WorldWideScience

Sample records for ceiling fans

  1. ENERGY STAR Certified Ceiling Fans

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Ceiling Fans that are effective as of April 1,...

  2. Costs and benefits of energy efficiency improvements in ceiling fans

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Nihar; Sathaye, Nakul; Phadke, Amol; Letschert, Virginie [Lawrence Berkeley National Lab., CA (United States). Environmental Energy Technology Division

    2013-10-15

    Ceiling fans contribute significantly to residential electricity consumption, especially in developing countries with warm climates. The paper provides analysis of costs and benefits of several options to improve the efficiency of ceiling fans to assess the global potential for electricity savings and green house gas (GHG) emission reductions. Ceiling fan efficiency can be cost-effectively improved by at least 50% using commercially available technology. If these efficiency improvements are implemented in all ceiling fans sold by 2020, 70 terawatt hours per year could be saved and 25 million metric tons of carbon dioxide equivalent (CO2-e) emissions per year could be avoided, globally. We assess how policies and programs such as standards, labels, and financial incentives can be used to accelerate the adoption of efficient ceiling fans in order to realize potential savings.

  3. 78 FR 25626 - Energy Conservation Program for Consumer Products: Energy Conservation Standards for Ceiling Fans...

    Science.gov (United States)

    2013-05-02

    ...On March 15, 2013, the U.S. Department of Energy (DOE) published a notice of public meeting and availability of the Framework Document regarding energy conservation standards for residential ceiling fans and ceiling fan light kits in the Federal Register. This document announces an extension of the public comment period for submitting comments on the Framework Document or any other aspect of......

  4. 10 CFR Appendix U to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Ceiling Fans

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Uniform Test Method for Measuring the Energy Consumption... Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of Ceiling Fans 1. Scope... significant digits as the previous step. Round the final energy consumption value to the nearest whole...

  5. 10 CFR Appendix V to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Ceiling Fan Light Kits

    Science.gov (United States)

    2010-01-01

    ... of Ceiling Fan Light Kits V Appendix V to Subpart B of Part 430 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS Test Procedures Pt. 430, Subpt. B, App. V Appendix V to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of Ceiling...

  6. 78 FR 62494 - Energy Conservation Program: Energy Conservation Standards for Ceiling Fans

    Science.gov (United States)

    2013-10-22

    ...'' (Framework Document), with a public comment period running through April 29, 2013. 78 FR 16443. The Framework... on the Framework Document until June 14, 2013. 78 FR 25626. During the Framework Document comment... Part 430 RIN 1904-AC87 Energy Conservation Program: Energy Conservation Standards for Ceiling...

  7. Diffuse Ceiling Ventilation

    DEFF Research Database (Denmark)

    Zhang, Chen; Heiselberg, Per; Nielsen, Peter V.

    2014-01-01

    and numerical studies on diffuse ceiling ventilation. Performance in terms of thermal comfort, air quality, pressure drop as well as radiant cooling potential are examined. Finally, a discussion on the proper design of the suspended ceiling and plenum to achieve a uniform air distribution and surface......As a novel air distribution system, diffuse ceiling ventilation combines the suspended acoustic ceiling with ventilation supply. Due to the low-impulse supply from the large ceiling area, the system does not generate draught when supplying cold air. However, heat sources play an important role on...... thermal comfort in the occupant zone. Another characteristic of this system is its lower pressure drop compared with conventional ventilation systems, which reduces the noise problem and, at the same time, the energy consumption of the fan can be reduced. This review is based on a number of experimental...

  8. Introduction of a Cooling-Fan Efficiency Index

    DEFF Research Database (Denmark)

    Schiavon, S.; Melikov, Arsen Krikor

    2009-01-01

    In a warm environment, air movement with elevated velocity is a well-known cooling strategy. The local air movement is typically generated by cooling fans (e.g., ceiling fan, table fans, etc.). Appearance, power input, and price are the main parameters considered today when purchasing cooling fan...

  9. Multiple Glass Ceilings

    OpenAIRE

    Russo, Giovanni; Hassink, Wolter

    2011-01-01

    Both vertical (between job levels) and horizontal (within job levels) mobility can be sources of wage growth. We find that the glass ceiling operates at both margins. The unexplained part of the wage gap grows across job levels (glass ceiling at the vertical margin) and across the deciles of the intra-job-level wage distribution (glass ceiling at the horizontal margin). This implies that women face many glass ceilings, one for each job level above the second, and that the glass ceiling is a p...

  10. Diffuse Ceiling Ventilation

    DEFF Research Database (Denmark)

    Zhang, Chen; Heiselberg, Per; Nielsen, Peter V.

    2014-01-01

    As a novel air distribution system, diffuse ceiling ventilation combines the suspended acoustic ceiling with ventilation supply. Due to the low-impulse supply from the large ceiling area, the system does not generate draught when supplying cold air. However, heat sources play an important role on...... temperature as well as optimizing the radiant cooling potential by combining with thermal mass is conducted and gives a direction for further investigation....

  11. Field Study of Diffuse Ceiling Ventilation Performance in a Landscape Office

    DEFF Research Database (Denmark)

    Zukowska-Tejsen, Daria; Wolsing, Marie; Grysbæk, Malene;

    2016-01-01

    Performance of diffuse ceiling ventilation with regard to thermal comfort and limits of the cooling capacity of the system was studied in a 97 m2-landscape office. Seven operation scenarios were tested: two for mixing ventilation with ceiling mounted fan coils and five with diffuse ceiling...... show that diffuse ceiling ventilation has substantial potential for landscape office applications because it can provide important cooling capacity while maintaining an acceptable comfort level in the occupied zone. It does not generate draught in the occupied zone even at large temperature differences...

  12. Stars on the Ceiling

    Science.gov (United States)

    Krupp, E. C.

    2016-01-01

    Astronomy and celestial imagery have been incorporated into architectural ceilings from antiquity to the present to reference the sky on behalf of a variety of agendas. Burial chambers in Egyptian pyramids and tombs, the Osiris chapel on the roof of Ptolemaic Egypt's Temple of Dendera, ancient Chinese tombs, painted rock shelters in California and the American Southwest, the cupola above a hot bath from medieval Jordan, elaborately illustrated ceilings in Italian cathedrals and palaces, the main concourse in New York's Grand Central Terminal, and a variety of other public buildings in America all brought the sky inside to convey relationships between the architecture, people, and the cosmos. In these interior environments, the symbolic function of the astronomical ceiling is driven by the thematic function of the building. At Griffith Observatory in Los Angeles three signature spaces are equipped with astronomically illustrated ceilings. In content and location, these prominent murals operate symbolically to convey meaning through public display and unexpectedly prompt people to think more expansively about the universe. This artwork is familiar in Los Angeles, but its use in a public observatory puts it outside the range of most commentaries on public art. Although experienced by more than seventy-six million persons over the last eighty years, Griffith Observatory's celestial murals are not well known. Their history, content, character, meaning, and purpose are detailed here.

  13. What Glass Ceiling?

    Science.gov (United States)

    Lynch, Michael; Post, Katherine

    1996-01-01

    A recent study drawing on data from the Census Bureau and the Bureau of Labor Statistics suggests that the wage gap between men and women has virtually disappeared, and that the so-called "glass ceiling" results more from age and qualifications than from explicit discrimination. (SLD)

  14. Glass ceilings of professionalisation.

    Science.gov (United States)

    Stott, Dawn L

    2016-04-01

    The term glass ceiling is a political term often used to describe an unbreakable barrier that isnot visible with the human eye, but it keeps minorities from rising up i.e. it is a barrier to minoritygroups, in the past (and sometimes still) for women, that stops them from achieving theirtrue potential. PMID:27290754

  15. Cambrian fans

    OpenAIRE

    Reading, Nathan; Speyer, David E.

    2006-01-01

    For a finite Coxeter group W and a Coxeter element c of W, the c-Cambrian fan is a coarsening of the fan defined by the reflecting hyperplanes of W. Its maximal cones are naturally indexed by the c-sortable elements of W. The main result of this paper is that the known bijection cl_c between c-sortable elements and c-clusters induces a combinatorial isomorphism of fans. In particular, the c-Cambrian fan is combinatorially isomorphic to the normal fan of the generalized associahedron for W. Th...

  16. Investigating Ceiling Effects in Longitudinal Data Analysis

    Science.gov (United States)

    Wang, Lijuan; Zhang, Zhiyong; McArdle, John J.; Salthouse, Timothy A.

    2008-01-01

    Score limitation at the top of a scale is commonly termed "ceiling effect." Ceiling effects can lead to serious artifactual parameter estimates in most data analysis. This study examines the consequences of ceiling effects in longitudinal data analysis and investigates several methods of dealing with ceiling effects through Monte Carlo simulations…

  17. Glass Ceiling : Women in management

    OpenAIRE

    Rantala, Virve

    2010-01-01

    This study has examined the phenomenon called Glass Ceiling. It has approached the phenomenon in two different views. One is career development and another one is women in management. Main purpose for this study was to inspect women working life and career opportunities. Why women’s career developments end in a certain level? What is glass ceiling and how to break it? Paper also investigates reasons behind the effect. Prejudices and biases are the worst enemies for women’s career. How to chan...

  18. Jagged Edges of the Glass Ceiling

    Science.gov (United States)

    Robinson, Victoria L.

    2004-01-01

    Although many aspiring young women might believe the glass ceiling was shattered a decade ago, they still need to understand how that glass ceiling impacted an older generation of women in educational leadership. They also must be aware that some segments of the glass ceiling might still exist. This article provides a historical overview of the…

  19. An Economic Theory of Glass Ceiling

    OpenAIRE

    Grout, Paul A.; In-Uck Park; Silvia Sonderegger

    2009-01-01

    In the 'glass ceiling' debate there appear to be two strongly held and opposing interpretations of the evidence, one suggesting it is really the result of gender differences and the other that there is discrimination by gender. This paper provides an economic theory of the glass ceiling and one of the main insights of our analysis is that in some real sense these two interpretations are not in conflict with each other. The glass ceiling emerges as an equilibrium phenomenon when firms compete ...

  20. Aggregate expenditure ceilings and allocative flexibility

    OpenAIRE

    Marc Robinson

    2012-01-01

    This article shows how to combine top-down budgeting – in the core sense of the establishment of a hard aggregate expenditure ceiling at the start of the budget preparation process – with flexibility in the allocation of the aggregate ceiling between spending ministries during budget preparation. It argues strongly against determining spending ministry shares of the aggregate expenditure ceiling without any prior opportunity for them to present formal new spending proposals. The keys to recon...

  1. The Glass Ceiling: Progress and Persistent Challenges

    Science.gov (United States)

    McLlwain, Wendy M.

    2012-01-01

    It has been written that since 2001, there has not been any significant progress and the glass ceiling is still intact. Women are still underrepresented in top positions (Anonymous, 2004). If this is true, the glass ceiling presents a major barrier between women and their desire to advance into executive or senior management positions. In addition…

  2. The Glass Ceiling Initiative. A Report.

    Science.gov (United States)

    Department of Labor, Washington, DC.

    While minorities and women have made considerable gains in entering the workforce in the last few decades, there remains a dearth of minorities and women at management levels. This phenomenon has come to be known as the "glass ceiling." The Department of Labor defines the glass ceiling as those artificial barriers based on attitudinal or…

  3. Women's Career Development at the Glass Ceiling.

    Science.gov (United States)

    Inman, Pamela L.

    1998-01-01

    For women, success in shattering the glass ceiling lies not in adapting to a male workplace culture but in using career strategies such as self-knowledge, multiple mentors, integration of body and soul, and fluid, customized careers. (SK)

  4. Diversity, culture and the glass ceiling.

    Science.gov (United States)

    Wilson, Eleanor

    2014-01-01

    A reference to the term, the glass ceiling, has come to embody more than gender equality among women and men. Today the term embraces the quest of all minorities and their journey towards equality in the workplace. The purpose of this article is to bring attention to the subject of diversity, culture, and the glass ceiling. The article will discuss the history of the glass ceiling and how its broadened meaning is relevant in today's workplace. It will also provide statistics showing how diversity and culture are lacking among the top echelon of today's executives, the barriers faced by minorities as they journey towards executive leadership, and how to overcome these barriers to truly shatter the glass ceiling. PMID:25306838

  5. An Economic Theory of the Glass Ceiling

    OpenAIRE

    Grout, Paul A.; In-Uck Park; Silvia Sonderegger

    2007-01-01

    The glass ceiling is one of the most controversial and emotive aspects of employment in organisations. This paper provides a model of the glass ceiling that exhibits the following features that are frequently thought to characterise the problem: (i) there is a lower number of female employees in higher positions, (ii) women have to work harder than men to obtain equivalent jobs, (iii) women are then paid less than men when promoted, and (iv) some organisations are more female friendly than ot...

  6. Seismic considerations for suspended ceiling systems

    International Nuclear Information System (INIS)

    Since Lawrence Livermore National Laboratory is engaged in sophisticated research and development activities and its geographic location makes the laboratory subject to the effect of earthquakes, in October 1984, ED2 International Architects and Planners were commissioned by LLNL to provide a Survey of commercially available suspended ceiling systems. The Survey was to include all ceilings types, their relative costs, and recommendations for seismic design. This Survey is in the format of a handbook with seven major headings: generic types of suspended ceiling systems; functional comparative analysis of the various systems; relative costs of various ceiling systems; seismic considerations and recommendations; detailed drawings and suggested methods of assembly; code references; listing of material suppliers, representatives, and available product lines and selection check lists. This Survey of ceiling systems was intended to be used as a guide and a working document for the comparison of available systems. In addition, it was meant to serve as a valuable tool in establishing a definitive code with applicable standards and design criteria for suspended ceiling systems at the laboratory. The work in progress also has replication value to other DOE facilities

  7. The Expert Ceiling in Epistemological Beliefs

    Science.gov (United States)

    Barnard, Lucy

    2007-01-01

    Paulsen and Wells (1998) stated that, "it seems unlikely that substantial differences in epistemological beliefs across domains would persist in studies of faculty or other more advanced experts," (p. 380). This statement implies the existence of an upper limit or ceiling effect in the epistemological beliefs among experts. Faculty members are…

  8. Glass Ceiling for Women in Higher Education.

    Science.gov (United States)

    Schedler, Petra; Glastra, Folke; Hake, Barry

    2003-01-01

    Discusses the place of women in higher education in the Netherlands. Suggests that it is not a question of numbers but of orientation, field, and the glass ceiling. Asserts that despite some improvement, higher education may be one of the last bastions against the recognition of women's worth. (Contains 42 references.) (JOW)

  9. Ouch! Or ESL and the Glass Ceiling.

    Science.gov (United States)

    Migliacci, Naomi

    The realities of the glass ceiling, which prevents qualified women, minorities, and many English-as-a-Second-Language (ESL) students from advancement and promotion, are rarely discussed in English for Special Purposes (ESP)/ESL programs and courses. This paper explores the barriers to success, focusing on the sociolinguistic factors of verbal and…

  10. The Real Glass Ceiling. Your Career.

    Science.gov (United States)

    Savage, Adrian

    2002-01-01

    There is a powerful and common glass ceiling (barrier that prevents capable employees from being promoted) that affects men as much as women. Between middle management and the executive level, corporate culture shifts to one based on power and a worker must play by new rules even if these have never been explained. (JOW)

  11. Operating mine fans

    Energy Technology Data Exchange (ETDEWEB)

    Kovalevskaya, V.I.; Fal' kov, B.S.; Spivak, V.A.

    1983-01-01

    The operation and repair of ventilation fans are described. Data are presented on periodicity and order of servicing, and organization of repairs. Repair variants of the least reliable assemblies are indicated. Methods are discussed for improving pressure and performance of the fans, and for decreasing electricity consumption. Aerodynamic and strength tests are considered, and plans for control and automation of electric drive are put forward. (In Russian)

  12. Beyond the glass ceiling: Does gender matter?

    OpenAIRE

    Adams, Ren??e; Funk, Patricia

    2009-01-01

    The representation of women in top corporate officer positions is steadily increasing. However, little is known about the impact this will have. A large literature documents that women are different from men in their choices and in their preferences, but most of this literature relies on samples of college students or workers at lower levels in the corporate hierarchy. If women must be like men to break the glass ceiling, we might expect gender differences to disappear among top executives. I...

  13. An intrinsic mobility ceiling of Si bulk

    OpenAIRE

    Garcia-Castello, Nuria; Prades, Joan Daniel; Cirera, Albert

    2011-01-01

    We compute by Density Functional Theory-Non Equilibrium Green Functions Formalism (DFT-NEGFF) the conductance of bulk Si along different crystallographic directions. We find a ceiling value for the intrinsic mobility of bulk silicon of $8.4\\cdot10^6 cm^2/V\\cdot s$. We suggest that this result is related to the lowest effective mass of the $$ direction.

  14. Politics, Economics, and the Debt Ceiling

    OpenAIRE

    Adam Talbot Jones; Cameron Visser

    2014-01-01

    Since the early 20th century, the Federal Government has chosen a self-imposed statutory limit on federal debt which has been increased, and occasionally reduced, in sporadic intervals. This paper uses a regression model to examine the time interval between changes in the statutory debt limit and whether the date of the next increase is pushed beyond the next national election. Results show the length of the extension and the likelihood that the ceiling limit lasts beyond the next election is...

  15. Operating mine fans

    Energy Technology Data Exchange (ETDEWEB)

    Kovalevskaya, V.I.; Fal' kov, B.S.; Spivak, V.A.

    1983-01-01

    Operation and repair of fans of main ventilation are described. Data are presented on periodicity and order of servicing, organization of repairs. Repair variants of the least reliable assemblies are indicated. Methods are presented for improving pressure and productivity of the fans, guarantee of the most economic mode of their operation in order to improve reliability and decrease consumption of electricity, methods of aerodynamic and strength tests. Signs are defined, reasons and orders for detecting malfunctions in the parts of assemblies and mechanical equipment, plans of control and automation of electric drive.

  16. Existence of Glass Ceiling in Public Universities of Lahore (Pakistan)

    OpenAIRE

    Asifa Ilyas

    2014-01-01

    Glass ceiling is a set of unseen factors which adversely affect females upward career growth and prevent them to get to top positions. This study is meant to explore existence of glass ceiling in public universities of Lahore (Pakistan); and factors responsible for creating this glass ceiling effect. The respondents of this study are females heading different departments in their respective universities. The results of this study show that different cultural and social, family and organizatio...

  17. Seville City Hall Chapter Room ceiling decoration

    Directory of Open Access Journals (Sweden)

    Robador, M. D.

    2010-02-01

    Full Text Available The present article describes a chemical and physical study of the colour, chemical composition and mineral phases of the decorative materials in the Seville City Hall Chapter House ceiling. The findings showed that the inner most layer of material, calcite, was covered with white lead, in turn concealed under a layer of gilded bole. The ceiling underwent re-gilding, also over bole, due in all likelihood to wear on the original gold leaf. In the nineteenth century, the entire ceiling with the exception of the inscriptions was whitewashed with calcite and white lead. Silver was employed on King John I’s sword (coffer 27. Gold leaf was used to adorn the royal attributes: crowns, belts, sceptres, swords and rosary beads. The high reliefs were likewise gilded. The pigments identified on the ceiling adornments included azurite, malachite, vermilion and gas black. A lime and ground dolomite mortar was used throughout.

    El objetivo de este trabajo es el estudio de diferentes aspectos, como el color, la composición química y las fases mineralógicas presentes en los diferentes materiales que forman la ornamentación del techo de la Sala Capitular del Ayuntamiento de Sevilla, mediante métodos físicos y químicos. Nuestros resultados muestran que el dorado fue realizado sobre una capa de bol previamente depositada sobre una lámina de blanco de plomo que cubría un estrato de calcita. Posteriormente, y probablemente debido a alteraciones en el dorado original, el techo fue de nuevo dorado usando una técnica similar. En el siglo XIX, casi todo el techo, excepto las zonas con inscripciones, fue blanqueado usando una mezcla de calcita y blanco de plomo. Se empleó plata para cubrir la espada del rey Juan I (casetón 27. Finísimas láminas de oro se usaron para decorar los atributos reales: coronas, cinturones, cetros, espadas y rosarios. En diferentes partes de la decoración fueron detectados pigmentos como azurita, malaquita, bermellón y

  18. Is There a Glass Ceiling in Sweden?

    OpenAIRE

    Albrecht, James; Björklund, Anders; Vroman, Susan

    2001-01-01

    Using data from 1998, we show that the gender log wage gap in Sweden increases throughout the wage distribution and accelerates in the upper tail of the distribution, which we interpret as a glass ceiling effect. Using earlier data, we show that the same pattern held at the beginning of the 1990?s but not in the prior two decades. Further, we do not find this pattern either for the log wage gap between immigrants and non-immigrants in the Swedish labor market or for the gender gap in the U.S....

  19. 78 FR 16443 - Energy Efficiency Program for Consumer Products: Energy Conservation Standards for Ceiling Fans...

    Science.gov (United States)

    2013-03-15

    ...) life-cycle cost and payback period; (5) national impacts; (6) manufacturer impacts; (7) utility impacts... to the docket Web page can be found at: www.regulations.gov/#!docketDetail ;dct=FR%252BPR%252BN%252BO... light kits in the CFR at 10 CFR 430.32(s). 70 FR 60407, 60413. An additional final rule...

  20. What a Football Fan

    Institute of Scientific and Technical Information of China (English)

    王保安; 孙鹏

    2004-01-01

    While the football fan was thrilled to be at the Super Bowl, he was disappointed with the location of his seat. Peering across the stadium through his binoculars, he spied an empty seat on the 50-yard line and made his way there.

  1. Centrifugal fans: Similarity, scaling laws, and fan performance

    Science.gov (United States)

    Sardar, Asad Mohammad

    Centrifugal fans are rotodynamic machines used for moving air continuously against moderate pressures through ventilation and air conditioning systems. There are five major topics presented in this thesis: (1) analysis of the fan scaling laws and consequences of dynamic similarity on modelling; (2) detailed flow visualization studies (in water) covering the flow path starting at the fan blade exit to the evaporator core of an actual HVAC fan scroll-diffuser module; (3) mean velocity and turbulence intensity measurements (flow field studies) at the inlet and outlet of large scale blower; (4) fan installation effects on overall fan performance and evaluation of fan testing methods; (5) two point coherence and spectral measurements conducted on an actual HVAC fan module for flow structure identification of possible aeroacoustic noise sources. A major objective of the study was to identity flow structures within the HVAC module that are responsible for noise and in particular "rumble noise" generation. Possible mechanisms for the generation of flow induced noise in the automotive HVAC fan module are also investigated. It is demonstrated that different modes of HVAC operation represent very different internal flow characteristics. This has implications on both fan HVAC airflow performance and noise characteristics. It is demonstrated from principles of complete dynamic similarity that fan scaling laws require that Reynolds, number matching is a necessary condition for developing scale model fans or fan test facilities. The physical basis for the fan scaling laws derived was established from both pure dimensional analysis and also from the fundamental equations of fluid motion. Fan performance was measured in a three times scale model (large scale blower) in air of an actual forward curved automotive HVAC blower. Different fan testing methods (based on AMCA fan test codes) were compared on the basis of static pressure measurements. Also, the flow through an actual HVAC

  2. 9 CFR 354.222 - Floors, walls, ceilings, etc.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Floors, walls, ceilings, etc. 354.222 Section 354.222 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... Facilities § 354.222 Floors, walls, ceilings, etc. (a) Floors. All floors in rooms where exposed products...

  3. Perceptions of the Glass Ceiling Effect in Community Colleges

    Science.gov (United States)

    Myers, Cheryl E.

    2010-01-01

    The purpose of this study was to determine the existence of a glass ceiling effect within community colleges by examining faculty, staff and administrator's perceptions of a glass ceiling as it relates to the advancement of women at their institutions. This was done by using a cross-sectional survey administered electronically to faculty, staff…

  4. Human Response to Personalized Ventilation Combined with Chilled Ceiling

    DEFF Research Database (Denmark)

    Lipczynska, Aleksandra; Kaczmarczyk, Jan; Marcol, Bartosz;

    2014-01-01

    , the use of radiant ceiling cooling will provide operative temperature lower than the air temperature and will improve further occupants’ thermal comfort at warm environment. Therefore combining PV with chilled ceiling may be an effective way to provide thermal comfort in rooms at temperature higher...... than the recommended in the standards upper temperature limit of 26°C. In this paper response of 24 human subjects to a PV combined with chilled ceiling system (CCPV) is compared with the response to mixing ventilation combined with chilled ceiling (CCMV). Participants were provided with control of....../return water temperature for chilled ceiling was 15,5/16,8°C at room air temperature of 26°C and 19,5/20,6°C at 28°C. During the experiment the subjects were performing typical office tasks at workstations with computers. Exposure included also increased activity level office work for a period of 25 min. At...

  5. Comparison of modern Mississippi fan with selected ancient fans

    Energy Technology Data Exchange (ETDEWEB)

    Shanmugam, G.; Moiola, R.J.; McPherson, J.G.; O' Connell, S.

    1988-09-01

    A comparison of the modern passive-margin Mississippi fan (DSDP Leg 96) with selected ancient active-margin fans reveals major differences in turbidite facies associations and seismic characteristics of the lower fan area. The lower Mississippi fan is composed of channel (facies B and F) and nonchannel sequences (facies C. and D), whereas lower fan areas of ancient active-margin fans are characterized by nonchannelized, thickening-upward depositional lobes (facies C and D) with sheetlike geometry. An absence of depositional lobes in the lower Mississippi fan is also suggested by a lack of mounded seismic reflections. Continuous and parallel seismic reflections of the lower Mississippi fan may represent sheet sands, but not those of true depositional lobes. In mature passive-margin fans, long, sinuous channels develop as a consequence of low gradients and the transport of sediment with a relatively low sand/mud ratio, and these channels develop lenticular sand bodies. In contrast, channels in active-margin fans are short and commonly braided as a result of high gradients and the transport of sediment with a relatively high sand/mud ratio. Braided channels characteristically develop sheetlike sand bodies.

  6. Numerical analysis of diffuse ceiling ventilation and its integration with a radiant ceiling system

    DEFF Research Database (Denmark)

    Zhang, Chen; Heiselberg, Per Kvols; Chen, Qingyan;

    2016-01-01

    A novel system combining diffuse ceiling ventilation and radiant ceiling was proposed recently, with the aim of providing energy efficient and comfort environment to office buildings. Designing of such a system is challenging because of complex interactions between the two subsystems and a large...... number of design parameters encountered in practice. This study aimed to develop a numerical model that can reliably predict the airflow and thermal performance of the integrated system during the design stage. The model was validated by experiments under different operating conditions. The validated......-uniformity air distribution and further led to the draught problem in the occupied zone. This system was recommended to apply in the small offices instead of large, open spaces....

  7. Women and Politics – The Glass Ceiling

    Directory of Open Access Journals (Sweden)

    Irina Zamfirache

    2010-03-01

    Full Text Available The role of women in modern politics is a subject that needs further insight, considering the growthin number of women that nowadays have relevant political positions on the international stage.There are studies today that emphasize the equality issue and all that is gender role related, but ourinterest is to analyze the women representation in power related positions. Due to the fastmodernization of the political environment and the rapid spreading of the feminist way of thought,several authors took interest in the gender differences in politics. The article follows some keydimensions in understanding the gender-role in politics: the glass ceiling, the role of the media indrawing the image of the woman politician, the gender affinity effect. In the end we would like topoint out the differences for men and women in exploiting the opportunities and securing the positions of power.

  8. Parental leave and the glass ceiling in Sweden

    OpenAIRE

    Albrecht, James W.; Skogmann Thoursie, Peter; Susan B. Vroman

    2015-01-01

    In this paper, we update and extend "Is There a Glass Ceiling in Sweden?" (Albrecht et al. 2003) by documenting the extent to which the gender log wage gap across the distribution in Sweden has changed over the period 1998-2008. We then examine the Swedish glass ceiling in 2008 in more detail by documenting how it differs for white-collar versus blue-collar workers and for private- versus public-sector workers. We also examine when in the life cycle the glass ceiling effect arises and how thi...

  9. WHO ARE FANS OF FACEBOOK FAN PAGES? AN ELECTRONIC WORD-OF-MOUTH COMMUNICATION PERSPECTIVE

    OpenAIRE

    Xiao Hu; Louisa Ha; Simeng Mo; Ying Xu

    2014-01-01

    Given its great business value and popularity, Facebook fan pages have attracted more and more attention in both industry and academia. Fans of Facebook fan pages play an important role in electronic word-of-mouth (eWOM) communication. This study focused on the population of fans on Facebook fan pages and examined the differences between fans and non-fans in terms of demographics, social network sites (SNS) use, Internet use, and online shopping behaviors. The results indicated that fans used...

  10. Existence of Glass Ceiling in Public Universities of Lahore (Pakistan

    Directory of Open Access Journals (Sweden)

    Asifa Ilyas

    2014-08-01

    Full Text Available Glass ceiling is a set of unseen factors which adversely affect females upward career growth and prevent them to get to top positions. This study is meant to explore existence of glass ceiling in public universities of Lahore (Pakistan; and factors responsible for creating this glass ceiling effect. The respondents of this study are females heading different departments in their respective universities. The results of this study show that different cultural and social, family and organizational barriers adversely affect females’ career growth and make them work in lower subordinate positions despite having suitable qualifications and experiences. The significance of this study comes from the fact that it investigates this issue by taking empirical evidence of those females who personally faced glass ceiling and managed to make their ways to occupy top positions in their respective departments.

  11. Skífan

    OpenAIRE

    Elín Ólafsdóttir 1969

    2011-01-01

    Skífan er eina fyrirtækið hér á landi sem sérhæfir sig í sölu á tónlist, mynddiskum, tölvuleikjum og leikjatölvum. Sú atvinnugrein sem Skífan tilheyrir hefur fengið að finna töluvert fyrir þróun internetsins þar sem mögulegt er að hlaða þessu efni niður hvort sem er með löglegum eða ólöglegum hætti. Markmið verkefnisins var að skoða hver áhrif sviðsmynda væru á rekstrarlíkan Skífunnar. Höfundur fór í gegnum atvinnuvega- og samkeppnisgreiningu með aðstoð eiganda og rekstrarstjóra Skífunnar...

  12. Multiprocessor Priority Ceiling Emulation for Safety-Critical Java

    DEFF Research Database (Denmark)

    Strøm, Torur Biskopstø; Schoeberl, Martin

    2015-01-01

    Priority ceiling emulation has preferable properties on uniprocessor systems, such as avoiding priority inversion and being deadlock free. This has made it a popular locking protocol. According to the safety-critical Java specication, priority ceiling emulation is a requirement for implementations....... However, implementing the protocol for multiprocessor systemsis more complex so implementations might perform worse than non-preemptive implementations. In this paper we compare two multiprocessor lock implementations with hardware support for the Java optimized processor: non-preemptive locking...

  13. The Glass Ceiling in Politics: Formalization and Empirical Tests

    OpenAIRE

    Folke, Olle; Rickne, Johanna

    2014-01-01

    There is a scarcity of women and minorities at the apex of political power. This paper formalizes the concept of the glass ceiling for political organizations and builds on previous research to suggest four testable criteria. A glass ceiling exists if women and/or racial minorities (1) are discriminated against in the organization's promotion process and (2) the discrimination increases in severity for the top levels of power and over an individual's career trajectory. We suggest a series of ...

  14. Ferromanganese micronodules from Bengal Fan

    Digital Repository Service at National Institute of Oceanography (India)

    Chauhan, O.S.; Gujar, A.R.; Rao, Ch.M.

    The occurrence of ferromanganese micronodules, hitherto unreported from any fan-valley system of the world, has been recorded from over 0.22 million km sup(2) area located in the middle fan region of the Bay of Bengal. Their abundance is higher...

  15. New peculiar cave ceiling forms from Carlsbad Caverns (New Mexico, USA): The zenithal ceiling tube-holes

    Science.gov (United States)

    Calaforra, Jose-Maria; De Waele, Jo

    2011-11-01

    During a trip to the Hall of the White Giant, Carlsbad Caverns (NM, USA) cigar-shaped vertically upward developing holes were observed on the ceiling at different heights of the passages. They have a circular cross-section with diameters of 1 to some centimetres and taper out towards their upper end. Their walls are smooth and their bottom edges are sharp, while their length can reach several decimetres. Sometimes gypsum can be found inside. They often occur randomly distributed in groups and their development is not necessarily controlled by fractures or other bedrock structures. We name these peculiar karren-like cave microforms “zenithal ceiling tube-holes” because of their origin by H2S environment corrosion processes and their vertical (zenithal) upward growth in ceilings. A comparison is made between zenithal ceiling tube-holes and other karstic or non karstic similar forms such as bell holes, oxidation vents, snailholes, Korrosionskolke (mixture-solution hollows) or pockets, röhrenkarren, light-oriented photokarren, borings of (often marine) organisms and negative stalactites. Zenithal ceiling tube-holes are created by the corrosive effect of sulphuric acid. H2S(g) dissolves in water giving rise to widespread sulphuric acid corrosion. When H2S bubbles are trapped underneath overhanging surfaces or ceilings and water level rises steadily the corrosive effect is concentrated vertically upwards, drilling vertical holes that can also completely pass overhanging rock ledges.

  16. The Crati Submarine Fan, Ionian Sea

    Science.gov (United States)

    Lucchi, F.R.; Colella, A.; Gabbianelli, G.; Rossi, S.; Normark, W.R.

    1984-01-01

    The Crati Fan is located in the tectonically active submerged extension of the Apennines chain and foretrough. The small fan system is growing in a relatively shallow (200 to 450 m), elongate nearshore basin receiving abundant input from the Crati River. The fan is characterized by a short, steep, channelized section (inner or upper fan) and a smooth, slightly bulging distal section (outer or lower fan). The numerous subparallel channels head in the shelf or littoral zone and do not form branching distributary patterns. Sand and mud depositional lobes of the outer fan stretch over more than 60% of fan length. ?? 1984 Springer-Verlag New York Inc.

  17. ENERGY STAR Certified Ventilating Fans

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 4.0 ENERGY STAR Program Requirements for Ventilating Fans that are effective as of...

  18. PFP supply fan motor starters

    International Nuclear Information System (INIS)

    The Plutonium Finishing Plant (PFP) is currently stabilizing about 25 kg of Pu sludge; upon completion of this task, PFP will be maintained in a safe standby condition to await decision from the PFP NEPA review. It can take about 10 years to initiate and complete terminal cleanout after this; the facility will then be decommissioned and decontaminated. The 234-5Z ventilation system must continue to operate until terminal cleanout. Part of the ventilation system is the seismic fan shutdown system which shuts down the ventilation supply fans in case of strong earthquake. This document presents criteria for installing solid state, reduced voltage motor starters and isolation contactors for the 8 main ventilation supply fans. The isolation contactors will shutdown the supply fans in event of earthquake

  19. Thermal behaviour of cooling ceilings; Thermisches Verhalten von Kuehldecken

    Energy Technology Data Exchange (ETDEWEB)

    Beck, C.

    2002-07-01

    The thermal behaviour of cooling ceilings is so far described by characteristic equations in the form of q=C x {delta}{theta}{sup n}. In special cases these equations are extended by terms which take into account the radiation exchange between heat sink and space user (operational ambient temperature). This is insufficient. Therefore a model is presented, which describes more exactly the individual processes (radiation, convection) at the cooled surface. As a first step the ceiling area is divided into three ranges in which different phenomena are affecting the heat transfer considerably: 1. Range under the influence of free convection in the space. 2. Range with forced convection caused by a plume along the window. 3. Range with forced convection caused by air flow through supply air outlets. For each of these ranges the fundamentals of heat transfer are applied using the substantial variables. The results of these models are then compared in a second step with results from laboratory tests. This model is developed first for steady-state conditions. It is extended by a second model to describe the dynamic processes (storage). Finally, both steady-state and unsteady conditions are investigated systematically. Results are presented for the cooling rate effected by the temperature of cooling ceiling, ambient conditions, supply air flow rate, supply air temperature and type of the air outlet. The results computed indicate that the maximum total cooling rate is always gained by a combination of a cooling ceiling and a supply air with minimum permissible temperature. In these cases the cooling rate of the ceiling is lower than that without ventilation of the space. However, the additional cooling rate of the ventilation compensates this effect in all cases investigated. This is an important finding, since cooling ceilings usually must be combined with an HVAC system for reasons of dehumidifying. Dried, cooled supply air can thus be supplied to the space without

  20. Perceptions of Primary School Women Managers Toward Glass Ceiling

    OpenAIRE

    ÇETİN, Münevver; ATAN, Elif

    2013-01-01

    This research is conducted to defi ne the women school managers’ perceptions toward glass ceiling and the rise of position of the women managers in primary schools.And this research is held out according to the perceptions of women school managers in glass ceiling. Data have been taken from 120 women school managers who have attendedto the research via survey. In analysis of data, such techniques as Independent Samples t- test, Kruskal Wallis and Mann- Whitney U are used. In the end of this r...

  1. Experimental study and modeling of cooling ceiling systems using steady-state analysis

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca Diaz, Nestor [Thermodynamic Laboratory, University of Liege Belgium, Campus du Sart Tilman, Bat: B49 - P33, B-4000 Liege (Belgium); Universidad Tecnologica de Pereira, Facultad de Ingenieria Mecuanica, AA. 97 Pereira (Colombia); Lebrun, Jean [Thermodynamic Laboratory, University of Liege Belgium, Campus du Sart Tilman, Bat: B49 - P33, B-4000 Liege (Belgium); Andre, Philippe [Departement Sciences et Gestion de l' Environnement, University of Liege Belgium, 185, Avenue de Longwy, B-6700 Arlon (Belgium)

    2010-06-15

    This article presents the results of an experimental study performed to develop a computational model of cooling ceiling systems. The model considers the cooling ceiling as a fin. Only the dry regime is considered. From ceiling and room dimensions, material description of the cooling ceiling and measurement of supply water mass flow rate and air and water temperatures, the model calculates the cooling ceiling capacity, ceiling surface average temperature and water exhaust temperature. Fin efficiency, mixed convection close to the cooling ceiling (generated by the ventilation system) and panel perforations influence are studied. The theoretical approach gives to the user an appropriate tool for preliminary calculation, design and diagnosis in commissioning processes in order to determine the main operating conditions of the system in cooling mode. A series of experimental results got on four types of cooling ceilings are used in order to validate the model. (author)

  2. Development of the damage assessment methodology for ceiling elements

    Science.gov (United States)

    Nitta, Yoshihiro; Iwasaki, Atsumi; Nishitani, Akira; Wakatabe, Morimasa; Inai, Shinsuke; Ohdomari, Iwao; Tsutsumi, Hiroki

    2012-04-01

    This paper presents the basic concept of a damage assessment methodology for ceiling elements with the aid of smart sensor board and inspection robot. In this proposed system, the distributed smart sensor boards firstly detect the fact of damage occurrence. Next, the robot inspects the damage location and captures the photographic image of damage condition. The smart sensor board for the proposed system mainly consists of microcontroller, strain gage and LAN module. The inspection robot integrated into the proposed system has a wireless camera and wireless LAN device for receiving signal to manipulate itself. At first, the effectiveness of the smart sensor board and inspection robot is tested by experiments of a full-scale suspended ceiling utilizing shaking table facilities. The model ceiling is subjected to several levels of excitations and thus various levels of damages are caused. Next, this robot inspection scheme is applied to the ceiling of a real structure damaged by the 2011 off the pacific coast of Tohoku Earthquake. The obtained results indicate that the proposed system can detect the location and condition of the damage.

  3. Smashing into the Glass Ceiling for Women Managers.

    Science.gov (United States)

    Veale, Camilla; Gold, Jeff

    1998-01-01

    Interviews with 10 women administrators in a British metropolitan district council revealed the glass ceiling to be a complex phenomenon reaching beyond the employment sphere. Their career progression was hindered by lack of career counseling, family-work conflicts, lack of management development for women, and particularly a managerial culture…

  4. "Training Floors" and "Training Ceilings": Metonyms for Understanding Training Trends

    Science.gov (United States)

    Felstead, Alan; Jewson, Nick

    2014-01-01

    This article outlines a conceptual framework for mapping and understanding training trends. It uses the metonyms of floors and ceilings to distinguish between different types of training configurations. The argument is made that the ups and downs of employer reports of training activity are a crude basis on which to make judgements about the…

  5. A Modest Manifesto for Shattering the Glass Ceiling.

    Science.gov (United States)

    Meyerson, Debra E.; Fletcher, Joyce K.

    2000-01-01

    Approaches to the glass ceiling--encouraging women to adopt "masculine" attributes, accommodating women's unique needs, or celebrating women's differences--have shortcomings. A fourth approach links equity and effectiveness. "Small wins" recognizes that gender inequity is rooted in cultural patterns and uses small initiatives to unearth and upend…

  6. Breaking through the glass ceiling : women in management

    OpenAIRE

    Wirth, Linda

    2001-01-01

    This book helps us to better understand the problems women face in rising through the ranks and securing top positions, and offers some useful strategies for shattering the glass ceiling. It examines current gender inequalities in the labour market and in political and social life.

  7. Managers' Beliefs about the Glass Ceiling: Interpersonal and Organizational Factors

    Science.gov (United States)

    Elacqua, Tina C.; Beehr, Terry A.; Hansen, Curtiss P.; Webster, Jennica

    2009-01-01

    The glass ceiling refers to the difficulty of women trying to be promoted into the top management levels. The present study examined managers' potential explanations, implicit or explicit, for why women rarely reach the top hierarchical levels in their own organization. Among 685 managers at a large Midwestern insurance company, a model was…

  8. Breaking the Educational Glass Ceiling: An Interview with Harry Lenderman

    Science.gov (United States)

    Lenderman, Harry; Sandelands, Eric

    2005-01-01

    Purpose - To examine the role that corporations can and are playing in removing restrictions to a college or university education for their employees - the educational glass ceiling. Design/methodology/approach - An interview format is used with an experienced academic, and learning and development practitioner, drawing upon experiences and…

  9. GROWTH EVALUATION OF FUNGI (PENICILLIUM AND ASPERGILLUS SPP.) ON CEILING TILES

    Science.gov (United States)

    The paper gives results of an evaluation of the potential for fungal growth on four different ceiling tiles in static chambers. It was found that even new ceiling tiles supported fungal growth under favorable conditions. Used ceiling tiles appeared to be more susceptible to funga...

  10. Measurements on Buoyant Jet Flows from a Ceiling-Mounted Slot Diffuser

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Möller, Åke T. A.

    Ceiling-mounted slot diffusers in ventilated rooms will often generate a flow of the wall jet type. The jet follows the ceiling, entrains air from the occupied zone and generates a recirculating flow in the whole room. This paper will deal with the flow in the ceiling region. The wall jet flow...

  11. Glass Ceiling in Academic Administration in Turkey: 1990s versus 2000s

    Science.gov (United States)

    Gunluk-Senesen, Gulay

    2009-01-01

    This paper assesses the glass ceiling for academics in the Turkish universities with reference to top administration positions: rectors and deans. Glass ceiling indicators show that the glass ceiling thickened from the 1990s to late 2000s. The findings are discussed against the background of the transformation in the Turkish universities in the…

  12. 46 CFR 116.422 - Ceilings, linings, trim, interior finish and decorations.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Ceilings, linings, trim, interior finish and decorations... PASSENGERS CONSTRUCTION AND ARRANGEMENT Fire Protection § 116.422 Ceilings, linings, trim, interior finish... Commandant. (b) Bulkheads, linings and ceilings may be covered by a combustible interior finish provided...

  13. Advance Noise Control Fan II: Test Rig Fan Risk Management Study

    Science.gov (United States)

    Lucero, John

    2013-01-01

    Since 1995 the Advanced Noise Control Fan (ANCF) has significantly contributed to the advancement of the understanding of the physics of fan tonal noise generation. The 9'x15' WT has successfully tested multiple high speed fan designs over the last several decades. This advanced several tone noise reduction concepts to higher TRL and the validation of fan tone noise prediction codes.

  14. WW1 Allies Flags Fans

    OpenAIRE

    Biger, Pierre-Henri

    2014-01-01

    International audience Several hand fans are decorated with flags of the main Allied countries during WW1. They show the entry of the United States into the war, and the departure of Russia. So these feminine utensils (and advertising items, for instance here for Champagne Eugene Clicquot) play their role in theWar effort.

  15. Effects of a thermal ceiling on postoperative hypothermia

    DEFF Research Database (Denmark)

    Henneberg, S; Eklund, A; Joachimsson, P O;

    1985-01-01

    postoperatively with or without external heating from a heating ceiling. Central and peripheral temperatures, oxygen consumption, plasma catecholamines and shivering were measured. A method for continuous measurement of oxygen consumption and carbon dioxide production during spontaneous breathing is described....... The results suggest that postoperative external heating decreases oxygen consumption, shivering and plasma catecholamine levels. At the same time, the comfort of the patient is increased considerably....

  16. Self-Positioning Robot Navigation Using Ceiling Image Sequences

    OpenAIRE

    Facchinetti Claudio; Tièche, François; Hügli, Heinz

    2008-01-01

    This paper presents the analysis of a vision-based homing behavior that provides self-positioning for a mobile robot using ceiling structures as landmarks. This new behavior enters the navigation approach we developed for mobile robots, which basic idea is to represent the robot spatial knowledge in a topological map, where nodes consist of self-positioning sites and edges may be any reactive behavior moving the robot between two nodes.

  17. Rent Sharing as a Driver of the Glass Ceiling Effect

    OpenAIRE

    Matano, Alessia; Naticchioni, Paolo

    2011-01-01

    In this paper we show that rent sharing plays a role in accounting for the glass ceiling effect. We make use of a unique employer-employee panel database for Italy from 1996 to 2003, which allows controlling for observed individual and firm heterogeneity and for collective bargaining. Moreover, by means of IV quantile fixed effects estimates we can cope with unobserved heterogeneity and endogeneity. We then go on to discuss the possible related explanations.

  18. Is the glass ceiling cracking? A simple test

    OpenAIRE

    Hu, Ting; Yun, Myeong-Su

    2008-01-01

    It has been reported that there is dramatic increase of female workers into manager level jobs during last few decades in the US labor market. Using Standard & Poor’s Compustat ExecuComp database over 14 years (1992 - 2005), this paper examines whether the glass ceiling in the executive market has been substantially weakened measured by relative compensation by gender and female representation in the top rung of the executive market. Though the status of females in the executive market seems ...

  19. Glass ceiling effects: the case of taiwanese top executives

    OpenAIRE

    Tzu-i Wang; Jennjou Chen

    2010-01-01

    Gender discrimination in labor markets has been an important issue in labor economics. The main purpose of this paper is to empirically study glass ceiling effects, and investigate whether female workers are indeed being discriminated against, particularly during the promotion process, in top management positions in Taiwan. This paper uses data from 4,485 large firms in Taiwan to study whether there are gender preferences when the chairperson of a company chooses a chief executive officer (CE...

  20. Expatriate Glass Ceiling : The Perception of Malaysian Female Employees

    OpenAIRE

    Ghosh, Chandrika

    2013-01-01

    Evidence from research has repeatedly pointed to the small number of women managers sent on expatriation. The percentage of female expatriates during the 1990’s was as low as 14% of all expatriate managers (Windham/NFTC, 1997). Researchers found that, similar to the glass ceiling that prevents women from reaching top management levels, there seems to be another glass barrier that stops them from taking up international assignments. This subtle, invisible barrier has been referred to as the ex...

  1. Gender Wage Gaps, 'Sticky Floors' and 'Glass Ceilings' in Europe

    OpenAIRE

    Christofides, Louis N.; Alexandros Polycarpou; Konstantinos Vrachimis

    2013-01-01

    We consider and attempt to understand the gender wage gap across 26 European countries, using 2007 data from the European Union Statistics on Income and Living Conditions. The size of the gender wage gap varies considerably across countries, definitions of the gap, and selection-correction mechanisms. Most of the gap cannot be explained by the characteristics available in this data set. Quantile regressions show that, in a number of countries, the wage gap is wider at the top (‘glass ceilings...

  2. WHO ARE FANS OF FACEBOOK FAN PAGES? AN ELECTRONIC WORD-OF-MOUTH COMMUNICATION PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    Xiao Hu

    2014-12-01

    Full Text Available Given its great business value and popularity, Facebook fan pages have attracted more and more attention in both industry and academia. Fans of Facebook fan pages play an important role in electronic word-of-mouth (eWOM communication. This study focused on the population of fans on Facebook fan pages and examined the differences between fans and non-fans in terms of demographics, social network sites (SNS use, Internet use, and online shopping behaviors. The results indicated that fans used SNS more frequently than non-fans. Additionally, from the eWOM perspective, the researchers moderated product types in the model of people’s word-of-mouth (WOM preferences and found that people had different preferences for eWOM and traditional WOM for different products. Traditional WOM is still the most important source of information for people when shopping online.

  3. Football – Feminisation – Fans

    DEFF Research Database (Denmark)

    Mintert, Svenja-Maria

    the number of female fans in football has grown over the past years. A national sense of community, emotion and passion for the game is in particular reached during the international tournaments at live football spectacles and many female fans cheer and sing for ‘their’ team with the utmost conviction......Football has long time been considered as a genuine masculine domain. However, in the current football culture, the dualism of masculinity and femaleness is in progress. More and more women consume football which is in many countries considered the most popular sport, not only in Scandinavia where....... Yet, the combination ‘women and football’ is still adhered to certain scepticism. Objective The overall objective of this Ph.D. thesis is to contribute to the body of knowledge associated with the distinct aspects of women’s football, female fandom and gender identities in European football drawing...

  4. Model fan passage flow simulation

    OpenAIRE

    Myre, David D.

    1992-01-01

    Approved for public release; distribution is unlimited Two-dimensional experimental and numerical simulations of a transonic fan blade passage were conducted at a Mach number of 1.4 to provide baseline data for the study of the effects of vortex generating devices on the suction surface shock-boundary layer interaction. In the experimental program, a probe and transverse system were designed and constructed. A new data acquisition system was adapted to record data from probe surveys and ...

  5. Fan deltas and braid deltas: conceptual problems

    Energy Technology Data Exchange (ETDEWEB)

    McPherson, J.G.; Shanmugam, G.; Moiola, R.J.

    1986-05-01

    The concept of fan deltas has been widely misinterpreted in the geologic literature. A true fan delta is defined as an alluvial fan deposited into a standing body of water. Such sequences are of limited areal extent and are, as expected, uncommon in the rock record. By contrast, braid deltas (herein defined), formed by progradation of a braided fluvial system into a standing body of water, are a common geomorphic feature in many modern settings, and their deposits are common in the geologic record. Braid-delta sequences are often identified as fan deltas, on the false premise that coarse-grained deposits in a deltaic setting are always part of an alluvial fan complex. The authors find that most published examples of so called fan deltas contain no direct evidence for the presence of an alluvial fan. Even in examples where an alluvial fan could be documented, the authors found that, in many cases, the alluvial fan complex was far removed from the shoreline, separated by an extensive braid plain. The authors suggest that such systems are better classified as braid deltas. They consider that it is essential to distinguish the environmental setting of true fan deltas from that of braid deltas. Misclassification will lead to incorrect interpretations of expected facies, sandstone geometry, reservoir quality, and tectonic settings. Criteria based on geometry, vertical and lateral lithofacies associations, and paleocurrent patterns should be used to correctly identify and distinguish these depositional systems.

  6. Parametrical analysis on the diffuse ceiling ventilation by experimental and numerical studies

    DEFF Research Database (Denmark)

    Zhang, Chen; Kristensen, Martin Heine; Jensen, Jakob Sølund;

    2016-01-01

    This paper aims to investigate the performance of diffuse ceiling ventilation in a classroom. An experimental study is carried out in a test chamber to examine the impact of diffuse ceiling opening area on the system cooling capacity and thermal comfort. The results indicate that diffuse ceiling...... ventilation provides a satisfied thermal comfort level in the occupied zone even under a high ventilation rate and a high heat load condition. A design chart method is adopted to compare different diffuse ceiling configurations, and the results indicate that the system with a 18% diffuse ceiling opening area...... is able to handle the highest heat load without discomfort. On the other hand, a CFD model is built where the diffuse ceiling is simulated with a porous media zone. This model is validated by experimental results and further used to analyze the effect of heat load distribution and room height. The...

  7. Seismic definition of fan lobe types of Mississippi Fan, Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Weimer, P.; Buffler, R.T.

    1986-05-01

    Detailed seismic stratigraphic studies in the upper and middle Mississippi Fan identified 12 fan lobes. Three different types of fan lobes are present. The type 1 fan lobe consists of two seismic sequences. At the base of the lower sequence are mounded reflectors that change upward to hummocky reflectors. The upper sequence has stacked high-amplitude reflectors flanked on either side by low-amplitude, laterally continuous reflectors. These type 1 fan lobes are interpreted as mass transport deposits overlain by a single channel with extensive overbank deposits. The type 2 fan lobe has seismic and geologic facies similar to the upper sequence of type 1. Both type 1 and type 2 fan lobes have a single channel that is sinuous in the middle fan. The type 3 fan lobe is characterized by several stacked high-amplitude reflectors, flanked by laterally continuous low-amplitude reflectors. These represent a bifurcating channel system showing several episodes of deposition and abandonment. Most of the sediments in the Mississippi Fan were deposited in type 2 or the upper sequence of type 1 fan lobes. Sediments in the lower sequence of the type 1 lobe are areally and volumetrically limited. Of the 12 fan lobes, 7 are type 1, 4 are type 2, and 1 is type 3. Deep Sea Drilling Project Leg 96 drilling penetrated only the modern lobe, which is a type 2 fan lobe.

  8. Air Distribution in Rooms with Ceiling-mounted Obstacles and Three-Dimensional Isothermal Flow

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Evensen, Louis; Grabau, Peter;

    The air supply openings in ventilated rooms are often placed close to the ceiling. A recirculating flow is generated in the room, and the region between the ceiling and the occupied zone serves as an entrainment and velocity decay area for the wall jets. Ceiling-mounted obstacles may disturb this...... flow and, in particular, certain dimensions and positions of the obstacles cause a downward deflection of the jets into the occupied zone resulting in reduced thermal comfort for the inhabitants....

  9. The Perception of 'Glass Ceiling' and its Impact on Career Progression of Female Managers in Malaysia

    OpenAIRE

    Khan, Maria

    2013-01-01

    The glass ceiling is a transparent barrier that prevents women and minorities from moving up in the management hierarchy. Glass ceiling researchers have attempted to determine whether a glass ceiling exists by examining the actual promotion decision to top management, the percentage of management positions held by women in an organization, salary of male versus female managers, and ratings of potential promotion candidates to top management. The aim of this research is to investigate the vari...

  10. Numerical investigation of diffuse ceiling ventilation in an office under different operating conditions

    DEFF Research Database (Denmark)

    Hviid, Christian Anker; Petersen, Steffen

    Diffuse ceiling ventilation is a novel air distribution device that combines the suspended acoustic ceiling with ventilation supply. A diffuse ceiling distributes the supply air above the acoustic tiles and has proven performance in both laboratory and class room experiments. This paper is a...... numerical study of the performance of a six person office equipped with diffuse ventilation ceiling. In total six extreme, yet realistic, operation scenarios were simulated to study the performance including different occupancy, ventilation rates and supply air temperatures. The performance was studied with...

  11. Cliff notes: the effects of the 2013 debt-ceiling crisis

    OpenAIRE

    Ali K. Ozdagli; Peek, Joe

    2013-01-01

    We investigate the effects of the 2013 debt-ceiling crisis on the Treasury bill market and possible spillovers to the commercial paper market and money market funds. We also compare this experience with the prior debt-ceiling crisis in 2011. We find that the 2013 debt-ceiling crisis reduced the demand for Treasury bills that were scheduled to mature right after the debt-ceiling deadline, but not for longer-term Treasury bills. Accordingly, we see that a hump formed at the shorter end of the t...

  12. An acoustical research of the undulating wooden ceiling in the Vyborg Library

    DEFF Research Database (Denmark)

    Mortensen, Bo

    2004-01-01

    Much has been written about the Undulating Ceiling at the lecture hall of the Vyborg Library. Alvar Aalto himself claimed the ceiling to be "ninety-nine per cent acoustically perfect" and the sketches showing the acoustical considerations behind the ceiling-design is often reproduced. But how did...... it actually function? Did the wave form have the claimed acoustical avantages or could the ceiling as well have been horisontal. Comprehensive acoustical investigations have been carried out including acoustical measurements in a 1:20 scale model and calculations in a 3D computer model of the lecture...

  13. Noise and noise abatement in fans and blowers: A review

    Science.gov (United States)

    Neise, W.

    1980-03-01

    Noise generation and its reduction industrial fans (ventilators) is addressed. A review is given of the fan types commonly in use and their practical applications, the mechanisms of the aerodynamic noise generation in fans, theoretical and empirical prediction methods for fan noise, acoustic similarity laws, and noise reduction methods by means of the fan construction and fan operation. Measurement procedures are discussed with respect to the noise radiated from different parts of a fan, e.g. from the fan inlet or outlet, from the fan casing, from the fan as a whole, and to the noise radiated into ducts connected to the fan. Finally, considerations are made, for which classes of fans noise standards can be defined to characterize the noise emission of the various fan types.

  14. Computing Gröbner fans

    DEFF Research Database (Denmark)

    Fukuda, K.; Jensen, Anders Nedergaard; Thomas, R.R.

    2005-01-01

    This paper presents algorithms for computing the Gröbner fan of an arbitrary polynomial ideal. The computation involves enumeration of all reduced Gröbner bases of the ideal. Our algorithms are based on a uniform definition of the Gröbner fan that applies to both homogeneous and non...... always normal fans of polyhedra in which case reverse search applies automatically. Computational results using our implementation of these algorithms in the software package Gfan are included....

  15. Laminated primary ceiling barriers for medical accelerator rooms

    International Nuclear Information System (INIS)

    In this work the performance of a number of laminated shields used as the primary ceiling barrier for high-energy accelerator rooms was investigated. The neutron and photon dose equivalent rates were measured outside each shield. Based on the measured photon level and the calculated x-ray leakage level the dose equivalent rate due to photons produced by neutron interactions with the shield materials was estimated. Shielding parameters for polyethylene were established for photons and neutrons. It was found that the barriers designed using the techniques given in an NCRP report suffered from excessive radiation leakage. (author)

  16. Measurement results of PCM climate ceilings; Meetresultaten PCM-klimaatplafonds

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, H. [Autarkis, Almere (Netherlands)

    2012-03-15

    The 'universal climate machine' is able to air-condition a building endlessly by itself through self-regulatory control. This is a PCM climate ceiling (PCM refers to Phase Change Materials) in which heat exchange takes place through radiation and free convection, but also through forced convection. [Dutch] De 'universele klimaatmachine' kan zelfregelend een gebouw eindeloos autarkisch klimatiseren. Het gaat hier om een PCM-klimaatplafond (PCM staat voor Phase Change Materials) waarbij de warmteoverdracht plaatsvindt door straling en vrije convectie, maar ook door gedwongen convectie.

  17. Enhanced Fan Noise Modeling for Turbofan Engines

    Science.gov (United States)

    Krejsa, Eugene A.; Stone, James R.

    2014-01-01

    This report describes work by consultants to Diversitech Inc. for the NASA Glenn Research Center (GRC) to revise the fan noise prediction procedure based on fan noise data obtained in the 9- by 15 Foot Low-Speed Wind Tunnel at GRC. The purpose of this task is to begin development of an enhanced, analytical, more physics-based, fan noise prediction method applicable to commercial turbofan propulsion systems. The method is to be suitable for programming into a computational model for eventual incorporation into NASA's current aircraft system noise prediction computer codes. The scope of this task is in alignment with the mission of the Propulsion 21 research effort conducted by the coalition of NASA, state government, industry, and academia to develop aeropropulsion technologies. A model for fan noise prediction was developed based on measured noise levels for the R4 rotor with several outlet guide vane variations and three fan exhaust areas. The model predicts the complete fan noise spectrum, including broadband noise, tones, and for supersonic tip speeds, combination tones. Both spectra and directivity are predicted. Good agreement with data was achieved for all fan geometries. Comparisons with data from a second fan, the ADP fan, also showed good agreement.

  18. Incorporating Judgement in Fan Charts

    OpenAIRE

    Österholm, Pär

    2006-01-01

    Within a decision-making group, such as the monetary-policy committee of a central bank,group members often hold differing views about the future of key economic variables. Such differences of opinion can be thought of as reflecting differing sets of judgement. This paper suggests modelling each agent’s judgement as one scenario in a macroeconomic model. Each judgement set has a specific dynamic impact on the system, and accordingly, a particular predictive density – or fan chart – associated...

  19. Active Control of Fan Noise

    Institute of Scientific and Technical Information of China (English)

    Nobuhiko YAMASAKI; Hirotoshi TAJIMA

    2008-01-01

    In the wake-rotor interaction fan noise, a number of the interacting modes at the blade passing frequency (BPF)and its harmonics are generated which are prescribed by the number of stator and rotor blades etc. In the present study, the dominant mode is tried to be suppressed by the secondary sound from the loudspeaker actuators. One of the novel features of the present system is the adoption of the control board with the Field Programmable Gate Array (FPGA) hardware and the LabVIEW software to synchronize the circumferentially installed loudspeaker actuators with the relative location of rotational blades under arbitrary fan rotational speeds. The experiments were conducted under the conditions of three rotational speeds of 2004, 3150, and 4002 [rpm]. The reduction in the sound pressure level (SPL) was observed for all three rotational speeds. The sound pressure level at the BPF was reduced approximately 13 [dB] for 2004 [rpm] case, but not so large reduction was attained for other cases probably due to the inefficiency of the loudspeaker actuators at high frequencies

  20. Ceiling art in a radiation therapy department: its effect on patient treatment experience

    International Nuclear Information System (INIS)

    A new initiative has been implemented at the Sunshine Hospital Radiation Therapy Centre, to provide a calming and comforting environment for patients attending radiation therapy treatment. As part of this initiative, the department's computed tomography (CT) room and radiation therapy bunkers were designed to incorporate ceiling art that replicates a number of different visual scenes. The study was undertaken to determine if ceiling art in the radiation therapy treatment CT and treatment bunkers had an effect on a patient's experience during treatment at the department. Additionally, the study aimed to identify which of the visuals in the ceiling art were most preferred by patients. Patients were requested to complete a 12-question survey. The survey solicited a patient's opinion/perception on the unit's unique ceiling display with emphasis on aesthetic appeal, patient treatment experience and the patient's engagement due to the ceiling display. The responses were dichotomised to ‘positive’ or ‘negative’. Every sixth patient who completed the survey was invited to have a general face-to-face discussion to provide further information about their thoughts on the displays. The results demonstrate that the ceiling artwork solicited a positive reaction in 89.8% of patients surveyed. This score indicates that ceiling artwork contributed positively to patients’ experiences during radiation therapy treatment. The study suggests that ceiling artwork in the department has a positive effect on patient experience during their radiation therapy treatment at the department

  1. The glass ceiling of corporate social responsibility : Consequences of a business case approach towards CSR

    NARCIS (Netherlands)

    Nijhof, A.H.J.; Jeurissen, R.J.M.

    2010-01-01

    Purpose – This paper aims to clarify that corporate social responsibility (CSR) has come a long way by the prevailing business case approach, but increasingly hits a glass ceiling. The glass ceiling metaphor refers to the inherent limitations created by a business case approach towards CSR. Design/m

  2. Airflow Pattern and Performance Analysis of Diffuse Ceiling Ventilation in an Office Room using CFD Study

    DEFF Research Database (Denmark)

    Zhang, Chen; Chen, Qingyan; Heiselberg, Per Kvols;

    2015-01-01

    Diffuse ceiling ventilation uses perforations in the suspended ceiling to deliver air into the occupied zone. Due to the complex geometry of the diffuser, it is not possible to build an exact geometrical model in CFD simulation. Two numerical models are proposed in this study, one is a simplified...

  3. Do Asian American Faculty Face a Glass Ceiling in Higher Education?

    Science.gov (United States)

    Lee, Sharon M.

    2002-01-01

    Evaluated the glass ceiling hypothesis in relation to Asian American faculty using data from the 1993 National Study of Post-Secondary Faculty for 1,019 Asian American faculty members. Data limitations prevent concluding that such faculty do or do not face a glass ceiling; however, baseline findings for future research are established. (SLD)

  4. Ceiling art in a radiation therapy department: its effect on patient treatment experience

    Energy Technology Data Exchange (ETDEWEB)

    Bonett, Jotham [Sunshine Hospital Radiation Therapy Centre, Melbourne, Vic. (Australia)

    2015-09-15

    A new initiative has been implemented at the Sunshine Hospital Radiation Therapy Centre, to provide a calming and comforting environment for patients attending radiation therapy treatment. As part of this initiative, the department's computed tomography (CT) room and radiation therapy bunkers were designed to incorporate ceiling art that replicates a number of different visual scenes. The study was undertaken to determine if ceiling art in the radiation therapy treatment CT and treatment bunkers had an effect on a patient's experience during treatment at the department. Additionally, the study aimed to identify which of the visuals in the ceiling art were most preferred by patients. Patients were requested to complete a 12-question survey. The survey solicited a patient's opinion/perception on the unit's unique ceiling display with emphasis on aesthetic appeal, patient treatment experience and the patient's engagement due to the ceiling display. The responses were dichotomised to ‘positive’ or ‘negative’. Every sixth patient who completed the survey was invited to have a general face-to-face discussion to provide further information about their thoughts on the displays. The results demonstrate that the ceiling artwork solicited a positive reaction in 89.8% of patients surveyed. This score indicates that ceiling artwork contributed positively to patients’ experiences during radiation therapy treatment. The study suggests that ceiling artwork in the department has a positive effect on patient experience during their radiation therapy treatment at the department.

  5. Blade Vibration Measurement System for Unducted Fans

    Science.gov (United States)

    Marscher, William

    2014-01-01

    With propulsion research programs focused on new levels of efficiency and noise reduction, two avenues for advanced gas turbine technology are emerging: the geared turbofan and ultrahigh bypass ratio fan engines. Both of these candidates are being pursued as collaborative research projects between NASA and the engine manufacturers. The high bypass concept from GE Aviation is an unducted fan that features a bypass ratio of over 30 along with the accompanying benefits in fuel efficiency. This project improved the test and measurement capabilities of the unducted fan blade dynamic response. In the course of this project, Mechanical Solutions, Inc. (MSI) collaborated with GE Aviation to (1) define the requirements for fan blade measurements; (2) leverage MSI's radar-based system for compressor and turbine blade monitoring; and (3) develop, validate, and deliver a noncontacting blade vibration measurement system for unducted fans.

  6. Experimental investigations of heat transfer in thermo active building systems in combination with suspended ceilings

    DEFF Research Database (Denmark)

    Alvarez, Maria Alonso; Hviid, Christian Anker; Weitzmann, Peter

    2014-01-01

    buildings to cover acoustic requirements hinders the use of TABS. To measure the reduction of the heat capacity, several experiments are performed in a room equipped with TABS in the upper deck and mixing ventilation. The heat transfer is measured for different suspended ceiling covering percentages......, occupancy scenarios and ventilation rates. The gained results indicate that the heat capacity coefficient of the ceiling surface is reduced by around 30% when the suspended ceiling covering is 70% of the total ceiling area, and 45% when the covering area is up to 87%. The results also demonstrate...... that the ventilation rate has a high influence on the convective heat capacity. When the ventilation rate is increased from 1.7 h-1 to 2.9 h-1, the heat transfer coefficient increases up to 16% for the same occupancy and suspended ceiling layout....

  7. Air Distribution in a Room with Ceiling-Mounted Diffusers

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Heby, Thomas; Moeller-Jensen, Bertil

    2006-01-01

    manikins, each sitting at a desk, two pc's and two desk lamps producing a total heat load of 480 W. The design of the air distribution system is in all five cases based on flow elements from the diffuser, a maximum velocity assumption and a critical vertical temperature gradient in the room. The...... and temperature conditions at the same and at slightly higher loads as can be obtained by a vertical ventilation system, a mixing ventilation system with wall-mounted diffuser and a displacement ventilation system with a low velocity wall-mounted diffuser. The comparison is extended by considering......Experiments with air distribution in rooms generated by a radial ceiling-mounted diffuser and a diffuser generating flow with swirl are compared with the air distribution obtained by mixing ventilation from a wall-mounted diffuser, vertical ventilation and displacement ventilation. The air...

  8. Climate ceilings in school buildings; Klimaatplafonds in scholen

    Energy Technology Data Exchange (ETDEWEB)

    Van Genderen, A.W. [Beekink Installatieadviseurs, Nieuwerkerk aan den IJssel (Netherlands); Van de Nes, R. [ONE Simulations, Leiden (Netherlands)

    2013-07-15

    The NL Agency programme 'Frisse Scholen' (Fresh Schools) stimulates schools to minimize their energy consumption while upgrading the internal climate. Computational Fluid Dynamics (CFD) simulations have been used to investigate the expected internal climate inside a class room equipped with a Frisse Scholen 2.0 Easy-Klima cooling and heating ceiling. The CFD simulations demonstrated that the climate inside the class room obtained class A for each of the themes Ventilation capacity, Operative temperature, Local thermal discomfort and Vertical temperature gradient [Dutch] Het Frisse Scholenproject van Agentschap NL stimuleert scholen om minder energie te gebruiken en het binnenmilieu te verbeteren. De aandacht richt zich voor een groot gedeelte op ventilatie terwijl temperatuurbeheersing en thermisch comfort in algemeenheid meer aanleiding vormen voor klachten. Door middel van Computational Fluid Dynamics (CFD) simulaties is het te verwachten binnenklimaat onderzocht voor een klaslokaal voorzien van een Frisse Scholen 2.0 klimaatplafond.

  9. Thresholds and Glass Ceilings: Career Pattern of Women Scientists

    Science.gov (United States)

    Sonnert, Gerhard

    2004-05-01

    The Project Access study examined the careers of men and women who had received prestigious postdoctoral fellowships and thus were presumably of about equal promise at the start of their professional careers. Had the women scientists in this elite group overcome a threshold beyond which they proceeded on equal footing with their male counterparts; or did a glass ceiling impede their careers? We found gender differences in career outcomes in the group we studied (699 questionnaires, 200 interviews), but these differences varied considerably by scientific discipline. Moreover, the career disparities for women, as a group, appear now to result chiefly from a series of subtle but identifiable and sometimes counterintuitive impediments as well as from slight gender differences in socialization. Each disadvantage by itself may be small, but in their accumulation they significantly influence women's careers.

  10. Turbofan gas turbine engine with variable fan outlet guide vanes

    Science.gov (United States)

    Wood, Peter John (Inventor); Zenon, Ruby Lasandra (Inventor); LaChapelle, Donald George (Inventor); Mielke, Mark Joseph (Inventor); Grant, Carl (Inventor)

    2010-01-01

    A turbofan gas turbine engine includes a forward fan section with a row of fan rotor blades, a core engine, and a fan bypass duct downstream of the forward fan section and radially outwardly of the core engine. The forward fan section has only a single stage of variable fan guide vanes which are variable fan outlet guide vanes downstream of the forward fan rotor blades. An exemplary embodiment of the engine includes an afterburner downstream of the fan bypass duct between the core engine and an exhaust nozzle. The variable fan outlet guide vanes are operable to pivot from a nominal OGV position at take-off to an open OGV position at a high flight Mach Number which may be in a range of between about 2.5-4+. Struts extend radially across a radially inwardly curved portion of a flowpath of the engine between the forward fan section and the core engine.

  11. Controls on alluvial fan long-profiles

    Science.gov (United States)

    Stock, J.D.; Schmidt, K.M.; Miller, D.M.

    2008-01-01

    Water and debris flows exiting confined valleys have a tendency to deposit sediment on steep fans. On alluvial fans where water transport of gravel predominates, channel slopes tend to decrease downfan from ???0.10-0.04 to ???0.01 across wide ranges of climate and tectonism. Some have argued that this pattern reflects grain-size fining downfan such that higher threshold slopes are required just to entrain coarser particles in the waters of the upper fan, whereas lower slopes are required to entrain finer grains downfan (threshold hypothesis). An older hypothesis is that slope is adjusted to transport the supplied sediment load, which decreases downfan as deposition occurs (transport hypothesis). We have begun to test these hypotheses for alluvial fan long-profiles using detailed hydraulic and particle-size data in sediment transport models. On four alluvial fans in the western U.S., we find that channel hydraulic radiiare largely 0.5-0.9 m at fan heads, decreasing to 0.1-0.2 m at distal margins. We find that median gravel diameter does not change systematically along the upper 60%-80% of active fan channels as slope declines, so downstream gravel fining cannot explain most of the observed channel slope reduction. However, as slope declines, channel-bed sand cover increases systematically downfan from areal fractions of America.

  12. Dynamic response of Hovercraft lift fans

    Science.gov (United States)

    Moran, D. D.

    1981-08-01

    Hovercraft lift fans are subjected to varying back pressure due to wave action and craft motions when these vehicles are operating in a seaway. The oscillatory back pressure causes the fans to perform dynamically, exhibiting a hysteresis type of response and a corresponding degradation in mean performance. Since Hovercraft motions are influenced by variations in lift fan pressure and discharge, it is important to understand completely the nature of the dynamic performance of lift fans in order to completely solve the Hovercraft seakeeping problem. The present study was performed to determine and classify the instabilities encountered in a centrifugal fan operating against time-varying back pressure. A model-scale experiment was developed in which the fan discharge was directed into a flow-measuring device, terminating in a rotating valve which produced an oscillatory back pressure superimposed upon a mean aerodynamic resistance. Pressure and local velocity were measured as functions of time at several locations in the fan volute. The measurements permitted the identification of rotating (or propagating) stall in the impeller. One cell and two cell configurations were classified and the transient condition connecting these two configurations was observed. The mechanisms which lead to rotating stall in a centrifugal compressor are presented and discussed with specific reference to Hovercraft applications.

  13. Large Fluvial Fans and Exploration for Hydrocarbons

    Science.gov (United States)

    Wilkinson, Murray Justin

    2005-01-01

    A report discusses the geological phenomena known, variously, as modern large (or large modern) fluvial fans or large continental fans, from a perspective of exploring for hydrocarbons. These fans are partial cones of river sediment that spread out to radii of 100 km or more. Heretofore, they have not been much recognized in the geological literature probably because they are difficult to see from the ground. They can, however, be seen in photographs taken by astronauts and on other remotely sensed imagery. Among the topics discussed in the report is the need for research to understand what seems to be an association among fluvial fans, alluvial fans, and hydrocarbon deposits. Included in the report is an abstract that summarizes the global distribution of large modern fluvial fans and a proposal to use that distribution as a guide to understanding paleo-fluvial reservoir systems where oil and gas have formed. Also included is an abstract that summarizes what a continuing mapping project has thus far revealed about the characteristics of large fans that have been found in a variety of geological environments.

  14. Small fan-in is beautiful

    Energy Technology Data Exchange (ETDEWEB)

    Beiu, V.; Makaruk, H.E.

    1997-09-01

    The starting points of this paper are two size-optimal solutions: (1) one for implementing arbitrary Boolean functions; and (2) another one for implementing certain subclasses of Boolean functions. Because VLSI implementations do not cope well with highly interconnected nets -- the area of a chip grows with the cube of the fan-in -- this paper will analyze the influence of limited fan-in on the size optimality for the two solutions mentioned. First, the authors will extend a result from Horne and Hush valid for fan-in {Delta} = 2 to arbitrary fan-in. Second, they will prove that size-optimal solutions are obtained for small constant fan-ins for both constructions, while relative minimum size solutions can be obtained for fan-ins strictly lower that linear. These results are in agreement with similar ones proving that for small constant fan-ins ({Delta} = 6...9) there exist VLSI-optimal (i.e., minimizing AT{sup 2}) solutions, while there are similar small constants relating to the capacity of processing information.

  15. Fan Database and Web-tool for Choosing Quieter Spaceflight Fans

    Science.gov (United States)

    Allen, Christopher S.; Burnside, Nathan J.

    2007-01-01

    One critical aspect of designing spaceflight hardware is the selection of fans to provide the necessary cooling. And with efforts to minimize cost and the tendancy to be conservative with the amount of cooling provided, it is easy to choose an overpowered fan. One impact of this is that the fan uses more energy than is necessary. But, the more significant impact is that the hardware produces much more acoustic noise than if an optimal fan was chosen. Choosing the right fan for a specific hardware application is no simple task. It requires knowledge of cooling requirements and various fan performance characteristics as well as knowledge of the aerodynamic losses of the hardware in which the fan is to be installed. Knowledge of the acoustic emissions of each fan as a function of operating condition is also required in order to choose a quieter fan for a given design point. The purpose of this paper is to describe a database and design-tool that have been developed to aid spaceflight hardware developers in choosing a fan for their application that is based on aerodynamic performance and reduced acoustic emissions as well. This web-based-tool provides a limited amount of fan-data, provides a method for selecting a fan based on its projected operating point, and also provides a method for comparing and contrasting aerodynamic performance and acoustic data from different fans. Drill-down techniques are used to display details of the spectral noise characteristics of the fan at specific operation conditions. The fan aerodynamic and acoustic data were acquired at Ames Research Center in the Experimental Aero-Physics Branch's Anechoic Chamber. Acoustic data were acquired according to ANSI Standard S12.11-1987, "Method for the Measurement of Noise Emitted by Small Air-Moving Devices." One significant improvement made to this technique included automation that allows for a significant increase in flow-rate resolution. The web-tool was developed at Johnson Space Center and is

  16. Performance of personalized ventilation combined with chilled ceiling in an office room: inhaled air quality and contaminant distribution

    DEFF Research Database (Denmark)

    Lipczynska, Aleksandra; Kaczmarczyk, Jan; Melikov, Arsen Krikor

    2014-01-01

    In a simulated two persons’ office room inhaled air quality and contaminant distribution provided with personalized ventilation combined with chilled ceiling, mixing ventilation only, chilled ceiling with mixing ventilation and chilled ceiling with mixing and personalized ventilation was studied...... people (exhaled air, bioeffluents) and building materials (wall painting). Personalized ventilation combined with chilled ceiling ensured highest air quality at the workstation under all conditions. Pollutant concentration in the occupied zone away from the workstations did not differ substantially...... between the tested systems. Chilled ceiling combined with personalized ventilation working as the only air supplying system may be optimal solution in many buildings....

  17. Knowing fans, knowing music : an exploration of fan interaction on Twitter

    OpenAIRE

    McCollum, Nick

    2011-01-01

    In this thesis, I examine what "knowing music" means to participants in online social musicking activities, along with the role Twitter plays in this process. I compare the way I came to "know" music through social networks with others' behaviors regarding music and social networking. Using Henry Jenkins's research framework as an aca-fan (a portmanteau word combining academic and fan), I study fan communities from the inside out. I begin by outlining my story of coming to know the music that...

  18. PICNIC - FANS, ULTRAS AND HOOLIGANS - INTERNAL DIFFERENTIATE OF SUBCULTURE GROUP FOOTBALL FANS IN POLAND

    Directory of Open Access Journals (Sweden)

    Maciej Solinski

    2006-01-01

    Full Text Available This article is a main part of "Internal differentiate of subculture group of football fans in Poland" project. Author has tried to show how the subculture of football fans can be differentiate. Author ha presented three different subgroups of Polish fans. It is very important to divide this subculture, because each subgroup has different mentality and style. That is why I have paid the most attention on this element.

  19. Hardware Locks with Priority Ceiling Emulation for a Java Chip-Multiprocessor

    DEFF Research Database (Denmark)

    Strøm, Torur Biskopstø; Schoeberl, Martin

    2015-01-01

    According to the safety-critical Java specification, priority ceiling emulation is a requirement for implementations, as it has preferable properties, such as avoiding priority inversion and being deadlock free on uni-core systems. In this paper we explore our hardware supported implementation...... of priority ceiling emulation on the multicore Java optimized processor, and compare it to the existing hardware locks on the Java optimized processor. We find that the additional overhead for priority ceiling emulation on a multicore processor is several times higher than simpler, non-premptive locks, mainly...

  20. Performance analysis of a new design of office diffuse ceiling ventilation system

    DEFF Research Database (Denmark)

    Fan, Jianhua; Hviid, Christian Anker; Yang, Honglu

    2013-01-01

    This paper aims to document and analyse performance of a new design of diffuse ceiling ventilation system in a typical office room. A full scale measurement is carried out in a climate chamber with an office setup at the Technical University of Denmark. Indoor air temperatures, air speeds, wall...... surface temperatures, pressure loss of the ceiling and ventilation effectiveness are measured for an air change rate of 3.5 h-1 and 5.1 h -1 respectively. A computational fluid dynamics model of the office with the diffuse ceiling ventilation system is built and validated by the full scale measurement...

  1. Does the Glass Ceiling Exist?: A Cross-National Perspective on Gender Income Mobility

    OpenAIRE

    Ira N. Gang; John S. Landon-Lane; Yun, Myeong-Su

    2003-01-01

    We compare male and female upward labor income mobility in Germany and the United States using the GSOEP-PSID Cross-National Equivalent File. Our main interest is to test whether a glass ceiling exists for women. Conventional thinking about the glass ceiling highlights the belief that the playing field is level for women and men in the labor market up to a certain point, after which there is an effective limit on advancement for women. We examine the glass ceiling hypothesis by looking at the...

  2. Does the Glass Ceiling Exist? A Cross-National Perspective on

    OpenAIRE

    Ira N. Gang; John S. Landon-Lane; Yun, Myeong-Su

    2003-01-01

    We compare male and female upward labor income mobility in Germany and the United States using the GSOEP-PSID Cross National Equivalent File. Our main interest is to test whether a glass ceiling exists for women. The standard glass ceiling hypothesis highlights the belief that the playing field is level for women and men in the labor market up to a point, after which there is an effective limit on advancement for women. We examine the glass ceiling hypothesis by looking at the dynamics of the...

  3. Thermal environment and air quality in office with personalized ventilation combined with chilled ceiling

    DEFF Research Database (Denmark)

    Lipczynska, Aleksandra; Kaczmarczyk, Jan; Melikov, Arsen Krikor

    2015-01-01

    The thermal environment and air quality conditions provided with combined system of chilled ceiling and personalized ventilation (PV) were studied in a simulated office room for two occupants. The proposed system was compared with total volume HVAC solutions used today, namely mixing ventilation...... and chilled ceiling combined with mixing ventilation. The objective of the study was to evaluate whether PV can be the only ventilation system in the rooms equipped with chilled ceiling. The room air temperature was 26°C in cases with traditional systems and 28°C when PV was used. PV supplied air with...

  4. Synchronous and Cogged Fan Belt Performance Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Cutler, D.; Dean, J.; Acosta, J.

    2014-02-01

    The GSA Regional GPG Team commissioned the National Renewable Energy Laboratory (NREL) to perform monitoring of cogged V-belts and synchronous belts on both a constant volume and a variable air volume fan at the Byron G. Rodgers Federal Building and U.S. Courthouse in Denver, Colorado. These motor/fan combinations were tested with their original, standard V-belts (appropriately tensioned by an operation and maintenance professional) to obtain a baseline for standard operation. They were then switched to the cogged V-belts, and finally to synchronous belts. The power consumption by the motor was normalized for both fan speed and air density changes. This was necessary to ensure that the power readings were not influenced by a change in rotational fan speed or by the power required to push denser air. Finally, energy savings and operation and maintenance savings were compiled into an economic life-cycle cost analysis of the different belt options.

  5. Quiet, High-Efficiency Vaneaxial Fans Project

    Data.gov (United States)

    National Aeronautics and Space Administration — During this Phase I effort, CRG proposes to demonstrate the ability to significantly reduce the acoustic signature of vaneaxial fans by establishing quiet...

  6. Mexican Fan Palm - Orange Co. [ds350

    Data.gov (United States)

    California Department of Resources — This dataset provides the known distribution of Mexican fan palm (Washingtonia robusta) in southern Orange County. The surveys were conducted from May to June, 2007...

  7. Active Vibration Reduction of Titanium Alloy Fan Blades (FAN1) Using Piezoelectric Materials

    Science.gov (United States)

    Choi, Benjamin; Kauffman, Jeffrey; Duffy, Kirsten; Provenza, Andrew; Morrison, Carlos

    2010-01-01

    The NASA Glenn Research Center is developing smart adaptive structures to improve fan blade damping at resonances using piezoelectric (PE) transducers. In this paper, a digital resonant control technique emulating passive shunt circuits is used to demonstrate vibration reduction of FAN1 Ti real fan blade at the several target modes. Single-mode control and multi-mode control using one piezoelectric material are demonstrated. Also a conceptual study of how to implement this digital control system into the rotating fan blade is discussed.

  8. Notes on GIT-fans for quivers

    OpenAIRE

    Chindris, Calin

    2008-01-01

    These are notes on the construction of the GIT-fans for quivers without oriented cycles. We follow closely the steps outlined by N. Ressayre in "The GIT-Equivalence for G-Line Bundles" (Geometriae Dedicata, Volume 81, Numbers 1-3, 2000). A simple construction of the GIT-fan for normal, affine G-varities has been recently given by Ivan V. Arzhantsev and Juergen Hausen in "Geometric Invariant Theory via Cox Rings"

  9. Wordplay, mindplay: fan fiction and postclassical narratology

    OpenAIRE

    Van Steenhuyse, Veerle

    2014-01-01

    Recent narrative theories on story worlds, or the worlds evoked by narratives, call attention to the process of fan reading and the role which the canon plays in that process. This paper posits that such theories can help us understand literary techniques that make a difference on the level of the reading experience that is implied by fan fiction texts. This is illustrated with a close reading of Naguabo's "The Mother of All Marriage Proposals," a Jane Austen fic.

  10. Fan affinity laws from a collision model

    International Nuclear Information System (INIS)

    The performance of a fan is usually estimated using hydrodynamical considerations. The calculations are long and involved and the results are expressed in terms of three affinity laws. In this paper we use kinetic theory to attack this problem. A hard sphere collision model is used, and subsequently a correction to account for the flow behaviour of air is incorporated. Our calculations prove the affinity laws and provide numerical estimates of the air delivery, thrust and drag on a rotating fan. (paper)

  11. Experimental Investigation of the Thermal Performance of Piezoelectric Fans

    OpenAIRE

    Acikalin, Tolga; Wait, Sydney M.; Garimella, S V; Raman, Arvind

    2004-01-01

    Piezoelectric fans are investigated as a cooling technology for the thermal management of electronic devices. Flow visualization experiments are conducted to better understand the physics of fan operation. Prototypes of the fans are built and tested to assess their feasibility and cooling performance and determine optimal locations for the fans. An enclosure the size of a cellular phone and a commercially available laptop computer are used to demonstrate the cooling feasibility of the fans. P...

  12. Investigating for failure of central ventilation fan blade

    International Nuclear Information System (INIS)

    During the operation, central ventilation fan stopped when switch 'on' condition. When central ventilation fan disassemble, ten blades of fan fractured. We have searched cause of failure. We had modeling one of the fan blades and analysis with computer programs. Thus we have find that fracture of central ventilation fan blades is alternative stress and vibration at hub. In this paper, we have described cause of failure

  13. Evaluation of recycled tiles and OSB ceiling materials in closed broiler house prototypes

    Directory of Open Access Journals (Sweden)

    JCM Cravo

    2009-12-01

    Full Text Available This study aimed at evaluating the thermal performance of a modular ceiling system for poultry houses. The reduced- and distorted-scale prototypes used ceiling modules made of reforested wood and were covered with recycled long-life package tiles. The following parameters were measured for 21 days: tile internal surface temperature (ST, globe temperature and humidity index (WBGT, and radiant heat load (RHL. Measurements were made at times of highest heat load (11:00 am, 13:00 pm, and 03:00 pm. Collected data were analyzed by "R" statistics software. Means were compared by multiple comparison test (Tukey and linear regression was performed, both at 5% significance level. The results showed that the prototype with the ceiling was more efficient to reduce internal tile surface temperature; however, this was not sufficient to provide a comfortable environment for broilers during the growout. Therefore, other techniques to provide proper cooling are required in addition to the ceiling.

  14. Modeling of a hydronic ceiling system and its environment as energetic auditing tool

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca Diaz, Nestor [Universidad Tecnologica de Pereira, Facultad de Ingenieria Mecanica (Colombia); University of Liege Belgium, Thermodynamics Laboratory Campus du Sart Tilman - Bat: B49 - P33, B-4000 Liege (Belgium)

    2011-03-15

    As a part of a commissioning study, the chilled ceiling system of a large commercial building located in Belgium is evaluated. A representative office has been instrumented and data on the chilled ceiling system operating in real conditions have been collected. The simulation of the whole system is performed by means of a transient thermal model of the building and its HVAC system. The model considers the hydronic panels as a transient-state finned heat exchanger connected to a simplified lumped transient model of the building. The behavior of the hydronic ceiling system and the interactions with its environment (walls, ventilated facade, internal loads and ventilation system) has been experimentally and numerically evaluated. Commissioning test results show that the influence of surfaces temperatures inside the room, especially the facade, is considerable. Then, it is clear that the hydronic ceiling system must be evaluated together with its designed environment and not as a separate HVAC equipment. (author)

  15. Diffuse Ceiling Ventilation and the Influence of Room Height and Heat Load Distribution

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm; Vilsbøll, Rasmus W; Liu, Li;

    2015-01-01

    Diffuse ceiling (inlet) ventilation is an air distribution system that supplies air from the entire ceiling surface, giving a low supply velocity. The flow pattern in the room is controlled by the heat sources. The system generates high mixing flow and the air velocities in the room are expected to...... be not much influenced by the flow rate to the room but dependent on the heat load. Previous studies have shown that diffuse ceiling ventilation has an ability to remove large heat loads without compromising the indoor climate. However, recent experiments indicate that the maximum accepted heat load...... decreases with a large room height and it decreases in connection with certain heat load distributions. Room geometries and heat load distributions that are optimal for diffuse ceiling ventilation are discussed. A simplified design procedure is introduced....

  16. Sustainability assessment of a lightweight biomimetic ceiling structure

    International Nuclear Information System (INIS)

    An intensive and continuous debate centres on the question of whether biomimetics has a specific potential to contribute to sustainability. In the context of a case study, the objective of this paper is to contribute to this debate by presenting the first systematic approach to assess the sustainability of a complex biomimetic product. The object of inquiry is a lecture hall's ribbed slab. Based on criteria suggested by the Association of German Engineers (VDI), it has been verified that the slab has been correctly defined as biomimetic. Moreover, a systematic comparative product sustainability assessment has been carefully carried out. For purposes of comparison, estimated static calculations have been performed for conceivable current state-of-the-art lightweight ceiling structures. Alternative options are a hollow article slab and a pre-stressed flat slab. Besides a detailed benefit analysis and a discussion of social effects, their costs have also been compared. A particularly detailed life cycle assessment on the respective environmental impacts has also been performed. Results show that the biomimetic ribbed slab built in the 1960s is able to keep up with the current state-of-the-art lightweight solutions in terms of sustainability. These promising results encourage a systematic search for a broad range of sustainable biomimetic solutions. (paper)

  17. Sustainability assessment of a lightweight biomimetic ceiling structure.

    Science.gov (United States)

    Antony, Florian; Grießhammer, Rainer; Speck, Thomas; Speck, Olga

    2014-03-01

    An intensive and continuous debate centres on the question of whether biomimetics has a specific potential to contribute to sustainability. In the context of a case study, the objective of this paper is to contribute to this debate by presenting the first systematic approach to assess the sustainability of a complex biomimetic product. The object of inquiry is a lecture hall's ribbed slab. Based on criteria suggested by the Association of German Engineers (VDI), it has been verified that the slab has been correctly defined as biomimetic. Moreover, a systematic comparative product sustainability assessment has been carefully carried out. For purposes of comparison, estimated static calculations have been performed for conceivable current state-of-the-art lightweight ceiling structures. Alternative options are a hollow article slab and a pre-stressed flat slab. Besides a detailed benefit analysis and a discussion of social effects, their costs have also been compared. A particularly detailed life cycle assessment on the respective environmental impacts has also been performed. Results show that the biomimetic ribbed slab built in the 1960s is able to keep up with the current state-of-the-art lightweight solutions in terms of sustainability. These promising results encourage a systematic search for a broad range of sustainable biomimetic solutions. PMID:24503487

  18. The glass ceiling in China: 'it is a virtue for women to have no capability'

    OpenAIRE

    Pilbeam, Stephen; Huang, Y.

    2013-01-01

    This MSc Business and Management Dissertation research examined obstacles that women face in business and management, the reasons for the 'glass ceiling', the strategies being used to access senior positions and the HR strategies adopted by employers to address the 'glass ceiling'. Fundamentally, it is focused on the challenges faced by women in aspiring to senior management positions in a Chinese context. There is evidence to suggest that HR practice is being westernised, principally driven ...

  19. What Are the "Glass Ceiling" Barriers Effects on Women Career Progress in Jordan?

    OpenAIRE

    Excimirey Amer Al-Manasra

    2013-01-01

    The purpose of this paper is to explore the impact of the glass ceiling barriers represented by the organizationalpractices and the existence of male culture, and the impact of family, social commitments on women careerprogress in Jordan.A sample of – working mid-level women managers in Jordan are selected to answer a questionnaire on glassceiling barriers and family and social commitments. The results showed that the impact of the glass ceiling ismore significant than the impact of family an...

  20. Prediction of Indoor Airflow Patterns in Livestock Buildings Ventilated through a Diffuse Ceiling

    DEFF Research Database (Denmark)

    Jacobsen, L.; Nielsen, Peter Vilhelm; Morsing, S.

    2004-01-01

    The airflow conditions in an experimental pig housing unit are examined both experimentally and numerically (simulation) with particular focus on the airflow conditions in the occupational zone of the animals. Two heating setups are used, and the temperature is measured in a horizontal profile at...... the floor and at the ceiling. Good concordances between the measurements and the simulations are reached at the floor level. At the ceiling level, the conformity to the measuring results is unsatisfactory...

  1. WOMEN, GLASS CEILING, AND PROFESSIONALIZATION IN FAMILY SMEs: A MISSED LINK

    OpenAIRE

    LUCREZIA SONGINI; LUCA GNAN

    2009-01-01

    Literature and practical evidence on the glass ceiling have showed that women's presence in ownership does not ensure that they can significantly influence firm decisional processes. Similarly women's presence in governance roles does not entail glass ceiling removal, even in family firms, which are expected to be a more favorable context.Moreover, literature on women's role in family firms has focused mostly on women's expectations, values, and objectives, on the decision-making processes le...

  2. MAINTENANCE CONSIDERATION IN SPECIAL ELEVATOR CAR ENGINEERING AND CONCEPT DESIGN FOR FIXING OF HEAVY LOWERED CEILINGS

    OpenAIRE

    Nguyen, Hiep

    2014-01-01

    The thesis objectives comprise of two major parts; one is to present design guidelines for friendlier maintenance in elevator cars, the other is to intro-duce concept designs of fixing mechanism of the lowered ceiling in special elevator car. KONE Industrial Ltd. is the commissioning organization of the dissertation. The obtained results are expected to improve main-tainability in the design of the elevator car; on the other hand, new fixing solutions of the ceiling can meet requirements of ...

  3. Development of LED Ceiling Light%LED天花灯的研制

    Institute of Scientific and Technical Information of China (English)

    刘光熙; 朱月华; 杨宝东

    2011-01-01

    介绍LED天花灯的结构组成,通过对其主要配件进行测试和分析,提出如何提高LED天花灯性能的建议。%This article introduces the structure of LED ceiling light,and presents some suggestions for improving the performance of LED ceiling light based on the testing and analyses.

  4. THE GLASS CEILING: STRUCTURAL, CULTURAL AND ORGANIZATIONAL CAREER BARRIERS FOR FRENCH AND TURKISH WOMEN EXECUTIVES

    OpenAIRE

    Cansu Akpinar-Sposito

    2013-01-01

    Abstract: This study is particularly focused on the glass ceiling issues and the main career obstacles for female executives based on the findings of a cross-country comparative study between Turkey and France. Prior to collecting the required data, a review was carried out in both countries, the current available and attitudinal studies related to the concept of the 'glass ceiling'. A comparative descriptive analysis was conducted to show differences in career barriers for women between coun...

  5. Do female researchers face a glass ceiling in France? A hazard model of promotions

    OpenAIRE

    Sabatier, Mareva; Carrère, Myriam

    2010-01-01

    Abstract The present article examines whether French female researchers face a glass ceiling, an invisible barrier to promotion. Using an original database from the National Institute for Agricultural Research, we estimate duration models for promotions. The methodology used allowed us to take into account censored observations and unobserved heterogeneity. Our results show a significant gender effect that does not contradict the glass-ceiling hypothesis. In addition, factors that ...

  6. The Glass Ceiling: Structural, Cultural and Organizational Career Barriers for French and Turkish Women Executives

    OpenAIRE

    Akpinar-Sposito, Cansu

    2013-01-01

    Abstract: This study is particularly focused on the glass ceiling issues and the main career obstacles for female executives based on the findings of a cross-country comparative study between Turkey and France. Prior to collecting the required data, a review was carried out in both countries, the current available and attitudinal studies related to the concept of the 'glass ceiling'. A comparative descriptive analysis was conducted to show differences in career barriers for women between coun...

  7. The relationship between glass ceiling and power distance as a cultural variable by a new method

    OpenAIRE

    Naide Jahangirov; Guler Saglam Ari; Seymur Jahangirov; Nuray Guneri Tosunoglu

    2015-01-01

    Glass ceiling symbolizes a variety of barriers and obstacles that arise from gender inequality at business life. With this mind, culture influences gender dynamics. The purpose of this research was to examine the relationship between the glass ceiling and the power distance as a cultural variable within organizations. Gender variable is taken as a moderator variable in relationship between the concepts. In addition to conventional correlation analysis, we employed a new method to investigate ...

  8. Cooling ceilings: Five shape the market; Kuehldecken: Fuenf praegen den Markt

    Energy Technology Data Exchange (ETDEWEB)

    Leisering, F. [Kosmos Kommunikation und Marketing gGmbH (Germany); Lohmueller, S.; Koob, C. [zehnvier Marketingberatung (Switzerland)

    2007-10-15

    The German market for cooling ceilings as well as the current competitive situation are difficult to be understood. Thus, the consulting companies Kosmos Kommunikation und Marketing gGmbH' (Osnabrueck, Federal Republic of Germany) and zehnvier Marketingberatung (Zurich, Switzerland) have compiled a model in order to structure the competition landscape and the market system for cooling ceilings clearer. The contribution under consideration reports on the fundamental considerations according this model, on the assembly as well as utilization of this model.

  9. Fan relationship management in football - going beyond traditional product offerings to win the hearts of fans

    DEFF Research Database (Denmark)

    Cortsen, Kenneth

    2015-01-01

    The management and control of fan relations should go beyond a football club’s traditional product and service offerings and touch the important experiential side of the football economy. This will create a stronger platform to optimize ROI, ROE and ROO relating to different fan segments....

  10. Use of Twitter usage by club fans

    Directory of Open Access Journals (Sweden)

    Selami Özsoy

    2012-09-01

    Full Text Available Social networking sites which are Web 2.0 applications have become widespread and there are of usage has increased. The study aims to investigate the purpose of using the social networking site, Twitter by club fans. The sample of the study is composed of fans from Spor Toto (Turkish football pool Football Super League Clubs Galatasaray and Trabzonspor with registered official Twitter accounts. A 20-item data collection tool was developed in line with the literature and expert views and was published in an internet site for a whole month in August. The views of the 452 fans that filled in the form were analyzed. Results show that the new social networking site Twitter has been mostly followed by males between 18-24 ages that are fans of sports clubs. Fans have stated that they mostly follow Twitter in order to learn about the views of footballers and sports managers. Its interactive features and provision of direct and reliable information by Twitter have been stated as the reasons of high preferences for Twitter compared with the other medias.

  11. 2D and 3D GPR imaging of structural ceilings in historic and existing constructions

    Science.gov (United States)

    Colla, Camilla

    2014-05-01

    GPR applications in civil engineering are to date quite diversified. With respect to civil constructions and monumental buildings, detection of voids, cavities, layering in structural elements, variation of geometry, of moisture content, of materials, areas of decay, defects, cracks have been reported in timber, concrete and masonry elements. Nonetheless, many more fields of investigation remain unexplored. This contribution gives an account of a variety of examples of structural ceilings investigation by GPR radar in reflection mode, either as 2D or 3D data acquisition and visualisation. Ceilings have a pre-eminent role in buildings as they contribute to a good structural behaviour of the construction. Primarily, the following functions can be listed for ceilings: a) they carry vertical dead and live loads on floors and distribute such loads to the vertical walls; b) they oppose to external horizontal forces such as wind loads and earthquakes helping to transfer such forces from the loaded element to the other walls; c) they contribute to create the box skeleton and behaviour of a building, connecting the different load bearing walls and reducing the slenderness and flexural instability of such walls. Therefore, knowing how ceilings are made in specific buildings is of paramount importance for architects and structural engineers. According to the type of building and age of construction, ceilings may present very different solutions and materials. Moreover, in existing constructions, ceilings may have been substituted, modified or strengthened due to material decay or to change of use of the building. These alterations may often go unrecorded in technical documentation or technical drawings may be unavailable. In many cases, the position, orientation and number of the load carrying elements in ceilings may be hidden or not be in sight, due for example to the presence of false ceilings or to technical plants. GPR radar can constitute a very useful tool for

  12. PERFORMANCE EVALUATION OF CEILING RADIANT COOLING SYSTEM IN COMPOSITE CLIMATE

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Anuj [Malaviya National Institute of Technology (MNIT), Jaipur, India; Mathur, Jyotirmay [Malaviya National Institute of Technology (MNIT), Jaipur, India; Bhandari, Mahabir S [ORNL

    2015-01-01

    Radiant cooling systems are proving to be an energy efficient solution due to higher thermal capacity of cooling fluid especially for the buildings that require individual zone controls and where the latent loads are moderate. The Conventional air conditioners work at very low temperature i.e.5-8 c (refrigerant evaporator inlet) while the radiant cooling systems, also referred as high temperature cooling system, work at high temperatures i.e. 14-18 c. The radiant cooling systems can maintain lower MRT (Mean Radiant Temperature) as ceiling panels maintain uniform temperature gradient inside room and provide higher human comfort. The radiant cooling systems are relatively new systems and their operation and energy savings potential are not quantified for a large number of buildings and operational parameters. Moreover, there are only limited numbers of whole building simulation studies have been carried out for these systems to have a full confidence in the capability of modelling tools to simulate these systems and predict the impact of various operating parameters. Theoretically, savings achieve due to higher temperature set point of chilled water, which reduces chiller-running time. However, conventional air conditioner runs continuously to maintain requisite temperature. In this paper, experimental study for performance evaluation of radiant cooling system carried out on system installed at Malaviya National Institute of Technology Jaipur. This paper quantifies the energy savings opportunities and effective temperature by radiant cooling system at different chilled water flow rates and temperature range. The data collected/ analysed through experimental study will used for calibration and validation of system model of building prepared in building performance simulation software. This validated model used for exploring optimized combinations of key parameters for composite climate. These optimized combinations will used in formulation of radiant cooling system

  13. The mediating role of facebook fan pages.

    Science.gov (United States)

    Chih, Wen-Hai; Hsu, Li-Chun; Wang, Kai-Yu; Lin, Kuan-Yu

    2014-01-01

    Using the dual mediation hypothesis, this study investigates the role of interestingness (the power of attracting or holding one's attention) attitude towards the news, in the formation of Facebook Fan Page users' electronic word-of-mouth intentions. A total of 599 Facebook fan page users in Taiwan were recruited and structural equation modeling (SEM) was used to test the research hypotheses. The results show that both perceived news entertainment and informativeness positively influence interestingness attitude towards the news. Interestingness attitude towards the news subsequently influences hedonism and utilitarianism attitudes towards the Fan Page, which then influence eWOM intentions. Interestingness attitude towards the news plays a more important role than hedonism and utilitarianism attitudes in generating electronic word-of-mouth intentions. Based on the findings, the implications and future research suggestions are provided. PMID:24875695

  14. ANALYTICAL METHODS FOR CALCULATING FAN AERODYNAMICS

    Directory of Open Access Journals (Sweden)

    Jan Dostal

    2015-12-01

    Full Text Available This paper presents results obtained between 2010 and 2014 in the field of fan aerodynamics at the Department of Composite Technology at the VZLÚ aerospace research and experimental institute in Prague – Letnany. The need for rapid and accurate methods for the preliminary design of blade machinery led to the creation of a mathematical model based on the basic laws of turbomachine aerodynamics. The mathematical model, the derivation of which is briefly described below, has been encoded in a computer programme, which enables the theoretical characteristics of a fan of the designed geometry to be determined rapidly. The validity of the mathematical model is assessed continuously by measuring model fans in the measuring unit, which was developed and manufactured specifically for this purpose. The paper also presents a comparison between measured characteristics and characteristics determined by the mathematical model as the basis for a discussion on possible causes of measured deviations and calculation deviations.

  15. Sediment sound velocities from sonobuoys: Arabian fan

    Energy Technology Data Exchange (ETDEWEB)

    Bachman, R.T.; Hamilton, E.L.

    1980-02-10

    Eight variable-angle seismic reflection stations in the Arabian Fan, Northwestern Indian Ocean, provided 40 determinations of sound velocity in sediment and sedimentary rock. Sound velocity in the homogeneous, largely terrigenous fan increases smoothly with depth. Regression analysis yielded the velocity-time relationship V (km/s)=1.510+1.863t, where V is instantaneous velocity and t is one-way travel time below the sea floor to 1 s. The velocity-depth function is V (km/s)=1.510+1.200h-0.253h/sup 2/+ 0.034h/sup 3/, where h is subbottom depth in km.

  16. Experimental alluvial fans: Advances in understanding of fan dynamics and processes

    Science.gov (United States)

    Clarke, Lucy E.

    2015-09-01

    Alluvial fans are depositional systems that develop because of a disparity between the upstream and downstream sediment transport capacity of a system, usually at the base of mountain fronts as rivers emerge from the constrained mountain area onto the plain. They are dynamic landforms that are prone to abrupt changes on a geomorphological (decades to centuries) time scale, while also being long-term deposition features that preserve sedimentary strata and are sensitive indictors of environmental change. The complexity of interactions between catchment characteristics, climate, tectonics, internal system feedbacks, and environmental processes on field alluvial fans means that it is difficult to isolate individual variables in a field setting; therefore, the controlled conditions afforded by experimental models has provided a novel technique to overcome some of these complexities. The use of experimental models of alluvial fans has a long history and these have been implemented over a range of different research areas utilising various experimental designs. Using this technique, important advances have been made in determining the primary factors influencing fan slope, understanding of avulsion dynamics, identifying autogenic processes driving change on fan systems independent of any change in external conditions, and the mechanics of flow and flood risk on alluvial fans, to name a few. However, experiments cannot be carried out in isolation. Thus, combining the findings from experimental alluvial fans with field research and numerical modelling is important and, likewise, using these techniques to inform experimental design. If this can be achieved, there is potential for future experimental developments to explore key alluvial fan issues such as stratigraphic preservation potential and simulating extra terrestrial fan systems.

  17. Glass Ceiling in the Workplace: An Analysis within the Stated-owned Enterprises and Multi-national Enterprises in China

    OpenAIRE

    Cao, Mengxi

    2015-01-01

    Currently, although the increasingly number of women has gained leadership positions, the glass ceiling phenomenon still exists in China, especially in multi-national enterprise. In brief, the road to the upper rungs for female is still challenging and difficult. Due to the nature of the enterprises, the performance of glass ceiling is different. The aim of this dissertation is to discuss different performance and influence of glass ceiling in the context of the multi-national enterprises (MN...

  18. Steady and transient CFD analysis of automotive fans

    Energy Technology Data Exchange (ETDEWEB)

    Damodaran, V. [General Motors, Pontiac Product Center, Pontiac, Michigan (United States)]. E-mail: vijay.damodaran@gm.com; Danciu, J. [Optimal CAE, Inc., Novi, Michigan (United States)]. E-mail: john.danciu@gm.com

    2002-07-01

    The objective of this paper is to study different approaches in the numerical generation of fan curves. A steady state approximation of the fan using a Multiple Reference Frame (MRF) method is the most common CFD approach to generate fan curves. In this paper both the MRF method of modeling the fan and a fully transient model of the fan with moving mesh were created to compare the differences between the two approaches. A methodology to compute the system resistance at a particular vehicle speed using fan curves is also discussed. One advantage of doing a transient analysis is to determine velocity and pressure signals downstream of the fan. These signals are transformed into the frequency domain using Fast Fourier Transforms (FFT). The peak signal frequencies showed a strong correlation to the blade passing frequency and the fan rpm. (author)

  19. Steady and transient CFD analysis of automotive fans

    International Nuclear Information System (INIS)

    The objective of this paper is to study different approaches in the numerical generation of fan curves. A steady state approximation of the fan using a Multiple Reference Frame (MRF) method is the most common CFD approach to generate fan curves. In this paper both the MRF method of modeling the fan and a fully transient model of the fan with moving mesh were created to compare the differences between the two approaches. A methodology to compute the system resistance at a particular vehicle speed using fan curves is also discussed. One advantage of doing a transient analysis is to determine velocity and pressure signals downstream of the fan. These signals are transformed into the frequency domain using Fast Fourier Transforms (FFT). The peak signal frequencies showed a strong correlation to the blade passing frequency and the fan rpm. (author)

  20. Alluvial Fan Study Submission for UMATILLA COUNTY, OREGON

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Alluvial fan study data as defined in FEMA Guidelines and Specifications, Appendix G: Guidance for Alluvial Fan Flooding Analyses and Mapping

  1. Improving Fan System Performance: A Sourcebook for Industry

    Energy Technology Data Exchange (ETDEWEB)

    None

    2003-04-01

    This is one of a series of sourcebooks on motor-driven equipment produced by the Industrial Technologies Program. It provides a reference for industrial fan systems users, outlining opportunities to improve fan system performance.

  2. Experimental study of diffuse ceiling ventilation coupled with a thermally activated building construction in an office room

    DEFF Research Database (Denmark)

    Zhang, Chen; Heiselberg, Per Kvols; Pomianowski, Michal Zbigniew;

    2015-01-01

    This paper presents and analyses the performance of an integrated system with diffuse ceiling ventilation and a thermally activated building construction. A full-scale experiment is carried out in a hot box with an office setup. The performance of the integrated system is evaluated under different...... boundary conditions, considering different weather conditions, internal heat loads, TABS activation modes and with/without diffuse ceiling. The measurement results indicate that the diffuse ceiling plays a beneficial role improving thermal comfort in the occupied zone. However, the diffuse ceiling has the...

  3. Effect of natural ventilation and wind direction on the thermal performance of a building ceiling

    Energy Technology Data Exchange (ETDEWEB)

    Abdel Aziz Ali, Ali [Banha Univ. (Egypt). Shoubra Faculty of Engineering; Nabil Milad, Guirguis; Mahmoud Aly, Hassan [Housing and Building Research Center, Cairo (Egypt)

    2008-07-01

    Natural ventilation is rapidly becoming a significant part in the design strategy of buildings in situations where electricity is scare or non-existent and saving energy becomes highly important. The aim of present work is to reduce the ceiling temperature by natural ventilation through different opening locations (one window in the front facade and the other window in the rear wall) with sill height ratios of 0.27, 0.36, 0.45, 0.54, and 0.63. Wind tunnel and smoke tunnel were used to investigate the effect of opening locations on the temperature and heat transfer coefficient of a ceiling of a naturally-ventilated room. Here, the ANSYS CFD software was used to determine the flow characteristics in the ventilated room with different opening locations and wind direction. Better flow pattern and heat transfer from the heated ceiling are observed when the front and rear openings are located nearest to the ceiling and center, respectively. An experimental correlation was obtained to predict the influence of sill opening height ratio of front and rear walls on the average heat transfer coefficient ratio of ceiling (h{sub av} / h{sub o}) where (h{sub o}) is the heat transfer coefficient in case of no wind. (orig.)

  4. Piezoelectric Fans using Higher Flexural Modes for Electronics Cooling Applications

    OpenAIRE

    Wait, Sydney M.; Basak, Sudipta; Garimella, S V; Raman, Arvind

    2007-01-01

    Piezoelectric fans are gaining in popularity as low-power-consumption and low-noise devices for the removal of heat in confined spaces. The performance of piezoelectric fans has been studied by several authors, although primarily at the fundamental resonance mode. In this article the performance of piezoelectric fans operating at the higher resonance modes is studied in detail. Experiments are performed on a number of commercially available piezoelectric fans of varying length. Both finite elem...

  5. Key drivers of consumer loyalty to Facebook fan pages

    OpenAIRE

    Ruiz Mafé, Carla; MARTÍ PARREÑO, JOSÉ; Sanz Blas, Silvia

    2014-01-01

    With the rapid expansion of social networking sites, researchers and practitioners are challenged to understand drivers of customer loyalty in fan pages. The purpose of this paper is to identify the main drivers of Facebook fan page loyalty in order to promote the creation of affective links and long-term relationships with users. The impact of trust, fan page content dependency, attitude and consumer beliefs on loyalty to fan pages was tested through structural equation modelling techniques....

  6. Fan-beam intensity modulated proton therapy

    OpenAIRE

    Hill, Patrick; Westerly, David; Mackie, Thomas

    2013-01-01

    Purpose: This paper presents a concept for a proton therapy system capable of delivering intensity modulated proton therapy using a fan beam of protons. This system would allow present and future gantry-based facilities to deliver state-of-the-art proton therapy with the greater normal tissue sparing made possible by intensity modulation techniques.

  7. 30 CFR 57.8519 - Underground main fan controls.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Underground main fan controls. 57.8519 Section... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Ventilation Surface and Underground § 57.8519 Underground main fan controls. All underground main fans...

  8. Alcohol-Related Fan Behavior on College Football Game Day

    Science.gov (United States)

    Glassman, Tavis; Werch, Chudley E.; Jobli, Edessa; Bian, Hui

    2007-01-01

    High-risk drinking on game day represents a unique public health challenge. Objective: The authors examined the drinking behavior of college football fans and assessed the support for related interventions. Participants: The authors randomly selected 762 football fans, including college students, alumni, and other college football fans, to…

  9. 76 FR 50739 - Hung Ta Fan: Debarment Order

    Science.gov (United States)

    2011-08-16

    ... bases this order on a finding that Mr. Fan was convicted of a felony under Federal law for conduct relating to the importation into the United States of an article of food. Mr. Fan was given notice of the.... As of July 13, 2011 (30 days after receipt of the notice), Mr. Fan had not responded. Mr....

  10. Regenerative Blower for EVA Suit Ventilation Fan

    Science.gov (United States)

    Izenson, Michael G.; Chen, Weibo; Paul, Heather L.

    2010-01-01

    Portable life support systems in future space suits will include a ventilation subsystem driven by a dedicated fan. This ventilation fan must meet challenging requirements for pressure rise, flow rate, efficiency, size, safety, and reliability. This paper describes research and development that showed the feasibility of a regenerative blower that is uniquely suited to meet these requirements. We proved feasibility through component tests, blower tests, and design analysis. Based on the requirements for the Constellation Space Suit Element (CSSE) Portable Life Support System (PLSS) ventilation fan, we designed the critical elements of the blower. We measured the effects of key design parameters on blower performance using separate effects tests, and used the results of these tests to design a regenerative blower that will meet the ventilation fan requirements. We assembled a proof-of-concept blower and measured its performance at sub-atmospheric pressures that simulate a PLSS ventilation loop environment. Head/flow performance and maximum efficiency point data were used to specify the design and operating conditions for the ventilation fan. We identified materials for the blower that will enhance safety for operation in a lunar environment, and produced a solid model that illustrates the final design. The proof-of-concept blower produced the flow rate and pressure rise needed for the CSSE ventilation subsystem while running at 5400 rpm, consuming only 9 W of electric power using a non-optimized, commercial motor and controller and inefficient bearings. Scaling the test results to a complete design shows that a lightweight, compact, reliable, and low power regenerative blower can meet the performance requirements for future space suit life support systems.

  11. An Efficient Ceiling-view SLAM Using Relational Constraints Between Landmarks

    Directory of Open Access Journals (Sweden)

    Hyukdoo Choi

    2014-01-01

    Full Text Available In this paper, we present a new indoor ‘simultaneous localization and mapping’ (SLAM technique based on an upward-looking ceiling camera. Adapted from our previous work [17], the proposed method employs sparsely-distributed line and point landmarks in an indoor environment to aid with data association and reduce extended Kalman filter computation as compared with earlier techniques. Further, the proposed method exploits geometric relationships between the two types of landmarks to provide added information about the environment. This geometric information is measured with an upward-looking ceiling camera and is used as a constraint in Kalman filtering. The performance of the proposed ceiling-view (CV SLAM is demonstrated through simulations and experiments. The proposed method performs localization and mapping more accurately than those methods that use the two types of landmarks without taking into account their relative geometries.

  12. Final report development of a regional nitrogen ceiling; Eindrapportage ontwikkeling regionaal stikstofplafond

    Energy Technology Data Exchange (ETDEWEB)

    Bleeker, A.; Hensen, A. [ECN Environment and Energy Engineering, Petten (Netherlands); Rougoor, C. [Centrum voor Landbouw en Milieu CLM, Culemborg (Netherlands)

    2013-01-15

    The development of a methodology in which integrated nitrogen ceilings can be studied on a regional level is described. Next to the agricultural sector, also other sectors are taken into consideration (traffic, industry, etc.) with respect to the development of the nitrogen ceiling methodology. The study consists of two parts: the feasibility of a nitrogen ceiling system and the actual development of such a system [Dutch] Deze rapportage beschrijft de ontwikkeling van een methodiek waarbij integrale stikstofplafonds op gebiedsniveau kunnen worden bestudeerd. Dit onderzoek beschouwt, naast landbouw, ook andere sectoren (verkeer, industrie, etc.) voor het ontwikkelen van de stikstofplafond methodiek. Het onderzoek bestaat uit twee onderdelen: bestuderen van de haalbaarheid van een stikstofplafond systematiek en het feitelijke ontwikkelen van een dergelijke systematiek.

  13. Integrated Solution in an Office Room with Diffuse Ceiling Ventilation and Thermally Activated Building Constructions

    DEFF Research Database (Denmark)

    Zhang, Chen; Heiselberg, Per Kvols; Pomianowski, Michal Zbigniew;

    2015-01-01

    An integrated system is proposed in this study to combine diffuse ceiling ventilation with a thermally activated building construction (TABS), aiming to provide cooling/ heating and ventilation to an office room all year around. The performance of the integrated system is evaluated by full......-scale experiments in a climate chamber. The experimental results indicate that diffuse ceiling can significantly improve thermal comfort in the occupied zone, by reducing draught risk and vertical temperature gradient. The linear function between pressure drop and air change rate points out that the air flow...... through diffuse ceiling is laminar. A thermal decay is found in the plenum air and the thermal performance of TABS may be influenced by water flow and air flow direction....

  14. Experimental study of perforated suspended ceilings as diffuse ventilation air inlets

    DEFF Research Database (Denmark)

    Hviid, Christian Anker; Svendsen, Svend

    2013-01-01

    An experimental study is reported in this paper for a diffuse ceiling ventilation concept. The analyses were carried out with two different porous surfaces mounted in a suspended ceiling: perforated tiles of aluminium and of gypsum. Ventilation air was supplied above the suspended ceiling...... effectively creating a plenum for air distribution. The experiments were carried out in a climatic chamber and documented an air change efficiency equal to fully mixed conditions with a pressure drop of 0.5–1.5Pa and with no evidence of thermal discomfort. The magnitude of the pressure drop was enough to...... surface which increases the potential and applicability of the concept. Risk of thermal discomfort was not disclosed but the study did show evidence of large fluctuating air movements which could stem from transient behaviour creating sensations of draught to the occupants....

  15. Validation of a numerical model of acoustic ceiling combined with TABS

    DEFF Research Database (Denmark)

    Rage, Nils; Kazanci, Ongun Berk; Olesen, Bjarne W.

    2016-01-01

    to understand to which extent a layer of hanging sound absorbers will impede the heating and cooling performance of the system, and how this translates on the thermal comfort for the occupants. In order to address these issues, this study focuses on validation of a new TRNSYS component (Type Ecophon Acoustic...... Elements) developed to simulate partially covered suspended ceilings such as hanging sound absorbers. The tool is validated by numerically modelling a set of similar experiments carried out in full-scale by a previous study. For this, a total of 12 scenarios from two case studies have been modelled......, with varying suspended ceiling coverage ratios, type of suspended ceilings, internal heat gains and TABS water supply temperatures. The results obtained from the simulations are very close to the experimental results. The first set of measurements analyzed the effect of the above-mentioned parameters...

  16. Experimental investigation on ducted counter-rotating axial flow fans

    OpenAIRE

    Nouri, Hussain; Ravelet, Florent; Bakir, Farid; Sarraf, Christophe

    2011-01-01

    An experimental study on counter-rotating axial-flow fans was carried out. The fans of diameter D = 375 mm were designed using an inverse method. The counter-rotating fans operate in a ducted-flow configuration and the overall performances are measured in a normalized test bench. The rotation rate of each fan is independently controlled. The axial spacing between the fans can vary from 10 to 50 mm by steps of 10 mm. The results show that the efficiency is strongly increased compared to a conv...

  17. Separation of the Heat Transfer Components for Diffusion Flames Impinging onto Ceilings

    OpenAIRE

    Wasson, Rachel Ann

    2014-01-01

    Two series of experiments were performed to determine the flow characteristics and to quantify the heat transfer components from a propane diffusion flame impinging onto a ceiling. A 0.3 m square sand burner with propane as the fuel type provided a steady-state fire. In the first series of experiments, measurements of gas temperature and velocity were made at 76 mm vertical intervals above the burner up to the ceiling. Fire heat release rates (HRRs) of 50 kW and 90 kW with free flame lengt...

  18. Gender wage gap and the glass ceiling effect: a firm-level investigation

    OpenAIRE

    Christine Barnet-Verzat; François-Charles Wolff

    2008-01-01

    Purpose – The purpose of this paper is to assess the relevance of the glass ceiling effect, according to which the gender log wage gap accelerates in the upper tail of the wage distribution, at the firm level. Design/methodology/approach – The empirical analysis is based on a sample of 4,654 employees, working in a French private company from the Defence and Aerospace sector. Quantile wage regressions were used to study whether a glass ceiling effect exits at the firm level. The difference be...

  19. Experimental Study of an Integrated System with Diffuse Ceiling Ventilation and Thermally Activated Building Constructions

    DEFF Research Database (Denmark)

    Zhang, Chen; Yu, Tao; Heiselberg, Per;

    of thermal comfort and energy performance. 20 cases with different boundary conditions are conducted varying on climate condition heat load. TABS water temperature and flow rate with or without diffuse ceiling. The energy evaluation includes energy balance of test room and cooling or heating capacity...... of TABS. And the thermal comfort is analyzed by draught rate vertical temperature gradient and radiant temperature asymmetry. Finally the effect of plenum and diffuse ceiling is discussed. This report mainly focuses on the experiment results and discussions. Therefore, some details about the...

  20. The Performance of Diffuse Ceiling Inlet and other Room Air Distribution Systems

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Jakubowska, Ewa

    2009-01-01

    The paper analyses different room air distribution systems, and describes a design chart which can be used for the evaluation of variables as air quality, air velocity and temperature gradient as a function of flow rate and temperature difference in the supply system. The design chart can also be...... ceiling-mounted diffuser with a swirling flow, displacement ventilation from a wall-mounted low velocity diffuser and vertical ventilation from a ceiling-mounted textile inlet. All these systems can be used in the case of cooling of the room....

  1. Effect of façade systems on the performance of cooling ceilings: In situ measurements

    Directory of Open Access Journals (Sweden)

    Katharina Eder

    2015-03-01

    Full Text Available This article presents an innovative façade system designed to increase the thermal comfort inside an office room and to enhance the cooling capacity of the suspended cooling ceiling. A series of measurements is conducted in an existing office building with different façade systems (i.e., a combination of glazing and shading. An innovative façade system is developed based on this intensive set of measurements. The new system enhances the thermal comfort and cooling capacity of the suspended cooling ceiling. The main usage of the new system is the refurbishment and improvement of existing façade systems.

  2. Mentoring Away the Glass Ceiling in Academia: A Cultured Critique edited by Brenda L. H. Marina

    OpenAIRE

    Campos, Magali

    2016-01-01

    Mentoring Away the Glass Ceiling in Academia: A Cultured Critiqued (2015) edited by Brenda L. H. Marina, is a comprehensive examination of women’s experiences in various stages in academia and the way in which mentoring can serve as a tool to break the glass ceiling that keep many women from reaching high positions in academia.Over a qualitative approach this book brings together narratives and counternarratives of women in academia to explore the ways mentorship can help the diversity gap fo...

  3. Fan-beam intensity modulated proton therapy

    International Nuclear Information System (INIS)

    Purpose: This paper presents a concept for a proton therapy system capable of delivering intensity modulated proton therapy using a fan beam of protons. This system would allow present and future gantry-based facilities to deliver state-of-the-art proton therapy with the greater normal tissue sparing made possible by intensity modulation techniques.Methods: A method for producing a divergent fan beam of protons using a pair of electromagnetic quadrupoles is described and particle transport through the quadrupole doublet is simulated using a commercially available software package. To manipulate the fan beam of protons, a modulation device is developed. This modulator inserts or retracts acrylic leaves of varying thickness from subsections of the fan beam. Each subsection, or beam channel, creates what effectively becomes a beam spot within the fan area. Each channel is able to provide 0–255 mm of range shift for its associated beam spot, or stop the beam and act as an intensity modulator. Results of particle transport simulations through the quadrupole system are incorporated into the MCNPX Monte Carlo transport code along with a model of the range and intensity modulation device. Several design parameters were investigated and optimized, culminating in the ability to create topotherapy treatment plans using distal-edge tracking on both phantom and patient datasets.Results: Beam transport calculations show that a pair of electromagnetic quadrupoles can be used to create a divergent fan beam of 200 MeV protons over a distance of 2.1 m. The quadrupole lengths were 30 and 48 cm, respectively, with transverse field gradients less than 20 T/m, which is within the range of water-cooled magnets for the quadrupole radii used. MCNPX simulations of topotherapy treatment plans suggest that, when using the distal edge tracking delivery method, many delivery angles are more important than insisting on narrow beam channel widths in order to obtain conformal target coverage

  4. Characterization of Composite Fan Case Resins

    Science.gov (United States)

    Dvoracek, Charlene M.

    2004-01-01

    The majority of commercial turbine engines that power today s aircraft use a large fan driven by the engine core to generate thrust which dramatically increases the engine s efficiency. However, if one of these fan blades fails during flight, it becomes high energy shrapnel, potentially impacting the engine or puncturing the aircraft itself and thus risking the lives of passengers. To solve this problem, the fan case must be capable of containing a fan blade should it break off during flight. Currently, all commercial fan cases are made of either just a thick metal barrier or a thinner metal wall surrounded by Kevlar-an ultra strong fiber that elastically catches the blade. My summer 2004 project was to characterize the resins for a composite fan case that will be lighter and more efficient than the current metal. The composite fan case is created by braiding carbon fibers and injecting a polymer resin into the braid. The resin holds the fibers together, so at first using the strongest polymer appears to logically lead to the strongest fan case. Unfortunately, the stronger polymers are too viscous when melted. This makes the manufacturing process more difficult because the polymer does not flow as freely through the braid, and the final product is less dense. With all of this in mind, it is important to remember that the strength of the polymer is still imperative; the case must still contain blades with high impact energy. The research identified which polymer had the right balance of properties, including ease of fabrication, toughness, and ability to transfer the load to the carbon fibers. Resin deformation was studied to better understand the composite response during high speed impact. My role in this research was the testing of polymers using dynamic mechanical analysis and tensile, compression, and torsion testing. Dynamic mechanical analysis examines the response of materials under cyclic loading. Two techniques were used for dynamic mechanical analysis

  5. Numerical Aerodynamic Evaluation and Noise Investigation of a Bladeless Fan

    Directory of Open Access Journals (Sweden)

    mohammad jafari

    2015-01-01

    Full Text Available Bladeless fan is a novel fan type that has no observable impeller, usually used for domestic applications. Numerical investigation of a Bladeless fan via Finite Volume Method was carried out in this study. The fan was placed in center of a 4×2×2m room and 473 Eppler airfoil profile was used as cross section of the fan. Performance and noise level of the fan by solving continuity and momentum equations as well as noise equations of Broadband Noise Source (BNS and Ffowcs Williams and Hawkings (FW-H in both steady state and unsteady conditions were studied. Flow increase ratio of the fan was captured. Furthermore, BNS method could find outlet slit of the air as the main source of the noise generation. In order to validation of aeroacousticcode results, a simulation of noise for NACA 0012 airfoil via FW-H method was compared to experimental results and good agreement was obtained.

  6. Fluent-based numerical simulation of flow centrifugal fan

    Institute of Scientific and Technical Information of China (English)

    LI Xian-zhang

    2011-01-01

    Testing centrifugal fan flow field by physical laboratory is difficult because the testing system is complex and the workload is heavy, and the results observed by naked-eye deviates far from the actual value. To address this problem, the computational fluid dynamics software FLUENT was applied to establish three-dimensional model of the centrifugal fan. The numeral model was verified by comparing simulation data to experimental data. The pressure centrifugal fan and the speed changes in distribution in centrifugal fan was simulated by computational fluid dynamics software FLUENT. The simulation results show that the gas flow velocity in the impeller increases with impeller radius increase. Static pressure gradually increases when gas from the fan access is imported through fan impeller leaving fans.

  7. What Do We Know about Glass Ceiling Effects? A Taxonomy and Critical Review to Inform Higher Education Research

    Science.gov (United States)

    Jackson, Jerlando F. L.; O'Callaghan, Elizabeth M.

    2009-01-01

    The concept of "glass ceiling effects" has emerged in social science research in general and higher education in particular over the past 20 years. These studies have described the impediments that women and people of color encounter in their quest for senior-level positions (e.g., CEOs) in society as glass ceiling effects. Literature, both…

  8. 26 CFR 1.501(h)-3 - Lobbying or grass roots expenditures normally in excess of ceiling amount.

    Science.gov (United States)

    2010-04-01

    ... excess of ceiling amount. 1.501(h)-3 Section 1.501(h)-3 Internal Revenue INTERNAL REVENUE SERVICE... § 1.501(h)-3 Lobbying or grass roots expenditures normally in excess of ceiling amount. (a) Scope. This section provides rules under section 501(h) for determining whether an organization that...

  9. DETECTION OF BACTERIAL CYTOTOXIC ACTIVITIES FROM WATER-DAMAGED CEILING TILE MATERIAL FOLLOWING INCUBATION ON BLOOD AGAR

    Science.gov (United States)

    Samples of ceiling tiles with high levels of bacteria exhibited cytotoxic activities on a HEP-2 tissue culture assay. Ceiling tiles containing low levels of bacterial colonization did not show cytotoxic activities on the HEP-2 tissue culture assay. Using a spread plate procedure ...

  10. Market chances for cooling ceilings in Germany. Competence counts; Marktchancen fuer Kuehldecken in Deutschland. Kompetenz der Akteure entscheidet

    Energy Technology Data Exchange (ETDEWEB)

    Lohmueller, S.; Goosmann, T.

    2005-11-01

    After the boom in cooling ceilings in the mid-nineties, interest went down. The market continued quietly, without current information on market volumes. Kosmos of Osnabrueck University made a current study on the German market for cooling ceilings. Excerpts are presented here. (orig.)

  11. Experimental investigation of cooling performance of a novel HVAC system combining natural ventilation with diffuse ceiling inlet and TABS

    DEFF Research Database (Denmark)

    Yu, Tao; Heiselberg, Per Kvols; Lei, Bo;

    2015-01-01

    Highlights •An experimental investigation of cooling performance of a combined HVAC system is carried out. •Cooling performance of TABS with and without the influence of diffuse ceiling is analyzed. •Radiant and convective heat transfer coefficients of TABS cooling are studied. •Cooling components...... from the diffuse ceiling are characterized....

  12. Consequences of ceilings on the use of Kyoto mechanisms. A tentative analysis of cost effects for EU member states

    International Nuclear Information System (INIS)

    To safeguard that domestic actions will be taken to meet commitments, the Kyoto Protocol suggests that domestic action should be the main means for reaching the reduction commitments. Imposing ceilings on the purchase of emission reductions is one of the ways to limit the net use of Kyoto mechanisms. Several kinds of ceilings have been suggested. This analysis gives some insight into the cost consequences for EU Member States that result from different types of ceilings for Kyoto mechanisms. The impacts of ceilings can be very large but the precise impact is difficult to estimate due to uncertainties about the price of emission reductions and the price elasticity of the supply of emission reduction. Consequently, decisions on ceilings on the use of Kyoto mechanisms need to be taken with great care. 7 refs

  13. Energy labeling for electric fans in Malaysia

    International Nuclear Information System (INIS)

    To reduce energy consumption in the residential sector, Malaysia Energy Commission is considering implementing energy labels for household electrical appliances including electric fans in 2005. The purpose of the energy labels is to provide the consumers a guideline to compare the size, features, price and efficiency of the appliance. This paper discusses the energy label for electric fans in this country based on Malaysian Standards developed by a technical committee that reviewed the performance of household electrical appliances. This study includes methodology for the calculation of the energy efficiency star rating and projected energy usage, performance requirements, details of the energy label and the requirements for the valid application in Malaysia. The label also can be adopted for other household electrical appliances with only slight modifications

  14. Fanning the Optimal Breeze with an Abanico

    Science.gov (United States)

    Goon, Grace; Marthelot, Joel; Reis, Pedro; MIT EGS Lab Team

    Flexible hand-held fans, or abanicos, are universally employed as cooling devices that are both portable and sustainable. Their to and fro axial motion about one's hand generates an airflow that increases the evaporation rate near the skin and refreshes. We study this problem in the context of fluid-structure interaction, through precision model experiments. We first characterize the elastic properties of a semi-circular thin plates with various thickness and evaluate their aerodynamic performance in a custom built apparatus. The air velocity profile that results from the flapping motion of the fan is characterized for different driving conditions. A systematic variation of the geometric and elastic parameters, along with an exploration of the parameter space of the periodic driving motion (amplitude and frequency), allows us to establish optimal design and operational conditions for maximal output of the generated airflow, while minimizing the input power.

  15. Evaluation of environmental and physiological factors of a whole ceiling-type air conditioner using a salivary biomarker

    Energy Technology Data Exchange (ETDEWEB)

    Tahara, Yusuke; Yamaguchi, Masaki [Graduate School of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551 (Japan); Morito, Naomi; Nishimiya, Hajime; Yamagishi, Hideyuki [Asahi Kasei Homes Corporation, R and D Laboratories, 2-1 Samejima, Fuji, Shizuoka 416-8501 (Japan)

    2009-06-15

    In order to improve environmental condition such as humidity and airflow in living spaces, a whole ceiling-type air conditioner is proposed. This novel air conditioner exhaust dispersed airflow from the whole ceiling by using a 3-dimensional knit fabric. The purpose of this paper is to reveal the effects when controlling humidity and airflow using the whole ceiling-type air conditioner compared to a commercialized concentrated exhaust air conditioner (normal-type air conditioner) under the same temperature. Salivary {alpha}-amylase activity (SAA) was used as an index of sympathetic nervous activity. An acute experiment for a 15 min period was conducted using 12 healthy young female adults. No significant differences in room and skin temperatures were observed between the whole ceiling-type air conditioner and the normal-type air conditioner. The whole ceiling-type air conditioner showed 11.1% lower humidity than the normal-type air conditioner. The whole ceiling-type air conditioner showed one-thirteenth the airflow of the normal-type air conditioner. As a result, the PMV of the whole ceiling-type air conditioner was more comfortable level than the normal one. Moreover, subjective evaluation questionnaire revealed a significant difference was observed in wind perception (windy). The SAA of subjects under the whole ceiling-type air conditioner showed significantly low values compared with the normal-type air conditioner. It was found that the subject's sympathetic nervous activity has been inactivated under the conditions of the whole ceiling-type air conditioner. Thus, it was revealed that the whole ceiling-type air conditioner provides a more comfortable air environment by reducing physical stimulations to humans. (author)

  16. Gigapixel Images Connect Sports Teams with Fans

    Science.gov (United States)

    2013-01-01

    Technology developed at Ames Research Center to take high-resolution imagery on Mars is now being used in baseball stadiums across the country. New York City-based Major League Baseball Advanced Media LP customized the platform to accommodate in-game shots that capture nearly the whole stadium. Fans navigate the photos online and tag themselves and their friends using social media tools.

  17. Piercing the sovereign ceiling: Issues in oil and gas project financing

    International Nuclear Information System (INIS)

    In the oil and gas sector, corporations and governments face huge capital spending requirements in order to transform large resource discoveries into producing, cash-generating assets. A significant portion of this funding is expected to be done on a project finance basis, where bank lenders or bond investors take a secured position in financing a discrete project, with the expectation of being paid back by the cash flows from that project after completion. This trend is increasing demand for crediting rating services to provide credit ratings for these project financings. A key challenge is to analyze and rate credit-worthy projects in countries that have relatively low foreign currency sovereign ceilings due to economic, political, and financial risks. In most cases, the credit ratings for projects financed in currencies outside the host country are capped at the country''s foreign currency ceiling. However, in a few instances, mainly in the oil and gas sector, Moody''s has pierced the foreign currency ceiling or rated certain projects above the sovereign ratings of the countries where they are domiciled. The purpose of this article is to briefly explain some of the qualitative factors and considerations that have allowed Moody''s to pierce the ceiling in the oil and gas sector, with a focus on two recent and noteworthy projects: Ras Laffan Liquefied Natural Gas in Qatar and Petrozuata in Venezuela

  18. Perceptions of Women in Management: A Thematic Analysis of Razing the Glass Ceiling

    Science.gov (United States)

    Baumgartner, Mindy S.; Schneider, David E.

    2010-01-01

    Despite advances that women have made in organizations over the past century, women continue to be underrepresented in upper management positions. Based on a review of literature, six issues that women face when encountering the glass ceiling were examined. The goal of the current study involved having women who have succeeded at breaking the…

  19. Giacomo Tencalla and ceiling painting in 17th century Bohemia and Moravia

    Czech Academy of Sciences Publication Activity Database

    Mádl, Martin

    2008-01-01

    Roč. 56, č. 1 (2008), s. 38-64. ISSN 0049-5123 R&D Projects: GA ČR GA408/05/0753 Institutional research plan: CEZ:AV0Z80330511 Keywords : baroque * fine arts * ceiling painting * architecture Subject RIV: AL - Art, Architecture, Cultural Heritage http://www.umeni-art.cz/cz/soubory/madl2.pdf

  20. Giuseppe Bragalli and Bolognese ceiling painting in the Czech Lands in the 17th century

    Czech Academy of Sciences Publication Activity Database

    Mádl, Martin

    2011-01-01

    Roč. 59, č. 5 (2011), s. 350-379. ISSN 0049-5123 R&D Projects: GA ČR GA408/08/0745 Institutional research plan: CEZ:AV0Z80330511 Keywords : baroque art * painting * ceiling painting * architecture Subject RIV: AL - Art, Architecture, Cultural Heritage

  1. Between Meditation and Propaganda. Explicit and Implicit Religious Imagery in Baroque Ceiling Painting

    Czech Academy of Sciences Publication Activity Database

    Mádl, Martin

    2011-01-01

    Roč. 16, 1/2 (2011), s. 11-28. ISSN 1408-0419 R&D Projects: GA ČR GA408/08/0745 Institutional research plan: CEZ:AV0Z80330511 Keywords : baroque * ceiling painting * iconography * church Subject RIV: AL - Art, Architecture, Cultural Heritage

  2. Study of insulator sleeve and ceiling effect in Mather type plasma focus

    International Nuclear Information System (INIS)

    Neutron emission from a small Mather-type Plasma Focus facility is studied. Specifically, the effects of insulator sleeve length and a ''ceiling'' introduced in front of the central electrode on the neutron yield and on the fluence anisotropy are investigated. 3 refs, 5 figs

  3. Microbial Volatile Organic Compound Emissions from Stachybotrys chartarum growing on Gypsum Wallboard and Ceiling tile

    Science.gov (United States)

    This study compared seven toxigenic strains of S. chartarum found in water-damaged buildings to characterize the microbial volatile organic compound (MVOC) emissions profile while growing on gypsum wallboard (W) and ceiling tile (C) coupons. The inoculated coupons with their sub...

  4. The Glass Ceiling for Women in Legal Education: Contract Positions and the Death of Tenure.

    Science.gov (United States)

    Angel, Marina

    2000-01-01

    Discussion of the glass ceiling for women in legal education first examines categories of law school personnel, especially the fast-growing category of legal-writing teachers, and then considers trends in law school hiring. Concludes that law school trends mirror those in college and university hiring generally, suggesting the weakening and…

  5. Comments by ABCT's first female president on overcoming the glass ceiling.

    Science.gov (United States)

    Nelson-Gray, Rosemery O

    2012-12-01

    At the annual convention of the Association for Behavioral and Cognitive Therapies in New York City in November 2009, a most interesting panel discussion occurred: Overcoming the Glass Ceiling: A Conversation With the Trailblazers. This article is a written version of my oral presentation at this panel discussion in my role as ABCT's first female president. PMID:23046772

  6. Working beyond the Glass Ceiling: Women Managers in Initial Teacher Training in England

    Science.gov (United States)

    Thompson, Barbara

    2007-01-01

    Recently in England, women have been successful in obtaining managerial responsibilities in the field of teacher training. In this setting at least, it could be argued that the glass ceiling that has kept women in lower-paid and lower status posts has been shattered. In order to explore this proposition from the perspective of those who work as…

  7. Making Sense of the Glass Ceiling in Schools: An Exploration of Women Teachers' Discourses

    Science.gov (United States)

    Moreau, Marie-Pierre; Osgood, Jayne; Halsall, Anna

    2007-01-01

    There is extensive evidence of a "glass ceiling" for women across the labour market. Though schools have widely been described as "feminized" work environments, the under-representation of women at school management level is well established. Based on a study of women teachers' careers and promotion in the English school sector (in early years,…

  8. Performance of Chilled Beam with Radial Swirl Jet and Diffuse Ceiling Air Supply in Heating Mode

    DEFF Research Database (Denmark)

    Bertheussen, Bård; Mustakallio, Panu; Melikov, Arsen Krikor;

    2013-01-01

    The performance of diffuse ceiling air supply and chilled beam with swirl jet (CSW) in heating mode (winter situation) was studied and compared with regard to the generated indoor environment. An office mock-up with one occupant was simulated in a test room (4.5 x 3.95 x 3.5 m3 (L x W x H...

  9. Beyond the Glass Ceiling : The Glass Cliff and Its Lessons for Organizational Policy

    NARCIS (Netherlands)

    Bruckmueller, Susanne; Ryan, Michelle K.; Rink, Floor; Haslam, S. Alexander

    2014-01-01

    It has been almost 30 years since the metaphor of the glass ceiling was coined to describe the often subtle, but very real, barriers that women face as they try to climb the organizational hierarchy. Here we review evidence for a relatively new form of gender discriminationcaptured by the metaphor o

  10. The relationship between glass ceiling and power distance as a cultural variable by a new method

    Directory of Open Access Journals (Sweden)

    Naide Jahangirov

    2015-12-01

    Full Text Available Glass ceiling symbolizes a variety of barriers and obstacles that arise from gender inequality at business life. With this mind, culture influences gender dynamics. The purpose of this research was to examine the relationship between the glass ceiling and the power distance as a cultural variable within organizations. Gender variable is taken as a moderator variable in relationship between the concepts. In addition to conventional correlation analysis, we employed a new method to investigate this relationship in detail. The survey data were obtained from 109 people working at a research center which operated as a part of the non-profit private university in Ankara, Turkey. The relationship between the variables was revealed by a new method which was developed as an addition to the correlation in survey. The analysis revealed that the female staff perceived the glass ceiling and the power distance more intensely than the male staff. In addition, the medium level relation was determined between the power distance and the glass ceiling perception among female staff.

  11. Is a Widening Gender Wage Gap Necessarily Caused by a Glass Ceiling?

    NARCIS (Netherlands)

    I.P. van Staveren (Irene)

    2012-01-01

    textabstractContrary to what is generally assumed, the gender wage gap and the glass ceiling may not necessarily be positively related. An exploratory analysis of aggregate public service personnel data for Uganda shows that the gender wage gap is small at the middle level of management, whereas it

  12. Thermal management of pico projector using a piezoelectric fan

    International Nuclear Information System (INIS)

    Highlights: • A fin-equipped pico projector cooled by a vibrating piezoelectric fan was studied. • The piezoelectric fan was actuated with four different frequencies at 90 Vrms. • Both the heater power and the fan vibrating frequency affected the fan amplitude. • Forced and natural convection might be equally significant at a high heater power. • Fan amplitude strongly affected the thermal resistance of pico projector. - Abstract: A fin-array-equipped test pico projector with horizontal or vertical orientation was cooled by a vibrating piezoelectric fan in this study. The 47 mm × 10 mm piezoelectric fan was operated at 90 Vrms at a frequency ranging from 135.5 Hz to 129.5 Hz. It was found that the fan vibrating amplitude was affected by both the input power of the heater and the fan operating frequency. The thermal resistance of the fan-cooled test pico projector not always reduced as the heater power increased, and would be equally affected by both forced convection and natural convection depending on Gr and Re numbers. Such phenomenon that might arise from the temperature effect on the fan blade material and the fluidic damping was especially marked when the plate-fin-array-equipped test pico projector was horizontally tested. The results also showed that the pin-fin array was more favorable than plate-fin array for the cooling of test pico projector as a piezoelectric fan vibrated at a specific frequency, regardless of the orientation. When the pin-fin array was cooled by a vibrating piezoelectric fan at 133.5 Hz at 7 W in a horizontally and vertically oriented projector, the maximum thermal resistance reduction was about 3.4 °C/W and 3.8 °C/W, respectively

  13. Assessment of nitrogen ceilings for Dutch agricultural soils to avoid adverse environmental impacts.

    Science.gov (United States)

    de Vries, W; Kros, H; Oenema, O; Erisman, J W

    2001-11-01

    In the Netherlands, high traffic density and intensive animal husbandry have led to high emissions of reactive nitrogen (N) into the environment. This leads to a series of environmental impacts, including: (1) nitrate (NO3) contamination of drinking water, (2) eutrophication of freshwater lakes, (3) acidification and biodiversity impacts on terrestrial ecosystems, (4) ozone and particle formation affecting human health, and (5) global climate change induced by emissions of N2O. Measures to control reactive N emissions were, up to now, directed towards those different environmental themes. Here we summarize the results of a study to analyse the agricultural N problem in the Netherlands in an integrated way, which means that all relevant aspects are taken into account simultaneously. A simple N balance model was developed, representing all crucial processes in the N chain, to calculate acceptable N inputs to the farm (so-called N ceiling) and to the soil surface (application in the field) by feed concentrates, organic manure, fertiliser, deposition, and N fixation. The N ceilings were calculated on the basis of critical limits for NO 3 concentrations in groundwater, N concentrations in surface water, and ammonia (NH3) emission targets related to the protection of biodiversity of natural areas. Results show that in most parts of the Netherlands, except the western and the northern part, the N ceilings are limited by NH 3 emissions, which are derived from critical N loads for nature areas, rather than limits for both ground- and surface water. On the national scale, the N ceiling ranges between 372 and 858 kton year(-1) depending on the choice of critical limits. The current N import is 848 kton year(-1). A decrease of nearly 60% is needed to reach the ceilings that are necessary to protect the environment against all adverse impacts of N pollution from agriculture. PMID:12805837

  14. Assessment of Nitrogen Ceilings for Dutch Agricultural Soils to Avoid Adverse Environmental Impacts

    Directory of Open Access Journals (Sweden)

    Wim de Vries

    2001-01-01

    Full Text Available In the Netherlands, high traffic density and intensive animal husbandry have led to high emissions of reactive nitrogen (N into the environment. This leads to a series of environmental impacts, including: (1 nitrate (NO3 contamination of drinking water, (2 eutrophication of freshwater lakes, (3 acidification and biodiversity impacts on terrestrial ecosystems, (4 ozone and particle formation affecting human health, and (5 global climate change induced by emissions of N2O. Measures to control reactive N emissions were, up to now, directed towards those different environmental themes. Here we summarize the results of a study to analyse the agricultural N problem in the Netherlands in an integrated way, which means that all relevant aspects are taken into account simultaneously. A simple N balance model was developed, representing all crucial processes in the N chain, to calculate acceptable N inputs to the farm (so-called N ceiling and to the soil surface (application in the field by feed concentrates, organic manure, fertiliser, deposition, and N fixation. The N ceilings were calculated on the basis of critical limits for NO3 concentrations in groundwater, N concentrations in surface water, and ammonia (NH3 emission targets related to the protection of biodiversity of natural areas. Results show that in most parts of the Netherlands, except the western and the northern part, the N ceilings are limited by NH3 emissions, which are derived from critical N loads for nature areas, rather than limits for both ground- and surface water. On the national scale, the N ceiling ranges between 372 and 858 kton year–1 depending on the choice of critical limits. The current N import is 848 kton year–1. A decrease of nearly 60% is needed to reach the ceilings that are necessary to protect the environment against all adverse impacts of N pollution from agriculture.

  15. Unraveling fan-climate relationships: Milankovitch cyclicity in a Miocene alluvial fan (Teruel Basin, Spain)

    Science.gov (United States)

    Ventra, D.; Abels, H. A.; Hilgen, F. J.; de Boer, P. L.

    2009-04-01

    The role of climate change in alluvial fan sedimentation is often evident in geomorphological studies dealing with Quaternary successions, but remains hard to assess in the pre-Quaternary stratigraphic record, for which an additional obstacle is represented by detailed chronologies difficult to established within coarse clastic systems. The Teruel Basin (eastern Spain) is an extensional trough whose main tectonic activity spanned from late Oligocene to Pliocene times. Permanent internal drainage and a Mediterranean semi-arid climate made the basin and its sedimentary signatures highly sensitive to climate fluctuations, especially in terms of hydrological balance. Recent studies have proved orbital control on the development of facies sequences from low-energy, basinal settings in Teruel. In particular, high-resolution chronological and paleoclimatic information has been derived by orbital tuning of mudflat to ephemeral lake deposits in the Prado area (Villastar), linking basic facies rhythms to alternating, relatively humid/arid phases paced mainly by climatic precession. Clastic lobes from a coeval alluvial fan distally interfinger with this reference section. Stratigraphic relationships show how fan sedimentation patterns were also influenced by climate cyclicity. Highest volumes of debris transfer towards the distal mudflat repeatedly coincide with relatively humid periods. Furthermore, distal to medial fan outcrops feature prominent rhythms of distinct, alternating coarse and fine clastic packages. Such a highly organized architecture, unusual in alluvial fan successions, points to the influence of a rhythmic forcing mechanism which might have been climate variability, as evidenced by the adjacent reference section. Rather than on processes of sediment transport basinwards, climate change would have acted on sediment production and availability at the source, within the fan catchment.

  16. Attenuation of Cross-Flow Fan Noise Using Porous Stabilizers

    Directory of Open Access Journals (Sweden)

    Huanxin Lai

    2011-01-01

    Full Text Available This paper presents a qualitative analysis of controlling the cross-flow fan noise by using porous stabilizers. The stabilizer was originally a folded plate. It is changed into a porous structure which has a plenum chamber and vent holes on the front wall. In order to investigate the influences of using the porous stabilizers, experiments are carried out to measure the cross-flow fan aerodynamic performances and sound radiation. Meanwhile, the internal flow field of the fan is numerically simulated. The results show that the porous stabilizers have not produced considerable effect on the cross-flow fan's performance curve, but the noise radiated from the fan is strongly affected. This indicates the feasibility of controlling the cross-flow fan noise by using the porous stabilizers with selected porosity.

  17. FACTORS INFLUENCING BRAND LOYALTY IN PROFESSIONAL SPORTS FANS

    OpenAIRE

    Yun-Tsan Lin; Chen-Hsien Lin

    2008-01-01

    Many researchers have provided comprehensive definitions for the term of brand loyalty and also examined the factors affecting brand loyalty with many empirical studies. But there is little research focusing on the brand loyalty of professional sports fans. The topic area about factors influencing brand loyalty in professional sports fans was identified because these fans bring significant financial benefits every year and stimulate economic growth in the United States. Although different con...

  18. On-site testing of crop drying fans

    OpenAIRE

    Winkelman, Paul M.

    1988-01-01

    The commercial peanut dryers used today were first conceived when energy was relatively inexpensive. Since then, energy costs have increased significantly, and more efficient peanuts dryers are desirable. To evaluate dryer efficiency, a mobile fan test facility was designed, built and calibrated for on-site fan airflow and energy measurements. Four-, six-, and eight-trailer peanut dryers were tested for performance. The characteristics observed were delivery of fan airflow as compared to m...

  19. Facing Up to Uncertain Life Expectancy: The Longevity Fan Charts

    OpenAIRE

    Dowd, Kevin; BLAKE, DAVID; CAIRNS, ANDREW J.G.

    2010-01-01

    This article uses longevity fan charts to represent the uncertainty in projections of future life expectancy. These fan charts are based on a mortality model calibrated on mortality data for English and Welsh males. The fan charts indicate strong upward sloping trends in future life expectancy. Their widths indicate the extent of uncertainty in these projections, and this uncertainty increases as the forecast horizon lengthens. Allowing for uncertainty in the parameter values of the model add...

  20. Relict alluvial fans of northwestern part of Matarsko podolje

    Directory of Open Access Journals (Sweden)

    Uroš Stepišnik

    2007-12-01

    Full Text Available Several types of contact karst are found within the Slovenian karst, but the most common is the ponor type, which appears between flysch and limestone. The most extensive contact of this type is in western Slovenia, in the area of Matarsko podolje, where a variety of typical contact karst depression features can be found. Relict alluvial fans on contact karst are the result of the gradual denudation of alluvial cover from flysch and chemical denudation of carbonate bedrock in the area of alluvial fans. Geomorphologic features and processes on alluvial fans, and the influences of alluvial fans on the development of local karst have been investigated in detail.

  1. K-pop Reception and Participatory Fan Culture in Austria

    Directory of Open Access Journals (Sweden)

    Sang-Yeon Sung

    2013-12-01

    Full Text Available K-pop’s popularity and its participatory fan culture have expanded beyond Asia and become significant in Europe in the past few years. After South Korean pop singer Psy’s “Gangnam Style” music video topped the Austrian chart in October 2012, the number and size of K-pop events in Austria sharply increased, with fans organizing various participatory events, including K-pop auditions, dance festivals, club meetings, quiz competitions, dance workshops, and smaller fan-culture gatherings. In the private sector, longtime fans have transitioned from participants to providers, and in the public sector, from observers to sponsors. Through in-depth interviews with event organizers, sponsors, and fans, this article offers an ethnographic study of the reception of K-pop in Europe that takes into consideration local interactions between fans and Korean sponsors, perspectives on the genre, patterns of social integration, and histories. As a case study, this research stresses the local situatedness of K-pop fan culture by arguing that local private and public sponsors and fans make the reception of K-pop different in each locality. By exploring local scenes of K-pop reception and fan culture, the article demonstrates the rapidly growing consumption of K-pop among Europeans and stresses multidirectional understandings of globalization.

  2. A measuring stand for a ducted fan aircraft propulsion unit

    Directory of Open Access Journals (Sweden)

    Hlaváček David

    2014-03-01

    Full Text Available The UL-39 ultra-light aircraft which is being developed by the Department of Aerospace Engineering, Faculty of Mechanical Engineering, Czech Technical University in Prague, is equipped with an unconventional ducted fan propulsion unit. The unit consists of an axial fan driven by a piston engine and placed inside a duct ended with a nozzle. This article describes the arrangement of a modernised measuring stand for this highly specific propulsion unit which will be able to measure the fan pressure ratio and velocity field in front of and behind the fan and its characteristic curve.

  3. Aerodynamic Modelling and Optimization of Axial Fans

    DEFF Research Database (Denmark)

    Sørensen, Dan Nørtoft

    integrated propertiesshow that the computed results agree well with the measurements.Integrating a rotor-only version of the aerodynamic modelwith an algorithm for numerical designoptimization, enables the finding of an optimum fan rotor.The angular velocity of the rotor, the hub radius and the spanwise...... velocity, pressure andradial position are derived from the conservationlaws for mass, tangential momentum and energy.The resulting system of equations is non-linear and, dueto mass conservation and pressure equilibrium far downstream of the rotor,strongly coupled.The equations are solved using the Newton...

  4. Jet fans for the Konan-Himawari tunnel of Yokohama-city; Yokohamashi Konan Himawari tunnel muke jet fan

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, H.; Fujisaki, M.; Toyoda, M. [Fuji Electric Co. Ltd., Tokyo (Japan)

    1998-07-10

    The above-said jet fans for ventilation are installed in the upper space of the tunnel. The jet fans can reverse the direction of the jets. Since it is so designed that the volume of air that a unit can handle is constant, the required volume of ventilation as a whole (dependent on the number of driving vehicles, etc.) is controlled by changing the number of jet fans to be in operation. Since such jet fans are required to exhibit the same performance in both directions, the flat plate airfoil is the design used for the blades in most of the jet fans of the conventional type and, inevitably, jet fans designed as such are inferior in performance to the unidirectional type. Under the circumstances, a cambered airfoil is employed in the jet fan introduced in this report. For the designing of the cambered airfoil, flows in the front and the rear of the blade are measures for both forward rotation and the reverse, and the results are compared with the analytical results. Since the fan is forced to repeat start and stop very frequently as the case may be, the rotor is fully analyzed for stress and tested for fatigue strength. The new fan is found to be 14% higher than the conventional type in terms of blower efficiency. The noise is reduced by 6dB from that of the conventional type thanks to noise reduction in the blade section and to the modification of the housing. 8 figs., 1 tab.

  5. Characterisation of fan-beam collimators

    International Nuclear Information System (INIS)

    Fan-beam collimators offer a good balance between resolution and noise. The collimator response may be included in iterative reconstruction algorithms in order to improve single-photon emission tomography (SPET) resolution. To this end, accurate determination of the focal region and characterisation of the collimator response as a function of the source co-ordinates must be performed. In this paper, a method to characterise fan-beam collimators is evaluated. First, we calculated the real focal region and the accuracy of the collimator convergence. Then, we confirmed the hypothesis that Gaussian distributions adequately fit the collimator responses, although no individualised treatment was performed for the tails of detector response which are associated with scattering and septal penetration. Finally, analytical functions were used to model the resolution and sensitivity. The parameter values in these functions were obtained from experimental measures by non-linear regression fitting. Our findings show differences of 1.43% between nominal and real focal length and standard deviations of 2.5 mm in the x-direction and 7.1 mm in the y-direction for the focal convergence. The correlation coefficients between experimental and predicted values were 0.994 for resolution and 0.991 for sensitivity. As a consequence, the proposed method can be used to characterise the collimator response. (orig.)

  6. Impact of personalized ventilation combined with chilled ceiling on eye irritation symptoms

    DEFF Research Database (Denmark)

    Lipczynska, Aleksandra; Marcol, Bartosz; Kaczmarczyk, Jan;

    2014-01-01

    , elevated air movement toward face and increased radiant cooling may have impact on the eye symptoms. Twenty four human subjects participated in experiments with PV combined with chilled ceiling system (CCPV) and with mixing ventilation (MV) combined with chilled ceiling (CCMV). In the experiments with PV...... at workstations with computers. Exposure included also a higher activity level office work for a period of 25 min outside computer workstations. The influence of the environment on eye symptoms was assessed by subjective votes and objective measurements. Subjects reported on the eye irritation and the intensity...... of eye dryness 6 times throughout each experiment. Eye tear film samples were taken at the beginning and the end of the exposure. The blinking rate was analysed in the beginning and at the end of exposures. The preliminary results of the analyses reveal that the environment subjects were exposed to had...

  7. The analysis of glass ceiling phenomenon in the promotion of women’s abilities in organizations

    Directory of Open Access Journals (Sweden)

    Mahboubeh Soleymanpour Omran

    2015-09-01

    Full Text Available Women constitute almost half of the workforce of a society and there has been considerable increase in women employment rate in recent years. However, their promotion to management positions has not been very tangible. Gender inequalities in the workplace especially in the domain of management have resulted in the lack of efficient use of potential capacities of women. Even though the previous research demonstrates that women are not less ambitious than men, wrong beliefs which attribute management to men make a kind of invisible barrier, known as glass ceiling, which prevents women’s promotion to top organizational positions. The purpose of this study was to investigate the reasons for the lack of promotion of women to top management levels in the society. It was conducted with a descriptive analytic method through the review of the related literature and emphasis on the concept of glass ceiling to present practical solutions to solve the problem.

  8. An Efficient Ceiling-view SLAM Using Relational Constraints Between Landmarks

    OpenAIRE

    Hyukdoo Choi; Ryunseok Kim; Euntai Kim

    2014-01-01

    In this paper, we present a new indoor ‘simultaneous localization and mapping’ (SLAM) technique based on an upward-looking ceiling camera. Adapted from our previous work [17], the proposed method employs sparsely-distributed line and point landmarks in an indoor environment to aid with data association and reduce extended Kalman filter computation as compared with earlier techniques. Further, the proposed method exploits geometric relationships between the two types of landmarks to provide ad...

  9. The Glass Ceiling and the Paper Floor: Gender Differences among Top Earners, 1981–2012

    OpenAIRE

    Fatih Guvenen; Greg Kaplan; Jae Song

    2014-01-01

    We analyze changes in the gender structure at the top of the earnings distribution in the United States over the last 30 years using a 10% sample of individual earnings histories from the Social Security Administration. Despite making large inroads, females still constitute a small proportion of the top percentiles: the glass ceiling, albeit a thinner one, remains. We measure the contribution of changes in labor force participation, changes in the persistence of top earnings, and changes in i...

  10. The Glass Ceiling in Europe: Why Are Women Doing Badly in the Labour Market?

    OpenAIRE

    Booth, Alison L

    2006-01-01

    Average gender pay gaps have absorbed the interest of economists for many years. More recently studies have begun to explore the degree to which observed gender wage gaps might differ across the wages distribution. The stylised facts from these studies, summarised in the first part of the paper, are that the gender pay gap in Europe is typically increasing across the wages distribution. This finding - more pronounced in the private than the public sector - has been interpreted as a glass ceil...

  11. Dynamic structural analysis concerning integrity assessment of a reinforced concrete ceiling due to impact loads

    International Nuclear Information System (INIS)

    In the framework of the activities concerning the safety of nuclear power plants (NPP) in Middle- and East Europe among others the behaviour of the reactor cavity bottom ceiling of a NPP of type WWER-1000 impinged by impact loads due to the postulated failure of the lower head of the reactor pressure vessel (RPV-LH) caused by an assumed core melt accident has been investigated. For the investigations of the structure dynamical behaviour of the reactor cavity ceiling the AUTODYN-Code was used. This code is using an explicit solver and is suitable particularly for the simulation of impact problems. For the investigations on the load bearing capacity of the cavity ceiling an axisymmetric Finite Element (FE) model of both the RPV-LH made of steel and the reactor cavity ceiling with detailed consideration of the reinforcement in the concrete was generated. The effects of the rebars were simulated by shell elements with adequate cross-sections based on the number of rebars. To represent the load and temperature dependent deformation of the heated RPV-LH during the impact phase the FE-model has steel layers of different temperature dependent material properties representing the assumed temperature distribution over the wall thickness at postulated failure. The assumed molten core material located above the inner surface of the RPV-LH is taken into account by adjusting the density of the lower head. In the dynamic calculations the internal pressure conditions at the time of failure and consequently the impact velocity were varied. The calculations show the damage of the concrete and the strains in the reinforcement were assessed by adequate failure criteria. (authors)

  12. Field evaluation of performance of radiant heating/cooling ceiling panel system

    DEFF Research Database (Denmark)

    Li, Rongling; Yoshidomi, Togo; Ooka, Ryozo; Olesen, Bjarne W.

    2015-01-01

    As in many other countries in the world, Japan has witnessed an increased focus on low-energy buildings.For testing different engineering solutions for energy-efficient buildings, a low-energy building was builtat the University of Tokyo as an experimental pilot project. In this building, a radia...... environment wasobtained using the radiant ceiling heating/cooling system.© 2014 Elsevier B.V. All rights reserved....

  13. Counting the Number of Site Swap Juggling Patterns with Respect to Particular Ceilings

    OpenAIRE

    Bracken, Carl

    2008-01-01

    Site swap is a mathematical notation used by jugglers to communicate, create and study complex juggling patterns. Determining the number of possible site swap juggling patterns with respect to certain limiting parameters such as number of balls etc., is a problem that has been much studied and solved by many mathematicians. However, when the patterns have a throw height restriction (ceiling) the problem becomes difficult and is in general still open. In this article we derive some formulae fo...

  14. Does Organizational Culture Affect the Perception Towards the Barriers of the Glass Ceiling?

    OpenAIRE

    Muruatetu, Ndunge

    2011-01-01

    Purpose : The purpose of this study was to examine the existence of the glass ceilling in Africa; and to investigate whether organizational culture affected the perception towards the barriers of the glass ceiling. Design/Methodology : This research used a quatitative approach, based on a descriptive design. Data was gathered from surveys issued to employees at a Non-Governmental organization; with the participants based in the Sierra Leone and Democratic Republic of Congo offices. Fi...

  15. Evidence on the glass ceiling effect in France using matched worker-firm data

    OpenAIRE

    Jellal, Mohamed; Nordman, Christophe; Wolff, François charles

    2008-01-01

    Abstract In this paper, we investigate the relevance of the glass ceiling hypothesis in France, according to which there exist larger gender wage gaps at the upper tail of the wage distribution. Using a matched worker-firm data set of about 130,000 employees and 14,000 employers, we estimate quantile regressions and rely on a principal component analysis to summarize information specific to the firms. Our different results show that accounting for firm-related characteristics reduc...

  16. Book review: Shattered, cracked or firmly intact? Women and the executive glass ceiling worldwide

    OpenAIRE

    Cuevas, Senia

    2013-01-01

    "Shattered, Cracked or Firmly Intact? Women and the Executive Glass Ceiling Worldwide." Farida Jalalzai. Oxford University Press. March 2013 --- In 1960, Sirimavo Bandaranaike of Sri Lanka made history when she was appointed the world’s first woman prime minister. In the half-century following her achievement, fewer than eighty women worldwide have attained the office of prime minister or president. In Shattered, Cracked, or Firmly Intact?, Farida Jalalzai aims to explain the mechanisms that ...

  17. Windows in the ceiling ... leadership advice and strategies from successful female executives

    OpenAIRE

    Setili, Colleen M.

    2001-01-01

    This thesis provides a framework for understanding specific strategies and personal characteristics women can utilize to enable them to reach the top levels of an organization. In order to do so, current literature was reviewed that was written primarily from a female perspective, and civilian women in high-grade positions working for the Army were interviewed to obtain their own personal strategies, personal characteristics, and opinions regarding the glass-ceiling concept and how to achieve...

  18. Experimental evaluation of a solar thermoelectric cooled ceiling combined with displacement ventilation system

    International Nuclear Information System (INIS)

    Highlights: • A novel solar thermoelectric cooled ceiling combined with displacement ventilation system is developed and tested. • The cooling and heating capacities and performance of the system are evaluated. • Its coefficient of performance could be comparable to those of conventional AC systems with ZT value of 2. • Typical application issues including condensation risk, coupling with a PV system, etc., are discussed. - Abstract: A novel solar thermoelectric cooled ceiling combined with displacement ventilation system (STCC-DV) is proposed and investigated in this paper. In STCC-DV system, thermoelectric modules are employed as heating source instead of conventional hydronic pipe, and the combined system dehumidifies the fresh air using a thermoelectric dehumidified system. Both the cooled ceiling and dehumidified ventilation system are powered by PV system. At this stage of our study, we are developing a solar thermoelectric cooled ceiling (STCC) system by using commercially TE technologies. The experiments have been done in a test room using radiant panels whose dimension is 1800 × 600 mm. The results show that the total heat flux and COP of the panel are strongly influenced by operating voltage, ambient temperature and indoor temperature. The total heat flux of the STCC system in cooling mode is higher than 60 W/m2 and the system COP can reaches 0.9 under operating voltage 5 V. In heating mode, the total heat flux of the STCC system under operating voltage 4 V is higher than 110 W/m2 and the COP of the system can reaches 1.9. This simply and environmentally friendly system is promising and worthwhile being applied to for low carbon buildings climate control

  19. Sector Differences in Glass Ceiling in Sweden -Is It Tied to Occupational Segregation?

    OpenAIRE

    Özcan, Gülay

    2010-01-01

    This paper explores sector differences in how the gender wage gap varies across the wage distribution and the role of occupational segregation in explaining this variation for Sweden. Results indicate that the phenomenon known as the glass ceiling, i.e. larger gender wage differentials at the high end of the wage distribution is stronger in the public sector than the private. This difference is found to be due to occupational segregation and, to a large extent, pre-market educational choices....

  20. Design of walls and/or ceilings for radiation endangered or radiation exposed rooms

    International Nuclear Information System (INIS)

    This invention has to do with wall or ceiling design for radiation endangered or radiation exposed rooms used for medical radiation therapy or industrial radiation applications (e.g. linear accelerators). The structure dispenses with moulds and reinforcement and consists of mountable precast concrete elements (bricks). Two elements form the structure's outer boundary surface. The interspace between them is filled with additional shielding materials like wet concrete, soil or other precast concrete elements

  1. Peak and ceiling effects in final-product analysis of mastoidectomy performance

    DEFF Research Database (Denmark)

    West, N; Konge, L; Cayé-Thomasen, P;

    2015-01-01

    BACKGROUND: Virtual reality surgical simulation of mastoidectomy is a promising training tool for novices. Final-product analysis for assessing novice mastoidectomy performance could be limited by a peak or ceiling effect. These may be countered by simulator-integrated tutoring. METHODS: Twenty-t...... instruction is important when using final-product analysis to assess novice mastoidectomy performance. Improved real-time feedback and tutoring could address the limitations of final product based assessment....

  2. Thou shalt not pass?: Examining the existence of an immigrant glass ceiling in Sweden, 1970-1990

    OpenAIRE

    Jonas Helgertz

    2011-01-01

    The paper studies a sample of natives and 18 immigrant nationalities in the Swedish labor market between 1970 and 1990. The purpose is examining the existence of an immigrant specific glass ceiling. Results suggest a considerable overall advantage in terms of the probability of experiencing upward occupational mobility for native Swedish males. Despite this, the pattern does not correspond to the theoretical expectations of a glass ceiling. Using the ISEI classification of occupational status...

  3. Glass Ceiling Converted Into Glass Transparency: A Study On The Factors Making Women Executives Successful In The Indian Banking Sector

    OpenAIRE

    Sachdeva, Dr Geeta

    2014-01-01

    Economic reforms in the Indian economy along with gradual opening up of a conservative society to a modern society preceded breaking the glass ceiling or conversion Glass ceiling into a Glass Transparency in the Indian Banking Sector. This is backed by a recent study of 240 top Indian companies by EMA Partners, the global executive-search firm, which says more than a half of India's women chief executives are accounted for by the banking and financial services industry. This paper studie...

  4. Effects of Glass Ceiling on Women Career Development in Private Sector Organizations – Case of Sri Lanka

    OpenAIRE

    Bombuwela P. M.; De Alwis A. Chamaru

    2013-01-01

    The study was entirely designed by centering the focal problem of the effect of Glass Ceiling on Women Career Development. The overall study was structure based on the conceptual framework built up using the information of literature survey. The study was conducted with the aim of obtaining the following objective. That is “To find out the Effect of Glass Ceiling on Women Career Development with regard to female executive level employees who are working in privatesector organizations.” At the...

  5. The performance of a centrifugal fan with enlarged impeller

    International Nuclear Information System (INIS)

    Highlights: → The influence of impeller enlargement is evaluated numerically and experimentally. → Variation equations of the operation points for enlarged impellers are derived. → Impeller enlargement leads to louder fan noise due to reduced impeller-volute gap. - Abstract: The influence of enlarged impeller in unchanged volute on G4-73 type centrifugal fan performance is investigated in this paper. Comparisons are conducted between the fan with original impeller and two larger impellers with the increments in impeller outlet diameter of 5% and 10% respectively in the numerical and experimental investigations. The internal characteristics are obtained by the numerical simulation, which indicate there is more volute loss in the fan with larger impeller. Experiment results show that the flow rate, total pressure rise, shaft power and sound pressure level have increased, while the efficiency have decreased when the fan operates with larger impeller. Variation equations on the performance of the operation points for the fan with enlarged impellers are suggested. Comparisons between experiment results and the trimming laws show that the trimming laws for usual situation can predict the performance of the enlarged fan impeller with less error for higher flow rate, although the situation of application is not in agreement. The noise frequency analysis shows that higher noise level with the larger impeller fan is caused by the reduced impeller-volute gap.

  6. Submarine-fan sedimentation, Ouachita Mountains, Arkansas and Oklahoma

    Energy Technology Data Exchange (ETDEWEB)

    Moiola, R.J.; Shanmugam, G.

    1984-09-01

    More than 10,000 m (32,808 ft) of interbedded sandstones and shales comprise the Upper Mississippian and Lower Pennsylvanian flysch succession (Stanley, Jackfork, Johns Valley, Atoka) in the Ouachita Mountains of Arkansas and Oklahoma. Deposited primarily by turbidity current and hemipelagic processes in bathyal and abyssal water depths, these strata formed major submarine-fan complexes that prograded in a westward direction along the axis of an elongate remnant ocean basin that was associated with the collision and suturing of the North American and African-South American plates. A longitudinal fan system is visualized as the depositional framework for these strata, which were deposited in a setting analogous to the modern Bengal fan of the Indian Ocean. Facies analysis of the Jackfork formation indicates that inner fan deposits are present in the vicinity of Little Rock, Arkansas; middle fan channel and interchannel deposits occur at DeGray Dam and Friendship, Arkansas; and outer fan depositional-lobe deposits are present in southeastern Oklahoma. Boulder-bearing units (olistostromes), many with exotic clasts, were shed laterally into the Ouachita basin. They occur throughout the flysch succession and in all fan environments (i.e., inner, middle, and outer). This relationship may serve as a useful criterion for recognizing analogous longitudinal fan systems in the rock record.

  7. Energy fan power consumption comparison of subway station HVAC system

    Institute of Scientific and Technical Information of China (English)

    JIANGYong; ZHUYingxin

    2003-01-01

    Subway thermal environment control system is a mass energy consumed system. The fan operation is the Key of energy saving. Some feasible fan operation modes are proposed and compared in this paper from the view of energy and operation cost saving. It is concluded that VAV is the optimal operation mode for metro system with highest energy saving.

  8. Nocturnal Fanning Suppresses Downy Mildew Epidemics in Sweet Basil

    Science.gov (United States)

    Cohen, Yigal; Ben-Naim, Yariv

    2016-01-01

    Downy mildew is currently the most serious disease of sweet basil around the world. The oomycete causal agent Peronospora belbahrii requires ≥ 4h free leaf moisture for infection and ≥7.5h of water-saturated atmosphere (relative humidity RH≥95%) at night for sporulation. We show here that continued nocturnal fanning (wind speed of 0.4–1.5 m/s) from 8pm to 8am dramatically suppressed downy mildew development. In three experiments conducted during 2015, percent infected leaves in regular (non-fanned) net-houses reached a mean of 89.9, 94.3 and 96.0% compared to1.2, 1.7 and 0.5% in adjacent fanned net-houses, respectively. Nocturnal fanning reduced the number of hours per night with RH≥95% thus shortened the dew periods below the threshold required for infection or sporulation. In experiments A, B and C, the number of nights with ≥4h of RH≥95% was 28, 10 and 17 in the non-fanned net-houses compared to 5, 0 and 5 in the fanned net-houses, respectively. In the third experiment leaf wetness sensors were installed. Dew formation was strongly suppressed in the fanned net-house as compared to the non-fanned net-house. Healthy potted plants became infected and sporulated a week later if placed one night in the non-fanned house whereas healthy plants placed during that night in the fanned house remained healthy. Infected potted basil plants sporulated heavily after one night of incubation in the non-fanned house whereas almost no sporulation occurred in similar plants incubated that night in the fanned house. The data suggest that nocturnal fanning is highly effective in suppressing downy mildew epidemics in sweet basil. Fanning prevented the within-canopy RH from reaching saturation, reduced dew deposition on the leaves, and hence prevented both infection and sporulation of P. belbahrii. PMID:27171554

  9. Sediment velocities from sonobuoys: Bengal Fan, Sunda Trench, Andaman Basin, and Nicobar Fan

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, E.L.; Bachman, R.T.; Curray, J.R.; Moore, D.G.

    1977-07-10

    New measurements of interval compressional wave velocities were made in the first sediment layer using the sonobuoy technique during two expeditions in the Bay of Bengal, in the Andaman Sea, and over the Nicobar Fan and Sunda Trench. Sediment interval velocities from these areas were added to those previously reported, and revised diagrams and regression equations of instantaneous and mean velocity versus one-way travel time are furnished for four areas of the Bengal Fan, and for the Anadman Basin, Nicobar Fan, Sunda Trench. The velocity gradients directly below the sea floor were used to separate the Bengal Fan into four geoacoustic provinces. In the north and west the velocity gradients are 0.86 and 1.28 s/sup -1/, respectively, whereas in the central part of the fan the gradient is 1.87 s/sup -1/. These variations indicate lesser increases of velocity with depth in the sea floor in the north and west, and they are probably due to more rapid deposition, less consolidation, and less lithification near the riverine source areas of the sediments. The near-surface velocity gradients in the other areas are the Andaman Basin, 1.53 s/sup -1/, the Nicobar Fan 1.63 s/sup -1/, and the Sunda Trench, 1.41 s/sup -1/. The linear velocity gradients (from the sediment surface to a given travel time) in 17 areas of the Indian Ocean, Pacific area, Atlantic Ocean, and Gulf of Mexico were averaged at each 0.1 s from 0 to 0.5 s of one-way travel time. These averaged gradients ranged from 1.32 s/sup -1/ at t=0 to 0.76 s/sup -1/ at t=0.5 s. The regression equation for the velocity gradients a, in s/sup -1/, as a function of one-way travel time t, in seconds, is a=1.316-1.117t (for use from t=0 to 0.5 s). These average velocity gradients can be used with sediment surface velocities and one-way travel times (measured from reflection records) to compute sediment layer thickness in areas of turbidites lacking interval velocity measurements in the first sediment layer.

  10. The Diagonal Compression Field Method using Circular Fans

    DEFF Research Database (Denmark)

    Hansen, Thomas

    2006-01-01

    modification of the traditional method, the modification consisting of the introduction of circular fan stress fields. To ensure proper behaviour for the service load the -value ( = cot, where  is the angle relative to the beam axis of the uniaxial concrete compression) chosen should not be too large. As a...... increased in regions with low shear stresses. Thus the shear reinforcement would be reduced and the concrete strength would be utilized in a better way. In the paper it is shown how circular fan stress fields may be used whenever changes in the concrete compression direction are desired. Between two...... homogeneous stress regions a circular fan stress field may be used to change the inclination of the concrete compression. Unfortunately, the circular fan stress field becomes strongly inhomogeneous if the angle between the two inclined faces limiting the fan becomes large. Thus normally more than one circular...

  11. Development of a Fan for Future Space Suit Applications

    Science.gov (United States)

    Paul. Heather L.; Converse, David; Dionne, Steven; Moser, Jeff

    2010-01-01

    NASA's next generation space suit system will place new demands on the fan used to circulate breathing gas through the ventilation loop of the portable life support system. Long duration missions with frequent extravehicular activities (EVAs), the requirement for significant increases in reliability and durability, and a mission profile that imposes strict limits on weight, volume and power create the basis for a set of requirements that demand more performance than is available from existing fan designs. This paper describes the development of a new fan to meet these needs. A centrifugal fan was designed with a normal operating speed of approximately 39,400 rpm to meet the ventilation flow requirements while also meeting the aggressive minimal packaging, weight and power requirements. The prototype fan also operates at 56,000 rpm to satisfy a second operating condition associated with a single fan providing ventilation flow to two spacesuits connected in series. This fan incorporates a novel nonmetallic "can" to keep the oxygen flow separate from the motor electronics, thus eliminating ignition potential. The nonmetallic can enables a small package size and low power consumption. To keep cost and schedule within project bounds a commercial motor controller was used. The fan design has been detailed and implemented using materials and approaches selected to address anticipated mission needs. Test data is presented to show how this fan performs relative to anticipated ventilation requirements for the EVA portable life support system. Additionally, data is presented to show tolerance to anticipated environmental factors such as acoustics, shock, and vibration. Recommendations for forward work to progress the technology readiness level and prepare the fan for the next EVA space suit system are also discussed.

  12. Low Frequency Noise Contamination in Fan Model Testing

    Science.gov (United States)

    Brown, Clifford A.; Schifer, Nicholas A.

    2008-01-01

    Aircraft engine noise research and development depends on the ability to study and predict the noise created by each engine component in isolation. The presence of a downstream pylon for a model fan test, however, may result in noise contamination through pylon interactions with the free stream and model exhaust airflows. Additionally, there is the problem of separating the fan and jet noise components generated by the model fan. A methodology was therefore developed to improve the data quality for the 9 15 Low Speed Wind Tunnel (LSWT) at the NASA Glenn Research Center that identifies three noise sources: fan noise, jet noise, and rig noise. The jet noise and rig noise were then measured by mounting a scale model of the 9 15 LSWT model fan installation in a jet rig to simulate everything except the rotating machinery and in duct components of fan noise. The data showed that the spectra measured in the LSWT has a strong rig noise component at frequencies as high as 3 kHz depending on the fan and airflow fan exit velocity. The jet noise was determined to be significantly lower than the rig noise (i.e., noise generated by flow interaction with the downstream support pylon). A mathematical model for the rig noise was then developed using a multi-dimensional least squares fit to the rig noise data. This allows the rig noise to be subtracted or removed, depending on the amplitude of the rig noise relative to the fan noise, at any given frequency, observer angle, or nozzle pressure ratio. The impact of isolating the fan noise with this method on spectra, overall power level (OAPWL), and Effective Perceived Noise Level (EPNL) is studied.

  13. Alluvial Fan Morphology, distribution and formation on Titan

    Science.gov (United States)

    Birch, S. P. D.; Hayes, A. G.; Howard, A. D.; Moore, J. M.; Radebaugh, J.

    2016-05-01

    Titan is a hydrologically active world, with dozens of alluvial fans that are evidence of sediment transport from high to low elevations. However, the distribution and requirements for the formation of fans on Titan are not well understood. We performed the first global survey of alluvial fans on Titan using Cassini Synthetic Aperture Radar (SAR) data, which cover 61% of Titan's surface. We identified 82 fans with areas ranging from 28 km2 to 27,000 km2. A significant fraction (∼60%) of the fans are restricted to latitudes of ±50-80°, suggesting that fluvial sediment transport may have been concentrated in the near-polar terrains in the geologically recent past. The density of fans is also found to be correlated with the latitudes predicted to have the highest precipitation rates by Titan Global Circulation Models. In equatorial regions, observable fans are not generally found in proximity to dune fields. Such observations suggest that sediment transport in these areas is dominated by aeolian transport mechanisms, though with some degree of recent equatorial fluvial activity. The fan area-drainage area relationship on Titan is more similar to that on Earth than on Mars, suggesting that the fans on Titan are smaller than what may be expected, and that the transport of bedload sediment is limited. We hypothesize that this has led to the development of a coarse gravel-lag deposit over much of Titan's surface. Such a model explains both the morphology of the fans and their latitudinal concentration, yielding insight into the sediment transport regimes that operate across Titan today.

  14. Life, death and revival of debris-flow fans on Earth and Mars : fan dynamics and climatic inferences

    NARCIS (Netherlands)

    de Haas, T.

    2016-01-01

    Alluvial fans are ubiquitous landforms in high-relief regions on Earth and Mars. They have a semi-conical shape and are located at the transition between highlands and adjacent basins. Alluvial fans can form by a range of processes including debris flows, which are water-laden masses of soil and roc

  15. Model for predicting noise of propeller fans in air conditioners; Kuchoyo propeller fan no soon hasei model no kento

    Energy Technology Data Exchange (ETDEWEB)

    Hakamaya, N.; Funabashi, S.; Takada, Y. [Hitachi, Ltd., Tokyo (Japan)

    1999-12-25

    A model for predicting noise of propeller fans has been developed experimentally. First, the frequency response of turbulence on the blade of a rotating propeller fan was experimentally measured. Then, propeller fan noise was predicted by this model, which calculates lift fluctuations by Sears's equation and sound pressure in the far field by Curle's equation. The model assumes that the normalized intensity of turbulence (i. e., velocity fluctuation) is small in the high-flow-coefficient range but increases sharply in the low-flow-coefficient range. And the model showed that propeller fan noise depends on averaged relative velocity, intensity of turbulence, and length scale of turbulence. These results agree with the experimental measurements. Accordingly, the model predicts propeller fan noise and noise spectrum over a wide range of flow coefficients with reasonable accuracy. (author)

  16. Failure analysis of air fan blades

    Institute of Scientific and Technical Information of China (English)

    WANG Yan-qing; JI Zhe; CUI Yong-li; CUI Chun-zhi; SUN Zhi

    2008-01-01

    The failure of all 12 blades of an air fan was investigated by metallurgical and mechanical experiments and an examina-tion of the fracture surface. The experimental results show that the cast aluminium-silicon alloy without any modification had a number of material defects, such as coarse grains, a loose structure, a large number of shrinkage holes, a long and thin bold-pin shaped silicon-phase, poor material strength and serious brittleness. In addition, installed on the spindle without elastic conjunction,blade No. 10 vibrated and inevitably.spun off due to the large centrifugal force. Therefore, blade No. 10 first cracked at the locking handle, then broke at the root, which caused all the other 11 blades to be broken by the crack of blade No.10.

  17. Evidence of Fanning in the Ophiuchus Stream

    CERN Document Server

    Sesar, B; Cohen, J G; Rix, H -W; Pearson, S; Johnston, K V; Bernard, E J; Ferguson, A M N; Martin, N F; Slater, C T; Chambers, K C; Flewelling, H; Wainscoat, R J; Waters, C

    2015-01-01

    The Ophiuchus stellar stream presents a dynamical puzzle: its old stellar populations ($\\sim 12$ Gyr) cannot be reconciled with (1) its orbit in a simple model for the Milky Way potential and (2) its short angular extent, both of which imply that the observed stream formed within the last $ 230$ km s$^{-1}$) against $\\sim 40$ other stars: their velocities are comparable to those of the stream, but would be exceptional if they were unrelated halo stars. Their positions and velocities are, however, inconsistent with simple extrapolation of the observed cold, high-density portion of the stream. These observations suggest that stream-fanning may be a real, observable effect and, therefore, that Ophiuchus may be on a chaotic orbit. They also show that the Ophiuchus stream is more extended and hence dynamically older than previously thought, easing the stellar population vs. dynamical age tension.

  18. Fan Fault Diagnosis Based on Wavelet Packet and Sample Entropy

    Directory of Open Access Journals (Sweden)

    Xiaogang Xu

    2013-06-01

    Full Text Available To accurately diagnose the mechanical failure of the fan, two diagnostic methods based on the wavelet packet energy feature and sample entropy feature are proposed. Vibration signals acquisition of 13 kinds of running states are achieved on the 4-73 No.8D centrifugal fan test bench. The wavelet packet energy feature vector of each vibration signal is rapidly extracted through the wavelet packet denoising, decomposition and reconstruction. The vibration signal wavelet packet energy feature vector of the five measuring points in the same instantaneous running state are fused into the fan fault feature vector. Finally, the fault diagnosis of the fan is achieved by using improved SVM (Support Vector Machine classifier, and the accuracy rate is 94.6%. A new fan fault feature vector is put forward, which is the integration of the vibration signal sample entropy of the five measuring points in the same instantaneous running state, and then the fault diagnosis of the fan is achieved by using improved BP (Back Propagation neural network, and the accuracy rate is 99.23%. The diagnostic results show that these two methods are able to effectively diagnose the category, severity and site of the fan mechanical failures, and suitable for online diagnosis.

  19. Use of booster fans in underground coal mining to advantage

    Institute of Scientific and Technical Information of China (English)

    Habibi A; Gillies A D S

    2011-01-01

    A booster fan is an underground main fan which is installed in series with a main surface fan and used to boost the air pressure of the ventilation to overcome mine resistance.Currently booster fans are used in several major coal mining countries including the United Kingdom,Australia,Poland and China.In the United States booster fans are prohibited in coal mines although they are used in several metal and non-metal mines.A study has been undertaken to examine alternatives for ventilating an underground room and pillar coal mine system.A feasibility study of a hypothetical situation has shown that current ventilation facilities are incapable of fulfilling mine air requirements in the future due to increased seam methane levels.A current ventilation network model has been prepared and projected to a mine five years plan.“Ventsim visual” software simulations of different possible ventilation options have been conducted in which varying methane levels are found at working faces.The software can also undertake financial simulations and project present value total costs for the options under study.Several scenarios for improving the ventilation situation such as improving main surface fans,adding intake shafts,adding exhaust shafts and utilizing booster fans have been examined.After taking into account the total capital and operating costs for the five years mine plan the booster fan scenarios are recommended as being the best alternatives for further serious consideration by the mine.The optimum option is a properly sized and installed booster fan system that can be used to create safe work conditions,maintain adequate air quantity with lowest cost,generate a reduction in energy consumption and decrease mine system air leakage.

  20. Boll weevil (Coleoptera: Curculionidae) survival through cotton gin trash fans.

    Science.gov (United States)

    Sappington, Thomas W; Brashears, Alan D; Parajulee, Megha N; Carroll, Stanley C; Arnold, Mark D; Baker, Roy V

    2004-10-01

    There is concern that cotton gins may serve as loci for reintroduction of boll weevils, Anthonomus grandis grandis Boheman, to eradicated or suppressed zones when processing weevil-infested cotton from neighboring zones. Previous work has shown that virtually all weevils entering the gin in the seed cotton will be removed before they reach the gin stand. Those not killed by the seed cotton cleaning machinery will be shunted alive into the trash fraction, which passes through a centrifugal trash fan before exiting the gin. The objective of this study was to determine survival potential of boll weevils passed through a trash fan. Marked adult weevils were distributed in gin trash and fed through a 82.6-cm (32.5-in.) diameter centrifugal fan operated across a range of fan-tip speeds. A small number of boll weevils were recovered alive immediately after passage through the fan, but all were severely injured and did not survive 24 h. In another experiment, green bolls infested with both adult- and larval-stage weevils were fed through the fan. Several teneral adults survived 24 h, and there was no evidence that fan-tip speed affected either initial survival of weevils, or the number of unbroken boll locks that could harbor an infesting weevil. Thus, designating a minimum fan-tip speed for ensuring complete kill is not possible for the boll weevil. Experiments suggest that a device installed in a gin that partially crushes or cracks bolls open before entering a trash fan will increase mortality, possibly enough that further precautions would be unnecessary. PMID:15568350

  1. K-pop Reception and Participatory Fan Culture in Austria

    OpenAIRE

    Sang-Yeon Sung

    2013-01-01

    K-pop’s popularity and its participatory fan culture have expanded beyond Asia and become significant in Europe in the past few years. After South Korean pop singer Psy’s “Gangnam Style” music video topped the Austrian chart in October 2012, the number and size of K-pop events in Austria sharply increased, with fans organizing various participatory events, including K-pop auditions, dance festivals, club meetings, quiz competitions, dance workshops, and smaller fan-culture gatherings. In the ...

  2. Computing Gröbner fans of toric ideals

    OpenAIRE

    Huber, Birkett; Thomas, Rekha R.

    2000-01-01

    The monomial initial ideals of a graded polynomial ideal are in bijection with the vertices of a convex polytope known as the state polytope of the ideal. The Gröbner fan of the ideal is the normal fan of its state polytope. In this paper we present a software system called TiGERS (Toric Gröbner bases Enumeration by Reverse Search) for computing the Gröbner fan of a toric ideal by enumerating the edge graph of its state polytope. The key contributions are an inexpensive algorithm for local ch...

  3. Turbine Engine with Differential Gear Driven Fan and Compressor

    Science.gov (United States)

    Suciu, Gabriel L. (Inventor); Pagluica, Gino J. (Inventor); Duong, Loc Quang (Inventor); Portlock, Lawrence E. (Inventor)

    2013-01-01

    A gas turbine engine provides a differential gear system coupling the turbine to the bypass fan and the compressor. In this manner, the power/speed split between the bypass fan and the compressor can be optimized under all conditions. In the example shown, the turbine drives a sun gear, which drives a planet carrier and a ring gear in a differential manner. One of the planet carrier and the ring gear is coupled to the bypass fan, while the other is coupled to the compressor.

  4. Large Fluvial Fans: Aspects of the Attribute Array

    Science.gov (United States)

    Wilkinson, Justin M.

    2015-01-01

    In arguing for a strict definition of the alluvial fan (coarse-grained with radii less than10 km, in mountain-front settings), Blair and McPherson (1994) proposed that there is no meaningful difference between large fluvial fans (LFF) and floodplains, because the building blocks of both are channel-levee-overbank deposits. Sediment bodies at the LFF scale (greater than 100 km long, fan-shaped in planform), are relatively unstudied although greater than 160 are now identified globally. The following perspectives suggest that the significance of LFF needs to be reconsidered.

  5. Performances and Acoustic Noise of Micro Multi-blade Fan

    Institute of Scientific and Technical Information of China (English)

    Ryotaro Hidaka; Toshiaki Kanemoto; Tetsuya Sunada

    2008-01-01

    In this paper, the performances and the acoustic noise of the traditional type micro multi-blade fan were investi-gated experimentally and numerically, to optimize the specifications of the fan for the resident circumstances. The acoustic noise level decreases but the efficiency deteriorates slightly with the increase of the blade number of the impeller. Besides, the acoustic noise decreases with the increase of the distance between the impeller outlet and the volute tongue, in accompanying with the increase of the input and the deterioration of the fan efficiency.

  6. Multiple view fan beam polarimetry on Tokamak devices

    International Nuclear Information System (INIS)

    A polarimeter diagnostic is under development which utilizes several fan beams to accumulate line integrated Faraday rotation data in a Tokamak plasma. The utilization of a fan beam configuration over that of conventional vertical view polarimeter systems significantly reduces access requirements. The high angular separation inherent in a fan beam implementation increases plasma coverage and eliminates the necessity of assumed plasma symmetries to generate high quality current density profiles. Codes have been developed to generate these high-resolution two-dimensional images of the plasma current profile from data collected at arbitrary positions and viewing angles. copyright 1997 American Institute of Physics

  7. COOLING FAN AND SYSTEM PERFORMANCE AND EFFICIENCY IMPROVEMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Ronald Dupree

    2005-07-31

    Upcoming emissions regulations (Tiers 3, 4a and 4b) are imposing significantly higher heat loads on the cooling system than lesser regulated machines. This work was a suite of tasks aimed at reducing the parasitic losses of the cooling system, or improving the design process through six distinct tasks: 1. Develop an axial fan that will provide more airflow, with less input power and less noise. The initial plan was to use Genetic Algorithms to do an automated fan design, incorporating forward sweep for low noise. First and second generation concepts could not meet either performance or sound goals. An experienced turbomachinery designer, using a specialized CFD analysis program has taken over the design and has been able to demonstrate a 5% flow improvement (vs 10% goal) and 10% efficiency improvement (vs 10% goal) using blade twist only. 2. Fan shroud developments, using an 'aeroshroud' concept developed at Michigan State University. Performance testing at Michigan State University showed the design is capable of meeting the goal of a 10% increase in flow, but over a very narrow operating range of fan performance. The goal of 10% increase in fan efficiency was not met. Fan noise was reduced from 0 to 2dB, vs. a goal of 5dB at constant airflow. The narrow range of fan operating conditions affected by the aeroshroud makes this concept unattractive for further development at this time 3. Improved axial fan system modeling is needed to accommodate the numbers of cooling systems to be redesigned to meet lower emissions requirements. A CFD fan system modeling guide has been completed and transferred to design engineers. Current, uncontrolled modeling practices produce flow estimates in some cases within 5% of measured values, and in some cases within 25% of measured values. The techniques in the modeling guide reduced variability to the goal of + 5% for the case under study. 4. Demonstrate the performance and design versatility of a high performance fan. A

  8. Is there still a glass ceiling for women in academic surgery?

    Science.gov (United States)

    Zhuge, Ying; Kaufman, Joyce; Simeone, Diane M; Chen, Herbert; Velazquez, Omaida C

    2011-04-01

    Despite the dramatically increased entry of women into general surgery and surgical subspecialties, traditionally male-dominated fields, there remains a gross under-representation of women in the leadership positions of these departments. Women begin their careers with fewer academic resources and tend to progress through the ranks slower than men. Female surgeons also receive significantly lower salaries than their male counterparts and are more vulnerable to discrimination, both obvious and covert. Although some argue that female surgeons tend to choose their families over careers, studies have actually shown that women are as eager as men to assume leadership positions, are equally qualified for these positions as men, and are as good as men at leadership tasks.Three major constraints contribute to the glass-ceiling phenomenon: traditional gender roles, manifestations of sexism in the medical environment, and lack of effective mentors. Gender roles contribute to unconscious assumptions that have little to do with actual knowledge and abilities of an individuals and they negatively influence decision-making when it comes to promotions. Sexism has many forms, from subtle to explicit forms, and some studies show that far more women report being discriminately against than do men. There is a lack of same-sex mentors and role models for women in academic surgery, thereby isolating female academicians further. This review summarizes the manifestation of the glass-ceiling phenomenon, identifies some causes of these inequalities, and proposes different strategies for continuing the advancement of women in academic surgery and to shatter the glass ceiling. PMID:21475000

  9. 30 CFR 57.8534 - Shutdown or failure of auxiliary fans.

    Science.gov (United States)

    2010-07-01

    ... auxiliary fan failure due to malfunction, accident, power failure, or other such unplanned or unscheduled... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Shutdown or failure of auxiliary fans. 57.8534... Ventilation Underground Only § 57.8534 Shutdown or failure of auxiliary fans. (a) Auxiliary fans installed...

  10. Bellholes: Ceiling Cavities Eroded By Bats in Caves of the Neotropical Climates

    Science.gov (United States)

    Miller, T.

    2014-12-01

    Hundreds of thousands of symmetrical, vertical, bullet-shaped cavities known as bellholes are present in the ceilings of caves restricted to the tropical Americas. Most have circular diameters (rarely influenced by joints or bedding) of at least 30 cm, and may be several meters in height. They are often paired with bellbasins (shallow depressions located vertically beneath them that contain guano produced by bats). Members of the species Artibeus jamaicensis (Jamaican Fruit Bat) are almost exclusive users of these roosts. Brown streaks flowing down the sides of the bellholes and centimeters-thick rinds of the basins below are largely apatite minerals produced by the reaction of the host limestone with phosphoric acids in the guano.Many bellholes have developed in speleothem in the cave ceilings, disproving early theories that they are the result of solution by phreatic currents in flooded caves. A. jamaicensis roosts singly or in harem groups of 2-14 that commonly cluster in the bellholes and it is likely that these social habits of this species focus corrosion resulting from the transfer of feces to rock (producing altered rock then removed by claws) to create discretely-spaced upward-growing cavities. Fossil evidence from Jamaica supports an arrival there from the mainland in the past 12,000 years, suggesting bellholes and bellbasins are geologically recent features in the Caribbean islands. Their locations (not all cave passages have bellholes) can provide information on the hydrological history or microclimate of a cave, due to the absence of both bellholes and bats in some specific situations, e.g. where physical barriers exist such as sumps, small airspaces above streams or through rock collapses, or with increasing distance from an entrance.Smaller circular, increasingly-indented ceiling cavities demonstrate a sequence of bellhole development. Small (23 cm diameter, 9 cm high), circular, streaked cavities in a limestone drainage tunnel constructed in 1927 in

  11. Building America Case Study: Raised Ceiling Interior Duct System, New Smyrna, Florida (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2014-09-01

    One of BA-PIRC's longtime Habitat for Humanity partners, S.E. Volusia CO (SEVHFH), was interested in building a home to the new Challenge Home standards. SEVHFH routinely builds ENERGY STAR V3.1 homes. The only modification to their design needed to comply with the Challenge Home criteria was the interior duct requirement. Unwilling to incur the added costs of a foam roof deck or wall heights above 8 feet to accommodate a fur-down chase SEVHFH opted to build a fur-up or raised ceiling chase.

  12. An acoustical analysis of a room with a concave dome ceiling element

    Science.gov (United States)

    Utami, Sentagi S.

    2001-05-01

    Concave surfaces are often considered detrimental in room acoustics, especially because of the impact they have on the distribution of sound energy. This paper explores certain acoustical characteristics and anomalies found in spaces below concave dome ceiling elements. The architectural design of the Darusshollah mosque in East Java, Indonesia is used as a case study with specific spatial and functional concerns. Investigations of the mosque have been conducted through both a 1:12 scale model and a computer model that utilizes ray tracing and image source methods. Analysis techniques are discussed. Results are presented and compared to provide useful insights into the acoustics of such distinctive environments.

  13. Experimental evaluation of heat transfer coefficients between radiant ceiling and room

    DEFF Research Database (Denmark)

    Causone, Francesco; Corgnati, Stefano P.; Filippi, Marco; Olesen, Bjarne W.

    2009-01-01

    The heat transfer coefficients between radiant surfaces and room are influenced by several parameters: surfaces temperature distributions, internal gains, air movements. The aim of this paper is to evaluate the heat transfer coefficients between radiant ceiling and room in typical conditions of...... occupancy of an office or residential building. Internal gains were therefore simulated using heated cylinders and heat losses using cooled surfaces. Evaluations were developed by means of experimental tests in an environmental chamber. Heat transfer coefficient may be expressed separately for radiation and...

  14. Reconstruction of a Baroque Open Beam Ceiling based on Material Analysis

    Czech Academy of Sciences Publication Activity Database

    Kloiber, Michal; Válek, Jan; Bláha, Jiří; Čechová, J.

    Vol. 688. Stafa-Zürich: Trans Tech Publications, 2013 - (Drochytka, R.; Vaněrek, J.), s. 10-19 ISBN 978-3-03785-679-6. ISSN 1022-6680. [Conference on the Rehabilitation and reconstruction of buildings /14./. Brno (CZ), 06.11.2012-07.11.2012] R&D Projects: GA MK(CZ) DF11P01OVV001 Keywords : roof * ceiling * reconstruction * lime coating Subject RIV: JN - Civil Engineering http://www.scientific.net/AMR.688.10

  15. Reconstruction of a Baroque Open Beam Ceiling Based on Material Analysis

    Czech Academy of Sciences Publication Activity Database

    Kloiber, Michal; Válek, Jan; Bláha, Jiří; Čechová, J.

    Uherské Hradiště: Vědeckotechnická společnost pro sanace staveb a péči o památky - WTA CZ, 2012 ISBN 978-82-02-02414-9. [Conference on the Rehabilitation and reconstruction of building /14./. Brno (CZ), 06.11.2012-07.11.2012] R&D Projects: GA MK(CZ) DF11P01OVV001; GA MK(CZ) DF11P01OVV010 Keywords : ceiling * lime coating * reconstruction * roof Subject RIV: JN - Civil Engineering

  16. Assessment of GEC Apollo X-ray tube ceiling suspension with GEC sectograph tomographic attachments

    International Nuclear Information System (INIS)

    The performance of a GEC Apollo X-ray tube ceiling suspension with GEC sectograph tomographic attachments was assessed in detail at the King's Centre for the Assessment of Radiological Equipment (KCARE). Particulars of the assessment and operational features of the equipment are described. The report indicates that the equipment is robustly and safely constructed and it has a versatility which enables it to be used for all the applications currently foreseen for such units. The use of the Apollo in conjunction with sectograph tomographic attachments can provide linear tomographs comparable in excellence with those produced on dedicated units. (U.K.)

  17. Is a Widening Gender Wage Gap Necessarily Caused by a Glass Ceiling?

    OpenAIRE

    Staveren, Irene

    2012-01-01

    textabstractContrary to what is generally assumed, the gender wage gap and the glass ceiling may not necessarily be positively related. An exploratory analysis of aggregate public service personnel data for Uganda shows that the gender wage gap is small at the middle level of management, whereas it is twice as high at the top. At the same time, the share of women in top positions appears to be twice as high as at the middle ranks. Hence, it seems that in the context of a very patriarchal cult...

  18. In Search of the Glass Ceiling: The Career Trajectories of Immigrant and Native-born Engineers

    OpenAIRE

    Waldinger, Roger; Bozorgmehr, Mehdi; Lim, Nelson; Finkel, Lucila

    1998-01-01

    This paper reports on an effort designed to search for the glass ceiling, through a study of the career trajectories of native white and Asian immigrant engineers. Using data drawn from a survey of the M.S. graduates of the engineering school at "Southern California U," we find that some form of labor market segmentation, so common at lower levels of the economy, is also restricting the mobility of highly skilled foreign-born engineers. Our key finding shows that immigrants receive a signific...

  19. Social impact of air pollution abatement. Societal cost benefit analysis of possible National Emission Ceilings

    International Nuclear Information System (INIS)

    In 2008, the European Commission will launch new proposals for revision of the NEC guideline (2001/81/EG) in which new emission ceilings are proposed for the year 2020. In order to determine which stand the Netherlands should take during the negotiations, the Dutch Ministry of Economic Affairs (also on behalf of the Ministry of Agriculture, Nature and Food Quality) asked CE Delft and Ecorys to conduct a societal cost benefit analysis in collaboration with the Environmental Assessment Agency. This report describes the results of the analysis of two alternative NEC targets for 2020. [mk

  20. Dropped Ceiling

    OpenAIRE

    Tabet, Rayyane

    2012-01-01

    On December 2nd 1950 the first drop of Saudi oil arrived to Lebanon via the newly constructed Trans-Arabian Pipeline, the world's longest pipeline and the largest American private investment in a foreign land. The 30inch wide structure which spanned 1213 kilometers passing through Saudi Arabia, Jordan, and Syria to end in Lebanon had required 3 years of planning and surveying, 2 years of installation, the fabrication of 256,000 tons of steel tubes, the employment of 30,000 workers, the ratifi...

  1. Supersonic through-flow fan engine and aircraft mission performance

    Science.gov (United States)

    Franciscus, Leo C.; Maldonado, Jaime J.

    1989-01-01

    A study was made to evaluate potential improvement to a commercial supersonic transport by powering it with supersonic through-flow fan turbofan engines. A Mach 3.2 mission was considered. The three supersonic fan engines considered were designed to operate at bypass ratios of 0.25, 0.5, and 0.75 at supersonic cruise. For comparison a turbine bypass turbojet was included in the study. The engines were evaluated on the basis of aircraft takeoff gross weight with a payload of 250 passengers for a fixed range of 5000 N.MI. The installed specific fuel consumption of the supersonic fan engines was 7 to 8 percent lower than that of the turbine bypass engine. The aircraft powered by the supersonic fan engines had takeoff gross weights 9 to 13 percent lower than aircraft powered by turbine bypass engines.

  2. Foil Gas Bearing Supported Quiet Fan for Spacecraft Ventilation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Developing a quiet fan for Environmental Control and Life Support systems to enhance the livable environment within the spacecraft has been a challenge. A Foil Gas...

  3. Field testing the prototype BNL fan-atomized oil burner

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, R.; Celebi, Y. [Brookhaven National Lab., Upton, NY (United States)

    1995-04-01

    BNL has developed a new oil burner design referred to as the Fan Atomized burner System. The primary objective of the field study was to evaluate and demonstrate the reliable operation of the Fan Atomized Burner. The secondary objective was to establish and validate the ability of a low firing rate burner (0.3-0.4 gph) to fully satisfy the heating and domestic hot water load demands of an average household in a climate zone with over 5,000 heating-degree-days. The field activity was also used to evaluate the practicality of side-wall venting with the Fan Atomized Burner with a low stack temperature (300F) and illustrate the potential for very high efficiency with an integrated heating system approach based on the Fan Atomized Burner.

  4. Autonomous Composite Fan Containment Integrity Monitoring (AUTOCONFIRM) System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — New engine fan blade containment structures are being manufactured with advanced composite structures such that they can withstand blade-out events. The use of...

  5. Low Cost/Low Noise Variable Pitch Ducted Fan Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ACI proposes a design for a Propulsor (Low Cost/Low Noise Variable Pitch Ducted Fan) that has wide application in all sectors of Aviation. Propulsor hardware of...

  6. EFFICIENT FAN-OUT RF VECTOR CONTROL ALGORITHM *

    International Nuclear Information System (INIS)

    A new RF vector control algorithm for fan-out power distribution using reactive transmission line circuit parameters for maximum power efficiency is presented. This control with fan-out power distribution system is considered valuable for large scale SRF accelerator systems to reduce construction costs and save on operating costs. In a fan-out RF power distribution system, feeding multiple accelerating cavities with a single RF power generator can be accomplished by adjusting phase delays between the load cavities and reactive loads at the cavity inputs for independent control of cavity RF voltage vectors. In this approach, the RF control parameters for a set of specified cavity RF voltage vectors is determined for an entire fan-out system. The reactive loads and phase shifts can be realized using high power RF phase shifters.

  7. Effect of material uncertainties on dynamic analysis of piezoelectric fans

    Science.gov (United States)

    Srivastava, Swapnil; Yadav, Shubham Kumar; Mukherjee, Sujoy

    2015-04-01

    A piezofan is a resonant device that uses a piezoceramic material to induce oscillations in a cantilever beam. In this study, lumped-mass modelling is used to analyze a piezoelectric fan. Uncertainties are associated with the piezoelectric structures due to several reasons such as variation during manufacturing process, temperature, presence of adhesive layer between the piezoelectric actuator/sensor and the shim stock etc. Presence of uncertainty in the piezoelectric materials can influence the dynamic behavior of the piezoelectric fan such as natural frequency, tip deflection etc. Moreover, these quantities will also affect the performance parameters of the piezoelectric fan. Uncertainty analysis is performed using classical Monte Carlo Simulation (MCS). It is found that the propagation of uncertainty causes significant deviations from the baseline deterministic predictions, which also affect the achievable performance of the piezofan. The numerical results in this paper provide useful bounds on several performance parameters of the cooling fan and will enhance confidence in the design process.

  8. Acceptance test procedure MICON software exhaust fan control modifications

    International Nuclear Information System (INIS)

    This acceptance test verifies the MICON program changes for the new automatic transfer switch ATS-2 alarms, the Closed Loop Cooling isolator status, the CB-3 position alarm, and the alarms for the new emergency fan damper backup air compressor

  9. The Female Vikings, a women's fan group in Denmark

    DEFF Research Database (Denmark)

    Mintert, Svenja-Maria; Pfister, Gertrud Ursula

    2014-01-01

    the historical development of a Danish women-only fan group called 'The Female Vikings', which support a professional football club, Lyngby Boldklub (BK), in a city north of Copenhagen. The article explores the backgrounds and motivations of female fans, as well as their ways of staging femininity in...... a man's world. Drawing on available information about football and fans in Denmark, we have reconstructed the developments of both Lyngby BK and its supporters. Special focus was placed on the histories and cultures as well as the experiences of female fans in this club. Insights into the foundation......Traditionally, football and fandom have been male domains and celebrations of masculinity. So far there has been some sociological and historical research on women's football; however, little is known about women's fandom, in particular about its formation and development. This article focuses on...

  10. Gender constructions and negotiations of female football fans

    DEFF Research Database (Denmark)

    Lenneis, Verena; Pfister, Gertrud Ursula

    2015-01-01

    While both the media and the academic literature focus primarily on male fans, in particular on violence and the prevention of hooliganism, little is known about female football supporters. This is also true of Denmark, a country that is known for its high degree of gender equality. This article...... aims to give insight into gender constructions and negotiations of female football fans in the stands. Drawing on a social constructivist perspective to gender and Bourdieu's (1984) approaches to field, capital and habitus, we explored the experiences and opinions of female fans. The methods employed...... were stadium observations as well as qualitative, guideline-based interviews with female supporters of three different clubs. The observations and interviews reveal that traditional gender norms, prejudices and sexism are widespread in the fan stands, and are often accepted and trivialised by the...

  11. Cooling efficiency of a brushless direct current stand fan

    OpenAIRE

    Yang, Bin; Schiavon, Stefano; Sekhar, Chandra; Cheong, David; Tham, Kwok Wai; Nazaroff, William W.

    2015-01-01

    In warm environments, isothermal cooling by deliberately enhanced air movement can maintain thermal comfort using less energy than compressor-based air conditioning. To evaluate the performance of a brushless direct current (DC) stand fan, the cooling fan efficiency (CFE) index was measured in a climatic chamber under four dry-bulb temperatures (24, 26, 28, and 30 °C), six speed In warm environments, isothermal cooling by deliberately enhanced air movement can maintain thermal comfort using l...

  12. Acoustic Fan Noise Cancellation in a Laptop Microphone System

    OpenAIRE

    Chokkarapu, Anil

    2012-01-01

    Speech communication involving audio conferencing, video conferencing, teleconferencing via laptops became greatly influenced in office environments i.e. between employer and employee, and also influenced in personal life meetings between friends or in-between parents and children. These meeting conversations will mostly disturbs by annoying noise, i.e. fan noise which is produced by laptop cooling fan, which suffers at the both ends of communication due to this noise. With this noise effect ...

  13. Reader, Please Follow Me : fan fiction, author instructions, and feedback

    OpenAIRE

    Lindgren Leavenworth, Maria

    2015-01-01

    The article examines forms of communication surrounding the publication and reception of fan fiction: on-line published stories working from an existing fictional universe. At focus are two fanfics that have Jane Austen’s Pride and Prejudice as s starting point, and their publication on the large site FanFiction.net. Already published in their entirety elsewhere, the daily chapter installments of the fanfics are designed to initiate contact with a new group of readers, reciprocated through re...

  14. Ultra Wideband Fan Shape Fractal Antenna for Microwave Application.

    OpenAIRE

    Bimal Raj Dutta; Devesh Kumar Singh Rathore

    2013-01-01

    This paper describes the design and simulation of Fan shape fractal antenna using IE3D electromagnetic simulation software. The fractal structure is advantageous in generating multiple frequencies or enhancing bandwidth. fan shape fractal antenna gives better performance in return loss, efficiency and directivity. This fractal antenna can be used in the Wi-Fi. Fractal antenna are very odd in concept and very new in design for wideband applications, many discontinues in the structure add in ra...

  15. Combined velocity and depth mapping on developing laboratory alluvial fans

    Science.gov (United States)

    Hamilton, P.; Strom, K. B.; Hoyal, D. C.

    2011-12-01

    Large-scale particle image velocimetry (LSPIV) is a nonintrusive method for measuring free-surface velocities using tracer patterns in a sequence of images. This method has been applied in both natural rivers and large-scale hydraulic models (Muste et al., 2008). Here the method is used to map channel and sheet flow velocity during the development of laboratory-scale alluvial fans. Measuring the time and space varying hydraulics on laboratory fans by traditional methods is not practical since flows are quite shallow (~1 cm). Additionally, the highly dynamic environment makes positioning of traditional probe-type instruments difficult and their physical presence could alter autogenic fan evolution. These difficulties can be overcome by using particle image velocimetry techniques. Furthermore, images collected in the LSPIV method can be used to extract flow depth using a calibrated dye-intensity method (Gran and Paola, 2001). This allows for simultaneous measurement of flow velocity and depth everywhere over the fan at any point in time. To validate the method, a set of controlled small-scale experiments were run for depths ranging from 0.2-1.5 cm and velocities from 10-100 cm/sec. Comparison of the LSPIV and dye-intensity method measurements to the known values indicated that the methodology was able to accurately capture simultaneous flow velocity and depth in this range of conditions, i.e., those encountered during the development of laboratory-scale alluvial fans and streams. The method is then used to map the hydraulics associated with various fan processes during development as demonstrated in figure 1. The ability to measure hydraulic properties during fan development is important since physical models provide an arena for observing the time evolution and morphodynamic feedback in depositional systems such as alluvial fans.

  16. Seismic stratigraphic interpretation of Mississippi Fan, Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Feeley, M.H.; Buffler, R.T.; Bryant, W.R.

    1984-04-01

    Examination of extensive multichannel and single-channel seismic data across the Mississippi Fan, Gulf of Mexico, reveals that at least 7 seismic sequences comprise the upper Pliocene-Pleistocene section of this giant fan. These sequences are divided into 2 groups based on continuity and amplitude of reflectors. The lower 3 sequences are generally characterized by high-amplitude, parallel to subparallel, continuous reflectors overlain in places by a hummocky clinoform reflection configuration. The reflection patterns suggest distal turbidites deposited in a relatively low-energy environment. In contrast, the upper 4 sequences are generally thicker and characterized by regionally extensive chaotic units interbedded with thin, high-amplitude, parallel to subparallel reflection packages. The chaotic zones grade laterally into more continuous, parallel to gently diverging reflection patterns, probably a lower energy, more distal turbidite facies. Isopach and structure maps of each sequence indicate a seaward and eastward migration in the Pliocene-Pleistocene depocenter during fan development. Channel, level, slump, turbidite, and hemipelagic deposits are interpreted within each sequence. Channel/level deposits are extensive, showing great variability in their morphology and distribution. On the upper fan, the channels are large with well-developed levee sequences. On the middle and lower fan, the channel sequences are smaller, confined mainly to the apex of lobes, and show little evidence of migration and abandonment during lobe development. Slumping off the slope apparently contributed a significant percentage of the material deposited on the upper fan. In addition, the truncation of prominent reflectors and the mounded, chaotic and diffracted patterns on the middle and lower fan suggest the slumping was continually active during fan development.

  17. Analýza konkurenceschopnosti podniku FANS, a.s.

    OpenAIRE

    Kodr, Jakub

    2013-01-01

    The goal of the bachelors work: "Analysis of competitiveness of the chosen company" is identification of a competitive advantage, based on external and internal environment FANS, a.s. company. The thesis is composed of two parts. In the theoretical section are described basic definitions from professional literature and the methods relating to competition and competitiveness. In the practical section PEST, SWOT, Porters model of 5 powers and financial analysis are applied on FANS, a.s. compan...

  18. Dynamic Bowtie for Fan-beam CT

    CERN Document Server

    Liu, Fenglin; Cong, Wenxiang; Hsieh, Scott; Pelc, Norbert

    2013-01-01

    A bowtie is a filter used to shape an x-ray beam and equalize its flux reaching different detector channels. For development of spectral CT with energy-discriminative photon-counting (EDPC) detectors, here we propose and evaluate a dynamic bowtie for performance optimization based on a patient model or a scout scan. Our dynamic bowtie modifies an x-ray beam intensity profile by mechanical rotation and adaptive adjustment of the x-ray source flux. First, a mathematical model for dynamic bowtie filtering is established for an elliptical section in fan-beam geometry, and the contour of the optimal bowtie is derived. Then, numerical simulation is performed to compare the performance of the dynamic bowtie in the cases of an ideal phantom and a realistic cross-section relative to the counterparts without any bowtie and with a fixed bowtie respectively. Our dynamic bowtie can equalize the expected numbers of photons in the case of an ideal phantom. In practical cases, our dynamic bowtie can effectively reduce the dy...

  19. PLSS 2.5 Fan Design and Development

    Science.gov (United States)

    Converse, David; Carra, Michael; Quinn, Gregory; Chullen, Cinda

    2015-01-01

    NASA is building a high fidelity prototype of an advanced portable life support system (PLSS) as part of the Advanced Exploration Systems Program. This new PLSS, designated as PLSS 2.5, will advance component technologies and systems knowledge in order to inform a future flight program. The oxygen ventilation loop of its predecessor, PLSS 2.0, is driven by a centrifugal fan developed using specifications from over five years ago. PLSS technology and system parameters have matured to the point where the existing fan will not perform adequately for the new prototype. In addition, areas of potential improvement have been identified with the existing fan that could be addressed in a new design. As a result, a new fan was designed and tested for the PLSS 2.5. The PLSS 2.5 fan is a derivative of the one used in PLSS 2.0. It uses the same basic non-metallic can around the motor, but with a larger volute and impeller to meet the higher pressure drop requirements of the PLSS 2.5 loop. This allows it to operate at rotational speeds that are matched to rolling element bearings, and which create reasonably low impeller tip speeds. Development of the fan also considered a shrouded impeller design that allows larger clearances for greater oxygen safety and better performance.

  20. Damage-Tolerant Fan Casings for Jet Engines

    Science.gov (United States)

    2006-01-01

    All turbofan engines work on the same principle. A large fan at the front of the engine draws air in. A portion of the air enters the compressor, but a greater portion passes on the outside of the engine this is called bypass air. The air that enters the compressor then passes through several stages of rotating fan blades that compress the air more, and then it passes into the combustor. In the combustor, fuel is injected into the airstream, and the fuel-air mixture is ignited. The hot gasses produced expand rapidly to the rear, and the engine reacts by moving forward. If there is a flaw in the system, such as an unexpected obstruction, the fan blade can break, spin off, and harm other engine components. Fan casings, therefore, need to be strong enough to contain errant blades and damage-tolerant to withstand the punishment of a loose blade-turned-projectile. NASA has spearheaded research into improving jet engine fan casings, ultimately discovering a cost-effective approach to manufacturing damage-tolerant fan cases that also boast significant weight reduction. In an aircraft, weight reduction translates directly into fuel burn savings, increased payload, and greater aircraft range. This technology increases safety and structural integrity; is an attractive, viable option for engine manufacturers, because of the low-cost manufacturing; and it is a practical alternative for customers, as it has the added cost saving benefits of the weight reduction.

  1. Development of axial flow fan with automatic blade inversion mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Saito, T.; Aranishi, Y.; Oikawa, T. (Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)); Masuoka, S. (IMEC, Tokyo (Japan))

    1991-04-01

    The simple mechanism air supply/exhaust axial fan was developed for underground spaces, subways and road tunnels which is featured by automatic blade inversion up to 180{degree} corresponding to the forward or reverse rotating direction of a fan motor. Rotatable asymmetric airfoil blades are attached to the hub directly connected with a motor shaft, and the small gear attached to the end of each blade shaft is engaged with a large gear. Rotation of the large gear connected to an electromagnetic brake decreases as braking force is applied to it during fan rotation, and the speed difference produced between the hub and large gear causes small gear rotation resulting in blade inversion. As such characteristics as an outlet velocity, fan efficiency, thrust produced, noise and durability were measured on a test fan with an impeller diameter of 1,250 mm and rated discharge velocity of 30 m/s, the efficiency as high as 75% was obtained as compared with that (67%) of a jet fan with equivalent specifications. No defects and marked wear were also found after inversion tests more than 600 times. 9 figs., 1 tab.

  2. D0 Cryo Ventilation Fan Controls and Monitoring

    International Nuclear Information System (INIS)

    This engineering note describes how exhaust fan 6 (EF-6) and exhaust fan 7 (EF-7) are controlled and monitored. Since these two fans are a vital link in the ODH safety system, they will be monitored, controlled and periodically operated by the programmable logic controller (PLC). If there should be a fault in the ventilation system, the PLC will print a warning message to the cryo control room printer and flash a descriptive warning on the ODH/ventilation graphics page. This fault is also logged to the Xpresslink graphics alarm page and to an alarm history hard disk file. The ventilation failure is also an input to the auto dialer which will continue it's automatic sequence until acknowledged. EF-6 delivers 13000 C.F.M. and is considered emergency ventilation. EF-7 delivers 4500 C.F.M. and will run 24 hrs a day. Both ventilation fans are located in an enclosed closet in the TRD gas room. Their ductwork, both inlets and outlets run along side the pipe chase, but are separated by an airtight wall. Their combination motor control starter cabinets are located in the TRD room in plain visible sight of the fans with the closet door open. The fans have signs that state they are automatically controlled and can energize at any time.

  3. Enhancing fan experience during live sports broadcasts through second screen applications

    OpenAIRE

    Centieiro, Pedro Miguel da Fonseca

    2015-01-01

    When sports fans attend live sports events, they usually engage in social experiences with friends, family members and other fans at the venue sharing the same affiliation. However, fans watching the same event through a live television broadcast end up not feeling so emotionally connected with the athletes and other fans as they would if they were watching it live, together with thousands of other fans. With this in mind, we seek to create mobile applications that deliver engaging social exp...

  4. Impact of the disease: acceptability, ceiling and floor effects and reliability of an instrument on heart failure

    Directory of Open Access Journals (Sweden)

    Simey de Lima Lopes Rodrigues

    2013-03-01

    Full Text Available This study evaluated the acceptability, ceiling/floor effects, and the reliability of the instrument for measuring the Impact of the Disease on the Daily Life of Patients with Valvular Disease (IDCV when applied to 135 patients with heart failure (HF. Acceptability was evaluated by the percentage of unanswered items and by the proportion of patients who responded to all items; the ceiling/floor effects by the percentage of patients who scored in the top of 10% best and worst results of the scale, respectively. Reliability was estimated by internal consistency (Cronbach's alpha coefficient and stability of the measure (intraclass correlation coefficient - ICC. All patients responded to all items. Ceiling/floor effects evidenced were of moderate magnitude. The Cronbach's alpha was satisfactory for the majority of the domains and ICC> 0.90 in all the domains. The IDCV proved to be an easy to understand questionnaire, with evidence of reliability in patients with HF.

  5. Influence of Ceiling Suspended Screen Positioning to the Scatter Radiation Levels in Interventional Cardiology

    International Nuclear Information System (INIS)

    The objective of this paper is to identify the effects of the ceiling suspended screen position to the scatter radiation levels in the interventional cardiology. The scatter radiation in terms of ambient dose equivalent H*(10) was measured for various positions of protective screen in the positions of the first operator, nurse and radiographer, at elevations 100-190 cm and in four different angulations of the x-ray tube. To assess the effectiveness of the protective screen, the scattered dose was also measured in the absence of any protection in all four angulations and elevations. To simulate real clinical situation the measurements were performed in the presence of 30 cm PMMA phantom using standard clinical protocol. The utility of protective screen varied for different positions and angulations. Scatter radiation levels varied in the range 70 - 3400 μSv/h for the first operator, 140 - 3200 μSv/h for the nurse and 50 - 560 μSv/h for radiographer. Ceiling suspended screens can provide a substantial level of protection (up to factor 18) in interventional cardiology, but they have to be properly managed and positioned to achieve sufficient level of protection. The guidance for optimal protection is provided in the paper.(author)

  6. The Spanish gasoline market: From ceiling regulation to open market pricing

    International Nuclear Information System (INIS)

    This paper examines the evolution of the Spanish gasoline market from the abolition of the state oil monopoly (January 1993) to complete liberalization (October 1998). With the restructuring of the Spanish oil sector during the 1980s and early 1990s, a highly concentrated oligopoly emerged in the automotive fuels market. A system of price ceilings replaced the state administered prices in July 1990. Since then, new domestic and foreign operators have entered the market, particularly along the coast, near import terminals. Prices went up and then declined. These developments can be explained by an interplay of factors such as: the gradual decline in co-operation among the Spanish firms; the loss of market share of the largest of these, Repsol; the entry of independent operators and supermarkets; and the impact of the ceiling price system. By mid-1998 this system was abolished as the government considered it an impediment to further market liberalization. However, some crucial barriers to the entry of new suppliers remain

  7. Geomorphometric analysis of cave ceiling channels mapped with 3-D terrestrial laser scanning

    Science.gov (United States)

    Gallay, Michal; Hochmuth, Zdenko; Kaňuk, Ján; Hofierka, Jaroslav

    2016-05-01

    The change of hydrological conditions during the evolution of caves in carbonate rocks often results in a complex subterranean geomorphology, which comprises specific landforms such as ceiling channels, anastomosing half tubes, or speleothems organized vertically in different levels. Studying such complex environments traditionally requires tedious mapping; however, this is being replaced with terrestrial laser scanning technology. Laser scanning overcomes the problem of reaching high ceilings, providing new options to map underground landscapes with unprecedented level of detail and accuracy. The acquired point cloud can be handled conveniently with dedicated software, but applying traditional geomorphometry to analyse the cave surface is limited. This is because geomorphometry has been focused on parameterization and analysis of surficial terrain. The theoretical and methodological concept has been based on two-dimensional (2-D) scalar fields, which are sufficient for most cases of the surficial terrain. The terrain surface is modelled with a bivariate function of altitude (elevation) and represented by a raster digital elevation model. However, the cave is a 3-D entity; therefore, a different approach is required for geomorphometric analysis. In this paper, we demonstrate the benefits of high-resolution cave mapping and 3-D modelling to better understand the palaeohydrography of the Domica cave in Slovakia. This methodological approach adopted traditional geomorphometric methods in a unique manner and also new methods used in 3-D computer graphics, which can be applied to study other 3-D geomorphological forms.

  8. Women's health and women's leadership in academic medicine: hitting the same glass ceiling?

    Science.gov (United States)

    Carnes, Molly; Morrissey, Claudia; Geller, Stacie E

    2008-11-01

    The term "glass ceiling" refers to women's lack of advancement into leadership positions despite no visible barriers. The term has been applied to academic medicine for over a decade but has not previously been applied to the advancement of women's health. This paper discusses (1) the historical linking of the advances in women's health with women's leadership in academic medicine, (2) the slow progress of women into leadership in academic medicine, and (3) indicators that the advancement of women's health has stalled. We make the case that deeply embedded unconscious gender-based biases and assumptions underpin the stalled advancement of women on both fronts. We conclude with recommendations to promote progress beyond the apparent glass ceiling that is preventing further advancement of women's health and women leaders. We emphasize the need to move beyond "fixing the women" to a systemic, institutional approach that acknowledges and addresses the impact of unconscious, gender-linked biases that devalue and marginalize women and issues associated with women, such as their health. PMID:18954235

  9. Derivation of factors for estimating the scatter of diagnostic x-rays from walls and ceiling slabs

    International Nuclear Information System (INIS)

    Computed tomography (CT) scanning rooms and interventional x-ray facilities with heavy workloads may require the installation of shielding to protect against radiation scattered from walls or ceiling slabs. This is particularly important for the protection of those operating x-ray equipment from within control cubicles who may be exposed to radiation scattered from the ceiling over the top of the protective barrier and round the side if a cubicle door is not included. Data available on the magnitude of this tertiary scatter from concrete slabs are limited. Moreover, there is no way in which tertiary scatter levels can be estimated easily for specific facilities. There is a need for a suitable method for quantification of tertiary scatter because of the increases in workloads of complex x-ray facilities. In this study diagnostic x-ray air kerma levels scattered from concrete and brick walls have been measured to verify scatter factors. The results have been used in a simulation of tertiary scatter for x-ray facilities involving summation of scatter contributions from elements across concrete ceiling slabs. The majority of the ceiling scatter air kerma to which staff behind a barrier will be exposed arises from the area between the patient/x-ray tube and the staff. The level depends primarily on the heights of the ceiling and protective barrier. A method has been developed to allow tertiary scatter levels to be calculated using a simple equation based on a standard arrangement for rooms with different ceiling and barrier heights. Coefficients have been derived for a CT facility and an interventional suite to predict tertiary scatter levels from the workload, so that consideration can be given to the protection options available. (paper)

  10. From the glass door to the glass ceiling: An analysis of the gender wage gap by age groups

    OpenAIRE

    Elena Dalla Chiara; Eleonora Matteazzi; Ilaria Petrarca

    2014-01-01

    Using 2009 EU-SILC data for France, Italy, the Netherlands and the United Kingdom, we decompose the gender wage gap for prime age workers. We adopt an age group approach to identify when and how the glass door and the glass ceiling effects arise and their persistency over time. The empirical results verify that the raw gender wage gap increases with age. In all considered countries, the glass ceiling effect is completely realized by the age of 30 and increases over time. French, Italian and B...

  11. Career barriers for women executives and the Glass Ceiling Syndrome: the case study comparison between French and Turkish women executives.

    OpenAIRE

    Akpinar, Cansu

    2012-01-01

    The situation where gender pay gaps are typically wider at the top of the wage distribution is known as the 'glass ceiling'. It is one of the most compelling metaphors recently used for analyzing inequality between men and women in the workplace, in order to describe a barrier to further advancement once women have attained a certain level. The general-case glass ceiling hypothesis states that not only is it more difficult for women than for men to be promoted up levels of authority hierarchi...

  12. Career barriers for women executives and the Glass Ceiling Syndrome : the case study comparison between French and Turkish women executives.

    OpenAIRE

    Akpinar-Sposito, Cansu

    2012-01-01

    The situation where gender pay gaps are typically wider at the top of the wage distribution is known as the 'glass ceiling'. It is one of the most compelling metaphors recently used for analyzing inequality between men and women in the workplace, in order to describea barrier to further advancement once women have attained a certain level. The general-case glass ceiling hypothesis states that notonly is it more difficult for women than for men to be promoted up levels of authority hierarchies...

  13. On the Crack Bifurcation and Fanning of Crack Growth Data

    Science.gov (United States)

    Forman, Royce G.; Zanganeh, Mohammad

    2015-01-01

    Crack growth data obtained from ASTM load shedding method for different R values show some fanning especially for aluminum alloys. It is believed by the authors and it has been shown before that the observed fanning is due to the crack bifurcation occurs in the near threshold region which is a function of intrinsic properties of the alloy. Therefore, validity of the ASTM load shedding test procedure and results is confirmed. However, this position has been argued by some experimentalists who believe the fanning is an artifact of the test procedure and thus the obtained results are invalid. It has been shown that using a special test procedure such as using compressively pre-cracked specimens will eliminate the fanning effect. Since not using the fanned data fit can result in a significantly lower calculated cyclic life, design of a component, particularly for rotorcraft and propeller systems will considerably be impacted and therefore this study is of paramount importance. In this effort both test procedures i.e. ASTM load shedding and the proposed compressive pre-cracking have been used to study the fatigue crack growth behavior of compact tension specimens made of aluminum alloy 2524-T3. Fatigue crack growth paths have been closely observed using SEM machines to investigate the effects of compression pre-cracking on the crack bifurcation behavior. The results of this study will shed a light on resolving the existing argument by better understanding of near threshold fatigue crack growth behavior.

  14. Impeller Design of a Centrifugal Fan with Blade Optimization

    Directory of Open Access Journals (Sweden)

    Yu-Tai Lee

    2011-01-01

    Full Text Available A method is presented for redesigning a centrifugal impeller and its inlet duct. The double-discharge volute casing is a structural constraint and is maintained for its shape. The redesign effort was geared towards meeting the design volute exit pressure while reducing the power required to operate the fan. Given the high performance of the baseline impeller, the redesign adopted a high-fidelity CFD-based computational approach capable of accounting for all aerodynamic losses. The present effort utilized a numerical optimization with experiential steering techniques to redesign the fan blades, inlet duct, and shroud of the impeller. The resulting flow path modifications not only met the pressure requirement, but also reduced the fan power by 8.8% over the baseline. A refined CFD assessment of the impeller/volute coupling and the gap between the stationary duct and the rotating shroud revealed a reduction in efficiency due to the volute and the gap. The calculations verified that the new impeller matches better with the original volute. Model-fan measured data was used to validate CFD predictions and impeller design goals. The CFD results further demonstrate a Reynolds-number effect between the model- and full-scale fans.

  15. EC-fans and fan control systems; EC-ventilatoren en ventilatorregelsystemen

    Energy Technology Data Exchange (ETDEWEB)

    Havenaar, D.

    2011-07-15

    Saving of energy can be achieved by the design and application of energy efficient components such as EC-fans (EC stands for Electronically Commutated technology), which are used in different types of cooling-refrigeration and air conditioning systems. In this article attention is paid to two products of Ziehl-Abigg: the Icontrol and the Fcontrol frequency converters. [Dutch] Het beperken van het energiegebruik en het verminderen van de uitstoot van het broeikasgas CO2 is voor de sector een belangrijke opgave. Door het ontwerpen en toepassen van energie-efficiente componenten zoals EC-ventilatoren (EC staat voor Electronically Commutated technologie) in allerlei koel-, vries- en luchtbehandelingsinstallaties kan veel bespaard worden in het energiegebruik. In dit artikel wordt aandacht besteed aan 2 producten van Ziehl-Abigg: de Icontrol en de Fcontrol frequentie omvormers.

  16. Ceiling erosion in caves: early studies and Zdeněk Roth as author of the concept

    Czech Academy of Sciences Publication Activity Database

    Bella, P.; Bosák, Pavel

    2015-01-01

    Roč. 44, č. 1 (2015), s. 139-144. ISSN 0583-6050 Institutional support: RVO:67985831 Keywords : ceiling channel * paragenesis * antigravitative erosion * definition * Zdeněk Roth * Domica Cave * Slovak Karst Subject RIV: DB - Geology ; Mineralogy Impact factor: 0.451, year: 2014

  17. Air Distribution and Ventilation Effectiveness in a room with Floor/Ceiling Heating and Mixing/Displacement Ventilation

    DEFF Research Database (Denmark)

    Wu, Xiaozhou; Fang, Lei; Olesen, Bjarne W.; Zhao, Jianing

    The present study investigated different combinations of floor/ceiling heating with mixing/displacement ventilation and their impacts on the indoor air distribution and ventilation effectiveness. Measurements were performed in a room during heating season in December. The results show that indoor...

  18. Academe's Glass Ceiling: Societal, Professional-Organizational, and Institutional Barriers to the Career Advancement of Academic Women.

    Science.gov (United States)

    Bain, Olga; Cummings, William

    2000-01-01

    A survey of 10 national systems of higher education found that less than 10 percent of professors were women, and the proportion of female professors was negatively related to institutional prestige. This academic "glass ceiling" was related to women's shorter careers, tenure issues during hard times, and women's lower level of academic…

  19. The Time Bounded Glass Ceiling and Young Women Managers: Career Progress and Career Success--Evidence from the UK.

    Science.gov (United States)

    Simpson, Ruth; Altman, Yochanan

    2000-01-01

    A study of 130 male and 91 female managers found that more younger women than men were in senior roles. Younger women achieved seniority faster than women over 35. However, once younger women have broken the glass ceiling at lower levels, they encounter new barriers at higher levels. (SK)

  20. Does the Glass Ceiling Exist? A Longitudinal Study of Women’s Progress on French Corporate Boards

    OpenAIRE

    Rey Dang; Duc Khuong Nguyen; Linh-Chi Vo

    2014-01-01

    In this article, we conduct a longitudinal study of women’s progress on French corporate boards of directors. We particularly focus on the extent to which women directors have circumvented the glass ceiling. Using a sample of SBF 120 companies over a 10

  1. Technology Solutions Case Study: Raised Ceiling Interior Duct System, New Smyrna, Florida

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-09-01

    Builder S.E. Volusia County Habitat for Humanity (SEVHFH) was interested in constructing a home to the new U.S. Department of Energy (DOE) Zero Energy Ready Home standards. SEVHFH partners with DOE team Building America Partnership for Improved Residential Construction on Habitat for Humanity homes and routinely builds to ENERGY STAR V3.1. The only modification to the design needed to comply with the Zero Energy Ready Home criteria was the interior duct requirement. Unwilling to incur the added costs of a foam roof deck or wall heights that exceed 8 ft to accommodate a fur-down chase, SEVHFH opted to build a fur-up or raised ceiling chase. This case study describes the project.

  2. Hierarchical rank and women's organizational mobility: glass ceilings in corporate law firms.

    Science.gov (United States)

    Gorman, Elizabeth H; Kmec, Julie A

    2009-03-01

    This article revives the debate over whether women's upward mobility prospects decline as they climb organizational hierarchies. Although this proposition is a core element of the "glass ceiling" metaphor, it has failed to gain strong support in previous research. The article establishes a firm theoretical foundation for expecting an increasing female disadvantage, with an eye toward defining the scope conditions and extending the model to upper-level external hires. The approach is illustrated in an empirical setting that meets the proposed scope conditions: corporate law firms in the United States. Results confirm that in this setting, the female mobility disadvantage is greater at higher organizational levels in the case of internal promotions, but not in the case of external hires. PMID:19824313

  3. Breaking the glass ceiling: an interview with Dr. Shirley Graves, a pioneering woman in medicine.

    Science.gov (United States)

    Ahmed, Zulfiqar; Mai, Christine L; Elder, Badrea; Rodriguez, Samuel; Yaster, Myron

    2014-04-01

    Shirley Graves M.D., D.Sc. (honorary) (1936), Professor Emeritus of Anesthesiology and Pediatrics at the University of Florida, was one of the most influential women in medicine in the 1960 and 1970s, a time when the medical profession was overwhelmingly male-dominated. In today's society, it is hard to believe that only 50 years ago, women were scarce in the field of medicine. Yet Dr. Graves was a pioneer in the fields of pediatric anesthesia and pediatric critical care medicine. She identifies her development of the pediatric intensive care unit and her leadership in the Division of Pediatric Anesthesia at the University of Florida as her defining contributions. Through her journal articles, book chapters, national and international lectures, and leadership in the American Society of Anesthesiology and the Florida Society of Anesthesiology, she inspired a generation of men and women physicians to conquer the unthinkable and break through the glass ceiling. PMID:24571660

  4. Physiological constraints to climate warming in fish follow principles of plastic floors and concrete ceilings.

    Science.gov (United States)

    Sandblom, Erik; Clark, Timothy D; Gräns, Albin; Ekström, Andreas; Brijs, Jeroen; Sundström, L Fredrik; Odelström, Anne; Adill, Anders; Aho, Teija; Jutfelt, Fredrik

    2016-01-01

    Understanding the resilience of aquatic ectothermic animals to climate warming has been hindered by the absence of experimental systems experiencing warming across relevant timescales (for example, decades). Here, we examine European perch (Perca fluviatilis, L.) from the Biotest enclosure, a unique coastal ecosystem that maintains natural thermal fluctuations but has been warmed by 5-10 °C by a nuclear power plant for over three decades. We show that Biotest perch grow faster and display thermally compensated resting cardiorespiratory functions compared with reference perch living at natural temperatures in adjacent waters. However, maximum cardiorespiratory capacities and heat tolerance limits exhibit limited or no thermal compensation when compared with acutely heated reference perch. We propose that while basal energy requirements and resting cardiorespiratory functions (floors) are thermally plastic, maximum capacities and upper critical heat limits (ceilings) are much less flexible and thus will limit the adaptive capacity of fishes in a warming climate. PMID:27186890

  5. Morphometric Characterization and Classification of Alluvial Fans in Eastern Oman

    Science.gov (United States)

    Leuschner, Annette; Mattern, Frank; van Gasselt, Stephan

    2015-04-01

    Morphologic characteristics of alluvial fans are a product of fluvial erosion, transportation and deposition. Consequently, fans have been described and defined on the basis of their shape, their composition, conditions and processes under which they from, their so-called "controlling factors", and their geomorphic and tectonic settings. The aim of our study is to reconstruct the morphologic evolution and to relate it to past and present climate conditions. In order to achieve this, we first characterize alluvial fans based on their climatic settings and conditions and classify them accordingly using satellite image data and digital elevation models. For mapping of different alluvial fan bodies multispectral images of the Landsat Enhanced Thematic Mapper (ETM+) with a scale of 15-30 m/px were utilized. For the detection of morphometric parameters as input data for subsequent hydrological studies digital terrain model data of the Shuttle Radar Topography Mission (SRTM) and the ASTER GDEM with a scale of 90 m/px and 30m, respectively, were used. Using these datasets morphological characteristics, such as sizes of drainage basins, transport areas and areas of deposition derived from spatial semi-automatic analysis, have been computed. The area of Muscat at the Oman Mountains has been selected as a study area because of its size, accessibility and climate conditions and it is considered well-suited for studying the development of alluvial fans and their controlling factors. The Oman Mountains are well-known for the world's largest intact and best exposed obducted ophiolite complex, the Semail Ophiolite. They are today subjected to a mild desert climate (Bwh), influenced by the Indian Ocean but they have experienced extensive pluvial periods in the geologic past. Formation of alluvial fans was, therefore, likely triggered by the interplay of increased sediment production caused by high rainfalls with enhanced erosion of hillslopes and transport rates during pluvial

  6. Detailed design of a quiet high flow fan

    Science.gov (United States)

    Soltau, J. D.; Orelup, M. J.; Beguhn, A. A.; Wiles, F. M.; Anderson, M. J.

    1977-01-01

    A single stage fan was designed to demonstrate the noise abatement properties of near-sonic inlet flow and long-chord stator vanes for the reduction of both upstream and downstream propagated fan source noise. It is designed to produce a pressure ratio of 1.653:1 with an adiabatic efficiency of 83.9%. The fan has a 508 mm inlet diameter with a hub/tip ratio of 0.426 and a design tip speed of 533.4 m/sec. The design inlet specific flow rate is 219.71 kg/sec sq m and there are 10 tandem stator vanes with a combined aspect ratio of 0.54.

  7. Model and field investigations of jet fans for face ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Konduri, I.M.; McPherson, M.J.; Topaz, E. [Virginia Polytechnic Institute and State University, Blacksburg, VA (United States). Dept. of Mining and Mineral Engineering

    1998-12-31

    Theoretical investigations and laboratory experiments demonstrated that there is a great potential for the use of jet-fan ventilation in mines. This paper summarizes research that consisted of laboratory-scale model tests, full-scale mine model tests and underground coal mine entry tests. The laboratory model used water as a fluid medium and simulated a typical 25-m long heading having a 1.5 x 6-m cross section. The effects of various nozzle positions and designs were investigated using still photography. It was also found that the use of jets in combination with line curtains enhanced the overall ventilating effect in the model entry. Flow measurements in the full-scale mine model and in the coal mine entry were conducted to evaluate the effectiveness of the jet fan. It was concluded that the designed jet-fan ventilation system was an effective means of ventilating blind airways. 16 refs., 9 figs.

  8. Design Optimization of a Centrifugal Fan with Splitter Blades

    Science.gov (United States)

    Heo, Man-Woong; Kim, Jin-Hyuk; Kim, Kwang-Yong

    2015-05-01

    Multi-objective optimization of a centrifugal fan with additionally installed splitter blades was performed to simultaneously maximize the efficiency and pressure rise using three-dimensional Reynolds-averaged Navier-Stokes equations and hybrid multi-objective evolutionary algorithm. Two design variables defining the location of splitter, and the height ratio between inlet and outlet of impeller were selected for the optimization. In addition, the aerodynamic characteristics of the centrifugal fan were investigated with the variation of design variables in the design space. Latin hypercube sampling was used to select the training points, and response surface approximation models were constructed as surrogate models of the objective functions. With the optimization, both the efficiency and pressure rise of the centrifugal fan with splitter blades were improved considerably compared to the reference model.

  9. Using Mobile Marketing to Engage NASCAR Fans and Increase Sales

    Directory of Open Access Journals (Sweden)

    MARK DODDS

    2011-01-01

    Full Text Available Mobile marketing displays engage the consumer. This sponsorship activation tactic is highly visible at NASCAR races. Some common elements include show cars, interactive race simulators, video games and race suit/equipment displays. The authors of this study argue that by using mobile marketing effectively as a sponsorship activation tactic, the race fans derive more enjoyment from the race experience. This increased enjoyment links to higher product sales for the sponsor. The implications of this study show that sponsors in other sports should use mobile marketing to increase the fan satisfaction of the game experience in order to increase their product sales. Additionally, event mangers should support mobile marketing as a sponsorship activation tactic with the intention of increasing fan enjoyment and improving attendance.

  10. Performance and Stability Analysis of a Shrouded-Fan UAV

    CERN Document Server

    de Divitiis, Nicola

    2009-01-01

    This paper deals with the estimation of the performance and stability for a shrouded-fan unmanned rotorcraft whose mission profile also prescribes the flight in ground effect. The not so simple estimation of the aerodynamic coefficients and of the thrust in the various situations makes the performance calculation and the stability analysis difficult tasks. This is due to the strong interaction between the fan flow and shroud that causes quite different flow structures about the airframe depending on flight conditions. A further difficulty is related to the ground effect which produces substantial modifications in the rotor thrust and aerodynamic coefficients. To evaluate performance and stability, two models have been developed. One determines the aerodynamic coefficients of the shroud, whereas the other one calculates thrust and moment of the rotors system. Both models take into account the mutual interference between fan flow and fuselage and ground effect. Performance and stability are then discussed with ...

  11. Female fans of men's football - a case study in Denmark

    DEFF Research Database (Denmark)

    Pfister, Gertrud Ursula; Lenneis, Verena; Mintert, Svenja-Maria

    2013-01-01

    Football is an invention by men for men, and today, the majority of players and fans are men. There is an abundance of literature on football and fandom; however, gender is mostly not an issue in these publications. Research about female football supporters and fans is very limited. This is also...... true for Denmark, the country, which is the focus of this article. Based on gender and socialization theories, this contribution addresses women and their (lack of) interest in men's football. The main questions refer to the numbers of female supporters and their patterns of football consumption. The...... sources of information are reader and user data of mass media, results of surveys about the habits of the Danish population and the results of an interview study with female fans. A specific focus of this article is on the minority of female supporters who attend football games. How do they adapt to a...

  12. Performance and flow characteristics of a forward swept propeller fan

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.K.; Kang, S.H. [Seoul National University, Seoul (Korea)

    2000-01-01

    Performance and flow characteristics of a small forward swept propeller fan for home refrigerators are studied experimentally. An unusual discontinuity is observed in the performance curve of the fan. Mean flow fields measured with a 5-hole pitot probe reveal that the flow is axial at the high flow rate and radial at the low flow rate. The flow structure changes abruptly across the discontinuity. Unsteady flow measurements with a set of hot-wire probes indicate that near the discontinuity a single-cell stall rotates at 40 % speed of the fan speed, while away from the discontinuity the flow shows periodic variation corresponding to the blade passage frequency. Phase-lock averaged flow fields measured with a triple-sensor hot-wire probe show that there appears radially inward flow over the pressure side of the blade and the outward passage flow over the tip. (author). 11 refs., 12 figs., 1 tab.

  13. Energy efficient engine fan component detailed design report

    Science.gov (United States)

    Halle, J. E.; Michael, C. J.

    1981-01-01

    The fan component which was designed for the energy efficient engine is an advanced high performance, single stage system and is based on technology advancements in aerodynamics and structure mechanics. Two fan components were designed, both meeting the integrated core/low spool engine efficiency goal of 84.5%. The primary configuration, envisioned for a future flight propulsion system, features a shroudless, hollow blade and offers a predicted efficiency of 87.3%. A more conventional blade was designed, as a back up, for the integrated core/low spool demonstrator engine. The alternate blade configuration has a predicted efficiency of 86.3% for the future flight propulsion system. Both fan configurations meet goals established for efficiency surge margin, structural integrity and durability.

  14. Climatic and technological ceilings for Chinese rice stagnation based on yield gaps and yield trend pattern analysis.

    Science.gov (United States)

    Zhang, Tianyi; Yang, Xiaoguang; Wang, Hesong; Li, Yong; Ye, Qing

    2014-04-01

    Climatic or technological ceilings could cause yield stagnation. Thus, identifying the principal reasons for yield stagnation within the context of the local climate and socio-economic conditions are essential for informing regional agricultural policies. In this study, we identified the climatic and technological ceilings for seven rice-production regions in China based on yield gaps and on a yield trend pattern analysis for the period 1980-2010. The results indicate that 54.9% of the counties sampled experienced yield stagnation since the 1980. The potential yield ceilings in northern and eastern China decreased to a greater extent than in other regions due to the accompanying climate effects of increases in temperature and decreases in radiation. This may be associated with yield stagnation and halt occurring in approximately 49.8-57.0% of the sampled counties in these areas. South-western China exhibited a promising scope for yield improvement, showing the greatest yield gap (30.6%), whereas the yields were stagnant in 58.4% of the sampled counties. This finding suggests that efforts to overcome the technological ceiling must be given priority so that the available exploitable yield gap can be achieved. North-eastern China, however, represents a noteworthy exception. In the north-central area of this region, climate change has increased the yield potential ceiling, and this increase has been accompanied by the most rapid increase in actual yield: 1.02 ton ha(-1) per decade. Therefore, north-eastern China shows a great potential for rice production, which is favoured by the current climate conditions and available technology level. Additional environmentally friendly economic incentives might be considered in this region. PMID:24130084

  15. Effects of Glass Ceiling on Women Career Development in Private Sector Organizations – Case of Sri Lanka

    Directory of Open Access Journals (Sweden)

    Bombuwela P. M.

    2013-06-01

    Full Text Available The study was entirely designed by centering the focal problem of the effect of Glass Ceiling on Women Career Development. The overall study was structure based on the conceptual framework built up using the information of literature survey. The study was conducted with the aim of obtaining the following objective. That is “To find out the Effect of Glass Ceiling on Women Career Development with regard to female executive level employees who are working in privatesector organizations.” At the same time, hypotheses are developed to find out whether there is a significant effect of Individual Factors, Family Factors, Organizational Factors and Cultural Factors on Women Career development. Merely this study has been completed with an empirical survey which was thoroughly conducted using a self-administered questionnaire and the sample consisted of 150 women executives. For presenting and analyzing the data both descriptive andinferential statistics were used. The findings reveal that the Glass Ceiling and Women Career Development have a moderate negative relationship, and also show that Individual Factors, OrganizationalFactors and Cultural Factors have a significant effect on Women Career Development whereas Family Factor has effects on the Glass Ceiling. Following the study results, a conclusion was eventually made that there are significant effects of the Glass Ceiling on WomenCareer Development of Executive level female employees working in private sector organizations in Sri Lanka. By taking all these facts into consideration, better recommendations have been made in this study. Finally, the most valuable suggestions for further studies and limitations of the study have been outlined.

  16. The Reasonable Explanation of Annihilation (fanā in Mysticism

    Directory of Open Access Journals (Sweden)

    Abulfazel Kiashemshaki

    2012-06-01

    Full Text Available Abstrak : Para mistikus melampaui tahap-tahap (derajat kesempurnaan mistik dan maqam spiritual dalam perjalanan mereka menuju Allah yang sulit dimengerti oleh non-mistikus. Karena itu, sebagian besar kalangan reflektif berusaha mengandalkan prinsip-prinsip intelektual dan teoritis mereka untuk memperoleh penjelasan atas pengalaman mistis dan ekstasi. Namun, keberhasilan penjelasannya sepenuhnya berada di bawah kuasa dan kekuatan dari prinsip-prinsip tersebut. (Fanā atau kesirnaan adalah salah satu tahap mistis atau keadaan yang sulit dimengerti oleh non-mistikus sehingga memunculkan berbagai teori yang berbeda untuk menjelaskannya. Pencapaian prestasi ilmiah dan filosofis merupakan penjelasan yang tepat atas fanā. Bagaimanapun upaya yang dilakukan dalam artikel ini membuktikan bahwa satu-satunya penjelasan yang sukses adalah penjelasan yang didasarkan pada prinsip-prinsip teosofi transendental dan mistisisme teoritis.Kata kunci : Fanā, Mistisisme, Penjelasan rasional, Mistisisme teoretis, Filsafat transendentalAbstract : Mystics are passing through stages (degrees of mystic perfection and esoteric abodes (spiritual stations in their spiritual journey to Allah which is difficult for unmystics to understand. Because of this, most of the reflective people are trying to rely on their intellectual and theoretical principles to obtain an understandable explanation of mystical experiences and ecstasy. However the success of such explanation completely lies in the power and strength of the above mentioned principles. (Fanā or annihilation is one of the mystical stages or states which unmystics find very difficult to reasonably understand, hence various and different theories have been provided for its explanation. Various scientific and philosophical achievements are appropriate explanations of annihilation (fanā which is valuable in its place; however effort had been made in this article to prove that the only successful explanation is an

  17. Interaction of fan rotor flow with downstream struts

    Science.gov (United States)

    Obrien, W. F., Jr.; Reimers, S. L.; Richardson, S. W.

    1983-01-01

    The detailed unsteady pressure field produced on the rotor blades of an axial-flow fan by interaction with downstream struts was investigated. The experimental arrangement was similar to that found in the fan casings of turbofan aircraft engines. Acoustically significant pressure fluctuations were measured on both thy suction and pressure sides of the rotor blades for several positions of the downstream struts. The level of the observed interaction decreased with increased spacing of the struts behind the rotor. An inviscid flow analysis for the disturbance level is compared with trends of the measured results.

  18. The Boundary Layer Interaction with Shock Wave and Expansion Fan

    Institute of Scientific and Technical Information of China (English)

    MaratA.Goldfeld; RomanV.Nestoulia; 等

    2000-01-01

    The results of experimental investigation of a turbulent boundary layer on compression and expansion surfaces are presented.They include the study of the shock wave and /or expansion fan action upon the boundary layer,boundary layer sepqartion and its relaxation.Complex events of paired interactions and the flow on compression convex-concave surfaces were studied.The posibility and conditions of the boundary layer relaminarization behind the expansion fan and its effect on the relaxation length are presented.Different model configurations for wide range conditions were investigated.Comparison of results for different interactions was carried out.

  19. On a Fixed Point Theorem of Ky Fan

    Institute of Scientific and Technical Information of China (English)

    DE BLASI Francesco S.; GEORGIEV Pando Gr.

    2002-01-01

    We generalize a theorem of Ky Fan about the nearest distance between a closed convex setD in a Banach space E and its image by a function f: D → E, in several directions: (1) for noncompactsets D, when f(D) precompact; (2) for compact D and upper semicontinuous multifunction f; andmore generally, (3) for noncompact D and upper semicontinuous multifunction f with f(D) Hausdorffprecompact.In particular, we prove a version of the fixed point theorem of Kakutani-Ky Fan for multifunctions,whose values are convex closed bounded, thus not necessarily compact.

  20. Performance evaluation methods and instrumentation for mine ventilation fans

    Institute of Scientific and Technical Information of China (English)

    LI Man; WANG Xue-rong

    2009-01-01

    Ventilation fans are one of the most important pieces of equipment in coal mines. Their performance plays an important role in the safety of staff and production. Given the actual requirements of coal mine production, we instituted a research project on the measurement methods of key performance parameters such as wind pressure, amount of ventilation and power. At the end a virtual instrument for mine ventilation fans performance evaluation was developed using a USB interface. The practical perform-ance and analytical results of our experiments show that it is feasible, reliable and effective to use the proposed instrumentation for mine ventilation performance evaluation.

  1. Blade Crack Detection of Centrifugal Fan Using Adaptive Stochastic Resonance

    OpenAIRE

    Bingbing Hu; Bing Li

    2015-01-01

    Centrifugal fans are widely used in various industries as a kind of turbo machinery. Among the components of the centrifugal fan, the impeller is a key part because it is used to transform kinetic energy into pressure energy. Crack in impeller’s blades is one of the serious hidden dangers. It is important to detect the cracks in the blades as early as possible. Based on blade vibration signals, this research applies an adaptive stochastic resonance (ASR) method to diagnose crack fault in cent...

  2. Investigation of Control Effectors for Ducted Fan VTOL UAVs

    OpenAIRE

    Harris, Jr., W. A.

    2007-01-01

    Ducted fan VTOL UAVs are currently being designed for use by the Army for surveillance and reconnaissance in the battlefield. The vehicle tested in this research is part of the Honeywell MAV program. Able to be carried in a backpack by a single soldier, it has a duct diameter of 11.5-in. and weighs approximately 20-lbs at takeoff. It is designed for flight up to 50-knots with fan speeds varying between 5000 and 8500 RPM. Reynolds numbers, based on the duct diameter, were on the order of R...

  3. Erosion and deposition on a debris-flow fan

    Science.gov (United States)

    Densmore, A. L.; Schuerch, P.; Rosser, N. J.; McArdell, B. W.

    2011-12-01

    The ability of a debris flow to entrain or deposit sediment controls the downstream evolution of flow volume, and ultimately dictates both the geomorphic impact of the flow and the potential hazard that it represents. Our understanding of the patterns of, and controls on, such flow volume changes remains extremely limited, however, partly due to a poor mechanistic grasp of the interactions between debris flows and their bed and banks. In addition, we lack a good understanding of the cumulative long-term effects of sequences of flows in a single catchment-fan system. Here we begin to address these issues by using repeated terrestrial laser scanning (TLS) to characterize the detailed surface change associated with the passage of multiple debris flows on the Illgraben fan, Switzerland. We calculate surface elevation change along a 300 m study reach, and from this derive the downfan rate of flow volume change, or lag rate; for comparison, we also derive the spatially-averaged lag rate over the entire ~2 km length of the fan. Lag rates are broadly comparable over both length scales, indicating that flow behavior does not vary significantly across the fan for most flows, but importantly we find that flow volume at the fan head is a poor predictor of volume at the fan toe. The sign and magnitude of bed elevation change scale with local flow depth; at flow depths deposition are approximately equally likely, but erosion becomes increasingly dominant for flow depths > 2 m. On the Illgraben fan, this depth corresponds to a basal shear stress of 3-4 kPa. Because flow depth is in part a function of channel cross-sectional topography, which varies strongly both within and between flows, this result indicates that erosion and deposition are likely to be highly dynamic. The dependence of flow volume change on both the channel topography and the flow history may thus complicate efforts to predict debris-flow inundation areas by simple flow routing. We then apply a 2d numerical

  4. Towards a three-component model of fan loyalty: a case study of Chinese youth.

    Science.gov (United States)

    Zhang, Xiao-xiao; Liu, Li; Zhao, Xian; Zheng, Jian; Yang, Meng; Zhang, Ji-qi

    2015-01-01

    The term "fan loyalty" refers to the loyalty felt and expressed by a fan towards the object of his/her fanaticism in both everyday and academic discourses. However, much of the literature on fan loyalty has paid little attention to the topic from the perspective of youth pop culture. The present study explored the meaning of fan loyalty in the context of China. Data were collected by the method of in-depth interviews with 16 young Chinese people aged between 19 and 25 years who currently or once were pop fans. The results indicated that fan loyalty entails three components: involvement, satisfaction, and affiliation. These three components regulate the process of fan loyalty development, which can be divided into four stages: inception, upgrade, zenith, and decline. This model provides a conceptual explanation of why and how young Chinese fans are loyal to their favorite stars. The implications of the findings are discussed. PMID:25886557

  5. Towards a three-component model of fan loyalty: a case study of Chinese youth.

    Directory of Open Access Journals (Sweden)

    Xiao-xiao Zhang

    Full Text Available The term "fan loyalty" refers to the loyalty felt and expressed by a fan towards the object of his/her fanaticism in both everyday and academic discourses. However, much of the literature on fan loyalty has paid little attention to the topic from the perspective of youth pop culture. The present study explored the meaning of fan loyalty in the context of China. Data were collected by the method of in-depth interviews with 16 young Chinese people aged between 19 and 25 years who currently or once were pop fans. The results indicated that fan loyalty entails three components: involvement, satisfaction, and affiliation. These three components regulate the process of fan loyalty development, which can be divided into four stages: inception, upgrade, zenith, and decline. This model provides a conceptual explanation of why and how young Chinese fans are loyal to their favorite stars. The implications of the findings are discussed.

  6. Low-pressure reversible axial fan designed with different specific work of elementary stages

    Directory of Open Access Journals (Sweden)

    Bogdanović Božidar P.

    2012-01-01

    Full Text Available Low-pressure axial fan impellers designed according to the principle of equal specific work of all elementary stages have blades whose profile near the fan hub is under a significantly larger inclination angle than at the impeller periphery. In order to minimize the spatial curvature of the fan blades and the fan hub length, impeller blades of low-pressure axial fans can be designed with different specific work of elementary stages, so that the specific work of elementary stages is smaller at the hub than at the periphery. This paper presents the operating characteristics of a low-pressure reversible axial fan with straight blade profiles, designed with different specific work of elementary stages. The fan was tested on a standard test rig, with air intake loading on the suction side of the fan.

  7. Advanced Subsonic Technology (AST) 22-Inch Low Noise Research Fan Rig Preliminary Design of ADP-Type Fan 3

    Science.gov (United States)

    Jeracki, Robert J. (Technical Monitor); Topol, David A.; Ingram, Clint L.; Larkin, Michael J.; Roche, Charles H.; Thulin, Robert D.

    2004-01-01

    This report presents results of the work completed on the preliminary design of Fan 3 of NASA s 22-inch Fan Low Noise Research project. Fan 3 was intended to build on the experience gained from Fans 1 and 2 by demonstrating noise reduction technology that surpasses 1992 levels by 6 dB. The work was performed as part of NASA s Advanced Subsonic Technology (AST) program. Work on this task was conducted in the areas of CFD code validation, acoustic prediction and validation, rotor parametric studies, and fan exit guide vane (FEGV) studies up to the time when a NASA decision was made to cancel the design, fabrication and testing phases of the work. The scope of the program changed accordingly to concentrate on two subtasks: (1) Rig data analysis and CFD code validation and (2) Fan and FEGV optimization studies. The results of the CFD code validation work showed that this tool predicts 3D flowfield features well from the blade trailing edge to about a chord downstream. The CFD tool loses accuracy as the distance from the trailing edge increases beyond a blade chord. The comparisons of noise predictions to rig test data showed that both the tone noise tool and the broadband noise tool demonstrated reasonable agreement with the data to the degree that these tools can reliably be used for design work. The section on rig airflow and inlet separation analysis describes the method used to determine total fan airflow, shows the good agreement of predicted boundary layer profiles to measured profiles, and shows separation angles of attack ranging from 29.5 to 27deg for the range of airflows tested. The results of the rotor parametric studies were significant in leading to the decision not to pursue a new rotor design for Fan 3 and resulted in recommendations to concentrate efforts on FEGV stator designs. The ensuing parametric study on FEGV designs showed the potential for 8 to 10 EPNdB noise reduction relative to the baseline.

  8. A NEW AIR CONDITIONING SYSTEM FAN MODEL BASED ON NUMERICAL ANALYSIS

    OpenAIRE

    Nabil Nassif; Raymond Tesiero; Nihal AlRaees

    2014-01-01

    A large portion of energy use in buildings is attributed to air movement devices. Accurate estimation of fan performance is a key element in maximizing fan efficiency. This study proposes a new fan model that can be used in several applications such as optimization and fault detection and can also be incorporated into any commercial building models. The model uses a numerical analysis based on an interpolation technique for the data generated by basic fan laws. It can use any two variables am...

  9. Fan Culture as an Informal Learning Environment : Presentation of a NGL project

    OpenAIRE

    Inose, Hiroko; Edfeldt, Chatarina; Fjordevik, Anneli

    2012-01-01

    Fan culture is a subculture that has developed explosively on the internet over the last decades. Fans are creating their own films, translations, fiction, fan art, blogs, role play and also various forms that are all based on familiar popular culture creations like TV-series, bestsellers, anime, manga stories and games. In our project, we analyze two of these subculture genres, fan fiction and scanlation. Amateurs, and sometimes professional writers, create new stories by adapting and develo...

  10. Performance model of a very high bypass ratio counter rotating turbo fan engine

    OpenAIRE

    Perrin, Martin

    2012-01-01

    Nowadays Snecma focuses on new engine architectures in order to meet the future demands in civil aviation. One of these considered concepts is aircrafts powered by counter rotating fan engines which aim at tackling both noise and polluting emissions. A powerful way to reduce the perceived noise is to reduce the fan rotating speeds, which requires to lower fan pressure ratio. This thesis continues a study on an innovative counter rotating fan architecture carried out by Snecma from 2005 to 201...

  11. Football Fan Aggression: The Importance of Low Basal Cortisol and a Fair Referee

    OpenAIRE

    Leander van der Meij; Fabian Klauke; Moore, Hannah L.; Ludwig, Yannick S.; Mercedes Almela; Van Lange, Paul A. M.

    2015-01-01

    Fan aggression in football (soccer) is a societal problem that affects many countries worldwide. However, to date, most studies use an epidemiological or survey approach to explain football fan aggression. This study used a controlled laboratory study to advance a model of predictors for fan aggression. To do so, football fans (n = 74) saw a match summary in which their favorite team lost against their most important rival. Next, we measured levels of aggression with the hot sauce paradigm, i...

  12. Analysis and Prediction of the Thermal Performance of Piezoelectrically Actuated Fans

    OpenAIRE

    Acikalin, T.; Garimella, S V

    2009-01-01

    An experimentally validated numerical model is developed to analyze the operation of a piezoelectrically actuated cantilever vibrating close to a heated surface. The vibrating cantilever acts as a fan and provides localized cooling. The numerical results for the flow field and heat transfer show satisfactory agreement with experiments. The numerical model is used to develop fan curves for the piezoelectric fans, using a methodology similar to that used in constructing pump or fan curves for c...

  13. SOME GENERALIZATIONS OF KY FAN'S BEST APPROXIMATION THEOREM

    Institute of Scientific and Technical Information of China (English)

    A.R.Khan; N.Hussain; A.B.Thaheem

    2004-01-01

    We pressent new Ky Fan type best approximation theorems for a discontinuous multivalued map on metrizable topological vector spaces and hyperconvex spaces. In addition, fixed point results are derived for the map studied. Our work generalizes severl results in approximation theory.

  14. Energy efficient engine shroudless, hollow fan blade technology report

    Science.gov (United States)

    Michael, C. J.

    1981-01-01

    The Shroudless, Hollow Fan Blade Technology program was structured to support the design, fabrication, and subsequent evaluation of advanced hollow and shroudless blades for the Energy Efficient Engine fan component. Rockwell International was initially selected to produce hollow airfoil specimens employing the superplastic forming/diffusion bonding (SPF/DB) fabrication technique. Rockwell demonstrated that a titanium hollow structure could be fabricated utilizing SPF/DB manufacturing methods. However, some problems such as sharp internal cavity radii and unsatisfactory secondary bonding of the edge and root details prevented production of the required quantity of fatigue test specimens. Subsequently, TRW was selected to (1) produce hollow airfoil test specimens utilizing a laminate-core/hot isostatic press/diffusion bond approach, and (2) manufacture full-size hollow prototype fan blades utilizing the technology that evolved from the specimen fabrication effort. TRW established elements of blade design and defined laminate-core/hot isostatic press/diffusion bonding fabrication techniques to produce test specimens. This fabrication technology was utilized to produce full size hollow fan blades in which the HIP'ed parts were cambered/twisted/isothermally forged, finish machined, and delivered to Pratt & Whitney Aircraft and NASA for further evaluation.

  15. Analytical parametric investigation of low pressure ratio fan noise

    Science.gov (United States)

    Metzger, F. B.; Hanson, D. B.; Menthe, R. W.; Towle, G. B.

    1973-01-01

    The results of an analytical study are reported which shows the effect of various physical and operating parameters on noise produced by low pressure ratio propulsive fans operating at subsonic top speeds. Acoustical duct lining effects are included in the study. The concepts used to develop the noise theory used in the study, as well as the correlation between the theory and model test results are also presented. It is shown that good correlation has been established between theory and experiment. Using the theory, it is shown that good aerodynamic design, maximum acceptable fan solidity, low tip speed operation and use of few blades and vanes leads to the lowest noise levels. Typical results of the study indicate that a fan operating at 1.2 fan pressure ratio and 700 ft/second tip speed with 12 blades and 7 vanes and including modest acoustic treatment on the duct wall would produce levels allowing a 100,000 lb. STOL aircraft to meet a noise level objective of 95 PNdB at 500 ft at takeoff.

  16. Submarine fan lobe models: Implications for reservoir properties

    Energy Technology Data Exchange (ETDEWEB)

    Shanmugam, G.; Moiola, R.J. (Mobil Research and Development Corp., Dallas, TX (USA))

    1990-09-01

    A multitude of submarine fan lobe models, advocating widely different reservoir properties, has been introduced into the sedimentologic literature. Four of these models are compared to show their differences in reservoir properties. Braided suprafan lobes are characterized by stacked sand bodies with good lateral and vertical communication, and they constitute excellent reservoir facies. The unchanneled depositional lobes, composed of sheetlike sand bodies with good lateral and moderate vertical communication, exhibit properties of good reservoir facies. Fanlobes, which refer to meandering channels and associated levee facies of large mud-rich submarine fans such as the Mississippi Fan in the Gulf of Mexico, are characterized by offset stacked sand bodies with poor lateral and vertical communication. These lenticular sands have the potential to be moderately good reservoir facies. Ponded lobes, which represent mud-rich slump facies of slope environments, comprise poor reservoir facies because of poor sand content and poor sand-body connectivity caused by chaotic bedding. Furthermore, the presence of slumped mud layers in ponded lobes is expected to hinder fluid flow. Because different lobe models vary significantly from one another in terms of reservoir properties, caution must be exercised to apply the proper lobe model to ancient fan sequences in hydrocarbon exploration and production.

  17. COMPARISON OF AXIAL FAN ROTOR EXPERIMENTAL DATA WITH CFD SIMULATION

    OpenAIRE

    Aleš Prachař

    2016-01-01

    Data obtained from an experimental simulation on a new test rig for axial fans are compared to a CFD simulation. The Edge solver is used and the development needed for the simulation (boundary conditions, free stream consistency) is described. Adequate agreement between the measured and calculated data is observed.

  18. COMPARISON OF AXIAL FAN ROTOR EXPERIMENTAL DATA WITH CFD SIMULATION

    Directory of Open Access Journals (Sweden)

    Aleš Prachař

    2016-02-01

    Full Text Available Data obtained from an experimental simulation on a new test rig for axial fans are compared to a CFD simulation. The Edge solver is used and the development needed for the simulation (boundary conditions, free stream consistency is described. Adequate agreement between the measured and calculated data is observed.

  19. Involvement of FAN in TNF-induced apoptosis.

    Science.gov (United States)

    Ségui, B; Cuvillier, O; Adam-Klages, S; Garcia, V; Malagarie-Cazenave, S; Lévêque, S; Caspar-Bauguil, S; Coudert, J; Salvayre, R; Krönke, M; Levade, T

    2001-07-01

    TNF-alpha is a pleiotropic cytokine activating several signaling pathways initiated at distinct intracellular domains of the TNF receptors. Although the C-terminal region is believed to be responsible for apoptosis induction, the functions of more membrane-proximal domains, including the domain that couples to neutral sphingomyelinase activation, are not yet fully elucidated. The roles of this region and of the associated adapter protein FAN (factor associated with neutral SMase activation) in the cytotoxic response to TNF have been investigated. We have now shown that stable expression in human fibroblasts of a dominant negative form of FAN abrogates TNF-induced ceramide generation from sphingomyelin hydrolysis and reduces caspase processing, thus markedly inhibiting TNF-triggered apoptosis. However, the cytotoxic responses to daunorubicin and exogenous ceramide remain unaltered, as do the TNF-induced p42/p44 MAPK activation and CD54 expression. Fibroblasts from FAN-knockout mice also proved to be resistant to TNF toxicity. These findings highlight the previously unrecognized role of the adapter protein FAN in signaling cell death induction by TNF. PMID:11435466

  20. Reflection of neutrons from fan-like magnetic systems

    OpenAIRE

    Ignatovich, V. K.; Radu, F.

    2009-01-01

    An analytical solution is found for neutron reflection coefficients from magnetic mirrors with fan-like magnetization. The main feature of the reflection curves related to this type of magnetization is pointed out. The results of calculations for some parameters of the system are presented. Time parity and detailed balance violation in the model are discussed.

  1. Composite Fan Blade Design for Advanced Engine Concepts

    Science.gov (United States)

    Abumeri, Galib H.; Kuguoglu, Latife H.; Chamis, Christos C.

    2004-01-01

    The aerodynamic and structural viability of composite fan blades of the revolutionary Exo-Skeletal engine are assessed for an advanced subsonic mission using the NASA EST/BEST computational simulation system. The Exo-Skeletal Engine (ESE) calls for the elimination of the shafts and disks completely from the engine center and the attachment of the rotor blades in spanwise compression to a rotating casing. The fan rotor overall adiabatic efficiency obtained from aerodynamic analysis is estimated at 91.6 percent. The flow is supersonic near the blade leading edge but quickly transitions into a subsonic flow without any turbulent boundary layer separation on the blade. The structural evaluation of the composite fan blade indicates that the blade would buckle at a rotor speed that is 3.5 times the design speed of 2000 rpm. The progressive damage analysis of the composite fan blade shows that ply damage is initiated at a speed of 4870 rpm while blade fracture takes place at 7640 rpm. This paper describes and discusses the results for the composite blade that are obtained from aerodynamic, displacement, stress, buckling, modal, and progressive damage analyses. It will be demonstrated that a computational simulation capability is readily available to evaluate new and revolutionary technology such as the ESE.

  2. Saving energy for ventilation using decentralised duct fans

    DEFF Research Database (Denmark)

    Gunner, Amalie; Bergsøe, Niels Christian; Afshari, Alireza

    2014-01-01

    pressure drops which in turn will increase energy use. This paper presents a novel procedure for balancing CAV-systems using decentralised duct fans instead of flat plate dampers. The procedure will result in lower pressure drops and consequently in a reduction of energy use for ventilation when compared...... mechanical ventilation systems with low energy use for new and renovation of buildings....

  3. Flight-Effects on Predicted Fan Fly-By Noise

    Science.gov (United States)

    Heidmann, M. F.; Clark, B. J.

    1977-01-01

    The impact on PNLT (Perceived Noise Level, Tone corrected) and Fly-by EPNL (Effective Perceived Noise Level) when forward motion reduces the noise generated by the bypass fan of an aircraft engine was studied. Calculated noise spectra for a typical subsonic tip speed fan designed for blade passage frequency (BPF) tone cutoff were translated in frequency by systematically varying the BPF from 0.5 to 8 kHz. Two cases of predicted flight-effects on fan source noises were considered: reduced BPF tone level of 8 db and reduced broadband noise level of about 2 db in addition to reduced tone level. The maximum reduction in PNLT of the noise as emitted from the fan occurred when the BPF was at 4 kHz where the reductions were 7.4 and 10.0 db. The maximum reduction in EPNL of the noise as received during a 500-foot altitude fly-by occurred when the BPF was at 2.5 kHz where the reductions were 5.0 and 7.8 db.

  4. A submarine fan in the Mesa Central, Mexico

    Science.gov (United States)

    Silva-Romo, G.; Arellano-Gil, J.; Mendoza-Rosales, C.; Nieto-Obregón, J.

    2000-10-01

    The contact between the Guerrero and Sierra Madre tectonostratigraphic terranes has been proposed to lie in the Mesa Central, east of the city of Zacatecas. Marine Triassic units have been assigned to the Guerrero Terrane. It is here proposed that this contact occurs to the west of the city of Zacatecas and the Triassic marine sequence assigned to the Sierra Madre Terrane. We analyzed the stratigraphic record and structural features of pre-Late Jurassic sequences at four localities in the Mesa Central. They contain a marine turbiditic Triassic unit, which includes La Bellena, Taray, and Zacatecas Formations, and a continental unit of probable Middle Jurassic age. Triassic sandstones were derived from a cratonic area, without the influence of arc volcanism. The sequences were affected by two phases of deformation. The Triassic formations are unconformably overlain by a continental volcano-sedimentary sequence that contains fragments of sandstones derived from the underlying unit. Sedimentologic characteristics of the Triassic unit fit a submarine fan model. The submarine fan developed at the continental margin of Pangaea during Triassic times. Turbidite associations in the San Rafael Area indicate a middle fan depositional environment, while in the Real de Catorce Area, they correspond to the distal part (basin plain facies). At La Ballena and Zacatecas the turbidite associations occur in the middle part and perhaps the external part of the fan.

  5. Blade Crack Detection of Centrifugal Fan Using Adaptive Stochastic Resonance

    Directory of Open Access Journals (Sweden)

    Bingbing Hu

    2015-01-01

    Full Text Available Centrifugal fans are widely used in various industries as a kind of turbo machinery. Among the components of the centrifugal fan, the impeller is a key part because it is used to transform kinetic energy into pressure energy. Crack in impeller’s blades is one of the serious hidden dangers. It is important to detect the cracks in the blades as early as possible. Based on blade vibration signals, this research applies an adaptive stochastic resonance (ASR method to diagnose crack fault in centrifugal fan. The ASR method, which can utilize the optimization ability of the grid search method and adaptively realize the optimal stochastic resonance system matching input signals, may weaken the noise and highlight weak characteristic and thus can diagnose the fault accurately. A centrifugal fan test rig is established and experiments with three cases of blades are conducted. In comparison with the ensemble empirical mode decomposition (EEMD analysis and the traditional Fourier transform method, the experiment verified the effectiveness of the current method in blade crack detection.

  6. Acceptance test report MICON software exhaust fan control modifications

    International Nuclear Information System (INIS)

    This report documents the results the acceptance test HNF-4108 which verifies the MICON program changes for the new automatic transfer switch ATS-2 alarms, the Closed Loop Cooling isolator status, the CB-3 position alarm, the alarms for the new emergency fan damper backup air compressor, and the generator sequencer logic

  7. Study of a new airfoil used in reversible axial fans

    Science.gov (United States)

    Li, Chaojun; Wei, Baosuo; Gu, Chuangang

    1991-01-01

    The characteristics of the reverse ventilation of axial flow are analyzed. An s shaped airfoil with a double circular arc was tested in a wind tunnel. The experimental results showed that the characteristics of this new airfoil in reverse ventilation are the same as those in normal ventilation, and that this airfoil is better than the existing airfoils used on reversible axial fans.

  8. Intermittent Flow Regimes in a Transonic Fan Airfoil Cascade

    Directory of Open Access Journals (Sweden)

    J. Lepicovsky

    2004-01-01

    velocity.To date, this flow behavior has only been observed in a linear transonic cascade. Further research is necessary to confirm this phenomenon occurs in actual transonic fans and is not the by-product of an endwall restricted linear cascade.

  9. Così fan tutte: Brilliance or Buffoonery?

    Directory of Open Access Journals (Sweden)

    Sarah Whitfield

    2011-12-01

    Full Text Available Hardly any opera has endured more scrutiny and self-preserving apology than Mozart’s Così fan tutte. Flagrant opposition and a long string of “rescue” attempts shroud the receptive history of the work. Since its premiere, Così fan tutte has long been recognized as a problem opera. Many critics found it implausible that Mozart—the consummate composer and man that warranted their idolization—could have stooped so low as to agree to such an immoral plot. The great beauty in Mozart’s musical parody is that it at once mocks and transforms the supposed superficial experiment of Lorenzo Da Ponte’s libretto. The parody in Così fan tutte must be correctly interpreted. It is rampant, but it exists for much more than a perfunctory laugh. The beauty of Mozart’s music—in both moments of wild parody and heartfelt emotion—succeeds in giving Così fan tutte a depth that is both challenging and transforming.

  10. 30 CFR 75.313 - Main mine fan stoppage with persons underground.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Main mine fan stoppage with persons underground... COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.313 Main mine fan stoppage with persons underground. (a) If a main mine fan stops while anyone is...

  11. Characterization and optimization of the thermal performance of miniature piezoelectric fans

    International Nuclear Information System (INIS)

    Piezoelectric fans have emerged as a viable cooling technology for the thermal management of electronic devices, owing to their low-power consumption, minimal noise emission, and small and configurable dimensions. Piezoelectric fans are investigated for application in the cooling of low-power electronics. Different experimental configurations are considered, and the effect of varying the fan amplitude, the distance between the fan and the heat source, the fan length, its frequency offset from resonance, and the fan offset from the center of the heat source are studied to assess the cooling potential of the fans. A design of experiments (DOE) analysis revealed the fan frequency offset from resonance and the fan amplitude as the critical parameters. Transfer functions are obtained from the DOE analysis for the implementation of these fans in electronics cooling. For the best case, an enhancement in convective heat transfer coefficient exceeding 375% relative to natural convection was observed, resulting in a temperature drop at the heat source of more than 36.4 oC. A computational model for the flow field and heat transfer induced by the piezoelectric fan is also developed. Effects of the flow on convection heat transfer for different fan-to-heat source distances and boundary conditions are analyzed. Transition between distinct convection patterns is observed with changes in the parameters. The computational results are validated against experimental measurements, with good agreement

  12. Zenithal ceiling tubes, a peculiar karst corrosion form in Carlsbad Caverns (New Mexico, USA)

    Science.gov (United States)

    Calaforra, José Maria; de Waele, Jo

    2010-05-01

    Carlsbad Caverns is a world renown show cave located in the Guadalupe Mountains (Chihuahuan desert, New Mexico) and managed by the United States National Park Service. The cave is hosted in the Permian Capitan Reef limestones that border the Delaware basin. It consists of elongated passages connecting wide rooms that extend to a depth of almost 300 m beneath the natural cave entrance, almost 200 m below the floor of nearby Walnut Canyon. As most caves of the Guadalupe mountains it has formed by rising hydrogen sulphide deriving from underlying oil and gas deposits, producing sulphuric acid by mixing with fresh water which corroded the limestone into unusually large chambers. This H2SO4 speleogenesis has produced gypsum that is present under various forms. Carlsbad Caverns has been widely studied by generations of cave scientists, and research has especially focalised on speleothems, mineralogy, speleogenesis, cave fauna and, mostly in the last decennia, microbiology. This has resulted in a large number of publications in many scientific journals, making Carlsbad Caverns one of the best studied caves of the world. During a trip to the Hall of the White Giant, in the squeezing crawlways that connect the main Corridor to the Sand Passage, several cylindrical vertical upward developing holes were observed on the ceiling at several heights. They have a circular cross-section with diameters of 1 to some centimetres and taper out towards their upper end. Their walls are smooth and their edges sharp. Their length can reach several decimetres. Sometimes gypsum can be found inside. They often occur randomly distributed in groups and their development is not necessarily controlled by fractures or other bedrock structures. These holes are similar in shape to the bellholes described from many tropical caves, but are much smaller. They also look like the holes described by Stanton (1986) from caves in the Mendip Hills. This author believed they formed by activity of snails (they

  13. Debris-flow hazards on tributary junction fans, Chitral, Hindu Kush Range, northern Pakistan

    Science.gov (United States)

    Khan, M. Asif; Haneef, M.; Khan, Anwar S.; Tahirkheli, Tazeem

    2013-01-01

    The Chitral district of northern Pakistan lies in the eastern Hindu Kush Range. The population in this high-relief mountainous terrain is restricted to tributary-junction fans in the Chitral valley. Proximity to steep valley slopes renders these fans prone to hydrogeomorphic hazards, including landslides, floods and debris flows. This paper focuses on debris-flow hazards on tributary-junction fans in Chitral. Using field observations, satellite-image analyses and a preliminary morphometry, the tributary-junction fans in the Chitral valley are classified into (1) discrete and (2) composite. The discrete fans are modern-day active landforms and include debris cones associated with ephemeral gullies, debris fans associated with ephemeral channels and alluvial fans formed by perennial streams. The composite fans are a collage of sediment deposits of widely different ages and formed by diverse alluvial-fan forming processes. These include fans formed predominantly during MIS-2/Holocene interglacial stages superimposed by modern-day alluvial and debris fans. Composite fans are turned into relict fans when entrenched by modern-day perennial streams. These deeply incised channels discharge their sediment load directly into the trunk river without significant spread on fan surface. In comparison, when associated with ephemeral streams, active debris fans develop directly at composite-fan surfaces. Major settlements in Chitral are located on composite fans, as they provide large tracts of leveled land with easy accesses to water from the tributary streams. These fan surfaces are relatively more stable, especially when they are entrenched by perennial streams (e.g., Chitral, Ayun, and Reshun). When associated with ephemeral streams (e.g., Snowghar) or a combination of ephemeral and perennial streams (e.g., Drosh), these fans are subject to frequent debris-flow hazards. Fans associated with ephemeral streams are prone to high-frequency (˜10 years return period) debris

  14. Experimental Evaluation of Installed Cooking Exhaust Fan Performance

    Energy Technology Data Exchange (ETDEWEB)

    Singer, Brett C.; Delp, William W.; Apte, Michael G.

    2010-11-01

    The installed performance of cooking exhaust fans was evaluated through residential field experiments conducted on a sample of 15 devices varying in design and other characteristics. The sample included two rear downdraft systems, two under-cabinet microwave over range (MOR) units, three different installations of an under-cabinet model with grease screens across the bottom and no capture hood, two devices with grease screens covering the bottom of a large capture hood (one under-cabinet, one wall-mount chimney), four under-cabinet open hoods, and two open hoods with chimney mounts over islands. Performance assessment included measurement of airflow and sound levels across fan settings and experiments to quantify the contemporaneous capture efficiency for the exhaust generated by natural gas cooking burners.Capture efficiency is defined as the fraction of generated pollutants that are removed through the exhaust and thus not available for inhalation of household occupants. Capture efficiency (CE) was assessed for various configurations of burner use (e.g., single front, single back, combination of one front and one back, oven) and fan speed setting. Measured airflow rates were substantially lower than the levels noted in product literature for many of the units. This shortfall was observed for several units costing in excess of $1000. Capture efficiency varied widely (from<5percent to roughly 100percent) across devices and across conditions for some devices. As expected, higher capture efficiencies were achieved with higher fan settings and the associated higher air flow rates. In most cases, capture efficiencies were substantially higher for rear burners than for front burners. The best and most consistent performance was observed for open hoods that covered all cooktop burners and operated at higher airflow rates. The lowest capture efficiencies were measured when a front burner was used with a rear backdraft system or with lowest fan setting for above the range

  15. Exergy analysis in a space with ceiling shield; Analisis exegetico en un espacio con techo escudo

    Energy Technology Data Exchange (ETDEWEB)

    Laboratorio de Energia Solar, Universidad Nacional Autonoma de Mexico (Mexico)

    2009-07-15

    The Solar Laboratory of Energy (LES) of the Universidad Nacional Autonoma de Mexico (UNAM) was designed to be comfortable in spite of the extreme climate where it was built. One of the novel characteristics was the shield type ceiling used in cubicles. In order to compare the effect that had had with respect to the environmental conditions, one had to resort to an exergy analysis, since exergy is a measurement of the capacity of the energy to carry out a work. As a first system the data of the national meteorological system as initial conditions were used. The comparative system used as initial conditions the temperature and relative humidity measurements obtained in 1992 in a cubicle of the LES. Both systems were taken as open. The final conditions were settled at 25 Celsius degrees and 50% of relative humidity in a first case and variables (with respect to the perimeter a comfort zone) in a second case. The saving obtained was of 69% and 33% respectively. Although it is not possible to determine what percentage corresponds to the exclusive saving of the ceiling shield, we see that the cover all altogether, presents a significant exergy saving in respect to modifying the environmental conditions directly. [Spanish] El Laboratorio de Energia Solar (LES) de la Universidad Nacional Autonoma de Mexico (UNAM) fue disenado para ser confortable a pesar del clima extremoso donde fue construido. Una de las caracteristicas novedosas fue el uso de techo tipo escudo en cubiculo. Para comparar el efecto que se tuvo respecto a las condiciones ambientales, se recurrio a un analisis exergetico, ya que la exergia es una medida de la capacidad de la energia para realizar un trabajo. Como un primer sistema se utilizaron los datos del sistema meteorologico nacional como condiciones iniciales. El sistema comparativo utilizo como condiciones iniciales las mediciones de temperatura y humedad relativas obtenidas en 1992 en un cubiculo del LES. Ambos sistemas fueron tomados como abiertos

  16. Development and maintenance of a telescoping debris flow fan in response to human-induced fan surface channelization, Chalk Creek Valley Natural Debris Flow Laboratory, Colorado, USA

    Science.gov (United States)

    Wasklewicz, T.; Scheinert, C.

    2016-01-01

    Channel change has been a constant theme throughout William L. Graf's research career. Graf's work has examined channel changes in the context of natural environmental fluctuations, but more often has focused on quantifying channel change in the context of anthropogenic modifications. Here, we consider how channelization of a debris flows along a bajada has perpetuated and sustained the development of 'telescoping' alluvial fan. Two-dimensional debris-flow modeling shows the importance of the deeply entrenched channelized flow in the development of a telescoping alluvial fan. GIS analyses of repeat (five different debris flows), high-resolution (5 cm) digital elevation models (DEMs) generated from repeat terrestrial laser scanning (TLS) data elucidate sediment and topographic dynamics of the new telescoping portion of the alluvial fan (the embryonic fan). Flow constriction from channelization helps to perpetuate debris-flow runout and to maintain the embryonic fan and telescoping nature of the alluvial fan complex. Embryonic fan development, in response to five debris flows, proceeds with a major portion of the flows depositing on the southern portion of the embryonic fan. The third through the fifth debris flows also begin to shift some deposition to the northern portion of the embryonic. The transfer of sediment from a higher portion of the embryonic fan to a lower portion continues currently on the embryonic fan. While channelized flow has been shown to be critical to the maintenance of the telescoping fan, the flow constriction has led to higher than background levels of sediment deposition in Chalk Creek, a tributary of the Arkansas River. A majority of the sediment from each debris flow is incorporated into Chalk Creek as opposed to being stored on the embryonic fan.

  17. Ancient sand-rich submarine fans: depositional systems, models, identification, and analysis

    Science.gov (United States)

    Mattern, F.

    2005-05-01

    Sand-rich submarine fans are radial or curved in plan view depending on the slope of the basin floor. They occur isolated or in coalescing systems. The fans' average lateral extent measures close to 25 km and their thickness usually less than 300 m. The thickness of outer fan sequences averages around 120 m and that of middle fan successions around 160 m. Rarely reported inner fan sequences have a maximum thickness of 80 m. The formation of sand-rich fans is closely related to tectonic activity. Their sediment is coarse-grained and compositionally immature as indicated by significant feldspar content due to close provenance and rapid transport by short rivers with a steep gradient controlled by tectonism. Tectonic activity also provides for narrow shelves making the fans relatively insensitive to sealevel changes. Formation of sand-rich fans typically occurs in restricted continental basins. The tectonic settings are highly variable. Sand-rich fans typically receive their sediment through submarine canyons which intercept sand from longshore drift and/or are fed more or less directly by regional rivers. The type of ancient fan system (radial, curved, isolated, coalescing) may be identified through paleocurrent map plots, facies map sketches, recognition of lateral thickness variations and sediment influx centers, as well as lateral bed correlations defining the minimum fan extent. Important in distinguishing different environments of ancient fans are detailed measured sections, their comparison and correlation. Channelized inner fan and middle fan deposits may be distinguished from the unchannelized outer fan successions through bed correlation tests which reflect their different stratigraphic architectures and bedding patterns. Bedding in outer fan deposits (lobes) is relatively simple, parallel, and regular. The lateral bed continuity is relatively high. Channel fills, especially those of middle fan distributary channels, display a complicated bedding pattern

  18. Radiant Ceiling Panels Combined with Localized Methods for Improved Thermal Comfort of Both Patient and Medical Staff in Patient Room

    DEFF Research Database (Denmark)

    Mori, Sakura; Barova, Mariya; Bolashikov, Zhecho Dimitrov;

    2012-01-01

    The objectives were to identify whether ceiling installed radiant heating panels can provide thermal comfort to the occupants in a patient room, and to determine a method for optimal thermal environment to both patient and medical staff simultaneously. The experiments were performed in a climate...... mattress were used to provide local heating for the patient. The effects of the methods were identified by comparing the manikin based equivalent temperatures. The optimal thermal comfort level for both patient and medical staff would obtained when two conventional cotton blankets were used with extra...... chamber resembling a single-bed patient room under convective air conditioning alone or combined with the ceiling installed radiant heating panels. Two thermal manikins simulated a patient lying in the bed and a doctor standing next to the patient. Conventional cotton blanket, electric blanket, electric...

  19. Thou shalt not pass?: Examining the existence of an immigrant glass ceiling in Sweden, 1970-1990

    Directory of Open Access Journals (Sweden)

    Jonas Helgertz

    2011-01-01

    Full Text Available The paper studies a sample of natives and 18 immigrant nationalities in the Swedish labor market between 1970 and 1990. The purpose is examining the existence of an immigrant specific glass ceiling. Results suggest a considerable overall advantage in terms of the probability of experiencing upward occupational mobility for native Swedish males. Despite this, the pattern does not correspond to the theoretical expectations of a glass ceiling. Using the ISEI classification of occupational status, the advantage experienced by Swedish males is consistent in the private manufacturing and private service sectors, compared to the experience of immigrants and women. The public sector generally suggests a similar pattern according to linguistic background. In this sector, certain groups of women are, however, observed to experience an advantage from low occupational status origins.

  20. Gas Turbine Engine Having Fan Rotor Driven by Turbine Exhaust and with a Bypass

    Science.gov (United States)

    Suciu, Gabriel L. (Inventor); Chandler, Jesse M. (Inventor)

    2016-01-01

    A gas turbine engine has a core engine incorporating a core engine turbine. A fan rotor is driven by a fan rotor turbine. The fan rotor turbine is in the path of gases downstream from the core engine turbine. A bypass door is moveable from a closed position at which the gases from the core engine turbine pass over the fan rotor turbine, and moveable to a bypass position at which the gases are directed away from the fan rotor turbine. An aircraft is also disclosed.

  1. EXPERIMENTAL INVESTIGATIONS ON THE DESIGN OF A DUCTED COUNTER-ROTATING AXIAL FLOW FANS SYSTEM

    OpenAIRE

    Nouri, Hussain; Ravelet, Florent; Bakir, Farid; Sarraf, Christophe

    2011-01-01

    An experimental study on counter-rotating axial-flow fans was carried out. The fans of diameter D = 375 mm were designed using an inverse method. The counter-rotating fans operate in a ducted-flow configuration and the overall performances are measured in a normalized test bench. The rotation rate of each fan is independently controlled. The distance between the fans can vary from 10 to 50 mm by steps of 10 mm. The results show that the efficiency is strongly increased compared to a conventio...

  2. Characterization and Optimization of the Thermal Performance of Miniature Piezoelectric Fans

    OpenAIRE

    Acikalin, Tolga; Garimella, S V; Raman, Arvind; Petroski, James

    2007-01-01

    Piezoelectric fans have emerged as a viable cooling technology for the thermal management of electronic devices, owing to their low- power consumption, minimal noise emission, and small and configurable dimensions. Piezoelectric fans are investigated for application in the cooling of low-power electronics. Different experimental configurations are considered, and the effect of varying the fan amplitude, the distance between the fan and the heat source, the fan length, its frequency offset from res...

  3. Growth of a post-Little Ice Age submarine fan, Glacier Bay, Alaska

    Science.gov (United States)

    Carlson, P.R.; Cowan, E.A.; Powell, R.D.; Cai, J.

    1999-01-01

    A small Holocene fan is forming where Queen Inlet, a hanging valley, enters West Arm fjord, Glacier Bay, Alaska. Queen fan formed in the last 80 years following retreat of the Little Ice Age glacier that filled Glacier Bay about 200 yr BP. It was built mainly by a turbidite system originating from Carroll Glacier delta, as the delta formed in the early 1900s at the head of Queen Inlet. The Late Holocene Queen fan is comparable to large Pleistocene fans that formed in the Gulf of Alaska and differs from trough-mouth fans formed by cooler climate glacier systems.

  4. The Effect of Gender on Perception of Glass Ceiling, Mediated by SRO and Attitude toward Women as Managers

    OpenAIRE

    Anoop Maithani; Manisha Misra; Saaylee Potnis; Shringar Bhuwania

    2012-01-01

    Purpose: The purpose of this research paper is to determine the effect of Gender on Perception of Glass Ceiling, mediated by Sex Role Orientation and Attitude towards Women as Managers.Design/methodology/approach: An online survey was floated to 189 B-School students via email and social networking sights, out of which a total of 153 responses were collected and analyzed. The respondents were surveyed on their Sex Role Orientation, Attitude towards Women as Managers and Perception of Glass Ce...

  5. Air pollution in surrounding environment of Sasa tailing dam – ambient air, plant dust and ceiling dust

    OpenAIRE

    Krstev, Boris; Krstev, Aleksandar; Golomeov, Blagoj; Golomeova, Mirjana; Zendelska, Afrodita; Danevski, Tome; Fidancev, Boris

    2013-01-01

    The current and recent activities in the lead-zinc Sasa mine or copper Bucim mine and flotation of galena and sphalerite or chalcopyrite, producing metals for market, are reason for possible troubles from tailing dam-pond and surrounding river, ambient air and plant or ceiling dust. This appearance is significant for the surrounding environment, but legislative and ecological law directive limited the quantity of these. In this paper will be present results of investigations from plant ...

  6. In Search of the Glass Ceiling: Gender and Earnings Growth among U.S. College Graduates in the 1990s

    OpenAIRE

    2011-01-01

    Gender-typical educational choices and the glass ceiling are widely believed to explain why older women earn far less than observably similar men. Using large panels drawn from the National Science Foundation's (NSF) National Survey of College Graduates and other data representative of U.S. college graduates from the 1990s, the author documents the small role of personal choices and finds evidence contrary to the predictions of both human capital and discrimination models. Rather than the dif...

  7. Development and evaluation of a ceiling ventilation system enhanced by solar photovoltaic thermal collectors and phase change materials

    International Nuclear Information System (INIS)

    Highlights: • A novel ceiling ventilation system enhanced by PVT and PCMs was proposed. • PCM was used to increase the local thermal mass and to serve as a storage unit. • The proposed system can enhance indoor thermal comfort in winter and summer. - Abstract: This paper presents the development and performance evaluation of a novel ceiling ventilation system integrated with solar photovoltaic thermal (PVT) collectors and phase change materials (PCMs). The PVT collectors are used to generate electricity and provide low grade heating and cooling energy for buildings by using winter daytime solar radiation and summer night-time sky radiative cooling, respectively. The PCM is integrated into the building ceiling as a part of the ceiling insulation and at the same time, as a centralized thermal energy storage to temporally store low grade energy collected from the PVT collectors. The performance of the proposed system was numerically evaluated based on a Solar Decathlon house using TRNSYS. The results showed that, in winter conditions, the proposed PVT–PCM integrated ventilation system can significantly improve the indoor thermal comfort of passive buildings without using air-conditioning systems with a maximum air temperature rise of 23.1 °C from the PVT collectors. Compared with the system using PCM but without using PVT collectors, the coefficient of thermal comfort enhancement in the kitchen, dining room and living room of the case building studied using the proposed system improved from almost zero to 0.9823 while the coefficient of thermal comfort enhancement in the study room improved from 0.0060 to 0.9921. In summer conditions, the proposed system can also enhance indoor thermal comfort through night-time sky radiative cooling

  8. Privacy-Preserved Behavior Analysis and Fall Detection by an Infrared Ceiling Sensor Network

    Directory of Open Access Journals (Sweden)

    Mineichi Kudo

    2012-12-01

    Full Text Available An infrared ceiling sensor network system is reported in this study to realize behavior analysis and fall detection of a single person in the home environment. The sensors output multiple binary sequences from which we know the existence/non-existence of persons under the sensors. The short duration averages of the binary responses are shown to be able to be regarded as pixel values of a top-view camera, but more advantageous in the sense of preserving privacy. Using the “pixel values” as features, support vector machine classifiers succeeded in recognizing eight activities (walking, reading, etc. performed by five subjects at an average recognition rate of 80.65%. In addition, we proposed a martingale framework for detecting falls in this system. The experimental results showed that we attained the best performance of 95.14% (F1 value, the FAR of 7.5% and the FRR of 2.0%. This accuracy is not sufficient in general but surprisingly high with such low-level information. In summary, it is shown that this system has the potential to be used in the home environment to provide personalized services and to detect abnormalities of elders who live alone.

  9. Kinetic and equilibrium studies of cesium adsorption on ceiling tiles from aqueous solutions

    International Nuclear Information System (INIS)

    A series of experiments were performed to quantify the adsorption of cesium on ceiling tiles as a representative of urban construction materials. Adsorption was carried out from solutions to mimic wet environmental conditions. Non-radioactive cesium chloride was used as a surrogate of the radioactive 137Cs. The experiments were performed in the range of initial cesium concentrations of 0.114-23.9 mg L-1 at room temperature (21 deg. C) around three weeks. Solution samples were taken after set periods of time and analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The quantity of adsorbed Cs was calculated by mass balance as a function of time. Two kinetic and three equilibrium models were employed to interpret the test results. Determination of kinetic parameters for adsorption was carried out using the first-order reaction model and the intra-particle diffusion model. Adsorption equilibrium was studied using Langmuir, Freundlich and three-parameter Langmuir-Freundlich adsorption isotherm models. A satisfactory correlation between the experimental and the predicted values was observed.

  10. Kinetic and equilibrium studies of cesium adsorption on ceiling tiles from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Miah, Muhammed Yusuf [Emergencies Science and Technology Section, Environment Canada, 335 River Road, Ottawa, Ontario, K1A 0H3 (Canada); Department of Applied Chemistry and Chemical Technology, Noakhali Science and Technology University (Bangladesh); Volchek, Konstantin, E-mail: Konstantin.Volchek@ec.gc.ca [Emergencies Science and Technology Section, Environment Canada, 335 River Road, Ottawa, Ontario, K1A 0H3 (Canada); Kuang, Wenxing [SAIC Canada, 335 River Road, Ottawa, Ontario, K1A 0H3 (Canada); Tezel, F. Handan [Department of Chemical and Biological Engineering, University of Ottawa, 161 Louis-Pasteur, Ottawa, Ontario, K1N 6N5 (Canada)

    2010-11-15

    A series of experiments were performed to quantify the adsorption of cesium on ceiling tiles as a representative of urban construction materials. Adsorption was carried out from solutions to mimic wet environmental conditions. Non-radioactive cesium chloride was used as a surrogate of the radioactive {sup 137}Cs. The experiments were performed in the range of initial cesium concentrations of 0.114-23.9 mg L{sup -1} at room temperature (21 deg. C) around three weeks. Solution samples were taken after set periods of time and analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The quantity of adsorbed Cs was calculated by mass balance as a function of time. Two kinetic and three equilibrium models were employed to interpret the test results. Determination of kinetic parameters for adsorption was carried out using the first-order reaction model and the intra-particle diffusion model. Adsorption equilibrium was studied using Langmuir, Freundlich and three-parameter Langmuir-Freundlich adsorption isotherm models. A satisfactory correlation between the experimental and the predicted values was observed.

  11. GIS approach to the definition of capacity and generation ceilings of renewable energy technologies

    International Nuclear Information System (INIS)

    There are no discrepancies about the advantages of achieving a sustainable energy system based on locally available natural resources. However, supporters of green energy generation system were lacking some scientific and consistent study to defend their proposals. In order to have such a study, Greenpeace commissioned Technology Research Institute at the Pontificia Comillas University to carry out a study to assess ceilings for the potential and generation of renewable technologies in Spain. It demonstrates firstly a far greater renewable potential than the targets set by long term policies, and secondly, the viability of meeting the entire electricity demand projected for 2050. GIS was used to add the geographical dimension to the original project in order to generate a technical analysis linked to the specific constrictions imposed by territory (natural and anthropogenic) and not just designed to cover a certain demand. Therefore, GIS spatial analysis took into account local conditions producing a more accurate assessment than evaluations made upon 'virtual' electrical spaces. This approach could be applied to other small scale general studies in order to assess the maximum contribution of renewable energy sources to particular energy generation mix and to help set development policies supporting high participation of renewable technologies

  12. Pride and prejudice beyond the glass ceiling: Brazilian female executives´ psychological type

    Directory of Open Access Journals (Sweden)

    Betania Tanure

    2014-08-01

    Full Text Available http://dx.doi.org/10.5007/2175-8077.2014v16n39p210This paper intends to relate characteristics of female executive psychological type with their male colleagues in corporations operating in Brazil (CEOs, VPs/directors and top managers. The theoretical framework explores the glass ceiling and the prejudices faced by female executives. It was developed a mixed qualitative-quantitative method. In the quantitative part we interviewed 743 men and 222 women from 344 corporations. We applied also the questionnaire MBTI to 430 of these executives. In the qualitative part we held focus groups with 227 individuals and 104 semi-structured interviews. The most active psychological MBTI type found was the ESTJ, both to men and women. The dominant characteristics in this type is more rational, logical and less emotional. Prejudices are huge: women need to work harder to show that they are as competent as men. They also live the society's pressure in relation to the roles as mother and wife.

  13. Modelling of cooled-ceiling air-conditioning systems: Influences on indoor environment and energy consumption. Doctoral thesis

    Energy Technology Data Exchange (ETDEWEB)

    Niu, J.

    1994-06-14

    The contents presented in this thesis consist of four principal parts: (1) the critical review of turbulence CFD (Computational Fluid Dynamics) techniques and their application in building air flow study, and the experimental evaluation of the widely used k-epsilon turbulence model for in-room air flow situations; (2) the development of a thermodynamic mathematical model for cooled-ceiling air-conditioning systems, and the enhancement of an existing computer code ACCURACY, and the experimental validation of the convective parameters involved in the models; (3) the combined use of building dynamic simulation and CFD technique for the investigation of thermal comfort and ventilation effectiveness performance of three typical air-conditioning systems, the air-panel type cooled-ceiling (ACC) system, and the water-panel type cooled ceiling (CC) system; and (4) the use of the dynamic model coupled with air-handling-unit (AHU) and primary equipment models to simulate the annual energy consumption of CC systems and all-air systems and to estimate thermal performances of some passive cooling schemes, especially the evaporative free-cooling scheme. The review of the state-of-the-art of turbulence modeling shows that the k-epsilon turbulence model still remains the most-widely used engineering model.

  14. The benefits of conducting factory performance tests for main mine fans

    Energy Technology Data Exchange (ETDEWEB)

    Ray, R.E.Jr. [PB Americas Inc., New York, NY (United States); Gamble, G.A. [Clarage Twin City Fan Co., Akron, OH (United States)

    2010-07-01

    Axial flow fans used in underground mining are also commonly used in subway tunnel ventilation fans to provide an evacuation path during a tunnel fire emergency. The axial flow fans provide sufficient air velocity to the fire site to prevent backlayering of smoke against the incoming airflow. Since the tunnels are used by the public, advance testing of fans and motors is conducted to confirm that the equipment will perform as specified during a fire. This paper discussed some of the advantages derived from conducting fan factory tests for tunnel projects that would also apply to mining applications. It also described other benefits from testing that are unique to mining. External factors that may cause the fan performance to vary considerably from the predicted performance measured at the factory were also discussed. These included air density changes and system effects produced by poorly designed shaft configurations and fan inlet ductwork. 11 refs., 6 figs.

  15. Aircraft Noise Prediction Program (ANOPP) Fan Noise Prediction for Small Engines

    Science.gov (United States)

    Hough, Joe W.; Weir, Donald S.

    1996-01-01

    The Fan Noise Module of ANOPP is used to predict the broadband noise and pure tones for axial flow compressors or fans. The module, based on the method developed by M. F. Heidmann, uses empirical functions to predict fan noise spectra as a function of frequency and polar directivity. Previous studies have determined the need to modify the module to better correlate measurements of fan noise from engines in the 3000- to 6000-pound thrust class. Additional measurements made by AlliedSignal have confirmed the need to revise the ANOPP fan noise method for smaller engines. This report describes the revisions to the fan noise method which have been verified with measured data from three separate AlliedSignal fan engines. Comparisons of the revised prediction show a significant improvement in overall and spectral noise predictions.

  16. Shaking table test study on seismic performance of dehydrogenation fan for nuclear power plants

    International Nuclear Information System (INIS)

    Seismic performance of the dehydrogenation fan for nuclear power plants was evaluated based on the shaking table test of earthquake simulation. Dynamic characteristics including the orthogonal tri-axial fundamental frequencies and equivalent damping ratios were measured by the white noise scanning method. Artificial seismic waves were generated corresponding to the floor acceleration response spectra for nuclear power plants. Furthermore, five OBE and one SSE shaking table tests for dehydrogenation fan were performed by using the artificial seismic waves as the seismic inputs along the orthogonal axis simultaneity. Operating function of dehydrogenation fan was monitored and observed during all seismic tests, and performance indexes of dehydrogenation fan were compared before and after seismic tests. The results show that the structural integrity and operating function of the dehydrogenation fan are perfect during all seismic tests; and the performance indexes of the dehydrogenation fan can remain consistent before and after seismic tests; the seismic performance of the dehydrogenation fan can satisfy relevant technical requirements. (authors)

  17. Performance of low pressure mechanical ventilation concept with diffuse ceiling inlet for renovation of school classrooms

    DEFF Research Database (Denmark)

    Terkildsen, Søren; Svendsen, Svend

    mechanical ventilation concept to lower energy consumption and improve the indoor environment, developed for refurbishment of school classrooms. The performance of the concept is investigated through computer simulations and measurements of energy consumption and indoor environment. The measurements are made...... demand. The measurements and simulation results show that the indoor environment fulfils indoor environment category II in EN 15251 and the CO2-concentration is kept below 800 ppm. The heat recovery efficiency is 85 % and the SFP-value of the system is measured to 495 J/m3 at the design flow rate, lower...... than 1/4 of the maximum requirement in the Danish building code. This result in a yearly fan power consumption of 4.0 kWh/m2, included a primary energy factor of 2.5. The results show that the indoor environment is improved to an acceptable level with little energy use, making the concept applicable...

  18. Compressor-fan unitary structure for air conditioning system

    Science.gov (United States)

    Dreiman, N.

    2015-08-01

    An extremely compact, therefore space saving unitary structure of short axial length is produced by radial integration of a revolving piston rotary compressor and an impeller of a centrifugal fan. The unitary structure employs single motor to run as the compressor so the airflow fan and eliminates duality of motors, related power supply and control elements. Novel revolving piston rotary compressor which provides possibility for such integration comprises the following: a suction gas delivery system which provides cooling of the motor and supplies refrigerant into the suction chamber under higher pressure (supercharged); a modified discharge system and lubricating oil supply system. Axial passages formed in the stationary crankshaft are used to supply discharge gas to a condenser, to return vaporized cooling agent from the evaporator to the suction cavity of the compressor, to pass a lubricant and to accommodate wiring supplying power to the unitary structure driver -external rotor electric motor.

  19. Detectability of minerals on desert alluvial fans using reflectance spectra

    Science.gov (United States)

    Shipman, Hugh; Adams, John B.

    1987-01-01

    The visible and near-infrared reflectance spectra of soil samples collected from desert alluvial and colluvial surfaces in the Cuprite mining district, Nevada, were analyzed. These surfaces are downslope from hydrothermally altered volcanic rocks that contain spectrally characteristic minerals such as alunite and kaolinite. Coarse fractions of the soils on the alluvial fans are mineralogically variable and express the upslope lithologies; fine fractions are remarkably similar mineralogically and spectrally in all samples because of dilution of local mineral components by regionally derived windblown dust. Theoretical models for spectral mixing and for particle-size effects were used to model the observed spectral variations. Diagnostic mineral absorption bands in the spectra of fan materials were enhanced by computationally removing the spectrum of the homogeneous fine-soil component. Results show that spectral mixing models are useful for analyzing data with high spectral resolution obtained by field and aircraft spectrometers.

  20. Natures of Rotating Stall Cell in a Diagonal Flow Fan

    Institute of Scientific and Technical Information of China (English)

    N. SHIOMI; K. KANEKO; T. SETOGUCHI

    2005-01-01

    In order to clarify the natures of a rotating stall cell, the experimental investigation was carried out in a high specific-speed diagonal flow fan. The pressure field on the casing wall and the velocity fields at the rotor inlet and outlet were measured under rotating stall condition with a fast response pressure transducer and a single slant hot-wire probe, respectively. The data were processed using the "Double Phase-Locked Averaging (DPLA)"technique, which enabled to obtain the unsteady flow field with a rotating stall cell in the relative co-ordinate system fixed to the rotor. As a result, the structure and behavior of the rotating stall cell in a high specific-speed diagonal flow fan were shown.

  1. Structural Evaluation of Exo-Skeletal Engine Fan Blades

    Science.gov (United States)

    Kuguoglu, Latife; Abumeri, Galib; Chamis, Christos C.

    2003-01-01

    The available computational simulation capability is used to demonstrate the structural viability of composite fan blades of innovative Exo-Skeletal Engine (ESE) developed at NASA Glenn Research Center for a subsonic mission. Full structural analysis and progressive damage evaluation of ESE composite fan blade is conducted through the NASA in-house computational simulation software system EST/BEST. The results of structural assessment indicate that longitudinal stresses acting on the blade are in compression. At a design speed of 2000 rpm, pressure and suction surface outer most ply stresses in longitudinal, transverse and shear direction are much lower than the corresponding composite ply strengths. Damage is initiated at 4870 rpm and blade fracture takes place at rotor speed of 7735 rpm. Damage volume is 51 percent. The progressive damage, buckling, stress and strength results indicate that the design at hand is very sound because of the factor of safety, damage tolerance, and buckling load of 6811 rpm.

  2. Wake Management Strategies for Reduction of Turbomachinery Fan Noise

    Science.gov (United States)

    Waitz, Ian A.

    1998-01-01

    The primary objective of our work was to evaluate and test several wake management schemes for the reduction of turbomachinery fan noise. Throughout the course of this work we relied on several tools. These include 1) Two-dimensional steady boundary-layer and wake analyses using MISES (a thin-shear layer Navier-Stokes code), 2) Two-dimensional unsteady wake-stator interaction simulations using UNSFLO, 3) Three-dimensional, steady Navier-Stokes rotor simulations using NEWT, 4) Internal blade passage design using quasi-one-dimensional passage flow models developed at MIT, 5) Acoustic modeling using LINSUB, 6) Acoustic modeling using VO72, 7) Experiments in a low-speed cascade wind-tunnel, and 8) ADP fan rig tests in the MIT Blowdown Compressor.

  3. Structural Integrity Evaluation of the Lear Fan 2100 Aircraft

    Science.gov (United States)

    Kan, H. P.; Dyer, T. A.

    1996-01-01

    An in-situ nondestructive inspection was conducted to detect manufacturing and assembly induced defects in the upper two wing surfaces (skin s) and upper fuselage skin of the Lear Fan 2100 aircraft E009. The effects of the defects, detected during the inspection, on the integrity of the structure was analytically evaluated. A systematic evaluation was also conducted to determine the damage tolerance capability of the upper wing skin against impact threats and assembly induced damage. The upper wing skin was divided into small regions for damage tolerance evaluations. Structural reliability, margin of safety, allowable strains, and allowable damage size were computed. The results indicated that the impact damage threat imposed on composite military aircraft structures is too severe for the Lear Fan 2100 upper wing skin. However, the structural integrity is not significantly degraded by the assembly induced damage for properly assembled structures, such as the E009 aircraft.

  4. On Passion and Sports Fans:A Look at Football

    OpenAIRE

    Vallerand, Robert J.; Ntoumanis, Nikos; Philippe, Frederick L; Lavigne, Genevieve L; Carbonneau, Noemie; Bonneville, Arielle; Lagac-Labont, Camille; Maliha, Gabrielle

    2008-01-01

    The purpose of the present research was to test the applicability of the Dualistic Model of Passion (Vallerand et al., 2003) to being a sport (football) fan. The model posits that passion is a strong inclination toward an activity that individuals like (or even love), that they value, and in which they invest time and energy. Furthermore, two types of passion are proposed: harmonious and obsessive passion. While obsessive passion entails an uncontrollable urge to engage in the passionate acti...

  5. Evaluation of Retrofit Variable-Speed Furnace Fan Motors

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, R.; Williamson, J.

    2014-01-01

    In conjunction with the New York State Energy Research and Development Authority (NYSERDA) and Proctor Engineering Group, Ltd. (PEG), the Consortium for Advanced Residential Buildings (CARB) has evaluated the Concept 3 (tm) replacement motors for residential furnaces. These brushless, permanent magnet (BPM) motors can use much less electricity than their PSC (permanent split capacitor) predecessors. This evaluation focuses on existing homes in the heating-dominated climate of upstate New York with the goals of characterizing field performance and cost-effectiveness. The results of this study are intended to be useful to home performance contractors, HVAC contractors, and home efficiency program stakeholders. The project includes eight homes in and near Syracuse, NY. Tests and monitoring was performed both before and after fan motors were replaced. Average fan power reductions were approximately 126 Watts during heating and 220 Watts during cooling operation. Over the course of entire heating and cooling seasons, these translated into average electric energy savings of 163 kWh. Average cost savings were $20 per year. Homes where the fan was used outside of heating and cooling mode saved an additional $42 per year on average. Results indicate that BPM replacement motors will be most cost-effective in HVAC systems with longer run times and relatively low duct static pressures. More dramatic savings are possible if occupants use the fan-only setting when there is no thermal load. There are millions of cold-climate, U.S. homes that meet these criteria, but the savings in most homes tested in this study were modest.

  6. Involvement of FAN in TNF-induced apoptosis

    OpenAIRE

    Ségui, Bruno; Cuvillier, Olivier; Adam-Klages, Sabine; Garcia, Virginie; Malagarie-Cazenave, Sophie; Lévêque, Sophie; Caspar-Bauguil, Sylvie; Coudert, Jérôme,; Salvayre, Robert; Krönke, Martin; Levade, Thierry

    2001-01-01

    TNF-α is a pleiotropic cytokine activating several signaling pathways initiated at distinct intracellular domains of the TNF receptors. Although the C-terminal region is believed to be responsible for apoptosis induction, the functions of more membrane-proximal domains, including the domain that couples to neutral sphingomyelinase activation, are not yet fully elucidated. The roles of this region and of the associated adapter protein FAN (factor associated with neutral SMase activation) in th...

  7. Flow phenomena modelling in the sifter of the fan mill

    Energy Technology Data Exchange (ETDEWEB)

    Dobrowolski, B.; Nowosielski, G. [Politech Opolska, Opole (Poland)

    2004-07-01

    This paper presents numerical tests of the air-pulverized coal mixture flow in the sifter of the fan mill. Numerical calculations were performed for a typical mill used in the boiler OP-650b. A three-dimensional model of the mill was worked out. Influence of the angle of separator blade position on gas and solid particle circulation inside the sifter was analyzed.

  8. Effect of vorticity distribution on the blades on fan noise

    Science.gov (United States)

    Koscso, Gabor

    Tests have been performed to determine the connection between noise emission of radial flow fans, impellers, with different inlet design, and vorticity distribution on the blades. An inlet cone protruding into the impeller was found to reduce significantly the radiated sound power level. Measurements showed that for the tested impellers about the duty point corresponding to maximum efficiency, vorticity distribution on the blades has little effect on the sound power level.

  9. Streaming Scholarship: Using Fan Vids to Teach "Harry Potter"

    Science.gov (United States)

    Winters, Sarah Fiona

    2013-01-01

    This article argues that Harry Potter fan vids can be used in the classroom as works of secondary criticism about J. K. Rowling's primary text. It makes two claims: the first is that vids can be read as criticism of a particular text (in this case Harry Potter) alongside other critical essays on that text; the second is that the practice of…

  10. Impeller Design of a Centrifugal Fan with Blade Optimization

    OpenAIRE

    Yu-Tai Lee; Vineet Ahuja; Ashvin Hosangadi; Michael E. Slipper; Lawrence P. Mulvihill; Roger Birkbeck; Coleman, Roderick M.

    2011-01-01

    A method is presented for redesigning a centrifugal impeller and its inlet duct. The double-discharge volute casing is a structural constraint and is maintained for its shape. The redesign effort was geared towards meeting the design volute exit pressure while reducing the power required to operate the fan. Given the high performance of the baseline impeller, the redesign adopted a high-fidelity CFD-based computational approach capable of accounting for all aerodynamic losses. The present eff...

  11. Thermoluminescence dating of Zhuoshui Fan-delta, Yunlin, Taiwan

    International Nuclear Information System (INIS)

    Five samples, collected from different depth of one core drilled from Zhuoshui Fan-delta, Yunlin, Taiwan of China, were preliminarily tested by thermoluminescence dating. Ages of the sample younger than 50 ka are consistent with those from 14C dating method. This result indicates that the TL dating is a feasible method for the age determination of late Quaternary coastal sediments in Taiwan, China

  12. Dual Fan Separator within the Universal Waste Management System

    Science.gov (United States)

    Stapleton, Tom; Converse, Dave; Broyan, James Lee, Jr.

    2014-01-01

    Since NASA's new spacecraft in development for both LEO and Deep Space capability have considerable crew volume reduction in comparison to the Space Shuttle, the need became apparent for a smaller commode. In response the Universal Waste Management System (UWMS) was designed, resulting in an 80% volume reduction from the last US commode, while enhancing performance. The ISS WMS and previous shuttle commodes have a fan supplying air flow to capture feces and a separator to capture urine and separate air from the captured air/urine mixture. The UWMS combined both rotating equipment components into a single unit, referred to at the Dual Fan Separator (DFS). The combination of these components resulted in considerable packaging efficiency and weight reduction, removing inter-component plumbing, individual mounting configurations and required only a single motor and motor controller, in some of the intended UWMS platform applications the urine is pumped to the ISS Urine Processor Assembly (UPA) system. It requires the DFS to include less than 2.00% air inclusion, by volume, in the delivered urine. The rotational speed needs to be kept as low as possible in centrifugal urine separators to reduce air inclusion in the pumped fluid, while fans depend on rotational speed to develop delivered head. To satisfy these conflicting requirements, a gear reducer was included, allowing the fans to rotate at a much higher speed than the separator. This paper outlines the studies and analysis performed to develop the DFS configuration. The studies included a configuration trade study, dynamic stability analysis of the rotating bodies and a performance analysis of included labyrinth seals. NASA is considering a program to fly the UWMS aboard the ISS as a flight experiment. The goal of this activity is to advance the Technical Readiness Level (TRL) of the DFS and determine if the concept is ready to be included as part of the flight experiment deliverable.

  13. Fan Atomized Burner design advances & commercial development progress

    Energy Technology Data Exchange (ETDEWEB)

    Kamath, B. [Heat-Wise, Inc., Ridge, NY (United States); Butcher, T.A. [Brookhaven National Lab., Upton, NY (United States)

    1996-07-01

    As a part of the Oil Heat Research and Development program, sponsored by the US Department of Energy, Brookhaven National Laboratory (BNL) has an on-going interest in advanced combustion technologies. This interest is aimed at: improving the initial efficiency of heating equipment, reducing long term fouling and efficiency degradation, reducing air pollutant emissions, and providing practical low-firing rate technologies which may lead to new, high efficiency oil-fired appliances. The Fan-Atomized Burner (FAB) technology is being developed at BNL as part of this general goal. The Fan-Atomized Burner uses a low pressure, air atomizing nozzle in place of the high pressure nozzle used in conventional burners. Because it is air-atomized the burner can operate at low firing rates without the small passages and reliability concerns of low input pressure nozzles. Because it uses a low pressure nozzle the burner can use a fan in place of the small compressor used in other air-atomized burner designs. High initial efficiency of heating equipment is achieved because the burner can operate at very low excess air levels. These low excess air levels also reduce the formation of sulfuric acid in flames. Sulfuric acid is responsible for scaling and fouling of heat exchanger surfaces.

  14. Types of submarine fan lobes: Models and implications

    Energy Technology Data Exchange (ETDEWEB)

    Shanmugam, G.; Moiola, R.J. (Mobil Research and Development Corp., Dallas, TX (United States))

    1991-01-01

    Different lobe models imply significantly different reservoir geometries; thus, one must apply the proper lobe model to ancient fan sequences. Braided suprafan lobes are characterized by stacked channel sand bodies with good lateral and vertical communication, and they constitute excellent reservoir facies. Depositional lobes, composed of sheet-like sand bodies with good lateral and moderate vertical communication, exhibit properties of good reservoir facies. Fanlobes, which refer to meandering channels and associated levee facies of large mud-rich submarine fans such as the Mississippi fan, are characterized by offset stacked sand bodies with poor lateral and vertical communication .These lenticular sands have the potential to be moderately good reservoir facies. Ponded lobes, which represent mud-rich slump facies of slope environments, comprise poor reservoir facies because of low sand content and poor sand-body connectivity. Furthermore, the presence of contorted mud layers in ponded lobes is expected to hinder fluid flow. External mounded reflections in seismic profiles often are interpreted as lobes; however, there are no definite seismic criteria to delineate mud-rich lobes from sand-rich lobes.

  15. Effects of Bifurcations on Aft-Fan Engine Nacelle Noise

    Science.gov (United States)

    Nark, Douglas M.; Farassat, Fereidoun; Pope, D. Stuart; Vatsa, Veer N.

    2004-01-01

    Aft-fan engine nacelle noise is a significant factor in the increasingly important issue of aircraft community noise. The ability to predict such noise within complex duct geometries is a valuable tool in studying possible noise attenuation methods. A recent example of code development for such predictions is the ducted fan noise propagation and radiation code CDUCT-LaRC. This work focuses on predicting the effects of geometry changes (i.e. bifurcations, pylons) on aft fan noise propagation. Beginning with simplified geometries, calculations show that bifurcations lead to scattering of acoustic energy into higher order modes. In addition, when circumferential mode number and the number of bifurcations are properly commensurate, bifurcations increase the relative importance of the plane wave mode near the exhaust plane of the bypass duct. This is particularly evident when the bypass duct surfaces include acoustic treatment. Calculations involving more complex geometries further illustrate that bifurcations and pylons clearly affect modal content, in both propagation and radiation calculations. Additionally, results show that consideration of acoustic radiation results may provide further insight into acoustic treatment effectiveness for situations in which modal decomposition may not be straightforward. The ability of CDUCT-LaRC to handle complex (non-axisymmetric) multi-block geometries, as well as axially and circumferentially segmented liners, allows investigation into the effects of geometric elements (bifurcations, pylons).

  16. Constant depression fan system a novel glovebox ventilation system

    International Nuclear Information System (INIS)

    In a conventional glovebox ventilation system the depression within the glovebox under normal operation is controlled by instrumentation. In the event of a breach the pressure within the box rises to atmospheric pressure, this pressure rise is detected by instrumentation which in turn operates a quick opening damper in a high depression extract to achieve a 1 metre/sec (200 fpm) inflow through the breach, which can take up to 2 seconds to establish. This system, although widely used, suffers from two distinct drawbacks: It takes a finite time to achieve the containment velocity of 1 metre/sec. It relies upon instrumentation to achieve its objectives. A new glovebox ventilation system has been developed by AWE to overcome these drawbacks. This is the Constant Depression Fan System (CDFS) which is based on an extract fan with a flat characteristic. This achieves all the requirements for the ventilation of gloveboxes and has the advantages that: It has only one moving part - the extract fan. It requires NO INSTRUMENTATION to achieve its objectives. It achieves the containment velocity of 1 metre/sec in the shortest possible time - approximately 0.2 seconds - and tests have shown that containment is maintained under breach conditions. Thus the CDFS is SAFER, SIMPLER and MORE RELIABLE

  17. On-chip grating coupler array on the SOI platform for fan-in/fan-out of multi-core fibers with low insertion loss and crosstalk

    DEFF Research Database (Denmark)

    Ding, Yunhong; Ye, Feihong; Peucheret, Christophe;

    2014-01-01

    We design and fabricate a compact multi-core fiber fan-in/fan-out using a fully-etched grating coupler array on the SOI platform. Lowest coupling loss of 6.8 dB with 3 dB bandwidth of 48 nm and crosstalk lower than ×32 dB are demonstrated....

  18. Building an Enhanced Vocabulary of the Robot Environment with a Ceiling Pointing Camera

    Directory of Open Access Journals (Sweden)

    Alejandro Rituerto

    2016-04-01

    Full Text Available Mobile robots are of great help for automatic monitoring tasks in different environments. One of the first tasks that needs to be addressed when creating these kinds of robotic systems is modeling the robot environment. This work proposes a pipeline to build an enhanced visual model of a robot environment indoors. Vision based recognition approaches frequently use quantized feature spaces, commonly known as Bag of Words (BoW or vocabulary representations. A drawback using standard BoW approaches is that semantic information is not considered as a criteria to create the visual words. To solve this challenging task, this paper studies how to leverage the standard vocabulary construction process to obtain a more meaningful visual vocabulary of the robot work environment using image sequences. We take advantage of spatio-temporal constraints and prior knowledge about the position of the camera. The key contribution of our work is the definition of a new pipeline to create a model of the environment. This pipeline incorporates (1 tracking information to the process of vocabulary construction and (2 geometric cues to the appearance descriptors. Motivated by long term robotic applications, such as the aforementioned monitoring tasks, we focus on a configuration where the robot camera points to the ceiling, which captures more stable regions of the environment. The experimental validation shows how our vocabulary models the environment in more detail than standard vocabulary approaches, without loss of recognition performance. We show different robotic tasks that could benefit of the use of our visual vocabulary approach, such as place recognition or object discovery. For this validation, we use our publicly available data-set.

  19. Building an Enhanced Vocabulary of the Robot Environment with a Ceiling Pointing Camera

    Science.gov (United States)

    Rituerto, Alejandro; Andreasson, Henrik; Murillo, Ana C.; Lilienthal, Achim; Guerrero, José Jesús

    2016-01-01

    Mobile robots are of great help for automatic monitoring tasks in different environments. One of the first tasks that needs to be addressed when creating these kinds of robotic systems is modeling the robot environment. This work proposes a pipeline to build an enhanced visual model of a robot environment indoors. Vision based recognition approaches frequently use quantized feature spaces, commonly known as Bag of Words (BoW) or vocabulary representations. A drawback using standard BoW approaches is that semantic information is not considered as a criteria to create the visual words. To solve this challenging task, this paper studies how to leverage the standard vocabulary construction process to obtain a more meaningful visual vocabulary of the robot work environment using image sequences. We take advantage of spatio-temporal constraints and prior knowledge about the position of the camera. The key contribution of our work is the definition of a new pipeline to create a model of the environment. This pipeline incorporates (1) tracking information to the process of vocabulary construction and (2) geometric cues to the appearance descriptors. Motivated by long term robotic applications, such as the aforementioned monitoring tasks, we focus on a configuration where the robot camera points to the ceiling, which captures more stable regions of the environment. The experimental validation shows how our vocabulary models the environment in more detail than standard vocabulary approaches, without loss of recognition performance. We show different robotic tasks that could benefit of the use of our visual vocabulary approach, such as place recognition or object discovery. For this validation, we use our publicly available data-set. PMID:27070607

  20. In search of the glass ceiling: gender and recruitment to management in Norway's state bureaucracy.

    Science.gov (United States)

    Storvik, Aagoth Elise; Schøne, Pål

    2008-12-01

    There are still fewer female than male managers in Norway's state bureaucracy. This article asks if there are organizational barriers which prevent women from entering these positions. Is there really a glass ceiling, or must one look outside the organizational environment to find an explanation? Is it rather the case that the scarcity of female managers is caused by women's own preferences or their life situations outside work? Or do both contribute to the situation? The study shows that female managers are treated just as well as male managers in central parts of the state bureaucracy. Employers give equal shares of respect and attention to both genders. Female managers are encouraged to apply for the same number of jobs as men and are offered an equal number of jobs as men when they apply; in fact, women are offered more jobs than men, when one controls for the number of job applications. This indicates that organizational barriers are not the problem. The study also shows that there are no differences in work orientation between male and female managers. Female managers are just as ambitious as male managers. Nor do female managers find it more difficult than male managers to combine work and family life. So, how can one explain the low number of female managers? The study shows that one reason can be that female managers apply for management jobs less often than their male colleagues. The cause of this seems to be anticipated discrimination rather than lack of ambition or self-confidence. However, this slows down women's movement into higher management positions in the state bureaucracy. PMID:19035920

  1. Building an Enhanced Vocabulary of the Robot Environment with a Ceiling Pointing Camera.

    Science.gov (United States)

    Rituerto, Alejandro; Andreasson, Henrik; Murillo, Ana C; Lilienthal, Achim; Guerrero, José Jesús

    2016-01-01

    Mobile robots are of great help for automatic monitoring tasks in different environments. One of the first tasks that needs to be addressed when creating these kinds of robotic systems is modeling the robot environment. This work proposes a pipeline to build an enhanced visual model of a robot environment indoors. Vision based recognition approaches frequently use quantized feature spaces, commonly known as Bag of Words (BoW) or vocabulary representations. A drawback using standard BoW approaches is that semantic information is not considered as a criteria to create the visual words. To solve this challenging task, this paper studies how to leverage the standard vocabulary construction process to obtain a more meaningful visual vocabulary of the robot work environment using image sequences. We take advantage of spatio-temporal constraints and prior knowledge about the position of the camera. The key contribution of our work is the definition of a new pipeline to create a model of the environment. This pipeline incorporates (1) tracking information to the process of vocabulary construction and (2) geometric cues to the appearance descriptors. Motivated by long term robotic applications, such as the aforementioned monitoring tasks, we focus on a configuration where the robot camera points to the ceiling, which captures more stable regions of the environment. The experimental validation shows how our vocabulary models the environment in more detail than standard vocabulary approaches, without loss of recognition performance. We show different robotic tasks that could benefit of the use of our visual vocabulary approach, such as place recognition or object discovery. For this validation, we use our publicly available data-set. PMID:27070607

  2. Experimental and Numerical Investigation of a 60cm Diameter Bladeless Fan

    Directory of Open Access Journals (Sweden)

    mohammad jafari

    2016-01-01

    Full Text Available Bladeless fan is a novel type of fan with an unusual geometry and unique characteristics. This type of fan has been recently developed for domestic applications in sizes typically up to 30cm diameter. In the present study, a Bladeless fan with a diameter of 60cm was designed and constructed, in order to investigate feasibility of its usage in various industries with large dimensions. Firstly, flow field passed through this fan was studied by 3D modeling. Aerodynamic and aeroacoustic performance of the fan were considered via solving the conservation of mass and momentum equations in their unsteady form. To validate the acoustic code, NACA 0012 airfoil was simulated in a two dimension domain and the emitted noise was calculated for Re=2×105. Good agreement between numerical and experimental results was observed by applying FW-H equations for predicting noise of the fan. To validate the simulated aerodynamic results, a Bladeless fan with a 60cm diameter was constructed and experimentally tested. In addition, the difference between the experimental and numerical results was acceptable for this fan. Moreover, the experimental results in the present study showed that this fan is capable to be designed and used for various industrial applications.

  3. The Conceptual Design of High Pressure Reversible Axial Tunnel Ventilation Fans

    Directory of Open Access Journals (Sweden)

    A. G. Sheard

    2012-01-01

    Full Text Available Tunnel ventilation fans, classically, must have the ability to both supply and extract air from a tunnel system, with the operator's choice dependent on the tunnel ventilation system's operating mode most appropriate at any given point in time. Consequently, tunnel ventilation fans must incorporate a reversible aerodynamic design which limits the maximum fan pressure rise. This paper presents three high pressure reversible fan concepts. These comprise a two-stage counter rotating fan, a single-stage high speed fan, and a two-stage fan with a single motor and impeller on each end of the motor shaft. The authors consider the relative merits of each concept. The third concept offers the most compact fan, transform, silencer, and damper package size. The authors discuss the mechanical design challenges that occur with a two-stage fan with a single motor and impeller on each end of the motor shaft. They present and consider a selected motor bearing arrangement and casing design for maintainability. Finally, the authors present both prototype fan and full-scale package aerodynamic and acoustic performance, before discussing the challenges presented by high temperature certification in accordance with the requirements of EN 12101-3: 2012.

  4. Health Assessment of Cooling Fan Bearings Using Wavelet-Based Filtering

    Directory of Open Access Journals (Sweden)

    Qiang Miao

    2012-12-01

    Full Text Available As commonly used forced convection air cooling devices in electronics, cooling fans are crucial for guaranteeing the reliability of electronic systems. In a cooling fan assembly, fan bearing failure is a major failure mode that causes excessive vibration, noise, reduction in rotation speed, locked rotor, failure to start, and other problems; therefore, it is necessary to conduct research on the health assessment of cooling fan bearings. This paper presents a vibration-based fan bearing health evaluation method using comblet filtering and exponentially weighted moving average. A new health condition indicator (HCI for fan bearing degradation assessment is proposed. In order to collect the vibration data for validation of the proposed method, a cooling fan accelerated life test was conducted to simulate the lubricant starvation of fan bearings. A comparison between the proposed method and methods in previous studies (i.e., root mean square, kurtosis, and fault growth parameter was carried out to assess the performance of the HCI. The analysis results suggest that the HCI can identify incipient fan bearing failures and describe the bearing degradation process. Overall, the work presented in this paper provides a promising method for fan bearing health evaluation and prognosis.

  5. Plate-fin array cooling using a finger-like piezoelectric fan

    International Nuclear Information System (INIS)

    In this study, the heat transfer of a plate-fin array cooled by a vibrating finger-like piezoelectric fan comprising four flexible rectangular blades was investigated. The results indicated that the heat transfer enhancement of the fin array cooled by a vibrating piezoelectric fan at x/L = 0.5 and H = 5 mm ranged between 1.5 and 3.3, regardless of the fin array orientation. However, the heat transfer enhancement caused by a fan being placed at either edge of the fin array yielded a dissimilar result between both of the fin array orientations because of the superimposed effects of the boundary layer development and the air flow induced by the fan. This dissimilarity was especially noticeable when the piezoelectric fan was composed of aluminum blades to accommodate the moderate Reynolds number. In addition to the Reynolds number, the ratio of the fan blade vibration envelope to the source area determined the Nu number of the piezoelectric fan-cooled fin array. This design enhanced the fin array heat transfer and reduced cooler volume by embedding multiple vibrating beams into the fin array. -- Highlights: • Heat transfer of a piezoelectric fan-cooled plate-fin array was investigated. • Effects of fan position, fan height and fan material on heat transfer were examined. • Similar heat transfer enhancement range was shown for both fin array orientations. • Fin heat transfer with a running Al fan at x = 0 was higher than that at x = 0.25L. • Besides fan Reynolds number, the area ratio also determined Nu of the fin array

  6. Study on the performance improvement of multiblade fans. Effects of suction cones; Tayoku fan no seino kaizen ni kansuru kenkyu. Suction cone no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Kuratani, F.; Ogawa, T. [Hyogo University of Teacher Education, Hyogo (Japan); Yamamoto, S.

    1999-07-25

    In order to improve the performance of a multiblade fan, the effects of three types of suction cones of the fan casing on the fan efficiency and noise are investigated experimentally. The first type of the suction cone is the insertion type, which is inserted into the inside of the fan impeller. The second type is the extrusion type, which extrudes outside from the casing surface. The third type is the combination type of two types. The results of those three types are compared with those of the commonly used suction cone. The followings are made clear: (1) The insertion type and the extrusion type are effective in improving the efficiency and reducing noise. (2) The optimal lengths of the insertion and the extrusion exist. (3) The combination type is more effective in improving the efficiency. (4) The combination type with the skewed cutoff of the fan casing shows the best effect. (author)

  7. Effect of Inlet Geometry on Fan Performance and Flow Field in a Half-Ducted Propeller Fan

    Directory of Open Access Journals (Sweden)

    Pin Liu

    2012-01-01

    Full Text Available In order to clarify the effect of rotor inlet geometry of half-ducted propeller fan on performance and velocity fields at rotor outlet, the experimental investigation was carried out using a hotwire anemometer. Three types of inlet geometry were tested. The first type is the one that the rotor blade tip is fully covered by a casing. The second is that the front one-third part of blade tip is opened and the rest is covered. The third is that the front two-thirds are opened and the rest is covered. Fan test and internal flow measurement at rotor outlet were conducted about three types of inlet geometry. At the internal flow measurement, a single slant hotwire probe was used and a periodical multisampling technique was adopted to obtain the three-dimensional velocity distributions. From the results of fan test, the pressure-rise characteristic drops at high flowrate region and the stall point shifts to high flowrate region, when the opened area of blade tip increases. From the results of velocity distributions at rotor outlet, the region with high axial velocity moves to radial inwards, the circumferential velocity near blade tip becomes high, and the flow field turns to radial outward, when the opened area increases.

  8. Numerical simulation of air flow field in high-pressure fan with splitter blades

    Institute of Scientific and Technical Information of China (English)

    Jianfeng LI; Junfu LU; Hai ZHANG; Qing LIU; Guangxi YUE

    2008-01-01

    For a deeper understanding of the flow char-acteristics in the high-pressure centrifugal blower of a fan of Model 9-26 with splitter blades, a three dimensional (3-D) numerical simulation of air flows in the fan was con-ducted with FLUENT software. The standard k-ε tur-bulent model and unstructured grids were used. The computational fluid dynamics (CFD) results showed that the performance of a fan could be improved by adding the splitter blades in the channel among the leaf blades. Under operational conditions, with the presence of splitter blades, the air flow rate of the fan increased about 5% and the total pressure at the outlet of the fan increased about 10% on average. It was also found that the length of the splitter blades affected the air flow and pressure drop. There is an optimal value for the length. The simulation results provide helpful information for improving the fan performance.

  9. Characterisation of the surface morphology of an alpine alluvial fan using airborne LiDAR

    OpenAIRE

    M. Cavalli; L. Marchi

    2008-01-01

    International audience Alluvial fans of alpine torrents are both natural deposition areas for sediment discharged by floods and debris flows, and preferred sites for agriculture and settlements. Hazard assessment on alluvial fans depends on proper identification of flow processes and their potential intensity. This study used LiDAR data to examine the morphology of the alluvial fan of a small alpine stream (Moscardo Torrent, Eastern Italian Alps). A high-resolution DTM from LiDAR data was ...

  10. Research paper no. 18. Trading rules for CO2 emission permits systems. A proposal for ceilings on quantities and prices

    International Nuclear Information System (INIS)

    Tradable emission permit (TEP) systems for greenhouse gases (GHGs) as they could develop following the Kyoto Protocol - that is if they are limited to Annex B countries and are not bound by exchange regulations) - do not appear to be greatly acceptable today, either to the United States or to the European Union. The problem of the uncertainty related to the cost of reducing emissions is strongly highlighted in the United States: in fact, the approach adopted in the Kyoto Protocol, that of quantitative emissions targets, leaves the question of the reduction programme costs wide open. For the European Union, the unregulated TEP system is hardly acceptable because it would not guarantee that the principle of 'supplementarity' adopted in the Kyoto Protocol, that is, the fact that the purchase of permits should be in addition to action taken within each of the Annex B countries. The section two of this paper is an in-depth economic analysis of the european proposal for ''concrete ceilings''. The alternative proposals, formulated in the United States and relating more to permit price ceilings or''trigger price'', are examined in Section 3. After showing that each of the foregoing proposals could have consequences unacceptable to some or others of the parties to the Protocol, Section 4 offers the proposal of a hybrid formula for regulating the rights market. In fact, the main aim of this paper is to show that the implementation of a 'hybrid solution', consisting of limiting the volume of exchanges while at the same time introducing a TEP price ceiling, could provide a market regulation framework effect allowing the benefits of most of the economic advantages to be enjoyed and also having characteristics acceptable to the various parties from an environmental as well as from an international fairness point of view. (A.L.B.)

  11. Evaluation of Coating Removal and Aggressive Surface Removal Surface Technologies Applied to Concrete Walls, Brick Walls, and Concrete Ceilings

    International Nuclear Information System (INIS)

    The purpose of this investigation was to test and evaluate innovative and commercially available technologies for the surface decontamination of walls and ceilings. This investigation supports the DOE's objectives of reducing risks to human health and the environment through its restoration projects at FEMP and MEMP. This project was performed at the Hemispheric Center for Environmental Technology (HCET) at Florida International University (FIU), where one innovative and four commercially available decontamination technologies were evaluated under standard, non-nuclear testing conditions. The performance data generated by this project will assist DOE site managers in the selection of the safest, most efficient, and most cost-effective decontamination technologies to accomplish their remediation objectives

  12. Full Scale Measurements and CFD Simulations of Diffuse Ceiling Inlet for Ventilation and Cooling of Densely Occupied Rooms

    DEFF Research Database (Denmark)

    Mikeska, Tomás; Fan, Jianhua

    2015-01-01

    gypsum boards with airtight connectionswas created utilizing the full potential of diffuse layer without undesirable crack flow reported by otherauthors. The measured values were used to validate the detailed Large Eddy Simulation model of testroom created in CFD software with aim to evaluate an indoor...... comfort numerically. Results of our investigations have shown that diffuse ceiling inlet is a suitable solution for the spaceswith high density occupancy. The results have shown that transient calculations using Large Eddy Simulation models can predict well temperatures and velocity magnitude of air flow...

  13. Comparison of the Performance of Chilled Beam with Swirl Jet and Diffuse Ceiling Air Supply: Impact of Heat Load Distribution

    DEFF Research Database (Denmark)

    Bertheussen, Bård; Mustakallio, Panu; Kosonen, Risto;

    2013-01-01

    The impact of heat load strength and positioning on the indoor environment generated by diffuse ceiling air supply and chilled beam with radial swirl jet was studied and compared. An office room with two persons and a meeting room with six persons were simulated in a test room (4.5 x 3.95 x 3.5 m3...... (ventilation effectiveness of 0.4) and the air flow rate had to be above minimum to safeguard the indoor air quality. The radial swirl jet of chilled beam also was not capable of creating complete mixing at high and concentrated heat load (ventilation effectiveness of 0.7)....

  14. Performance of radiant cooling ceiling combined with personalized ventilation in an office room: identification of thermal conditions

    DEFF Research Database (Denmark)

    Lipczynska, Aleksandra; Kaczmarczyk, Jan; Melikov, Arsen Krikor

    2014-01-01

    were performed in a test room arranged as an office with 2 workstations and 2 seating occupants resembled by thermal manikins. Heat gain of 66-72 W/m2 was simulated in the room (occupants, computers, lighting, solar gain). The air temperature in the chamber was maintained at 26°C and 28°C. Personalized...... ventilation supplied air at non-isothermal condition with temperature of 25°C. Results showed that the compared methods generated almost the same thermal environment in the occupied zone. However at the workstations the personalized ventilation combined with chilled ceiling provided more cooling and decreased...

  15. Temperature control of an automotive engine cooling system utilizing a magneto-rheological fan clutch

    International Nuclear Information System (INIS)

    In this note, the temperature control of an automotive engine cooling system is undertaken using a magneto-rheological (MR) fluid-based fan clutch (MR fan clutch in short). In order to achieve this goal, an appropriate size of controllable fan clutch using an MR fluid is firstly devised by considering the design parameters of a conventional fan clutch to reflect the practical application. Then, the principal design parameters of the MR fan clutch such as the length of the disc are optimally determined through finite element analysis. The drum-type MR fan clutch is manufactured and its time response to input current is experimentally evaluated. A robust sliding mode controller is then formulated by treating the time constant of the fan clutch system as an uncertain parameter. After identifying the relationship between angular velocity of the MR fan clutch and the temperature of the cooling system, the sliding mode controller is experimentally realized for the cooling system. It has been clearly demonstrated that the proposed sliding mode controller follows well the desired temperature with a small regulating error. It is expected from this feasibility work that the proposed control system associated with an MR fan clutch can be effectively utilized for the automotive cooling system to improve the fuel efficiency. (technical note)

  16. Design of a high performance low aerodynamic noise axial flow fan

    OpenAIRE

    Lanuza Fabregat, Manuel

    2007-01-01

    The project starts with a description of the main sources of noise in an axial flow fan for concluding that the thing we should avoid is the trailing edge noise. After that the formulas for designing a fan and an aerodynamics background are presented. Once we get the results of these formulas a low noise optimization is carried on for leading us to a table of results where the main characteristics of design for our fan are obtained. After these tables the design of the fan is obtained with Pr...

  17. Football fan aggression: the importance of low Basal cortisol and a fair referee.

    Directory of Open Access Journals (Sweden)

    Leander van der Meij

    Full Text Available Fan aggression in football (soccer is a societal problem that affects many countries worldwide. However, to date, most studies use an epidemiological or survey approach to explain football fan aggression. This study used a controlled laboratory study to advance a model of predictors for fan aggression. To do so, football fans (n = 74 saw a match summary in which their favorite team lost against their most important rival. Next, we measured levels of aggression with the hot sauce paradigm, in which fans were given the opportunity to administer a sample of hot sauce that a rival football supporter had to consume. To investigate if media exposure had the ability to reduce aggression, before the match fans saw a video in which fans of the rival team commented in a neutral, negative, or positive manner on their favorite team. Results showed that the media exposure did not affect aggression. However, participants displayed high levels of aggression and anger after having watched the match. Also, aggression was higher in fans with lower basal cortisol levels, which suggests that part of the aggression displayed was proactive and related to anti-social behavior. Furthermore, aggression was higher when the referee was blamed and aggression was lower when the performance of the participants' favorite team was blamed for the match result. These results indicate that aggression increased when the match result was perceived as unfair. Interventions that aim to reduce football fan aggression should give special attention to the perceived fairness of the match result.

  18. Experimental Investigation on Design Enhancement of Axial Fan Using Fixed Guide Vane

    Science.gov (United States)

    Munisamy, K. M.; Govindasamy, R.; Thangaraju, S. K.

    2015-09-01

    Airflow passes through the rotating blade in an axial flow fan will experience a helical flow pattern. This swirling effect leads the system to experience swirl energy losses or pressure drop yet reducing the total efficiency of the fan system. A robust tool to encounter this air spin past the blade is by introducing guide vane to the system. Owing to its importance, a new approach in designing outlet guide vane design for a commercial usage 1250mm diameter axial fan with a 30° pitch angle impeller has been introduced in this paper. A single line metal of proper curvature guide vane design technique has been adopted for this study. By choosing fan total efficiency as a target variable to be improved, the total and static pressure on the design point were set to be constraints. Therefore, the guide vane design was done based on the improvement target on the static pressure in system. The research shows that, with the improvement in static pressure by 29.63% through guide vane installation, the total fan efficiency is increased by 5.12%, thus reduces the fan power by 5.32%. Good agreement were found, that when the fan total efficiency increases, the power consumption of the fan is reduced. Therefore, this new approach of guide vane design can be applied to improve axial fan performance.

  19. Noise reduction for centrifugal fan with non-isometric forward-swept blade impeller

    Institute of Scientific and Technical Information of China (English)

    Jianfeng MA; Datong QI; Yijun MAO

    2008-01-01

    To reduce the noise of the T9-19No.4A centri-fugal fan, whose impeller has equidistant forward-swept blades, two new impellers with different blade spacing were designed and an experimental study was conducted. Both the fan's aerodynamic performance and noise were measured when the two redesigned impellers were com-pared with the original ones. The test results are discussed in detail and the effect of the noise reduction method for a centrifugal fan using impellers with non-isometric for-ward-swept blades was analyzed, which can serve as a reference for researches on reduction of fan noise.

  20. High fidelity phase locked PIV measurements analysing the flow fields surrounding an oscillating piezoelectric fan

    International Nuclear Information System (INIS)

    Piezoelectric fans have been studied extensively and are seen as a promising technology for thermal management due to their ability to provide quiet, reliable cooling with low power consumption. The fluid mechanics of an unconfined piezoelectric fan are complex which is why the majority of the literature to date confines the fan in an attempt to simplify the flow field. This paper investigates the fluid mechanics of an unconfined fan operating in its first vibration frequency mode. The piezoelectric fan used in this study measures 12.7 mm × 70 mm and resonates at 92.5 Hz in air. A custom built experimental facility was developed to capture the fan's flow field using phase locked Particle Image Velocimetry (PIV). The phase locked PIV results are presented in terms of vorticity and show the formation of a horse shoe vortex. A three dimensional A2 criterion constructed from interpolated PIV measurements was used to identify the vortex core in the vicinity of the fan. This analysis was used to clearly identify the formation of a horse shoe vortex that turns into a hairpin vortex before it breaks up due to a combination of vortex shedding and flow along the fan blade. The results presented in this paper contribute to both the fluid dynamics and heat transfer literature concerning first mode fan oscillation.

  1. High fidelity phase locked PIV measurements analysing the flow fields surrounding an oscillating piezoelectric fan

    Science.gov (United States)

    Jeffers, Nicholas; Nolan, Kevin; Stafford, Jason; Donnelly, Brian

    2014-07-01

    Piezoelectric fans have been studied extensively and are seen as a promising technology for thermal management due to their ability to provide quiet, reliable cooling with low power consumption. The fluid mechanics of an unconfined piezoelectric fan are complex which is why the majority of the literature to date confines the fan in an attempt to simplify the flow field. This paper investigates the fluid mechanics of an unconfined fan operating in its first vibration frequency mode. The piezoelectric fan used in this study measures 12.7mm × 70mm and resonates at 92.5Hz in air. A custom built experimental facility was developed to capture the fan's flow field using phase locked Particle Image Velocimetry (PIV). The phase locked PIV results are presented in terms of vorticity and show the formation of a horse shoe vortex. A three dimensional A2 criterion constructed from interpolated PIV measurements was used to identify the vortex core in the vicinity of the fan. This analysis was used to clearly identify the formation of a horse shoe vortex that turns into a hairpin vortex before it breaks up due to a combination of vortex shedding and flow along the fan blade. The results presented in this paper contribute to both the fluid dynamics and heat transfer literature concerning first mode fan oscillation.

  2. The performance and flow characteristics of a small propeller fan with a back-plate

    Energy Technology Data Exchange (ETDEWEB)

    Kang, S.H. [Seoul National University, Seoul (Korea, Republic of); Kim, J.K. [Seoul National University Graduate School, Seoul (Korea, Republic of); Lee, S.B. [Sam Sung Electronics Co., Ltd. (Korea, Republic of)

    1996-04-01

    Unstable performance deterioration was found on the performance curve of a small propeller fan with a back plate. To investigate this phenomenon and the effects of the back-plate on the performance of the fan, performance tests and flow measurement using 3-hole pitot tube were carried out. Measurements showed that when the flow rate is small, the radial flow dominates, and when the flow rate is large, the axial flow dominates. Performance characteristic of the propeller fan changes from radial to axial type as the flow rate increases. Unstable performance changes are the result of type change of the flow through the fan. (author). 4 refs., 15 figs.

  3. Influence of Coanda surface curvature on performance of bladeless fan

    Science.gov (United States)

    Li, Guoqi; Hu, Yongjun; Jin, Yingzi; Setoguchi, Toshiaki; Kim, Heuy Dong

    2014-10-01

    The unique Coanda surface has a great influence on the performance of bladeless fan. However, there is few studies to explain the relationship between the performance and Coanda surface curvature at present. In order to gain a qualitative understanding of effect of the curvature on the performance of bladeless fan, numerical studies are performed in this paper. Firstly, three-dimensional numerical simulation is done by Fluent software. For the purpose to obtain detailed information of the flow field around the Coanda surface, two-dimensional numerical simulation is also conducted. Five types of Coanda surfaces with different curvature are designed, and the flow behaviour and the performance of them are analyzed and compared with those of the prototype. The analysis indicates that the curvature of Coanda surface is strongly related to blowing performance, It is found that there is an optimal curvature of Coanda surfaces among the studied models. Simulation result shows that there is a special low pressure region. With increasing curvature in Y direction, several low pressure regions gradually enlarged, then begin to merge slowly, and finally form a large area of low pressure. From the analyses of streamlines and velocity angle, it is found that the magnitude of the curvature affects the flow direction and reasonable curvature can induce fluid flow close to the wall. Thus, it leads to that the curvature of the streamlines is consistent with that of Coanda surface. Meanwhile, it also causes the fluid movement towards the most suitable direction. This study will provide useful information to performance improvements of bladeless fans.

  4. Numerical evaluation of tandem rotor for highly loaded transonic fan

    Institute of Scientific and Technical Information of China (English)

    ZHAO Bin; LIU Bao-jie

    2011-01-01

    Transonic tandem rotor was designed for highly loaded fan at a corrected tip speed of 381 m/s and another conventional rotor was designed as a baseline to evaluate the loading superiority of tandem rotor with three-dimensional (3-D) numerical simulation. The aft blade solidity and its impact on total loading level were studied in depth. The result indicates that tandem rotor has potential to achieve higher loading level and attain favorable aerodynamic performance in a wide range of loading coefficient 0. 55 ~ 0.68, comparing with the conventional rotor which produced a total pressure ratio of 2.0 and loading coefficient of 0. 42.

  5. On topological groups containing a Fr\\'echet-Urysohn fan

    CERN Document Server

    Banakh, Taras

    2009-01-01

    Suppose G is a topological group containing a (closed) topological copy of the Frechet-Urysohn fan. If G is a perfectly normal sequential space (a normal k-space) then every closed metrizable subset in $G$ is locally compact. Applying this result to topological groups whose underlying topological space can be written as a direct limit of a sequence of closed metrizable subsets, we get that every such a group either is metrizable or is homeomorphic to the product of a $k_\\omega$-space and a discrete space.

  6. Infrared and Visible Observations of South Polar Spots and Fans

    Science.gov (United States)

    Christensen, P. R.; Kieffer, H. H.; Titus, T. N.

    2005-12-01

    A variety of relatively low-albedo features that form in regions of the south polar cap during early spring have been previously reported. Four types of these dark features have been recognized: spots, fans, blotches, and halos. The spots are typically direction within a given area. Blotches are larger than spots, 100's of m to 10's of km in size, with less distinct boundaries, and, unlike most spots, have albedo patterns that match from winter to summer. Halos are roughly circularly symmetric annuli 10's to 100's of m in diameter surrounding spots. All of these features are only slightly darker than the surrounding ice, with TES-derived albedos of 0.22 versus 0.23 for the ice. We have observed these features with THEMIS in 100-m per pixel infrared and 18-m per pixel visible imaging, focusing intensely on a specific region (99 E, 86.2 S) where spot and fan formation was observed the previous Mars year. A few dark spots form before sunrise, with significant spot formation occurring immediately following sunrise. A large number of spots form fans within 10-20 days. All of these features are within 5 C of CO2 ice temperatures, indicating that they must be must be a very thin layer (vents that jet CO2 gas, carrying dark granular material to the surface to form spots. Some of this material is subsequently blown downwind to form fans. The small differences in albedo between the dark material on the surface and the dark substrate results in nearly equal solar energy input and nearly equal sublimation. However, in the spots the sublimation occurs at the surface, whereas over the rest of the cap the sublimation occurs at the base. As a result of this near equality, the dark spots do not burrow down to the substrate, but instead the entire upper surface slowly lowers. Eventually the ice is completely removed and the dark granular material is back on the surface. Operating each year, this process will winnow out the finest grained materials that can be carried away by the

  7. Fr\\'{e}chet-Urysohn fans in free topological groups

    CERN Document Server

    Banakh, Taras; Zdomskyy, Lyubomyr

    2008-01-01

    In this paper we answer the question of T. Banakh and M. Zarichnyi constructing a copy of the Fr\\'echet-Urysohn fan $S_\\w$ in a topological group $G$ admitting a functorial embedding $[0,1]\\subset G$. The latter means that each autohomeomorphism of $[0,1]$ extends to a continuous homomorphism of $G$. This implies that many natural free topological group constructions (e.g. the constructions of the Markov free topological group, free abelian topological group, free totally bounded group, free compact group) applied to a Tychonov space $X$ containing a topological copy of the space $\\IQ$ of rationals give topological groups containing $S_\\w$.

  8. A 20 GHz circularly polarized, fan beam slot array antenna

    Science.gov (United States)

    Weikle, D. C.

    1982-03-01

    An EHF waveguide slot array was developed for possible use as a receive-only paging antenna for ground mobile terminals. The design, fabrication, and measured performance of this antenna are presented. The antenna generates a circularly polarized fan beam that is narrow in azimuth and broad in elevation. When mechanically rotated in azimuth, it can receive a 20 GHz satellite transmission independent of mobile terminal direction. Azimuth plane sidelobe levels, which are typically <-40 dB from the main lobe, provide for discrimination against ground and airborne jammers.

  9. Intermittent Flow Regimes in a Transonic Fan Airfoil Cascade

    OpenAIRE

    2004-01-01

    A study was conducted in the NASA Glenn Research Center (NASA-GRC) linear cascade on the intermittent flow on the suction surface of an airfoil section from the tip region of a modern low aspect ratio fan blade. Experimental results revealed that, at a large incidence angle, a range of transonic inlet Mach numbers exist where the leading-edge shock-wave pattern was unstable. Flush-mounted, high-frequency response pressure transducers indicated large local jumps in the pressure in the leading ...

  10. Analysis of high velocity impact on hybrid composite fan blades

    Science.gov (United States)

    Chamis, C. C.; Sinclair, J. H.

    1979-01-01

    This paper describes recent developments in the analysis of high velocity impact of composite blades using a computerized capability which consists of coupling a composites mechanics code with the direct-time integration features of NASTRAN. The application of the capability to determine the linear dynamic response of an intraply hybrid composite aircraft engine fan blade is described in detail. The predicted results agree with measured data. The results also show that the impact stresses reach sufficiently high magnitudes to cause failures in the impact region at early times of the impact event.

  11. The Diagonal Compression Field Method using Circular Fans

    DEFF Research Database (Denmark)

    Hansen, Thomas

    2005-01-01

    This paper presents a new design method, which is a modification of the diagonal compression field method, the modification consisting of the introduction of circular fan stress fields. The traditional method does not allow changes of the concrete compression direction throughout a given beam if...... if the -value for a given beam could be set to a low value in regions with high shear stresses and thereafter increased in regions with low shear stresses. Thus the shear reinforcement would be reduced and the concrete strength would be utilized in a better way. In the paper it is shown how circular...

  12. Numerical analysis of aerodynamic noise radiated from cross flow fan

    Institute of Scientific and Technical Information of China (English)

    Anbang CHEN; Song LI; Dongtao HUANG

    2008-01-01

    The flow field in a cross flow fan was simulated by solving the 2-D unsteady Reynolds-averaged Navier-Stokes equations. The calculated pressure fluctuations of the blades, the vortex wall, and the rear wall were then used as noise sources to calculate the sound field. The Ffowcs Williams-Hawkings (FW-H) equation was employed to predict the noise field caused by these sources. The predictions show that the rear wall and the vortex wall sources contribute significantly to the total noise and that both the predicted aerodynamic perform-ance and noise agree well with the experimental results.

  13. Development of regularized expectation maximization algorithms for fan-beam SPECT data

    International Nuclear Information System (INIS)

    SPECT using a fan-beam collimator improves spatial resolution and sensitivity. For the reconstruction from fan-beam projections, it is necessary to implement direct fan-beam reconstruction methods without transforming the data into the parallel geometry. In this study, various fan-beam reconstruction algorithms were implemented and their performances were compared. The projector for fan-beam SPECT was implemented using a ray-tracing method. The direct reconstruction algorithms implemented for fan-beam projection data were FBP (filtered backprojection), EM (expectation maximization), OS-EM (ordered subsets EM) and MAP-EM OSL (maximum a posteriori EM using the one-step late method) with membrane and thin-plate models as priors. For comparison, the fan-beam projection data were also rebinned into the parallel data using various interpolation methods, such as the nearest neighbor, bilinear and bicubic interpolations, and reconstructed using the conventional EM algorithm for parallel data. Noiseless and noisy projection data from the digital Hoffman brain and Shepp/Logan phantoms were reconstructed using the above algorithms. The reconstructed images were compared in terms of a percent error metric. For the fan-beam data with Poisson noise, the MAP-EM OSL algorithm with the thin-plate prior showed the best result in both percent error and stability. Bilinear interpolation was the most effective method for rebinning from the fan-beam to parallel geometry when the accuracy and computation load were considered. Direct fan-beam EM reconstructions were more accurate than the standard EM reconstructions obtained from rebinned parallel data. Direct fan-beam reconstruction algorithms were implemented, which provided significantly improved reconstructions

  14. Development of regularized expectation maximization algorithms for fan-beam SPECT data

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Soo Mee; Lee, Jae Sung; Lee, Dong Soo [Seoul National University College of Medicine, Seoul (Korea, Republic of); Lee, Soo Jin [Paichai University, Daejeon (Korea, Republic of); Kim, Kyeong Min [Korea Institute of Radiology and Medical Sciences, Seoul (Korea, Republic of)

    2005-10-15

    SPECT using a fan-beam collimator improves spatial resolution and sensitivity. For the reconstruction from fan-beam projections, it is necessary to implement direct fan-beam reconstruction methods without transforming the data into the parallel geometry. In this study, various fan-beam reconstruction algorithms were implemented and their performances were compared. The projector for fan-beam SPECT was implemented using a ray-tracing method. The direct reconstruction algorithms implemented for fan-beam projection data were FBP (filtered backprojection), EM (expectation maximization), OS-EM (ordered subsets EM) and MAP-EM OSL (maximum a posteriori EM using the one-step late method) with membrane and thin-plate models as priors. For comparison, the fan-beam projection data were also rebinned into the parallel data using various interpolation methods, such as the nearest neighbor, bilinear and bicubic interpolations, and reconstructed using the conventional EM algorithm for parallel data. Noiseless and noisy projection data from the digital Hoffman brain and Shepp/Logan phantoms were reconstructed using the above algorithms. The reconstructed images were compared in terms of a percent error metric. For the fan-beam data with Poisson noise, the MAP-EM OSL algorithm with the thin-plate prior showed the best result in both percent error and stability. Bilinear interpolation was the most effective method for rebinning from the fan-beam to parallel geometry when the accuracy and computation load were considered. Direct fan-beam EM reconstructions were more accurate than the standard EM reconstructions obtained from rebinned parallel data. Direct fan-beam reconstruction algorithms were implemented, which provided significantly improved reconstructions.

  15. Setting limits: The development and use of factor-ceiling distributions for an urban assessment using macroinvertebrates

    Science.gov (United States)

    Carter, J.L.; Fend, S.V.

    2005-01-01

    Lotic habitats in urban settings are often more modified than in other anthropogenically influenced areas. The extent, degree, and permanency of these modifications compromise the use of traditional reference-based study designs to evaluate the level of lotic impairment and establish restoration goals. Directly relating biological responses to the combined effects of urbanization is further complicated by the nonlinear response often observed in common metrics (e.g., Ephemeroptera, Plecoptera, and Trichoptera [EPT] species richness) to measures of human influence (e.g., percentage urban land cover). A characteristic polygonal biological response often arises from the presence of a generalized limiting factor (i.e., urban land use) plus the influence of multiple additional stressors that are nonuniformly distributed throughout the urban environment. Benthic macroinvertebrates, on-site physical habitat and chemistry, and geographical information systems-derived land cover data for 85 sites were collected within the 1,600-km2 Santa Clara Valley (SCV), California urban area. A biological indicator value was derived from EPT richness and percentage EPT. Partitioned regression was used to define reference conditions and estimate the degree of site impairment. We propose that an upper-boundary condition (factor-ceiling) modeled by partitioned regression using ordinary least squares represents an attainable upper limit for biological condition in the SCV area. Indicator values greater than the factor-ceiling, which is monotonically related to existing land use, are considered representative of reference conditions under the current habitat conditions imposed by existing land cover and land use.

  16. Coupling ant colony and the degraded ceiling algorithm for the redundancy allocation problem of series-parallel systems

    International Nuclear Information System (INIS)

    The redundancy allocation problem (RAP) is a well known NP-hard problem which involves the selection of elements and redundancy levels to maximize system reliability given various system-level constraints. As telecommunications and internet protocol networks, manufacturing and power systems are becoming more and more complex, while requiring short developments schedules and very high reliability, it is becoming increasingly important to develop efficient solutions to the RAP. This paper presents an efficient algorithm to solve this reliability optimization problem. The idea of a heuristic approach design is inspired from the ant colony meta-heuristic optimization method and the degraded ceiling local search technique. Our hybridization of the ant colony meta-heuristic with the degraded ceiling performs well and is competitive with the best-known heuristics for redundancy allocation. Numerical results for the 33 test problems from previous research are reported and compared. The solutions found by our approach are all better than or are in par with the well-known best solutions

  17. Investigation of the Thermal Insulation Properties of Selected Ceiling Materials used in Makurdi Metropolis (Benue StateNigeria

    Directory of Open Access Journals (Sweden)

    Gesa, F. Newton

    2014-11-01

    Full Text Available In this research, the thermal insulation properties of three selected materials namely: Plaster of Paris (P.o.P, Plywood and Isorel (Masonite used as ceiling boards in Makurdi, Benue state-Nigeria have been investigated. The selection of these insulation materials is based upon their predominant usage as padding materials in the tropical Makurdi metropolis. To achieve this, the steady-state method using Lee-Charton’s apparatus was adopted to analyze the thermal conductivities of the chosen materials. The results obtained show that, P.o.P exhibits the best insulation property followed by Plywood then Isorel ceiling board with thermal conductivities of 0.1185w/mk, 0.1768w/mk and 0.4498w/mk respectively. Their corresponding thermal resistivities are 8.4388mk/w, 5.6561mk/w and 2.2232mk/w. From the results, P.o.P is recommended for its best insulation property. The research therefore provides a guide to intending builders and civil Engineers for selecting of housing insulation materials in Makurdi metropolis as well as other humid zones of tropical Africa.

  18. Piezoelectric Vibration Damping Study for Rotating Composite Fan Blades

    Science.gov (United States)

    Min, James B.; Duffy, Kirsten P.; Choi, Benjamin B.; Provenza, Andrew J.; Kray, Nicholas

    2012-01-01

    Resonant vibrations of aircraft engine blades cause blade fatigue problems in engines, which can lead to thicker and aerodynamically lower performing blade designs, increasing engine weight, fuel burn, and maintenance costs. In order to mitigate undesirable blade vibration levels, active piezoelectric vibration control has been investigated, potentially enabling thinner blade designs for higher performing blades and minimizing blade fatigue problems. While the piezoelectric damping idea has been investigated by other researchers over the years, very little study has been done including rotational effects. The present study attempts to fill this void. The particular objectives of this study were: (a) to develop and analyze a multiphysics piezoelectric finite element composite blade model for harmonic forced vibration response analysis coupled with a tuned RLC circuit for rotating engine blade conditions, (b) to validate a numerical model with experimental test data, and (c) to achieve a cost-effective numerical modeling capability which enables simulation of rotating blades within the NASA Glenn Research Center (GRC) Dynamic Spin Rig Facility. A numerical and experimental study for rotating piezoelectric composite subscale fan blades was performed. It was also proved that the proposed numerical method is feasible and effective when applied to the rotating blade base excitation model. The experimental test and multiphysics finite element modeling technique described in this paper show that piezoelectric vibration damping can significantly reduce vibrations of aircraft engine composite fan blades.

  19. Evaluation of Retrofit Variable-Speed Furnace Fan Motors

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, R. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Williamson, J. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2014-01-01

    In conjunction with the New York State Energy Research and Development Authority (NYSERDA) and Proctor Engineering Group, Ltd. (PEG), the Consortium for Advanced Residential Buildings (CARB) has evaluated the Concept 3™ replacement motors for residential furnaces. These brushless, permanent magnet (BPM) motors can use much less electricity than their PSC (permanent split capacitor) predecessors. This evaluation focuses on existing homes in the heating-dominated climate of upstate New York with the goals of characterizing field performance and cost effectiveness. The project includes eight homes in and near Syracuse, NY. Tests and monitoring was performed both before and after fan motors were replaced. Results indicate that BPM replacement motors will be most cost effective in HVAC systems with longer run times and relatively low duct static pressures. More dramatic savings are possible if occupants use the fan-only setting when there is no thermal load. There are millions of cold-climate, U.S. homes that meet these criteria, but the savings in most homes tested in this study were modest.

  20. A Fan Beam Model for Radio Pulsars. I. Observational Evidence

    CERN Document Server

    Wang, Hong Guang; Zheng, Xiao Ping; Deng, Chun Lan; Wen, Sai Qin; Ye, Feng; Guan, Kai Ying; Liu, Yi; Xu, Li Qing

    2014-01-01

    We propose a novel beam model for radio pulsars based on the scenario that the broadband and coherent emission from secondary relativistic particles, as they move along a flux tube in a dipolar magnetic field, forms a radially extended sub-beam with unique properties. The whole radio beam may consist of several sub-beams, forming a fan-shaped pattern. When only one or a few flux tubes are active, the fan beam becomes very patchy. This model differs essentially from the conal beam models in the respects of beam structure and predictions on the relationship between pulse width and impact angle $\\beta$ (the angle between line of sight and magnetic pole) and the relationship between emission intensity and beam angular radius. The evidence for this model comes from the observed patchy beams of precessional binary pulsars and three statistical relationships found for a sample of 64 pulsars, of which $\\beta$ were mostly constrained by fitting polarization position angle data with the Rotation Vector Model. With appr...

  1. Effect of attack angle on flow characteristic of centrifugal fan

    Science.gov (United States)

    Wu, Y.; Dou, H. S.; Wei, Y. K.; Chen, X. P.; Chen, Y. N.; Cao, W. B.

    2016-05-01

    In this paper, numerical simulation is performed for the performance and internal flow of a centrifugal fan with different operating conditions using steady three-dimensional incompressible Navier-Stokes equations coupled with the RNG k-e turbulent model. The performance curves, the contours of static pressure, total pressure, radial velocity, relative streamlines and turbulence intensity at different attack angles are obtained. The distributions of static pressure and velocity on suction surface and pressure surface in the same impeller channel are compared for various attack angles. The research shows that the efficiency of the centrifugal fan is the highest when the attack angle is 8 degree. The main reason is that the vortex flow in the impeller is reduced, and the jet-wake pattern is weakened at the impeller outlet. The pressure difference between pressure side and suction side is smooth and the amplitude of the total pressure fluctuation is low along the circumferential direction. These phenomena may cause the loss reduced for the attack angle of about 8 degree.

  2. Jet Engine Fan Blade Containment Using an Alternate Geometry

    Science.gov (United States)

    Carney, K.S.; Pereira, J.M.; Revilock, D.M.; Matheny, P.

    2008-01-01

    With a goal of reducing jet engine weight, simulations of a fan blade containment system with an alternate geometry were tested and analyzed. A projectile simulating a fan blade was shot at two alternate geometry containment case configurations using a gas gun. The first configuration was a flat plate representing a standard case configuration. The second configuration was a flat plate with a radially convex curve section at the impact point. The curved surface was designed to force the blade to deform plastically, dissipating energy before the full impact of the blade is received by the plate. The curved case was able to tolerate a higher impact velocity before failure. The computational model was developed and correlated with the tests and a weight savings assessment was performed. For the particular test configuration used in this study the ballistic impact velocity of the curved plate was approximately 60 m/s (200 ft/s) greater than that of the flat plate. For the computational model to successfully duplicate the test, the very high strain rate behavior of the materials had to be incorporated.

  3. Cost analysis of composite fan blade manufacturing processes

    Science.gov (United States)

    Stelson, T. S.; Barth, C. F.

    1980-01-01

    The relative manufacturing costs were estimated for large high technology fan blades prepared by advanced composite fabrication methods using seven candidate materials/process systems. These systems were identified as laminated resin matrix composite, filament wound resin matrix composite, superhybrid solid laminate, superhybrid spar/shell, metal matrix composite, metal matrix composite with a spar and shell, and hollow titanium. The costs were calculated utilizing analytical process models and all cost data are presented as normalized relative values where 100 was the cost of a conventionally forged solid titanium fan blade whose geometry corresponded to a size typical of 42 blades per disc. Four costs were calculated for each of the seven candidate systems to relate the variation of cost on blade size. Geometries typical of blade designs at 24, 30, 36 and 42 blades per disc were used. The impact of individual process yield factors on costs was also assessed as well as effects of process parameters, raw materials, labor rates and consumable items.

  4. A fan effect in anaphor processing: effects of multiple distractors

    Science.gov (United States)

    Autry, Kevin S.; Levine, William H.

    2014-01-01

    Research suggests that the presence of a non-referent from the same category as the referent interferes with anaphor resolution. In five experiments, the hypothesis that multiple non-referents would produce a cumulative interference effect (i.e., a fan effect) was examined. This hypothesis was supported in Experiments 1A and 1B, with subjects being less accurate and slower to recognize referents (1A) and non-referents (1B) as the number of potential referents increased from two to five. Surprisingly, the number of potential referents led to a decrease in anaphor reading times. The results of Experiments 2A and 2B replicated the probe-recognition results in a completely within-subjects design and ruled out the possibility that a speeded-reading strategy led to the fan-effect findings. The results of Experiment 3 provided evidence that subjects were resolving the anaphors. These results suggest that multiple non-referents do produce a cumulative interference effect; however, additional research is necessary to explore the effect on anaphor reading times. PMID:25120519

  5. Intermittent Flow Regimes in a Transonic Fan Airfoil Cascade

    Science.gov (United States)

    Lepicovsky, J.; McFarland, E. R.; Chima, R. V.; Capece, V. R.; Hayden, J.

    2002-01-01

    A study was conducted in the NASA Glenn Research Center linear cascade on the intermittent flow on the suction surface of an airfoil section from the tip region of a modern low aspect ratio fan blade. Experimental results revealed that, at a large incidence angle, a range of transonic inlet Mach numbers exist where the leading-edge shock-wave pattern was unstable. Flush mounted high frequency response pressure transducers indicated large local jumps in the pressure in the leading edge area, which generates large intermittent loading on the blade leading edge. These measurements suggest that for an inlet Mach number between 0.9 and 1.0 the flow is bi-stable, randomly switching between subsonic and supersonic flows. Hence, it appears that the change in overall flow conditions in the transonic region is based on the frequency of switching between two stable flow states rather than on the continuous increase of the flow velocity. To date, this flow behavior has only been observed in a linear transonic cascade. Further research is necessary to confirm this phenomenon occurs in actual transonic fans and is not the byproduct of an endwall restricted linear cascade.

  6. Rapid delineation of alluvial fans using IfSAR-derived DEM for selected provinces in the Philippines

    Science.gov (United States)

    Ortiz, Iris Jill; Aquino, Dakila; Norini, Gianluca; Narod Eco, Rodrigo; Mahar Lagmay, Alfredo

    2015-04-01

    Alluvial fans are fan-shaped geomorphic features formed when sediments from a watershed are transported and deposited downstream via tributaries flowing out from the sudden break of a slope. Hazards usually associated with alluvial fans are flooding and debris flows. In this study, we used an Interferometric Synthetic Aperture Radar-derived digital elevation model of Pangasinan and Nueva Ecija Provinces in the Philippines to identify and delineate alluvial fans. Primary parameters considered include the geomorphic characteristics of the catchment area, stream network and slopes ranging from 0.11 to 8 degrees. Using this method, 12 alluvial fans were identified in Pangasinan and 16 in Nueva Ecija with areas ranging from 0.35 to 80 sq. km. The largest fan identified is the Mangatarem-Aguilar fan in Pangaisnan with a total area of 80.87 sq km while the Gabaldon fan in Nueva Ecija with total area of 48.11 sq km. We observed from the results that some alluvial fans have multiple feeder streams, and others have overlapping lateral extents with adjacent fans. These overlapping fans are called bajadas. In addition, the general location of fans and their apices in the two provinces appear to coincide with segments of the Philippines Fault System. There are about people 1.4 million living within these alluvial fans. Mapping and characterizing and identifying their associated hazards is crucial in the disaster preparedness efforts of the exposed population.

  7. Variable scale channel avulsion history using fan architecture and stratigraphy, and sediment provenance of Sutlej-Yamuna fans in northwest Gangetic plains during Late Quaternary

    Science.gov (United States)

    Singh, Ajit; Gupta, Sanjeev; Sinha, Rajiv; Densmore, Alexander; Buylaert, Jan-Pieter; Carter, Andrew; Van-Dijk, Wout M.; Joshi, Suneel; Nayak, Nibedita; Mason, Philippa J.; Kumar, Dewashish; Mondal, Setbandhu; Murray, Andrew; Rai, Shiv P.; Shekhar, Shashank

    2016-04-01

    Channel avulsion during fan development controls distribution and deposition of channel sandbodies and hence alluvial architecture of a fan system. Variable scale spatio-temporal information of fluvial responses to past climate changes is stored in these channel sandbodies. Further these channel sandbodies form fluvial aquifers in alluvial fans and therefore understanding of alluvial architecture and stratigraphy of a fan is crucial for development of groundwater management strategies. In this study we used multiple approaches to map subsurface fluvial aquifer architecture and alluvial stratigraphy, and to estimate sediment provenance using U-Pb dating of detrital zircon grains of Sutlej-Yamuna fan system in northwest India. Satellite imagery based geomorphic mapping shows two large fan system with interfan area. The fan surfaces show presence of major and minor paleochannels. 2D resistivity tomography along several transects across fan surfaces shows distinct layers with contrasting resistivity values. These geo-electric facies corresponds to presence of channel sandbodies beneath surface signature of paleochannels and finer floodplain deposits useful to demarcate lateral extent of subsurface channel sandbodies. A more detailed subsurface stratigraphy using ~50m deep sediment cores and their luminescence ages from across fan surface shows presence of multi-storey sandbodies (MSB) separated by floodplain fines. Within the MSB, individual channel deposits are identified by presence of channel scour surfaces located at coarse sand overlying fine sand layer. Depositional ages of MSB's ranges from ~81 ka (late MIS5) to ~15 ka (MIS2) with major depositional break during MIS3 in parts of the fans. Sediment aggradation rate varies laterally across fan surface as well as vertically down the depth with an average rate of 0.54 mm/year. Fluvial channel persistence for studied time interval (about last 81 ka BP) shows major depositional breaks (and possible incision) at ~41 ka

  8. Labor and net energy effects of a national ceiling insulation program. Final report. [Energy and labor requirements of cellulose-insulation industry

    Energy Technology Data Exchange (ETDEWEB)

    Ford, C.

    1978-09-01

    Improving the thermal efficiency of homes has been widely publicized as an important energy saver. This study examines the energy and labor implications of retrofitting single-family detached homes with ceiling insulation. Calculations are made of the energy savings which would be realized if all ceilings which are now underinsulated were retrofitted to meet each of two sets of current recommendations. A maximum feasible implementation level of 70% is proposed, and the resulting effects on labor demands and energy use in the insulation industries and throughout the economy are then analyzed. A hybrid analysis is performed to determine the energy and labor requirements of the relatively new cellulose-insulation industry.

  9. shallow seismic profiling of onland Leogane fan-delta, Haiti, for imaging fan stratigraphy and buried faults associated with the January 12, 2010, earthquake

    Science.gov (United States)

    Dowla, N.; Stewart, R.; Mann, W. P.; Chang, L.

    2012-12-01

    The Léogane fan of southern Haiti is the largest subaerial fan-delta in the Caribbean with an exposed land area of 109 km2. The southern Léogane fan-delta is located adjacent to the epicenter and main aftershocks of the M 7.0 January 12, 2010, Haiti earthquake. This catastrophic event was produced by movement along a buried thrust fault beneath the fan that is associated with the Enriquillo-Plantain Garden (EPGFZ) left-lateral strike-slip fault zone. Coseismic uplift of the western fan edge at the coast reached up to 62 cm and aftershocks of the buried thrust reached to within about 1 km of the top fan surface. Extreme ground shaking of the Léogane fan directly above these buried faults produced some of the greatest loss of life and destruction of buildings during the 2010 earthquake: between 20,000 and 30,000 estimated lives were lost, almost every concrete building was leveled in the city of Léogane and surrounding agricultural areas, and liquefaction of road beds and beach areas was commonplace. A large 1770 earthquake also believed to be nucleated on the EPGFZ shook the fan area in 1770, destroyed the French colonial town of Léogane and produced widespread liquefaction effects. In January, 2011, we collected gravity and shallow seismic measurements. Our goal was to begin to understand the stratigraphy of the Leogane fan and to image buried thrust faults responsible for shaking and coseismic, coastal uplift in 2010 and likely in future events. Three-component seismic data were acquired along a 402-m-long, north-south profile located 3 km north of the EPGFZ in the area of maximum coseismic, coastal uplift to investigate the thickness and geotechnical properties of the Leogane fan. Using sledge hammers on a metal plate as a source, penetration was excellent down to a depth of 400 m. We identified discontinuous layering interpreted as 50-60-m thick channel bodies deposited on previous fan surfaces. Discontinuities indicate shallow faulting in the depth range

  10. Numerical Experiment of the Solid Particle Erosion of Bionic Configuration Blade of Centrifugal Fan

    Institute of Scientific and Technical Information of China (English)

    Junqiu ZHANG; Zhiwu HAN; Wei YIN; Huiyuan WANG; Chao GE; Jialian JIANG

    2013-01-01

    In this paper,a bionic method was presented to improve the erosion resistance of blade of the centrifugal fan.A numerical investigation of the solid particle erosion on the standard and bionic configuration blade of 4-72N_o10C centrifugal fan was presented.The numerical study employs computational fluid dynamics (CFD) software,based on a finite volume method,in which the discrete phase model was used to modele the solid particles flow,and the Eulerian conservation equation was adopt to simulate the continuous phase.Moreover,user-defined function was used to define wear equation.The various diameters of the particles were taken into account.The positions of collision of standard and bionic fan blades were discussed,and two kinds of centrifugal fan blade wear were compared.The results show that the particles from the incident source with different positions have different processes of turning and movement when enter into the impeller.The trajectories of flow in the fan channel are significantly different for the particles with different diameters.Bionic fan blade have lower erosion rate than the standard fan blade when the particle size is 20 μm.The anti-erosion mechanism of the bionic fan blade was discussed.

  11. Bottom of the Iceberg: The Archontic Text - Review of Fanged Fan Fiction (McFarland, 2013)

    DEFF Research Database (Denmark)

    Schubart, Rikke

    2014-01-01

    Anmeldelse af Lindgren, Maria og Malin Isaksson, Fanged Fan Fiction: Variations on Twilight, True Blood and The Vampire Diaries (McFarland, 2013)......Anmeldelse af Lindgren, Maria og Malin Isaksson, Fanged Fan Fiction: Variations on Twilight, True Blood and The Vampire Diaries (McFarland, 2013)...

  12. 14 CFR 33.27 - Turbine, compressor, fan, and turbosupercharger rotors.

    Science.gov (United States)

    2010-01-01

    ... turbosupercharger rotors. 33.27 Section 33.27 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Turbine, compressor, fan, and turbosupercharger rotors. (a) Turbine, compressor, fan, and turbosupercharger rotors must have sufficient strength to withstand the test conditions specified in paragraph...

  13. Performance and Internal Flow of Sirocco Fan Using Contra-Rotating Rotors

    Institute of Scientific and Technical Information of China (English)

    J. Fukutomi; T.Shigemitsu; T. Yasunobu

    2008-01-01

    A sirocco fan using contra-rotating rotors in which an inner rotor is settled inside the sirocco fan rotor end each rotor rotates in an opposite direction was proposed for the purpose of getting the higher pressure and making the structure of a sirocco fan more compact. If the high discharge pressure is obtained with the adoption of the contra-rotating rotors, it could be used for various purposes. Pressure coefficient of a sirocco fan with contra-rotating rotors is 2.5 times as high as the conventional sirocco fan and the maximum efficiency point of contra-rotating rotors shifts to larger flow rate than a conventional sirocco fan. On the other hand, it was clarified from the flow measurement results that circumferential velocity component at the outlet of the outer rotor of contra-rotating rotors becomes larger than a conventional one. In the present paper, the performance of a conventional sirocco fan and a sirocco fan with contra-rotating rotors are shown and the internal flow field at the outlet of outer rotor of both cases is clarified. Then, the effect of different kind of contra-rotating rotors on the performance and internal flow field is investigated and the rotor design with higher performanco would be discussed.

  14. Measurement of airflow and pressure characteristics of a fan built in a car ventilation system

    Science.gov (United States)

    Pokorný, Jan; Poláček, Filip; Fojtlín, Miloš; Fišer, Jan; Jícha, Miroslav

    2016-03-01

    The aim of this study was to identify a set of operating points of a fan built in ventilation system of our test car. These operating points are given by the fan pressure characteristics and are defined by a pressure drop of the HVAC system (air ducts and vents) and volumetric flow rate of ventilation air. To cover a wide range of pressure drops situations, four cases of vent flaps setup were examined: (1) all vents opened, (2) only central vents closed (3) only central vents opened and (4) all vents closed. To cover a different volumetric flows, the each case was measured at least for four different speeds of fan defined by the fan voltage. It was observed that the pressure difference of the fan is proportional to the fan voltage and strongly depends on the throttling of the air distribution system by the settings of the vents flaps. In case of our test car we identified correlations between volumetric flow rate of ventilation air, fan pressure difference and fan voltage. These correlations will facilitate and reduce time costs of the following experiments with this test car.

  15. Portable Life Support System 2.5 Fan Design and Development

    Science.gov (United States)

    Quinn, Gregory; Carra, Michael; Converse, David; Chullen, Cinda

    2016-01-01

    NASA is building a high-fidelity prototype of an advanced Portable Life Support System (PLSS) as part of the Advanced Exploration Systems Program. This new PLSS, designated as PLSS 2.5, will advance component technologies and systems knowledge to inform a future flight program. The oxygen ventilation loop of its predecessor, PLSS 2.0, was driven by a centrifugal fan developed using specifications from the Constellation Program. PLSS technology and system parameters have matured to the point where the existing fan will not perform adequately for the new prototype. In addition, areas of potential improvement were identified with the PLSS 2.0 fan that could be addressed in a new design. As a result, a new fan was designed and tested for the PLSS 2.5. The PLSS 2.5 fan is a derivative of the one used in PLSS 2.0, and it uses the same nonmetallic, canned motor, with a larger volute and impeller to meet the higher pressure drop requirements of the PLSS 2.5 ventilation loop. The larger impeller allows it to operate at rotational speeds that are matched to rolling element bearings, and which create reasonably low impeller tip speeds consistent with prior, oxygen-rated fans. Development of the fan also considered a shrouded impeller design that could allow larger clearances for greater oxygen safety, assembly tolerances and particle ingestion. This paper discusses the design, manufacturing and performance testing of the new fans.

  16. NASA Clean-Sheet Fans: Design, Build Analyze, Test, and Report

    Science.gov (United States)

    Koch, L. Danielle

    2008-01-01

    A suggested topic in small fan research is presented. Presentation briefly describes the scope of an effort to design, build and test a ventilation class cooling fan. Comments are included for the following categories: information (available and needed), benefits and values, concerns, variations and alternatives, and interest.

  17. Engaging in distancing tactics among sport fans: effects on self-esteem and emotional responses.

    Science.gov (United States)

    Bizman, Aharon; Yinon, Yoel

    2002-06-01

    The authors examined the effects of distancing tactics on self-esteem and emotions, following a win or loss of one's favorite team. They measured state self-esteem and emotional responses of basketball fans as they exited the sport arena after their team had won or lost an official game. Half of the fans were given the opportunity to increase or decrease their association with the team before the measures of self-esteem and emotions; the remaining fans were given the opportunity after the measures. The fans tended to associate more with the team after team success than after team failure. In addition, self-esteem and positive emotions were higher, and negative emotions lower, when measured after, rather than before, the opportunity to increase or decrease association with the team. Those effects were more pronounced among high-team-identification fans than among low-team-identification fans. The results suggest a distinction between the short- and long-term effects of game outcome on the willingness to associate with one's team. In the short term, willingness to associate with the team may oscillate in accordance with team performance, even among high-team-identification fans; in the long term, only high-team-identification fans may maintain their allegiance to the team. PMID:12058976

  18. Measurement of airflow and pressure characteristics of a fan built in a car ventilation system

    Directory of Open Access Journals (Sweden)

    Pokorný Jan

    2016-01-01

    Full Text Available The aim of this study was to identify a set of operating points of a fan built in ventilation system of our test car. These operating points are given by the fan pressure characteristics and are defined by a pressure drop of the HVAC system (air ducts and vents and volumetric flow rate of ventilation air. To cover a wide range of pressure drops situations, four cases of vent flaps setup were examined: (1 all vents opened, (2 only central vents closed (3 only central vents opened and (4 all vents closed. To cover a different volumetric flows, the each case was measured at least for four different speeds of fan defined by the fan voltage. It was observed that the pressure difference of the fan is proportional to the fan voltage and strongly depends on the throttling of the air distribution system by the settings of the vents flaps. In case of our test car we identified correlations between volumetric flow rate of ventilation air, fan pressure difference and fan voltage. These correlations will facilitate and reduce time costs of the following experiments with this test car.

  19. Fangirls as Teachers: Examining Pedagogic Discourse in an Online Fan Site

    Science.gov (United States)

    Lammers, Jayne C.

    2013-01-01

    Videogames, such as "The Sims," are a digital media passion drawing adolescents to online spaces where they create and share content. This article explores how discourses and expectations are taught in one online, videogame-related fan site of adolescents who read and write "Sims" fan fiction. Using Bernstein's pedagogic…

  20. The Role of Physical Education and Other Formative Experiences of Three Generations of Female Football Fans

    Science.gov (United States)

    Pope, Stacey; Kirk, David

    2014-01-01

    The experiences of female sports fans have been largely marginalised in academic research to date and little research has examined the formative sporting experiences of female spectators. This article draws on 51 semi-structured interviews with three generations of female fans of one (men's) professional football club (Leicester City), to…

  1. Propeller fan and outdoor machine using the same for air-conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Satoh, Ryoji; Nagai, Makoto; Yoneyama, Hiroyasu; Mori, Yutaka; Mochizuki, Masaaki; Mochizuki, Yoshihiko; Otaguro, Toshio

    1997-09-12

    A low-noise propeller fan of a low manufacturing cost by improving the rigidity of fan blades in the axial and radial directions thereof and reducing the thickness of the fan blades to as great an extent as possible in spite of the larger diameter of the fan, whereby the moldability of and molding time for the material for the propeller fan is improved and reduced respectively, and by minimizing the amount of use of a material the cost of which accounts for a large percentage of the fan manufacturing cost. A plurality of plate type circumferential ribs projecting from acting faces towards the negative pressure side and a plurality of radial ribs projecting from the acting faces toward the negative pressure side are provided on the reverse (negative pressure) side of the fan blades, whereby the thickness of the fan blades is reduced, so that the amount of material used decreases. This causes the influence of the ribs upon a flow of the air to be minimized, and the occurrence of noise to be suppressed. (author)

  2. The underground main fan study at the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    The Waste Isolation Pilot Plant (WIPP) performed a feasibility analysis for the purpose of either modifying, supplementing, or replacing its two main mine fans. The WIPP, located near Carlsbad, New Mexico, is a US Department of Energy (DOE) facility designed to demonstrate the permanent, safe disposal of US defense-generated transuranic waste in a deep bedded salt deposit. Since the centrifugal fans were installed in 1988, multiple operational and performance concerns have been identified. A comprehensive engineering study was conducted in 1995 to: (1) qualify and quantify operational concerns; (2) evaluate possible alternatives; and (3) recommend an optimum solution. Multiple system modification and/or replacement scenarios were evaluated with associated cost estimates developed. The study considered replacement with either centrifugal or axial fans. Multiple fan duties are required at the WIPP. Therefore, Variable Frequency Drives and Inlet Vane Controls (IVC) were investigated for centrifugal fans. In-flight adjustable blades were investigated for axial fans. The study indicated that replacing the existing system with two double-width, double-inlet centrifugal fans equipped with IVCs was the best choice. This alternative provided the most desirable combination of: (1) ensuring the required operational readiness, and (2) improving system performance. The WIPP is currently planning to replace the first fan in 1997

  3. Use of morphometric analysis and self-organizing maps for alluvial fan classification: case study on Ostorankooh altitudes, Iran

    International Nuclear Information System (INIS)

    The aim of this study is to classify alluvial fans formed by high-gradient braided streams and torrents that discharge into the Oshtorankook altitudes in the Lorestan province, Iran. The morphology of the fans and their watershed is quantitatively described through estimated morphometric parameters. For relationships between geomorphological features of the fans and their drainage basins, self-organizingmaps (SOM) were used. In SOM, according to both qualitative data and morphometric variables, the clustering tendency of alluvial fans was investigated using 15 alluvial fans parameters. The results of the analysis showed that several morphologically different fan types were recognizedbased on their geomorphological characteristics in the study area. A strong positive relationship was found between the drainage basin area and size of the fan with a simple power function. In addition, the relationship between fan slope and drainage area was found to be negative and moderately strong with a simple power function

  4. Energy-optimal speed control of fans and compressor in a refrigeration system

    DEFF Research Database (Denmark)

    Jakobsen, Arne; Rasmussen, Bjarne D.

    1998-01-01

    Use of variable speed compressors and variable speed fans for both the evaporator and the condenser makes the refrigeration system more flexible, adds to the degree of freedom of the control system and therefore makes it possible to (on-line) optimise the various speeds involved. Say, for example...... that the cooling capacity must be increased due to increased cooling load. This can be done by increasing the compressor speed and/or the evaporator fan speed and also to some extent by increasing the condenser fan speed. The general control problem is to obtain the desired temperature of the cooled...... air, while choosing the combination of compressor speed, evaporator fan and condenser fan speeds which minimises the total power consumption of the motors involved. A system and integrated control viewpoint is necessary as a “component-oriented” and “single-loop-control” approach will not lead to the...

  5. An investigation of FLUENT's fan model including the effect of swirl velocity

    International Nuclear Information System (INIS)

    The purpose of this paper is to investigate and discuss the reliability of simplified models for the computational fluid dynamics (CFD) simulation of air flow through automotive engine cooling fans. One of the most widely used simplified fan models in industry is a variant of the actuator disk model which is available in most commercial CFD software, such as FLUENT. In this model, the fan is replaced by an infinitely thin surface on which pressure rise across the fan is specified as a polynomial function of normal velocity or flow rate. The advantages of this model are that it is simple, it accurately predicts the pressure rise through the fan and the axial velocity, and it is robust

  6. Statistic inversion of multi-zone transition probability models for aquifer characterization in alluvial fans

    CERN Document Server

    Zhu, Lin; Gong, Huili; Gable, Carl; Teatini, Pietro

    2015-01-01

    Understanding the heterogeneity arising from the complex architecture of sedimentary sequences in alluvial fans is challenging. This paper develops a statistical inverse framework in a multi-zone transition probability approach for characterizing the heterogeneity in alluvial fans. An analytical solution of the transition probability matrix is used to define the statistical relationships among different hydrofacies and their mean lengths, integral scales, and volumetric proportions. A statistical inversion is conducted to identify the multi-zone transition probability models and estimate the optimal statistical parameters using the modified Gauss-Newton-Levenberg-Marquardt method. The Jacobian matrix is computed by the sensitivity equation method, which results in an accurate inverse solution with quantification of parameter uncertainty. We use the Chaobai River alluvial fan in the Beijing Plain, China, as an example for elucidating the methodology of alluvial fan characterization. The alluvial fan is divided...

  7. OPTIMIZATION DESIGN OF GAS-PARTICLE TWO-PHASE AXIAL-FLOW FAN

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Based on the shaping theory of writhed blade in streamline design, the geometric shape of blade is designed and then computational formulas for the dynamic design of fan with writhed the blades in gas-particle two-phase axial-flow are derived with the two-phase continuum coupling model. Concurrently, the correlation between the structure of impeller and flow-field dynamic functional parameters is presented. Further, the software for the optimization design of gas-particle two-phase axial-flow fan with writhed blades is obtained. By means of the available software, a sample fan is formed with its all dynamic characteristic curves and geometric shape. Finally, the conclusion on the effect of particles on fan running is reached, quantitatively and qualitatively, as is expected in the fan industry.

  8. Fan Performance Testing and Oxygen Compatibility Assessment Results for Future Space Suit Life Support Systems

    Science.gov (United States)

    Paul, Heather L.; Jennings, Mallory A.; Vogel, Matthew

    2009-01-01

    An advanced portable life support system (PLSS) for the space suit will require a small, robust, and energyefficient system to transport the ventilation gas through the space suit for lunar Extravehicular Activity (EVA) operations. A trade study identified and compared ventilation transport technologies in commercial, military, and space applications to determine which technologies could be adapted for EVA use. Based on the trade study results, five commercially available, 24-volt fans were selected for performance testing at various pressures and flow rates. Measured fan parameters included fan delta-pressures, input voltages, input electrical currents, and in some cases motor windings electrical voltages and currents. In addition, a follow-on trade study was performed to identify oxygen compatibility issues and assess their impact on fan design. This paper outlines the results of the fan performance characterization testing, as well as the results from the oxygen compatibility assessment.

  9. Aero-Acoustics of Modern Transonic Fans—Fan Noise Reduction from Its Sources

    Institute of Scientific and Technical Information of China (English)

    L. Xu; J.D. Denton

    2003-01-01

    The noise of aerodynamics nature from modern transonic fan is examined from its sources with the perspective of noise reduction through aero-acoustics design using advanced Computational Fluid Dynamics (CFD) tools.In particular the problems associated with the forward propagating noise in the front is addressed. It is identified that the shock wave spillage from the leading edge near the fan tip is the main source of the tone noise. Two different approaches have been studied to reduce the forward arc tone noise and two state-of-art transonic fans are designed using the strategies developed. The following rig tests show that while the fans exhibit other noise problems,the primary goals of noise reduction have been achieved through both fans and the novel noise reduction concept vindicated.

  10. Method for modifying axial fan's guard grill and its impact on operating characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Alic, G. [Hidria Institute Klima d.o.o., Godovic (Slovenia); Sirok, B.; Hocevar, M. [Faculty of Mechanical Engineering, Ljubljana (Slovenia)

    2010-06-15

    This paper presents the impact of guard grill on aerodynamic integral characteristic, the spectrum of sound pressure level and total sound power level at four characteristic operating points of axial fans with standard guard grill, with optimized guard grill and without guard grill. The study of guard grill's impact was conducted with measurements at integral level and local outflow velocity field of the axial fan without guard grill. The measurement results of the local outflow velocity field of the axial fan without guard grill at optimal operating point were used to model the optimized guard grill contour. The guard grill of axial fan has a significant impact on aerodynamic integral characteristic at free flow and mostly used operating region. The influence of guard grill is also characteristically reflected in the spectrum of sound pressure level via vortex shedding frequency and consequently at total sound power level of compared axial fans. (orig.)

  11. The evaluation and calibration of fan-beam collimators

    International Nuclear Information System (INIS)

    The aims of this study were (a) to determine the true focal length of a fan-beam collimator and (b) to calibrate image size (mm/pixel) for each collimator to permit inter-comparison of image data acquired on different gamma camera systems. A total of six fan-beam collimators on three dual-head gamma camera systems were evaluated using a set of four cobalt-57 point source markers. The markers were arranged in a line in the transverse plane with a known separation between them. Tomographic images were obtained at three radii of rotation. From reconstructed transaxial images the distance between markers was measured in pixels and used to determine pixel size in mm/pixel. The system value for the focal length of the collimator was modified by up to ±100 mm and transaxial images were again reconstructed. To standardize pixel size between systems, the apparent radius of rotation during a single-photon emission tomography (SPET) acquisition was modified by changes to the effective collimator thickness. SPET images of a 3D brain phantom were acquired on each system and reconstructed using both the original and the modified values of collimator focal length and thickness. Co-registration and subtraction of the reconstructed transaxial images was used to evaluate the effects of changes in collimator parameters. Pixel size in the reconstructed image was found to be a function of both the radius of rotation and the focal length. At the correct focal length, pixel size was essentially independent of the radius of rotation. For all six collimators, true focal length differed from the original focal length by up to 26 mm. These differences in focal length resulted in up to 6% variation in pixel size between systems. Pixel size between the three systems was standardized by altering the value for collimator thickness. Subtraction of the co-registered SPET images of the 3D brain phantom was significantly improved after optimization of collimator parameters, with a 35%-50% reduction

  12. Bruce NGS A/B assessment of reactor vault fans on air mixing patterns

    International Nuclear Information System (INIS)

    The development and results of numerical simulations of air mixing patterns in the CANDU Bruce Nuclear Generating Station reactor vault, as a function of vault cooling fan combinations, are presented. The results of this analysis will serve as a basis for selecting appropriate fan combination scenarios to consider in the upcoming post-LOCA (loss of coolant) hydrogen-air-steam mixing analysis. Following a severe reactor accident in which fuel cooling is impaired, a significant amount of hydrogen may be produced from the steam/Zircaloy reaction and subsequently released into containment. The hydrogen ignition system mitigates the consequences of hydrogen burns to within acceptable safety limits. Igniters deliberately initiate a burn of the hydrogen-air-steam mixture as it reaches its flammability limits. However without adequate mixing, the igniters may become blinded by a region of non-flammable hydrogen mixture while an unfavourable hydrogen mixture forms elsewhere. The vault cooling fans play an important role in promoting mixing in the vault atmosphere. To help assess the effects of vault cooling fans on air mixing, an analysis was carried out to identify the air mixing patterns as a function of different fan availability combinations. The three-dimensional containment code, GOTHIC, was used to model the Bruce containment with modelling emphasis on the reactor vault geometry and the vault cooling system fans. Twenty-five fan combination air mixing simulations and eight tracer gas fan dispersion simulations were performed. The results showed that air mixing patterns created by individual fans can be superimposed to determine the effects of various fan combinations, there was symmetry of flow patterns between the west and east vault halves, and there was a general absence of significant stagnant regions in the reactor vault. 8 refs., 7 figs., 3 tabs

  13. Channel Networks on Large Fans: Refining Analogs for the Ridge-forming Unit, Sinus Meridiani

    Science.gov (United States)

    Wilkinson, Justin

    2009-01-01

    Stream channels are generally thought of as forming within confined valley settings, separated by interfluves. Sinuous ridges on Mars and Earth are often interpreted as stream channels inverted by subsequent erosion of valley sides. In the case of the ridge-forming unit (RFU), this interpretation fails to explain the (i) close spacing of the ridges, which are (ii) organized in networks, and which (iii) cover large areas (approximately 175,000 km (exp 2)). Channel networks on terrestrial fans develop unconfined by valley slopes. Large fans (100s km long) are low-angle, fluvial features, documented worldwide, with characteristics that address these aspects of the RFU. Ridge patterns Channels on large fans provide an analog for the sinuous and elongated morphology of RFU ridges, but more especially for other patterns such as subparallel, branching and crossing networks. Branches are related to splays (delta-like distributaries are rare), whose channels can rejoin the main channel. Crossing patterns can be caused by even slight sinuosity splay-related side channels often intersect. An avulsion node distant from the fan apex, gives rise to channels with slightly different, and hence intersecting, orientations. Channels on neighboring fans intersect along the common fan margin. 2. Network density Channels are the dominant feature on large terrestrial fans (lakes and dune fields are minor). Inverted landscapes on subsequently eroded fans thus display indurated channels as networks of significantly close-spaced ridges. 3. Channel networks covering large areas Areas of individual large terrestrial fans can reach >200,000 km 2 (105-6 km 2 with nested fans), providing an analog for the wide area distribution of the RFU.

  14. Methodologies for hydraulic hazard mapping in alluvial fan areas

    Science.gov (United States)

    Milanesi, L.; Pilotti, M.; Ranzi, R.; Valerio, G.

    2014-09-01

    Hydraulic hazards in alluvial fan areas are mainly related to torrential floods and debris flows. These processes are characterized by their fast time evolution and relevant sediment load. Rational approaches for the estimation of hazard levels in flood-prone areas make use of the maps of depth and velocity, which are provided by numerical simulations of the event. This paper focuses on national regulations regarding quantitative debris-flow hazard mapping and compares them to a simple conceptual model for the quantification of the hazard levels on the basis of human stability in a flood. In particular, the proposed method takes into account, in a conceptual fashion, both the local slope and the density of the fluid, that are crucial aspects affecting stability for processes in mountain environments. Physically-based hazard criteria provide more comprehensible and objective maps, increasing awareness among stakeholders and providing more acceptable constraints for land planning.

  15. Market assessment for the fan atomized oil burner

    Energy Technology Data Exchange (ETDEWEB)

    Westphalen, D. [A.D. Little, Inc., Cambridge, MA (United States)

    1996-07-01

    The market potential for the fan atomized burner (FAB) in water and space heating applications was examined. The major findings of the study are as follows. (1). The FAB`s low-input capability allows development of oil-fired room heaters and wall furnaces, a new market area for oil heat. (2). Among conventional oil-fired products, furnaces will benefit most from the burner`s low input capability due to (1) their quick delivery of heat and (2) their more prevalent use in warmer climates and smaller homes. (3). The greatest potential for increased product sales or oil sales exists in the use of the burner with new products (i.e., room heaters). Sales of boilers and direct-fired water heaters are not likely to increase with the use of the burner. (4). Acceptance of the burner will be dependent on proof of reliability. Proof of better reliability than conventional burners would accelerate acceptance.

  16. Yoga fans in Beijing%你瑜珈了吗?

    Institute of Scientific and Technical Information of China (English)

    雷顿

    2002-01-01

    @@ 瑜珈运动在北京白领女性中流行是近两年的事情,逐渐形成了一个比较稳固的"瑜珈饭(Fan)"群体,她们年龄大致集中在30-40 岁之间,多为企业中高层经理、主管.虽然工作很忙,但她们还是努力挤出时间去瑜珈,她们都同样热爱这项运动,乐此不疲.她们喜欢安静,据说"瑜珈饭"的血型多为A型和O型.

  17. Reconstructions from parallel- and fan-beam data with truncations

    Science.gov (United States)

    Xia, Dan; Zou, Yu; Pan, Xiaochuan

    2006-03-01

    A formula was recently described by Clackdoyle et. al. for image reconstruction within a region of interest (ROI) from knowledge of its truncated 2D Radon transform. In this work, we present an alternative, simple derivation of the formula by using the well-known relationship between the parallel-beam and fan-beam geometries. Based upon our derivation, the role of parameter t in the formula in ROI-image reconstruction can be clearly identified. We show that the parameter t determines the size of a reconstructible ROI from parallel-beam data containing truncations. Numerical studies were performed to by use of the formula with different t. We show that the formula yields ROI images with smaller sizes and lower quality than does our backprojection filtration algorithm.

  18. Functional Planning and Design of a Fan Shaped Technical Museum

    Directory of Open Access Journals (Sweden)

    Dr. Lovely K M

    2014-04-01

    Full Text Available The proposed building aims at the development of the built environment. The principal objective of this paper is the functional planning, analysis and design of a fan shaped technical museum. Technical museum is a museum that tells the stories of architecture, engineering and design. The functional planning was done according to the clauses given by Museum Building Design and Exhibition Layout: Patterns of Interactions, ICOM Code of Ethics for Museum, and Key Concepts of Museology. Plan, elevation and section were drawn in AutoCAD 2010. The design involves load calculations and analyzing the whole structure by STAAD.ProV8i. The design methods used in STAAD.ProV8i analysis are limit state design conforming to Indian Standard Code of practice. Also the building was analyzed for all possible load combinations.

  19. SPORT FAN MOTIVATION QUESTIONNAIRE: A STUDY OF VALIDITY AND RELIABILITY

    Directory of Open Access Journals (Sweden)

    Muhammed Emin KAFKAS

    2012-04-01

    Full Text Available The purpose of this research, Yousof Al-Thibiti (2004 Fan Motivational scale was developed by Turkish adapts and scales to analyze the validity and reliability. The study group was composed that Inonu University studying at different faculty of education between the age of 17-31 494’ü (%54 women and 421’i (%46 male students. Firstly of linguistic equivalence of the scale were examined. Secondly after linguistic equivalence was performed reliability analysis. The total scale internal consistency coefficients for sizes .85 and subscale range of .70-.78, the re-test reliability coefficients were between .79-.89. at the same time, exploratory factor analysis and confirmatory factor analysis is carried out with the scale and found to comply with the data. As a result of scale to measure the status of individuals to participate in sporting activities was found to have an appropriate structure.

  20. A simplified fragility analysis of fan type cable stayed bridges

    Institute of Scientific and Technical Information of China (English)

    R. A. Khan; T. K. Datta; S. Ahmad

    2005-01-01

    A simplified fragility analysis of fan type cable stayed bridges using Probabilistic Risk Analysis (PRA)procedure is presented for determining their failure probability under random ground motion. Seismic input to the bridge support is considered to be a risk consistent response spectrum which is obtained from a separate analysis. For the response analysis, the bridge deck is modeled as a beam supported on springs at different points. The stiffnesses of the springs are determined by a separate 2D static analysis of cable-tower-deck system. The analysis provides a coupled stiffness matrix for the spring system. A continuum method of analysis using dynamic stiffness is used to determine the dynamic properties of the bridges .The response of the bridge deck is obtained by the response spectrum method of analysis as applied to multidegree of freedom system which duly takes into account the quasi - static component of bridge deck vibration. The fragility analysis includes uncertainties arising due to the variation in ground motion, material property, modeling, method of analysis,ductility factor and damage concentration effect. Probability of failure of the bridge deck is determined by the First Order Second Moment (FOSM) method of reliability. A three span double plane symmetrical fan type cable stayed bridge of total span 689 m, is used as an illustrative example. The fragility curves for the bridge deck failure are obtained under a number of parametric variations. Some of the important conclusions of the study indicate that (i) not only vertical component but also the horizontal component of ground motion has considerable effect on the probability of failure; (ii) ground motion with no time lag between support excitations provides a smaller probability of failure as compared to ground motion with very large time lag between support excitation; and (iii) probability of failure may considerably increase for soft soil condition.