Microscopic theory of pion production and sidewards flow in heavy ion collisions

Nuclear collisions from 0.3 to 2 GeV/nucleon are studied in a microscopic theory based on Vlasov's self-consistent mean field and Uehling-Uhlenbeck's two-body collision term which respects the Pauli principle. The theory explains simultaneously the observed collective flow and the pion multiplicity and gives their dependence on the nuclear equation of state

Wind turbine generator interaction with conventional diesel generators on Block Island, Rhode Island. Volume 2: Data analysis

Assessing the performance of a MOD-OA horizontal axis wind turbine connected to an isolated diesel utility, a comprehensive data measurement program was conducted on the Block Island Power Company installation on Block Island, Rhode Island. The detailed results of that program focusing on three principal areas of (1) fuel displacement (savings), (2) dynamic interaction between the diesel utility and the wind turbine, (3) effects of three models of wind turbine reactive power control are presented. The approximate two month duration of the data acquisition program conducted in the winter months (February into April 1982) revealed performance during periods of highest wind energy penetration and hence severity of operation. Even under such conditions fuel savings were significant resulting in a fuel reduction of 6.7% while the MOD-OA was generating 10.7% of the total electrical energy. Also, electrical disturbance and interactive effects were of an acceptable level

Wind turbine generator interaction with conventional diesel generators on Block Island, Rhode Island. Volume 1: Executive summary

Primary results are summarized for a three-part study involving the effects of connecting a MOD-OA wind turbine generator to an isolated diesel power system. The MOD-OA installation considered was the third of four experimental nominal 200 kW wind turbines connected to various utilities under the Federal Wind Energy Program and was characterized by the highest wind energy penetration levels of four sites. The study analyses address: fuel displacement, dynamic interaction, and three modes of reactive power control. These analyses all have as their basis the results of the data acquisition program conducted on Block Island, Rhode Island

On the particle paths and the stagnation points in small-amplitude deep-water waves

In order to obtain quite precise information about the shape of the particle paths below small-amplitude gravity waves travelling on irrotational deep water, analytic solutions of the nonlinear differential equation system describing the particle motion are provided. All these solutions are not closed curves. Some particle trajectories are peakon-like, others can be expressed with the aid of the Jacobi elliptic functions or with the aid of the hyperelliptic functions. Remarks on the stagnation points of the small-amplitude irrotational deep-water waves are also made.Comment: to appear in J. Math. Fluid Mech. arXiv admin note: text overlap with arXiv:1106.382

Understanding School Board Members\u27 Perceptions of Superintendents\u27 Leader Behaviors

The study of school leadership has been a topic of considerable investigation. Primarily, this literature has focused on the leadership of principals and superintendents. Although school boards work hand in hand with school leaders concerning the decision making functions of district business, a literature base specifically focused on school board members and their perceptions of school superintendents\u27 leadership behavior is lacking. This paper provides a framework for understanding school board members’ perceptions and suggests that school board members’ views of superintendents\u27 leadership behaviors may be influenced by demographic factors including years of experience and gender of board members

Portraying Design Essence

Recent discourse in the Design Science Research community addresses the necessity to accumulate and reuse design knowledge. However, design methods are complex and so are the traditional ways to document design knowledge. Inspired by the high business and academic impact of Business Model Canvas, we argue that a single-page portrayal of nine design elements can help designers to capture design knowledge and eventually share it with other designers. This paper reports on our attempt to create, demonstrate, and evaluate an instance of such tools, one that we call the Portrait of Design Essence

Life-Course Differences in Occupational Mobility Between Vocationally and Generally Trained Workers in Germany

Vocational education is considered beneficial to young workers entering the labor market but disadvantageous late in their careers. Many studies assume that late-career disadvantages stem from lower levels of occupational mobility, but do not explicitly study this mechanism. This study is the first to empirically assess whether and to what extent occupational mobility differs between workers with a general education and those with vocational training and to examine how these differences develop over workers’ life courses. Using multilevel linear probability models on panel data spanning 36 years of labor market participation in Germany, we find that vocationally educated workers are less mobile, but only in the first half of their careers. In the second half, mobility rates for vocationally and generally trained workers converge. Our findings support earlier research that links vocational education to less turbulent early careers. Yet, they do not support the notion of late-career mobility disparities between workers with different types of training. Implications for research on education-based differences in career outcomes are discussed

The social environment affects mate guarding behavior in Japanese beetles, Popillia japonica

The effect of the social environment on post-copulatory mate guarding duration in Japanese beetles, (Popillia japonica Newman), was examined in a laboratory experiment. The mate guarding durations of beetles in different sex ratios and densities were observed for 10 hours. Guarding duration was longer when females were larger, suggesting the presence of ‘cryptic’ male mate choice. Densities, but not sex ratio, affected the duration of guarding bouts, with males guarding for longer at higher densities. This result implies that males increase their guarding duration under conditions in which their female may be likely to be encountered by other males. The lack of a sex ratio effect on the duration of guarding bouts is consistent with other studies on this species that indicate males have difficulty distinguishing females from males. Consequently, because the sex ratio on food plants is typically male-biased, a paired male may react just to density, treating surrounding individuals as if they were mostly males. The total amount of time males spent guarding was lower at lower densities and at male-biased sex ratios; this suggests that after ceasing to guard one female, males were less able to find a subsequent mate under these conditions