bluuebunny/crossref_metadata_2025 huggingface dataset:
Effectiveness of the implementation of probing-prompting learning model on student learning outcomes in the discussion of static fluid
Authors: Lutfia A , Asyhari A , Saidy
Published: July 2020

This study aims to determine the effectiveness of the Probing-Prompting learning model on student learning outcomes. To see student learning outcomes, researchers use a test in the form of multiple-choice questions. This research is to know the effectiveness of the learning model Probing Prompting towards the Learning Outcomes of students in the static fluid material class XI IPA SMAN 1 Sukadana 2018/2019 school year. This research is a quasi-experimental research. This study uses two classes as an experimental class and one class as a control class. The sampling technique used was purposive sampling. The research sample is by choosing a class that is contained in class XI MIA, which has low learning outcomes. Then the researchers gave treatment to class XI MIA 2 as an experimental class by applying the learning model Probing Prompting in learning, and class XI MIA 1 as a control class applied to the learning model in Discovery Learning accordance with the habits of educators. To find out the differences in learning outcomes in the control class and the experimental class a t-test was conducted using the Polled Variance formula. The results of the analysis of learning outcomes show tcount = 9.51 while ttable = 2.01 so that tcount>ttable, and H1 received. The learning model is Probing-Prompting more effective in improving student learning outcomes, and effectiveness can be seen with the effect size test. The results of the test Effect size are, therefore, included in the medium category (d = 1,021 <0.8). Based on these results, it can be concluded that the learning model is Probing Prompting effective in improving student learning outcomes.
Identification of students’ misconceptions using the Certainty of Response Index (CRI) from work and energy material
Authors: Mustari M , Anggereni S , Sodikin  , Fitria  , Yusandika A D
Published: July 2020

Research has been conducted at SMAN 1 Pesisir Selatan aimed to determine the level of students’ misconceptions on work and energy materials. This research is quantitative descriptive with students from class X MIPA 2 SMAN 1 Pesisir Selatan as objects. The sampling in this study uses purposive sampling method. The data also is analyzed quantitatively. The results shows that the students’ misconception level is 13.11% in which the criteria for the level of misconception is low.
Magnetic properties of Ga-doped and As-doped hydrogenated silicene: Density Functional Theory (DFT) calculations
Authors: Pamungkas M A , Sari F , Abdurrouf  , Nurhuda M
Published: July 2020

Computational studies of silicene, which is a two-dimensional silicon material with honeycomb structure, has been carried out using Density Functional Theory Calculation. This study was aimed to determine the effects of doping gallium (Ga) atom and arsenic (As) atom on the magnetic properties of hydrogenated silicene. The results showed that pure silicene has very small magnetic properties, can be considered as non-magnetic. The process of hydrogenation on silicene changes it to become a magnetic material. The effects of Ga/As dopant on the magnetic properties of hydrogenated silicene depends on positions of Ga/As atom. Silicene with As atom at hollow site has the highest magnetic moment of 0.0592 μB
. This value increases from the magnetic moment of hydrogenated silicene magnet by 104%.
Simulation of physical activities effect and treatment exogenous insulin for managing plasma glucose concentration in type 1 diabetes mellitus
Authors: Kartono A , Sari M , Wahyudi S T
Published: July 2020

The simulation model of glucose level dynamics system during physical activity is important to represent an actually of the normal living conditions. These simulation results can be to accelerate the development of the artificial pancreatic design because of an administration of glucose through the oral according to the actual conditions then followed by administering insulin through infusion is following the actual conditions. In this study, the effects of insulin injection and physical activity on the glucose concentration level of type 1 diabetes mellitus (T1DM) will be simulated. A modified oral minimal model using the effects of physical activity and external insulin treatment was developed in the present study. Based on this simulation study, the main objective of this study was to vary insulin injections while carrying out physical activities that could validate the effects of decreased blood glucose levels in T1DM patients. These simulation results showed that the greater the injection of insulin during physical activity, the faster the rate of blood glucose concentration decreases. The optimum experiment simulation has been obtained to represent a treatment accurately by comparing the experimental data of a normal glucose concentration.
Solution of d-dimension time independent cosmic string using supersymmetry quantum mechanics method for rosen morse, scarf II and scarf I non-central potentials
Authors: Suparmi A , Anggraini D , Cari C , Ma’arif M
Published: July 2020

Solution of d-dimension time independent cosmic string for rosen morse, scarf II and scarf I non-central potentials was solved using supersymmetry quantum mechanics method. Variable separation method was applied to the d-dimension time independent cosmic string equation, and then the d-dimension time independent cosmic string equation was reduced into d one dimensional schrodinger equation. Supersymmetry quantum mechanics method was used to analyze radial wave function, angular wave functions, and energy level. Energy levels were higher by the presence of rosen morse, scarf II and scarf I potentials parameters. The increased value of nr
, n

θ
2
and n

θ
4
caused the increase in energy levels, the decrease of cosmic string α parameter, caused the decrease of energy levels and the increasing of number n

θ
1
and n

θ
3
caused the decrease of energy levels.
STEM literacy load analysis on the planning and implementation of science learning on the topic of simple machine
Authors: Surani E , Jalmo T , Abdurrahman
Published: July 2020

The purpose of this study was to determine STEM literacy in the planning and implementation of science learning on the topic of simple machine. This research method is a descriptive qualitative method. Data were obtained using observations, document analysis, and interviews, which involved 200 junior high school science teachers in six districts of Lampung province, data analyzed with percentage. The results of STEM literacy analysis on the planning of natural science learning on the topic of simple machine have a high category of planning average (61%) and the average category of implementation is also of a high category (65%). Data analysis shows that learning science in simple machine material had integrated STEM but focused more on science and rarely used technology in student learning. Also, teachers realize that applying the STEM approach makes student learning more relevant, stimulates the emergence of meaningful experiences, encourages students to think higher and solve problems and increase retention. So that by the demands of the revolutionary education era 4.0.
The thickness effect to optical properties of SnO2 thin film with doping fluorine
Authors: Susilawati  , Doyan A , Muliyadi L , Hakim S , Taufik M
Published: July 2020

Synthesis of SnO2:F thin layer was grown using the sol-gel spin coating method on a glass substrate with various layers (one to four layers). The purpose of the synthesis was to determine the optical properties of thin layers including transmittance, absorbance, energy bandgap, and activation energy. The optical properties of the layers were characterized using UV-Vis spectrophotometers with a wavelength of 200-1100 nm. The results showed that at a wavelength of 300 nm the absorbance value decreased with an increasing number of layers. Absorbance values obtained for variations in layers (one to four layers) for the percentage of 95:5% and 75:25%, respectively 3.59-2.85 and 4.30-3.42, while the transmittance value decreased, namely 96.8-79.6% and 98.3-81.1%. Besides, the energy bandgap obtained decreases with an increasing number of layers. The energy bandgap decreased from 3.69-3.56 eV and 3.59-3.42 eV for direct allowed, while 4.00-3.91 eV and 3.96-3.83 eV for indirect allowed. Activation energy decreased from 0.23-0.07 eV and 4.35-1.43 eV.
Estimation of execution time for multi-stage control operations
Authors: Balakin A , Kopp V
Published: July 2020

The paper considers issues related to such a multiple measurements approach where the measurement results affect the number of measurements taken. This may result in a significant increase in the measurement time. The work takes into account the change in the probability that the product will be suitable after a specific measurement. These probabilities depend on the number of measurements. The given algorithm for controlling the measurement process shows the random nature of the duration of its execution, which in turn leads to the need to study the duration of multiple measurements. In this paper, a semi-Markov model is constructed that allows us to determine the functions of time distribution between events in the output flow formed after measurements. The resulting model makes it possible to connect it with models of elements of the highest levels of the hierarchy of the production structure. After a specified maximum number of measurements, the model assumes that a part of the measured product is defective and thus shall be rejected. The constructed semi-Markov model may be used to predict the performance of a technical system that uses multiple measurements to improve accuracy.
Hydromechanical method of control of drillstring torsional vibrations
Authors: Bashmur K A , Petrovsky E A , Smirnov N A , Tynchenko V S , Bukhtoyarov V V , Kukartsev V V , Kurashkin S O
Published: July 2020

The article discusses issues related to the vibrations of drillstring (DS). The relevance of the fight against torsional fluctuations DS and the reasons for their occurrence are analyzed. The hydromechanical method of control of torsional oscillations DS and device for its implementation is proposed. This method is characterized by its versatility and practically does not depend on the conditions of well drilling. Characteristics of the developed control method are determined by means of the hydraulic model of drilling mud behavior. The model illustrates the operability of the method and can assist in the selection of parameters for regulator design.
Technological potential of impact vibration damper of drill string with discrete working medium
Authors: Zagulyaev A V , Bashmur K A , Petrovsky E A , Tynchenko V S , Smirnov N A , Kukartsev V V , Kurashkin S O
Published: July 2020

The article discusses issues related to vibrations of drilling string bottom layout during construction of oil and gas wells. Analysis of causes of longitudinal vibrations occurring during rotary drilling is carried out. Invention proposes using vibration dampers of impact principle of action using discrete working medium. We described a device of this type of vibration dampers for drill columns. A probabilistic model of shock vibration damper operation with discrete operating medium is given. Analysis of the model shows the efficiency of using these types of vibration dampers to eliminate high-amplitude vibrations of drill columns.
Methodological and technological aspects of creation of digital platforms in ideology of open information systems
Authors: Boichenko A V , Lukinova O V
Published: July 2020

In the article it is shown that the process of digitalization of the information society, which is now a trend of world development, should be considered in the context of consumer, management and technological aspects. The conceptual model of interrelation of concepts of digital economy, which are associated with objects of digitalization, is described: digital transformation, cloud computing, information infrastructure, the digital platform, the integrated digital platform, platform economy, an ecosystem. These concepts are interpreted from the point of view of service-oriented architectures; properties of public service are described. Methodological and technological aspects of digital economy platforms design are considered in terms of open systems model, for which the main definitions and properties are given. The example of the OSE/RM open systems model shows the specifics of digital platforms related to their reorientation towards application industries. It is stressed that a feature of digital platforms is the fact that the platform becomes a provider of application platform services to external consumers. The tasks that the digital platform should solve in a new capacity are formulated.
On the location of a power line fault
Authors: Buryanina N S , Korolyuk Y F , Koryakina M L , Lesnykh E V , Suslov K V
Published: July 2020

The paper proposes an algorithm to exclude the aperiodic components from short circuit currents. The computer-implemented algorithm allows locating a fault and a phase failure in 0.5 - 0.6 milliseconds. During this time interval, the magnetic cores of current transformers (CTs) do not reach saturation and processors receive undistorted information from the current transformers. Four measurements of instantaneous values of currents that are made in equal time intervals (sampling intervals) are sufficient to implement the algorithm. The exclusion of aperiodic components increases the accuracy of the fault location. The algorithm can also be used in the location of open-phase fault and in the digital relay protection based on the measurement of current and voltage.
Analysis of the life cycle of a library information resource using Process Mining technology
Authors: Dorrer M G , Popov A A , Bartuzanova A N
Published: July 2020

The purpose of this work is to evaluate the applicability of the Process Mining methodology for the analysis of life cycle models of information resources. ProM software was used with the Inductive visual miner plugin. The source data was a database of the Seattle Public library hosted on the site Kaggle.com. Even from a fragment of the transaction history of library information resources, it was possible to recover the lifecycle model. The result confirms that it is possible to build and analyze models of the life cycle of information resources based on the event history logs.
Influence of the oxide phase on the process of inflation of composition from highly dispersed porous iron
Authors: Alibekov S Ya , Dovydenkov V A , Zvereva O S , Egorov A V , Pavlov A I , Lysyannikov A V , Kaizer Yu F , Demchenko A I
Published: July 2020

The article describes a new technology for the production of steel parts for structural purposes. The technology is based on molding mixtures of iron powders, iron oxide powders and a binder. Technological processes include the processes of vacuum reduction of iron oxide and a binder material with subsequent sintering of the mixture. The study of the features of the brass infiltration process is carried out on highly porous iron-based blanks with pore sizes less than 1 μm with various percentages of the starting components. The analysis of the structures and mechanical properties of materials obtained on the basis of the developed technology has been performed. The mechanism of infiltration of highly iron-based preforms based on iron obtained by casting from the compositions “iron-iron oxide-phenol-formaldehyde resin” obtained in three stages is established. Recommendations have been developed for the pilot production of products of complex shape from iron-based metal powders, including of casting molding operations, oxide reduction and sintering operations, followed by brass infiltration and heat treatment of the products. The introduction of new technology makes it possible to produce products of complex shapes with a high level of mechanical properties, improved dimensional accuracy and lower cost.
Identification of the parallel 3-PRRR manipulator parameters considering the workspace boundaries and the passive orthosis movements
Authors: Malyshev D I , Nozdracheva A V , Kholoshevskaya L R
Published: July 2020

The article discusses a system of rehabilitation of the lower extremities based on a passive orthosis in the form of a sequential RRRR mechanism and an active parallel 3-PRRR robot. Effective numerical methods and algorithms were developed and tested that made it possible to determine the minimum geometric parameters of the active parallel mechanism that ensure the movement of a passive orthosis within the working area in accordance with clinical data when simulating walking. The simulation results are presented by visualizing the exported workspaces in the STL format.
Reduced energy consumption when feeding raw materials to the reactor for the production of carbon black
Authors: Mukhamadeev E Z
Published: July 2020

This article describes possible ways to reduce the energy consumption of pumps that supply liquid hydrocarbon feed to the nozzles of reactors for the production of carbon black. For achieving this goal, it is proposed to separate the functions performed by the pumps. Some pumps provide circulation, heating, dehydration of raw materials, and supply them to the reactor compartment. Other pumps increase the pressure of the liquid directly in front of the nozzles of the reactors. It is advisable to use piston pumps with pulsation smoothing pumps to increase the pressure.
Analogies method application to increase the involvement degree in the deposits development of the Jurassic oil and gas complex in Western Siberia
Authors: Mukhametshin V V , Kuleshova L S
Published: July 2020

About 250 objects of the Jurassic and Paleozoic ages of four oil and gas regions of the West Siberian oil and gas province under development were identified and grouped. Eight groups of objects were identified based on the use of data on tectonic-stratigraphic confinement and data on the bedding conditions, geological, physical, and physicochemical properties of the strata and the fluids saturating them. The dominant influence of tectonic-stratigraphic confinement of objects in the formation of the features of the geological structure of deposits and their filtration-capacitive properties is established. The selected groups of objects are ranked according to the degree of similarity and difference in the multidimensional space of parameters that have a collective effect on the process of reserves development. Clusters are presented that make it possible to use the accumulated experience of developing deposits of the Jurassic and Paleozoic ages not only within the considered oil and gas regions but also regions adjacent to them. The results obtained made it possible to create a methodological base for searching not only objects but also groups of similar objects for deposits leaving exploration to engage in active development and increase the degree of oil reserves development in the Jurassic oil and gas complex deposits.
Instrumental monitoring of the load of the automotive alternator during the movement of the vehicle
Authors: Puzakov A V
Published: July 2020

The charge balance of the vehicle indicates whether the starter battery is being charged while the vehicle is running. For normal operation of the power supply system, the charge balance must remain positive, preventing progressive discharge of the battery. A decisive influence on the balance of electricity is provided by the current output of the alternator, which depends on the rotor speed. The maximum current output of the alternator is described by a current-speed characteristic depending on the technical condition of the alternator. In the process of vehicle movement, the rotor speed and alternator current strength vary over a wide range determined experimentally. The ratio of these parameters is the alternator efficiency coefficient, which can be used to assess the technical condition of the automotive alternator. The productivity of the vehicle’s charge balance is objectively evaluated by the alternator load factor. Further research will be aimed at identifying changes in the charge balance of the vehicle in the event of a malfunction of the automotive alternator and starter battery.
Formation of shot dimples during shot peening
Authors: Koltsov V P , Vinh Le Tri , Rakitskaya V B , Tardybaeva E V
Published: July 2020

In the aircraft industry, the technology of shot peen treatment is successfully used for the manufacture of long panels and sheaths, both for forming and finishing hardening. Shot dimples increase the roughness of the treated surface, so after the shot peening, the surface should be grinded with flap wheels to improve the roughness values by partially removing the traces of shot impact. To assess the quality of shot peening as a monitoring indicator, in practice the degree of coverage of shot dimples on the treated surface is used, which is determined by the percentages of the total area of shot dimples to the total area of the considered treatment part. To assign the modes of subsequent grinding with flap wheels, it is necessary to determine the allowance for grinding, which is determined by the value of the maximum depth of the largest dimple within the base area of the treated surface. The paper presents a method of creating a mathematical model to determine the size of dimples in shot peening, as well as modeling and engineering analysis of the shot peening process with the finite element method.
Microstructure and magnetic properties of Co58Ni10Fe5B16Si11 and Co58Ni10Fe5B16Si11–Al2O3 bulk amorphous coatings prepared by plasma spraying
Authors: Denisova E A , Nemtsev I V , Telegin S V , Iskhakov R S , Kuzovnikova L A , Shepeta N A
Published: July 2020

The bulk soft magnetic glassy Co58Ni10Fe5B16Si11 alloy specimens have been prepared by plasma spray deposition. In order to increase resistivity of the material, the bulk Co58Ni10Fe5B16Si11–Al2O3 composite materials were fabricated. The investigations of structure and magnetic properties of the bulk samples were carried out by X-ray diffraction, electron microscopy and magnetic measurements. The relation of the structural features and magnetic characteristics of the bulk coating to the main parameters of the deposition regimes was determined. Optimized plasma spray deposition parameters allowed obtaining bulk glassy samples with magnetic parameters that are not inferior to the characteristics of a thermally treated rapidly quenched ribbon with the same composition. It was found that the bulk amorphous coatings can be characterized as a heterophase system. The relaxation annealing of the Co58Ni10Fe5B16Si11 bulk coating leads to a phase transition in this alloy in the precrystallization temperature range. The magnetic properties of the both kinds of coatings are correlated with changes in the microstructure. The appearance of nanocrystalline phase with TC˜640 K during relaxation heat treatment leads to a decrease of the coercivity and to an increase of the permeability. A comparison between the magnetic properties of the CoNiFe-BSi coating and (CoNiFe-BSi)–Al2O3, composite coating is carried out.
The pattern of changes in the velocity of propagation of ultrasonic waves in frozen soil samples during thawing
Authors: Shikhov A I , Potapov A I
Published: July 2020

The locations of mining and processing enterprises in the areas of permafrost distribution are associated with monitoring the state of the ice-ground massif. The monitoring problem is exacerbated by climate change trends, and the reduction of suitable for the existence of permafrost zones. The increase in the number of emergencies associated with the degradation of permafrost soils in the regions of the Republic of Sakha and the Norilsk industrial region are direct evidence of this problem. The main consequences of thawing soils are uneven troughs of subsidence of foundations, frosty swelling, and waterlogging. The article considers the possibility of using the ultrasonic monitoring method in order to monitor the state of permafrost soils, along with existing monitoring methods. Existing methods for monitoring the state of permafrost soils are considered. The results of experimental studies of changes in the velocity of propagation of an ultrasonic wave during the thawing of various permafrost soils, humidity and particle size distribution are presented. It has been proved experimentally that the sensitivity of the speed of propagation of an ultrasonic wave to a change in temperature in frozen soil samples. When the soil passes from a frozen state to a plastic-frozen state, there occurs a sharp drop in the speed of the ultrasonic propagation.
Development of methodology for formalized selection of technological operations when designing technological process manufacturing of machinery
Authors: Sokolnikov R A , Bozheeva T V , Govorkov A S
Published: July 2020

This article presents the possibility of automating a formalized selection of technological operations by interconnecting dependencies between all the component components of the technological process. It is shown that the dependencies are folded, including the specifics of working with an enterprise or an enterprise. The study demonstrates the nuances that make it difficult for production and law to affect the approach to selecting a tool and equipment for performing one or one technological operation. An example of a technological process forming for manufacturing a detail in the example of an aviation part of the profile type is given.
The study of surface roughness after thermal-chemical treatment and subsequent grinding
Authors: Ulakhanov N S , Mishigdorzhiyn U L
Published: July 2020

The paper deals with the issues connected to the final machining of diffusion layers formed on the 3Kh2V8F die steel surface by boroaluminizing method. It was established that the surface roughness after boroaluminizing increases by 2.6-5.8 times depending on the time-temperature parameters. Therein the temperature affects the surface roughness ascent more significantly than process duration. After boroaluminizing at 950 °C, Ra has increased from initial 1.5 μm to 4 μm and to 5.44 μm after 2 and 4 hours process duration respectively. As for the 1050°C-process, the values increased to 7.7 μm and 8.76 μm after 2 and 4 hours. Fine grinding as a final machining operation (FMO) of diffusion layers reduces surface roughness by 5.8-45 times depending on the boroaluminizing parameters. However, it was established that Ra values after FMO depend on the initial surface roughness after boroaluminizing. The higher the initial roughness, the higher the roughness after fine grinding. This dependence allows proposing technological heredity effect for the investigated study.
Stationary characteristics of the restorable system with the sequential structure, temporal time reserve and disabling of elements
Authors: Peschansky A I , Zamoryonov M V
Published: July 2020

The object of study is a multicomponent restored system with a consistent structure and element-wise temporary redundancy, in which in case of failure of one of the elements, all other elements are disabled. It is assumed that all the random variables describing the evolution of the system in time have distribution functions of a general form. The average stationary times of stay of the system in operable and failure states are found; stationary availability factor and average system specific profit. A numerical example shows the dependence of the stationary characteristics of the system on the value of the temporary reserve. The problem of determining the volume of the temporary reserve of elements that ensures the system availability factor is not lower than the system availability coefficient with a structurally loaded reserve, each element of which is duplicated by an equally reliable element.
Both day and night warming reduce tree growth in extremely dry soils
Authors: Zhu Chen , Cui Erqian , Xia Jianyang
Published: July 2020

Trees in global forests are exposed to warming climate, the rate of which is different between day and night, and associated with soil drought. Previous studies commonly show that forest growth responds positively to daytime warming but negatively to night warming. However, it remains unclear whether such asymmetric responses of forest growth to day and night warming still exist in extremely dry soils. Here, based on the long-term records of the normalized difference vegetation index and ring-width index at 2294 forest sites across the Northern Hemisphere, we found that the rising daytime maximum temperature (T
max) reduces stem growth but the rising nighttime minimum temperature (T
min) lowers canopy greenness when the soil is drier than a threshold. We further discuss three mechanisms that could drive such negative impacts. For example, data from experimental studies showed that the shifted biomass allocation from wood to leaves is one important mechanism driving the reductions of wood growth under day warming. These findings indicate that climate warming could negatively affect tree growth in extremely dry soils, regardless of whether temperature rises during the daytime or at night. Thus, understanding the interactions of water and temperature on the sub-diurnal scale is critical for improving our ability to predict the forest dynamics under future climate change.
Impacts of two types of El-Niño on the winter North Pacific storm track
Authors: Yang Minghao , Li Chongyin , Tan Yanke , Li Xin , Chen Xiong
Published: July 2020

In the present study, the impacts of eastern Pacific (EP) and central Pacific El-Niño on the winter North Pacific storm track (WNPST) are investigated, and the possible reasons for the different responses of the WNPST to the two types of El-Niño are revealed. It is found that only EP El-Niño episodes have a distinct influence on the strength and movement of the WNPST. During EP El-Niño episodes, the WNPST is significantly enhanced and extended equatorward. The patterns of atmospheric baroclinicity anomalies are consistent during the two types of El-Niño. The enhancement and equatorward extension of the WNPST during EP El-Niño episodes can be attributed to anomalous baroclinic energy conversion. In addition, EP El-Niño episodes can also intensify the strength of the WNPST by warming the lower-tropospheric air upstream of the WNPST, which generates more synoptic-scale disturbances entering the WNPST.
The growth performance and survival rate of catfish (Clarias sp.) that given probiotic controlling nitrogen
Authors: Yosmaniar  , Pantjara B , Setiadi E
Published: July 2020

The water quality can be improved by using probiotics as bioremediation. The probiotics are a consortium of nitrification and denitrification bacteria (Pseudomonas aeruginosa and Achromobacter insuavis), which both of the indigenous bacteria are the products of the Research Institute for Freshwater Aquaculture and Fisheries Extension (RIFA). The objective study is to determine the adding frequency of RIFA probiotic into the water fish pond of catfish culture concerning growth performance and survival. The catfish fingerling with a size of 7-8 cm long and weighing 16.45 ± 0.3 g was used. The stocking density was 750 fish/pond. Nine plastic sheet ponds with a water volume of 1.6 m3 and completed with aeration were used. A dose of probiotics was 10 mL/m3. The difference in adding the frequency of probiotic as a treatment was as followed: A) every 5 days; B) every 10 days, and C) without probiotics. The parameters measured survival rate (SR), absolute weight growth, specific growth rate (SGR), feed conversion ratio (FCR), water quality. One way ANOVA with three treatments and three replications were performed. The results showed that the use of probiotics could control nitrogen compounds in catfish cultivation, where the frequency of administration every 5 days gives the best results.
Food preferences of nilem carp (Osteochilus hasselti) at paddy-fish culture pond in Kuningan, Garut and Tasikmalaya, West Java Province
Authors: Iskandar  , Anna Z , Zidni I , Hermawan D , Pratiwy F M
Published: July 2020

The research aims are to determine the availability of natural feed resources and to study the food habits of nilem carp (Osteochilus hasselti) in the paddy-fish culture system in Kuningan (300 m from sea level), Garut (700 m from sea level) and Tasikmalaya (500 m from sea level) districts. The research used a survey method with descriptive analysis. The treatment was without commercial feeding so that it utilizes natural feed, and consists of two replications in each location. The research was conducted in August 2018 - May 2019. The fish used was java carp with a length of 5-7 cm and a stocking density of 2000 fish/paddy field 200 m2. The results showed that there were two types of feed composition, namely phytoplankton and zooplankton. The preponderance index of nilem carp in each location generally utilizes phytoplankton from the phylum Bacillariophyta as its main feed. The index of electivity shows that the preference level of Java carp for phytoplankton has similarities in each region. Its mostly preferred phytoplankton, such as Cyclotella, Gomphonema, Gyrosigma, Navícula, Nitzschia, and Synedra from Bacillariophyta and Closterium, Coelastrum and Cosmarium from Chlorophyta.
Eichhornia crassipes aquatic plant management technology for water resources enhancement
Authors: Krismono  , Nastiti A S , Suryandari A , Haryadi J
Published: July 2020

Degradation of inland waters, rivers, lakes, reservoirs, swamps, and other fish feeding areas for fish farming are increasing, resulting in the impact of fish production and the environmental health of the waters. Eichhornia crassipes is a floating aquatic that is highly invasive in hypertrophic water. The proliferation of water hyacinth closure from the surface water column by decreasing the concentration of dissolved oxygen in the bottom water column, causing disturbance to the growth of aquaculture fish, so it is necessary to control/eradicate the water hyacinth weed. The technology to control/eliminate water hyacinth is physical, biological, and chemical or a combination of the three. Technology to control/eradicate water hyacinth must consider the negative impact on the environment. Some technologies to eradicate water hyacinth are positive and significant using filled Chinese carp (Ctenopharyngodon idella) or confined in cages depending on the body of water. The caged system in lake waters considers fish and native/endemic plants while in reservoir water with a stocking system. In the lake waters, aquaculture is carried out with a floating net cage system measuring 5 × 5 × 5 m3 with a total of 100 plots, each plot filled with 500 Chinese carp (100 g/fish) fed 50 kg of water hyacinth on day-1. The maintenance period is 3 months per season for 3 seasons (1 year). The results show that water hyacinth is reduced by 300 ha. The adoption of technology to improve water quality is one of the management of water bodies to increase fish production.
Controlling pollution from floating cage culture in reservoir and lake using SMART-FCC system
Authors: Astuti L P , Hendrawan A L S , Warsa A
Published: July 2020

Floating net cages culture (FCC) activity is growing rapidly and becoming one of the largest national freshwater fish producers. Most of the lake/reservoir in Indonesia has been utilized for aquaculture in the FCC system. The positive impact of the FCC includes opening up employment opportunities and increasing the income of farmers and labourers leading to the economic improvement of local community. However, there are negative impacts caused by uneaten feed such as water quality degradation, blooming of macrophytes and algae, hydropower turbine damage due to corrosion, a decreased in the abundance of fish species and others. For this reason, environmentally friendly FCC might offer a solution to control or reduce the release of uneaten feed. One of these technologies is SMART FCC that integrates fish culture and hydroponic or called aquaponics systems applied in open waters of reservoirs/lakes. The main advantage of SMART FCC is its ability to reduce FCC waste because the uneaten feed is not dispersed into the waters, rather it is collected and settles in SMART FCC. The deposited wasted feed can be used as liquid organic fertilizer for the hydroponic plants. At the end, the fish farmers get not only harvested fish but also gain additional benefits and profits from organic plant production.
Sustainable aquaculture of a protected species: The case of juvenile humphead wrasse (Cheilinus undulatus) around the Anambas Islands
Authors: Syam A R , Mujiyanto  , Indriatmoko
Published: July 2020

Humphead wrasse (Cheilinus undulatus), also called napoleon fish or “katepas “ in Anambas Archipelago Regency, Indonesia, is a reef fish which commonly found in tropical seas. Napoleon fish exploitation is still getting higher especially in Indonesia. Nevertheless, this species had listed as a protected species by the Indonesian Government as well as enlisted in Appendix II of CITES (Convention on International Trade in Endangered Species). Following a dialog among Indonesian officials, FAO and CITES, quota permission has been given to the fisherman community of Anambas Regency. This permission was legally allowed the Anambas Fishermen to fishing the napoleon fish juveniles and reared them in floating net cages for 3-4 years to reach commercial size. About 147,000 napoleon fish were estimated to be reared in Anambas Island. The first export of Napoleon fish was recorded in 2018 by one of the Indonesian fish exporters from Anambas to Hong Kong with 1,000 fish or Rp 1 billion worth and equivalent to $ USD 71.4/kg. The aim of this research was to analyse spatial distribution, juveniles abundance and water quality of the Anambas Islands to improve the sustainability of napoleon fish juveniles resources. Juveniles and water quality data were collected during field survey in 2014 and 2015. The abundance of the juvenile was estimated from monthly data recording by fishermen and water samples were measured in-situ. Post to the measurement of the physical and chemical properties, water quality was determined by using the National Sanitation Foundation Water Quality Index (NSF-WQI) based on The Classification of the Index numerical values. The results showed that napoleon fish juveniles were concentrated in several specific locations around Anambas waters. The highest abundance of napoleon fish juvenile was observed in November and December. The waters quality indexes show good and very good conditions for culturing the juvenile in floating net cages. The success in napoleon fish juvenile rearing is a starting point to achieve the fish sustainable aquaculture-based fisheries management. This research concludes that the identified natural rearing areas of juvenile napoleon fish, good water conditions, and improved existing rearing technology might support sustainable ranching-based aquaculture of humphead wrasse in Anambas Islands waters.
Building and improving the capacity of fish and environmental health management strategy in Indonesia
Authors: Lusiastuti A M , Taukhid  , Maskur  , Murwantoko  , Prayitno S B , Sugiani D , Caruso D
Published: July 2020

Fish mortality due to outbreak and to the decrease in the quality of the environment is a latent problem increasingly complex in Indonesia. Extreme weather conditions with high rainfall intensity, reacute actually bring back several opportunistic pathogens of diseases such as Motile Aeromonads Septicemia. Various cases of mass fish deaths re-emerged, especially in public waters such as Maninjau Lake and Cirata reservoir is the sign of the decline in the quality and carrying capacity of the environment and it is suspected to be the main cause of the case. Over the past four years, fish mortality in public water has been regularly recorded and a peak of massive fish mortality occurred in 2016. A total of 4,725 tons of dead fish occurred which is estimated around 0.95 percent of the total production of freshwater net cages cultivation nationally. This amount is estimated to cost economic losses up to IRD 47.25 billion equivalent to 3.3 million US$ (assuming the price of fish is IDR 10,000/0.71US$ per kg). The occurrence of mass mortality of fish from net cages may reduce the aquaculture production originating from public waters up to 23.5 percent. Furthermore, risk of a new cross- border disease such as Acute Hepatopancreatic Necrosis Disease (AHPND); White Fecal Syndrome (WFS); Enterozytozoon hepatopenaei (EHP) and Tilapia Lake Virus (TiLV) heavily threaten aquaculture businesses. There is a need for cross-sectoral and even cross-country collaborative efforts, especially in anticipating the spread of cross-border fish diseases. This condition requires commitment and awareness from all stakeholders involved. Therefore, in order to promote sustainable aquaculture production, a national aquatic animal health (NAAH) strategy was formulated and will assist Indonesia government to: improve the national fish health services skills, make aware fish farmers undertaking responsible fish health management and to improve their capacity on emergency responses and contingency planning against diseases, reduce of important fish diseases and the use of chemicals in aquaculture, and prevent introduction of exotic disease. The implementation of the NAAH strategy needs guidance, support and full commitment from the government. The Ministry of Marine Affairs and Fisheries through Directorate General of Aquaculture is the competent authorities who will share responsibilities in the implementation of NAAH strategy.
Productivity and profitability of rice-freshwater prawn culture in different stocking density of prawn
Authors: Dewi R R S P S , Krettiawan H , Anggraeni F , Kusnendar E , Kusdiarti
Published: July 2020

Integrated farming of fish and rice is a form of rational use of limited land resources. The rice-fish culture has been developed in several countries, especially in Asian countries. This is because rice and fish are important commodities for Asian people. Rice-fish culture can provide almost three times the benefits compared to paddy fields that are only planted with rice alone. The system is environmentally friendly, low cost, low risk, and also provides a source of animal protein food for the community. Indonesia not only develops rice-fish culture but also rice-freshwater prawn culture. In 2014, the Fish Breeding Research Institute produced a strain of fast-growing giant prawn called GI Macro II (Genetic Improvement of Macrobrachium
rosenbergii II). The use of GI Macro II giant prawns in the rice - prawn system is expected to increase the production of giant prawns. This research was conducted to determine the optimal density of giant prawns in the rice - prawn culture system. We hypothesize that using an optimal stocking density will increase the productivity of rice and giant prawns. This research was conducted in March-November 2016 in four locations in Pakem District, Sleman Regency, Yogyakarta Province, Indonesia. Trenches for giant prawns culture were made around the paddy fields to achieve a ratio of 20% of the paddy field. The size of the trenches was 1 m in wide and a minimum depth of 50 cm, and the main trench with a width of 3-4 m which contained a harvest basin was made. Giant prawn seeds stocked have a total length of 5.8 ± 1.09 cm or weight of 2.2 ± 1.42 g. The depth of the puddle in the paddy field was less than 5 cm in the vegetative phase and more than 10 cm in the generative phase until harvesting. After 14 days of rice planting, giant prawn seeds were spread into prepared trenches. The treatment consisted of two levels of stocking density of giant prawns, 10 ind/m2 and 15 ind/m2. Density at 10 ind/m2 yielded higher growth and survival (1.76 ± 0.39% BW/day & 62.53 ± 17.43%) and lower feed conversion ratio (1.04 ± 0.38) compared with density of 15 ind/m2 (1.3 ± 0.20% BW/day; 46.3 ± 4.28%; and 1.66 ± 0.49%). Production of rice and prawns in an area of 1000 m2 with a density of 10 ind/m2 were 698 kg of rice and 112 kg of giant prawns. As for the stocking density of 15 ind/m2, rice production was 795 kg and prawns were 107 kg. The benefit obtained from the stocking density of 10 ind/m2 was IDR 5,037,000 with a B/C ratio of 1.7. As for the stocking density of 15 ind/m2, the benefit obtained was IDR 3,942,000 with a B/C ratio of 1.1. Thus, stocking density of 10 ind/m2 produces higher prawn production and higher profits than stocking density of 15 ind/m2.
Factors that influence the level of fish consumption in Tabanan Regency, Bali Province
Authors: Widihastuti R , Arthatiani F Y
Published: July 2020

Fish is an important source of animal protein and unsaturated fatty acids needed for the development of children and to prevent several other diseases. The promotion of fish nutrition benefits (fish eating) has been carried out for more than 10 years by the local government and by the Ministry of Maritime Affairs and Fisheries through some activities. Specifically in Tabanan Regency, a fish-eating program targeting students and women of reproductive age has been developed in the area. Apart from these activities, no significant changes in fish consumption in the target group were observed and in 2017. Tabanan was ranked the second lowest in the Province of Bali for fish consumption, with a value of 15.25 kg/cap/year. In 2016, fish consumption by 17.46 kg/capita/year. Thus, fish consumption in 2017 has decreased by 2.21 kg/capita/year compared to 2016. However, considering that in 2019 macro data processing has not been carried out, this study will conduct micro data processing to determine the development of fish consumption in 2019 using representative respondents in Tabanan Regency. The purpose of this study was to determine the factors that influence the level of fish consumption in Tabanan Regency. The independent variable consisted of age, education, occupation, status, and income, and the dependent variable was fish consumption. analyzed using multiple linear regression. This study involved 31 respondents to fill out questionnaires and interviews, as well as interviews with key informants in the district. Primary data were obtained through a closed questionnaire that was used to distribute data collection in addition to secondary data obtained from marine and fisheries services, as well as from district food security services. The analysis shows that age is an independent variable that affects the level of fish consumption in Tabanan. The age factor that affects the level of fish consumption has the highest percentage of samples at the age of 45-49 years which is 58.1% and a significance value (P<0.05). To realize programs to increase fish consumption that are more supported by the community, it is recommended to involve family heads aged 45-49 in the process of educating the community. Besides having a productive age, they also have insights that can be used as a way to facilitate education to the community and family. Thus, the realization of stunting prevention and handling program can be more resolved.