bluuebunny/crossref_metadata_2025_split huggingface dataset:
Jet direction control using secondary flows
Authors: Tamanoi Y , Watanabe Y , Kobayashi R , Sato K 
Published: May 2021

Abstract
In recent years, studies on the fundamental principle of thrust vectoring using jets have been conducted with the aim of application to next-generation aircraft. Consequently, the improvement of aircraft motion performance is expected. Previously, a method using secondary flow with a Coanda surface was proposed for the direction control of the primary jet, and some valuable results were reported. The effect of ejection or suction on the traveling direction of the primary jet was examined. However, as many physical quantities dominate the phenomenon in this complicated situation, parametric studies are insufficient. The present study is a fundamental study of fluidic thrust vectoring. The effect of secondary injection or suction flow near the Coanda surface on the travel direction of primary jets was investigated parametrically using the momentum ratio, nozzle width ratio, etc. without changing the nozzle geometry. A larger deflection of the primary jet was observed because of the suction rather than ejection at the same momentum ratio. Furthermore, the effect of the slot width ratio on the dead zone where the traveling direction of the second jet does not depend on the momentum of the secondary flow was studied.
Advanced signal processing techniques for helicopter’s gearbox monitoring
Authors: Mauricio A , Wang W , Antoni J , Gryllias K 
Published: May 2021

Abstract
Planetary gearboxes nowadays serve as the heart of complicated structures such as helicopters, presenting a number of advantages. They have compact size and low weight, achieving high power density and high efficiency. Moreover the gearing can be very accurate with virtually no backlash and modular, as most stages can be stacked. Furthermore, the last years planetary gearboxes have been introduced in the area of air breathing engines, helping to deliver improved efficiency over a wide range of thrusts. Planetary gearboxes consist of various shafts, gears and bearings and operate under varying conditions under excessive friction, heat and high mechanical forces. Their use in such critical applications demands for monitoring systems that can track the health condition of different components, such as bearings and gears, focusing towards early and accurate fault detection with limited rate of false alarms and missed detections, and on trending of the system degradation targeting to prognostics. Therefore the aim of this paper is the analysis of a dedicated dataset using a basic diagnostic indicator named Squared Envelope Spectrum. The indicator is applied and evaluated on a comprehensive dataset that has been generated in 1992 by Westland Helicopters Ltd (WHL), at their Universal Transmission Test Rig, testing a CH46 aft transmission, for the United States Navy.
Turbine Design and Optimization Tool for LUMEN Expander Cycle Demonstrator
Authors: Hahn R. H. S. , Deeken J. , Oschwald M. , Schlechtriem S. 
Published: May 2021

Abstract
This paper describes the tool created for design and optimize supersonic partial admission impulse turbine for LRE [ 1 ] application, which is commonly used in open cycle applications, while focusing on the models used to better predict the operational conditions of turbines for small thrust range engines. Also, the tool for turbine blade profile generation and the main assumptions for its optimization are discussed and the preliminary results presented, showing the possibility to improve the turbine performance for LUMEN Demonstrator operational range
Bending and torsion vibrations of a beam excited by a moving load
Authors: Holl Helmut J. , Keplinger Lukas 
Published: May 2021

Abstract
The linear dynamic bending- and torsion vibrations of a simply supported Bernoulli-Euler beam under a moving load with constant velocity are analysed. The main target is to derive an analytical solution of the governing partial differential equations. The deformations of the beam are computed based on the eigenmode expansion. For the computation of the solution first the method of generalized finite integral transformation is used followed by a transformation using the Laplace-Carson integral transformation. The resulting algebraic equation then is rearranged considering the boundary and initial conditions. The inverse transformation has to consider the position of the poles and after a further transformation the solution in the time domain results. The convergence and the necessary number of eigenmodes of this procedure is analysed. For the pure bending load the analysis is performed and the beam vibrations are calculated for various longitudinal speeds. For the special case of static deflections the solution is also given. The resulting deformations are plotted over time and space and the occurring phenomena are discussed. For the pure torsion deformation the Saint-Venant torsion theory is used. The described methods for solving the equations are used again. Based on the boundary and initial conditions the solution shows a similar structure like the pure bending solution. Finally the analytic solutions are compared to a numerical calculation of a finite element model which shows good agreement of the two solutions.
Reduction of the unbalance excited vibrations during the resonance passage of a rotor
Authors: Simader Victoria , Holl Helmut J 
Published: May 2021

Abstract
Many rotor dynamic systems are faced with large oscillation amplitudes while passing through the resonance. The coupled differential equations for the position of the center of the shaft and the rotation angle describe the dynamic behaviour of the rotordynamic system. With an appropriate external excitation the amplitude of the oscillations can be reduced. An unbalance excited oscillator is used to study the effects of a modulated angular velocity, where the angular velocity is prescribed as linear increasing with a superimposed harmonic function. The resulting excitation force is expressed as a series of Bessel functions of the first kind. In order to achieve small amplitudes near the resonance frequency of the system, special conditions for the ratio of the modulation frequency and the angular acceleration and the argument of the Bessel function of the first kind with integer order zero are derived. These requirements are first developed for a linear oscillator with an excitation force. Due to the analogy of the solution of the equation of motion these solutions are then applied directly to an unbalance excited oscillator. The results show smaller displacement amplitudes compared to the case with only linear increasing angular velocity. For the resulting motion the required torque is computed.
Investigation of Internal Flow in Centrifugal Pump Diffuser using Laser Doppler Velocimetry (LDV) and Computational Fluid Dynamics
Authors: Sugiyama Daisuke , Ichinose Asuma , Takeda Tomoki , Miyagawa Kazuyoshi , Negishi Hideyo , Tsunoda Atsuhiro 
Published: May 2021

Abstract
An unshrouded impeller is being developed for high head pumps to reduce costs and disk friction losses. On the other hand, research of internal flow in a diffuser did not clearly reveal flow structure. In this experiment, we measured the velocity distribution at the diffuser inlet and outlet plane using laser doppler velocimetry (LDV) to capture the flow from the unshrouded impeller. The relation between the total pressure and velocity distribution was evaluated. The circumferential velocity and meridian velocity were measured by short-focus LDV (Diode Laser, 74mW) about the circumferential and the height direction of the vane direction. Operating conditions in this steady measurement are at the design point flow rate. The result was compared with computational fluid dynamics (CFD) simulations carried out in steady conditions at the previously defined operation points. In this experiment, a phenomenon that the streamline moved toward the shroud side was confirmed. There was also a region where the static pressure increased on the shroud side at the diffuser inlet. This phenomenon was caused by the influence of the tip leakage flow of the unshrouded impeller downstream and the gap of the impeller’s main plate. Furthermore, two high velocity regions on the hub and shroud side at the diffuser outlet were observed because of the secondary flow in the diffuser. From the above studies, it was clarified that the ununiform flow in the diffuser was caused by the influence of the secondary flow in the unshrouded impeller.
Influence of Forward Skew Blade Angle on Positive Slope Characteristics of Mixed Flow Pumps
Authors: Ikuta Akihiro , Nitta Naruki , Miyagawa Kazuyoshi , Shinozuka Yasushi , Tomimatsu Shigeyuki 
Published: May 2021

Abstract
Under the part-load conditions, the flow instability in a mixed-flow pump could lead to strong pressure fluctuations and vibrations, posing a great threat to the safety of the system. The current paper investigates effect of the forward skew blade angle on the positive slope characteristic in a high specific speed mixed flow pump using Reynolds averaged Navier-Stokes (RANS) equations coupled with the SST k-ω model. The simulation results are compared with the experimental data and show good accordance. In the present study, five types of the mixed-flow pumps with different skew blade angles are prepared based on the conventional pump. It is found that with the increasing of the skew angle, the positive slope region becomes wider and moves towards a deeper part-load region. Further investigations are carried out by calculating the impeller head. Results depict that compared with the dynamic pressure head H
d, the static pressure head H
st plays more significant role in the formulation of the positive slope characteristic (PSC). Besides, the relative static pressure head H
rel drops dramatically while the pump operates under the positive slope region, which matches with the pump performance well. Finally, analysis on the spanwise velocity profiles are further investigated in this paper, and results indicate that the flow accumulated near the impeller hub is one of the reasons to alleviate the head drop and shift the positive slope region to a deeper part-load condition.
Influence of Fluid-Induced Forces on Cavitating Turbopumps Rotordynamics in Forced Whirl Experiment
Authors: Bertelli F. , Pasini A. , Bottai R. 
Published: May 2021

Abstract
As typically highlighted in the experimental results, in unshrouded axial inducers the fluid-induced rotordynamic forces are significantly dependent on the flow coefficient and do not present a quadratic behavior with respect to the whirl ratio, as commonly reported in radial pumps. Moreover these forces show destabilizing peaks that typically increase with decreasing cavitation number. The present paper illustrates the development of a theoretical model of the rotordynamic system capable of assessing the influence of fluid-induced rotordynamic forces on the dynamic response of turbopumps under cavitating/non-cavitating conditions. The implementation of the fluid-induced rotordynamic forces in the dynamic model has been proposed through the so-called F.I.R.F. model, which is applied to a test set-up for forced whirl experiments, in order to characterize the whirl natural frequencies and the relative mode shapes. The model has been successfully applied to a rotordynamic system including an unshrouded axial inducer and the corresponding computed critical speeds are summarized in the Campbell diagrams pointing out the difference between dry and wet analysis results.
Carbon sequestration from bamboo biochar on the productivity of ultisols and soybean [Glycine max L.] plants
Authors: Maulana A , Prima S , Rezki D , Sukma V , Fitriani A , Herviyanti  
Published: May 2021

Abstract
Soil carbon is very important in food security, ecosystems, and environmental health, especially in the context of global climate change. This study was to determine the effect of carbon sequestration from bamboo biochar on increasing the productivity of marginal soils in the second planting season planted with soybean [Glycine max L.]. This study used a completely randomized design with 3 replications in 5 treatments: A = 0.0% [0g pot−1] B = 0.5% [173g pot−1]; C = 1.0% [348g pot−1]; D = 1.5% [520g pot−1] and E = 2.0 [693g pot−1] of bamboo biochar. The results showed that carbon sequestration from bamboo biochar had a significant effect on the chemical properties of Ultisols, such as increasing pH, available P, organic C, total N, CEC, and Ca-exch and could reduce Al-exch, by 0.90 units, 2.50 ppm P, 1.12% C, 0.13% N, 5.48; 1.79 and 0.88 cmolckg−1, compared to controls and increase in soybean growth and NPK nutrient uptake in stems and leaves [3.57g N, 2.61g P, 4.64g K], also in roots [0.93g N, 1.03g P, 0.94g K], compared to controls. Carbon sequestration from bamboo biochar with 2% application can increase the productivity of marginal soil [Ultisols] and soybean [Glycine max L.].
Activation of sub-bituminous coal with dolomite to improve chemical properties and palm oil growth on ultisols
Authors: Herviyanti H , Maulana A , Prasetyo T B , Darfis I , Hakim L , Ryswaldi R 
Published: May 2021

Abstract
Sub-bituminous coal [SC] activation with dolomite is the future technology in utilizing coal as an alternative organic material [Humic Substance]. This study aims to study the effect of SC activated with dolomite in improving the chemical properties of Ultisols and palm oil growth at the main-nursery stage [Elaeis guineensis Jacq.] In Dharmasraya. The experimental design was in Randomized Completely Block Design with three replications consisting of 6 treatments : A = 150g SC planting hole−1; B = 300g SC planting hole−1; C = 450g SC planting hole−1; D = 150g SC + 10% [15g] dolomite planting hole−1; E = 300g + 10% [30g] dolomite planting hole−1 and F = 450g SC + 10% [45g] dolomite planting hole−1. The results showed that the effect of activation on SC differs from those treatments without activation with dolomite. Effect of 450g SC activated with dolomite planting hole−1 is significant on the chemical properties of Ultisols, such as increasing in pH, available P, organic C, total N, CEC [Cation exchange capacity], and K, Ca, Exch-Mg, by 0.44 units, 1.33 ppm P, 0.44% C, 0.04% N, 0.25, 0.27, and 0.29 cmolckg−1, compared to 450g SC without activator and an increase in palm oil growth on height [12.33cm], stem diameter [0.84cm] and N, P, and K nutrient concentration from leaf of plant [0.014% N, 0.004% P, 0.002% K], compared to 450g SC without activator.
Comparative genomic of biosynthetic gene cluster of andrimid antibiotic from Serratia plymuthica UBCF_13
Authors: Fatiah R , Sulianyah I , Tjong D H , Jamsari J 
Published: May 2021

Abstract

Serratia plymuthica UBCF_13 was a promising bacterium to control plant pathogenic fungal. Availability of this bacterium genome and genome mining approaches has assisted to identify gene-encoded antibiotics. In this study, we identified the biosynthetic gene cluster (BGC) of andrimid and compared it with andrimid BGC from other bacterial strains and species. Andrimid is a hybrid non-ribosomal peptide-polyketide antibiotic that blocks the carboxyl-transfer reaction of bacterial acetyl-CoA carboxylase (ACC) and thereby inhibits fatty acid biosynthesis with submicromolar potency. Andrimid encoded by a gene cluster containing 20 genes, AdmA-T. Understanding the mechanism of synthesis of the non-ribosomal peptide (NRP) and polyketide assembly will assist the effort to manipulate production and increase efficacy of this antibiotic.
Simulated mutations in the geminivirus replicase gene using in-silico CRISPR / Cas9-based methods
Authors: Hidayati R , Nova B , Cania D , Runifah T , Tjong D H , Jamsari J 
Published: May 2021

Abstract
Geminivirus is one of the causes of losses in the agricultural sector. This virus infects many horticultural crops such as tomatoes, potatoes, eggplant, cucumbers, and chilies. All genes in geminivirus have an important and interrelated role in the success of infection. Replicase is a gene that is key in the replication of the viral genome in its host. The occurrence of mutations in this gene is thought to stop the virus from multiplying in the host. This will lead to the failure of the virus to infect the plant. To achieve this, an in-silico mutation simulation can be performed first. Mutations were simulated following the CRISPR / Cas9 method using Phyre2, ProFunc, CASTp, and Chimera software. This simulation succeeded in predicting that the CRISPR / Cas9 system on the replicase gene could inhibit viral replication. The success of this simulation will become a reference and consideration for CRISPR/Cas9 further research at the laboratory scale.
Traditional Fisherman Resilience Strategy to Coastal Pollution Pressure Impact of Tin Mining in Central Bangka District
Authors: Bidayani E , Reniati  
Published: May 2021

Abstract
This study aimed to analyze the income of traditional fishermen, the characteristics of individual traditional fishermen who have the ability to resilience, the factors that support the resilience of traditional fishermen, and the resilience strategies of traditional fishermen against the coastal pollution pressure from the impact of tin mining. This research used a survey method with a purposive sampling technique. The research was conducted in Bangka Tengah Regency, covering Sampur village, Pangkalan Baru sub-district and Baskara Bhakti village, Namang sub-district. The respondents in this study were traditional fishermen with more than 20 years of experience. Data collection methods in this study included primary data and secondary data. Primary data was collected using questionnaires, observation and documentation tools. Secondary data was collected through a literature study. The data was analyzed using a descriptive quantitative method. The result of the research showed that the average income of traditional fishermen is IDR 300,000 - IDR 800,000 per month. Fishermen have individual characteristics including: Insight, Independence, Relationships, Initiative, Creativity, Humor, and Morality. The factors that support the resilience of traditional fishermen are: individuals (the ability to overcome problems; family (family support); and Community (environmental support to deal with pressure). The strategy of traditional fishermen’s resilience to coastal pollution pressures due to tin mining is innovative and creative. So it is suggested that as an effort to empower traditional fishermen, the government can develop a capture fishery business into a larger business scale increase the income of traditional fishermen.
Genetic variation in the Asian seabass (Lates calcarifer Bloch, 1790) from Wallacea Region estimated using random amplified polymorphic DNA (RAPD) markers
Authors: Irmawati  , Malina Asmi Citra , Husain Aidah A.A. , Annisa Andi Rezky , Kadriah Ince Ayu Khaerana , Alimuddin Alimuddin 
Published: May 2021

Abstract
The Asian seabass (Lates calcarifer) is an important marine food fish in Southeast Asia. To facilitate a selective breeding program conducted in Indonesia, we genotyped 29 Asian seabass specimens collected from four wild populations in the Wallacea Region originating from coastal waters in two seaways: the Makassar Strait (Bulungan in North Kalimantan and Maros in South Sulawesi) and the Gulf of Bone (Siwa and Bone in South Sulawesi). We used four polymorphic markers with a random amplified polymorphic DNA (RAPD) method. A total of 43 alleles were detected at four loci across the four populations, four of which were shared by all the accessions while 39 were polymorphic. Of these 43 alleles, 34.88% were unique, with 46.67% in the Gulf of Bone and 53.33% in the Makassar Strait. Asian seabass within-population genetic distance was greater in Bone Bay than the Makassar Strait, and an ongoing speciation phenomenon is suspected. The greatest genetic distance (0.291) was between the Asian seabass populations from Bulungan, North Kalimantan and Cenranae River estuary, Bone Regency; the lowest (0.086) was between the Bulungan and Maros populations. In the phylogenetic analysis, Gulf of Bone and Makassar Strait specimens formed separate clades. Commercial scale cross-breeding between Asian seabass from Makassar Strait and the Gulf of Bone may produce highly adaptable seed. These results will be helpful in future Asian seabass breeding programs as well as for optimising management and conservation strategies for wild Asian seabass populations.
Papain Enzyme as Feed Additive for Grouper Cantang (Epinephelus fuscoguttatus-lanceolatus) and Silver Pompano (Triachonus blochii)
Authors: Rostika Rita , Iskandar Iskandar , Andriani Yuli , Purnama Mochammad Ichsan C. , Pratiwy Fittrie Meyllianawaty , Permana Rega 
Published: May 2021

Abstract
This research aims to observe growth and intestines condition of mariculture fish species, grouper cantang dan silver pompano which feed had been incorporated with papain enzyme (PE) containing papaya derived protease. The research was conducted in 2018 at The Floating Net Cages at Pangandaran Beach, Indonesia. A complete randomized design with five treatments and three repetitions was performed. The treatments involved were A (control ) B (1, 2.5% of PE added to feed), C (2.50% of PE added to feed), D (3.75% of PE added to feed), E (5.00% of PE added to feed). In addition, the research experiment if silver pompano with the same manner was conducted in 2020. The treatments were V (2% of PE added to feed), W (3% of PE added to feed), X (4% of PE added to feed), Y (5% of PE added to feed) and Z (6% of PE added to feed) for 2 months of observation time. The results showed that additional PE incorporation to feed could increase Average Daily Gain (ADG) and Feed Convertion Ratio (FCR) on fish. The addition of the papain enzyme dose in cantang grouper feed has a positive effect on the growth and intestinal conditions of the fish. At doses of 3.75% and 5% gave the best response to ADG (2.26 grams/day and 2.30 grams/day), FCR (1.41% and 1.40%) and SR (68% and 69%). The cantang grouper intestine which was given the addition of papain enzyme was 3.75% and 5%, the best conditions were the number of villi (52 and 53 pieces), the best length of the cantang grouper villi was in the 125% and 5% treatments, namely 539.3 and 524.5. Meanwhile the papain enzyme at a dose of 5% gave the best response to body weight, ADG (2.46 gram/day), SGR (0.83 %/day) and SR in silver pompano (100%).
Integrate of culture area for seaweed (Eucheuma cottonii) and fishing ground for Stripped Mullet (Mugil cephalus) in marine coastal waters
Authors: Musbir Musbir , Bohari Ridwan 
Published: May 2021

Abstract
Seaweed culture play role in human food, animal feed, and environmental quality. The intensively study of seaweed culture was conducted in many places. The need to assess seaweed production, fish catch and the water quality of the seaweed culture area was necessary. The present study investigates the integrated system for seaweed culture and fishing ground for Mugil cephalus in marine coastal waters area. The purpose of study was to assess the production of cultured seaweed (Eucheuma Cottonii) and caught Stripped Mullet (Mugil cephalus) in marine coastal waters. The study was conducted from October 2019 until March 2020 in southern marine coastal waters of Bulukumba Regency, South Sulawesi, Indonesia. The method of seaweed culture was longline with a rope length of 50 and the distance between rope stretches of 1 meter with the average number of rope stretches 50 stretches perunit. Stripped Mullet was caught using a surface gillnet 100 length, 2.5 m depth and 1,3/4 inch mesh size. The water quality such as water temperature, salinity, pH, brightness, current velocity was measured. The production of seaweed in this area during planting period between 40-45 days ranged 8.300-11.600 kg wet/ha and catch Stripped Mullet ranged 43-162 individuals/one day trip. The results of study suggest that a seaweed culture influence on the production of cultured seaweed and caught mullet in marine coastal waters. The water quality parameters during study were favorable for seaweed production grey mullet fish catching.