bluuebunny/crossref_metadata_2025_split huggingface dataset:
RANCANG BANGUN MOTOR BRSUHLESS DIRECT CURRENT THREE PHASE AXIAL FLUX NYLON CARBON FIBER PADA UNMANNED AERAL VEHICLE (UAV)
Authors: Rahardi Gamma Aditya , Putranto Adi , Hadi Widyono 
Published: July 2022

Abstrak
Pesawat tanpa awak atau Pesawat nirawak (Unmanned Aerial Vehicle atau UAV), adalah sebuah mesin terbang yang berfungsi dengan kendali jarak jauh oleh pilot. drone telah diterapkan dalam berbagai layanan seperti pengawasan Infrastruktur, pemetaan daerah pertanian, dan pemetaan daerah industry. Perancangan motor BLDC Axial Flux Nylon Carbon Fiber pada Unmanned Aerial Vehicle (UAV) ini menggunakan bahan nylon carbon fiber pada penampang stator dan rotornya karena memiliki berat yang ringan dan kuat. Pengujian pertama mengetahui kinerja dari empat motor BLDC Axial Flux Nylon Carbon Fiber dengan variasi sinyal dari throttle yang diberikan menghasilkan arus , daya dan kecepatan motor yang berbeda, untuk daya didapatkan dari hasil perhitungan akar tiga dikalikan dengan tegangan dikali arus. Setelah data terkumpul selanjutnya yaitu membandingkan motor pertama kedua ketiga dan keempat apakah ke empat motor yang di buat dengan konstruksi yang sama memiliki perbedaan arus, daya, gaya angkat maupun kecepatannya. Hasil pengujian menghasilkan motor BLDC Axial Flux Nylon Carbon Fiber tersebut mempunyai beberapa kelebihan yaitu berat dari motor menggunakan bahan Nylon Carbon Fiber.
Kata Kunci :Unmanned Aerial Vehicle, motor BLDC, Axial flux, Nylon Carbon Fiber.
Abstract
Unmanned aircraft or Unmanned Aerial Vehicle (UAV), is a flying machine that functions with remote control by the pilot. drones have been applied in various services such as infrastructure surveillance, mapping of agricultural areas, and mapping of industrial areas. The design of the Axial Flux Nylon Carbon Fiber BLDC motor on this Unmanned Aerial Vehicle (UAV) uses nylon carbon fiber material on the stator and rotor cross sections because it has lightweight and is strong. The first test was to determine the performance of the four BLDC Axial Flux Nylon Carbon Fiber motors with the variation of the signal from the given throttle resulting in different current, power, and motor speed, for power, obtained from the calculation of the root of three multiplied by the voltage times the current. After the data has been collected, the next step is to compare the first, second, third, and fourth motors, whether the four motors made with the same construction have different currents, power, lift, and speed. The test results produce a BLDC Axial Flux Nylon Carbon Fiber motor that has several advantages, namely the weight of the motor using Nylon Carbon Fiber material.
Keywords : Unmanned Aerial Vehicle, motor BLDC, Axial flux, Nylon Carbon Fiber.
Improvement of Catfish (Claris sp.) Production on Limited Land in Bukit Dempo Village, Belinyu
Authors: Andriyono Sapto , Patmawati Patmawati , Amin Muhamad , Syarif Ahmad Fahrul , Hudatwi Mu’alimah 
Published: July 2022

The potential of freshwater fisheries in Bangka Regency, Bangka Belitung Province, is sufficient to support fisheries activities in this area. An activity that is quite prominent is catfish farming using swamps and tarpaulin ponds on limited land. In this study, the analysis of cultivation activities was carried out on the Bukit Dempo community group who became partners in the national community service activities, in cooperation with Universitas Airlangga and Bangka Belitung University. Characteristics of the pond using a combination of fixed nets with a net diameter of 0.5 cm. In the pond also found water plants in the form of water hyacinth which is expected to be able to make a symbiotic use of the organic material that has been left behind from feed and catfish waste. The cultivation system is classified as semi-intensive with a combination of commercial feed with high protein (31-33%). The main problem in this cultivation system is low productivity and the lack of technology applied in an effort to increase production efficiency Furthermore, high production yields are marketed to Pangkal Pinang City and also to local areas around the Belinyu sub-district. Technical constraints include Motile Aeromonas Septicemia (MAS) due to the bacterium Aeromonas hydrophylla, which causes about 10% of mortality in commodities before harvest. There has been no treatment action in overcoming the disease, so it is necessary to be careful in avoiding death due to disease by observing catfish at the change of seasons.
Evaluation of Flock Volume Levels on Water Quality and Production Performance of Catfish (Clarias gariepinus) Culture Using Micropore Pipe As Aeration Diffusers.
Authors: Sumitro Sumitro , Afandi Arfan , Safia Wa Ode 
Published: July 2022

High floc accumulation in intensive catfish culture will increase the bacterial consumption of oxygen and affects the dissolved oxygen in the media is relatively low then affecting the fish growth. For control the floc accumulation is to remove the flock regularly. However, removing a large amount of floc will affect the flock's ability to control nitrogen waste in the water and the utilization of the flock as feed for fish will be minimum. The research was conducted to evaluate of floc volume levels on water quality and production performance of catfish culure in the biofloc system. The research design used a completely randomized design (CRD) with 4 treatments and 3 replications. The research treatments were floc volume level (KVF), namely (KVF) 20-40 ml/L, (KVF) 40-60 ml/L, (KVF) 60-80 ml/L and (KVF) 80-100 ml/L. The results showed that the water quality in all treatment were within the safe level for catfish. (KVF) 60-80 ml/L and 80-100 ml/L had higher survival rates of 100% (P <0.05). The growth rate in (KVF) 80-100 ml/L showed the lowest value compared of other treatments (P <0.05). (KVF) 60-80 ml/L can improve feed conversion ratio and increase protein retention by 59.17%, significantly different compared to other floc level treatment (P <0.05).
Growth and Lipid Profiles of Melosira sp. in response to Different Salinity Levels.
Authors: Suryaningtyas Indyaswan Tegar , Permadi Sandi , Solikin  , Jasmadi  , Sapulete Sherly , Suparmo  , Widyartini Dwi Sunu 
Published: July 2022

The Diatom of Melosira sp. is one of the potential microalgae candidates for future biofuel resource due to its high lipid profile and fatty acid content, high growth rate, and a quick deposition rate. Salinity stress is one of the environmental factors affecting the growth of microalgae and their lipid content. This research was conducted to identify the response of Melosira sp. treated with different salinity levels on the cell growth rate, biomass productivity, and lipid production. The microalgae cells were incubated for 8 days in 1 liter of F/2 growth medium with different salinity levels from 10 ppt to 35 ppt. Cell’s growth, SGR, biomass, lipid, and water quality factors were measured during incubation. This study revealed that the growth pattern of Melosira sp. cells under various salinities was customarily similar. Observation in the 35 ppt salt presenting the biomass productivity was 711.04 ± 69.38 mg.L-1 with lipid productivity which was 60.49 ± 1.72 mg.L-1. On the other hand, the observation of the lowest salt concentration displaying the biomass productivity was 316.64 ± 16.66 mg.L-1 with the lipid productivity which was 41.46 ± 6.94 mg.L-1. Hence, the results demonstrated that the lower salinity stress in 10 ppt enabled significant cell’s lipid production than the higher salinity of Melosira sp. in F/2 medium. Furthermore, lipid productivity was uncorrelation with biomass production pattern. This information may be useful in optimizing Melosira sp. lipid performance as a supporting knowledge.
Prediction of Dynamic Characteristics of Thermocouples with Thin-Wire Sensing Elements
Authors: Safina I. A. , Artemyeva S. A. 
Published: July 2022

Thermocouples dynamic characteristicsʼ prediction is one of the relevant directions in the field of dynamic measurements of non-stationary temperatures of liquid and gaseous media. Thermocouples dynamic characteristicsʼ prediction makes it possible to provide effective continuous correction in automatic control systems for non-stationary temperatures. The purpose of this paper was to develop a theoretically justified relation linking the current or expected time constant of fine-wire thermocouples with the known time constant established at known parameters of liquid and gaseous media.A formula linking the time constant of fine-wire thermocouples with the conditions of heat exchange with the measured medium and the thermophysical characteristics of the thermocouple sensing elements has been deducted. An approximate formula is also given for calculating the internal resistance of wire sensing elements of thermocouples, which must be considered when calculating the time constant of a thermocouple. In consideration of the obtained formulas, a multi-parameter relation linking the current or expected time constant of fine-wire thermocouples with the known time constant set at the known parameters of the measured media has been formed.It is suggested to simplify the formed multi-parameter relation and make it dependent, for example, on the “expected velocity of the measured medium × expected density of the measured medium” complex (Vm2 ρm2 ). Simplified relations in the form of hyperbolic functions with constant parameters and argument in the form of Vm2 ρm2 complex were obtained for airflowat different temperatures, pressures, and velocities.On the example of airflow, it is shown that the complex multi-parametric relation linking the expectedand known time constants of thermocouples can be simplified to a hyperbolic dependence, where the argument can be the Vm2 ρm2 complex. Moreover, the degree of approximation of hyperbolic dependencies to the exact values of the multi-parametric relation can reach the R-square = 0.9592 criterion.A multi-parametric relation has been proposed. That relates the known time constant of a thermocouple to the expected or current time constant of the same thermocouple at other parameters of the measured medium from the point of view of the heat exchange and thermal conduction theory. The proposed relation can be used in automatic control systems of non-stationary temperature of various liquid or gaseous media to provide continuous correction of thermocouples dynamic characteristics. Depending on the number of measured medium parameters, the suggested multi-parameter relation can be replaced by simplified relations with other complexes containing, for example, density, velocity, flow rate and pressure of the measured medium.
Fracture Propagation Behavior of Bedding Shale in the Process of Multistage Cluster Fracturing considering the Intercluster Stress Interference
Authors: Zhang Qingqing , Yang Huanqiang , Liu Yang , Xiong Dong , Mei Yuntao 
Published: July 2022

Abstract
Staged multicluster fracturing in horizontal wells is the key technology for forming complex fractures in shale reservoirs. The existence of shale bedding plays a conspicuous role for the propagation path of hydraulic fractures, affecting the propagation of the fracture height direction prominently. A 3D finite element model containing three clusters signed as side clusters and middle cluster was established based on the cohesive zone model and the dynamic distribution mechanism of interfracture flow. And the correctness of the model was verified by literature comparison. Some factors including cluster spacing, horizontal stress difference, shale bedding strength, perforation density, injection rate, and viscosity of fracturing fluid which influenced fracture propagation behavior of bedding shale were simulated. The results indicate that the stress interference of the middle cluster by the clusters on both sides will be prominently obvious when the cluster spacing is less than 10 m. Multiclusters will penetrate across the shale bedding when the horizontal stress difference is more than 4 MP, which will conspicuously reduce the activated probability of discontinuities and the complexity of fracture geometry. In correspondence with increase of horizontal stress difference, the interference between clusters also increases prominently, which will conspicuously decrease the propagation of the middle cluster. In order to comprehensively equalize the length of multiclusters, the inhibition of intercluster stress interference on the middle cluster propagation can be counteracted by improving pressure drop in perforation. The high injection rate and viscosity of fracturing fluid will contribute to the shale bedding shear slip increasingly, which is conducive to the formation of complex fractures in areas with well-developed bedding. The study has a certain guiding significance for the operation parameter design of multicluster fracturing in bedded shale.
Investigation on Mechanism of Coal Burst Induced by the Geological Weak Surface Slip in Coal Seam Bifurcation Area: A Case Study in Zhaolou Coal Mine, China
Authors: Mu Zong-long , Yang Jing , Liu Guang-jian , Zhang Yu-chen , Jiao Jian-hang 
Published: July 2022

Abstract
The coal seam bifurcation area (CSBA) exists widely in coal measure strata, where the geological weak surface (GWS) slip in overburden structure is easy to induce coal burst. The coal mass of coal face shows overall instability failure and high-speed throwing characteristics during the coal burst, seriously threatening the safe and efficient coal mine production. In order to understand the GWS-induced coal burst caused by the slip in CSBA and find the main controlling factors of GWS slip, the GWS slip criterion in CSBA was established based on the coal burst case analysis of overburden structure in CSBA of 1305 coal face (1305CF) in Zhaolou Coal Mine. The case study showed that the angle and range of CSBA are the main controlling factors affecting GWS slip. The FLAC3D numerical model of CSBA was established to analyze the influence effect of main control factors. The results show that the increase of angle and range of CSBA will increase the influence scope and degree of coal face mining, improving coal face burst risk. However, the peak point region of abutment pressure will not be affected, gradually reaching its peak within 0 m ~10 m from the coal seam merging area. With the increase of the angle of CSBA, the integrity of the triangular wedged rock mass along the GWS slip will be enhanced, aggravating the dynamic disturbance to the coal mass. With the increase of the range of CSBA, the slip of triangular wedged rock mass along GWS gradually changes from integral slip to phased slip, which will intermittently disturb the coal mass of the coal face. The research results have certain theoretical significance and practical value for preventing and controlling coal bursts in CSBA.
Acoustic Emission Characteristics of Fracture and Damage in Coal Samples under Overstress Loading and Unloading Paths
Authors: Zhu Guang-an , Su Bo-ru , Liu Hai-yang , Jiang Qi-peng , Liu Huan 
Published: July 2022

Abstract
As coal mining depth is over 1000 m, an overstressed effect is commonly observed around working face which shows a higher stress than the ultimate strength of the coal mass. Aiming at the problem of dynamic disasters induced by overstress loading and loading, a true triaxial AE monitoring unit was designed to systematically investigate the acoustic emission (AE) characteristics of fracture and damage. The AE results show that the ring counts of coal sample under true triaxial loading are influenced by three factors: loading level, individual differences, and loading rates. When under lower true triaxial loads, the coal sample damage represented by ring counts appears largely in loading phase, and the quantity is few. When true triaxial loads increase, the number of ring counts, especially in packing phase, increases significantly, which indicates that the damage process is transferred from loading phase to packing phase. The study on evolution laws of microcracks, wave velocity, and energy indicates that, during the initially true triaxial loads, the primary microcracks and the initial loading on primary dense areas contributes to a small amount of lower and higher velocity regions in the sample. Along with the increase of true triaxial loading, the closure of the primary microcracks and the fracture of the dense area result in a transfer and expansion of higher velocity regions and the formation of velocity anomaly regions. When approaching failure, the macrocracks throughout the sample present a large area of lower velocity band. The formation and closure of cracks, the fast transfer of high velocity region, and the velocity anomaly region indicate the unstable status of the sample. During the packing phase of true triaxial loads, the cracks are compacted, and the inner structures are thoroughly damaged in the sample, which eventually presents a continuous damage in a form of the shrink of the lower velocity region and the increase of integral velocity of the sample.
Phase Behavior and Physical Properties of Dimethyl Ether/CO2/Water/Heavy Oil Systems under Reservoir Conditions
Authors: Huang Desheng , Li Yunlong , Yang Daoyong 
Published: July 2022

Summary
In this paper, techniques have been developed to quantify phase behavior and physical properties including phase boundaries, swelling factors (SFs), and phase volumes for reservoir fluids containing polar components from both experimental and theoretical aspects. Experimentally, a total of seven pressure-volume-temperature (PVT) experiments, including one set of dimethyl ether (DME)/heavy oil system, one set of DME/water/heavy oil system, three sets of DME/CO2/heavy oil systems, and two sets of DME/CO2/water/heavy oil systems, have been carried out to measure saturation pressures, phase volumes, and SFs by using a versatile PVT setup. Theoretically, the modified Peng-Robinson equation of state (PR EOS) incorporated with the Huron-Vidal (HV) mixing rule and the Péneloux volume-translation strategy is used as the thermodynamic model to perform phase equilibrium calculations. Once validated with the measured phase compositions of DME/water mixtures collected from the literature, the theoretical model developed in this work is used to reproduce the experimental measurements for the aforementioned reservoir fluids. It is observed that the saturation pressures of DME/CO2/water/heavy oil mixtures are higher than those of DME/CO2/heavy oil mixtures at the same temperature and same molar ratio of solvents and heavy oil, owing to the fact that more water molecules can be evaporated into the vapor phase. The binary interaction parameters (BIPs) between DME/heavy oil and CO2/DME pair, which are obtained by matching the measured saturation pressures of DME/CO2/heavy oil mixtures, work well for DME/CO2/heavy oil mixtures in the absence and presence of water. In addition, the swelling effect of heavy oil can be enhanced by adding the DME and CO2 mixtures compared with only DME or CO2. The new model developed in this work is capable of accurately reproducing the experimentally measured multiphase boundaries, SFs, and phase volumes with root-mean-squared relative errors (RMSREs) of 4.68, 0.71, and 9.35%, respectively, indicating that it can accurately provide fundamental data for simulating, designing, and optimizing the hybrid steam-solvent recovery processes for heavy oil reservoirs.
From planetary to regional nitrogen boundaries for targeted policy support
Authors: Schulte-Uebbing Lena , Beusen Arthur , Bouwman Alexander , de Vries Wim 
Published: July 2022

Abstract
Excessive agricultural nitrogen (N) use causes serious environmental problems globally1, to an extent that scientists have claimed that the safe planetary boundary has been exceeded2. Earlier estimates for the planetary N boundary3,4, however, did not account for spatial variability in both ecosystems’ sensitivity to nitrogen pollution and agricultural nitrogen losses. Here we used a spatially explicit model to establish regional boundaries for agricultural nitrogen surplus from thresholds for eutrophication of terrestrial and aquatic ecosystems and nitrate in groundwater. We show that regional boundaries for agricultural nitrogen pollution reveal both overuse and room for intensification. The aggregated global surplus boundary to respect all thresholds is 43 Mt N yr-1, 64% lower than current (2010) nitrogen surplus (119 Mt N yr-1). Allowing nitrogen surplus to increase to close yield gaps in regions where environmental thresholds are not exceeded lifts the planetary nitrogen boundary to 57 Mt N yr-1. Feeding the world without trespassing regional and planetary nitrogen boundaries requires large increases in nitrogen use efficiencies accompanied by mitigation of non-agricultural nitrogen sources such as sewage water. This asks for coordinated action, recognizing the heterogeneity of agricultural systems, non-agricultural nitrogen losses, and environmental vulnerabilities.
Computational probing of Nigella sativa bioactive metabolites against chikungunya nsP2 cysteine protease
Authors: Kumar Sushil , Choudhir Gourav , Y Vimala , Joshi Nidhi , Tiwari Abhay , Singh Garima 
Published: July 2022

Abstract
Background and Aim:
Instances of chikungunya reported throughout the world in the past two decades of the present century. There is a lack of effective medicine or vaccine for chikungunya treatment. Non-structural protein, the nsP2 cysteine protease (nsP2pro) is an attractive target for inhibitors. It is a key enzyme for proteolytic cleavage of polyprotein precursors and produces functional proteins for replication and multiplication of the virus. Bioactive metabolites from Nigella sativa L; a popular spice and well-known medicinal plant, were selected for the current study against nsP2pro to search for potent non-toxic natural inhibitors of nsP2pro.
Experimental procedure:
Out of 54 bioactive metabolites from N. sativa 27 qualified drug likeliness properties. Virtual screening of 27 selected molecules was performed using AutoDock Vina. Top four molecules Kaempferol, (-)-Epicatechin, (+)-Catechin, and Apigenin with the least binding energy were taken for molecular docking employing AUTODOCK4. These metabolites were subjected to molecular dynamics simulation and MMPBSA, and the resilience of protein-ligand complexes had been assessed in terms of RMSD, RMSF, Rg, SASA, and hydrogen bonding.
Results and Conclusions:
Drug likeliness, molecular docking, molecular dynamics simulation properties, and MMPBSA analyses made clear that Kaempferol, (-)- Epicatechin, (+)- Catechin, and Apigenin all seem to be potential nsP2pro potent inhibitors and strong candidates for chikungunya virus drug development.
A Case of Transverse Myelitis Secondary to COVID-19 Infection
Authors: Borra Rahul , Patel Neal , Shaikh Raheel , Parmar Mayur , Borra Sujatha 
Published: July 2022

Abstract
Infection with COVID-19 (SARS-CoV-2) is associated with a variety of generalized and specific symptoms, including neurological complications of both the peripheral and central nervous system. In this case report, we present the case of a previously healthy 55-year-old woman who was diagnosed with transverse myelitis following a previous infection with COVID-19. Her initial presenting symptoms were numbness and tingling of the abdomen, neurogenic bladder, hyperreflexia of the bilateral lower extremities, positive Babinski sign, sensory decrement to pin prick below T5 dermatome, and generalized weakness over the previous 20 days with slow progression caudally into the bilateral lower extremities that resulted in difficulties ambulating. She had no symptoms of the upper extremities or face and denied ever previously experiencing similar symptoms. MRI showed progressive demyelination of the cervical, and thoracic spinal cord, cerebrospinal fluid (CSF) showed increased levels of protein and red blood cells and no markers of infection, including negative PCR for COVID-19 antibodies. The patient was treated with a course of methylprednisolone, multiple treatments of plasmapheresis, and ongoing treatment with rituximab, all of which were well-tolerated. She was instructed to follow-up with her primary care physician 5–7 days after hospital discharge.