Halogened hydrocarbons – current trends

Current trends in industrial synthesis of selected halogened hydrocarbons (HHCs) were presented in detail. Special emphasis was put on the most popular compounds, such as chloromethanes (CH3Cl, CH2Cl2, CHCl3, CCl4), chloroethene (vinyl chloride H2C = CHCl), chlorobenzene, 1-4-dichlorbenzene and epichlorohydrin. The possibility methods of modification technologies based on literature information were also reported. Presented simple schema, with production conditions, should be helpful in understanding the issues discussed.

DYNAMIC DISTRIBUTED MODEL OF MULTI-DRIVE BELT CONVEYOR

The article deals with a problem of long multi-drive belt conveyors modeling. Disadvantages of existed methods prevent from using multi-drive long conveyors for ore reloading. The author has described two types of models. In the first type, all loading is calculated and reduced to a torque on a drum. In the second type, the conveyor operation is closely examined. The methods of the first type result in dot patterns, which optimize conveyor operation in the routine mode. The methods of the second type allow calculating breakage of the belt, but the drive dynamics should be determined beforehand. The author has designed a distributed model of such conveyors based on quite simple partial models of physics of conveyor elements. The whole belt should be divided into short segments, forces acting upon segments being integrated along the belt. Features of segment positions should be taken into account: whether the segment is on a driving drum, on a drum without torque, loaded or unloaded, at the place of loading, reloading, or discharge, etc. The algorithm of forces and accelerations calculation is based on the method of simple iterations. The software includes a simple schema editor and subroutines of a model. The adequacy of the modeling results has been shown in the course of normal conveyor regime, in the course of overloading and slipping. The updated model has been considered to be used for synthesis of the system management, in particular, for developing a program for the loaded conveyor start after emergency stop.

Varieties of Homeland Security: An Assessment of US State-level Definitions

Homeland Security continues to struggle to define itself as a field of practice and scholarship. The difficulty in defining the field has led to a variety of conflicts over membership, content, and focus. This article reviews some of the prominent debates over the meaning of homeland security as a field of study and practice. It then defines a simple schema for definitions of homeland security inspired by the academic and legislative debates over the issue. A frequency cataloging of definitions from US state agencies illustrates the continued relevance of a “partial membership” approach to defining the field. The article concludes with a discussion of the implications of the diversity of homeland security definitions for the development of the field.

Refugees in Diaspora: From Durable Solutions to Transnational Relations

When people flee conflict or persecution, a common pattern is for most to seek safety in other parts of their country, for a substantial number to look for refuge in a neighbouring country or countries, and for a smaller number to seek asylum in countries further afield, perhaps on other continents. If displacement persists and people consolidate themselves in their territories of refuge, complex relations will develop among these different domains of what we may call the “refugee diaspora”: that is, among those at home, those in neighbouring territories, and those spread further afield. Each of these domains corresponds to some extent to one of the sites associated with the three “durable solutions” that UNHCR is charged with pursuing for refugees: integration in the country of first asylum, resettlement in a third country, or return to the homeland. Taking its cue from the burgeoning literature on diasporas and transnationalism, this paper explores whether the notion of “durable solutions” can be squared with the transnational character of refugees. It offers a simple schema for considering diaspora and transnational relations, and suggests that transnationalism might be considered in itself as an “enduring” if not a “durable” solution to displacement.

The Internet for Pathologists: A Simple Schema for Evaluating Pathology-Related Web Sites and a Catalog of Sites Useful for Practicing Pathologists

Context.—With the increasing popularity of the Internet as a primary medical information source, it is critical for pathologists to be able to use and evaluate both general medical- and pathology-related Web sites. Several published models for evaluating Web sites prove cumbersome to use and often involve computer- or statistic-based algorithms. Objectives.—To develop a simple group of scoring criteria to objectively evaluate medical Web sites and provide a list of the highest-scoring pathology-related sites that will be useful to the practicing pathologist. Design.—Using 11 commonly used Internet search engines, the top 50 “hits” retrieved from the search term websites for pathologists were scored using 5 criteria, including accuracy, ease of navigation, relevance, updates, and completeness. A possible 6 to 12 points per area were awarded, and the total score was summated. Results.—Scores obtained ranged from 12 to 21. Thirty-five Web sites, all scoring 15 or higher based on these criteria, were listed as most useful. Conclusion.—A simple, easy-to-use, 5-category scoring system can prove useful in evaluating pathology- and medical-related Web sites.

THE KEY TO SUCCESS IN INNOVATION PART II: THE ART OF CHOOSING GOOD SPOKESPERSONS

"Solve the technical problems first", we often hear, "then we'll deal with the market". The real history of innovations does not generally follow this simple schema; it is made of adaptations, series of trial and error and countless negotiations between numerous social actors. A genuine combat from which conquerors who know how to choose good representatives emerge.

Control properties of motor units

This review will deal with two evolving concepts which describe and attempt to unify various observations concerning the behaviour of motor units that have been reported during the past decade. The two concepts are: The common drive which describes the behaviour of the firing rates of motor units, and appears to provide a simple schema for controlling motor units; and the firing rate/recruitment interaction which appears to enhance the smoothness of the force output of a muscle. The evolution of these concepts has been expedited by the development of recent techniques such as our decomposition technique which enables us accurately to decompose the myoelectric signal into the constituent motor unit action potential trains. For details refer to LeFever & De Luca (1982), Mambrito & De Luca (1983) and Mambrito & De Luca (1984).

The concept of coping

SynopsisCoping is action directed at the resolution or mitigation of a problematic situation. There are a number of ways in which this may be attempted, and a number of ways of classifying coping strategies. This paper presents a simple schema of six coping themes, ordered in terms of their defensiveness and the degree of attempted personal control which they imply. They comprise rejection, control, resignation, dependency, avoidance and minimization, and characterize the meaning or qualitative ‘style’ of the individual's response, rather than the formal characteristics of the strategies employed. Data from studies of breast cancer and surgical patients are cited to illustrate the substance of the themes.