bluuebunny/crossref_metadata_2025 huggingface dataset:
Forecasting energy production of a PV system connected by using NARX neural network model
Authors: Ibrahim Marwa M. , Elfeky Amr A. , El Berry Amal
Published: August 2024

Applying artificial neural network techniques to forecast the electricity production of photovoltaic (PV) power plants is a novel concept. A reliable analytical model for calculating the energy output of a grid-connected solar plant is very difficult to establish because of hourly, daily, and seasonal variations in climate. The current study estimated and predicted the energy production of a connected PV system that was installed in Cairo, Egypt (30.13° N and 31.40 ° E) using an artificial neural network. Four seasons' worth of data (summer, autumn, winter, and spring) were methodically assessed using information from the climate database. The parameters that had an impact on the electrical data of PV modules included meteorological and irradiation variables, energy output, and the user's needs used to verify the NARX feedback neural networks. Prediction performance metrics were obtained, such as the correlation coefficient (R) and root mean square error (RMSE). The observed correlation coefficient ranged from 99% to 100%, indicating that the expected results are verified, while the mean error fluctuates very little.
On neutrosophic ideals and prime ideals in rings
Authors: Hummdi Ali Yahya , Elrawy Amr
Published: August 2024

This article aims to introduce and explore the concept of neutrosophic ideals in the context of rings. Besides, we investigate how the property of regularity in a ring can be understood through the lens of neutrosophic ideals. We further present the concept of neutrosophic prime ideals and systematically identify all neutrosophic prime ideals in $ \mathbb{Z} $.
Resonance analysis and time-delay feedback controllability for a fractional horizontal nonlinear roller system
Authors: Cui Zhoujin , Zhang Xiaorong , Lu Tao
Published: August 2024

In this paper, we investigated the nonlinear vibration characteristics and time-delay feedback controllability of a fractional horizontal roll system, which is described by a fractional Duffing-van der Pol oscillator under an external harmonic excitation. We focused on the resonance of fractional roller systems and conducted corresponding vibration control. The amplitude-frequency equations of primary resonance and superharmonic resonance were obtained using the multiple scale method. The amplitude-frequency characteristic curves of the system with different parameters were presented, and the influence of system parameters on the curves was analyzed. In addition, the time-delay feedback controller was designed to control the parameter excitation vibration. The numerical simulation results have verified the effectiveness of the time-delay controller in eliminating the jumping and hysteresis phenomena of the rolling system. The comparisons of approximate analytical solution and numerical solution was fulfilled, and the result certifies the correctness and satisfactory precision of the approximately analytical solution. The analysis results provide certain theoretical guidance for the vibration reduction of the horizontal nonlinear roller system.
Fungal photoinactivation doses for UV radiation and visible light–a data collection
Authors: Gierke Anna-Maria , Vatter Petra , Hessling Martin
Published: August 2024

Nearly two million people die each year from fungal infections. Additionally, fungal crop infections jeopardize the global food supply. The use of 254 nm UVC radiation from mercury vapor lamps is a disinfection technique known to be effective against all microorganisms, and there are surveys of published UVC sensitivities. However, these mainly focus on bacteria and viruses. Therefore, a corresponding overview for fungi will be provided here, including far-UVC, UVB, UVA, and visible light, in addition to the conventional 254 nm UVC inactivation.

The available literature was searched for photoinactivation data for fungi in the above-mentioned spectral ranges. To standardize the presentation, the mean log-reduction doses were retrieved and sorted by fungal species, spectral range, wavelength, and medium, among others. Additionally, the median log-reduction dose was determined for fungi in transparent liquid media.

Approximately 400 evaluable individual data sets from publications over the last 100 years were compiled. Most studies were performed with 254 nm radiation from mercury vapor lamps on Aspergillus niger, Candida albicans, and Saccharomyces cerevisiae. However, the data found were highly scattered, which could be due to the experimental conditions.

Even though the number of individual data sets seems large, many important fungi have not been extensively studied so far. For example, UV irradiation data does not yet exist for half of the fungal species classified as “high priority” or “medium priority” by the World Health Organization (WHO). In addition, researchers should measure the transmission of their fungal suspensions at the irradiation wavelength to avoid the undesirable effects of either absorption or scattering on irradiation results.
Estimation of NO$ _{x} $ and O$ _{3} $ reduction by dissipating traffic waves
Authors: Briani Maya , Manzo Rosanna , Piccoli Benedetto , Rarità Luigi
Published: August 2024

Current research directions indicate that vehicles with autonomous capabilities will increase in traffic contexts. Starting from data analyzed in R. E. Stern et al. (2018), this paper shows the benefits due to the traffic control exerted by a unique autonomous vehicle circulating on a ring track with more than 20 human-driven vehicles. Considering different traffic experiments with high stop-and-go waves and using a general microscopic model for emissions, it was first proved that emissions reduces by about 25%. Then, concentrations for pollutants at street level were found by solving numerically a system of differential equations with source terms derived from the emission model. The results outline that ozone and nitrogen oxides can decrease, depending on the analyzed experiment, by about 10% and 30%, respectively. Such findings suggest possible management strategies for traffic control, with emphasis on the environmental impact for vehicular flows.
Monitoring the impact of the Corona pandemic on nitrogen dioxide emissions at large scales via Google Earth Engine
Authors: Öçer Nuri Erkin , Matcı Dilek Küçük , Avdan Uğur
Published: August 2024

Advances in Earth observation capabilities and the expanded accessibility of data provide the opportunity to monitor air pollution on a global scale. The Google Earth Engine (GEE) enables the efficient conduct of such large-scale research. This article examines the impact of the COVID-19 pandemic on NO2 emissions at various supranational scales, with particular consideration of the Human Development Index of the countries, using GEE. The findings for the first three months of 2020 indicating a reduction in emissions of more than 4% per month, demonstrate that not only were the restrictions and closures imposed by governments effective in the global decline of NO2 levels, but also voluntary restrictions imposed by people on their own mobility with the motive of protection from the pandemic.
Transforming Healthcare
Authors: Aravind K. , Arun S. , S. Ivo Romauld , Pazhamalai Vivek
Published: August 2024

The processes of disease detection, therapy, and prevention are all part of the complicated healthcare system. This prescriptive research's goal is to provide decision-makers with an improved knowledge of three new technologies in the healthcare sector by outlining the technology's fundamentals, current uses, potential risks, and associated managerial concerns. By enhancing clinical outcomes and perhaps moving medical care from hospitals to homes in industrialized nations, telemedicine provides an alternative to traditional healthcare. Technology, economics, and societal effects all influence its expansion. With augmented reality (AR), computer-generated pictures are superimposed over the physical world to provide users access to new information. In contrast, virtual reality immerses users in wholly artificial surroundings. AR combines virtual components with the physical world. Healthcare could be transformed by these technologies, which present new opportunities and difficulties for decision-makers to take into account.
Leveraging Green AI and Big Data Informatics for Personalized Disease Prediction in Clinical Decision Making
Authors: Yadav Mohit , Singh Priyank Kumar , Gochhait Saikat , Gaur Nisha , Wijethilaka Puwakpitiyage Gayan Dhanushka
Published: August 2024

This chapter explores the potential of green AI and big data informatics for personalized disease prediction in clinical decision making. Green AI prioritizes efficiency, minimizing computational resources needed to analyze vast healthcare datasets. Big data informatics provides the platform to manage and analyze these datasets for knowledge discovery. This chapter delves into how green AI algorithms optimize resource utilization while big data platforms leverage diverse patient data for more accurate, individual risk assessments. The applications in clinical decision-making encompass early detection, risk stratification, and personalized treatment plans. However, ethical considerations regarding data privacy, bias, and potential job displacement require careful attention. Finally, the future directions highlight advancements in green AI efficiency, explainable models, and integration with other health technologies, paving the way for a future of proactive healthcare and patient empowerment.
Explainable AI (XAI) for Green AI-Powered Disease Prognosis
Authors: Mittal Shashank , Singh Priyank Kumar , Gochhait Saikat , Kumar Shubham
Published: August 2024

Accurate disease prognosis is crucial for improved healthcare outcomes. Artificial intelligence (AI) offers immense potential in this domain, but traditional “black-box” models lack interpretability. This chapter explores the integration of Explainable AI (XAI) with Green AI, a resource-efficient and sustainable approach to AI development. They discuss how XAI can enhance trust in Green AI models for disease prognosis, mitigate potential biases, and promote responsible AI development. They highlight the challenges of balancing interpretability with efficiency and propose future research directions to unlock the full potential of XAI for Green AI-powered disease prognosis. This approach has the potential to revolutionize healthcare by providing accurate, transparent, and environmentally friendly tools for early disease detection and improved patient outcomes.
Education in the Time of the Pandemic
Authors: Ajithkumar Usha
Published: August 2024

The proposed study is focused on the impact of school closure on barriers to access, opportunities, and outcomes from the perspective of students. The study adopted survey cum correlation method. The study used quantitative method for collecting data from 200 students, from eight schools spread across four zones of Tamil Nadu. A self-designed questionnaire containing questions on perception of barriers to access, opportunities, and outcomes was constructed. Descriptive statistics, independent t-test, Pearson's correlation, and multiple linear regression were used to analyze the data. The study suggests COVID-19 has been a major barrier to access and opportunities in education and impacted the learning outcomes. The coping strategies students adopted was revealed through qualitative analysis of the interview data. The findings call for initiatives by stakeholders to respond to mitigate the learning loss.
Embracing Inclusivity
Authors: Singha Surjit
Published: August 2024

The chapter explores the critical role of diversity and inclusion in contemporary education in the context of the COVID-19 pandemic and global conflicts. It provides strategies for the cultivation of equitable learning environments, with a focus on the integration of technology, the development of secure spaces, and the development of culturally responsive teaching. Forging community partnerships, empowering student voices, and conducting ongoing assessments of inclusive practices are prioritized. Educators can ensure that all students have equitable opportunities by adopting these methods, enabling them to accommodate their diverse requirements better. Education is positioned as a catalyst for equity and social justice in our interconnected world, and the chapter advocates for a sustained commitment to inclusivity.
Pursuing Grant Funds in Higher Education Post-“Sugar High” From Government Pandemic Funds
Authors: Hai-Jew Shalin
Published: August 2024

Some governments provided financial assistance to their respective populations during the shutdowns and social distancing period of the SARS-CoV-2 / COVID-19 pandemic of late 2019 – mid 2023. In that time, institutions of higher education were able to access funds to maintain programs from the federal, state, and county governments. By 2024, with the end of the pandemic and people partially returned to work, community colleges were again having to reach broadly to find grant funds for supplementary funding to bolster higher education, as the schools are fast approaching the “enrollment cliff” (a large drop in student enrollments) based on population demographics expected in 2025. This work describes some observations about grant writing in higher education from this particular slice-in-time, based on work-based observations and abductive logic.
Modern Technology for Specific Skills Development for Women to Succeed in Tomorrow's Labor Market
Authors: Darwish Dina
Published: August 2024

Digital skills, both general and specialized, have become even more vital than they were in the past for a wide variety of sectors and professions. This is because the nature of the technology world is such that it is always evolving. It is possible that effective innovation, which is achieved via the appropriate use of new technology, could be hampered if there is a continued lack of skills in the workforce. Additionally, there are considerable discrepancies in the readiness of the labor force to fill the expanding skill demands associated with digitalization across a variety of economic sectors, countries, and even various worker demographics. These differences may be seen in the workforce. In this context, it will be essential to increase the number of programs that aim to reskill and upskill workers, particularly those who come from certain communities. The purpose of this chapter is to discuss the significance of acquiring the essential digital skills that are now available, and the digital abilities that women need to acquire to be competitive in the employment market.
Closing the Digital Divide in India
Authors: Lavanya Reganti , Mamilla Rajesh
Published: August 2024

The digital gender divide in India remains a substantial impediment to women's participation in the burgeoning digital economy, maintaining disparities in economic, social, and political empowerment. This chapter investigates the various barriers to women's access to and use of digital technology for business goals. Using a variety of scholarly literature and empirical evidence, it identifies important contributors to the digital gender gap and recommends ways for fostering gender-inclusive digital access and engagement. These measures include making technological infrastructure more accessible, encouraging digital literacy and skill development, confronting socio-cultural obstacles and gender stereotypes, and implementing gender-inclusive policies and programs. By addressing these barriers and fostering inclusive digital participation, India can solve the full ability of women as entrepreneurs, innovators, and leaders in the digital age, advancing economic development., innovation, and sustainability while promoting the advancement of women.
Medical Tourism and Health Gateways in International Health Market Places
Authors: Singh Bhupinder , Kaunert Christian , Riswandi Budi Agus , Arora Manmeet Kaur , Lal Sahil
Published: August 2024

Medical tourism has the ability to reshape how patients move around in global healthcare, providing new opportunities for access to high standardised services and quality resources as industries progress through innovation and technological advancements. A critical factor for medical tourism is that this newfound option must be imbued with sustainability; it has to go hand in hand respecting equity and social responsibility. It is structured such that it provides insights for those interested in creating policies, practicing medicine, or dealing with diagnosis. This chapter investigates the contribution of medical tourism in supporting sustainability and technological transfer, at the global health market. It will look at what is driving the growth of medical tourism and why patients are seeking healthcare abroad, as well as some of the hurdles and benefits with this burgeoning space for both patient consumers and provider stakeholders.
Exploring Menstrual Health and Hygiene in India
Authors: Khadar Amiya Abdul , Kansra Pooja , Lodh Kaushik
Published: August 2024

Menstrual health refers to a woman's overall physical and psychological well-being throughout their menstrual cycle. Having good menstrual health means that a person experiences a regular and predictable menstrual cycle, without significant pain or discomfort. It also involves having the availability of nontoxic and effective products for menstruation and adequate information about menstrual health. The absence of proper hygienic menstrual facilities and sanitation put women and girls at threat of several health issues, such as infections in the urinary and reproductive tract. Additionally, menstrual stigma often leads to communal separation and omission from daily activities like school and work. In the present study, an attempt has been made to explore the state of menstrual health and hygiene in India and also identify the most popular menstrual product types among women of different age groups, educational backgrounds, places of residence, and religions.
Socio-Economic Factors of Maternal Healthcare in India
Authors: Prakash Bishwajeet , Yadav Urmila , Kumar Indrajit , Gautam Supriya , Arora Atul , Arora Mehak , Sharma Richa
Published: August 2024

Pregnancy and childbirth should be times of joy. However, safe motherhood and childbirth depend on the care and attention provided to pregnant women and newborns. Maternal health remains major health problem in India, with large inter- and intra-state inequities in maternal health service use and maternal deaths. Maternal health care coverage includes maternal mortality; and antenatal care includes post- and pre-natal care. The post mortality in both women and child is increased in many countries throughout the world, especially in developing countries due to low level of socio-economic development. The present study examines the contribution of India's National Health Mission (NHM) to maternal health includes both pre- and post-natal care at health institution with inequalities in various determinates of major health outcomes, at least visit of six ANC. In furthermore, the study examines socio-demographic factors of maternal healthcare utilization among Indian women. The data has been collected from an Indian National Family health survey between 2005-06 and 2019-21. A multiple logistic regression model has been used to estimate ratios associated with various visited ANC. It has been observed from the data post implementation of National Health that the institutional delivery increased by 58 percent to 88 percent, which indicates persistent increase in both rural and urban areas. It further observed the proportion of ANC visit by pregnant women is increased dramatically, with a higher percent at 89.38 percent—indicating rich women are more times visited to ANC, compared to poorer women. In further, study has indicated that educational attainment among women and family is most significant predicators of maternal healthcare utilization. As a result, maternal mortality has removed the inter and intra state disparities and forces women to make their delivery in more institutional and ensuring the reduction of child and mother mortality rate in the country, which helps to meet the sustainable development goals.
Trips Plus Provisions
Authors: Niyada P. Raniyal , Sanjaya Karun
Published: August 2024

The primary goal of granting intellectual property rights was to encourage innovation, particularly in the healthcare industry. The Paris Convention provided for worldwide protection for ideas, and the global harmonization of intellectual property protection (TRIPs) broadened the scope of protection. The pharmaceutical sector, including Pfizer, played a key role in TRIPS lobbying. However, corporations were dissatisfied with TRIPS flexibilities used by developing nations. To combat this, they turned the forum towards bilateral and regional trade agreements, providing additional economic incentives. The United States is at the forefront of these efforts, which include clauses that restrict affordable access and generic entry. This research investigates the history, mechanisms, and techniques of forum shifting and outlines key areas of Free Trade Agreements that directly impact access to medicine.
Choosing the Right Emic Lens
Authors: El Messaoudi Mohammed
Published: August 2024

The current study sets out to provide a thorough overview of core qualitative research designs widely deployed in social sciences in general and management science in particular. A scoping review of 160 articles, following PRISMA, was conducted to expose the philosophical underpinnings, key characteristics, and practical applications of each design. The scoping review was geared towards investigating commonly used qualitative research designs through the lens of ontology, epistemology, and axiology. The study general analysis model provides a subtle understanding of the strengths and limitations of each design. Importantly, the study acknowledges the potential challenges associated with each design, such as issues of generalizability and researcher bias. In a few words, this scholarly work aims at arming researchers with the required knowledge to select the most appropriate qualitative research design for their specific research objectives.
Application of Content Analysis for a Qualitative Approach
Authors: Li Gwee Ming , Khairatun Siti Nurhayati , Tan Tai Boon
Published: August 2024

This study explains the application of content analysis to examine food safety regulations, analyzing regulatory frameworks and enforcement mechanisms across different regions. By comparing legislative texts and enforcement practices, the study identifies key differences in regulatory focus and methods used to enforce these regulations. It conducts a detailed examination of laws, guidelines, and the roles of agencies responsible for enforcement. The analysis reveals variations in regulatory approaches, such as permissible levels of additives, inspection protocols, and penalties for non-compliance. The study offers insights into the effectiveness of different food safety systems, highlighting how jurisdictions maintain consumer confidence in their food supply chains. It aims to inform policymakers, industry stakeholders, and researchers about critical elements that contribute to robust food safety standards and public health protection through improved regulatory practices.
Factors Influencing Student Well-Being Within Institutions of Higher Education
Authors: Mishra Richa , Sharma Deepti , Venugopal Sunitha
Published: August 2024

The chapter presents various factors which directly or indirectly impact students' wellbeing and consequently their academic performance also gets affected. These factors range from academic to social, financial, awareness of mental health issues and support services provided by the universities. The authors conducted a survey where almost 200 UG, PG, PhD students participated. The academic factors include the resources, guidance provided by the faculty, the various tasks and responsibilities that are assigned to the students for their academic excellence. The major findings indicate a need to have a balanced approach while assigning academic work. The results indicate that students feel stressed when multiple academic assignments are given, and they have other tasks too to complete at the same time. The universities may think of better ways to train the students on how to manage their academic affairs without getting anxious. Social factors, which are also important, cover students' feeling of belongingness to the university, group dynamics, their social life and the instances where they felt alienated. The responses show that almost 38% of students feel or felt isolation occasionally. The universities may create a more conducive environment and plan activities which promotes more social interactions and meetings. More social and cultural activities can be organised where students may get along and can build rapport with each other. Another important factor is physical activities which include lifestyle, physical activities, sleep, etc. The results imply that students are fairly aware of the importance of maintaining a good and healthy lifestyle as it is directly related to their academic performance. Besides physical health, mental well-being is an equally important factor. The universities have become aware of promoting mental health. The responses reveal that the students feel low at times but the mentoring support which is provided by the universities help them overcoming their anxiety and stress. These initiatives by the universities have proved extremely helpful for the mental health of the students. Financial factors are also crucial and affect the students' performance. Financial factors imply students' sense of financial stability. The students' financial insecurity leads to their academic loss. Some students take part time jobs to bear the expenses of their education. The support services which are provided by the universities such as resources, financial aid, counselling, faculty guidance, play a vital role in students' academic journey. The students acknowledge the support provided to them yet there is a need to highlight and being articulative about the support services so that maximum students may take advantage of them.
Exploring Risk Factors of Well-Being of Students in Universities
Authors: Aloka Peter Jo , Mnyamana Nzukiso , Okongo Calvins O. , Orao Remi
Published: August 2024

In order to highlight risk factors of well-being among students in higher education institutions, such as stress, anxiety, and depression (SAD), transition to university, excessive parental control, autism, inadequate social problem-solving skill, negative self-perception/inferiority complex, loneliness and paranoia, thematic review of the literature employed the theoretical framework based on Centeredness theory. In addition to mental health detioration, risk factors exacerbate the inability of students to maintain their resilience in the face of adversity. A variety of well-being dimensions were also examined in the review, eudaimonia, non-eudaimonic objective list well-being, life satisfaction, desire fulfilment, hedonic well-being, and eudaimonia.
Protective Factors of Well-Being Among Students in Higher Education Institutions
Authors: Aloka Peter Jo , Zindoga Lilian , Okello Lazarus Millan , Orao Remi
Published: August 2024

Several issues affect students in higher education institutions including pressure of studies, cost of education, inadequate sleep, and stress. While mobile learning offers some advantages for the students in terms of convenience and flexibility matters, there are also disadvantages of using mobile devices, including addiction, health, distraction, and privacy because mobile phones can be distracting. The chapter indicates that protective factors also contribute to mental health as well as allow a person to be resilient in the face of challenges. The review also looked at different types of well-being, including emotional, physical dimension, occupational, social, spiritual, intellectual, environmental, and financial wellbeing.
Institutional Barriers to the Healthy Promoting of Universities in Higher Education in Africa
Authors: Tomas Nestor , Poroto Annarosa , Mangundu Andrias Musigeni
Published: August 2024

Poor mental health among students in higher education is a growing public health and policy concern. There is a lack of literature that synthesizes the available evidence on the barriers faced by educational institutions in becoming health promoting universities (HPUs) and the recommendations for implementing health promotion among university students in Africa. To identify the major institutional barriers and how they affect student well-being in Africa, a scoping review of various electronic databases were searched spanning from January 2000 to May 2024. Two themes emerged: a) Institutional barriers to health promotion university; b) recommendations for the implementation of HPU in Africa. The findings serve as a catalyst in fostering collaboration, both locally and internationally, to enhance the well-being of students throughout Africa and help them thrive and succeed in their academic pursuits. The review calls for African universities to join the International Network of HPU, as well as training academics to effectively teach health promotion concepts.
Addressing Student Well-Being in Universities
Authors: Vetrivel S. C. , Sabareeshwari V. , Arun V. P. , Sowmiya K. C.
Published: August 2024

As universities strive to provide holistic education, prioritizing student well-being has become paramount. This chapter explores the multifaceted approaches to fostering a supportive campus environment conducive to student wellness. It examines the significance of mental health services, academic support systems, and inclusive policies in promoting student flourishing. Drawing on research and best practices, the chapter underscores the importance of proactive intervention strategies and community engagement initiatives. Furthermore, it discusses the role of technology and innovative programs in augmenting student support services. By cultivating a culture of empathy and resilience, universities can effectively address the diverse needs of their student populations, ultimately nurturing thriving individuals poised for success in academia and beyond.
Coping With Poor Well-Being Issues
Authors: Pathak Vijendra Nath , Kaur Ripandeep , Jain Muskan , Chechi Vijay Kumar , Pathak Anjalee
Published: August 2024

The chapter “Coping With Poor Well-Being Issues Among Students in Higher Education Institutions” underscores the importance of tackling the growing coping and poor well-being issues among students in higher education. It suggests a new approach to integrating coping strategies and support systems throughout campus life. Drawing from academic sources, it explores how student well-being relates to academic performance. The chapter aims to create a varied strategy to address different well-being needs, encouraging proactive actions and collaboration among the campus community. It hopes to build strong and successful student communities by focusing on prevention and early support. Ultimately, it advocates for a proactive and cooperative method to handle student well-being issues in higher education, striving to create environments where students can excel academically, socially, and emotionally.
Normally-Off 1200V Silicon Carbide JFET Diode with Low VF
Authors: Cho Kevin Kyu Heon , Park Chang Joon , Kim Yeon Jeong , Park Kyeong Seok , Allerstam Fredrik
Published: August 2024

Novel diode structure which looks like DMOSFETs with the gate-shorted to n+ source has been developed for the first time. The lateral JFET channel as a built-in channel instead of gate oxide is integrated and it is pinched-off under the zero bias condition. As JFET diode decreases the forward voltage drop using JFET channel efficiency rather than the cell pitch reduction or the increase of doping concentration in n-SiC drift region, VF and capacitive charges which have a trade-off relationship typically could be decreased simultaneously and a better switching performance is also expected accordingly. Figure-of-Merit (=VF×QC) of the proposed JFET diode has been improved by 20.2% in average compared to that of JBS diode and this FOM would be the best in class among 1200V SiC diode products.
A Geometry-Scalable Physically-Based SPICE Compact Model for SiC MPS Diodes Including the Snapback Mechanism
Authors: Terracciano Vincenzo , Borghese Alessandro , Boccarossa Marco , d'Alessandro Vincenzo , Irace Andrea
Published: August 2024

In this paper, a simple compact model for the static behavior of SiC MPS diodes is developed in the form of a SPICE-compatible subcircuit. The model is suited to describe the undesired snapback mechanism likely to occur in unoptimized high-voltage MPS structures with narrow width of the PiN portion and/or very thick drift layer; in particular, the model accounts for the snapback mechanism both as the cell extension varies and as individual portions of Schottky and PiN vary. Sentaurus TCAD simulations of a 10-kV MPS diode are used as a reference for the calibration of the model parameters and accuracy verification.
Facilitation of ICTs for Rural-Urban Economic Transformation in Sri Lanka
Authors: Jayasooriya S. P.
Published: August 2024

The spread of ICTs has a huge impact on rural economic transformation. The purpose
of this paper is to comprehend the significance of ICTs in facilitating transformation
in Sri Lanka. The information came from a national survey of 26,600 people. The Probit
endogenous switching model was used. The results show that the marginal probability of
getting ICT-related jobs has increased by 6.8%, ICT users have reduced their poverty
level by 12.6%, and access to digital information has increased by 28.1% in the rural
sector. These shards of evidence demonstrate that ICT dispersion causes rural-urban
transformation in Sri Lanka.
Glucocorticoids Suppress NF-κB–Mediated Neutrophil Control of Aspergillus fumigatus Hyphal Growth
Authors: Thrikawala Savini U , Anderson Molly H , Rosowski Emily E
Published: August 2024

Glucocorticoids are a major class of therapeutic anti-inflammatory and immunosuppressive drugs prescribed to patients with inflammatory diseases, to avoid transplant rejection, and as part of cancer chemotherapy. However, exposure to these drugs increases the risk of opportunistic infections such as with the fungus Aspergillus fumigatus, which causes mortality in >50% of infected patients. The mechanisms by which glucocorticoids increase susceptibility to A. fumigatus are poorly understood. In this article, we used a zebrafish larva Aspergillus infection model to identify innate immune mechanisms altered by glucocorticoid treatment. Infected larvae exposed to dexamethasone succumb to infection at a significantly higher rate than control larvae. However, both macrophages and neutrophils are still recruited to the site of infection, and dexamethasone treatment does not significantly affect fungal spore killing. Instead, the primary effect of dexamethasone manifests later in infection with treated larvae exhibiting increased invasive hyphal growth. In line with this, dexamethasone predominantly inhibits neutrophil function rather than macrophage function. Dexamethasone-induced mortality also depends on the glucocorticoid receptor. Dexamethasone partially suppresses NF-κB activation at the infection site by inducing the transcription of IκB via the glucocorticoid receptor. Independent CRISPR/Cas9 targeting of IKKγ to prevent NF-κB activation also increases invasive A. fumigatus growth and larval mortality. However, dexamethasone treatment of IKKγ crispant larvae further increases invasive hyphal growth and host mortality, suggesting that dexamethasone may suppress other pathways in addition to NF-κB to promote host susceptibility. Collectively, we find that dexamethasone acts through the glucocorticoid receptor to suppress NF-κB–mediated neutrophil control of A. fumigatus hyphae in zebrafish larvae.
Experiments and Modelling of Multicopter Rotor Response to Sinusoidal Vertical Gusts
Authors:   German Aerospace Center - DLR, Gardner A.D. , Kostek A.A. , Lossle F. , Braukmann J.N.
Published: August 2024

Multicopters operate in environments subject to strongly gusting winds, and need good aeromechanical models to improve the aircraft. A common, convenient, assumption is that the gusting inflow is quasi-static at each instant, but this assumption has never been tested. This paper shows that there is a solid physical basis for the simplified aerodynamic models of multicopter response to gusts. Experiments and computations show that using the static relationship between thrust or power and aerodynamic angle of attack for a multicopter rotor (the quasi-static assumption) in sinusoidally pitching sideflow can be used to predict the thrust or power for unsteady variation of angle of attack if the instantaneous flow angle of the freestream is known. Vertical (angle) gusts up to 1885°/s (k=2.2 based on diameter) and with a wavelength longer than the rotor diameter were shown to be covered by this assumption.
Evaluation of Virtual and Mixed Reality Technologies in Helicopter Simulation
Authors:   German Aerospace Center - DLR, Martini Tanja
Published: August 2024

Helicopters, because of their vertical take-off and landing capability, are an important vehicle for demanding missions such as search and rescue operations and transportation into confined areas. Therefore, training is essential to minimize the risk of helicopter missions due to human error. To date, more and more simulation is used for helicopter training where typically certified full-flight simulators are utilized. The use of simulation has several advantages. Challenging and risky tasks can be practiced in a safe environment. At the same time, the operational costs of a helicopter can be saved. Likewise, training scenarios can be simulated that cannot be trained in reality, such as a tail rotor failure. However, the use of simulation for training does not only have advantages. For example, simulation training can cause simulation sickness. Also, the lack of simulation fidelity can hinder transfer of training. With innovative technologies, there are new opportunities for helicopter simulation to increase the fidelity of the simulation. In this paper it is discussed to which extent Virtual Reality (VR), Mixed Reality (MR) and Augmented Reality (AR) technologies can be used as visual system in the helicopter simulation environment. The aim is to increase the immersion of the helicopter simulation and thus enhancing the learning effect and transfer of training. In a piloted study an AR (with see-through display), MR and VR (monitor-based display) setup is compared to conventional helicopter simulation at a research simulator.
Study of Advanced Occupant Models to Quantify Injury Risk for eVTOL Vehicles
Authors:   Virginia Tech, Jones Nathaniel ,   NASA Langley Research Center, Putnam Jacob , Untaroiu Costin
Published: August 2024

Urban transportation is currently evolving from traditional ground-based vehicles (cars, taxis, and buses) to include air-based electric vertical take-off and landing (eVTOL) vehicles which can be utilized for on-demand transportation, cargo transport, and emergency services. These new eVTOL vehicles are designed to be small, lightweight, and able to operate autonomously without user intervention. Safety is a big part of eventual eVTOL adoption, however gaps in the consideration of safety features exist. Anthropomorphic test devices (ATDs) are used in aerospace crashworthiness standards to quantify occupant injury risk and develop improved safety designs for emergency landing situations, but the ATDs currently used in aircraft certification requirements were developed many decades ago. Developments have occurred over the years involving ATD technology, which includes a host of newer and more biofidelic ATDs such as the Test Device for Human Occupant Restraint (THOR). Increased computing power has also allowed for detailed computational human body models (HBMs) to be created, such as the Global Human Body Model Consortium (GHBMC). This study aims to assess the capability of both HBMs and new ATD designs to identify injury mechanisms within eVTOL relevant emergency landing conditions. Finite element (FE) analysis was used to expand upon full-scale and seat level impact testing conducted by researchers at the National Aeronautics and Space Administration (NASA) to look at effects of occupant model configurations on prediction of injury. The GHBMC HBM and THOR ATD models were simulated in the seat level test conditions to characterize differences between these advanced assessment tools and traditional ATDs in the isolated seat loading environment. Results identified key differences in the responses from each of the models utilized and compared their impact response in head, neck, and spinal injury metrics. The THOR model identified potential risks for head injuries due to head impacts on the seat, however it predicted lower spinal loads than the other occupant surrogates. The GHBMC showed distinctly different biomechanical responses compared to the ATD. The GHBMC model is much more deformable than the ATDs and it exhibited higher distribution of forces and increased sensitivity to the duration of acceleration pulses. Both models incorporated into this study identified key mechanisms for injury that should be considered for passenger safety in the development of these novel aircraft. In addition, this study demonstrated the value of FE modeling for running a variety of complex human surrogates to identify potential injury mechanisms for consideration in regulation and development of new aircraft. Continued research in this field to improve validation these models will only lead to safer aircraft and more comprehensive safety measures.
Experimental Investigation of Rotor Blade Structural Response In Hovering and Advance Flight
Authors:   University of Glasgow, Croke Alexander ,   University of Maryland, Wild Oliver , Green Richard , Jones Anya
Published: August 2024

A towing tank investigation of a single rotor blade operating at hovering and high advance ratio conditions is presented. A custom blade was manufactured and instrumented with fully bridged axial strain gauges to monitor the flap bending strain at three radial locations. Measurements of rotor thrust and torque were obtained to characterise the rotor aerodynamic environment for advance ratios ranging from 0.4 to 1.00 and to identify the presence of stalled and reverse flow. Strain measurements obtained at three locations across the blade span show minima and maxima at approximately the same azimuthal location as the load data. Moreover, the strain distribution shows a growth in strain magnitude with increasing advance ratio. Spectra of strain shows a dominant 1/rev signal and for the ∅ = 25° collective, non-harmonic frequencies are observed due to aperiodic vortex shedding from the presence of stalled flow.
Tiltwing Transition Flight Analysis Using High-Fidelity CFD
Authors:   NASA Ames Research Center, Perez David , Diaz Patricia , Sanguinetti Anthony , Yoon Seokkwan
Published: August 2024

Transition from hover to forward flight and vice versa represents the most critical flight phase of tiltwing aircraft. Despite its importance to ensure a safe operation, the aerodynamics of this maneuver are not sufficiently understood. This paper focuses on the study of transition flight for NASA's six-passenger tiltwing air taxi by means of high-fidelity computational fluid dynamics simulations. On the basis of a static trim solution, four points within the transition corridor are analyzed: transition mode at wing tilt angles of 60! and 44!, and airplane mode at airspeeds of 110 kt and 155 kt. We investigate the balance of forces and moments for rotor-borne and wing-borne regimes, and how rotor-on-rotor and rotor-on-wing interactions affect performance. The simulations indicate that during the early stages of transition, the vortices remain in close proximity to the proprotors, inducing large fluctuations on the order of the mean blade loading. Additionally, the blowing and swirling effects of the proprotor wakes delay flow separation over a portion of the wing. The mid-transition conditions appear to be critical, with extensive regions of separated flow over the wing. In airplane mode, proprotor-wing slipstream effects can be exploited to enhance lift generation. The results of this paper contribute to a deeper understanding of the complex aerodynamic interactions during transition flight to enable a safer and more efficient operation of tiltwing aircraft.
Multi-Fidelity Investigation of Aerodynamics and Acoustics of the Joby Aviation Aircraft
Authors:   US Army CCDC AvMC, Roget Beatrice ,   Science and Technology Corporation, Jude Dylan ,   Joby Aviation, Escobar Daniel , Sitaraman Jay , Lim Joon , Thai Austin , Bain Jeremy
Published: August 2024

The rotorcraft simulation tool HPCMP CREATE™-AV Helios is used to compute aerodynamics and acoustics for the Joby Aviation aircraft. This configuration is a six-propeller, all electric vertical take-off and landing aircraft designed to operate in an urban environment, for which noise minimization is a priority. The objective of this study is to demonstrate and improve key capabilities in Helios: multi-fidelity modeling, full-vehicle trim, and noise predictions. In this paper, we compare aerodynamics and acoustics predictions obtained using different levels of fidelity available in Helios: high-fidelity computations using discrete body-conforming meshes for propeller blades, and mid-fidelity computations using blades modeled as actuator lines. The isolated propeller is first analyzed in hover, followed by the full aircraft configuration in cruise. Trimmed flight conditions are obtained using a new trim solver in Helios by means of both the pitch control and RPM control approaches. Finally, an acoustics propagation module is introduced in Helios and used to obtain noise predictions, which are compared with experimental data and peer analyses.
Comprehensive Aerodynamic Analysis of PIV Measurements in the NFAC 80- by 120-ft Test Section Towards Understanding HVAB Hovering Rotor Characteristics
Authors:   US Army CCDC AvMC, Ramasamy Manikandan ,   NASA Ames Research Center, Heineck James , Yamauchi Cloria , Schairer Edward , Norman Thomas
Published: August 2024

Stereoscopic particle image velocimtery (PIV) was used to characterize a hovering rotor wake at four collective pitch settings in the world's largest wind tunnel test section. The PIV measurements are a subset of a comprehensive dataset acquired during the hover test of the HVAB rotor. Substantial effort was made to cross-validate PIV results with other test measurements and fluid mechanic theories to ensure accuracy in the reported HVAB dataset. Blade coning and flap bending were validated against early tip vortex locations. Tip vortex trajectory was compared against shadowgraphy results and free-jet boundaries. Tip vortex circulation was evaluated using a line-integral approach and least-squares curve-fit to a vortex model. Downwash velocity was compared against momentum theory values. Best practices were followed to correct inherent tip vortex aperiodicity. PIV-specific challenges were exacerbated by testing in a large facility, such as identifying and removing noisy vector fields caused by inadequate seeding. Towards this end, two new filtering methodologies were developed: (1) Modal Outlier Method (MOM), and (2) Projection on Phaseaverage (POP). Significant reduction in standard deviation was observed when outlier vector fields were removed. Lastly, inverse Betz theory was applied on PIV flow fields to relate trailed wake circulation and the sectional bound circulation. The resulting PIV-based loading distribution was used with lifting-line calculations and Helios simulations to analyze wake evolution. Blade-vortex interaction played a significant role in the airloads distribution that, in turn, affected the strength and evolution of the tip vortices themselves. The similarities and differences found among the PIV-, Helios-, and surface pressure sensor-based airloads were analyzed in detail to help plan future experiments.