bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimal control of boiler system based on IoT and energy consumption simulation
Authors: Xianru Wang , Xinmin Zhang , Han Zhu , Xuyun Yu
Published: May 2021

The energy consumption of building heating in China is enormous and reducing heating energy consumption is of great significance to promote energy saving and emission reduction in China. A reasonable boiler heating strategy can effectively reduce heating energy consumption. This paper presents an optimal control method based on the IoT system and an interface that makes Energy Plus in the cloud server work together with the IoT system. The boiler can make corresponding adjustments to the outlet temperature according to weather conditions and other factors to achieve energy-saving. The results show that the intelligent control method proposed in this paper can reduce the boiler outlet temperature by 2-8 °C and can reduce energy consumption by about 15%.
Review of Non-Fluorinated Durable Water Repellent and Stain-Resistant Materials and Their Future development
Authors: Guo Wenzhuo , Li Zhiyun , Ma Zixi
Published: May 2021

Materials with superhydrophobic surfaces have significant values in industrial applications for the reason that these materials usually has the abilities of self-cleaning and stain-resisting. Currently, most superhydrophobic materials are fluorinated ones because fluorinated groups contribute to decreasing the surface energy and surface tension of materials. Nevertheless, toxicity of fluorinated materials prevents them from being widely used in some industrial areas. Thus, this paper aims to have a review of methods used to fabricate non-fluorinated materials with superhydrophobic surfaces. This work introduces both the advantages and disadvantages of fluorinated materials and displays the reasons why materials can be superhydrophobic. In addition, hierarchical structures and re-entrant structures are shown in this passage and methods of making these structures are listed. Besides, this paper presents some methods to fabricate structures which contribute to superhydrophobization. Furthermore, some non-fluorinated materials are listed and their abilities of repelling water and stains are displayed, consisting of silanes, organic materials, and inorganic materials. At last, this paper illustrates current limitation of non-fluorinated materials and their future developments.
Noise mechanisms in a radial fan without volute
Authors: Sanjosé Marlène , Hub Sandra , Lörcher Frieder , Moreau Stéphane
Published: May 2021

The noise emission of a large radial fan with 7 backward curved blades is investigated. When decreasing the flow rate, the broadband levels below 1 kHz increase and the tones decrease, and a broad hump appears at about 80% of the BPF. The present numerical investigation aims at identifying the mechanism responsible for the broadband hump in the spectra. The configuration is simulated using the Lattice Boltzmann PowerFLOW solver for four flow-rate conditions. The low flow-rate condition is run longer to achieve statistical convergence at low frequencies. The simulations capture reasonably well the acoustic spectra and in particular the broadband hump at lower flow rate. The flow in the fan shows an unsteady flow detachment in some blade passages shed from the leading edge of the blade, while other blade passages experienced a fully detached flow along the whole blade chord. A spectral proper orthogonal decomposition is applied to identify the modal structures of the flow responsible for this mechanism. Several azimuthal modes are obtained from the decomposition for the different frequencies in the acoustic spectra. In addition an axial acoustic mode in the fan bowl is found at a frequency in the broadband hump.
Towards the definition of a benchmark for low Reynolds number propeller aeroacoustics
Authors: Casalino D. , Grande E. , Romani G. , Ragni D. , Avallone F.
Published: May 2021

Experimental and numerical results of a propeller of 0.3 m diameter operated in quiescent standard ambient conditions at 5000 RPM and axial velocity ranging from 0 to 20 m/s and advance ratio ranging from 0 to 0.8 are presented as a preliminary step towards the definition of a benchmark configuration for low Reynolds number propeller aeroacoustics. The corresponding rotational tip Mach number is 0.231 and the Reynolds number based on the blade sectional chord and flow velocity in the whole radial and operational domain ranges from about 54000 to 106000. Force and noise measurements carried out in a low-speed semi-anechoic wind-tunnel are compared with scale-resolved CFD and low-fidelity numerical results. Results identify the experimental and numerical challenges of the benchmark and the relevance of fundamental research questions related to transition and other low Reynolds number effects.
Influence of the rotor blade aspect ratio on the performance of an axial fan
Authors: Theis A , Böhle M
Published: May 2021

An axial fan with four different number of blades for the rotor is investigated. In this contribution varying the blade aspect ratio means the number of blades is changed while every other dimensionless design parameters and the design point are kept constant. By varying the blade aspect ratio, the length of the blades alters and as a result the Reynolds number which is related to the chord length of each blade is changed as well. The considered Reynolds numbers are lying between 2.38 × 105 and 7.13 × 105. For the stator the blade aspect ratio as well as the spacing ratio are the same during the investigation.

For comparison and validation both numerical and experimental investigations are performed. For the numerical investigations, due to the low Reynolds numbers the k-ω-SST transition model with the intermittency function is applied. Transient simulations are carried out. The experimental investigations are performed a pipe test bench. The results are compared in terms of performance differences for part load, overload and design conditions. The flow structure in the rotor passages is visualized and compared using the numerical results to show the influence of the blade aspect ratio on the performance.
Experimental study of a centrifugal compressor with two successive and counter-rotating impellers
Authors: Nguyen Van-Thang , Danlos Amélie , Paridaens Richard , Ravelet Florent , Deligant Michael , Khelladi Sofiane , Bakir Farid
Published: May 2021

In many industries, reducing the size of the compression system represents a significant goal for designers. In fact, increasing the power density of the compressor actually means lowering production costs. The chief purpose of this study is to compare, in terms of aerodynamic performances, a centrifugal compressor consisting of an impeller and a volute, to an innovative concept based on the principle of two successive impellers and designed to work in counter-rotation. To simplify the experimental research in this study, the volute of the conventional compressor is maintained for the new design. The conventional impeller has been replaced by two successive impellers having the same meridian profile, and whose diameter of the rear impeller is identical to that of the conventional impeller. The impellers design of the counter-rotation stage was carried out granting to an approach proposed here. The numerical results underline the advantage of the innovative compressor, in terms of power density, compared to the conventional design. The numerical forecasts also agree significantly with the results of experimental tests got on a test bench exclusively designed for compressors. Experimental optimization of the rotational speed ratio of the two counter-rotating impellers has demonstrated the possibility of increasing the compression ratio and efficiency over a wide range of flow.
Effects of some settings of rotational-molding process on the aeromechanical performance of an axial fan.
Authors: Dang Vu-Dinh , Danlos Amélie , Pereira Michaël , Shirinbayan Mohammadali , Ravelet Florent , Bakir Farid , Tcharkhtchi Abbas
Published: May 2021

The study purposes to establish the influence of some settings of the conventional rotational-molding process on the aeromechanical performance of a hollow-blade axial fan. It is recognized that the surface state quality, the material characteristics and the blades design have an effect on the performances of the turbomachines. The use of conventional rotational-molding is an innovative method well suited for achieved hollow-blade fans, reduced cost and relatively easy manufactured. In the present work the material employed represents one grade of linear low-density polyethylene (LLDPE-3200 natural, supplied by “C4-Polymers Company”). The variables of the process studied attend the initial mass of polyethylene powder, the oven temperature and the heating time. For comparisons, a fan of similar geometry machined in an aluminium block serves additionally as a reference. The results show an optimal choice of the settings of the manufacturing process is necessary to achieve the desired aeromechanical performances for this fan.
Aerodynamic design optimization of a bellmouth shaped air intake for jet engine testing purposes and its experiment based validation
Authors: Sevinç Koray
Published: May 2021

Jet engine ground tests are carried out with bellmouth shaped air intakes in order to measure the mass flow rate and the inlet flow quantities while supplying the engine an undisturbed flow. Although there are a variety of design standards and academic guidelines for the design of bellmouths, they can be designed to reach a lower total pressure loss coefficient, a less disturbed radial velocity profiles for the engine and a less thickened boundary layer at the engine inlet. This enhanced design can be achieved with the help of optimization algorithms and computational fluid dynamics (CFD) computations thanks to the increasing average computational power and simplicity of the flow problem. In this study, a genetic algorithm based optimization method and a RANS solver under a commercial software platform are applied to find a bellmouth design with less loss and less disturbed flow. An elliptical bellmouth lip profile with a linear extension part is defined with parametrization and a wide range of parameter space is investigated during the design work. Optimum design candidates are presented comparatively regarding the design purpose. The selected design candidate is produced and tested for CFD validation.
Assessment of single passage simulations for the aeroelastic stability of a multistage centrifugal compressor
Authors: Placzek Antoine
Published: May 2021

In this paper, the aeroelastic flutter stability of an impeller is investigated numerically with single passage and full annulus URANS simulations carried out on one side on a single stage configuration including a strut and the impeller and on the other side on a multistage configuration in which two additional diffusers are considered downstream. The robustness of single passage simulations relying on the use of multiple frequency phase-lagged boundary conditions is put to the test especially in the case of the multistage configuration for which both blade passage and aeroelastic effects have to be taken into account. Comparisons between single passage simulations on the single and multistage configurations indicate that the impeller-diffuser interaction acts locally on the impeller fluid-structure interface and has only little effect on the generalized aerodynamic forces. Full annulus simulations have also been carried out to assess the accuracy and efficiency of single passage simulations which introduce additional hypotheses of periodicity in the flow. Full annulus simulations are competitive in terms of wall clock since the convergence to the periodic state is faster than with single passage simulations involving the Fourier approximation of the flow field.
Sealing Performance of a Turbine Rim Chute Seal Under Rotationally-Induced Ingestion
Authors: Revert Anna Bru , Beard Paul F. , Chew John W. , Bottenheim Sebastiaan
Published: May 2021

This study focuses on the sealing capability of a turbine rim seal subject to hot gas ingestion driven purely by the rotor disc pumping effect rather than that induced by mainstream features such as vane and rotor blade passing. The aim is to provide useful data for conditions in which rotation dominates, and to clarify the flow physics involved in rim sealing. Experimental measurements of sealing effectiveness for a chute seal are presented for the first time without and with an axial, axisymmetric mainstream flow external to the seal. The test matrix covers a range of rotational Reynolds number, Reø, from 1.5x106 to 3x106, and non-dimensional flow rate, Cw, from 0 to 4x104 with the mainstream flow (when present) scaled to match engine representative conditions of axial Reynolds number, Reax. Results from steady pressure and gas concentration measurements within the rotor-stator disc cavity and the rim seal gap are presented and compared to published data for other seal designs. Sealing performance of the chute seal is somewhat similar to that of axial clearance seals with the same minimum clearance.
Influence of meridional plane shape on performance and internal flow of high head contra-rotating small hydroturbine
Authors: Hosotani Takuji , Shigemitsu Toru , Kawaguchi Yuki , Inamoto Takuya , Ishiguro Takeru , Nan Ding
Published: May 2021

It is requested that the hydroturbine be a small size and have high performance. Therefore, we adopted contra-rotating rotors, which can be expected to achieve radial compactification and high performance. However, a conventional contra-rotating rotor was composed of two axial flow rotors, so it had a specification suitable for high flow rate and low head. In order to achieve small hydroturbine suitable for low flow rate and high head, we propose a new type of contra-rotating rotors, which are composed of a hybrid rotor and a centrifugal rotor. In the present paper, we focus on the meridional plane shape at the connection between the front rotor and the rear rotor of the hydroturbine composed of these rotors as a first step of this research, and investigate performance by the numerical analysis. As a result, we clarified that the relationship between the performance and internal flow when the blade width at the connection between the front rotor and the rear rotor changed.
Comparative Study on Starting Characteristics of Turbines for Wave Energy Conversion
Authors: Takao M , Kanetsuki K , Alam M M A , Okuhara S , Kinoue Y
Published: May 2021

Wells and impulse turbines for bi-directional airflow have been proposed as typical turbines for wave energy conversion. Each of them has some advantages and disadvantages. In recent years, the authors have proposed Wells turbine with booster and a counter-rotating impulse turbine for bi-directional airflow in order to overcome their drawbacks. In this study, the starting characteristics of four types of turbines for bi-directional airflow were compared by conducting a CFD analysis under a steady flow condition.
Transport of heat and material properties in continuous casting of steel
Authors: Holl Helmut J. , Simon Gottfried
Published: May 2021

Liquid steel solidifies within a containment of a continuous casting machine and moves in axial direction as the solidified shell is withdrawn towards the end of the machine. A mechanical model for computing the deformation of the solidifying steel in the roll containment is developed based on the beam theory and on a ferro-static pressure load. The material properties of the steel at high temperatures result from high temperature constitutive equations including creep for the solidified shell between the rolls. The temperature distribution within the solidified shell is computed based on the thermal boundary conditions as in the secondary cooling zone water is spread onto the surface of the steel shell and heat is removed. The solidified steel shell thickness increases along the machine containment up to the point of total solidification. A suitable discretization of the region by the finite beam elements is used to get a suitable mechanical model. The ferro-static pressure acts inside of the solidified shell and causes some bulging of the shell between the roll containment. As there is a slow axial motion of the solidifying shell the numerical modeling of the transport e.g. of heat and of the creep strain, which is computed in each time step, has to be as accurate as possible as a lot of time steps are necessary. Different numerical strategies have been analysed with respect to the accuracy of the computation results.
Challenges in 3D CFD Modelling of Rotary Positive Displacement Machines
Authors: Kovacevic Ahmed , Rane Sham
Published: May 2021

The use of Computational Fluid Dynamics (CFD) and Computational Continuum Mechanics (CCM) for analysis of rotary positive displacement machines is exponentially increasing which was mostly allowed by the development of methods for generating numerical grids of complex domains within the machines. However there are several challenges with the commercial CFD/CCM codes which are preventing generic use of CFD. These are conservativeness of spatial discretisation caused by the inappropriate grid generation, numerical instabilities and dissipations caused by misalignments and application of inappropriate discretisation of equations and the speed and accuracy of multiphase models used in CFD of positive displacement machines.

In this paper the authors will review methods used for modelling of rotary positive displacement machines and challenges which developers and users of these methods face. The paper will also offer some solutions and directions for resolving these issues.
Discussion of Numerical Methods used in Positive Displacement Comprehensive Mechanistic Models: Case Study using the Z-Compressor
Authors: Bradshaw Craig R , Ziviani Davide , Groll Eckhard A
Published: May 2021

Comprehensive mechanistic models have been widely used for simulating positive displacement (PD) compressors or expanders. Such models are based on a thermodynamic analysis of generic control volumes that describe the working chambers. The thermodynamic analysis results in a set of non-linear ordinary differential equations (ODEs) that describe conservation of mass and energy. The derived ODEs are used to predict the evolution of the thermodynamic properties of the working fluid with respect to crank angle or time. The solution scheme of a mechanistic model involves different layers of solvers that handle the step-by-step integration, the cycle-to-cycle continuity as well as the overall energy balance. Since most of the PD machines feature multiple control volumes that merge or split (e.g. scroll-type) or wrap-around a rotor (e.g. screw-type) the integration scheme faces challenges due to the stiffness of the equations or discontinuities in the control volume definition.

In this paper, a discussion of different integration schemes and numerical considerations are proposed that are applied to a novel compressor called the z-compressor which presents a high-degree of intrinsic stiffness. A simplified comprehensive model is developed which is validated against experimental mass flow rate data for a prototype compressor with an average model-predicted error of less than 2%. This model is used to explore the differences in two ODE solvers from the ODE suite in MATLAB, (ODE15s, and ODE113). These results are further compared against an existing, simplified, Z-compressor model developed in PDSim which uses an explicit, lower order, solver the Adaptive Runge-Kutta (RKF). The results suggest that the semi-implicit solver (ODE15s) provides an efficient means for stepping through the compression process ODEs compared to the explicit solvers.
Energy balance analysis for a canned motor pump used for heat supply system
Authors: Song Xueyi , Yu Weiping , Pan Xiaohui , Luo Xianwu
Published: May 2021

A canned motor pump is widely used for transporting the liquids without leakage. In this work, the pump is applied for heat supply system. For this application, between the rotor and stator for cooling the canned motor there is a circulating flow, which will flow back in the pump passage with higher temperature, and bring the mixing of the liquid having different temperature between the main stream and the circulating flow. The steady state internal flow has been investigated for the pump, and the pump hydraulic performance has been compared with the experimental data. With the consideration of both mechanical energy and internal energy as the effective energy increment of the working fluid, an efficiency assessment is proposed for a canned motor pump. The proposed efficiency shows the same tendency as hydraulic efficiency, and is more understandable compared with that of the conventional method. The present results indicate that the proposed method of evaluating the efficiency of the canned motor pump can reasonably depict the energy balance inside the whole canned motor pump. Further, the introduction of circulating flow is helpful to predict the internal flow and heat transfer for the canned motor pump in numerical simulation with better accuracy. The present study is helpful for both development and application of high performance canned motor pump for various industries.
Effect of axial offset of rotor on thrust characteristics of a centrifugal pump
Authors: Takamine T , Nakano S , Watanabe S , Watanabe H
Published: May 2021

To ensure the reliability of multi-stage centrifugal pumps, the prediction of axial thrust is an important issue for the design of balancing device and selection of thrust bearing. However, it is known that the fluid forces acting on rotor could be sensitively affected by the geometrical relations between rotor and stator especially at the low flow rate. Among them, the effect of axial offset of rotor has not been studied sufficiently though the axial offset is easily caused by accumulation of manufacturing tolerances and assembling errors. In this study, experimental/numerical investigations on the effect of axial rotor offset in a final stage model of a three-stage centrifugal pump are carried out. The axial offset is intentionally given to shaft system to the both of discharge/suction side. As a result, the axial thrust is significantly affected by the axial offset in the flow rate range below 50% of the design. It is shown by CFD analysis that this effect of axial offset is caused by the interaction between the back flow from the diffuser and the main flow.
Analysis of Morton Effect Induced Vibration based on Transfer Function Model: Influence of L/D ratio of Journal Bearing and Rotational speed
Authors: Suzuki Takafumi , Chiba Jotaro , Yabui Shota , Tomimatsu Shigeyuki , Inoue Tsuyoshi
Published: May 2021

The Morton effect is the vibration phenomena that occur due to a thermal imbalance in the oil film in the journal bearing. In previous studies, the qualitative evaluation was performed based on theoretical modeling and numerical simulation. On the other hand, authors proposed that the characteristic of the journal bearing was considered as a proportional differential controller from a control engineering point of view. In the proposed model, the vibration due to the Morton effect can be evaluated based on the transfer function models. The proposed model is based on frequency characteristics identified from the experimental data directly, therefore, the model can be easily applied to the actual rotating machineries. The authors focus this study on applying the proposed method to the actual design, and investigated the relationship of the parameters of the transfer function between the L/D ratio and rotating speed. The relationship indicates the degree of influence of the L/D ratio and rotating speed to the vibration due to the Morton effect. The author measured the vibration by arbitrarily setting the L/D ratio, and analyzed the influence to the vibration due to the Morton effect based on the transfer function model. As a result, the author was able to predict the influence of the bearing L/D and rotating speed on the Morton effect.
Effect of Pulsating Flow on Surge Frequency of a Turbocharger Compressor
Authors: Asanaka Y , Kobayashi K , Sakakibara M , Itagaki Y , Nakamura Y , Miyagawa K
Published: May 2021

Turbocharger compressors operate under pulsating flow due to continuous opening and closing of engine valves placed downstream of the compressor but exhibit a hysteresis loop deviating from steady characteristics. As the flow in a compressor is throttled, both pressure and flow discharge unstably oscillate. The instability is known as surge and it affects not only the compressor itself but also its whole engine-turbocharger system. For estimating the stable operation range, partial flow tests of a turbocharger compressor under pulsating flow were conducted. Using a compressor test apparatus with a pulsating flow generator and a tank whose capacity can be changed, the flow rate was controlled by a valve. Under steady flow, surge hysteresis loops caused by oscillating pressure and flow rate were obtained in each rotational speed. By Fast Fourier Transform (FFT) of pressure signals, the occurrence of surge with different frequencies was confirmed depending on the tank capacity. Next in pulsating flow tests, a compressor rotational speed is fixed, and pulsating frequencies given by the pulsating flow generator are changed. The obtained surge frequencies were different from those in steady flow tests. Especially, it is likely to be drawn to the frequency that is equal, two times and a half rate of the pulsating frequency. Numerical computation with one-dimensional calculation is conducted to investigate such a phenomenon.
Seed vigor testing of coffee [Coffea sp.] to gibberellin hormone [GA3] concentration and water temperature differences
Authors: Suhendra D , Efendi S , Aisyah S , Saragih S H Y
Published: May 2021

West Sumatra is one producing coffee region in Indonesia that contributes to the economy in Indonesia because unstable need expand. Optimizing generative propagation of coffee plants with gibberellin hormone treatment and different water temperatures on coffee seed germination stage. The research was conducted at the Seed Technology Laboratory Faculty Agriculture, Andalas University from July to September 2020. Research methods used randomized block design [RBD] with 2 treatments namely concentration hormone gibberellin and immersion water temperature differences. Measurement parameters are maximum growth potential [%], First Count Test [FCT] [%], and Index Value Test [IVT] [days]. All parameter observation results showed a significant effect on the treatment of gibberellin hormone concentration and water temperature treatment. G4S1 sample [the combination of 200 ppm gibberellin hormone concentration and room water temperature treatments] has resulted as the best treatment for all parameters. Respectively, 0.79 days for index value test, 76.67% for the first count test, and 85% for the maximum growth potential parameters.
Physicochemical characterization of starch from seven genotypes banana in West Sumatera
Authors: Syukriani L , Yunita R , Jamsari J
Published: May 2021

Banana fruit has the potential to be developed as a functional food. For that reason, a detailed characterization of its fruit is necessary. We collected seven banana local genotypes that are widely cultivated in West Sumatra, Indonesia. This study is aimed to determine the physical characteristics and functional properties of banana starch. The analysis was carried out for its starch and proximate variables, XRD, XRF, and RVA. The results showed that the average water content of the starch from the 7 types bananas is ranging from 8.3 to 15.8%, while their ash content is ranging from 0.5 to 2.29%. Protein is in a range between 1.28 to 1.58%, while the fat content is ranging from 0.12 to 0.7%. The crystallinity structure types A involving Pisang Sipuluik, Randah, and Gadang genotypes. Genotype Rotan, Tinalun, and Jantan are classified as type B. While, Pisang Mas is classified as type C. The average starch gelatinization temperature from all 7 genotypes ranges from 70°C to 75.7°C.
Genetic parameters of F6 upland rice with lodging resistance derived from landraces x national varieties
Authors: Mustikarini E D , Prayoga G I , Santi R , Hairul H
Published: May 2021

Developing rice varieties with lodging resistance is important to maintain yields. The selection of lodging resistance lines should be related to genetic parameters to determine the genetic character of plants. This study aimed to determine the variability, heritability, and genetic advances of 6th generation [F6] upland rice “padi gogo” and selected the promising lines that can be used as candidates for new superior varieties. The research was held in Experiment and Research Garden, Universitas Bangka Belitung. The study used an experimental method with a randomized block design. The treatment consisted of 10 F6 genotypes, 4 parental plants, and 3 check plants, with 2 replications. Quantitative data were analyzed by calculating the values of variability, heritability, and expected genetic advance. The results showed broad phenotypic variability and high heritability for all characters. The expected genetic advance showed low criterion except for the number of grain filled. The F6 lines that can be used as candidates for new superior varieties are 23A-56-20-07-20 and 23A-56-22-20-05 lines that have better lodging resistance scores and higher production than parental and check varieties.
Study on chemical and biological properties of paddy soils in Nagari Taram, Harau District, Lima Puluh Kota Regency
Authors: Emalinda O , Juniarti J , Darfis I , Ramayani Y , Putri D D
Published: May 2021

Intensive cultivation of paddy soil without giving rest to the soil for years will affect the chemical properties and the presence of microorganisms in the soil. This study aims to examine some of the chemical properties of paddy soil such as pH, CEC, Total organic carbon, exchangeable bases, Total N, Available P, silica content and calculating the population and respiration of microorganisms at various slopes. This research is located in Nagari Taram, Harau District, Limapuluh Kota Regency. The study used a survey method in four stages, namely preparation, pre-survey, main survey and sampling, laboratory analysis and data processing. Samples were taken on rice fields that have been cultivated for approximately 100 years at a depth of 0-20 cm at 5 slopes those are 0-3%, 3-8%, 8-15%, 15-25% and 25-45%. Based on the results of the data analysis it is known that differences in slope affect the chemical and biological properties of the soil. The higher the slope, the decreased several soil chemical properties such as pH, C-organic, P-available, total N, CEC and silica. Soil microorganism populations varied for each slope. The highest bacterial and fungal populations were found on land with a slope of 0-3%, while the highest respiration of soil microorganisms occurred on lands with a slope of 3-8% that is 13.8 mg / kg / day.
The soils physicochemical properties of monoculture land in several slopes at Northern Areas of Mount Talang
Authors: Harianti M , Junaidi J , Emalinda O , Herviyanti H , Azizah A , Pulunggono HB
Published: May 2021

In the northern area of Mount Talang with some steep slopes (more than 30°), the local community implements an intensive monoculture agricultural system that can accelerate land degradation in the long term. Study was aimed to examine the soils physicochemical properties of monoculture land on several slopes in the northern foothill of Mount Talang. Survey method and soil sampling were implemented in this research, using a purposive random sampling toward the monoculture land on slopes> 45%, 25-45%, 15-25%, 8-15%, and the forest as control, at 0-20 cm and 20-40 cm depth. The results revealed that the soil texture that dominates the forest and monoculture cropping system is sandy loam. In addition, soil water content increases by the increased soil layer depth as well, with highest level observed in monoculture cropping system 25-45% (73.72%). Soil bulk density ranging from 0.4-0.6 g / cm3, or have the same tendency at both soil depths. The total pore space of forest land and monoculture agricultural land is 75%, categorized as high. The highest soil organic C content was found in monoculture agricultural land with a slope of >45%. The value of pH for all land uses was 5.15-5.29 on acid criteria. The cation exchange capacity was above 40 me / 100g and the total N content is 0.8-1.6%, so both of them are categorized as very high. Based on the data, the soils physicochemical properties of monoculture cropping system on several slope classes similar to the forest. The land quality for monoculture cropping system is still maintained, even though it is on the upper slopes of the foothill of Mount Talang. However, in the monoculture cropping systems will trigger the loss of soil organic matter, so the addition of soil organic matter content should be prioritized, especially in the agricultural land management of this area.
The improvement of paddy soil chemical properties following the application of rice husk derived biocharin the Regency of Sijunjung
Authors: Hermansah  , Sandi N , Naspendra Z
Published: May 2021

The district of Dharmasraya, Sijunjung and Pasaman Barat are the three main locations of illegal gold mining in West Sumatra. This kind of activity triggers a lot of land-use changes and the loss of agricultural land within those areas and creates environmental problems as well. Decreasing agricultural land will bring a significant impact on food availability within the region. To protect the scarcity of food, we conducted remediation of ex-gold mining land on those three locations by using biochar made from rice husk. This study was carried on at Batu Manjulur village, Kupitan sub-district in Sijunjung for four months, where soil sample was analyzed at Soil Science Department, Faculty of Agriculture, Andalas University. The experiment use 6 level of biochar application, run from A [without biochar]; B [fulfil of 2% soil organic matter content [SOM]]; C [fulfil 3% SOM]; D [fulfil 4% SOM], E [fulfil 5% SOM] and F [fulfil 6% SOM] with three replication. The result shows the application of rice husk-derived biochar increased soil quality including the chemical properties of the soil and improving nutrient retention and land productivity.
Improvement of nutrient status in ex-gold mining land with the application of rice terra preta biochar technology
Authors: Gusmini  , Adrinal  , Yaherwandi  , Putri E L , Panji R
Published: May 2021

This research on the escalation of nutrient status aims to determine the effect of giving Terra Preta Biochar Padi (Tetadi) on ex-gold mining land to P-available land in Nagari Padang Sibusuk Sijunjung Regency, West Sumatra. Soil samples were taken from the former gold mining soil with a depth of 0-20 cm randomly. This research was conducted using a completely randomized design with 6 treatments and 4 replications consisting of control (A), Tetadi 10 tons / ha (B), Tetadi 15 tons / ha (C), Tetadi 20 tons / ha (D), Tetadi 25 tonnes / ha (E), and Tetadi 30 tonnes / ha. The results showed that giving Terra Preta Biochar Rice to ex-gold mining land could increase the highest available P of soil in the treatment of rice Terra Preta Biochar 30 tonnes / ha with the results of the 5% DMRT statistical test very significantly different from the control treatment and 10 tonnes / ha and 15 tonnes / ha. Soil pH also showed the highest increase in the treatment of 30 tonnes / ha with a pH value of H2O of 5.7 and followed by a pH of KCl with a value of 4.6 and statistical test results showed that the treatment of 30 tonnes / ha was also very significantly different from control and treatment.
Utilization of Arbuskular Mikoriza Fungi [AMF] for growth and ready to release of three genotype gaharu [Aquilaria spp.]
Authors: Satria B , Fadli M , Herawati N , Aprisal
Published: May 2021

The agarwood sapling has low viability or about 47 % cause undeveloped roots. This problem was overcome through the application of Arbuscular Mycorrhizal Fungus [AMF] at the acclimatization stage. AMF has the capability to improve root growth and coverage area, enabling a better capacity to absorb water and nutrients through its hyphae. to know the effective dose for enhancing the growth of agarwood saplings is the goal of this research. The genotypes used in this study were Aquilaria malacensis and Aquilaria microcarpa. The AMF doses were 7.5; 15; 22.5, and 30 gr/polybag. Saplings were acclimatized in soil that had been supplemented by husk charcoal and organic fertilizer Super UPPO [product of Andalas University CSR Program 2017]. The observations including the number of the viable sapling, the height, the leaf number, the leaf length, the root number, the percentage of the AMF infection, and the ready-to-release sapling. The best performance was an application of 30 g per polybag. These doses infected 70% of root surfaces, and 90% of saplings were categorized as ready-to-release saplings.
Role of the C4 protein PepYLCV in viral symptom determinant: In silico approach
Authors: Nova B , Cania D , Hidayati R , Runifah T , Chaniago I , Suliansyah I , Jamsari J
Published: May 2021

The C4 protein of the monopartite begomovirus pepper yellow leaf curl virus [PepYLCV] plays a major role in the pathogenicity of plant virus infection. Complement gene [C4], in virus, is overlapped with complement gene 1 [C1] or known as Replicase gene [Rep]. The C1 protein is directly involved in virus DNA replication, but not the C4 protein. Recent studies suggested that the C4 is a viral symptom determinant but the molecular mechanism has not been elucidated. In this study, the C4 gene of the novel PepYLCV Alahan Panjang was isolated. To further investigate the role of C4 in symptom determinants, in silico approached was used. Computational modeling of C4 was constructed with homology and ab initio modeling software and the model was checked with Ramachandran Plot. The optimum model of the C4 was used in the surface analysis to predict binding sites and key residues. The mutant structure of the C4 protein and its prospect for CRISPR-Cas9 utilization are discussed.
The diversity and abundance of butterfly [Lepidoptera] in several urban green spaces of Malang city
Authors: Azizah A , Mustafa I , Gama Z P , Leksono A S
Published: May 2021

Urban green spaces have become one of the butterfly habitat remnants, which decreased by the expansion of cities and urbanization. In this study, we analyze the diversity and abundance of butterfly communities in several urban green spaces of Malang City. We used a scan sampling method along the transect line in five study sites, namely, Taman Singha Merjosari, Kebun Bibit Mojolangu, Taman Slamet, and Alun-Alun Malang. The composition of butterfly communities was analyzed regarding the number of individuals, species richness, Shanon Wiener diversity index, importance value index, similarity cluster and analysis of CCA to determine the correlation of abiotic factor and butterfly community. A total of 1284 individuals, 38 species which belong to 4 families with Leptosia nina as the most dominant species. The highest diversity index was found in Taman Singha Merjosari. According to the diversity index, all four urban green spaces in Malang city were on a moderate level (index value between 1 to 3). This attributed to the fact that butterfly diversity in urban green spaces still had not been completely disturbed yet.
YIL counteracts ghrelin-inhibited insulin release in pancreatic islets of langerhans
Authors: Rita R S , Dezaki K , Yada T
Published: May 2021

Ghrelin is a peptide hormone that is produced mainly from the stomach. Ghrelin is reported to have many biological functions, such as modulating feeding behavior, energy balance, and glucose homeostasis. This study aimed to examine whether YIL, a ghrelin receptor antagonist, could counteract the effect of ghrelin-inhibited insulin release in the pancreatic islet of Langerhans. This study is experimental research using wild-type C57BL/6J mice [8-10 weeks old]. Islet of Langerhans was isolated by collagenase digestion and the insulin release [ng/islet/h] from the islet is examined by the ELISA method. Data represent means ± SEM and is analyzed by one-way ANOVA. The result showed that 8.3 mM glucose concentration increase insulin release compared to 2.8 mM glucose, respectively [0,393 ± 0,025 vs 0,219 ± 0,022 ng/islet/h]. In the presence of 8.3 mM glucose, ghrelin 1 nM showed a decrease in insulin release significantly compared to 8.3 mM glucose only [0,283 ± 0,001 vs 0,393 ± 0,025, p < 0,01]. In contrast, in the presence of 8.3 mM glucose and ghrelin 1 nM, YIL 1 μM induced insulin secretion [0,386 ± 0,012 vs 0,283 ± 0,001, p < 0,01]. In conclusion, YIL is significantly counteracted ghrelin-inhibited insulin release in pancreatic islets of Langerhans. Furthermore, YIL is one of the candidates for the treatment of type 2 diabetes.
Peanut Crab Pinnotheres halingi, a symbiotic commensal or parasite of Sandfish Holothuria scabra?
Authors: Tresnati J , Yasir I , Aprianto R , Yanti A , Bestari A D , Tuwo A
Published: May 2021

High mortality of sandfish Holothuria scabra broodstock is one of the main problems in sea cucumber hatcheries. Broodstock collected from wild are very difficult to keep alive for long periods because the broodstock readily eviscerate. One cause of evisceration and death is probably due to the presence of peanut crabs Pinnotheres halingi in body cavity as commensal. This study aimed to analyse the mortality of sandfish due to the presence of peanut crabs as commensal. Sandfish samples were collected in Liukang Tupabbiring Utara District, Pangkep Regency in South Sulawesi, Indonesia. During the study, 139 sandfish were observed in rearing nine tanks at the laboratory. The results of this study are not strong enough to state that peanut crab is a symbiotic commensal or parasite. The peanut crab is thought to have turned into a predator when it starved. Peanut crab malignancy as a predator can cause the death of 139 sandfish in 92 days. This is thought to be the reason why broodstock is very difficult to rear for a long period in a controlled tank in a laboratory or hatchery.
Main catch, bycatch, discard catch of set lift net fisheries with Light Emitting Diode (LED) as light attractor in marine coastal waters of Pangkep, Makassar Strait, Indonesia
Authors: Musbir  , Kurnia Muhammad , Sudirman
Published: May 2021

Application of light emitting diode (LED) is considered to energy saving and increased catches in lift net fisheries. Set lift net fisheries in marine coastal waters of Pangkep used compact fluorescent lamp (CFL) but this lamps consumed high energy and fuels. Application of light emitting diode (LED) is considered to energy saving and increased catches in lift net fisheries. The experimental fishing trial was conducted on 22 July-25 August 2020 in marine coastal waters of Pangkep, Makassar Strait, Indonesia. The study using 1 units of set lift net with LED as light attractor. The result of study show that The fishes catch consist of main catch 149.21 kg (67.73 %), by catch 37.28 kg (16.93 %), and discard catch 43.76 kg (19.86 %).
Antimicrobial susceptibility and minimum inhibition concentration of Vibrio parahaemolyticus, Vibrio vulnificus and Vibrio harveyi isolated from a white shrimp (Litopenaeus vannamei) pond
Authors: Yudiati Ervia , Subagiyo  , Azhar Nuril
Published: May 2021

Shrimp infection byVibriospp. has led to loss of production. To control this bacterial epidemic, people have applied antibiotics. Uncontrolled antibiotic treatments have led toVibriospp. pathogenic-resistance. This study aimed to determine the antimicrobial susceptibility and minimum inhibition concentration (MIC) ofVibrio parahaemolyticus, Vibrio vulnificusandVibrio harveyitowards certain antibiotics. The trials used 10 and 100 ppm concentrations of 10 antibiotics: Chloramphenicol, Gentamicin, Amoxicillin, Co-Amoxiclay, Ciprofloxacin HCL, Azithromycin, Doxycycline, Tetracyclin, Erythromycin stearate and Ampicillin. Paper disc diffusion followed standard methods with incubation for 24 hrs. The inhibition zone was then measured. The results showed that at 100 ppm all antibiotics had activity toward all threeVibriospp. (100 ppm). At 10 ppm, Amoxicillin and Ampicillin did not produce an inhibition zone in theV. parahaemolyticusculture. Antibacterial activity at 100 ppm resulted in inhibition zone diameters ranging from 6.93±0.34 mm (Ampicillin/V. parahaemolyticus) to 31.85±2.5 mm (Gentamicin/V.harveyi). The reduction in bacterial activity ranged from 3.89% (Doxycycline/V. harveyi) to 75.30% (Gentamicin/V.parahaemolyticus). The MIC was determined for six antibiotics. The lowest MIC was ≤0.625 ppm (Gentamicin/allVibriospp.), and the highest was 10 ppm (Doxycycline/V. vulnificus, V. harveyiand Ampicillin/V. vulnificus). This research revealed that some antibiotics, especially Amoxicillin and Ampicillin, were ineffective against Vibriosis, conforming that theVibriospp. isolates used in this research were resistant to these antibiotics.
Blue swimming crab (Portunus pelagicus) megalopa stage seed feed enrichment with beta carotene
Authors: Yusneri Andi , Hadijah  , Budi Sutia
Published: May 2021

This study aimed to increase the nutritional value of natural rotifer and Artemia feed by adding beta carotene sourced from carrots. This research was conducted in May 2020 at the hatchery unit of the Brackish Water Aquaculture Fishery Centre (BPBAP) Takalar. The research design used was a completely randomized design (CRD) with 4 treatments and 3 replications. The experimental animals used were small blue swimming crab larvae (Portunus pelagicus) in the megalopa stage, which were stocked with a density of 5 individuals/L, and kept until they entered the crab stage. The expected output of this research is natural feed enrichment technology for rotifers and Artemia using beta carotene from carrots. The results showed that providing the right frequency of feed after enriching with beta carotene could increase the survival and growth of small blue swimming crab larvae. The optimum feeding frequency for megalopa stage blue swimming crab larvae was 3 times/day.
Screening for Antioxidant Activity in Extracts of the Marine Macro algae Enteromorpha flexuosa (Wulfen) J. Agardh from South Aceh
Authors: Gazali Mohamad , Nurjanah  , Zamani Neviaty P. , Nasution M. Arif , Zuriat  , Syafitri Rina
Published: May 2021

Indonesia is the world’s largest archipelagic nation with high marine biodiversity that can provide added value for local communities through using renewable resources. Aceh is one of the provinces in Indonesia directly facing the Indian Ocean with many marine biota distributed along the coast. Marine macroalgae are marine biota with potential for medicines and foodstuffs that have long been consumed by local communities in Aceh. Many marine macroalgae in Aceh coastal waters, especially along the south coast, contain a wide range of bioactive compounds with potential antioxidant activity. The aim of this study was to screen for antioxidant activity in extracts of the green macroalga Enteromorpha flexuosa. Green algae of E. flexuosa were taken from along the South Aceh coastal zone. The research methods included extraction followed by phytochemical and antioxidant activity assays. The rendement of E. flexuosa extracts were ethanol with value of 1.38%; ethyl acetate with value of 1.11%; and n-hexane with value of 0.42%. The phytochemical analysis showed phenol and flavonoid compounds in the E. flexuosa extracts. The CUPRAC method for determining antioxidant activity showed activity of 96.40 μmol troloks/g in the ethanol extract; 16.77 μmol troloks/g in the ethyl acetate extract; and 22.38 μmol troloks/g in the n-hexane extract. These results showed that the ethanolic extract possesses the antioxidant capacity strongly than other extracts. There are indications that phenol compounds influenced antioxidant activity in the E. flexuosa extracts. Using the FRAP method to determine the antioxidant activity of the extracts was: ethanol extract 474%, ethyl acetate 363.50% and n-hexane 239.50%. These levels of antioxidant activity in the extracts point to E. flexuosa as a potential source of antioxidants that could provide benefits when used in marine natural products.