Potential Cost Savings Ideas for FAA and Users

Science.gov (United States)

1997-06-04

The intent of this paper is to catalogue potential cost-savings ideas which : impact both the FAA and the aviation community. These ideas have come from : various sources including MITRE, Coopers & Lybrand (C&L), FAA studies, General : Accounting Off...

47 CFR 73.4102 - FAA communications, broadcast of.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false FAA communications, broadcast of. 73.4102 Section 73.4102 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES Rules Applicable to All Broadcast Stations § 73.4102 FAA communications...

FAA statistical handbook of aviation, calendar year 1988

Science.gov (United States)

1988-08-15

The FAA Statistical Handbook of Aviation is published annually by the Federal Aviation Administration (FAA). The handbook is provided here in MS Excel. format as downloadable files and as text tables that can be viewed in PDF format. The prime purpos...

Advisory Circular checklist and status of other FAA publications

Science.gov (United States)

1997-08-15

This 1997 circular transmits the revised checklist of the Federal Aviation : Administration's (FAA) Advisory Circulars (AC's). It also lists certain other : FAA publications sold by the Superintendent of Documents.

78 FR 6400 - Results of FAA Nitrous Oxide BLEVE Characterization Testing

Science.gov (United States)

2013-01-30

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Results of FAA Nitrous Oxide BLEVE Characterization Testing AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of public... FAA sponsored testing of nitrous oxide (N 2 O) characteristics. Nitrous oxide is an important oxidizer...

NASA/FAA helicopter simulator workshop

Science.gov (United States)

Larsen, William E. (Editor); Randle, Robert J., Jr. (Editor); Bray, Richard S. (Editor); Zuk, John (Editor)

1992-01-01

A workshop was convened by the FAA and NASA for the purpose of providing a forum at which leading designers, manufacturers, and users of helicopter simulators could initiate and participate in a development process that would facilitate the formulation of qualification standards by the regulatory agency. Formal papers were presented, special topics were discussed in breakout sessions, and a draft FAA advisory circular defining specifications for helicopter simulators was presented and discussed. A working group of volunteers was formed to work with the National Simulator Program Office to develop a final version of the circular. The workshop attracted 90 individuals from a constituency of simulator manufacturers, training organizations, the military, civil regulators, research scientists, and five foreign countries.

47 CFR 17.7 - Antenna structures requiring notification to the FAA.

Science.gov (United States)

2010-10-01

... the FAA. 17.7 Section 17.7 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL CONSTRUCTION... Antenna structures requiring notification to the FAA. A notification to the Federal Aviation... area of each heliport specified in paragraph (d) of this section. (c) When requested by the FAA, any...

49 CFR 26.105 - What enforcement actions apply in FAA programs?

Science.gov (United States)

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false What enforcement actions apply in FAA programs? 26... Enforcement § 26.105 What enforcement actions apply in FAA programs? (a) Compliance with all requirements of this part by airport sponsors and other recipients of FAA financial assistance is enforced through the...

14 CFR 11.73 - How does FAA process petitions for rulemaking?

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false How does FAA process petitions for... for Exemption § 11.73 How does FAA process petitions for rulemaking? After we have determined the disposition of your petition, we will contact you in writing about our decision. The FAA may respond to your...

14 CFR 11.31 - How does FAA process direct final rules?

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false How does FAA process direct final rules? 11... PROCEDURAL RULES GENERAL RULEMAKING PROCEDURES Rulemaking Procedures General § 11.31 How does FAA process direct final rules? (a) A direct final rule will take effect on a specified date unless FAA receives an...

14 CFR 11.85 - Does FAA invite public comment on petitions for exemption?

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Does FAA invite public comment on petitions... Rulemaking and for Exemption § 11.85 Does FAA invite public comment on petitions for exemption? Yes, FAA... the reasons for requesting it; and (e) A request for comments to assist FAA in evaluating the petition. ...

76 FR 7893 - FAA Policy Statement on Expungement of Certain Enforcement Actions

Science.gov (United States)

2011-02-11

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration FAA Policy Statement on Expungement.... SUMMARY: The FAA has temporarily suspended its policy of expunging certain records of legal enforcement... effects on pilots is available at: http://www.faa.gov/pilots/lic_cert/pria/guidance/pilotfaq . Further...

FAA Flight Plan 2009-2013

Science.gov (United States)

2009-01-01

The Flight Plan is the strategic plan for the agency, the plan to help us prepare for the future. The majority of FAAs responsibilities are our core functionsour everyday roles and responsibilitieswhich are not specifically highlighted in th...

14 CFR 11.39 - How may I participate in FAA's rulemaking process?

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false How may I participate in FAA's rulemaking process? 11.39 Section 11.39 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... participate in FAA's rulemaking process? You may participate in FAA's rulemaking process by doing any of the...

An Instructional Systems Approach or FAA Student Centered Training.

Science.gov (United States)

Federal Aviation Administration (DOT), Washington, DC.

The Federal Aviation Administration (FAA) Academy has been using a systems approach as part of its training program since 1969. This booklet describes the general characteristics of an instructional system and explains the steps the FAA goes through in implementing the approach. These steps are: 1) recognize a need for training, 2) specify the…

14 CFR 11.25 - How does FAA issue rules?

Science.gov (United States)

2010-01-01

...) Whom to call if you have questions about the rulemaking document. (5) The date, time, and place of any... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false How does FAA issue rules? 11.25 Section 11... RULES GENERAL RULEMAKING PROCEDURES Rulemaking Procedures General § 11.25 How does FAA issue rules? (a...

FAA Energy Order 1053.1A - Energy and Water Management Program For FAA Buildings and Facilities

Science.gov (United States)

1996-12-27

This order provides Federal Aviation Administration (FAA) policies, procedures, and organizational responsibilities, in a focused and expanded agency energy and water planning and conservation program, for complying with the national mandates for the...

FAA Certificated Maintenance Agencies Directory (1997)

Science.gov (United States)

1997-05-06

This advisory circular (AC) transmits a consolidated directory of all : certificated Federal Aviation Administration (FAA) repair stations and : manufacturer's maintenance facilities. The repair stations and manufacturer's : maintenance facilities we...

Determinação do teor de sílica em madeira por espectroscopia de absorção atômica de chama versus espectroscopia no ultravioleta-visível.

Directory of Open Access Journals (Sweden)

Laécio Carneiro Rodrigues

2009-10-01

Full Text Available Normal 0 21 MicrosoftInternetExplorer4 O presente trabalho teve como objetivo comparar o desempenho de duas técnicas analíticas, espectroscopia de absorção atômica de chama (FAAS e espectroscopia no ultravioleta-visível (UV-VIS, na determinação do teor de sílica em materiais lignocelulósicos. Os métodos foram testados em amostras de madeira de três árvores de Apuleia leiocarpa (Vog. Macbride. Os resultados mostraram que ambas as técnicas apresentam bons resultados, no entanto, a FAAS apresenta melhor precisão, rapidez e simplicidade operacional. Entretanto, a aplicação da espectroscopia UV-VIS é justificada pelo fato de os custos de aquisição e manutenção de um espectrofotômetro UV-VIS serem muito inferiores àqueles de um espectrômetro de absorção atômica. O uso da técnica FAAS deve ser preferido apenas quando os teores de sílica a serem determinados forem muito baixos, tendo em vista que a espectroscopia UV-VIS, nesses casos, não apresenta boa precisão.

The Acyl-CoA synthetases encoded within FAA1 and FAA4 in Saccharomyces cerevisiae function as components of the fatty acid transport system linking import, activation, and intracellular Utilization

DEFF Research Database (Denmark)

Færgeman, Nils J.; Black, P N; Zhao, X D

2001-01-01

CoA levels were defined following incubation of wild type and mutant cells with limiting concentrations of exogenous oleate. These studies demonstrated oleoyl CoA levels were reduced to less than 10% wild-type levels in faa1 Delta and faa1 Delta faa4 Delta strains. Defects in metabolic utilization...

14 CFR 11.75 - Does FAA invite public comment on petitions for rulemaking?

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Does FAA invite public comment on petitions... Rulemaking and for Exemption § 11.75 Does FAA invite public comment on petitions for rulemaking? Generally, FAA does not invite public comment on petitions for rulemaking. ...

Index to FAA Office of Aviation Medicine reports : 1961 through 1995.

Science.gov (United States)

1996-01-01

An index to Federal Aviation Administration (FAA) Office of Aviation Medicine Reports (1964-1995) and Civil Aeromedical Institute Reports is presented for those engaged in aviation medicine and related activities. The index lists all FAA aviation med...

FAA Helicopter/Vertiport Lighting Conference - Proceedings

National Research Council Canada - National Science Library

Smith, Robert

1999-01-01

As the vertical flight industry moves into instrument flight rules (IFR) operations at heliports, it has become apparent to both FAA and the users that there is research and development to be done on heliport lighting...

76 FR 56968 - [Docket No. FAA-2011-0490; Airspace Docket No. 11-AWP-5

Science.gov (United States)

2011-09-15

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 71 [Docket No. FAA-2011... Administration (FAA), DOT. ACTION: Final rule. SUMMARY: This action modifies Class E airspace at Tonopah, NV, to... reference action under 1 CFR Part 51, subject to the annual revision of FAA Order 7400.9 and publication of...

Air Traffic Control: Immature Software Acquisition Processes Increase FAA System Acquisition Risks

Science.gov (United States)

1997-03-01

The General Accounting Office (GAO) at the request of Congress reviewed (1) : the maturity of Federal Aviation Administration's (FAA's) Air Traffic Control : (ATC) modernization software acquisition processes, and (2) the steps/actions : FAA has unde...

14 CFR 11.23 - Does FAA follow the same procedures in issuing all types of rules?

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Does FAA follow the same procedures in... § 11.23 Does FAA follow the same procedures in issuing all types of rules? Yes, in general, FAA follows the same procedures for all rule types. There are some differences as to which FAA official has...

14 CFR 193.7 - What does it mean for the FAA to designate information as protected?

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false What does it mean for the FAA to designate... INFORMATION § 193.7 What does it mean for the FAA to designate information as protected? (a) General. When the FAA issues an order designating information as protected under this part, the FAA does not disclose...

14 CFR 11.29 - May FAA change its regulations without first issuing an ANPRM or NPRM?

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false May FAA change its regulations without... General § 11.29 May FAA change its regulations without first issuing an ANPRM or NPRM? The FAA normally adds or changes a regulation by issuing a final rule after an NPRM. However, FAA may adopt, amend, or...

14 CFR Appendix B to Part 187 - Fees for FAA Services for Certain Flights

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Fees for FAA Services for Certain Flights B... (CONTINUED) ADMINISTRATIVE REGULATIONS FEES Pt. 187, App. B Appendix B to Part 187—Fees for FAA Services for... pay a fee for the FAA's rendering or providing certain services, including but not limited to the...

Federal Aviation Administration (FAA airworthiness certification for ceramic matrix composite components in civil aircraft systems

Directory of Open Access Journals (Sweden)

Gonczy Stephen T.

2015-01-01

Full Text Available Ceramic matrix composites (CMCs are being designed and developed for engine and exhaust components in commercial aviation, because they offer higher temperature capabilities, weight savings, and improved durability compared to metals. The United States Federal Aviation Administration (FAA issues and enforces regulations and minimum standards covering the safe manufacture, operation, and maintenance of civil aircraft. As new materials, these ceramic composite components will have to meet the certification regulations of the FAA for “airworthiness”. The FAA certification process is defined in the Federal Aviation Regulations (Title 14 of the Code of Federal Regulations, FAA policy statements, orders, advisory circulars, technical standard orders, and FAA airworthiness directives. These regulations and documents provide the fundamental requirements and guidelines for design, testing, manufacture, quality assurance, registration, operation, inspection, maintenance, and repair of aircraft systems and parts. For metallic parts in aircraft, the FAA certification and compliance process is well-established for type and airworthiness certification, using ASTM and SAE standards, the MMPDS data handbook, and FAA advisory circulars. In a similar manner for polymer matrix composites (PMC, the PMC industry and the FAA have jointly developed and are refining parallel guidelines for polymer matrix composites (PMCs, using guidance in FAA circulars and the CMH-17 PMC handbook. These documents discuss design methods and codes, material testing, property data development, life/durability assessment, production processes, QA procedures, inspection methods, operational limits, and repairs for PMCs. For ceramic composites, the FAA and the CMC and aerospace community are working together (primarily through the CMH-17 CMC handbook to define and codify key design, production, and regulatory issues that have to be addressed in the certification of CMC components in

14 CFR 11.38 - What public comment procedures does the FAA follow for Special Conditions?

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false What public comment procedures does the FAA... § 11.38 What public comment procedures does the FAA follow for Special Conditions? Even though the Administrative Procedure Act does not require notice and comment for rules of particular applicability, FAA does...

14 CFR Appendix A to Part 415 - FAA/USSPACECOM Launch Notification Form

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false FAA/USSPACECOM Launch Notification Form A Appendix A to Part 415 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH LICENSE Pt. 415, App. A Appendix A to Part 415—FAA...

Aviation safety courses available through the FAA.

Science.gov (United States)

2009-02-02

The FAA Civil Aerospace Medical Institute (CAMI) offers a 1-day training course to familiarize U.S. civil aviation pilots and flight crews with the physiological and psychological stresses of flight. Pilots who are knowledgeable about physiological p...

49 CFR 1540.117 - Threat assessments regarding aliens holding or applying for FAA certificates, ratings, or...

Science.gov (United States)

2010-10-01

... applying for FAA certificates, ratings, or authorizations. 1540.117 Section 1540.117 Transportation Other... applying for FAA certificates, ratings, or authorizations. (a) Applicability. This section applies when TSA... applying for, an airman certificate, rating, or authorization issued by the FAA Administrator, poses a...

14 CFR 406.105 - Separation of functions for prosecuting civil penalties and advising the FAA decisionmaker.

Science.gov (United States)

2010-01-01

... civil penalties and advising the FAA decisionmaker. 406.105 Section 406.105 Aeronautics and Space... INVESTIGATIONS, ENFORCEMENT, AND ADMINISTRATIVE REVIEW Rules of Practice in FAA Space Transportation Adjudications § 406.105 Separation of functions for prosecuting civil penalties and advising the FAA...

Comparison between EDXRF and FAAS for Zn determination in terrestrial molluscs

International Nuclear Information System (INIS)

Melo, Julyanne T.B.; Cantinha, Rebeca S.; Santos, Mariana L.O.; Santos, Katarine M.B.; Franca, Elvis J.; Melo, Ana M.M.A.

2015-01-01

Even with the most advanced analytical techniques, achieving the true values of a given analyte in a sample cannot be an easy task. Energy Dispersive X-Ray Fluorescence (EDXRF) and Flame Atomic Absorption Spectrometry (FAAS) have been widely used for analysis of the chemical composition of biological matrices in environmental studies. However, depending on the sample matrix, a combination of techniques could be needed for the correct determination of the analyte. Zinc distribution in Littoraria angulifera and Melampus coffea is quite dependent on the environment, so that, diverse methods could be necessary to evaluate the chemical composition of these mollusks. This study aimed at the comparison between EDXRF and FAAS techniques for determining Zn in the soft tissues of terrestrial mollusks. The animals were collected in three mangroves in the State of Pernambuco, Brazil. After shell removal, tissues were lyophilized and milled in a mortar. Test portions of 500 mg were analyzed by EDXRF, followed by chemical treatment for FAAS analysis. For the quality of the analytical procedure, the standard reference material SRM 2976 Mussel Tissue was analyzed together with the samples. The results for the analysis of the certified reference material SRM 2976 indicated the quality of the analytical procedure for both techniques. Adjusted-R 2 between EDXRF and FAAS results was 0.95, indicating a good equivalence of Zn determination by both techniques. However, some improvement of EDXRF determination could be necessary because of the tendency of lower results compared to FAAS, probably related to spectral interferences during the analysis. (author)

Comparison between EDXRF and FAAS for Zn determination in terrestrial molluscs

Energy Technology Data Exchange (ETDEWEB)

Melo, Julyanne T.B.; Cantinha, Rebeca S.; Santos, Mariana L.O.; Santos, Katarine M.B.; Franca, Elvis J., E-mail: julyanne.melo@ufpe.br, E-mail: rebecanuclear@gmail.com, E-mail: marianasantos_ufpe@hotmail.com, E-mail: katarine.mizan@gmail.com, E-mail: ejfranca@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Melo, Ana M.M.A., E-mail: amdemelo@hotmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Biofisica e Radiobiologia

2015-07-01

Even with the most advanced analytical techniques, achieving the true values of a given analyte in a sample cannot be an easy task. Energy Dispersive X-Ray Fluorescence (EDXRF) and Flame Atomic Absorption Spectrometry (FAAS) have been widely used for analysis of the chemical composition of biological matrices in environmental studies. However, depending on the sample matrix, a combination of techniques could be needed for the correct determination of the analyte. Zinc distribution in Littoraria angulifera and Melampus coffea is quite dependent on the environment, so that, diverse methods could be necessary to evaluate the chemical composition of these mollusks. This study aimed at the comparison between EDXRF and FAAS techniques for determining Zn in the soft tissues of terrestrial mollusks. The animals were collected in three mangroves in the State of Pernambuco, Brazil. After shell removal, tissues were lyophilized and milled in a mortar. Test portions of 500 mg were analyzed by EDXRF, followed by chemical treatment for FAAS analysis. For the quality of the analytical procedure, the standard reference material SRM 2976 Mussel Tissue was analyzed together with the samples. The results for the analysis of the certified reference material SRM 2976 indicated the quality of the analytical procedure for both techniques. Adjusted-R{sup 2} between EDXRF and FAAS results was 0.95, indicating a good equivalence of Zn determination by both techniques. However, some improvement of EDXRF determination could be necessary because of the tendency of lower results compared to FAAS, probably related to spectral interferences during the analysis. (author)

76 FR 44978 - Notice of FAA Intent To Carry Over Airport Improvement Program (AIP) Entitlement Funds

Science.gov (United States)

2011-07-27

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration [Docket No. 2011-0786] Notice of FAA... notify, in writing, the designated representative in the appropriate FAA Regional or Airports District... apportioned for fiscal year 2011, regardless of whether the FAA has authority to obligate those funds. After...

41 CFR 102-75.405 - What responsibilities does the Federal Aviation Administration (FAA) have after receiving a copy...

Science.gov (United States)

2010-07-01

... does the Federal Aviation Administration (FAA) have after receiving a copy of the notice (and a copy of... responsibilities does the Federal Aviation Administration (FAA) have after receiving a copy of the notice (and a..., the FAA must inform the disposal agency of its determination. Then, the FAA must provide assistance to...

41 CFR 102-33.230 - May we use military FSCAP on non-military FAA-type certificated Government aircraft?

Science.gov (United States)

2010-07-01

... FSCAP on non-military FAA-type certificated Government aircraft? 102-33.230 Section 102-33.230 Public... Aircraft Parts Managing Aircraft Parts § 102-33.230 May we use military FSCAP on non-military FAA-type... installation by the FAA. See detailed guidance in FAA Advisory Circular 20-142, “Eligibility and Evaluation of...

47 CFR 17.14 - Certain antenna structures exempt from notification to the FAA.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Certain antenna structures exempt from notification to the FAA. 17.14 Section 17.14 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL... § 17.14 Certain antenna structures exempt from notification to the FAA. A notification to the Federal...

49 CFR 1540.115 - Threat assessments regarding citizens of the United States holding or applying for FAA...

Science.gov (United States)

2010-10-01

... United States holding or applying for FAA certificates, ratings, or authorizations. 1540.115 Section 1540... of the United States holding or applying for FAA certificates, ratings, or authorizations. (a... the officer next in rank below the Administrator. FAA Administrator means the Administrator of the...

The Fanconi anemia proteins FAA and FAC function in different cellular compartments to protect against cross-linking agent cytotoxicity.

Science.gov (United States)

Kruyt, F A; Youssoufian, H

1998-10-01

Fanconi anemia (FA) is an autosomal recessive disease characterized by chromosomal instability, bone marrow failure, and a high risk of developing malignancies. Although the disorder is genetically heterogeneous, all FA cells are defined by their sensitivity to the apoptosis-inducing effect of cross-linking agents, such as mitomycin C (MMC). The cloned FA disease genes, FAC and FAA, encode proteins with no homology to each other or to any known protein. We generated a highly specific antibody against FAA and found the protein in both the cytoplasm and nucleus of mammalian cells. By subcellular fractionation, FAA is also associated with intracellular membranes. To identify the subcellular compartment that is relevant for FAA activity, we appended nuclear export and nuclear localization signals to the carboxy terminus of FAA and enriched its localization in either the cytoplasm or the nucleus. Nuclear localization of FAA was both necessary and sufficient to correct MMC sensitivity in FA-A cells. In addition, we found no evidence for an interaction between FAA and FAC either in vivo or in vitro. Together with a previous finding that FAC is active in the cytoplasm but not in the nucleus, our results indicate that FAA and FAC function in separate subcellular compartments. Thus, FAA and FAC, if functionally linked, are more likely to be in a linear pathway rather than form a macromolecular complex to protect against cross-linker cytotoxicity.

NASA-FAA-NOAA Partnering Strategy

Science.gov (United States)

Colantonio, Ron

2003-01-01

This viewgraph presentation provides an overview of NASA-FAA (Federal Aviation Administration) and NOAA (National Oceanic and Atmospheric Administration) collaboration efforts particularly in the area of aviation and aircraft safety. Five technology areas are being jointly by these agencies: (1) aviation weather information; (2) weather products; (3) automet technologies; (4) forward looking weather sensors and (5) turbulence controls and mitigation systems. Memorandum of Agreements (MOU) between these agencies are reviewed. A general review of the pros and pitfalls of inter-agency collaborations is also presented.

Federal Aviation Administration (FAA) Reauthorization : an overview of legislative action in the 111th Congress

Science.gov (United States)

2009-10-08

This report tracks the status of ongoing legislative action and debate related to FAA : reauthorization. It is organized into six major program areas: aviation system finance; airport : financing; FAA management and organizational issues; system capa...

78 FR 33146 - Notice of Proposal Policy for Distribution of FAA Data and Information; Extension of Comment Period

Science.gov (United States)

2013-06-03

... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration [Docket No. FAA-2013-0392; Notice No.] RIN 2120-AJ61 Notice of Proposal Policy for Distribution of FAA Data and Information; Extension of Comment Period AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice for Data and Information...

Proceedings of the FAA-NASA symposium on the continued airworthiness of aircraft structures : part 2

Science.gov (United States)

1997-07-01

This publication contains the fifty-two technical papers presented at the FAA-NASA Symposium on the Continued Airworthiness of Aircraft Structures. The symposium, hosted by the FAA Center of Excellence for Computational Modeling of : Aircraft Structu...

Proceedings of the FAA-NASA symposium on the continued airworthiness of aircraft structures : part 1

Science.gov (United States)

1997-07-01

This publication contains the fifty-two technical papers presented at the FAA-NASA Symposium on the Continued Airworthiness of Aircraft Structures. The symposium, hosted by the FAA Center of Excellence for Computational Modeling of : Aircraft Structu...

Factors associated with continuance commitment to FAA matrix teams.

Science.gov (United States)

1993-11-01

Several organizations within the FAA employ matrix teams to achieve cross-functional coordination. Matrix team members typically represent different organizational functions required for project accomplishment (e.g., research and development, enginee...

FAA-NASA Sixth International Conference on the Continued Airworthiness of Aircraft Structures

Science.gov (United States)

1995-12-01

Administration, and Colin G. Drury , State University of New York at Buffalo The Aging Aircraft Nondestructive Inspection Validation Center - A R esource for...William T. Shepherd FAA-Office of Aviation Medicine Washington, DC and Colin G. Drury State University of New York at Buffalo Buffalo, NY INTRODUCTION FAA’s...improvement, changing the task, the operator (inspector), machine, or environment as appropriate, e.g., review in Drury , 1992 (Ref. 1). 2. From the

Evaluation of the FAA Advanced Flow Control Procedures.

Science.gov (United States)

1972-01-01

The report is an evaluation of the present FAA Advanced Flow Control Procedures (AFCP), based on data gathered from its implementation on February 5, 1971 and on a fast-time digital simulation of traffic feeding into the NY airports on that day. The ...

14 CFR 13.234 - Petition to reconsider or modify a final decision and order of the FAA decisionmaker on appeal.

Science.gov (United States)

2010-01-01

... decision and order of the FAA decisionmaker on appeal. 13.234 Section 13.234 Aeronautics and Space FEDERAL... PROCEDURES Rules of Practice in FAA Civil Penalty Actions § 13.234 Petition to reconsider or modify a final decision and order of the FAA decisionmaker on appeal. (a) General. Any party may petition the FAA...

FAA/NASA Joint University Program for Air Transportation Research 1994-1995

Science.gov (United States)

Remer, J. H.

1998-01-01

The Joint University Program for Air Transportation Research (JUP) is a coordinated set of three grants co-sponsored by the Federal Aviation Administration (FAA) and the National Aeronautics and Space Administration (NASA). Under JUP, three institutions: the Massachusetts Institute of Technology, Princeton, and Ohio Universities receive research grants and collaborate with FAA and NASA in defining and performing civil aeronautics research in a multitude of areas. Some of these disciplines are artificial intelligence, control theory, atmospheric hazards, navigation, avionics, human factors, flight dynamics, air traffic management, and electronic communications.

14 CFR 11.51 - May I request that FAA hold a public meeting on a rulemaking action?

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false May I request that FAA hold a public... Meetings and Other Proceedings § 11.51 May I request that FAA hold a public meeting on a rulemaking action? Yes, you may request that we hold a public meeting. FAA holds a public meeting when we need more than...

14 CFR 11.91 - How does FAA inform me of its decision on my petition for exemption?

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false How does FAA inform me of its decision on... for Rulemaking and for Exemption § 11.91 How does FAA inform me of its decision on my petition for exemption? The FAA will notify you in writing about its decision on your petition. A copy of this decision...

14 CFR 11.27 - Are there other ways FAA collects specific rulemaking recommendations before we issue an NPRM?

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Are there other ways FAA collects specific... Rulemaking Procedures General § 11.27 Are there other ways FAA collects specific rulemaking recommendations before we issue an NPRM? Yes, the FAA obtains advice and recommendations from rulemaking advisory...

41 CFR 102-37.530 - What are FAA's responsibilities in the donation of surplus property to public airports?

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What are FAA's... § 102-37.530 What are FAA's responsibilities in the donation of surplus property to public airports? In the donation of surplus property to public airports, the Federal Aviation Administration (FAA), acting...

14 CFR 193.9 - Will the FAA ever disclose information that is designated as protected under this part?

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Will the FAA ever disclose information that... VOLUNTARILY SUBMITTED INFORMATION § 193.9 Will the FAA ever disclose information that is designated as protected under this part? The FAA discloses information that is designated as protected under this part...

Aviation Safety: FAA Oversight of Repair Stations Needs Improvement

Science.gov (United States)

1997-10-24

This report by the General Accounting Office examines the Federal Aviation : Administration's (FAA) oversight of the aviation repair station industry. : Specifically, this report addresses the following questions: (1) What is the : nature and scope o...

A qualitative phenomenological study: Enhanced, risk-based FAA oversight on part 145 maintenance practices

Science.gov (United States)

Sheehan, Bryan G.

The purpose of this qualitative phenomenological study was to examine the phenomenon of enhanced, risk-based Federal Aviation Administration (FAA) oversight of Part 145 repair stations that performed aircraft maintenance for Part 121 air carriers between 2007 and 2014 in Oklahoma. Specifically, this research was utilized to explore what operational changes have occurred in the domestic Part 145 repair station industry such as variations in management or hiring practices, training, recordkeeping and technical data, inventory and aircraft parts supply-chain logistics, equipment, and facilities. After interviewing 12 managers from Part 145 repair stations in Oklahoma, six major theme codes emerged from the data: quality of oversight before 2007, quality of oversight after 2007, advantages of oversight, disadvantages of oversight, status quo of oversight, and process improvement . Of those six major theme codes, 17 subthemes appeared from the data that were used to explain the phenomenon of enhanced oversight in the Part 145 repair station industry. Forty-two percent of the participants indicated a weak FAA oversight system that has hindered the continuous process improvement program in their repair stations. Some of them were financially burdened after hiring additional full-time quality assurance inspectors to specifically manage enhanced FAA oversight. Notwithstanding, the participants of the study indicated that the FAA must apply its surveillance on a more standardized and consistent basis. They want to see this standardization in how FAA inspectors interpret regulations and practice the same quality of oversight for all repair stations, particularly those that are repeat violators and fail to comply with federal aviation regulations. They believed that when the FAA enforces standardization on a consistent basis, repair stations can become more efficient and safer in the performance of their scope of work for the U.S. commercial air transportation industry.

14 CFR 11.21 - What are the most common kinds of rulemaking actions for which FAA follows the Administrative...

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false What are the most common kinds of rulemaking actions for which FAA follows the Administrative Procedure Act? 11.21 Section 11.21 Aeronautics... actions for which FAA follows the Administrative Procedure Act? FAA follows the Administrative Procedure...

41 CFR 102-75.415 - What happens after the disposal agency receives the FAA's recommendation for disposal of the...

Science.gov (United States)

2010-07-01

... disposal agency receives the FAA's recommendation for disposal of the property for a public airport? 102-75... receives the FAA's recommendation for disposal of the property for a public airport? The head of the disposal agency, or his or her designee, may convey property approved by the FAA for use as a public...

Caracterização anatômica e histoquímica de raízes e folhas de plântulas de Anacardium occidentale L. (Anacardiaceae

Directory of Open Access Journals (Sweden)

Ana Luísa Lopes Ernesto Reis

2014-04-01

Full Text Available Anacardium occidentale L. (Anacardiaceae é uma espécie típica do Cerrado do Brasil Central e possui valor socioeconômico. Objetivou-se caracterizar anatômica e histoquimicamente as raízes e folhas desta espécie em diferentes estádios iniciais de desenvolvimento. Para a caracterização anatômica, as amostras foram fixadas em FAA50, incluídas em parafina e submetidas aos procedimentos usuais para microscopia de campo claro. Foram realizados testes histoquímicos para detecção de lipídios totais, taninos, lignina, amido e terpenoides com grupo carbonila nas folhas, bem como teste para amido nas raízes em cortes frescos. A raiz apresenta epiderme unisseriada, floema com canais secretores e xilema tetrarco. Aos cinco dias após a germinação, a planta apresenta regiões com crescimento secundário e possui região medular na raiz, com função de armazenamento de grãos de amido. As folhas exibem epiderme unisseriada, com tricomas glandulares, cutícula espessa e estômatos paracíticos, em ambas as faces. O mesofilo é dorsiventral, e a nervura central apresenta feixes vasculares colaterais com canais secretores associados ao floema. A caracterização histoquímica da folha evidenciou lipídios totais e compostos fenólicos, entre eles taninos e lignina, em diferentes tecidos da folha. A plântula apresenta características que demonstram sua adaptação ao ambiente Cerrado, como cutícula espessa, mesofilo dorsiventral, crescimento secundário e presença de tricomas, mesmo sendo cultivada em condições de viveiro.

Aviation Safety: FAA and DOD Response to Similar Safety Concerns

National Research Council Canada - National Science Library

2002-01-01

.... The Federal Aviation Administration (FAA) and the military services often face common safety issues as they oversee the operation of similar aircraft or even dissimilar aircraft that use common parts and materials...

NASA and FAA Programs in Air Traffic Management

Science.gov (United States)

Condon, Gregory W.

1995-01-01

This presentation will present an overview of NASA and joint NASA/FAA R&D programs related to Air Traffic Management. In addition it will address the plans for the new Advanced Air Transportation Technologies program, which will investigate methods for achieving the airline industries needs for increased flexibility in the nation's air traffic management system.

14 CFR 406.177 - Petition to reconsider or modify a final decision and order of the FAA decisionmaker on appeal.

Science.gov (United States)

2010-01-01

... decision and order of the FAA decisionmaker on appeal. 406.177 Section 406.177 Aeronautics and Space... INVESTIGATIONS, ENFORCEMENT, AND ADMINISTRATIVE REVIEW Rules of Practice in FAA Space Transportation Adjudications § 406.177 Petition to reconsider or modify a final decision and order of the FAA decisionmaker on...

14 CFR 39.21 - Where can I get information about FAA-approved alternative methods of compliance?

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Where can I get information about FAA-approved alternative methods of compliance? 39.21 Section 39.21 Aeronautics and Space FEDERAL AVIATION... information about FAA-approved alternative methods of compliance? Each airworthiness directive identifies the...

14 CFR 11.89 - How much time do I have to submit comments to FAA on a petition for exemption?

Science.gov (United States)

2010-01-01

... to FAA on a petition for exemption? 11.89 Section 11.89 Aeronautics and Space FEDERAL AVIATION... Petitions for Rulemaking and for Exemption § 11.89 How much time do I have to submit comments to FAA on a petition for exemption? The FAA states the specific time allowed for comments in the Federal Register...

14 CFR 193.15 - What FAA officials exercise the authority of the Administrator under this part?

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false What FAA officials exercise the authority of the Administrator under this part? 193.15 Section 193.15 Aeronautics and Space FEDERAL AVIATION... SUBMITTED INFORMATION § 193.15 What FAA officials exercise the authority of the Administrator under this...

Management Advisory Memorandum of FAA Service Agreement, JFK Control Tower

Science.gov (United States)

1997-02-12

This Management Advisory Memorandum is in response to the Federal Aviation Administration's (FAA) request to audit costs claimed for Fiscal Year (FY) 1995 by the Port Authority of New York and New Jersey (Port Authority) related to Contract No. DTFA0...

Assessment of Head-Injured Aircrew: Comparison of FAA and USAF Procedures

National Research Council Canada - National Science Library

Fiedler, Edna

2001-01-01

.... The purpose of this paper is to first explain the major differences in missions between the USAF and the FAA, and then outline these procedures and rules, note their similarities and differences...

NASA/FAA Tailplane Icing Program Overview

Science.gov (United States)

Ratvasky, Thomas P.; VanZante, Judith Foss; Riley, James T.

1999-01-01

The effects of tailplane icing were investigated in a four-year NASA/FAA Tailplane Icing, Program (TIP). This research program was developed to improve the understanding, of iced tailplane aeroperformance and aircraft aerodynamics, and to develop design and training aides to help reduce the number of incidents and accidents caused by tailplane icing. To do this, the TIP was constructed with elements that included icing, wind tunnel testing, dry-air aerodynamic wind tunnel testing, flight tests, and analytical code development. This paper provides an overview of the entire program demonstrating the interconnectivity of the program elements and reports on current accomplishments.

DOT/FAA Human Factors Workshop on Aviation (6th). Transcript.

Science.gov (United States)

1982-05-01

This document is a verbatim transcript of the proceedings of the DOT/FAA Sixth Human Factors Workshop on Aviation held at the Mike Monroney Aeronautical Center, Oklahoma City, Oklahoma on July 7-8, 1981. The subject of the workshop was aviation maint...

Inspection Report: FAA's Alleged Circumvention of National Performance Review Staffing Requirements

Science.gov (United States)

1996-12-09

This report responds to a complaint received by the Office of Inspector General : (OIG), Department of Transportation. The complainant alleges the Federal : Aviation Administration (FAA) planned to circumvent National Performance : Review (NPR) staff...

Air Traffic Control: Observations on FAA's Air Traffic Control Modernization Program

National Research Council Canada - National Science Library

1999-01-01

In 1981, FAA began a multibillion-dollar modernization effort to improve the safety, capacity, and efficiency of this system to meet the increasing demand for air traffic services and to replace aging equipment...

Current status of Joint FAA/NASA Runway Friction Program

Science.gov (United States)

Yager, Thomas J.; Vogler, William A.

1989-01-01

Tests with specially instrumented NASA B-737 and FAA B-727 aircraft together with several different ground friction measuring devices have been conducted for a variety of runway surface types and wetness conditions. This effort is part of the Joint FAA/NASA Aircraft Ground Vehicle Runway Friction Program aimed at obaining a better understanding of aircraft ground handling performance under adverse weather conditions and defining relationships between aircraft and ground vehicle tire friction measurements. Aircraft braking performance on dry, wet, snow-, and ice-covered runway conditions is discussed together with ground vehicle friction data obtained under similar runway conditions. For the wet, compacted snow- and ice-covered runway conditions, the relationship between ground vehicles and aircraft friction data is identified. The influence of major test parameters on friction measurements such as speed, test tire characteristics, and surface contaminant type are discussed. The test results indicate that use of properly maintained and calibrated ground vehicles for monitoring runway friction conditions should be encouraged particularly under adverse weather conditions. The current status of the runway friction program is summarized and future test plans are identified.

14 CFR 11.87 - Are there circumstances in which FAA may decide not to publish a summary of my petition for...

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Are there circumstances in which FAA may decide not to publish a summary of my petition for exemption? 11.87 Section 11.87 Aeronautics and Space... in which FAA may decide not to publish a summary of my petition for exemption? The FAA may not...

Self-Assembling of Tetradecylammonium Chain on Swelling High Charge Micas (Na-Mica-3 and Na-Mica-2): Effect of Alkylammonium Concentration and Mica Layer Charge.

Science.gov (United States)

Pazos, M Carolina; Cota, Agustín; Osuna, Francisco J; Pavón, Esperanza; Alba, María D

2015-04-21

A family of tetradecylammonium micas is synthesized using synthetic swelling micas with high layer charge (Na(n)Si(8-n)Al(n)Mg6F4O20·XH2O, where n = 2 and 3) exchanged with tetradecylammonium cations. The molecular arrangement of the surfactant is elucidated on the basis of XRD patterns and DTA. The ordering conformation of the surfactant molecules into the interlayer space of micas is investigated by IR/FT, (13)C, (27)Al, and (29)Si MAS NMR. The structural arrangement of the tetradecylammonium cation in the interlayer space of high-charge micas is more sensitive to the effect of the mica layer charge at high concentration. The surfactant arrangement is found to follow the bilayer-paraffin model for all values of layer charge and surfactant concentration. However, at initial concentration below the mica CEC, a lateral monolayer is also observed. The amount of ordered conformation all-trans is directly proportional to the layer charge and surfactant concentration.

77 FR 4219 - FAA-Approved Portable Oxygen Concentrators; Technical Amendment

Science.gov (United States)

2012-01-27

... CONTACT: For technical questions concerning this action, contact DK Deaderick, Air Transportation Division...; telephone: (202) 267-7480; email: DK[email protected] . For legal questions concerning this action, contact....gov . SUPPLEMENTARY INFORMATION: Background On July 12, 2005, the FAA published SFAR 106, ``Use of...

Index to FAA Office of Aerospace Medicine Reports : 1961 Through 2006

Science.gov (United States)

2007-01-01

An index to Federal Aviation Administration Office of Aerospace Medicine Reports (1964-2006) and Civil : Aeromedical Institute Reports (1961-1963) is presented for those engaged in aviation medicine and related : activities. The index lists all FAA a...

Index to FAA Office of Aerospace Medicine reports : 1961 through 2002.

Science.gov (United States)

2003-01-01

An index to Federal Aviation Administration Office of Aerospace Medicine Reports (1964-2002) : and Civil Aeromedical Institute Reports (1961-1963) is presented for those engaged in aviation : medicine and related activities. The index lists all FAA A...

Index to FAA Office of Aviation Medicine reports : 1961 through 1998.

Science.gov (United States)

1999-01-01

An index to Office of Aviation Medicine Reports (1964-1998) and Civil Aeromedical Research Institute Reports is presented for those engaged in aviation medicine and related activities. The index lists all FAA aviation medicine reports published from ...

Index to FAA Office of Aerospace Medicine reports : 1961 through 2004.

Science.gov (United States)

2005-01-01

An index to Federal Aviation Administration Office of Aerospace Medicine Reports (1964-2004) and : Civil Aeromedical Institute Reports (1961-1963) is presented for those engaged in aviation medicine and : related activities. The index lists all FAA a...

Index to FAA Office of Aviation Medicine reports : 1961 through 1999.

Science.gov (United States)

2000-01-01

An index to Federal Aviation Administration Office of Aviation Medicine Reports (1964-1999) and : Civil Aeromedical Institute Reports (1961-1963) is presented for those engaged in aviation medicine : and related activities. The index lists all FAA av...

Index to FAA Office of Aerospace Medicine reports : 1961 through 2008.

Science.gov (United States)

2009-01-01

An index to Federal Aviation Administration Office of Aerospace Medicine Reports (1964-2008) and Civil : Aeromedical Institute Reports (1961-1963) is presented for those engaged in aviation medicine and related : activities. The index lists all FAA a...

Aeromedical Hazard Comparison of FAA Medically Certified Third-Class and Medically Uncertified Pilots.

Science.gov (United States)

Ricaurte, Eduard M; Mills, William D; DeJohn, Charles A; Laverde-Lopez, Maria C; Porras-Sanchez, Daniel F

2016-07-01

Since 2004, in the United States, light sport aircraft (LSA) and some aircraft with standard airworthiness certificates can be operated for recreational purposes with a valid state driver's license rather than a Federal Aviation Administration (FAA)-issued aeromedical certificate. There have been recent efforts to allow operation of much larger, heavier, faster, and more complex aircraft without requiring a medical certificate. The primary objective of this research was to compare hazards to flight safety identified in fatally injured pilots required to possess a valid FAA third-class medical certificate to hazards in fatally injured pilots who were not required to possess a valid medical certificate. A search of all fatal U.S. aircraft accidents in the FAA Medical ANalysis and TRAcking (MANTRA) registry between January 1, 2011, and April 30, 2014, identified 1084 individuals. A review of accident pilots' medical, autopsy, and toxicological data was conducted. After applying exclusion criteria, 467 pilots remained, including 403 medically certified and 64 medically uncertified pilots. A significant difference was found in a surrogate measure for risk between medically certified and uncertified pilots (25% vs. 59%). This difference remained significant after adjustment for age. No significant difference was found in the proportions of hazards identified on toxicological review. The results of this study suggest that the risk of an adverse medical event is reduced in pilots required to possess a valid medical certificate. Ricaurte EM, Mills WD, DeJohn CA, Laverde-Lopez MC, Porras-Sanchez DF. Aeromedical hazard comparison of FAA medically certified third-class and medically uncertified pilots. Aerosp Med Hum Perform. 2016; 87(7):618-621.

NextGen Technologies on the FAA's Standard Terminal Automation Replacement System

Science.gov (United States)

Witzberger, Kevin; Swenson, Harry; Martin, Lynne; Lin, Melody; Cheng, Jinn-Hwei

2014-01-01

This paper describes the integration, evaluation, and results from a high-fidelity human-in-the-loop (HITL) simulation of key NASA Air Traffic Management Technology Demonstration - 1 (ATD- 1) technologies implemented in an enhanced version of the FAA's Standard Terminal Automation Replacement System (STARS) platform. These ATD-1 technologies include: (1) a NASA enhanced version of the FAA's Time-Based Flow Management, (2) a NASA ground-based automation technology known as controller-managed spacing (CMS), and (3) a NASA advanced avionics airborne technology known as flight-deck interval management (FIM). These ATD-1 technologies have been extensively tested in large-scale HITL simulations using general-purpose workstations to study air transportation technologies. These general purpose workstations perform multiple functions and are collectively referred to as the Multi-Aircraft Control System (MACS). Researchers at NASA Ames Research Center and Raytheon collaborated to augment the STARS platform by including CMS and FIM advisory tools to validate the feasibility of integrating these automation enhancements into the current FAA automation infrastructure. NASA Ames acquired three STARS terminal controller workstations, and then integrated the ATD-1 technologies. HITL simulations were conducted to evaluate the ATD-1 technologies when using the STARS platform. These results were compared with the results obtained when the ATD-1 technologies were tested in the MACS environment. Results collected from the numerical data show acceptably minor differences, and, together with the subjective controller questionnaires showing a trend towards preferring STARS, validate the ATD-1/STARS integration.

Index to FAA Office of Aviation Medicine reports : 1961 through 1996.

Science.gov (United States)

1997-01-01

An index to Office of Aviation Medicine Reports (1964-1996) and Civil Aeromedical Research Institute Reports is presented as a reference for those engaged in aviation medicine and related activities. The index lists all FAA aviation medicine reports ...

Index to FAA Office of Aviation Medicine reports : 1961 through 1993.

Science.gov (United States)

1994-01-01

An index to Office of Aviation Medicine Reports (1964-1993) and Civil Aeromedical Research Institute Reports is presented as a reference for those engaged in aviation medicine and related activities. It lists all FAA aviation medicine reports publish...

Index to FAA Office of Aviation Medicine reports : 1961 through 1991.

Science.gov (United States)

1992-01-01

An index to Office of Aviation Medicine Reports (1964-1991) and Civil Aeromedical Research Institute Reports (1961-1963) is presented as a reference for those engaged in aviation medicine and related activities. It lists all FAA aviation medicine rep...

14 CFR 11.101 - May I ask FAA to reconsider my petition for rulemaking or petition for exemption if it is denied?

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false May I ask FAA to reconsider my petition for... Rulemaking Procedures Petitions for Rulemaking and for Exemption § 11.101 May I ask FAA to reconsider my petition for rulemaking or petition for exemption if it is denied? Yes, you may petition FAA to reconsider...

41 CFR 102-75.420 - What happens if the FAA informs the disposal agency that it does not recommend disposal of the...

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What happens if the FAA... Real Property Disposal Property for Public Airports § 102-75.420 What happens if the FAA informs the... property that the FAA does not recommend for disposal as a public airport must be disposed of in accordance...

Proposal to FAA for the "Global Analysis and Information Network" ca 1996

Data.gov (United States)

National Aeronautics and Space Administration — Response to the FAA request for comments on zero accidents. The responses propose estimating the age-specific field reliability of all aircraft service parts, not...

Aviation Acquisition: A Comprehensive Strategy Is Needed for Cultural Change at FAA

Science.gov (United States)

1996-08-22

The Federal Aviation Administration's (FAA) timely acquisition of new air : traffic control equipment has become increasingly critical for aviation safety : and efficiency. However, persistent acquisition problems raise questions about : the agency's...

Index to FAA Office of Aviation Medicine reports : 1961 through 1997.

Science.gov (United States)

1998-01-01

An index to Office of Aviation Medicine Reports (1964-1971) and is presented as a quick reference for those engaged in aviation medicine and related activities. It provides a listing of all FAA aviation medicine reports published from 1961 through 19...

Index to FAA Office of Aviation Medicine reports : 1961 through 1978.

Science.gov (United States)

1979-01-01

An index to Office of Aviation Medicine Reports (1964-1978) and Civil Aeromedical Research Institute Reports (1961-1963) is presented as a reference for those engaged in aviation medicine and related activities. It provides a listing of all FAA aviat...

Index to FAA Office of Aviation Medicine reports : 1961 through 1980.

Science.gov (United States)

1981-01-01

An index to Office of Aviation Medicine Reports (1964-1978) and Civil Aeromedical Research Institute Reports (1961-1963) is presented as a reference for those engaged in aviation medicine and related activities. It provides a listing of all FAA aviat...

Index to FAA Office of Aviation Medicine reports : 1961 through 1986.

Science.gov (United States)

1987-01-01

An index to Office of Aviation Medicine Reports (1964-1982) and Civil Aeromedical Research Institute Reports (1961-1963) is presented as a reference for those engaged in aviation medicine and related activities. It provides a listing of all FAA aviat...

Index to FAA Office of Aviation Medicine reports : 1961 through 1971.

Science.gov (United States)

1972-03-01

An index to Office of Aviation Medicine Reports (1964-1971) and Civil Aeromedical Research Institute Reports (1961-1963) is presented as a quick reference for those engaged in aviation medicine and related activities. It provides a listing of all FAA...

Index to FAA Office of Aviation Medicine reports : 1961 through 1976.

Science.gov (United States)

1977-01-01

An index to Office of Aviation Medicine Reports (1964-1971) and is presented as a quick reference for those engaged in aviation medicine and related activities. It provides a listing of all FAA aviation medicine reports published from 1961 through 19...

Index to FAA Office of Aviation Medicine reports : 1961 through 1982.

Science.gov (United States)

1983-01-01

An index to Office of Aviation Medicine Reports (1964-1982) and Civil Aeromedical Research Institute Reports (1961-1963) is presented as a reference for those engaged in aviation medicine and related activities. It provides a listing of all FAA aviat...

Index to FAA Office of Aerospace Medicine reports : 1961 through 2012.

Science.gov (United States)

2013-01-01

An index to Office of Aviation Medicine Reports (1964-1971) and Civil Aeromedical Research Institute Reports (1961-1963) is presented as a quick reference for those engaged in aviation medicine and related activities. It provides a listing of all FAA...

Elemental analysis of some Egyptian medicinal plants using INAA and FAAS techniques

International Nuclear Information System (INIS)

Walley El-Dine, N.; Sroor, A.; Hammed, S.S.; El-Shershaby, A.; Alsamed, M.A

2009-01-01

Thirteen Egyptian medicinal plants used for the treatment and cure of various diseases have been elementally analyzed by instrumental neutron activation analysis (INAA) and flame atomic absorption spectrometry (FAAS). The pneumatic rabbit transfer system (PRTS)of 100 kw Budapest research reactor (BRR) was used , for short time irradiation, 300 s, with a thermal neutron flux of 2.4 * 10 12 n/(cm 2 .s). Long time irradiation, 4 hours, was performed at the second research Egyptian reactor (Et-Rr-2) with thermal neutron flux of 5.6 * 10 13 n/(cm 2 .s).Gamma ray spectra were measured by a HPGe detection system . The concentrations of fifteen elements namely Sc,Cr,Fe,Co ,Zn,Rb ,Mo,Sb,La,Ce,Nd, Sm, Yb, Hf and Pa have been determined by long irradiation time and some of them were determined also by FAAS technique. Fourteen elements Na,Mg,Al ,Cd,Cl,K,Ca,Ti,V,Mn ,Ni, Sr,Pb,and Cu, have been identified by short irradiation time and FAAS technique. The precision and accuracy of the method were evaluated using the standard reference material NIST SRM-1571. Comparison of the data obtained give agreement between the concentration of elements determined by the two techniques. The importance of these elements related to human health and nutrition has been discussed

Aplicação de métodos de dimensionamento de pavimentos aeroportuários da FAA ao Aeroporto Internacional Presidente Juscelino Kubitschek

Directory of Open Access Journals (Sweden)

Bernardo Antonio Silva Ramos

2017-12-01

Full Text Available This article addresses the design of the flexible pavement runway 11R/29L of the Inter­national Airport Presidente Juscelino Kubitschek using the design procedures of the Federal Aviation Administration (FAA published at the AC 150/5320-6D, in 1995, and at the AC 150/5320-6E, in 2009, considering the original design air traffic and that up­dated to the year 2013. It was possible to observe the sensibility of the FAA 2009 pro­cedure in resulting on structures more reliable for the solicitations of the air traffic considered. Based on the results obtained, it was possible to observe: (i the design thickness obtained with the use of the FAA 2009 procedure, for the same design air traffic, resulted is 10 cm lower than that determined with the use of FAA 1995 proce­dure; (ii the design thickness determined using the FAA 1995 procedure, and the cur­rent air traffic was 2.5 cm higher than that determined using the original design air traffic; and (iii for the current air traffic, the design thickness determined using the FAA 2009 procedure was 21.5 cm lower than that obtained with the use of the FAA 1995 procedure.

Two studies on participation in decision-making and equity among FAA personnel.

Science.gov (United States)

1991-07-01

Study 1 Moderated multiple regression analyses on data collected from 2,177 FAA air traffic controller specialists indicated that equity perceptions moderated the relationship between participation in decision-making and level of job satisfaction. Sp...

National airspace system : FAA reauthorization issues are critical to system transformation and operations statement of Gerald L. Dillingham, Ph.D.

Science.gov (United States)

2009-02-01

As requested, this statement discusses issues for the reauthorization of the Federal Aviation Administration (FAA). The aviation industry is in a period of economic turmoil and faces an : uncertain future. At the same time, FAA is undertaking one of ...

Mejoramiento de los límites de detección del análisis por inyección en flujo en espectrofotometría de absorción atómica con llama, mediante promediado conjunto de la señal analítica.

OpenAIRE

Montoya, Eduardo; Torres, Blanca

2002-01-01

El presente trabajo describe un sistema simple que permite al análisis por espectrofotometría de absorción atómica con llama (FAAS) mediante FIA, la conocida técnica de promediado conjunto de la señal analítica con la finalidad de incrementar la relación señal / ruido, mejorando los límites de detección obtenibles en un laboratorio con equipamiento corriente.

Report on FAA Deicing Program at La Guardia and O'Hare Airports

Science.gov (United States)

1996-10-02

The Office of Inspector General, Department of Transportation; conducted a : followup inspection of the Federal Aviation Administration (FAA) Deicing : Program. We initiated this study to observe deicing operations as a followup to : our report on th...

14 CFR 11.33 - How can I track FAA's rulemaking activities?

Science.gov (United States)

2010-01-01

... search the Federal Docket Management System (FDMS) for information on most rulemaking proceedings. You... rulemaking document proceeding. Each rulemaking document FAA issues in a particular rulemaking proceeding, as....regulations.gov. If you can't find the material in the electronic docket, contact the person listed under FOR...

INFORMATION SECURITYy: Serious Weaknesses Put State Department and FAA Operations at Risk

National Research Council Canada - National Science Library

Dodaro, Gene

1998-01-01

We are pleased to be asked to discuss our work in computer security. As requested, our testimony will focus on the results of our recent reviews of the Department of State and the Federal Aviation Administration (FAA...

FAA computer security : concerns remain due to personnel and other continuing weaknesses

Science.gov (United States)

2000-08-01

FAA has a history of computer security weaknesses in a number of areas, including its physical security management at facilities that house air traffic control (ATC) systems, systems security for both operational and future systems, management struct...

Caracterização anatômica, histoquímica e de classes de metabólitos secundários de folhas de Guzmania lingulata (L. Mez.

Directory of Open Access Journals (Sweden)

E.M. Belotto

2014-03-01

Full Text Available Na medicina natural pouco se sabe sobre a importância curativa da maior parte das espécies pertencentes à Bromeliaceae. Tal fato evidencia a necessidade da realização de investigações para a comprovação de possíveis potenciais fitoterápicos em espécies dessa família. Guzmania lingulata é caracterizada como sendo uma das espécies de bromélia mais comercializada e conhecida popularmente, a qual é amplamente propagada no Brasil. O presente trabalho objetivou a caracterização anatômica e a identificação de classes de metabólitos secundários presentes em G. lingulata, por meio de análises anatômicas, histoquímicas e químicas. As folhas foram fixadas em FAA 50 e transferidas para etanol 50%. Para o estudo anatômico, secções transversais da porção mediana das lâminas foliares foram obtidas à mão livre e submetidas ao processo de dupla coloração com safranina e azul de astra, sendo, logo após, montadas em gelatina glicerinada. Para a triagem das classes de metabólitos secundários foram coletadas 10 folhas frescas que passaram pelo processo de maceração em solução hidroalcoólica 70% por sete dias, à temperatura ambiente. O filtrado resultante da filtração a vácuo foi evaporado sob vácuo a temperatura de 50ºC até a remoção total do etanol, sendo obtido desta forma o extrato bruto hidroalcoólico a frio (EBHF. Os resultados das secções histológicas permitiram a caracterização anatômico-foliar baseada na qualidade das secções manuais obtidas. Os testes em relação às classes de metabólitos secundários revelaram a presença de antocianinas e taninos e ausência de flavonóides e saponinas. Esses resultados estimulam a realização de estudos mais aprofundados para identificar e quantificar os compostos dessas e de outras classes de metabólitos.

Fuel storage tanks at FAA facilities : Order 1050.15A : executive summary.

Science.gov (United States)

1997-04-30

The Federal Aviation Administration (FAA) has over 4,000 fuel storage tanks (FST) in its inventory. Most of these FSTs are underground storage tanks (UST) that contain fuel for emergency backup generators providing secondary power to air navigational...

The Consequences of the FAA not Offering Emergency Agricultural UAS Rules for Water Conservation During the 2012 Drought

Science.gov (United States)

Darling, R. G.

2016-12-01

The FAA's policies for agricultural Unmanned Aerial Systems (UAS) is essential towards preservation and optimization of water use in the parched Western United States. Had FAA applied emergency rules putting farmers on equal-footing with hobbyists for sUAS use at the beginning of the 2012 drought, the Western US could have been able to save approximately 3 Million/AF of water through improved irrigation management. For perspective, Los Angeles city's annual current consumption is 587,000 acre-feet. This study uses various assumptions about developed water use in agriculture and urban areas to determine water use, energy consumption, monetary loss through delay in FAA regulations. If the saved water was added to the ground the energy savings could have been approximately 1.27 Terra-Watt hours, enough energy to power the entire University of California system for 5 years. It remains unclear if new FAA regulations are sufficiently permissive to allow for widespread adoption of sUAS based precision agriculture. Substantial opportunities exist for utilizing UAS traffic management software in rural areas of less crowed airspace: incorporating geofencing and a notification system to operators and air traffic control as an alternative to a difficult examination process.

Rapid and sensitive ultrasonic-assisted derivatisation microextraction (UDME) technique for bitter taste-free amino acids (FAA) study by HPLC-FLD.

Science.gov (United States)

Chen, Guang; Li, Jun; Sun, Zhiwei; Zhang, Shijuan; Li, Guoliang; Song, Cuihua; Suo, Yourui; You, Jinmao

2014-01-15

Amino acids, as the main contributors to taste, are usually found in relatively high levels in bitter foods. In this work, we focused on seeking a rapid, sensitive and simple method to determine FAA for large batches of micro-samples and to explore the relationship between FAA and bitterness. Overall condition optimisation indicated that the new UDME technique offered higher derivatisation yields and extraction efficiencies than traditional methods. Only 35min was needed in the whole operation process. Very low LLOQ (Lower limit of quantification: 0.21-5.43nmol/L) for FAA in twelve bitter foods was obtained, with which BTT (bitter taste thresholds) and CABT (content of FAA at BTT level) were newly determined. The ratio of CABT to BTT increased with decreasing of BTT. This work provided powerful potential for the high-throughput trace analysis of micro-sample and also a methodology to study the relationship between the chemical constituents and the taste. Copyright © 2013 Elsevier Ltd. All rights reserved.

Growth of highly textured SnS on mica using an SnSe buffer layer

International Nuclear Information System (INIS)

Wang, S.F.; Fong, W.K.; Wang, W.; Surya, C.

2014-01-01

We report the growth of SnS thin films on mica substrates by molecular beam epitaxy. Excellent 2D layered structure and strong (001) texture were observed with a record low rocking curve full width at half maximum of ∼ 0.101° for the SnS(004) diffraction. An interface model is used to investigate the nucleation of SnS on mica which indicates the co-existence of six pairs of lateral growth orientations and is in excellent agreement with the experimental Φ-scan measurements indicating 12 peaks separated by 30° from each other. To control the lateral growth of the SnS epilayers we investigate the utilization of a thin SnSe buffer layer deposited on the mica substrate prior to the growth of the SnS thin film. The excellent lattice match between SnSe and mica enhances the alignment of the nucleation of SnS and suppresses the minor lateral orientations along the mica[110] direction and its orthogonal axis. Detailed low-frequency noise measurement was performed to characterize the trap density in the films and our results clearly demonstrate substantial reduction in the density of the localized states in the SnS epilayer with the use of an SnSe buffer layer. - Highlights: • A record low rocking curve FWHM for deposited SnS on mica • Investigation of the nucleation of SnS on mica using the interface model • Investigation of nucleation mechanism by phi-scan measurement • Grain boundary formation from crystallites of various nucleation orientations • Suppression of nucleation orientations using an SnSe buffer layer

Zirconia toughened mica glass ceramics for dental restorations.

Science.gov (United States)

Gali, Sivaranjani; K, Ravikumar; Murthy, B V S; Basu, Bikramjit

2018-03-01

The objective of the present study is to understand the role of yttria stabilized zirconia (YSZ) in achieving the desired spectrum of clinically relevant mechanical properties (hardness, elastic modulus, fracture toughness and brittleness index) and chemical solubility of mica glass ceramics. The glass-zirconia mixtures with varying amounts of YSZ (0, 5, 10, 15 and 20wt.%) were ball milled, compacted and sintered to obtain pellets of glass ceramic-YSZ composites. Phase analysis was carried out using X-ray diffraction and microstructural characterization with SEM revealed the crystal morphology of the composites. Mechanical properties such as Vickers hardness, elastic modulus, indentation fracture toughness and chemical solubility were assessed. Phase analysis of sintered pellets of glass ceramic-YSZ composites revealed the characteristic peaks of fluorophlogopite (FPP) and tetragonal zirconia. Microstructural investigation showed plate and lath-like interlocking mica crystals with embedded zirconia. Vickers hardness of 9.2GPa, elastic modulus of 125GPa, indentation toughness of 3.6MPa·m 1/2 , and chemical solubility of 30μg/cm 2 (well below the permissible limit) were recorded with mica glass ceramics containing 20wt.% YSZ. An increase in hardness and toughness of the glass ceramic-YSZ composites with no compromise on their brittleness index and chemical solubility has been observed. Such spectrum of properties can be utilised for developing a machinable ceramic for low stress bearing inlays, onlays and veneers. Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

FAA's Implementation of the Commercial Space Launch Amendments Act of 2004- The Experimental Permit

Science.gov (United States)

Repcheck, J. Randall

2005-12-01

A number of entrepreneurs are committed to the goal of developing and operating reusable launch vehicles for private human space travel. In order to promote this emerging industry, and to create a clear legal, regulatory, and safety regime, the United States (U.S.) Congress passed the Commercial Space Launch Amendments Act of 2004 (CSLAA). Signed on December 23, 2004 by U.S. President George W. Bush, the CSLAA makes the Federal Aviation Administration (FAA) responsible for regulating human spaceflight. The CSLAA, among other things, establishes an experimental permit regime for developmental reusable suborbital rockets. This paper describes the FAA's approach in developing guidelines for obtaining and maintaining an experimental permit, and describes the core safety elements of those guidelines.

Air Traffic Control: Status of FAA's Implementation of the Display System Replacement Project

National Research Council Canada - National Science Library

1999-01-01

...) implementation of the Display System Replacement (DSR) project. DSR, which replaces the controllers' workstations and other equipment in the nation's en route centers, is one of FAA's major projects under the air traffic control modernization program...

41 CFR 102-37.535 - What information must FAA provide to GSA on its administration of the public airport donation...

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What information must FAA provide to GSA on its administration of the public airport donation program? 102-37.535 Section... Donations to Public Airports § 102-37.535 What information must FAA provide to GSA on its administration of...

Variable pathogenicity of exon 43del (FAA) in four Fanconi anaemia patients within a consanguineous family.

Science.gov (United States)

Koc, A; Pronk, J C; Alikasifoglu, M; Joenje, H; Altay, C

1999-01-01

Four Fanconi anaemia group A (FAA) patients within two related consanguineous families are presented: the propositus (male, 13 years, transplanted at age 10), and his three cousins (one male, 8 years, and two female newborns). Assignment of the patients to FAA was based on the functional complementation analysis by somatic cell hybridization and confirmed by mutation screening showing a homozygous deletion of exon 43 (4267-4404del) in the FAA gene to be present in all four patients. The newborn patients had been diagnosed prenatally by DNA analysis. In spite of identical molecular pathology and close familial relationship the clinical phenotypes of the four patients were not concordant. Discordant symptoms included birthweight, pigmentation abnormalities, skeletal, renal and genital abnormalities, whereas microcephaly and possibly the haematological course were concordant. Differences in environmental conditions and/or genetic make-up along with chance effects during development may explain discordant phenotypes despite identical molecular pathology in these patients. However, our results do not rule out the possibility that the exon 43del mutation may have prognostic value for the haematological course of the disease.

Mica fission detectors

International Nuclear Information System (INIS)

Wong, C.; Anderson, J.D.; Hansen, L.; Lehn, A.V.; Williamson, M.A.

1977-01-01

The present development status of the mica fission detectors is summarized. It is concluded that the techniques have been refined and developed to a state such that the mica fission counters are a reliable and reproducible detector for fission events

The effect of acetylcholine, LatA and FAA on phloem assimilates translocation of Raphanus sativus L

International Nuclear Information System (INIS)

Yang Chongjun; Zhang Ping

2005-01-01

The petiole phloem of Raphanus sativus L. is treated with the medicaments of acetylcholine (Ach, the expansionist material of protoplasm), latrunculin A (LatA, the dissolubility of microfilament) and FAA (the regularization of phloem). The effects of treatments are measured by the accumulated content of dissoluble sugar and starch in the leaves, and 14 C-labelled assimilates. The regulating role of three medicaments on the translocation of assimilates in the phloem of Raphanus sativus L are investigated. The results indicate that low Ach improves assimilates translocation while LatA and FAA inhibit it in petiole phloem of Raphanus sativus L.. (authors)

Biotermodin?mica en animales

OpenAIRE

Granados Moreno, Jairo Enrique

2014-01-01

El documento presenta como la termodin?mica es la ciencia que estudia las relaciones entre calor y las dem?s formas de transferencias de energ?a. Se explica que toda transformaci?n biofisicoqu?mica implica, generalmente, un cambio energ?tico. Se tratan los conceptos de temperatura, escalas de temperatura, calor, calor de combusti?n, postulados de la termodin?mica, entrop?a y energ?a libre metab?lica

Proceedings of the FAA-NASA Symposium on the Continued Airworthiness of Aircraft Structures. Volume 2

Science.gov (United States)

Bigelow, Catherine A. (Compiler)

1997-01-01

This publication contains the fifty-two technical papers presented at the FAA-NASA Symposium on the Continued Airworthiness of Aircraft Structures. The symposium, hosted by the FAA Center of Excellence for Computational Modeling of Aircraft Structures at Georgia Institute of Technology, was held to disseminate information on recent developments in advanced technologies to extend the life of high-time aircraft and design longer-life aircraft. Affiliations of the participants included 33% from government agencies and laboratories, 19% from academia, and 48% from industry; in all 240 people were in attendance. Technical papers were selected for presentation at the symposium, after a review of extended abstracts received by the Organizing Committee from a general call for papers.

Proceedings of the FAA-NASA Symposium on the Continued Airworthiness of Aircraft Structures. Volume 1

Science.gov (United States)

Bigelow, Catherine A. (Compiler)

1997-01-01

This publication contains the fifty-two technical papers presented at the FAA-NASA Symposium on the Continued Airworthiness of Aircraft Structures. The symposium, hosted by the FAA Center of Excellence for Computational Modeling of Aircraft Structures at Georgia Institute of Technology, was held to disseminate information on recent developments in advanced technologies to extend the life of high-time aircraft and design longer-life aircraft. Affiliations of the participants included 33% from government agencies and laboratories, 19% from academia, and 48% from industry; in all 240 people were in attendance. Technical papers were selected for presentation at the symposium, after a review of extended abstracts received by the Organizing Committee from a general call for papers.

FAA Center of Excellence for Alternative Jet Fuels & Environment : Annual Technical Report : December, 2016 : For the period September 13, 2013 - September 30, 2015

Science.gov (United States)

2015-12-01

This report covers the period between the initial establishment of the FAA Center of Excellence for Alternative Jet Fuels and Environment on September 13, 2013 through September 30, 2015. The Center was established by the authority of FAA solicitatio...

Ninth DOD/NASA/FAA Conference on Fibrous Composites in Structural Design, volume 1

Science.gov (United States)

Soderquist, Joseph R. (Compiler); Neri, Lawrence M. (Compiler); Bohon, Herman L. (Compiler)

1992-01-01

This publication contains the proceedings of the Ninth DOD/NASA/FAA conference on Fibrous Composites in structural Design. Presentations were made in the following areas of composite structural design: perspectives in composites; design methodology; design applications; design criteria; supporting technology; damage tolerance; and manufacturing.

Digital avionics systems - Overview of FAA/NASA/industry-wide briefing

Science.gov (United States)

Larsen, William E.; Carro, Anthony

1986-01-01

The effects of incorporating digital technology into the design of aircraft on the airworthiness criteria and certification procedures for aircraft are investigated. FAA research programs aimed at providing data for the functional assessment of aircraft which use digital systems for avionics and flight control functions are discussed. The need to establish testing, assurance assessment, and configuration management technologies to insure the reliability of digital systems is discussed; consideration is given to design verification, system performance/robustness, and validation technology.

FIA-FAAS method for tannin determination based on a precipitation reaction with hemoglobin

Directory of Open Access Journals (Sweden)

Ferreira Edilene C.

2003-01-01

Full Text Available A flow system, coupled with flame atomic absorption spectrometry (FIA-FAAS, was developed for tannin determination in pigeon pea samples, exploring the precipitation reaction between tannins and proteins. Sample extracts obtained by sonication with a 50% (v/v methanol solution were introduced into the system and induced to react with a hemoglobin solution. The precipitate produced was retained on a filter located in the analytical flow. A reversed flow of 1% (w/v sodium dodecyl sulfate solution was used for solubilization of the precipitate from the filter and to conduct the tannin-hemoglobin complex to the FAAS, to quantify the iron ions present in the hemoglobin structure. A tannic acid solution was used to prepare the analytical curve. The proposed method allowed determination of 30 samples per hour, a standard deviation of 9.7% (n=10, and a quantification limit of 0.27 mg L-1 for tannic acid.

The FAA altitude chamber training flight profile : a survey of altitude reactions, 1965-1989.

Science.gov (United States)

1990-09-01

Reactions from 1,161 trainees out of 12,759 trainees subjected to the FAA altitude chamber training flights from 1965-1989 are annotated in this survey. Although there were some mild and expected reactions, these training profiles appear to provide a...

14 CFR 61.41 - Flight training received from flight instructors not certificated by the FAA.

Science.gov (United States)

2010-01-01

... the FAA. (a) A person may credit flight training toward the requirements of a pilot certificate or... flight instructor described in paragraph (a) of this section is only authorized to give endorsements to...

Field experience with the FAA's Web-based medical certification system "AMCS/DIWS". Federal Aviation Administration.

Science.gov (United States)

Angelici, Arnold A; Mohler, Stanley R

2002-04-01

The October 1, 1999, introduction in the U.S. of a Web-based medical certification process for civil aircrew opened a new era within civil aviation. The Federal Aviation Administration's (FAA) Aeromedical Certification System/Document Imaging Workflow System (AMCS/DIWS) has imposed certain new requirements on the designated Aviation Medical Examiners (AMEs), including the use of Internet systems and procedures. A number of AMEs elected to discontinue their work as the classic medical certification processes were replaced. The authors document their personal experience with respect to the new system, and cite the overall advantages that modernized medical certification procedures bring. These advantages include far fewer "mistakes of omission" by AMEs, more timely receipt by the FAA of aircrew certification data, and a developing master aircrew database for analytic studies.

Comparison study on flexible pavement design using FAA (Federal Aviation Administration) and LCN (Load Classification Number) code in Ahmad Yani international airport’s runway

Science.gov (United States)

Santoso, S. E.; Sulistiono, D.; Mawardi, A. F.

2017-11-01

FAA code for airport design has been broadly used by Indonesian Ministry of Aviation since decades ago. However, there is not much comprehensive study about its relevance and efficiency towards current situation in Indonesia. Therefore, a further comparison study on flexible pavement design for airport runway using comparable method has become essential. The main focus of this study is to compare which method between FAA and LCN that offer the most efficient and effective way in runway pavement planning. The comparative methods in this study mainly use the variety of variable approach. FAA code for instance, will use the approach on the aircraft’s maximum take-off weight and annual departure. Whilst LCN code use the variable of equivalent single wheel load and tire pressure. Based on the variables mentioned above, a further classification and rated method will be used to determine which code is best implemented. According to the analysis, it is clear that FAA method is the most effective way to plan runway design in Indonesia with consecutively total pavement thickness of 127cm and LCN method total pavement thickness of 70cm. Although, FAA total pavement is thicker that LCN its relevance towards sustainable and pristine condition in the future has become an essential aspect to consider in design and planning.

Ninth DOD/NASA/FAA Conference on Fibrous Composites in Structural Design, volume 2

Energy Technology Data Exchange (ETDEWEB)

Soderquist, J.R.; Neri, L.M.; Bohon, H.L.

1992-09-01

This publication contains the proceedings of the Ninth DOD/NASA/FAA Conference on Fibrous Composites in Structural Design held at Lake Tahoe, Nevada, during 4-7 Nov. 1991. Presentations were made in the following areas of composite structural design: perspectives in composites, design methodology, design applications, design criteria, supporting technology, damage tolerance, and manufacturing.

Ninth DOD/NASA/FAA Conference on Fibrous Composites in Structural Design, volume 3

Science.gov (United States)

Soderquist, Joseph R. (Compiler); Neri, Lawrence M. (Compiler); Bohon, Herman L. (Compiler)

1992-01-01

This publication contains the proceedings of the Ninth DOD/NASA/FAA Conference on Fibrous Composites in Structural Design held at Lake Tahoe, Nevada, during 4-7 Nov. 1991. Presentations were made in the following areas of composite structural design: perspectives in composites, design methodology, design applications, design criteria, supporting technology, damage tolerance, and manufacturing.

Ninth DOD/NASA/FAA Conference on Fibrous Composites in Structural Design, volume 2

Science.gov (United States)

Soderquist, Joseph R. (Compiler); Neri, Lawrence M. (Compiler); Bohon, Herman L. (Compiler)

1992-01-01

This publication contains the proceedings of the Ninth DOD/NASA/FAA Conference on Fibrous Composites in Structural Design held at Lake Tahoe, Nevada, during 4-7 Nov. 1991. Presentations were made in the following areas of composite structural design: perspectives in composites, design methodology, design applications, design criteria, supporting technology, damage tolerance, and manufacturing.

The FAA's postmortem forensic toxicology self-evaluated proficiency test program: the second seven years.

Science.gov (United States)

Chaturvedi, Arvind K; Craft, Kristi J; Cardona, Patrick S; Rogers, Paul B; Canfield, Dennis V

2009-05-01

During toxicological evaluations of samples from fatally injured pilots involved in civil aviation accidents, a high degree of quality control/quality assurance (QC/QA) is maintained. Under this philosophy, the Federal Aviation Administration (FAA) started a forensic toxicology proficiency-testing (PT) program in July 1991. In continuation of the first seven years of the PT findings reported earlier, PT findings of the next seven years are summarized herein. Twenty-eight survey samples (12 urine, 9 blood, and 7 tissue homogenate) with/without alcohols/volatiles, drugs, and/or putrefactive amine(s) were submitted to an average of 31 laboratories, of which an average of 25 participants returned their results. Analytes in survey samples were correctly identified and quantitated by a large number of participants, but some false positives of concern were reported. It is anticipated that the FAA's PT program will continue to serve the forensic toxicology community through this important part of the QC/QA for laboratory accreditations.

A microwave inverse Cerenkov Accelerator (MICA)

International Nuclear Information System (INIS)

Hirshfield, Jay L.

1999-01-01

The objective of this Phase II SBIR research program was to complete the final design originated during Phase I for a prototype Microwave Inverse Cerenkov Accelerator (MICA), to fabricate the-prototype MICA, and to test its performance as an electron accelerator. This report contains details of the design, predictions of accelerator performance, results of cold tests on the MICA structure, and details of the installation of MICA on the Yale Beam Physics Laboratory 6-MeV beamline. Discussion of future work is also included

Ninth DOD/NASA/FAA Conference on Fibrous Composites in Structural Design, volume 1

Energy Technology Data Exchange (ETDEWEB)

Soderquist, J.R.; Neri, L.M.; Bohon, H.L.

1992-09-01

This publication contains the proceedings of the Ninth DOD/NASA/FAA conference on Fibrous Composites in structural Design. Presentations were made in the following areas of composite structural design: perspectives in composites; design methodology; design applications; design criteria; supporting technology; damage tolerance; and manufacturing. Separate abstracts have been indexed into the database for articles from this report.

Enhanced FAA-hybrid III numerical dummy model in Madymo for aircraft occupant safety assessment

NARCIS (Netherlands)

Boucher, H.; Waagmeester, C.D.

2003-01-01

To improve survivability and to minimize the risk of injury to occupants in helicopter crash events, a complete Cabin Safety System concept including safety features and an enhanced FAA-Hybrid III dummy were developed within the HeliSafe project. A numerical tool was also created and validated to

Air traffic control : FAA enhanced the controller-in-charge program, but more comprehensive evaluation is needed

Science.gov (United States)

2001-10-01

In negotiating its 1998 collective bargaining agreement with its controllers' union (the National Air Traffic Controllers Association, or NATCA), the Federal Aviation Administration (FAA) agreed to a national plan that would reduce by attrition the n...

Layer-controlled large area MoS{sub 2} layers grown on mica substrate for surface-enhanced Raman scattering

Energy Technology Data Exchange (ETDEWEB)

Xu, Y.Y.; Yang, C. [College of Physics and Electronics, Shandong Normal University, Jinan 250014 (China); Jiang, S.Z. [College of Physics and Electronics, Shandong Normal University, Jinan 250014 (China); State Key Lab of Crystal Materials Shandong University, Jinan 250100 (China); Man, B.Y., E-mail: byman@sdnu.edu.cn [College of Physics and Electronics, Shandong Normal University, Jinan 250014 (China); Liu, M.; Chen, C.S.; Zhang, C.; Sun, Z.C.; Qiu, H.W. [College of Physics and Electronics, Shandong Normal University, Jinan 250014 (China); Li, H.S. [Department of Radiation Oncology, Key Laboratory of Radiation Oncology of Shandong Province, Shandong Cancer Hospital and Institute, Jinan 250117 (China); Feng, D.J. [College of Information Science and Engineering, Shandong University, Jinan 250100 (China); Zhang, J.X. [College of Physics and Electronics, Shandong Normal University, Jinan 250014 (China)

2015-12-01

Highlights: • Layer-controlled large-area and continuous MoS{sub 2} atomic layers were obtained on mica substrate by thermally decomposing ammonium thiomolybdate at relatively low temperature. • The as-grown MoS{sub 2}/mica substrate was demonstrated to be suitable as a substrate for enhancing Raman signals without any modification and we even collected Raman signals of R6G as low as 10{sup −7} M. • Using the Raman peak of R6G at 1361 cm{sup −1} as a signature, Raman intensity showed an approximately linear increase with the increasing of the logarithm of R6G concentrations. - Abstract: Molybdenum disulfide has recently raised more and more interest due to its layer-related properties and potential applications in optoelectronics and electronics. Here, layer-controlled large-area and continuous MoS{sub 2} atomic layers were obtained on mica substrate by thermally decomposing ammonium thiomolybdate. The obtained MoS{sub 2} film is three layers uniformly. Because of the small lattice mismatch between MoS{sub 2} and mica, the epitaxial MoS{sub 2} film is well grown on the substrate. The as-grown MoS{sub 2}/mica substrate is demonstrated to be suitable as a substrate for enhancing Raman signals of adsorbed molecules without any modification, which even can compare with graphene and will expand the application of MoS{sub 2} to microanalysis.

21 CFR 73.1350 - Mica-based pearlescent pigments.

Science.gov (United States)

2010-04-01

... LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1350 Mica-based pearlescent pigments. (a) Identity. (1) The color additive is formed by depositing titanium and/or iron salts onto mica, followed by...; titanium dioxide and iron oxide on mica. Mica used to manufacture the color additive shall conform in...

21 CFR 73.350 - Mica-based pearlescent pigments.

Science.gov (United States)

2010-04-01

... LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.350 Mica-based pearlescent pigments. (a) Identity. (1) The color additive is formed by depositing titanium salts onto mica, followed by heating to produce titanium dioxide on mica. Mica used to manufacture the color additive shall conform in identity to...

FAA aircraft certification human factors and operations checklist for standalone GPS receivers (TSO C129 Class A)

Science.gov (United States)

1995-04-01

This document is a checklist designed to assist Federal Aviation Administration(FAA) certification personnel and global : positioning system (GPS) receiver manufacturers in the evaluation of the pilot-system interface characteristlcs of GPS : recieve...

Ninth DOD/NASA/FAA Conference on Fibrous Composites in Structural Design, volume 3

Energy Technology Data Exchange (ETDEWEB)

Soderquist, J.R.; Neri, L.M.; Bohon, H.L.

1992-09-01

This publication contains the proceedings of the Ninth DOD/NASA/FAA Conference on Fibrous Composites in Structural Design held at Lake Tahoe, Nevada, during 4-7 Nov. 1991. Presentations were made in the following areas of composite structural design: perspectives in composites, design methodology, design applications, design criteria, supporting technology, damage tolerance, and manufacturing. Separate abstracts have been prepared for articles from this report.

FAA and NASA UTM Research Transition Team: Communications and Navigation (CN) Working Group (WCG) Kickoff Meeting

Science.gov (United States)

Jung, Jaewoo; Larrow, Jarrett

2017-01-01

This is NASA FAA UTM Research Transition Team Communications and Navigation working group kick off meeting presentation that addresses the followings. Objectives overview Overall timeline and scope Outcomes and expectations Communication method and frequency of meetings Upcoming evaluation Next steps.

The FAA/NASA flight loads monitoring program - The prototype system and its benefits for the aviation community

Science.gov (United States)

Whitehead, Julia H.; Thomas, Mitchel E.; Carrelli, David J.; Crabill, Norman L.

1992-01-01

The FAA established the flight load monitoring program to collect a data base of typical flight operational loads experienced by commercial transports. This system will provide a comprehensive monitoring of aircraft loading conditions with over 20 flight parameters being recorded simultaneously. NASA is designing and testing a prototype data collection and analysis system which will be implemented into an FAA operational program. This paper presents the program's objectives and the proposed development testing on a commercial Boeing 737-400. The prototype system, its data processing schemes, and reports are described. The searching criteria or flight attributes generated for each flight are listed. The data processing system will provide the aviation community with a powerful tool for the study of transport flight loading conditions and the system's flexibility will accommodate individual studies and specialized concerns.

MICA: The Meta-Institute for Computational Astrophysics

Science.gov (United States)

McMillan, Stephen L. W.; Djorgovski, S. G.; Hut, P.; Vesperini, E.; Knop, R.; Portegies Zwart, S.

2009-05-01

We describe MICA, the Meta Institute for Computational Astrophysics, the first professional scientific and educational, non-profit organization based in virtual worlds [VWs]. Most MICA activities are currently conducted in Second Life, arguably the most popular and best developed VW; we plan to expand our presence into other VWs as those venues evolve. The goals of MICA include (1) exploration, development and promotion of VWs and virtual reality [VR] technologies for professional research in astronomy and related fields; (2) development of novel networking venues and mechanisms for virtual scientific communication and interaction, including professional meetings, visualization, and telecollaboration; (3) use of VWs and VR technologies for education and public outreach; and (4) exchange of ideas and joint efforts with other scientific disciplines in promoting these goals for science and scholarship in general. We present representative example of MICA activities and achievements, and outline plans for expansion of the organization. For more information on MICA, please visit http://mica-vw.org .

Acute Antibody-Mediated Rejection in Presence of MICA-DSA and Successful Renal Re-Transplant with Negative-MICA Virtual Crossmatch.

Directory of Open Access Journals (Sweden)

Yingzi Ming

Full Text Available The presence of donor-specific alloantibodies (DSAs against the MICA antigen results in high risk for antibody-mediated rejection (AMR of a transplanted kidney, especially in patients receiving a re-transplant. We describe the incidence of acute C4d+ AMR in a patient who had received a first kidney transplant with a zero HLA antigen mismatch. Retrospective analysis of post-transplant T and B cell crossmatches were negative, but a high level of MICA alloantibody was detected in sera collected both before and after transplant. The DSA against the first allograft mismatched MICA*018 was in the recipient. Flow cytometry and cytotoxicity tests with five samples of freshly isolated human umbilical vein endothelial cells demonstrated the alloantibody nature of patient's MICA-DSA. Prior to the second transplant, a MICA virtual crossmatch and T and B cell crossmatches were used to identify a suitable donor. The patient received a second kidney transplant, and allograft was functioning well at one-year follow-up. Our study indicates that MICA virtual crossmatch is important in selection of a kidney donor if the recipient has been sensitized with MICA antigens.

FAA Alleged Waste and Mismanagement of Air Route Traffic Control Centers Critical and Essential Power Systems Project

Science.gov (United States)

1996-10-16

The Office of Inspector General (OIG) reviewed a complaint from Congressman Deal on behalf of a constituent. The constituent alleged waste and mismanagement occurred in the Federal Aviation Administration (FAA) Air Route Traffic Control Centers Criti...

78 FR 63276 - Interim Policy, FAA Review of Solar Energy System Projects on Federally Obligated Airports

Science.gov (United States)

2013-10-23

... the orientation and tilt of the solar energy panels, reflectance, environment, and ocular factors are... energy systems on the airport must attach the SGHAT report, outlining solar panel glare and ocular impact... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Interim Policy, FAA Review of Solar...

Two-mica granites of northeastern Nevada.

Science.gov (United States)

Lee, D.E.; Kistler, R.W.; Friedman, I.; Van Loenen, R. E.

1981-01-01

The field settings are described and analytical data are presented for six two-mica granites from NE Nevada. High delta 18O and 87Sr/86Sr values indicate that all are S-type granite, derived from continental crust. The major element chemistry and accessory mineral contents of these rocks also are characteristic of S-type granites. Chemical, X ray, and other data are presented for the micas recovered from these granites. The muscovites are notably high in Fe2O3, FeO, and MgO. Except for one hydrobiotite, each of the biotites has an MgO content near 6.0 wt%. Two different types of two-mica granites are recognized in the area of this study. One type is distinguished by the presence of many biotite euhedra within muscovite phenocrysts and by an unusual suite of accessory minerals completely devoid of opaque oxides. This type probably resulted from anatexis of late Precambrian argillites under conditions of relatively low oxygen fugacity, along a line that roughly coincides with the westward disappearance of continental basement. In the other textural type of two-mica granite the micas are equigranular and there is a greater variety of accessory minerals. The magmatic evolution of this type also appears to reflect the influence of late Precambrian argillites; there may be age differences between the two types of two-mica granites.-Author

NASA/FAA experiments concerning helicopter IFR airworthiness criteria

Science.gov (United States)

Lebacqz, J. V.

1983-01-01

A sequence of ground and flight simulation experiments was conducted as part of a joint NASA/FAA program to investigate helicopter instrument flight rules (IFR) airworthiness criteria. The first six of these experiments are described and the results summarized. Five of the experiments were conducted on large amplitude motion base simulators; V/STOLAND UH-1H variable stability helicopter was used in the flight experiment. Airworthiness implications of selected variables that were investigated across all of the experiments are discussed, including the level of longitudinal static stability, the type of stability and control augmentation, the addition of flight director displays, and the type of instrument approach task. Among the specific results reviewed are the adequacy of neutral longitudinal statics for dual pilot approaches and the requirement for pitch and roll attitude stabilization in the stability and control augmentation system to achieve flying qualities evaluated as satisfactory.

La coyuntura económica nacional

Directory of Open Access Journals (Sweden)

Arturo Huerta González

2003-01-01

Full Text Available El objetivo de este artículo es analizar los problemas de contracción económica que enfrenta nuestro país como resultado de la política económica predominante, que lo ha llevado a depender de la economía estadounidense. Cuando ésta enfrentó problemas de crecimiento también frenó el crecimiento de la economía nacional. El gobierno mexicano no instrumenta política fiscal anticíclica (expansión del gasto para contrarrestar la caída de exportaciones y recuperar la dinámica económica por considerar que ello originaría presiones sobre precios y el sector externo y pudiera llevar a un contexto de especulación y crisis. Es por esto que se opta por seguir priorizando políticas contraccionistas para evitar la inflación, como si éste fuese el principal problema del país. Asimismo, el gobierno insiste en las reformas estructurales (apertura eléctrica, petrolera, reforma fiscal y laboral para ampliar la esfera de influencia del sector privado nacional y extranjero y para consolidar el saneamiento fiscal y abaratar el costo de la fuerza de trabajo, impulsando así la dinámica económica. Sin embargo, tales reformas ya las hemos vivido —desde el gobierno de Salinas de Gortari a la fecha— y sus resultados han sido crecimientos espurios que han desembocado en crisis y en el actual estancamiento. Mientras prosiga la actual política económica seguirá deteriorándose la esfera productiva y aumentando el desempleo, sin que se logre un crecimiento sostenido y menos vulnerable de la economía

QUÍMICA VERDE: UN NUEVO RETO

Directory of Open Access Journals (Sweden)

Nerlis Paola Pájaro Castro

2011-01-01

Full Text Available En la actualidad, existe un enorme deterioro del medio ambiente que ha generado la necesidad de buscar alternativas que conduzcan a la sostenibilidad ambiental. Una de estas herramientas es la ¿química verde¿, concepto que contempla el diseño de productos y procesos que reduzcan la generación de sustancias peligrosas y maximicen la eficiencia en la utilización de recursos materiales y energéticos. El empleo de tecnologías menos contaminantes, permitirá a las empresas químicas mitigar los efectos ambientales asociados a su actividad, reduciendo el consumo de materiales e incrementando la participación de recursos renovables. Para alcanzar estas metas, se han propuesto 12 principios básicos de química verde, aplicables en diferentes campos, tales como la medicina, la agricultura, la industria química y farmacéutica. Esta revisión detalla los principios y usos principales de la química verde, y su aplicación como una filosofía de trabajo para avanzar hacia un verdadero desarrollo sostenible.

MICA: Multiple interval-based curve alignment

Science.gov (United States)

Mann, Martin; Kahle, Hans-Peter; Beck, Matthias; Bender, Bela Johannes; Spiecker, Heinrich; Backofen, Rolf

2018-01-01

MICA enables the automatic synchronization of discrete data curves. To this end, characteristic points of the curves' shapes are identified. These landmarks are used within a heuristic curve registration approach to align profile pairs by mapping similar characteristics onto each other. In combination with a progressive alignment scheme, this enables the computation of multiple curve alignments. Multiple curve alignments are needed to derive meaningful representative consensus data of measured time or data series. MICA was already successfully applied to generate representative profiles of tree growth data based on intra-annual wood density profiles or cell formation data. The MICA package provides a command-line and graphical user interface. The R interface enables the direct embedding of multiple curve alignment computation into larger analyses pipelines. Source code, binaries and documentation are freely available at https://github.com/BackofenLab/MICA

Paragenesis of Cr-rich muscovite and chlorite in green-mica ...

Indian Academy of Sciences (India)

peculiar green colour is attributed to the concen- tration of .... mica quartzite, 1g: white mica (paucity of green mica) with ..... lacking in the white micas. 6.2 Chlorites. Chlorites are associated with green micas in the. Palasgaon–Saigaon area. EPMA analysis of the representative chlorites has been obtained. Cations.

Algoritmos para genómica comparativa

OpenAIRE

Figueiras, Vasco da Rocha

2010-01-01

Com o surgimento da Genómica e da Proteómica, a Bioinformática conduziu a alguns dos avanços científicos mais relevantes do século XX. A Unidade de Investigação e Desenvolvimento do Biocant, parque biotecnológico de Cantanhede, assume actualmente o papel de motor no desenvolvimento da Genómica. O Biocant possui um importante sequenciador de larga escala que permite armazenar um elevado número de genomas, nomeadamente, genomas de bactérias. O estudo proposto reflecte a necessidade do Bio...

Differences between tethered polyelectrolyte chains adsorbed onto bare mica and hydrophobically modified mica, comparison with theory.

Science.gov (United States)

Balastre, Marc; Tamashiro, Mario N.; Hernandez, Ernesto; Pincus, Philip; Tirrell, Matthew

2001-03-01

End-grafted polymers generated from the adsorption of asymmetric diblock copolymers on solid surface play an important role in many areas of science and technology. While the small insoluble block acts as an anchor, the charged soluble block confers useful properties to the surface. This study looks at tethered layers of poly(styrene sulfonate)/poly(t-butyl styrene) (PtBS-PSS) adsorbed on both mica (hydrophilic) and octadecyltriethoxysilane (OTE) modified mica (hydrophobic). Normal compressing forces at two different constant grafting densities (bare and modified mica) were measured with the surface force apparatus and compared with theoretical prediction. The effect of salt concentration (Cs) upon the thickness of the self-assembled layers (Lo) was measured in each case. For adsorption of diblock copolymers onto OTE the resulting scaling relationship is much closer to the brush theory, Lo Cs-1/3. This result suggests that the adsorbed amount on mica is not high enough to form a brush.

14 CFR 11.35 - Does FAA include sensitive security information and proprietary information in the Federal Docket...

Science.gov (United States)

2010-01-01

... RULEMAKING PROCEDURES Rulemaking Procedures General § 11.35 Does FAA include sensitive security information and proprietary information in the Federal Docket Management System (FDMS)? (a) Sensitive security information. You should not submit sensitive security information to the rulemaking docket, unless you are...

Morphology and photoresponse of crystalline antimony film grown on mica by physical vapor deposition

Directory of Open Access Journals (Sweden)

Shafa Muhammad

2016-09-01

Full Text Available Antimony is a promising material for the fabrication of photodetectors. This study deals with the growth of a photosensitive thin film by the physical vapor deposition (PVD of antimony onto mica surface in a furnace tube. The geometry of the grown structures was studied via scanning electron microscopy (SEM, X-ray diffraction (XRD, energy-dispersive X-ray spectroscopy (EDX and elemental diffraction analysis. XRD peaks of the antimony film grown on mica mostly matched with JCPDF Card. The formation of rhombohedral crystal structures in the film was further confirmed by SEM micrographs and chemical composition analysis. The Hall measurements revealed good electrical conductivity of the film with bulk carrier concentration of the order of 1022 Ω·cm-3 and mobility of 9.034 cm2/Vs. The grown film was successfully tested for radiation detection. The photoresponse of the film was evaluated using its current-voltage characteristics. These investigations revealed that the photosensitivity of the antimony film was 20 times higher than that of crystalline germanium.

Química general II

OpenAIRE

Olba Torrent, Amparo

2018-01-01

El document forma part dels materials docents programats mitjançant l'ajut del Servei de Política Lingüística de la Universitat de València Temes de l'assignatura: Química general II del primer curs del Grau de Química Topics of the course: General Chemistry II in the first year of the Degree in Chemistry

La enseñanza de la química desde la perspectiva de la Química Verde

Directory of Open Access Journals (Sweden)

Pía José González García

2016-06-01

Full Text Available La Química Verde, como área de investigación, se comprende como el desarrollo de metodologías para modificar los productos o procesos con la finalidad de reducir o eliminar los riesgos que existen para el medio ambiente y la salud. De este modo, permite proyectar líneas de investigación en la construcción de un conocimiento y enfoques didácticos de las ciencias, y  para ser considerada como parte de los programas Ministeriales. El objetivo del estudio fue conocer y comprender el significado que le otorgan los(as docentes del área a la Química Verde como perspectiva para su enseñanza. A partir de los discursos emanados por los docentes participantes del estudio, se construyeron 4 categorías, las cuales son: la Química Verde como: contexto para la enseñanza de la química, medio de apropiación significativo del aprendizaje de la química, motivadora de la conciencia ambiental y reflejo de la Institución y su relación con los docentes. The teaching of chemistry from the Green Chemistry perspective Green Chemistry (GC, as a research area, understood as the development of methodologies to modify products or processes in order to reduce or eliminate the risks posed to the environment and human health. Thus it is allowing research project lines in building knowledge and didactic approaches of the sciences, and to be considered as part of the ministerial programs. The objective of this study was to know and understand the significance given by teachers in the area to GC as a perspective for education. From the speeches issued by teachers participating in the study, four categories, was built. GC as: context for teaching chemistry, through significant learning chemistry appropriation, motivating environmental awareness and reflection of the institution and its relationship with teachers.  O ensino de química, na perspectiva da Química verde A Química verde, como área de investigação, é compreendida como o desenvolvimento de

[A peak recognition algorithm designed for chromatographic peaks of transformer oil].

Science.gov (United States)

Ou, Linjun; Cao, Jian

2014-09-01

In the field of the chromatographic peak identification of the transformer oil, the traditional first-order derivative requires slope threshold to achieve peak identification. In terms of its shortcomings of low automation and easy distortion, the first-order derivative method was improved by applying the moving average iterative method and the normalized analysis techniques to identify the peaks. Accurate identification of the chromatographic peaks was realized through using multiple iterations of the moving average of signal curves and square wave curves to determine the optimal value of the normalized peak identification parameters, combined with the absolute peak retention times and peak window. The experimental results show that this algorithm can accurately identify the peaks and is not sensitive to the noise, the chromatographic peak width or the peak shape changes. It has strong adaptability to meet the on-site requirements of online monitoring devices of dissolved gases in transformer oil.

BIOÉTICA Y GENÓMICA BIOÉTICA E GENÔMICA BIOETHICS AND GENOMICS

Directory of Open Access Journals (Sweden)

José Alberto Mainetti

2003-01-01

Full Text Available Los avances científicos en el campo de la genómica abren las puertas a los fantasmas de la humanidad. Por esto, el Proyecto Genoma Humano (PGH ha sido el primer gran proyecto de investigación internacional que ha tenido un subproyecto sobre la problemática ética, legal y social asociada al mismo: Ethical, Legal, and Social Issues (ELSI. Esta preocupación bioética surgió como espacio de dilucidación de las diferentes preocupaciones éticas y sociales que nacían a la par de los avances de la genómica. La genómica, expresada como la clave que revelará el misterio del ser (la lámpara de Aladino o como la herramienta de destrucción ecológica, el determinismo genético, el reduccionismo genético y la eugenesia, es decir, como la caja de Pandora. El PGH posee un incalculable valor para el diagnóstico de nuevas enfermedades, nuevos fármacos y nuevas terapias, pero abre también riesgos y temores que han de ser estudiados y analizados desde una perspectiva más amplia que la científicotécnica, es decir, como una reflexión bioética sobre la genómicaOs avanços científicos no campo da genômica abrem as portas aos fantasmas da humanidade. Por isso, o Projeto Genoma Humano (PGH foi o primeiro grande projeto de pesquisa internacional que teve um subprojeto sobre a problemática ética, legal e social associada ao mesmo. Esta preocupação bioética surgiu como espaço de elucidação das diferentes preocupações éticas e sociais que surgiam ao par dos avanços da genômica. A genômica, expressa como a chave que revelará o mistério do ser ( a lâmpada de Aladim ou como a ferramenta de destruição ecológica, o determinismo gen´tico, o reducionismo genético e a eugenésia, isto é, como a caixa de Pandora. O PGH possui um incalculável valor para o diagnóstico de novas enfermidades, novos fármacos e novas terapias, porém abrem também riscos e temores que devem ser estudados e analisados numa perspectiva mais ampla que a

Solid-phase extraction and separation procedure for trace aluminum in water samples and its determination by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS).

Science.gov (United States)

Ciftci, Harun; Er, Cigdem

2013-03-01

In the present study, a separation/preconcentration procedure for determination of aluminum in water samples has been developed by using a new atomic absorption spectrometer concept with a high-intensity xenon short-arc lamp as continuum radiation source, a high-resolution double-echelle monochromator, and a charge-coupled device array detector. Sample solution pH, sample volume, flow rate of sample solution, volume, and concentration of eluent for solid-phase extraction of Al chelates with 4-[(dicyanomethyl)diazenyl] benzoic acid on polymeric resin (Duolite XAD-761) have been investigated. The adsorbed aluminum on resin was eluted with 5 mL of 2 mol L(-1) HNO(3) and its concentration was determined by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS). Under the optimal conditions, limit of detection obtained with HR-CS FAAS and Line Source FAAS (LS-FAAS) were 0.49 μg L(-1) and 3.91 μg L(-1), respectively. The accuracy of the procedure was confirmed by analyzing certified materials (NIST SRM 1643e, Trace elements in water) and spiked real samples. The developed procedure was successfully applied to water samples.

Atomically flat platinum films grown on synthetic mica

Science.gov (United States)

Tanaka, Hiroyuki; Taniguchi, Masateru

2018-04-01

Atomically flat platinum thin films were heteroepitaxially grown on synthetic fluorophlogopite mica [KMg3(AlSi3O10)F2] by van der Waals epitaxy. Platinum films deposited on a fluorophlogopite mica substrate by inductively coupled plasma-assisted sputtering with oxygen introduction on a synthetic mica substrate resulted in the growth of twin single-crystalline epitaxial Pt(111) films.

Malvaceae endémicas del Perú

Directory of Open Access Journals (Sweden)

Magda Chanco

2013-10-01

Full Text Available La familia Malvaceae es reconocida en el Perú con 38 géneros y 264 especies (Brako & Zarucchi 1993, Ulloa et al. 2004, mayormente arbustos y hierbas. En este trabajo reconocemos 87 especies endémicas en 16 géneros. El género más rico en especies endémicas es Nototriche. Las especies endémicas se encuentran en varias regiones ecológicas, entre ellas Altoandina, Mesoandina y Puna Húmeda y Seca, por encima de los 2500 m, hasta alcanzar los límites de la vegetación a 5100 m de altitud. Se aplicaron las categorías y criterios de la UICN a 84 especies. Once especies endémicas se encuentran presentes en el Sistema Nacional de Áreas Naturales Protegidas por el Estado.

Vochysiaceae endémicas del Perú

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Blanca León

2013-10-01

Full Text Available La familia Vochysiaceae es reconocida en el Perú por presentar cuatro géneros y 32 especies (Brako & Zarucchi, 1993; Ulloa Ulloa et al., 2004, todas árboles. En este trabajo reconocemos dos especies endémicas en el género Qualea. Estas especies endémicas han sido encontradas en la región Bosques Húmedos Amazónicos, entre los 100 y 160 m de altitud. Ninguna especie endémica se encuentra representada dentro del Sistema Nacional de Áreas Naturales Protegidas por el Estado.

FAA/NASA Joint University Program for Air Transportation Research, 1992-1993

Science.gov (United States)

Morrell, Frederick R. (Compiler)

1994-01-01

The research conducted during the academic year 1992-1993 under the FAA/NASA sponsored Joint University Program for Air Transportation Research is summarized. The year end review was held at Ohio University, Athens, Ohio, 17-18 June 1993. The Joint University Program is a coordinated set of three grants sponsored by the Federal Aviation Administration and NASA Langley Research Center, one each with the Massachusetts Institute of Technology, Ohio University, and Princeton University. Completed works, status reports, and annotated bibliographies are presented for research topics, which include navigation, guidance, and control theory and practice, aircraft performance, human factors and air traffic management. An overview of the year's activities for each university is also presented.

Mechanistic Indicators of Childhood Asthma (MICA) Study

Science.gov (United States)

The Mechanistic Indicators of Childhood Asthma (MICA) Study has been designed to incorporate state-of-the-art technologies to examine the physiological and environmental factors that interact to increase the risk of asthmatic responses. MICA is primarily a clinically-bases obser...

Further increased production of free fatty acids by overexpressing a predicted transketolase gene of the pentose phosphate pathway in Aspergillus oryzae faaA disruptant.

Science.gov (United States)

Tamano, Koichi; Miura, Ai

2016-09-01

Free fatty acids are useful as source materials for the production of biodiesel fuel and various chemicals such as pharmaceuticals and dietary supplements. Previously, we attained a 9.2-fold increase in free fatty acid productivity by disrupting a predicted acyl-CoA synthetase gene (faaA, AO090011000642) in Aspergillus oryzae. In this study, we achieved further increase in the productivity by overexpressing a predicted transketolase gene of the pentose phosphate pathway in the faaA disruptant. The A. oryzae genome is predicted to have three transketolase genes and overexpression of AO090023000345, one of the three genes, resulted in phenotypic change and further increase (corresponding to an increased production of 0.38 mmol/g dry cell weight) in free fatty acids at 1.4-fold compared to the faaA disruptant. Additionally, the biomass of hyphae increased at 1.2-fold by the overexpression. As a result, free fatty acid production yield per liter of liquid culture increased at 1.7-fold by the overexpression.

A new approach for the beryl mineral decomposition: elemental characterisation using ICP-AES and FAAS

International Nuclear Information System (INIS)

Nathan, Usha; Premadas, A.

2013-01-01

A new approach for the beryl mineral sample decomposition and solution preparation method suitable for the elemental analysis using ICP-AES and FAAS is described. For the complete sample decomposition four different decomposition procedures are employed such as with (i) ammonium bi-fluoride alone (ii) a mixture of ammonium bi-fluoride and ammonium sulphate (iii) powdered mixture of NaF and KHF 2 in 1: 3 ratio, and (iv) acid digestion treatment using hydrofluoric acid and nitric acid mixture, and the residue fused with a powdered mixture NaF and KHF 2 . Elements like Be, Al, Fe, Mn, Ti, Cr, Ca, Mg, and Nb are determined by ICP-AES and Na, K, Rb and Cs are determined by FAAS method. Fusion with 2g ammonium bifluoride flux alone is sufficient for the complete decomposition of 0.400 gram sample. The values obtained by this decomposition procedure are agreed well with the reported method. Accuracy of the proposed method was checked by analyzing synthetic samples prepared in the laboratory by mixing high purity oxides having a chemical composition similar to natural beryl mineral. It indicates that the accuracy of the method is very good, and the reproducibility is characterized by the RSD 1 to 4% for the elements studied. (author)

Moraceae endémicas del Perú

Directory of Open Access Journals (Sweden)

Pamela Cáceres

2013-10-01

Full Text Available La familia Moraceae es reconocida en el Perú por presentar 19 géneros y 128 especies (Brako & Zarucchi, 1993; Ulloa Ulloa et al., 2004, la mayoría arbóreas y/o hemiepífitos. En este trabajo reconocemos dos especies endémicas en igual número de géneros. Las especies endémicas se encuentran en la región Bosques Húmedos Amazónicos, entre los 115 y 220 m de altitud. Ambas especies endémicas se encuentran dentro del Sistema Nacional de Áreas Naturales Protegidas por el Estado.

Rosaceae endémicas del Perú

Directory of Open Access Journals (Sweden)

Wilfredo Mendoza

2013-10-01

Full Text Available La familia Rosaceae es reconocida en el Perú por presentar 24 géneros y 113 especies (Brako & Zarucchi, 1993; Mendoza, 2005; Ulloa Ulloa et al., 2004, entre hierbas, arbustos y árboles. En este trabajo reconocemos 14 especies endémicas en cuatro géneros. Las especies endémicas se encuentran principalmente en las regiones Bosques Pluviales Montanos, Bosques Muy Húmedos Montanos y Páramo, entre los 1900 y 3800 m de altitud. Seis especies endémicas se encuentran representadas dentro del Sistema Nacional de Áreas Naturales Protegidas por el Estado.

77 FR 23673 - Notice of Stakeholder Meeting: Industry Roundtable-DON/USDA/DOE/DOT-FAA Advanced Drop-In Biofuels...

Science.gov (United States)

2012-04-20

...--DON/USDA/DOE/ DOT-FAA Advanced Drop-In Biofuels Initiative AGENCY: Department of the Navy, DoD. ACTION... participants in the biofuels supply chain. The purpose of the roundtable meeting is for the federal government... Biofuels Production Project. Questions related to the Special Notices or the pending Broad Agency...

Understanding overpressure in the FAA aerosol can test by C3H2F3Br (2-BTP).

Science.gov (United States)

Linteris, Gregory Thomas; Babushok, Valeri Ivan; Pagliaro, John Leonard; Burgess, Donald Raymond; Manion, Jeffrey Alan; Takahashi, Fumiaki; Katta, Viswanath Reddy; Baker, Patrick Thomas

2016-05-01

Thermodynamic equilibrium calculations, as well as perfectly-stirred reactor (PSR) simulations with detailed reaction kinetics, are performed for a potential halon replacement, C 3 H 2 F 3 Br (2-BTP, C 3 H 2 F 3 Br, 2-Bromo-3,3,3-trifluoropropene), to understand the reasons for the unexpected enhanced combustion rather than suppression in a mandated FAA test. The high pressure rise with added agent is shown to depend on the amount of agent, and is well-predicted by an equilibrium model corresponding to stoichiometric reaction of fuel, oxygen, and agent. A kinetic model for the reaction of C 3 H 2 F 3 Br in hydrocarbon-air flames has been applied to understand differences in the chemical suppression behavior of C 3 H 2 F 3 Br vs. CF 3 Br in the FAA test. Stirred-reactor simulations predict that in the conditions of the FAA test, the inhibition effectiveness of C 3 H 2 F 3 Br at high agent loadings is relatively insensitive to the overall stoichiometry (for fuel-lean conditions), and the marginal inhibitory effect of the agent is greatly reduced, so that the mixture remains flammable over a wide range of conditions. Most important, the flammability of the agent-air mixtures themselves (when compressively preheated), can support low-strain flames which are much more difficult to extinguish than the easy-to extinguish, high-strain primary fireball from the impulsively released fuel mixture. Hence, the exothermic reaction of halogenated hydrocarbons in air should be considered in other situations with strong ignition sources and low strain flows, especially at preheated conditions.

Highly charged swelling mica reduces Cu bioavailability in Cu-contaminated soils

Energy Technology Data Exchange (ETDEWEB)

Stuckey, Jason W. [Department of Crop and Soil Sciences, Pennsylvania State University, 116 ASI Building, University Park, PA 16802 (United States); Neaman, Alexander [Facultad de Agronomia, P. Universidad Catolica de Valparaiso, Centro Regional de Estudios en Alimentos Saludables (Chile); Ravella, Ramesh; Komarneni, Sridhar [Department of Crop and Soil Sciences, Pennsylvania State University, 116 ASI Building, University Park, PA 16802 (United States); Martinez, Carmen Enid [Department of Crop and Soil Sciences, Pennsylvania State University, 116 ASI Building, University Park, PA 16802 (United States)], E-mail: cem17@psu.edu

2009-01-15

This is the first test of a highly charged swelling mica's (Na-2-mica) ability to reduce the plant-absorbed Cu in Cu-contaminated soils from Chile. Perennial ryegrass (Lolium perenne L.) was grown in two acid soils (Sector 2: pH 4.2, total Cu = 172 mg Cu kg{sup -1} and Sector 3: pH 4.2, total Cu = 112 mg Cu kg{sup -1}) amended with 0.5% and 1% (w/w) mica, and 1% (w/w) montmorillonite. At 10 weeks of growth, both mica treatments decreased the shoot Cu of ryegrass grown in Sector 2 producing shoot Cu concentrations above 21-22 mg Cu kg{sup -1} (the phytotoxicity threshold for that species), yet the mica treatments did not reduce shoot Cu concentrations when grown in Sector 3, which were at a typical level. The mica treatments improved shoot growth in Sector 3 by reducing free and extractable Cu to low enough levels where other nutrients could compete for plant absorption and translocation. In addition, the mica treatments improved root growth in both soils, and the 1% mica treatment reduced root Cu in both soils. This swelling mica warrants further testing of its ability to assist re-vegetation and reduce Cu bioavailability in Cu-contaminated surface soils. - In situ remediation of Cu-contaminated soils with a synthetic mica (Na-2-mica) will aid in re-vegetative efforts.

DNA adsorption and desorption on mica surface studied by atomic force microscopy

Energy Technology Data Exchange (ETDEWEB)

Sun Lanlan [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Graduate school of the Chinese Academy of Sciences, Chinese Academy of Sciences, Renmin Street 5625, Changchun 130022 (China); Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 16 East Nan-Hu Road, Open Economic Zone, Changchun 130033 (China); Zhao Dongxu [Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 16 East Nan-Hu Road, Open Economic Zone, Changchun 130033 (China); Zhang Yue; Xu Fugang [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Graduate school of the Chinese Academy of Sciences, Chinese Academy of Sciences, Renmin Street 5625, Changchun 130022 (China); Li Zhuang, E-mail: zli@ciac.jl.cn [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Graduate school of the Chinese Academy of Sciences, Chinese Academy of Sciences, Renmin Street 5625, Changchun 130022 (China)

2011-05-15

The adsorption of DNA molecules on mica surface and the following desorption of DNA molecules at ethanol-mica interface were studied using atomic force microscopy. By changing DNA concentration, different morphologies on mica surface have been observed. A very uniform and orderly monolayer of DNA molecules was constructed on the mica surface with a DNA concentration of 30 ng/{mu}L. When the samples were immersed into ethanol for about 15 min, various desorption degree of DNA from mica (0-99%) was achieved. It was found that with the increase of DNA concentration, the desorption degree of DNA from the mica at ethanol-mica interface decreased. And when the uniform and orderly DNA monolayers were formed on the mica surface, almost no DNA molecule desorbed from the mica surface in this process. The results indicated that the uniform and orderly DNA monolayer is one of the most stable DNA structures formed on the mica surface. In addition, we have studied the structure change of DNA molecules after desorbed from the mica surface with atomic force microscopy, and found that the desorption might be ascribed to the ethanol-induced DNA condensation.

DNA adsorption and desorption on mica surface studied by atomic force microscopy

International Nuclear Information System (INIS)

Sun Lanlan; Zhao Dongxu; Zhang Yue; Xu Fugang; Li Zhuang

2011-01-01

The adsorption of DNA molecules on mica surface and the following desorption of DNA molecules at ethanol-mica interface were studied using atomic force microscopy. By changing DNA concentration, different morphologies on mica surface have been observed. A very uniform and orderly monolayer of DNA molecules was constructed on the mica surface with a DNA concentration of 30 ng/μL. When the samples were immersed into ethanol for about 15 min, various desorption degree of DNA from mica (0-99%) was achieved. It was found that with the increase of DNA concentration, the desorption degree of DNA from the mica at ethanol-mica interface decreased. And when the uniform and orderly DNA monolayers were formed on the mica surface, almost no DNA molecule desorbed from the mica surface in this process. The results indicated that the uniform and orderly DNA monolayer is one of the most stable DNA structures formed on the mica surface. In addition, we have studied the structure change of DNA molecules after desorbed from the mica surface with atomic force microscopy, and found that the desorption might be ascribed to the ethanol-induced DNA condensation.

La Industria Química: Importancia y Retos

Directory of Open Access Journals (Sweden)

Nancy Montes-Valencia

2015-06-01

Full Text Available La química siempre ha estado presente en la vida del hombre para satisfacer sus necesidades y mejorar su calidad de vida. Hoy en día la industria química es un importante sector industrial presente en la mayoría de países, que dinamiza el crecimiento económico, genera empleo y ofrece diversidad de productos, no obstante produce contaminación al medio ambiente y utiliza recursos naturales no renovables. Por lo tanto surge el concepto de química verde como respuesta a la problemática ambiental cuya estructura es la sostenibilidad, siendo su principal objetivo prevenir la generación de emisiones y armonizar la química con los recursos naturales. Existe un gran reto para la industria química y es encontrar fuentes alternativas de energía para no seguir dependiendo del petróleo, el gas natural y el carbón, una de estas es el uso de la biomasa para la obtención de combustibles líquidos.

Peak-interviewet

DEFF Research Database (Denmark)

Raalskov, Jesper; Warming-Rasmussen, Bent

Peak-interviewet er en særlig effektiv metode til at gøre ubevidste menneskelige ressourcer bevidste. Fokuspersonen (den interviewede) interviewes om en selvvalgt, personlig succesoplevelse. Terapeuten/coachen (intervieweren) spørger ind til processen, som ledte hen til denne succes. Herved afdæk...... fokuspersonen ønsker at tage op (nye mål eller nye processer). Nærværende workingpaper beskriver, hvad der menes med et peak-interview, peakinterviwets teoretiske fundament samt metodikken til at foretage et tillidsfuldt og effektiv peak-interview....

'Peak oil' or 'peak demand'?

International Nuclear Information System (INIS)

Chevallier, Bruno; Moncomble, Jean-Eudes; Sigonney, Pierre; Vially, Rolland; Bosseboeuf, Didier; Chateau, Bertrand

2012-01-01

This article reports a workshop which addressed several energy issues like the objectives and constraints of energy mix scenarios, the differences between the approaches in different countries, the cost of new technologies implemented for this purposes, how these technologies will be developed and marketed, which will be the environmental and societal acceptability of these technical choices. Different aspects and issues have been more precisely presented and discussed: the peak oil, development of shale gases and their cost (will non conventional hydrocarbons modify the peak oil and be socially accepted?), energy efficiency (its benefits, its reality in France and other countries, its position in front of the challenge of energy transition), and strategies in the transport sector (challenges for mobility, evolution towards a model of sustainable mobility)

“Nadie es profeta en su tierra”: Etnografía económica de las dinámicas comerciales de los Kichwa-Otavalo en San Victorino, Bogotá

OpenAIRE

López Ávila, Diego Felipe

2015-01-01

La presente monografía describe las dinámicas económicas de los Kichwas Otavalo en la zona comercial de San Victorino, Bogotá. Dichas dinámicas son examinadas a partir de la Nueva Sociología Económica (Smelser & Swedberg, 2005) y la Etnografía Económica (Dufy & Weber, 2009) para mostrar las divergentes racionalidades que surgen al interior del mercado. Esto nos lleva a debatir con la ciencia económica ortodoxa y los supuestos que manejan frente a la racionalidad, el mercado y la competencia....

Automated Peak Picking and Peak Integration in Macromolecular NMR Spectra Using AUTOPSY

Science.gov (United States)

Koradi, Reto; Billeter, Martin; Engeli, Max; Güntert, Peter; Wüthrich, Kurt

1998-12-01

A new approach for automated peak picking of multidimensional protein NMR spectra with strong overlap is introduced, which makes use of the program AUTOPSY (automatedpeak picking for NMRspectroscopy). The main elements of this program are a novel function for local noise level calculation, the use of symmetry considerations, and the use of lineshapes extracted from well-separated peaks for resolving groups of strongly overlapping peaks. The algorithm generates peak lists with precise chemical shift and integral intensities, and a reliability measure for the recognition of each peak. The results of automated peak picking of NOESY spectra with AUTOPSY were tested in combination with the combined automated NOESY cross peak assignment and structure calculation routine NOAH implemented in the program DYANA. The quality of the resulting structures was found to be comparable with those from corresponding data obtained with manual peak picking.

Onagraceae endémicas del Perú

Directory of Open Access Journals (Sweden)

Susy Castillo

2013-10-01

Full Text Available Esta es la familia de las «fucsias», la cual es reconocida en el Perú por presentar seis géneros y 76 especies (Brako & Zarucchi, 1993; Ulloa Ulloa et al., 2004, principalmente arbustos y hierbas. En este trabajo reconocemos 24 especies endémicas, la mayoría en el género Fuchsia. Las especies endémicas se encuentran mayormente en la región Bosques Muy Húmedos Montanos, entre los 1600 y 2500 m de altitud. Diez especies endémicas se encuentran representados dentro del Sistema Nacional de Áreas Naturales Protegidas por el Estado.

Competitividad Sistémica. Niveles analíticos para el fortalecimiento de sectores de actividad económica

Directory of Open Access Journals (Sweden)

Juliana Ferrer

2005-01-01

Full Text Available Un desarrollo industrial exitoso no se logra meramente considerando la función de producción en el nivel microeconómico, o las condiciones macroeconómicas estables; sino también por la existencia de medidas específicas del gobierno y de organizaciones privadas de desarrollo, orientadas a fortalecer la competitividad de los sectores de actividad económica. Además, la capacidad de vincular las iniciativas, está en función de un conjunto de estructuras político- económicas y de factores socioculturales y patrones básicos de organización, que caracterizan el proceso sistémico de competitividad de cada país. Se concluye que existe una marcada desarticulación entre los niveles de competitividad sistémica; reflejada por una incoherencia entre las políticas de Estado, los requerimientos de sectores de actividad y el reflejo de la necesidad real de las comunidades cada vez más desprovistas de recursos. Se recomienda la necesidad de superar la ardua fase que representa establecer una economía de mercado dirigida a mejorar la condición de vida de la población; por lo que será importante facilitar procesos autónomos de búsqueda y aprendizaje significativos, para el desarrollo de la competitividad de los sectores de actividad económica latinoamericanos.

14 CFR 193.17 - How must design and production approval holders handle information they receive from the FAA...

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false How must design and production approval... REGULATIONS PROTECTION OF VOLUNTARILY SUBMITTED INFORMATION § 193.17 How must design and production approval... under § 193.9(a)(2) to the holders of design approvals of production approvals issued by the FAA, the...

APRENDIENDO ELECTROQUÍMICA. UN ESTUDIO COMPARATIVO

Directory of Open Access Journals (Sweden)

Maria I. Vera

2011-01-01

Full Text Available Se realizó un seguimiento del proceso de enseñanza y aprendizaje de Electroquímica y se compararon los resultados obtenidos en evaluaciones parciales, con el objetivo de analizar si existen diferencias significativas en la apropiación de contenidos entre alumnos de carreras con diferentes perfiles. Se trabajó en los años 2009 y 2010 con dos grupos de alumnos en cada año, pertenecientes a carreras químicas y no químicas respectivamente. En ambos grupos se desarrollaron, con la misma carga horaria, contenidos conceptuales y procedimentales en clases teóricas con prácticas de resolución de problemas y de laboratorio. Para la evaluación se presentaron idénticas situaciones problemáticas, cuyos resultados muestran diferencias no significativas entre ambos grupos en la identificación del cátodo y del ánodo y cálculo de la fem estándar de la celda; en cambio en la aplicación de la Ecuación de Nernst y la identificación de especies químicas que reaccionan en los electrodos, hay diferencias significativas en las respuestas dadas.

Preparation of mica/apatite glass-ceramics biomaterials

International Nuclear Information System (INIS)

Liu Yong; Sheng Xiaoxian; Dan Xiaohong; Xiang Qijun

2006-01-01

Glass-ceramics have become more and more important biomaterials. In this work mica glass/apatite composites with various compositions were prepared by casting and subsequent heat treatments. The effects of composition, phase constitution and crystallinity on mechanical properties, including elastic modulus and transverse rupture strength (TRS), were investigated by using X-ray diffraction analyses (XRD), scanning electron microscopy (SEM) and mechanical tests. Results show that addition of apatite composition in mica glass accelerates the crystallization process and induces the formation of fluoroapatite phase, and the nucleation of apatite crystals occurs before that of mica crystals. The fuoroapatite in this work is needle-like, which is almost the same to that in human bone. The transverse rupture strength increases with the content of fluoroapatite and the crystallinity increasing, except that at a low apatite content the mechanical properties are lower than those of mica glass under the same processing conditions. The transverse rupture strength and elastic modulus obtained in this work fall in the range of those of human bone. SBF immersion test demonstrates good bioactivity of this biomaterial

Understanding overpressure in the FAA aerosol can test by C3H2F3Br (2-BTP)✩

Science.gov (United States)

Linteris, Gregory Thomas; Babushok, Valeri Ivan; Pagliaro, John Leonard; Burgess, Donald Raymond; Manion, Jeffrey Alan; Takahashi, Fumiaki; Katta, Viswanath Reddy; Baker, Patrick Thomas

2018-01-01

Thermodynamic equilibrium calculations, as well as perfectly-stirred reactor (PSR) simulations with detailed reaction kinetics, are performed for a potential halon replacement, C3H2F3Br (2-BTP, C3H2F3Br, 2-Bromo-3,3,3-trifluoropropene), to understand the reasons for the unexpected enhanced combustion rather than suppression in a mandated FAA test. The high pressure rise with added agent is shown to depend on the amount of agent, and is well-predicted by an equilibrium model corresponding to stoichiometric reaction of fuel, oxygen, and agent. A kinetic model for the reaction of C3H2F3Br in hydrocarbon-air flames has been applied to understand differences in the chemical suppression behavior of C3H2F3Br vs. CF3Br in the FAA test. Stirred-reactor simulations predict that in the conditions of the FAA test, the inhibition effectiveness of C3H2F3Br at high agent loadings is relatively insensitive to the overall stoichiometry (for fuel-lean conditions), and the marginal inhibitory effect of the agent is greatly reduced, so that the mixture remains flammable over a wide range of conditions. Most important, the flammability of the agent-air mixtures themselves (when compressively preheated), can support low-strain flames which are much more difficult to extinguish than the easy-to extinguish, high-strain primary fireball from the impulsively released fuel mixture. Hence, the exothermic reaction of halogenated hydrocarbons in air should be considered in other situations with strong ignition sources and low strain flows, especially at preheated conditions. PMID:29628525

Trayectorias evolucionistas en la dinámica de la empresa: una aproximación por dinámica de sistemas

Directory of Open Access Journals (Sweden)

Germán Eduardo Vargas

2006-05-01

Full Text Available La actividad de las firmas, como unidad socioeconómica, en el marco evolucionista está orientada integralmente por procesos de identidad, cohesión y mecanismos de adaptación y evolución; en este orden, el presente documento ilustra, a través de un modelo por dinámica de sistemas, cómo la orientación e integración estratégica basada en el conocimiento para la innovación se constituye como un imperativo de desarrollo que, a partir de un pequeño apalancamiento, permite distinguir entre dos trayectorias de evolución, a saber: firmas económicas tradicionales (inerciales, pues introducen mejoras incrementales esporádicas y modernas (dinámicas y radicalmente innovadoras, hecho a partir del cual se obtienen reveladoras conclusiones y desafíos para intervenir y adecuar el comportamiento de las empresas.2

FAA/NASA Joint University Program for Air Transportation Research: 1993-1994

Science.gov (United States)

Hueschen, Richard M. (Compiler)

1995-01-01

This report summarizes the research conducted during the academic year 1993-1994 under the NASA/FAA sponsored Joint University Program for Air Transportation Research. The year end review was held at Ohio University, Athens, Ohio, July 14-15, 1994. The Joint University Program is a coordinated set of three grants sponsored by NASA Langley Research Center and the Federal Aviation Administration, one each with the Massachusetts Institute of Technology (NGL-22-009-640), Ohio University (NGR-36-009-017), and Princeton University (NGL-31-001-252). Completed works, status reports, and annotated bibliographies are presented for research topics which include navigation, guidance and control theory and practice, aircraft performance, human factors, and expert systems concepts applied to aircraft and airport operations. An overview of the year's activities for each university is also presented.

Use of Ground Penetrating Radar at the FAA's National Airport Pavement Test Facility

Science.gov (United States)

Injun, Song

2015-04-01

The Federal Aviation Administration (FAA) in the United States has used a ground-coupled Ground Penetrating Radar (GPR) at the National Airport Pavement Test Facility (NAPTF) since 2005. One of the primary objectives of the testing at the facility is to provide full-scale pavement response and failure information for use in airplane landing gear design and configuration studies. During the traffic testing at the facility, a GSSI GPR system was used to develop new procedures for monitoring Hot Mix Asphalt (HMA) pavement density changes that is directly related to pavement failure. After reviewing current setups for data acquisition software and procedures for identifying different pavement layers, dielectric constant and pavement thickness were selected as dominant parameters controlling HMA properties provided by GPR. A new methodology showing HMA density changes in terms of dielectric constant variations, called dielectric sweep test, was developed and applied in full-scale pavement test. The dielectric constant changes were successfully monitored with increasing airplane traffic numbers. The changes were compared to pavement performance data (permanent deformation). The measured dielectric constants based on the known HMA thicknesses were also compared with computed dielectric constants using an equation from ASTM D4748-98 Standard Test Method for Determining the Thickness of Bound Pavement Layers Using Short-Pulse Radar. Six inches diameter cylindrical cores were taken after construction and traffic testing for the HMA layer bulk specific gravity. The measured bulk specific gravity was also compared to monitor HMA density changes caused by aircraft traffic conditions. Additionally this presentation will review the applications of the FAA's ground-coupled GPR on embedded rebar identification in concrete pavement, sewer pipes in soil, and gage identifications in 3D plots.

Ultrasonic Transducer Peak-to-Peak Optical Measurement

Directory of Open Access Journals (Sweden)

Pavel Skarvada

2012-01-01

Full Text Available Possible optical setups for measurement of the peak-to-peak value of an ultrasonic transducer are described in this work. The Michelson interferometer with the calibrated nanopositioner in reference path and laser Doppler vibrometer were used for the basic measurement of vibration displacement. Langevin type of ultrasonic transducer is used for the purposes of Electro-Ultrasonic Nonlinear Spectroscopy (EUNS. Parameters of produced mechanical vibration have to been well known for EUNS. Moreover, a monitoring of mechanical vibration frequency shift with a mass load and sample-transducer coupling is important for EUNS measurement.

Major histocompatibility complex class I-related chain A/B (MICA/B) expression in tumor tissue and serum of pancreatic cancer: Role of uric acid accumulation in gemcitabine-induced MICA/B expression

International Nuclear Information System (INIS)

Xu, Xiulong; Rao, Geetha S; Groh, Veronika; Spies, Thomas; Gattuso, Paolo; Kaufman, Howard L; Plate, Janet; Prinz, Richard A

2011-01-01

Major histocompatibility complex class I-related chain A and B (MICA/B) are two stress-inducible ligands that bind the immunoreceptor NKG2D and play an important role in mediating the cyotoxicity of NK and T cells. In this study, we sought to study MICA/B expression in pancreatic cancer and to determine whether and how genotoxic drugs such as gemcitabine can affect MICA/B expression and natural killer cytotoxity. Seven pancreatic cancer cell lines were analyzed for MICA/B expression by flow cytometry and for their sensitivity to NK-92 cell killing by a 51 Cr release assay. MICA/B expression in tumor tissues and sera of pancreatic cancer was analyzed by immunohistochemical staining (IHC) and ELISA, respectively. Two MICA/B-positive cell lines were sensitive to the cytotoxic activity of NK-92 cells. Other two MICA/B-positive cell lines and three MICA/B-negative cell lines were resistant to NK-92 cell killing. MICA/B expression was positive in 17 of 25 (68%) pancreatic ductal adenocarcinomas but not in normal pancreatic ductal epithelial cells. Serum MICA/B levels were significantly elevated in patients with pancreatic adenocarcinomas but did not correlate with the stage of pancreatic cancer and patient survival. Gemcitabine therapy led to increased serum MICA levels in 6 of 10 patients with detectable serum MICA. Allopurinol, an inhibitor of xanthine oxidoreductase that converts xanthine to uric acid, blocked uric acid production, MICA/B expression, and sensitivity to NK-92 cell killing toward a PANC-1 cancer cell line exposed to radiation and two genotoxic drugs, gemcitabine and 5-fluorouracil. The levels of MICA/B expression in serum and tissue of pancreatic cancer are elevated. DNA damage-induced MICA/B expression is mediated through increased uric acid production

Major histocompatibility complex class I-related chain A/B (MICA/B expression in tumor tissue and serum of pancreatic cancer: Role of uric acid accumulation in gemcitabine-induced MICA/B expression

Directory of Open Access Journals (Sweden)

Kaufman Howard L

2011-05-01

Full Text Available Abstract Background Major histocompatibility complex class I-related chain A and B (MICA/B are two stress-inducible ligands that bind the immunoreceptor NKG2D and play an important role in mediating the cyotoxicity of NK and T cells. In this study, we sought to study MICA/B expression in pancreatic cancer and to determine whether and how genotoxic drugs such as gemcitabine can affect MICA/B expression and natural killer cytotoxity. Methods Seven pancreatic cancer cell lines were analyzed for MICA/B expression by flow cytometry and for their sensitivity to NK-92 cell killing by a 51Cr release assay. MICA/B expression in tumor tissues and sera of pancreatic cancer was analyzed by immunohistochemical staining (IHC and ELISA, respectively. Results Two MICA/B-positive cell lines were sensitive to the cytotoxic activity of NK-92 cells. Other two MICA/B-positive cell lines and three MICA/B-negative cell lines were resistant to NK-92 cell killing. MICA/B expression was positive in 17 of 25 (68% pancreatic ductal adenocarcinomas but not in normal pancreatic ductal epithelial cells. Serum MICA/B levels were significantly elevated in patients with pancreatic adenocarcinomas but did not correlate with the stage of pancreatic cancer and patient survival. Gemcitabine therapy led to increased serum MICA levels in 6 of 10 patients with detectable serum MICA. Allopurinol, an inhibitor of xanthine oxidoreductase that converts xanthine to uric acid, blocked uric acid production, MICA/B expression, and sensitivity to NK-92 cell killing toward a PANC-1 cancer cell line exposed to radiation and two genotoxic drugs, gemcitabine and 5-fluorouracil. Conclusions The levels of MICA/B expression in serum and tissue of pancreatic cancer are elevated. DNA damage-induced MICA/B expression is mediated through increased uric acid production.

USAF Enlisted Air Traffic Controller Selection: Examination of the Predictive Validity of the FAA Air Traffic Selection and Training Battery versus Training Performance

National Research Council Canada - National Science Library

Carretta, Thomas R; King, Raymond E

2008-01-01

.... The current study examined the utility of the FAA Air Traffic Selection and Training (AT-SAT) battery for incrementing the predictiveness of the ASVAB versus several enlisted ATC training criteria...

Algunas reflexiones sobre la distancia entre "hablar química" y "comprender química"

Directory of Open Access Journals (Sweden)

Lydia Raquel Galagovsky

2014-12-01

Full Text Available Una clase de química puede ser considerada como un espacio de comunicación entre el docente experto y los estudiantes novatos, donde los lenguajes utilizados son la interfase explícita y observable del intercambio comunicativo. En el presente trabajo se muestra con dos ejemplos cómo la diversidad de lenguajes químicos en lugar de favorecer la comprensión de los estudiantes, puede actuar como fuente de obstáculos que dificultan la comunicación en el aula. Así mismo, se analizará con otros dos ejemplos cómo el discurso con el que se enseña la disciplina también es potencial generador de errores en los estudiantes, cuando ellos construyen sus modelos mentales idiosincrásicos a partir de un discurso recortado y simplificado, desde las mejores intenciones de realizar buenas transposiciones didácticas. Se plantea que un enfoque de análisis de la situación de aula como un encuentro comunicativo entre experto y novato conduce a una necesaria diferenciación entre "hablar química" y "comprender química".

NASA-FAA helicopter Microwave Landing System curved path flight test

Science.gov (United States)

Swenson, H. N.; Hamlin, J. R.; Wilson, G. W.

1984-01-01

An ongoing series of joint NASA/FAA helicopter Microwave Landing System (MLS) flight tests was conducted at Ames Research Center. This paper deals with tests done from the spring through the fall of 1983. This flight test investigated and developed solutions to the problem of manually flying curved-path and steep glide slope approaches into the terminal area using the MLS and flight director guidance. An MLS-equipped Bell UH-1H helicopter flown by NASA test pilots was used to develop approaches and procedures for flying these approaches. The approaches took the form of Straight-in, U-turn, and S-turn flightpaths with glide slopes of 6 deg, 9 deg, and 12 deg. These procedures were evaluated by 18 pilots from various elements of the helicopter community, flying a total of 221 hooded instrument approaches. Flying these curved path and steep glide slopes was found to be operationally acceptable with flight director guidance using the MLS.

Preparation and characterization of aluminum based alloy - mica composites

International Nuclear Information System (INIS)

Rashid, M.A.; Shamim, A.

1999-01-01

In this work, six pallets each of 2.0 cm dia and 0.5 cm thickness were prepared by powder metallurgy; half of them also contained 1% mica-powder to form a composite. Inclusion of mica resulted in a decreased density and an increased porosity of the sample. Brinell hardness was found to be 21% less for the composite than for the pure alloy. Micro-graphs of different areas of the sample show uniform distribution of mica particles and avoids around them. (author)

Microstructures and luminescent properties of Ce-doped transparent mica glass-ceramics

International Nuclear Information System (INIS)

Taruta, Seiichi; Iwasaki, Yoshitomo; Nishikiori, Hiromasa; Yamakami, Tomohiko; Yamaguchi, Tomohiro; Kitajima, Kunio; Okada, Kiyoshi

2012-01-01

Highlights: ► Ce-doped transparent glass-ceramics and their parent glasses. ► TEM and STEM images for the microstructures. ► Each mica crystal did not contain Ce uniformly. ► Emission due to Ce 3+ ions in the glass phase and/or Ce 3+ ions in the mica crystals. - Abstract: Transparent mica glass-ceramics were prepared by heating parent glasses that had been doped with 0.5–15 mol% CeO 2 . During the melting and heat treatment, Ce 4+ ions in the specimens were reduced to Ce 3+ ions, and one or both of these ion species were then replaced with Li + ions in the interlayers of the separated mica crystals. However, scanning transmission electron microscope (STEM) and Z-contrast imaging revealed that the mica crystals did not contain the same amount of Ce. On excitation at 254 nm, the parent glasses and glass-ceramics emitted blue light, which originated from the 5d to 4f transition of the Ce 3+ ions. The emission of the glass-ceramic containing a smaller amount of Ce was attributed to the Ce 3+ ions in both the glass phase and the mica crystals, whereas that of the glass-ceramics containing a larger amount of Ce was caused mainly by Ce 3+ ions in the mica crystals. The dependence of the emission band of the parent glasses on the amount of Ce was a unique feature of the Ce-doped transparent mica glass-ceramics and was not observed in previous studies of Eu-doped parent glasses and mica glass-ceramics.

Determinação direta de Ca, Mg, Mn e Zn em amostras de leite de búfala da Ilha de Marajó por espectrometria de absorção atômica com chama (FAAS Direct determination of Ca, Mg, Mn and Zn in buffalo milk of the Marajó Island by FAAS

Directory of Open Access Journals (Sweden)

João B. Pereira Junior

2009-01-01

Full Text Available This work proposes an analytical procedure for direct determination of calcium, magnesium, manganese and zinc in buffalo milk by flame atomic absorption spectrometry (FAAS. Samples were diluted with a solution containing 10% (v/v of water-soluble tertiary amines (CFA-C at pH 8. For comparison, buffalo milk samples were digested with HNO3 and H2O2. According to a paired t-test, the results obtained in the determination of Ca, Mg, Mn and Zn in digested samples and in 10% (v/v CFA-C medium were in agreement at a 95% confidence level. The developed procedure is simple, rapid, decrease the possibility of contamination and can be applied for the routine determination of Ca, Mg, Mn and Zn in buffalo milk samples without any difficulty caused by matrix constituents, such as fat content, and particle size distribution in the milk emulsion.

Gentianaceae endémicas del Perú

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Susy Castillo

2013-10-01

Full Text Available La familia Gentianaceae es reconocida en el Perú por presentar alrededor de 15 géneros y aproximadamente de 170 especies (Brako & Zarucchi, 1993; Ulloa Ulloa et al., 2004; S. Castillo, com.pers., mayormente hierbas y arbustos. En este trabajo se reconoce 103 especies endémicas en siete géneros. Los géneros con mayor número de especies endemicas son Gentianella y Macrocarpaea. Las especies endémicas ocupan principalmente las regiones de la Puna Húmeda y Seca, Páramo y Bosque Muy Húmedo Montano, entre los 1000 y 5100 m de altitud. Se aplicaron las categorías y criterios de la UICN a 99 especies. Treinta y tres especies endémicas se encuentran representadas dentro de un área protegida.

FAA Center of Excellence Alternative Jet Fuels & Environment : Annual Technical Report 2016 : For the Period October 1, 2015 - September 30, 2016

Science.gov (United States)

2016-09-01

This report covers the period October 1, 2015 through September 30, 2016. The Center was established by the authority of FAA solicitation 13-C-AJFE-Solicitation. During that time the ASCENT team launched a new website, which can be viewed at https://...

Química de Heterociclos. Quinolina e isoquinolina

OpenAIRE

Collado, Daniel

2014-01-01

Quinolinas e isoquinolinas: propiedades. Reactividad química: SEAr, SNAr. Reacciones en cadenas laterales. Reacciones de quinolinio e isoquinolinio. Síntesis de quinolinas e isoquinolinas. Otros ciclos. Capítulo sexto de temario de la Asignatura Ampliación de Química Orgánica Avanzada. Quinolina e isoquinolina.

ANALOGIAS EM LIVROS DIDÁTICOS DESTINADOS AO ENSINO SUPERIOR: QUÍMICA ORGÂNICA VERSUS FÍSICO-QUÍMICA

Directory of Open Access Journals (Sweden)

Josué Martins Gonçalves

2016-12-01

Full Text Available Os livros didáticos de Química, via de regra, fazem uso de analogias por se tratar de uma disciplina que envolve inúmeros conceitos abstratos. No entanto, há pouca pesquisa envolvendo identificação e explicação sobre as analogias utilizadas em livros didáticos direcionados ao ensino superior. Nesse sentido, o presente trabalho apresenta um estudo comparativo entre as analogias encontradas em livros de Química Orgânica e Físico-química destinados a estudantes do ensino superior. Foram identificadas 277 analogias nos livros analisados e categorizadas conforme sistemas adaptados de Thiele e Treagust (1994 e Francisco Junior (2009.Uma forma de abordagem mais adequada de utilização das analogias nesses livros foi realizada, bem como a verificação da importância do papel dos professores no uso desse recurso didático. Os resultados indicam que esses livros são ricos em analogias simples, dando ênfase às análogos estruturais no caso de livros de Química Orgânica e análogos funcionais nos de Físico-Química. As analogias simples são mais fáceis de induzirem os alunos a erros conceituais, pois mostram poucas similaridades entre os domínios comparados. É importante ressaltar que nesta pesquisa observa-se uma baixa ocorrência de analogias em que o autor do livro reconhece as limitações e/ou discute estas, repassando toda a responsabilidade ao professor e ao aluno no que se refere à explicação e percepção das analogias, respectivamente. É mister afirmar que muitas das analogias encontradas em alguns capítulos dos livros analisados, poderiam ser suprimidas sem perda significativa da compreensão dos conceitos abordados.

Electricity Portfolio Management: Optimal Peak / Off-Peak Allocations

OpenAIRE

Huisman, Ronald; Mahieu, Ronald; Schlichter, Felix

2007-01-01

textabstractElectricity purchasers manage a portfolio of contracts in order to purchase the expected future electricity consumption profile of a company or a pool of clients. This paper proposes a mean-variance framework to address the concept of structuring the portfolio and focuses on how to allocate optimal positions in peak and off-peak forward contracts. It is shown that the optimal allocations are based on the difference in risk premiums per unit of day-ahead risk as a measure of relati...

CONFLICTO, VIOLENCIA SOCIOECONÓMICA Y DESPLAZAMIENTO FORZADO EN COLOMBIA

Directory of Open Access Journals (Sweden)

Andrés Felipe Mora Cortés

2013-12-01

Full Text Available Este artículo introduce el concepto de violencia socioeconómica, que se refiere a mecanismos de regulación de conflictos distributivos y prácticas gubernamentales que eliminan las condiciones base para la reproducción de la vida. Se identifican tres expresiones clave de la violencia socioeconómica: el despojo, la inseguridad económica y la no generación de oportunidades. El artículo insiste en el efecto desproporcionado que dichas expresiones de violencia socioeconómica tienen sobre la población desplazada; también defiende la necesidad de una agenda mínima que erradique la violencia como lógica reguladora de los conflictos distributivos y que sirva de base para la construcción de paz con justicia social en Colombia.

Peak regulation right

International Nuclear Information System (INIS)

Gao, Z. |; Ren, Z.; Li, Z.; Zhu, R.

2005-01-01

A peak regulation right concept and corresponding transaction mechanism for an electricity market was presented. The market was based on a power pool and independent system operator (ISO) model. Peak regulation right (PRR) was defined as a downward regulation capacity purchase option which allowed PRR owners to buy certain quantities of peak regulation capacity (PRC) at a specific price during a specified period from suppliers. The PRR owner also had the right to decide whether or not they would buy PRC from suppliers. It was the power pool's responsibility to provide competitive and fair peak regulation trading markets to participants. The introduction of PRR allowed for unit capacity regulation. The PRR and PRC were rated by the supplier, and transactions proceeded through a bidding process. PRR suppliers obtained profits by selling PRR and PRC, and obtained downward regulation fees regardless of whether purchases are made. It was concluded that the peak regulation mechanism reduced the total cost of the generating system and increased the social surplus. 6 refs., 1 tab., 3 figs

Moessbauer spectra of white micas from the Central Western Carpathians Mountains

International Nuclear Information System (INIS)

Sitek, J; Toth, I; Sulak, M; Putis, M

2010-01-01

Potassium white micas from the rocks included into Cretaceous deformation zones (ca. 100-70 Ma in age) of the Central Western Carpathians were investigated by Moessbauer spectroscopy. White micas formed during a polystage evolution and changing P-T conditions of their crystallization in crustal-scale shear zones. We found criteria for distinguishing generations of celadonite-poor (muscovitic) and celadonite-rich (phengitic) white micas using Moessbauer spectroscopy. This method revealed contrasting spectra characterized by typical quadrupole doublets corresponding to Fe 2+ Fe 3+ contents in white micas. They are in the range of 2.9-3.0 mm/s for phengite, and 2.6-2.7 mm/s for muscovite. Moessbauer spectra reflect well the chemical changes in white mica aggregates, especially of those close to the end-member muscovite and (alumino-)celadonite compositions.

Moessbauer spectra of white micas from the Central Western Carpathians Mountains

Energy Technology Data Exchange (ETDEWEB)

Sitek, J; Toth, I [Department of Nuclear Physics and Technology, Faculty of Electrical Engineering and Information Technology, Slovak University of Technology, Ilkovicova 3, Bratislava (Slovakia); Sulak, M; Putis, M, E-mail: jozef.sitek@stuba.s [Department of of Mineralogy and Petrology, Faculty of Natural Sciences, Comenius University Bratislava, Mlynska dolina G, 842 15 Bratislava (Slovakia)

2010-03-01

Potassium white micas from the rocks included into Cretaceous deformation zones (ca. 100-70 Ma in age) of the Central Western Carpathians were investigated by Moessbauer spectroscopy. White micas formed during a polystage evolution and changing P-T conditions of their crystallization in crustal-scale shear zones. We found criteria for distinguishing generations of celadonite-poor (muscovitic) and celadonite-rich (phengitic) white micas using Moessbauer spectroscopy. This method revealed contrasting spectra characterized by typical quadrupole doublets corresponding to Fe{sup 2+} Fe{sup 3+} contents in white micas. They are in the range of 2.9-3.0 mm/s for phengite, and 2.6-2.7 mm/s for muscovite. Moessbauer spectra reflect well the chemical changes in white mica aggregates, especially of those close to the end-member muscovite and (alumino-)celadonite compositions.

Prognostic value of MICA/B in cancers: a systematic review and meta-analysis.

Science.gov (United States)

Zhao, Yijing; Chen, Naifei; Yu, Yu; Zhou, Lili; Niu, Chao; Liu, Yudi; Tian, Huimin; Lv, Zheng; Han, Fujun; Cui, Jiuwei

2017-11-10

MHC class I chain related-proteins A (MICA) and B (MICB) are natural killer group 2D ligands that mediate tumor surveillance. Several studies have suggested that MICA/B levels predict clinical outcomes in patients with cancer; however, this remains contentious. Here, we present a systematic review and meta-analysis of available studies of the prognostic value of MICA/B in cancer. We searched PubMed, Embase, Clinicaltrials.gov, and Cochrane Library to identify studies published from inception to July 2017 that assessed MICA/B in patients with cancer. The hazard ratio (HR) and 95% confidence interval (CI) of MICA/B were extracted for overall survival (OS) analysis. A total of 19 studies comprising 2,588 patients with 10 different types of cancer were included in the study. Low sMICA/B levels were found associated with significantly longer OS (HR = 1.65, 95% CI [1.42-1.92], P < 0.00001). Patients with cancers of digestive system that exhibited high MICA/B expression had significantly longer OS in (HR = 0.56, 95% CI [0.39-0.80], P = 0.002) compared with those with lower MICA/B expression ( I 2 = 35%, P = 0.18). Serum soluble MICA/B represents a potential prognostic marker in various human cancers. High cell-surface MICA/B expression in cancers of the digestive system was found associated with increased survival.

Assessment of the environmental impact of the FAA proposed rule making affecting the conditions of transport of radioactive materials on aircraft

International Nuclear Information System (INIS)

Hall, R.J.; Hendrickson, P.L.; King, J.C.; McSweeney, T.I.; Shipler, D.B.; Brown, C.L.; Davis, D.K.; Watson, E.C.

1975-01-01

Amendments to Federal Aviation Administration (FAA) regulations relating to the transporting of radioactive materials on commercial aircraft are presented. Potential effects of the proposed changes are examined in the environmental impact statement, which is presented in the 10 sections and 5 appendices of this document. (JGB)

Phyllitic minerals in hydrothermal uranium deposits. I. Crystalchemistry of relict and newly formed micas

International Nuclear Information System (INIS)

Leroy, Jacques; Cathelineau, Michel

1982-01-01

Several generations of white micas have been recognised in four two mica granite massifs which are associated with uranium deposits in the Hercynian chain. These different generations correspond to distinct geological phenomena belonging to the deuteric and hydrothermal stages of the history of these massifs. Crystalchemical studies of these micas with the aid of the electronic microprobe show that each of these phenomena corresponds a phengite of different, well defined compositions. An increase in the phengitic character and a decrease in the paragonite component are observed over time. Strong similarities exist between micas of the same generation belonging to different granite massifs. The study of the evolution of the earliest deuteric micas during later hydrothermal phenomena, mica episyenitisation and deposition of pitchblende, has shown two opposed trends. In the case of mica episyenitisation, the micas tend to reequilibrate, while in the case of pitchblende deposition and the vein stage in general, the micas preserve their primary character [fr

An overview of the joint FAA/NASA aircraft/ground runway friction program

Science.gov (United States)

Yager, Thomas J.

1989-01-01

There is a need for information on runways which may become slippery due to various forms and types of contaminants. Experience has shown that since the beginning of all weather aircraft operations, there have been landing and aborted takeoff incidents and/or accidents each year where aircraft have either run off the end or veered off the shoulder of low friction runways. NASA Langley's Landing and Impact Dynamics Branch is involved in several research programs directed towards obtaining a better understanding of how different tire properties interact with varying pavement surface characteristics to produce acceptable performance for aircraft ground handling requirements. One such effort, which was jointly supported by not only NASA and the FAA but by several aviation industry groups including the Flight Safety Foundation, is described.

Limitation of peak fitting and peak shape methods for determination of activation energy of thermoluminescence glow peaks

CERN Document Server

Sunta, C M; Piters, T M; Watanabe, S

1999-01-01

This paper shows the limitation of general order peak fitting and peak shape methods for determining the activation energy of the thermoluminescence glow peaks in the cases in which retrapping probability is much higher than the recombination probability and the traps are filled up to near saturation level. Right values can be obtained when the trap occupancy is reduced by using small doses or by post-irradiation partial bleaching. This limitation in the application of these methods has not been indicated earlier. In view of the unknown nature of kinetics in the experimental samples, it is recommended that these methods of activation energy determination should be applied only at doses well below the saturation dose.

Graphene Visualizes the Ion Distribution on Air-Cleaved mica

NARCIS (Netherlands)

Bampoulis, Pantelis; Sotthewes, Kai; Siekman, Martin Herman; Zandvliet, Henricus J.W.; Poelsema, Bene

2017-01-01

The distribution of potassium (K+) ions on air-cleaved mica is important in many interfacial phenomena such as crystal growth, self-assembly and charge transfer on mica. However, due to experimental limitations to nondestructively probe single ions and ionic domains, their exact lateral organization

Make peak flow a habit

Science.gov (United States)

Asthma - make peak flow a habit; Reactive airway disease - peak flow; Bronchial asthma - peak flow ... 2014:chap 55. National Asthma Education and Prevention Program website. How to use a peak flow meter. ...

Effect of Mica and Hematite (001) Surfaces on the Precipitation of Calcite

OpenAIRE

Huifang Xu; Mo Zhou; Yihang Fang; H. Henry Teng

2018-01-01

The substrate effect of mica and hematite on the nucleation and crystallization of calcite was investigated using scanning electron microscope (SEM), X-ray diffraction (XRD), and electron backscatter diffraction (EBSD) methods. On mica, we found, in the absence of Mg2+, the substrates’ (001) surfaces with hexagonal and pseudo-hexagonal two-dimensional (2-D) structure can affect the orientation of calcite nucleation with calcite (001) ~// mica (001) and calcite (010) ~// mica (010) to be the m...

Effects of Doping Concentration on the Structural and Optical Properties of Spin-Coated In-doped ZnO Thin Films Grown on Thermally Oxidized ZnO Film/ZnO Buffer Layer/Mica Substrate

Energy Technology Data Exchange (ETDEWEB)

Kim, Byunggu; Leem, Jae-Young [Inje University, Gimhae (Korea, Republic of)

2017-01-15

ZnO buffer layers were deposited on mica substrates using a sol-gel spin coating method. Then, a thin film of metallic Zn was deposited onto the ZnO buffer layer/mica substrate using a thermal evaporator, and the deposited Zn thin films were then thermally oxidized in a furnace at 500 ℃ for 2 h in air. Finally, In-doped ZnO (IZO) thin films with different In concentrations were grown on the oxidized ZnO film/ZnO buffer layer/mica substrates using the sol-gel spin-coating method. All the IZO films showed ZnO peaks with similar intensities. The full width at half maximum values of the ZnO (002) peak for the IZO thin films decreased with an increase in the In concentration to 1 at%, because the crystallinity of the films was enhanced. However, a further increase in the In concentration caused the crystal quality to degrade. This might be attributed to the fact that the higher In doping resulted in an increase in the number of ionized impurities. The Urbach energy (EU) values of the IZO thin film decreased with an increase in the In concentration to 1 at % because of the enhanced crystal quality of the films. The EU values for the IZO thin films increased with the In concentration from 1 at%to 3 at%, reflecting the broadening of localized band tail state near the conduction band edge of the films.

Effects of Doping Concentration on the Structural and Optical Properties of Spin-Coated In-doped ZnO Thin Films Grown on Thermally Oxidized ZnO Film/ZnO Buffer Layer/Mica Substrate

International Nuclear Information System (INIS)

Kim, Byunggu; Leem, Jae-Young

2017-01-01

ZnO buffer layers were deposited on mica substrates using a sol-gel spin coating method. Then, a thin film of metallic Zn was deposited onto the ZnO buffer layer/mica substrate using a thermal evaporator, and the deposited Zn thin films were then thermally oxidized in a furnace at 500 ℃ for 2 h in air. Finally, In-doped ZnO (IZO) thin films with different In concentrations were grown on the oxidized ZnO film/ZnO buffer layer/mica substrates using the sol-gel spin-coating method. All the IZO films showed ZnO peaks with similar intensities. The full width at half maximum values of the ZnO (002) peak for the IZO thin films decreased with an increase in the In concentration to 1 at%, because the crystallinity of the films was enhanced. However, a further increase in the In concentration caused the crystal quality to degrade. This might be attributed to the fact that the higher In doping resulted in an increase in the number of ionized impurities. The Urbach energy (EU) values of the IZO thin film decreased with an increase in the In concentration to 1 at % because of the enhanced crystal quality of the films. The EU values for the IZO thin films increased with the In concentration from 1 at%to 3 at%, reflecting the broadening of localized band tail state near the conduction band edge of the films.

PLACAS CERÂMICAS - UMA INTRODUÇÃO

Directory of Open Access Journals (Sweden)

Carlos Maurício F. Vieira

2010-05-01

Full Text Available Este trabalho tem por objetivo apresentar uma revisão geral sobre as principais características exigidas para a obtenção de placas cerâmicas (pisos e revestimentos. As principais rotas de processamento são discutidas. Dados de mercado são apresentados com a finalidade de mostrar a importância e a situação atual da indústria cerâmica nacional no setor de pisos e revestimentos.

TICs en la enseñanza de la Química: Propuesta de evaluación de Laboratorios Virtuales de Química (LVQs

Directory of Open Access Journals (Sweden)

Cataldi, Zulma

2012-01-01

Full Text Available Los LVQs son unas nuevas formas de enseñanza de la química a través del uso de TICs. En este contexto se presenta el relevamiento de los laboratorios virtuales de química (LVQs más apropiados para la enseñanza de la química. Se analizan las ventajas de su aplicación en química básica y se delinean las pautas para su evaluación y selección de acuerdo a los indicadores propuestos, articulados con el marco teórico y con las dimensiones de análisis. Se propone una evaluación centrada en tres ejes: a dimensiones tecnológicas y técnicas, b dimensiones pedagógicas y c otras dimensiones como costo y comercialización. Se realizan pruebas de ajuste y aplicación del instrumento según los siguientes objetivos: a Analizar las estrategias didácticas docentes y la percepción en el uso de las TICs y b Delinear acciones formativas en didáctica de la química con uso de TICs.

Peak tree: a new tool for multiscale hierarchical representation and peak detection of mass spectrometry data.

Science.gov (United States)

Zhang, Peng; Li, Houqiang; Wang, Honghui; Wong, Stephen T C; Zhou, Xiaobo

2011-01-01

Peak detection is one of the most important steps in mass spectrometry (MS) analysis. However, the detection result is greatly affected by severe spectrum variations. Unfortunately, most current peak detection methods are neither flexible enough to revise false detection results nor robust enough to resist spectrum variations. To improve flexibility, we introduce peak tree to represent the peak information in MS spectra. Each tree node is a peak judgment on a range of scales, and each tree decomposition, as a set of nodes, is a candidate peak detection result. To improve robustness, we combine peak detection and common peak alignment into a closed-loop framework, which finds the optimal decomposition via both peak intensity and common peak information. The common peak information is derived and loopily refined from the density clustering of the latest peak detection result. Finally, we present an improved ant colony optimization biomarker selection method to build a whole MS analysis system. Experiment shows that our peak detection method can better resist spectrum variations and provide higher sensitivity and lower false detection rates than conventional methods. The benefits from our peak-tree-based system for MS disease analysis are also proved on real SELDI data.

Effect of Mica and Hematite (001 Surfaces on the Precipitation of Calcite

Directory of Open Access Journals (Sweden)

Huifang Xu

2018-01-01

Full Text Available The substrate effect of mica and hematite on the nucleation and crystallization of calcite was investigated using scanning electron microscope (SEM, X-ray diffraction (XRD, and electron backscatter diffraction (EBSD methods. On mica, we found, in the absence of Mg2+, the substrates’ (001 surfaces with hexagonal and pseudo-hexagonal two-dimensional (2-D structure can affect the orientation of calcite nucleation with calcite (001 ~// mica (001 and calcite (010 ~// mica (010 to be the major interfacial relationship. On hematite, we did not observe frequent twinning relationship between adjacent calcite gains, but often saw preferentially nucleation of calcite at surface steps on hematite substrate. We suggest that calcite crystals initially nucleate from the Ca2+ layers adsorbed on the surfaces. The pseudo-hexagonal symmetry on mica (001 surface also leads to the observed calcite (001 twinning. A second and less common orientation between calcite {104} and mica (001 was detected but could be due to local structure damage of the mica surface. Results in the presence of Mg2+ show that the substrate surfaces can weaken Mg toxicity to calcite nucleation and lead to a higher level of Mg incorporation into calcite lattice.

Filogenómica y genómica de la adaptación

OpenAIRE

Zardoya, Rafael; Sánchez-Gracia, Alejandro; Rozas Liras, Julio A.

2017-01-01

La posibilidad técnica actual de secuenciar genomas y transcriptomas completos de cualquier especie abre la puerta a cumplir la predicción de Darwin de poder reconstruir de forma rigurosa el árbol de la vida (las relaciones filogenéticas de todos los seres vivos actuales) mediante la filogenómica.

Aircraft and ground vehicle friction correlation test results obtained under winter runway conditions during joint FAA/NASA Runway Friction Program

Science.gov (United States)

Yager, Thomas J.; Vogler, William A.; Baldasare, Paul

1988-01-01

Aircraft and ground vehicle friction data collected during the Joint FAA/NASA Runway Friction Program under winter runway conditions are discussed and test results are summarized. The relationship between the different ground vehicle friction measurements obtained on compacted snow- and ice-covered conditions is defined together with the correlation to aircraft tire friction performance under similar runway conditions.

Relaciones económicas bilaterales entre Ecuador y Brasil

OpenAIRE

Herrera Díaz, Stefany Natalie

2015-01-01

Dentro de la dinámica mundial actual, resulta de especial interés para Ecuador el análisis de sus relaciones económicas bilaterales con Brasil, debido al papel protagónico que ha alcanzado este país tanto a nivel regional como mundial. A nivel regional, varios de los países vecinos han delineado, incluso, su política exterior en función de potenciar sus relaciones políticas y económicas con él, y a nivel internacional, su participación en la geopolítica mundial es cada vez mayor. En términos ...

La argumentación en la formación de profesores de química: relaciones con la comprensión de la historia de la química

Directory of Open Access Journals (Sweden)

Pablo Antonio Archila

2014-01-01

Full Text Available En este artículo se trata el tema de la argumentación en ciencias de la naturaleza como habilidad de pensamiento y se promueve su inclusión en la formación inicial de profesores de química, pues se reconocen sus potencialidades para la mejora de las comprensiones que los futuros profesores podrían construir acerca de la historia de la química. Para tal fin, se aborda una breve revisión histórica de uno de los hitos de la química, como lo es el desarrollo de la química estructural, con lo cual se sugiere una de las actividades que forman parte de un módulo propuesto para la preparación en argumentación de profesores de química. Finalmente, se discuten algunas reflexiones y perspectivas que resultarían de la articulación entre argumentación e historia de la química.

Peak Experience Project

Science.gov (United States)

Scott, Daniel G.; Evans, Jessica

2010-01-01

This paper emerges from the continued analysis of data collected in a series of international studies concerning Childhood Peak Experiences (CPEs) based on developments in understanding peak experiences in Maslow's hierarchy of needs initiated by Dr Edward Hoffman. Bridging from the series of studies, Canadian researchers explore collected…

Dinámica ambiental y económica en la localidad de Puente Aranda en Bogotá

Directory of Open Access Journals (Sweden)

Carlos Fernando Parra Moreno

2014-01-01

Full Text Available Este documento muestra los resultados parciales de la investigación “Responsabilidad social y ambiental de la industria manufacturera en la localidad de Puente Aranda en la ciudad de Bogotá como alternativa al desarrollo humano integral sustentable”, realizados dentro del marco de trabajo del grupo de investigación Girsa. El estudio se basó en el análisis de la dinámica poblacional, ambiental y económica de la dicha localidad, a través de la metodología de la matriz de Vester. Con este instrumento se logró identificar las relaciones e interacciones dinámicas de todos los actores locales en el tiempo y en el espacio. Dentro de los problemas críticos que se encontraron en la localidad de Puente Aranda se encontró el agotamiento de fuentes hídricas, poca conciencia y educación ambiental de la población, una mala disposición de basuras, la no disponibilidad de servicios públicos para los nuevos asentamientos y altos niveles de emisión de partículas contaminantes.

Temas de Física para Ingeniería: Primer principio de la termodinámica

OpenAIRE

Beléndez Vázquez, Augusto

1992-01-01

Acústica, fluidos y termodinámica: "Primer principio de la termodinámica". Objetivos y caracteres generales de la termodinámica. Conceptos fundamentales de la termodinámica. Capacidad calorífica, calor específico y calor latente. Trabajo. Primer principio de la termodinámica: energía interna. Algunas aplicaciones del primer principio.

MICA diversity and linkage disequilibrium with HLA-B alleles in renal-transplant candidates in southern Brazil.

Science.gov (United States)

Yamakawa, Roger Haruki; Saito, Patrícia Keiko; Gelmini, Geórgia Fernanda; da Silva, José Samuel; Bicalho, Maria da Graça; Borelli, Sueli Donizete

2017-01-01

The major histocompatibility complex (MHC) class I chain-related gene A (MICA) is located centromerically to the human leukocyte antigen (HLA)-B. The short distance between these loci in the MHC indicates the presence of linkage disequilibrium (LD). Similarly to the HLA, the MICA is highly polymorphic, and this polymorphism has not been well documented in different populations. In this study, we estimated the allelic frequencies of MICA and the linkage disequilibrium with HLA-B alleles in 346 renal-transplant candidates in southern Brazil. MICA and HLA were typed using the polymerase chain reaction-sequence-specific primer method (PCR-SSO), combined with the Luminex technology. A total of 19 MICA allele groups were identified. The most frequent allele groups were MICA*008 (21.6%), MICA*002 (17.0%) and MICA*004 (14.8%). The most common haplotypes were MICA*009-B*51 (7.8%), MICA*004-B*44 (6.06%) and MICA*002-B*35 (5.63%). As expected from the proximity of the MICA and HLA-B loci, most haplotypes showed strong LD. Renal patients and healthy subjects in the same region of Brazil showed statistically significant differences in their MICA polymorphisms. The MICA*027 allele group was more frequent in renal patients (Pc = 0.018, OR: 3.421, 95% CI: 1.516-7.722), while the MICA*019 allele group was more frequent in healthy subjects (Pc = 0.001, OR: 0.027, 95% CI: 0.002-0.469). This study provided information on the distribution of MICA polymorphisms and linkage disequilibrium with HLA-B alleles in Brazilian renal-transplant candidates. This information should help to determine the mechanisms of susceptibility to different diseases in patients with chronic kidney disease, and to elucidate the mechanisms involved in allograft rejection associated with MICA polymorphisms in a Brazilian population.

Using X-ray photoelectron spectroscopy to discriminate among different sorption sites of micas: With implications for heterogeneous reduction of chromate at the mica-water interface

Energy Technology Data Exchange (ETDEWEB)

Ilton, E.S.; Moses, C.O.; Veblen, D.R.

2000-04-01

This contribution uses Cr2p and 3p binding energies (BEs) determined by X-ray photoelectron spectroscopy (XPS) to distinguish Cr{sup III} sorbed to different mica sorption sites. The results were used to better understand mechanisms for coupled sorption-reduction of Cr{sub (aq)}{sup VI} by ferrous micas. The research is important because: (1) Cr contamination is a serious and wide spread problem associated with a variety of industries; (2) Micas are important sorbents for Cr because they are ubiquitous, sorb cations and anions over a wide range of pH, and participate in heterogeneous redox reactions via structural Fe{sup II} and FE{sup III}; and (3) The mobility of cations sorbed by micas will depend, in part, on the dominant sorption site. Micas (two biotites, end member phologopite and muscovite) were reacted with Cr{sup III} solutions that contained variable concentrations of NaCl and KCl. Samples were extracted at times intervals and mica edge orientations were analyzed by ZPS. Cr{sub (aq)}{sup III} sorption was greater in Cr{sup III}-NaCl solutions relative to Cr{sup III}-KCl solutions. Cr2p and 3p BEs were bracketed by those for Cr{sup III} in the structure of silicates and in Cr{sup III}-oxyhydroxides. The BE of Cr{sup III} sorbed to micas was higher by about 0.3 eV after reaction with Cr{sup III}-NaCl solutions compared to Cr{sup III}-KCl aqueous solutions. At the experimental conditions, Na{sup +} and K{sup +} differentially block permanent charge sites but not variably charged edge sites of micas. Using the constraints inherent in the experimental design, the authors interpret the difference in CR{sup III} BE between the Cr{sup III}-NaCl and Cr{sup III}-KCl experiments to reflect a change in the dominant sorption site, where high and low Cr BEs indicate Cr sorbed by the interlamellar region and variably charged functional groups at mica edges, respectively. They conclude that small BE shifts for cations sorbed to silicates can be interpreted with

Alfabetización económica y actitudes hacia la compra en universitarios posterior a un programa de educación económica

Directory of Open Access Journals (Sweden)

Marianela Denegri Coria

2016-01-01

después de participar en el programa de Educación Económica se les aplicó la Escala de Actitudes hacia la Compra y el Consumo y el Test de Alfabetización Económica para adultos (TAE-A. Los resultados indican una menor tendencia hacia la impulsividad en la compra y el consumo en los estudiantes después de participar en la intervención. Las implicancias de este estudio enfatizan la necesidad de crear tempranamente programas de formación económica para favorecer el cambio actitudinal y el consumo reflexivo.

Experiencias divertidas de electroquímica casera

OpenAIRE

Santiago Heredia-Avalos

2007-01-01

La química, dentro de la cual se incluye la electroquímica, es una materia que los estudiantes suelen ver como complicada, aburrida, carente de interés y que, además requiere de material de laboratorio sofisticado y reactivos químicos inaccesibles. Nada más lejos de la realidad, tal y como se pondrá de manifiesto en este trabajo, donde se proponen varias experiencias sencillas usando sustancias baratas, la mayoría de las cuales pueden encontrarse en un supermercado, y utensilio...

Scrophulariaceae endémicas del Perú

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Blanca León

2013-10-01

Full Text Available La familia Scrophulariaceae es reconocida en el Perú por presentar alrededor de 18 géneros y 35 especies (Brako & Zarucchi, 1993; Ulloa Ulloa et al., 2004, principalmente herbáceas. En este trabajo reconocemos dos especies endémicas en dos géneros, las cuales se encuentran principalmente en la región Bosques Húmedos Amazónicos, entre los 200 y 1000 m de altitud. Ninguna de las especies endémicas se encuentra representada dentro del Sistema Nacional de Áreas Naturales Protegidas por el Estado.

Oleaceae endémicas del Perú

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Isidoro Sánchez

2013-10-01

Full Text Available La familia Oleaceae es reconocida en el Perú por presentar seis géneros y 13 especies (Brako & Zarucchi, 1993, la mayoría árboles. En este trabajo reconocemos dos especies endémicas en igual número de géneros. Las especies endémicas han sido encontradas en las regiones Matorral Desértico y Bosques Húmedos Amazónicos, entre los 250 y 1850 m de altitud. Ambas especies se encuentran dentro del Sistema Nacional de Áreas Naturales Protegidas por el Estado.

El Área de Ciencia y Tecnologías Químicas del CSIC: ¿Un Área de químicas?

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García-López, María Teresa

2002-08-01

Full Text Available Not available

El artículo titulado "El Area de Ciencia y Tecnologías Químicas del CSIC: ¿un Area de químicas?» pretende mostrar una breve panorámica del lugar que ocupa el género femenino dentro de la citada Area. En la primera parte se aportan las estadísticas que reflejan el número y porcentaje de científicas totales en los distintos Institutos del Area, así como su distribución entre las tres escalas de personal científico del Organismo. Una segunda parte está dedicada a recoger las aportaciones personales de varias científicas del Area acerca del tema, visto desde sus propias experiencias.

Dinámicas de la actividad científica del Instituto de Investigaciones Socio-Económicas de la Universidad Nacional de San Juan de Argentina

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Gonzalo Miguel Castillo

2018-02-01

Full Text Available Este artículo fue un estudio de caso en torno a las capacidades de investigación generadas en el Instituto de Investigaciones Socio-Económicas de la Facultad de Ciencias Sociales, perteneciente a la Universidad Nacional de San Juan, en Argentina. Aborda los principales acontecimientos históricos de la institución y su dinámica actual, tuvo en cuenta las áreas de conocimiento en las cuales se desarrollan sus investigaciones. A su vez, este trabajo ha descrito las dinámicas de la revista académica producida en este instituto, denominada REVIISE. La metodología fue un abordaje objetivo/descriptivo. Se procedió a analizar el papel, devenir y accionar del IISE y las modalidades de proyectos de investigación ejecutados. Fueron indagados el funcionamiento de la REVIISE, identificando perfiles académicos de sus autores, circuitos de difusión y redes académicas; y la conformación de comités y consejos editoriales y académicos que componen esta publicación. Se propone realizar un recorrido que atraviesa lo institucional, los agentes académicos y la principal red de difusión de la producción de conocimiento para comprender las capacidades investigativas del Instituto de Investigaciones Socio Económicas.

Morphology and thermal degradation study of poly(lactic acid)/synthetic mica composites

International Nuclear Information System (INIS)

Souza, D.H.S.; Dias, M.L.

2010-01-01

Poly(lactic acid) (PLA)/synthetic mica composites has been little studied in the literature. In this work, an organophilic synthetic mica was used to prepare PLA nanocomposites. The composites were obtained at an internal mixer containing 3, 5, 7 and 10 wt% of mica. The materials were analyzed by x-ray diffraction, thermogravimetric analysis and gel permeation chromatography. (author)

Fracture Analysis of the FAA/NASA Wide Stiffened Panels

Science.gov (United States)

Seshadri, B. R.; Newman, J. C., Jr.; Dawicke, D. S.; Young, R. D.

1999-01-01

This paper presents the fracture analyses conducted on the FAA/NASA stiffened and unstiffened panels using the STAGS (STructural Analysis of General Shells) code with the critical crack-tip-opening angle (CTOA) fracture criterion. The STAGS code with the "plane-strain" core option was used in all analyses. Previous analyses of wide, flat panels have shown that the high-constraint conditions around a crack front, like plane strain, has to be modeled in order for the critical CTOA fracture criterion to predict wide panel failures from small laboratory tests. In the present study, the critical CTOA value was determined from a wide (unstiffened) panel with anti-buckling guides. The plane-strain core size was estimated from previous fracture analyses and was equal to about the sheet thickness. Rivet flexibility and stiffener failure was based on methods and criteria, like that currently used in industry. STAGS and the CTOA criterion were used to predict load-against-crack extension for the wide panels with a single crack and multiple-site damage cracking at many adjacent rivet holes. Analyses were able to predict stable crack growth and residual strength within a few percent (5%) of stiffened panel tests results but over predicted the buckling failure load on an unstiffened panel with a single crack by 10%.

Peak Oil and other threatening peaks-Chimeras without substance

International Nuclear Information System (INIS)

Radetzki, Marian

2010-01-01

The Peak Oil movement has widely spread its message about an impending peak in global oil production, caused by an inadequate resource base. On closer scrutiny, the underlying analysis is inconsistent, void of a theoretical foundation and without support in empirical observations. Global oil resources are huge and expanding, and pose no threat to continuing output growth within an extended time horizon. In contrast, temporary or prolonged supply crunches are indeed plausible, even likely, on account of growing resource nationalism denying access to efficient exploitation of the existing resource wealth.

Fundamental, electron transfer mechanism by pyrylium-type ions for the anticancer drugs 5,6-dimethylxanthenone-4-acetic acid (DMXAA) and flavone-8-acetic acid (FAA).

Science.gov (United States)

Kovacic, Peter

2005-09-01

Pyrylium-type salts derived from DMXAA and FAA are proposed to play an important mechanistic role in anticancer action. Electron transfer (ET) processes apparently initiate cell signaling cascades that lead to the observed effects, such as, antivascular influences, cytokine induction, and apoptosis. Possible participation of nitric oxide and serotonin is discussed. Structure-activity relationships involving DMXAA, FAA, acridines, and quinolines support the hypothetical framework, as well as electrochemistry and photochemistry. Similarity is pointed out to the action of plant hormones, e.g. ethylene. Involvement of ET pathways places the cationic salts within the general mechanistic framework for other anticancer agents. Other drug activities of xanthenones are in accord with the ET approach. Insight into fundamental mechanistic aspects should aid in development of improved drugs in this class through rational design.

Mössbauer spectra of white micas from the Central Western Carpathians Mountains

Science.gov (United States)

Sitek, J.; Sulák, M.; Putiš, M.; Tóth, I.

2010-03-01

Potassium white micas from the rocks included into Cretaceous deformation zones (ca. 100-70 Ma in age) of the Central Western Carpathians were investigated by Mössbauer spectroscopy. White micas formed during a polystage evolution and changing P-T conditions of their crystallization in crustal-scale shear zones. We found criteria for distinguishing generations of celadonite-poor (muscovitic) and celadonite-rich (phengitic) white micas using Mössbauer spectroscopy. This method revealed contrasting spectra characterized by typical quadrupole doublets corresponding to Fe2+ Fe3+ contents in white micas. They are in the range of 2.9-3.0 mm/s for phengite, and 2.6-2.7 mm/s for muscovite. Mössbauer spectra reflect well the chemical changes in white mica aggregates, especially of those close to the end-member muscovite and (alumino-)celadonite compositions.

Clinical relevance of pre and post-transplant immune markers in kidney allograft recipients: anti-HLA and MICA antibodies and serum levels of sCD30 and sMICA.

Science.gov (United States)

Solgi, Ghasem; Furst, Daniel; Mytilineos, Joannis; Pourmand, Gholamreza; Amirzargar, Ali Akbar

2012-03-01

This retrospective study aims to determine the prognostic values of HLA and MICA antibodies, serum levels of sCD30 and soluble form of MHC class I related chain A (sMICA) in kidney allograft recipients. Sera samples of 40 living unrelated donor kidney recipients were tested by ELISA and Flow beads techniques for the presence of anti HLA and MICA antibodies and the contents of sCD30 and sMICA. HLA and MICA antibody specification was performed by LABScreen single antigen beads to determine whether the antibodies were directed against donor mismatches. Within first year post operatively 9 of 40 patients (22.5%) showed acute rejection episodes (ARE) that four of them lost their grafts compared to 31 functioning transplants (P=0.001). The presence of HLA antibodies before and after transplantation was significantly associated with ARE (P=0.01 and P=0.02 respectively). Sensitization to HLA class II antigens pre-transplant was strongly associated with higher incidence of ARE (P=0.004). A significant correlation was found between ARE and appearance of non-donor specific antibodies (P=0.02). HLA antibody positive patients either before or after transplantation showed lower graft survival rates than those without antibodies during three years follow-up (P=0.04 and P=0.02). Anti-MICA antibodies were observed in 8/40(20%) and 5/40(12.5%) of patients pre and post-transplant respectively. Coexistence of HLA and MICA antibodies was shown in 2 of 4 cases with graft loss. A significant increased level of sCD30 at day 14 (P=0.001) and insignificant decreased levels of sMICA pre and post operatively were detected in rejecting transplants compared to functioning graft group. Our findings support the view that monitoring of HLA and MICA antibodies as well as sCD30 levels early after transplant has predictive value for early and late allograft dysfunctions and the presence of these factors are detrimental to graft function and survival. Copyright © 2012 Elsevier B.V. All rights

AVALIAÇÃO FÍSICA, QUÍMICA, BIOQUÍMICA E AGRONÔMICA DE CULTIVARES DE FEIJÃO-GUANDU (CAJANUS CAJAN (L MILL

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SOLANGE GUIDOLIM CANNIATTI-BRAZACA

2009-07-01

Full Text Available

RESUMO: Foram estudadas as características físicas, químicas, bioquímicas e agronômicas de 40 cultivares de feijão-guandu (Cajanus cajan (L Mill provenientes da EMBRAPA de São Carlos (SP e originárias de diversas regiões do Brasil e da Índia. Pode-se observar entre os cultivares variações expressivas no tempo de cocção, no teor de lectinas e na produtividade. Os resultados obtidos quanto ao teor protéico e à digestibilidade do guandu, quando comparadas com os resultados obtidos na literatura, mostraram-se semelhantes aos dos grãos de feijão-comum. Pode-se, também, observar baixos teores de taninos entre os cultivares estudados. Foram selecionados três cultivares por apresentarem melhores características entre os parâmetros estudados. PALAVRAS-CHAVE: Feijão-guandu; proteínas; fatores antinutricionais; produtividade.

Precision Departure Release Capability (PDRC) Overview and Results: NASA to FAA Research Transition

Science.gov (United States)

Engelland, Shawn; Davis, Tom.

2013-01-01

NASA researchers developed the Precision Departure Release Capability (PDRC) concept to improve the tactical departure scheduling process. The PDRC system is comprised of: 1) a surface automation system that computes ready time predictions and departure runway assignments, 2) an en route scheduling automation tool that uses this information to estimate ascent trajectories to the merge point and computes release times and, 3) an interface that provides two-way communication between the two systems. To minimize technology transfer issues and facilitate its adoption by TMCs and Frontline Managers (FLM), NASA developed the PDRC prototype using the Surface Decision Support System (SDSS) for the Tower surface automation tool, a research version of the FAA TMA (RTMA) for en route automation tool and a digital interface between the two DSTs to facilitate coordination.

O uso de técnica eletroquímica para a descontaminação de estruturas cerâmicas vítreas porosas

OpenAIRE

Assis,O. B. G.; Silva,E. R.

2010-01-01

Apresentamos neste trabalho os resultados de ensaios preliminares para avaliar o uso de técnica de eletro-osmose para a remoção de contaminantes orgânicos em estruturas porosas cerâmicas, como filtros ou similares. A técnica consiste em forçar a migração de contaminantes retidos na estrutura interna ou na superfície dos poros por meio da aplicação de tensão controlada em célula eletroquímica projetada para este fim. As moléculas absorvidas na superfície cerâmica estarão sujeitas as ações cisa...

Actitudes y rendimiento académico: su evolución desde química general e inorgánica hasta química orgánica

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María S. Reyes

2014-01-01

Full Text Available Esta investigación tiene un doble propósito, en primer lugar, valorar las actitudes hacia la química de alumnos universitarios de carreras biológicas en dos cursos relacionados con esta disciplina y, por otro lado, relacionar dichas actitudes con el rendimiento académico presentado por los estudiantes. El instrumento elegido para medir las actitudes de los alumnos fue un cuestionario según la escala Likert, encuestándose a la totalidad de estudiantes que cursaban cada uno de los cursos de química analizados: Química General e Inorgánica (QGI y Química Orgánica (QO. Para estimar el rendimiento académico se analizaron actas de parciales y se realizaron cálculos de correlación. Los alumnos que cursaban QGI presentaron actitudes hacia la química valoradas como indiferentes. Sin embargo al finalizar el curso de QO sus actitudes fueron evolucionando favorablemente, ya que la puntuación media obtenida para los ítems positivos y negativos estuvo en el rango de actitudes positivas. Los valores del coeficiente de Pearson obtenidos para los dos cursos estudiados fueron superiores a 0,80, lo que indica una fuerte relación entre las variables implicadas, por lo cual se infiere la importancia de desarrollar actitudes positivas hacia la química para favorecer el rendimiento académico de los alumnos.

Relative left frontal activity in reappraisal and suppression of negative emotion: Evidence from frontal alpha asymmetry (FAA).

Science.gov (United States)

Choi, Damee; Sekiya, Takahiro; Minote, Natsumi; Watanuki, Shigeki

2016-11-01

Previous studies have shown that reappraisal (changing the way that one thinks about emotional events) is an effective strategy for regulating emotion, compared with suppression (reducing emotion-expressive behavior). In the present study, we investigated relative left frontal activity when participants were instructed to use reappraisal and suppression of negative emotion, by measuring frontal alpha asymmetry (FAA). Two electroencephalography (EEG) experiments were conducted; FAA was analyzed while 102 healthy participants (59 men, 43 women) watched negative images after being instructed to perform reappraisal (Experiment 1) and suppression (Experiment 2). Habitual use of reappraisal and suppression was also assessed using the emotion regulation questionnaire (ERQ). The results of Experiment 1 showed that relative left frontal activity was greater when instructed to use reappraisal of negative images than when normally viewing negative images. In contrast, we observed no difference between conditions of instructed suppression and normal viewing in Experiment 2. In addition, in male participants, habitual use of reappraisal was positively correlated with increased relative left frontal activity for instructed reappraisal, while habitual use of suppression did not show a significant correlation with changes in relative left frontal activity for instructed suppression. These results suggest that emotional responses to negative images might be decreased for instructed reappraisal, but not suppression. These findings support previous reports that reappraisal is an effective emotion regulation strategy, compared with suppression. Copyright © 2016 Elsevier B.V. All rights reserved.

Peak power ratio generator

Science.gov (United States)

Moyer, R.D.

A peak power ratio generator is described for measuring, in combination with a conventional power meter, the peak power level of extremely narrow pulses in the gigahertz radio frequency bands. The present invention in a preferred embodiment utilizes a tunnel diode and a back diode combination in a detector circuit as the only high speed elements. The high speed tunnel diode provides a bistable signal and serves as a memory device of the input pulses for the remaining, slower components. A hybrid digital and analog loop maintains the peak power level of a reference channel at a known amount. Thus, by measuring the average power levels of the reference signal and the source signal, the peak power level of the source signal can be determined.

Transparent Indium Tin Oxide Electrodes on Muscovite Mica for High-Temperature-Processed Flexible Optoelectronic Devices.

Science.gov (United States)

Ke, Shanming; Chen, Chang; Fu, Nianqing; Zhou, Hua; Ye, Mao; Lin, Peng; Yuan, Wenxiang; Zeng, Xierong; Chen, Lang; Huang, Haitao

2016-10-26

Sn-doped In 2 O 3 (ITO) electrodes were deposited on transparent and flexible muscovite mica. The use of mica substrate makes a high-temperature annealing process (up to 500 °C) possible. ITO/mica retains its low electric resistivity even after continuous bending of 1000 times on account of the unique layered structure of mica. When used as a transparent flexible heater, ITO/mica shows an extremely fast ramping (solar cells (PSCs) with high efficiency.

Dinamizando el proceso de enseñanzaaprendizaje de la química. Las demostraciones químicas como una opción para cambiar la forma tradicional de enseñar química

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Manuel Molina Caballero

2009-10-01

Full Text Available Creemos que la “quimifobia” que existe a nivel social está generada en buena medida por la forma cómo se realiza la enseñanza de la química en las aulas. Para generar un cambio en las metodologías habituales proponemos, en este trabajo, el uso de las demostraciones químicas, mostrando un ejemplo a partir de la descomposición del peróxido de hidrógeno, buscando la forma de incorporar las demostraciones en el aula y considerando su carácter atractivo, la participación del estudiante, su vínculo conceptual y las cuestiones de seguridad a tener en cuenta. Dejamos a los profesores la propuesta, esperando que con su ayuda quizá podamos dar un toque especial a la enseñanza de la química.

A dinâmica dos homicídios no Nordeste e em Pernambuco

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José Maria Nóbrega Júnior

2010-10-01

Full Text Available O objetivo deste artigo é analisar a dinâmica das mortes por homicídio no Nordeste, região mais violenta do país em termos desse tipo de crime. Indicadores de homicídios foram analisados para todos os estados nordestinos, com ênfase em Pernambuco. A análise dos números demonstra um crescimento das mortes violentas e intencionais na região pelo menos desde o início da década de 1990, com maior impacto nos últimos 10 anos, chegando a ultrapassar os números do Sudeste em 2006. Buscou-se tabular esses números por grupos como faixa etária, nível de escolaridade e por regiões de Pernambuco, revelando-se as diferentes dimensões dessa dinâmica. The aim of the article The dynamics of homicides in the Northeast and Pernambuco is to review the dynamics of deaths by homicide in the Northeast ofBrazil, the most violent region in the country in terms of this kind of crime. Murder rates were analysed for all the North-eastern states, with special focus on Pernambuco. The statistical analysis shows a growth in violent and intentional deaths in the region at least since the start of the 1990s, peaking in the last 10 years and surpassing the figures for the Southeast in 2006. Associations were then sought with groups like age group, level of schooling and by regions of Pernambuco, revealing the different dimensions of the dynamics.

La imagen pública de la química y su relación con la generación de actitudes hacia la química y su aprendizaje

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William Manuel Mora Penagos

2012-04-01

Full Text Available El presente ensayo muestra cómo la imagen popular y escolar de la química se caracteriza por ser negativa, lo que viene incidiendo en la generación de actitudes negativas hacia esta ciencia y su aprendizaje. Las inadecuadas formas de comunicación del conocimiento de la química que se muestran en el cine, la TV y las revistas de ciencia popular, la visión irreconciliable entre ciencia y religión, y la poca claridad de las formas de producción del conocimiento químico mostradas en las aulas de clase, aparecen como las principales causas de esta situación. Superar esta imagen implica reconciliar la visión científica con la visión social de la química, por lo que el conocimiento en epistemología e historia de la química y la línea de investigación conocida como Public Understanding of Science desde el enfoque Ciencia/Tecnología/ Sociedad y Ambiente (CTS-A, son fundamentales para una didáctica de la química orientada hacia la alfabetización en química y a la formación docentes en torno al diseño curricular y la enseñanza de contenidos articulados a la generación de actitudes hacia el impacto social y ambiental de la química.

Teores de nutrientes minerais e metais pesados em açúcar mascavo produzido por diferentes sistemas orgânicos e convencionais

OpenAIRE

Paulo Dirceu Luchini

2014-01-01

Quantificou-se os teores de Cu, Zn, Mn, Fe, Pb e Cd em açúcar mascavo oriundo de canas produzidas por diferentes formas de cultivo de sistemas orgânicos e convencionais. Os metais Pb e Cd foram determinados por espectrometria de absorção atômica com atomização eletrotérmica em forno de grafite (GFAA) e os metais Cu, Zn, Mn e Fe foram determinados por espectrometria de absorção atômica com chama (FAAS). Os teores de Cu, Zn, Mn e Fe foram detectados apenas em valores abaixo do limite recomendad...

Cuscutaceae endémicas del Perú

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Blanca León

2013-10-01

Full Text Available La familia Cuscutaceae es reconocida en el Perú por presentar un género, Cuscuta, y 19 especies (Brako & Zarucchi, 1993, todas ellas hierbas. En este trabajo reconocemos siete especies endémicas, aunque en necesidad de revisión taxonómica y colecciones botánicas; por ello no se aplicaron las categorías y criterios de la UICN. Estos taxones endémicos ocupan principalmente la región Mesoandina, por debajo de los 3200 m de altitud. Aparentemente, sólo una de estas especies se encuentra representada dentro del Sistema Nacional de Áreas Naturales Protegidas por el Estado.

Dilleniaceae endémicas del Perú

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Blanca León

2013-10-01

Full Text Available La familia Dilleniaceae es una adición reciente a la flora endémica peruana; los endemismos han sido recolectados y reconocidos hacia fines de los 1990. Está representada en el Perú por seis géneros y 23 especies (Brako & Zarucchi, 1993; Ulloa Ulloa et al., 2004, la mayoría lianas. En este trabajo reconocemos tres endemismos en dos géneros. Las especies endémicas ocupan la región Bosques Húmedos Amazónicos, entre los 100 y 125 m de altitud. No se encuentra representada en el Sistema Nacional de Áreas Naturales Protegidas por el Estado.

Determination of Fe Content of Some Food Items by Flame Atomic Absorption Spectroscopy (FAAS): A Guided-Inquiry Learning Experience in Instrumental Analysis Laboratory

Science.gov (United States)

Fakayode, Sayo O.; King, Angela G.; Yakubu, Mamudu; Mohammed, Abdul K.; Pollard, David A.

2012-01-01

This article presents a guided-inquiry (GI) hands-on determination of Fe in food samples including plantains, spinach, lima beans, oatmeal, Frosted Flakes cereal (generic), tilapia fish, and chicken using flame atomic absorption spectroscopy (FAAS). The utility of the GI experiment, which is part of an instrumental analysis laboratory course,…

Las cooperativas: Una alternativa económica y social frente a la crisis

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Javier Divar Garteiz-Aurrecoa

2013-12-01

Full Text Available El Cooperativismo nació como alternativa económica y social, impulsado por la piedad religiosa y reglado bajo los principios democráticos. La solidaridad y la democracia económica hacen de las cooperativas  sociedades especialmente resistentes frente a las dificultades económicas.Recibido: 29.05.2013Aceptado: 26.06.2013

Combined discrete nebulization and microextraction process for molybdenum determination by flame atomic absorption spectrometry (FAAS)

International Nuclear Information System (INIS)

Oviedo, Jenny A.; Jesus, Amanda M.D. de; Fialho, Lucimar L.; Pereira-Filho, Edenir R.

2014-01-01

Simple and sensitive procedures for the extraction/preconcentration of molybdenum based on vortex-assisted solidified floating organic drop microextraction (VA-SFODME) and cloud point combined with flame absorption atomic spectrometry (FAAS) and discrete nebulization were developed. The influence of the discrete nebulization on the sensitivity of the molybdenum preconcentration processes was studied. An injection volume of 200 μ resulted in a lower relative standard deviation with both preconcentration procedures. Enrichment factors of 31 and 67 and limits of detection of 25 and 5 μ L -1 were obtained for cloud point and VA-SFODME, respectively. The developed procedures were applied to the determination of Mo in mineral water and multivitamin samples. (author)

PolyaPeak: Detecting Transcription Factor Binding Sites from ChIP-seq Using Peak Shape Information

Science.gov (United States)

Wu, Hao; Ji, Hongkai

2014-01-01

ChIP-seq is a powerful technology for detecting genomic regions where a protein of interest interacts with DNA. ChIP-seq data for mapping transcription factor binding sites (TFBSs) have a characteristic pattern: around each binding site, sequence reads aligned to the forward and reverse strands of the reference genome form two separate peaks shifted away from each other, and the true binding site is located in between these two peaks. While it has been shown previously that the accuracy and resolution of binding site detection can be improved by modeling the pattern, efficient methods are unavailable to fully utilize that information in TFBS detection procedure. We present PolyaPeak, a new method to improve TFBS detection by incorporating the peak shape information. PolyaPeak describes peak shapes using a flexible Pólya model. The shapes are automatically learnt from the data using Minorization-Maximization (MM) algorithm, then integrated with the read count information via a hierarchical model to distinguish true binding sites from background noises. Extensive real data analyses show that PolyaPeak is capable of robustly improving TFBS detection compared with existing methods. An R package is freely available. PMID:24608116

Principios de laboratorio y aplicaciones en la práctica clínica de las técnicas moleculares, genómicas y proteómicas

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Jenny Hernández Betancourt

2014-10-01

Full Text Available La heterogénea expresión clínica de las enfermedades, la necesidad de la interpretación de los procesos fisiológicos y fisiopatológicos, así como la búsqueda incesante de nuevas estrategias diagnósticas y terapéuticas, han conducido al desarrollo de las biociencias, en particular de la genética, la genómica, la biología molecular y las tecnologías asociadas. Han emergido en los últimos años disciplinas como la trascriptómica, la epigenómica, la proteómica y la metabolómica, cada una con un objeto de estudio determinado, que deriva de los tipos moleculares específicos y sus relaciones y todas con aplicaciones potenciales dentro de una nueva medicina con un enfoque personalizado. Hoy se dispone de técnicas moleculares que se basan en la hibridación de ácidos nucleicos, tanto in situ como el dot-blot, el Southern blot y el Northern blot. Otros métodos requieren la amplificación del ADN, como la reacción en cadena de la polimerasa, los microarreglos y la secuenciación. La proteómica se perfila como una potente herramienta para el estudio de aspectos fisiológicos y patológicos del ser humano; sus técnicas incluyen la electroforesis bidimensional, la espectrometría de masas y las micromatrices de proteínas. La búsqueda activa de biomarcadores a partir de casi todos los líquidos biológicos y tejidos de varias naturalezas es una de las principales aplicaciones de la proteómica. Es importante atender, comprender e introducir estos nuevos métodos en la práctica clínica por sus potencialidades para el diagnóstico, el desarrollo de estrategias terapéuticas, la predicción y estratificación de riesgo, de la resistencia al tratamiento y las posibilidades de supervivencia

Funciones Económicas en un Entorno Incierto

OpenAIRE

Lazzari, Luisa L; Chiodi, Jorge A; Moulia, Patricia I

2015-01-01

El mundo está atravesando una de las crisis económicas más profundas de los últimos tiempos. Los escenarios actuales y futuros están plagados de incertidumbre que, en general, no se considera en el análisis de las distintas funciones económicas de interés para el desarrollo del negocio, y la realidad se representa mediante modelos estáticos y casi perfectos del comportamiento de los mercados. La teoría de conjuntos borrosos permite construir modelos adecuados a partir de realidades inciertas ...

CD56+ immune cell infiltration and MICA are decreased in breast lobules with fibrocystic changes.

Science.gov (United States)

Kerekes, Daniel; Visscher, Daniel W; Hoskin, Tanya L; Radisky, Derek C; Brahmbhatt, Rushin D; Pena, Alvaro; Frost, Marlene H; Arshad, Muhammad; Stallings-Mann, Melody; Winham, Stacey J; Murphy, Linda; Denison, Lori; Carter, Jodi M; Knutson, Keith L; Degnim, Amy C

2018-02-01

While the role of natural killer (NK) cells in breast cancer therapy has been investigated, little information is known about NK cell function and presence in nonmalignant and premalignant breast tissue. Here, we investigate and quantify NK cell marker CD56 and activating ligand MICA in breast tissue with benign breast disease. Serial tissue sections from 88 subjects, 44 with benign breast disease (BBD) who remained cancer-free, and 44 with BBD who later developed cancer, were stained with H&E, anti-MICA, and anti-CD56. Up to ten representative lobules were identified on each section. Using digital image analysis, MICA and CD56 densities were determined for each lobule, reported as percent of pixels in the lobule that registered as stained by each antibody. Analyses were performed on a per-subject and per-lobule basis. Per-subject multivariate analyses showed associations of CD56 and MICA with age: CD56 was increased in older subjects (p = 0.03), while MICA was increased in younger subjects (p = 0.005). Per-lobule analyses showed that CD56 and MICA levels were both decreased in lobules with fibrocystic change, with median levels of CD56 and MICA staining, respectively, at 0.31 and 7.0% in fibrocystic lobules compared to 0.76 and 12.2% in lobules without fibrocystic change (p fibrocystic lobules, proliferative/atypical lobules showed significantly lower expression compared to nonproliferative lobules for MICA (p = 0.02) but not for CD56 (p = 0.80). Levels of CD56+ NK cells and activating ligand MICA were decreased in breast lobules with fibrocystic change, and MICA levels showed a significant stepwise decrease with increasing histopathologic abnormality. MICA levels were also significantly decreased in older subjects, who generally have higher risk of developing cancer. These findings advance a model in which MICA promotes cytotoxic activity in CD56+ NK cells to protect against tumorigenesis in breast lobules, and suggest further research is warranted.

Enroute NASA/FAA low-frequency propfan test in Alabama (October 1987): A versatile atmospheric aircraft long-range noise prediction system

Science.gov (United States)

Tsouka, Despina G.

In order to obtain a flight-to-static noise prediction of an advanced Turboprop (propfan) Aircraft, FAA went on an elaboration of the data that were measured during a full scale measuring program that was conducted by NASA and FAA/DOT/TSC on October 1987 in Alabama. The elaboration process was based on aircraft simulation to a point source, on an atmospheric two dimensional noise model, on the American National Standard algorithm for the calculation of atmospheric absortion, and on the DOT/TSC convention for ground reflection effects. Using the data of the Alabama measurements, the present paper examines the development of a generalized, flexible and more accurate process for the evaluation of the static and flight low-frequency long-range noise data. This paper also examines the applicability of the assumptions made by the Integrated Noise Model about linear propagation, of the three dimensional Hamiltonian Rays Tracing model and of the Weyl-Van der Pol model. The model proposes some assumptions in order to increase the calculations flexibility without significant loss of accuracy. In addition, it proposes the usage of the three dimensional Hamiltonian Rays Tracing model and the Weyl-Van der Pol model in order to increase the accuracy and to ensure the generalization of noise propagation prediction over grounds with variable impedance.

Influencia de la autoeficacia académica y la procrastinación académica sobre el cansancio emocional de estudiantes de la Universidad Alas Peruanas, Lima, 2015

OpenAIRE

Gutiérrez Torres, Andrés Martín

2015-01-01

Objetivo: determinar cuánta es la influencia de la autoeficacia académica y la procrastinación académica sobre el cansancio emocional de estudiantes de la Universidad Alas Peruanas, Lima, 2015. Metodología: se usó un diseño observacional, transversal, retrospectivo y correlacional-causal. La muestra no probabilística fue de 332 estudiantes de Psicología de una universidad privada de Lima, quienes fueron evaluados con tres instrumentos: Escala de Autoeficacia para Situaciones Académicas, E...

Peak capacity and peak capacity per unit time in capillary and microchip zone electrophoresis.

Science.gov (United States)

Foley, Joe P; Blackney, Donna M; Ennis, Erin J

2017-11-10

The origins of the peak capacity concept are described and the important contributions to the development of that concept in chromatography and electrophoresis are reviewed. Whereas numerous quantitative expressions have been reported for one- and two-dimensional separations, most are focused on chromatographic separations and few, if any, quantitative unbiased expressions have been developed for capillary or microchip zone electrophoresis. Making the common assumption that longitudinal diffusion is the predominant source of zone broadening in capillary electrophoresis, analytical expressions for the peak capacity are derived, first in terms of migration time, diffusion coefficient, migration distance, and desired resolution, and then in terms of the remaining underlying fundamental parameters (electric field, electroosmotic and electrophoretic mobilities) that determine the migration time. The latter expressions clearly illustrate the direct square root dependence of peak capacity on electric field and migration distance and the inverse square root dependence on solute diffusion coefficient. Conditions that result in a high peak capacity will result in a low peak capacity per unit time and vice-versa. For a given symmetrical range of relative electrophoretic mobilities for co- and counter-electroosmotic species (cations and anions), the peak capacity increases with the square root of the electric field even as the temporal window narrows considerably, resulting in a significant reduction in analysis time. Over a broad relative electrophoretic mobility interval [-0.9, 0.9], an approximately two-fold greater amount of peak capacity can be generated for counter-electroosmotic species although it takes about five-fold longer to do so, consistent with the well-known bias in migration time and resolving power for co- and counter-electroosmotic species. The optimum lower bound of the relative electrophoretic mobility interval [μ r,Z , μ r,A ] that provides the maximum

NASA,FAA,ONERA Swept-Wing Icing and Aerodynamics: Summary of Research and Current Status

Science.gov (United States)

Broeren, Andy

2015-01-01

NASA, FAA, ONERA, and other partner organizations have embarked on a significant, collaborative research effort to address the technical challenges associated with icing on large scale, three-dimensional swept wings. These are extremely complex phenomena important to the design, certification and safe operation of small and large transport aircraft. There is increasing demand to balance trade-offs in aircraft efficiency, cost and noise that tend to compete directly with allowable performance degradations over an increasing range of icing conditions. Computational fluid dynamics codes have reached a level of maturity that they are being proposed by manufacturers for use in certification of aircraft for flight in icing. However, sufficient high-quality data to evaluate their performance on iced swept wings are not currently available in the public domain and significant knowledge gaps remain.

Loranthaceae endémicas del Perú

Directory of Open Access Journals (Sweden)

Blanca León

2013-10-01

Full Text Available La familia Loranthaceae está representada en la flora peruana por 11 géneros y 63 especies (Brako & Zarucchi, 1993; Ulloa Ulloa et al., 2004, la mayoría arbustos. En este trabajo se reconoce 14 especies endémicas en cinco géneros. Los endemismos en esta familia ocupan diversas regiones, como la Mesoandina, Puna Húmeda y Seca y Bosques Muy Húmedos Montanos, desde los 1400 hasta los 4200 m de altitud. Se aplicaron las categorías y criterios de la UICN a 11 especies. Cinco especies endémicas se encuentran representadas en del Sistema Nacional de Áreas Naturales Protegidas por el Estado.

Crassulaceae endémicas del Perú

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Blanca León

2013-10-01

Full Text Available La familia Crassulaceae es reconocida en el Perú por presentar cinco géneros y 29 especies (Brako & Zarucchi, 1993, mayormente arbustos y hierbas. En este trabajo reconocemos 13 especies y dos variedades como endemismos peruanos en tres géneros. Echeveria es el género con el mayor número de especies endémicas. Los taxones endémicos ocupan principalmente las regiones Mesoandina y Puna Húmeda y Seca, entre los 1700 y 4500 m de altitud. Se aplicaron las categorías y criterios de la UICN a nueve taxones. Dos Crassulaceae endémicas están representados dentro del Sistema Nacional de Áreas Naturales Protegidas por el Estado.

Optimal PMU location in power systems using MICA

Directory of Open Access Journals (Sweden)

Seyed Abbas Taher

2016-03-01

Full Text Available This study presented a modified imperialist competitive algorithm (MICA for optimal placement of phasor measurement units (PMUs in normal and contingency conditions of power systems. The optimal PMU placement problem is used for full network observability with the minimum number of PMUs. For this purpose, PMUs are installed in strategic buses. Efficiency of the proposed method is shown by the simulation results of IEEE 14, 30, 57, and 118-bus test systems. Results of the numerical simulation on IEEE-test systems indicated that the proposed technique provided maximum redundancy measurement and minimum request of PMUs so that the whole system could be topologically observable by installing PMUs on the minimum system buses. To verify the proposed method, the results are compared with those of some recently reported methods. When MICA is used for solving optimal PMU placement (OPP, the number of PMUs would be usually equal to or less than those of the other existing methods. Results indicated that MICA is a very fast and accurate algorithm for OPP solution.

Late Paleozoic onset of subduction and exhumation at the western margin of Gondwana (Chilenia Terrane): Counterclockwise P-T paths and timing of metamorphism of deep-seated garnet-mica schist and amphibolite of Punta Sirena, Coastal Accretionary Complex, central Chile (34° S)

Science.gov (United States)

Hyppolito, T.; García-Casco, A.; Juliani, C.; Meira, V. T.; Hall, C.

2014-10-01

In this study, the Paleozoic albite-epidote-amphibolite occurring as meter-sized intercalations within garnet-mica schist at Punta Sirena beach (Pichilemu region, central Chile) is characterized for the first time. These rocks constitute an unusual exposure of subduction-related rocks within the Paleozoic Coastal Accretionary Complex of central Chile. Whereas high pressure (HP) greenschist and cofacial metasediments are the predominant rocks forming the regional metamorphic basement, the garnet-mica schist and amphibolite yield higher P-T conditions (albite-epidote amphibolite facies) and an older metamorphic age. Combining detailed mineral chemistry and textural information, P-T calculations and Ar-Ar ages, including previously published material from the Paleozoic Accretionary Complex of central Chile, we show that the garnet-mica schist and associated amphibolite (locally retrograded to greenschist) are vestiges of the earliest subducted material now forming exotic bodies within the younger HP units of the paleo-accretionary wedge. These rocks are interpreted as having been formed during the onset of subduction at the southwestern margin of Gondwana. However, we show that the garnet-mica schist formed at a slightly greater depth (ca. 40 km) than the amphibolite (ca. 30 km) along the same hot-subduction gradient developed during the onset of subduction. Both lithotypes reached their peak-P conditions at ca. 335-330 Ma and underwent near-isobaric cooling followed by cooling and decompression (i.e., counterclockwise P-T paths). The forced return flow of the garnet-mica schist from the subduction channel started at ca. 320 Ma and triggered the exhumation of fragments of shallower accreted oceanic crust (amphibolite). Cores of phengite (garnet-mica schist) and amphibole (amphibolite) grains have similar chemical compositions in both the S1 and S2 domains, indicating rotation of these grains during the transposition of the burial-related (prograde peak-T) foliation S1

14 CFR 11.61 - May I ask FAA to adopt, amend, or repeal a regulation, or grant relief from the requirements of a...

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false May I ask FAA to adopt, amend, or repeal a regulation, or grant relief from the requirements of a current regulation? 11.61 Section 11.61 Aeronautics... to adopt, amend, or repeal a regulation, or grant relief from the requirements of a current...

Computadores y democracia económica

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Allin Cottrell

2008-12-01

Full Text Available El colapso del socialismo anteriormente existente obedeció a causas integradas en su mecanismo económico, que no son inherentes a todos los socialismos posibles. El artículo muestra que la teoría económica marxista, junto con la informática, proporciona el fundamento para adelantar un programa económico socialista viable y que el desarrollo de la informática y de Internet hace posible la planificación económica. Además, argumenta que el movimiento socialista nunca desarrolló un programa constitucional correcto y que la tecnología moderna abre nuevas oportunidades para la democracia. Por último, revisa los argumentos austriacos contra la posibilidad del cálculo socialista a la luz de la nueva capacidad informática y de las limitaciones del Protocolo de Kyoto.

Farmacogenómica

OpenAIRE

Izaguirre Pasquel, Victor

2014-01-01

La farmacogenómica, área de investigación innovadora y de reciente desarrollo, surge para explicar las diferencias interindividuales en la respuesta a los fármacos y evitar reacciones adversas y costes innecesarios. Básicamente, esta nueva ciencia tiene dos orientaciones, una centrada en el diseño de fármacos para el tratamiento de una enfermedad que tiene un marcado carácter genético y otra, en el diseño de fármacos con menor toxicidad para pacientes con deficiencias y/o alteraciones génicas...

The role of herbometallic preparations in traditional medicine--a review on mica drug processing and pharmaceutical applications.

Science.gov (United States)

Wijenayake, Apsara; Pitawala, Amarasooriya; Bandara, Ratnayake; Abayasekara, Charmalie

2014-09-11

Biotite mica enriched with Fe(2+) ions are widely used as a major mineral ingredient in traditional pharmaceutical science of alchemy (Rasashastra). Abhrak bhasma (mica ash), a pharmaceutical product containing treated mica, is utilized, for example, in Ayurvedic treatments for ailments such as gastritis, renal disease, skin disease and mainly in rejuvenation formulations. However, the untreated mica minerals may be harmful when used directly, as they carry considerably high amounts of trace-elements that can cause undesirable effects in the human body. In order to remove toxic factors and produce readily absorbable materials having high nutrient capacity, specific thermal and chemical treatments (purification, detoxification, particle size reduction and incineration) are performed during the preparation of Rasashastra. This review evaluates the chemical and pharmacological aspects of mica ash as well as the technological aspects of mica ash production. The detailed literature review on the chemistry and scientific basis of mica ash, its preparation techniques, mica alterations and pharmaceutical applications was carried out by using published Ayurvedic text books and research articles, available from Science Direct, on mica minerals, mica ash and their physico-chemical alteration processes and pharmacological applications. During the purification and detoxification procedures, heating followed by quenching (in ionic medium) influences the structural distortion and the development of stress-induced cracks and spallations of the micaceous plates. Thus, the efficient diffusion of the external medium takes place at successive heating and quenching steps. Acidic organic liquids and animal byproducts can enhance the cation exchange capacity and solubility of mica. Further, these natural compounds facilitate the removal of toxic-elements in the structure. When treated-mica and paddy husks are tied up in a cloth and squeezed, particle size reduction and further

Molecular dynamics study of room temperature ionic liquids with water at mica surface

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Huanhuan Zhang

2018-04-01

Full Text Available Water in room temperature ionic liquids (RTILs could impose significant effects on their interfacial properties at a charged surface. Although the interfaces between RTILs and mica surfaces exhibit rich microstructure, the influence of water content on such interfaces is little understood, in particular, considering the fact that RTILs are always associated with water due to their hygroscopicity. In this work, we studied how different types of RTILs and different amounts of water molecules affect the RTIL-mica interfaces, especially the water distribution at mica surfaces, using molecular dynamics (MD simulation. MD results showed that (1 there is more water and a thicker water layer adsorbed on the mica surface as the water content increases, and correspondingly the average location of K+ ions is farther from mica surface; (2 more water accumulated at the interface with the hydrophobic [Emim][TFSI] than in case of the hydrophilic [Emim][BF4] due to the respective RTIL hydrophobicity and ion size. A similar trend was also observed in the hydrogen bonds formed between water molecules. Moreover, the 2D number density map of adsorbed water revealed that the high-density areas of water seem to be related to K+ ions and silicon/aluminum atoms on mica surface. These results are of great importance to understand the effects of hydrophobicity/hydrophicility of RTIL and water on the interfacial microstructure at electrified surfaces. Keywords: Room temperature ionic liquids, Hydrophobicity/hydrophicility, Water content, Electrical double layer, Mica surface

MeV fullerene impacts on mica

Energy Technology Data Exchange (ETDEWEB)

Doebeli, M.; Scandella, L. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Ames, F. [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

1997-09-01

Hillock heights on mica irradiated with MeV C{sub 60} ions have been investigated systematically. Results show that the small range of secondary particles along the track plays a crucial role in defect production. (author) figs., tab., refs.

La elite económica Argentina, 1810-1914

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Roy Hora

2014-12-01

Full Text Available Este artículo analiza los principales rasgos del sector más poderoso de la elite económica argentina del período 1810-1914. El trabajo discute las principales interpretaciones sobre las características y naturaleza de este grupo, pone de relieve algunas de limitaciones de los enfoques más habituales sobre el tema, y sugiere de qué manera conceptualizarlo de forma productiva. Aunque el objeto de este trabajo es la elite económica, todo análisis de este actor supone a la vez una manera de concebir las características del sistema de poder y del entorno económico en el que se desenvuelve la acción de los hombres de fortuna. Por este motivo, este trabajo formula algunas consideraciones generales sobre las características del Estado (argentino y el capitalismo (pampeano, con el fin de precisar mejor qué tipo de elite económica dominó la producción rural y la economía argentina en el período de crecimiento exportador que se extendió desde la Independencia hasta la Primera Guerra Mundial. El trabajo toma distancia de los estudios que enfatizan la importancia de la dimensión política para explicar el proceso de constitución y reproducción de esta elite económica, enfatizando en cambio los determinantes económicos de este proceso. El ensayo no aporta nueva evidencia empírica, sino una reflexión a partir de la literatura existente.

Peak-by-peak correction of Ge(Li) gamma-ray spectra for photopeaks from background

Energy Technology Data Exchange (ETDEWEB)

Cutshall, N H; Larsen, I L [Oak Ridge National Lab., TN (USA)

1980-12-01

Background photopeaks can interfere with accurate measurement of low levels of radionuclides by gamma-ray spectrometry. A flowchart for peak-by-peak correction of sample spectra to produce accurate results is presented.

The nanostructure formation on muscovite mica surface induced by intermediate-energy ions

Energy Technology Data Exchange (ETDEWEB)

Zhou, P.; Zhang, HQ., E-mail: zhanghq@lzu.edu.cn; Zhang, Q.; Liu, Z.; Guan, S.; Wang, G.; Zhou, C.; Jia, J.; Lv, X.; Shao, J.; Cui, Y.; Chen, L.; Chen, X., E-mail: chenxm@lzu.edu.cn

2013-07-15

Muscovite mica sheets were bombarded by lithium, carbon and oxygen ions in the energy range from several hundred keV to several MeV. The induced surface structures were measured in the air with atomic force microscopy (AFM) in the tapping mode. The hillock-like structure on the mica surface was observed. The height of the hillock increases linearly when the energy loss is above 1.2 keV/nm. The induced structures are similar with the similar electronic stopping powers but different projectiles for muscovite mica.

El Derecho de Competencia Económica en la Constitución del Ecuador

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Marcelo Marín Sevilla

2011-12-01

Full Text Available Este trabajo permite establecer las bases de la Constitución Económica y del Derecho de Competencia Constitucionalizado.  También analiza si las normas de Derecho de la Competencia Económica y su doctrina están acorde y son adecuadas frente a la Constitución del Ecuador. El Derecho de la Competencia Económica tiene normas para investigar y sancionar las Prácticas colusorias; los Abusos de posición de dominio; las normas  para el control de concentraciones económicas; las conductas de Abuso de dependencia económica, y las conductas  de competencia desleal.  Siempre la Autoridad de Competencia analizará estas conductas en función del bienestar del mercado y del consumidor.

Peaking-factor of PWR

International Nuclear Information System (INIS)

Morioka, Noboru; Kato, Yasuji; Yokoi, M.

1975-01-01

Output peaking factor often plays an important role in the safety and operation of nuclear reactors. The meaning of the peaking factor of PWRs is categorized into two features or the peaking factor in core (FQ-core) and the peaking factor on the basis of accident analysis (or FQ-limit). FQ-core is the actual peaking factor realized in nuclear core at the time of normal operation, and FQ-limit should be evaluated from loss of coolant accident and other abnormal conditions. If FQ-core is lower than FQ-limit, the reactor may be operated at full load, but if FQ-core is larger than FQ-limit, reactor output should be controlled lower than FQ-limit. FQ-core has two kinds of values, or the one on the basis of nuclear design, and the other actually measured in reactor operation. The first FQ-core should be named as FQ-core-design and the latter as FQ-core-measured. The numerical evaluation of FQ-core-design is as follows; FQ-core-design of three-dimensions is synthesized with FQ-core horizontal value (X-Y) and FQ-core vertical value, the former one is calculated with ASSY-CORE code, and the latter one with one dimensional diffusion code. For the evaluation of FQ-core-measured, on-site data observation from nuclear reactor instrumentation or off-site data observation is used. (Iwase, T.)

Peak-by-peak correction of Ge(Li) gamma-ray spectra for photopeaks from background

International Nuclear Information System (INIS)

Cutshall, N.H.; Larsen, I.L.

1980-01-01

Background photopeaks can interfere with accurate measurement of low levels of radionuclides by gamma-ray spectrometry. A flowchart for peak-by-peak correction of sample spectra to produce accurate results is presented. (orig.)

A QUÍMICA NA ODONTOLOGIA: CONTRIBUIÇÕES PARA O ENSINO

OpenAIRE

Greyce Arrúa Storgatto

2016-01-01

Esta pesquisa considera a temática Química na Odontologia como ponto de partida para a contextualização de conteúdos químicos, a fim de contribuir para o processo de ensino e aprendizagem de conteúdos de Química para estudantes de 3 série do Ensino Médio de uma escola estadual da cidade de Santa Maria, RS. Ao tratar da Química envolvida em materiais comuns na prática odontológica, bem como ao abordar problemas comuns de saúde bucal e aspectos de sua prevenção e tratamento, a Qu...

Evaluation of different time domain peak models using extreme learning machine-based peak detection for EEG signal.

Science.gov (United States)

Adam, Asrul; Ibrahim, Zuwairie; Mokhtar, Norrima; Shapiai, Mohd Ibrahim; Cumming, Paul; Mubin, Marizan

2016-01-01

Various peak models have been introduced to detect and analyze peaks in the time domain analysis of electroencephalogram (EEG) signals. In general, peak model in the time domain analysis consists of a set of signal parameters, such as amplitude, width, and slope. Models including those proposed by Dumpala, Acir, Liu, and Dingle are routinely used to detect peaks in EEG signals acquired in clinical studies of epilepsy or eye blink. The optimal peak model is the most reliable peak detection performance in a particular application. A fair measure of performance of different models requires a common and unbiased platform. In this study, we evaluate the performance of the four different peak models using the extreme learning machine (ELM)-based peak detection algorithm. We found that the Dingle model gave the best performance, with 72 % accuracy in the analysis of real EEG data. Statistical analysis conferred that the Dingle model afforded significantly better mean testing accuracy than did the Acir and Liu models, which were in the range 37-52 %. Meanwhile, the Dingle model has no significant difference compared to Dumpala model.

Una solución dinámica para juegos con utilidades transferibles

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Juan Carlos Cesco

2008-01-01

Full Text Available En este trabajo definimos un tipo de solución dinámica para juegos con utilidades transferibles. La solución dinámica fue introducida por Shenoy (1980 en el marco de juegos abstractos como un medio para describir algunos procesos de negociación. En el contexto de los juegos con utilidades transferibles estudiamos su comportamiento tanto en la clase de los juegos equilibrados (con Core no vacío como en el de los juegos no equilibrados. En esta última subclase mostramos que la solución dinámica debe contener los elementos de ciertos ciclos de preimputaciones denominados ciclos maximales. Estos ciclos aparecen en relación con un esquema dinámico elaborado originalmente para aproximar puntos en el Core de un juego. En la subclase de los juegos equilibrados, la solución dinámica coincide con el Core, lo que establece un enfoque unificado de solución. El problema de existencia de ciclos maximales no está completamente resuelto, pero en algunas subclases de juegos podemos exhibir teoremas de existencia y una descripción completa de la solución dinámica.

EL PAPEL DE LA QUÍMICA ANALÍTICA EN LAS CIENCIAS AMBIENTALES

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María A. Dosal

2014-01-01

Full Text Available En este trabajo se presenta una propuesta para abordar la didáctica de la Química Analítica con enfoque de Química Sostenible y de Control de Calidad. Esta propuesta considera un conocimiento razonado de la reactividad química y el diseño de experiencias prácticas representativas de equilibrios químicos en las que se utilicen técnicas comunes pa ra análisis cuantitativo; las experiencias que se proponen fueron diseñadas de acuerdo c on los Principios de la Química Verde buscando iniciar al futuro profesional en el diseño de procesos químicos escalables a nivel industrial y acordes con los requerimi entos de una civilización sostenible; todas fueron probadas y aceptadas por estudiantes de licenciatura y posgrado.

Layered graphene-mica substrates induce melting of DNA origami

Science.gov (United States)

Green, Nathaniel S.; Pham, Phi H. Q.; Crow, Daniel T.; Burke, Peter J.; Norton, Michael L.

2018-04-01

Monolayer graphene supported on mica substrates induce melting of cross-shaped DNA origami. This behavior can be contrasted with the case of origami on graphene on graphite, where an expansion or partially re-organized structure is observed. On mica, only well-formed structures are observed. Comparison of the morphological differences observed for these probes after adsorption on these substrates provides insights into the sensitivity of DNA based nanostructures to the properties of the graphene monolayer, as modified by its substrate.

Caracterização anatômica e química de folhas de Jacaranda puberula (Bignoniaceae presente na Mata Atlântica

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Maria Bernadete Gonçalves Martins

Full Text Available A espécie Jacaranda puberula (Bignoniaceae é conhecida popularmente como "carobinha" sendo utilizada na medicina popular em comunidades tradicionais. O objetivo deste trabalho foi realizar a caracterização anatômica e química das folhas de J. puberula. Para a análise anatômica utilizou-se a microscopia de luz e microscopia eletrônica de varredura (MEV. Para a análise química utilizou-se a Cromatografia Líquida de Alta Eficiência (CLAE. O mesofilo é dorsiventral, a epiderme unisseriada com cutícula espessa, tricomas glandulares do tipo peltado e tricomas tectores em ambas as faces da epiderme, parênquima clorofiliano com duas a três camadas de células paliçádicas e quatro a cinco camadas de células formando o parênquima lacunoso, de tamanho pequeno, com muitos espaços intercelulares, hipoestomática com nervura pinada. Os estudos através de MEV evidenciaram a epiderme recoberta com cera epicuticular e glândulas peltadas com maior incidência na epiderme da face abaxial, constituídas por oitos células secretoras apicais. A análise cromatográfica do extrato etanólico evidenciou a presença de fitoquinóides e flavonóides.

Ecología química en el bentos antártico

OpenAIRE

Ballesteros, Manuel (Ballesteros Vázquez); Núñez Pons, Laura; Vázquez, J.; Cristobo, F.J.; Taboada Moreno, Sergio; Figuerola Balañá, Blanca; Ávila Escartín, Conxita

2011-01-01

El estudio de las interacciones entre los organismos mediadas por sustancias químicas, lo que se denomina ecología química, nos da información sobre la biología de las especies implicadas, el funcionamiento de la comunidad en que viven y nos puede proporcionar además el conocimiento de nuevas sustancias que pueden ser útiles para el ser humano. En el marco de nuestros estudios sobre la ecología química de los invertebrados antárticos, en el proyecto ECOQUIM (2003-2006) se recolectaron numeros...

Caracterización química de la cerámica arqueológica de Cotahuasi mediante análisis por activación neutrónica

OpenAIRE

Bedregal, Patricia; Mendoza, Pablo; Ubillús, Marco; Montoya, Eduardo

2010-01-01

Se ha determinado las concentraciones de As, Ba, Ce, Co, Cr, Cs, Eu, Fe, Hf, La, Na, Rb, Sb, Sc, Sm, Th, Yb, en 121 fragmentos de cerámicos arqueológicos encontrados en el valle de Cotahuasi, mediante análisis por activación neutrónica instrumental, según el método k-subcero. Se ha comparado los resultados con la composición química elemental de la cerámica Tiwanaku y la cerámica Wari de Ayacucho y Cusco, encontrándose que los grupos de Ayacucho, Cotahuasi, Cusco y Tiwanaku se encuentran sepa...

Multiscale peak detection in wavelet space.

Science.gov (United States)

Zhang, Zhi-Min; Tong, Xia; Peng, Ying; Ma, Pan; Zhang, Ming-Jin; Lu, Hong-Mei; Chen, Xiao-Qing; Liang, Yi-Zeng

2015-12-07

Accurate peak detection is essential for analyzing high-throughput datasets generated by analytical instruments. Derivatives with noise reduction and matched filtration are frequently used, but they are sensitive to baseline variations, random noise and deviations in the peak shape. A continuous wavelet transform (CWT)-based method is more practical and popular in this situation, which can increase the accuracy and reliability by identifying peaks across scales in wavelet space and implicitly removing noise as well as the baseline. However, its computational load is relatively high and the estimated features of peaks may not be accurate in the case of peaks that are overlapping, dense or weak. In this study, we present multi-scale peak detection (MSPD) by taking full advantage of additional information in wavelet space including ridges, valleys, and zero-crossings. It can achieve a high accuracy by thresholding each detected peak with the maximum of its ridge. It has been comprehensively evaluated with MALDI-TOF spectra in proteomics, the CAMDA 2006 SELDI dataset as well as the Romanian database of Raman spectra, which is particularly suitable for detecting peaks in high-throughput analytical signals. Receiver operating characteristic (ROC) curves show that MSPD can detect more true peaks while keeping the false discovery rate lower than MassSpecWavelet and MALDIquant methods. Superior results in Raman spectra suggest that MSPD seems to be a more universal method for peak detection. MSPD has been designed and implemented efficiently in Python and Cython. It is available as an open source package at .

Automated asteroseismic peak detections

DEFF Research Database (Denmark)

de Montellano, Andres Garcia Saravia Ortiz; Hekker, S.; Themessl, N.

2018-01-01

Space observatories such as Kepler have provided data that can potentially revolutionize our understanding of stars. Through detailed asteroseismic analyses we are capable of determining fundamental stellar parameters and reveal the stellar internal structure with unprecedented accuracy. However......, such detailed analyses, known as peak bagging, have so far been obtained for only a small percentage of the observed stars while most of the scientific potential of the available data remains unexplored. One of the major challenges in peak bagging is identifying how many solar-like oscillation modes are visible...... of detected oscillation modes. The algorithm presented here opens the possibility for detailed and automated peak bagging of the thousands of solar-like oscillators observed by Kepler....

Environmental impacts of public transport. Why peak-period travellers cause a greater environmental burden than off-peak travellers

International Nuclear Information System (INIS)

Rietveld, P.

2002-01-01

Given the difference between peak and off-peak occupancy rates in public transport, emissions per traveller kilometre are lower in the peak than in the off-peak period, whereas the opposite pattern is observed for cars. It is argued that it is much more fruitful to analyse environmental effects in marginal terms. This calls for a careful analysis of capacity management policies of public transport suppliers that are facing increased demand during both peak and off-peak periods. A detailed analysis of capacity management by the Netherlands Railways (NS) revealed that off-peak capacity supply is mainly dictated by the demand levels during the peak period. The analysis included the effects of increased frequency and increased vehicle size on environmental impacts, while environmental economies of vehicle size were also taken into account. The main conclusion is that the marginal environmental burden during the peak hours is much higher than is usually thought, whereas it is almost zero during the off-peak period. This implies a pattern that is the precise opposite of the average environmental burden. Thus, an analysis of environmental effects of public transport based on average performance would yield misleading conclusions [nl

Farmacogenómica: Aplicaciones cardiovasculares

Directory of Open Access Journals (Sweden)

Luis Quiñones S., PH.D.

2015-03-01

Este trabajo pretende dar una visión general acerca de farmacogenómica cardiovascular y la posibilidad de utilizar, en la consulta clínica, herramientas genéticas para apoyar la decisión farmacoterapéutica, con el objeto de mejorar la respuesta al tratamiento de enfermedades cardiovasculares, un paso hacia la medicina personalizada en Chile.

Interacciones sociales y explotación económica

Directory of Open Access Journals (Sweden)

Andrés Montaña

2012-01-01

se desarrollan interacciones sociales. El modelo permite identificar la posición de un agente en el espacio social y hacer comparaciones interpersonales. A partir del modelo de interacción social general, planteo un modelo de explotación económica. Una autoridad desde este modelo de explotación puede establecer áreas de restricción para determinar la explotación económica de los agentes. El cálculo de las dotaciones y las combinaciones de éstas, pueden permitir a una autoridad determinar si existe o no explotación de unos agentes por otros, fijar categorías de explotación, e identificar áreas de atención prioritarias. El modelo se podría constituir en una herramienta más apropiada para la identificación de la condición laboral o económica de los niños y niñas.

Drivers of peak sales for pharmaceutical brands

NARCIS (Netherlands)

Fischer, Marc; Leeflang, Peter S. H.; Verhoef, Peter C.

2010-01-01

Peak sales are an important metric in the pharmaceutical industry. Specifically, managers are focused on the height-of-peak-sales and the time required achieving peak sales. We analyze how order of entry and quality affect the level of peak sales and the time-to-peak-sales of pharmaceutical brands.

Antropología Económica: una Reseña Introductoria

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Norberto G. Demonte

2007-12-01

Full Text Available El artículo expone las principales perspectivas teóricas de la antropología económica, entendida como el estudio de los procesos de producción, distribución, circulación y consumo enlas sociedades precapitalistas. Se presenta a la antropología económica comoun área de complementación de esfuerzos entre economistas, historiadores y antropólogos, resaltando su importancia en las facultades de ciencias económicas. Se comentan brevemente las cuestiones fundamentales de esta ciencia,tales como la discusión sobre el carácter abstracto de la economía, la polémica entre sustantivistas y formalistas, los aportes dediversos estudios etnográficos, la perspectiva de la escuela marxista y la controversia entre materialistas y culturalistas. Finalmente, el trabajo detalla las líneas de investigación en América Latina y en Argentina y brinda una abundante bibliografía para profundizar los aspectos de interés para el investigador.

Diagenetic replacement of Micas by Carbonates

NARCIS (Netherlands)

Oele, E.

1961-01-01

In the Ordovician sandstones of the Cantabrian Mountains a replacement of the micas by carbonate minerals could be observed. The absence of metamorphic minerals suggests a diagenetic replacement. This is supported by the finding of the same type of replacement in some undisturbed Pliocene sediments

Analysis of Peak-to-Peak Current Ripple Amplitude in Seven-Phase PWM Voltage Source Inverters

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Gabriele Grandi

2013-08-01

Full Text Available Multiphase systems are nowadays considered for various industrial applications. Numerous pulse width modulation (PWM schemes for multiphase voltage source inverters with sinusoidal outputs have been developed, but no detailed analysis of the impact of these modulation schemes on the output peak-to-peak current ripple amplitude has been reported. Determination of current ripple in multiphase PWM voltage source inverters is important for both design and control purposes. This paper gives the complete analysis of the peak-to-peak current ripple distribution over a fundamental period for multiphase inverters, with particular reference to seven-phase VSIs. In particular, peak-to-peak current ripple amplitude is analytically determined as a function of the modulation index, and a simplified expression to get its maximum value is carried out. Although reference is made to the centered symmetrical PWM, being the most simple and effective solution to maximize the DC bus utilization, leading to a nearly-optimal modulation to minimize the RMS of the current ripple, the analysis can be readily extended to either discontinuous or asymmetrical modulations, both carrier-based and space vector PWM. A similar approach can be usefully applied to any phase number. The analytical developments for all different sub-cases are verified by numerical simulations.

FAAS determination of thallium after preconcentration using nitroso-S and TDBA onto benzophenone

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Mohammad Ali Taher

2005-06-01

Full Text Available Thallium is quantitatively retained by 2-nitroso-1-naphthol-4-sulfonic acid (nitroso-S and tetradecyldimethylbenzylammonium chloride (TDBA onto benzophenone in the pH range 10.0-11.5 from large volumes of aqueous solutions of various samples. After filtration, each solid mass consisting of thallium complex and benzophenone is dissolved with 5 mL of dimethylformamide and the metal was determined by flame atomic absorption spectrophotometry (FAAS. Eight replicate determinations of 10.0 μg/mL of thallium in final dimethylformamide (DMF solution gave a mean absorbance of 0.150 with a relative standard deviation of 1.9%. The sensitivity for 1% absorption was 0.293 μg/mL. The method of extraction and preconcentration is economical, rapid, sensitive, highly selective and satisfactory. The interference of a number of anions and cations has been studied and the optimized conditions developed were utilized for the trace determination of thallium in various samples.

CARACTERIZAÇÃO ANATÔMICA E HISTOQUÍMICA DAS FOLHAS DE EUGENIA UNIFLORA L.

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Rafaela Damasceno Sá

2016-10-01

Full Text Available Eugenia uniflora L., popularmente conhecida como pitangueira, é uma importante frutífera muito utilizada na medicina tradicional brasileira para o tratamento de diarreia e disenteria, gripe, parasitas intestinais, febre, hipertensão e como calmante e diurético. Devido ao seu amplo interesse popular e com o intuito de ampliar as informações farmacobotânicas da espécie, este trabalho tem como objetivo realizar a caracterização anatômica e histoquímica das folhas de E. uniflora. Foram confeccionadas e analisadas em microscópico de luz lâminas semipermanentes contendo secções transversais de pecíolo e lâmina foliar, além de secções paradérmicas de lâmina foliar. Realizou-se também testes histoquímicos em secções transversais de lâmina foliar A análise microscópica permitiu a identificação de estruturas importantes na diagnose da espécie: cavidades secretoras no pecíolo e na lâmina foliar; cristais prismáticos no floema do pecíolo e da lâmina foliar, bem como no mesofilo e nas células parenquimáticas e colenquimáticas da nervura central; drusas estão presentes apenas no parênquima do pecíolo e no mesofilo, parênquima e colênquima da lâmina foliar; presença de cutícula espessa no pecíolo e na lâmina foliar; feixes vasculares bicolaterais e mesofilo dorsiventral, com parênquima paliçádico bisseriado. Através da histoquímica evidenciou-se na lâmina foliar a presença de compostos fenólicos, taninos, lignina, compostos lipofílicos, óleos essenciais, triterpenos e esteroides e cristais de oxalato de cálcio. Os resultados apresentados são úteis para a identificação correta da espécie.

A COMPLEXIDADE ECONÔMICA DOS DIREITOS HUMANOS: UMA DIMENSÃO ESCONDIDA DO DESENVOLVIMENTO HUMANO

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Leilane Serratine Grubba

2012-10-01

Full Text Available Este artigo tem por objeto a complexidade econômica dos direitos humanos, mais precisamente, a investigação da relação entre a complexidade econômica e o desenvolvimento humano. Nesse sentido, objetivou demonstrar a intrínseca relação e dependência do desenvolvimento humano à complexidade econômica dos direitos humanos, que influi na positivação dos direitos, assim como na luta pelo acesso aos bens necessários a uma vida digna. Por meio do método dedutivo, o artigo problematizou a relação entre o ser humano e seu contexto econômico-social para o desenvolvimento da vida em dignidade. Diante disso, em primeiro lugar, foi apresentada a noção de complexidade dos direitos humanos, isto é, as suas múltiplas dimensões. No segundo momento, foi analisada a questão econômica do desenvolvimento humano, ou seja, a relação entre o desenvolvimento da vida digna e a dimensão econômica da sociedade, e, finalmente, foi apresentada a complexidade econômica dos direitos humanos. O desenvolvimento humano não está apenas vinculado à dimensão econômica, mas compreende todas as dimensões (complexidade que perfazem uma vida digna de ser vivida. A vida se desenvolve em dignidade mediante o acesso aos bens materiais e imateriais. As políticas do desenvolvimento humano, nesse sentido, devem se integrar a uma estrutura que apoie um crescimento com equidade e sustentabilidade. Palavras-chave: Pensamento complexo. Complexidade econômica. Direitos humanos. Desenvolvimento humano. Dignidade humana.

Síntesis y Caracterización de Microesferas Cerámicas

NARCIS (Netherlands)

Quercia Bianchi, G.

2007-01-01

El presente estudio se basó en la utilización de materiales de desecho tipo escoria, para la producción de microesferas cerámicas de bajo costo, con el objetivo principal de profundizar en las metodologías de producción de estas a escala nacional. Generalmente las microesferas cerámicas son

VARIABLES MACROECONÓMICAS Y MICROECONÓMICAS QUE INFLUYEN EN LA ESTIMACIÓN DEL COSTO DE CAPITAL: UN ESTUDIO DE CASO

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DANIEL CARDONA ECHEVERRI

2017-01-01

Full Text Available Este artículo identifica y contrasta la significancia estadística de variables macroeconómicas y mi- croeconómicas, que desde la teoría pueden influir sobre el costo de capital. Utilizando información de las empresas listadas en la Bolsa de Valores de Colombia (BVC entre los periodos 2003-4 a 2012-1 y modelos de paneles dinámicos para explicar el Costo de Capital Promedio Ponderado (WACC, se encuentra que la mayoría de las variables propuestas resultan estadísticamente significativas, así mismo se prueba la e xistencia de inercia entre el costo de capital actual y el del periodo pasado.

Cerámicas Estampilladas de Salvatierra de Tormes (Salamanca. Contribución al Estudio de las Cerámicas Tardorromanas del Valle del Duero

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Enrique CERRILLO MARTÍN DE CÁCERES

2009-10-01

Full Text Available Dentro del conjunto de yacimientos del Valle del Duero han sido exhaustivamente analizados diversos materiales en bloque (cuchillos, bronces, vidrios, adornos de uso personal, etc. que ponen de manifiesto una indudable unidad cultural de esta zona en un momento determinado, concretamente en los siglos iv y v d. de C. Sin embargo, y a pesar de que el Prof. Palol promete un estudio sobre las cerámicas tardorromanas de estos yacimientos, añadimos a las ya conocidas un lote bastante homogéneo de cerámicas de factura local, pero que a pesar de ello observan unos caracteres muy concretos e interesantes para el estudio de la cerámica del Duero en estos momentos que siempre han quedado vacíos al clasificar cronológicamente los hallazgos, bien de época romana, o bien de época visigoda.

How to use your peak flow meter

Science.gov (United States)

... meter - how to use; Asthma - peak flow meter; Reactive airway disease - peak flow meter; Bronchial asthma - peak ... 2014:chap 55. National Asthma Education and Prevention Program website. How to use a peak flow meter. ...

Measurement of friction force between two mica surfaces with multiple beam interferometry

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Jung J.C.

2010-06-01

Full Text Available Friction forces play a crucial role in the tribological behaviour of microcomponents and the application of MEMS products. It is necessary to develop a measurement system to understand and control the material characteristics. In this study, a microscopic measurement system based on multiple beam interferometry is developed to measure the friction force between two mica thin films. Some frictional behaviour between the two mica sheets in contact are reported. The evaluated shear strength of mica agrees well to the existing data. It is possible to use the developed system for micro-tribology study.

La influencia socioeconómica en el comportamiento de juego de preescolares

OpenAIRE

Pfeifer, Luzia Iara; Rombe, Patrícia Gonçalves; Santos, Jair Licio Ferreira

2009-01-01

Considerando que o contexto econômico influencia o brincar de crianças, este trabalho teve por objetivo analisar as diferenças entre os brinquedos utilizados por crianças de duas diferentes classes socioeconômicas. Os dados foram coletados junto a 50 mães de crianças com idade entre três e seis anos, metade pertencentes à classe econômica A2 (Grupo 2), e a outra metade pertencente à classe econômica D (Grupo 1), segundo o Critério Brasil. Os resultados apontam para a existência de diferenças ...

El origen de la cerámica en el Este de Asia

OpenAIRE

Sola Fernández de Zuazo, Garazi

2017-01-01

Este trabajo trata sobre el origen de la cerámica. Las teorías tradicionales situaban esta innovación en el Próximo Oriente durante la “Revolución Neolítica” descrita por Gordon Childe. En cambio, los nuevos descubrimientos realizados en yacimientos del Este de Asia nos muestran que la cerámica apareció varios milenios antes en esta zona. La cerámica más antigua fue hallada en yacimientos en cuevas del sur de China y presenta una cronología varios milenios anterior a la aparición de asentamie...

Molecular regulation of MICA expression after HDAC inhibitor treatment of cancer cells

DEFF Research Database (Denmark)

Jensen, Helle

and NKG2D-ligands are upregulated on the surface of abnormal cells. We have previously shown that cancer cells can be stimulated to express the NKG2D-ligands MICA/B after exposure to HDAC-inhibitors (HDAC-i), an occurrence that is not observed in healthy cells. Here we characterize the molecular signal...... pathways that lead to MICA expression after HDAC-inhibitor treatment of cancer cells. Chelating Calcium with Bapta-AM or EGTA potently inhibited HDAC-inhibitor and CMV mediated MICA/B expression. It was further observed that ER Calcium stores were depleted after HDAC-inhibitor treatment. NF-kB activity can...

Enseñanza de química a alumnos con discapacidad visual

OpenAIRE

Gerson de Souza, M.; Patrícia Neves, R.; Rejane Ferreira, P.

2009-01-01

La educación formal en Brasil tiene como primer principio la “igualdad de condiciones de acceso y permanencia en la escuela” (Brasil, 1996). En este contexto, el proyecto “Enseñanza de Química a Alumnos con Discapacidad Visual” busca desarrollar recursos y metodologías para una enseñanza de Química que atienda alumnos con ceguera o baja visión. En este proyecto, con el objetivo de atender alumnos y profesores de la enseñanza secundaria, iniciamos la adaptación del libro “Química e Sociedade” ...

Aprendizaje autorregulado, metas académicas y rendimiento en evaluaciones de estudiantes universitarios

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Marcela Valencia Serrano

2013-01-01

Full Text Available Objetivo. Explorar la relación entre aprendizaje autorregulado, metas académicas y rendimiento en una evaluación académica de ocho estudiantes universitarias. Método. Se realizó una entrevista semi- estructurada, una observación directa de una sesión de estudio y protocolos verbales durante y después de la sesión. Resultados. En relación con las metas académicas, se encontró que tres estudiantes tuvieron u na única orientación a metas de dominio por aproximación, mientras que cinco orien taron a múltiples metas académicas. Respecto al aprendizaje autorregulado, se encontraron estudiantes con b ajos y altos niveles. En la relación entre aprendizaje autorregulado, metas académicas y rendimiento en la evaluación fue posible identificar tres grupos de estudiantes: (a altos niveles de autorregulación y orientación única a metas de dominio por aproximación, (b bajos niveles de autorregulación y múltipl e orientación a metas de dominio y ejecución en tendencias de aproximación y evitación, y (c variaciones en el nivel de autorregulación con múltiple orientación a metas académicas. Todas las estudiantes obtuvieron cali ficaciones aprobatorias en la evaluación, independientemente de su nivel de autorregulación y de la orientaci ón a metas académicas. Conclusión. El abordaje procedimental del aprendizaje autorregulado, en función de las metas académicas, permitió obtener información relevante para la comprensión de este proceso, por lo que se recomienda seguir realizando este tipo de estudios para dar cuenta de los diferentes fu ncionamientos de las estudiantes universitarias en tiempo real, de sus variaciones y relación con otros aspectos motivacionales involucrados en sus procesos de aprendizaje.

Caracterización de la región cromosómica 15q11-q13 del genoma humano. Variabilidad genómica en el autismo e identificación de ncRNAs

OpenAIRE

Cerrato Rivera, Celia

2007-01-01

La tesis doctoral con título "Caracterización de la región cromosómica 15q11-13 del genoma humano. Variabilidad genómica en el autismo e identificación de ncRNAs" se basa en el estudio de la región cromosómica 15q11-q13, centrándonos en los aspectos de la variabilidad genómica y su significado funcional. En la primera parte del estudio buscamos reordenamientos de 15q11-q13 en pacientes con autismo, mediante la genotipación de marcadores microsatélites cubriendo dicha región, y definimos una d...

La industria cerámica brasileña

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Pacheco Jordao, M. A.

2001-02-01

Full Text Available Ceramics play an important role in the Brazilian economy, with a participation estimated in 1% of the GNP ( Gross National Product, corresponding to about 6 billion dollars. The abundance of natural raw-materials, alternative energy sources, and the availability of practical technologies within the industrial equipments, caused a rapid evolution of the Brazilian industries, and several types of products from the various ceramic segments attained international quality levels, with significative exportation. He ceramic sector is very diverse and can be divided into the following classes: heavy clay ceramics, wall and floor tiles, refractory materials, sanitary ware, porcelain electric insulators, tableware, decorative china, ceramic filters and reservoirs for domestic use, technical ceramics, and thermal insulators. All these segments exist in Brazil, in a higher or lower stage of development and production capacity. Moreover, there are also manufacturers of synthetic glazes and colorants, plaster of paris, equipments and some auxiliary chemicals. In this paper, an overview of the main Brazilian ceramic segments is presented, excluding the glass, cement, and lime sectors, which, despite being ceramic, are generally treated in separate.

La cerámica juega un papel muy importante para la economía del país brasileño con una participación en el P.I.B (Producto Interior Bruto estimado en el 1%, correspondiendo a cerca de 6 millones de dólares. La abundancia de materias primas naturales, fuentes alternativas de energía y una amplia tecnología incorporada a los equipos industriales, han hecho que las industrias brasileñas evolucionasen rápidamente de forma que muchos tipos de productos de diferentes segmentos de la actividad cerámica alcanzasen niveles de calidad mundial, con cifras apreciables destinadas a la exportación. El sector industrial de la cerámica incluye producciones muy diversificados y puede ser dividido en los siguientes

Broad MICA/B Expression in the Small Bowel Mucosa: A Link between Cellular Stress and Celiac Disease

Science.gov (United States)

Allegretti, Yessica L.; Bondar, Constanza; Guzman, Luciana; Cueto Rua, Eduardo; Chopita, Nestor; Fuertes, Mercedes; Zwirner, Norberto W.; Chirdo, Fernando G.

2013-01-01

The MICA/B genes (MHC class I chain related genes A and B) encode for non conventional class I HLA molecules which have no role in antigen presentation. MICA/B are up-regulated by different stress conditions such as heat-shock, oxidative stress, neoplasic transformation and viral infection. Particularly, MICA/B are expressed in enterocytes where they can mediate enterocyte apoptosis when recognised by the activating NKG2D receptor present on intraepithelial lymphocytes. This mechanism was suggested to play a major pathogenic role in active celiac disease (CD). Due to the importance of MICA/B in CD pathogenesis we studied their expression in duodenal tissue from CD patients. By immunofluorescence confocal microscopy and flow cytometry we established that MICA/B was mainly intracellularly located in enterocytes. In addition, we identified MICA/B+ T cells in both the intraepithelial and lamina propria compartments. We also found MICA/B+ B cells, plasma cells and some macrophages in the lamina propria. The pattern of MICA/B staining in mucosal tissue in severe enteropathy was similar to that found in in vitro models of cellular stress. In such models, MICA/B were located in stress granules that are associated to the oxidative and ER stress response observed in active CD enteropathy. Our results suggest that expression of MICA/B in the intestinal mucosa of CD patients is linked to disregulation of mucosa homeostasis in which the stress response plays an active role. PMID:24058482

Caracterização fitoquímica e físico-química das folhas de Bauhinia forficata Link coletada em duas regiões brasileiras

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Graziella Silvestre Marques

2012-01-01

Full Text Available Folhas da espécie vegetal Bauhinia forficata Link, popularmente conhecida como pata de vaca, apresentam amplo potencial terapêutico no tratamento do diabetes mellitus. Amostras desta espécie vegetal, obtidas em duas regiões do Brasil (Minas Gerais e Paraná, foram submetidas à caracterização fitoquímica e físico-química (granulometria, perda por dessecação, teor de cinzas e teor de extrativos para realização de um estudo comparativo entre indivíduos cultivados em regiões distintas, bem como estabelecimento de especificações para seu controle de qualidade. Para a caracterização fitoquímica, extratos metanólicos das amostras foram avaliados através de cromatografia de camada delgada (CCD para pesquisa das principais classes de metabolitos secundários. Enquanto que, para as análises físico-químicas foram adotadas metodologias farmacopeicas. A análise estatística dos dados realizouse através dos testes F de Fischer e t de Student. De acordo com a avaliação fitoquímica foi possível observar um perfil similar para ambas as amostras com presença dos seguintes grupos: flavonóides, proantocianidinas, leucoantocianidinas, triterpenos, esteróides, açúcares redutores, além de substâncias antioxidantes com bandas coincidentes às dos compostos flavonoídicos. Por outro lado, as amostras apresentaram algumas propriedades físico-químicas diferentes tais como granulometria e umidade residual em virtude da origem e do processamento adotados pelos fornecedores. Já os valores do teor de cinzas mostraram-se dentro das especificações e não foi observada diferença significativa para o teor de extrativos. Os resultados obtidos neste trabalho contribuíram no processo de identificação e padronização de parâmetros de qualidade para as folhas de B. forficata.

Influence of the surface free energy of silane-coupled mica substrate on the fixing and straightening of DNA

International Nuclear Information System (INIS)

Sasou, Megumi; Sugiyama, Shigeru; Ishida, Takao; Ohtani, Toshio; Miyake, Koji

2009-01-01

Methyltrimethoxysilane (MTMS)-coupled mica substrate is reportedly suitable for fixing and straightening of DNA, but 3-aminopropyltriethoxysilane (APTES)-coupled mica substrate has been found less suitable. On MTMS-coupled mica substrate, the straightness of fixed DNA was sufficient, and the adsorption of contaminants was not observed using fluorescence microscopy and atomic force microscopy. For the APTES-coupled mica substrate, however, aggregated or curved DNA and adsorption of contaminants were observed. To clarify the surface factors that are responsible for this suitability, we analyzed the surface free energies of these substrates using the extended Fowkes theory. In each of the surface free energy components, the dispersion force component in the MTMS-coupled mica substrate was lower than that in the APTES-coupled mica substrate. The ratio of the polar force component on the MTMS-coupled mica substrate was about one order of magnitude on the APTES-coupled mica substrate. In addition, the ratio of the hydrogen-bonding force component for the MTMS-coupled mica substrate was about two times larger than that of the APTES-coupled mica substrate. These results suggest that the polar force and hydrogen-bonding force components are important factors for the fixation and straightening of DNA and that the dispersion force components influence the production and adsorption of contaminants.

La Alianza del Pacífico y Mercosur: evidencias de convergencia económica

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José Ustorgio Mora Mora

2016-10-01

Full Text Available Mediante el cálculo de un índice de convergencia económica y el análisis de correlaciones entre varias variables macroeconómicas, se estudia la posibilidad de convergencia económica entre los países miembros de la Alianza del Pacífico con los de Mercosur. Para ello se utiliza información estadística del periodo 1980-2014. A partir de lo anterior, los resultados no son concluyentes, no es posible determinar el rumbo a seguir por estos dos acuerdos para una expansión y una mayor integración económica, aunque los patrones observados sobre las decisiones de los países miembros para este objetivo sugieren que esta pudiera ser bastante factible en el mediano plazo y el índice de convergencia económica refleja esa tendencia. Sin embargo, el análisis de correlaciones no permite establecer una conclusión definitiva.

Não-linearidades: da dinâmica do simples à dinâmica do complexo

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José Roberto Castilho Piqueira

1994-01-01

Full Text Available Foram apresentados alguns conceitos relativos à utilização da Teoria dos Sistemas Dinâmicos em problemas de sistemas complexos. A apresentação destes conceitos centra-se no estabelecimento de duas dinâmicas: uma de curto termo e outra de longo termo, relacionando-as com os processos de organização dos sistemas.

Association of MICA gene polymorphisms with liver fibrosis in schistosomiasis patients in the Dongting Lake region

Energy Technology Data Exchange (ETDEWEB)

Gong, Zheng; Luo, Qi-Zhi; Lin, Lin [Department of Immunology, College of Basic Medical Sciences, Central South University, Changsha, Hunan Province (China); Su, Yu-Ping; Peng, Hai-Bo [Central Blood Bank in Yueyang, Yueyang, Hunan Province (China); Du, Kun; Yu, Ping [Department of Immunology, College of Basic Medical Sciences, Central South University, Changsha, Hunan Province (China); Wang, Shi-Ping [Key Laboratory of Schistosomiasis in Hunan, Department of Parasitology, College of Basic Medical Sciences, Central South University, Changsha, Hunan Province (China)

2012-03-02

Major histocompatibility complex class I chain-related A (MICA) is a highly polymorphic gene located within the MHC class I region of the human genome. Expressed as a cell surface glycoprotein, MICA modulates immune surveillance by binding to its cognate receptor on natural killer cells, NKG2D, and its genetic polymorphisms have been recently associated with susceptibility to some infectious diseases. We determined whether MICA polymorphisms were associated with the high rate of Schistosoma parasitic worm infection or severity of disease outcome in the Dongting Lake region of Hunan Province, China. Polymerase chain reaction-sequence specific priming (PCR-SSP) and sequencing-based typing (SBT) were applied for high-resolution allele typing of schistosomiasis cases (N = 103, age range = 36.2-80.5 years, 64 males and 39 females) and healthy controls (N = 141, age range = 28.6-73.3 years, 73 males and 68 females). Fourteen MICA alleles and five short-tandem repeat (STR) alleles were identified among the two populations. Three (MICA*012:01/02, MICA*017 and MICA*027) showed a higher frequency in healthy controls than in schistosomiasis patients, but the difference was not significantly correlated with susceptibility to S. japonicum infection (Pc > 0.05). In contrast, higher MICA*A5 allele frequency was significantly correlated with advanced liver fibrosis (Pc < 0.05). Furthermore, the distribution profile of MICA alleles in this Hunan Han population was significantly different from those published for Korean, Thai, American-Caucasian, and Afro-American populations (P < 0.01), but similar to other Han populations within China (P > 0.05). This study provides the initial evidence that MICA genetic polymorphisms may underlie the severity of liver fibrosis occurring in schistosomiasis patients from the Dongting Lake region.

Association of MICA gene polymorphisms with liver fibrosis in schistosomiasis patients in the Dongting Lake region

International Nuclear Information System (INIS)

Gong, Zheng; Luo, Qi-Zhi; Lin, Lin; Su, Yu-Ping; Peng, Hai-Bo; Du, Kun; Yu, Ping; Wang, Shi-Ping

2012-01-01

Major histocompatibility complex class I chain-related A (MICA) is a highly polymorphic gene located within the MHC class I region of the human genome. Expressed as a cell surface glycoprotein, MICA modulates immune surveillance by binding to its cognate receptor on natural killer cells, NKG2D, and its genetic polymorphisms have been recently associated with susceptibility to some infectious diseases. We determined whether MICA polymorphisms were associated with the high rate of Schistosoma parasitic worm infection or severity of disease outcome in the Dongting Lake region of Hunan Province, China. Polymerase chain reaction-sequence specific priming (PCR-SSP) and sequencing-based typing (SBT) were applied for high-resolution allele typing of schistosomiasis cases (N = 103, age range = 36.2-80.5 years, 64 males and 39 females) and healthy controls (N = 141, age range = 28.6-73.3 years, 73 males and 68 females). Fourteen MICA alleles and five short-tandem repeat (STR) alleles were identified among the two populations. Three (MICA*012:01/02, MICA*017 and MICA*027) showed a higher frequency in healthy controls than in schistosomiasis patients, but the difference was not significantly correlated with susceptibility to S. japonicum infection (Pc > 0.05). In contrast, higher MICA*A5 allele frequency was significantly correlated with advanced liver fibrosis (Pc < 0.05). Furthermore, the distribution profile of MICA alleles in this Hunan Han population was significantly different from those published for Korean, Thai, American-Caucasian, and Afro-American populations (P < 0.01), but similar to other Han populations within China (P > 0.05). This study provides the initial evidence that MICA genetic polymorphisms may underlie the severity of liver fibrosis occurring in schistosomiasis patients from the Dongting Lake region

Combined discrete nebulization and microextraction process for molybdenum determination by flame atomic absorption spectrometry (FAAS); Avaliacao da combinacao da nebulizacao discreta e processos de microextracao aplicados a determinacao de molibdenio por espectrometria de absorcao atomica com chama (FAAS)

Energy Technology Data Exchange (ETDEWEB)

Oviedo, Jenny A.; Jesus, Amanda M.D. de; Fialho, Lucimar L.; Pereira-Filho, Edenir R., E-mail: erpf@ufscar.br [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Quimica

2014-04-15

Simple and sensitive procedures for the extraction/preconcentration of molybdenum based on vortex-assisted solidified floating organic drop microextraction (VA-SFODME) and cloud point combined with flame absorption atomic spectrometry (FAAS) and discrete nebulization were developed. The influence of the discrete nebulization on the sensitivity of the molybdenum preconcentration processes was studied. An injection volume of 200 μ resulted in a lower relative standard deviation with both preconcentration procedures. Enrichment factors of 31 and 67 and limits of detection of 25 and 5 μ L{sup -1} were obtained for cloud point and VA-SFODME, respectively. The developed procedures were applied to the determination of Mo in mineral water and multivitamin samples. (author)

Effect of synthetic mica on the thermal properties of poly(lactic acid

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Diego Holanda Saboya Souza

2014-01-01

Full Text Available Poly(lactic acid/Somasif fluoromica nanocomposites were prepared by melt blending and their thermal properties investigated by DSC, TGA and DMA. Three different types of synthetic mica (Somasif ME-100, Somasif MAE and Somasif MPE were used at different contents (2.5, 5.0 and 7.5 wt %. The melt blending of PLA and these micas is characterized by a considerable reduction in the matrix molecular weight, which decreases when the nanofiller content is increased. For all nanocomposites, the thermal stability increases when mica is added to the polymer, with the Somasif MPE, producing the highest increase of the degradation temperature and highest reduction of Tg.

Automated asteroseismic peak detections

Science.gov (United States)

García Saravia Ortiz de Montellano, Andrés; Hekker, S.; Themeßl, N.

2018-05-01

Space observatories such as Kepler have provided data that can potentially revolutionize our understanding of stars. Through detailed asteroseismic analyses we are capable of determining fundamental stellar parameters and reveal the stellar internal structure with unprecedented accuracy. However, such detailed analyses, known as peak bagging, have so far been obtained for only a small percentage of the observed stars while most of the scientific potential of the available data remains unexplored. One of the major challenges in peak bagging is identifying how many solar-like oscillation modes are visible in a power density spectrum. Identification of oscillation modes is usually done by visual inspection that is time-consuming and has a degree of subjectivity. Here, we present a peak-detection algorithm especially suited for the detection of solar-like oscillations. It reliably characterizes the solar-like oscillations in a power density spectrum and estimates their parameters without human intervention. Furthermore, we provide a metric to characterize the false positive and false negative rates to provide further information about the reliability of a detected oscillation mode or the significance of a lack of detected oscillation modes. The algorithm presented here opens the possibility for detailed and automated peak bagging of the thousands of solar-like oscillators observed by Kepler.

Otra ciencia económica

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Daniel Innerarity

2012-04-01

Full Text Available El autor hace una crítica a la pretensión de la ciencia económica de constituirse como un saber exacto e hiperespecializado al considerar que esta pretensión se ha traducido en una pérdida de la capacidad que es necesaria para comprender la complejidad social de las realidades económicas. Seducida por el objetivo de la exactitud, la economía parece haber olvidado su carácter de construcción social. Además, la economía ha olvidado que es una más entre las ciencias sociales y el largo periodo en el que se ha separado de ellas reivindicando su plena autonomía no ha sido satisfactorio ni para ella ni para el resto de las ciencias sociales. Según el autor la crítica al capitalismo contemporáneo, si quiere ser más radical que moralizante, debe dirigirse a combatir el supuesto realismo de la ciencia económica dominante.The author criticizes the pretension of economic sciences of being an exact science and its tendency to specialization. The consequences of those pretensions are a loss of its capacity to understand the social complexity of the economic realities. The economy, seduced by its aim of exactitude, seems to forget that it is a social construction. Moreover, economy seems to forget that it is just a social science, and for a long period of time economy evolved as a separated and autonomous science; that time was not good neither for economic science neither for social sciences in general. According to the author, if we want to build a more radical and not only moralizing critique to contemporary capitalism, we must criticize the hypothetical realism of the economic science. 

Towards completely miscible PMMA nanocomposites reinforced by shear-stiff, nano-mica.

Science.gov (United States)

Ziadeh, Mazen; Weiss, Stephan; Fischer, Bianca; Förster, Stephan; Altstädt, Volker; Müller, Axel H E; Breu, Josef

2014-07-01

Optimizing the reinforcement of polymers with nanoplatelets requires optimization of the aspect ratio and the moduli of the filler while providing a complete stress transfer. Employing a novel shear-stiff, nano-mica with large aspect ratio, we focus on maximizing the interfacial interaction between filler and matrix. External surfaces of the nano-mica were selectively modified by a polycationic macro-initiator and two PMMA-polymer brushes of length below and above critical entanglement length, respectively, and the mechanical properties of the three PMMA nanocomposites were measured. The multiple electrostatic anchoring groups of the macro-initiator not only provide reliable adhesion but at the same time allow the variation of the degree of protonation providing a local match between the charge densities of the clay surface and the adsorbed macro-initiator. PMMA coating of the nano-mica via surface initiated polymerization yielded long-term stable suspensions in THF that showed birefringence of a nematic phase. Solution blending of the PMMA coated nano-mica allows for dispersing single clay tactoids in the translucent PMMA nanocomposites at 5 wt% clay loading as determined by transmission electron microscopy (TEM). Although significantly improved mechanical properties could be achieved as compared to nanocomposites made with conventional clay fillers, the full potential - as expressed by Halpin-Tsai equations - of the PMMA coated nano-mica can still not be completely utilized. This is attributed to the non-wetting character of the densely packed PMMA brushes attached to planar nanoplatelets. Copyright © 2014 Elsevier Inc. All rights reserved.

Nutrigenómica, obesidad y salud pública.

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Manuela Belén Silveira

2007-01-01

Full Text Available El desarrollo de la genómica funcional en los próximos años condicionará cambios en el conocimiento teórico y la práctica clínica de la nutrición. La posibilidad de determinar el perfil genético de un individuo (variaciones genéticas y modificaciones epigenéticas y de conseguir la integración de estos datos en una compleja red de interacciones metabólicas constituye un desafío sin precedentes en la nutrición humana. La aplicación práctica del conocimiento científico puro derivado de la nutrigenómica, en términos de prevención y tratamiento de la obesidad, la DM2 y las enfermedades cardiovasculares, y sus implicaciones en la salud pública, son en este momento todavía indeterminadas. La posibilidad de una intervención nutricional en periodos críticos del desarrollo y la capacidad de modificar la susceptibilidad genética a ciertas enfermedades a través de la alimentación es el gran reto de la nutrigenómica, más allá del diseño de dietas o alimentos funcionales “personalizados”.

Simultaneous collection method of on-peak window image and off-peak window image in Tl-201 imaging

International Nuclear Information System (INIS)

Murakami, Tomonori; Noguchi, Yasushi; Kojima, Akihiro; Takagi, Akihiro; Matsumoto, Masanori

2007-01-01

Tl-201 imaging detects the photopeak (71 keV, in on-peak window) of characteristic X-rays of Hg-201 formed from Tl-201 decay. The peak is derived from 4 rays of different energy and emission intensity and does not follow in Gaussian distribution. In the present study, authors made an idea for the method in the title to attain the more effective single imaging, which was examined for its accuracy and reliability with phantoms and applied clinically to Tl-201 scintigraphy in a patient. The authors applied the triple energy window method for data acquisition: the energy window setting was made on Hg-201 X-rays photopeak in three of the lower (3%, L), main (72 keV, M) and upper (14%, U) windows with the gamma camera with 2-gated detector (Toshiba E. CAM/ICON). L, M and U images obtained simultaneously were then constructed to images of on-peak (L+M, Mock on-peak) and off-peak (M+U) window settings for evaluation. Phantoms for line source with Tl-201-containing swab and for multi-defect with acrylic plate containing Tl-201 solution were imaged in water. The female patient with thyroid cancer was subjected to preoperative scintigraphy under the defined conditions. Mock on-, off-peak images were found to be equivalent to the true (ordinary, clinical) on-, off-peak ones, and the present method was thought usable for evaluation of usefulness of off-peak window data. (R.T.)

Análise das variações anatômicas do canal da mandíbula encontradas em radiografias panorâmicas

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Yza Daniella Nunes Andrade

Full Text Available INTRODUÇÃO: No âmbito da clínica odontológica, o bloqueio do nervo alveolar inferior é o mais utilizado; todavia, diversos estudos têm mostrado as mais altas taxas de fracasso, as quais, normalmente, têm como motivo a falha na observação da posição, da forma e da anatomia dos nervos. Essas falhas decorrentes da variação anatômica do nervo alveolar inferior já vêm sendo estudadas na literatura, através de estudos com a análise de radiografias panorâmicas, como proposto neste estudo. OBJETIVO: O objetivo deste estudo foi verificar a ocorrência e a prevalência das variações anatômicas, bem como a correlação das variações do canal da mandíbula com lado e sexo, que podem ocorrer no canal mandibular, por meio de radiografias panorâmicas de pacientes atendidos no Departamento de Odontologia da Universidade Federal de Sergipe (UFS. MATERIAL E MÉTODO: Foram analisadas 1.500 radiografias panorâmicas de pacientes atendidos pelo Departamento de Odontologia da Universidade Federal de Sergipe (UFS. Imagens radiográficas foram observadas sobre um negatoscópio, utilizando-se uma máscara preta ao redor das radiografias, em ambiente com luminosidade apropriada. RESULTADO: Neste estudo, foram observados 5,3% de bifurcações do canal mandibular; 47,5% de canais altos; 16,8% de canais intermediários; 27,1% de canais baixos, e 8,6% de canais com outras variações. CONCLUSÃO: Baseando-se na altura do canal mandibular, houve maior prevalência dos canais altos do que os demais nas mulheres, sendo que não houve diferenças entre os gêneros com relação aos demais tipos e lados afetados. Na classificação dos canais bífidos, não houve diferença estatisticamente significante entre homens e mulheres. Observou-se que a maior prevalência foi para canais sem bifurcação.

Bombacaceae endémicas del Perú

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Blanca León

2013-10-01

Full Text Available En este trabajo, la familia Bombacaceae es considerada aparte de las Malvaceae, con la cual se considera forma un grupo natural (ver Judd et al. 1997 y la página de internet de Angiosperm Phylogeny Group. En el Perú, las Bombacaceae incluyen 15 géneros y 56 especies (Brako & Zarucchi, 1993; Ulloa Ulloa et al., 2004, generalmente árboles. Siete especies en cinco géneros son endemismos del país. Estas especies endémicas ocupan principalmente las regiones Bosques Secos y Bosques Húmedos Amazónicos, entre los 1300 y 3000 m de altitud. Se aplicaron las categorías y criterios de la UICN a cuatro especies. Ninguna de las Bombacaceae endémicas está representada en el Sistema Nacional de Áreas Naturales Protegidas por el Estado.

Temas de Física para Ingeniería: Segundo principio de la termodinámica

OpenAIRE

Beléndez Vázquez, Augusto

1992-01-01

Acústica, fluidos y termodinámica: "Segundo principio de la termodinámica". Necesidad y enunciado del segundo principio. Rendimiento de las máquinas térmicas y frigoríficas. Ciclo de Carnot. Escala termodinámica de temperaturas. Entropía. Variaciones de entropía en procesos reversibles e irreversibles. Entropía y segundo principio.

Recubrimientos por PVD decorativos sobre cerámicas

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García, J. A.

2006-08-01

Full Text Available During the last years PVD coatings has been used for decorative purposes on ceramics and other substrates. Standards layers like TiN, CrN, TiCN, etc, give us the possibly of obtaining a wide range of colours, with a good mechanical, chemical properties. This paper gathers the works carried out in the Center of Advance Surface engineering of AIN during the three last years in the field of the decorative coatings. Different layer have been deposited by means of a METAPLAS 232 PVD equipment. A complete chemical and mechanical characterisation have been carried out on the different deposited layers like ultramicroindentation, scratch tests, wear resistance and GDOES.

En los últimos años se ha venido estudiado la aplicabilidad de las técnicas de depósitos mediante métodos físicos en fase vapor (PVD, para la realización de recubrimientos sobre cerámicas y otros substratos con fines decorativos. Los recubrimientos estándar por PVD como el TiN, CrN, TiCN, etc, ofrecen la posibilidad de conseguir acabados de apariencia metálica, de una amplia gama de colores, y con buenas propiedades mecánicas y químicas, como resistencia a la abrasión, estabilidad térmica, o resistencia a la corrosión. En este trabajo se recogen las experiencias realizadas en el recubrimiento y caracterización de cerámicas decorativas, durante los tres últimos años, en el Centro de Ingeniería de Superficies de la Asociación de la Industria Navarra. Los distintos tipos de recubrimientos se han realizado mediante un equipo de PVD modelo METAPLAS 232, con seis evaporadores de arco eléctrico y sistema de limpieza iónica patentado AEGD. Los recubrimientos han sido caracterizados, tanto química como mecánicamente, empleando las más modernas técnicas tribológicas (ultramicrodureza, scrascth tests, resistencia al desgaste... y espectroscópicas óptica por descarga luminiscente (GDOES. Los resultados obtenidos muestran que las técnicas de PVD son una

Sumérgete en la Bioquímica

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Josep M. Fernández Novell

2013-11-01

Full Text Available Hace ya dos años que el Departamento de Bioquímica y Biología Molecular de la Universidad de Barcelona con la colaboración de la SEBBM viene realizando anualmente unas sesiones prácticas de Bioquímica “Sumérgete en la Bioquímica”. Sesiones de mañana o de tarde dirigidas a los jóvenes de tercero y cuarto de la Enseñanza Secundaria Obligatoria (ESO. Estos jóvenes han recibido una información exhaustiva sobre qué es y de qué trata la Bioquímica, al mismo tiempo, han realizado una serie de experimentos en el laboratorio. En éstos, además de aprender las normas de seguridad, cómo utilizar el material volumétrico y las pipetas automáticas, han experimentado sobre: la obtención de ADN de vegetales, cómo medir la concentración de glucosa o de proteína de una muestra utilizando un espectrofotómetro, la producción de una proteína como la GFP en bacterias y las condiciones de precipitación de la caseína de la leche. También, desde Internet, han trabajado sobre cómo extraer el ADN humano y cómo clonar un ratón. Al finalizar cada sesión se recogieron dos tipos de encuestas, una dirigida al alumnado y la otra al profesorado de secundaria para saber el grado de aceptación de dicha actividad. El resultado de unas y otras indica que para todos ellos han sido unas actividades muy apreciadas e interesantes que sirven para aumentar el interés de los estudiantes hacia las ciencias y hacia la Bioquímica en particular. Esta experiencia se ha desarrollado en los laboratorios del Departamento de Bioquímica y Biología Molecular de la UB durante dos semanas entre el mes de Enero y el de Febrero época en que no están ocupados por la enseñanza habitual del Departamento. Este último curso han participado más de 750 estudiantes, la demanda ha superado nuestras previsiones obligándonos a preparar una tercera semana para el curso 2013-2014.

Química recreativa i eines 2.0 per a la didàctica i divulgació de la química

OpenAIRE

Vieta i Corcoy, Pep Anton; Guillaumes, Laia; Güell, Mireia; Duran, Josep; Simon, Sílvia

2012-01-01

Que la societat sovint té una visió negativa de la química i que la recerca científica que té lloc a les universitats es percep com a llunyana per part de la població són fets coneguts. En aquest article, fruit de la presentació feta per l'autor principal a la VII Trobada de Joves Investigadors dels Països Catalans, organitzada el febrer de 2012 per la Societat Catalana de Química (SCQ), es presenten diversos projectes duts a terme des de la Càtedra de Cultura Científica i Comunicació Digi...

Statistical analysis of the low-temperature dislocation peak of internal friction (Bordoni peak) in nanostructured copper

International Nuclear Information System (INIS)

Vatazhuk, E.N.; Natsik, V.D.

2011-01-01

The temperature-frequency dependence of internal friction in the nanostructured samples of Cu and fibred composite C-32 vol.%Nb with the sizes of structure fragments approx 200 nm is analyzed. Experiments are used as initial information for such analysis. The characteristic for the heavily deformed copper Bordoni peak, located nearby a temperature 90 K, was recorded on temperature dependence of vibration decrement (frequencies 73-350 kHz) in previous experiments. The peak is due to the resonance interaction of sound with the system of thermal activated relaxators, and its width considerably greater in comparison with the width of standard internal friction peak with the single relaxation time. Statistical analysis of the peak is made in terms of assumption that the reason of broadening is random activation energy dispersion of relaxators as a result of intense distortion of copper crystal structure. Good agreement of experimental data and Seeger theory considers thermal activated paired kinks at linear segments of dislocation lines, placed in potential Peierls relief valley, as relaxators of Bordoni peak, was established. It is shown that the registered peak height in experiment correspond to presence at the average one dislocation segment in the interior of crystalline grain with size of 200 nm. Empirical estimates for the critical Peierls stress σp ∼ 2x10 7 Pa and integrated density of the interior grain dislocations ρ d ∼ 10 13 m -2 are made. Nb fibers in the composite Cu-Nb facilitate to formation of nanostructured copper, but do not influence evidently on the Bordoni peak.

La racionalidad económica y la secularización

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ANDRÉS BILBAO

1996-01-01

Full Text Available La racionalidad económica es uno de los principales rasgos de la modernidad. Esta racionalidad es, aparentemente, resultado de la ruptura con la vieja superstición religiosa. Sin embargo, sus raíces están en ese mundo religioso, que cree haber superado. en este sentido, el proceso de secularización, del que nace la moderna racionalidad, no es más que la interiorización de los valores religiosos del cristianismo. La creencia de que el individuo, siguiendo sus propios intereses, da lugar a un mundo ordenado, es el rasgo característico de la racionalidad económica. Esta creencia tiene sus raíces en la doctrina cristiana en más de un mundo providencia. El desarrollo de la racionalidad económica no constituye a la superstición religiosa, sino que ella misma, como una nueva forma de superstición, se desarrolla en paralelo con ella.

Catalizadores Organometálicos en la Industria Química

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Alfonso Enrique Ramírez Sanabria

2015-10-01

Full Text Available Los procesos catalíticos son cada vez más importantes en la industria. Gran número de productos químicos incluyen dentro de su producción reacciones catalizadas. La catálisis se entiende como un proceso por el cual se aumenta la velocidad de una reacción química, debido a la participación de una especie química denominada catalizador. El presente trabajo recopila cinco procesos industriales en los cuales son empleados catalizadores organometálicos en fase homogénea. Busca resaltar la importancia que tienen los complejosorganometálicos como catalizadores, para la industria de química fina y farmacéutica. Se detallan aspectos mecanísticos en los que se puede ver el papel del centro metálico en las propiedades catalíticas del sistema, así como en la estructura del producto final.

Vida académica de la facultad

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Facultad de Medicina Revista

1999-10-01

Full Text Available Distinciones académicas / Novedades docentes / Libro' 'Manual de Rehabilitación Médica" / Texto de Obstetricia y Perinatología / xv Curso Anual Medicina Interna / Libros Publicados en la Facultad de Medicina Universidad Nacional De Colombia, 1999.

On the rare elements geochemistry in mica mega crystals from alkaline basaltoids of Southern Tien-Shane

International Nuclear Information System (INIS)

Mogarovskiy, V.V.; Sharapov, N.V.

1992-01-01

Rare elements without coherent in the mica and basalts are divided in 2 groups: First (K, Rb, Pb) in the first stage of meta soma tos are brought, and located in the mica. The second (Li, Cs, Sn) which brings after micas appearing, using in other minerals and without mineral location

Influence of the nonexchangeable potassium of mica on radiocesium uptake by paddy rice

International Nuclear Information System (INIS)

Eguchi, Tetsuya; Ohta, Takeshi; Ishikawa, Tetsuya; Matsunami, Hisaya; Takahashi, Yoshihiko; Kubo, Katashi; Yamaguchi, Noriko; Kihou, Nobuharu; Shinano, Takuro

2015-01-01

A pot cultivation experiment was conducted to elucidate the influence of the nonexchangeable potassium (K) of mica on radiocesium ( 137 Cs) uptake by paddy rice (Oryza sativa L. cv. Koshihikari), and to evaluate the potential of mica application as a countermeasure to reduce radiocesium transfer from soil to paddy rice. The increase in the exchangeable K concentrations of soils, measured before planting, due to mica (muscovite, biotite, and phlogopite) application was negligible. However, in trioctahedral mica (biotite and phlogopite)-treated soil, the release of nonexchangeable K from the mica interlayer maintained the soil-solution K at a higher level during the growing season in comparison to the control, and consequently decreased the 137 Cs transfer factor for brown rice (TF). The sodium tetraphenylboron (TPB)-extractable K concentration of the soils, measured before planting, was strongly negatively correlated with the TF, whereas the exchangeable K concentration of the soils, also measured before planting, was not correlated with the TF. Therefore, we conclude that TPB-extractable K is more reliable than exchangeable K as a basis of fertilizer recommendations for radiocesium-contaminated paddy fields. Phlogopite-treated soils exhibited higher TPB-extractable K concentrations and lower TF values than biotite-treated soils. We thus conclude that phlogopite application is an effective countermeasure to reduce radiocesium uptake in paddy rice. - Highlights: • Nonexchangeable K of added trioctahedral mica decreased 137 Cs uptake by paddy rice. • TPB-extractable K would be a more reliable indicator than exchangeable K. • Phlogopite would be a good amendment for radiocesium-contaminated paddy fields

mica – music information center austria

OpenAIRE

2010-01-01

1994 wurde das österreichische Musikinformationszentrum (mica) im Auftrag des österreichischen Bundesministers für Unterricht und Kunst (Rudolf Scholten) von den Bundeskuratoren für Musik (L. Knessl, Christian Scheib) gegründet (Geschäftsführer 1994–99 Matthias Finkentey, 1999–09 Peter Rantasa, ab 2009 Sabine Reiter).

The peak in neutron powder diffraction

International Nuclear Information System (INIS)

Laar, B. van; Yelon, W.B.

1984-01-01

For the application of Rietveld profile analysis to neutron powder diffraction data a precise knowledge of the peak profile, in both shape and position, is required. The method now in use employs a Gaussian shaped profile with a semi-empirical asymmetry correction for low-angle peaks. The integrated intensity is taken to be proportional to the classical Lorentz factor calculated for the X-ray case. In this paper an exact expression is given for the peak profile based upon the geometrical dimensions of the diffractometer. It is shown that the asymmetry of observed peaks is well reproduced by this expression. The angular displacement of the experimental profile with respect to the nominal Bragg angle value is larger than expected. Values for the correction to the classical Lorentz factor for the integrated intensity are given. The exact peak profile expression has been incorporated into a Rietveld profile analysis refinement program. (Auth.)

Temas de Física para Ingeniería: Dinámica del punto material

OpenAIRE

Beléndez, Augusto; Pastor Antón, Carlos; Bernabeu, Guillermo

1988-01-01

Apuntes de Mecánica: "Dinámica del punto material". Introducción, dinámica del punto. Fuerzas en la naturaleza. Sistemas de referencia. Leyes de Newton. Fuerzas de rozamiento. Ley de la gravitación universal. Aplicación de las leyes de Newton a la resolución de problemas de dinámica. Momento lineal y conservación. Redefinición de fuerza. Momento angular y conservación, fuerzas centrales. Impulso mecánico.

Aprendiendo química con golosinas

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José Manuel Rodríguez Rodríguez

2011-01-01

Full Text Available Las golosinas (caramelos, chicles, nubes, palotes, papas fritas, etc. nos gustan a casi todos y gozan de una imagen positiva, a pesar de sus efectos secundarios si no se consumen con moderación. Aprovechándonos de esa buena imagen y de la gran variedad de golosinas que existen en el mercado, hemos diseñado una serie de experimentos con los que podemos explicar distintos tipos de reacciones químicas (ácido-base, oxidación reducción, endotérmicas¿, la actuación de un indicador e, incluso, podemos comparar cantidades de vitamina C. En todas las actividades se persigue explicar algún aspecto de la Química que, en general, el público desconoce, captando su atención, por ejemplo, mediante cambios de color espectaculares y con las golosinas como protagonistas. Así mismo, estas experiencias pueden emplearse como recursos didácticos para alumnos de 4º E.S.O. y Bachillerato, apoyando los contenidos teóricos del currículum.

Method and apparatus for current-output peak detection

Science.gov (United States)

De Geronimo, Gianluigi

2017-01-24

A method and apparatus for a current-output peak detector. A current-output peak detector circuit is disclosed and works in two phases. The peak detector circuit includes switches to switch the peak detector circuit from the first phase to the second phase upon detection of the peak voltage of an input voltage signal. The peak detector generates a current output with a high degree of accuracy in the second phase.

Experiments on the incorporation of concentrated solutions of fission products in glasses and micas; Essais d'incorporation de solutions concentrees de produits de fission dans des verres et des micas

Energy Technology Data Exchange (ETDEWEB)

Bonniaud, R; Cohen, P; Sombret, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

1) The plants designed for extracting the plutonium of the G1, G2, G3 reactors fuel rods will produce extremely concentrated tions of fission products. 2) Let us consider a synthetic solution of the 'G2' type: (2N NO{sub 3}H - 2,25 meq/cm{sup 3} AI{sup +++} - 5.10{sup -3} {sup 134}Cs - {sup 137}Cs tracer). We made various glasses and micas by adding and mixing the necessary adjuvants and baking (900 to 1400 deg. C) in a graphite crucible. 3) The products obtained had either the shape of a cylindrical pellet or were reduced into a fine powder. They were mixed with 300 cm{sup 3} of synthetic sea water during variable periods of time in order to study leaching of the activity. 4) Experiments were first carried on caesium because of its solubility. 5) Fabrication of micas on a large scale sets many technological problems more difficult to solve (1400 deg. C) than in the case of glasses (1000 deg. C). A comparative study on both micas and glasses showed that leaching of activity was more important in the micas. (author)Fren. [French] 1) La mise en service de l'Usine d'Extraction du Plutonium destinee en particulier au traitement des barres de combustibles de G1, G2, G3 fournira des solutions residuaires concentrees de produits de fission. 2) Partant d'une solution synthetique 'G2': (2N NO{sub 3}H - 2,25meq/cm{sup 3} AI{sup +++} - 5.10{sup -3} {sup 134}Cs - {sup 137}Cs traceur) nous avens realise differents verres et micas apres adduction et melange des adjuvants necessaires suivis de cuisson (900 a 1400 deg. C) dans un creuset de graphite. 3) Les produits obtenus ont ete, soit sous forme d'eprouvette cylindrique, soit sous forme de poudre finement broyee, mis en contact et agites avec 300 cm{sup 3} d'eau de mer synthetique, durant des temps varies pour etudier la retention de l'activite. 4) Le cesium a ete choisi pour ces essais a cause de sa solubilite. 5) La fabrication de micas a grande echelle pose des problemes technologiques plus difficiles (1400 deg. C) a

Gamma-Ray Peak Integration: Accuracy and Precision

International Nuclear Information System (INIS)

Richard M. Lindstrom

2000-01-01

The accuracy of singlet gamma-ray peak areas obtained by a peak analysis program is immaterial. If the same algorithm is used for sample measurement as for calibration and if the peak shapes are similar, then biases in the integration method cancel. Reproducibility is the only important issue. Even the uncertainty of the areas computed by the program is trivial because the true standard uncertainty can be experimentally assessed by repeated measurements of the same source. Reproducible peak integration was important in a recent standard reference material certification task. The primary tool used for spectrum analysis was SUM, a National Institute of Standards and Technology interactive program to sum peaks and subtract a linear background, using the same channels to integrate all 20 spectra. For comparison, this work examines other peak integration programs. Unlike some published comparisons of peak performance in which synthetic spectra were used, this experiment used spectra collected for a real (though exacting) analytical project, analyzed by conventional software used in routine ways. Because both components of the 559- to 564-keV doublet are from 76 As, they were integrated together with SUM. The other programs, however, deconvoluted the peaks. A sensitive test of the fitting algorithm is the ratio of reported peak areas. In almost all the cases, this ratio was much more variable than expected from the reported uncertainties reported by the program. Other comparisons to be reported indicate that peak integration is still an imperfect tool in the analysis of gamma-ray spectra

EL CONGRESO DE KARLSRUHE: PASO DEFINITIVO HACIA LA QUÍMICA MODERNA

Directory of Open Access Journals (Sweden)

Ramón Cid Manzano

2009-01-01

Full Text Available Estamos celebrando en este año 2009 el 140 aniversario de la publicación de la primera tabla periódica y el 90 aniversario de la creación del IUPAC. Ambos acontecimientos se relacionan directamente con el congreso de Karlsruhe llevado a cabo en esa ciudad alemana en 1860. Este congreso fué convocado para que los químicos europeos pudieran discutir sobre asuntos muy controvertidos, como la naturaleza atómica de la materia, la nomenclatura química y los pesos atómicos. El objetivo de este artículo es proporcionar a los lectores algunos datos sobre este congreso para entender mejor cómo la tabla periódica fue desarrollada y cómo la química se convirtió en una ciencia moderna.

El sector inmobiliario y las crisis económicas

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Antonio Daher

2013-09-01

Full Text Available La creciente urbanización de la economía y la doble concentración -económica y territorial- de los sectores inmobiliario y financiero en las metrópolis, fundamentan la relación entre los ciclos inmobiliarios y las crisis económicas detonadas por sus burbujas, la alta incidencia macroeconómica del sector inmobiliario y su rol articulador entre el sector financiero y la economía real. Antes de la última crisis (2008, las instituciones financieras y fondos de inversión inmobiliaria transnacionales encontraron en la financiarización y titulización una vía eficaz para su diversificación geográfica y distribución del riesgo hipotecario. Fue también la vía expedita del contagio de una crisis con ubicuidad financiera, aunque no social ni territorial. Las hipotecas subprime fueron para las minorías marginadas en los barrios con más hispanos, negros, inmigrantes y pobres: la vivienda social estadounidense, financiarizada, "inmobiliarizó" al sector financiero y desfinanciarizó la banca internacional, en una crisis global con dramáticas consecuencias sociales y políticas.

MORFOMETRÍA, HIDRODINÁMICA Y FÍSICO-QUÍMICA DEL AGUA DE LA LAGUNA DE CHAUTENGO, GUERRERO, MÉXICO

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Rendón-Dircio JA

2012-02-01

Full Text Available Se realizó un estudio del comportamiento de las variables morfométricas, batimétricas, hidrodinámicas y físico-químicas de la Laguna de Chautengo, Guerrero, a partir de fotografías aéreas y trabajo de campo con muestreos bimensuales de variables morfométricas, hidrodinámicas y físico-químicas del agua. Los resultados indicaron que la laguna presentó marcadas variaciones anuales en su morfometría y batimetría. El área máxima estimada fue de 29.6 km2. La barra de la laguna es recta y está colonizada en un 36.8 % por comunidades de manglar, tiene una longitud de 10 km y una anchura media de 0.52 km. Las tres islas que presenta la laguna se ubican cerca de la desembocadura y tienen un área de 83,000, 3,680 y 61,440 m2 respectivamente. La variación vertical de la columna de agua fluctuó entre 6 y 12 cm diarios, presentándose el máximo nivel a las 18:00 y 0:00 h y el mínimo a las 6:00 h. Las corrientes presentaron un valor promedio de velocidad de 1.97 m/min. La temperatura media anual fue de 29.8 oC, con una variación entre la superficie y el fondo de 0.23 oC; la salinidad varió de 0.7 a 38 ‰; el oxígeno disuelto se registró en promedio en 4.71 mg/L, existiendo una diferencia del 8.7 % entre la superficie. La laguna presenta características de un cuerpo de agua somero y tropical en un proceso avanzado de evolución, pero con condiciones adecuadas para el desarrollo de la fauna y flora acuática. Este estudio servirá de base para el diseño de un plan de manejo sostenible de las pesquerías y acuicultura de la Laguna de Chautengo.

Liberalização financeira, performance econômica e estabilidade macroeconômica no Brasil: uma avaliação do período 1994-2007

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Luiz Fernando de Paula

2013-05-01

Full Text Available Este artigo objetiva avaliar a relação entre liberalização da conta capital, performance econômica e estabilidade macroeconômica no Brasil. Para tanto, além de uma revisão da literatura, o artigo realiza uma avaliação em-pírica dos efeitos da liberalização financeira no Brasil sobre um conjunto de variáveis macroeconômicas com o uso da metodologia VAR, utilizando, para tanto, dois modelos: um com um índice de jure de liberalização financeira (ILF, e outro com um índice de facto de integração financeira (IIF. Procura-se, no primeiro caso, avaliar a hipótese de que a liberalização financeira resulta em redução no risco país e, consequentemente, na taxa de juros doméstica; no segundo caso, avalia-se a hipótese de que a liberalização financeira tem impacto positivo sobre o crescimento econômico e a estabilidade macroeconômica vis-à-vis à hipótese dos críticos da liberalização financeira de que esta gera efeitos instabilizadores em países em desenvolvimento.

Indiscernibilidade e identidade em química: aspectos filosóficos e formais

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Jaison Schinaider

2014-06-01

Full Text Available Neste artigo tratamos, de um ponto de vista formal e filosófico, com alguns conceitos que fazem parte da química usual. As teorias da química, e seus conceitos, normalmente são apresentadas de um ponto de vista informal (não axiomatizada, e isso pode trazer dificuldades filosóficas (embora a química propriamente - bem como também as outras disciplinas da ciência aplicada - pareçam não sofrer qualquer restrição quanto a isso. Aqui estaremos ocupados em um aspecto parti-cu-lar, que diz respeito à indiscernibilidade de alguns objetos básicos da química, tais como átomos, moléculas, bem como de seus componentes. Começamos com uma visão geral da identidade destes compostos e seus componentes a partir de uma perspectiva filosófica e, em seguida, mostramos em que sentido o conceito de identidade dos compostos químicos é problemático em relação ao conceito correspondente de identidade na lógica e matemática clássicas (que, como em geral é suposto, estão 'alicerçando' as teorias químicas. Argumentamos que, por um lado, a química parece supor que esses objetos básicos precisam ser 'idênticos' (indistinguíveis uns aos outros (como enfatizado há muito tempo por John Dalton, como veremos. Por outro lado, do ponto de vista formal, se a lógica subjacente à teoria atômica for a lógica clássica (que também é pano de fundo da matemática padrão, coisas idênticas devem ser a mesma coisa e logo 'colapsar' em apenas uma (e este não é o caso em química, uma vez que temos uma enorme quantidade de átomos e moléculas semelhantes, mas não apenas um. Esta aparente contradição pode ser tratada de várias perspectivas e, aqui, propomos o uso de uma teoria de conjuntos não-clássica (a saber, a teoria de quase-conjuntos para alicerçar uma formulação axiomática de certas teoria químicas, mostrando como essa diferente base matemática pode nos levar a uma visão que está mais perto da química em si. Como esta

Química de Heterociclos

OpenAIRE

Collado, Daniel

2014-01-01

Heterociclos aromáticos con cinco miembros. Pirrol, furano y tiofeno: propiedades. Sustitución electrofílica aromática. Reacciones de los sustituyentes alquílicos. Sustitución nucleofílica. Radicales y carbenos, aperturas de anillo. Síntesis. Capítulo segundo del temario del segundo bloque de la asignatura Ampliación de Química Orgánica Avanzada. Heterociclos aromáticos de cinco miembros.

Cerámicas de circona para aplicaciones biomédicas

OpenAIRE

Delgado García-Menocal, José Angel; Morejón, L.; Martínez, S.; Gil, F. X. (Francesc Xavier)

2003-01-01

Se tratan los aspectos mas significativos de distintos biomateriales empleados para la sustitución del tejido óseo pero haciendo énfasis en las cerámicas de óxido de zirconio (circonas). Se destacan las características de las cerámicas de circona que lo convierten en un material muy atractivo por sus excelentes propiedades mecánicas, en particular su elevada tenacidad a la fractura relacionada con la transformación martensítica que se produce cuando el material es sometido a un...

Relationships between electroencephalographic spectral peaks across frequency bands

Directory of Open Access Journals (Sweden)

Sacha Jennifer Van Albada

2013-03-01

Full Text Available The degree to which electroenencephalographic (EEG spectral peaks are independent, and the relationships between their frequencies have been debated. A novel fitting method was used to determine peak parameters in the range 2–35 Hz from a large sample of eyes-closed spectra, and their interrelationships were investigated. Findings were compared with a mean-field model of thalamocortical activity, which predicts near-harmonic relationships between peaks. The subject set consisted of 1424 healthy subjects from the Brain Resource International Database. Peaks in the theta range occurred on average near half the alpha peak frequency, while peaks in the beta range tended to occur near twice and three times the alpha peak frequency on an individual-subject basis. Moreover, for the majority of subjects, alpha peak frequencies were significantly positively correlated with frequencies of peaks in the theta and low and high beta ranges. Such a harmonic progression agrees semiquantitatively with theoretical predictions from the mean-field model. These findings indicate a common or analogous source for different rhythms, and help to define appropriate individual frequency bands for peak identification.

Relationships between Electroencephalographic Spectral Peaks Across Frequency Bands

Science.gov (United States)

van Albada, S. J.; Robinson, P. A.

2013-01-01

The degree to which electroencephalographic spectral peaks are independent, and the relationships between their frequencies have been debated. A novel fitting method was used to determine peak parameters in the range 2–35 Hz from a large sample of eyes-closed spectra, and their interrelationships were investigated. Findings were compared with a mean-field model of thalamocortical activity, which predicts near-harmonic relationships between peaks. The subject set consisted of 1424 healthy subjects from the Brain Resource International Database. Peaks in the theta range occurred on average near half the alpha peak frequency, while peaks in the beta range tended to occur near twice and three times the alpha peak frequency on an individual-subject basis. Moreover, for the majority of subjects, alpha peak frequencies were significantly positively correlated with frequencies of peaks in the theta and low and high beta ranges. Such a harmonic progression agrees semiquantitatively with theoretical predictions from the mean-field model. These findings indicate a common or analogous source for different rhythms, and help to define appropriate individual frequency bands for peak identification. PMID:23483663

Hubbert's Peak -- A Physicist's View

Science.gov (United States)

McDonald, Richard

2011-04-01

Oil, as used in agriculture and transportation, is the lifeblood of modern society. It is finite in quantity and will someday be exhausted. In 1956, Hubbert proposed a theory of resource production and applied it successfully to predict peak U.S. oil production in 1970. Bartlett extended this work in publications and lectures on the finite nature of oil and its production peak and depletion. Both Hubbert and Bartlett place peak world oil production at a similar time, essentially now. Central to these analyses are estimates of total ``oil in place'' obtained from engineering studies of oil reservoirs as this quantity determines the area under the Hubbert's Peak. Knowing the production history and the total oil in place allows us to make estimates of reserves, and therefore future oil availability. We will then examine reserves data for various countries, in particular OPEC countries, and see if these data tell us anything about the future availability of oil. Finally, we will comment on synthetic oil and the possibility of carbon-neutral synthetic oil for a sustainable future.

The geomorphic structure of the runoff peak

Directory of Open Access Journals (Sweden)

R. Rigon

2011-06-01

Full Text Available This paper develops a theoretical framework to investigate the core dependence of peak flows on the geomorphic properties of river basins. Based on the theory of transport by travel times, and simple hydrodynamic characterization of floods, this new framework invokes the linearity and invariance of the hydrologic response to provide analytical and semi-analytical expressions for peak flow, time to peak, and area contributing to the peak runoff. These results are obtained for the case of constant-intensity hyetograph using the Intensity-Duration-Frequency (IDF curves to estimate extreme flow values as a function of the rainfall return period. Results show that, with constant-intensity hyetographs, the time-to-peak is greater than rainfall duration and usually shorter than the basin concentration time. Moreover, the critical storm duration is shown to be independent of rainfall return period as well as the area contributing to the flow peak. The same results are found when the effects of hydrodynamic dispersion are accounted for. Further, it is shown that, when the effects of hydrodynamic dispersion are negligible, the basin area contributing to the peak discharge does not depend on the channel velocity, but is a geomorphic propriety of the basin. As an example this framework is applied to three watersheds. In particular, the runoff peak, the critical rainfall durations and the time to peak are calculated for all links within a network to assess how they increase with basin area.

Van der Waals epitaxy and photoresponse of hexagonal tellurium nanoplates on flexible mica sheets.

Science.gov (United States)

Wang, Qisheng; Safdar, Muhammad; Xu, Kai; Mirza, Misbah; Wang, Zhenxing; He, Jun

2014-07-22

Van der Waals epitaxy (vdWE) is of great interest due to its extensive applications in the synthesis of ultrathin two-dimensional (2D) layered materials. However, vdWE of nonlayered functional materials is still not very well documented. Here, although tellurium has a strong tendency to grow into one-dimensional nanoarchitecture due to its chain-like structure, we successfully realize 2D hexagonal tellurium nanoplates on flexible mica sheets via vdWE. Chemically inert mica surface is found to be crucial for the lateral growth of hexagonal tellurium nanoplates since it (1) facilitates the migration of tellurium adatoms along mica surface and (2) allows a large lattice mismatch. Furthermore, 2D tellurium hexagonal nanoplates-based photodetectors are in situ fabricated on flexible mica sheets. Efficient photoresponse is obtained even after bending the device for 100 times, indicating 2D tellurium hexagonal nanoplates-based photodetectors on mica sheets have a great application potential in flexible and wearable optoelectronic devices. We believe the fundamental understanding of vdWE effect on the growth of 2D tellurium hexagonal nanoplate can pave the way toward leveraging vdWE as a useful channel to realize the 2D geometry of other nonlayered materials.

La superación en gestión académica del directivo universitario

Directory of Open Access Journals (Sweden)

Vicenta Aveiga Macay

2013-12-01

Full Text Available Se planteó como objetivo sistematizar los fundamentos teóricos que sustentan el proceso de superación a directivos universitarios para la gestión académica. Se utilizó métodos del nivel teórico y empírico como el histórico lógico, analítico-sintético, el análisis documental, la observación, el inventario de dificultades, cuestionarios, entrevistas, los cuales posibilitaron caracterizar epistemológicamente el proceso de superación a directivos universitarios con énfasis en la gestión académica, arribar a nuevos conceptos, y distinguir aspectos significativos de la superación a directivos en gestión académica. PALABRAS CLAVES: Directivos, gestión académica, proceso formativo, superación.

Evolución hacia la cerámica fotovoltaica

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Sánchez-Muñoz, L.

2011-02-01

Full Text Available Nowadays there are two types of ceramic materials, i.e. traditional and advanced. The origin and development of the first one occurred before the revolutionary changes in Science and Technology of the nineteenth century, while the second one is its direct consequence. The traditional ceramics, which are related primarily to elementary human needs, in particular its constructions, is very homogeneous with respect to their formulations, being their diversity mainly linked to the decorative aspects of one surface. Advanced ceramics are characterized by a wide variety of materials with specific physical and chemical responses to radiation and electromagnetic fields, where major economic benefits are mainly related to secondary human needs such as telecommunications. As a result of the current global crisis, traditional buildings could be rehabilitated and/or replaced by energy efficient buildings, also called zero-energy buildings. In them there is a balance between energy consumed and produced “in situ”, and also using environmentally friendly materials. The direct consequence of this trend will be the evolution of ceramics by partial hybridization of its two ancestors, with special importance of semiconductor compounds, to the production of electrical energy as the basic objective, in this work called photovoltaic ceramics.

Actualmente se distinguen dos tipos de cerámica, una tradicional y otra avanzada. El origen y desarrollo de la primera es anterior a los cambios revolucionarios en Ciencia y Tecnológica del siglo XIX, mientras que la segunda es su consecuencia directa. La cerámica tradicional, que está relacionada sobre todo con las necesidades humanas primarias y en particular a sus construcciones, es muy homogénea respecto a sus formulaciones, estando su diversidad ligada principalmente a los aspectos decorativos de una de sus superficies. La cerámica avanzada se caracteriza por una gran diversidad de materiales con

Dinámica fisicoquímica de las aguas de un sistema de planicies inundables tropicales

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Yimmy Montoya M

2013-01-01

Full Text Available Se estudió el cambio de algunas variables fisicoquímicas en el agua de siete caños y siete ciénagas pertenecientes a la zona de planos de inundación de Ayapel en nueve muestreos durante el periodo 2006-2009. El valor medio de la conductividad eléctrica en la ciénaga es tres veces inferior al valor medio de las ciénagas de la región. 100 μS/cm puede considerarse como discriminante entre ciénagas con valores inferiores y los caños con valores superiores. No hubo relación entre la transparencia y la concentración de pigmentos fotosintéticos, lo que podría considerarse como indicador de un nivel de estado trófico bajo del sistema. A nivel temporal todas las formas de nutrientes evaluadas presentaron diferencias lo que indica la importancia del efecto del pulso de inundación a través del ciclo hidrológico. Con la disminución de la columna de agua en época de estiaje, se evidenció un aumento de las concentraciones de nitrógeno, las cuales se ven favorecidas por la resuspensión de material del fondo de la ciénaga. La concentración de fósforo es más sensible a la variación espacial, ya que el ciclo de este nutriente estuvo asociado a los sedimentos y a la composición del suelo de cada microcuenca. Se encontró que para una misma fase del pulso en ciclos sucesivos, se registran diferencias en la dinámica del sistema, por lo que el momento hidrológico en el que se realiza el muestreo es el factor principal en el comportamiento de las condiciones fisicoquímicas del sistema.

La contaminación Química

OpenAIRE

Jimbo G., Marcelo

2003-01-01

La contaminación química de la leche se puede verificar mediante cuatro vías: a. Detergentes y desinfectantes usados en las operaciones de lavado. b.Antielmínticos. c. Insecticidas y anticriptogámicos usados en agricultura. d. Elementos radioactivos, sustancias dicersas, metales.

Influence of the nonexchangeable potassium of mica on radiocesium uptake by paddy rice.

Science.gov (United States)

Eguchi, Tetsuya; Ohta, Takeshi; Ishikawa, Tetsuya; Matsunami, Hisaya; Takahashi, Yoshihiko; Kubo, Katashi; Yamaguchi, Noriko; Kihou, Nobuharu; Shinano, Takuro

2015-09-01

A pot cultivation experiment was conducted to elucidate the influence of the nonexchangeable potassium (K) of mica on radiocesium ((137)Cs) uptake by paddy rice (Oryza sativa L. cv. Koshihikari), and to evaluate the potential of mica application as a countermeasure to reduce radiocesium transfer from soil to paddy rice. The increase in the exchangeable K concentrations of soils, measured before planting, due to mica (muscovite, biotite, and phlogopite) application was negligible. However, in trioctahedral mica (biotite and phlogopite)-treated soil, the release of nonexchangeable K from the mica interlayer maintained the soil-solution K at a higher level during the growing season in comparison to the control, and consequently decreased the (137)Cs transfer factor for brown rice (TF). The sodium tetraphenylboron (TPB)-extractable K concentration of the soils, measured before planting, was strongly negatively correlated with the TF, whereas the exchangeable K concentration of the soils, also measured before planting, was not correlated with the TF. Therefore, we conclude that TPB-extractable K is more reliable than exchangeable K as a basis of fertilizer recommendations for radiocesium-contaminated paddy fields. Phlogopite-treated soils exhibited higher TPB-extractable K concentrations and lower TF values than biotite-treated soils. We thus conclude that phlogopite application is an effective countermeasure to reduce radiocesium uptake in paddy rice. Copyright © 2015 Elsevier Ltd. All rights reserved.

Compreensão econômica de estudantes entre 10 e 15 anos

Directory of Open Access Journals (Sweden)

Sonia Bessa

2014-08-01

Full Text Available Nos últimos 50 anos, ocorreram significativas mudanças sociais, culturais, políticas, econômicas e tecnológicas que afetam o comportamento de pré-adolescentes e jovens. Essa faixa etária necessita de investigações sobre sua compreensão do mundo econômico e o papel da família no processo de socialização econômica. Por isso, a presente pesquisa tem por objetivo principal caracterizar a compreensão econômica de 830 estudantes de 10 a 15 anos de diferentes níveis socioeconômicos, moradores da cidade de São Paulo. O instrumento utilizado foi o Teste de Alfabetização Econômica para crianças, TAE-N. Com abordagem qualitativa e quantitativa, utilizou-se o desenho descritivo-comparativo e correlacional. Apresenta-se a frequência das variáveis categóricas; valores de frequência absoluta, percentual; média e desvio-padrão; utilizou-se o coeficiente alfa de Cronbach; teste Qui-Quadrado. Para a comparação de medidas contínuas ou ordenáveis, valeu-se dos testes Mann-Whitney e Kruskal-Wallis. Os resultados demonstram uma socialização econômica insuficiente para lidar com as exigências do mundo econômico.

CSLAA and FAA'S Rules: Incorporating a 'Risk Management Framework' to Minimise Human Space Flight Risks

Science.gov (United States)

Chaddha, S.

2012-01-01

th This year marks the 50 anniversary of a landmark victory for humankind in its endeavour of entering and exploring the final frontier. During these years of space activity, we have witnessed a number of cumulative successes. One of which is the emergence of the commercial human space flight, or "space tourism", market. Commercial companies have the aim of travelling people into space safely and affordably. This paper shall consider the U.S. regulatory framework governing the space tourism market. It scrutinises the adequacy of the Commercial Space Launch and Amendment Act of 2004 (CSLAA), as bolstered by the FAA's requirements, to protect launching passengers to an acceptable standard of safety from the inherent risks associated with human space flights. It is argued that the legislative regime embeds a three-limb "risk management framework" as an appropriate response to address the concern over the safety of public space travel.

Attitudes on En Route Air Traffic Control Training and Work: A Comparison of Recruits Initially Trained at the FAA Academy and Recruits Initially Trained at Assigned Centers.

Science.gov (United States)

Mathews, John J.; And Others

In the comparison, questionnaires concerning aspects of training-related and work-related attitudes were sent to 225 Air Traffic Control (ATC) trainees who represented groups of attritions and retentions in two En Route training programs; viz, programs that provided basic training at the FAA Academy and programs that provided basic training at the…

Mastocitosis sistémica: repercusión ósea

Directory of Open Access Journals (Sweden)

Francisco R. Spivacow

2012-06-01

Full Text Available La mastocitosis sistémica es una enfermedad caracterizada por acumulación de mastocitos en varios órganos, de los cuales el más afectado es la piel. La repercusión ósea de esta enfermedad es poco frecuente y en general se la asocia al desarrollo de osteoporosis secundaria con o sin fracturas óseas. Se presentan tres pacientes con lesiones características en piel de mastocitosis y diferentes manifestaciones óseas; el primer caso es una mujer de 51 años en la que se observó una variante esclerosante muy poco frecuente, con densitometría ósea en valores normales-altos y aumento de la densidad ósea observada en varias vértebras por radiografías. Una punción-biopsia de cresta ilíaca confirmó el compromiso óseo de su enfermedad de base. El segundo caso fue una mujer de 57 años que mostró signos característicos de mastocitosis sistémica con diarreas, gastritis, flushes y reacciones cutáneas particulares ante exposición a alérgenos. Se observó además grave disminución de la densidad mineral ósea tanto en columna lumbar como en cuello de fémur con parámetros bioquímicos de aumento de la resorción ósea, por lo que fue necesario tratarla con bisfosfonatos. La tercera paciente, de 67 años de edad, presentó varias fracturas vertebrales, con densitometría ósea levemente disminuida. En esta última paciente se constató una hiperplaquetosis con diagnóstico histológico de trombocitemia esencial, cuadro que suele asociarse a la mastocitosis sistémica. En definitiva, se presentan y discuten tres variantes óseas diferentes de mastocitosis sistémica.

Atomically Thin Mica Flakes and Their Application as Ultrathin Insulating Substrates for Graphene

NARCIS (Netherlands)

Castellanos-Gomez, Andres; Wojtaszek, Magdalena; Tombros, Nikolaos; Agrait, Nicolas; van Wees, Bart J.; Rubio-Bollinger, Gabino; Agraït, Nicolás

2011-01-01

By mechanical exfoliation, it is possible to deposit atomically thin mica flakes down to single-monolayer thickness on SiO(2)/Si wafers. The optical contrast of these mica flakes on top of a SiO(2)/Si substrate depends on their thickness, the illumination wavelength, and the SiO(2) substrate

Dinâmica molecular ab initio:aplicações ao estudo de propriedades electrónicas de sistemas moleculares

OpenAIRE

Martiniano, Hugo Filipe de Mesquita Costa, 1978-

2013-01-01

Tese de doutoramento, Química (Química-Física), Universidade de Lisboa, Faculdade de Ciências, 2013 O método da dinâmica molecular ab initio exibe vantagens significativas para o estudo da estrutura e propriedades electrónicas de sistemas moleculares complexos. No entanto, uma das suas desvantagens é o elevado custo computacional, quando comparado com os métodos de dinâmica molecular clássicos. Um dos modos de resolver este problema é adoptar uma abordagem sequencial, na qual a dinâmica é ...

Passive radio frequency peak power multiplier

Science.gov (United States)

Farkas, Zoltan D.; Wilson, Perry B.

1977-01-01

Peak power multiplication of a radio frequency source by simultaneous charging of two high-Q resonant microwave cavities by applying the source output through a directional coupler to the cavities and then reversing the phase of the source power to the coupler, thereby permitting the power in the cavities to simultaneously discharge through the coupler to the load in combination with power from the source to apply a peak power to the load that is a multiplication of the source peak power.

Peak load arrangements : Assessment of Nordel guidelines

Energy Technology Data Exchange (ETDEWEB)

2009-07-01

Two Nordic countries, Sweden and Finland, have legislation that empowers the TSO to acquire designated peak load resources to mitigate the risk for shortage situations during the winter. In Denmark, the system operator procures resources to maintain a satisfactory level of security of supply. In Norway the TSO has set up a Regulation Power Option Market (RKOM) to secure a satisfactory level of operational reserves at all times, also in winter with high load demand. Only the arrangements in Finland and Sweden fall under the heading of Peak Load Arrangements defined in Nordel Guidelines. NordREG has been invited by the Electricity Market Group (EMG) to evaluate Nordel's proposal for 'Guidelines for transitional Peak Load Arrangements'. The EMG has also financed a study made by EC Group to support NordREG in the evaluation of the proposal. The study has been taken into account in NordREG's evaluation. In parallel to the EMG task, the Swedish regulator, the Energy Markets Inspectorate, has been given the task by the Swedish government to investigate a long term solution of the peak load issue. The Swedish and Finnish TSOs have together with Nord Pool Spot worked on finding a harmonized solution for activation of the peak load reserves in the market. An agreement accepted by the relevant authorities was reached in early January 2009, and the arrangement has been implemented since 19th January 2009. NordREG views that the proposed Nordel guidelines have served as a starting point for the presently agreed procedure. However, NordREG does not see any need to further develop the Nordel guidelines for peak load arrangements. NordREG agrees with Nordel that the market should be designed to solve peak load problems through proper incentives to market players. NordREG presumes that the relevant authorities in each country will take decisions on the need for any peak load arrangement to ensure security of supply. NordREG proposes that such decisions should be

Peak capacity, peak-capacity production rate, and boiling point resolution for temperature-programmed GC with very high programming rates

Science.gov (United States)

Grall; Leonard; Sacks

2000-02-01

Recent advances in column heating technology have made possible very fast linear temperature programming for high-speed gas chromatography. A fused-silica capillary column is contained in a tubular metal jacket, which is resistively heated by a precision power supply. With very rapid column heating, the rate of peak-capacity production is significantly enhanced, but the total peak capacity and the boiling-point resolution (minimum boiling-point difference required for the separation of two nonpolar compounds on a nonpolar column) are reduced relative to more conventional heating rates used with convection-oven instruments. As temperature-programming rates increase, elution temperatures also increase with the result that retention may become insignificant prior to elution. This results in inefficient utilization of the down-stream end of the column and causes a loss in the rate of peak-capacity production. The rate of peak-capacity production is increased by the use of shorter columns and higher carrier gas velocities. With high programming rates (100-600 degrees C/min), column lengths of 6-12 m and average linear carrier gas velocities in the 100-150 cm/s range are satisfactory. In this study, the rate of peak-capacity production, the total peak capacity, and the boiling point resolution are determined for C10-C28 n-alkanes using 6-18 m long columns, 50-200 cm/s average carrier gas velocities, and 60-600 degrees C/min programming rates. It was found that with a 6-meter-long, 0.25-mm i.d. column programmed at a rate of 600 degrees C/min, a maximum peak-capacity production rate of 6.1 peaks/s was obtained. A total peak capacity of about 75 peaks was produced in a 37-s long separation spanning a boiling-point range from n-C10 (174 degrees C) to n-C28 (432 degrees C).

Justicia epistémica y epistemologías del Sur

Directory of Open Access Journals (Sweden)

Miguel Mandujano Estrada

2017-05-01

Full Text Available Realizaré, en este trabajo, una síntesis de la dimensión epistemológica de la obra de Boaventura de Sousa Santos. A partir de la idea de justicia e injusticia epistémica, reconstruiré la dimensión metodológica de su plataforma crítica, a saber, la ecología de saberes. Intentaré establecer la relación de la injusticia epistémica con el colonialismo y defender la particularidad descolonial de las prácticas inscritas en las epistemologías del Sur y el cosmopolitismo subalterno.

Interacciones sociales y explotación económica

Directory of Open Access Journals (Sweden)

Andrés Montaña

2012-05-01

Full Text Available Planteo aquí un nuevo modelo de interacción social general basado en lasdotaciones de información, heurística y recursos de los agentes de una organización social. A partirde estas dotaciones se puede hacer una representación en un espacio social determinado en el quese desarrollan interacciones sociales. El modelo permite identificar la posición de un agente en elespacio social y hacer comparaciones interpersonales.A partir del modelo de interacción social general, planteo un modelo de explotación económica.Una autoridad desde este modelo de explotación puede establecer áreas de restricción para determinarla explotación económica de los agentes.El cálculo de las dotaciones y las combinaciones de éstas, pueden permitir a una autoridaddeterminar si existe o no explotación de unos agentes por otros, fijar categorías de explotación, eidentificar áreas de atención prioritarias. El modelo se podría constituir en una herramienta másapropiada para la identificación de la condición laboral o económica de los niños y niñas.

CARACTERIZACIÓN QUÍMICA Y CLASIFICACIÓN TAXONÓMICA DE ALGUNOS SUELOS CULTIVADOS CON BANANO EN LAS LLANURAS ALUVIALES DEL CARIBE DE COSTA RICA

Directory of Open Access Journals (Sweden)

Fulvio Arias

2010-01-01

Full Text Available Se realizó la caracterización morfológica, química y la clasificación taxonómica de algunos suelos cultivados con banano en las 11 cuencas hidrográficas que confluyen en las llanuras aluviales de la Vertiente Caribe de Costa Rica. Se identificaron 2 sectores con suelos que tienen propiedades morfológicas, químicas, y taxonómicas diferentes. En una zona, se encontraron principalmente Inceptisoles formados a partir de materiales fluvio-volcánicos con propiedades ándicas (Andic Eutrudepts, Aquandic Endoaquepts, Inceptisoles dístricos (Fluventic Dystrudepts y Andisoles (Typic Hapludands; caracterizados por presentar la mayoría buen drenaje, texturas medias (franco arenosa, franca, franca limosa, una suma de bases entre 10 y 19 cmol.l–1, una CIC entre 13 y 28 cmol.l–1 y carga permanente en la arcillas. En la otra zona, se encontraron principalmente Inceptisoles formados a partir de aluviones de origen sedimentario depositados por inundaciones frecuentes (Fluventic Endoaquepts, Dystric Fluventic Eutrudepts, Fluvaquentic Eutrudepts, Fluvaquentic Endoaquepts, con una suma de bases entre 18 y 46 cmol.l–1, una CIC entre 19 y 46 cmol.l–1, sin propiedades ándicas, texturas finas y moderadamente finas (franco arcillosa, franco arcillosa limosa, arcillosa, arcillosa limosa y con problemas de drenajes en algunos casos (Endoaquepts, Epiaquepts, Fluvaquentic. Geográficamente, estas zonas fueron separadas por la subcuenca formada por los ríos Vueltas-Silencio-Parismina, de forma que hacia el noroeste se encuentran suelos con influencia volcánica y fertilidad media, y hacia el sureste suelos sin influencia volcánica y de fertilidad alta.

Degree of conversion of resin-based materials cured with dual-peak or single-peak LED light-curing units.

Science.gov (United States)

Lucey, Siobhan M; Santini, Ario; Roebuck, Elizabeth M

2015-03-01

There is a lack of data on polymerization of resin-based materials (RBMs) used in paediatric dentistry, using dual-peak light-emitting diode (LED) light-curing units (LCUs). To evaluate the degree of conversion (DC) of RBMs cured with dual-peak or single-peak LED LCUs. Samples of Vit-l-escence (Ultradent) and Herculite XRV Ultra (Kerr) and fissure sealants Delton Clear and Delton Opaque (Dentsply) were prepared (n = 3 per group) and cured with either one of two dual-peak LCUs (bluephase(®) G2; Ivoclar Vivadent or Valo; Ultradent) or a single-peak (bluephase(®) ; Ivoclar Vivadent). High-performance liquid chromatography and nuclear magnetic resonance spectroscopy were used to confirm the presence or absence of initiators other than camphorquinone. The DC was determined using micro-Raman spectroscopy. Data were analysed using general linear model anova; α = 0.05. With Herculite XRV Ultra, the single-peak LCU gave higher DC values than either of the two dual-peak LCUs (P < 0.05). Both fissure sealants showed higher DC compared with the two RBMs (P < 0.05); the DC at the bottom of the clear sealant was greater than the opaque sealant, (P < 0.05). 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Lucirin(®) TPO) was found only in Vit-l-escence. Dual-peak LED LCUs may not be best suited for curing non-Lucirin(®) TPO-containing materials. A clear sealant showed a better cure throughout the material and may be more appropriate than opaque versions in deep fissures. © 2014 BSPD, IAPD and John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

La flexibilitat en els àcids nucleics: Un estudi de dinàmica molecular

OpenAIRE

Noy Freixa, Agnès

2008-01-01

[cat] L'estat de l'art de les simulacions de dinàmica molecular és utilitzat per estudiar l'estructura, dinàmica, propietats d'interacció molecular i flexibilitat dels dúplexs d'ADN i ARN en solució acuosa. Les nostres simulacions suggereixen que el concepte de flexibilitat, rigidesa i deformabilitat són molt més complexes del que habitualment es creu, i que per tant no és sempre veritat que l'ADN sigui més flexible que l'ARN. La dinàmica molecular és a més utilitzada per investigar les prop...

Flexibilitat en els àcids nucleics: Un estudi de dinàmica molecular, La

OpenAIRE

Noy Freixa, Agnès

2008-01-01

L'estat de l'art de les simulacions de dinàmica molecular és utilitzat per estudiar l'estructura, dinàmica, propietats d'interacció molecular i flexibilitat dels dúplexs d'ADN i ARN en solució acuosa. Les nostres simulacions suggereixen que el concepte de flexibilitat, rigidesa i deformabilitat són molt més complexes del que habitualment es creu, i que per tant no és sempre veritat que l'ADN sigui més flexible que l'ARN.La dinàmica molecular és a més utilitzada per investigar les propietats d...

ANÁLISE DINÂMICA DE ESTRUTURAS DE AÇO SUPORTES DE MÁQUINAS ROTATIVAS

OpenAIRE

FERRO, R. M.

2014-01-01

Uma análise dinâmica adequada é necessária para verificação de estruturas suportes de equipamentos mecânicos visando assegurar não somente o conforto humano dos usuários como também boas condições para o funcionamento dos equipamentos da estrutura. Em recentes estudos de dinâmica estrutural e dinâmica de equipamentos, verifica-se a dificuldade de realizar modelos reais de estruturas suportes de máquinas rotativas. Considerando que as duas áreas têm o estudo comum na análise das vibrações prod...

Peak experiences of psilocybin users and non-users.

Science.gov (United States)

Cummins, Christina; Lyke, Jennifer

2013-01-01

Maslow (1970) defined peak experiences as the most wonderful experiences of a person's life, which may include a sense of awe, well-being, or transcendence. Furthermore, recent research has suggested that psilocybin can produce experiences subjectively rated as uniquely meaningful and significant (Griffiths et al. 2006). It is therefore possible that psilocybin may facilitate or change the nature of peak experiences in users compared to non-users. This study was designed to compare the peak experiences of psilocybin users and non-users, to evaluate the frequency of peak experiences while under the influence of psilocybin, and to assess the perceived degree of alteration of consciousness during these experiences. Participants were recruited through convenience and snowball sampling from undergraduate classes and at a musical event. Participants were divided into three groups, those who reported a peak experience while under the influence of psilocybin (psilocybin peak experience: PPE), participants who had used psilocybin but reported their peak experiences did not occur while they were under the influence of psilocybin (non-psilocybin peak experience: NPPE), and participants who had never used psilocybin (non-user: NU). A total of 101 participants were asked to think about their peak experiences and complete a measure evaluating the degree of alteration of consciousness during that experience. Results indicated that 47% of psilocybin users reported their peak experience occurred while using psilocybin. In addition, there were significant differences among the three groups on all dimensions of alteration of consciousness. Future research is necessary to identify factors that influence the peak experiences of psilocybin users in naturalistic settings and contribute to the different characteristics of peak experiences of psilocybin users and non-users.

Extragalactic Peaked-spectrum Radio Sources at Low Frequencies

Energy Technology Data Exchange (ETDEWEB)

Callingham, J. R.; Gaensler, B. M.; Sadler, E. M.; Lenc, E. [Sydney Institute for Astronomy (SIfA), School of Physics, The University of Sydney, NSW 2006 (Australia); Ekers, R. D.; Bell, M. E. [CSIRO Astronomy and Space Science (CASS), Marsfield, NSW 2122 (Australia); Line, J. L. B.; Hancock, P. J.; Kapińska, A. D.; McKinley, B.; Procopio, P. [ARC Centre of Excellence for All-Sky Astrophysics (CAASTRO) (Australia); Hurley-Walker, N.; Tingay, S. J.; Franzen, T. M. O.; Morgan, J. [International Centre for Radio Astronomy Research (ICRAR), Curtin University, Bentley, WA 6102 (Australia); Dwarakanath, K. S. [Raman Research Institute (RRI), Bangalore 560080 (India); For, B.-Q. [International Centre for Radio Astronomy Research (ICRAR), The University of Western Australia, Crawley, WA 6009 (Australia); Hindson, L.; Johnston-Hollitt, M. [School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6140 (New Zealand); Offringa, A. R., E-mail: joseph.callingham@sydney.edu.au [Netherlands Institute for Radio Astronomy (ASTRON), Dwingeloo (Netherlands); and others

2017-02-20

We present a sample of 1483 sources that display spectral peaks between 72 MHz and 1.4 GHz, selected from the GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey. The GLEAM survey is the widest fractional bandwidth all-sky survey to date, ideal for identifying peaked-spectrum sources at low radio frequencies. Our peaked-spectrum sources are the low-frequency analogs of gigahertz-peaked spectrum (GPS) and compact-steep spectrum (CSS) sources, which have been hypothesized to be the precursors to massive radio galaxies. Our sample more than doubles the number of known peaked-spectrum candidates, and 95% of our sample have a newly characterized spectral peak. We highlight that some GPS sources peaking above 5 GHz have had multiple epochs of nuclear activity, and we demonstrate the possibility of identifying high-redshift ( z > 2) galaxies via steep optically thin spectral indices and low observed peak frequencies. The distribution of the optically thick spectral indices of our sample is consistent with past GPS/CSS samples but with a large dispersion, suggesting that the spectral peak is a product of an inhomogeneous environment that is individualistic. We find no dependence of observed peak frequency with redshift, consistent with the peaked-spectrum sample comprising both local CSS sources and high-redshift GPS sources. The 5 GHz luminosity distribution lacks the brightest GPS and CSS sources of previous samples, implying that a convolution of source evolution and redshift influences the type of peaked-spectrum sources identified below 1 GHz. Finally, we discuss sources with optically thick spectral indices that exceed the synchrotron self-absorption limit.

The dislocation-internal friction peak γ in tantalum

International Nuclear Information System (INIS)

Baur, J.; Benoit, W.; Schultz, H.

1989-01-01

Torsion-pendulum measurements were carried out on high-purity single crystal specimens of tantalum, having extremely low oxygen contents ( 2 peak, which appears close to γ is small traces of oxygen are presents. The γ 2 peak was formerly explained as a ''dislocation-enhanced Snoek peak''. The γ peak recovers at the peak temperature, whereas the γ 2 peak is more stable. On the basis of their results, and making use of earlier investigations of Rodrian and Schultz, the authors suggest that γ 2 is modified γ relaxation, related to screw-dislocation segments, stabilized by oxygen-decorated kinks. The stability of the γ 2 peak allows an accurate determination of the activation energy, found to be 1.00 +- 0.03 eV. This value is distinctly lower than the activation energy of the oxygen Snoek effect (1.10 eV) and is related here to the mechanism of ''kink-pair formation'' in screw dislocations, as the original γ peak. The numerical value is compatible with recent values derived from flow-stress measurements. The peak γ 2 shows increasing stability with increasing oxygen content. This is explained by single- and multi-decorated kinks

Individual vision and peak distribution in collective actions

Science.gov (United States)

Lu, Peng

2017-06-01

People make decisions on whether they should participate as participants or not as free riders in collective actions with heterogeneous visions. Besides of the utility heterogeneity and cost heterogeneity, this work includes and investigates the effect of vision heterogeneity by constructing a decision model, i.e. the revised peak model of participants. In this model, potential participants make decisions under the joint influence of utility, cost, and vision heterogeneities. The outcomes of simulations indicate that vision heterogeneity reduces the values of peaks, and the relative variance of peaks is stable. Under normal distributions of vision heterogeneity and other factors, the peaks of participants are normally distributed as well. Therefore, it is necessary to predict distribution traits of peaks based on distribution traits of related factors such as vision heterogeneity and so on. We predict the distribution of peaks with parameters of both mean and standard deviation, which provides the confident intervals and robust predictions of peaks. Besides, we validate the peak model of via the Yuyuan Incident, a real case in China (2014), and the model works well in explaining the dynamics and predicting the peak of real case.

Estudos ecológicos preliminares e caracterização química dos Cnidaria da costa noroeste portuguesa

OpenAIRE

Gadelha, Juliana Rodrigues

2007-01-01

O levantamento de recursos em espécies marinhas em Portugal ainda é incipiente, considerando que este domínio de investigação tem sido amplamente desenvolvido noutros pontos do globo, pescas, química, bioquímica e farmacologia de organismos marinhos, de modo a obter informações sobre a química de produtos naturais e ecologia química de organismos marinhos derivadas destes organismos. São de realçar a importância das defesas químicas para as relações ecológicas de predação, comp...

Isotope resolution of the iron peak

International Nuclear Information System (INIS)

Henke, R.P.; Benton, E.V.

1977-01-01

A stack of Lexan detectors from the Apollo 17 mission has been analyzed to obtain Z measurements of sufficient accuracy to resolve the iron peak into its isotopic components. Within this distribution several peaks are present. With the centrally located, most populated peak assumed to be 56 Fe, the measurements imply that the abundances of 54 Fe and 58 Fe are appreciable fractions of the 56 Fe abundance. This result is in agreement with those of Webber et al. and Siegman et al. but in disagreement with the predictions of Tsao et al. (Auth.)

RF Characteristics of Mica-Z Wireless Sensor Network Motes

National Research Council Canada - National Science Library

Koh, Swee J

2006-01-01

... network characteristics. Link-break and re-association distances with their corresponding RF power measurements were recorded to determine the Mica-Z s range characteristics under these different operating environments...

Deserción universitaria y alfabetización académica

OpenAIRE

Giohanny Olave-Arias; llene Rojas-García; Mireya Cisneros-Estupiñán

2013-01-01

El artículo pone en relación la deserción universitaria con la alfabetización académica, entendida como el nivel de desarrollo de la lectura y la escritura. El desarrollo del artículo consta de tres momentos: contextualización del problema de la deserción universitaria en Colombia; prácticas de lectura y escritura que generan dificultades de aprendizaje; importancia de la alfabetización académica para mejorar las habilidades lectoras de los estudiantes.

Instream flow needs below peaking hydroelectric projects

International Nuclear Information System (INIS)

Milhous, R.T.

1991-01-01

This paper reports on a method developed to assist in the determination of instream flow needs below hydroelectric projects operated in a peaking mode. Peaking hydroelectric projects significantly change streamflow over a short period of time; consequently, any instream flow methodology must consider the dual flows associated with peaking projects. The dual flows are the lowest flow and the maximum generation flow of a peaking cycle. The methodology is based on elements of the Physical Habitat Simulation System of the U.S. Fish and Wildlife Service and uses habitat, rather than fish numbers or biomas, as at basic response variable. All aquatic animals are subject to the rapid changes in streamflow which cause rapid swings in habitat quality. Some aquatic organisms are relatively fixed in location in the stream while others can move when flows change. The habitat available from a project operated in peaking mode is considered to be the minimum habitat occurring during a cycle of habitat change. The methodology takes in to consideration that some aquatic animals can move and others cannot move during a peaking cycle

flowPeaks: a fast unsupervised clustering for flow cytometry data via K-means and density peak finding.

Science.gov (United States)

Ge, Yongchao; Sealfon, Stuart C

2012-08-01

For flow cytometry data, there are two common approaches to the unsupervised clustering problem: one is based on the finite mixture model and the other on spatial exploration of the histograms. The former is computationally slow and has difficulty to identify clusters of irregular shapes. The latter approach cannot be applied directly to high-dimensional data as the computational time and memory become unmanageable and the estimated histogram is unreliable. An algorithm without these two problems would be very useful. In this article, we combine ideas from the finite mixture model and histogram spatial exploration. This new algorithm, which we call flowPeaks, can be applied directly to high-dimensional data and identify irregular shape clusters. The algorithm first uses K-means algorithm with a large K to partition the cell population into many small clusters. These partitioned data allow the generation of a smoothed density function using the finite mixture model. All local peaks are exhaustively searched by exploring the density function and the cells are clustered by the associated local peak. The algorithm flowPeaks is automatic, fast and reliable and robust to cluster shape and outliers. This algorithm has been applied to flow cytometry data and it has been compared with state of the art algorithms, including Misty Mountain, FLOCK, flowMeans, flowMerge and FLAME. The R package flowPeaks is available at https://github.com/yongchao/flowPeaks. yongchao.ge@mssm.edu Supplementary data are available at Bioinformatics online.

Topographic characterization of the self-assembled nanostructures of chitosan on mica surface by atomic force microscopy

International Nuclear Information System (INIS)

Wang, Li; Wu, Jiafeng; Guo, Yan; Gong, Coucong; Song, Yonghai

2015-01-01

Graphical abstract: - Highlights: • Nanocomposites of chitosan film were prepared by simple self-assembly from solvent media. • Chitosan molecules assembled on mica surface of nanoparticles, fibril and membrane with varied chitosan concentration. • Chitosan molecules assembled with different nanostructure under varied pH. • The optimum drying temperature for forming chitosan membrane is about 65 °C. - Abstract: In this work, the self-assembled nanostructures of chitosan on mica surface formed from various solvents were investigated by using atomic force microscopy. The effects of various factors on the self-assembled nanostructures of chitosan on mica surface, including solvents, the concentration of chitosan, the pH of solution and the drying temperature, were explored in detail. Our experimental data resulted in the conclusion that chitosan molecules could self-assemble on mica surface to form various nanostructures such as nanoparticles, fibril and film. Nanoparticles were always formed on mica surface from CCl_4, C_6H_6, CH_2Cl_2 solution, fibril preferred to form on mica surface from CH_3CH_2OH and CH_3OH solution and the optimal solvent to form film was found to be CH_3CN. Low concentration, pH and temperature were helpful for the formation of nanoparticles, medium concentration, pH and temperature resulted in fibril and high concentration, pH and temperature were often beneficial to forming chitosan films. The study of self-assembled nanostructures of chitosan on mica surface would provide new insight into the development of chitosan-based load-bearing materials.

Algunas características económicas del mantenimiento no correctivo del software a medida.

OpenAIRE

Torralba Martínez, José María; Rodenes Adam, Manuel

2001-01-01

Se presentan algunas características económicas del servicio de mantenimiento del software, relativas pricipalmente al área comercial: mercado, producto, precio y clientización, apuntando la importancia económica que tiene tanto para

Some mica-vermiculite alterations-relation to the exchange capacity

International Nuclear Information System (INIS)

Misak, N.Z.; Abdel-Gawad, A.S.; Maghrawy, H.B.; Shafik, A.; Sayyah, T.

1983-01-01

The effect of treatment of six Indian mica-vermiculite minerals with sodium cobaltinitrite (I) and NaCl+H 2 O 2 (II) with the aim of producing more vermiculite in the structure and thus a higher sorption capacity, was studied. The changes occuring in the minerals were followed by X-ray, TG, DTA, and chemical analyses. The measured Sr 2+ and Co 2+ capacities were in basic agreement with the detected changes that revealed generally a minor alteration due to treatment I and a considerable one but to treatment II. Treatment II increased tremendously the capacity of the main-mica minerals, having a very small capacity in the natural form, and made them suitable for use as potential ion exchangers

Particle size and kind of mica in synthesis of nontoxic bronze and gold pearlescent pigments based on nanoencapsulated hematite

Directory of Open Access Journals (Sweden)

Maryam Hosseini-Zori

2015-12-01

Full Text Available Nano-encapsulated iron oxide in Zirconium oxide-coated mica pigments are thermally stable,innocuous to human health, non-combustible, and they do not conduct electricity. They could beapplied in several industries such as thermoplastics, cosmetics, food packaging, children toys, paints,automobiles coating, security purposes, and banknotes. Nowadays, they are highly desirable inceramic decoration. In the present study, intensively dark gold to bronze colored mica clay pigments,which were based on mica flakes covered with a layer of nano-iron oxide-Zirconium oxide particles,were prepared by homogeneous precipitation of iron nitrate and Zirconium chloride ammonia in thepresence of mica flakes in two kinds of ore clay-based phlogopite and muscovite minerals. The finalcolor was obtained by thermal annealing of precipitates at a temperature of 800◦C. The pigments werecharacterized by X-Ray Diffraction, Particle size analysis, Scanning electron microscopy,Transmission electron microscopy, X-Ray fluorescence, and Simultaneous thermal analysis. Resultsindicate that nano-encapsulated iron oxide in zirconia particles have been formed on mica flakes andkinds of clay-mica can be related to obtained shade from dark gold to bronze pearl. Higher particlesize of mica flakes about phlogopite type of mica introduced pearl effects with higher L* changes indifferent angles. Muscovite performed higher hue and better pearl effect than phlogopite.

Diagnóstico y tendencias económicas del Corredor Tijuana-Rosarito-Ensenada

Directory of Open Access Journals (Sweden)

Wilfrido Ruiz Ochoa

2015-01-01

Full Text Available En este artículo se proponen estrategias que pudieran implementarse para romper con un escenario económico inercial adverso que, hipotéticamente, pudiera restarle viabilidad económica a futuro al Corredor Costero Tijuana- Rosarito-Ensenada. Esto, a partir de un diagnóstico económico sustentado en índices multidimensionales, en el que se aporta información censal sobre el perfil sectorial y espacial del corredor, así como de sus tendencias de crecimiento para 2030. Sobre esta base se elaboran propuestas para afrontar la desaceleración económica reciente de la zona, mediante la identificación de sus vocaciones económicas y de algunos proyectos estratégicos.

El derecho de propiedad privada y libertad económica

Directory of Open Access Journals (Sweden)

Santiago M. Castro Videla

2014-03-01

Full Text Available Este artículo ofrece diversos elementos legales, filosóficos y económicos para una teoría general del derecho de propiedad y libertad económica, que permita explicar por qué es un derecho fundamental. En primer lugar, plantea una visión unificada del derecho de propiedad privada y libertad económica, el que debe distinguirse analíticamente de los distintos derechos de propiedad susceptibles de reglamentación y expropiación estatal. En segundo lugar, explica, desde la teoría tomista del derecho natural, en qué sentido este derecho es un derecho natural secundario. En tercer lugar, señala, desde la teoría austríaca del proceso de mercado, cómo la protección del derecho de propiedad privada y libertad económica da lugar a un proceso virtuoso que genera mayor desarrollo, reducción de la pobreza y paz social. Y finalmente, explica también cómo la violación de dicho derecho genera los efectos contrarios: subdesarrollo, pobreza y conflicto social.

Upper limit of peak area

International Nuclear Information System (INIS)

Helene, O.A.M.

1982-08-01

The determination of the upper limit of peak area in a multi-channel spectra, with a known significance level is discussed. This problem is specially important when the peak area is masked by the background statistical fluctuations. The problem is exactly solved and, thus, the results are valid in experiments with small number of events. The results are submitted to a Monte Carlo test and applied to the 92 Nb beta decay. (Author) [pt

A pura química : Curso a distancia para alumnos e Ingeniería

OpenAIRE

Tocci, Ana María; Fertitta, A. E.; Visintin, Arnaldo

2015-01-01

La Facultad de Ingeniería de la ciudad de La Plata (UNLP) requiere para permitir el ingreso a la misma aprobar un examen de matemáticas, el cual se rinde en el mes de diciembre, o aprobar un curso nivelatorio de la misma materia durante el mes de febrero. En ese curso no está contemplada la materia Química. Los docentes de la cátedra de Química General (materia del primer cuatrimestre de primer año) para Ingeniería Química y Materiales, encontramos un vacío en lo que respecta a conocimientos ...

Deserción universitaria y alfabetización académica

Directory of Open Access Journals (Sweden)

Giohanny Olave-Arias

2013-12-01

Full Text Available El artículo pone en relación la deserción universitaria con la alfabetización académica, entendida como el nivel de desarrollo de la lectura y la escritura. El desarrollo del artículo consta de tres momentos: contextualización del problema de la deserción universitaria en Colombia; prácticas de lectura y escritura que generan dificultades de aprendizaje; importancia de la alfabetización académica para mejorar las habilidades lectoras de los estudiantes.

Mutaciones dinámicas

Directory of Open Access Journals (Sweden)

Cesar A. Parra

1994-10-01

Full Text Available EI descubrimiento de repeticiones amplificadas de trinucleótidos variables en número, en pacientes con distrofia miotónica, síndrome de X-frágil, corea de Huntington y enfermedad de Kennedy, al igual que alteraciones en dinucleótidos del DNA microsatélite en pacientes con carcinoma proximal de colon, ha dado origen al concepto de mutaciones dinámicas. Esto representa una nueva avenida en teoría genética contemporánea que explica fenómenos como lo anticipación y la paradoja de Sherman que se salen del patrón mendeliano clásico.

Estrategias sociales y económicas de los nuevos jubilados.

Directory of Open Access Journals (Sweden)

Antonio Trinidad Requena

2006-01-01

Full Text Available Desde mediados de la década de los ochenta, las personas mayores han ido adquiriendo una especial relevancia y un mayor protagonismo en las sociedades modernas. El jubilado de hoy no es el jubilado del pasado, siendo necesario distinguir entre el jubilado tradicional y el nuevo jubilado, que será el jubilado del futuro. Este nuevo jubilado es el objetivo de este trabajo, centrado en conocer las estrategias sociales y económicas que utilizan para adaptarse a la nueva situación. Para conocer las estrategias sociales y económicas del nuevo jubilado nos centramos en el análisis de sus discursos.

Nucleation and crystallization behaviors of nano-crystalline lithium–mica glass–ceramic prepared via sol–gel method

Energy Technology Data Exchange (ETDEWEB)

Tohidifar, M.R. [Department of Materials Science and Engineering, Tarbiat Modares University, P.O. Box 14115-143, Tehran (Iran, Islamic Republic of); Alizadeh, P., E-mail: p-alizadeh@modares.ac.ir [Department of Materials Science and Engineering, Tarbiat Modares University, P.O. Box 14115-143, Tehran (Iran, Islamic Republic of); Riello, P. [Department of Molecular Sciences and Nanosystems, University of Ca’Foscari, Venice (Italy)

2012-06-15

Graphical abstract: The effects of nucleation and crystallization treatments on nano-crystalline lithium–mica glass–ceramic, synthesized by sol–gel technique, were investigated. It was found that MgF{sub 2} crystals act as nuclei centers for the mica crystallization so that a large quantity of mica crystallites was obtained following nucleation process. The crystallization activation energy for both the un-nucleated and nucleated samples was measured as 400.2 and 229.6 kJ mol{sup −1}, respectively. The calculated Avrami exponents demonstrated that the growth mechanism of mica crystallites changes from the needle-like to three-dimensional growth with applying the appropriate nucleation treatment ▪. Highlights: ► Crystallization temperature shifts to 625 from 680 °C following nucleation process. ► Activation energy of crystallization for the nucleated specimen is 229.6 kJ mol{sup −1}. ► Crystallization activation energy for the un-nucleated specimen is 400.2 kJ mol{sup −1}. ► Needle-like growth is predominant growth mechanism for un-nucleated sample. ► Three-dimensional growth is predominant growth mechanism for nucleated sample. -- Abstract: The paper investigates the effects of nucleation and crystallization treatments on nano-crystalline lithium–mica glass–ceramics, taking the composition LiMg{sub 3}AlSi{sub 3(1+x)}O{sub 10+6x}F{sub 2} (x = 0.5) and 8 mass% MgF{sub 2} synthesized by sol–gel technique. Here, X-ray diffraction, thermal analysis and transmission electron microscopy were used to assess the structural evolutions of as-synthesized nano-crystalline lithium–mica glass–ceramics. It was found that MgF{sub 2} crystals perform as nuclei centers for the mica crystallization hence; a large quantity of mica crystallites obtained following the nucleation process at 400 °C for 12 h. For both the un-nucleated and nucleated samples, the crystallization activation energy was measured as 400.2 and 229.6 kJ mol{sup −1

Angeitis necrotizante sistémica no supurativa

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Gabriel Toro G.

1972-04-01

Full Text Available 1. Se estudian 3 casos de angeítis necrotizante sistémica no supurativa: un hombre de 36 y una mujer de 58 años con granulomatosis de Wegener y un hombre de 30 años con granulomatosis alérgica del tipo descrito por Churg y Strauss. 2. Se prefiere el hombre de angeítis necrotizante sistémica no supurativa como lo ha hecho Paronetto cuando trata este capítulo desde el punto de vista inmunopatológico. 3. Consideran los autores que la lesión renal es la periglomerulitis granulomatosa parahiliar y que su presencia ya en la biopsia tiene gran valor diagnóstico. 4. Se subraya que el cuadro clínico, la marcada eosinofilia tisular y la presencia de imágenes micromultinodulares en el ganglio linfático, apoyan sólidamente un diagnóstico de granulomatosis alérgica de la forma descrita por Churg y Strauss. 5. Se hace una amplia revisión bibliográfica.

Habilidades académicas en estudiantes de nuevo ingreso a la Universidad del Zulia

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Mariana Fernández Reina

2015-01-01

Full Text Available Al inicio de su carrera universitaria algunos jóvenes demuestran no poseer las habilidades académicas necesarias para alcanzar la culminación de sus estudios. Esta investigación se enfoca en diagnosticar las habilidades académicas de los estudiantes cuando ingresan a la universidad. Se plantea una investigación descriptiva, con un diseño transeccional, univariable, de campo, no experimental. La población de estudio estuvo conformada por 940 estudiantes que ingresaron al Núcleo Costa Oriental del Lago de la Universidad del Zulia en las carreras de Ingeniería, Ciencias Económicas y Sociales, y Educación, para el primer período de 2012. La muestra seleccionada fue no probabilística, conformada por 179 estudiantes. El instrumento empleado para la recolección de datos fue la escala de habilidades académicas en estudiantes universitarios, compuesta por 40 reactivos, tipo Likert, la cual alcanzó una confiabilidad alfa de Cronbach de 0,86. Según los resultados los estudiantes de nuevo ingreso poseen un nivel bajo de habilidades académicas (organización; empleo de técnicas; motivación, lo cual no les permite abordar con éxito los retos de la vida universitaria. Se sugiere reforzar las mismas a través de la práctica.

Visualisation Ability of Senior High School Students with Using GeoGebra and Transparent Mica

International Nuclear Information System (INIS)

Thohirudin, M; Maryati, TK; Dwirahayu, G

2017-01-01

Visualisation ability is an ability to process, inform, and transform object which suitable for geometry topic in math. This research aims to describe the influence of using software GeoGebra and transparent mica for student’s visualisation ability. GeoGebra is shortness of geometry and algebra. GeoGebra is an open source program that is created for math. Transparent mica is a tool that is created by the author to transform a geometry object. This research is a quantitative experiment model. The subject of this research were students in grade XII of science program in Annajah Senior High School Rumpin with two classes which one as an experiment class (science one) and another one as a control class (science two). Experiment class use GeoGebra and transparent mica in the study, and control class use powerpoint in the study. Data of student’s visualisation ability is collected from posttest with visual questions which are gifted at the end of the research to both classes with topic “transformation geometry”. This research resulted that studying with GeoGebra and transparent mica had a better influence than studying with powerpoint to student’s visualisation ability. The time of study in class and the habit of the students to use software and tool affected the result of research. Although, GeoGebra and transparent mica can give help to students in transformation geometry topic. (paper)

Employer Attitudes towards Peak Hour Avoidance

NARCIS (Netherlands)

Vonk Noordegraaf, D.M.; Annema, J.A.

2012-01-01

Peak Hour Avoidance is a relatively new Dutch mobility management measure. To reduce congestion frequent car drivers are given a financial reward for reducing the proportion of trips that they make during peak hours on a specific motorway section. Although previous studies show that employers are

Employer attitudes towards peak hour avoidance

NARCIS (Netherlands)

Noordegraaf, D.M.V.; Annema, J.A.

2012-01-01

Peak Hour Avoidance is a relatively new Dutch mobility management measure. To reduce congestion frequent car drivers are given a financial reward for reducing the proportion of trips that they make during peak hours on a specific motorway section. Although previous studies show that employers are

KiDS-450: cosmological constraints from weak-lensing peak statistics - II: Inference from shear peaks using N-body simulations

Science.gov (United States)

Martinet, Nicolas; Schneider, Peter; Hildebrandt, Hendrik; Shan, HuanYuan; Asgari, Marika; Dietrich, Jörg P.; Harnois-Déraps, Joachim; Erben, Thomas; Grado, Aniello; Heymans, Catherine; Hoekstra, Henk; Klaes, Dominik; Kuijken, Konrad; Merten, Julian; Nakajima, Reiko

2018-02-01

We study the statistics of peaks in a weak-lensing reconstructed mass map of the first 450 deg2 of the Kilo Degree Survey (KiDS-450). The map is computed with aperture masses directly applied to the shear field with an NFW-like compensated filter. We compare the peak statistics in the observations with that of simulations for various cosmologies to constrain the cosmological parameter S_8 = σ _8 √{Ω _m/0.3}, which probes the (Ωm, σ8) plane perpendicularly to its main degeneracy. We estimate S8 = 0.750 ± 0.059, using peaks in the signal-to-noise range 0 ≤ S/N ≤ 4, and accounting for various systematics, such as multiplicative shear bias, mean redshift bias, baryon feedback, intrinsic alignment, and shear-position coupling. These constraints are ˜ 25 per cent tighter than the constraints from the high significance peaks alone (3 ≤ S/N ≤ 4) which typically trace single-massive haloes. This demonstrates the gain of information from low-S/N peaks. However, we find that including S/N KiDS-450. Combining shear peaks with non-tomographic measurements of the shear two-point correlation functions yields a ˜20 per cent improvement in the uncertainty on S8 compared to the shear two-point correlation functions alone, highlighting the great potential of peaks as a cosmological probe.

Bayesian Peak Picking for NMR Spectra

KAUST Repository

Cheng, Yichen

2014-02-01

Protein structure determination is a very important topic in structural genomics, which helps people to understand varieties of biological functions such as protein-protein interactions, protein–DNA interactions and so on. Nowadays, nuclear magnetic resonance (NMR) has often been used to determine the three-dimensional structures of protein in vivo. This study aims to automate the peak picking step, the most important and tricky step in NMR structure determination. We propose to model the NMR spectrum by a mixture of bivariate Gaussian densities and use the stochastic approximation Monte Carlo algorithm as the computational tool to solve the problem. Under the Bayesian framework, the peak picking problem is casted as a variable selection problem. The proposed method can automatically distinguish true peaks from false ones without preprocessing the data. To the best of our knowledge, this is the first effort in the literature that tackles the peak picking problem for NMR spectrum data using Bayesian method.

Practical load management - Peak shaving using photovoltaics

International Nuclear Information System (INIS)

Berger, W.

2009-01-01

This article takes a look at how photovoltaic (PV) power generation can be used in a practical way to meet peak demands for electricity. Advice is provided on how photovoltaics can provide peak load 'shaving' through the correlation between its production and the peak loads encountered during the day. The situation regarding feed-in tariffs in Italy is discussed, as are further examples of installations in Germany and Austria. Further, an initiative of the American Southern California Edison utility is discussed which foresees the installation of large PV plant on the roofs of commercial premises to provide local generation of peak energy and thus relieve demands on their power transportation network.

La caja negra de la dinámica empresarial

Directory of Open Access Journals (Sweden)

María Callejón

2009-01-01

Full Text Available Este artículo intenta aportar conocimientos sobre la contribución a la política industrial de la investigación en dinámica empresarial. Los programas de fomento a la creación de empresas se han generalizado aunque se desconoce cuál es el ritmo óptimo de creación y destrucción empresarial. El análisis económico destaca la heterogeneidad empresarial como característica dominante en la dinámica industrial. La profundización en el conocimiento de los tipos de emprendedores, su comportamiento, y su contribución diferencial a la innovación y el crecimiento permitirá ver en la "caja negra" y diseñar programas públicos adecuados. El análisis empírico realizado encuentra que la naturaleza económica del autoempleo es muy diferente de las empresas con empleados. Los programas públicos deberían priorizar entrantes con capacidad de sobrevivir y no maximizar la entrada indiscriminadamente. La supervivencia de las nuevas empresas se encuentra positivamente relacionada con su tamaño al nacer. La innovación y la inversión mejoran la supervivencia de las nuevas empresas manufactureras. La inversión en I+D aumenta el riesgo de las nuevas empresas, aunque mejore la competitividad de las empresas establecidas.

La caja negra de la dinámica empresarial

Directory of Open Access Journals (Sweden)

María Callejón

2009-10-01

Full Text Available Este artículo intenta aportar conocimientos sobre la contribución a la política industrial de la investigación en dinámica empresarial. Los programas de fomento a la creación de empresas se han generalizado aunque se desconoce cuál es el ritmo óptimo de creación y destrucción empresarial. El análisis económico destaca la heterogeneidad empresarial como característica dominante en la dinámica industrial. La profundización en el conocimiento de los tipos de emprendedores, su comportamiento, y su contribución diferencial a la innovación y el crecimiento permitirá ver en la “caja negra” y diseñar programas públicos adecuados. El análisis empírico realizado encuentra que la naturaleza económica del autoempleo es muy diferente de las empresas con empleados. Los programas públicos deberían priorizar entrantes con capacidad de sobrevivir y no maximizar la entrada indiscriminadamente. La supervivencia de las nuevas empresas se encuentra positivamente relacionada con su tamaño al nacer. La innovación y la inversión mejoran la supervivencia de las nuevas empresas manufactureras. La inversión en I+D aumenta el riesgo de las nuevas empresas, aunque mejore la competitividad de las empresas establecidas.

MICA: desktop software for comprehensive searching of DNA databases

Directory of Open Access Journals (Sweden)

Glick Benjamin S

2006-10-01

Full Text Available Abstract Background Molecular biologists work with DNA databases that often include entire genomes. A common requirement is to search a DNA database to find exact matches for a nondegenerate or partially degenerate query. The software programs available for such purposes are normally designed to run on remote servers, but an appealing alternative is to work with DNA databases stored on local computers. We describe a desktop software program termed MICA (K-Mer Indexing with Compact Arrays that allows large DNA databases to be searched efficiently using very little memory. Results MICA rapidly indexes a DNA database. On a Macintosh G5 computer, the complete human genome could be indexed in about 5 minutes. The indexing algorithm recognizes all 15 characters of the DNA alphabet and fully captures the information in any DNA sequence, yet for a typical sequence of length L, the index occupies only about 2L bytes. The index can be searched to return a complete list of exact matches for a nondegenerate or partially degenerate query of any length. A typical search of a long DNA sequence involves reading only a small fraction of the index into memory. As a result, searches are fast even when the available RAM is limited. Conclusion MICA is suitable as a search engine for desktop DNA analysis software.

Compatibilidad entre nueve cepas de Biomphalaria glabrata de áreas endémicas y no endémicas y una cepa de Schistosoma mansoni venezolanas

OpenAIRE

Pino,Luz A.; Matinella,Liboria; Morales C.,Gustavo

1999-01-01

Se infectaron experimentalmente 9 lotes de 32 caracoles B. glabrata (de 5 a 7mm de diámetro) con miracidios de la cepa C5 de Schistosoma mansoni a razón de 5 miracidios por caracol, pertenecientes a las siguientes cepas: En el área endémica de transmisión de Esquistosomiasis mansoni a) Sector Puerta Negra, Lago Valencia, b) Cagua c) Ingenio Bolívar (Estado Aragua) d) Mariara e) Caserío El 25 f) Güigüe (Estado Carabobo). Fuera del área endémica de transmisión g) Anzoátegui (Estado Lara), h) Ch...

Mejora en la motivación por la Lectura Académica: la mirada de estudiantes motivados

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Carla Muñoz

2016-01-01

Full Text Available Dada la importancia de la lectura académica en la formación universitaria y que uno de los factores gravitantes en este tipo de tarea son los aspectos motivacionales, el presente trabajo tuvo como objetivo identificar los elementos, que según los propios protagonistas explicarían el incremento de su motivación por la lectura de textos académicos. El estudio de carácter mixto se realizó en dos fases. En una primera fase fueron identificados a partir de una muestra amplia (n=1205 estudiantes con alta motivación por la lectura académica y que hubiesen experimentado un cambio motivacional positivo (n=10. En una segunda fase, estos casos fueron sujetos de entrevistas en profundidad y el análisis de estas entrevistas se recogen en este artículo. Los resultados muestran como causas de la mejora de la motivación por la lectura académica, dinámicas vinculadas con el desafío, el ingreso a la lógica universitaria (desescolarización y las proyecciones académico/profesionales de estos estudiantes; procesos que se encuentran vinculados a los primeros años de formación, favorecidos por docentes que promueven una dinámica académica en la formación. Se discuten finalmente las implicaciones de estas dinámicas para la formación universitaria.

Speciative Determination of Dissolved Inorganic Fe(II), Fe(III) and Total Fe in Natural Waters by Coupling CPE with FAAS

International Nuclear Information System (INIS)

Gurkan, R.; Altunay, N.

2013-01-01

A new cloud point extraction (CPE) method for the preconcentration of trace iron speciation in natural waters prior to determination by flame atomic absorption spectrometry (FAAS) was developed in the present study. In this method, Fe(II) sensitively and selectively reacts with Calcon carboxylic acid (CCA) in presence of cetylpyridinium chloride (CPC) yielding a hydrophobic complex at pH 10.5, which is then entrapped in surfactant-rich phase. Total Fe was accurately and reliably determined after the reduction of Fe(III) to Fe(II) with sulfite. The amount of Fe(III) in samples was determined from the difference between total Fe and Fe(II). CPC was used not only as an auxiliary ligand in CPE, but also as sensitivity enhancement agent in FAAS. The nonionic surfactant, polyethylene glycol tert-octylphenyl ether (Triton X-114) was used as an extracting agent. The analytical variables affecting CPE efficiency were investigated in detail. The preconcentration/enhancement factors of 50 and 82 respectively, were obtained for the preconcentration of Fe(II) with 50 mL solution. Under the optimized conditions, the detection limit of Fe(II) in linear range of 0.2-60 μg L/sup -1/ was 0.06 μg L/sup -1/. The relative standard deviation was 2.7 percentage (20 μg L/sup -1/, N: 5), recoveries for Fe(II) were in range of 99.0-102.0 percentage for all water samples including certified reference materials (CRMs). In order to verify its accuracy, two CRMs were analyzed and the results obtained were statistically in good agreement with the certified values. (author)

Electrohidrodinámica de cristales líquidos nemáticos

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Rosalío F. Rodríguez

2001-01-01

Full Text Available Se presenta un formalismo analítico que permite describir una amplia variedad de fenómenos ópticos no lineales que ocurren cuando una onda electromagnética se propaga en un cristal líquido. A partir de propiedades termodinámicas y de simetría, primero se construye un conjunto cerrado de ecuaciones hidrodinámicas que proporcionan una descripción completa de la dinámica de un nemático de bajo peso molecular en ausencia de campos externos. Posteriormente, se incluye la presencia de un campo electromagnético externo que se propaga en el fluido. Se discute el carácter no lineal y acoplado de las ecuaciones y, para resolverlas, se propone un método iterativo de aproximaciones sistemáticas en términos de potencias de parámetros con una interpretación física precisa. Se concluye discutiendo las ventajas y limitaciones del punto de vista adoptado en este trabajo..

Statistics of peaks of Gaussian random fields

International Nuclear Information System (INIS)

Bardeen, J.M.; Bond, J.R.; Kaiser, N.; Szalay, A.S.; Stanford Univ., CA; California Univ., Berkeley; Cambridge Univ., England; Fermi National Accelerator Lab., Batavia, IL)

1986-01-01

A set of new mathematical results on the theory of Gaussian random fields is presented, and the application of such calculations in cosmology to treat questions of structure formation from small-amplitude initial density fluctuations is addressed. The point process equation is discussed, giving the general formula for the average number density of peaks. The problem of the proper conditional probability constraints appropriate to maxima are examined using a one-dimensional illustration. The average density of maxima of a general three-dimensional Gaussian field is calculated as a function of heights of the maxima, and the average density of upcrossing points on density contour surfaces is computed. The number density of peaks subject to the constraint that the large-scale density field be fixed is determined and used to discuss the segregation of high peaks from the underlying mass distribution. The machinery to calculate n-point peak-peak correlation functions is determined, as are the shapes of the profiles about maxima. 67 references

A dinâmica do crédito no Brasil entre 1990-2006.

Directory of Open Access Journals (Sweden)

Juliano Morais Galle

2008-05-01

Full Text Available Este artigo aborda, dentro de um contexto de globalização financeira, a dinâmica e o desenvolvimento recente do mercado financeiro e de crédito no Brasil. É mostrado que a dinâmica do crédito se caracterizou por três fases distintas entre 1990 e 2003. Além disso, discute-se que, após a implantação do Plano Real, houve um grande esforço por parte do governo brasileiro em reestruturar e reforçar o Sistema Financeiro Nacional, e que a conjuntura econômica observada atualmente no Brasil é bem mais favorável ao crescimento da relação crédito/PIB que no início da década de 2000.

Fast Metabolite Identification in Nuclear Magnetic Resonance Metabolomic Studies: Statistical Peak Sorting and Peak Overlap Detection for More Reliable Database Queries.

Science.gov (United States)

Hoijemberg, Pablo A; Pelczer, István

2018-01-05

A lot of time is spent by researchers in the identification of metabolites in NMR-based metabolomic studies. The usual metabolite identification starts employing public or commercial databases to match chemical shifts thought to belong to a given compound. Statistical total correlation spectroscopy (STOCSY), in use for more than a decade, speeds the process by finding statistical correlations among peaks, being able to create a better peak list as input for the database query. However, the (normally not automated) analysis becomes challenging due to the intrinsic issue of peak overlap, where correlations of more than one compound appear in the STOCSY trace. Here we present a fully automated methodology that analyzes all STOCSY traces at once (every peak is chosen as driver peak) and overcomes the peak overlap obstacle. Peak overlap detection by clustering analysis and sorting of traces (POD-CAST) first creates an overlap matrix from the STOCSY traces, then clusters the overlap traces based on their similarity and finally calculates a cumulative overlap index (COI) to account for both strong and intermediate correlations. This information is gathered in one plot to help the user identify the groups of peaks that would belong to a single molecule and perform a more reliable database query. The simultaneous examination of all traces reduces the time of analysis, compared to viewing STOCSY traces by pairs or small groups, and condenses the redundant information in the 2D STOCSY matrix into bands containing similar traces. The COI helps in the detection of overlapping peaks, which can be added to the peak list from another cross-correlated band. POD-CAST overcomes the generally overlooked and underestimated presence of overlapping peaks and it detects them to include them in the search of all compounds contributing to the peak overlap, enabling the user to accelerate the metabolite identification process with more successful database queries and searching all tentative

CARACTERIZACIÓN MORFOLÓGICA Y ANATÓMICA DEL GÉNERO STEREOCAULON HOFFMANN (ASCOMYCETES-LIQUENIZADOS EN COLOMBIA

Directory of Open Access Journals (Sweden)

ANGÉLICA RINCÓN-ESPITIA

2013-12-01

Full Text Available El género Stereocaulon presenta una gran plasticidad en sus estructuras morfológicas y anatómicas, que de no ser reconocidas se puede recaer en errores taxonómicos a nivel intraespecífico. Por esta razón, se presenta una diferenciación morfoanatómica de los caracteres diagnósticos: los filocladios, los cefalodios y los soredios para facilitar el proceso de identificación taxonómica. En esta contribución se reconocen 19 especies junto con cinco variedades de Stereocaulon para Colombia, se amplían los datos de distribución geográfica y se incluye una clave taxonómica para la identificación de las especies en el país.

Sobre lo económico de la Historia Económica: Dos concepciones contrapuestas

Directory of Open Access Journals (Sweden)

Nicolás Mohaded

2013-05-01

Full Text Available Las tendencias a incrementar las contribuciones interdisciplinarias no son ajenas a la ciencia económica. Desde distintas vertientes teóricas gran cantidad de autores han intentado lograr explicaciones más comprehensivas sobre la realidad social a partir de la confluencia de disciplinas. El caso de la historia económica como conjunción de la economía y la historia puede dar cuenta de ello. Sin embargo, no existe una única manera de enfocar el análisis en esta dirección. En este sentido, este trabajo presenta dos corrientes teóricas distintas en relación a la historia económica. Por un lado el enfoque neo-institucionalista de North y Thomas y por otro el enfoque marxista de Dobb. Se plantean las distintas perspectivas teóricas que cada uno de estos dos aparatos analíticos proponen, particular-mente en lo referido a lo económico de la historia económica, y sus implicancias sobre el análisis de la realidad social.

Planificación de trayectorias para un robot tipo con restricciones dinámicas

Directory of Open Access Journals (Sweden)

Leonardo Solaque Guzmán

2008-01-01

Full Text Available Este documento presenta una aproximación a la planificación de caminos óptimos para un sistema con restricciones dinámicas y desplazándose dentro de un espacio libre de obstáculos. Se considera el modelo dinámico del dirigible y un análisis para el planteamiento de modelos simplificados o comúnmente conocidos como modelos de control. Se propone una planificación de la trayectoria desde el punto de vista de la teoría óptima utilizando un modelo de la dinámica de un robot móvil (que se desplaza a velocidad constante y en avance, es decir con restricciones dinámicas como punto de partida para la primera aproximación a los caminos óptimos. Para el suavizado de las trayectorias del dirigible se proponen dos modelos con relajación en la dinámica de la variable de control y finalmente se presenta una simulación de la comparación de los diferentes resultados.

Direct Zinc Determination in Brazilian Sugar Cane Spirit by Solid-Phase Extraction Using Moringa oleifera Husks in a Flow System with Detection by FAAS

OpenAIRE

Alves, Vanessa N.; Borges, Simone S. O.; Coelho, Nivia M. M.

2011-01-01

This paper reports a method for the determination of zinc in Brazilian sugar cane spirit, (cachaça in Portuguese), using solid-phase extraction with a flow injection analysis system and detection by FAAS. The sorbent material used was activated carbon obtained from Moringa oleifera husks. Flow and chemical variables of the proposed system were optimized through multivariate designs. The factors selected were sorbent mass, sample pH, sample flow rate, and eluent concentration. The optimum extr...

Probabilistic peak detection for first-order chromatographic data.

Science.gov (United States)

Lopatka, M; Vivó-Truyols, G; Sjerps, M J

2014-03-19

We present a novel algorithm for probabilistic peak detection in first-order chromatographic data. Unlike conventional methods that deliver a binary answer pertaining to the expected presence or absence of a chromatographic peak, our method calculates the probability of a point being affected by such a peak. The algorithm makes use of chromatographic information (i.e. the expected width of a single peak and the standard deviation of baseline noise). As prior information of the existence of a peak in a chromatographic run, we make use of the statistical overlap theory. We formulate an exhaustive set of mutually exclusive hypotheses concerning presence or absence of different peak configurations. These models are evaluated by fitting a segment of chromatographic data by least-squares. The evaluation of these competing hypotheses can be performed as a Bayesian inferential task. We outline the potential advantages of adopting this approach for peak detection and provide several examples of both improved performance and increased flexibility afforded by our approach. Copyright © 2014 Elsevier B.V. All rights reserved.

DINÂMICA ECONÔMICA E REDE URBANA CEARENSE NO INÍCIO DO SÉCULO XXI

Directory of Open Access Journals (Sweden)

Fernando Cezar de Macedo

2012-03-01

Full Text Available Este artigo discute a dinâmica econômica e a evolução da rede urbana do Ceará nesta primeira década do século XXI. Além das heranças seculares, toma como elemento decisivo na estruturação do espaço cearense as diversas políticas implementadas pelos governos estaduais que articularam a economia cearense aos movimentos das economias brasileira e internacional, influenciando sua organização espacial. Mostra que foi no período colonial que a capital cearense tornou-se principal centro urbano do estado graças à centralização dos excedentes das atividades sertanejas sustentadas no binômio pecuária-algodão. Posteriormente, apresenta as transformações verificadas na fase de integração do mercado nacional, quando se concentraram os principais investimentos na cidade de Fortaleza. Dada essa grande concentração, observam-se esforços de descentralização da atividade produtiva, a partir de uma ação deliberada do governo do estado, através dos instrumentos da guerra fiscal que atraíram para o interior importantes investimentos, sem, contudo, reduzir as disparidades intraestaduais ainda fortemente marcadas pelo predomínio metropolitano. Não obstante, surgem focos dinâmicos na economia cearense, contribuindo para uma maior diferenciação do interior do estado.

A crise econômica de 2014/2017

Directory of Open Access Journals (Sweden)

Fernando de Holanda Barbosa Filho

Full Text Available Resumo Este artigo mostra que a crise de 2014/2017 é fruto de uma combinação de choques de oferta e demanda resultado de erros de política econômica. Esses choques produziram uma redução da capacidade de crescimento da economia brasileira e risco de insolvência das finanças públicas. A solução da crise fiscal, através da PEC do teto dos gastos, fará que o país retome o crescimento econômico a partir de 2017, utilizando a capacidade ociosa da economia. No entanto, a taxa de crescimento do produto potencial não recuperará o ritmo anterior devido aos efeitos duradouros das políticas da Nova Matriz Econômica (NME que reduziram o produto potencial nacional. Recomenda-se, portanto, a adoção de políticas que induzam uma recuperação da produtividade da economia brasileira.

Introducción a la Química Orgánica

OpenAIRE

Autino, Juan Carlos; Romanelli, Gustavo Pablo; Ruiz, Diego Manuel

2013-01-01

Esta obra ha sido concebida atendiendo a las características del Curso de Química Orgánica que ofrecemos en la Facultad de Ciencias Agrarias y Forestales de la Universidad Nacional de La Plata a nuestros alumnos del primer año de las Carreras de Ingeniería Agronómica e Ingeniería Forestal, así como del segundo año de la Licenciatura en Biología. En la misma incorporamos elementos didácticos que hemos introducido y mejorado gradualmente durante varios años, logrando un cierto grado de original...

Avaliação física, química e fitoquímica de frutos de Physalis, ao longo do período de colheita

Directory of Open Access Journals (Sweden)

Cláudia Simone Madruga Lima

2012-12-01

Full Text Available Physalis peruviana L. é uma espécie que vem sendo incorporada em plantios de pequenas frutas. Esta frutífera é tratada como anual, e o principal método de propagação é por sementes. Seu cultivo apresenta uma dinâmica de colheita diferenciada, com duração do período de colheita superior a três meses. Acredita-se que, devido ao extenso período de colheita, associado a diferentes épocas de semeadura, irão ocorrer variações nas características dos frutos. O objetivo deste trabalho foi avaliar as características físicas, químicas e fitoquímicas de frutos de Physalis peruviana ao longo do período de colheita, em função de duas épocas de plantio. O experimento foi realizado no período de 2007/2008. A semeadura foi realizada em duas épocas (04-09-2007 e 26-11-2007, e o transplante foi realizado quando as plantas estavam no estádio de duas folhas verdadeiras. Os frutos foram colhidos aos 120; 150; 180; 210 e 240 dias após o transplante e avaliados quanto à massa total e a coloração da epiderme, assim como quanto aos seus teores de sólidos solúveis (SS, acidez titulável (AT, fenóis e de carotenoides totais, razão SS/AT e atividade antioxidante. Os frutos de Physalis apresentaram variações físicas, químicas e fitoquímicas ao longo do período de colheita, para as duas datas de semeadura. O desenvolvimento das plantas, após o transplantio, levou a acréscimo nos valores de massa, nos teores de sólidos solúveis, fenóis e carotenoides, assim como na razão SS/AT. Na coloração e na atividade antioxidante, os maiores valores foram obtidos na primeira colheita (120 dias. A semeadura realizada em setembro proporcionou a obtenção de frutos com melhor qualidade.

Peak load pricing lowers generation costs

International Nuclear Information System (INIS)

Lande, R.H.

1980-01-01

Before a utility implements peak load pricing for different classes of consumers, the costs and the benefits should be compared. The methodology described enables a utility to determine whether peak load pricing should be introduced for specific users. Cost-benefit analyses for domestic consumers and commercial/industrial consumers, showing break-even points are presented. (author)

Evaluation of gamma and neutron irradiation effects on the properties of mica film capacitors

International Nuclear Information System (INIS)

Roy, Rajesh; Pandya, Arun

2005-01-01

We present an investigation of gamma and neutron radiation effects on mica film capacitors from an electrical point of view. We have studied quantitatively the effects of gamma and neutron irradiation on mica film capacitors of thickness, 20 and 40 μm (0.7874 and 1.5748 mil) with two different areas, 01 and 04 cm 2 . The capacitance has been measured at room temperature in the frequency range 100 Hz-10 MHz. Negligible change in the capacitance due to high gamma dose of 60 Co, 15 kGy at dose rate 0.25 kGy/h, has been observed. However, appreciable change in the capacitance has been observed due to low doses of fast neutrons (cumulative dose, 115 cGy) with flux ∼ 9.925 X 10 7 neutrons/cm 2 h from 252 Cf neutron source of fluence, 2.5 x 10 7 neutrons/s. We have also observed that the impact of gamma and neutron irradiation is more at frequencies higher than 10 kHz, These results show that the mica capacitors do not show any radiation response below 10 kHz. The study shows the radiation response of mica film capacitors to gamma and fast neutron radiations. Mica capacitors show low gamma radiation response in comparison to fast neutron radiation, because a total dose of kGy order has been given by gamma source and only few cGy dose has been given by fast neutron source. (author)

Complement-fixing antibodies against denatured HLA and MICA antigens are associated with antibody mediated rejection.

Science.gov (United States)

Cai, Junchao; Terasaki, Paul I; Zhu, Dong; Lachmann, Nils; Schönemann, Constanze; Everly, Matthew J; Qing, Xin

2016-02-01

We have found antibodies against denatured HLA class I antigens in the serum of allograft recipients which were not significantly associated with graft failure. It is unknown whether transplant recipients also have denatured HLA class II and MICA antibodies. The effects of denatured HLA class I, class II, and MICA antibodies on long-term graft outcome were further investigated based on their ability to fix complement c1q. In this 4-year retrospective cohort study, post-transplant sera from 975 kidney transplant recipients were tested for antibodies against denatured HLA/MICA antigens and these antibodies were further classified based on their ability to fix c1q. Thirty percent of patients had antibodies against denatured HLA class I, II, or MICA antigens. Among them, 8.5% and 21.5% of all patients had c1q-fixing and non c1q-fixing antibodies respectively. There was no significant difference on graft survival between patients with or without antibodies against denatured HLA/MICA. However, when these antibodies were further classified according to their ability to fix c1q, patients with c1q-fixing antibodies had a significantly lower graft survival rate than patients without antibodies or patients with non c1q-fixing antibodies (p=0.008). In 169 patients who lost renal grafts, 44% of them had c1q-fixing antibodies against denatured HLA/MICA antigens, which was significantly higher than that in patients with functioning renal transplants (25%, pantibodies were more significantly associated with graft failure caused by AMR (72.73%) or mixed AMR/CMR (61.9%) as compared to failure due to CMR (35.3%) or other causes (39.2%) (p=0.026). Transplant recipients had antibodies against denatured HLA class I, II, and MICA antigens. However, only c1q-fixing antibodies were associated with graft failure which was related to antibody mediated rejection. Copyright © 2015 Elsevier Inc. All rights reserved.

Vida académica de la facultad

OpenAIRE

Facultad de Medicina Revista

1999-01-01

Enciclopedia Académica sobre el Lenguaje en las Ciencias de la Salud / Convenio con la Universidad de Alcalá de Henares / Libro de Biología / XI Congreso de actualización en Rehabilitación Médica. Dolor crónico, diagnóstico y manejo integral / Primer Congreso Latinoamericano de Estudiantes de Nutrición y Dietética

La imagen y el cine en la enseñanza de la historia económica

Directory of Open Access Journals (Sweden)

Joan Miguel Tejedor Estupiñán

2018-01-01

Full Text Available Este artículo presenta el modelo de enseñanza desarrollado en las asignaturas de Historia Económica de Colombia e Historia Económica Mundial, en el programa de Economía de la Universidad Católica de Colombia, 2014 y 2015, cuyo objetivo es abordar los problemas históricos de la economía, a través de las fuentes tradicionales, complementadas con la fotografía, el cine, y demás herramientas que brindan las nuevas tecnologías de la comunicación. En la primera parte se describe el contexto de la educación en Colombia en lo que se refiere a la catedra de Historia Económica, en la segunda parte, se describe el modelo de enseñanza de la historia económica a través del cine, en la tercera parte se presenta un listado de films para complementar el proceso de enseñanza de la historia económica, en la cuarta parte se enumeran algunos recursos didácticos y fuentes de investigación que ofrece la internet, y finalmente se presentan las conclusiones.

Uso de rejeitos de granitos como matérias-primas cerâmicas

Directory of Open Access Journals (Sweden)

Menezes R. R.

2002-01-01

Full Text Available A indústria do beneficiamento de granito gera uma enorme quantidade de rejeitos, que poluem e degradam o meio ambiente. Assim este trabalho tem por objetivo caracterizar e avaliar as possibilidades de utilização dos rejeitos da serragem de granitos gerados pelas indústrias de beneficiamento da Região Nordeste, como matéria-prima cerâmica alternativa na produção de blocos e revestimentos cerâmicos. Foram coletadas amostras de resíduos da serragem de granito em empresas da Paraíba, Ceará e Pernambuco, em seguida foi realizada sua caracterização através da determinação da distribuição granulométrica, massa específica real e área específica (BET e de análise química, ATD, ATG, DRX, MEV. Após caracterização foram conduzidos ensaios tecnológicos com composições cerâmicas a fim de avaliar a possibilidade de adição dos resíduos em massas cerâmicas para confecção de blocos e revestimentos cerâmicos. Com base nos resultados verificou-se que os resíduos apresentam características físicas e mineralógicas semelhantes as das matérias-primas cerâmicas convencionais e que corpos cerâmicos formulados com resíduos apresentam características dentro das especificações da normalização brasileira tanto para blocos como para revestimentos cerâmicos.

Peak Shaving Considering Streamflow Uncertainties | Iwuagwu ...

African Journals Online (AJOL)

The main thrust of this paper is peak shaving with a Stochastic hydro model. In peak sharing, the amount of hydro energy scheduled may be a minimum but it serves to replace less efficient thermal units. The sample system is die Kainji hydro plant and the thermal units of the National Electric Power Authority. The random ...

Inmigrantes sirio-libaneses y sus prácticas económicas (ilegales en Colombia, 1880-1930

Directory of Open Access Journals (Sweden)

Ana Milena Rhenals Doria

2018-01-01

Full Text Available Entre 1880 y 1930, Colombia recibió un número significativo de inmigrantes procedentes de Siria y Líbano, quienes, a través de distintas actividades empresariales, terminaron siendo parte de la élite económica de varias ciudades colombianas. En este artículo estudio ese proceso de consolidación económica, haciendo énfasis en las prácticas económicas ilegales en las que incurrieron algunos de los inmigrantes siriolibaneses que se establecieron en el circuito comercial existente entre la provincia del Sinú, Cartagena y el Atrato. Argumento que actividades como la falsificación de monedas, el contrabando y el acaparamiento de tierras intervinieron en el proceso de acumulación de capital y de consolidación económica que algunos de estos inmigrantes lograron.

Peak Oil, Peak Coal and Climate Change

Science.gov (United States)

Murray, J. W.

2009-05-01

Research on future climate change is driven by the family of scenarios developed for the IPCC assessment reports. These scenarios create projections of future energy demand using different story lines consisting of government policies, population projections, and economic models. None of these scenarios consider resources to be limiting. In many of these scenarios oil production is still increasing to 2100. Resource limitation (in a geological sense) is a real possibility that needs more serious consideration. The concept of 'Peak Oil' has been discussed since M. King Hubbert proposed in 1956 that US oil production would peak in 1970. His prediction was accurate. This concept is about production rate not reserves. For many oil producing countries (and all OPEC countries) reserves are closely guarded state secrets and appear to be overstated. Claims that the reserves are 'proven' cannot be independently verified. Hubbert's Linearization Model can be used to predict when half the ultimate oil will be produced and what the ultimate total cumulative production (Qt) will be. US oil production can be used as an example. This conceptual model shows that 90% of the ultimate US oil production (Qt = 225 billion barrels) will have occurred by 2011. This approach can then be used to suggest that total global production will be about 2200 billion barrels and that the half way point will be reached by about 2010. This amount is about 5 to 7 times less than assumed by the IPCC scenarios. The decline of Non-OPEC oil production appears to have started in 2004. Of the OPEC countries, only Saudi Arabia may have spare capacity, but even that is uncertain, because of lack of data transparency. The concept of 'Peak Coal' is more controversial, but even the US National Academy Report in 2007 concluded only a small fraction of previously estimated reserves in the US are actually minable reserves and that US reserves should be reassessed using modern methods. British coal production can be

Peak Oil, threat or energy worlds' phantasm?

International Nuclear Information System (INIS)

Favennec, Jean-Pierre

2011-01-01

The concept of Peak Oil is based on the work of King Hubbert, a petroleum geologist who worked for Shell in the USA in the 1960's. Based on the fact that discoveries in America reached a maximum in the 1930's, he announced that American production would reach a maximum in 1969, which did actually occur. Geologists members of the Association for the Study of Peak Oil have extrapolated this result to a worldwide scale and, since oil discoveries reached a peak in the 1960's, argued that production will peak in the very near future. It is clear that hydrocarbon reserves are finite and therefore exhaustible. But little is known regarding the level of ultimate (i.e. total existing) reserves. There are probably very large reserves of non conventional oil in addition to the reserves of conventional oil. An increasing number of specialists put maximum production at less than 100 Mb/d more for geopolitical than physical reasons. Attainable peak production will probably vary from year to year and will depend on how crude oil prices develop

Role of tumor necrosis factor in flavone acetic acid-induced tumor vasculature shutdown

International Nuclear Information System (INIS)

Mahadevan, V.; Malik, S.T.; Meager, A.; Fiers, W.; Lewis, G.P.; Hart, I.R.

1990-01-01

Flavone acetic acid (FAA), a novel investigational antitumor agent, has been shown to cause early vascular shutdown in several experimental murine tumors, and this phenomenon is believed to be crucial to FAA's antitumor effects. However, the basis of this FAA-induced tumor vascular shutdown is unknown. In this study a radioactive tracer-clearance technique has been used as an objective indication of tumor blood flow to show that i.p. administered FAA induces a progressive and sustained reduction in blood flow in a colon 26 tumor growing s.c. in syngeneic mice. As early as 1 h after administration, there was a significant increase in the t1/2 clearance value for intratumorally injected 133Xe, reaching a peak at 3 h (117.3 +/- 36.4 versus 7.8 +/- 0.85 min for controls). Significant inhibition of blood flow was still apparent 48 h after a single injection of drug. This FAA-induced vascular shutdown was virtually abolished in tumor-bearing mice pretreated with an antiserum against tumor necrosis factor, while no such effect was observed in controls pretreated with nonimmune serum (t1/2 of 10.8 +/- 1.2 versus 65.6 +/- 8.0 min for controls). Furthermore, in vitro FAA was seen to induce tumor necrosis factor secretion from murine peritoneal cells and splenocytes. These studies suggest that FAA-induced tumor vascular shutdown in the colon 26 tumor is mediated by tumor necrosis factor

Cargas aerodinâmicas e pré-projeto estrutural de asa de aeronave de 50 passageiros

OpenAIRE

Lauro Cavalcanti de Sá

2010-01-01

Neste trabalho foi realizado o cálculo das cargas aerodinâmicas e o pré-projeto estrutural de asa de uma aeronave de 50 passageiros durante o Mestrado Profissionalizante em Engenharia Aeronáutica e Mecânica, ministrado pelo ITA em parceria com a EMBRAER, através do seu Programa de Especialização em Engenharia. Primeiramente, o modelo estrutural foi desenvolvido baseando-se nas características aerodinâmicas iniciais da aeronave, possibilitando que o programa de análise aerodinâmica BLWF fosse ...

7 CFR 457.163 - Nursery peak inventory endorsement.

Science.gov (United States)

2010-01-01

... 7 Agriculture 6 2010-01-01 2010-01-01 false Nursery peak inventory endorsement. 457.163 Section... CORPORATION, DEPARTMENT OF AGRICULTURE COMMON CROP INSURANCE REGULATIONS § 457.163 Nursery peak inventory endorsement. Nursery Crop Insurance Peak Inventory Endorsement This endorsement is not continuous and must be...

Resinas quelantes amidoxímicas Amidoxime chelating resins

Directory of Open Access Journals (Sweden)

Fernanda M. B. Coutinho

1999-12-01

Full Text Available Resinas quelantes com grupos amidoxima foram sintetizadas por copolimerização em suspensão de acrilonitrila (AN e divinilbenzeno (DVB e subsequente modificação química dos grupos ciano por reação com hidroxilamina. Na copolimerização, a proporção de divinilbenzeno e o grau de diluição foram variados. Gelatina e carbonato de cálcio foram usados como estabilizadores de suspensão e sulfato de sódio foi adicionado para reduzir a solubilidade da acrilonitrila em água, por meio do efeito salting out. Os copolímeros de AN/DVB e as resinas amidoxímicas obtidos foram caracterizados por meio de densidade aparente, área específica, volume de poros e teor de nitrogênio. As resinas amidoxímicas foram também avaliadas em relação a capacidade de complexação de íons cobre.Chelating resins with amidoxime groups were synthesized by suspension copolymerization of acrylonitrile (AN and divinylbenzene (DVB and subsequent chemical modification of cyano groups by reaction with hydroxylamine. In the copolymerization, the proportion of divinylbenzene and the dilution degree were varied. Gelatin and calcium carbonate were used as suspension stabilizers and sodium sulphate was added in order to reduce acrylonitrile solubility in water, by salting out effect. The AN/DVB copolymers and amidoxime resins obtained were characterized by apparent density, surface area, pore volume and by the content of nitrogen. The amidoxime resins were also evaluated in relation to the complexation capacity of copper ion.

Diffraction peaks in x-ray spectroscopy: Friend or foe?

International Nuclear Information System (INIS)

Tissot, R.G.; Goehner, R.P.

1992-01-01

Diffraction peaks can occur as unidentifiable peaks in the energy spectrum of an x-ray spectrometric analysis. Recently, there has been increased interest in oriented polycrystalline films and epitaxial films on single crystal substrates for electronic applications. Since these materials diffract x-rays more efficiently than randomly oriented polycrystalline materials, diffraction peaks are being observed more frequently in x-ray fluorescent spectra. In addition, micro x-ray spectrometric analysis utilizes a small, intense, collimated x-ray beam that can yield well defined diffraction peaks. In some cases these diffraction peaks can occur at the same position as elemental peaks. These diffraction peaks, although a possible problem in qualitative and quantitative elemental analysis, can give very useful information about the crystallographic structure and orientation of the material being analyzed. The observed diffraction peaks are dependent on the geometry of the x-ray spectrometer, the degree of collimation and the distribution of wavelengths (energies) originating from the x-ray tube and striking the sample

Automatic Peak Selection by a Benjamini-Hochberg-Based Algorithm

KAUST Repository

Abbas, Ahmed; Kong, Xin-Bing; Liu, Zhi; Jing, Bing-Yi; Gao, Xin

2013-01-01

A common issue in bioinformatics is that computational methods often generate a large number of predictions sorted according to certain confidence scores. A key problem is then determining how many predictions must be selected to include most of the true predictions while maintaining reasonably high precision. In nuclear magnetic resonance (NMR)-based protein structure determination, for instance, computational peak picking methods are becoming more and more common, although expert-knowledge remains the method of choice to determine how many peaks among thousands of candidate peaks should be taken into consideration to capture the true peaks. Here, we propose a Benjamini-Hochberg (B-H)-based approach that automatically selects the number of peaks. We formulate the peak selection problem as a multiple testing problem. Given a candidate peak list sorted by either volumes or intensities, we first convert the peaks into p-values and then apply the B-H-based algorithm to automatically select the number of peaks. The proposed approach is tested on the state-of-the-art peak picking methods, including WaVPeak [1] and PICKY [2]. Compared with the traditional fixed number-based approach, our approach returns significantly more true peaks. For instance, by combining WaVPeak or PICKY with the proposed method, the missing peak rates are on average reduced by 20% and 26%, respectively, in a benchmark set of 32 spectra extracted from eight proteins. The consensus of the B-H-selected peaks from both WaVPeak and PICKY achieves 88% recall and 83% precision, which significantly outperforms each individual method and the consensus method without using the B-H algorithm. The proposed method can be used as a standard procedure for any peak picking method and straightforwardly applied to some other prediction selection problems in bioinformatics. The source code, documentation and example data of the proposed method is available at http://sfb.kaust.edu.sa/pages/software.aspx. © 2013

Automatic Peak Selection by a Benjamini-Hochberg-Based Algorithm

KAUST Repository

Abbas, Ahmed

2013-01-07

A common issue in bioinformatics is that computational methods often generate a large number of predictions sorted according to certain confidence scores. A key problem is then determining how many predictions must be selected to include most of the true predictions while maintaining reasonably high precision. In nuclear magnetic resonance (NMR)-based protein structure determination, for instance, computational peak picking methods are becoming more and more common, although expert-knowledge remains the method of choice to determine how many peaks among thousands of candidate peaks should be taken into consideration to capture the true peaks. Here, we propose a Benjamini-Hochberg (B-H)-based approach that automatically selects the number of peaks. We formulate the peak selection problem as a multiple testing problem. Given a candidate peak list sorted by either volumes or intensities, we first convert the peaks into p-values and then apply the B-H-based algorithm to automatically select the number of peaks. The proposed approach is tested on the state-of-the-art peak picking methods, including WaVPeak [1] and PICKY [2]. Compared with the traditional fixed number-based approach, our approach returns significantly more true peaks. For instance, by combining WaVPeak or PICKY with the proposed method, the missing peak rates are on average reduced by 20% and 26%, respectively, in a benchmark set of 32 spectra extracted from eight proteins. The consensus of the B-H-selected peaks from both WaVPeak and PICKY achieves 88% recall and 83% precision, which significantly outperforms each individual method and the consensus method without using the B-H algorithm. The proposed method can be used as a standard procedure for any peak picking method and straightforwardly applied to some other prediction selection problems in bioinformatics. The source code, documentation and example data of the proposed method is available at http://sfb.kaust.edu.sa/pages/software.aspx. © 2013

Neosporosis epidémica y endémica: descripción de dos eventos en bovinos para cría

Directory of Open Access Journals (Sweden)

Patricio M Calandra

2014-12-01

Full Text Available El objetivo de este trabajo es describir dos eventos producidos en la provincia de Buenos Aires en los cuales Neospora caninum estuvo asociado a la ocurrencia de abortos en bovinos de cría para carne. En uno de ellos se registraron 11 abortos en 57 vaquillonas durante 45 días, en este evento fue 5 veces más probable que una vaquillona que sufrió un aborto fuera seropositiva a N. caninum que una que no lo sufrió (odds ratio [OR] = 4,9 IC 1,2-19,9 (p 0,05. Se analizaron dos fetos de cada evento: estos resultaron negativos a otros patógenos de la reproducción, aunque presentaron anticuerpos específicos y lesiones histopatológicas compatibles con infecciones por N. caninum. Estos resultados sugieren dos posibles modalidades de presentación de abortos en bovinos causados por N. caninum: una epidémica, como la del primer evento aquí referido, y una endémica, como la del segundo.

Analysis of fuel end-temperature peaking

Energy Technology Data Exchange (ETDEWEB)

Xu, Z.; Jiang, Q.; Lai, L.; Shams, M. [CANDU Energy Inc., Fuel Engineering Dept., Mississauga, Ontario (Canada)

2013-07-01

During normal operation and refuelling of CANDU® fuel, fuel temperatures near bundle ends will increase due to a phenomenon called end flux peaking. Similar phenomenon would also be expected to occur during a postulated large break LOCA event. The end flux peaking in a CANDU fuel element is due to the fact that neutron flux is higher near a bundle end, in contact with a neighbouring bundle or close to heavy water coolant, than in the bundle mid-plane, because of less absorption of thermal neutrons by Zircaloy or heavy water than by the UO{sub 2} material. This paper describes Candu Energy experience in analysing behaviour of bundle due to end flux peaking using fuel codes FEAT, ELESTRES and ELOCA. (author)

El etanol como materia prima petroquímica

Directory of Open Access Journals (Sweden)

Luis M. Carballo

1981-07-01

Full Text Available En este trabajo se presentan los aspectos relevantes de un programa a de investigación, aprobado por el CINDEC y COLCIENCIAS, sobre el desarrollo y estudio cinético de catalizadores para algunas reacciones químicas en las que el etanol está involucrado como reactante.

La construcción de identidades docentes como constructo de estructura y dinámica sistémicas: argumentación y virtualidades teóricas y prácticas

Directory of Open Access Journals (Sweden)

Amélia Lopes

2007-01-01

Full Text Available Resaltando la importancia de que, en los estudios sobre la identidad docente, se invierta en la configuración de una perspectiva teórica integrada y elaborada y teniendo como referente la biografía investigativa de la autora, este artículo tiene como objetivos presentar la “construcción de identidades profesionales docentes” como un constructo de estructura y dinámica sistémicas e indicar sus virtualidades teóricas y prácticas. Tras una exposición inicial sobre las concepciones de identidad enmarcadas por el interaccionismo simbólico y el sentido que en ellas se vislumbra, se desarrolla una argumentación en dos fases: una relativa a la crisis de identidad de los profesores y otra referente a la construcción de nuevas identidades. Se concluye destacando las virtualidades de considerar a la construcción de nuevas identidades docentes como un constructo de estructura y dinámica sistémicas, concretamente: la posibilidad de que se relacione la construcción de identidades profesionales y los procesos de profesionalización docente; y la importancia de que se piense la formación de profesores a los diversos niveles del sistema, teniendo en cuenta sus especificidades e interacciones

La Química, la Ingeniería Química y su relación con otras disciplinas La Química, la Ingeniería Química y su relación con otras disciplinas

Directory of Open Access Journals (Sweden)

Antonio Valiente Barderas

2012-02-01

Full Text Available Chemical Engineering as such has a little more than a hundred years of existence. During this time, his development has generated research, data and books which made innovations in the curriculum and new paradigms in education. The development of this discipline has influenced the creation or modification of others such as Environmental Engineering, Food Engineering, Electrochemical Engineering, Metallurgical Engineering, etc. The future presents new challenges and opportunities for development in the area of biofuels, nanotechnology and climate control.La Ingeniería Química, como tal, tiene apenas un poco más de cien años de existencia. Durante ese tiempo la enseñanza de la misma ha ido cambiando conforme se generaron investigaciones, datos y libros que produjeron innovaciones en el currículo y nuevos pa­radigmas de la enseñanza. El desarrollo de esta disciplina ha incidido en la creación o modificación de otras más, tal como la Ingeniería Ambiental, la Ingeniería de Alimentos, la Bioingeniería, la Ingeniería Electroquímica y la Ingeniería Metalúrgica, etc. En el futuro se presentan nuevos retos y oportunidades de desarrollo en el área de los biocombustibles, la nanotecnología, los nuevos materiales y el control climático.

EL PROTEOMA DEL TEJIDO ADIPOSO SUBCUTÁNEO MUESTRA HETEROGENEIDAD ANATÓMICA

Science.gov (United States)

Martos-Moreno, G.A.; Sackmann-Sala, L.; Berryman, D.E.; Blome, D.W.; Argente, J.; Kopchick, y J.J.

2015-01-01

Introducción El tejido adiposo blanco (TAB) subcutáneo (Sc) humano podría variar dependiendo de su localización anatómica, con diferencias en su perfil proteómico. Pacientes y métodos Se obtuvieron aspirados de TAB-Sc de seis mujeres con IMC >25 kg/m2, sometidas a liposucción. Dicho TAB-Sc se obtuvo de seis localizaciones anatómicas: abdominal superior e inferior, muslo, dorsal, flanco y cadera, analizándose su perfil proteómico mediante electroforesis bidimensional. En muslo y abdomen superior se compararon, además, las muestras obtenidas de las dos capas del TAB-Sc (profunda y superficial). Resultados Se detectaron 21 proteínas que mostraban una intensidad de expresión diferente entre las seis localizaciones anatómicas y 14 entre las capas superficial y profunda de una misma región. Entre las proteínas identificadas se incluyen: vimentina (proteína estructural); proteínas “heat-shock” (HSPs), superóxido-dismutasa, (estrés/chaperoninas); proteína fijadora de ácidos grasos 4 (FABP-4) y alfa-enolasa (metabolismo lipídico y de los hidratos de carbono, respectivamente) y ATP-sintetasa (producción de energía). Entre las regiones estudiadas, el TAB-Sc dorsal mostraba un perfil proteómico particular, con menor expresión de proteínas implicadas en la producción de energía y metabolismo (ATP-sintetasa, alfa-enolasa, HSPs y FABP-4) que el resto de regiones. Conclusiones Los niveles de expresión de diversas proteínas en el TAB-Sc humano no son homogéneos, difiriendo entre localizaciones anatómicas. Esto sugiere la existencia de diferencias funcionales en el TAB-Sc de acuerdo con su localización anatómica, lo que debe considerarse antes de asumir la extrapolación de los datos derivados del TAB-Sc de una determinada localización al de otras partes de la anatomía. PMID:23228439

Effect of waste mica on transfer factors of 134Cs to spinach and lettuce

International Nuclear Information System (INIS)

Sreenivasa Chari, M.; Manjaiah, K.M.; Sachdev, P.; Sachdev, M.S.

2011-01-01

A greenhouse pot culture experiment was conducted to study the effect of graded levels of waste mica (0, 10, 20 and 40 g kg -1 ) on reducing the radiocesium uptake by spinach (Spinacia olerecea L) and lettuce (Lactuca sativa L.) grown in 134 Cs-contaminated (at 37 k Bq kg -1 soil) Inceptisols, Vertisols and Ultisols. The biomass yield, and potassium content and its uptake by crops have been significantly improved by waste mica application. The crops grown in Vertisols recorded higher biomass yield, and K content and its uptake as compared with Inceptisols and Ultisols. The average 134 Cs transfer factor values recorded were: 0.21, 0.17 and 0.26 at the first cutting, 0.15, 0.12 and 0.28 at the second cutting and 0.07, 0.05 and 0.23 at the third cutting from Inceptisols, Vertisols and Ultisols, respectively. Waste mica significantly suppressed radiocesium uptake, the effect being more pronounced at 40 g mica kg -1 soil. There exists an inverse relationship between the 134 Cs transfer factors with plant potassium content and also the K uptake by the crops. (authors)

Experiments on the incorporation of concentrated solutions of fission products in glasses and micas

International Nuclear Information System (INIS)

Bonniaud, R.; Cohen, P.; Sombret, C.

1958-01-01

1) The plants designed for extracting the plutonium of the G1, G2, G3 reactors fuel rods will produce extremely concentrated solutions of fission products. 2) Let us consider a synthetic solution of the 'G2' type: (2N NO 3 H - 2,25 meq/cm 3 AI +++ - 5.10 -3 134 Cs - 137 Cs tracer). We made various glasses and micas by adding and mixing the necessary adjuvants and baking (900 to 1400 deg. C) in a graphite crucible. 3) The products obtained had either the shape of a cylindrical pellet or were reduced into a fine powder. They were mixed with 300 cm 3 of synthetic sea water during variable periods of time in order to study leaching of the activity. 4) Experiments were first carried on caesium because of its solubility. 5) Fabrication of micas on a large scale sets many technological problems more difficult to solve (1400 deg. C) than in the case of glasses (1000 deg. C). A comparative study on both micas and glasses showed that leaching of activity was more important in the micas. (author) [fr

EL CURRÍCULO UNIVERSITARIO COMO ESCENARIO DE TENSIONES SOCIALES Y ACADÉMICAS

OpenAIRE

Mercedes Collazo

2017-01-01

Los retos que hoy plantean al currículo universitario los nuevos requerimientos de ajuste entre educación superior, empleo y sociedad en el marco de las dinámicas de globalización advierten la necesidad de construir una mirada académica que profundice los alcances y límites de los campos de formación, en razón de sus estructuras de conocimiento implicadas y en el contexto de sus particulares tradiciones profesionales y educativas. En tal sentido, el presente trabajo procura abordar el...

Avaliação econômica de plantações de eucalipto submetidas a desbaste

Directory of Open Access Journals (Sweden)

Soares Thelma Shirlen

2003-01-01

Full Text Available O objetivo deste estudo foi determinar, através de métodos de avaliação econômica, a idade econômica de corte de plantações de eucalipto submetidas a desbaste. Para tanto, foram utilizados dados de um experimento de desbastes estabelecido na região nordeste da Bahia. Foram consideradas as variações de intensidades de desbaste (0, 20, 40 e 60% de retirada em área basal para projeções realizadas em diferentes classes de local. O método de avaliação econômica utilizado foi o valor anual equivalente. Na análise de sensibilidade foram levadas em conta taxas de desconto de 6, 9 e 12%. Os resultados evidenciaram que a rotação econômica propicia maior lucratividade quando se realiza desbaste.

Effect of protein solution components in the adsorption of Herbaspirillum seropedicae GlnB protein on mica.

Science.gov (United States)

Ferreira, Cecília F G; Benelli, Elaine M; Klein, Jorge J; Schreiner, Wido; Camargo, Paulo C

2009-10-15

The adsorption of proteins and its buffer solution on mica surfaces was investigated by atomic force microscopy (AFM). Different salt concentration of the Herbaspirillum seropedicae GlnB protein (GlnB-Hs) solution deposited on mica was investigated. This protein is a globular, soluble homotrimer (36kDa), member of PII-like proteins family involved in signal transducing in prokaryote. Supramolecular structures were formed when this protein was deposited onto bare mica surface. The topographic AFM images of the GlnB-Hs films showed that at high salt concentration the supramolecular structures are spherical-like, instead of the typical doughnut-like shape for low salt concentration. AFM images of NaCl and Tris from the buffer solution showed structures with the same pattern as those observed for high salt protein solution, misleading the image interpretation. XPS experiments showed that GlnB protein film covers the mica surface without chemical reaction.

¿Oferta o renovación académica?

OpenAIRE

Serani Prádenas, Edmundo

2017-01-01

Aunque sin divulgar una definición, lo que es altamente preocupante, las autoridades universitarias han legitimado el término "Renovación de la Oferta Académica", el que en nuestra opinión tiene importantes limitaciones.

Vida académica de la facultad

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Facultad de Medicina Revista

1999-07-01

Full Text Available Enciclopedia Académica sobre el Lenguaje en las Ciencias de la Salud / Convenio con la Universidad de Alcalá de Henares / Libro de Biología / XI Congreso de actualización en Rehabilitación Médica. Dolor crónico, diagnóstico y manejo integral / Primer Congreso Latinoamericano de Estudiantes de Nutrición y Dietética

Gestão econômica de investimentos em ativos fixos

OpenAIRE

Catelli,Armando; Parisi,Cláudio; Santos,Edilene Santana

2003-01-01

Num ambiente global de intensas mudanças competitivas, a mensuração dos ativos, especificamente dos ativos fixos, requer a superação da rigidez dos custos históricos e da depreciação linear, próprios da contabilidade tradicional, e a adoção de critérios que permitam avaliar adequadamente a realidade econômica desses ativos. Partindo da premissa de que o patrimônio líquido deve representar o valor da empresa, e de que sua variação expressa o resultado econômico, o Sistema de Gestão Econômica -...

Modelagem de uma unidade de produção para caprinos leiteiros utilizando a dinâmica de sistemas

OpenAIRE

Guimarães, Vinicius Pereira

2007-01-01

O trabalho foi desenvolvido buscando abordar as características de dinâmica, complexidade e inter- relacionamento de um sistema de produção de caprinos. Buscou-se, através da metodologia de modelagem e simulação Dinâmica de Sistemas, identificar o impacto na dinâmica e rentabilidade econômica de rebanhos caprinos leiteiros provocados por modificações no manejo reprodutivo, mortalidade, qualidade do alimento e na idade para o início da vida reprodutiva em cabritas. Buscou-se também avaliar a u...

PODOLSKY'S ELECTRODYNAMICS UNDER A CHIRAL APPROACH ELECTRODINÁMICA DE PODOLSKY BAJO UN ENFOQUE QUIRAL

OpenAIRE

Héctor Torres-Silva

2008-01-01

In this paper we show that a new approach leads to Maxwell's and Podolsky's electrodynamics, provided we start from chiral constitutive relations instead of the usual Coulomb's law.En este trabajo se muestra que un nuevo esquema conduce a la electrodinámica de Maxwell y a la electrodinámica de Podolsky, partiendo con relaciones constitutivas quirales en lugar de la usual ley de Coulomb.

Bayesian approach for peak detection in two-dimensional chromatography.

Science.gov (United States)

Vivó-Truyols, Gabriel

2012-03-20

A new method for peak detection in two-dimensional chromatography is presented. In a first step, the method starts with a conventional one-dimensional peak detection algorithm to detect modulated peaks. In a second step, a sophisticated algorithm is constructed to decide which of the individual one-dimensional peaks have been originated from the same compound and should then be arranged in a two-dimensional peak. The merging algorithm is based on Bayesian inference. The user sets prior information about certain parameters (e.g., second-dimension retention time variability, first-dimension band broadening, chromatographic noise). On the basis of these priors, the algorithm calculates the probability of myriads of peak arrangements (i.e., ways of merging one-dimensional peaks), finding which of them holds the highest value. Uncertainty in each parameter can be accounted by adapting conveniently its probability distribution function, which in turn may change the final decision of the most probable peak arrangement. It has been demonstrated that the Bayesian approach presented in this paper follows the chromatographers' intuition. The algorithm has been applied and tested with LC × LC and GC × GC data and takes around 1 min to process chromatograms with several thousands of peaks.

La polémica del nacionalismo

Directory of Open Access Journals (Sweden)

Germán Posada

1961-10-01

Full Text Available La polémica empezó con el artículo de Hernando Téllez, hace veinte días. Con el pretexto de defender a los escritores de su propia generación, a quienes, según él, se viene acusando sistemáticamente de producir una literatura desarraigada y ausente de la vida nacional, Téllez se lanzó a combatir las teorías de " nacionalismo literario'' que actualmente se agitan en Colombia.

Development of the modified sum-peak method and its application

International Nuclear Information System (INIS)

Ogata, Y.; Miyahara, H.; Ishihara, M.; Ishigure, N.; Yamamoto, S.; Kojima, S.

2016-01-01

As the sum-peak method requires the total count rate as well as the peak count rates and the sum peak count rate, this meets difficulties when a sample contains other radionuclides than the one to be measured. To solve the problem, a new method using solely the peak and the sum peak count rates was developed. The method was theoretically and experimentally confirmed using "6"0Co, "2"2Na and "1"3"4Cs. We demonstrate that the modified sum-peak method is quite simple and practical and is useful to measure multiple nuclides. - Highlights: • A modified sum-peak method for simple radioactivity measurement was developed. • The method solely requires the peak count rates and the sum peak count rate. • The method is applicable to multiple radionuclides.

Peak broadening in paper chromatography and related techniques : III. Peak broadening in thin-layer chromatography on cellulose powder

NARCIS (Netherlands)

Ligny, C.L. de; Remijnse, A.G.

1968-01-01

The mechanism of peak broadening in thin-layer chromatography on cellulose powder was investigated by comparing the peak widths obtained in chromatography with those caused only by diffusion in the cellulose powder, for a set of amino acids of widely differing RF values and six kinds of cellulose

Determinação de metais em óleos lubrificantes, provenientes de motores de ônibus urbano, utilizando a FAAS

Directory of Open Access Journals (Sweden)

Eva Lúcia Cardoso Silveira

2010-01-01

Full Text Available This work proposed a procedure to examine ashes produced in burning lubricating oils used in public transportation, in Teresina PI. Sulphanilic acid was added to the oil samples, which were burned at 550 °C for three hours and 650 °C for two hours. The ash solutions were analyzed by FAAS and there were significant differences in the metal contents of the waste oil produced from normal car service. The quantification limits in μg g-1 were 5.9 (Fe, 4.4 (Pb, 1.7 (Ni, 2.1 (Cu, and 1.2 (Zn. The results showed positive accuracy and precision with recoveries between 88 and 108%, and RSD lower than 10%.

Peak effect in twinned superconductors

International Nuclear Information System (INIS)

Larkin, A.I.; Marchetti, M.C.; Vinokur, V.M.

1995-01-01

A sharp maximum in the critical current J c as a function of temperature just below the melting point of the Abrikosov flux lattice has recently been observed in both low- and high-temperature superconductors. This peak effect is strongest in twinned crystals for fields aligned with the twin planes. We propose that this peak signals the breakdown of the collective pinning regime and the crossover to strong pinning of single vortices on the twin boundaries. This crossover is very sharp and can account for the steep drop of the differential resistivity observed in experiments. copyright 1995 The American Physical Society

Biomimetic FAA-certifiable, artificial muscle structures for commercial aircraft wings

Science.gov (United States)

Barrett, Ronald M.; Barrett, Cassandra M.

2014-07-01

This paper is centered on a new form of adaptive material which functions much in the same way as skeletal muscle tissue, is structurally modeled on plant actuator cells and capable of rapidly expanding or shrinking by as much as an order of magnitude in prescribed directions. Rapid changes of plant cell shape and sizes are often initiated via ion-transport driven fluid migration and resulting turgor pressure variation. Certain plant cellular structures like those in Mimosa pudica (sensitive plant), Albizia julibrissin (Mimosa tree), or Dionaea muscipula (Venus Flytrap) all exhibit actuation physiology which employs such turgor pressure manipulation. The paper begins with dynamic micrographs of a sectioned basal articulation joint from A. julibrissin. These figures show large cellular dimensional changes as the structure undergoes foliage articulation. By mimicking such structures in aircraft flight control mechanisms, extremely lightweight pneumatic control surface actuators can be designed. This paper shows several fundamental layouts of such surfaces with actuator elements made exclusively from FAA-certifiable materials, summarizes their structural mechanics and shows actuator power and energy densities that are higher than nearly all classes of conventional adaptive materials available today. A sample flap structure is shown to possess the ability to change its shape and structural stiffness as its cell pressures are manipulated, which in turn changes the surface lift-curve slope when exposed to airflows. Because the structural stiffness can be altered, it is also shown that the commanded section lift-curve slope can be similarly controlled between 1.2 and 6.2 rad-1. Several aircraft weight reduction principles are also shown to come into play as the need to concentrate loads to pass through point actuators is eliminated. The paper concludes with a summary of interrelated performance and airframe-level improvements including enhanced gust rejection, load

Biomimetic FAA-certifiable, artificial muscle structures for commercial aircraft wings

International Nuclear Information System (INIS)

Barrett, Ronald M; Barrett, Cassandra M

2014-01-01

This paper is centered on a new form of adaptive material which functions much in the same way as skeletal muscle tissue, is structurally modeled on plant actuator cells and capable of rapidly expanding or shrinking by as much as an order of magnitude in prescribed directions. Rapid changes of plant cell shape and sizes are often initiated via ion-transport driven fluid migration and resulting turgor pressure variation. Certain plant cellular structures like those in Mimosa pudica (sensitive plant), Albizia julibrissin (Mimosa tree), or Dionaea muscipula (Venus Flytrap) all exhibit actuation physiology which employs such turgor pressure manipulation. The paper begins with dynamic micrographs of a sectioned basal articulation joint from A. julibrissin. These figures show large cellular dimensional changes as the structure undergoes foliage articulation. By mimicking such structures in aircraft flight control mechanisms, extremely lightweight pneumatic control surface actuators can be designed. This paper shows several fundamental layouts of such surfaces with actuator elements made exclusively from FAA-certifiable materials, summarizes their structural mechanics and shows actuator power and energy densities that are higher than nearly all classes of conventional adaptive materials available today. A sample flap structure is shown to possess the ability to change its shape and structural stiffness as its cell pressures are manipulated, which in turn changes the surface lift-curve slope when exposed to airflows. Because the structural stiffness can be altered, it is also shown that the commanded section lift-curve slope can be similarly controlled between 1.2 and 6.2 rad −1 . Several aircraft weight reduction principles are also shown to come into play as the need to concentrate loads to pass through point actuators is eliminated. The paper concludes with a summary of interrelated performance and airframe-level improvements including enhanced gust rejection, load

Dinámica económica e institucionalización de la tributación directa. Trasnformaciones institucionales el caso de administración de impuestos 1920-1935

OpenAIRE

Oscar Rodríguez Salazar

1999-01-01

Las tres primeras décadas del presente siglo son el escenario de profundas transformaciones en la estructura económica del país y en el modelo institucional. El desarrollo de la economía cafetera, el acceso a la economía de crédito internacional, los cambios en la política económica, la ampliación de la infraestructura, el acelerado proceso de urbanización, los cambios demográficos, la proletarización de un contingente considerable de masas campesinas y el inicio del proceso de industrializac...

OccuPeak: ChIP-Seq peak calling based on internal background modelling

NARCIS (Netherlands)

de Boer, Bouke A.; van Duijvenboden, Karel; van den Boogaard, Malou; Christoffels, Vincent M.; Barnett, Phil; Ruijter, Jan M.

2014-01-01

ChIP-seq has become a major tool for the genome-wide identification of transcription factor binding or histone modification sites. Most peak-calling algorithms require input control datasets to model the occurrence of background reads to account for local sequencing and GC bias. However, the

Rare earth ion controlled crystallization of mica glass-ceramics

International Nuclear Information System (INIS)

Garai, Mrinmoy; Karmakar, Basudeb

2016-01-01

In understanding the effects of rare earth ions to control the crystallization and microstructure of alkaline boroaluminosilicate system, the CeO_2, Nd_2O_3, Sm_2O_3 and Gd_2O_3 doped K_2O−MgO−B_2O_3−Al_2O_3−SiO_2−F glasses were synthesized by melt-quenching at 1550 °C. Higher density (2.82–3.06 g cm"−"3) and thermal stability (glass phase) is experiential on addition of rare earth content, which also affects in increasing the glass transition temperature (T_g) and crystallization temperature (T_c). Decrease of thermal expansion in glasses with rare earth ion content is maintained by the stabilization of glass matrix owing to their large cationic field strength. A significant change in the non-isothermal DSC thermogram observed at 750–1050 °C is attributed to fluorophlogopite crystallization. Opaque glass-ceramics were prepared from such glasses by single step heat-treatment at 1050 °C; and the predominant crystalline phases are identified as fluorophlogopite mica, KMg_3(AlSi_3O_1_0)F_2 by XRD and EDX analysis. The compact glass-ceramic microstructure by the agglomeration of fluorophlogopite mica crystallites (crystal size ∼ 100–500 nm, FESEM) is achieved in attendance of rare earth ion; and such microstructure controlled the variation of density, thermal expansion and microhardness value. Higher thermal expansion (11.11–14.08 × 10"−"6/K at 50–800 °C and 50–900 °C) of such glass-ceramics approve that these rare earth containing glasses can be useful for high temperature vacuum sealing application with metal or solid electrolyte. The increase of Vickers microhardness (5.27–5.61 GPa) in attendance of rare earth ions is attributed to the compact crystallinity of fluorophlogopite mica glass-ceramic microstructure. - Highlights: • Synthesis of rare earth oxide doped alkaline boroaluminosilicate glasses. • Development of opaque fluorophlogopite mica glass-ceramics by single-step heat treatment. • Nanocrystalline glass