bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Stress Interaction on Multi-Stress Accelerated Life Test Plan: Assessment Based on Particle Swarm Optimization
Authors: Okafor Ekene Gabriel , Vinson Whit , Huitink David Ryan
Published: February 2023

Sustainability of products that seek to maintain ecosystem balance, such as electric vehicles or solar system inverters, often require extensive testing during their developmental stages in a manner that minimizes wastage and drives creativity. Multi-stress accelerated test planning is often used for these products, their subsystems and components if their in-service failures are driven by multiple stress factors. Multi-stress accelerated life testing (ALT) often expedites time to failure for highly reliable products. Many studies assume model parameters that may not be appropriate for the considered stress factors. Most importantly, the effect stress interaction has on the ALT plan is often ignored, especially for cases where historical data are lacking. To address this gap, in this work, a technique based on a combination of rapid experimental data collection and heuristic-based optimization is proposed for ALT planning. In addition, the effect of stress interaction on the ALT plan was also evaluated. Specifically, the Arrhenius model was used to develop a maximum likelihood mathematical expression for multi-stress factor scenarios with and without interaction. Subsequently, two optimization stages based on particle swarm optimization (PSO) were carried out using time varying inertia weight constants to drive early and late global and local searches, respectively. In the first stage, model parameters were estimated, while, in the second stage, an ALT optimal plan was generated based on a D-optimality criterion. Verification of stress factor interactions was carried out using graphical response analysis. An experiment, designed to investigate electromigration in solder joints under three stress factors (temperature, current density and mechanical load), was used to validate the study. The variation in the choice of Latin hypercube design (LHD) results in disparity in the levels of stress within each stress combination as well as sample allocation. Our results clearly show the need to investigate stress interactions prior to multi-stress acceleration planning.
Intensification of Lead, Copper and Antimony Removal Using Brown Algae Adsorption Coupled to Hydrodynamic Cavitation
Authors: Medina-Collana Juan Taumaturgo , Sejje Suárez Wilfredo David , Anyosa Cáceres Noemí , Carrasco Venegas Luis Americo , Diaz Bravo Pablo Belizario , Lopez Herrera Jorge Amador , Grados Gamarra Juan Herber , Astocondor Villar Jacob
Published: February 2023

In the present study, a calcium alginate bead adsorbent was prepared from brown algae (Macrosystis pyrifera) and was used for removal of Pb+2, Cu+2, and Sb+3 ions from aqueous solutions, using a fixed bed column. The initial concentration of metal ions, mass of adsorbent, recirculation flow, hydrodynamic cavitation, and contact time were examined, and the adsorption kinetics and isotherms were systematically studied. The Taguchi five-factor methodology was used for the development at three levels of experimentation. Experiment N° 24 (concentration, 10 mg/L; flow rate, 10 mL/s; adsorbent mass, 10 g; hydrodynamic cavitation with maximum air flow, and treatment time 240 min) resulted in the maximum removal of 92%, 78%, and 16% of lead, copper, and antimony ions, respectively. The average rate constants corresponding to pseudo-second-order kinetics for lead, copper, and antimony ions were 5.3 × 10−3, 1.4 × 10−3, and 7 × 10−5 g.mg−1min−1, respectively. In the adsorption process, they closely approximate to Langmuir and Freundlich isotherms, with adsorption capacities for Pb2+, Cu2+, and Sb3+ of 7.60, 2.07, and 0.37 mg/g, respectively, with good bioadsorption affinity of Pb > Cu > Sb. It was demonstrated that the bioadsorption equipment, with proper control of the factors, achieves concentration values of lead and copper ions below the current environmental regulations. The results of these studies indicated that calcium alginate is a promising adsorbent for separating and recovering heavy metal ions from contaminated water, although further research is needed for antimony ions.
A Novel Adaptive Generation Method for Initial Guess Values of Component-Level Aero-Engine Start-Up Models
Authors: Zhou Wenxiang , Lu Sangwei , Kai Wenjie , Wu Jichang , Zhang Chenyang , Lu Feng
Published: February 2023

To solve the difficult problem of selecting initial guess values for component-level aero-engine start-up models, a novel method based on the flow-based back-calculation algorithm (FBBCA) is investigated. By exploiting the monotonic feature of low-speed aero-engine component characteristics and the principle of flow balance abided by components in the start-up process, this method traverses all the flows in each component characteristic at a given engine rotor speed. This method also limits the pressure ratios and flow rates of each component, along with the surplus power of the high-pressure rotor. Finally, a set of “fake initial values” for iterative calculation of the aero-engine start-up model can be generated and approximate true initial guess values that meet the accuracy requirement according to the Newton–Raphson iteration method. Extensive simulation verifies the low computational cost and high computational accuracy of this method as a solver for the initial guess values of the aero-engine start-up model.
Generic Multi-Layered Digital-Twin-Framework-Enabled Asset Lifecycle Management for the Sustainable Mining Industry
Authors: El Bazi Nabil , Mabrouki Mustapha , Laayati Oussama , Ouhabi Nada , El Hadraoui Hicham , Hammouch Fatima-Ezzahra , Chebak Ahmed
Published: February 2023

In the era of digitalization, many technologies are evolving, namely, the Internet of Things (IoT), big data, cloud computing, artificial intelligence (IA), and digital twin (DT) which has gained significant traction in a variety of sectors, including the mining industry. The use of DT in the mining industry is driven by its potential to improve efficiency, productivity, and sustainability by monitoring performance, simulating results, and predicting errors and yield. Additionally, the increasing demand for individualized products highlights the need for effective management of the entire product lifecycle, from design to development, modeling, simulating, prototyping, maintenance and troubleshooting, commissioning, targeting the market, use, and end-of-life. However, the problem to be overcome is how to successfully integrate DT into the mining business. This paper intends to shed light on the state of art of DT case studies focusing on concept, design, and development. The DT reference architecture model in Industry 4.0 and value-lifecycle-management-enabled DT are also discussed, and a proposition of a DT multi-layered architecture framework for the mining industry is explained to inspire future case studies.
Salinity-Induced Extinction of Zostera marina in Lake Grevelingen? How Strong Habitat Modification May Require Introduction of a Suitable Ecotype
Authors: van Katwijk Marieke M. , Cronau Rens J. T. , Lamers Leon P. M. , Kamermans Pauline , van Tussenbroek Brigitta I. , de Jong Dick J.
Published: February 2023

During the 1980s–1990s, 4600 hectares of the seagrass Zostera marina were permanently lost from Lake Grevelingen (the Netherlands), and restoration is planned. In 1971, the lake was fully marine (salinity 30), and seagrass covered 1300 hectares. After closure in that year, the lake gradually became brackish (salinity of 23 by 1978), and the meadows expanded to 4600 hectares. However, with the creation of a sluice connection to the sea in 1978, the lake returned to marine conditions and a fatal decline initiated. We revisit traditionally suggested causes of the disappearance of the seagrass, finding them unsatisfactory. We hypothesize that during the lower salinity conditions from 1971 to 1978, selection of low-salinity genotypes occurred, and these genotypes were not adapted to returning marine conditions. This hypothesis is no longer testable through genetic analysis in Lake Grevelingen but is supported by previously unpublished experiments that found a lack of seed germination at even moderately high salinity for the now extinct population. Such processes could be relevant for, and tested in, environmentally modified water systems worldwide, particularly when isolated. Based on our assessment, the abiotic environment of Lake Grevelingen seems suitable for Z. marina restoration using a donor from a high salinity environment.
Assessment of Whole Milk Powder Production by a Cumulative Exergy Consumption Approach
Authors: Uçal Esmanur , Yildizhan Hasan , Ameen Arman , Erbay Zafer
Published: February 2023

The production of food is a sector that consumes a significant amount of energy and encompasses both agricultural and industrial processes. In this study, the energy consumption of whole milk powder production, which is known to be particularly energy-intensive, was examined. The study used a cumulative exergy consumption approach to evaluate the overall production process of whole milk powder, including the dairy farm (raw milk production) and dairy factory (powder production) stages. The results showed that raw milk production dominated energy and exergy consumption and carbon dioxide emissions. An amount of 68.3% of the total net cumulative exergy consumption in the system was calculated for raw milk production. In the dairy factory process, the highest energy/exergy consumption occurred during spray drying, followed by evaporation and pasteurization. In these three processes, 98.3% of the total energy consumption, 94.6% of the total exergy consumption, and 95.7% of the total carbon dioxide emissions in powder production were realized. To investigate the improvement potentials in the system, replacing fossil fuels with renewable energy sources and using pasture feeding in animal husbandry were evaluated. While using alternative energy sources highly influenced powder production, pasture feeding had a high impact on consumption in raw milk production. By using renewable energy and pasture feeding, the exergy efficiency, cumulative degree of perfection, renewability index, and exergetic sustainability index values for the overall process increased from 40.5%, 0.282, −0.22, and 0.68 to 68.9%, 0.433, 0.65, and 2.21, respectively.
Statistical Approach Model to Evaluate Permanent Deformation of Steel Fiber Modified Asphalt Mixtures
Authors: Shaffie Ekarizan , Mohd Nasir Alma Aina , Putra Jaya Ramadhansyah , Arshad Ahmad Kamil , Mohamad Rais Nuryantizpura , Al-Saffar Zaid Hazim
Published: February 2023

A good asphalt mixture is very important to maintain the triangle of sustainability. Many accidents occur due to pavement damage such as permanent deformation caused by the external loads induced by heavy traffic. Stone Mastic Asphalt (SMA) has a low resistance to moisture and other performances. Many researchers have conducted on SMA using various types of fiber. However, not much research has been done using steel fiber in the SMA mixture and has analyzed the result obtained using a statistical approach. The objective of this research was to identify the optimum amount of steel fiber in a modified asphalt mixture and characterize the performance of steel fiber in the SMA mixture using the statistical approach of Response Surface Methodology (RSM) in Design Expert Software. In this study, various steel fiber proportions of 0 percent, 0.3 percent, 0.5 percent, and 0.7 percent by the total weight of the SMA mixture were used. The Marshall stability and flow test, dynamic creep and moisture susceptibility test, and ultimately, RSM analysis were used to evaluate the properties and performance of the steel fiber-modified SMA, which contained 6.2 percent of PEN 60/70 asphalt binder content. The testing findings unmistakably demonstrated that the addition of steel fiber greatly improves the SMA mixture’s resistance to moisture and permanent deformation. An amount of 0.3 percent was found to be the most optimum steel fiber content from the optimization by using Response Surface Methodology, thus proven with additional steel fiber in the SMA mixture enhancing the performance of the mixture. As a result, it can be determined that the addition of steel fiber to SMA asphalt mixtures has improved the properties and performance in the construction of asphalt pavements, and the RSM method is an efficient statistical method for producing an appropriate empirical model for relating parameters and predicting the best performance of an asphaltic mixture.
Collective Excitation in High-Energy Nuclear Collisions—In Memory of Professor Lianshou Liu
Authors: Huang Huan Zhong , Liu Feng , Luo Xiaofeng , Shi Shusu , Wang Fuqiang , Xu Nu
Published: February 2023

We celebrate the legacies of our friend and mentor Professor Lianshou Liu who was one of the pioneers for the phenomenology of multi-particle interactions and initiated the physics of relativistic heavy-ion collisions in China. In this article, we discuss some of the recent exciting experimental observations on the collective phenomena including collectivity, chirality, criticality, strangeness production, and thermal equilibrium in high-energy nuclear collisions. Future directions, especially the physics at high baryon density, will be discussed with a focus on the first-order phase boundary and hyperon–nucleon interactions.
Experimental Study on the Influence of Interfacial Energy Instability on the Flow Pattern Spatiotemporal Evolution of Thermal- Buoyant Capillary Convection
Authors: Zhang Shuo , Liang Ruquan , Yang Shuo
Published: February 2023

The effect of the instability of the interface morphology due to mechanical disturbances and acceleration changes (or gravity flutter) on Marangoni convective stability has been confirmed via space experiments. However, compared with the research on Marangoni convection with an axisymmetric liquid bridge, research on the transition and interface flow behavior of Marangoni convection with a non-axisymmetric liquid bridge is not sufficiently deep. Based on the thermal-buoyant capillary convection (TBCC) experiment of the conventional liquid bridge, in this study, the influence of the interfacial energy instability triggered by the gravitational tilt angle (GTA) on the spatiotemporal evolution of the flow pattern and velocity distribution of the thermal-buoyant capillary convection is examined by applying the GTA to form the non-axisymmetric liquid bridge model. The results show that the non-equilibrium change in the interface curvature due to GTA leads to a non-axisymmetric liquid bridge morphology. With increasing GTA, the cell-flow morphology during the development process is restricted, transverse/longitudinal velocity component is suppressed, and velocity peak value position gradually approaches the interface. In the oscillating TBCC stage, the deviation of cell flow vortex cores from the intermediate height intensifies with the increasing GTA, resulting in the expansion of the alternating flow zone in the center. Furthermore, the longitudinal velocity component distribution is transformed into the “two peaks and one valley” morphology (“M”-type) from the original multi-peak morphology. The interfacial energy instability due to the GTA can increase the critical temperature difference of the oscillating TBCC, maintain its stability, and delay the onset of the oscillating flow. Simultaneously, the oscillation frequency of the oscillating TBCC is reduced and the development of the oscillating TBCC is suppressed.
Gymnodinium catenatum Paralytic Shellfish Toxin Production and Photobiological Responses under Marine Heat Waves
Authors: Lopes Vanessa M. , Court Mélanie , Seco Martim Costa , Borges Francisco O. , Vicente Bernardo , Lage Sandra , Braga Ana Catarina , Duarte Bernardo , Santos Catarina Frazão , Amorim Ana , Costa Pedro Reis , Rosa Rui
Published: February 2023

Marine heatwaves (MHWs) have doubled in frequency since the 1980s and are projected to be exacerbated during this century. MHWs have been shown to trigger harmful algal blooms (HABs), with severe consequences to marine life and human populations. Within this context, this study aims to understand, for the first time, how MHWs impact key biological and toxicological parameters of the paralytic shellfish toxin (PST) producer Gymnodinium catenatum, a dinoflagellate inhabiting temperate and tropical coastal waters. Two MHW were simulated—category I (i.e., peak: 19.9 °C) and category IV (i.e., peak: 24.1 °C)—relative to the estimated baseline in the western coast of Portugal (18.5 °C). No significant changes in abundance, size, and photosynthetic efficiency were observed among treatments. On the other hand, chain-formation was significantly reduced under category IV MHW, as was PSP toxicity and production of some PST compounds. Overall, this suggests that G. catenatum may have a high tolerance to MHWs. Nevertheless, some sublethal effects may have occurred since chain-formation was affected, suggesting that these growth conditions may be sub-optimal for this population. Our study suggests that the increase in frequency, intensity, and duration of MHWs may lead to reduced severity of G. catenatum blooms.
Técnicas de manejo de enfermedades poscosecha en frutos de cítricos.
Authors: Chávez Caicedo Cristhian Jesús , Castro Olaya Jessenia Rosanna , Celi Soto Adriana del Carmen , Chirinos Torres Dorys Terezhina
Published: February 2023

A nivel mundial la producción de cítricos ha incrementado debido a la creciente demanda por parte de países productores y exportadores. Sin embargo, las pérdidas poscosecha son un reto para los citricultores, en especial las causadas por los hongos Penicillium digittaum y P. italilicum; además de los microorganismos causantes de enfermedades precosecha, que persisten en el tiempo y se presentan durante el almacenamiento de los cítricos. La investigación tuvo como objetivo recopilar información sistémica, aplicativa y de gran utilidad sobre técnicas de manejo de enfermedades poscosecha en frutos de cítricos (Citrus spp.) en Ecuador. Una de las técnicas de manejo, es el uso de fungicidas sintéticos, en especial el Imidazol y Bencimidazol y las sales, como ortofenil fenato de sodio. Entre las opciones biológicas, se usan hongos, bacterias y levaduras con capacidad antagónica y antifúngica. Dentro de las medidas físicas, se emplea el almacenamiento en condiciones de baja temperatura, que varía de acuerdo a la especie de cítricos y la luminosidad, sugiriéndose como una excelente medida de manejo para los hongos causantes de la pudrición, P. digitatum y P. italicum. El manejo de enfermedades poscosecha debe contar con un plan que incluya al menos dos medidas de control.
Costing the benefit of low noise surfacing
Authors: Muirhead Matthew
Published: February 2023

Low noise pavements are an important mitigation measure in the drive to minimise the impact of traffic noise on all our lives. The benefit provided by such surfaces is an important element of any associated life cycle cost analysis. There are existing methodologies for monetising the
relative noise reductions from quieter pavements in terms of the societal cost of the associated health benefits. However, this approach requires input data on the potential reduction in exposure to traffic noise. For a particular road scheme such data are often derived from a detailed noise
model, but this is not possible when considering potential benefits at a regional or national level. This paper examines potential approaches in estimating the comparative reduction in traffic noise exposure between different surface types at this strategic level. This includes methods for
considering population density, noise exposure and the extent to which a low noise surface will impact the surrounding sound environment.
Towards a low cost method for measuring the airborne sound insulation of partitions
Authors: Whittle Gabriel , Wong-McSweeney Daniel , Meggitt Joshua , Elliott Andrew
Published: February 2023

BS EN ISO 10140-2 outlines a method for estimating the airborne sound insulation of a partition using adjacent rooms. In this paper, a new method is presented by which the airborne sound insulation is obtained without the need for a transmission suite. Using a stand-alone partition,
a representative blocked pressure field is applied numerically to a measured frequency response function matrix characterising the partition. The incident and transmitted powers are determined from the blocked pressure and velocity field on the source and receiver sides, respectively. Results
of several partitions measured using the proposed methodology will be compared against estimates obtained according to BS EN ISO 10140-2.
A quantitative approach to density-based clustering of flight trajectories for efficient air traffic noise simulations
Authors: Mysore Guruprasad Shreyas , Felix Greco Gil , P. Ring Tobias , C. Langer Sabine
Published: February 2023

The continuous growth of air traffic and increased availability of open source data has enabled the application of data-driven approaches for the prediction of noise contours around airports. Aiming at efficient noise simulations, this contribution proposes a framework for the probabilistic
description of the air traffic around an airport. The methodology is based on using the density-based clustering algorithm OPTICS to cluster flight trajectories. The clustered trajectories serve as a basis for the creation of backbone and dispersion tracks, which, together with a prescribed
number of flight operations per aircraft type, provide a probabilistic description of the air traffic to the noise simulations. A major focus is given to quantitatively assess the sensitivity of the OPTICS algorithm to different hyper-parameters to reduce the dimensionality of the problem.
This framework is demonstrated utilizing a dataset of ADS-B trajectory data associated with flights approaching Hannover airport. Noise simulations based on the ECAC Doc. 29 best-practice method are conducted using SoundPLAN. A good agreement between noise contours is obtained when comparing
simulations performed using the proposed framework and the full dataset while the computational time required decreased. Furthermore, this approach identifies most of the trajectory patterns with the least amount of outliers.
Uncertainty of structure-borne sound source quantities and the installed power from interlaboratory test results according to EN 15657
Authors: Scheck Jochen , Wittstock Volker , Villot Michel
Published: February 2023

Structure-borne sound sources affect the acoustic quality inside buildings. Based on many years of research, methods have been standardised to characterise structure-borne sound sources in the laboratory (EN 15657) and to predict the sound transmission from these sources when installed
in buildings (EN 12354-5). This contribution is about the uncertainty of the source descriptors used in EN 15657 and the predicted installed sound power which is the input quantity for EN 12354-5. Recently an interlaboratory test with 7 participating laboratories has been performed. The task
was to measure the blocked force, free velocity and mobility of an artificial source and the blocked force of the ISO tapping machine. From the evaluation of the measurement results estimates for the uncertainties of the source quantities and the installed power could be deduced.
The influence of model assumptions in a hybrid prediction tool for railway induced vibration
Authors: Thompson David , Ntotsios Evangelos , Bouvet Pascal , Nélain Brice , Nuber Andreas , Fröhling Bernd , Seyfaddini Fakhraddin , Herremans Geertrui , Reumers Pieter , Lombaert Geert , Degrande Geert
Published: February 2023

Within the SILVARSTAR project, a user-friendly frequency-based hybrid prediction tool is developed to assess the environmental impact of railway induced vibration. This will be implemented in the existing noise mapping software IMMI. The vibration level in a building in each frequency
band is expressed as the product of source, propagation and receiver terms. A hybrid approach is used that combines experimental data with numerical predictions, providing increased flexibility and applicability. The train and track properties can be selected from a database or as numerical
values. The user can select soil impedance and transfer functions from a database, pre-computed for a wide range of parameters with the MOTIV and TRAFFIC models. An experimental database of force densities, transfer functions, free field vibration and input parameters is also integrated into
the new tool. The building response is estimated by means of empirical correction factors. Assumptions within the modelling approach can influence the prediction accuracy and the present paper aims to quantify these. We focus on the influence of train speed and soil properties on the compliance
of the track-soil system, the dynamic axle loads, and the free field response, as well as on the load transfer between track and soil.
Validation of a potential-based active sound control methodology
Authors: Lim Hyun , Gomez-Agustina Luis
Published: February 2023

This paper describes a global active sound control methodology based on difference potentials in a three-dimensional space. The proposed alternative method allows the reduction of a boundary value problem set in a complex domain to a boundary equation. The only input data needed by
the methodology are the acoustic quantities at the perimeter of the protected region. By minimizing the number of input data, the characteristics of the method provide a practical and cost-effective control system. Moreover, these quantities may pertain to the overall acoustic field composed
of both the unwanted and wanted components. The most distinctive feature of this methodology is its ability to automatically differentiates between the wanted sounds and unwanted noise within targeted domains. The proposed approach requires information of neither the wanted nor unwanted component
separately, but the measurements of the total field on the boundaries of the shielded domain only. This capability can be very useful for the applications related to personal audio and building acoustics as it enables protection of the predefined personal space against the noise coming from
the outside. In doing so, the controls will not interfere with the detectors' recognition of the wanted sound or communication among speakers in the room.
Five Levels of Soundscape Design
Authors: Siebein Gary
Published: February 2023

Siebein (2010) identified 5 levels of architectural soundscapes: inspiration; planning; conceptual structure; tectonics; and detail. Case studies of the use of the levels are presented to illustrate how architects often use inspiration and planning metaphors to begin the design of a
building. A conceptual structure is the underlying set of principles and ultimately geometries that form the basis for the intellectual and formal aspects of the project. Tectonics are the elements that form the architectural system that the soundscape occurs within. Details are the connections
among the tectonic elements that support and express the inspiration and the conceptual structure of the project. The case studies illustrate how these levels define the places in the design process where soundscape theory can be effectively implemented to become an integrated part of the
creation of architectural space. The case studies provide a working model for the creation of architectural spaces with designed soundscapes that occur as part of an integrated, participatory design process. These are parts of the process that are philosophical and abstract in nature where
one seeks the poetic expression of the essence of the project prior to the beginning of traditional design.
Investigation of vibration-based measurements of impact and airborne noise insulation
Authors: Dong Wayland , LoVerde John , Shafer Ben , Girdhar Sunit
Published: February 2023

Standard impact and airborne noise insulation testing is based on measuring the average sound level in a reverberant field in order to estimate the incident and/or radiated sound power. While this method is straightforward, the variation under reproducibility conditions is significant
and attempt to reduce the uncertainty has so far proven unsuccessful. It is possible that a significant portion of the uncertainty is due to unavoidable variation in reverberation rooms, and that measuring the vibration on the surfaces of an assembly may be a better measurement of the impact
or airborne isolation of the assembly. Preliminary investigations have been performed by measuring the vibration levels on wall and floor assemblies in situ while excited by airborne and impact sources, and the results are compared to conventional test methods.
A Study on Improving the Robustness of Virtual Sensing Methods in ANC Systems
Authors: Kajikawa Yoshinobu , Kajikawa Yoshinobu
Published: February 2023

Active noise control (ANC) system generates anti-noise with the same amplitude and opposite phase to reduce unwanted acoustic noise based on acoustic wave superposition. In general, ANC can generate a zone of quiet (ZoQ) around the error microphone position. However, if the microphone
cannot be placed at the desired position we want to realize noise reduction, the reduction effect may not be sufficient in the desired position. In such a case, we need to use the virtual sensing method to move the ZoQ to the desired position. Several virtual sensing methods have been proposed,
each with different robust performance due to the different way the system is designed. It is known that the noise reduction is degraded when there are perturbations in the environment such as plant and noise. In this paper, we investigate how to improve the robust performance of the virtual
sensing method.
The effects of different sound environments on physiological stress recovery and perceived restorativeness.
Authors: Masullo Massimiliano , Toma Roxana Adina , Navarro Ruiz Juan Miguel , Hernandez Bellot Jorge , Maffei Luigi
Published: February 2023

In a threatening situation, various physiological and psychological processes are activated. The activation of the sympathetic nervous system, in particular, is responsible for the increase in heart rate, electrodermal activity, and negative emotions. According to Ulrich's theory, stress
recovery involves physiological and psychological components, while the recharging of anabolic energy involved in the psychophysiological response to a stress factor falls under the broader concept of Restorativenes. Indoor, outdoor, natural and built environments can affect differently stress
recovery and perceived Restorativeness. Through a test conducted within the Catholic University of San Antonio campus in Murcia (UCAM), this still ongoing study investigates the changes of some physiological variables and subjective assessment in different multisensory environmental conditions
(i.e., acoustic, temperature, relative humidity) and presents some preliminary results.
Low order modelling of thermoacoustic instabilities in aero-propulsion engines
Authors: Surendran Aswathy , Boakes Charles , Yang Dong , Morgans Aimee
Published: February 2023

In the present work, we investigate the thermoacoustic stability behaviour of a combustor-heat exchanger assembly pertinent to the Synergetic Air Breathing Rocket Engine (SABRE) of Reaction Engines Ltd. Since the thermoacoustic behaviour of heat exchangers is poorly understood, we have
approximated it to a combination of heat transfer/heat sink and aeroacoustic scattering (dissipation) mechanisms. The ε-NTU method is used to characterise the low frequency, linearised unsteady heat transfer (heat exchanger transfer function) behaviour in compact heat exchangers. The aeroacoustic
response of the tube row is evaluated from the linearised conservation equations, wherein the hydrodynamics of the bias flow in the tube row is described as being similar to that of an isentropic contraction followed by a sudden expansion. The stability predictions are carried out through
low order modelling of the combustor and subsequent eigenvalue analysis. The flame dynamics is approximated using the n-τ law, with τ being a parameter. Stability predictions show that the thermoacoustic response of the heat exchanger was dominated by aeroacoustic dissipation. Only
one mode was predicted to be unstable and can be stabilised by moving the heat exchanger upstream. Further work is required to better characterise the flame and the heat exchanger transfer functions.
The soundscape approach for people with dementia; using psychoacoustic parameters to select suitable sounds
Authors: Talebzadeh Arezoo , Van Renterghem Timothy , Thomas Pieter , Devos Paul , Botteldooren Dick
Published: February 2023

Sound augmentation as an environmental intervention to improve mood and cognitive behaviour illustrated promising results in recent years. The same approach has a positive effect in reducing anxiety, stress, agitation and improving sleep quality in people with cognitive disabilities.
In the soundscape approach, people have agency in evaluating their sonic environment, either a neighbourhood, a hospital or a care unit. This method is hardly possible when designing for people with dementia, as the severity of the disease makes communication incomprehensible in most cases.
Therefore, caregivers and nurses are the best sources of evaluation; their familiarity with patients and their knowledge of patients' behaviour and psychology is crucial to evaluate the soundscape and the environment. This research uses caregivers' evaluation of a designed soundscape and shows
the possible scientific way of selecting a suitable sound by assessing the character of the sound and its psychoacoustic parameter in relation to the caregivers' and nurses' feedback. Using feedback data and psychoacoustic parameters of sounds, a logistic regression model with a single independent
variable demonstrated the chance of a positive outcome (sound) versus continuous indicator value (psychoacoustic parameter). The preliminary result revealed a possibility of sound augmentation using psychoacoustic parameters to identify suitable sounds.
Confidence in Room Acoustic Design: an Empirical Approach for Classrooms
Authors: Wei Weigang , Harvie-Clark Jack
Published: February 2023

Methods to predict reverberation time range from the simple Sabine or Eyring relation to more elaborate means such as geometric and numerical acoustic modelling. Classrooms often have a very uneven distribution of sound absorption; measured reverberation times can exhibit a much wider
range of values between equivalent rooms than prediction methods would generally indicate. The analytical tools can commonly fail to provide what the designer actually needs: a simple and robust method to advise on solutions for sound absorption that can routinely achieve the stated reverberation
time criteria. This paper presents an empirical approach to room acoustic design for classrooms with free-hanging absorbent rafts, wall panels and furniture. Statistical analysis of the measured reverberation time in over a hundred rooms is used to determine confidence intervals for design.
With this approach, the acoustic designer can not only describe the proposed requirements to the design team, they can also identify with a stated confidence the anticipated compliance rate. Although this empirical approach is based on measurements in school classrooms, it may be also used
to predict the reverberation time for other spaces with similar acoustic characteristics.
How the causal structures of noise annoyance and sleep effects changed under the significant decrease of aircraft noise
Authors: Nguyen Tran Thi Hong Nhung , Trieu Bach Lien , Nguyen Thu Lan , Morinaga Makoto , Morihara Takashi , Hiraguri Yasuhiro , Sasazawa Yosiaki
Published: February 2023

Many models have been proposed to clarify the interactive effects of acoustic and non-acoustic variables on human perception of noise. Due to the corona pandemic, all flights were closed at the end of March 2020, causing an unprecedented change in the acoustic environment around Tan
Son Nhat Airport (TSN). Before the outbreak, TSN was the busiest airport in Vietnam and had severe noise problems. This study focused on determining how acoustic and non-acoustic factors affect community health before and after this change. Approximately 1200 responses were obtained from surveys
conducted in 12 residential areas around TSN in 2019 and 2020. Structural equation models (SEM) for noise annoyance and insomnia were developed by linking the questionnaire items of the social surveys. The first effort aims to achieve a common model of noise annoyance and insomnia corresponding
to community response to noise before and after the change. It has been found that the degrees of annoyance and insomnia were not reduced, as expected, but increased in 2020. The final constructed SEM indicates that acoustic and non-acoustic factors affected the community health in different
structures before and after the noise reduction.
Aircraft Approach Noise Trials
Authors: Johansson Anders
Published: February 2023

This article presents the results from a series of aircraft approach trials that were conducted with the aim to investigate noise reduction procedures within the boundaries of a normal ILS approach. The significant decline in air traffic at Stockholm Arlanda, that occurred during the
pandemic meant that the empty airspace and the availability of grounded aircrafts could be utilized to perform controlled flights - something that would have been difficult to achieve during normal traffic conditions. The approach trials were performed by two Airbus A321, which alternately
carried out interrupted landing procedures starting 17 nautical miles (nm) from the runway threshold. During the trials, the aircraft speed and configuration (high lift devises and landing gear) were varied according to a predetermined schedule. To capture these variations, flight data (FDR)
were recorded while the noise on ground was measured at positions approximately once every nautical mile along the flight track. Results suggest that speed and configuration recommendations can be effective to reduce noise, especially for the final 7 nautical miles of the flight track. However,
whether a low speed is to be advocated during the entire approach is currently unclear.
Audio augmentation of car journeys to improve occupants' well-being
Authors: Podwinska Zuzanna , Harris Lara , Jackson Andrew , Welham Connor , Elliott Andrew
Published: February 2023

Car interiors are often designed with the aim of being as quiet as possible. This has the benefit of eliminating most of the unwanted sound such as engine or tyre noise, but it also blocks out environmental sounds which might be perceived as positive and even desirable. Bringing in
some of these positive sounds - particularly of nature or human activity - could enhance the experience of both the driver and the passengers. The literature has shown that being exposed to pleasant soundscapes has the potential to aid recovery from stress and is associated with lower heart
rate than being exposed to unpleasant soundscapes. Therefore, increasing pleasantness of the sound environment in the car could lead to improved well-being. We will report on an immersive audio-visual listening experiment investigating how listeners perceive journeys augmented with realistic
soundscapes. To increase realism and ecological validity, the experiment uses spatial audio, 360-degree videos presented through a virtual reality headset, and a car seat with vibrations corresponding to the presented drive.
DecoWind: Development of low-noise and cost-effective wind farm control technology
Authors: Bertagnolio Franck , Fischer Andreas , Feng Ju , Nyborg Camilla , Vignaroli Andrea , Madsen Helge Aa. , Hansen Kurt S. , Peña Alfredo , Shen Wen Zhong , Hansen Thomas , Oerlemans Stefan , Søndergaard Lars S. , Thysell Erik , Volk Christer , Sørensen Thomas
Published: February 2023

DecoWind is a 3-year Danish research project whose goal is to devise advanced control strategies for wind turbines and farms for minimizing their acoustic impact. Noise propagation models (Nord2000 and WindStar) are verified through dedicated measurement campaigns onshore. Long-range
offshore measurements are also conducted to understand these specific conditions. A Parabolic Equation method for noise propagation, which have mostly been restricted to academic use in the past, is integrated into an engineering context for wind farm control. This framework can be used to
define a wind farm optimal control strategy. The energy production is maximized while limiting the noise impact at dwellings, depending on the considered site, by operating the turbines using their different noise operational modes. This framework is demonstrated through numerical test-cases.
In addition, a public survey is conducted to assess the socio-acoustical impact of wind turbine noise, looking at several factors. The ultimate goal is to produce a set of recommendations regarding wind turbine noise regulations that would connect the new engineering design capabilities and
the findings regarding public annoyance. The project is a collaboration between DTU, Siemens-Gamesa Renewable Energy, FORCE Technology, and EMD International. In this contribution, the main achievements of the project are summarized.
Annoyance and sleep disturbance due to vibrations from trains in the Netherlands: results from the second study "Living Alongside Railway Tracks"
Authors: Van Kempen Elise , Simon Sendrick , van Wijnen Harm , Kok Arnaud , Mabjaia Nick , Van Kamp Irene
Published: February 2023

In 2013, RIVM investigated how people, living in the vicinity of railways, experience vibrations due to trains. As a follow-up, and in response to questions from Parliament on the expansion of the Dutch rail network, the Secretary of State of the Ministry of Infrastructure and Water
management commissioned a second study and a repeated measurement of the persons who participated in 2013. This abstract focusses on the second study. The most important objective of this study was to derive exposure-response relationships between exposure to vibrations caused by trains and
annoyance and sleep disturbance. The results are important for the further development of policy, and possibly also regulations, on railway vibration in The Netherlands. For this second study, 16.000 people living within 300 meters of a railway track were invited to participate. By means of
an online questionnaire, that was administered in September 2021, information was gathered about annoyance, sleep disturbance due vibrations and noise from trains and the determinants of those. The participants' exposure to vibrations from trains was estimated by means of an improved version
of the Dutch calculation model for railway vibrations n (OURS). During the conference, the first findings will be presented.
Development of flow-vibroacoustic coupled numerical methods for prediction of noise radiation due to flow-born vibration of compressor discharge piping system
Authors: Lee Sangheon , Cheong Chulung , Park Jinhyung
Published: February 2023

The compressor and fan in air conditioner outdoor unit are the core component which deter-mines noise performance as well as cooling or heating performance. Among these, the com-pressor has larger contribution to the noise of outdoor units. For high efficiency air condition-er, the
size and operating speed of compressor are smaller and faster. The high-speed com-pressor causes loud noise which is complaints for the customer. Traditionally, it is well-known that the vibration of compressor and connected duct is main noise source. However, as the compressor speed increases,
the refrigerant flow in the compressor discharge duct also emerged as a major noise source. To reduce the compressor noise operating at high speed, it is necessary to analyze vibrational and acoustic characteristics of compressor discharge duct. This duct noise has the two-types source: structure
born noise and flow induced noise. The structure born noise is generated by the duct vibration caused by compressor movement. For the flow induced noise, the static pressure field of refrigerant flow in the duct is vibrational source. In this paper, the compressor discharge duct noise considering
two mechanisms was investigated. The refrigerant flow is solved using CFD and duct vibration and noise radiation are computed by FE-BE method.
A machine learning- and compressed sensing-based approach for surrogate modelling in environmental acoustics: towards fast evaluation of building façade road traffic noise levels
Authors: Baclet Sacha , Venkataraman Siddharth , Gomez Erik , Bouchouireb Hamza
Published: February 2023

State-of-the-art urban road traffic noise propagation simulation methods such as the CNOSSOS-EU framework rely on ray tracing to estimate noise levels at specific locations on façades, so-called receiver points; this method is computationally expensive and its cost increases
with the number of receiver points, which limits the spatial accuracy of such simulations in the context of real-time or near-real-time urban noise simulation applications. This contribution aims to investigate the applicability of multiple data-driven methods to the surrogate modelling of
traffic noise propagation for fast façade noise calculation as an alternative to these traditional, ray-tracing-based methods. The proposed approach uses compressed sensing to select a small subset of receiver points from which the data set of the entire façade may be reconstructed,
associated with a Kriging model and neural networks, used to predict noise levels for these sensors. The prediction performance of each of these steps is evaluated on an academic test case, with two levels of complexity based on the dimensionality of the problem.
Modelling and visualization of surround buckling in electrodynamic audio transducers
Authors: Cobianchi Mattia , Spear Christopher
Published: February 2023

The surround (or front-suspension) of electrodynamic transducers typically used in loudspeakers and headphones is a device that provides the axial restoring force for the diaphragm movement and restrains the lateral and tilting movements. A non-linear phenomenon typical of surrounds
is pressure-induced buckling, a sudden change in the shape of the surround under load. The question addressed by this paper is how to predict the conditions under which a surround will buckle, and how to measure and visualize it in physical prototypes. The modelling methodology was based on
structural finite-element analysis, while the measurement of transducer displacement and video recording with a high-speed camera allowed the experimental verification. This methodology has been applied and tested on semi-circular rubber surrounds. The impact of working temperature and manufacturing
tolerances are also discussed. It was found that it's possible to predict the pressure threshold triggering a specific buckling mode within a 10% error. Full 3D modelling is advisable to assess the buckling pressure of non-axisymmetric modes common in real transducers. At the same time, 2D
modelling has been proven enough for the evaluation of the worst-case scenario / lowest buckling pressure.