164 research outputs found

    Thermal decomposition of allantoin as probed by matrix isolation FTIR spectroscopy

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    The optimized geometries, energies of the possible conformers of allantoin (2,5-dioxo-4-imidazolidinyl urea, the diureide of glyoxylic acid) as well as the barriers for conformational interconversion have been calculated using the density functional theory [DFT(B3LYP)/6-311++G(d,p)] method. The calculations predicted the existence of four conformers (gC, tT, g′C, and g′T; where the first and second symbols in the name of the conformers designate the conformation around the exocyclic NHC–NHCO and CNH–CO axes, respectively), with the gC form contributing to more than 98% of the population in gas phase at room temperature. This conformer is different from that corresponding to the monomeric unit found in crystalline RS-allantoin (g′C; Mootz, D. Acta Crystallogr.1965, 19, 726), stressing the importance of intermolecular H-bonding in determining the structure of the crystal. Upon sublimation under vacuum (10−6 mbar), the compound was found to undergo extensive decomposition to urea, isocyanic acid, NH3, and carbon. The identification of the decomposition products was made by using matrix isolation infrared spectroscopy. In consonance with the theoretical predictions, the allantoin molecules surviving thermal decomposition were found to undergo conformational isomerization and be present in the cryogenic argon matrix in both the gC and g′C conformations. The solid state room temperature infrared spectrum of allantoin was also investigated and assigned

    RELATIONSHIP OF THE GRIP AND PINCH STRENGTH OF THE DOMINANT HAND WITHANTHROPOMETRIC MEASUREMENTS OF FOREARM

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    Amaç: Çalısmanın amacı ön kol uzunluğunun ön kol çevresine oranı ile el kavrama kuvveti ve parmak kavrama kuvveti arasındaki iliskiyi incelemekti. Gereç ve yöntem: Çalısmaya Dokuz Eylül Üniversitesi Fizik Tedavi ve Rehabilitasyon Yüksekokulu'nda öğrenim gören 28 kadın, 31 erkek öğrenci dahil edildi. Olguların yas, boy, vücut ağırlığı, beden kütle indeksi, dominant ekstremite kavrama kuvveti, parmak kavrama kuvveti, ön kol uzunluğunun ön kol çevresine oranı kaydedildi. El kavrama kuvveti ölçümleri için Jamar El Dinamometresi, parmak kavrama kuvvetinin ölçümü için pinchmetre kullanıldı. El kavrama ve parmak kavrama kuvveti ölçümleri, Amerikan El Terapistleri Derneği tarafından önerilen standart pozisyonda yapıldı. Bulgular: Ön kol uzunluğunun çevre ölçümüne oranı ile el kavrama ve parmak kavrama kuvveti arasında olumsuz yönde, anlamlı bir iliski bulundu. Sonuç: Dominant elde, el ve parmak kavrama kuvveti önkolun antropometrik ölçümleri ile iliskilidir. Objective: The purpose of the study was to investigate the relationship between forearm length to forearm circumference ratio and grip and pinch strength. Material and method: 28 female and 31 male students from Dokuz Eylül University School of Physical Therapy and Rehabilitation participated in this study. Age, height, body weight, body mass index, dominant hand, grip strength, pinch strength, forearm length to forearm circumference ratio were recorded. Jamar Hand Dynomometer and pinchmeter were used to measure grip and pinch strength. Grip and pinch strength were performed at the standart position which is recommended by American Society of Hand Therapists. Results: A significant negative correlation was found between the grip and pinch strength and forearm length to forearm circumference ratio.Conclusion: Grip and pinch strength of dominant hand were related with the anthropometric measurements of forearm

    The Mind’s Eye on Personal Profiles: A Cognitive Perspective on Profile Elements that Inform Initial Trustworthiness Assessments in Virtual Project Teams

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    Rusman, E., Van Bruggen, J., Sloep, P., Valcke, M., & Koper, R. (2013). The Mind’s Eye on Personal Profiles: A Cognitive Perspective on Profile Elements that Inform Initial Trustworthiness Assessments and Social Awareness in Virtual Project Teams. Computer Supported Cooperative Work (CSCW), 22(2-3), 159-179.Collaboration in virtual project teams heavily relies on interpersonal trust, for which perceived trustworthiness is an important determinant. This study provides insight in the information that trustors value to assess a trustee’s professional trustworthiness in the initial phase of a virtual project team. We expect trustors in virtual teams to value those particular information elements that provide them with relevant cues of trust warranting properties of a trustee. We identified a list of commonly highly valued information elements to inform trustworthiness assessments (n=226). We then analysed explanations for preferences with the help of a theory-grounded coding scheme. Results show that respondents value those particular information elements that provide them with multiple cues to assess the trustworthiness of a trustee. This enables them to become aware of and assess the trustworthiness of another. Information elements that provide unique cues could not be identified. Insight in these information preferences can inform the design of artefacts, such as personal profile templates, to support acquaintanceships in the initial phase of a virtual project team

    Situation-Specific Models of Color Differentiation

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    Constructing a virtual Tower of Babel: a case study in cross-cultural collaboration across three continents

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    The collaboration project described in this paper revolves around the construction of a virtual Tower of Babel in a 3D Collaborative Virtual Environment (3D CVE). It involved students across three cooperating institutions, on three different continents in different time zones. It addresses the increasing need for students to engage in international collaboration, as much of today's Information and Communication Technology work demands it. This requires cross-cultural understandings with one's co-collaborators, yet there are few opportunities for this to occur in a pedagogical setting. Therefore, this paper discusses a pedagogically-oriented case study of the use of a 3D CVE as a multi-cultural classroom, describing and discussing different phases in the cross-cultural collaborative process

    Earth system data cubes unravel global multivariate dynamics

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    Understanding Earth system dynamics in light of ongoing human intervention and dependency remains a major scientific challenge. The unprecedented availability of data streams describing different facets of the Earth now offers fundamentally new avenues to address this quest. However, several practical hurdles, especially the lack of data interoperability, limit the joint potential of these data streams. Today, many initiatives within and beyond the Earth system sciences are exploring new approaches to overcome these hurdles and meet the growing interdisciplinary need for data-intensive research; using data cubes is one promising avenue. Here, we introduce the concept of Earth system data cubes and how to operate on them in a formal way. The idea is that treating multiple data dimensions, such as spatial, temporal, variable, frequency, and other grids alike, allows effective application of user-defined functions to co-interpret Earth observations and/or model-data integration. An implementation of this concept combines analysis-ready data cubes with a suitable analytic interface. In three case studies, we demonstrate how the concept and its implementation facilitate the execution of complex workflows for research across multiple variables, and spatial and temporal scales: (1) summary statistics for ecosystem and climate dynamics; (2) intrinsic dimensionality analysis on multiple timescales; and (3) model-data integration. We discuss the emerging perspectives for investigating global interacting and coupled phenomena in observed or simulated data. In particular, we see many emerging perspectives of this approach for interpreting large-scale model ensembles. The latest developments in machine learning, causal inference, and model-data integration can be seamlessly implemented in the proposed framework, supporting rapid progress in data-intensive research across disciplinary boundaries. © 2020 Institute of Electrical and Electronics Engineers Inc.. All rights reserved
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