bluuebunny/crossref_metadata_2025 huggingface dataset:
Flowback Characteristics Analysis and Rational Strategy Optimization for Tight Oil Fractured Horizontal Well Pattern in Mahu Sag
Authors: Tian Hui , Liao Kai , Liu Jiakang , Chen Yuchen , Ma Jun , Wang Yipeng , Song Mingrui
Published: December 2023

With the deep development of tight reservoir in Mahu Sag, the trend of rising water cut during flowback concerns engineers, and its control mechanism is not yet clear. For this purpose, the integrated numerical model of horizontal well pattern from fracturing to production was established, and its applicability has been demonstrated. Then the flowback performance from child wells to parent wells and single well to well pattern was simulated, and the optimization method of reasonable flowback strategy was discussed. The results show that the formation pressure coefficient decreases as well patterns were put into production year by year, so that the seepage driving force of the matrix is weakened. The pressure-sensitive reservoir is also accompanied by the decrease of permeability, resulting in the increase of seepage resistance, which is the key factor causing the prolongation of flowback period. With the synchronous fracturing mode of well patterns, the stimulated reservoir volume (SRV) is greatly increased compared with that of single well, which improves the reservoir recovery. However, when the well spacing is less than 200 m, well interference is easy to occur, resulting in the rapid entry and outflow of fracturing fluid, and the increased water cut during flowback. Additionally, the well patterns in target reservoir should adopt a drawdown management after fracturing, with an aggressive flowback in the early stage and a slow flowback in the middle and late stage. With pressure depletion in different development stages, the pressure drop rate should be further slowed down to ensure stable liquid supply from matrix. This research can provide a theoretical guidance for optimizing the flowback strategy of tight oil wells in Mahu sag.
Panoramic Semiquantitave Analysis for Multielement Characterization of Liquid and Solid Waste Samples
Authors: Lyubomirova Valentina , Belovezhdova Iva , Djingova Rumyana , Petrov Petar , Todorova Ekaterina
Published: December 2023

Wastewater treatment results in large amounts of sewage sludge in the wastewater treatment plant (WWTP) which imposes on its reuse. The most promising application is as a fertilizer in agriculture which is regulated by national and European legislation. Along with the mandatory determination of potentially toxic elements (PTEs), in order to assess not only the risks, but also the beneficial properties, the determination of the total chemical composition is desirable. Inductively coupled plasma mass spectrometry (ICP-MS) is the most promising technique for multielement characterization which can be applied both for quantitative and semiquantitative analysis. A significant difference between the approaches is that the semiquantitative analysis is performed after a calibration with one standard solution containing at least three elements, but, at the same time, the accuracy is worse. In the present work, the accuracy of semiquantitative analysis with a different number of calibration elements using both water standard solutions and certified reference material (CRM) for calibration was investigated for the determination of 69 elements in sewage sludge CRMs and samples. It has been found that the accuracy can vary within a wide range, depending on the concentration of the elements, the number of calibration elements, and/or the presence of neighboring masses. In order to obtain an accuracy of up to 30%, it is recommended to shorten the mass intervals and perform the calibration with at least 18 elements, mainly microelements. The method was applied for fast panoramic analysis of sewage sludge samples from WWTPs and the concentrations were close to the data from quantitative analysis.
Interaction between Groundwater and Rock Fractures under Stress and Seepage Based on Extractive Water Resource Utilisation
Authors: Shi Zhuolin , Yao Qiangling , Wu Chengle , Xu Yingnan , Wang Furong , Wang Weinan , Sun Jialong
Published: December 2023

In the fragile mining areas of western China, the contradiction between coal mining and water resource protection coexists prominently. Facing this issue, it is necessary to understand the dynamic relationship between mining-induced shear stress and groundwater seepage, as well as the fracture morphology of the overlying strata. In this study, the seepage characteristics of rough fractures within the rock mass are thoroughly investigated, with an emphasis on studying the effects of shear stress and seepage erosion. This research is carried out through seepage experiments and 3D fracture morphology scanning, and the research results are mainly as follows: (a) Rocks with higher shear strengths show less fluctuation in changes in fracture morphology and seepage velocity. (b) The permeability of sandstone and concrete fractures is inversely proportional to the shear stress. The layering of coal greatly limits seepage through the fractures and the permeability of coal is about one-tenth of the permeability of sandstone and concrete under the same conditions. (c) The mechanism of erosion damage to the rock by water-force coupling is the result of the shear and extrusion generated by rock fractures and the transport of rock particles. Changes in fracture erosion and seepage characteristics brought about by the damage will mutually promote and intensify the erosive effect of water force. (d) The degree of change in fracture morphology (fracture damage) under the same conditions is coal > concrete > sandstone. There are differences in the response of different types of rock to the shear stress–seepage erosion, but all show obvious changes in fracture damage and seepage characteristics.
A Calibration of the Contact Parameters of a Sesbania Seed Discrete Element Model Based on RSM
Authors: Ma Wenpeng , Zhang Shining , Yin Xiang , Chen Kai , Zhu Lu
Published: December 2023

In order to simulate and analyze the mechanized seeding process of sesbania seeds by using a discrete element method and improve the reliability of the discrete element simulation test, the contact parameters of sesbania seeds were calibrated in combination with the actual seed drop test and the simulated seed drop test. Through measurements, the intrinsic parameters of the sesbania seed were determined, and the discrete element simulation model of the sesbania seed was established. A measuring device that can simultaneously measure the resting angle and the stacking angle of the population was designed. The rest angle error and the stack angle error of the actual seed drop test and the simulated seed drop test were used as test indicators. The Plackett–Burman test screened out the contact parameters that had a significant effect on the test indicators. The response surface method (RSM) was used to carry out the three-factor quadratic rotation orthogonal combination test, and the mathematical regression model between the significant contact parameters and the test indexes was established. The optimal combination of contact parameters was determined using the multi-objective optimization method as follows: collision recovery coefficient between seeds of 0.463, static friction coefficient between seeds of 0.520, and rolling friction coefficient between seeds of 0.072. The discrete element model and calibration parameters of sesbania seeds were tested and verified using a fluted roller feed mechanism. The results showed that the average relative error between the measured value and the simulated value of the mass flow rate of the sesbania seeds was 2.74%, less than 5%, indicating that the discrete element simulation model of sesbania seeds and the calibration results of the contact parameters had high accuracy and reliability, which could be used for the discrete element simulation test of sesbania seeds.
Analysis of Solid-Liquid Two-Phase Flow in the Area of Rotor and Tailpipe
Authors: Xie Gengda , Li Qifei , Xin Lu , Li Zhanyong
Published: December 2023

In order to study the internal flow state and wear law of a bulb cross-flow unit based on the particle non-uniform phase model in the Euler–Euler method, the solid-liquid two-phase flow condition of the hydraulic turbine under different solid-phase diameters, concentrations, and guide vane openings is calculated. The results show that (1) Under the same solid-phase physical parameters, the distribution of solid-phase concentration on the working surface of the blade is positively correlated with the opening degree of the guide vane, the concentration of the solid phase on the back of the blade is negatively correlated with the opening degree of the guide vane. (2) The addition of the solid phase changes the time-domain period of pressure pulsations at the rotor inlet and the tailpipe inlet under clear water conditions, and the tailpipe pressure pulsation coefficient decreases with increasing solid-phase concentration. The pressure pulsation coefficient increases with increasing solid-phase diameter and concentration at the inlet of the rotor. (3) Numerical simulation of the wear characteristics of cross-flow turbine by Finne’s wear model reveals that the two-phase flow condition with high concentration, large particle size and small openings has a more serious effect on turbine blade wear.
Assessing the Impact of BMPs on Water Quality and Quantity in a Flat Agricultural Watershed in Southern Ontario
Authors: Miele Peter , Shukla Rituraj , Prasher Shiv , Rudra Ramesh Pal , Daggupati Prasad , Goel Pradeep Kumar , Stammler Katie , Gupta Anand Krishna
Published: December 2023

Non-point source pollution poses a continuous threat to the quality of Great Lakes waters. To abate this problem, the Great Lakes Agricultural Stewardship Initiative (GLASI) was initiated in Ontario, Canada, with the primary aim of reducing phosphorus pollution. Therefore, a case-study analysis of the Wigle Creek watershed, one of the six priority watersheds under the GLASI program, was undertaken to evaluate the effectiveness of various existing and potential future Best Management Practices (BMPs) and to identify BMPs that might aid in mitigating the watershed’s contribution to phosphorus loads reaching Lake Erie. Given the watershed’s very flat topography, hydrological/nutrient modeling proved an extremely challenging exercise. The Soil and Water Assessment Tool (SWAT) model was used in this evaluation. Several digital elevation model (DEM) options were considered to accurately describe the watershed and represent flow conditions. A 30 m resolution DEM, implementing a modified burning in of streams based on ground truthing, was finally employed to develop the SWAT model’s drainage framework. The model was first calibrated for flow, sediment, and phosphorus loads. The calibrated model was used to evaluate the ability of potential BMPs (minimum tillage, no-till, retiring croplands into pasture, retiring croplands into forest, winter wheat cover crop, and vegetative filter strips) to reduce phosphorus loads compared to implemented practice. Converting all croplands into pasture or forest significantly decreased P loads reaching Lake Erie. Comparatively, a winter wheat cover crop had minimal effect on reducing phosphorus loading.
On-Orbit Calibration Method for Correction Microwave Radiometer of the HY-2 Satellite Constellation
Authors: Ma Xiaofeng , Lin Mingsen , Zhao Jin , Jia Yongjun , Jiang Chengfei
Published: December 2023

The HY-2D satellite was successfully launched in 2022, which marks the first phase of the HY-2 satellite constellation. In order to reduce the deviation of wet path delay (WPD) between different satellites in the HY-2 satellite constellation and increase precision in the correction microwave radiometer (CMR) products, on-orbit calibration must be performed to the brightness temperature (BT) of the CMR in this constellation. This study describes the principle and process of on-orbit calibration for CMR in detail. For the three satellites of the HY-2 satellite constellation, after cross-matching with each other within a limited spatio-temporal range, the HY-2B satellite with sounding on the global ocean is selected to the calibration source, calibrating BT from the CMR of the HY-2C and HY-2D satellites to the BT dimension of the HY-2B satellite CMR. To check on-orbit calibration, a retrieval algorithm is built using atmospheric profile data from ECMWF and BT data, obtained from the CMR of the HY-2B satellite; this is used to calculate the atmospheric water vapor (AWV) and WPD from the HY-2 satellite constellation. After on-orbit calibration to the CMRs of the HY-2 satellite constellation, the deviation between the CMR products of different satellites is significantly reduced by over 20%, and the RMS of WPD for the same type of products from the Jason-3 satellite is less than 1 cm. It may be concluded that on-orbit calibration improves the accuracy of AWV and WPD by normalizing the BT dimension for CMRs of the HY-2 satellite constellation, so this calibration method is effective and credible for enhancing the quality of altimeter products in the HY-2 satellite constellation.
Wavelet Transform Feature Enhancement for Semantic Segmentation of Remote Sensing Images
Authors: Li Yifan , Liu Ziqian , Yang Junli , Zhang Haopeng
Published: December 2023

With developments in deep learning, semantic segmentation of remote sensing images has made great progress. Currently, mainstream methods are based on convolutional neural networks (CNNs) or vision transformers. However, these methods are not very effective in extracting features from remote sensing images, which are usually of high resolution with plenty of detail. Operations including downsampling will cause the loss of such features. To address this problem, we propose a novel module called Hierarchical Wavelet Feature Enhancement (WFE). The WFE module involves three sequential steps: (1) performing multi-scale decomposition of an input image based on the discrete wavelet transform; (2) enhancing the high-frequency sub-bands of the input image; and (3) feeding them back to the corresponding layers of the network. Our module can be easily integrated into various existing CNNs and transformers, and does not require additional pre-training. We conducted experiments on the ISPRS Potsdam and ISPRS Vaihingen datasets, with results showing that our method improves the benchmarks of CNNs and transformers while performing little additional computation.
Reconstruction of Continuous High-Resolution Sea Surface Temperature Data Using Time-Aware Implicit Neural Representation
Authors: Wang Yang , Karimi Hassan A. , Jia Xiaowei
Published: December 2023

Accurate climate data at fine spatial resolution are essential for scientific research and the development and planning of crucial social systems, such as energy and agriculture. Among them, sea surface temperature plays a critical role as the associated El Niño–Southern Oscillation (ENSO) is considered a significant signal of the global interannual climate system. In this paper, we propose an implicit neural representation-based interpolation method with temporal information (T_INRI) to reconstruct climate data of high spatial resolution, with sea surface temperature as the research object. Traditional deep learning models for generating high-resolution climate data are only applicable to fixed-resolution enhancement scales. In contrast, the proposed T_INRI method is not limited to the enhancement scale provided during the training process and its results indicate that it can enhance low-resolution input by arbitrary scale. Additionally, we discuss the impact of temporal information on the generation of high-resolution climate data, specifically, the influence of the month from which the low-resolution sea surface temperature data are obtained. Our experimental results indicate that T_INRI is advantageous over traditional interpolation methods under different enhancement scales, and the temporal information can improve T_INRI performance for a different calendar month. We also examined the potential capability of T_INRI in recovering missing grid value. These results demonstrate that the proposed T_INRI is a promising method for generating high-resolution climate data and has significant implications for climate research and related applications.
Research on the Mechanical Properties and Temperature Compensation of an Intelligent Pot Bearing for a Pipe-Type Welding Strain Gauge
Authors: Deng Nianchun , Zhang Haitang , Ning Feng , Tang Zhiyu
Published: December 2023

As an important component connecting the upper and lower structures of a bridge, bridge bearings can reliably transfer vertical and horizontal loads to a foundation. Bearing capacity needs to be monitored during construction and maintenance. To create an intelligent pot bearing, a portable small spot welding machine is used to weld pipe-type welding strain gauges to the pot bearing to measure strain and force values. The research contents of this paper include the finite element analysis of a basin bearing, optimal arrangement of welding strain gauges, calibration testing, and temperature compensation testing of the intelligent basin bearing of the welding strain gauges. Polynomial fitting is used for the fitting and analysis of test data. The results indicate that the developed intelligent pot bearing has a high-precision force measurement function and that after temperature compensation, the measurement error is within 1.8%. The intelligent pot bearing has a low production cost, and the pipe-type welding strain gauges can be conveniently replaced. The novelty is that the bearing adopts a robust pipe-type welding strain gauge and that automatic temperature compensation is used. Therefore, the research results have excellent engineering application value.
Fiducial Objects: Custom Design and Evaluation
Authors: García-Ruiz Pablo , Romero-Ramirez Francisco J. , Muñoz-Salinas Rafael , Marín-Jiménez Manuel J. , Medina-Carnicer Rafael
Published: December 2023

Camera pose estimation is vital in fields like robotics, medical imaging, and augmented reality. Fiducial markers, specifically ArUco and Apriltag, are preferred for their efficiency. However, their accuracy and viewing angle are limited when used as single markers. Custom fiducial objects have been developed to address these limitations by attaching markers to 3D objects, enhancing visibility from multiple viewpoints and improving precision. Existing methods mainly use square markers on non-square object faces, leading to inefficient space use. This paper introduces a novel approach for creating fiducial objects with custom-shaped markers that optimize face coverage, enhancing space utilization and marker detectability at greater distances. Furthermore, we present a technique for the precise configuration estimation of these objects using multiviewpoint images. We provide the research community with our code, tutorials, and an application to facilitate the building and calibration of these objects. Our empirical analysis assesses the effectiveness of various fiducial objects for pose estimation across different conditions, such as noise levels, blur, and scale variations. The results suggest that our customized markers significantly outperform traditional square markers, marking a positive advancement in fiducial marker-based pose estimation methods.
RRGA-Net: Robust Point Cloud Registration Based on Graph Convolutional Attention
Authors: Qian Jian , Tang Dewen
Published: December 2023

The problem of registering point clouds in scenarios with low overlap is explored in this study. Previous methodologies depended on having a sufficient number of repeatable keypoints to extract correspondences, making them less effective in partially overlapping environments. In this paper, a novel learning network is proposed to optimize correspondences in sparse keypoints. Firstly, a multi-layer channel sampling mechanism is suggested to enhance the information in point clouds, and keypoints were filtered and fused at multi-layer resolutions to form patches through feature weight filtering. Moreover, a template matching module is devised, comprising a self-attention mapping convolutional neural network and a cross-attention network. This module aims to match contextual features and refine the correspondence in overlapping areas of patches, ultimately enhancing correspondence accuracy. Experimental results demonstrate the robustness of our model across various datasets, including ModelNet40, 3DMatch, 3DLoMatch, and KITTI. Notably, our method excels in low-overlap scenarios, showcasing superior performance.
NOBEL-BOX: Development of a Low-Cost Ship-Based Instrument for Ocean Monitoring
Authors: Purba Noir P. , Faizal Ibnu , Martasuganda Marine K. , Wulandari Ajeng , Kusuma Rd. Salsa D. , Ilmi Muhammad H. , Febriani Choerunnissa , Alfarez Raffy R. , Argeta Fickry , Wicaksana Jati S.
Published: December 2023

This research aims to develop an inexpensive ocean observation instrument with the project name NOBEL (Nusantara Oceanography Backdoor Experiment Laboratory)-BOX. The device can be installed on all types of vessels for mapping the water conditions, providing accurate data for managing a marine area, particularly regarding water quality. The principle of NOBEL-BOX is to attach six sensors in a container connected to a microcontroller and then measure specific data directly and automatically. The methodology employed included experimental design, laboratory and field tests, and data evaluation to develop the necessary system and instruments. The design process encompassed the construction of the instrument and the fabrication, involving the creation of three-dimensional drawings and the design of microcontrollers and data transmission systems and power capacity. This instrument is box-shaped with a microcontroller, sensors, a battery, and cables located inside. The testing phase included data validation, testing of the device in the laboratory, and field testing showed that the device worked. The data provided from this instrument could meet the specific criteria for seawater analysis.
Textile-Based Body Capacitive Sensing for Knee Angle Monitoring
Authors: Galli Valeria , Ahmadizadeh Chakaveh , Kunz Raffael , Menon Carlo
Published: December 2023

Monitoring human movement is highly relevant in mobile health applications. Textile-based wearable solutions have the potential for continuous and unobtrusive monitoring. The precise estimation of joint angles is important in applications such as the prevention of osteoarthritis or in the assessment of the progress of physical rehabilitation. We propose a textile-based wearable device for knee angle estimation through capacitive sensors placed in different locations above the knee and in contact with the skin. We exploited this modality to enhance the baseline value of the capacitive sensors, hence facilitating readout. Moreover, the sensors are fabricated with only one layer of conductive fabric, which facilitates the design and realization of the wearable device. We observed the capability of our system to predict knee sagittal angle in comparison to gold-standard optical motion capture during knee flexion from a seated position and squats: the results showed an R2 coefficient between 0.77 and 0.99, root mean squared errors between 4.15 and 12.19 degrees, and mean absolute errors between 3.28 and 10.34 degrees. Squat movements generally yielded more accurate predictions than knee flexion from a seated position. The combination of the data from multiple sensors resulted in R2 coefficient values of 0.88 or higher. This preliminary work demonstrates the feasibility of the presented system. Future work should include more participants to further assess the accuracy and repeatability in the presence of larger interpersonal variability.
Objective Measurement of Posture and Movement in Young Children Using Wearable Sensors and Customised Mathematical Approaches: A Systematic Review
Authors: Hendry Danica , Rohl Andrew L. , Rasmussen Charlotte Lund , Zabatiero Juliana , Cliff Dylan P. , Smith Simon S. , Mackenzie Janelle , Pattinson Cassandra L. , Straker Leon , Campbell Amity
Published: December 2023

Given the importance of young children’s postures and movements to health and development, robust objective measures are required to provide high-quality evidence. This study aimed to systematically review the available evidence for objective measurement of young (0–5 years) children’s posture and movement using machine learning and other algorithm methods on accelerometer data. From 1663 papers, a total of 20 papers reporting on 18 studies met the inclusion criteria. Papers were quality-assessed and data extracted and synthesised on sample, postures and movements identified, sensors used, model development, and accuracy. A common limitation of studies was a poor description of their sample data, yet over half scored adequate/good on their overall study design quality assessment. There was great diversity in all aspects examined, with evidence of increasing sophistication in approaches used over time. Model accuracy varied greatly, but for a range of postures and movements, models developed on a reasonable-sized (n > 25) sample were able to achieve an accuracy of >80%. Issues related to model development are discussed and implications for future research outlined. The current evidence suggests the rapidly developing field of machine learning has clear potential to enable the collection of high-quality evidence on the postures and movements of young children.
Construction of Green Ecological Network in Qingdao (Shandong, China) Based on the Combination of Morphological Spatial Pattern Analysis and Biodiversity Conservation Function Assessment
Authors: Tao Ling , Chen Yanni , Chen Fang , Li Haifang
Published: December 2023

Building urban green ecological network systems and increasing urban and rural landscape connectivity are effective ways to improve urban biodiversity and landscape sustainability. The ecological sources in the main urban area of Qingdao City (Shandong, China) were identified based on morphological spatial pattern analysis (MSPA) combined with a biodiversity conservation function assessment, with the ecological corridors established and the ecological network structure optimized. The results showed that (1) the study area lacked high-quality patches with strong landscape connectivity; (2) the potential green ecological network of the study area was composed of 38 ecological sources, 703 ecological corridors, and 284 ecological nodes, effectively connecting urban and suburban green spaces; (3) after optimization, the green ecological network contained a total of 223 important corridors and 61 key nodes, with significantly increased network connectivity; (4) the optimal ecological corridor width in Qingdao was determined to be 30 m. Our study provided important guidance for the construction of ecological security patterns and scientific evidence to support urban green space planning and sustainable development in Qingdao.
Factors Affecting Social Learning in Nearby Pockets on Tropical Campus Grounds: Towards a Sustainable Campus
Authors: Alzamil Waleed , Salih Sarah Abdulkareem , Ismail Sumarni , Ajlan Ali , Azmi Athira
Published: December 2023

Nearby natural environments on campus grounds have become imperative in enhancing sustainable academic experiences by facilitating sustainable social learning. However, tropical region campuses prioritise traditional education while neglecting sustainable social learning. Therefore, the purpose of this study was to facilitate the use of nearby sustainable pocket settings on campus grounds to enhance social learning experiences. The present study aimed to identify factors affecting social learning experiences in nearby (sustainable) pocket spaces on tropical campuses. It utilised a verbal questionnaire survey conducted in three research universities in Malaysia to investigate the factors affecting 408 respondents in nearby (sustainable) pockets. The respondents were selected using stratified judgemental sampling. This study’s findings revealed that many influencing factors predicted the social learning experience in tropical universities’ nearby pockets, which were arranged into four domain factors: elements and activities, natural environment factors, perceived environment factors, and social factors. This provided a proven correlation between the lack of social learning in nearby pockets and the factors of these sustainable settings. The findings also showed that students’ demographic factors, including education status and university affiliation, influenced their social learning experience. The present study significantly linked education to sustainability by integrating social learning into nearby sustainable pocket settings.
Ordering Decisions with an Unreliable Supplier under the Carbon Cap-and-Trade System
Authors: Ren Yuheng , Bian Wenliang , Li Haicheng , Ma Xiaxia
Published: December 2023

The global focus on carbon reduction has intensified, prompting numerous high-energy-consuming enterprises to venture into the carbon cap-and-trade system. However, in recent years, the emergence of destabilizing factors has introduced disruptions to supply chains. The study addresses the two-stage ordering problem for a manufacturer under the carbon cap-and-trade system. In the first stage, the manufacturer engages in green investments and places orders with both an unreliable and a reliable supplier. After updating demand forecast information in the second stage, orders are placed with the backup supplier, and carbon allowances are settled at the end of the period. Under these conditions, three supply scenarios of the unreliable supplier are considered: time-varying supply with imperfect demand updates, all-or-nothing supply with imperfect demand updates, and time-varying supply with perfect demand updates. Optimal ordering decisions are provided for each scenario. We find that when demand updates are imperfect, the manufacturer will invariably engage with the unreliable supplier. However, when demand updates are perfect, the manufacturer may choose to forgo the unreliable supplier. Next, we analyze the influence of carbon trading prices on ordering decisions in these scenarios. We find that when the probability of disruption is substantial, dual sourcing must exist in the first stage under the all-or-nothing supply. Finally, we conduct numerical analysis by utilizing parameters, such as carbon trading prices, as referenced in the existing literature. Through numerical analysis, we find that opting for the all-or-nothing supplier becomes economically advantageous for the manufacturer when the backup supplier is profitable. Conversely, when the backup supplier is not profitable, the manufacturer tends to opt for the unreliable supplier with time-varying supply. Moreover, optimal profit for the manufacturer is not achieved when demand updates are perfect.
Exploring the Pathways to Tourist Loyalty in Pakistani Tourism Industry: The Role of Destination Image, Service Quality, E-WOM, and Social Media
Authors: Rahman Afshan , Farooq Naveed , Haleem Muhammad , Shah Syed Mohsin Ali , El-Gohary Hatem
Published: December 2023

Tourism plays a pivotal role in Pakistan’s economic landscape. Understanding the drivers of tourist loyalty is paramount for sustainable growth. This study delves into the factors influencing tourist loyalty within Pakistan’s tourism sector, examining the destination image, service quality, electronic word of mouth, and tourist satisfaction. Data sourced from a tourist survey at popular Pakistani destinations unveil significant relationships and mediation effects. The results underscore that a positive destination image and superior services directly impact tourist loyalty. Furthermore, electronic word of mouth and tourist satisfaction mediate these relationships, highlighting how positive perceptions and satisfaction bolster loyalty. Social media also exerts a moderating influence on the destination image, service quality, and tourist loyalty dynamics. These findings offer crucial insights for tourism stakeholders and destination marketers to refine strategies. By enhancing its destination image, delivering exceptional services, and leveraging social media, Pakistan can both attract and retain tourists, bolstering its tourism sector’s growth and prosperity. This study contributes to the existing literature and offers practical guidance for promoting tourism in developing nations like Pakistan.
Enrichment of a Mixed Culture of Purple Non-Sulfur Bacteria for Hydrogen Production from Organic Acids
Authors: Smith Sean C. , Toledo-Alarcón Javiera , Schiappacasse María Cristina , Tapia-Venegas Estela
Published: December 2023

Hydrogen (H2) as a clean fuel holds global potential and can be produced through bio-processes. To enhance bioH2 yields, integrated systems have been proposed, combining dark fermentation (DF) of wastewater with a subsequent photofermentation (PF) stage involving purple non-sulfur (PNS) bacteria. Mixed cultures of PNS bacteria and their microbial ecology have been relatively understudied despite the known benefits of mixed cultures in industrial applications. The aim of this study was to obtain various mixed cultures of PNS bacteria under different environmental conditions during the enrichment stage. Four different mixed cultures were obtained (A, B, C, and D). However, in the H2 production phase, only Consortium A, which had been enriched with malic acid as the carbon source, exposed to 32 W m−2 of irradiance, and subjected to intermittent agitation, produced H2 with a yield of 9.37 mmol H2 g−1 COD. The consortia enriched were a hybrid of PF and DF bacteria. Especially in Consortium A, Rhodopseudomonas palustris was the dominant organism, and various DF bacteria were positively associated with H2 production, with their dominance comparable to that of PNS bacteria. Despite the reported low yields, optimizing environmental conditions for this culture could potentially enhance hydrogen production from DF effluents.
Spatial and Information Accessibility of Museums and Places of Historical Interest: A Comparison between London and Thessaloniki
Authors: Koustriava Eleni , Koutsmani Maria
Published: December 2023

Accessibility to the cultural heritage of museums is an inalienable right of all individuals. However, these places appear to be very unfriendly and unsustainable towards individuals with mobility, sensory, and cognitive difficulties, resulting in their exclusion from cultural heritage. The aim of the research was to examine the spatial and information accessibility in certain museums and places of historical interest in two culturally important European cities, London (Great Britain) and Thessaloniki (Greece). Fifteen museums in London and fifteen in Thessaloniki were visited and assessed thoroughly. The tools used were a) an extended checklist of accessibility criteria and standards developed in the context of the present research and b) a semi-structured interview. The results showed that the London museums are slightly more accessible than the museums in Thessaloniki, especially with reference to spatial accessibility. All participant museums should focus more on individuals with impairments other than physical/mobility since their main accessibility features appear to serve only mobility and navigation needs. Moreover, while the buildings of the recent past are more accessible, buildings that are listed or are themselves of historical interest are difficult to adjust. The results present which specific categories need to be urgently targeted and, thus, in which direction any corrective action towards accessibility should be placed. These findings are of great interest for all stakeholders in cultural accessibility and social inclusion.
Travel Experience and Reasons for the Use and Nonuse of Local Public Transport: A Case Study within the Community Interregional Project SaMBA (Sustainable Mobility Behaviors in the Alpine Region)
Authors: Bina Manuela , Biassoni Federica
Published: December 2023

Knowing the reasons for mobility choices, how users evaluate the characteristics of public transport and how satisfied they are with their travel experience is essential to promote the use of LPT (local public transport), especially in rural or suburban areas where the use of private cars is often prevalent. The present study aimed to investigate the mobility experience and the reasons for use and nonuse of the LPT in a suburban area by the people traveling to a large hospital center in a province of the north-east of Italy. An anonymous questionnaire was completed by people from different categories traveling to the hospital (students, employees, clients), who were user and nonusers of the LPT. The results showed that insufficient hourly coverage and accessibility of the service are the primary reasons for opting not to use LPT and, together with reliability and comfort, these factors contribute to user satisfaction with their travel experience. The perceived sustainability of LPT contributes to overall travel satisfaction. However, perceived sustainability alone does not appear to influence the choice of LPT if the service lacks adequate accessibility and does not meet the needs of travelers in terms of hourly coverage.
Criteria for and Policy Implications of Setting Recovery Priorities of National Functions during Disruptions by Disasters
Authors: Hong Seok Bum , Lee Jin Byeong , Shin Jeong Hoon , Yun Hong Sik
Published: December 2023

National functions are categories of operations prioritised for restoration when disrupted by emergencies such as disasters. However, the simultaneous restoration of all national functions when some or all are paralysed is limited by time and resources. Delays in the restoration of key functions can lead to public dissatisfaction. Thus, it is necessary to broadly classify national functions and analyse their restoration priorities based on criticality. This study identifies 19 national functions from Republic of Korea’s comprehensive Business Reference Model. A survey was conducted among citizens and officials to determine the criticality of each function. Statistical analyses verified the consistency (Cronbach’s alpha = 0.860) and correlation (average Cramer’s V = 0.107) of the criticality responses across regions. The null hypothesis of no regional differences in the criticality of national functions was accepted, validating their universality. Restoration priorities were derived from these criticality values, with ‘Disaster Safety Response’ as the highest priority and ‘Regional Development’ as the lowest. These results provide foundational data for the post-disaster restoration priorities of national functions and emphasise the need to consider public opinion, needs, and government resource limitations in disaster management planning.
Feasibility Analysis of Offshore Wind Power Projects in the Caribbean Region of Colombia: A Case Study Using FAHP–GIS
Authors: Castro Adalberto Ospino , Robles-Algarín Carlos , Hernández-Callejo Luis , Muñoz Maldonado Yecid , Cordero Amanda Mangones
Published: December 2023

Planning for offshore wind energy projects is intricate due to the consideration of multiple variables in identifying optimal project areas. The primary challenge lies in locating suitable sites, a process that often necessitates extensive feasibility studies spanning several years. The primary goal of this study is to apply the Fuzzy Analytic Hierarchy Process (FAHP) to prioritize criteria and sub-criteria, facilitating decision-making in choosing appropriate locations for offshore wind projects in the Colombian Caribbean Sea. The weights derived from FAHP were utilized in a Geographic Information System (GIS) to analyze the physical characteristics of the Caribbean Sea’s surface. This tool plays a critical role in evaluating and selecting sites that fulfill established criteria, providing a database of indicators and map visualizations. Four criteria were defined: technical, environmental, social, and economic, along with fourteen sub-criteria, which were prioritized through FAHP based on expert judgment. The results revealed that the most relevant sub-criteria were protected areas and wind speed. Utilizing the ArcGIS Pro software, five zones meeting the predetermined criteria were identified, defining the most feasible areas for offshore wind farm installation, located in the departments of Guajira, Magdalena, Atlántico and Bolívar. The GIS–FAHP methods proved to be useful for feasibility analysis.
Classification of Genus Three Zero-Divisor Graphs
Authors: Asir Thangaraj , Mano Karuppiah , Alsuraiheed Turki
Published: December 2023

In this paper, we consider the problem of classifying commutative rings according to the genus number of its associating zero-divisor graphs. The zero-divisor graph of R, where R is a commutative ring with nonzero identity, denoted by Γ(R), is the undirected graph whose vertices are the nonzero zero-divisors of R, and the distinct vertices x and y are adjacent if and only if xy=0. Here, we classify the local rings with genus three zero-divisor graphs.
Proteomic Analysis of the Mitochondrial Responses in P19 Embryonic Stem Cells Exposed to Florfenicol
Authors: Dong Zhihua , Hou Xueke , Wang Xueying , Shen Zihui , Pang Huiqing , Chen Lingli , Yin Zhihong , Ren Fei , Li Weiguo , Ge Yaming , Ning Hongmei , Hu Dongfang
Published: December 2023

Florfenicol (FLO) has been shown to elicit diverse toxic effects in plants, insects, and mammals. Previously, our investigations revealed that FLO induced abnormal cardiac development and early embryonic mortality in chicken embryos. However, the effect of FLO on mitochondrial responses in stem cells remains unclear. In this study, we show that FLO significantly diminishes proliferation viability and obstructs the directed differentiation of P19 stem cells (P19SCs) into cardiomyocytes. Proteomic analysis revealed 148 differentially expressed proteins in response to FLO. Functional analysis has pinpointed FLO interference with biological processes associated with oxidative phosphorylation within the mitochondria. In alignment with the results of proteomic analysis, we confirmed that FLO inhibits the expression of both nuclear DNA-encoded and mitochondrial DNA-encoded subunits of the electron transport chain. Subsequent experiments demonstrated that FLO disrupts mitochondrial dynamics and induces the mitochondrial unfolded protein response to maintain mitochondrial homeostasis. These findings collectively highlight the significance of mitochondrial dynamics and the mitochondrial unfolded protein response to mediate the decreased proliferation viability and directed differentiation potential in P19SCs treated with FLO. In conclusion, this study provides a comprehensive overview of mitochondrial responses to FLO-induced cytotoxicity and enhances our understandings of the molecular mechanisms underlying FLO-induced embryonic toxicity.
Semi-Correlations for Building Up a Simulation of Eye Irritation
Authors: Toropov Andrey A. , Toropova Alla P. , Roncaglioni Alessandra , Benfenati Emilio
Published: December 2023

The OECD recognizes that data on a compound’s ability to treat eye irritation are essential for the assessment of new compounds on the market. In silico models are frequently used to provide information when experimental data are lacking. Semi-correlations, as they are called, can be useful to build up categorical models for eye irritation. Semi-correlations are latent regressions that can be used when the endpoint is expressed by two values: 1 for an active molecule and 0 for an inactive molecule. The regression line is based on the descriptor values which serve to distribute the data into four classes: true positive, true negative, false positive, and false negative. These values are applied to calculate the corresponding statistical criterion for assessing the predictive potential of the categorical model. In our model, the descriptor is the sum of what are termed correlation weights. These are defined by optimization using the Monte Carlo method. The target function of the optimization is related to the determination coefficient and the mean absolute error for the training set. Our model gives results that are better than those previously reported for the same endpoint.
Microcystin Concentrations, Partitioning, and Structural Composition during Active Growth and Decline: A Laboratory Study
Authors: Pierce Emily F. , Schnetzer Astrid
Published: December 2023

Microcystin can be present in variable concentrations, phases (dissolved and particulate), and structural forms (congeners), all which impact the toxicity and persistence of the algal metabolite. Conducting incubation experiments with six bloom assemblages collected from the Chowan River, North Carolina, we assessed microcystin dynamics during active growth and biomass degradation. Upon collection, average particulate and dissolved microcystin ranged between 0.2 and 993 µg L−1 and 0.5 and 3.6 µg L−1, respectively. The presence of congeners MC-LA, -LR, -RR, and -YR was confirmed with MC-RR and MC-LR being the most prevalent. Congener composition shifted over time and varied between dissolved and particulate phases. Particulate microcystin exponentially declined in five of six incubations with an average half-life of 10.2 ± 3.7 days, while dissolved microcystin remained detectable until the end of the incubation trials (up to 100 days). Our findings suggest that concerns about food-web transfer via intracellular toxins seem most warranted within the first few weeks of the bloom peak, while dissolved toxins linger for several months in the aftermath of the event. Also, it was indicated there were differences in congener profiles linked to the sampling method. We believe this study can inform monitoring strategies and aid microcystin-exposure risk assessments for cyanobacterial blooms.
Binary Black Hole Spins: Model Selection with GWTC-3
Authors: Périgois Carole , Mapelli Michela , Santoliquido Filippo , Bouffanais Yann , Rufolo Roberta
Published: December 2023

The origin of the spins of stellar-mass black holes is still controversial, and angular momentum transport inside massive stars is one of the main sources of uncertainty. Here, we apply hierarchical Bayesian inference to derive constraints on spin models from the 59 most confident binary black hole merger events in the third gravitational-wave transient catalogue (GWTC-3). We consider up to five parameters: chirp mass, mass ratio, redshift, effective spin, and precessing spin. For the model selection, we use a set of binary population synthesis simulations spanning drastically different assumptions for black hole spins and natal kicks. In particular, our spin models range from the maximal to minimal efficiency of angular momentum transport in stars. We find that if we include the precessing spin parameter into our analysis, models predicting only vanishingly small spins are in tension with GWTC-3 data. On the other hand, models in which most spins are vanishingly small but that also include a subpopulation of tidally spun-up black holes are a good match to the data. Our results show that the precessing spin parameter has a crucial impact on model selection.