bluuebunny/crossref_metadata_2025 huggingface dataset:
Sleep characteristics and parameters of bone turnover and strength in the adult population: results from the Study of Health in Pomerania‐TREND
Authors: Rassow Kathrin , Obst Anne , Nauck Matthias , Völzke Henry , Stubbe Beate , Fietze Ingo , Penzel Thomas , Ewert Ralf , Hannemann Anke
Published: August 2023

Poor sleep quality or sleep deprivation may be related to decreased bone mineral density. We aimed to assess whether associations of sleep characteristics and bone turnover or strength are present in adults from the general population and whether these are independent of common risk factors such as sex, age, and obesity. A total of 1037 participants from the Study of Health in Pomerania‐TREND underwent laboratory‐based polysomnography and quantitative ultrasound measurements at the heel. Of these participants, 804 completed standardised questionnaires to assess daytime sleepiness, insomnia, and sleep quality. Serum concentrations of two bone turnover markers, intact amino‐terminal propeptide of type 1 procollagen (P1NP) and carboxy‐terminal telopeptide of type 1 collagen (CTX) were measured. Cross‐sectional associations of polysomnography variables (total sleep time, sleep efficiency, time spent wake after sleep onset, oxygen desaturation index, apnea–hypopnea index, and obstructive sleep apnea [OSA]), as well as sleep questionnaire scores with the bone turnover markers and the ultrasound‐based stiffness index were assessed in linear regression models. In adjusted models, higher insomnia scores and lower sleep quality scores were related to a higher bone turnover in women but not in men. However, associations between polysomnography variables or questionnaire scores and the stiffness index were absent. Our study provides limited evidence for relationships between sleep characteristics and bone turnover and strength independent of common risk factors for OSA and osteoporosis. Nevertheless, women reporting poor sleep or insomnia in combination with risk factors for osteoporosis might benefit from an evaluation of bone health.
Effects of feeding and habitat on resting metabolic rates of the Pacific walrus
Authors: Rode Karyn D. , Rocabert Joan , Borque‐Espinosa Alicia , Ferrero‐Fernández Diana , Fahlman Andreas
Published: August 2023

Arctic marine mammals live in a rapidly changing environment due to the amplified effects of global warming. Pacific walruses (Odobenus rosmarus divergens) have responded to declines in Arctic sea‐ice extent by increasingly hauling out on land farther from their benthic foraging habitat. Energy models can be useful for better understanding the potential implications of changes in behavior on body condition and reproduction but require behavior‐specific metabolic rates. Here we measured the resting metabolic rates (RMR) of three captive, adult female Pacific walruses through breath‐by‐breath respirometry when fed and fasted resting out of water (sitting and lying down) and while fed resting in water. RMR in and out of water were positively related with pretrial energy intake when not fasted and 25% higher than RMR when walruses were fasted and out of water. Overall, RMR was higher than previously estimated for this species. Fasting RMR out of water was only 25% lower than subsurface swimming metabolic rates suggestive of relatively efficient swimming in adult females. Our results identify the importance of considering feeding status and species‐specific differences in affecting metabolic costs. Further research is needed to better understand potential energetic costs of thermoregulation at temperatures experienced by wild walruses.
Challenges of delivering care to older persons in the intensive care unit: A qualitative study based on the third wave of COVID‐19 in China
Authors: Tang Li , Wu Xiaoyu , Li Jiuhong , Xie Xia , Huang Lingzhi
Published: August 2023

Background

With the aging population and the ongoing pandemic, older persons account for a large proportion of ICU admissions. Despite numerous studies on the impact of COVID‐19 on older persons, there has been a small body of research investigating nursing practice with critically ill older patients admitted to ICU for COVID‐19.

Aims

To explore current challenges in the nursing care of older persons with severe COVID‐19 through the experience of frontline nurses.

Study Design

A qualitative descriptive design was used. In‐depth and semi‐structured interviews with 18 ICU nurses were conducted to explore the experience of providing care for older persons with severe COVID‐19 in the Omicron wave. A content analysis approach was adopted to analyse qualitative data.

Findings

Three themes emerged as follows: (1) no plan survives first contact with the enemy, (2) expectations versus Reality and (3) difficulty in providing holistic care.

Conclusions

Challenges could be encountered in different stages of providing care for older persons with severe COVID‐19, including the preparation and training of knowledge and skills in the early stage, the challenges posed by old age in the diagnostic and treatment stage and the challenges of psychological care and rehabilitation care.

Relevance to Clinical Practice

With the regular prevention and control of COVID‐19, our study provides guidance for establishing measures (training courses of ICU nurses) to improve the nursing quality of older persons with severe COVID‐19.
The epistemic insignificance of phenomenal force
Authors: Teng Lu
Published: August 2023

Does phenomenal force, the distinctive phenomenology attributed to perceptual experience, really form an integral part of the latter? If not, what implications does it have for perceptual justification? In this paper, I first argue for a metacognitive account, according to which phenomenal force constitutes a separate, metacognitive state. This account opens up a previously unexplored path for challenging phenomenal conservatism or dogmatism, which has been a prominent theory of perceptual justification over the past two decades. Moreover, I investigate several alternative possibilities in which phenomenal force might still be deemed as significant, but ultimately demonstrate that its epistemic role remains marginal at best.
Divergent rainforest tree microbiomes between phases of the monsoon cycle, host plants and tissues
Authors: Calvert J. , McTaggart A. , Carvalhais L. C. , Rensink S. , Dennis P. G. , Drenth A. , Shivas R.
Published: August 2023

The Australian Monsoon Tropics (AMT) contain some of the most biodiverse forests on the continent. Little is known about the dynamics of rainforest plant microbiomes in general, and there have been no community‐level studies on Australian rainforest endophytes, their seasonality, tissue and host specificity.

We tested whether community composition of tropical tree endophytes (fungi and bacteria) differs: (i) at different points during a monsoon cycle, (ii) between leaf and stem tissues, (iii) between forest microclimates (gully/ridge), and between (iv) host plant species, and (v) host plant clade, using amplicon sequencing of the bacterial 16S and fungal ITS2 gene regions.

Results indicated that the composition of rainforest plant microbiomes differs between wet and dry seasons, which may be explained by physiological shifts in host plants due to annual climate fluctuations from mesic to xeric. Endophyte microbiomes differed between leaves and stems. Distinct fungal communities were associated with host species and clades, with some trees enriched in a number of fungal taxa compared to host plants in other clades. Diversity of bacterial endophytes in plant stems increased in the dry season.

We conclude that the microbiomes of tropical plants are responsive to monsoonal climate variation, are highly compartmentalised between plant tissues, and may be partly shaped by the relatedness of their host plants.
Factors associated with depression and suicidal ideation among oldest‐old adults aged 85 years or older based on gender, using the survey data of South Korea
Authors: Kim Yujeong , Nam Eunhee , Yun Younghee
Published: August 2023

Background

South Korea is predicted to become a superaged society around 2025. Depression in older adults is a major factor influencing suicide. South Korea exhibits the highest suicide rate among the Organization for Economic Co‐operation and Development countries.

Methods

This study aimed to examine the factors associated with depression and suicidal ideation among individuals aged 85 years or older based on gender. Data were obtained from the Korea Institute for Health and Social Affairs, 2017. Overall, 768 individuals aged ≥85 years were included in the final analysis. The participants' general, health‐related, and social characteristics were analyzed as factors influencing depression and suicidal ideation.

Results

Among male oldest‐old adults, living arrangements and the number of chronic diseases were factors affecting depression, while activities of daily living restrictions and the number of chronic diseases were factors affecting suicidal ideation. Among female oldest‐old adults, only the number of chronic diseases affected depression, while financial status and the number of chronic diseases were the factors affecting suicidal ideation.

Conclusions

The healthcare and welfare services for older adults must be expanded to cater to oldest‐old adults who live alone, have activities of daily living restrictions, and have lower financial status. Additionally, the oldest age group's psychological health must be monitored regularly for depression and suicidal ideation to implement active interventions for this high‐risk group.
Leading digital transformation: A narrative perspective
Authors: Nielsen Jeppe Agger , Elmholdt Kasper Trolle , Noesgaard Mette Strange
Published: August 2023

Change communication is a critical dimension for leading digital transformation. Existing literature predominantly theorizes change communication as part of the earliest stages of the transformation, but how it evolves over time to remain relevant in this context is understudied. We address this shortcoming through a four‐year study of a digital transformation initiative in a local government's health care department. Drawing on a narrative perspective, we offer a processual account and describe the ongoing communicative work of public managers as they attempt to shape frontline workers' expectations of digital transformation. We theorize three narrative types—aspirational, setback, and persistence—that work as communicative resources in dealing with hopes, delays, and emerging concerns. Our article contributes to the literature on leading digital transformation in the public sector by providing a narrative perspective that details how managers produce narratives, navigate existing ones, and tailor them to emerging concerns.
Optimal fiscal policy under monopolistic competition with firm heterogeneity
Authors: Chang Cheng‐wei
Published: August 2023

Government spending is a policy instrument used to sustain economic development and improve social welfare. Empirical observations, however, reveal a significant decrease in the government spending to GDP ratio for the United States. In addition, the United States has been observed to exhibit a rise in firm heterogeneity in productivity in recent decades. This paper shows that the optimal size of government expenditure will decrease as firm heterogeneity increases. We thus indicate that the rise in firm heterogeneity in productivity may serve as a plausible vehicle to explain the decline in the share of government spending in GDP for the United States.
Improved estimation of average treatment effects under covariate‐adaptive randomization methods
Authors: Wang Jun , Yu Yahe
Published: August 2023

Estimation of the average treatment effect is one of the crucial problems in clinical trials for two or multiple treatments. The covariate‐adaptive randomization methods are often applied to balance treatment assignments across prognostic factors in clinical trials, such as the minimization and stratified permuted blocks method. We propose a model‐free estimator of average treatment effects under covariate‐adaptive randomization methods, which is least square adjustment for the estimator of outcome models. The proposed estimator is not only applicable to the case of binary treatment, but also can be extended to the case of multiple treatment. The proposed estimator is consistent and asymptotically normally distributed. Simulation studies show that the proposed estimator and Ye's estimator are comparable, and it performs better than Bugni's estimator when the outcome model is linear. The proposed estimator has some advantages over targeted maximum likelihood estimator, Bugni's estimator and Ye's estimator in terms of the standard error and root mean squared error when the outcome model is nonlinear. The proposed estimator is stable for the from of outcome model. Finally, we apply the proposed methodology to a dataset that studies the causal effect promotional videos mode on the school‐age children's educational attainment in Peru.
Effects of freeze–thaw cycles and the soil water content on carbon and nitrogen changes in different soil types of Heilongjiang Province, China
Authors: Kong Fandan , Gao Yu , Li Tianxiao , Fu Qiang , Liu Dong , Su Zhongbin , Shen Weizheng , Wang Jinwu , Zhou Wenqi , Wang Yijia
Published: August 2023

To reveal the influence of freeze–thaw cycles (FTCs) on soil carbon and nitrogen changes, six typical soils in Northeast China were selected as the research objects to conduct a FTC simulation test in an artificial climate chamber. Three soil volumetric water contents (10%, 20%, 30%) and eight FTCs (0, 2, 4, 6, 8, 10, 15, 20) were set. The results showed that the soil organic carbon (SOC) and microbial biomass carbon (MBC) contents of different soil types under the FTCs initially exhibited a downward and then an upward trend, while the dissolved organic carbon (DOC) content exhibited an upward and then a downward trend. Otherwise, the fourth and sixth FTCs were the key points of change. The SOC, MBC and DOC contents in paddy fields were higher than those in dry fields, showing upward and then downward trends spatially from northeast to southwest. The SOC and MBC contents in each soil type were the highest at the 20% water content, and the DOC content gradually increased with increasing water content. The ammonium nitrogen (NH4+‐N) content in different soil types at different water contents under the FTCs showed an upward trend first, then a downward trend and finally an upward trend. The NH4+‐N content in paddy fields was higher than that in dry fields. The nitrate nitrogen (NO3‒‐N) content showed a downward trend first, then an upward trend and finally a downward trend. The NO3‒‐N content in dry fields was higher than that in paddy fields. The NH4+‐N contents in the three soil types on the Sanjiang Plain were significantly higher than those on the Songnen Plain. The NH4+‐N and NO3‒‐N contents showed upward trends with increasing water content, but the differences were not significant. The results have implications for the study of different types of soils and provide references for research on the mechanism of soil carbon and nitrogen transformation in typical farming areas in Northeast China.
The sovereign citizen superconspiracy: Contemporary issues in native title anthropology
Authors: Taplin Pascale , Holland Claire , Billing Lorelei
Published: August 2023

The Australian Native Title Act 1993 (Cth) provides for the recognition of rights and interests which arise from the traditional laws and customs of Australian First Nation peoples. Processing applications for a determination of native title can take many years and involves numerous stakeholders, presentation of evidence of ongoing connection with the land and sea within a claim area, negotiations with other parties including from industry and government, as well as negotiations between Indigenous groups. The process can be long, arduous, and often outcomes fail to satisfy the expectations of native title claimants. In this paper we investigate how individuals who either disagree with the premise underlying native title, or who have suffered negative impacts through the course of native title claims, may be either targeted by, or swept up in, Australian sovereign citizen rhetoric. We aim to contextualise presentations of sovereign citizen ideas in native title claim processes by providing an overview of the history of sovereign citizen thought, and examples of its contemporary expression in some Australian online forums. In doing this we aim to provide a broad foundation for future research into the issue. The dialogue in sovereign citizen online communities exposes people to extremism and superconspiracies. This article will provide a theoretical framework and historical context to the Australian sovereign citizen phenomena and describe online amplification of disinformation in Australia that has the potential to cause harm. We illustrate how stakeholders who are drawn to relatively moderate online content (such as opposing native title) may be radicalised through gradual exposure to extremist anti‐government sentiment and hate speech. This article highlights the need for further research into sovereign citizenry in Australia, and strategies for native title practitioners to engage claimants who subscribe to and disseminate sovereign citizen disinformation in native title processes.
The spacing effect: Improving electrocardiogram interpretation
Authors: Cunningham John M. , Johnson Melissa , Kincaid Troy , Christensen Wendy , Baker Jaime , Turbyfill William , Adams Jennifer E.
Published: August 2023

Background

Accurate electrocardiogram (ECG) interpretation is critical for safe patient care, making this skill a necessary competency for medical school graduation. Improved long‐term memory retention with repeated exposure to material is one of the most evidenced‐based components of adult learning science. This curricular innovation aimed to determine if implementing spaced repetition and retrieval practice using ECG quizzes during the principal clinical year would improve ECG interpretation skills among medical students enrolled in a Longitudinal Integrated Clerkship (LIC).

Approach

The curricular innovation applied the spacing effect and retrieval practice. Cognitive science demonstrates enhanced long‐term retention through repeated interval exposure to learned material. Studies of spaced retrieval indicate that memory retention is enhanced through tests involving effortful recall. LIC students in an intervention group were exposed to the spacing effect with periodic ECG quizzes throughout their clinical clerkship year.

Evaluation

The results of the 17‐item post‐test for 140 students were analysed: LIC intervention, N = 54; block control, N = 62; and LIC control, N = 24. The ANOVA test was significant (p < 0.001). Games–Howell post hoc testing showed that the mean score in the LIC intervention group was significantly higher compared with the LIC control group (p < 0.001) and the block control group (p < 0.001). There was no significant difference between the LIC control and block control groups (p = 0.59).

Implications

Spaced repetition of material through ECG quizzes improved ECG interpretation skills on an ECG post‐test and mitigates the forgetting curve, maintaining student competency in ECG interpretation.
MACHINE LEARNING METHODS FOR EARLY-STAGE DIAGNOSIS OF PARKINSON'S DISEASE THROUGH HANDWRITING DATA
Authors: Dionela Matthew C. , B. Arroyo Carey Louise , S. Torres Mhica , P. Alaan Miguel , C. Lauguico Sandy , Vicerra Ryan Rhay , Concepcion II Ronnie
Published: August 2023

Parkinson's disease (PD) deteriorates human cognitive and motor functions, causing slowness of movements and postural shakiness. PD is currently incurable, and managing symptoms in its late stages is difficult. PD diagnosis also has gaps in accuracy due to several clinical challenges. Thus, early-stage detection of PD through its symptoms, such as handwriting abnormality, has become a popular research area using machine learning. Since most related studies focus on advanced algorithms, this study aims to determine the classification accuracies of simpler classical models using the NewHandPD-NewMeander dataset. This study used the 9 features extracted from the meanders drawn by healthy participants and participants diagnosed with Parkinson’s disease and 3 features about the individual. The same features were reduced to the 8 best according to univariate selection and recursive feature elimination. The machine learning algorithms used for the models in this study are Logistic regression, Multilayer perceptron, and Naive Bayes. Additionally, hyperparameter optimization was done. Results have shown that feature selection improved the performances of the default model, while optimization had varying effects depending on the feature selection method used. Among 15 models built, Multilayer perceptron, which utilized top 8 features from univariate selection with default hyperparameters (MLPU8), performed best. It yielded an accuracy of 84.4% in cross-validation, 87.5% in holdout validation, and an F1-score of 87.5%. Remaining models had accuracies ranging from 81.4% - 84.4% in cross-validations and 82.5% - 85.0% in holdout validations. Other studies done on diagnosing PD using similar handwritten datasets resulted in lower accuracies of 87.14% and 77.38% despite utilizing complex algorithms for its models. This proved that the 15 models built using simple architecture can outperform complex classification methods. The 15 models built accurately classify meander data and can be used as an early assessment tool for detecting PD.
ANALYSIS OF MUD DENSITY BY USING CUTTING CAPACITY ANNULUS METHOD
Authors: Husla Ridha , R.W Apriandi Rizkina , Yulia Prayang Sunny , Yasmaniar Ghanima , Ridaliani Onnie , Samsol Samsol
Published: August 2023

Drilling mud has an important role in drilling operations, as well as lifting the cutting to the surface, controlling the pressure of the formation, and preventing the collapse of the borehole. Therefore, the drilling operations can be continued without obstacles. The function of the drilling mud depends on the conditions of the formation to be drilled for optimal results. One of the main functions is to lift cutting from a bottom hole to the surface. In the annulus, the minimum speed for lifting the cutting to the surface was calculated. The Cutting Capacity Annulus (CCA) is the value of the level of solids in the annulus. The proper concentration of cutting in the annulus is not more than 5%, to avoid drilling problems, such as decreased rate of penetration (ROP), increased drag and torque, and stuck pipe related to hole cleaning problems. In analyzing the lifting ability of cutting, CCA is very suitable to be used because it accounts for the parameters of ROP value. This study conducted a comparison of two types of natural polymers that have a function to help the hole cleaning in the drilling process. The two types of polymers are cellulose polymers (drispac) and polysaccharide polymers (starch). Furthermore, it also had been tested on a field scale using the cutting transport ratio (CTR) method to find out how much ratio is obtained in the two types of polymer mud. Based on the test of the two mud samples on the cutting removal process in the CCA method at a temperature of 150oF, the mud samples containing starch ranged from 1.0731% to 1.0792%, while the mud samples containing drispac ranged from 1.0730% to 1.0793%. At 200oF the mud samples containing starch ranged from 0.7357% to 1.3604%, while the mud samples containing drispac ranged from 0.7357% to 1.3603%. At a temperature of 250oF, the mud samples containing starch ranged from 0.2652% to 0.4903%, while the mud samples containing drispac ranged from 0.265178% to 0.4907%. Although the density of the starch-containing mud sample was greater than drispac, the CCA value did not have much effect due to the difference in density of the two mud samples of 0.1 ppg. Both samples were able to optimally lift the cutting above the surface because the CCA value was less than 5%.
A PROPOSED TECHNIQUE FOR IMPROVING THE ACCURACY OF TIDAL MODELING OF RIVER NETWORKS CONNECTING TO THE DADAHUP IRRIGATION AREA
Authors: Zevri Asril , Rahardjo Adam Pamudji , Legono Djoko
Published: August 2023

Optimizing the operational management of tidal irrigation networks is a significant factor in the reactivation program of the swamp irrigation areas in Central Kalimantan Province. Appropriate water level and flow rate control in a tidal environment would provide a better solution for this effort. Monitoring water parameters and hydraulic modeling is an intelligent technique for evaluating irrigation canals' gate system operations. This paper focuses on providing more accurate hydraulic modeling that requires proper boundary conditions and calibration of the canal roughness coefficient. This study aims to obtain a more precise downstream boundary condition data calibration method with an appropriate river cross-sectional roughness coefficient value to improve the overall hydraulic modeling accuracy of the river network connecting to the Dadahup Irrigation Area. The hydraulic modeling utilized the HEC-RAS Software, where input data preparation used geometric data derived from the National Geospatial Agency's DEM in the form of river channel network chain, cross-section, and long-section data. Boundary condition data evaluation compared and selected data generated from references and the Tides Application Software. The results show that the tide prediction from the Tides Application Software provides the slightest difference between the predicted tide and the measured ones. The river network's channel roughness coefficient calibration utilized the generated boundary condition tide and simultaneously measured water level data at several locations. The results show that the most minor Root Mean Squared Error (RMSE) of the Manning roughness coefficient differences of the river channel network can reach 0.04 with a minimum RMSE value of 0.027.
MCBM: IMPLEMENTATION OF MULTICLASS AND TRANSFER LEARNING ALGORITHM BASED ON DEEP LEARNING MODEL FOR EARLY DETECTION OF DIABETIC RETINOPATHY
Authors: Meshram Amita , Dembla Deepak
Published: August 2023

Diabetic retinopathy (DR), the primary cause of a visible disease in working-age adults, is often controlled with the aid of early detection to prevent sight loss. This research proposes a collection of automated deep-learning techniques for DR screening. In this paper, we collected total 3662 Images from the Kaggle. Out of the total 3662 images, 90% (3295) images taken for the training purpose and 10% (367) for the testing purpose. This study measured the performance and comparative study of five Deep Learning models such as CNN, Efficient Net, VGG 16, Mobile Net, and RESNET 50 are demonstrated to improve the accuracy by changing various parameters of these models to classify DR in different stages. Out of the total images. Our finding shows that Efficient Net achieved a training accuracy of 0.9342 and a testing accuracy is 0.8181 and RESNET 50 achieved 0.9329 accuracies for the train data set and the test data set with 0.8116 accuracies. Efficient Net and Res Net 50 have achieved better accuracy out of the five models. Hence these two models perform well as compared to the other 3 Models.
ENSEMBLING DEEP CONVOLUTIONAL NEURAL NEWORKS FOR BALINESE HANDWRITTEN CHARACTER RECOGNITION
Authors: Dewi Desak Ayu Sista , Arsa Dewa Made Sri , Putri Gusti Agung Ayu , Setiawati Ni Luh Putu Lilis Sinta
Published: August 2023

While deep learning has proven its performance in various problems and applications, it also opens opportunities in a new way to promote the heterogeneity of cultures and heritages. Balinese script is a cultural heritage in Bali, where it is used to write on palm-leaf manuscripts and contains essential information. Most manuscripts were damaged due to age and lack of maintenance, so a digitalization technique should be developed. In this study, we propose an ensemble of deep convolutional neural networks to recognize the handwritten characters in the Balinese script. We extensively compared various deep convolutional neural network architectures, and the results showed that our ensemble methods achieved the state of the art.
3.5 GHZ VIVALDI ANTENNAS: A COMPREHENSIVE PARAMETRIC ANALYSIS FOR UNLEASHING 5G COMMUNICATION TECHNOLOGY
Authors: Othman Mohd. Azlishah , Ruslan Nur Aishah Shahirah , Misran Mohamad Harris , Meor Said Maizatul Alice , Abdul Manap Redzuan , Jaafar Abd Shukur , Hassan Nurmala Irdawaty , Suhaimi Shadia
Published: August 2023

In this study, we discuss the design and testing of a Vivaldi antenna operating at 3.5 GHz, which is well-suited for mobile mid-band 5G connection. CST Microwave Studio software was used to simulate and evaluate the suggested antenna design, which was printed utilising state-of-the-art 3D printing processes and materials (polylactic acid (PLA) and FR-4 circuit board material). The measured results show that the antenna has a reflection frequency of 3.51 GHz and a gain of -23.695 dB. Parametric analysis was carried out to examine the relationship between antenna performance and design parameters, with special focus on the separation between the antenna and the PLA material in the middle of the spherical construction. The Vivaldi antenna is an attractive choice for 5G mid-band applications because of its wideband features, ease of manufacture using typical industrial processes, and simplicity of impedance matching to the feeding line using microstrip line modelling.
EFFECTS OF ACID AND ALKALINE TREATMENTS ON EFFICIENCY OF DIATOMACEOUS EARTH IN REMOVAL OF TETRACYCLINE IN AQUEOUS SOLUTION
Authors: Sinpichai Sarawut , Yuangsawad Ratanaporn , Na-Ranong Duangkamol
Published: August 2023

Contamination of tetracycline (TC) in environment may cause serious problems relating to increase of antibiotic resistance and development of new deceases. This paper focuses on TC removal by simple adsorption treatment and utilization of natural diatomaceous earth (NDE) as a cheap adsorbent. To improve efficiency of NDE, an impregnation method using acid (H2SO4) or base (KOH) was applied to modify NDE and influences of important activation parameters, concentration of reagent (Creagent), ratio of NDE weight and activating solution volume (NDE-to-Sol), temperature (Tact) and time (tact), on the efficiencies of the obtained acid and base activated diatomaceous earths (ADE and BDE) were investigated. Batch adsorption experiment was performed at the same condition to evaluate TC adsorption capacities at equilibrium (qe, TC) of NDE, ADE and BDE. It was found that acid activation negatively affected qe, TC and increases of CH2SO4, Tact and tact resulted in poorer ADE. In contrast, qe, TC was successfully enhanced through activation by KOH; Tact and tact played more significant roles on the enhancement, comparing with CKOH and NDE-to-Sol; impregnation at higher Tact and longer tact could improve efficiency of BDE and the best BDE (BDE-B) with the highest qe, TC (86.31 mg/g) was obtained at 3 M, 0.1 g/ml, 80 °C and 9 h.
Climate-sensitive Design in Traditional Residential Architecture: Kars Karakurt Houses
Authors: Çakıcı Fatma Zehra , Takva Çağatay
Published: August 2023

Design based on performance and energy efficiency is important in residential buildings. The design approach, which considers climatic data and energy conservation, was also used in traditional building design. In this context, it is aimed to evaluate the Karakurt houses in Kars, built during the Russian occupation period (1878-1918) in Turkey, within the scope of climate-sensitive design. The inadequacy of studies in the literature on Kars Karakurt houses, which are traditional architectural examples that preserve the original texture of the region as qualified representatives of Baltic architecture, constitutes a research gap. In this study, qualitative and quantitative research methods were used. The architectural plan and facade typologies of the buildings in Karakurt village were obtained by measuring techniques and tools. In the qualitative research part, information about the buildings was obtained from on-site investigations and a situation analysis was made. In the quantitative research part, orientation analyses of buildings and spaces, and window-wall area ratios of facades have been evaluated according to climate-sensitive design approaches. In the research findings, design criteria such as plan, facade, roof and material properties of 10 Karakurt houses, were examined and it was seen that the buildings were standardized within the scope of climate-sensitive design. It is seen that the north direction, where the wind is dominant and the sunlight penetration is the least, is not preferred for the orientation of the buildings and the space, and the window/wall area ratio is kept to a minimum, reducing the energy loss especially due to the openings.
Citizen’s Perception on Eco-friendly Lifestyle for Conserving Endangered Oriental White Stork and Crested Ibis Bird Species in Japan – Case Studies in Toyoka, Sado and Konosu Cities
Authors: Kawashima Hideo , Fukahori Kiyotaka , Parveen Mahfuza , Wathsala Lakpriya Gunawardena Garu Muni , Asaeda Takashi
Published: August 2023

This study aims to find out the relationship between an eco-friendly lifestyle and the attitude towards conservation of endangered Oriental White Stork and Japanese Crested Ibis bird species in Toyooka, Sado, and Konosu cities in Japan. Citizens were surveyed to assess their willingness to spend an eco-friendly lifestyle to protect the above-mentioned endangered bird species through questionnaire surveys. Ecological Mind Evaluation Scale (EM Evaluation scale) developed by Tanaka and Joh (2012) based on Hirose model and Bandura’s research on Self Efficacy was applied in this research. This Ecological Mind Evaluation Scale includes 10 factors and it was applied to develop the questionnaire survey. The factor analysis was undertaken based on 4 groups of questionnaire results; environmental awareness, attitude towards environmental conservation, environmental consciousness and self-efficacy. Factor analysis was performed using the varimax method and sample data set comprised 686 valid responses from the three study sites. The KMO values were over 0.80 indicating the sampling was adequate. According to the factor analysis Sado city scored high for environmental awareness and environment consciousness. Toyooka city scored high on self-efficacy and environmental consciousness. Konosu city was compared with the Toyooka and Sado cities, where more advanced habitat conservation activities are already implemented. Findings displayed that the citizens in Konosu city had low awareness about these bird conservation activities, however, they are willing to contribute in such activities in the future. Thus, this study demonstrated that by engaging in environmentally friendly lifestyles, the citizens can contribute to habitat conservation of endangered bird species
Stress and Sleep Quality among Engineering Students
Authors: Hasim Nurhamizah , Yusof Junaidah , Ibrahim Farah Adibah , Bungsu Mohd Sharial , Yakub Nur Asyikin Yakub , Shari Nurul Izzah
Published: August 2023

Stress is a normal occurrence in human lives, and university students can never escape from experiencing stress at least once during their university years, during which they have to face a variety of stressors. Poor sleep quality happens to people of all ages worldwide, particularly university students. Numerous studies have reported that stress significantly correlates with sleep quality among university students from various courses. However, these variables were less explored by past researchers, specifically on engineering students. In order to explore more information on these variables among engineering university students, a cross-sectional, quantitative, correlational study is conducted to identify the relationship between stress and sleep quality among engineering students in Malaysia. A total of 272 undergraduate engineering students from three public universities in Malaysia were involved in the study. The Perceived Stress Scale (PSS-10) and Pittsburgh Sleep Quality Index (PSQI) were used. The result from the correlational analysis shows that there is a significant negative relationship between stress and sleep quality among engineering students. The study’s findings could be used as a reference for future studies and recommend interventions to improve students’ stress and sleep quality levels.
Family Business Succession Plan for Bumiputera-Owned Small and Medium Enterprises: A Review
Authors: Yaakop Siti Noor Kamariah , Othman Nooraini
Published: August 2023

Transgenerational entrepreneurship is defined as the creative and initiative-taking creation of self-sufficiency in a family-owned business that lasts generations. The process of passing on management and ownership of a family business to the next generation through inheritance is known as family business succession. A succession plan is crucial for ensuring the company's transition and continuity. The process of selecting a replacement in a small and medium enterprise (SME) is more difficult because the number of successor candidates is smaller than in a corporate firm. Therefore, the purpose of this study is to identify the challenges and factors that incumbents must consider when selecting a successor and implementing a succession plan. The study's findings indicate that internal conflicts between the leader's business and family, the leader's obsession with his leadership legacy, and the successor's level of willingness to accept responsibility are the main obstacles to implementing a succession plan. The succession planning process considers a variety of factors, including education, competencies, demographic factors, relationships with family members and incumbents, experience, integrity, birth order, and primogeniture.
Optimal Control Formulation for Manual Wheelchair Locomotion Simulations: Influence of Anteroposterior Stability
Authors: Loisel Jade , Rouvier Théo , Hybois Samuel , Bascou Joseph , Sauret Christophe
Published: August 2023

Manual wheelchair (MWC) locomotion exposes the user's upper-body to large and repetitive loads, which can lead to upper limbs pain and injuries. A thinner understanding of the influence of MWC settings on propulsion biomechanics could allow for a better adaptation of MWC configuration to the user, thus limiting the risk of developing such injuries. Advantageously compared to experimental studies, simulation methods allow numerous configurations to be tested. Recent studies have developed predictive locomotion simulation using optimal control methods. However, those models do not consider MWC anteroposterior stability, potentially resulting in unreasonable propulsion strategies. To this extent, this study aimed at confirming if constraining MWC anteroposterior stability in the optimal control formulation could lead to a different simulated movement. For this purpose, a four-link rigid-body system was used in a forward dynamics optimization paired with an anteroposterior stability constraint to predict MWC locomotion dynamics of the upper limbs during both startup and steady-state propulsion. Simulation results indicated the occurrence of MWC tipping when stability was not constrained, and that the constrained optimal control algorithm predicted different propulsion strategies. Hence, further proceedings of MWC locomotion simulation and optimal control investigations should take the anteroposterior stability into account to achieve more realistic simulations. Additionally, the implementation of the anteroposterior stability constrains unexpectedly resulted in a reduction of the computational time.
Physical Insight Into Whoosh Noise in Turbocharger Compressors Using Computational Fluid Dynamics
Authors: Dehner Rick , Selamet Ahmet , Sriganesh Pranav , Banerjee Deb , Selamet Emel , Karim Ahsanul , Brewer Todd , Morelli Anthony
Published: August 2023

Whoosh is typically the primary noise concern for turbocharger centrifugal compressors without ported shroud recirculating casing treatments, utilized for spark-ignition automotive applications. Whoosh is characterized by broadband elevation of noise in approximately the 4–13 kHz range, where the lower frequency boundary is dictated by the cut-on frequency of the first multidimensional acoustic mode. At mid-to-low compressor flow rates, swirling, reversed flow emanates from the leading-edge tip region of the main impeller blades, comprising an annular zone at the inducer plane. High velocity gradients are observed near the shear layer between the bidirectional forward and reverse flow which results in the formation of rotating instability cells. Whoosh noise is generated due to the interaction of these rotating instabilities with the leading edge of main impeller blades. Along a line of constant rotational speed, whoosh noise exhibits a dome-like character, where its maximum value occurs in the mid-to-low flow region and the levels decrease at elevated and reduced mass flow rates. To provide insight into the variation of broadband whoosh noise with flowrate, this work includes experimentally validated computational fluid dynamics predictions for five mass flow rates at a fixed rotational speed. These predictions span the constant speed flow range from just below the peak efficiency to near the surge boundary. Computational predictions capture the physical mechanism responsible for the dome-like character of whoosh noise as a function of flowrate at a given rotational speed.
Virtual Dynamics Model for Five-Axis Machining of Thin-Walled Blades
Authors: Karimi Behnam , Altintas Yusuf
Published: August 2023

The five-axis ball-end milling dynamics of thin-walled blades is presented. The cutting forces are predicted from the ball-end mill–blade geometry engagement maps along the toolpath. The Frequency Response Function (FRF) of the thin-walled blade is predicted using Finite Element shell elements, and it is updated along the toolpath as the metal is removed. The predicted cutting forces are applied on both the workpiece and tool FRFs to predict the forced vibrations and chatter stability at each tool location. A simplified method to update the cutter-workpiece engagement (CWE) is used to obtain the three-dimensional stability lobe diagram at each desired point on the blade. The integrated model is used to simulate the five-axis machining of thin-walled blades in the digital environment. The proposed digital model is experimentally validated by machining a series of thin-walled rectangular plates and a twisted fan blade.
A Dynamic Reliability Prognosis Method for Reusable Spacecraft Mission Planning Based on Digital Twin Framework
Authors: Gao Bo , Ye Yumei , Pan Xin , Yang Qiang , Xie Weihua , Meng Songhe , Huo Yanyan
Published: August 2023

Reusable spacecraft has great potential in reducing space launch cost. Structural reliability evaluation is critical for mission planning of reusable spacecraft. A dynamic reliability prognosis method based on digital twin framework is proposed for mission planning in the paper. In this method, Uncertainties integration and dynamic model updating are implemented through a dynamic Bayesian network. A maintenance point is set when the predicted structural reliability level is lower than a threshold or unexpected conditions such as landing impact occur. Then, inspected data can be assimilated by the framework to dynamically update the structural reliability. Thus, it supports dynamic adjustment of maintenance interval, early warning of structure failure, and mission planning with quantified risk. A numerical example considering single point crack growth under fatigue load and landing impact of a simplified spacecraft structure is used for demonstration. Results show that the crack size predictions can be calibrated by inspected data and its uncertainties can be reduced. The proper selection of landing impact probability in reliability prediction is helpful to control the maintenance interval. The reliability of the spacecraft can be increased through model updating with new inspected data, representing a potential lifetime extension can be realized by the proposed method.
Intrinsic and atomic layer etching enhanced area-selective atomic layer deposition of molybdenum disulfide thin films
Authors: Soares Jake , Jen Wesley , Hues John D. , Lysne Drew , Wensel Jesse , Hues Steven M. , Graugnard Elton
Published: August 2023

For continual scaling in microelectronics, new processes for precise high volume fabrication are required. Area-selective atomic layer deposition (ASALD) can provide an avenue for self-aligned material patterning and offers an approach to correct edge placement errors commonly found in top-down patterning processes. Two-dimensional transition metal dichalcogenides also offer great potential in scaled microelectronic devices due to their high mobilities and few-atom thickness. In this work, we report ASALD of MoS2 thin films by deposition with MoF6 and H2S precursor reactants. The inherent selectivity of the MoS2 atomic layer deposition (ALD) process is demonstrated by growth on common dielectric materials in contrast to thermal oxide/ nitride substrates. The selective deposition produced few layer MoS2 films on patterned growth regions as measured by Raman spectroscopy and time-of-flight secondary ion mass spectrometry. We additionally demonstrate that the selectivity can be enhanced by implementing atomic layer etching (ALE) steps at regular intervals during MoS2 growth. This area-selective ALD process provides an approach for integrating 2D films into next-generation devices by leveraging the inherent differences in surface chemistries and providing insight into the effectiveness of a supercycle ALD and ALE process.
Theoretical studies of magnetic domain phase diagrams from micromagnetic simulation
Authors: Huang Dao-Jing , Lai Yi-Sheng , Su Yen-Hsun
Published: August 2023

A skyrmion is a kind of quasiparticle observed on the surface of a magnetic material, and the topologically protected vortex structure is known to be produced via spintronics. The special properties allow skyrmions to exist in the interface of devices with an ultralow accumulation rate and a high transportation rate. Magnetic domain walls such as the multiple wormhole domain show up from the ground state with different dendritic densities and shapes when the material is stimulated. The Dzyaloshinskii–Moriya interaction (Ms), anisotropy constant (K), and stiffness coefficient (A) are key parameters that affect the magnetic field relative to the representation of the skyrmion. By tuning these parameters, we can adjust the fragmentation of the magnetic domain, the stability, and the radius of the skyrmion. These parameters also modulate characteristics such as the skyrmion number and helicity, which describe the behavior of the spintronic vortex and strongness. This research shows the relation between the parameters and characteristics with the phase diagram and indicates the range of stable skyrmion existence and its size. The higher saturation magnetization Ms and the lower stiffness coefficient A cause the domain wall width to become thicker. Besides, the skyrmion number N decreases with an increase in the skyrmion size until it transforms into a deformed domain.