2,822 research outputs found
Spinarc gas tungsten arc torch holder
Semiautomatic welding torch enables operator to control arc length, torch angle, and spring tension when welding small diameter aluminum tubing. Tungsten is preset for the weld to make arc initiation easier and to eliminate searching for the joint through a dark welding lens
System software for the finite element machine
The Finite Element Machine is an experimental parallel computer developed at Langley Research Center to investigate the application of concurrent processing to structural engineering analysis. This report describes system-level software which has been developed to facilitate use of the machine by applications researchers. The overall software design is outlined, and several important parallel processing issues are discussed in detail, including processor management, communication, synchronization, and input/output. Based on experience using the system, the hardware architecture and software design are critiqued, and areas for further work are suggested
Cultural, Historical, and Subcultural Contexts of Adolescence: Implications for Health and Development
Although clearly influenced by biological and psychological growth, adolescent development is also molded by the social and cultural context in which it occurs. As the transition from childhood to adulthood, adolescence is closely tied to the structure of adult society, and the expectations for youth during this period reflect, in important ways, the skills and qualities deemed important for success in adult roles (Benedict, 1937; Havighurst, 194811972). Furthermore, prevailing demographic, economic, and political conditions determine the adult occupational and social roles to which young people can aspire, as well as the access to and competition for those roles (Elder, 1975). The integral connection between adolescence and the societal context means that, despite universals such as puberty and cognitive development, adolescents\u27 experiences will vary across cultures and over history. The settings in which young people develop, the skills they are expected to acquire, and the ways in which their progress toward adulthood is marked and celebrated depend on the cultural and historical contexts. Within stratified, heterogeneous societies, the experience of adolescence also differs among subgroups of youth. Economic and social resources, as well as access to valued adult roles, may differ for youth from distinct racial-ethnic groups, social classes, and geographic regions. Lack of resources and opportunities in some settings may profoundly shape the course of adolescent development by influencing the timing of key developmental transitions and the supports available for coping with these transitions. Moreover, to the extent that anticipated adult lives differ for youth from distinct social subgroups, differences in socialization patterns and goals would be expected (Ogbu, 1985). In heterogeneous societies, therefore, local ecological conditions may alter considerably the normative template of adolescent development, with important implications for adolescents\u27 current health and future life course. Thus, both macrolevel, societal arrangements and local conditions help shape adolescents\u27 experiences and the course of their development. Both kinds of influences may also have consequences for adolescent health. In particular, they affect the health risks to which young people are exposed before and during adolescence, as well as the protective factors that may shield them from these risks. In this chapter, I examine the impact of both societal and local contexts, highlighting some of their implications for adolescent health. Essentially, the chapter addresses two questions: First, how has adolescent health and development been affected by changing social and economic conditions in the United States? Second, how does the health and development of adolescents in the contemporary United States vary as a function of the local ecology? Before turning to these issues, however, an overview of sociocultural influences on adolescent development will be presented
Home at work: households and the structuring of women's employment in late nineteenth century Dundee
The past decade has witnessed a debate in the
literature over the best way to explain patterns of
gender inequality. The central objective of
contributions has been to understand the processes which
underlie differences in the experiences of men and
women. Particular concern is directed at processes which
lead to women's unpaid labour in the home and to their
position vis-a-vis men, in paid employment where they
are found in segregated and low paid occupations.
Theoretical developments range from dual systems
approaches, which try to explain gender by combining a
theory of patriarchy with a Marxist theory of
capitalism, to approaches which argue for a single
integrated explanation of production and reproduction.
This thesis assesses these developments and finds
current understandings lacking in two respects. Firstly,
although there is a recognition of the inadequacy of
Marxist categories in accounting for gender they are,
none the less, given a central place in explanations.
Similarly, variations in the experience of men and women
are often discussed but are rarely incorporated into
theoretical explanations as significant categories. A
large part of the problem stems from the abstract level
at which the development of explanations has been
carried out. The argument presented here is that
advances in theoretical explanation require that the
processes underlying patterns of gendered experience are
properly identified, and that this can only be achieved
by thorough empirical examination of the wider context
in which women labour. Those contributing to the debate
have focused on a few symbolic occurrences in the
nineteenth century such as protective legislation, male
trade union exclusivism and the family wage. In a study
of Dundee, a Scottish textile city, the broader context
of everyday life is explored for women working in the
industry during the late nineteenth century. To begin
with information on wages is matched to occupations
enabling the hierarchy of women's textile jobs to be
established. Dundee provides a unique opportunity to
look at a variety of households, and here the
composition of households from a sample of the 1891
Census is outlined and the distinctive features of those
headed by women are discussed. The structure of
households which emerges from this exercise is related
to the structure of occupations, making it possible to
identify processes of inequality which are composed of
household/employment experiences. In the Dundee sample
processes of this sort are found to be of great
importance in gaining access to employment. The
structure of opportunity which exists and the patterns
of inequality associated with it have consequences for
what people are required to do in order to make ends
meet
Effects of Intensity of Clipping of Three Range Grasses from Grazed and Ungrazed Areas in West-Central Kansas
This investigation was an attempt to determine the vigor of various types of range grasses under different intensities of clipping. Three range grasses selected for study were: (1) a tall grass, big bluestem (Andropogon gerardi Vitman); (2) a mid-grass, side-oats grama (Bouteloua curtipendula (Michx.) Torr.); and (3) a short grass, blue gram (Bouteloua gracilis (H. B. K.) Lag. ex: Steud.). Sods of these grasses were taken from two areas: (1) an area which had been fairly heavily utilized for several years; and (2) an area which had been protected from grazing for over fifty years. Limiting factors in this study were that the areas had been subjected to above average growing conditions, i.e., ideal rainfall and temperature, for two years preceding collection of the sods and that the grazed area had been less heavily grazed than it had in the past. All top growth was removed and sods were transplanted in phytometers, and subjected to the following treatments: (1) those plants which were not clipped form beginning to end of the study; (2) those which were clipped to the crown each week. Three replications for each treatment were established. This phase of the study was carried on for about 12 weeks. Measurements recorded or calculated included: (1) weekly and cumulative height and weight of new shoot growth; (2) bi-weekly variation in number of shoots; (3) cumulative weight per tiller; (4) length and weight of new root growth; and (5) shoot-root ratio. In addition, a method of descending paper chromatography was used to measure the amount of readily available carbohydrates at beginning and end of the study to determine gain or loss under different intensities of clipping. Findings were as follows: (1) When closely clipped, all plants studied were severely restricted in shoot production, new root growth, and production of carbohydrates. (2) Moderate clipping seemed to stimulate shoot growth, but restricted, to some degree, the production of new roots. The production of carbohydrates was no severely affected by moderate clipping. (3) Growth differences in plants form the two areas were not a significant except under non-clipped conditions. (4) Shoot-Root ratio increased with intensity of clipping. (5) Clipping tended to reduce species significance. (6) Development of flowers caused a decrease in carbohydrate content of plants. Tables, graphs, and photographs were used to present and illustrate the results of the various studies
Home Range, Movements, And Habitat Use Of Blanding\u27s Turtle (Emydoidea blandingil) in St. Lawrence County, New York.
I studied the movements, activity centers, and horne ranges of Blanding\u27 s turtles (Emydoidea blandingii) at three sites in St. Lawrence County, New York where it is currently listed as State Threatened. I monitored 24 adult Blanding\u27 s turtles (seven males and 1 7 females) using radiotelemetry from May 2003- August 2004 to provide information on spatial requirements and movements in previously undocumented populations at the easternmost limit of this species\u27 contiguous range, Movement and home range analyses were performed on 1 6 telemetered adult Blanding\u27s turtles (4 males and 1 2 females) with a minimum of 20 locations and assignment of a radio transmitter from at least 1 0 June through 1 5 October in either 2003 or 2004, which covered the majority of the active season. There was no significant difference between male and female home range sizes within and between the study sites, which differed in available wetland area. Additionally, there was no significant difference among the home range sizes of females at each study site. Based on the Minimum Convex Polygon (MCP) home range estimate, the mean home range area for all telemetered females was 1 2.26 (1 . 1 3- 44. 1 4) ha and 7.54 (± 2.63) ha for telemetered males (n = 4). Home range size differed significantly between female and males. The number of activity centers differed among the females (n = 1 2) ranging from one to five. Males (n = 4) had a greater number of activity centers than females, ranging from two to four. In this study, daily movements of males (x = 46.03 ±5 . 1 2 m) were significantly longer and more frequent than females (x = 20.77 ±7. 1 8 m). Four of females that were radio-tagged in 2003 and followed through 2004 showed nest site fidelity across both years. These females traveled up to 1 3 65 m round-trip to nesting areas and back to their home wetlands in consecutive years. A management and conservation concern identified in this study that could have a negative impact on the Blanding\u27s turtle populations in northern New York is the location of nesting areas. Telemetry data revealed that gravid females utilize areas up to 1.5 km away from resident wetlands for nesting. My study suggests that areas in the vicinity of occupied wetlands that are suitable for nesting are very important to the longevity of these populations. Further studies on the distribution, population dynamics, habitat use and requirements, and nesting ecology of Blanding\u27s turtle populations in northern New York should be conducted to assist with the conservation of this species in the eastern periphery of its contiguous Great Lakes range
Agency in the Life Course: Concepts and Processes
The capacity of humans to influence their lives has long been a theme within Western literature, philosophy, and psychology. In recent years, the theme of human agency has crystallized in the psychological literature in the concepts of control, self-regulation, and self-efficacy. As a result, considerable attention has been devoted to the psychological processes through which control is exerted, such as cognitive appraisals, goal setting, and planning, as well as control beliefs and the potentially debilitating effects of loss of control (e.g., Bandura, 1997; Boekaerts, Pintrich, & Zeidner, 2000; Carver & Scheier, 1998; Seligman, 1975). Although this body of work has yielded pivotal insights into the mental processes underlying human agency, it has tended to focus on the person, with scant attention to the environmental exigencies over which the person seeks to exert control. An environment is assumed, but it is the individual\u27s perception of and response to that environment that is considered central, rather than the environment per se. Accordingly, there has been little attempt to delineate the facets of the environment that may be influential in shaping the expression of self-determination
Social uncertainty is heterogeneous and sometimes valuable
To win friends, help the needy, avoid exploitation or influence strangers, people must make decisions that are inherently uncertain. In their compelling and insightful perspective on resolving social uncertainty1, FeldmanHall and Shenhav (henceforth F&S) join a growing movement combining computational approaches with social psychological theory. F&S identify a range of negative and positive aspects of social uncertainty. Here we offer additional ways to think about social uncertainty and suggest potential avenues for future research
- …