitaxy (PA-MBE) technique. Such epitaxial structures can be used as a buffer layer for obtaining high quality GaN epilayers. Structural, electrical and chemical properties of these samples were studied. It was demonstrated that KOH etching of the grown GaN/Si(111) samples results in the separation of the GaN epilayer from the substrate.
Analysis of the AlN phase transition on a sapphire surface within a universal 2D lattice gas model in MBE
Authors: Milakhin D S , Malin T V , Mansurov V G , Galitsyn Yu G , Zhuravlev K S
Published: April 2021

The AlN phase transition on the (0001) Al2O3 surface was investigated. It was experimentally estimated that the AlN formation rate as a function of temperature has a different character in two temperature regions. In the region of relatively low temperatures (T < 1210 K), the AlN formation rate is limited by chemical reactions. At higher temperatures (T > 1210 K), the formation of an ordered AlN phase is determined by a continuous two-dimensional phase transition within the filled AlN-lattice-gas cells formed on the sapphire surface. A three-parameter isotherm is proposed to describe the process. The observed phase transition in the AlN lattice gas is a continuous phase transition or a second-order transition.
Selective-area growth and optical properties of GaN nanowires on patterned SiOx/Si substrates
Authors: Gridchin V O , Reznik R R , Kotlyar K P , Dragunova A S , Dvoretckaia L N , Parfeneva A V , Shevchuk D S , Kryzhanovskaya N V , Mukhin I S , Cirlin G E
Published: April 2021

We present the results of selective-area growth of GaN nanowires by molecular beam epitaxy on patterned SiOx/Si substrates without using seed layers. The morphological and optical properties of selectively grown GaN nanowires are compared to the properties of GaN nanowires grown on the amorphous SiOx layer. The experimental results show that the selectivity of GaN nanowires is achieved at a substrate temperature of 825 °C which is the lower limit for the selective-area growth of GaN nanowires on SiOx/Si substrates. The study of the photoluminescence spectra of the grown nanowires, measured at 77 K show an emission line at 3.47 eV, which corresponds to strain-free GaN.
Increase in the radiative decay rate of the indirect exciton due to application of the magnetic field
Authors: Belov P A
Published: April 2021

The indirect excitons in double quantum well structures can appear in the ground state under application of an external electric field along the growth axis. The relatively slow radiative decay rate of the indirect exciton can be enhanced by a magnetic field pointing in the same direction. In this report, we numerically calculate the exciton energy levels in the GaAs-based double quantum well structure as well as optimize parameters of the structure to allow a noticeable increase in the radiative decay rate of the indirect exciton there by application of the magnetic field.
Amplified spontaneous emission in colloidal solutions of two-photon-excited CdSe/CdS nanoplatelets
Authors: Laktaev I D , Saidzhonov B M , Vasiliev R B , Smirnov A M , Butov O V
Published: April 2021

Two-photon processes in CdSe/CdS nanoplatelets were investigated under high intensity excitation by femtosecond laser radiation (1064 nm, 100kHz). The open-aperture z-scan technique and the measurement of photoluminescence spectra were utilized for studying their nonlinear optical properties. As a result, two-photon absorption and amplified spontaneous emission at high intensity were found in these nanoplatelets.
InP nanowires on Si(111) for piezotronic applications
Authors: Vershinin A V , Soshnikov I P , Kotlyar K P , Kudryashov D A , Samsonenko Y B , Lysak V V , Cirlin G E
Published: April 2021

III-V nanowires (NWs) are a promising technology for piezotronic and nanooptoelctronic applications. In this work, we investigate the processes of fabricating a structure with InP NW arrays on a silicon substrate for piezotronic applications. The coating of the NW array with a polymer and the fabrication of a transparent electrical contact to NWs is studied. The piezoelectric effect for the structures with a nonzero piezoelectric modulus d
33 is demonstrated in an oil environment at voltage amplitudes of about 100 mV. The experimental electromechanical coupling is about 0.049, which is close to the theoretical estimate of 0.053.
Effect of additional annealing on the electrophysical properties of large-size CVD-graphene samples
Authors: Tonkov D N , Gasumyants V E
Published: April 2021

This paper is devoted to the comparative study of the resistivity temperature dependences for large-size 1–2 layered graphene samples prepared by the CVD method and subjected to additional annealing in an Ar/H mixture at different temperatures. The influence of the annealing temperature on the temperature dependences of resistivity was qualitatively analyzed for two types of initial samples demonstrating a metallic- or semiconductor-like ρ(T) dependence. This made it possible to elucidate the processes occurring in the samples upon annealing, as well as to assess the degree of their influence on the electrical properties of the annealed samples. This analysis showed that the main processes initiated by annealing are the formation of additional defects and cleaning of the graphene surface. To confirm this conclusion, we performed a numerical analysis of the experimental ρ(T) dependences, based on a model taking into account different scattering mechanisms of charge carriers in graphene samples. This allowed us to determine the concentrations of impurities on the graphene surface and defects in the graphene crystal structure for all investigated samples. The character of the change in these values depending on the annealing temperature for samples with different types of the ρ(T) dependence is discussed.
Passively Q-switched fiber laser with various phases of Ni-S as a saturable absorber
Authors: Kuznetsov P I , Savelyev E A , Sudas D P , Yakushcheva G G
Published: April 2021

Nanoparticles of NiS (amorphous α and crystalline β phases), Ni3S2 and Ni were obtained by passing H2S through a solution of NiSO4•7H2O followed by drying or annealing of washed precipitate in hydrogen or nitrogen atmospheres. The synthesized materials were mixed with a polymer (polydimethylsiloxane elastomer) and applied to the surface of chemically prepared conical constrictions on SMF-28 fiber. Passive Q-switches were integrated into a specially designed erbium ring fiber laser and tested. For the first time, the generation of µs pulses was realized using these compositions of the binary system Ni-S. The best parameters of a pulsed laser obtained using β-NiS nanoparticles as a saturable absorber were a repetition rate of 21.7 kHz, an average output power of 26.72 mW, and a pulse energy of 1230 nJ.
Characteristics of double-cascade photodiodes based on p-i-n AlGaAs/GaAs diodes connected by n++-GaAs/i-GaAs/i-AlGaAs/p++-AlGaAs tunnel diodes
Authors: Kontrosh E V , Kalinovskii V S , Klimko G V , Vaulin N V , Ya Ber B
Published: April 2021

Characteristics of double-cascade nonmonolithic p-i-n AlGaAs/GaAs photovoltaic converters of high-power laser radiation, electrically combined with n++-GaAs/i-GaAs/i-AlGaAs/p++-AlGaAs tunnel diodes, have been studied. The AlGaAs/GaAs p-i-n structures of the photovoltaic converters and n++-GaAs/i-GaAs/i-AlGaAs/p++-AlGaAs tunnel diodes were grown by molecular-beam epitaxy. The photoelectric characteristics of the double-cascade AlGaAs/GaAs photovoltaic converters were examined in the temperature range from 103 to 298 K under excitation with a laser light wavelength of 809 nm and a power density ⩽92 W/cm2. The double-cascade p-i-n AlGaAs/GaAs nonmonolithic photovoltaic converters of planar design had a fill factor of 0.88 and efficiency of 58.2% at a temperature of 103 K. It was shown experimentally that the current-voltage characteristics of the connecting n++-GaAs/i-GaAs/i-AlGaAs/p++-AlGaAs tunnel diodes affect the photoelectric parameters of the double-cascade photovoltaic converters of high-power laser light.
Centers of cold electron emission from molybdenum thin films
Authors: Bizyaev I S , Osipov V S , Babyuk V Ye , Struchkov A I , Gnuchev N M
Published: April 2021

Thin-film semiconductor devices and functional metal-oxide-semiconductor structures have drawn attention as being applicable for on-chip electronics. Similar structures, however, were also reported to be promising as efficient sources of electrons. This paper presents the results of scanning electron microscopy analysis of molybdenum thin films capable of low-macroscopic-field electron emission. Supposedly, the images show the centres of cold-field emission at different stages of their life cycles from activation to destruction. It is assumed that initially continuous Mo films experience dewetting under heating and ion bombardment, which are caused by the emission current flow. The results contribute to understanding the mechanism of low-field emission from thin metal films, which seems to be different from those previously proposed for thin carbon coatings.
Utilization of chitosan clam bloodshells as a coagulant for processing electroplatting waste
Authors: Wulandari C D , Setyobudiarso H , Koteldae M
Published: April 2021

Utilization of coagulants with natural ingredients has been widely developed, the advantage of using biocoagulant is the availability of abundant material, easy to obtain it, from renewable materials, and low toxicity. This research compare chitosan clam bloodshells (Anadara granosa) coagulan and alum coagulan, to reduce concentration total chrome, nickel and turbidity in electroplating waste. The variations of coagulan, 300 mg/l and 600 mg/l, variation of the speed used is 150 rpm and 300 rpm. Results of the research, Alum and Chitosan can reduce the concentration of TSS, Nickel and Total Chrome. Alum can removel TSS by 93.75% at dose 300 mg/l, stirring speed of 150 rpm, Nickel by 32.49% at dose of 600 mg/l, stirring speed of 300 rpm, total Chrome removal of 64.09% at dose of 600 mg/l, stirring speed of 300 rpm. Coagulant chitosan TSS by 97.79% at dose 300 mg/l and 600 mg/l, stirring speed of 150 rpm, Nickel by 50,73% at dose of 600 mg/l, stirring speed of 150 rpm, the total chromium by 72.88% at dose of 600 mg/l, stirring speed of 150 rpm. Alum and chitosan coagulant the ability to neutralize the pH in accordance with the standard quality standard of electroplating waste, from 6.2 to 7.6.
Comparison of phenolic, flavonoid, and tannin contents from ethanol extract of Kratom stem (Mitragyna speciosa Korth.) and senggani flower (Melastoma malabathrium L.)
Authors: Hanifah H N , Hadisoebroto G , Dewi L
Published: April 2021

Indonesia is a country known for its useful natural resources, especially for a health maintenance and treatment of diseases. Some of the plants that can be used as traditional medicine are kratom (Mitragyna speciosa Korth) and Senggani (Melastoma malabathrium L.). The purpose of this research was to determine the total phenolic content, total flavonoids content, and total tannins content in the ethanol extract of kratom stems and flowers using the UV-Vis spectrophotometric method. The comparator used in determining the phenolic content was gallic acid, for the flavonoid content was quercetin, and for the tannin content was tannic acid. The results of this study showed that the total phenolic content in the kratom stem extract was 23.59 mg/gram of extract, while in the senggani flower was 43.97 mg/gram of extract. The total flavonoid content in the kratom stem extract was 10.65 mg/gram of extract, while the senggani flower was 11.26 mg/gram of extract. Lastly, the total tannin content in the kratom stem extract was 17.99 mg/gram of extract, while in the senggani flower it was 13.74 mg/g extract.
The effect of different storage times at 5°C on the quality of yogurt with the addition of local taro starch (Colocasiaesculenta) as stabilizer
Authors: Krisnaningsih A T N , Rosyidi D , Radiati L E , Purwadi P , Hadiani D P P , Wae R L
Published: April 2021

The purpose of this research was to determine the effect of storage time at 5°C on the quality of yogurt with the addition of local Taro Starch as Stabilizer. The materials were used: fresh cow’s milk, skim milk, starter and taro starch. The research method used was a laboratory experiment using a Completely Randomized Design (CRD) with different storage times at 5°C, namely: 5 treatments including: P1: 1 day, P2: 7 days, P3: 14 days, P4: 21 days, P5: 28 days. Each treatment was repeated 4 times so that 20 research units were obtained. The variables observed were the syneresis, WHC, pH, and total acid of the yogurt. Data were analyzed by one way Anova and followed by Duncan’s multiple range test (DMRT). The results showed storage time at a refrigerator temperature of 5°C gave a very significant difference (P≤0.01) to the syneresis, WHC, pH, and total acid of the yogurt. Based on the research results, it can be concluded that the storage time of yogurt can last up to 21 days.
Chemical analysis and organoleptic properties of banana blossoms (Musa paradisiaca) as filler for catfish (Clarias sp.) fish floss
Authors: Perdana W W , Widowaty W , Sofia D R , Setiawan Y , Hadayanti D , Zakaria A
Published: April 2021

Meat floss or known as Abon (Indonesian) made from dried meat and has a fluffy texture similar to cotton coarse. The crude protein content of meat floss was less than 15%. Catfish (Clarias sp.) has rough fiber and does not contain many bones that are ideal for the main ingredients for meat floss. Catfish (Clarias sp.) cultivated from freshwater can be used as main ingredients for meat floss. To raise the economic value of meat floss, some use banana blossoms (Musa paradisiaca) as a filler. This study aims to determine the effect of banana blossoms as a filler and frying temperature on the chemical quality and organoleptic properties of catfish meat floss. The Method of this research is to make catfish meat floss with various banana blossoms and various frying temperatures. The method used is the analysis of variance or the factorial pattern of analysis of variance (ANOVA). The result showed the most preferred sample was the treatment sample with 60% banana blossoms filling and a frying temperature of 170 °C. The samples have the moisture content of 6,8%, the protein content of 14,91%, and fat content of 9,73%, as well as the preferred parameters of color, fragrant, flavor, and texture. The results showed that the use of banana blossoms as a filler in catfish floss improved the quality of shredded and has the potential to be used as a form of food product diversification.
Quality evaluation for chili hybrid variety candidate cultivated on highland
Authors: Rahayu S T , Kirana R , Levianny P S
Published: April 2021

Chili is one of potential vegetable due to its high demand and as an important source of nutrition. Hybrid chili has several advantages so it is beneficial to be cultivated. The purpose of this study is to examine the quality of several prospective varieties of large chili hybrids which will be released as new varieties. This research was conducted in Indonesian Vegetable Research Institute in 2019 at the Post Harvest Physiology Laboratory, West Bandung Regency, West Java. The materials used in the study were 3 chili variety candidates and 2 existing varieties that harvested in Lembang during rainy season. The study used randomized block design with 5 treatments and 5 replications. Physical parameters observed were weight, diameter, length, and texture. Chemical parameters include water content (gravimetric method), Total Soluble Solid (TSS), vitamin C (titration method), and ash content. Organoleptic test was carried out by 15 untrained panelists using scale from 1 (like extremely) to 5 (dislike extremely) in order to determine consumer acceptance of the freshness of chillies. The organoleptic tests were conducted on days 0, 4, and 7. The results showed Genotype number. 4 had weight, diameter and vitamin C close to the comparative varieties. Genotypes number 2 and 3 have quality parameters (color, shape, size, appearance, and freshness) preferred by consumers during storage until the 7th day at room temperature in Lembang area of West Java.
Biodiversity of prokaryotic microorganisms in whey tofu from Lembang, Sumedang and Garut West Java
Authors: Junitasari A , Warganegara F M , Widhiastuty M P
Published: April 2021

Tofu is one of the products processed from soybeans that contain nutrients for the body. Tofu from Lembang, Tofu from Sumedang and Tofu from Garut are three types tofu that are produced in different places. Types of microorganisms found in whey can influence the flavor of tofu. This research was conducted to find out the type of microorganisms contained in whey Tofu from Lembang, Sumedang and Garut through metagenom approach. Through this approach, the microbial species in an environment can be known, even without the need to cultivate the microorganism. Whey samples filtered by cellulose acetate membrane of 0.2 µm. Total DNA was isolated by the Klijn method, and used as a template to obtain a fragment of 16S rRNA with ± 400 bp long using touchdown PCR. Amplicons obtained then separated again by DGGE analysis. Optimization of DGGE was made with 8% gel and a denaturant range of 30%-80%. The microorganisms contained in whey Tofu from Lembang have closer homology to the Bacterium EM, microorganisms contained in Tofu from Sumedang were closer with Acinobacter sp. and Uncultured Bacterium, while microorganisms contained in Tofu from Garut were closer to Uncultured bacterium.
The effect of concentration and temperature on the activities of kenikir (cosmos caudatus) leaf extract as iron corrosion inhibitor in electrolyte solution of NaCl
Authors: Sudiarti T , Yulianti Y , Supriadin A
Published: April 2021

Ethyl acetate extracts from kenikir leaves contain flavanoid, alkaloids and tannins compounds. This compound can be used as a corrosion inhibitor because it contains nitrogen and oxygen atoms with a pair of free electrons so that it allows adsorbed strongly on the surface of the iron and increases the activity of corrosion inhibition. The inhibitory activity was analyzed by wheel test method or measurement of weight loss in NaCl 1 % medium with variations in concentration, temperature and electron microscopy (SEM) analysis. The inhibitory activity of kenikir leaf extract increases with increasing concentration of inhibitor. The optimum inhibition efficiency of was obtained at a concentration of 32 ppm with an inhibition efficiency of 86.84%. An increase in temperature from 25-55 ° C causes decreased inhibitory activity and achieves optimum inhibition efficiency at 25°C. Kenikir leaf extract has adsorption properties that correspond to the Langmuir adsorption isotherm with free energy of ΔGads of -14.98 KJ/mol. The results of the surface analysis by Scanning Electron Microscopy (SEM) showed that the kenikir leaf extract could inhibit corrosion rates with iron surfaces that had fewer pores than without inhibitors.
Aplication of nanogold and nanosilver to reduce rheumatic arthritis: Case study at leprosy patients
Authors: Taufikurohmah T , Rusmini R , Soepardjo D
Published: April 2021

This study aims to ensure the treatment of rheumatoid arthritis cases suffered by leprosy patients. Special inspection is carried out every 2 weeks during the treatment. Treatment by giving nanogold and nanosilver volunteers every morning and night as much as 20 ml 20 ppm in drinking water. The number of volunteers 24 people with an age range of 40-70 years. The sex of male volunteers is 12 people and women are 12 people. The condition is divided into 4 categories; weight, moderate, mild and cured. In the beginning, volunteers were chosen in the weight and moderate categories. Research data were medical records and interviews. The results show a gradual recovery process towards recovery. One person with an initial condition in the weight category had not recovered for 3 months of treatment. Overall there was an improvement in conditions from weight to moderate, mild and recovered. Gender has no effect on the recovery process. The conclusions of the nanogold and nanosilver case studies succeeded in alleviating to cure rheumatoid arthritis volunteers for leprosy patients. This case study has the impact give new hopes for leprosy patients to keep their spirits alive. This is very important for the future of leprosy patients free from rheumatoid arthritis.
Investigating the potency of bioactive compounds from ficus religiosa as anti-inflammatory agent
Authors: Utami W , Aziz H A , Nasrudin D , Kusmawan A , Anwar Z , Maulana M , Daryanto M
Published: April 2021

The previous studies explain that bioactive compounds from Ficus religiosa are known as an anti-inflammatory agent. In this research, we investigated the potency of bioactive compounds from Ficus religiosa by using molecular docking between eight bioactive compounds and the COX-2 receptor. The eight ligands were collected from www.pubchem.ncbi.nlm.nih.gov., while the receptor was taken from www.rcsb.org. The result of this study could be a reference for the research in the synthesis of the bioactive compound to minimize failure. The collected data was calculated through Autodock Vina embedded in MGL Tools 1.5.6, and these processes were performed using 100 runs of the Lamarckian Genetic Algorithm (LGA). The lowest energy of complexes was visualized by using Biovia Discovery Studio Visualizer. This result proved that 28-Isofucosterol-COX-2 had smaller binding energy compared to the reference ligand.
Development of protein metabolism electronic module by flip PDF professional application
Authors: Susanti T , Kurniadewi F , Nurjayadi M
Published: April 2021

The 21st century learning innovations must be optimized using appropriate media and learning resources. The use of technology has become an efficient alternative in the implementation of learning. This research aims to produce electronic-modules (e-modules) as teaching materials for protein metabolism using Flip PDF Professional application. The method used refers to research and development. The contents of the module are developed based upon the learning design in the Biomolecular Metabolism course according to the curriculum of the Chemistry Education undergraduate study program. In addition, the e-module is equipped with videos, images, animations, links to various main sources and formative tests on each material in accordance with the learning outcomes over the course. Product validation is carried out by material, language and media experts using standard instruments with the Likert scale. The results of expert validation of the developed e-modules show well to very good at interpretations. Based on the results from the validation it can be concluded that the electronic metabolism protein module is ready to be used as a learning material in supporting the improvement of students’ critical thinking. Dissemination of the e-modules in the biochemical learning process is being carried out and will be published in the next article.
Developing the Computer-Based Test (CBT) on the basic chemistry throughout a web-based application
Authors: Yunita L , Nurjayadi M , Hariwibowo H
Published: April 2021

Nowadays, the development of technology emphasizes the educators to be able to utilize the technology greatly in teaching and learning processes, including the learning assessment. In fact, the implementation of the technology, such as the utilization of an online-based test, seems to develop in the process of learning assessment. Hence, this present research proposes to develop the computer-based test (CBT) application for the comprehensive test of basic chemistry in measuring the higher order thinking skill (HOTS) of the undergraduate students in the major of chemistry education department. Furthermore, to facilitate their necessaries in optimizing the computer-based test (CBT) application, it seems to indicate that the application needs a new innovation in the certain parts in terms of the design itself and the simplicity of the online test that enables to be accessed either from the mobile phones or the students’ laptops. Notably, the development of the computer-based test application in the present research attempts to use the programming language PHP and MySQL in producing the database. Moreover, the author administrates five phases in promoting the application, such as developing the devices within the preliminary study, planning, creating the product design, testing the limited product, and revising the limited product testing. As the result, the findings of the research are expected to become the primary component in developing the online assessment. In other words, it enables to measure the learners’ competencies in comprehending the learning materials of basic chemistry and the higher order thinking skill for the undergraduate students of chemistry education department.
Effect of addition of white turmeric extract against antibacterial properties in edible film sweet potato starch and whey protein
Authors: Amalia V , Adipraja F W , Supriadin A , Khasanah N N , Junitasari A
Published: April 2021

The addition of white turmeric extract as an antibacterial to edible starch-based films aims to improve the resilience of food packaged against bacteria so that the quality is more maintained. The method carried out in this study consists of three things. The first step was the preparation and characterization of orange sweet-potato starch (including starch and moisture content). The second stage is the preparation and characterization of white Tumeric extract by phytochemical tests. The third stage is the preparation and characterization of edible films (including water resistance tests, mechanical properties tests. The result of starch characterization obtained the starch content of 43.16% with a moisture content of 13.95%. The result of the characterization of edible films by adding the best white turmeric extract was 7% with the tensile strength, and combined-successful elongation values were 40.9209 ± 2.5290 MPa and 18.03%. The results of antibacterial testing on E.Coli ATCC 11229 did not produce an inhibitory zone and on S. aureus ATCC 6538 was a clear zone but could not construct that indicates the presence of very weak antibacterial potential in edible films by adding white turmeric extract.
Utilization of e-module in polymer synthetic based on green chemistry to improve student high level thinking
Authors: Astuti D D , Rahmatullah S , Sukmawardani Y , Subarkah C Z
Published: April 2021

Increased thinking at a high level is needed so that students are able to solve the problems faced in their lives based on Islamic values. This study aims to analyze the improvement of higher order thinking skills based on Islamic values on the application of green chemistry-based synthetic polymer e-modules. The research design used was a one-group pretest and posttest with research subjects that were 26 semester VI students of the Chemistry Education Study Program. The results of this study indicate that the application of synthetic chemistry based on green chemistry e-module can improve the ability of high-level thinking based on Islamic values based on the average gain of n-gain 0.647 which is included in the medium category. Learning using this e-module can improve learning outcomes by making learning situations more active so as to better understand the concept of synthetic polymers based on green chemistry. Thus, the application of synthetic chemistry based on green chemistry e-module can improve the ability to think at a high level.
Developing renewable thermo-hydrothermic bioinorganic materials from bone wastes of slaughterhouses
Authors: Karyasa I W
Published: April 2021

Adding value of slaugtherhouses products and wastes today become greater attention, especially bone wastes for renewable biomaterials, in supporting sustainable green industries. However, the high potency of developing the renewable bioinorganic materials from bone wastes needs a comprehensive need assessment. The need assessment was conducted through three steps: literature search metaanalisis study for defining the needs, collecting and analysis data, and making decision of the needs. Results of the study showed that (1) there were prospective and sustainable raw materials from slaughterhouses in Indonesia, especially bones, for developing phosphate based bioinorganic materials; (2) there were some needs of developing bioinorganic nanoparticles materials in M-Si-P-O, M-Al-P-O, and M-Al-Si-P-O systems (with M = main and/or transition metals) for artificial bones and teeth purposes; and (3) there were some needs of developing thermo-hydrochromic bioinorganic materials sensoric temperature and humidity for supporting artificial insemination as well as medicinal purposes. The last result of the study was supported by current finding on natural inorganic thermo-hydrochromic pigment.
Effect of cooking time on the quality of nila nyat-nyat (Oreochromis niloticus)
Authors: Pandit I G S , Permtananda P A N K , Yudha K
Published: April 2021

The right time for cooking nila nyat-nyat is very influential on subjective and objective value of nila nyat-nyat. The goal of this study was to determine the best time in cooking tilapia in order to get the best quality of nila nyat-nyat. The research was conducted at the Laboratory of the Faculty of Agriculture, Warmadewa University and the Faculty of Food Technology, Udayana University. This research used experimental method with completely randomized design of single factors with 6 different treatments and 4 replications. Quality assessment includes subjective tests through organoleptic analysis such as appearance, texture, odor, and taste, and also objective tests or nutritional analysis, such as water, fat, protein, and ash content. Statistical analysis with anova showed that the difference in cooking time gave significant influence in the organoleptic quality and nutritional value of tilapia (p value < 0.01). From this research, we conclude the best time for cooking tilapia was 30 minutes.
Application of manure types in breeding several varieties of chili (Capsicum frutescens L.)
Authors: Yuliartini M S , Wirajaya A A N M , Assegaf A U R Z , Situmeang Y P
Published: April 2021

The study aims to determine the effects of giving several types of manures on various chili pepper varieties. The experiment is a factorial experiment using a randomized block design (RBD) consisting of two treatment factors, namely type of manure (R) of 3 levels: R1 = Chicken Manure, R2 = Cow Manure, R3 = Rabbit Manure and type of varieties (V) of 4 levels: V1 = Genie varieties, V2 = Dewata varieties, V3 = Sigantung varieties, V4 = Gendut varieties. The interaction of varieties and type of manure as a very significant effect on the number of leaves and root fresh weight and significant effect on fresh weight and oven-dry leaves. The highest fresh weight and oven-dry weight was obtained in the interaction of Genie varieties with cow manure, namely 10.06 g and 1.68 g with an increase of 285.44% and 342.10% compared with the interaction of Sigantung varieties with cow manure, namely 2.61g and 0.38 g. The highest fresh root weight was obtained in the interaction of Genie varieties with cow manure, which was 3.09 g or increased 286.25% compared to interaction between Dewata varieties and cow manure, which was 0.80 g. Genie varieties with cow manure types provide better chili seedling growth compared to Dewata varieties and Sigantung varieties.
Cellulase-producing yeast isolated from fermented cocoa beans as biocontrol for pathogenic mold chocolate fruit collected from Sentul, Jawa Barat, Indonesia
Authors: Sukmawati D , Sondana G A , Fikriyyah N N , Afifah Z N , Firhandini A , Khumaiya U , Komsiatun D A , Asmara Y T , Supiyani A , Puspitaningrum R , Ridawati R , Prihantini N B , Husna S N A , El Enshasy H A , Hanapi S Z , Dailin D J , Surono S
Published: April 2021

Mold is one of the microorganisms that can cause damage in chocolate fruit by producing phytopathogenic toxins. Until now, pesticides have been widely used for controlling postharvest loss in fruit. Yeasts can produce secondary metabolites, which can inhibit the growth of pathogenic mold. In this study, we isolate, identify, and apply yeasts isolated from fermented cocoa beans to control the growth of pathogenic mold in chocolate fruit collected from Sentul, Indonesia. This research includes yeast isolation using the dilution method with YMA medium, mold isolation using direct planting method on PDA medium, screening ability to produce cellulase using diffusion method on CMC medium, and in-vitro antagonist testing using dual culture method on PDA medium. The results showed that 128 yeast isolates and 37 mold isolates were obtained in this study. The results of screening representative cellulase capability of 77 yeast obtained 6 positive yeast isolates produced cellulase with the highest cellulolytic index of 0.23-0.30. The 6-yeast antagonism test with the highest cellulolytic index showed that C3.3.1 isolate had the best ability to inhibit pathogenic molds with 37.36% inhibitory power.
Environmentally safe technology with the conversion of used cooking oil into soap
Authors: Rahayu S , Pambudi K A , Afifah A , Fitriani S R , Tasyari S , Zaki M , Djamahar R
Published: April 2021

Cooking oil consumption in Indonesia is very high and tends to rise every year, reaching 500,000 tons/year. Waste of used cooking oil pollute water and reduces the biota. Therefore, the conversion of used cooking oil will help to reduce environmental damage. One of the conversions done is making the bulk cooking oil into soap. This study aims to determine the effect of NaOH concentration on the quality of soap made from purified used cooking oil. Activated charcoal from sugarcane bagasse was used in the conversion of soap to diminish odor and brown color. This study was designed using an experimental method with descriptive analysis. The treatment in this study was the difference in NaOH concentrations of 10%, 30%, and 50% with each concentration repeated three times. The results obtained showed that the most optimal NaOH concentration is 50% since it has a dense soap consistency. In contrast, the 30% NaOH concentration has a semi-solid soap consistency. At 10% NaOH concentration the consistency of soap is still liquid. It can be concluded that the concentration of NaOH affects the quality of the soap.
Assessing the feasibility of chemical laboratory safety videos
Authors: Fitriani E , Darwis Z , Ananda L R , Rahmadianty A , Paristiowati M
Published: April 2021

Laboratory activities are inseparable from learning chemistry. Consequently, chemistry students should master several skills in the laboratory, which they might not have it in secondary school. However, there are many potential hazards to be considered in activities in chemical laboratories. The lack of knowledge and experience of first-year chemistry students causes the possibility of accidents in the chemical laboratory higher. Therefore, in this study, chemistry laboratory safety videos were developed and assessed by experts, while questioners and interviews were used to collect the data. The assessment result is that the videos are feasible and ready to use after the input from experts and users are implemented in the developed videos.