bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling Carbon Emissions of Post-Selective Logging in the Production Forests of Ulu Jelai, Pahang, Malaysia
Authors: Saad Siti Nor Maizah , Wan Mohd Jaafar Wan Shafrina , Omar Hamdan , Abdul Maulud Khairul Nizam , Muhmad Kamarulzaman Aisyah Marliza , Adrah Esmaeel , Mohd Ghazali Norzalyta , Mohan Midhun
Published: February 2023

Harvested timber and constructed infrastructure over the logging area leave massive damage that contributes to the emission of anthropogenic gases into the atmosphere. Carbon emissions from tropical deforestation and forest degradation are the second largest source of anthropogenic emissions of greenhouse gases. Even though the emissions vary from region to region, a significant amount of carbon emissions comes mostly from timber harvesting, which is tightly linked to the selective logging intensity. This study intended to utilize a remote sensing approach to quantify carbon emissions from selective logging activities in Ulu Jelai Forest Reserve, Pahang, Malaysia. To quantify the emissions, the relevant variables from the logging’s impact were identified as a predictor in the model development and were listed as stump height, stump diameter, cross-sectional area, timber volume, logging gaps, road, skid trails, and incidental damage resulting from the logging process. The predictive performance of linear regression and machine learning models, namely support vector machine (SVM), random forest, and K-nearest neighbor, were examined to assess the carbon emission from this degraded forest. To test the different methods, a combination of ground inventory plots, unmanned aerial vehicles (UAV), and satellite imagery were analyzed, and the performance in terms of root mean square error (RMSE), bias, and coefficient of correlation (R2) were calculated. Among the four models tested, the machine learning model SVM provided the best accuracy with an RMSE of 21.10% and a bias of 0.23% with an adjusted R2 of 0.80. Meanwhile, the linear model performed second with an RMSE of 22.14%, a bias of 0.72%, and an adjusted R2 of 0.75. This study demonstrates the efficacy of remotely sensed data to facilitate the conventional methods of quantifying carbon emissions from selective logging and promoting advanced assessments that are more effective, especially in massive logging areas and various forest conditions. Findings from this research will be useful in assisting the relevant authorities in optimizing logging practices to sustain forest carbon sequestration for climate change mitigation.
The Impact of Infrastructure Development on China–ASEAN Trade-Evidence from ASEAN
Authors: Shen Chen
Published: February 2023

From the formal dialogue between China and ASEAN in 1991 to the establishment of the China–ASEAN FTA in 2010, the economic and trade relations between China and ASEAN countries have developed rapidly. With the continuous development of economic and trade relations, the infrastructural level between China and ASEAN has far lagged behind the needs of exchanges and trade. How to promote the development of bilateral trade through infrastructure construction and interconnection has become a concern of governments of all countries. In the context of China’s “Belt and Road” Initiative and the “Master Plan for ASEAN Connectivity”, new ideas and opportunities are provided for ASEAN infrastructure construction and its interconnection with China. Based on panel data from 2004 to 2020, this paper analyzes the impact of ASEAN infrastructure on the China–ASEAN trade volume. The analysis finds that road, port, shipping and communication infrastructure positively impact the bilateral trade volume, among which ports exert the greatest impact on the bilateral trade volume and roads have the least impact. For a more in-depth study, the transportation infrastructures of land and island countries are compared and analyzed separately. The impact of road infrastructure on trade is significant for land countries, while the impact of port infrastructure on trade is more remarkable for island countries. Finally, measures and suggestions on how to promote the development of bilateral trade are proposed on the basis of the above analysis.
Smart Agriculture and Rural Revitalization and Development Based on the Internet of Things under the Background of Big Data
Authors: Ma Xi
Published: February 2023

Smart agriculture refers to the specific performance of the smart economy in the field of agriculture; it is a form of agricultural smart economy and an important part of the smart economy. It has played a certain role in promoting rural revitalization and development. The purpose of this paper was to study the role of smart agriculture based on the Internet of Things in rural revitalization and development under the background of big data. The purpose was to use Internet of Things technology to realize smart agriculture under the background of big data, so as to promote rapid rural revitalization and development. Therefore, in this paper, a fuzzy PID algorithm and genetic algorithm were proposed. Finally, through experimental analysis, the fuzzy PID algorithm was used to carry out experiments in the laboratory. The temperature and humidity of the laboratory were measured. The average difference between the collected and actual temperature values was 0.6 °C, and the maximum difference between the collected and actual humidity values was 1.32% RH. The laboratory simulation results satisfied the performance indicators and technical requirements of the system. The system operated normally and could be directly applied to field tests. The experimental results show that the role of Internet of Things technology in the smart agricultural economy is irreplaceable, which further illustrates the positive relationship between smart agriculture based on the Internet of Things and rural revitalization and development. As one of the most mature technologies in today’s society, the Internet of Things technology combined with smart agriculture not only offers new perspectives, but also promotes the revitalization and development of rural areas, indicating a new direction for its future research.
Development and Constitutive Model of Fluid–Solid Coupling Similar Materials
Authors: Li Baiping , Cheng Yunhai , Li Fenghui
Published: February 2023

The Cretaceous Zhidan group (K1zh) pore fissure-confined water aquifer in Yingpanhao Coal Mine, Ordos City, China, has loose stratum structure, high porosity, strong permeability and water conductivity. In order to explore the fluid–solid coupling similar material and its constitutive model suitable for the aquifer, a kind of fluid–solid coupling similar material with low strength, strong permeability and no disintegration in water was developed by using 5~20 mm stone as aggregate and P.O32.5 Portland cement as binder. The controllable range of uniaxial compressive strength is 0.394~0.528 MPa, and the controllable range of elastic modulus is 342.22~400.24 MPa. The stress–strain curve and elastic modulus of similar materials are analyzed. It is found that the elastic modulus of similar materials with different water–cement ratios conforms to the linear law, the elastic modulus of similar materials with the same water–cement ratio after soaking treatment and without soaking treatment also conforms to the linear law. Based on the material failure obeying the maximum principal stress criterion and Weibull distribution, combined with the elastic modulus fitting formula, a constitutive model suitable for the fluid–solid coupling similar material was established, and the parameters of the constitutive model were determined by differential method. By comparing the theoretical stress–strain curve with the experimental curve, it is found that the constitutive model can better describe and characterize the fluid–solid coupling similar materials with different water–cement ratios and before and after soaking.
Differentiation of Rare Earth Elements in Coal Combustion Products from the Handan Power Plant, Hebei Province, China
Authors: Hu Yafan , Ma Juanjuan , Wang Jinxi , Niu Hongya , Yang Zhen , Hao Huidi , Panchal Balaji
Published: February 2023

As a potential source of REY (rare earth elements and yttrium), coal and its products have attracted much attention. In this paper, we aimed to study the enrichment and differentiation of rare earth elements in fly ash with different particle sizes and promote the full recovery and utilization of rare earth elements in fly ash. Our objective was to focus on the REY concentration in feed coal and its combustion products from the Handan Power Plant. We particularly focused on the distribution of REY in relation to different particle sizes, as well as on the state of occurrence (affinity), by applying stepwise chemical extraction and performing examinations using inductively coupled plasma mass spectrometry (ICP-MS), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The results show that the REY content is affected by the mineral composition of coal ash, and REY is more easily enriched in slag and fine ash than coarse ash. In general, the REY content decreased with the decrease in particle size in coarse ash, whereas the REY content increased with the decrease in particle size in fine ash. It was found that the concentration distribution of REY in solid combustion products is as follows: light REY (LREY) > medium REY (MREY) > heavy REY (HREY). This indicates that the enrichment of REY in solid coal products decreases with the increase in atomic number. The results also show that the occurrence state of REY in raw coal and coal ash undergoes no obvious change (residue state > organic/sulfide-bound state > iron–manganese-oxide-bound state > carbonate-bound state > exchangeable state).
Quantifying Shape Variation in an Antisymmetrical Trait in the Tropical Fish Xenophallus umbratilis
Authors: Nielsen Mary-Elise , Johnson Jerald B.
Published: February 2023

Antisymmetry is a striking, yet puzzling form of biological asymmetry. The livebearing fish Xenophallus umbratilis exhibits antisymmetry in the male intromittent organ and provides a system that is well-suited for studying the nature of variation in antisymmetrical traits. Using geometric morphometrics, we test the hypothesis that because the gonopodium is critical to fitness there will not be significant differences in gonopodium shape between the two gonopodial morphs in this species. Our results are consistent with this prediction, though we found that gonopodium shape differed with gonopodium size.
Antimicrobial Compounds from Skin Secretions of Species That Belong to the Bufonidae Family
Authors: Ibarra-Vega Rodrigo , Galván-Hernández Alan Roberto , Salazar-Monge Hermenegildo , Zataraín-Palacios Rocio , García-Villalvazo Patricia Elizabeth , Zavalza-Galvez Diana Itzel , Valdez-Velazquez Laura Leticia , Jiménez-Vargas Juana María
Published: February 2023

Skin secretions of toads are a complex mixture of molecules. The substances secreted comprise more than 80 different compounds that show diverse pharmacological activities. The compounds secreted through skin pores and parotid glands are of particular interest because they help toads to endure in habitats full of pathogenic microbes, i.e., bacteria, fungi, viruses, and protozoa, due to their content of components such as bufadienolides, alkaloids, and antimicrobial peptides. We carried out an extensive literature review of relevant articles published until November 2022 in ACS Publications, Google Scholar, PubMed, and ScienceDirect. It was centered on research addressing the biological characterization of the compounds identified in the species of genera Atelopus, Bufo, Duttaphrynus, Melanophryniscus, Peltopryne, Phrynoidis, Rhaebo, and Rhinella, with antibacterial, antifungal, antiviral, and antiparasitic activities; as well as studies performed with analogous compounds and skin secretions of toads that also showed these activities. This review shows that the compounds in the secretions of toads could be candidates for new drugs to treat infectious diseases or be used to develop new molecules with better properties from existing ones. Some compounds in this review showed activity against microorganisms of medical interest such as Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Coronavirus varieties, HIV, Trypanosoma cruzi, Leishmania chagasi, Plasmodium falciparum, and against different kinds of fungi that affect plants of economic interest.
The Relationship between Pain and Spasticity and Tell-Tale Signs of Pain in Children with Cerebral Palsy
Authors: Wong Christian
Published: February 2023

Pain and quality of life are closely interrelated in children with cerebral palsy (CCP). Even though 67% of CCP experience pain, it is overlooked and untreated. In this study, our purpose was two-fold: first, to examine the relationship between pain and spasticity by evaluating the effects of AbobotulinumtoxinA/Dysport (BoNT), and second, to describe the symptoms and location of pain in CCP. The subjects were 22 CCP in at least moderate pain. They were evaluated for spasticity by the modified Ashworth and Tardieu scale and for pain by the r-FLACC and the pediatric pain profile. After one injection of BoNT, the subjects were re-evaluated. We found a significant reduction in pain, but no significant relationship between the reduction of pain and spasticity. We found no association between the dose of BoNT and pain or spasticity. Pain in the lower extremity was located primarily in the hip region. The effect of ultrasound-guided intermuscular injections of BoNT suggests that pain in CCP has an extra-articular component. We found that pain in CCP manifests as specific tell-tale signs and problems in daily living. In conclusion, we found no relationship between pain and spasticity. Signs and manifestations of pain are described in detail. Lower extremity (hip) pain seems to have a soft tissue/extra-articular component.
Damping Scenarios of Kink Oscillations of Solar Coronal Loops
Authors: Nakariakov Valery M. , Yelagandula Naga V.
Published: February 2023

The transition from the large-amplitude rapidly-decaying regime of kink oscillations of plasma loops observed in the corona of the Sun to the low-amplitude decayless oscillations is modelled. In this study, the decayless regime is associated with the energy supply from coronal plasma flows, i.e., self-oscillations, or random movements of footpoints of the oscillating loop. The damping is attributed to the linear effect of resonant absorption. We demonstrate that the decay of an impulsively excited kink oscillation to the self-oscillatory stationary amplitude differs from the exponential decay. The damping time is found to depend on the oscillation amplitude to the power of a negative constant whose magnitude is less than unity. In this scenario, a better model for the damping seems to be super-exponential. In the separately considered case of the decayless oscillatory regime supported by a random driver, the oscillation amplitude experiences an exponential decay to the decayless level. Implications of this finding for magnetohydrodynamic seismology of the solar corona based on the effect of resonant absorption are discussed.
A Highly Conserved Region in BRCA2 Suppresses the RAD51-Interaction Activity of BRC Repeats
Authors: Zhu Zida , Kitano Taisuke , Morimatsu Masami , Ochiai Kazuhiko , Ishiguro-Oonuma Toshina , Oosumi Kosuke , Lin Xianghui , Orino Koichi , Yoshikawa Yasunaga
Published: February 2023

Mammary tumors are the most prevalent type of tumors in female dogs. Breast cancer 2, early onset (BRCA2) malignant mutations are associated with tumorigenesis in humans and dogs. BRCA2 plays a pivotal role in homologous recombination repair by recruiting RAD51 recombinase to DNA damage sites to maintain genome stability. To recruit RAD51, BRCA2 must interact with RAD51 via BRC repeats, but the regulation of this interaction has been unclear. In this study, we focused on a highly conserved region (HCR) near BRC repeats. Using co-immunoprecipitation and mammalian two-hybrid assay, we found that HCR suppressed the RAD51-interaction activity of BRC repeats and that substitutions of HCR phosphorylation sites affected it. In canine tumor samples, we found ten mutations, including a novel HCR mutation (I1110M) from canine tumor samples. The effect of four HCR mutations, including I1110M, on the RAD51-interaction activity of BRC repeats was tested. One of the HCR mutations found in canine mammary tumors increased the interaction, but the two mutations found in human breast cancers decreased it. This study suggested that the HCR regulated the RAD51-interacting activity of BRC repeats through HCR phosphorylation and that mutations in HCR may be related to tumorigenesis in both dogs and humans.
Herd Health Troubles Potentially Related to Aluminium Grass Silage Content in Dairy Cows
Authors: Eppe Justine , Djebala Salem , Rollin Frédéric , Guyot Hugues
Published: February 2023

In ruminants, the main documented clinical manifestation of aluminium (Al) intoxication is similar to grass tetany. In a 50 dairy cow Belgian herd, the farmer reported excessive uterine bleeding at calving and decreased milk production. Dairy cows received a mixed ration (MR) with high Al concentration (453 ppm/kg of dry matter (DM)). Various analyses were sampled from 10 sick cows and compared with 10 healthy cows (from another herd). Sick cows presented anaemia and marginal hypozincaemia and 6/10 showed subclinical ketosis. Their urine analysis revealed hypomagnesaemia and a high Al/creatinine ratio. It was advised to determine soil pH, add salts to the ration to chelate the Al and support cows with mineral supplements and propylene glycol. A visit was carried out 2 years later and highlighted an improvement in the situation, but all examined animals presented subclinical ketosis. Grass silage Al content remained high (700 ppm/kg DM), as did butyric acid concentration (11.22 g/kg DM). Al could be incriminated at different stages: micronutrient deficiencies, anaemia and negative energy balance. However, Al was probably not the only culprit. This case report is a concern for future years in these areas due to droughts, scarcity of forage and an increase in contaminated soil ingestion.
Evaluation of Human Health Risks Associated with Groundwater Contamination and Groundwater Pollution Prediction in a Landfill and Surrounding Area in Kaifeng City, China
Authors: Mao Xiaoming , Zhang Shengyan , Wang Shuhong , Li Tengchao , Hu Shujie , Zhou Xiaoqing
Published: February 2023

Landfill accumulation can cause its leachate to seep into groundwater, which can lower the quality of local groundwater. Exploring the risks of groundwater contamination to human health in the area around a landfill can offer a clear understanding of the current situation of regional groundwater and provide a theoretical basis for groundwater remediation and governance. By taking a landfill in Kaifeng City, China as the research object, this study explored the chemical types and sources of groundwater in the study area, used the entropy-weighted water quality index (EWQI) to evaluate the groundwater quality and assessed human health risks in the study area. The results show that the groundwater in the study area is neutral (7.14 ≤ pH ≤ 7.86), and the water chemical type is HCO3−—Ca·Na. The EWQI results indicated that the overall water quality in the study area ranges from 48.4 to 250.26, which is above the medium level, and that the local water quality is poor. The deterioration of groundwater quality in the study area is mainly influenced by NH4+-N, Mn, As, F− and Pb. According to the human health risk assessment model, the non-carcinogenic risk to humans through oral and dermal exposure can be assessed. In this paper, five ions, NH4+-N, Mn, As, F− and Pb in groundwater, were selected for the analysis of groundwater in the study area to assess non-carcinogenic risk to humans through oral administration. The results showed that the hazard quotient (HQ) values for NH4+-N, Mn, As, F− and Pb varied in the following ranges: 9.14 × 10−4—0.03; 0.07—0.22; 0.02–0.07; 0.16—0.23; and 0.01—0.13, respectively (all of these are less than 1, and so the potential risks to human health can be ignored). The characteristic pollutant Pb was selected as a predictor to study the influence on groundwater quality in eastern fish ponds and farmlands under continuous leakage. The leakage can be detected timeously to reduce the effects downstream by using enhanced monitoring measures.
Efficient Removal of Rhodamine B in Wastewater via Activation of Persulfate by MnO2 with Different Morphologies
Authors: Zhang Xinyi , Gan Xinrui , Cao Shihu , Shang Jiangwei , Cheng Xiuwen
Published: February 2023

In recent years, typical organic pollutants were frequently found in aquatic environments. Among them, synthetic dyes were widely used in many industries, which resulting in a large amount of wastewater contained dyes. Because of the characteristic of complex components, poor biodegradability and high toxicity, this kind of wastewater brought lots of harm to the ecological environment and organism. In this study, three different types of manganese dioxide (MnO2) with the rod-like, needle-like and mixed morphologies respectively were successfully fabricated by hydrothermal method with changing the preparation conditions and addition of the metal ions, and utilized as activator of persulfate (PS) to remove the dyes aqueous. Subsequently, these MnO2 nanocomposite was characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) measurements. In addition, Rhodamine B (Rh B), as a representative substance of xanthene dyes was chosen as the target degradants to researched and compared the efficiency of removal via PS activated by different MnO2. By exploring the influences of different reaction parameters on the result of removal, results indicated that PS activated by the acicular MnO2 (α-MnO2) can remove 97.41% of Rh B over 60 min, with the optimal catalyst/PS ratio of 2:1 (the concentration of the α-MnO2 and PS were 1.2 g/L and 0.6 g/L, respectively), pH value of 3, at the temperature of 20 °C. Meanwhile, the probable degradation mechanism was also proposed. At last, as the catalyst was reused for four times, the degradation rate of target degradants decreased less than 10%.
A Non-Intrusive Load Monitoring Model for Electric Vehicles Based on Multi-Kernel Conventional Neural Network
Authors: Yin Yanhe , Xu Baojun , Zhong Yi , Bao Tao , Wang Pengyu
Published: February 2023

With the widespread use of electric vehicles (EVs), the charging behavior of these resources has brought a large amount of load growth to the grid, leading to a series of problems such as increased peak valley load difference and line flow violation. Non-intrusive load monitoring (NILM) is a key technology that can be employed to monitor the multi-source load data information in the power grid and support the high-proportion access of electric vehicles. However, traditional NILM approaches are designed to identify the operation of household appliances and cannot be applied at the substation level directly due to frequent and intricate switching events of electrical equipment at this stage. In this paper, a NILM algorithm that can be applied for the monitoring of the charging behavior of electric vehicles at the substation level is proposed to support the high-proportion injection of distributed energy resources. The proposed approach employs a deep learning framework and a multi-kernel convolutional neural network (multi-kernel CNN) framework is used. The performance of the proposed method is verified on the self-organized datasets based on Pecan Street data and results showed that the obtained f1 score is over 90% for both the training sets and testing sets.
Queer Young People and Couchsurfing: Entry Pathways, Service Provision, and Maintenance Strategies
Authors: Hail-Jares Katie
Published: February 2023

Previous research into queer or LGBTQ+ youth homelessness has relied upon samples recruited from shelters or the streets; such strategies might miss the experiences of young people who are couchsurfing. Couchsurfing is a growing form of homelessness in many countries, including Australia. Here, drawing upon interviews with 31 young queer people, aged 16–27, who are or have recently couchsurfed, we map out their entry into homelessness, their previous use of social services, and their strategies for maintaining accommodation while couchsurfing. Respondents typically entered homelessness following a complex array of factors including deteriorating mental health, escalating family alienation, and stigmatisation following coming out. Once couchsurfing, most young people did not access services as they did not view themselves as homeless. Those who did were often told they were less of a priority given their roofed status. Finally, interviewees reported trading chores, rent, or sex to maintain housing. The difference between sex work and sexual exchange, as explained by young people, is also discussed. We conclude by suggesting a harm-reduction approach to understanding and serving young people.
The three methods of calculating population exposure according to CNOSSOS-EU
Authors: Hartog Van Banda Erwin
Published: February 2023

In December 2020, the EU commission published amendments on CNOSSOS-EU in report 'C(2020) 9101 final'. In this report an additional method for the calculation of population exposure is described, based on a Median value. In the original CNOSSOS document, 2 methods are described, Method
1 - Most exposed façade and Method 2 - Length of representative façade. Method 1 is used for buildings that represent a single dwelling or 1 dwelling per floor. Method 2 is used for apartment buildings that have dwellings with a single façade exposed to noise. The new
Method 3 can be used for apartment buildings that have more than 1 façade exposed to noise, or for apartment buildings where no information on how many facades are exposed to noise is available. It will be difficult for authorities to create a dataset that distinguishes between a single
façade and multiple façades exposed to noise. Therefore, it seems likely that Method 3 will be more frequently used. When comparing Methods 2 and 3, it is found that Method 3 leads to a higher number of exposed people and dwellings. In this paper the 3 methods are explained and
compared using noise and population data for a city in Europe.
Enhancing the noise reduction capability of serrations usinglow-profile vortex generators
Authors: Sundeep Shivam , Zhou Peng , Zheng Chuntai , Jiang Hanbo , Zhong Siyang , Zhang Xin
Published: February 2023

This paper presents an experimental investigation on improving the noise reduction capability of the trailing edge serrations using vortex generators. Experiments were conducted on a 150 mm chord flat plate at four angle of attack between 0° and 9° and flow speeds of 20-50 m/s.
The Reynolds number based on the chord length ranges from 2.1×105 to 5×105. Vane type vortex generators with various heights of h/δ = 0.16-0.25 were placed along with the serration roots, where δ is the boundary layer thickness at the trailing
edge without the vortex generators. The aeroacoustic measurements were made with a phased microphone array, and the aerodynamic measurement near the trailing edge was measured using a hot-wire. Additionally, the lift and drag forces were measured by load cells. The source integrated noise
spectra showed a slight reduction in the trailing edge noise over a broadband frequency range. The generation of streamwise vortices by vortex generators can be identified in the wake measurement. These streamwise vortices were further found to counteract the cross-flow generated at serration
roots, hence improving the performance of the serration. Moreover, the presence of low-profile vortex generators was found to have an insignificant effect on the lift and drag coefficients.
A review of a proposed noise quota system for Dublin Airport
Authors: King Eoin
Published: February 2023

In 2007, the airport authority for Dublin Airport (DAA) was granted planning permission to build a new runway. This permission included several planning conditions, including operating restrictions during the night-time due to noise considerations. The plans were then put on hold due
to the economic downturn, but in 2016, with increasing passenger numbers, the plans were revived. In the intervening years, the planning and legislative environment related to aircraft noise changed in Ireland, particularly with the implementation of Regulation 598/2014 and the establishment
of the Aircraft Noise Competent Authority (ANCA). Then, in December 2020 the DAA submitted a planning application to the Planning Authority seeking to amend those 2007 conditions associated with night-time operating restrictions. The application was referred to ANCA for an assessment of the
associated noise impact, and in November 2021 they issued a draft regulatory decision report. This report proposes a number of mitigation measures for Dublin airport, including the introduction of a noise quota system. This paper reviews the proposed noise quota system.
Impact of railroad switches on rail noise exposure near stations
Authors: Genell Anders , Ögren Mikael , Nyberg Erik , Gustafson Andreas , Jerson Tomas
Published: February 2023

According to Common NOise aSSessment methOdS in EUrope (CNOSSOS-EU) in Annex II of Directive 2002/49/EC, noise from road, rail and airplane traffic, as well as noise from industries, shall be assessed using this common method. For railway noise in Sweden, noise assessment has previously
been done using the Nordic Assesment Method for Train Noise, revised 1996 (NMT96). NMT96 includes a simple correction for rail joints of +3dB and for rail switches of +6dB. CNOSSOS-EU instead introduces a speed dependent correction based on a third octave band wavelength spectrum adding up
to 20dB rolling noise energy in lower frequencies and down to -40 dB in higher frequencies. Measurements recently performed for two different rail switch types along the Swedish rail system indicate that the frequency distribution corresponds well to the CNOSSOS-EU correction for one type
of rail switch but not for the other, and for the overall level difference the opposite is true. In order to investigate to what extent this deviation is affecting noise exposure an inventory of more than 11000 rail switches along the swedish railroad network has been performed to identify
what types are situated in densely populated areas such as railway stations.
Evolutionary optimization processes for acoustic applications where size matters
Authors: Galiana Nieves Jaime , Redondo Javier , Benítez Aragón Daniel , Ramírez-Solana David , Herrero Juan Manuel
Published: February 2023

In acoustics, the relevance of size, scale and shape of the structures involved in a problem often brings complications when it comes to find the best possible solution. Scenarios such as the design of a room or a sound diffuser are some of the problems that we can find in which shape
and size are factors to consider. In recent years, computational optimization methods have been developed to bring a different approach to the solving of these problems. These methods, based on genetic algorithms, provides us with continuous modifications and combinations between the elements
involved in a problem that can help us obtain solutions that would be almost impossible to find with regular analytic solving. Our goal is to develop a multi-objective genetic algorithm to optimize various parameters of a design problem, being one of them related to the physical size of the
element under study. For this purpose, we will not treat the objects being optimized as individuals, but as groups of individuals with the same proportions but variable scale, called "concepts". With this method, we should obtain the optimum proportions for the problem faced, not
only optimized individuals.
Fluid-Structure Interactions and Aeroacoustic coupling of Airfoil with Flexible Membrane(s)
Authors: Arif Muhammad Irsalan , Leung Randolph Chi Kin , Lam Garret , Naseer Muhammad Rehan
Published: February 2023

In this paper, fluid-structure interactions of a NACA 0012 airfoil mounted with short flexible membrane(s) and its coupling effect on airfoil aeroacoustics are presented. A time-domain direct aeroacoustic simulation coupled with structural dynamics is carried out at a low Reynolds number
of 50,000 to explore the aeroacoustic-structural interactions. Two different airfoil configurations based on single and dual membranes are analyzed. The membrane deflections and their impact on the flow field are characterized in wavenumber-frequency domain to analyze the structural dynamics
due to flow unsteadiness within the laminar boundary layer and the resulting acoustic waves emanating from the airfoil trailing edge. A strong correlation between the membrane displacement and downstream propagating flow is observed for all configurations whereas the correlation is considerably
weakened between the membrane displacement and upstream acoustic waves which ultimately results in the airfoil self-noise reduction without affecting the airfoil aerodynamics. The extent of noise reduction for dual membrane airfoil configuration is observed to be considerably higher than the
single membrane airfoil configuration which corresponds to a much lower correlation among the upstream propagating acoustic waves and membrane deflection for both the membranes and redistribution of upstream flow energy into different frequencies.
Can you really put a price on a good night's sleep?
Authors: Zelem Lukáš , Vandenberghe Arnon , Vargová Andrea , Chmelík Vojtech , Rychtáriková Monika
Published: February 2023

This article focuses on estimation of willingness of people to pay extra price for increased sound insulation quality. As a case study a typical 3 room apartment in Bratislava was chosen. Online listening tests were used as a tool to understand the preferred price-quality ratio. The
primary financial value of a case study apartment was estimated on real estate market in the third quarter of 2020. Later, nine (9) different variants of sound insulation of partition walls separating dwellings were considered. These walls were chosen on basis of different construction system
(1) heavy weight brick walls, (1) light-weight gypsum board walls and (2) double walls. Each construction base was divided into three categories of defined by weighed sound transmission index Rw (53 dB, 55 dB and 59 dB). The four types of sounds (pink noise, cough, quarrel, party noise) were
filtered through the frequency spectra R(dB) of chosen walls. These sounds were presented during the online listening test along with a total price for the particular apartment. The test subjects were asked to decide, which apartment they would choose based on an increased acoustic comfort
and increased price of the apartment. In total, 60 subjects performed the test.
Sound generation by entropy waves accelerated by blades
Authors: Guzman-Inigo Juan , Morgans Aimee
Published: February 2023

Entropy noise is the sound produced by the acceleration of convective temperature fluctuations (entropy waves) by non-uniform flows and is a major contributor to indirect combustion noise. Entropy waves are accelerated by nozzles in rocket engines or by the turbine blade rows in the
combustors of gas turbines. While several analytical models have been developed for entropy noise generated by nozzles, not many efficient models exist for the case of blade rows. This is due to the more complex physical mechanisms involved: when entropy waves pass through cascades of blades,
sound is produced due to the acceleration and turning of the entropy waves in the interblade region, but also unsteady forces are created in the blades and vorticity is shed from the trailing edge of the aerofoils. All these mechanisms are strongly coupled and affect the generated entropy
noise. In this work, we explore numerically the importance of these mechanisms. To this end, we present time- and frequency-domain simulations of entropy waves interacting with several canonical aerofoils. Finally, a simple model is presented to estimate the entropy noise generated by each
configuration.
Accelerating knowledge transfer from research to sound aware practice
Authors: Gisladottir Arnthrudur , Maag Trond
Published: February 2023

Sound is a crucial factor for the health of inhabitants in city environments and plays an essential role in people's general well-being and how they perceive spaces within the urban realm. However, sound is seldom an influential parameter within urban development projects unless there
are regulations to fulfill. During the last decades, increased knowledge of the subject has been gained through research activities. Still, findings only slowly reach into the work fields of architects and urban designers. This paper presents a series of workshops designed to gain input on
how the transfer of knowledge of urban sound from research findings to the urban planning and design practice could be accelerated. Furthermore, the paper explores how sound experience walks additionally can improve understanding of the relationship between sound and urban space. In particular,
developed as city sound models, the walks can support practitioners' knowledge and public involvement in the acoustic environment.
Effect of Pitch Ratio of Tube Banks on Passive Acoustic Properties
Authors: VADDAMANI CHARITHA , Boji Susann , Boden Hans , Karlsson Mikael
Published: February 2023

Tube banks are common design elements in heat exchangers. The most common tube bank patterns are In-line tube banks and Staggered tube banks. These are characterized by their longitudinal and transverse pitch ratios (pitches to diameters). The tube bank with a pitch ratio of less than
1.25 is considered a compact tube bank and a pitch ratio greater than 2 is considered as widely spaced. In this paper, the attention is focused on the effects of pitch ratio in tube banks on its passive acoustics properties which are experimentally investigated. The flow duct experimentation
is performed with and without flow to analyse the passive acoustic properties of tube banks. The Experiment is conducted for both the In-line and Staggered tube banks with pitch ratios from 1.2 to 2.5. Experimental results consist of scattering matrix coefficients and power balance. The results
are compared to see the pitch ratio effect.
Sub-band attention CNN with feature evaluation for chatter detection
Authors: Jeong Kwanghun , Jeon Jonghoon , Park Junhong
Published: February 2023

In chatter detection, feature evaluation is an important task to identify mechanical systems and achieve higher classification accuracy. The importance of frequency bands is useful under various operating conditions. In this study, we propose a new methodology to identify the importance
of frequency bands based on sub-band attention CNN. The sub-band attention CNN is a structure that combines the sub-band CNN and the attention layer. Unlike conventional CNNs that treat all frequency components with the same filter, the sub-band CNN processes different filters for each band.
The attention layer is used to evaluate the importance of each band. The time-varying variance in frequency domain is used to extract chatter characteristics that vary greatly with time and it is used as an input for chatter detection. The useful frequency bands for chatter detection are obtained
from the sub-band attention CNN. The importance of the frequency band is analyzed with the frequency response of the mechanical system.
Nonlinear dynamical features of vortex-acoustic lock-on in a backward-facing step combustor
Authors: Vasanth Joel , Chakravarthy Satyanarayanan
Published: February 2023

Unstable shear layers characteristic of step combustors display strong vortex shedding and play a dominant role in combustion instability. Past non-premixed flame experiments with Reynolds number (Re) as the bifurcation parameter showed that during instability, the frequency of acoustic
oscillations locks-on to the natural vortex shedding mode for a range of Re. In the present work, we study the dynamical features of this type of lock-on. We employ a vortex model to bring out the nonlinearity in the flame response to vortical perturbations. This is coupled with a Galerkin
model for the acoustic field. Regimes of aperiodic oscillations, low-amplitude lock-on and high-amplitude lock-on are predicted in agreement with experimental trends. Phase portraits show a transition to instability during lock-on via a supercritical Hopf bifurcation with an increase in limit
cycle amplitudes. Synchronisation between the acoustic pressure and vortex-driven heat release perturbation is studied using recurrence analysis. The system transitions from asynchronous to phase synchronisation in the low-amplitude lock-on regime, characterised by an increasing degree of
phase correlation. In the high-amplitude lock-on regime, a state of generalised synchronisation exists, where in addition to the phase, the amplitudes also show strong correlation.
Towards Wayside Wheel Flat Detection and Classification Based on Psychoacoustic Quantities
Authors: Egeler Jonas , Forstreuter Melissa , Huth Christine , Liepert Manfred
Published: February 2023

Somewhat similar to the acoustic problems that were uncovered with the replacement of combustion engines with electric motors in cars, the retrofitting of all DB Cargo freight wagons with low-noise brakes caused other disturbing noise emissions to become more prominent. Among these,
the periodic beating sounds originating from flattened wheel treads attract most attention. As there is no sufficiently validated solution for wayside wheel flat detection which meets the requirements of precise detection, focus on acoustic relevance and economic feasibility, the German Federal
Environmental Agency has initiated a research project to determine an acoustic maintenance criterion for flat spots. In this contribution, we present the results of psychoacoustic analyses performed on a dataset comprising audio recordings of 200 cargo train passings. Regions with perceptible
flat spots are labelled by trained ears. Common acoustic and psychoacoustic quantities are calculated for signal windows of classes "flat spot" and "no flat spot" and statistical analyses are performed to find quantities which qualify best for a separation of both classes.
The effects of window size and sample rate are examined. Based on the results of listening tests, an acoustic classification criterion for the annoyance of wheel flats is proposed.
Objective and subjective analysis of the acoustic performance of a ZEB test-building
Authors: Scrosati Chiara , Scamoni Fabio , Depalma Michele , Danza Ludovico
Published: February 2023

The paper describes an experimentation campaign, including both objective and subjective analysis, carried out in a Zero-Energy full-scale test building and aiming at analysing the acoustic performance of the construction and the acoustic comfort of the rooms. The objective analysis
consists of sound insulation measurements of facades and partitions, noise level measurements of service equipment and environmental noise level monitoring. The subjective analysis is based on a survey carried out on 100 participants to collect the answers about their evaluation of the acoustic
quality in two different test rooms. The outcomes of the questionnaire were compared to the outcomes of the measurements in order to find a relationship between the subjective and objective data.
Study On the Effect of Operating Conditions on Acoustic Three-Port Measurements of Perforates in presence of Grazing Flow
Authors: Shah Shail , Bodén Hans , Boij Susann
Published: February 2023

Different impedance eduction methods have been previously used to study the acoustic properties of perforated plates in the presence of grazing flow, giving varying results. The work presented here is to contribute to the ongoing experimental research on the acoustic behaviour of perforates
under different acoustic excitations and flow conditions. Here, a three-port technique is used to study the aero-acoustic properties of perforates, which allows to observe the acoustic field on both sides of the perforate. Experimentally determined characteristics of the perforate are dependent
on the operating conditions like grazing flow speed, microphone distances, standing wave pattern, and temperature. This study aims to provide the experimental analysis on the effect these factors have on the calculated perforate properties, namely the transfer impedance and the scattering
matrix. Global sensitivity analysis is performed to study the individual effect of these factors in the post-processing, as well as the overall effect of error in the determination of these operating conditions.
Numerical analysis of acoustic noise from an electronic cooling fan at flow disturbed by an external obstacle
Authors: Wasala Sahan , Stevens Lon , Sosseh Raye , Persoons Tim
Published: February 2023

Axial cooling fans are widely used in data center dense Hard Disk Drive (HDD) storage systems. However, these fans emit high noise levels and degrade HDD performance at certain frequencies. Flow at the fan's inlet can be highly turbulent due to the wake generated by fan components such
as struts, finger guards, stators/guide vanes, shrouds, and other external system components such as connectors and mounts, power cables and components, circuits etc. The wake-fan interaction also causes high tonal noise. Therefore a proper understanding of this noise mechanism will help optimize
the cooling system in next-generation high-performance HDD enclosure systems. This paper focuses on studying this phenomenon using numerical simulations of a typical data center cooling fan combined with various simplified strut geometries as the obstacle. The high-fidelity Computational Fluid
Dynamic (CFD) method, Large Eddy Simulation (LES), was used to obtain a transient flow field. The Ffowcs-Williams and Hawkings acoustic analogy was used to predict far-field noise.
A new approach to generate diffuse sound pressure fields
Authors: Van hoorickx Cédric , Reynders Edwin
Published: February 2023

If the acoustic wavelength is small compared to the characteristic size of an enclosed space, the sound field in that space is often modeled as diffuse. A diffuse sound field is conventionally defined as a zero-mean circularly-symmetric complex Gaussian random field. A more recent,
generalized definition is that of a sound field having mode shapes that are diffuse in the conventional sense, and eigenfrequencies that conform to the Gaussian Orthogonal Ensemble. Such a generalized diffuse sound field can represent a random ensemble of sound fields that share gross features
such as modal density and reverberation time, but otherwise have any possible arrangement of local wave scattering features. In this contribution, realizations of a conventional diffuse sound field or, equivalently, of the mode shapes of a generalized diffuse sound field, are generated in
a Monte Carlo framework. As a discrete decomposition is numerically expensive when the sound pressures at many locations are of interest, a fast analytical decomposition based on prolate spheroidal wave functions is developed. The approach is numerically validated by comparison with a detailed
room model, where random wave scatterers are explicitly modeled, and good correspondence is observed. Applications involving correlated sound sources and sound-structure interaction are presented.