bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aerothermal characterization of the CALLISTO vehicle during descent
Authors: Ecker Tobias , Ertl Moritz , Klevanski Josef , Krummen Sven , Dumont Etienne 
Published: July 2024

Abstract

Aerothermal loads are a design driving factor during launcher development as the thermal loads directly influence TPS design and trajectory. Recent developments in reusable launch vehicles (RLV) (e.g. SpaceX, Blue Origin) have added the dimension of refurbishment to the challenges the thermal design must consider. For disposable launchers the heat flux due to base heating during ascent needs to be considered for aft thermal protections system (TPS) and structural design. With the current European long term strategy moving towards a reusable first stage - aerothermal loads may significantly change. The CALLISTO vehicle is a flight demonstrator for future reusable launcher stages and their technologies. The program involves three countries and their space organizations: CNES for France, DLR for Germany and JAXA for Japan. The first tests will be conducted in 2024 from CSG, Europe's Spaceport. The challenge is to develop, all along the project, the skills of the partners. This know-how includes products and vehicle design, ground segment set up, and post-flight operations for vehicle recovery then reuse. For the CALLISTO vehicle the highest heat fluxes are mainly due to heating from hot exhaust gases and heated air in proximity of the aft bay and on the exposed structures like legs and fins. The development of the plume extension is different for the considered re-entry, when compared to Falcon 9, or other studies presented in the past. As shown in previous studies the plume remains relatively concentrated at the aft end of the vehicle due to high atmospheric pressure and only very low fractions of actual exhaust gas species enclosing the vehicle. In the current study we conducted computational fluid dynamics (CFD) studies in order to determine the aerothermal loads on the vehicle during descent through the landing approach corridor for both phase B and phase C aeroshapes. The database development for vehicle phase B and phase C are described in detail and analyzed for some of the most prominent interfaces. The final phase C database presented allows interpolation of interface heatfluxes for the entire flight domain (M, $\rho)$ at varying angle of attack (between 180 deg and 160 deg). Further the sensitivity of the plume-vehicle interaction to angle of attack, chemistry, thrust vector deflection and engine throttling are investigated for a critical Mach number indicating further area of improvement for future databases.
A Multisite Inventory Study of Neonatal Syringe Pumps in Zambia
Authors: Norton Oliver , Jha Prashant , Kazuma Seke , Lupupa Mumbi , Mmwamba Esther 
Published: July 2024

Abstract

Background: The global neonatal mortality rate is due to miss the third Sustainable Development Goal of 12 deaths per 100 live births by 2030. However, medical devices can play a crucial role in improving the quality of care given to neonates, helping to reduce the rate further.
Methods: This study focuses on quantifying the availability of syringe pumps to newborns at key hospital locations in Zambia. Inventories of syringe pumps on neonatal intensive care units (NICUs) were conducted at 7 different hospitals.
Results: Syringe pumps were only available on 3 of the 8 NICUs. Only 1 of the 13 syringe pumps were found in the Copperbelt region, despite 5 of the hospitals being located there. The largest syringe pump-to-bed ratio was 0.17 at Livingstone University Teaching Hospital.
Conclusions: In Zambia, there is a disproportionate availability of syringe pumps, for neonatal care, in the Lusaka and Southern regions compared to the Copperbelt region in the north.
Taming the chaos gently: a Predictive Alignment learning rule in recurrent neural networks
Authors: Asabuki Toshitake , Clopath Claudia 
Published: July 2024

Abstract

Recurrent neural circuits often face inherent complexities in learning and generating their desired outputs, especially when they initially exhibit chaotic spontaneous activity. While the celebrated FORCE learning rule can train chaotic recurrent networks to produce coherent patterns by suppressing chaos, it requires non-local plasticity rules and extremely quick plasticity, raising the question of how synapses adapt on local, biologically plausible timescales to handle potential chaotic dynamics. We propose a novel framework called "Predictive Alignment", which tames the chaotic recurrent dynamics to generate a variety of patterned activities via a biologically plausible plasticity rule. Unlike most recurrent learning rules, predictive alignment does not aim to directly minimize output error to train recurrent connections, but rather it tries to efficiently suppress chaos by aligning recurrent prediction with chaotic activity. We show that the proposed learning rule can perform supervised learning of multiple target signals, including complex low-dimensional attractors, delay matching tasks that require short-term temporal memory, and finally even dynamic movie clips with high-dimensional pixels. Our findings shed light on how predictions in recurrent circuits can support learning.
Assessment of groundwater hydrogeological processes, isotopic composition, and associated health risks of the Banaz (Usak) Basin, Turkey
Authors: Aksever Fatma 
Published: July 2024

ABSTRACT

The study area covers the Banaz (Usak) basin located in the Aegean Region in the western part of Turkey. Metamorphic, sedimentary, ultramafic, and volcanic rocks are dominant in the basin. The groundwaters in the study area are used for domestic, irrigational, and industrial purposes. Hence, the groundwater chemistry and major geochemical processes in the region were determined. The dominance of major elements was of the order of Ca2+ &gt; Mg2+ &gt; Na+ &gt; K+ and HCO3− &gt; CO3− &gt; Cl− &gt; SO42−. Piper, Durov, Chadha, and Radial plots identified generally Ca2+-Mg2+-HCO3− type waters as the dominant types of water in this area. In terms of physical parameters in the basin, the waters are suitable for drinking. However, arsenic content in Yesilyurt and Corum settlements exceeds the limit values of drinking water standards. In addition, the ammonium value is high in the water sample in the Corum region. Isotope contents in water samples from 2008 to 2023 were evaluated in the study area. The waters in the basin are of meteoric origin according to their stable isotope content. Tritium content in the plain waters indicates recent recharge. Additionally, for children, As and U elements were identified as risky with oral intake and As with dermal contact.
The performance of encoder–decoder neural networks for leak detection in water distribution networks
Authors: Mohan Doss Prasanna , Rokstad Marius Møller , Tscheikner-Gratl Franz 
Published: July 2024

ABSTRACT

This work outlines the performance of three variants of deep neural networks for leak detection in water distribution networks, namely – autoencoders (AEs), variational autoencoders (VAEs), and long short-term memory autoencoders (LSTM-AEs). The multivariate pressure signals reconstructed from these models are analysed for leakage identification. The leak onset time is estimated using a fast approximation sliding window technique, which computes statistical discrepancies in prediction errors. The performance of all three variants is validated using the widely studied L-Town benchmark network. Furthermore, their feasibility for real-world application is studied by applying them to a real-world case study representing the data availability and network design often found in smaller- and medium-sized utilities in Norway. The results for the benchmark network showed that AE and LSTM-AE showed comparable detection performance for abrupt leaks with VAE performing the least. For incipient leaks, the LSTM-AE showed better detection performance with few false-positives. For the real-world dataset, the performance was significantly lower due to the quantity and quality of data available, and the contradiction of inherent requirements of data-driven models. In addition, the analysis revealed that the positioning of pressure sensors in the network is critical for the leak detection performance of these models.
Progress of metal-loaded biochar-activated persulfate for degradation of emerging organic contaminants
Authors: Zhou Tianhong , Shi Chao , Wang Yangyang , Wang Xiaoshu , Lei Zhenle , Liu Xunjie , Wu Jinyu , Luo Fengxiang , Wang Lei 
Published: July 2024

ABSTRACT
In recent years, studies on the degradation of emerging organic contaminants by sulfate radical (SO4−·) based advanced oxidation processes (SR-AOPs) have triggered increasing attention. Metal-loaded biochar (Me-BC) can effectively prevent the agglomeration and leaching of transition metals, and its good physicochemical properties and abundant active sites induce outstanding in activating persulfate (PS) for pollutant degradation, which is of great significance in the field of advanced oxidation. In this paper, we reviewed the preparation method and stability of Me-BC, the effect of metal loading on the physicochemical properties of biochar, the pathways of pollutant degradation by Me-BC-activated PS (including free radical pathways: SO4−·, hydroxyl radical (·OH), superoxide radicals (O2–·); non-free radical pathways: singlet oxygen (1O2), direct electron transfer), and discussed the activation of different active sites (including metal ions, persistent free radicals, oxygen-containing functional groups, defective structures, etc.) in the SR-AOPs system. Finally, the prospect was presented for the current research progress of Me-BC in SR-AOPs technology.
A novel approach to integrate CCHP systems with desalination for sustainable energy and water solutions in educational buildings
Authors: Mohammed Bashir Faizah , Falude Emmanuel , Alsadun Ibtihaj Saad Rashed , Hamdoun Haifa Youssef , Mohamed Mohamed Ahmed Said , Shannan Nahla M. , Naibi Ahmad Usman 
Published: July 2024

ABSTRACT

This study presents a novel approach to integrating combined cooling, heating, and power (CCHP) systems with water desalination for enhanced energy and water management in educational buildings. Two distinct layouts for CCHP and desalination systems are introduced: one prioritizing efficient power generation to meet electricity demands while providing waste heat for desalination, and the other focusing on balancing cooling and heating loads alongside water desalination. Both layouts are tailored to meet the building's energy and water demands while considering operational efficiency. Optimization of these layouts against traditional systems using the bat search algorithm emphasizes economic viability and the gas engine's operational flexibility, which are crucial for partial load operation. In addition, an environmental assessment compares the proposed CCHP-desalination systems with conventional setups, assessing CO2 emission reductions and overall sustainability. The evaluation encompasses key environmental metrics, such as resource consumption and the integration of renewable energy sources. Results highlight significant CO2 emission reductions across various gas engine capacities, with notable enhancements in economic and environmental performance achieved by selecting a 3,250 kW gas engine within the CCHP-desalination system. This choice not only maximizes the annual profit but also reduces CO2 emissions by 57% compared to conventional systems, underscoring the system's sustainability benefits.
The role of hyetograph shape and designer subjectivity in the design of an urban drainage system
Authors: Pritsis Spyros , Pons Vincent , Rokstad Marius Møller , Clemens-Meyer Francois H. L. R. , Kleidorfer Manfred , Tscheikner-Gratl Franz 
Published: July 2024

ABSTRACT

Even though it has been established that a hyetograph's shape affects the results of hydrological simulations, common engineering practice does not always account for this fact. Instead, a single design storm is often considered sufficient for designing a urban drainage system. This study examines the impact that this design paradigm, combined with the uncertainty introduced by subjective choices made during the design process, has on the robustness of a designed system. To do so, we evaluated a set of individual designs created by engineering students using the same Chicago hyetograph as a design storm. We then created ensembles of hyetographs with the same precipitation volume and duration as the Chicago hyetograph and evaluated the designs' hydrological responses. The results showed that designs, which performed equally well for the initial design storm, triggered varying responses for the storms in the ensembles and, consequently, showed different levels of robustness, hinting at a need to adapt the current design approach.
Studi Analisa Keruntuhan Bendungan Wonogiri dengan Program HEC-RAS dan INASAFE
Authors: Grisham Haliq Pambudi  , Suwanto Marsudi  , Jadfan Sidqi Fidari  
Published: July 2024

Abstrak: Bendungan Wonogiri adalah bendungan serba guna yang dibangun pada tahun 1976 dan selesai pada tahun 1981. Bendungan Wonogiri mulai beroperasi pada tahun 1982 telah beroperasi selama 39 tahun. Oleh karena itu perlunya mengkaji dokumen yang memuat isi konsep keamanan bendungan. Tujuan dari penelitian ini adalah untuk mengetahui debit maksimum desain atau kondisi ekstrim yang masuk ke Bendungan Wonogiri di DAS Bengawan Solo Hulu, karakteristik skenario banjir maksimum, tingkat klasifikasi banjir dan besarnya kerugian akibat keruntuhan Bendungan Wonogiri. Dalam analisis keruntuhan bendungan menggunakan aplikasi program HEC-RAS dan InaSAFE. Hasil penelitian menunjukkan bahwa debit puncak periode ulang PMF dengan metode HSS Nakayasu yang telah dikalibrasi dengan debit pengamatan adalah 11.729,93 m3/detik. Hasil analisis menggunakan aplikasi HEC-RAS diperoleh luas genangan banjir maksimum yaitu pada kondisi lower piping dengan kedalaman banjir 26,58 m dan luas genangan 6,481 km2. Berdasarkan simulasi InaSAFE, sebagian besar wilayah terdampak banjir dengan kedalaman lebih dari 3 m dan dilambangkan dengan layer berwarna merah. Kerugian dalam faktor ekonomi yang disebabkan oleh sebaran banjir akibat keruntuhan Bendungan Wonogiri sebesar Rp 56.297.932.372.
Abstract: Wonogiri Dam is a multi-purpose dam that was built in 1976 and completed in 1981. Wonogiri Dam began operating in 1982 it has been operating for 39 years. Hence the necessity to review documents that contain the content of the dam safety concept. This study aims to determine the maximum discharge design or extreme conditions that enter the Wonogiri Dam in the Upper Bengawan Solo River Watershed, the characteristics of the maximum flood scenario, the level of flood classification and the amount of loss due to the Wonogiri Dam collapse. In the analysis of dam collapse using the HEC-RAS and InaSAFE program applications. The results show that the peak discharge of the PMF return period with the Nakayasu HSS method which has been calibrated with the observation discharge is 11,729.93 m3/ second. The analysis results using the HEC-RAS application obtained the maximum flood inundation area in the lower piping condition with a flood depth of 26.58 m and an inundation area of 6.481 km2. Based on the InaSAFE simulation, most area are affected by floods with a depth of more than 3 m and are denoted by a red layer. Losses in economic factors caused by the distribution of floods due to the Wonogiri Dam collapse amounted to Rp 56.297.932.372.
Patterns of Ownership and Usage of Wearable Devices in the United States, 2020-2022: Survey Study (Preprint)
Authors: Nagappan Ashwini , Krasniansky Adriana , Knowles Madelyn 
Published: July 2024

BACKGROUND

Although wearable technology has become increasingly common, comprehensive studies examining its ownership across different sociodemographic groups are limited.

OBJECTIVE

The aims of this study were to (1) measure wearable device ownership by sociodemographic characteristics in a cohort of US consumers and (2) investigate how these devices are acquired and used for health-related purposes.

METHODS

Data from the Rock Health Digital Health Consumer Adoption Survey collected from 2020 to 2022 with 23,974 US participants were analyzed. The sample was US Census–matched for demographics, including age, race/ethnicity, gender, and income. The relationship between sociodemographic factors and wearable ownership was explored using descriptive analysis and multivariate logistic regression.

RESULTS

Of the 23,974 respondents, 10,679 (44.5%) owned wearables. Ownership was higher among younger individuals, those with higher incomes and education levels, and respondents living in urban areas. Compared to those aged 18-24 years, respondents 65 years and older had significantly lower odds of wearable ownership (odds ratio [OR] 0.18, 95% CI 0.16-0.21). Higher annual income (≥US $200,000; OR 2.27, 95% CI 2.01-2.57) and advanced degrees (OR 2.23, 95% CI 2.01-2.48) were strong predictors of ownership. Living in rural areas reduced ownership odds (OR 0.65, 95% CI 0.60-0.72). There was a notable difference in ownership based on gender and health insurance status. Women had slightly higher ownership odds than men (OR 1.10, 95% CI 1.04-1.17). Private insurance increased ownership odds (OR 1.28, 95% CI 1.17-1.40), whereas being uninsured (OR 0.41, 95% CI 0.36-0.47) or on Medicaid (OR 0.75, 95% CI 0.68-0.82) decreased the odds of ownership. Interestingly, minority groups such as non-Hispanic Black (OR 1.14, 95% CI 1.03-1.25) and Hispanic/Latine (OR 1.20, 95% CI 1.10-1.31) respondents showed slightly higher ownership odds than other racial/ethnic groups.

CONCLUSIONS

Our findings suggest that despite overall growth in wearable ownership, sociodemographic divides persist. The data indicate a need for equitable access strategies as wearables become integral to clinical and public health domains.
Traumatic Memory in Mahfud Ikhwan’s Dawuk Dwilogy as a Cultural Manifestation of East Java's Northern Coastal Communities
Authors: Alifian Muhammad Afnani , Saryono Djoko , Karkono  , Rahman Norhayati Ab. 
Published: July 2024

Traumatic memory can become a manifestation of a community's cultural wisdom when the community collectively continues to maintain fear of the object of trauma. Mahfud Ikhwan's Dwilogi Dawuk novel tells the story of traumatic memory rooted in the community's trauma to the livelihood of blandong and the forestry ministry that has been maintained for generations. The purpose of this study is to describe the symptoms of trauma in the Dawuk duogy experienced by the characters to produce findings that traumatic memory can become the cultural wisdom of the community. The data of this research are novel texts in the form of character utterances, narrator monologues, and dialogues between characters. The source of the research data is the Dawuk bilingual novel, namely Dawuk; The Gray Tale of Rumbuk Randu and Anwar Tohari Mencari Mati. Data collection is done with documentation technique. The main instrument in the research is the researcher himself who is supported by a data search grid table. The flow of data analysis in this study, namely (1) data collection, (2) data condensation, (3) data presentation, and (4) conclusion drawing. Once collected, the data were analyzed based on the research focus of traumatic memory symptoms. The results showed that flashback symptoms were experienced when the characters and people of Rumbuk Randu felt, heard, and recalled the traumatic events. Nightmare symptoms occur to characters who feel fear of the traumatized object while in an unconscious state. Meanwhile, the repetitive phenomenon occurs when the Rumbuk Randu community equates current events with bad events in the past. Based on the research results, it can be concluded that this novel is a medium for conveying traumatic memory symptoms about the conflict between blandongan and the forestry ministry on the north coast of East Java, precisely in the Lamongan area.
La comprensión de conceptos estadísticos en la educación secundaria
Authors: Ocampo Castaño Adriana 
Published: July 2024

Las competencias derivadas de las matemáticas tradicionales como la estadística, han cobrado un importante protagonismo los años recientes. El objetivo fundamental del presente artículo es analizar si el estudiante logra comprender los conceptos estadísticos en la formación secundaria. Para la investigación, se abordó el problema desde un enfoque cuantitativo de corte descriptivo, mediante la aplicación de uncuestionario a una muestra compuesta por 83 estudiantes del nivel secundario de colegios comerciales de la ciudad de Pereira. Los resultados finales, permitieron conocer que el 42,2% de los estudiantes tienen problemas para comprender conceptos relacionados con las medidas de dispersión, mientras que 54,2%tiene problemas con el cálculo de probabilidades. El estadístico Chi Cuadrado permite concluir que el nivel de dominio guarda relación con el colegio en el que se estudie (X2 =33,065; p=0,00).
Switching Costs and Market Power in Auditing: Evidence from a Structural Approach
Authors: Guo Qiang , Koch Christopher , Zhu Aiyong 
Published: July 2024

ABSTRACT
This study provides novel evidence on the magnitude of switching costs in auditing. Using a discrete choice approach, we infer switching costs from clients’ audit firm choices. The demand estimation reveals that switching costs are significant and vary by direction, with the highest costs associated with switching from non-Big 4 to Big 4 audit firms. Counterfactual analyses of forced switches suggest that switching costs are substantial, ranging from 0.7 billion U.S. dollars (14.2 percent of audit fees) to 1.2 billion U.S. dollars (24.0 percent of audit fees) when aggregated across all clients. Counterfactual analyses of voluntary switching show that the audit market would become highly dynamic and more concentrated if switching costs were removed. Additionally, clients would gain consumer surplus of up to 306 million U.S. dollars (5.4 percent of audit fees) in such a scenario. Overall, our study documents the importance of switching costs for understanding audit market dynamics.
Data Availability: Data are available from the public sources cited in the text.
JEL Classifications: M42; M48; L11; L84.