bluuebunny/crossref_metadata_2025 huggingface dataset:
Distribution of atomic rearrangement vectors in a metallic glass
Authors: Annamareddy Ajay , Wang Bu , Voyles Paul M. , Morgan Dane
Published: November 2022

Short-timescale atomic rearrangements are fundamental to the kinetics of glasses and frequently dominated by one atom moving significantly (a rearrangement), while others relax only modestly. The rates and directions of such rearrangements (or hops) are dominated by the distributions of activation barriers (Eact) for rearrangement for a single atom and how those distributions vary across the atoms in the system. We have used molecular dynamics simulations of Cu50Zr50 metallic glass below Tg in an isoconfigurational ensemble to catalog the ensemble of rearrangements from thousands of sites. The majority of atoms are strongly caged by their neighbors, but a tiny fraction has a very high propensity for rearrangement, which leads to a power-law variation in the cage-breaking probability for the atoms in the model. In addition, atoms generally have multiple accessible rearrangement vectors, each with its own Eact. However, atoms with lower Eact (or higher rearrangement rates) generally explored fewer possible rearrangement vectors, as the low Eact path is explored far more than others. We discuss how our results influence future modeling efforts to predict the rearrangement vector of a hopping atom.
Generalized Langevin dynamics simulation with non-stationary memory kernels: How to make noise
Authors: Widder Christoph , Koch Fabian , Schilling Tanja
Published: November 2022

We present a numerical method to produce stochastic dynamics according to the generalized Langevin equation with a non-stationary memory kernel. This type of dynamics occurs when a microscopic system with an explicitly time-dependent Liouvillian is coarse-grained by means of a projection operator formalism. We show how to replace the deterministic fluctuating force in the generalized Langevin equation by a stochastic process, such that the distributions of the observables are reproduced up to moments of a given order. Thus, in combination with a method to extract the memory kernel from simulation data of the underlying microscopic model, the method introduced here allows us to construct and simulate a coarse-grained model for a driven process.
Flow of polymer blends—Developing a deformation-induced morphology followed by analytical scanning electron microscopy
Authors: Malkin A. Ya. , Gumennyi I. V.
Published: November 2022

We applied a new experimental method for studying the evolution of the morphology in the flow of polymer blends. This so-called analytic scanning electron microscopy is based on spectroscopy of Auger electron transitions, which is widely used for catching foreign atoms in metals, alloys, and ceramic articles but has remained unknown in polymer science. The possibility of applying this approach to polymer blends became possible when choosing two polymers that are composed of different atoms. We have used polysulfone with sulfur in the main chain and a thermotropic liquid crystalline copolymer (LCP) of polyethylene terephthalate and p-hydroxybenzoic acid, which has significantly more oxygen atoms in its composition than polysulfone. In addition, LCP has lower viscosity. The blends with different ratios of components were extruded through a capillary at different shear rates. The components are randomly distributed, and no significant changes in the spatial distribution or the radial migration over the volume were observed during the low shear deformations. At high shear rates, phase separation takes place, emulsification of dispersed droplets of a low-viscous phase occurs, and these droplets were drawn along the streamlines, forming a self-arranged bundle of the strings. The increase in the radial transfer, leading to the phase separation, is most likely determined by the deformations and not by the shear rate. If the concentration of the low-viscous phase is high enough, it squeezed out of the extrudate body, forming a coverlayer on the convergent stream at the capillary inlet. The apparent viscosity of the blend strongly depends on the concentration of the low-viscous component. This can be explained by the combination of the predominant flow inside low-viscous strings and the existence of the low viscous “lubricant” on the periphery of the stream. The structure of the blend is destroyed at sufficiently high deformation rates apparently due to the emergence of the elastic turbulence.
Reappraisal of the hyperdiverse
Authors: Teixeira Marcos A. L. , Langeneck Joachim , Vieira Pedro E. , Hernández José Carlos , Sampieri Bruno R. , Kasapidis Panagiotis , Mucciolo Serena , Bakken Torkild , Ravara Ascensão , Nygren Arne , Costa Filipe O.
Published: November 2022

Morphologically similar species are often overlooked but molecular techniques have been effective in signalling potential hidden diversity, boosting the documentation of unique evolutionary lineages and ecological diversity. Platynereis dumerilii and Platynereis massiliensis are part of a recognised species complex, where differences in the reproductive biology have mainly been highlighted to date. Analyses of DNA sequence data (COI, 16S rDNA and D2 region of the 28S rDNA) of populations of the apparent morphotype of P. dumerilii obtained from a broader sampling area along European marine waters, including the Azores and Webbnesia islands (Madeira and Canaries), provided compelling evidence for the existence of at least 10 divergent evolutionary lineages. Complementing the genetic data, morphological observations of the better represented lineages revealed two major groups with distinctive paragnath patterns. Two new Platynereis species were erected: P. nunezi sp. nov., widespread in the Azores and Webbnesia islands, and P. jourdei sp. nov., restricted to the western Mediterranean. The new combination P. agilis is also proposed for Nereis agilis, previously unaccepted for one of the lineages present both in the Northeast Atlantic and western Mediterranean. Platynereis dumerilii is redescribed based on topotypic material. However, uncertainty in the identity of P. massiliensis due to the original brief description and the absence of type and topotypic material prevents the unequivocal assignment to the lineage assumed in this and previous studies. The remaining five lineages are represented by only a few small specimens with morphological features poorly preserved and were therefore not described in this study. ZooBank: urn:lsid:zoobank.org:pub:50079615-85E5-447E-BDD7-21E81C2A6F4D
Solving Tolman–Oppenheimer–Volkoff equations in f(T) gravity: a novel approach
Authors: Fortes H G M , Araujo J C N
Published: November 2022

The torsion models have stood out among the proposals for an alternative description of gravity. The simplest of them, the Teleparallel theory, is equivalent to general relativity and there are many studies dealing with its extension to more general functions of the torsion T. The purpose of our study is to consider a family of f(T) models and apply their corresponding Tolman–Oppenheimer–Volkoff equations to compact objects such as neutron stars.Thus, through a numerical analysis, calculate, among other things, the maximum mass allowed by the model for a neutron star, which also allows us to evaluate which models agree with the observations. In the present paper, the first in the series, we show explicitly the set of equations that must be solved, and how to solve it, in order to model compact stars in f(T) gravity without the need to adopt any particular form for the metric functions or consider any perturbative approach, as has been done in some works in the literature. Examples are given of how our approach works, modelling polytropic stars. We also show that some numerical instabilities reported in a previous study by other authors do not appear in our novel approach. This is an important advance, since it is possible to answer an issue not responded in a previous study, because numerical instabilities prevented proceeding with the calculations. Last but not least, we explicitly show the torsion behaviour inside and outside the star. This is an important question, because with this study we can understand the role of torsion in the structure of the star.
Contrastive uncertainty based biomarkers detection in retinal optical coherence tomography images
Authors: Liu Xiaoming , Zhou Kejie , Yao Junping , Wang Man , Zhang Ying
Published: November 2022

Objective. Retinal biomarker in optical coherence tomography (OCT) images plays a key guiding role in the follow-up diagnosis and clinical treatment of eye diseases. Although there have been many deep learning methods to automatically process retinal biomarker, the detection of retinal biomarkers is still a great challenge due to the similar characteristics to normal tissue, large changes in size and shape and fuzzy boundary of different types of biomarkers. To overcome these challenges, a novel contrastive uncertainty network (CUNet) is proposed for retinal biomarkers detection in OCT images. Approach. In CUNet, proposal contrastive learning is designed to enhance the feature representation of retinal biomarkers, aiming at boosting the discrimination ability of network between different types of retinal biomarkers. Furthermore, we proposed bounding box uncertainty and combined it with the traditional bounding box regression, thereby improving the sensitivity of the network to the fuzzy boundaries of retinal biomarkers, and to obtain a better localization result. Main results. Comprehensive experiments are conducted to evaluate the performance of the proposed CUNet. The experimental results on two datasets show that our proposed method achieves good detection performance compared with other detection methods. Significance. We propose a method for retinal biomarker detection trained by bounding box labels. The proposal contrastive learning and bounding box uncertainty are used to improve the detection of retinal biomarkers. The method is designed to help reduce the amount of work doctors have to do to detect retinal diseases.
Investigation of 3D Dirac semimetal supported terahertz dielectric-loaded plasmonic waveguides
Authors: Liang Yubo , Wang Guangqing , Cheng Yan , Cao Duo , Yang Dejun , He Xiaoyong , Lin Fangting , Liu Feng
Published: November 2022

The tunable propagation properties of 3D Dirac semimetal (DSM)-supported dielectric-loaded surface plasmons structures have been investigated in the THz regime, including the influences of the Fermi level of 3D DSM layer, the fiber shape and operation frequencies. The results indicate that the shape of dielectric fiber affects the hybrid mode significantly, on the condition that if a

x
(the semi-minor axis length of the dielectric semi-ellipse) is relatively small, the fiber shows good mode confinement and low loss simultaneously, and the figure of merit reaches more than 200. The propagation property can be manipulated in a wide range by changing the Fermi level of 3D DSM, e.g. if the Fermi level varies in the range of 0.05 eV–0.15 eV, the propagation length changes in the range of 9.073 × 103–2.715 × 104
μm, and the corresponding modulation depth is 66.5%. These results are very helpful to understand the tunable mechanisms of the 3D DSM plasmonic devices, such as switchers, modulators, and sensors.
Colossal negative magnetoresistance from hopping in insulating ferromagnetic semiconductors
Authors: Liu Xinyu , Riney Logan , Guerra Josue , Powers William , Wang Jiashu , Furdyna Jacek K. , Assaf Badih A.
Published: November 2022

Ferromagnetic semiconductor Ga1–x
Mn
x
As1–y
P
y
thin films go through a metal–insulator transition at low temperature where electrical conduction becomes driven by hopping of charge carriers. In this regime, we report a colossal negative magnetoresistance (CNMR) coexisting with a saturated magnetic moment, unlike in the traditional magnetic semiconductor Ga1–

x
Mn
x
As. By analyzing the temperature dependence of the resistivity at fixed magnetic field, we demonstrate that the CNMR can be consistently described by the field dependence of the localization length, which relates to a field dependent mobility edge. This dependence is likely due to the random environment of Mn atoms in Ga1–x
Mn
x
As1–y
P
y
which causes a random spatial distribution of the mobility that is suppressed by an increasing magnetic field.
Fault Detection and Diagnosis of Gear Train Based on Motor Current Signature Analysis
Authors: Diao Junjie , Tian Yuan , Zhang Yuelong , Huang Shisheng , Xin Yijun , Guo Yulong
Published: November 2022

Gear fault diagnosis generally uses oscillation signals to extract fault features, but the oscillation identify technique is inconvenient to set up sensors and is easily affected by the surrounding and noise. The motor itself has the property of a sensor, and signals such as motor current is able to reflect the change of the load torque. This paper proposes a gear fault detection approach, which applies the Motor Current Signature Analysis (MCSA) to exploit spectral characteristics to recognize malfunction in servo motor drive gears. First, we calculate the nominal revolutions per minute (rpm) to explore frequencies of interest. Second, frequency bands where faulty signals would be appear are constructed. Next, we extract power spectral density (PSD) feature data. Finally, the paper computes spectral metrics for the frequency band of interest. By using two spectral metrics, gear health and failure data are clearly grouped in different areas of the scatter chart. The experimental results give evidence of the effectiveness of analyzing current characteristics of servo motors to classify fault and health data.
Optimization Design of Propeller for Ultra-high-altitude Unmanned Aerial Vehicle
Authors: Yao Yuan , Ma Dongli , zhang Liang , Yang Xiaopeng
Published: November 2022

Ultra-high-altitude unmanned aerial vehicle raises a high demand for the efficiency of propeller at low Reynolds numbers. An optimization method for low Reynolds number propeller is established by iterative optimizations of the sectional airfoils and the chord, pitch distributions in this paper. Different from the traditional method, each sectional airfoil is continuously optimized under the specific Reynolds number and lift coefficient which are updated with the iteration in the proposed method. Adopting this method, the propeller for an ultra-high-altitude unmanned aerial vehicle is optimized. And the result shows that the optimized propeller can achieve 3.6% higher efficiency than the propeller designed by the traditional Betz method at the cruising condition (Re≈4.0×104).
Comprehensive Risk Assessment of Satellite on-Orbit Operation
Authors: Feng Ru , Zheng Heng , Zhou Bo , Xie Zongsheng , Hu Xuemei , Shang Xia , Chen Lei
Published: November 2022

Aiming at the lack of research on quantitative evaluation of satellite on-orbit operation risk, this paper from two aspects: the special features and general quality characteristics analysis and identify factors that influence the satellite provide services, and on the basis build satellite on-orbit operation risk comprehensive evaluation index system. By combining analytic hierarchy process (AHP) and satellite availability evaluation model, this paper complete the research on comprehensive evaluation of satellite on-orbit operation risk. The results of the case show that the satellite is in good operating condition and capable of providing services normally. Thus, this method can realize the comprehensive quantitative evaluation of the actual operational risks of satellites on-orbit, find out the weak points of risks according to the evaluation results, and provide effective support for the operational health management of satellites on-orbit.
Study on bottom thermal environment of launch vehicle during high altitude flight
Authors: Zhao Chen-geng , Sun Zhong-yi , Su Yi-fei , Wang Yi-chen , Le Gui-gao
Published: November 2022

Aiming at the problem of the thermal environment at the bottom of the launch vehicle in the high-altitude flight stage, taking the launch vehicle with core stage four-way machine as the model, the coupled convection / radiation heat transfer problem at the high-altitude of the launch vehicle is deeply studied through the numerical simulation method, the gas jet flow model of the launch vehicle in the high-altitude flight stage is established, and the flow field information of the rocket under different working conditions and the heat flow at the bottom of the rocket are obtained. The numerical results are compared with the experimental data to verify the effectiveness of the selected model and calculation method. The research shows that the external flow field of the rocket body will have a great impact on the thermal environment at the bottom. With the continuous increase of flight altitude, the convective heat flow at the bottom of the rocket body first rises and then decreases. In the high-altitude stage, the total heat flow at the bottom of the rocket body is dominated by radiant heat flow, the convective heat flow outside the main nozzle is dominant, and the radiant heat flow outside the traveling jet nozzle is dominant.
Acceleration and performance analysis of a compressible Euler solver with CUDA
Authors: Chen Yuqiao , Liang Jianhan , Ding Meng , Zhang Lin , Guan Qingdi , Wang Xinxin
Published: November 2022

To develop high performance computing methods for compressible flow calculation, a GPU-accelerated compressible flow solver is developed with Compute Unified Device Architecture (CUDA). The WENO5 scheme is adopted for spatial discretization, and the third-order Runge-Kutta scheme is used for time discretization. According to the algorithm and programming model, the heterogeneous computing method of the solver is designed. Different kernels are designed to implement different computing functions, and shared memory is used for time-advanced computations. The solver is verified by the one-dimensional shock tube case, and a good acceleration effect is obtained with the increase of the grid size. And the impact of execution configuration on kernel performance was investigated. When the block size is reduced under different grid sizes, the speedup changes in the same way, but the performance parameters change differently.
Aerodynamic Analysis of Large Aspect Ratio Parafoil
Authors: Li Chongxian , Li Xinfeng , Zhong Hongen
Published: November 2022

Large aspect ratio parafoils are more attractive compared with moderate ones less than 3.5, since they either improves load-carrying capacity with the same aero-dynamical area or decreases taxing speed with the same load. Based on its original airfoil, one open-source elliptical parafoil with 4.7 AR is modified while scaling the canopy geometric parameters, then CFD simulations, solving the incompressible Reynolds time-averaged Navier-Stokes equation with the (SST) K-ω turbulence model in the finite volume method, are adopted to analyze its aerodynamics in forward taxing mode as well as steering mode with lateral wind. With the numerical simulation results of this canopy, lift and drag are analyzed according to their attack angle profiles for taxing. The steering mode with the deflection of one-side flap increases the drag coefficient significantly, even it raises its lift simultaneously, reduces the lift-drag ratio, and generate rolling and yaw moments; The rolling moment due to lateral wind during steering mode has two phases of rising linked by a short straight line when sideslip angle increases, while yaw moment increases to a peak value then reduces, finally followed by a relatively stable trend. Compared with the above two moments, the pitching moment changes moderately with the increase of the sideslip angle, although it has an overall decreasing trend; The simulation of the modified canopy provides a calculation basis for its following manufacture and dynamical modelling.
Numerical Study on the Water Takeoff Performance of Unmanned Seaplane
Authors: Wu Chengyi , Wang Yichong , Wang Aihua , Chen Hang , Zhang Fei
Published: November 2022

The research on the water takeoff performance of unmanned seaplane is of great significance to its overall optimization design and taxiing stability control system. This paper proposes a new numerical method for solving the water takeoff performance of unmanned seaplane. The aerodynamics and hydrodynamics are solved separately by decoupling solution principle. The influence of aerodynamic force and moment, engine thrust and moment on hydrodynamic force and taxiing attitude is considered synthetically by the vertical approximate balance hypothesis and instantaneous pitch balance hypothesis. The discrete velocity piecewise solution is used to solve the takeoff process. The results show that the taxi resistance peak appeared in the range of 0.3~0.35 times of takeoff velocity, and the greater is the trim angle, the smaller are the hydrodynamic resistance and hydrodynamic moment when the unmanned seaplane taxiing at medium or high speed. What's more, compared with the fixed trim angle hypothesis, the combined trim angle method is more consistent with the actual takeoff process.
Research on drag reduction characteristics of the surface of springtail cuticle
Authors: Fu Benshuai , Xiao Haiyan , Lu Bingju , Qin Liping , Zhu Zhu
Published: November 2022

The technology of underwater drag reduction is one of critical paths to break through the problem of ocean-going, and the bionic drag reduction is a very promising method. The bionic drag reduction uses sliding effect on the liquid-gas interface to reduce the drag, while the gas film is very unstable and the drag reduction function is easy to fail. The concave corner microstructure of springtail cuticle can make the air retention, which has very important significance to solve the problem of instability of gas film. In the paper, a model is established by referring to the concave corner microstructures of springtail cuticle. The k-ε turbulence model and volume of fluid multiphase flow model were used. The results show: the simulation model can be used to calculate the flow characteristics of the concave corner microstructure of springtail cuticle; as the area ratio of free shear increases, so does the drag reduction rate, which is beneficial for drag reduction; the drag reduction rate of different microstructure is slightly different, but it is mainly related to the area ratio of free shear of microstructure.
The Principle and State-of-Art Approach for Black Hole Detection
Authors: Guan Lingyan , Tang Xianzhe , Tian Jialing , Wu Jiayi
Published: November 2022

Black hole is a kind of special celestial subject whose density is so great that even the light cannot escape, which has always been a popular topic. This study will present the recent progress of observation related to three quantities of black holes. As a leading-in, we first introduced some of the most commonly discussed black holes by demonstrating their field equations, metric, and some other representative quantities. On this basis, the formation process of a black hole will be described. In addition, a picture of the detectors used in cosmology observation is discussed before getting any further into the methods applied in observation. Subsequently, we summarized observations regarding the three elements of a black hole (mass, charge and spin). For these three different characters of black hole, different methods and theories were put into use, including gravitational retro-lensing, twin-peak QPOs, accretion disks, continuum fitting method, and black body radiation. Eventually, possible limitations are evaluated and possible improving approaches on current observations are proposed. Overall, these results shed light on guiding further researches focusing on exploring the black holes.
Study of Combustion Mode Identification Method on Dual-Mode Solid Rocket Scramjet
Authors: Zhao Libei , Xia Zhixun , Ma Likun , Li Chaolong , Feng Yunchao , Chen Binbin , Yang Pengnian
Published: November 2022

A Direct connection experiment study of combustion mode transition was completed under the air conditions with Mach 2.2, total pressure 1.1 MPa and total temperature 1660 K, and a real-time identification method of combustion mode on dual-mode solid rocket scramjet was proposed. Based on the adiabatic assumption, the Mach number at the isolator exit could be calculated and used as the criterion for identifying the combustion mode. The pressure of the upper engine wall was measured during the test. It was found that the pressure of the isolator changes significantly during the combustion mode transition by analyzing the pressure changes in the isolator. The ratio of pressure between the exit and inlet P
𝑖/P
0 is below 2 when the combustion works in scram-mode, while the value of P
𝑖/P
0 is over 2 when it is in ram-mode.
Rocket Recovery Carbin Section Passive location based on whale optimization algorithm
Authors: Lu Chao , Wang pei , Dong Zhiyuan , Ye Zhihui
Published: November 2022

The accurate location of the rocket recovery cabin section is one of the key technologies to realize the reliable recovery rockets. Based on the multi-station time difference of arrival (TDOA) passive location principle, a technical solution for the recovery and positioning of the rocket recovery cabin section is designed. Through the active radiation signal of the recovery cabin, the whale optimization algorithm (WOA) is used to locate the position of the rocket recovery cabin section. The recovery process trajectory of the rocket's stage 1 cabin was adopted to verify the feasibility of the designed recovery positioning technical scheme.
Catastrophe conditions for vector fields in
Rn
Authors: Jeffrey Mike R
Published: November 2022

Practical conditions are given here for finding and classifying high codimension intersection points of n hypersurfaces in n dimensions. By interpreting those hypersurfaces as the nullclines of a vector field in

R

n

, we broaden the concept of Thom’s catastrophes to find bifurcation points of (non-gradient) vector fields of any dimension. We introduce a family of determinants

, such that a codimension r bifurcation point is found by solving the system

, subject to certain non-degeneracy conditions. The determinants

generalize the derivatives

∂
j

∂

x
j

F
(
x
)

that vanish at a catastrophe of a scalar function F(x). We do not extend catastrophe theory or singularity theory themselves, but provide a means to apply them more readily to the multi-dimensional dynamical models that appear, for example, in the study of various engineered or living systems. For illustration we apply our conditions to locate butterfly and star catastrophes in a second order partial differential equation.
Different routes to the classical limit of backflow
Authors: Mousavi S V , Miret-Artés S
Published: November 2022

Decoherence is a well established process for the emergence of classical mechanics in open quantum systems. However, it can have two different origins or mechanisms depending on the dynamics one is considering, speaking then about intrinsic decoherence for isolated systems and environmental decoherence due to dissipation/fluctuations for open systems. This second mechanism can not be considered for backflow since no thermal fluctuation terms can be added in the formalism in order to keep an important requirement for the occurrence of this effect: only contributions of positive momenta along time should be maintained. The purpose of this work is to analyze the backflow effect in the light of the underlying intrinsic decoherence and the dissipative dynamics. For this goal, we first deal with the Milburn approach where a mean frequency of the unitary evolution steps undergone for the system is assumed. A comparative analysis is carried out in terms of the Lindblad master equation. Second, the so-called quantum-to-classical transition wave equation is analyzed from a linear scaled Schrödinger equation which is derived and expressed in terms of a continuous parameter covering from the quantum to the classical regime as well as all in-between dynamical non-classical regimes. This theoretical analysis is inspired by the Wentzel–Kramers–Brillouin approximation. And third, in order to complete our analysis, the transition wave equation formalism is also applied to dissipative backflow within the Caldirola–Kanai approach where the dissipative dynamics comes from an effective Hamiltonian. In all the cases treated here, backflow is gradually suppressed as the intrinsic decoherence process is developing, paying a special attention to the classical limit. The route to classicality is not unique.
Contextuality degree of quadrics in multi-qubit symplectic polar spaces
Authors: de Boutray Henri , Holweck Frédéric , Giorgetti Alain , Masson Pierre-Alain , Saniga Metod
Published: November 2022

Quantum contextuality takes an important place amongst the concepts of quantum computing that bring an advantage over its classical counterpart. For a large class of contextuality proofs, aka. observable-based proofs of the Kochen-Specker Theorem, we formulate the contextuality property as the absence of solutions to a linear system and define for a contextual configuration its degree of contextuality. Then we explain why subgeometries of binary symplectic polar spaces are candidates for contextuality proofs. We report the results of a software that generates these subgeometries, decides their contextuality and computes their contextuality degree for some small symplectic polar spaces. We show that quadrics in the symplectic polar space W

n
are contextual for

n
=
3
,
4
,
5

. The proofs we consider involve more contexts and observables than the smallest known proofs. This intermediate size property of those proofs is interesting for experimental tests, but could also be interesting in quantum game theory.
Environmental management system: The internal and external impact of ISO 14001 implementation on the manufacturing companies
Authors: Widiatami A K , Pitaloka L K , Nurkhin A
Published: November 2022

The activities of manufacturing companies are closely related to the environmental damage that occurs. It gives an imprint on the environmental damage from the production process until the community consumes the product . However, many manufacturing companies have tried to reduce the damage to nature by implementing an environmental management system. Being certified to ISO 14001 is the actual action of a manufacturing company in implementing an environmental management system. This study explores the impact of implementing an environmental management system that is ISO 14001 certified to the company internally and externally. Using a purposive sampling technique to the manufacturing companies listed on the IDX from 2017 - to 2020, 327 manufacturing companies were obtained as a sample of this study. The results of hypothesis testing using Panel Data Regression shows that the environmental management system has a significant positive effect on manufacturing cost, raw material cost, the number of outstanding shares, market value-added, and sales growth. Furthermore, an environmental management system is proven to significantly impact the company because it increases the number of outstanding shares, provides company value, and increases the company’s sales growth.
Application of Hazard and Operability Study Methods (HAZOP) to asses and control hazard risk in spinning department using at textile industrial
Authors: Susanto Novie , Azzahra Faradhina , Putra Alldo Haswandana
Published: November 2022

PT. XYZ is a textile industry company located in Sukoharjo, Central Java. PT. XYZ produces 4 products, namely, yarn, greige, dyed and printed fabric, uniform and apparel. Based on initial observations, sources of danger were identified with a low hazard percentage of 11.7%, medium danger of 29.4%, high danger of 47.05%, and extreme danger of 11.7%. In effort to minimize workplace accidents, work accident analysis can be carried out using the Hazard and Operability Study (HAZOP) method through ranking priorities. The study results found 17 hazards in the spinning division and can be categorized into four hazard classes. From the results of the risk level assessment, there are two hazard sources classified as extreme, eight hazard sources classified as high, five hazard sources classified as moderate risk, and two hazard sources classified as low risk. This study provides recommendations based on control hierarchy with examples of inspection form, signs or posters regarding the use and need for PPE, supervision (punishment system and reward), prohibition of entering the work area without wearing PPE or work cards, and engineering controls.
Environmental impact assessment Approach to Dynamic Safety Evaluation : A Liquefied Natural Gas Plant Case Study
Authors: Bouafia Abderraouf , Bougofa Mohammed , Zeroauli Bilal , Kharzi Rabeh , Chakhrit Ammar , Baziz Amin , Aberkane Salah , Medjram Mohamed Salah , Mebarki Ahmed
Published: November 2022

Industrial discharges pose global ecological risks. This study investigates Algeria’s GL1K (gas liquification complex of Skikda) plant’s hazardous effluents. The impact assessment evaluates the environmental repercussions of the researched facilities, including the effects on populations and their way of life. Thus, it is possible to stress suggestions to improve facility design to remove or restrict negative effects and to minimize or compensate for the current facility’s unfavorable repercussions. This technique is consistent with establishing and monitoring the industrial plant’s environmental management system. The method utilized to determine impacts in this EIA can be used to evaluate the EMS’s significant aspects and effects and provide improvement options. An evaluation matrix can rate impacts, the grid and criteria are based not regulation but on “good practices” for this type of assessment, and results obtained from modelling the effects using PHAST software. Therefore, they can be modified to fit the facility’s activity. Based on examining activities and identifying elements likely to interact with the environment, environmental aspects are identified using the proposed grid and criteria. This study describes a section-by-section approach. Each determined environmental impact can be graded based on environmental factor criteria.
A Time-Series Analysis on the Covid-19 Mortality, PM2.5 Levels, and Weather Variables in Denpasar City, Indonesia
Authors: Suhendarto Amari Dihaning , Dhokhikah Yeny , Rohman Abdur
Published: November 2022

The objective of this study is to explore the relationship between Covid-19 mortality cases and environmental variables, namely PM2.5 concentration and weather variables, in Denpasar City, Indonesia. Regression models were used. The response variable was the monthly Covid-19 mortality from March 2020 to December 2021 and the predictor variables were the mean concentration of PM2.5, temperature, wind speed, rainfall and duration of sunshine. All data analyzed were provided by the Indonesian Government. Simple linear regression (SLR) and dynamic regression with ARIMA error models were used. Further, of the 22 monthly data, the first 19 months data were used to train the models and the remaining data were used as the test data. It is found that both wind speed and the interaction between PM2.5 concentration and wind speed have statistically significant relationships with Covid-19 mortality. The estimates of SLR and ARIMA (0,1,1) with interaction models show that on average, in case of 0.5 m/s wind speed, an increase of 1 𝜇g/m3 in the monthly mean of daily PM2.5 concentrations associates with 17.4 and 16.3 increase in the monthly Covid-19 mortality case, respectively. Although this study is observational, its findings suggest the importance of controlling PM2.5 concentration.
Utilization of green mussel shell waste for calcium carbonate synthesis through the carbonation method with temperature variation
Authors: Prihanto A , Muryanto S , Ismail R , Jamari J , Bayuseno AP
Published: November 2022

In this study, PCC (precipitate calcium carbonate) was synthesized from green mussel shell waste via calcination and subsequent carbonation methods. Organic substances were removed from green mussel shell powder using a 5-hour calcination at 900 °C. Furthermore, the carbonation method was used in the Ca (NO3)2 solution at constant stirring speed with pH control by NH4OH, followed by the injection of carbon dioxide at 50, 70, and 90 °C temperature variations to precipitate calcium as CaCO3 (PCC). According to Rietveld’s quantitative XRD analysis, PCC products at 50 °C, 70 °C, and 90 °C exhibited primarily calcite and aragonite phases, with a significant needle-like morphology of aragonite growth during synthesis. Aragonite growth appears to have increased with increasing temperature. The results show that a simple, low-cost approach to green recycling works.
Increasing The Efficiency of Bone Charcoal in Water Defluoridation Using Eggshell Powder and Dry Banana Peel Medium (DBPM)
Authors: Gathere P W , Sudarno  , Sarminingsih A
Published: November 2022

The world health organization (WHO) has set an upper limit of 1.5 mg/l fluoride concentration in water meant for human consumption. Ground water has high fluoride level which exceeds the value recommended by the WHO. Defluoridation is the only viable way of dealing with the issue of high fluoride levels in water. The most common defluoridation method is the use of bone charcoal. This research shows how adding dry banana peel medium (DBPM) and egg shell powder to bone charcoal increases its defluoridation capacity as well as the water defluoridation rate. Raw water samples were collected from different boreholes and their initial fluoride concentration measured. The groundwater was then subjected to different adsorbent combinations of bone charcoal, eggshell powder and DBPM and the rate of fluoride removal as well as the final concentration of fluoride in the water after two hours, were determined. Eggshell powder and DBPM were found to increase the fluoride removal capacity of bone charcoal by more than 20%. The highest fluoride removal was achieved when bone charcoal was combined compositely with eggshell powder and DBPM. Hence the addition of eggshell powder and DBPM was found to increase the defluoridation rate as well as the fluoride removal capacity of bone charcoal.
Producing Fe and Cu ions and oxides in water with electrolysis as artificial liquid waste
Authors: Wahyono Y , Irviandi R , Lo N K , Rahman M I A , Herdiansyah F , Haliza B T , Nurauliyaa A H , Baihaqi R A , Prabahandari K A , Hariyono Y , Pratiwi N I
Published: November 2022

Water - in the context of an inland water source - is complex when used as an object of research. Often when using river water samples, researchers struggle to find the desired composition. Therefore, a simple and controlled method is needed to produce test samples with specific substance compositions. This study aims to use electrolysis to produce artificial heavy metal waste. Iron (Fe) and copper (Cu) provided the electrodes and water the electrolytes. Electrolysis of water with Fe electrodes produced Fe3+ ions and Fe(OH)3 precipitation. Electrolysis of water with Cu electrodes produced Cu2+ ions and Cu(OH)2 precipitation. Electrolyte samples were collected at intervals of 30 min for 180 min and were tested with atomic absorption spectroscopy. Fe and Cu concentrations increased during electrolysis. Electrolysis can therefore be used to produce artificial heavy metal waste cheaply and on a small scale.
Does water accounting support sustainable water management? A review
Authors: Mahmud A , Susilowati N , Susanti A , Sari P N
Published: November 2022

The business risks experienced by clean water companies include losses and decreased loyalty of water users. This risk occurs due to the absence of accountability, reliability, and transparency in sustainable clean water management. It can be overcome by implementing water accounting. This narrative review explains a sustainable water management model using a water accounting approach. The narrative review method consists of compilation, tabulation, comparison of research results, and summarizing. The literature review study collected articles from accredited journal sites (Sinta, Emerald, Science Direct). After searching for research keywords criteria, 29 articles were taken as samples. The results show that water accounting, in addition to reducing business risk for clean water service providers, also supports sustainable water management. Water accounting components such as gross inflow, net inflow, available water, water depletion, and outflow provide transparent and accountable information. The components of water accounting can analyze water use, scarcity, and productivity to predict the need for clean water because the amount of water discharge produced and used in one day can be known with certainty. Management and community commitment are needed to realize sustainable groundwater use conservation to ensure that the community enjoys the long-term supply of clean water.
Adsorption of Oil and Grease in Wastewater using Activated Carbon Derived from Sewage Sludge
Authors: Anifah Eka Masrifatus , Ariani Ismi Khairunnissa , Hayati Rina Noor , Nugraha Satria Arya
Published: November 2022

Oil and grease are organic contaminants that are detrimental to the environment. The high concentration of oil and grease can cause clogging in the sewer. Clogged sewers can deteriorate sanitary conditions. Adsorption is one technique to reduce oil and grease concentration in wastewater. Adsorption using natural resources can overcome the high cost of commercial activated carbon. Sewage sludge has potential as raw material for activated carbon because of the high carbon content. The studies aim to investigate the capability of activated carbon derived from sewage sludge to remove oil and grease from restaurant wastewater. The studies were carried out in the batch experiment. Adsorbent dosage ranged from 2-6 g/L, and a contact time range of 5-45 minutes was performed in the experiment. Sewage sludge was chemically activated using KOH 4M and physically activated at a temperature of 700°C for 60 minutes. The result shows that the optimum adsorbent dosage and contact time are 4 g/L and 25 minutes, respectively. The highest adsorption capacity of sewage sludge to remove oil and grease was 63.75 mg/g. Under observed data, the adsorption fit the second-pseudo-order, and Langmuir isotherm indicated that the adsorption process was chemisorption.
Investigation of time impact on electrocoagulation process to treat ablution wastewater
Authors: Mudofir Mudofir , Taufik Moh. , Rusdan Ilzamha Hadijah , Silviani Wahyu Dian , Purwono Purwono
Published: November 2022

The ablution ritual performed by Muslims before praying requires large amounts of clean water (3.9 L - 4.42 L/person). This is a challenge that needs to be addressed, as in some places, water is a scarce commodity. This study aims to treat ablution wastewater at Masjid Al-Bukhari UIN Raden Mas Said Surakarta using electrocoagulation. The treated water is expected to be reused for ablution rituals in the mosque. Laboratory-scale research methods were performed to treat ablution wastewater. The effect of electrolysis time was evaluated to determine efficiency of the method on the parameters of pH, temperature, total dissolved solid (TDS), conductivity, and ammonia level. Interestingly, ablution wastewater treated using electrocoagulation meets clean water quality standards. This means that the water is safe to reuse for ablution activities in mosques. The electrolysis time has a significant effect on the increase of pH value and the decrease of ammonia level. TDS levels decreased to 65.3% when treated for 40 min. Meanwhile, the conductivity value decreased to 526 µS/cm from the initial value of 1108 µS/cm when the water was treated for 60 min. Statistically, electrolysis time has a significant effect on the decrease of TDS, conductivity, and ammonia levels (α<0.05).
Developing a Visual Counting Method to Quantify Riverine Plastic Litter: A Case Study of Rivers in Semarang City, Indonesia
Authors: Sarminingsih A , Andarani P , Nugraha W D
Published: November 2022

Indonesia has established a national action plan on marine plastic debris to tackle the issue of marine plastic debris. Because most of the marine plastic debris in Indonesia is likely due to mismanaged plastic waste, it is important to address the problem of riverine plastic river problem in Indonesia. The objectives of this study are to visually observe the condition of the river in terms of plastic pollution, to quantify plastic litter in the river, and to develop a visual counting model of plastic litter quantification. The visual counting of plastic debris (> 2.5 cm) method based on the European standard method was applied to a river in Indonesia. The main challenge was the high turbidity of the water that obstructed visual observation. The deployment of the fishing net was also not appropriate to collect debris. Most of the plastic debris was stranded on the riverbanks, indicating that the plastic flow was likely elevated due to runoff during the rainy season. Four types of plastic litter polymers were obtained, i.e., polyethylene terephthalate (PET), low-density polyethylene (LDPE), polypropylene (PP), and polystyrene (PS). The highest percentage of macroplastics is LDPE, which usually used as daily packaging (90%).
Potential Carbon Storage In The Forest Area Of Mount Merbabu National Park (MMbNP) Resort Selo Central Java
Authors: Kusumaningrum Lia , Izdihar Rinoa Salsabila
Published: November 2022

Forests play a very large function in the solution of climate problems. Trees are capable of absorbing carbon dioxide (CO2) in the photosynthesis process and store it in the form of biomass, thereby reducing the concentration of carbon in the atmosphere. The forest area of Mount Merbabu National Park (MMbNP) has great potential to absorb carbon emissions and mitigate climate. The purpose of this study was to determine the potential for carbon storage in MMbNP. The research method used is quantitative descriptive and analyzed by allometric method adapted to tree species at low, medium, and high densities. The estimated carbon storage refers to the Indonesian National Standard (SNI) 7724 of 2011. The potential for total carbon storage in the forest area is 129.357,71 tons. In detail, the total carbon storage in low density land cover types is 10.201,87 tons, medium density is 23.729.66 tons, and high density is 95.426,18 tons. This type of land cover with high density has the highest carbon absorption capacity; this is relevant to the presence of the number of trees that are able to absorb more carbon and have a larger area than other types of land cover.
The Effect of Mewis Duct Energy Saving Device to Propeller Performance
Authors: Trimulyono A , Mulyatno I P , Rachmat A F
Published: November 2022

Installation of ESD (Energy Saving Device) can improve ship propulsion performance. Mewis Duct is one type of ESD (Energy Saving Device) multi-component device that combines nozzle and fin into the nozzle. The structure can minimize losses due to small losses at the ship's stern and rotational losses or loss of thrust in the slipstreams area. Mewis Duct can reduce power by about 3-8% and increase thrust on the propeller by about 2-5%. This study aims to improve the performance of the INSEAN e779a propeller type using Mewis Duct. The modified Mewis ducts are the number of fins four, five, six asymmetrical and four symmetrical fins using the computational fluid dynamics (CFD) approach. The CFD code is based on the RANS (Reynolds - Averaged Navier Stokes) equation with the turbulent model is k-ε. This study found that installing Mewis duct as ESD in a ship increased the propeller thrust by 3-5% and the torque by 3-4%.