bluuebunny/crossref_metadata_2025 huggingface dataset:
Diffusion effect on passive solute transport inside an infinite two-dimensional array of vortices
Authors: Maryshev Boris S , Klimenko Lyudmila S
Published: February 2021

The transport process of solute in a two-dimensional liquid flow is studied. The infinite plane is “covered” by square cells with periodic conditions at its boundaries. The flow is provided by a periodic external force. If the amplitude of the external force reaches a certain critical value, then the flow in each cell contains a pair of vortices. The analysis of the transport of a passive solute in such a flow is investigated in terms of a special flow. In the framework of this approach the transport process is described by mapping functions that determine the coordinates of the particle at the end of the unit cell and the time of passage of the cell as a function of the coordinates at the entrance to the cell. These functions are obtained numerically by the random walk method taking diffusion into account. Using the special flow approach the distribution of an initially uniform distributed ensemble of passive particles with time is calculated for the passage of a long array of the unit cells. It is shown that for tiny values of diffusivity the transport slowing down some particles regarding the ensemble is observed. The speed-up of some particles regarding the ensemble is observed for moderate values of diffusivity and for high diffusivity we obtain the standard diffusion.
Concentration-dependent diffusion of lithium, sodium, potassium, and cesium hydroxides in water
Authors: Mizev Alexey I , Shmyrov Andrey V , Mosheva Elena A
Published: February 2021

The diffusion coefficients of aqueous solutions of lithium, sodium, potassium, and cesium hydroxide in a concentration range of 0 to 3.0 mol/L were obtained at 25 °C and normal pressure. The Fizeau interferometer and the spatial phase-shifting method were used to measure the spatial distribution of concentration of the investigated substances. The concentration dependence of the diffusion coefficient was determined from the Matano-Boltzmann analysis. The experimental setup and techniques, as well as the image and data processing procedure, were tested using an aqueous solution of nitric acid. The comparison made for lithium, sodium, and potassium hydroxides indicated good agreement between the obtained results and the data collected from the literature. The concentration dependence of the diffusion coefficient for cesium hydroxide in water was found experimentally for the first time.
Non-axisymmetric flow excited by fluid oscillations in a rotating cylinder with sloping ends
Authors: Subbotin Stanislav
Published: February 2021

Fluid flow in non-uniform rotating (librating) cylinder with sloping ends is experimentally investigated. Periodical changes in the rotation rate lead to the appearance of inertial oscillations of the fluid. Due to the azimuthal inhomogeneity of the geometry of the ends, inertial oscillations are non-axisymmetric. The most intense pulsating motion of the fluid is observed at the frequency corresponding to the mode {1, 1, 1}, which is a global single-vortex flow. As a result of the nonlinear response, a non-axisymmetric steady flow arises along the cavity side wall.
Determination of the stability boundary of a two-layer system of miscible liquids with linear diffusion laws
Authors: Vyatkin Vladimir , Bratsun Dmitry
Published: February 2021

The authors consider the problem of determining the stability boundary of a two-layer system of miscible liquids placed in a gravity field. Liquids are aqueous solutions of non-reacting substances with different diffusion coefficients, which are linear functions of concentrations. At the very beginning of the evolution, the solutions are separated from each other by an infinitely thin horizontal contact surface. Such a configuration can be easily realized experimentally, although it is more difficult for theoretical analysis since the base state of the system is non-stationary. Once brought into contact, the solutions begin to mix penetrating each other and creating conditions for the development of the double-diffusive instability since the initial configuration of the system is assumed to be statically stable. The problem of the convective instability of a mixture includes the equation of motion written in the Darcy and Boussinesq approximations, the continuity equation, and two transport equations for the concentrations. We apply the linearization method suggested by Wiedeburg (1890) to find a closed-form solution to the non-stationary base state problem including concentration-dependent diffusion laws for species. We derive analytical expressions for neutral stability curves and study corrections introduced by nonlinear diffusion to the stability analysis.
Experimental study of liquid-liquid interface oscillating in radial hele-shaw cell
Authors: Karpunin Ivan E , Kozlov Nikolai V , Kozlov Viktor G
Published: February 2021

The dynamics of the interface between two immiscible liquids with a high viscosity contrast is studied experimentally under steady displacement of interface and periodic variation of the flow rate of the pumped liquid in radial Hele-Shaw cell. Classic Saffman–Taylor instability, which develops when the viscous fluid is monotonously displaced by the inviscid one, is well known. In the present work, the excitation of Saffman–Taylor instability by means of oscillations of the liquid-liquid interface is demonstrated. The interphase boundary performs axisymmetric radial oscillations at small amplitude of oscillations and in the absence of an average pumping. With the growth of the amplitude of radial oscillations the interface instability is excited, which manifests itself in the development of an azimuthally periodic finger structure during a part of the period. “Finger-like” instability is determined by the relative amplitude of the oscillations of the interphase boundary and under the conditions of the performed experiments depends neither on the oscillation frequency nor on the radial size of the interface.
On dispersion relation for Faraday waves in a near-critical fluid under weightlessness
Authors: Lyubimova T , Ivantsov A , Beysens D
Published: February 2021

One reports experiments and numerical simulations of Faraday waves at the liquid - vapor interface of fluids (typically CO2 and H2) near its critical point when submitted to vibration in a weightlessness environment. It is known that in such a system striation is formed under the action of vibrations. The boundary between the liquid and gas phases is located perpendicular to the direction of vibrations, and a streaky structure in the form of periodic stripes (striations) is formed in the cavity. It is shown that under vibrations of sufficient intensity an instability develops on the striation interface perpendicular to the direction of vibrations, leading to Faraday waves. A theoretical and numerical study of this instability is carried out, the critical parameters of the appearance of Faraday waves are determined taking into account the interaction of waves on adjacent striations. Dispersion relations for Faraday waves are obtained numerically. It is shown that in the vicinity of the critical point there is a significant deviation of the dispersion relation from the classical theoretical dependence.
On the mechanism of selective fixation of bubbles under the action of ultrasound in NaCl and KCl solutions during degassing
Authors: Lyubimova T P , Rybkin K A , Fattalov O O , Kuchinskiy M O , Kozlov M V , Kugaevskaya A A
Published: February 2021

This paper describes the experimental study of the mechanism of selective fixation of bubbles formed in a liquid under the influence of ultrasound on the surface of plates of various degrees of wettability when the liquid is degassed as a result of ultrasonic action. The experiments used solutions of NaCl and KCl of various concentrations, as well as distilled water. The plates are made of organic glass (wetting angle 51°) and Teflon (wetting angle 118°). As a result of the study, the experimental data on the surface area occupied by bubbles on the surface of plates were obtained, and the mechanism of selective fixation of bubbles under the influence of ultrasound in the conditions of emerging degassing was shown.
Buoyancy-driven instabilities induced by a neutralization reaction in immiscible fluids
Authors: Mizev Aleksey , Shmyrova Anastasia
Published: February 2021

Buoyancy-driven instabilities triggered by neutralization reaction in an immiscible two-layer system placed in a vertically oriented narrow cell were studied experimentally. The initial density of the layers was always set to exclude the development of the Rayleigh-Taylor instability. The problem was examined for the surface-inactive species, namely hydrochloric acid and sodium hydroxide, which allowed studying a convective instability development solely due to buoyancy-driven mechanisms, excluding Marangoni effects. We show that one of two global scenarios develops in the system right after the layers came into contact. These scenarios, called by us diffusion-controlled and convection-controlled, essentially differ in the prevailing mechanism of mass transfer and, therefore, in the rate of reaction-diffusion-convection processes. The authors introduce the nondimensional parameter, the value of which determines the border between the two scenarios in the regime map.
Blow-up singular dynamics in breast cancer metabolism
Authors: Rogotnev A , Nikitiuk A , Bayandin Yu , Naimark O
Published: February 2021

Cancer cells have an altered metabolism, which results in specific kinetics of the heat localization and coherent pattern formation. Modified nonlinear Pennes equation was used for the modeling of the metabolic temperature dynamics. The numerical experiments were conducted in order to identify the tissue metabolic reactions in terms of multiscale correlation parameters (spatial invariants) as the characteristics of globally convergent dynamics of blow-up collective modes and the cancer precursor.
Effect of rotation on thermal convection in horizontal plane layer subject to circular vibration
Authors: Rysin Kirill , Kozlov Victor , Vjatkin Alexei
Published: February 2021

The stability of quasi-equilibrium of a horizontal liquid plane layer with isothermal boundaries of different temperatures, subject to circular vibrations in the horizontal plane, is experimentally studied. The rotation of the cavity around the vertical axis is set independently. In order to exclude from consideration the destabilizing effect of the gravity field, the layer is heated from the top. In the absence of rotation, the circular vibrations lead to the threshold excitation of vibrational thermal convection in the layer of nonisothermal liquid, in spite of its stable stratified in the gravity field. At given vibration amplitude and temperature difference at the layer boundaries, the threshold is determined by sharp increase in heat transfer with a monotonic increase in the vibration frequency. The size of the convective spatial structures is determined by the layer thickness. In the case of high-frequency vibrations, convection is determined by dimensionless parameters: gravitational Rayleigh number Ra
and vibrational parameter R
v. The thresholds of vibrational convection excitation on the plane of these parameters in the case of circular vibrations coincide with the theoretically predicted stability boundary for linear vibrations. It is shown that rotation has a stabilizing effect on vibroconvective stability, similar to the case of gravitational convection. The threshold value of the vibration parameter R
v grows with an increase in the dimensionless rotation velocity ω
rot. Under conditions of the performed experiment, the structure of convective cells and the wave number of structures in the supercritical region do not change in comparison with ω
rot = 0.
Stirring of liquid metal in electrovortex flow in a hemispherical volume under the influence of external magnetic field
Authors: Vinogradov D , Teplyakov I , Ivochkin Yu
Published: February 2021

The results of calculations of the stirring rate of liquid metal in a system simulating a DC arc furnace are presented. The equations of motion and transfer of impurity were solved for the electric vortex flow of a liquid metal between two hemispherical electrodes under the influence of an external axial magnetic field. The quality of mixing was characterized by the deviation of the impurity concentration from the mean and was calculated at each time step. It is shown that the effect of an external magnetic field can both accelerate and slow down mixing. These results can be used in electrometallurgy to assess the effectiveness of electromagnetic stirring.
Effect of laser surface modification on the hardness and wear resistance of structural bearing steel for roller screw mechanism
Authors: Zhdanov A.V. , Belyaev I.V. , Morozov V.V.
Published: February 2021

The article is devoted to the analysis of the effect of laser surface modification on the hardness and wear resistance of steel SHX15SG used in the manufacture of roller screw mechanisms. Experiments on laser surface modification were performed on the Russian domestic SVAROG-1-5DR laser system. to get the maximum hardness value. When laser processing without melting the surface of steel SHX15SG, the laser radiation power should be in the region of 5 kW, which corresponds to the maximum power for the installation used. The speed of movement of the laser beam relative to the treated surface should be equal to 25 mm/s, and the focal length should be at least 60 mm. In the case of laser treatment with surface reflow, higher hardness values are obtained at a power of 2 kW. Increasing the power of laser radiation to 5 kW leads to a decrease in hardness. In this case, the speed value should be equal to 25 mm/s, and the focal length should be close to 85 mm. When the focal length is reduced to 60 mm, laser treatment no longer causes melting of the surface of the material under study.
Structural and scattering characteristics model of a fractal nanoclustered island Ag-Au films
Authors: Bukharov D.N. , Novikova O.A. , Essaka S.P.Eyoum , Arakelian S.M.
Published: February 2021

Samples of Ag/Au nanocluster/island fractal nanofilms obtained by thermal diffusion deposition from a colloidal solution are presented. Modeling and evaluation of the features of their structure in the approximation of diffusion-limited aggregation are carried out. The evaluation of the scattering characteristics of the study on the model samples in the framework of the Fischer-Burford relation is made.
Model of formation a metal nanoclusters under laser action in colloidal solution
Authors: Bukharov D.N. , Samyshkin V.D. , Osipov A.V. , Nazarenko B.S. , Arakelian S.M.
Published: February 2021

The results of experimental studies of the production of metal nanoclusters in colloidal solutions are presented. Models based on the Smoluchowski equation for concentrations of nanoparticles of various sizes, as well as a model of cluster-cluster aggregation, are proposed, which can be useful in studying the processes of nanocluster formation in colloidal solutions.
Nir mono and bi 2-vinylthiophene substituted boron dipyrrin dyes: from practice to theory to further practice
Authors: Shagurin A.Yu. , Molchanov E.E. , Sbytov D.A. , Marfin Yu.S.
Published: February 2021

Boron dipyrrin (BODIPY) family is one of the most studied collection of fluorophores, many of which are specifically designed for vital medical uses, such as cell imaging. In this research area, near-infrared absorbing and emitting compounds play the key role. Because of their long wavelength of absorption, they can be effectively excited by taking advantage of therapeutic window of human tissues. Herein we report the repeat of the synthesis of two vinylthiophene-substituted derivatives with extended π-electron systems and their computational investigation. Those dyes were prepared starting from methyl-substituted ones via addition reaction of aldehyde-containing thiophene following the literature. Obtained experimental and theoretical data will allow us to design promising tools not only for cell imaging, but also for fluorescent detection of heavy cations via coordination and possibly more.
A novel statistical decomposition of the historical change in global mean surface temperature
Authors: Qian Gangzhen , Li Qingxiang , Li Chao , Li Haiyan , Wang Xiaolan L , Dong Wenjie , Jones Phil
Published: February 2021

According to the characteristics of forced and unforced components to climate change, sophisticated statistical models were used to fit and separate multiple scale variations in the global mean surface temperature (GMST) series. These include a combined model of the multiple linear regression and autoregressive integrated moving average models to separate the contribution of both the anthropogenic forcing (including anthropogenic factors (GHGs, aerosol, land use, Ozone, etc) and the natural forcing (volcanic eruption and solar activities)) from internal variability in the GMST change series since the last part of the 19th century (which explains about 91.6% of the total variances). The multiple scale changes (inter-annual variation, inter-decadal variation, and multi-decadal variation) are then assessed for their periodic features in the remaining residuals of the combined model (internal variability explains the rest 8.4% of the total variances) using the ensemble empirical mode decomposition method. Finally, the individual contributions of the anthropogenic factors are attributed using a partial least squares regression model.
Enhance capability of separable ball criterion for the bipartite quantum states
Authors: Qian Lilong , Chu Delin
Published: February 2021

The largest separable ball is a meaningful geometric sufficient condition for separability of bipartite quantum states which tells that all the states in the unit ball in Frobenius norm centered at the identity matrix are separable. In this paper, we propose an algorithm that can improve the capability of this criterion to detect the separability outside the unit ball by solving an optimization problem based on the invertible local operators, that is, to optimize

(

A
⊗
B

)

ρ

(

A
⊗
B

)

†

−
1

F

with respect to the invertible square matrices A and B. The numerical examples have shown that our algorithm is more powerful than the original separable ball criterion.
The Equifinal Achievement of the Total Antioxidant Activity of Flavonoids by Plants in Various Habitats
Authors: Scherbakov A V , Ivanov V B , Ivanova A V , Usmanov I Yu
Published: February 2021

The most important nonspecific stress-protecting function of flavonoids is antioxidant, which is associated with blocking the spread of free radicals in cells. Moreover, the effectiveness of individual classes of flavonoids as antioxidants is different; in particular, substances can differ by three or more times. The accumulation of flavonoids by individual plants is exceptionally high in plasticity. To estimate the total potential antioxidant activity, we proposed an indicator – the antioxidant status of flavonoids, taking into account the qualitative and quantitative composition of the identified flavonoids. It has been shown that relatively close values of this indicator can be formed due to different quantitative ratios of flavonoids – either a relatively large number of low-efficiency flavonoids or a much smaller number of high-efficiency ones can accumulate in plants. It has been established that this is characteristic of various species of plants that live in a variety of conditions – from horse marshes to the steppe zone and salt marshes.
Tests of the Iodine Level in Food Supplies of the Population in Central Yakutia
Authors: Sazonov N N , Kuzmina S S
Published: February 2021

Yakutia is an endemic territory for iodine content in the environment. The region of Central Yakutia belongs to the biogeochemical areas known for iodine deficiency. Goiter etiology is associated with low levels of iodine in food. Thus, we analyzed the iodine content in local raw materials (plants, animals, and natural water) in the biogeochemical areas of Central Yakutia. The obtained results show a low amount of iodine in various water sources (river water, lake water, snow water, and rainwater), even in other areas of Yakutia. The iodine content analysis was carried out in food of local origin (beef, horse meat, milk, potatoes, beets, and carrots) as essential food products. Compared to table values, the lowest iodine level was found in milk (3.3 times lower than the standard rate), vegetables (1.7 times lower), and fish (2 times lower). Satisfying values were registered only in meat. The approximate daily iodine intake of a resident has averaged 65.3 mcg, while the standard input is 130–150 mcg/day.
Thermophysical Properties of Chernozem Soils Growing Ornamental Plants in Summer
Authors: Makarychev S V , Shishkin A V , Khlebnikova V V , Chepushtanov S A , Limonov K A
Published: February 2021

Currently, there is no data on the transfer of heat and moisture of arboretum soils that grow such ornamental plants as Meyer lilac (Syringa meyeri), rowan “Alaya” (Sorbus aucuparia), and dwarf thuja “Danica” (Thuja occidentals). We experimentally determined that the thermophysical qualities of chernozems in lilac plantations changed with the water regime in the growing season. The sample maximum values of volumetric heat capacity and thermal conductivity were observed in the dense illuvial horizon. The sample minimums were registered in the AB transition horizon. Thermal diffusivity was the highest at the lowest humidity. In rowan plantations, the moisture content in transitional and illuvial horizons AB and B changed insignificantly. Such moisture distribution corresponds to the slope aspect and the features of rowan. The thermophysical coefficients also slightly fluctuated in rowan plantations, especially in the underlying horizons AB and B. The same horizons displayed the sample maximum of thermal diffusivity. It corresponded to the moisture content of capillarity disruption (MCCD from now onward). MCCD is a value lying between the minimal water potential of soil and the Briggs-Shantz wilting coefficient. It denotes the water content, at which moisture mobility and conductivity sharply decrease. In thuja plantations, the indexes of volumetric heat capacity and thermal conductivity in the upper soil horizon were minimal. In the illuvial horizon, these indexes were 42% and 12% higher, respectively. However, the uniform distribution of moisture in the soils that grow thuja has equalized thermal diffusivity in the AB and B horizons. Overall, the soil profile of rowan plantations contained less moisture than that of lilac and thuja plantations. Therefore, the volumetric heat capacity and thermal conductivity were lower, since they corresponded to the soil moisture content.
The Transformation of Forest Resources in the South of Western Siberia: Data from the Altai Krai
Authors: Otto O V , Redkin A G , Yesimova D D
Published: February 2021

The organization of sustainable forest management is of particular importance in low-forest areas, where forest ecosystems are the source of productive resources performing essential ecological functions. Therefore, the impact of economic activities on the natural vegetation cover can be direct (associated with the withdrawal of resources) or indirect (which occurs due to changes in the environmental conditions of plant growth). As a result of these processes, the productivity of ecosystems is reduced. We identified the main negative changes in the Altai Krai forest cover, which belongs to the West Siberian subtaiga forest-steppe and the Altai-Sayan subtaiga vegetation area. The decrease in forest productivity in the first district is associated with irrational felling, forest fires, and pests. The decrease in forest cover of the territory is particularly evident. The quality of foothill and mountain forests worsened due to the anthropogenic impact. Artificial restoration does not compensate for the damage to forest resources.
Drinking-water Quality Risk Assessment Based on Parameters with Organoleptic (Taste and Odor) Effects Observed in Water from Surface Water Intake and Infiltration Water Intake Facilities
Authors: Yalaletdinova A V , Kantor E A , Galimova Yu O
Published: February 2021

Risks of organoleptic (taste and odor) effects in drinking water from three water intake facilities are assessed, and research results are presented. The highest risk values for water hardness were identified in samples from infiltration water intake; the value for color-related risks was constant and equal to 0.001. For surface water intake samples, the values of water hardness and associated organoleptic risk are the lowest, compared to other water intakes, and do not exceed 0.008. Risk values of organoleptic effects associated with color at the surface water intake facilities are within the range of 0.001-0.003. The risk values for the taste, and odor effects due to turbidity are constant for all water intakes and equal to 0.002. There is no risk of developing organoleptic-olfactory products associated with the chemical oxygen demand parameter in all samples. The research shows that the overall values of the organoleptic risks are the highest in instances form infiltration water intakes compared with the surface water intake. In addition, the water hardness parameter contributes the most to overall organoleptic risks for all water intakes. The authors conclude that the risks associated with organoleptic (taste and odor) effects do not exceed an acceptable level, both for each indicator considered separately and for their combined effect.
Gill and skin pathology of hybrid grouper (E. fuscoguttatus x E. lanceolatus) infested Zeylanicobdella arugamensis worms in different infestations degree
Authors: Nisa M , Mahasri G , Sulmartiwi L
Published: February 2021

Zeylanicobdella arugamensisis one of the marine parasites that attacks Hybrid grouper fish(E. fuscoguttatus x E. lanceolatus)rearing. Death of infested fish occurs in a period of 3 days after infestation due to secondary infections caused by pathogenic bacteria such asVibrio alginolyticus. Severe infestation ofZeylanicobdella arugamensisoccurs in Pacific salmon (Oncorhynchusspp.) and in hybrid groupers the prevalence is 59%. This research used survey method by sampling 50 hybrid groupers. The study aimed to determine the anatomic and histopathological pathology of the gills and skin of the hybrid grouper at different degrees of infestation. The pathology of gill and skin anatomy of the hybrid grouper infested byZeylanicobdella arugamensisare red, thickening and pale. The highest histopathological damage of the skin at severe infestations of 2.4a± 0.87 results in erosion, inflammation, congestion and hemorrhage. The highest histopathological damage to the gills at the degree of severe infestation 2.8a± 0.87 had fusion, telangeactasis and hyperplasia. The Kruskal Wallis test showed a significant degree of infestation on the severity of histopathological changes in the gills and skin of the grouper that is 0.00 (p≤0.05).
Analysis of the density and intensity of metallothionein in Crassostrea cucullata oyster hulls in the coastal fishing port of Mayangan Probolinggo, East Java using immunohistochemical techniques
Authors: Isroni W , Maulida N , Mubaroqi M I
Published: February 2021

The purpose of this study was to determine the relationship between heavy metal levels in the stomach of Crassostrea cucullata. Descriptive methods and oyster sampling were carried out at 3 stations and 3 oyster samples were taken from each station. Station I, it is suspected that the pollution came from waste from ship engine oil, or waste from ship repair, Station II is suspected of having contamination originating from TPI or SPN. Station III, it is suspected that the pollution came from domestic waste from the community who used the river as a disposal site. The results of the metalothionein density are in accordance with the response of the oyster hull to heavy metal absorption which indicates that the heavy metal content in the stomach at station 1 is higher when compared to station 2 and station 3. The highest metalothionein intensity is found at station 1 which is the dock area, while the lowest metalothionein intensity is found. located at station 1. station 3, namely the mangrove area. The color intensity of metalothionein varies at each station depending on the absorption rate of heavy metals by the oyster body. Average Metallothionein Intensity Graph.
Koi (Cyprinus carpio) Hatchery techniques: its performance in BBI Boyolali
Authors: Laksono M G , Sugianta  , Santanumurti M B
Published: February 2021

One type of freshwater ornamental fish favored by the Indonesian community is koi (Cyprinus carpio). Therefore, koi hatchery conducted by farmers is increasing each year. This study reported the performance of koi hatchery activity at the Balai Benih Ikan (BBI), Boyolali, Central Java, which is known as one of the koi aquaculture sites in Indonesia. The working method used in this study was a descriptive method. The koi hatchery activities showed a fecundity of 420,000 eggs with a hatching rate of 85.71%. The spawned eggs hatch within 3-5 days after the spawning process. Growth sampling on larvae was carried out 4 times during the hatchery period. The larvae on day 21 have an average length of 2.78 cm while on day 28 had an average length of 3.32 cm while the survival rate reached 75%.
Ectoparasite infestation and survival rate of pacific white shrimp (Litopenaeus vannamei) that immunized with crude protein Zoothamnium penaei in intensive ponds
Authors: Mahasri G , Mukti A T , Nisa M , Prakosa G C , Satyantini W H
Published: February 2021

The aim of research was to determine ectoparasite infestation and survival rate of L. vannamei immunized with Zoothamnium penaei crude protein in intensive ponds. This research was an experimental study to determine the effect of using feed and added crude protein Z. penaei to L. vannamei. The sample used was 10,000 (PL-11) L. vannamei. The collected data of ectoparasite infestatiton were analyzed by descriptive and variance analysis. There was a significant difference between the pacific white shrimp immunized with crude protein Z. penaei on the 1th, 30th, 60th and 90th days of maintenance (p< 0.05). The highest ectoparasite infestation occurred in L. vannamei aged 60 days, and 30 days respectively. An increase of ectoparasites infestation occurred on shrimp aged 30 to 60 days in the ponds, though there was no significant difference (P> 0.05). On 90 days of maintenance, there was an increase of ectoparasites infestation and it was significantly different from the infestations in shrimp aged 60 days in ponds (p<0.005). The survival rate of pacific white shrimp immunized with crude protein was the age of 90 days in the pond (79%). crude protein Z. penaei could suppress ectoparasite infestation and vannamei shrimp mortality in intensive ponds.
The effectiveness combination of maggot (Hermetia illucens) flour with commercial feed on growth rate, feed conversion ratio, and feed efficiency of tilapia (Oreochromis niloticus)
Authors: Indriawati V , Rahardja B S , Prayogo
Published: February 2021

Tilapia (Oreochromis niloticus) is a freshwater fish commodity that has high economic value. One way to increase tilapia production is to conduct intensive culture efforts by providing artificial feed. However, an important problem in tilapia farming is the high price of commercial feed. One way to reduce the cost of producing expensive commercial feed is by utilizing alternative raw materials that are easily available. Maggot flour is an alternative raw material that has high nutritional value ranging from 30-45% at a cheaper price. This study aims to determine the addition of maggot flour to commercial feed can increase the growth rate and feed efficiency, and reduce the feed conversion ratio of tilapia. The method was experimental with a completely randomized design (CRD) as an experimental design. This research used five treatments and four repetitions consisting of P0 (0%), P1 (24%), P2 (49%), P3 (74%) and P4 (94%). The results showed that the addition of maggot flour to commercial feed had no effect (p> 0.05) on growth rate, feed conversion ratio, and feed efficiency of tilapia. The concentration of adding maggot flour which can produce values of growth rate, feed conversion ratio, and feed efficiency of tilapia is 24%.
Depuration of heavy metals Pb and Cd content in blood cockles (Anadara antiquata) with different filters
Authors: Arifin W , Rahardja B S , Pursetyo K T
Published: February 2021

The presence of heavy metals in the waters has a negative effect on the growth, reproduction, and survival of aquatic biota. Lead (Pb) is a toxic material that easily accumulates in human organs and can cause health problems in the form of anemia, impaired kidney function, disorders of the nervous system, brain and skin. The limit consumption of Pb is 0.2 - 2.0 mg per day. Cadmium (Cd) is the heavy metal most commonly found in the environment, especially the water environment, and has a high toxic effect, even at low concentrations. This study aim to determine the best filter to reduce the Pb and Cd content of blood cockle (Anadara antiquata). The research method is experimental using a completely randomized design (CRD) with 4 treatments and 5 replications. The treatments test used Gracillaria sp, zeolite and activated carbon filters. The test for heavy metal content used the AAS test. The results showed that the difference of filter have an effect on the reduction of Pb and Cd content in blood cockle. Giving activated charcoal filters can decreased the Pb and Cd content higher, with an average percentage of 31.5% for Pb and 28.56% for Cd.
Effect of Culture Combination on Growth and Carrageenan Content of Kappaphycus alvarezii Green and Red Variety
Authors: Abdillah A A , Triastuti J
Published: February 2021

Indonesia as second of the biggest Kappaphycus alvarezii producer in the world, which were cultured using a different variety called green and red variety of K. alvarezii. The aims of this study is to determine the effect of culture combination method on growth and yield of carrageenan extracted a red and green variety of K. alvarezii, which were used the randomized block design was conducted in. The result demonstrated among red and green did not show significantly (p>0.05) in growth at two weeks of culture periods. However, beyond 3-5 weeks of culture periods, K. alvarezii green variety showed significantly different (p<0.05), which mix culture method showed better growth than the red variety. Interestingly, K. alvarezii green variety demonstrated higher carrageenan content when mixed with red variety in one raft during the culture period, which was presented correlation with growth parameter. Furthermore, combination culture method could be suggested for seaweed farmers that face problems in occupying mono variety K. alvarezii seed during seaweed culture.
Examination of Taura Syndrome Virus (TSV) in white shrimp (Litopenaeus vannamei) and tiger prawn (Penaeus monodon) with Polymerase Chain Reaction (PCR) method
Authors: Fadilah A N , Fasya A H
Published: February 2021

Frozen shrimp is one type of fishery product. Fishery products are a type of food that is susceptible to damage due to pathogenic microbial contamination. Virus is a type of pathogen that can attack fishery commodities including shrimp. One type of virus that attacts shrimp namely Taura Syndrome Virus (TSV). This study aims to detect Taura Syndrome Virus in frozen white shrimp (Litopenaeus vannamei) and tiger prawn (Penaeus monodon) products. The research was carried out in December 2019 - January 2020 at the Fish Quarantine Center, Quality Control and Safety of Fishery Products in Surabaya II. Materials used in this study consist of two types of frozen shrimp, namely 5 samples of tiger prawn and 2 samples of white shrimp. Virus testing samples were detected molecularly using the conventional Polymerase Chain Reaction (PCR) method which consisted of an extraction stage using a Silica Extraction Kit, an amplification stage, electrophoresis and result visualization. This research was observative, then the data obtained were analyzed descriptively. The results showed that all shrimp samples consisting of white shrimp dan tiger prawn were negative of the Taura Syndrome Virus (TSV).
Effect of temperature and Mg-Zn catalyst ratio on decarboxylation reaction to produce green diesel from kapok oil with saponification pretreatment using NaOH
Authors: Chumaidi A , Dewajani H , Sulaiman M A , Angestine F , Putri A , Pravitasari S A
Published: February 2021

Green diesel is an emerging option to solve the increasing consumption of diesel (fossil based fuel). It involves converting readily available vegetable oils and animal fats to alkane hydrocarbons that can be considered to be drop-in replacements for petroleum-based fuel component. This review journal investigate the results of diesel-like hydrocarbon fuel by catalytic thermal decarboxylation of Mg-Zn basic soap by saponification using NaOH from kapok oil. Specifically, it outlines a comparative assessment of the operating parameters of the temperature and mole ratio of Mg-Zn catalyst to select the appropriate path based on the desired conversion, yield and selectivity. The results of the literature study show that kapok oil can produce diesel equivalent biohydrocarbon products by reviewing the main composition of the kapok oil which containing linoleic acid. An increase in the temperature of the decarboxylation reaction can increase the conversion to green diesel products, n-heptadecane. The result from previous experiment showed that the highest conversion of decarboxylation of castor oil is 65% at 475°C. However, high temperatures can cause decreased selectivity due to the production of undesirable products like in the decarboxylation experiment of soybean oil which showed that the yield at 400°C is decreased to 25%. The mole ratio of Mg-Zn used in the decarboxylation reaction does not have a significant effect on the yield of green diesel products.
The development of five - level trays type biodryer reactor for processing of organic waste and vinasse mixture into solid recovered fuel
Authors: Naryono E , Susanto S , Wulan D R , Alqavid A , Nasukha I , Auliya T I N
Published: February 2021

At Malang city, municipal solid waste (MSW) composition is mostly an organic waste that can utilize for Solid Recovered Fuel (SRF). Vinasse is a side product of the bioethanol industry, that mixed with MSW and dried by biodrying technique for solid fuel. The purpose of this research is to evaluate SRF characteristics of organic waste and vinasse mixture generate from biodrying. Research performed by drying the mixture of organic waste and vinasse at (0, 10, 20, 30, 40%) b/b ratio using biodrying reactor with five-level trays. This mixture inserted into the reactor tray, aerated at aeration flow rate 2 L/min from the compressor for nine days. The resulting SRF performed then characterized its moisture content, burning rate, and calorific value. The results showed that the biodryer reactor was successfully made with dimensions of 165 x 50 x 70 cm, consisting of five-level tray with a size of each level tray biodryer of 60 x 45 x 5 cm. The best SFR which has the highest heating value obtained from organic waste with vinasse 10%. It has a moisture content of 11.56%, the burning rate of 0.0135 g/sec, and calorific value of 3912.56 cal/g.
Analysis of the condensate phase in offshore pipe gas company
Authors: Zamrudy W , Rahmatullah A , Prayitno P , Wibowo A A
Published: February 2021

Gas transportation is usually done using pipes. As was done in one of the Gas Companies. In gas transportation consists of suppliers (Station A) and receivers (station C). From the supplier to the receiver goes through a very far pipe. Gas that passes through the pipeline has a composition consisting mostly of methane, but it is undeniable that there is still heavy carbon and impurities in the gas. Heavy carbon and various impuritis contained in the gas will disrupt gas transportation in the pipeline because it can cause condensate. Condensate consists of heavy carbon and impuritis which changes phase into liquid. The occurrence of liquid is caused by external and also internal influences, especially on the temperature and pressure that is treated to the gas. Condensate in the pipe will cause obstruction or decrease the volume in the pipe and otherwise it will cause internal corrosion. In the Gas Company there is an offshore pipeline that has the deepest depth of 70 meters. This elevation allows condensate inundation to occur in the offshore pipeline. The purpose of this study was to determine the effect of operating conditions on the occurrence of the existing condensate phase in the offshore pipeline between B Station B and C Station, which is 105 km away. The method used is the collection of gas composition data through gas chromatography analysis at station A, piping specifications, operating conditions at station B, and Hysys Aspen Simulation. It can be concluded that the offshore pipeline between B station and C station formed condensate (liquid phase) on 2nd day. The operating pattern of the envelope phase shows that in this condition natural gas condensate is formed because it is in the gas-liquid phase. If the methane composition and sea temperature are getting smaller, the possibility of natural gas condensate formation will be even greater.
Literature study of production dry cellulase from Trichoderma reesei, Aspergillus niger, and Bacillus subtilis
Authors: Maryanty Y , Wulan D R , Hidayati M D , Rizal D A , Aliffandri F
Published: February 2021

Cellulase is an enzyme that can degrade cellulose through a catalytic process. The enzyme that works synergistically to release sugar (glucose). This review aims to determine cellulase enzymes’ activation from three different microorganisms, Aspergillus niger, Bacillus subtilis, and Trichoderma reesei. Enzymes’ activation using various kinds of lignocellulosic substrates and the effect of adding carrier agents on the freeze-drying process. The cellulase enzyme from Trichoderma reesei has an activity of 3.4 IU / mL. This enzyme is produced by pre-treatment 1% H2O2 in lignocellulosic media. Aspergillus niger has a cellulase enzyme activity of 0.229 IU / mL using a sugarcane bagasse substrate that has been pre-treated by shiitake mushrooms. The cellulase enzyme from Bacillus subtilis has an activity of 0.907 IU / mL, with the addition of CMC levels of 5% as an inducer. Cellulase enzymes in liquid form are susceptible to denaturation during storage. The production of cellulase enzymes in solid form is expected to maintain the stability of the resulting cellulase enzyme activity longer. The addition of non-reducing sugar as a carrier agent in the freeze-drying process is reported to preserve the biological activity. The addition of sucrose and trehalose, each with a concentration of 300 mM, maintained the amylase enzyme activity up to 90%. The addition of sucrose with an optimum concentration of 60 mM protects both total protein stability and good lysozyme activity. It is suspected that a carrier agent with an optimal concentration can maintain protein stability in cellulase enzyme activity in this review.
Hydrothermal synthesis and characterization of nano-particles γ-Al2O3
Authors: Buwono H P , Adiwidodo S , Wicaksono H , Firmansyah H I
Published: February 2021

The study of hydrothermal treatment on the phase formation and the crystallites of gamma-alumina (γ-Al2O3) was performed. Different reaction time and temperature of hydrothermal treatment were investigated. The preparation of γ-Al2O3 includes precipitation of aluminum nitrate nonahydrate by ammonia, aging, washing, transferred the gel into the hydrothermal reactor, drying, and calcination at 600 °C. The precipitation was stopped at pH equals 7.5. The reaction times of hydrothermal treatment were 1 – 2 hours, and the temperatures were 140 – 200 °C. X-Ray Diffraction analysis was used to investigate the phase formation and the particle size. The results show all the samples represented pure nano γ-Al2O3. The examination of hydrothermal treatment of y-Al2O3 reveals as the reaction time longer, the crystallite grows bigger, as well as the higher temperature applied. The smallest γ-Al2O3 obtained based on the Scherrer equation is 4 nm and the biggest is 6.5 nm. Interestingly, the peaks of the γ-Al2O3 prepared by hydrothermal treatment at the longest time and the highest temperature have shifted into a higher diffraction angle. In the case of this sample, the peaks shifted into a higher diffraction angle. That is means there is a change in the lattice structure of γ-Al2O3 probably was affected by the lattice of hydroxyl content.
D-limonene from orange (Citrus Maxima) peel extraction as destructive agent of styrofoam waste
Authors: Hardjono H , Dewi E N , Lusiani C E , Febriansyah I , Bachtiar R I
Published: February 2021

Styrofoam is widely used for food packaging because it has good weight, stability, and stiffness but it cannot be decomposed naturally by microorganisms. D-Limonene, one of the monoterpene derivatives, is an environmentally friendly styrofoam solvent. This monoterpene is the main component of essential oil that can be extracted from orange peel. The aim of this study is to destruct styrofoam wastes (foods packaging, electronics packaging, foam boards and cup noodles) using d-limonene from orange (Citrus Maxima) peel extraction by water distillation process. The orange peel after size reduction is extracted by water distillation process at 94°C for 7 hours to produce essential oils. It was used to destruct styrofoam waste at the different volume ratio (1:0:0; 1:0:3; 1:1:2; 1:2:1) of the essential oil mixture (essential oil : ethanol: water). The result of this study shows that styrofoam wastes can be destructed using d-limonene from orange (Citrus Maxima) peel extraction. D-limonene of essential oil from orange (Citrus Maxima) peel can be used as destructive agent of styrofoam waste. The fastest destruction time of styrofoam waste occurs at electronic packaging with essential oil mixture by volume ratio of 1:1:2.
Performance evaluation of soil water content observation from satellite images in sediment disaster-prone area
Authors: Hapsari R I , Putri R I , Aponno G
Published: February 2021

Soil water content observations from remote sensing are growing for landslide disaster management due to the potential of wide coverage and fine resolution. Characteristic evaluation of various soil water content products is necessary for improving the accuracy. This study assesses soil water content products from Soil Moisture Active Passive from Global Modelling and Assimilation NASA, Soil Moisture and Ocean Salinity from ESA, and Soil Water Index (SWI) from Copernicus Global Land Service. Results are compared with soil test in terms of spatial and temporal distribution, time series, and quantitative performance indices. The study is conducted in Brantas River Basin Indonesia, where the upstream is vulnerable for landslide disaster. The investigation has shown that with correlation coefficient 0.81, SWI is suitable for further application in the study area. This finding has important implications for modelling the landslide hazard using quantitative soil water content product from satellite imagery.