bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal Management of Air-Cooling Lithium-Ion Battery Pack
Authors: Du Jianglong , Tao Haolan , Chen Yuxin , Yuan Xiaodong , Lian Cheng , Liu Honglai
Published: December 2021

Lithium-ion battery packs are made by many batteries, and the difficulty in heat transfer can cause many safety issues. It is important to evaluate thermal performance of a battery pack in designing process. Here, a multiscale method combining a pseudo-two-dimensional model of individual battery and three-dimensional computational fluid dynamics is employed to describe heat generation and transfer in a battery pack. The effect of battery arrangement on the thermal performance of battery packs is investigated. We discuss the air-cooling effect of the pack with four battery arrangements which include one square arrangement, one stagger arrangement and two trapezoid arrangements. In addition, the air-cooling strategy is studied by observing temperature distribution of the battery pack. It is found that the square arrangement is the structure with the best air-cooling effect, and the cooling effect is best when the cold air inlet is at the top of the battery pack. We hope that this work can provide theoretical guidance for thermal management of lithium-ion battery packs.
Electron spectra for twisted electron collisions
Authors: Plumadore A , Harris A L
Published: December 2021

Ionization collisions have important consequences in many physical phenomena, and the mechanism that leads to ionization is not universal. Double differential cross sections (DDCSs) are often used to identify ionization mechanisms because they exhibit features that distinguish close collisions from grazing collisions. In the angular DDCS, a sharp peak indicates ionization through a close binary collision, while a broad angular distribution points to a grazing collision. In the DDCS energy spectrum, electrons ejected through a binary encounter collision result in a peak at an energy predicted from momentum conservation. These insights into ionization processes are well-established for plane wave projectiles. However, the recent development of sculpted particle wave packets reopens the question of how ionization occurs for these new particle wave forms. We present theoretical DDCSs for (e, 2e) ionization of atomic hydrogen for electron vortex projectiles. Our results predict that the ionization mechanism for vortex projectiles is similar to that of non-vortex projectiles, but that the projectile’s momentum uncertainty causes noticeable changes to the shape and magnitude of the vortex DDCSs. Specifically, there is a broadening and splitting of the angular DDCS peak for vortex projectiles, and an increase in the cross section for high energy ejected electrons.
A comparison of particle and fluid models for positive streamer discharges in air
Authors: Wang Zhen , Sun Anbang , Teunissen Jannis
Published: December 2021

Both fluid and particle models are commonly used to simulate streamer discharges. In this paper, we quantitatively study the agreement between these approaches for axisymmetric and 3D simulations of positive streamers in air. We use a drift–diffusion–reaction fluid model with the local field approximation and a particle-in-cell, Monte Carlo collision particle model. The simulations are performed at 300 K and 1 bar in a 10 mm plate–plate gap with a 2 mm needle electrode. Applied voltages between 11.7 and 15.6 kV are used, which correspond to background fields of about 15–20 kV cm−1. Streamer properties like maximal electric field, head position and velocity are compared as a function of time or space. Our results show good agreement between the particle and fluid simulations, in contrast to some earlier comparisons that were carried out in 1D or for negative streamers. To quantify discrepancies between the models, we mainly look at streamer velocities as a function of streamer length. For the test cases considered here, the mean deviation in streamer velocity between the particle and fluid simulations is less than 4%. We study the effect of different types of transport data for the fluid model, and find that flux coefficients lead to good agreement whereas bulk coefficients do not. Furthermore, we find that with a two-term Boltzmann solver, data should be computed using a temporal growth model for the best agreement. The numerical convergence of the particle and fluid models is also studied. In fluid simulations the streamer velocity increases somewhat using finer grids, whereas the particle simulations are less sensitive to the grid. Photoionization is the dominant source of stochastic fluctuations in our simulations. When the same stochastic photoionization model is used, particle and fluid simulations exhibit similar fluctuations.
Bell nonlocality in networks
Authors: Tavakoli Armin , Pozas-Kerstjens Alejandro , Luo Ming-Xing , Renou Marc-Olivier
Published: December 2021

Bell’s theorem proves that quantum theory is inconsistent with local physical models. It has propelled research in the foundations of quantum theory and quantum information science. As a fundamental feature of quantum theory, it impacts predictions far beyond the traditional scenario of the Einstein-Podolsky-Rosen paradox. In the last decade, the investigation of nonlocality has moved beyond Bell's theorem to consider more sophisticated experiments that involve several independent sources which distribute shares of physical systems among many parties in a network. Network scenarios, and the nonlocal correlations that they give rise to, lead to phenomena that have no counterpart in traditional Bell experiments, thus presenting a formidable conceptual and practical challenge. This review discusses the main concepts, methods, results and future challenges in the emerging topic of Bell nonlocality in networks.
Characterizing the stress and electrical properties of superconducting molybdenum films
Authors: Wang Yeru , Liang Yajie , Ding Jiao , Chen Naihui , Chen Yanling , Cui Wei , Huang Rui , Li Chengzhe , Li Fajun , Liu Jiejia , Jin Hai , Wang Guole , Wang Sifan , Zhang Yuning
Published: December 2021

In the process of minimizing stress in sputtered molybdenum (Mo) films for fabricating transition-edge sensor devices, we have investigated correlations between the stress and film deposition parameters. At a fixed sputtering power, the tensile stress of our film samples decreases toward both low and high ends of Ar pressure, suggestive of two physical mechanisms at work: an ‘atomic peening’ effect at low Ar pressure and the development of voids at high Ar pressure. We have also carried out correlative studies of the stress and electrical properties (including superconducting critical temperature and residual resistivity) of the film samples, and found that the results are complex. We have made extensive comparisons with the published results, and attempted to explain the discrepancies in terms of film deposition techniques, sample preparation and treatment, and dynamical ranges of measurements. It is fairly clear that the microscopic properties, including porosity and disorder, of Mo films may have significant impact on the correlations.
Power-law distribution found in city-scale traffic flow simulation
Authors: Umemoto Daigo , Ito Nobuyasu
Published: December 2021

Origin of a power-law in traffic-volume distribution found in traffic simulations of Kobe city was studied. The traffic distribution which was obtained from a shortest path search with randomized OD (origin-destination) set in Kobe city digital map obeys power-law. The toy model that Cayley tree is embedded in the network is also verified. It is theoretically shown that the traffic distribution with all possible OD set in a Cayley tree obeys power-law like distribution. With randomized OD set, the distribution is diffused from the theoretical point sets. Relationship between these facts and the origin of power-law is discussed.
Intelligent Vehicle Design based on PaddlePaddle and Deep Learning
Authors: He Song , Xue Hao , Guo Lejiang , Chen Xin , Hu Jun
Published: December 2021

ABSTRACT.In order to visualize the applications of deep learning based intelligent vehicle in the real field vividly, especially in the unmanned cases in which it realizes the integration of various technologies such as automatic data acquisition, data model construction, automatic curve detection, traffic signs recognition, verification of the unmanned driving, etc. A M-typed Model intelligent vehicle that is embedded with a high-performance board from Baidu named Edge Board is adopted by this study. The vehicle is trained under the PaddlePaddle deep learning frame and Baidu AI Studio Develop platform. Through the autonomous control scheme design and the non-stop study on the deep learning algorithm, an intelligent vehicle model based on PaddlePaddle deep learning is here. The vehicle has the function of automatic driving on the simulated track. In addition, it can distinguish several traffic signs and make feedbacks accordingly.
Research on load balancing of parallel component programs based on quantum particle swarm optimization algorithm
Authors: Peng Yunfeng , Gao Guowei , Shi Congming , Liu Hai , Wang Jianan
Published: December 2021

Parallel component applications are often deployed on heterogeneous clusters. Load balancing is very important for their performance requirement. Existing load balancing methods have high performance cost and poor balance effect. Based on the analysis of structures of parallel component applications, we established the mathematical model of load balancing for parallel components on heterogeneous clusters. We use the quantum particle swarm optimization algorithm to search the optimal solution of the proposed mathematical model and determine the best load balancing scheme. Comparing with the methods based on real-time detection and other swarm intelligence optimization algorithms, our method has lower balance cost, less number of iterations and better performance.
An Interval Type-2 Possibilistic C-Means Clustering Algorithm and Its Application
Authors: Xing Haihua , Chen Huannan , Lin Hongyan , Wu Xinghui
Published: December 2021

In this paper, we aim at the fuzzy uncertainty caused by noise in pattern data. The advantages of PCM algorithm to deal with noise and interval type-2 fuzzy sets to deal with high-order uncertainties are used, respectively. An interval type-2 probability C-means clustering (IT2-PCM) based on penalty factor is proposed. The performance of the algorithm is evaluated by two sets of data sets and two groups of images segmentation experiments. The results show that IT2-PCM algorithm can assign proper membership degrees to clustering samples with noise, and it can detect noise points effectively, and it has good performance in image segmentation.
Research on Security Protocol Analysis Tool SmartVerif
Authors: Lu Siqi , Han Qingdi , Miao Xuyang , Liu Yubo
Published: December 2021

Security protocols have been designed to protect the security of the network. However, many security protocols cannot guarantee absolute security in real applications. Therefore, security tests of the network protocol become particularly important. In this paper, firstly, we introduce SmartVerif, which is the first formal analysis tool to automatically verify the security of protocols through dynamic strategies. And then, we use SmartVerif to verify the pseudo-randomness of the encapsulated key of the Two-Pass AKE protocol, which was proposed by Liu’s in ASIACRYPT in 2020. Finally, we summary our work and show some limitations of SmartVerif. At the same time, we also point out the direction for future improvement of SmartVerif.
The l-good-neighbor edge connectivity of graphs
Authors: Zhang Shumin , Li Yalan , Ye Chengfu
Published: December 2021

The l -good-neighbor edge connectivity is an useful parameter to measure the reliability and tolerance of interconnection networks. For a graph H with order p and an integer l (l ≥ 0), an edge subset X ⸦ E(H) is called a l-good-neighbor edge-cut if H − X is disconnected and the minimum degree of every component of H − X is at least £. The order of the minimum l-good-neighbor edge-cut of H is called the l-good-neighbor edge connectivity of H, denoted by λ
l
(H). In this paper, we show λ(H) ≤ λ
l+1(H), obtain the bounds of λl
(H) when 0 ≤ l ≤ [p-2/2], character some graphs with the small λl
(H) and get some results about the Erdös-Gallai-type problem about λl
(H).
Electric-field-tunable linear unipolar magnetic switch based on a spin-valve multiferroic heterostructure
Authors: Liu Mengli , Du Wei , Su Hua , Liu Bo , Meng Hao , Tang Xiaoli
Published: December 2021

This work reports an energy-efficient strategy for realizing linear unipolar giant magnetoresistance (GMR) switch by using electric fields (E-fields). Herein, a modified spin-valve (SV) structure of double antiferromagnetic (AFM) pinning layers was adopted. Since the magnetization direction of ferromagnetic (FM) layer can be controlled via the strain-mediated magnetoelectric (ME) effect, a multiferroic heterostructure of SV/PMN-PT was fabricated. By applying an E-field on the PMN-PT substrate, an effective magnetic field Heff
was produced along the [1-10] direction of PMN-PT. It can turn the magnetic moments of FM layer toward [1-10] direction. Accordingly, a linear GMR curve with a wide sensing field range was achieved. This E-field-induced linear magnetic switch can satisfy the demand for different switching field ranges in the same application system.
An Electric Equipment Analysis Method based on Knowledge Reasoning
Authors: Zhang Xinjie , Wang Yao , Lin Run , Zhang Yuze , Li Xu , Wang Jian
Published: December 2021

Facing the increasingly complex power grid architecture and high equipment failure risk, a comprehensive equipment condition analysis method based on knowledge reasoning is proposed in this paper, mainly using the large amount of characteristic information to realize the condition evaluation, fault detection and early warning. Firstly, it statistically analyzes the historical data, extracts the characteristic information of equipment health status and builds a knowledge mapping library of key factors for equipment-centered status analysis; secondly, it establishes an intelligent early warning library of equipment index data, and gets the probability of equipment defects and fault risks through induction-based knowledge reasoning method; finally, it gets the equipment status rating through logic and rule-based knowledge reasoning method and the closed-loop system of equipment status evaluation is established. The reasonableness of the evaluation method is verified by the examples, which realizes supervision equipment operation status mining early warning, sensing equipment operation status in advance and reducing potential operation risk of power grid.
Intervention analysis with autoregressive integrated moving average models for time series of urban air pollutants
Authors: Manco-Perdomo L A , Pérez-Padilla L A , Zafra-Mejía C A
Published: December 2021

The objective of this paper is to show an intervention analysis with autoregressive integrated moving average models for time series of air pollutants in a Latin American megacity. The interventions considered in this study correspond to public regulations for the control of urban air quality. The study period comprised 10 years. Information from 10 monitoring stations distributed throughout the megacity was used. Modelling showed that setting maximum emission limits for different pollution sources and improving fuel were the most appropriate regulatory interventions to reduce air pollutant concentrations. Modelling results also suggested that these interventions began to be effective between the first 4 days-15 days after their publication. The models developed on a monthly timescale had a short autoregressive memory. The air pollutant concentrations at a given time were influenced by the concentrations of up to three months immediately preceding. Moving average term of the models showed fluctuations in time of the air pollutant concentrations (3 months - 14 months). Within the framework of the applications of physics for the air pollution control, this study is relevant for the following findings: the usefulness of autoregressive integrated moving average models to temporal simulate air pollutants, and for its suitable performance to detect and quantify regulatory interventions.
Numerical analysis of a tire shredder machine to produce rubber particulate material
Authors: García-León R A , Jaramillo H Y , Gómez-Camperos J A
Published: December 2021

The main objective of this work is to develop a numerical analysis of a shredder machine to generate rubber particulate material for its implementation in different sectors such as construction, artisanal, and road as aggregates in the raw material. As part of the methodology, modern design theories were considered to select the materials for the different elements of the crushing machine; for this purpose, the SolidWorks design software was used to obtain a conceptual design model of the prototype. The mathematical and numerical results indicate that the prototype of the crushing machine will work in good conditions, always guaranteeing high levels of safety and performance based on the mechanical and physical properties of the materials selected through the design theories. Likewise, this machine will be low-cost to promote growth and competitive capacity for studies of different products with rubber aggregates to solve global environmental problems. Finally, the physical behavior of the new materials can be obtained with rubber particles aggregate will allow evaluating and optimizing a different kind of products that can be used in different sectors aiding sustainability sources.
Numerical simulation to analyze the physical behavior of centrifugal pumps as a turbine
Authors: Prada Botia G C , Pabón León J A , Orjuela Abril M S
Published: December 2021

In this research, a methodology based on the development of numerical simulations is proposed to analyze the physical behavior of centrifugal pumps such as a turbine. Numerical simulations were carried out using OpenFOAM software. For the validation of the numerical model, the construction of an experimental test bench was carried out. The analysis carried out involves the evaluation of performance parameters of the pump as a turbine, such as head, power, and efficiency. Additionally, the effect of the rotation speed on the previous parameters is evaluated. From the results obtained, it was shown that the maximum relative error was 4%, 3.4%, and 3.8% for the head, power, and efficiency parameters, respectively. In general, it was evidenced that the proposed numerical simulation has the ability to describe the real trends of the pump as a turbine for different flow conditions. In addition, an 11% increase in rotational speed was shown to cause a 12%, 1.9%, and 3% increase in head, power, and maximum efficiency. The proposed methodology is considered an adequate tool to analyze performance and identify the best efficiency point of pump systems such as a turbine. In this way, greater energy use is guaranteed.
Effect of a regenerator on hybrid solar gas turbine performance in Barranquilla, Colombia
Authors: Moreno-Gamboa F , Acevedo-Paéz J C , Sanin-Villa D
Published: December 2021

A thermodynamic analysis of a hybrid gas turbine solar plant, represented in three basic subsystems related to the power cycle, the combustion chamber subsystem, and the solar concentrator subsystem, allows evaluating the performance of a hybrid cycle from a reduced number of parameters, which include energy losses in each of its components. The solar radiation values are estimated with an evaluated and validated theoretical model, the combustion chamber uses natural gas as fuel and the numerical values of the system are taken from the Solugas experimental plant in Spain. This work presents an integrated model that allows to estimate the operation of a hybrid solar Brayton power plant in any place and day of the year. The evaluation of the plant in Barranquilla, Colombia is shown from the influence of the regenerator has on the plant performance and solar concentrating system. The results show that the regenerator can increase the overall efficiency of the plant by 29% and allows reaching a maximum temperature of the central receiver of the concentrator of 1044 K at noon, when solar radiation is maximum.
Strength of the flexural joint of mortar joints and solid fired clay brick prisms
Authors: Afanador García N , Guerrero Gómez G , Nolasco Serna C
Published: December 2021

Masonry constructions built with mortar and solid fired clay bricks are subject to: high cement content, excessive water-cement ratio causing problems of mortar shrinkage during curing and differential movements between the brick and mortar caused by movements due to wind or seismic events. Earth movements generate some failures in simple masonry walls and confined masonry in solid brick joints, mainly with failure inclination angles varying from 45 degrees to 50 degrees. The objective of this research work was to estimate the flexural bond strength of the mortar joint and the solid fired clay brick and thus establish design parameters for non-structural masonry in the municipality of Ocanña, Colombia. From the fired clay brick manufacturers, 18 in total, simple random sampling was used to determine the sample size, 4 manufacturers were randomly selected. In addition, the characterization of the solid fired clay brick units was carried out with respect to their compressive strength, initial absorption rate and final absorption, as well as the mortar with respect to its compressive strength at 28 days, according to the Colombian standard for earthquake resistant constructions; for the determination of the flexural strength of the bonding mortar and solid brick units, a semiautomatic machine for flexural strength testing of masonry units, Pinzuar model PC-13, with a force measurement of 1000 N and an accuracy of 0.1 N, was designed. The flexural strength at the masonry joint was obtained for mortar type M with a value of 0.26 MPa, with a standard deviation of 0.01 MPa and a coefficient of variation of 4.72%. As for mortars type N and S, the average strength value was equal to 0.24 MPa for the two types of mortar, with standard deviation of 0.03 MPa and 0.01 MPa respectively, and coefficient of variation of 11.4% and 3.18% respectively. Given the importance of the variables, an interpretation of physical of the relationship between the properties was made: compressive strength of the solid fired clay brick and flexural strength at the masonry joint, since their average values were similar.
Vernier time-to-digital converter with ring oscillators for in-pixel time-of-arrival and time-over-threshold measurement in 28 nm CMOS
Authors: Kadlubowski L.A. , Kmon P.
Published: December 2021

The paper describes a design of a prototype chip in 28 nm CMOS technology, consisting of 8 × 4 pixels with 50 μm pitch, dedicated for the precise measurement of Time-of-Arrival (ToA) and Time-over-Threshold (ToT) with a resolution within the picosecond range. To address this requirement, in-pixel Vernier time-to-digital converter (TDC) has been implemented, which utilizes two ring oscillators per pixel. Overall chip architecture is introduced as well as pixel architecture and selected simulation results. The pixel consists of a recording channel and TDC part. The recording channel is composed of an inverter-based front-end amplifier with Zimmerman feedback, a discriminator, a calibration block and a threshold setting block. TDC part includes two ring oscillators together with their calibration blocks and additional logic with counters/shift registers that allow for precise ToA measurement (using Vernier method) as well as ToT measurement (using one of the oscillators). Alternatively, single photon counting (SPC) mode can be used. Frequency of oscillators is set in three steps. First, two global 8-bit digital-to-analog converters (DACs) are used for initial setting of all ring oscillators. Then, per-oscillator capacitance bank and 6-bit DAC are used for fine setting. Simulation results of core blocks suggest that the ToA resolution on the order of tens of picoseconds may be achieved. The chips are already fabricated and are currently being prepared for measurements.
Method and portable bench for tests of the laser optical calibration system components for the Baikal-GVD underwater neutrino Cherenkov telescope
Authors: Allakhverdyan V.A. , Avrorin A.D. , Avrorin A.V. , Aynutdinov V.M. , Bannasch R. , Bardačová Z. , Belolaptikov I.A. , Borina I.V. , Brudanin V.B. , Budnev N.M. , Dik V.Y. , Domogatsky G.V. , Doroshenko A.A. , Dvornický R. , Dyachok A.N. , Dzhilkibaev Zh.-A.M. , Eckerová E. , Elzhov T.V. , Fajt L. , Fialkovski S.V. , Gafarov A.R. , Golubkov K.V. , Gorshkov N.S. , Gress T.I. , Katulin M.S. , Kebkal K.G. , Kebkal O.G. , Khramov E.V. , Kolbin M.M. , Konischev K.V. , Kopański K.A. , Korobchenko A.V. , Koshechkin A.P. , Kozhin V.A. , Kruglov M.V. , Kryukov M.K. , Kulepov V.F. , Malecki Pa. , Malyshkin Y.M. , Milenin M.B. , Mirgazov R.R. , Naumov D.V. , Nazari V. , Noga W. , Petukhov D.P. , Pliskovsky E.N. , Rozanov M.I. , Rushay V.D. , Ryabov E.V. , Safronov G.B. , Shaybonov B.A. , Shelepov M.D. , Šimkovic F. , Sirenko A.E. , Skurikhin A.V. , Solovjev A.G. , Sorokovikov M.N. , Štekl I. , Stromakov A.P. , Sushenok E.O. , Suvorova O.V. , Tabolenko V.A. , Tarashansky B.A. , Yablokova Y.V. , Yakovlev S.A. , Zaborov D.N.
Published: December 2021

The Large-scale deep underwater Cherenkov neutrino telescopes like Baikal-GVD, ANTARES or KM3NeT, require calibration and testing methods of their optical modules. These methods usually include laser-based systems which allow us to check the telescope responses to the light and for real-time monitoring of the optical parameters of water such as absorption and scattering lengths, which show seasonal changes in natural reservoirs of water. We will present a testing method of a laser calibration system and a set of dedicated tools developed for Baikal-GVD, which includes a specially designed and built, compact, portable, and reconfigurable scanning station. This station is adapted to perform fast quality tests of the underwater laser sets just before their deployment in the telescope structure, even on ice, without a darkroom. The testing procedure includes the energy stability test of the laser device, 3D scan of the light emission from the diffuser and attenuation test of the optical elements of the laser calibration system. The test bench consists primarily of an automatic mechanical scanner with a movable Si detector, beam splitter with a reference Si detector and, optionally, Q-switched diode-pumped solid-state laser used for laboratory scans of the diffusers. The presented test bench enables a 3D scan of the light emission from diffusers, which are designed to obtain the isotropic distribution of photons around the point of emission. The results of the measurement can be easily shown on a 3D plot immediately after the test and may be also implemented to a dedicated program simulating photons propagation in water, which allows us to check the quality of the diffuser in the scale of the Baikal-GVD telescope geometry.
Multi-detector approach to enhance the sensitivity of neutrino telescopes to low-energy astrophysical sources
Authors: de Wasseige G.
Published: December 2021

While large neutrino telescopes have so far mainly focused on the detection of TeV-PeV astrophysical neutrinos, several efforts are ongoing to extend the sensitivity down to the GeV level for transient sources. Only a handful of neutrino searches have been carried out at the moment leaving the signature of astrophysical transients poorly known in this energy range. In this contribution, we discuss the motivations for high-energy neutrino telescopes to explore the GeV energy range and summarize the current limitations of detectors, such as IceCube and KM3NeT. We then present and compare different approaches for multi-detector analyses that may enhance the sensitivity to a transient GeV neutrino flux.
Regional-specific meniscal extracellular matrix hydrogels and their effects on cell–matrix interactions of fibrochondrocytes
Authors: Wu Jinglei , Xu Jiazhu , Huang Yihui , Tang Liping , Hong Yi
Published: December 2021

Decellularized meniscal extracellular matrix (ECM) material holds great potential for meniscus repair and regeneration. Particularly, injectable ECM hydrogel is highly desirable for the minimally invasive treatment of irregularly shaped defects. Although regional-specific variations of the meniscus are well documented, no ECM hydrogel has been reported to simulate zonally specific microenvironments of the native meniscus. To fill the gap, different (outer, middle, and inner) zones of porcine menisci were separately decellularized. Then the regionally decellularized meniscal ECMs were solubilized by pepsin digestion, neutralized, and then form injectable hydrogels. The hydrogels were characterized in gelation behaviors and mechanical properties and seeded with bovine fibrochondrocytes to evaluate the regionally biochemical effects on the cell–matrix interactions. Our results showed that the decellularized inner meniscal ECM (IM) contained the greatest glycosaminoglycan (GAG) content and the least collagen content compared with the decellularized outer meniscal ECM (OM) and middle meniscal ECM (MM). The IM hydrogel showed lower compressive strength than the OM hydrogel. When encapsulated with fibrochondrocytes, the IM hydrogel accumulated more GAG, contracted to a greater extent and reached higher compressive strength than that of the OM hydrogel at 28 days. Our findings demonstrate that the regionally specific meniscal ECMs present biochemical variation and show various effects on the cell behaviors, thus providing information on how meniscal ECM hydrogels may be utilized to reconstruct the microenvironments of the native meniscus.
Smallholder agriculture results in stable forest cover in riverine Amazonia
Authors: Coomes Oliver T , Kalacska Margaret , Takasaki Yoshito , Abizaid Christian , Grupp Tristan
Published: December 2021

Recent studies point to a rapid increase in small-scale deforestation in Amazonia. Where people live along the rivers of the basin, customary shifting cultivation creates a zone of secondary forest, orchards and crop fields around communities in what was once was old-growth terra firme forest. Visible from satellite imagery as a narrow but extensive band of forest disturbance along rivers, this zone is often considered as having been deforested. In this paper we assess forest disturbance and the dynamics of secondary forests around 275 communities along a 725 km transect on the Napo and Amazon Rivers in the Peruvian Amazon. We used high-resolution satellite imagery to define the ‘working area’ around each community, based on the spatial distribution of forest/field patches and the visible boundary between old-growth and secondary forests. Land cover change was assessed between ca. 1989 and 2015 using CLASlite™ image classification. Statistical analyses using community and household-level data from the Peruvian Amazon Rural Livelihoods and Poverty project identified the predictors of the extent of forest disturbance and the dynamics of secondary forests around communities. Although shifting cultivation is the primary driver of old-growth forest loss, we find that secondary forest cover, which replaces old-growth forests, is stable through time, and that both the area and rate of expansion into old-growth forests are modest when compared to forest conversion in Peru for colonization and plantation development. Our findings challenge the notion that smallholder agriculture along rivers is an important threat to terra firme forests in Amazonia and point to the importance of protecting forests on community lands from loggers, colonists and other outsiders.
Identifying The Quantity of Combustion Heat when Briquetting Oil Waste Process
Authors: Zhumagulov T Zh , Yeleuova E Sh , Abzhalelov B B , Demin D V
Published: December 2021

During the works by calculation, there were grounded the makeup of fuel briquettes, which are produced from oil wastes, coal and biomass - rice husk. Within changing considered makeups and concentration, combustion heat values calculated, which in future will allow to compare the experimental values of the fuel characteristics of the briquettes with an assigned structural composition
Investigation of the physicochemical properties of magnetic nanoparticles: size, magnetic properties, concentration
Authors: Kuryakov VN , Sergeev I V , Efanova O O , Zheludkova O K
Published: December 2021

This work presents the results of studies of a series of samples of aqueous dispersions of magnetic nanoparticles. The particle sizes were measured for these samples by the dynamic scattering method. Using the method of ultramicroscopy, the number concentration of particles in the samples and the concentration of particles remaining in the volume of the samples after exposure to a magnetic field at various time intervals were measured.
Application of ferromagnetic nanoparticles and rotating electromagnetic fields for oil desulfurization
Authors: Andreev S N , Bazhenov V P , Spiridonov E N , Spiridonov N I
Published: December 2021

An innovative technology for desulfurization of hydrocarbon raw materials, based on the effect of a rotating electromagnetic field of high power and ferromagnetic nanoparticles located in the working area of the device on oil or fuel oil, has been developed and implemented on a pilot scale. The basis of the technology is the device named “electromagnetic process activator”, which is based on the principle of converting the energy of the electromagnetic field into other types of energy. The reduction of sulfur in oil by 2.5 times and fuel oil by 3 times was achieved at energy costs of up to 1.0 kW per ton of processed raw materials, which allows us to conclude that the developed technology is highly efficient and productive.
Substantiation of paleohydrodynamic sedimentation modes and identification of missed oil-and-gas saturated areas that are promising for additional exploration of the Lower Cretaceous deposits of the Albian stage of the Achikulak oil field according to geophysical well logging data
Authors: Ibragimova T V , Tumanova Ye Yu , Sterlenko Z V , Yeriomina N V , Rozhnova A A , Budaev Kh S , Abakarov M A
Published: December 2021

In the development of the oil and gas complex, the improvement of methods for studying the patterns of distribution of hydrocarbon deposits is of particular importance. At the same time, scientific research can be carried out in different directions. These include increasing the resolution of various methods of borehole and areal geological and geophysical studies of lithological features and oil-and-gas content, developing new approaches to interpreting well logging results, analyzing the productivity of poorly studied regions and areas of the section, identifying low-amplitude folds and non-anticlinal deposits. The development of hydrocarbon deposits in the Stavropol Territory has been going on for many decades, which has led to reduction of deposits within medium and large anticlinal uplifts. Therefore, the main attention is now paid to the prospect for low-amplitude and small-size uplifts and traps of the non-anticlinal type, which include lithological and stratigraphic ones.
Prospects for using the reflected electromagnetic wave-CDP method to search for small geological oil-and-gas prospective objects
Authors: Kaigorodov E P , Volokamirskaya L B , Dolgikh Y N , Sanin S S , Kuznetsov V I , Gulevich A , Reznikov A E , Varenkov V V , Kiselev O V , Savranskaya M P , Savenkov E V
Published: December 2021

The publication presents the key results of testing the reflected electromagnetic waves method at one of the fields of the Yamal-Nenets Autonomous District, including a description of the field research methodology, the principal aspects of the use of sounding equipment for subsurface studying based on the GROT-12 series deep ground-penetrating radars, as well as comparative examples of successful experience in the electromagnetic field processing using software designed for seismic data processing. For the first time in the world practice, the depth of the study averaging 500 - 550 meters, was achieved and confirmed by the speed characteristics of the medium.
Segmentation of Enhalus acoroides seagrass from underwater images using the Mask R-CNN method
Authors: Pamungkas S A , Jaya I , Iqbal M
Published: December 2021

Seagrass is a Spermatophyta plant that has many roles, including as a primary producer in the food chain in the waters. Monitoring of seagrass meadows and conditions needs to be done in order to achieve a healthy marine ecosystem. The steps taken in monitoring seagrass are by detecting and segmenting it. The purpose of the study is to implement and get information about the performance of the Mask R-CNN algorithm in detecting and segmenting the Enhalus acoroides. The dataset consists of 500 Enhalus acoroides images that had gone through a color correction and labelling process. The training process was performed with the configuration of 0.001 learning rate, batch size of 4 and some image augmentation was used to avoid overfitting. The optimum weight value was obtained after conducting the learning process with 100 epochs. A confusion matrix was used to evaluate detection performance, and linear regression was used to evaluate the segmentation produced by the model. The model evaluation results showed an accuracy value of 0.9246, a precision value of 0.9507, a recall value of 0.9712 and a correlation coefficient value of 0.8771. The value indicates that the model can detect and segment the seagrass Enhalus acoroides well and accurately.
Changes of seagrass area in Beralas Pasir and Beralas Bakau Island observed from Sentinel-2 Satellite and verified by Unmanned Surface Vehicle (USV)
Authors: Yashira F , Arhatin R E , Jaya I
Published: December 2021

Today, the area of seagrass ecosystems in Indonesia is estimated to have shrunk significantly. Bintan Island has quite a large seagrass ecosystems area. Along with the development of satellite technology, monitoring of conditions and changes to a coastal ecosystem can be carried out effectively through remote sensing technology. One satellite image that is relatively new and has good spatial quality is Sentinel-2 with a spatial resolution value of 10×10 m2 / pixel. Field data retrieval is facilitated by the use of Unmanned Surface Vehicle (USV). This research went through several stages such as image pre-processing, water column correction, masking, unsupervised classification, and detection of changes of seagrass area. The data obtained from the USV becomes the data for the accuracy-test in the supervised classification. Seagrass area was obtained in Beralas Pasir and Beralas Bakau Island is 84.27 ha (2016), 81.3 ha (2019) and 77.4 ha (2021). Detection of seagrass to non-seagrass area changes resulting 31.35 ha (2016-2019) and 30.91 ha (2019-2021). On the other hand non-seagrass to seagrass area is 24.84 ha (2016-2019) and 27.98 ha (2019-2021). The accuracy test of 2019 image classification and Unmanned Surface Vehicle data resulting overall accuracy at 62.20%.
Detection of seagrass distribution in Bintan Island using SPOT-7 Satellite Imagery and Unmanned Surface Vehicle (USV)
Authors: Tamba P P , Arhatin R E , Jaya I
Published: December 2021

Seagrass has a very important role as a natural barrier to currents and waves from open water. In addition, it plays a significant role in carbon sequestration and storage. In this study, we used SPOT-7 Satellite to detect seagrass distribution in Bintan Island. Bintan Island has the largest seagrass conservation area in Indonesia. The field survey for data collection used anUnmanned Surface Vehicle(USV). Seagrass area is obtained by classifying several objects in the shallow water by using Maximum Likehood Classification algorithm. The seagrass area in the Bintan Island covered about 142.45 ha in 2018, and from the underwater visual system, it was detected that the type of seagrass that dominates the area isThallasia hemprichiiandEnhalus accroides. Therefore, by combining the SPOT-7 satellite imagery and USV we can detect and quantify the seagrass.
New host record of microhabitat preferences of the Banggai cardinalfish (Pterapogon kauderni) in the introduced habitat in Luwuk waters, Sulawesi
Authors: Arbi U Y , Faricha A
Published: December 2021

Banggai cardinalfishPterapogon kauderniis an endemic apogonid fish from Banggai Islands, Central Sulawesi, which is discovered in strong association with black sea urchin (Diademaspp.). These fish also protected themselves from predators associated with sea anemones, hard coral branching, mushroom coral, soft coral, seagrass, and mangrove roots. The Banggai cardinalfish juveniles generally prefer to associate with sea anemones or mushroom corals as microhabitats. However, they are looking for similar microhabitats if they cannot find sea anemones or mushroom coralHeliofungia actiniformis. Microhabitat observation of Banggai cardinalfish was carried out in Luwuk waters, Banggai Regency. The result showed a new host record for juvenile phases of Banggai cardinalfish associated with upside-down jellyfishCassiopea andromedaas a microhabitat. Further study is needed to represent areas and seasons to get more evidence between the Banggai cardinalfish and jellyfish association concepts.
Modeling of habitat suitability for sea cucumber ranching in Sintok Island, Karimunjawa National Park, Indonesia
Authors: Hartati R , Alya T S , Zainuri M , Ambariyanto A , Widianingsih W , Ario R , Pratikto I , Sulisyati R
Published: December 2021

Increasing demand for marine resources, such as sea cucumber, has led to widespread interest in their conservation, one of which is sea ranching. This study sought to identify habitat suitability for sea cucumber Holothuria scabra ranching. The proposed location was Sintok Island, one small island part of Karimunjawa Archipelagos. The HSI (Habitat Suitability Index) model was used to identify potential sites for sea cucumber ranching. Twelve habitat factors were used as input variables for the HSI model: sediment classification, water temperature, salinity, pH, dissolved oxygen, depth, transparency, current, depth, organic matter and chlorophyll-a of the sediment, seagrass density, and tide. The weighting of each habitat factor was defined through the Delphi method. Sediment classification and seagrass density were the most and less important condition affecting the HSI of H. scabra in the different study areas with weighing index of 0.2191 and 0.015 respectively. The HSI of Southern Station (Station 1) was relatively low (0.79-0.81), meaning the site was not suitable for sea ranching of H. scabra. In contrast, the western (Station 2) and the northern part (Station 3) of Sintok Island, were preferable sites, suitable as habitats for restoration efforts in sea ranching.
Genetic structure and phylogenetic relationships of Phyllidiellapustulosa species from Seribu Islands, North Sulawesi, Halmahera, and West Papua
Authors: Yonatika N O , Widiasih N , Hamidah M , Nurhakim M D , Budiarto H , Bintang D M C , Sani L M I , Lestari D F , Setyaningsih W A , Subhan B , Madduppa H
Published: December 2021

Phyllidiella pustulosa are brightly coloured gastropod molluscs frequently found in coral reefs of the tropical Indo-Pacific. Phyllidiella pustulosa is widely distributed in Indonesia, such as Seribu Island, North Sulawesi, West Papua, and Halmahera. Based on the genetic characteristics of an individual’s DNA sequence, differences between species can be identified. In this paper, we would like to provide the molecular analysis and phylogenetic relationship among nudibranchs from Indonesian waters. Identification was made by measuring the genetic distance between species. The phylogenetic tree reconstruction was made using the Kimura 2-parameter model with 1000 times bootstrap with neighbor-joining and maximum likelihood method. There is 46 DNA Sequence obtained from 4 different regions (Seribu Island, Halmahera, North Sulawesi, and West Papua). The genetic distance of West Papua and Halmahera has the smallest value among other populations, which is between 0.0051-1.4629, compared to the population in Halmahera. The phylogenetic tree also shows populations from West Papua and Halmahera are on the same lineage, indicating that the population in West Papua and Halmahera had the closest relation. The study suggested that North Sulawesi, Halmahera and West Papua have genetic mixing of the same region, which is distinctive from Seribu Island.
Overview of bioactivity studies on marine natural products
Authors: Zamani N P , Rahman L , Rosada R L , Tirtama W
Published: December 2021

Marine natural products are sourced from marine biodiversity as natural raw materials for various commercial products. This study aims to review natural products of marine organisms and gap analysis for future research or challenges. A total of 109 references from 24 countries were collected. The analysis was carried out quantitatively and qualitatively. The bioactive compounds produced wereantioxidants, antibacterial, anticancer, antimicrobial, anti-fouling, antifungal, and anti-tumoral substances. Some marine organisms that can store chemical compounds through secondary metabolite processes are mangroves, seagrasses, macroalgae, microalgae, soft corals, molluscs, echinoderms, gastropods, cnidarians, sponges, fungi, and bacteria. Most of the papers only discuss the identification stage of the active compound, and some focus on product development. There are very few studies on prospects of commercialization and mass production. The problem to achieve mass production is due to the lack of interdisciplinary research collaboration. Future research challenges need to develop a transdisciplinary approach to study bioprospection research from upstream to downstream, starting from the potential identification of bioactive ingredients, product development, the availability of raw materials for mass production as well as commercialization and marketing.
Geological interpretation of offshore Central Sumatra basin using topex satellite gravity data
Authors: Setiadi I , Widodo J , Nainggolan T B
Published: December 2021

Topex is a geodetic satellite to map earth surface topography with very high precision. Two types of data can be obtained from Topex satellite, namely topographic and free-air gravity field data. Then, it is processed to produce Bouguer anomaly which will be used to interpret the subsurface geology of a specific study area. The purpose of this study was to delineate sedimentary basin and basement configurations. The methods used in this research are spectral analysis, band-pass filter and 2D forward modeling. The spectral analysis results show the average thickness of the sedimentary rocks is 2.1 km. Sub-basin patterns based on the band-pass filter are 7 sedimentary sub-basins and the structural patterns found in this area comprise basement height, graben and fault. The 2D modeling results show that the bedrock in the eastern part of the Central Sumatra basin is granitic with a mass density value of 2.67 gr/cc and the layer above the bedrock is interpreted as a sedimentary rock with a mass density value of 2.35 gr/cc. Analysis of the gravity data shows significant results as initial information to delineate sedimentary sub-basin and regional structure to enhance information to the next stage of hydrocarbon exploration.