Miracle-dz/UniFAR-FTUs huggingface dataset:
Mathematical Modelling of Non-Isolated Bi-Directional DC-DC Converter on Transients and Steady State Response

Energy management strategy is gaining much popularity because now the load is taking energy from different non-conventional/conventional sources as well as from energy storage element to provide uninterruptable power supply to the load. The bi-directional converter placed in between a DC voltage source and a battery to allow energy transfer. The converter connected with high voltage DC-bus and also the converter backed up with battery. Using the bi-directional dc-dc converter operation modes (Buck and Boost) this battery will be charged and discharged as per the suitable condition for uninterrupted power supply to the load. In this paper, a nonisolated half-bridge bi-directional dc-dc converter is studied for hybrid vehicle technology. The state space formulation of the bidirectional dc-dc converter in ideal case as well as with parasitics in different modes of operations is derived. The averaging and linearization technique is applied to get the small signal model of the converter. To verify the methodology, converter model is developed in MATLAB/SIMULINK environment. Keywords-Bi-directional DC-DC Converter, Energy management system,State space modelling, Small-Signal Analysis Hybrid electric vehicle etc.
Design Formulas for Flat Gradient Index Lenses With Planar or Spherical Output Wavefront

A semi-analytical method is presented for the design of gradient index (GRIN) flat lenses. Closed-form expressions are derived to define the refractive index distribution of the lens, for several cases: collimating lenses with on-axis feed, collimating lenses with off-axis feed, lenses converting spherical wavefronts with different wavenumbers, lenses changing the focal number of a quasi-optical system, and Fresnel zone lenses. The design equations are validated by ray-tracing simulations in inhomogeneous media, implemented by numerical solution of the Eikonal equation.
Energy Distribution Of Macronutrient Among Adolescents In Indonesia: Secondary Analysis Of Total Diet Study Data

In nutrition through the lifecycle concept, nutritional adequacy for each age group should be seriously considered, including in adolescent group. Adolescent balanced nutrition needs to be addressed in order to prevent future diseases. Balanced nutrition can be assessed based on the energy distribution of macronutrients that have been formulated through national summit. Thus, this study aims to evaluate energy distribution of macronutrients as well as percent adequacy intake of energy, protein, and fat among adolescence in East Java province, Indonesia. Data from Total Diet Study were used to investigate the intakes of macronutrient and demographic data of adolescents aged 16 – 18 years who lives in East Java Province (n=708). Data of intakes were assessed using 24 hr recall. Mann-Whitney U tests and Independent t-test were conducted to compare macronutrient consumption, percent adequacy intake of energy, protein, and fat between sex and locality. The results show energy distribution of macronutrient was 56.55% energy from carbohydrate: 14.36% energy from protein: 29.09% energy from fat. Energy distribution of macronutrient of adolescent was changed from 2010 in which energy from protein and fat were increase while energy from carbohydrate was decrease. Percent distribution of energy from carbohydrate was significantly higher in boys (p=0.000), but percent energy from protein was significantly higher in girls (p=0.000). There was no significant different in energy distribution of macronutrients between urban and rural adolescents. Compared to Indonesian Recommended Dietary Allowances (RDA), mean intake of energy, protein, and fat were 75.17%, 101.45%, and 74.82%, respectively. There was no significant different in percent adequacy intake of macronutrients both for sex and locality. This analysis demonstrates a balanced energy distribution of macronutrient intake. These results should be considered by those responsible for ensuring adequate nutrient intakes of adolescents.
Board 143: Challenges Faced by Students Transitioning from High School to College

: The COVID-19 pandemic has caused significant disruptions in the educational system at both the K-12 and university levels. At the university level, students are struggling with deficiencies in math knowledge and with the lack of skills needed to succeed in college. According to the 2022 report from the American College Testing (ACT), only one in five students graduating from high school are prepared to take university level courses in math and science. In 2022, the ACT composite results fell to the lowest values since 1991. This generation of students is more distressed, disengaged, digitally distracted, and discouraged when compared with previous cohorts. The purpose of this project is to identify the challenges faced by students transitioning from high school to college after the COVID-19 pandemic. For this study, we are focused on the transition of first-generation students as they experience their first semester in college. We believe that the COVID-19 pandemic has caused significant shifts in the struggles and needs of incoming students. For the analysis, first semester students enrolled in an engineering program in the Mid-Atlantic region were tasked to write a reflective essay explaining the challenges faced in their first four weeks in college. A thematic analysis of the qualitative data was used to analyze the reflective essays. This “work in progress” paper will summarize the main results of the study. Based on the analysis, we propose interventions to assist these students in their transition from high school to college. This project is relevant to institutions seeking to improve the retention of students in their engineering programs.
Reviewing big data's role in the digital economy: USA and Africa focus

In the dynamic landscape of the digital economy, the integration and utilization of Big Data have emerged as pivotal factors influencing economic growth and innovation. This paper undertakes a comprehensive review of the contrasting roles that Big Data plays in shaping the digital economies of the United States and Africa. By examining the unique socio-economic contexts and infrastructural landscapes of these regions, the study seeks to shed light on the divergent trajectories of Big Data adoption and its impact on economic development. In the context of the United States, where a mature digital infrastructure prevails, Big Data has become a linchpin for innovation, competitiveness, and economic resilience. The paper delves into specific industries, such as technology, finance, and healthcare, to elucidate how Big Data analytics is leveraged to drive efficiency, inform decision-making, and foster disruptive advancements. The study extends beyond the corporate sector to explore the implications of Big Data on policy formulation and governance. Conversely, the study shifts its focus to Africa, a region characterized by diverse economic landscapes and varying degrees of technological development. The analysis explores the challenges and opportunities posed by Big Data adoption in Africa, highlighting the potential for leapfrogging traditional development stages through strategic data-driven initiatives. Additionally, the paper addresses issues related to data privacy, security, and the need for collaborative efforts to bridge the digital divide. Ultimately, this comparative review aims to contribute to a nuanced understanding of the role of Big Data in shaping the digital economies of the USA and Africa. By delineating the divergent trajectories, challenges, and opportunities, the study provides a foundation for informed policy recommendations, fostering inclusive and sustainable economic development in the digital age.
CAMELON: A System for Crime Metadata Extraction and Spatiotemporal Visualization From Online News Articles

Crimes result in not only loss to individuals but also hinder national economic growth. While crime rates have been reported to decrease in developed countries, underdeveloped and developing nations still suffer from prevalent crimes, especially those undergoing rapid expansion of urbanization. The ability to monitor and assess trends of different types of crimes at both regional and national levels could assist local police and national-level policymakers in proactively devising means to prevent and address the root causes of criminal incidents. Furthermore, such a system could prove useful to individuals seeking to evaluate criminal activity for purposes of travel, investment, and relocation decisions. Recent literature has opted to utilize online news articles as a reliable and timely source for information on crime activity. However, most of the crime monitoring systems fueled by such news sources merely classified crimes into different types and visualized individual crimes on the map using extracted geolocations, lacking crucial information for stakeholders to make relevant, informed decisions. To better serve the unique needs of the target user groups, this paper proposes a novel comprehensive crime visualization system that mines relevant information from large-scale online news articles. The system features automatic crime-type classification and metadata extraction from news articles. The crime classification and metadata schemes are designed to serve the need for information from law enforcement and policymakers, as well as general users. Novel interactive spatiotemporal designs are integrated into the system with the ability to assess the severity and intensity of crimes in each region through the novel Criminometer index. The system is designed to be generalized for implementation in different countries with diverse prevalent crime types and languages composing the news articles, owing to the use of deep learning cross-lingual language models. The experiment results reveal that the proposed system yielded 86%, 51%, and 67% F1 in crime type classification, metadata extraction, and closed-form metadata extraction tasks, respectively. Additionally, the results of the system usability tests indicated a notable level of contentment among the target user groups. The findings not only offer insights into the possible applications of interactive spatiotemporal crime visualization tools for proactive policymaking and predictive policing but also serve as a foundation for future research that utilizes online news articles for intelligent monitoring of real-world phenomena.
Molecularly Mixed Composite Membranes for Gas Separation Based on Macrocycles Embedded in a Polyimide

Polyimides are a polymer class that has been extensively investigated as a membrane material for gas separation owing to its interesting permselective properties in a wide range of operation temperatures and pressures. In order to improve their properties, the addition of different filler types is currently studied. p-tert-Butylcalix[n]arene macrocycles (PTBCs) with different cavity sizes (PTBC4, PTBC6, PTBC8) were used as fillers in a commercial thermoplastic polyimide, with a concentration in the range 1–9 wt%, to develop nanocomposite membranes for gas separation. The selected macrocycles are attractive organic compounds owing to their porous structure and affinity with organic polymers. The nanocomposite membranes were prepared in the form of films in which the polymeric matrix is a continuous phase incorporating the dispersed additives. The preparation was carried out according to a pre-mixing approach in a mutual solvent, and the solution casting was followed by a controlled solvent evaporation. The films were characterized by investigating their miscibility, morphology, thermal and spectral properties. The gas transport through these films was examined as a function of the temperature and also time. The results evidenced that the incorporation of the chosen nanoporous fillers can be exploited to enhance molecular transport, offering additional pathways and promoting rearrangements of the polymeric chains.
Assessing Various Pedagogical Features of Remote Versus In-Person Iterations of a First-Year Engineering, Makerspace Course

This evidence-based practice paper is a follow-up to an ASEE 2022 conference proceeding that was focused on the challenges in development, in addition to resulting student perceptions upon delivery, of a remote iteration (Spring 2021, due to the COVID-19 pandemic) of a conventionally hands-on, active learning-based makerspace course; of which employs integration and application of fundamental engineering skills and all institutional first-year engineering students are required to take. Specifically, this paper is focused on the ensuing iteration of the course (Spring 2022) in which students resumed in-person course execution, and aims to disseminate comparative resulting student perceptions on course features between the remote iteration versus the in-person iteration and, in some cases, the course iteration prior to the pandemic. At the conclusion of the 2022 (post-COVID) semester, more than 300 student participants were surveyed on respective perceptions in Perceived Belonging Uncertainty and Interest in Engineering. Resultant responses were then compared to responses to the same surveys conducted by pre-pandemic students in addition to students that experienced the course during the pandemic (in which students experienced the course under a remote environment). Student participants during the 2022 course iteration were further surveyed with a quantitative forced-choice ranking. Specifically, students were asked to rank pedagogical effectiveness of six select course features – 3D modeling, circuitry, engineering design, programming, teamwork, and technical writing – and these six features were predominantly determined by qualitative identification of effective and/or ineffective features by the (2021) remote cohort. Respective responses from the during-COVID cohort versus the post-COVID cohort were compared and assessed. Resultant implications, limitations, and revelations of these findings conclude this paper.
THE SWEDISH IBP/PT TUNDRA BIOME PROJECT OBJECTIVES - PLANNING -SITE

The Swedish IBP/PT Tundra Biome Project (1970-1974) formed part of an international ecological effort that involved 11 countries and aimed at obtaining basic information on the productivity of the tundra areas of the world. The project was designed according to a joint research programme for studying the structure and function of tundra ecosystems. It was carried out on a subarctic ombro trophic mire on permafrost at Stordalen near Abisko, northern Sweden (68? 21'N; 19? 05'E). The investigations were interdisciplinary, and researchers from all the Swedish universities and the Swe dish colleges of forestry and agriculture took part. Destructive sampling in the site was carried out according to a statistical two-stage sampling plan with four 50 x 50 m blocks, each containing twen ty-five 5 x 5 m squares. A fifth block constituted the sampling area for climatic and other abiotic variables.
Knowledge, Attitudes, and Practice of General Practitioners Toward Screening of Age-Related Hearing Loss in Community: A Cross-Sectional Study in Shanghai, China

Background Age-related hearing loss (ARHL) is experiencing a continuously rising in prevalence among the elderly worldwide. General practitioners (GPs) may have a unique position in its community detection and management. Objective This study aims to assess the KAP of GPs regarding ARHL through questionnaire, to investigate the role of them in the management and to propose strategies for the hearing screening within the community. Methods An online survey was administered to 1173 GPs, selected from 56 community health centers (CHCs) in Shanghai during April to June 2022. A scale endorsed by a panel of multidisciplinary experts was used to assess knowledge (7 items), attitudes (12 items), and practice (10 items). A mean score was computed and converted into a scale ranging from 0 to 100. Odds ratios (ORs) were calculated for potential predictors of higher levels of KAP scores (with mean value as a cutoff point) through logistic modelling. Results A total of 1022 GPs completed the questionnaire with response rate 87.13%. The average scores are 69.90 ± 32.27, 66.09 ± 7.15, and 59.89 ± 21.99 for Knowledge, attitude, and practice, respectively. 24.3% of participants achieve a complete score of knowledge, whereas 5.48% receive zero. 11.6% consider ARHL as not a disease. Above 30.0% are not familiar with the screening tool. 10.8% refuse to undergo hearing screening. Higher levels of compliance in practice are found in the participants with higher levels of knowledge (OR=1.409, p=0.000) and more favorable attitude (OR=1.028, p=0.000). Male (OR=0.708, p=0.036) is associated with lower levels of attitudes. Conclusion GPs have a low level of ARHL knowledge, a lack of positive attitude towards the detection and management of it, and lower awareness in practice. Further research is required to gain a more comprehensive understanding of the attitudes held by GPs and explore more accessibility strategies.
Charting the Irreversible Degradation Modes of Low Bandgap Pb‐Sn Perovskite Compositions for De‐Risking Practical Industrial Development

The commercialization of a solar technology necessitates the fulfillment of specific requirements both regarding efficiency and stability to enter and gain space in the photovoltaic market. These aims are heavily dependent on the selection of suitable materials, which is critical for suppressing any reliability risks arising from inherent instabilities. Focusing on the absorber material, herein the most suitable low bandgap lead‐tin composition candidate for all‐perovskite tandem applications is investigated by studying their degradation mechanisms with both widely available and advanced characterization techniques. Three irreversible degradation processes are identified in narrow bandgap Pb‐Sn perovskite absorbers: 1) Tin (Sn) oxidation upon air exposure, 2) methylammonium (MA) loss upon heat exposure, and 3) formamidinium (FA) and cesium (Cs) segregation leading to impurity phase formation. From an industrial perspective, it is proposed to refocus attention on FASn0.5Pb0. 5I3 which minimizes all three effects while maintaining a suitable bandgap for a bottom cell and good performance. Moreover, a practical and highly sensitive characterization method is proposed to monitor the oxidation, which can be deployed both in laboratory and industrial environments and provide useful information for the technological development process, including, the effectiveness of encapsulation methods, and the acceptable time windows for air exposure.
Long‐range transport of NH3, CO, HCN, and C2H6 from the 2014 Canadian Wildfires

We report the first long‐term measurements of ammonia (NH3) in the high Arctic. Enhancements of the total columns of NH3, carbon monoxide (CO), hydrogen cyanide (HCN), and ethane (C2H6) were detected in July and August 2014 at Eureka, Nunavut, and Toronto, Ontario. Enhancements were attributed to fires in the Northwest Territories using the FLEXPART Lagrangian dispersion model and the Moderate Resolution Imaging Spectroradiometer Fire Hot Spot data set. Emission estimates are reported as average emission factors for HCN (0.62 ± 0.34 g kg−1), C2H6 (1.50 ± 0.75 g kg−1), and NH3 (1.40 ± 0.72 g kg−1). Observations of NH3 at both sites demonstrate long‐range transport of NH3, with an estimated NH3 lifetime of 48 h. We also conclude that boreal fires may be an important source of NH3 in the summertime Arctic.
Influence of Storage Temperature on Starch Retrogradation and Digestion of Chinese Steamed Bread

Chinese steamed bread (CSB), which is widely consumed in East Asia, usually undergoes storage before consumption, but it is unclear how different storage temperatures affect CSB starch retrogradation and digestion properties, which are important for consumers. CSB was stored for 2 days at 25 °C, 4 °C, −18 °C, 4 °C/25 °C temperature cycling (i.e., 24 h at 4 °C, followed by 24 h at 25 °C) and −18 °C/ 25 °C temperature cycling. The results revealed for the first time that more orderly starch double helices are formed when CSB was stored at 4 °C or 4 °C/25 °C. Storage under −18 °C produced lower amounts of, but more heterogenous, starch double helices, with fewer B-type, but more V-type, crystallites. Compared to other storage temperatures, more long-range intermolecular interactions formed between the starch and protein at 4 °C or 4 °C/25 °C. CSB samples showed the slowest starch digestibility when stored at 4 °C. The impact of storage temperature on the starch retrogradation properties and digestibility of CSB also depended on the wheat variety, attributed to differences in the starch molecular structure. These results have significance and practical applications to help the CSB food industry to control starch retrogradation and digestibility. For example, CSB could be stored at 4 °C for 2 days in order to reduce its starch digestibility.
Comparative Analysis of Growth, Survival, and Virulence Characteristics of Listeria monocytogenes Isolated from Imported Meat

Listeria monocytogenes is an important foodborne pathogen with worldwide prevalence. Understanding the variability in the potential pathogenicity among strains of different subtypes is crucial for risk assessment. In this study, the growth, survival, and virulence characteristics of 16 L. monocytogenes strains isolated from imported meat in China (2018–2020) were investigated. The maximum specific growth rate (μmax) and lag phase (λ) were evaluated using the time-to-detection (TTD) method and the Baranyi model at different temperatures (25, 30, and 37 °C). Survival characteristics were determined by D-values and population reduction after exposure to heat (60, 62.5, and 65 °C) and acid (HCl, pH = 2.5, 3.5, and 4.5). The potential virulence was evaluated via adhesion and invasion to Caco-2 cells, motility, and lethality to Galleria mellonella. The potential pathogenicity was compared among strains of different lineages and subtypes. The results indicate that the lineage I strains exhibited a higher growth rate than the lineage II strains at three growth temperatures, particularly serotype 4b within lineage I. At all temperatures tested, serotypes 1/2a and 1/2b consistently demonstrated higher heat resistance than the other subtypes. No significant differences in the log reduction were observed between the lineage I and lineage II strains at pH 2.5, 3.5, and 4.5. However, the serotype 1/2c strains exhibited significantly low acid resistance at pH 2.5. In terms of virulence, the lineage I strains outperformed the lineage II strains. The invasion rate to Caco-2 cells and lethality to G. mellonella exhibited by the serotype 4b strains were higher than those observed in the other serotypes. This study provides meaningful insights into the growth, survival, and virulence of L. monocytogenes, offering valuable information for understanding the correlation between the pathogenicity and subtypes of L. monocytogenes.
High Frequency Modelling of Permanent Magnet Synchronous Machine

This paper addresses the modelling of PMSM under high frequency PWM control. The high frequency components of input voltage have different responses in terms of induced current and iron losses, due to eddy currents in the magnets, phase conductors and in the core lamination. Both inductance and HF iron loss behavior of the machine were investigated through experiment, modelled, and reproduced by circuit simulation. Inductance is treated separately for low frequency and high frequency components to build the current response of the machine. HF iron losses are determined for each HF cycle individually, according to peak-to-peak HF current. The configuration of the model can be realized either from locked rotation tests or from Finite Element Analysis. The model is suited for the optimization of control strategy with respect to losses, including adaptation of switching frequency or over-modulation.