Psychological Determinants of Using Facebook: A Research Review

In recent years, Facebook has become the most popular of social networking sites (SNSs). Due to its increasing popularity and rising number of its users, the phenomenon of Facebook has aroused academic interest as well. There has been a growing number of studies on this subject. The aim of this article is to present the main trends in Facebook research and to provide an overview of major empirical findings. Among the most intensively explored topics in Facebook research, studies that concentrate on personality and individual differences among users, the role of self-efficacy, and motivation for using that specific SNS were identified. There is also a growing trend in empirical studies that focuses on testing advanced theoretical models of Facebook usage determinants. Technology acceptance model, presented in this article, is one of the most often used among them. This kind of approach may serve as a suggestion for a methodological conceptualization in the future confirmatory research on Facebook.     

Drop breakage and coalescence in the toluene/water dispersions with dissolved surface active polymers PVA 88% and 98%

The influence of two PVAs of the same molecular weight (13,000–23,000) and different degree of hydrolysis equal to 88% and 98% on breakage and coalescence of toluene droplets in the liquid/liquid dispersion were considered for PVA concentration range 0.001–0.01%. Analysis of experimental results shows that drop coalescence is significant only in the system containing 0.001% PVA. Drop coalescence for polymer concentration range 0.002–0.01% is strongly limited. Therefore, population balance was solved using breakage and coalescence expressions with assumed partially mobile drop interfaces for the lowest PVA concentration. For c ≥ 0.002% drop size distributions were properly predicted using only breakage model. Multifractal formalism was used to take into account intermittent character of turbulence and explain drop behavior. Larger drop size reduction by PVA of lower degree of hydrolysis observed experimentally was confirmed by the model.     

Influence of laminate type on tin whisker growth in tin-rich lead-free solder alloys

This paper describes variations in whisker growth on the surface of tin-rich, lead-free alloys soldered on a Cu layer depending on the laminate used for the printed circuit board, which can be either glass-epoxy or paper-phenol. The structure of the glass-epoxy laminate surface is characterized by spatial nonuniformity caused by the regular structure formed by regions of glass fibers and resin in the top layer of the laminate. The higher value of thermal expansion of the resin than of the glass fiber means that the area of the resin expands more than that of the glass fiber. This causes local compressive stress in the solder layer and as a result promotes whisker growth in the area of the alloy soldered on the Cu layer over the glass fiber. This effect does not occur on the surface of an alloy soldered on Cu layer over a paper-phenol laminate.     

K‐12 Outreach: Identifying the Broader Impacts of Four Outreach Projects

Over the last four years, a series of outreach programs have been offered through the Colorado School of Mines to middle school teachers from eleven school districts in the State of Colorado in the United States. Each of these programs is designed to illustrate through hands‐on activities the application of mathematics to science and engineering. Each also has an academic year follow‐up such that a faculty member, an expert teacher, or a graduate student assists the teachers in the classroom. An expected outcome of this effort is the improvement of instruction in mathematics and science in the participating middle schools; an unexpected outcome has been the impact of these projects on the culture of the participating schools, both middle schools and university. Based on our assessment efforts, this article describes the qualitative and quantitative outcomes of this sequence of projects on middle school students, teachers, graduate students, professors, and college curriculum.     

A grid-based assessment of global water scarcity including virtual water trading

A 0.5-degree grid-based assessment of the scarcity of global water resources including virtual water trading has been made. The three components of water availability considered for each grid were local runoff, routed flow from upstream and virtual water trading. Several assumptions were postulated to convert country-base estimations of virtual water trading to grid values. The results show that unequal spatial distribution of global water resources had been considerably neutralized by virtual water trading. A large proportion of people in the Middle-East, North-Africa and Sub-Sahara region are able to relieve their water stress through virtual water import. The paper also reports two hypothetical scenarios with extremes of natural flow availability based on the presence and absence of routed upstream flow.     

Phase diagram and thermodynamic properties of the system MnCl2-UCl4, prediction and investigation results

The MnCl₂-UCl₄ system was studied employing differential thermal analysis, common thermal analysis and high-temperature cryometry. From the results obtained, both the phase diagram and the thermodynamic characteristics of liquid phases of the system have been determined. The results were discussed in terms of regularities found in the phase equilibria of binary salt systems with common anion and compared with those for other systems of the type MCl_n-UCl₄. It appeared that the results confirmed earlier predictions on the title system.     

Designing for human use: Examples of kitchen interiors for persons with disability and elderly people

Around 15% of the global population has a moderate or severe disability. For this reason, a design where the needs of elderly and disabled population are included, should become more common practise and should not be limited only to medical and rehabilitation products. In this study, the inclusive design practices related to the kitchens were applied. All the important stages in a design process, such as market research, planning, concept designing, detailed designing, research (ergonomic assessment), and production preparation were completed. In market research we market research examined the preferences of 216 respondents. Sixty percent of them were either elderly and/or disabled persons (direct users), 40% were caretakers, physiotherapists, and managers of care centres (indirect users). Implementation of obtained results is three kitchen lines with assistive technology solutions, which are the response to the requirements identified as appropriate in meeting the needs of the elderly and disabled kitchen users. The main conclusion of the article is the statement that the needs of seniors can and should be efficiently included in a design process of home interiors. It can be recognised as an important “social” designing criterion which can constitute a good basis for going beyond the traditional design and going toward the sustainable design.     

Influence of ultrasonic conditioning of flocculant on the aggregation process in a tank with turbine mixer

Aggregation is a very widely encountered phenomenon in nature as well as in industrial processes. It plays an important role in processing of air and water, e.g. wastewater treatment plants, power plants, mining facilities. The new, cost-effective solutions are developed. Among the others modification of the flocculants by means of ultrasounds, mixtures with surfactants or polydispersive flocculant blends can be mentioned. Flocculants used in the aggregation process are long-chain polymers that can be of negative, positive or neutral charge. The aggregation caused by usage of such flocculants is the result of three different mechanisms: bridging, charge neutralization or electrostatic patch. The influence of ultrasonic field on the efficiency of different flocculants was investigated. Suspension of chalk in water was used and the measurements were taken in the laser particle sizer. The influence of the sonication time on flow curves is also presented.