353 research outputs found

    The symbolic value of ethnic spaces

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    This is the final version. Available on open access from SAGE Publications via the DOI in this recordIn four experiments, students read that their university was creating either an ethnic space (a space geared to people of particular ethnic groups) or a general space for students. In an internal meta-analysis, underrepresented students of color (N = 205), but not White students (N = 760), who read about the ethnic space reported greater belonging, value of underrepresented students by the university, support, and academic engagement compared to those who read about a general space. Ethnic spaces may hold broader psychological significance than that of mere gathering places, improving outcomes even for those who do not frequently use them. Creating ethnic spaces may be one strategy for making university environments more welcoming for underrepresented students of color.Economic and Social Research Council (ESRC

    How diverse is your team? Investigating gender and nationality diversity in GitHub teams

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    Open Access: This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.Background Building an effective team of developers is a complex task faced by both software companies and open source communities. The problem of forming a “dream” team involves many variables, including consideration of human factors and it is not a dilemma solvable in a mathematical way. Empirical studies might provide interesting insights to explain which factors need to be taken into account in building a team of developers and which levers act to optimise productivity among developers. Aim In this paper, we present the results of an empirical study aimed at investigating the link between team diversity (i.e., gender, nationality) and productivity (issue fixing time). Method We consider issues solved from the GHTorrent dataset inferring gender and nationality of each team’s members. We also evaluate the politeness of all comments involved in issue resolution. Results Results show that higher gender diversity is linked with a lower team average issue fixing time (higher productivity), that nationality diversity is linked with lower team politeness and that gender diversity is linked with higher sentiment.Peer reviewedFinal Published versio

    Concentration of apricot juice using complex membrane technology

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    In this study, pressed apricot (Prunus armeniaca L.) juice was concentrated using complex membrane technology with different module combinations: UF-RO-OD, UF-RO-MD, UF-NF-OD and UF-NF-MD. In case of the best combination a cross-flow polyethylene ultrafiltration membrane (UF) was applied for clarification, after which preconcentration was done using reverse osmosis (RO) with a polyamide membrane, and the final concentration was completed by osmotic distillation (OD) using a polypropylene module. The UF-RO-OD procedure resulted in a final concentrate with a 65-70 °Brix dry solid content and an excellent quality juice with high polyphenol content and high antioxidant capacity.Nanofiltration (NF) and membrane distillation (MD) were not proper economic solutions.The influence of certain operation parameters was examined experimentally. Temperatures of UF and RO were: 25, 30, and 35 °C, and of OD 25 °C. Recycle flow rates were: UF: 1, 1.5, and 2 m3 h−1; RO: 200, 400, and 600 l h−1; OD: 20, 30 and 40 l h−1. The flow rates in the module were expressed by the Reynolds number, as well. Based on preliminary experiments, the transmembrane pressures of UF and RO filtration were 4 bar and 50 bar, respectively. Each experimental run was performed three times. The following optimal operation parameters provided the lowest total cost: UF: 35 °C, 2 m3 h−1, 4 bar; RO: 35 °C, 600 l h−1, 50 bar; OD: 20, 30 and 40 l h−1; temperature 25 °C.In addition, experiments were performed for apricot juice concentration by evaporation, which technique is widely applied in the industry using vacuum and low temperature.For description the UF filtration, a dynamic model and regression by SPSS 14.0 statistics software were applied

    Evaluation of cleaning efficiency of ultrafiltration membranes fouled by BSA using FTIR–ATR as a tool

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    The goal of this paper was to study the cleaning of two polyethersulfone (PES) membranes of different molecular weight and fouled with BSA solution. Ultrafiltration (UF) membranes were tested in a flat sheet module. Fouling experiments were carried out at a transmembrane pressure of 2 bar and cross flow velocity of 2 m/s during 2 h. Cleaning experiments were performed at 1 bar and 2.2 m/s. To compare the efficiency of different cleaning solutions (NaOH and P3-Ultrasil 115), quantification of residual pro-teins on the membrane was carried out by FTIR ATR. To have a better understanding of the cleaning pro-cess, characteristics of the feed solution and of the membranes were considered and contact angle of the membranes before and after the cleaning was measured. Membrane resistances were also calculated at the different stages. Results from resistances showed that reversible fouling prevail over irreversible fouling for both membranes. P3-Ultrasil 115 was a better cleaning agent than NaOH solution since cleaning efficiencies (CE) of 100% for both membranes were achieved for P3-Ultrasil 115 solution. Residual pro-teins on the membrane after the cleaning were measured both by FTIR ATR and Pierce-BCA method. Results showed that 100% of permeability recovery did not imply the complete BSA removal from the membrane. However, these measurements corroborated that P3-Ultrasil 115 had removed a higher amount of proteins than NaOH solution.This work was supported by the Spanish Ministry of Science and Innovation (CTM 2010-20.186).Luján Facundo, MJ.; Mendoza Roca, JA.; Cuartas Uribe, BE.; Alvarez Blanco, S. (2015). Evaluation of cleaning efficiency of ultrafiltration membranes fouled by BSA using FTIR–ATR as a tool. Journal of Food Engineering. 163:1-8. https://doi.org/10.1016/j.jfoodeng.2015.04.015S1816
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