jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Priya Anka Lekhi
Source: cIRcle (University of British Columbia) (article, 2018-01-01)
Field: Chemistry — Physical and Theoretical Chemistry

International students' epistemologies and learning experiences in specially designed first-year chemistry courses First-year university science courses are often challenging for a majority of students coming out of high school, with international students having even greater adjustment difficulties. This may be due to differences between the epistemologies held by the students and the epistemological expectations of the science courses. Active learning environments have different epistemological expectations than traditional lectures and international students may have inadequate prior experiences with this mode of learning science. Thus, an exploratory case study approach to investigate first-year international students’ epistemologies and experiences in their chemistry courses within the Vantage One Science Program was conducted. Vantage One Programs, which reside in Vantage College at the University of British Columbia, admits and offers first-year programs to international students from non-English speaking countries. The case study largely employed a mixed methods methodology that used both quantitative and qualitative tools for data collection. To assess the students’ epistemologies, the Epistemological Beliefs about Physical Sciences (EBAPS) instrument was administered three times during the program. The three data sets were analyzed using exploratory and confirmatory factor analysis to determine dominant factors underlying the students’ responses to the items on the EBAPS, interpreted as a description of the key student epistemologies. Student grades from CHEM 121 and CHEM 123 courses were also collected and correlated with scores from the EBAPS questionnaire. Qualitative methods were used to examine students’ epistemologies and their views on their experiences. These methods included classroom observations, one-on-one semi-structured and task-based interviews and focus group interviews. The results indicate that some aspects of student epistemologies transformed over the course of the first year Vantage program while others aspects remained the same. When factors did transform, they transformed towards more canonical epistemologies. Transformations included valuing peers and oneself as a source of science knowledge and becoming more aware of the nature of science. Some of these transformations can be attributed to the pedagogy experienced in Vantage One Science Program, including the use of peer-learning pedagogy and inquiry-based learning. Both qualitative and quantitative data suggest that more canonical views are associated with positive study approaches, problem-solving strategies, and academic performance. Mathematics education ; Chemistry ; Pedagogy ; Psychology ; Computer science ; Engineering ethics ; Engineering Various Chemistry Research Topics
Authors: Megan E. Harries
Source: CU Scholar (University of Colorado Boulder) (article, 2018-01-01)
Field: Chemistry — Organic Chemistry

Vapor-Liquid Equilibria Pertaining to the Study of Alternative Fuels and the Forensic Analysis of Chemical Evidence Measurement of the vapor-liquid equilibrium (VLE) of fluid mixtures with many components presents a challenge. Data describing such mixtures, like fuels, are important for the development of alternative energy sources and to support forensic science, but there is a lack of suitable instrumentation to provide data with reasonable uncertainty for mixtures with many components. In this thesis, three different techniques for fluid characterization are explored: the advanced distillation curve (ADC), the advanced distillation curve with reflux (ADCR), and PLOT-cryoadsorption.\nTwo pyrolysis fuels similar to gasoline and diesel fuel made from polypropylene were studied with respect to volatility, composition, and energy content using the advanced distillation curve. The diesel fuel demonstrated volatility very similar to previously measured diesel fuels. The gasoline was less volatile than petroleum-derived counterparts and did not meet specifications. Two pyrolysis crude oils made from ponderosa pine and dairy manure were assessed using the ADC coupled to an approach for characterizing fluids with multiple, immiscible liquid phases. Both oils contained high water levels and would require further refinement before use. The organic phases of each oil contained components indicative of the feedstock used.\nA modification of the ADC method, the advanced distillation curve with reflux, was introduced as an approach to measuring the VLE of fluids with many components. The ADCR additionally approximates the weathering of an ignitable liquid that occurs during an arson fire and measures VLE across a range of weathered conditions. The method was demonstrated using two simple mixtures. The measurements agreed well with models, indicating that ADCR is a suitable VLE metrology.\nVapor-liquid equilibrium data are crucial for interpreting the results of headspace characterization used often in forensic science. One headspace method, portable PLOT-cryoadsorption, was tested in a series of experiments in the laboratory and then deployed for the first time in a field environment that simulated a cargo container. The technology was found to be rapid and sensitive to a variety of compounds of interest to forensic science. Each of the three techniques described in this thesis contribute valuable property data for multicomponent mixtures, towards the development of high-quality predictive models. Chemistry ; Biochemical engineering ; Petroleum engineering ; Environmental science ; Waste management ; Engineering Chemical Thermodynamics and Molecular Structure
Authors: Aleksandar Bojić | Milena Miljković | Tatjana Anđelković | Aleksandra Zarubica | Marjan Ranđelović | Jelena Mitrović
Source: Chemia Naissensis (article, 2018-01-01)
Field: Chemistry — Organic Chemistry

Chair of Applied and Environmental Chemistry Chair of the Applied and Environmental Chemistry was established in 1995 on the initiative of Prof. Dr. Milovan Purenović, who has been in the position of Head of the Chair since its establishment until his retirement in 2011. Prof. Dr. Aleksandar Bojić is currently Head of the Chair. Since its establishment until now, professors and associates of the Chair of Applied and Environmental Chemistry have been dedicated to the applied research, within the framework of innovative and development projects, which were realized through cooperation with industry. Also, a significant contribution has been made in the field of environmental protection, especially in the treatment of drinking and wastewater. Several operational technologies have been developed, some of them are protected by patents of the Intellectual Property Office of the Republic of Serbia. The Chair of Applied and Environmental Chemistry consists of four full professors, one associate professor, and one assistant professor. Library science ; Engineering ; Management ; Engineering management ; Engineering ethics ; Political science ; Computer science Inorganic and Organometallic Chemistry ; Analytical chemistry methods development ; Environmental Toxicology and Ecotoxicology
Authors: B. Davier
Source: HAL (Le Centre pour la Communication Scientifique Directe) (preprint, 2018-11-29)
Field: Materials Science — Materials Chemistry

Theoretical study of thermoelectric properties in nanostructures Les générateurs thermoélectriques convertissent directement l'énergie thermique en énergie électrique. Ils pourraient devenir de plus en plus utiles à des fins de récupération d'énergie et font l'objet de recherches actives. Cependant, les meilleurs matériaux thermoélectriques sont rares et polluants.Le Silicium et le Germanium seraient des matériaux intéressants si leur efficacité thermoélectrique était améliorée. Pour ce faire, la nanostructuration est une voie possible, par exemple en introduisant des faces rugueuses ou de nouvelles interfaces semi-transparentes.Récemment, des nanofils polyphasés (composés d'une alternance de phases cubiques et hexagonales de Si et Ge) ont été fabriqués, mais la caractérisation expérimentale de nanostructures aussi complexes comprenant des matériaux exotiques peut être difficile. Dans cette thèse, nous étudions en détail le transport thermique dans des nanostructures avec des simulations numériques. Une méthode Monte Carlo originale a été développée, avec une description "full band" des matériaux. Elle inclut des modèles pour les faces rugueuses et les interfaces entre matériaux. Des simulations de Dynamique Moléculaire sont également effectuées pour caractériser les propriétés des interfaces.Nous confirmons que les phases hexagonales de Si et Ge ont une conductivité thermique inférieure à celle des phases cubiques correspondantes. Le modèle "full band" montre que le flux thermique est fortement anisotrope. Des modèles semi-analytiques habituels n'ont pas pu reproduire la conductivité thermique des nanostructures simulées avec des faces rugueuses.De plus, ces faces ont tendance à concentrer le flux de chaleur dans la direction principale de la nanostructure. Enfin, certaines interfaces polyphasées peuvent avoir une conductance thermique presque aussi faible que les interfaces Si/Ge, et pourrait ainsi améliorer significativement l'efficacité thermoélectrique des nanofils polyphasés. La méthode Monte Carlo présentée peut facilement être utilisée pour étudier une large gamme de matériaux, et elle est capable de modéliser des nanostructures arbitrairement complexes. A l'avenir, les simulations en Dynamique Moléculaire seront utilisées pour paramétrer un modèle plus réaliste d'interfaces. Materials science ; Thermoelectric effect ; Nanowire ; Nanostructure ; Thermoelectric materials ; Thermal conductivity ; Condensed matter physics ; Nanotechnology ; Germanium ; Anisotropy ; Silicon ; Optoelectronics ; Thermodynamics ; Physics ; Composite material ; Optics Chemical and Physical Properties of Materials ; Advanced Physical and Chemical Molecular Interactions ; Thermal properties of materials
Authors: Yasasvi Bommireddy | Ankit Agarwal | Vikas Yettella | Vikas Tomar | Marcial Gonzalez
Source: arXiv (Cornell University) (preprint, 2018-12-14)
Field: Materials Science — Biomaterials

Loading-unloading contact law for micro-crystalline cellulose particles\n under large deformations A semi-empirical mechanistic contact law for micro-crystalline cellulose\n(Avicel PH-200) particles is proposed and characterized experimentally using\nforce-displacement curves obtained from diametrical compression of single\nparticles. The concepts of a shape factor and a master contact law are\nintroduced first for elastic ellipsoidal particles, and subsequently\ngeneralized to plastic irregular particles. The proposed loading-unloading\ncontact law is a function of three characteristic diameters (lengths of the\nprincipal axes of an approximated ellipsoid), a geometric parameter associated\nwith the loading condition, three plastic and one elastic material properties.\nThe force-displacement curves obtained using a micro-compression tester exhibit\nan apparent strain-hardening at distinctly different strain values, which is\ncaptured by the shape factor function and its geometric parameter. The three\nplastic material properties are log-normal distributions estimated from the\nloading experimental curves, while the elastic property is estimated from the\nunloading experimental curves. The study shows a very good agreement between\npredictions of the calibrated loading-unloading contact law and the\nexperimental values.\n Materials science ; Ellipsoid ; Hardening (computing) ; Composite material ; Displacement (psychology) ; Strain hardening exponent ; Elasticity (physics) ; Mechanics ; Physics Advanced Cellulose Research Studies ; Advanced Materials and Mechanics ; Natural Fiber Reinforced Composites
Authors: Dana D. Burfeind | Christine Devine | Iwona Czaplinski
Source: QUT ePrints (Queensland University of Technology) (article, 2018-01-01)
Field: Chemistry — Physical and Theoretical Chemistry

Kitchen Chemistry: Taking the cookbook out of undergraduate laboratory experience Lab based learning experiences provide rich opportunities for students to practise science in an authentic context, developing and evidencing core discipline-specific graduate capabilities. Despite the inherent value, laboratory based practicals are expensive to resource (materials, staff time, laboratory space, etc), and therefore are typically constrained and prescriptive. Given these limitations, how do we prioritise and safeguard skill based learning to prepare students for careers in STEM disciplines?&lt;br/&gt;&lt;br/&gt;This showcase aims to highlight a novel solution to facilitate the transition from first year STEM undergraduate to skilled STEM professional. “Kitchen Chemistry” provides a ‘low-stakes’ lab-based learning environment where the emphasis is on developing technical proficiency, problem solving skills and scientific literacy, without academic consequence. &lt;br/&gt;&lt;br/&gt;Through immersion in a typical undergraduate laboratory practical, participants will have the opportunity to reflect on the value of low-stakes skill-based learning to enhance problem-solving and creative thinking competencies, resilience and building scientific ‘identity’. Further, we encourage participation from both secondary and tertiary STEM educators at the showcase; identifying and understanding the skill-based learning curve for first year STEM undergraduates will help both parties of educators implement strategies to ensure a smooth transition from high school to university. Context (archaeology) ; Mathematics education ; Value (mathematics) ; Scientific literacy ; Next Generation Science Standards ; Pedagogy ; Engineering ethics ; Engineering ; Psychology ; Science education ; Computer science Various Chemistry Research Topics ; Genetics, Bioinformatics, and Biomedical Research ; Innovative Teaching Methods
Authors: Sibel Kılınç Alpat | Özge Özbayrak Azman | Şenol Alpat
Source: Trakya Eğitim Dergisi (article, 2018-01-25)
Field: Chemistry — Physical and Theoretical Chemistry

Madde-Işık Etkileşimine Dayanan Spektroskopik Analiz Yöntemi Uygulamalarında Proje Tabanlı Öğrenme Yaklaşımının Kimya Öğretmen Adaylarının Akademik Başarılarına Etkisi Bu çalışmada, Analitik Kimya laboratuvar dersi “Madde-ışık etkileşimine dayanan UV/Görünür bölge spektroskopik analiz yöntemi uygulamaları” konusunda, proje tabanlı öğrenme yaklaşımının öğrencilerin akademik başarılarına etkisi incelenmiştir. Araştırmada, ön ve son test kontrol gruplu yarı deneysel desen kullanılmıştır. Deney grubunda konu, proje tabanlı öğrenme yaklaşımı ile kontrol grubunda ise öğretim programına uygun şekilde yürütülmüştür. Son test akademik başarı puanlarının Mann-Whitney U Testi analizi sonuçlarına göre; öğrencilerin akademik başarılarında proje tabanlı öğrenme yaklaşımının kullanıldığı deney grubu lehine anlamlı bir fark olduğu gözlenmiştir (p<.05). Wilcoxon işaretli sıralar testi sonuçları; deney ve kontrol gruplarının her ikisinde de grup içi akademik başarı puanlarında artış olduğunu göstermiştir. Cohen’s d değerine göre, deney grubunda uygulanan öğrenme yaklaşımının büyük etki değerine sahip olduğu söylenebilir (d=0,88). Yarı yapılandırılmış görüşmelerin içerik analizinden elde edilen sonuçlar, deney grubu öğrencilerinin konunun uygulanan öğrenme yaklaşımı ile işlenmesini daha akılda kalıcı bulduklarını göstermiştir. Physics ; Psychology ; Mathematics Various Chemistry Research Topics ; Science Education and Pedagogy
Authors: Andrea Viridiana Quezada del Villara | Luis Alberto Rodríguez‐Picón | Iván Juan Carlos Pérez-Olguín | Iván Rodríguez Borbón
Source: Mundo FESC (article, 2018-07-01)
Field: Chemistry — Analytical Chemistry

Procesos estocásticos aplicados en análisis de datos de degradación-revisión de literatura Improving, calculating and projecting the reliability of products is a fundamental task nowadays in the industry. The most common stochastic process models in the literature and applications are the Gamma and Wiener processes. However, both models are insufficient to adjust all degradation data. There are applications where they do not fit at all and can lead to erroneous conclusions. In this manner, the Gaussian inverse process is a very attractive option for degradation data. In order to compare the Wiener, gamma and Gaussian inverse processes, we searched for written literature (books and articles) and online data-bases (virtual libraries, Academic Google and different data bases) for which some applications were obtained in different areas of study and the tendency of the use of the different processes through the last years. In addition, to identify characteristics and differences between each of the stochastic processes. Keywords: Reliability, Degradation model, Stochastic process degradation, Gamma processes degradation, Inverse Gaussian Process degradation, Wiener Process degradation Philosophy Analytical Methods in Pharmaceuticals ; Water Quality Monitoring and Analysis
Authors: Víctor Vicente-Palacios | Santiago Vicente Tavera | P. Ignacio Dorado-Díaz | Antonio Sánchez-Puente | Jesús Sampedro-Gómez | Purificación Galindo‐Villardón | Itzíar Gómez | J. Alberto San Román | Francisco Fernández‐Avilés | Pedro L. Sánchez
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2018-10-16)
Field: Chemistry — Analytical Chemistry

Exploratory and prospective model of stent restenosis after Percutaneous Coronary Intervention using Multivariate Gaussian Subspatial Regression A new statistical analysis methodology, “Multivariate Gaussian Subspatial Regression” (MGSR), has been applied to randomized clinical trial data collected from percutaneous coronary intervention (PCI) patients, which combines the descriptive quality of Factorial Techniques and the predictive power of Gaussian Processes. This model has been built from 3 different quantitative coronary angiographic core-lab measures of the same lesion from 2 separate angiograms (at baseline before PCI, at baseline immediately after PCI and at 12 months follow-up). Measurements of the pre-PCI variables of a patient are mapped to the factorial plane and predictions are visualized as regions of interest in this plane. MGSR makes it possible to detect patients at risk of coronary stent restenosis or patients in whom ruling out the disease, in a graphical way; avoiding unnecessary, costly and possibly risky treatments for patients with no complications predicted; and advising to closely follow patients at risk. In addition, the model recovers missing values regardless of the variables, and once fitted, it corrects itself when more dependent variables are included. MGSR software is freely available online at https://github.com/victorvicpal/MGSR . Conventional PCI ; Percutaneous coronary intervention ; Restenosis ; Multivariate statistics ; Stent ; Cardiology ; Medicine ; Internal medicine ; Regression ; Gaussian process ; Gaussian ; Coronary artery disease ; Radiology ; Statistics ; Myocardial infarction ; Mathematics Spectroscopy and Chemometric Analyses ; Statistical Methods and Inference ; Coronary Interventions and Diagnostics
Authors: Daniele Buongiorno | Marisa Michelini
Source: OAR@UM (University of Malta) (article, 2018-01-01)
Field: Chemistry — Physical and Theoretical Chemistry

An educational path on optical spectroscopy as a bridge from classical to modern Physics to overcome conceptual knots Optical spectroscopy is a conceptual referent linking classical and modern physics which provides experiments on the atomic structure and light-matter interaction. Its disciplinary relevance, as well as its importance on the cultural and social levels is widely recognized but few efforts have been made to integrate those aspects in education. Our Physics Education Research Unit from Udine University (Italy) designed an educational method on optical spectroscopy for secondary school students to directly involve them in experimental and interpretative tasks which allow them to highlight the link between energy level in atoms and luminous emission. In the theoretical framework of the Model of Educational Reconstruction, the educational approach involves an analysis of the main conceptual knots on the basis of a significant - if not vast - literature concerning the interpretation of optical spectra. By means of design-based research methods, we designed several intervention modules in which interpretative issues related to the analysis of simple optical spectra from different sources are highlighted using inquiry-based learning strategies. Learning outcomes were monitored by means of empirical research using pre/post-tests and tutorials. Path (computing) ; Bridge (graph theory) ; Spectroscopy ; Physics ; Theoretical physics ; Computer science ; Astronomy Various Chemistry Research Topics ; Science Education and Pedagogy ; Experimental and Theoretical Physics Studies
Authors: Yuanying Lou
Source: Iowa State University Digital Repository (Iowa State University) (article, 2018-01-01)
Field: Chemistry — Analytical Chemistry

Systematic analysis of food visual estimation methods and applications in school lunch Valid and reliable dietary assessment methods play a vital role in understanding children’s dietary behaviors and intake. Photo-based visual estimation methods with high flexibility, cost-effectiveness, and lower burden have been developed rapidly and applied widely recently. To promote its further application, it is necessary to perform a systematic analysis to investigate various commonly used visual estimation systems in the context of considering various influencing factors. A photo-based online survey was developed in the first study to evaluate the accuracy of four visual estimation systems: Third, Quarter, Eighth, and Continuous. Participants’ information including sex, age, height and weight, and major background characteristics was collected to explore the effects of these factors on visual estimation accuracy. Overall, the Quarter and Eighth systems had higher accuracy than the Third and Continuous systems. The system accuracy may also be affected by personal- and food-related factors in different ways among the four systems. Additionally, a majority of the survey population (59%) preferred to use the Quarter system for food visual estimations. Therefore, Quarter system was applied to evaluate the effects of SWITCH programming on improving students’ fruit and vegetable consumption (study 2), as well as energy and nutrient intake (study 3). Students in the 5th grade participating in the National School Lunch Program from four elementary schools were involved in both studies. Two schools participated in SWITCH and two did not. Results of the second study demonstrated that students participating in SWITCH significantly increased fruit consumption from 0.37 cups at baseline to 0.50 cups at endpoint. The increase in fruit consumption might potentially enhance students’ nutrient intake during lunch, which was supported by the third study. Students participating in SWITCH significantly increased their fiber selection and decreased their sodium selection and intake. The percentage of students meeting 2010 IOM recommendations for energy and fiber were also increased in SWITCH schools. Findings from this dissertation provide valuable guidance on selecting proper visual estimation systems as well as support the SWITCH program as a promising school wellness initiative to enhance children’s healthy eating and nutrition status. Estimation ; Computer science ; Economics Spectroscopy and Chemometric Analyses ; Sensory Analysis and Statistical Methods ; Meat and Animal Product Quality