bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

Abstract
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

Abstract
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

Abstract
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

AbstractDecoherence 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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.
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

AbstractThe 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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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%.
Does higher income lead to more renewable energy consumption? evidence from Indonesia
Authors: Setyadharma A , Prasetyo P E , Oktavilia S , Fortuna B D , Wahyuningrum I F S 
Published: November 2022

Abstract
Indonesia is aimed to reach the use of renewable energy by up to 23 percent by 2025. Increasing society’s income is considered as one of the effective ways to encourage society to shift to renewable energy consumption. Therefore, the aim of this study was to investigate the impact of income on renewable energy consumption in Indonesia. This study employed Engle Granger Error Correction Model and used hydroelectricity consumption as the proxy of the renewable energy consumption and real gross domestic product (GDP) per capita as the proxy of the income. The result of this study suggested that hydroelectricity consumption can be written as a quadratic function of real GDP per capita. It means that at the beginning, increasing real GDP per capita reduced the hydroelectricity consumption, and at a certain level it turns to opposite direction, where the rise of the real GDP per capita increased hydroelectricity consumption. In conclusion, higher income leads to higher renewable energy consumption. The policy implication for policymakers is straightforward, i.e., it is important to increase the income of the society, not only for the sake of the wealth of the society, but also for the protection of the environment through more clean energy consumption.