Science.gov

Sample records for allowable temperature limits

  1. Morphological changes in human and animal enamel rods with heating--especially limits in temperature allowing discrimination between human and animal teeth.

    PubMed

    Yamamoto, K; Ohtani, S; Kato, S; Sugimoto, H; Miake, K; Nakamura, T

    1990-03-01

    Little has been revealed about making discrimination between human and animal using a piece of tooth found in a burned cadaver. From the viewpoint of forensic dental medicine, it is a theme no less valuable. This experimental study was attempted for this reason. Teeth from an individual body of human, monkey, dog, rabbit and rat were heated in turn on the muffle furnace. The heating temperatures were from 200 degrees C to 1,000 degrees C in time spans of 5, 30 and 60 minutes. After heating, each tooth and its control were observed by a scanning electron microscope (magnifying power: 3,500 x or 3,600 x). At heating temperature of 500 degrees C or 600 degrees C, enamel starts to come off in lumps and cracks appear in the enamel rods. The arcaded form in human and monkey, hexagon in dog, elongated chain in rabbit, rows of short, diagonal parallel lines equally directed at every other row in rat--these basic morphological features of the enamel rods--are retained till the heat reaches 700 degrees C. The enamel rods in monkey yield to heat more easily than those in human. At 600 degrees C many cracks appear and deformation of the arcaded form starts. With heating of 5 minutes at 800 degrees C the outline of the pattern is obscured. Human and animal teeth get varied forms of cracks in the enamel rods with heating more than 5 minutes at 800 degrees C. The structure of the enamel rods is broken and morphological characteristics are lost. This makes discrimination of human and animal quite difficult.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2133796

  2. 30 CFR 33.33 - Allowable limits of dust concentration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., EVALUATION, AND APPROVAL OF MINING PRODUCTS DUST COLLECTORS FOR USE IN CONNECTION WITH ROCK DRILLING IN COAL MINES Test Requirements § 33.33 Allowable limits of dust concentration. (a) The concentration of dust... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Allowable limits of dust concentration....

  3. 30 CFR 33.33 - Allowable limits of dust concentration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Allowable limits of dust concentration. 33.33... MINES Test Requirements § 33.33 Allowable limits of dust concentration. (a) The concentration of dust determined by the control sample shall be subtracted from the average concentration of dust determined by...

  4. 30 CFR 33.33 - Allowable limits of dust concentration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Allowable limits of dust concentration. 33.33... MINES Test Requirements § 33.33 Allowable limits of dust concentration. (a) The concentration of dust determined by the control sample shall be subtracted from the average concentration of dust determined by...

  5. 30 CFR 33.33 - Allowable limits of dust concentration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Allowable limits of dust concentration. 33.33... MINES Test Requirements § 33.33 Allowable limits of dust concentration. (a) The concentration of dust determined by the control sample shall be subtracted from the average concentration of dust determined by...

  6. 43 CFR 418.13 - Maximum allowable limits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Conditions of Water Delivery § 418.13 Maximum allowable limits. (a) Maximum allowable diversions. (1) A provisional water budget in the Newlands Project Water Budget table must be recalculated for each irrigation season to reflect anticipated water-righted acres to be irrigated. At the start of the irrigation...

  7. 43 CFR 418.13 - Maximum allowable limits.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... calculated annually to ensure an adequate water supply for all water right holders whose water use complies... subsequent decisions concerning transfers of Project water rights, using the methodology established in this... Conditions of Water Delivery § 418.13 Maximum allowable limits. (a) Maximum allowable diversions. (1)...

  8. 43 CFR 418.13 - Maximum allowable limits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... calculated annually to ensure an adequate water supply for all water right holders whose water use complies... subsequent decisions concerning transfers of Project water rights, using the methodology established in this... Conditions of Water Delivery § 418.13 Maximum allowable limits. (a) Maximum allowable diversions. (1)...

  9. 30 CFR 33.33 - Allowable limits of dust concentration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Allowable limits of dust concentration. 33.33 Section 33.33 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS DUST COLLECTORS FOR USE IN CONNECTION WITH ROCK DRILLING IN...

  10. Allowable exposure limits for carbon dioxide during extravehicular activity

    NASA Technical Reports Server (NTRS)

    Seter, Andrew J.

    1993-01-01

    The intent was to review the research pertaining to human exposure to carbon dioxide (CO2) and to recommend allowable exposure limits for extravehicular activity (EVA). Respiratory, renal, and gastrointestinal systems may be adversely affected by chronic low dose CO2 exposure. Ventilation was increased 15 percent with 1 percent CO2 and 50 percent with 2 percent CO2. Chronic exposure to less than 2 percent CO2 led to 20 day cycles of uncompensated and compensated respiratory acidosis. Acid-base changes were small. Histopathologic changes in guinea pig lungs have been noted with long term exposure to 1 percent CO2. No changes were seen with exposure to 0.5 percent CO2. Cycling of bone calcium stores with associated changes in blood and urinary calcium levels occurs with long term CO2 exposure. Histologic changes in bone have been noted in guinea pigs exposed to 1 percent CO2. Renal calcification has been noted in guinea pigs with exposure to as low as 0.5 percent CO2. An increase in gastric acidity was noted in subjects with long term exposure to 1 percent CO2. Cardiovascular and neurologic function were largely unaffected. A decrease in the incidence of respiratory, renal, and gastrointestinal disease was noted in submariners coincident with a decrease in ambient CO2 from 1.2 percent to 0.8-0.9 percent. Oxygen (O2) and CO2 stimulate respiration independently and cumulatively. The addition of CO2 to high dose O2 led to the faster onset of seizure activity in mice. Experiments evaluating the physiologic responses to intermittent, repetitive exposures to low dose CO2 and 100 percent O2 mixtures should be performed. A reduction in the current NASA standard for CO2 exposure during EVA of 1 percent (7.6 mmHg) for nominal and 2 percent (15.2 mmHg) for heavy exertion to 0.5 percent (3.8 mmHg) for nominal and 1 percent (7.6 mmHg) for heavy exertion may be prudent. At a minimum, the current NASA standard should not be liberalized.

  11. 34 CFR 609.41 - What are allowable costs and what are the limitations on allowable costs?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false What are allowable costs and what are the limitations on allowable costs? 609.41 Section 609.41 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION STRENGTHENING HISTORICALLY BLACK GRADUATE INSTITUTIONS PROGRAM...

  12. 34 CFR 607.30 - What are allowable costs and what are the limitations on allowable costs?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false What are allowable costs and what are the limitations on allowable costs? 607.30 Section 607.30 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION STRENGTHENING INSTITUTIONS PROGRAM What Conditions Must a Grantee...

  13. 34 CFR 606.30 - What are allowable costs and what are the limitations on allowable costs?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 3 2011-07-01 2011-07-01 false What are allowable costs and what are the limitations on allowable costs? 606.30 Section 606.30 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION DEVELOPING...

  14. 34 CFR 606.30 - What are allowable costs and what are the limitations on allowable costs?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 3 2014-07-01 2014-07-01 false What are allowable costs and what are the limitations on allowable costs? 606.30 Section 606.30 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION DEVELOPING...

  15. 34 CFR 606.30 - What are allowable costs and what are the limitations on allowable costs?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 3 2012-07-01 2012-07-01 false What are allowable costs and what are the limitations on allowable costs? 606.30 Section 606.30 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION DEVELOPING...

  16. 34 CFR 606.30 - What are allowable costs and what are the limitations on allowable costs?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 3 2013-07-01 2013-07-01 false What are allowable costs and what are the limitations on allowable costs? 606.30 Section 606.30 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION DEVELOPING...

  17. 34 CFR 606.30 - What are allowable costs and what are the limitations on allowable costs?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false What are allowable costs and what are the limitations on allowable costs? 606.30 Section 606.30 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION DEVELOPING...

  18. 41 CFR 302-17.3 - Types of moving expenses or allowances covered and general limitations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-RELOCATION INCOME TAX (RIT) ALLOWANCE § 302-17.3 Types of moving expenses or allowances covered and general limitations. The RIT allowance is limited by law as to the types of moving expenses that can be covered. The... furnished in kind or for which reimbursement or an allowance is provided to the transferred employee by...

  19. High temperature superconducting fault current limiter

    DOEpatents

    Hull, John R.

    1997-01-01

    A fault current limiter (10) for an electrical circuit (14). The fault current limiter (10) includes a high temperature superconductor (12) in the electrical circuit (14). The high temperature superconductor (12) is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter (10).

  20. High temperature superconducting fault current limiter

    DOEpatents

    Hull, J.R.

    1997-02-04

    A fault current limiter for an electrical circuit is disclosed. The fault current limiter includes a high temperature superconductor in the electrical circuit. The high temperature superconductor is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter. 15 figs.

  1. 75 FR 359 - Guidance on Simultaneous Transmission Import Limit Studies; Notice Allowing Post-Technical...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-05

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Guidance on Simultaneous Transmission Import Limit Studies; Notice Allowing... provide guidance for performing Simultaneous Transmission Import Limit (SIL) studies. All...

  2. 46 CFR 54.05-30 - Allowable stress values at low temperatures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Allowable stress values at low temperatures. 54.05-30... PRESSURE VESSELS Toughness Tests § 54.05-30 Allowable stress values at low temperatures. (a) The Coast... nonferrous materials at low temperature for the purpose of establishing allowable stress values for...

  3. 46 CFR 54.05-30 - Allowable stress values at low temperatures.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Allowable stress values at low temperatures. 54.05-30... PRESSURE VESSELS Toughness Tests § 54.05-30 Allowable stress values at low temperatures. (a) The Coast... nonferrous materials at low temperature for the purpose of establishing allowable stress values for...

  4. 46 CFR 54.05-30 - Allowable stress values at low temperatures.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Allowable stress values at low temperatures. 54.05-30... PRESSURE VESSELS Toughness Tests § 54.05-30 Allowable stress values at low temperatures. (a) The Coast... nonferrous materials at low temperature for the purpose of establishing allowable stress values for...

  5. 46 CFR 54.05-30 - Allowable stress values at low temperatures.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Allowable stress values at low temperatures. 54.05-30... PRESSURE VESSELS Toughness Tests § 54.05-30 Allowable stress values at low temperatures. (a) The Coast... nonferrous materials at low temperature for the purpose of establishing allowable stress values for...

  6. 46 CFR 54.05-30 - Allowable stress values at low temperatures.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Allowable stress values at low temperatures. 54.05-30... PRESSURE VESSELS Toughness Tests § 54.05-30 Allowable stress values at low temperatures. (a) The Coast... nonferrous materials at low temperature for the purpose of establishing allowable stress values for...

  7. 34 CFR 608.40 - What are allowable costs and what are the limitations on allowable costs?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... BLACK COLLEGES AND UNIVERSITIES PROGRAM What Conditions Must a Grantee Meet? § 608.40 What are allowable... paragraphs (b) and (c) of this section, a grantee may expend grant funds for activities that are related to.... Grant funds shall be used so that they supplement, and to the extent practical, increase the funds...

  8. Nitrogen and phosphorous limitations significantly reduce future allowable CO2 emissions

    NASA Astrophysics Data System (ADS)

    Zhang, Qian; Wang, Ying-Ping; Matear, Richard; Pitman, Andy; Dai, Yongjiu

    2014-05-01

    Earth System Models (ESMs) can be used to diagnose the emissions of CO2 allowed in order to follow the representative concentration pathways (RCPs) that are consistent with different climate scenarios. By mass balance, the allowable emission is calculated as the sum of the changes in atmospheric CO2, land and ocean carbon pools. Only two ESMs used in the fifth assessment (AR5) of International Panel on Climate Change (IPCC) include nitrogen (N) limitation, and none include phosphorous (P) limitation. In this study we quantified the effects of N and P limitations on the allowable emissions using an ESM simulating land and ocean CO2 exchanges to the atmosphere in RCPs used for IPCC AR5. The model can run with carbon cycle alone (C only), carbon and nitrogen (CN) or carbon, nitrogen and phosphorus (CNP) cycles as its land configurations. We used the simulated land and ocean carbon accumulation rates from 1850 to 2100 to diagnose the allowable emissions for each of three simulations (C only, CN or CNP). These were then compared with the emissions estimated by the Integrated Assessment Models (IAMs) used to generate RCP2.6 and RCP8.5. N and P limitations on land in our ESM led to systematically lower land carbon uptake, and thus reduced allowable emissions by 69 Pg C (21%) for RCP2.6, and by 250 Pg C (13%) for RCP8.5 from 2006 to 2100. Our results demonstrated that including N and P limitations requires a greater reduction in human CO2 emissions than assumed in the IAMs used to generate the RCPs. Reference: Zhang, Q., Y. P. Wang, R. J. Matear, A. J. Pitman, and Y. J. Dai (2014), Nitrogen and phosphorous limitations significantly reduce future allowable CO2 emissions, Geophys. Res. Lett., 41, doi:10.1002/2013GL058352.

  9. 34 CFR 280.41 - What are the limitations on allowable costs?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 1 2011-07-01 2011-07-01 false What are the limitations on allowable costs? 280.41 Section 280.41 Education Regulations of the Offices of the Department of Education OFFICE OF ELEMENTARY AND SECONDARY EDUCATION, DEPARTMENT OF EDUCATION MAGNET SCHOOLS ASSISTANCE PROGRAM What...

  10. 34 CFR 280.41 - What are the limitations on allowable costs?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 1 2012-07-01 2012-07-01 false What are the limitations on allowable costs? 280.41 Section 280.41 Education Regulations of the Offices of the Department of Education OFFICE OF ELEMENTARY AND SECONDARY EDUCATION, DEPARTMENT OF EDUCATION MAGNET SCHOOLS ASSISTANCE PROGRAM What...

  11. 34 CFR 280.41 - What are the limitations on allowable costs?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 1 2013-07-01 2013-07-01 false What are the limitations on allowable costs? 280.41 Section 280.41 Education Regulations of the Offices of the Department of Education OFFICE OF ELEMENTARY AND SECONDARY EDUCATION, DEPARTMENT OF EDUCATION MAGNET SCHOOLS ASSISTANCE PROGRAM What...

  12. 34 CFR 280.41 - What are the limitations on allowable costs?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 1 2014-07-01 2014-07-01 false What are the limitations on allowable costs? 280.41 Section 280.41 Education Regulations of the Offices of the Department of Education OFFICE OF ELEMENTARY AND SECONDARY EDUCATION, DEPARTMENT OF EDUCATION MAGNET SCHOOLS ASSISTANCE PROGRAM What...

  13. 34 CFR 280.41 - What are the limitations on allowable costs?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false What are the limitations on allowable costs? 280.41 Section 280.41 Education Regulations of the Offices of the Department of Education OFFICE OF ELEMENTARY AND SECONDARY EDUCATION, DEPARTMENT OF EDUCATION MAGNET SCHOOLS ASSISTANCE PROGRAM What...

  14. US Supreme Court allows limits on AIDS-related insurance benefits.

    PubMed

    Elliott, R

    2000-01-01

    In a ruling issued on 10 January 2000 with respect to Doe v Mutual of Omaha Insurance, the US Supreme Court refused to review a lower-court decision allowing an insurance company to limit health-care benefits for AIDS-related claims to less than one-tenth of what it pays under the same policies for expenses related to other illnesses. The lower court had ruled that anti-discrimination legislation does not apply to insurance policies.

  15. Limits on the lunar temperature profile

    NASA Astrophysics Data System (ADS)

    Hood, L. L.; Sonett, C. P.

    1982-01-01

    Limits on the selenotherm are estimated using (1) a preferred set of bounds on the lunar electrical conductivity profile; (2) published laboratory conductivity vs. temperature data for an olivine and several aluminous orthopyroxenes; and (3) estimates for the Al2O3 content of the deep interior suggested by bulk composition models. The inferred limits are narrowest in the depth range 450 to 1350 km and are in accord with independent geophysical constraints. Thermal history models which yield present-day selenotherms that are in best agreement with these limits are those which permit subsolidus convection at depths greater than 800 km in the moon.

  16. UHV Modifications & Cleaning Techniques to Allow High Temperature Operation in TCS/upgrade

    NASA Astrophysics Data System (ADS)

    Miller, K. E.

    2005-10-01

    FRCs have been formed and sustained by Rotating Magnetic Fields in the TCS experiment. Steady-state operation has been achieved with many new and exciting features. The plasma density is set by the RMF parameters, but the temperature has been severely limited by high impurity content, with up to 80% of the input power lost to radiation. In order to improve the temperatures and flux levels, TCS is being extensively upgraded. Improvements include UHV qualified bonding of Invar bellows to the quartz tube section necessary to allow RMF application, and the use of wire seals to replace O-rings. The remainder of the system is stainless steel, and heater blankets will allow baking to 200 C. Provisions are included for Ti/Li gettering and glow discharge cleaning. PVD deposition of Ta and W films is used on surfaces in near proximity to the FRC or its exhaust plasma, and control of recycling will be a priority. Extensive testing using an electron micro-probe and various spectroscopic techniques have been performed to establish appropriate UHV cleaning methods. Detailed data and methodology will be presented.

  17. Investigation on the presence of sulphites in fresh meat preparations: estimation of an allowable maximum limit.

    PubMed

    Iammarino, Marco; Di Taranto, Aurelia; Muscarella, Marilena

    2012-02-01

    Sulphiting agents are commonly used food additives. They are not allowed in fresh meat preparations. In this work, 2250 fresh meat samples were analysed to establish the maximum concentration of sulphites that can be considered as "natural" and therefore be admitted in fresh meat preparations. The analyses were carried out by an optimised Monier-Williams Method and the positive samples confirmed by ion chromatography. Sulphite concentrations higher than the screening method LOQ (10.0 mg · kg(-1)) were found in 100 samples. Concentrations higher than 76.6 mg · kg(-1), attributable to sulphiting agent addition, were registered in 40 samples. Concentrations lower than 41.3 mg · kg(-1) were registered in 60 samples. Taking into account the distribution of sulphite concentrations obtained, it is plausible to estimate a maximum allowable limit of 40.0 mg · kg(-1) (expressed as SO(2)). Below this value the samples can be considered as "compliant".

  18. Limiting Temperatures of Spherical Shock Wave Implosion.

    PubMed

    Liverts, Michael; Apazidis, Nicholas

    2016-01-01

    Spherical shock wave implosion in argon is studied both theoretically and experimentally. It is shown that as the strength of the converging shock increases the nonideal gas effects become dominant and govern the evolution of thermal and transport gas properties limiting the shock acceleration, lowering the gas adiabatic index and the achievable energy density at the focus. Accounting for multiple-level ionization, excitation, Coulomb interaction and radiation effects, the limiting equilibrium temperatures to be achieved during the shock implosion are estimated. Focal temperatures of the order of 30 000 K are measured in experiments where converging spherical shock waves are created using a conventional gas-dynamic shock tube facility. PMID:26799021

  19. Studies of Limits on Uncontrolled Heavy Ion Beam Losses for Allowing Hands-On Maintenance

    SciTech Connect

    Reginald M. Ronningen; Igor Remec

    2010-09-11

    Dose rates from accelerator components activated by 1 W/m beam losses are obtained semiempirically for a 1 GeV proton beam and by use of Monte Carlo transport codes for the proton beam and for 777 MeV/u 3He, 500 MeV/u 48Ca, 86Kr, 136Xe, and 400 MeV/u 238U ions. The dose rate obtained by the semi-empirical method, 0.99 mSv/h (99 mrem/h) at 30 cm, 4 h after 100 d irradiation by a 1-GeV proton beam, is consistent with studies at several accelerator facilities and with adopted hands-on maintenance dose rate limits. Monte Carlo simulations verify this result for protons and extend studies to heavy ion beam losses in drift-tube linac and superconducting linac accelerating structures. The studies indicate that the 1 W/m limit imposed on uncontrolled beam losses for high-energy proton beams might be relaxed for heavy ion beams. These studies further suggest that using the ratio of neutrons produced by a heavy ion beam to neutrons produced by a proton beam along with the dose rate from the proton beam (for thin-target scenarios) should allow an estimate of the dose rates expected from heavy ion beam losses.

  20. Temperature and Pressure Sensors Based on Spin-Allowed Broadband Luminescence of Doped Orthorhombic Perovskite Structures

    NASA Technical Reports Server (NTRS)

    Eldridge, Jeffrey I. (Inventor); Chambers, Matthew D. (Inventor)

    2014-01-01

    Systems and methods that are capable of measuring pressure or temperature based on luminescence are discussed herein. These systems and methods are based on spin-allowed broadband luminescence of sensors with orthorhombic perovskite structures of rare earth aluminates doped with chromium or similar transition metals, such as chromium-doped gadolinium aluminate. Luminescence from these sensors can be measured to determine at least one of temperature or pressure, based on either the intense luminescence of these sensors, even at high temperatures, or low temperature techniques discussed herein.

  1. Cricket frogs maintain body hydration and temperature near levels allowing maximum jump performance.

    PubMed

    Walvoord, Mark E

    2003-01-01

    One goal of this study was to determine the combination of hydration and temperature in the northern cricket frog Acris crepitans that allowed maximum jump distance in the laboratory. Second, environmental variables in the field were measured to determine the best predictor(s) of mean body temperature and hydration and to determine whether frogs maintain levels of temperature and hydration yielding maximum jump distance. Laboratory data revealed that hydration and the hydration-temperature interaction significantly affected jump performance. Frogs at 95% and 85% hydration jumped significantly better than frogs at 75% hydration, but frogs at 95% hydration at 15 degrees C jumped significantly poorer than those at 95% hydration at 30 degrees C. Animals at 85% hydration at 30 degrees C and 85% hydration at 15 degrees C jumped just as well as those at 95% hydration at 30 degrees C. Mean body temperature of 55 frogs in the field was 28.0 degrees C, and hydration was 97.4%. Sky condition (sunny, cloudy, or partly cloudy) was the best predictor of frog hydration, and air temperature was the best predictor of frog body temperature. Cricket frogs in the field maintain a hydration and temperature near those found to yield maximum jump distances in laboratory trials. This may be a behavioral adaptation to allow maximum jump distance during predator avoidance.

  2. Determination of design allowable strength properties of elevated-temperature alloys. Part 1: Coated columbium alloys

    NASA Technical Reports Server (NTRS)

    Favor, R. J.; Maykuth, D. J.; Bartlett, E. S.; Mindlin, H.

    1972-01-01

    A program to determine the characteristics of two coated columbium alloy systems for spacecraft structures is discussed. The alloy was evaluated as coated base material, coated butt-welded material, and material thermal/pressure cycled prior to testing up to 30 cycles. Evaluation was by means of tensile tests covering the temperature range to 2400 F. Design allowables were computed and are presented as tables of data. The summary includes a room temperature property table, effect of temperature curves, and typical stress-strain curves.

  3. 41 CFR 302-17.3 - Types of moving expenses or allowances covered and general limitations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... actually paid or incurred, and are not allowable as a moving expense deduction for tax purposes. The types....) (e) Househunting trip. Travel (including per diem) and transportation expenses of the employee and spouse for one round trip to the new official station to seek permanent residence quarters. (See part...

  4. 26 CFR 1.270-1 - Limitation on deductions allowable to individuals in certain cases.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... as provided in § 1.172-5, or 26 CFR (1939) 39.122-4(c) (Regulations 118), as the case may be and, in... to drought, (v) The net operating loss deduction allowed by section 172, or the corresponding... and expenses must be directly attributable to drought conditions and not to other causes such...

  5. 26 CFR 1.270-1 - Limitation on deductions allowable to individuals in certain cases.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... as provided in § 1.172-5, or 26 CFR (1939) 39.122-4(c) (Regulations 118), as the case may be and, in... to drought, (v) The net operating loss deduction allowed by section 172, or the corresponding... and expenses must be directly attributable to drought conditions and not to other causes such...

  6. 26 CFR 1.270-1 - Limitation on deductions allowable to individuals in certain cases.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... as provided in § 1.172-5, or 26 CFR (1939) 39.122-4(c) (Regulations 118), as the case may be and, in... to drought, (v) The net operating loss deduction allowed by section 172, or the corresponding... and expenses must be directly attributable to drought conditions and not to other causes such...

  7. Low retinal noise in animals with low body temperature allows high visual sensitivity.

    PubMed

    Aho, A C; Donner, K; Hydén, C; Larsen, L O; Reuter, T

    1988-07-28

    The weakest pulse of light a human can detect sends about 100 photons through the pupil and produces 10-20 rhodopsin isomerizations in a small retinal area. It has been postulated that we cannot see single photons because of a retinal noise arising from randomly occurring thermal isomerizations. Direct recordings have since demonstrated the existence of electrical 'dark' rod events indistinguishable from photoisomerization signals. Their mean rate of occurrence is roughly consistent with the 'dark light' in psychophysical threshold experiments, and their thermal parameters justify an identification with thermal isomerizations. In the retina of amphibians, a small proportion of sensitive ganglion cells have a performance-limiting noise that is low enough to be well accounted for by these events. Here we study the performance of dark-adapted toads and frogs and show that the performance limit of visually guided behaviour is also set by thermal isomerizations. As visual sensitivity limited by thermal events should rise when the temperature falls, poikilothermous vertebrates living at low temperatures should then reach light sensitivities unattainable by mammals and birds with optical factors equal. Comparison of different species at different temperatures shows a correlation between absolute threshold intensities and estimated thermal isomerization rates in the retina.

  8. Solar geoengineering to limit the rate of temperature change.

    PubMed

    MacMartin, Douglas G; Caldeira, Ken; Keith, David W

    2014-12-28

    Solar geoengineering has been suggested as a tool that might reduce damage from anthropogenic climate change. Analysis often assumes that geoengineering would be used to maintain a constant global mean temperature. Under this scenario, geoengineering would be required either indefinitely (on societal time scales) or until atmospheric CO2 concentrations were sufficiently reduced. Impacts of climate change, however, are related to the rate of change as well as its magnitude. We thus describe an alternative scenario in which solar geoengineering is used only to constrain the rate of change of global mean temperature; this leads to a finite deployment period for any emissions pathway that stabilizes global mean temperature. The length of deployment and amount of geoengineering required depends on the emissions pathway and allowable rate of change, e.g. in our simulations, reducing the maximum approximately 0.3°C per decade rate of change in an RCP 4.5 pathway to 0.1°C per decade would require geoengineering for 160 years; under RCP 6.0, the required time nearly doubles. We demonstrate that feedback control can limit rates of change in a climate model. Finally, we note that a decision to terminate use of solar geoengineering does not automatically imply rapid temperature increases: feedback could be used to limit rates of change in a gradual phase-out.

  9. Temperature dependence of the energy gap of semiconductors in the low-temperature limit.

    PubMed

    Cardona, Manuel; Meyer, T A; Thewalt, M L W

    2004-05-14

    The temperature dependence of the electronic states and energy gaps of semiconductors is an old but still important experimental and theoretical topic. Remarkably, extant results do not clarify the asymptotic T-->0 behavior. Recent breakthroughs in the spectroscopy of enriched 28Si allow us to measure changes in the band gap over the liquid 4He temperature range with an astounding precision of one part in 10(8), revealing a T4.0+/-0.2 decrease with increasing T. This is in excellent agreement with a theoretical argument predicting an exponent of 4. This power law should apply, in the low temperature limit, to the temperature dependence of the energies of all electronic states in semiconductors and insulators.

  10. Colloidal lenses allow high-temperature single-molecule imaging and improve fluorophore photostability

    PubMed Central

    Schwartz, Jerrod J.; Stavrakis, Stavros; Quake, Stephen R.

    2014-01-01

    Although single-molecule fluorescence spectroscopy was first demonstrated at near-absolute zero temperatures (1.8 K)1, the field has since advanced to include room-temperature observations2, largely owing to the use of objective lenses with high numerical aperture, brighter fluorophores and more sensitive detectors. This has opened the door for many chemical and biological systems to be studied at native temperatures at the single-molecule level both in vitro3–4 and in vivo5–6. However, it is difficult to study systems and phenomena at temperatures above 37 °C, because the index-matching fluids used with high-numerical-aperture objective lenses can conduct heat from the sample to the lens, and sustained exposure to high temperatures can cause the lens to fail. Here, we report that TiO2 colloids with diameters of 2 μm and a high refractive index can act as lenses that are capable of single-molecule imaging at 70 °C when placed in immediate proximity to an emitting molecule. The optical system is completed by a low-numerical-aperture optic that can have a long working distance and an air interface, which allows the sample to be independently heated. Colloidal lenses were used for parallel imaging of surface-immobilized single fluorophores and for real-time single-molecule measurements of mesophilic and thermophilic enzymes at 70 °C. Fluorophores in close proximity to TiO2 also showed a 40% increase in photostability due to a reduction of the excited-state lifetime. PMID:20023643

  11. 30 CFR 18.23 - Limitation of external surface temperatures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Limitation of external surface temperatures. 18.23 Section 18.23 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... and Design Requirements § 18.23 Limitation of external surface temperatures. The temperature of...

  12. 30 CFR 18.23 - Limitation of external surface temperatures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Limitation of external surface temperatures. 18.23 Section 18.23 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... and Design Requirements § 18.23 Limitation of external surface temperatures. The temperature of...

  13. 30 CFR 18.23 - Limitation of external surface temperatures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Limitation of external surface temperatures. 18.23 Section 18.23 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... and Design Requirements § 18.23 Limitation of external surface temperatures. The temperature of...

  14. 30 CFR 18.23 - Limitation of external surface temperatures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Limitation of external surface temperatures. 18.23 Section 18.23 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... and Design Requirements § 18.23 Limitation of external surface temperatures. The temperature of...

  15. 30 CFR 18.23 - Limitation of external surface temperatures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Limitation of external surface temperatures. 18... and Design Requirements § 18.23 Limitation of external surface temperatures. The temperature of the external surfaces of mechanical or electrical components shall not exceed 150 °C. (302 °F.) under...

  16. Influence of longitudinal temperature distribution on current limiting function of Superconducting Fault Current Limiting Cable (SFCLC)

    NASA Astrophysics Data System (ADS)

    Kojima, H.; Osawa, T.; Hayakawa, N.; Hanai, M.; Okubo, H.

    2014-05-01

    We have proposed a Superconducting Fault Current Limiting Cable (SFCLC), which is an HTS cable with fault current limiting function. SFCLC is expected to limit the fault current and also immediately recover the cable function after the fault clearance. In the SFCLC operation, a longitudinal temperature distribution will exist due to heat penetration, AC loss, dielectric loss and the performance of cryocooling system, which will influence its current limitation characteristics. In this paper, we investigate the influence of the longitudinal temperature distribution on current limiting function and temperature rise after the current limitation of SFCLC. We suggested the effective measures of parameter control, i.e. decreasing the critical current (Ic@77K), n value at flux flow region (n1-0), increasing the coefficient of longitudinal temperature gradient (α), inflow temperature (Tin) to achieve both the higher current limiting function and the lower temperature rise.

  17. 40 CFR Table 2 to Subpart Tttt of... - Leather Finishing HAP Emission Limits for Determining the Allowable HAP Loss

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Leather Finishing HAP Emission Limits for Determining the Allowable HAP Loss 2 Table 2 to Subpart TTTT of Part 63 Protection of Environment... Leather Finishing Operations Pt. 63, Subpt. TTTT, Table 2 Table 2 to Subpart TTTT of Part...

  18. Determination of allowable fluid temperature during start-up operation of outlet header under the assumption of constant and temperature-dependent material properties

    NASA Astrophysics Data System (ADS)

    Rząsa, Dariusz; Duda, Piotr

    2013-09-01

    Modern supercritical power plants operate at very high temperatures and pressures. Thus the construction elements are subjected to both high thermal and mechanical loads. As a result high stresses in those components are created. In order to operate safely, it is important to monitor stresses, especially during start-up and shut-down processes. The maximum stresses in the construction elements should not exceed the allowable stresses that are defined according to boiler regulations. It is important to find optimum operating parameters, that can assure safe heating and cooling processes. The optimum parameters define temperature and pressure histories that can keep the highest stresses within allowable limit and reduce operation time as much as possible. In this paper a new numerical method for determining optimum working fluid parameters is presented. In this method, properties of steel can be assumed as constant or temperature dependent. The constant value is taken usually at the average temperature of the operation cycle. For both cases optimal parameters are determined. Based on these parameters start-up operations for both cases are conducted. During entire processes stresses in the heated element are monitored. The results obtained are compared with German boiler regulations - Technische Regeln fur Dampfkessel 301.

  19. Determination of Temperature Limits for Radioactive Waste Tanks

    SciTech Connect

    Wiersma, B.J.

    1999-08-31

    This document provides a systematic approach for determining the temperature limits for a tank given that the supernate concentration is known, or for ''dry'' tanks, given that the supernate concentration from the last sample of free supernate that was collected is known. A decision tree was developed to provide the logic for the temperature limit determination.

  20. Using the written description requirement to limit broad patent scope, allow competition, and encourage innovation in biotechnology.

    PubMed

    Mull, William C

    2004-01-01

    The biotechnology research and development process is extremely expensive and companies must attract investors to this high-risk industry to pay for these costs. Biotechnology companies rely on their ability to exclude others from exploiting the benefits of their research through patent protection to attract these investors. Consequently, they seek strong patent protection for their inventions by claiming a broad scope of patent protection for their inventions. Biotechnology is an industry where the scope of protection should be limited. Science-based technologies exploit the perceived technological opportunities from recent scientific developments, concentrating the attention of many inventors on the same areas. This poses several unique problems. First, only the first of several inventors will receive a patent to the invention. Second, due to publicly available, basic techniques, the actual contribution made by the inventor may be relatively small. Finally, there is a significant risk that permitting an overbroad patent scope may permit original patentees to control a variety of improvements and a number of applications. Additionally, a broad scope of protection for an invention tends to cause underutilization of many potential inventions or improvements. By limiting the scope of protection, one allows competitors to utilize these potential inventions or improvements and encourages the advancement of the technology. Traditionally, courts have used the scope of the disclosure to limit a patent with an overly broad scope of protection. The Federal Circuit is correctly applying the written description requirement as part of the disclosure to limit broad claim scope in biotechnology patents. The written description requirement is separate from the enablement requirement and applies to all claims. By requiring a written description to allow a PHOSITA to determine the structural characteristics of the claimed invention, the Federal Circuit is able limit biotechnology

  1. Thermal environment. [physiological basis for temperature tolerance limits

    NASA Technical Reports Server (NTRS)

    Waligora, J. M.

    1979-01-01

    The physiological effects, discomfort, and performance degradation associated with an imbalanced thermal environment are discussed. Temperature tolerance limits are set using thermoregulation models and experimental results. The effects of interacting environmental factors, individual variations, and exposure duration on tolerance limits are considered.

  2. Initial-temperature profiles on the PDX inner toroidal limiter

    SciTech Connect

    Ulrickson, M.; Kugel, H.W.

    1983-09-01

    The temperature profiles resulting from plasma operation on the PDX vertical, large area, inner toroidal limiter have been measured during both ohmic and neutral-beam-heated discharges using a scanning infrared camera. An asymmetric double-peaked temperature profile is seen after neutral-beam-heated discharges. Disruptions in ohmically heated discharges are found to be preceded by a single-peaked deposition and succeeded by an initially symmetric double-peaked deposition. The results were compared with the Schmidt model for scrape-off at a toroidal limiter and it was found that the measured double-peaked temperature profiles yielded scrape-off lengths consistent with previous measurements.

  3. Initial temperature profiles of the PDX inner toroidal limiter

    SciTech Connect

    Ulrickson, M.; Kugel, H.W.

    1983-09-01

    The temperature profiles resulting from plasma operation on the PDX vertical, large area, inner toroidal limiter have been measured during both ohmic and neutral beam heated discharges using a scanning infrared camera. An asymmetric double peaked temperature profile is seen after neutral beam heated discharges. Disruptions in ohmically heated discharges are found to be preceded by a single peaked deposition and succeeded by a initially symmetric double peaked deposition. The results were compared with the Schmidt model for scrapeoff at a toroidal limiter and it was found that the measured double peaked temperature profiles yielded scrape-off lengths consistent with previous measurements.

  4. Asymmetric thermal acclimation responses allow sheepshead minnow Cyprinodon variegatus to cope with rapidly changing temperatures.

    PubMed

    Fangue, Nann A; Wunderly, Martin A; Dabruzzi, Theresa F; Bennett, Wayne A

    2014-01-01

    Thermal acclimation responses in sheepshead minnow Cyprinodon variegatus were quantified by transfer and reciprocal transfer of fish between 11.1° and 18.2°C, between 18.2° and 25.7°C, or between 25.7° and 32.8°C. Changes in thermal acclimation status were assessed by posttransfer time series determinations of thermal tolerance (i.e., critical thermal minima and maxima). In general, heat tolerance gain and loss were complete in 20 and 25 d, respectively. Cold tolerance gain was achieved ca. 24 d posttransfer, but attrition was complete after only 12-13 d. Heat tolerance was gained asymmetrically, with fish acquiring approximately one-half of their accruable tolerance at the lowest transfer temperature. Likewise, the majority of cold tolerance accruement occurred during the warmest temperature transfer. Relatively uniform losses of heat and cold tolerance were seen in reciprocal transfers. Acclimation patterns were related to initial acclimation temperature, final acclimation temperature, and acclimation time and could be accurately modeled by multiple linear regression. The results suggest that sheepshead minnow accrue a majority of their high- or low-temperature tolerance early in the acclimation process well before potential damaging temperatures are likely to occur. This novel pattern of asymmetric heat and cold tolerance acquisition in sheepshead minnow may be a key adaptation for surviving rapid and unpredictable water temperature changes commonly encountered in their natural environment. PMID:25461645

  5. Heat pipes for spacecraft temperature control: Their usefulness and limitations

    NASA Technical Reports Server (NTRS)

    Ollendorf, S.; Stipandic, E.

    1972-01-01

    Heat pipes are used in spacecraft to equalize the temperature of structures and maintain temperature control of electronic components. Information is provided for a designer on: (1) a typical mounting technique, (2) choices available in wick geometries and fluids, (3) tests involved in flight-qualifying the design, and (4) heat pipe limitations. An evaluation of several heat pipe designs showed that the behavior of heat pipes at room temperature does not necessarily correlate with the classic equations used to predict their performance. They are sensitive to such parameters as temperature, fluid inventory, orientation, and noncondensable gases.

  6. Surface chemistry allows for abiotic precipitation of dolomite at low temperature.

    PubMed

    Roberts, Jennifer A; Kenward, Paul A; Fowle, David A; Goldstein, Robert H; González, Luis A; Moore, David S

    2013-09-01

    Although the mineral dolomite is abundant in ancient low-temperature sedimentary systems, it is scarce in modern systems below 50 °C. Chemical mechanism(s) enhancing its formation remain an enigma because abiotic dolomite has been challenging to synthesize at low temperature in laboratory settings. Microbial enhancement of dolomite precipitation at low temperature has been reported; however, it is still unclear exactly how microorganisms influence reaction kinetics. Here we document the abiotic synthesis of low-temperature dolomite in laboratory experiments and constrain possible mechanisms for dolomite formation. Ancient and modern seawater solution compositions, with identical pH and pCO2, were used to precipitate an ordered, stoichiometric dolomite phase at 30 °C in as few as 20 d. Mg-rich phases nucleate exclusively on carboxylated polystyrene spheres along with calcite, whereas aragonite forms in solution via homogeneous nucleation. We infer that Mg ions are complexed and dewatered by surface-bound carboxyl groups, thus decreasing the energy required for carbonation. These results indicate that natural surfaces, including organic matter and microbial biomass, possessing a high density of carboxyl groups may be a mechanism by which ordered dolomite nuclei form. Although environments rich in organic matter may be of interest, our data suggest that sharp biogeochemical interfaces that promote microbial death, as well as those with high salinity may, in part, control carboxyl-group density on organic carbon surfaces, consistent with origin of dolomites from microbial biofilms, as well as hypersaline and mixing zone environments.

  7. Surface chemistry allows for abiotic precipitation of dolomite at low temperature

    NASA Astrophysics Data System (ADS)

    Roberts, Jennifer A.; Kenward, Paul A.; Fowle, David A.; Goldstein, Robert H.; González, Luis A.; Moore, David S.

    2013-09-01

    Although the mineral dolomite is abundant in ancient low-temperature sedimentary systems, it is scarce in modern systems below 50 °C. Chemical mechanism(s) enhancing its formation remain an enigma because abiotic dolomite has been challenging to synthesize at low temperature in laboratory settings. Microbial enhancement of dolomite precipitation at low temperature has been reported; however, it is still unclear exactly how microorganisms influence reaction kinetics. Here we document the abiotic synthesis of low-temperature dolomite in laboratory experiments and constrain possible mechanisms for dolomite formation. Ancient and modern seawater solution compositions, with identical pH and pCO2, were used to precipitate an ordered, stoichiometric dolomite phase at 30 °C in as few as 20 d. Mg-rich phases nucleate exclusively on carboxylated polystyrene spheres along with calcite, whereas aragonite forms in solution via homogeneous nucleation. We infer that Mg ions are complexed and dewatered by surface-bound carboxyl groups, thus decreasing the energy required for carbonation. These results indicate that natural surfaces, including organic matter and microbial biomass, possessing a high density of carboxyl groups may be a mechanism by which ordered dolomite nuclei form. Although environments rich in organic matter may be of interest, our data suggest that sharp biogeochemical interfaces that promote microbial death, as well as those with high salinity may, in part, control carboxyl-group density on organic carbon surfaces, consistent with origin of dolomites from microbial biofilms, as well as hypersaline and mixing zone environments.

  8. Consideration of Lower Allowable Impact Temperature for DOP-26 Iridium Alloy Fueled Clads

    NASA Astrophysics Data System (ADS)

    Skrabek, Emanuel A.

    2005-02-01

    The current DOE General Purpose Heat Source (GPHS) was developed specifically for a SiGe Radioisotope Thermoelectric Generator (RTG) which was to be launched on a Space Shuttle. In such a launch, if the final stage of the deployed spacecraft failed to ignite, the spacecraft and RTG would reenter the atmosphere after about three months in a Shuttle parking orbit. The indium alloy clad containing the radioisotope fuel would have then been at about 1300° C for the entire time on orbit. This would lead to some grain growth in the clad material, which would tend to decrease its ductility. Due to these constraints, it was concluded by the heat source community that safety considerations would require that the clads be maintained at a temperature of at least 930° C through impact. The safety testing for the GPHS RTG programs was therefore conducted with these conditions as guides. Within this set of guidelines, the heat source was shown to be able to safely handle all credible launch and reentry accident events in these missions. Currently proposed missions plan to use different power conversion systems and launch scenarios that are able to utilize much lower operating temperatures. Imposing the high operating and impact temperatures required by the SiGe RTG onto these new systems would lead to unnecessary added design complexity and probably a less robust system. If the heat source is operated so that the iridium alloy clads are generally maintained at less than 1000° C, essentially no grain growth would be experienced over normal mission lifetimes, and the clads would stay more ductile and able to safely withstand the resulting lower impact temperatures. Therefore DOE has embarked on a study to determine the lowest safe operating and impact temperatures for the GPHS. This paper presents the historical background and some preliminary results of this study.

  9. Final Report-- A Novel Storage Method for Concentrating Solar Power Plants Allowing Storage at High Temperature

    SciTech Connect

    Morris, Jeffrey F.

    2014-09-29

    The main objective of the proposed work was the development and testing of a storage method that has the potential to fundamentally change the solar thermal industry. The development of a mathematical model that describes the phenomena involved in the heat storage and recovery was also a main objective of this work. Therefore, the goal was to prepare a design package allowing reliable scale-up and optimization of design.

  10. A Low Temperature Limit for Life on Earth.

    PubMed

    Clarke, Andrew; Morris, G John; Fonseca, Fernanda; Murray, Benjamin J; Acton, Elizabeth; Price, Hannah C

    2013-01-01

    There is no generally accepted value for the lower temperature limit for life on Earth. We present empirical evidence that free-living microbial cells cooling in the presence of external ice will undergo freeze-induced desiccation and a glass transition (vitrification) at a temperature between -10°C and -26°C. In contrast to intracellular freezing, vitrification does not result in death and cells may survive very low temperatures once vitrified. The high internal viscosity following vitrification means that diffusion of oxygen and metabolites is slowed to such an extent that cellular metabolism ceases. The temperature range for intracellular vitrification makes this a process of fundamental ecological significance for free-living microbes. It is only where extracellular ice is not present that cells can continue to metabolise below these temperatures, and water droplets in clouds provide an important example of such a habitat. In multicellular organisms the cells are isolated from ice in the environment, and the major factor dictating how they respond to low temperature is the physical state of the extracellular fluid. Where this fluid freezes, then the cells will dehydrate and vitrify in a manner analogous to free-living microbes. Where the extracellular fluid undercools then cells can continue to metabolise, albeit slowly, to temperatures below the vitrification temperature of free-living microbes. Evidence suggests that these cells do also eventually vitrify, but at lower temperatures that may be below -50°C. Since cells must return to a fluid state to resume metabolism and complete their life cycle, and ice is almost universally present in environments at sub-zero temperatures, we propose that the vitrification temperature represents a general lower thermal limit to life on Earth, though its precise value differs between unicellular (typically above -20°C) and multicellular organisms (typically below -20°C). Few multicellular organisms can, however

  11. Low plasma edge temperatures for the self-pumped limiter

    SciTech Connect

    Terry, W.K.; Brooks, J.N.

    1985-03-01

    Transport code calculations have been performed to study the operation of an INTOR-like tokamak plasma from which helium is removed by a self-pumped limiter, which traps helium, but not hydrogen, in its surface layers. To prevent saturation by helium, the surface is renewed by continuous injection of the surface material (vanadium in this study) into the scrape-off layer. The presence of the injected vanadium leads to plasma temperatures well below 50 eV in the scrape-off layer, with supplementary rf heating. Operation in this edge temperature regime is essential for the use of medium- and high-Z limiter coatings.

  12. Surface chemistry allows for abiotic precipitation of dolomite at low temperature

    PubMed Central

    Roberts, Jennifer A.; Kenward, Paul A.; Fowle, David A.; Goldstein, Robert H.; González, Luis A.; Moore, David S.

    2013-01-01

    Although the mineral dolomite is abundant in ancient low-temperature sedimentary systems, it is scarce in modern systems below 50 °C. Chemical mechanism(s) enhancing its formation remain an enigma because abiotic dolomite has been challenging to synthesize at low temperature in laboratory settings. Microbial enhancement of dolomite precipitation at low temperature has been reported; however, it is still unclear exactly how microorganisms influence reaction kinetics. Here we document the abiotic synthesis of low-temperature dolomite in laboratory experiments and constrain possible mechanisms for dolomite formation. Ancient and modern seawater solution compositions, with identical pH and pCO2, were used to precipitate an ordered, stoichiometric dolomite phase at 30 °C in as few as 20 d. Mg-rich phases nucleate exclusively on carboxylated polystyrene spheres along with calcite, whereas aragonite forms in solution via homogeneous nucleation. We infer that Mg ions are complexed and dewatered by surface-bound carboxyl groups, thus decreasing the energy required for carbonation. These results indicate that natural surfaces, including organic matter and microbial biomass, possessing a high density of carboxyl groups may be a mechanism by which ordered dolomite nuclei form. Although environments rich in organic matter may be of interest, our data suggest that sharp biogeochemical interfaces that promote microbial death, as well as those with high salinity may, in part, control carboxyl-group density on organic carbon surfaces, consistent with origin of dolomites from microbial biofilms, as well as hypersaline and mixing zone environments. PMID:23964124

  13. Temperature manifold for a stopped-flow machine to allow measurements from -10 to +40°C.

    PubMed

    Walklate, Jonathan; Geeves, Michael A

    2015-05-01

    Conducting enzymatic stopped-flow experiments at temperatures far removed from ambient can be very problematic because extremes in temperature (<10°C or >30°C) can damage the machine or the enzyme. We have devised a simple manifold that can be attached to most commercial stopped-flow systems that is independently heated or cooled separate from the main stopped-flow system. Careful calibration of the flow circuit allows the sample to be heated or cooled to the measurement temperature (-8 to +40°C) 1 to 2s before mixing in the reaction chamber. This approach allows measurements at temperatures where the stopped flow or the protein is normally unstable. To validate the manifold, we investigated the well-defined ATP-induced dissociation of rabbit muscle myosin subfragment 1 (S1) from its complex with pyrene-labeled actin. This process has both temperature-dependent and -independent components. Use of ethylene glycol allowed us to measure the reaction below 0°C and up to 42°C, and as expected the second-order rate constant (K1k+2) and the maximum rate of dissociation (k+2) both increased with temperature, whereas 1/K1 is unaffected by the change in temperature.

  14. Unstable, self-limiting thermochemical temperature oscillations in Macrozamia cycads.

    PubMed

    Roemer, Robert B; Terry, L Irene; Walter, Gimme H

    2008-06-01

    Field measurements and laboratory experiments on the Australian cycads Macrozamia lucida and Macrozamia macleayi demonstrate that their cones' diel peak thermogenic temperature increase varies systematically with cone stage, with single thermogenic temperature peaks occurring daily for up to 2 weeks and reaching 12 degrees C above ambient at midstage. The initiation, magnitude and timing of those peaks are strongly modulated by ambient temperature; the period between successive thermogenic temperature peaks is not circadian, and light is neither necessary nor sufficient to initiate a thermogenic event. A mathematical analysis is developed that provides a unified explanation of the experimental results. It describes these unstable, self-limiting thermogenic events in terms of conservation of energy and a first-order chemical reaction rate model that includes an Arrhenius equation dependence of the cone's metabolic heating rate on the cone temperature. PMID:18266900

  15. Unstable, self-limiting thermochemical temperature oscillations in Macrozamia cycads.

    PubMed

    Roemer, Robert B; Terry, L Irene; Walter, Gimme H

    2008-06-01

    Field measurements and laboratory experiments on the Australian cycads Macrozamia lucida and Macrozamia macleayi demonstrate that their cones' diel peak thermogenic temperature increase varies systematically with cone stage, with single thermogenic temperature peaks occurring daily for up to 2 weeks and reaching 12 degrees C above ambient at midstage. The initiation, magnitude and timing of those peaks are strongly modulated by ambient temperature; the period between successive thermogenic temperature peaks is not circadian, and light is neither necessary nor sufficient to initiate a thermogenic event. A mathematical analysis is developed that provides a unified explanation of the experimental results. It describes these unstable, self-limiting thermogenic events in terms of conservation of energy and a first-order chemical reaction rate model that includes an Arrhenius equation dependence of the cone's metabolic heating rate on the cone temperature.

  16. Upsettability and forming limit of magnesium alloys at elevated temperatures

    NASA Astrophysics Data System (ADS)

    Park, Heung Sik; Kim, Si Pom; Park, Young Chul; Park, Joon Hong; Baek, Seung Gul

    2012-11-01

    In recent years, Magnesium (Mg) and its alloys have become a center of special interest in the automotive industry. Due to their high specific mechanical properties, they offer a significant weight saving potential in modern vehicle constructions. Most Mg alloys show very good machinability and processability, and even the most complicated die casting parts can be easily produced. In this study, Microstructure, Vickers hardness and tensile tests were examined and performed for each specimen to verify effects of forming conditions. Also to verify upsettability and forming limit of the specimen at room temperature and elevated temperature, upsetting experiments were performed. For comparison, experiments at elevated temperature were performed for various Mg alloy, such as AZ31, AZ91, and AM50. The experimental results were compared with those of CAE analysis to propose forming limit of Magnesium alloys.

  17. Elephant Seals and Temperature Data: Calibrations and Limitations.

    NASA Astrophysics Data System (ADS)

    Simmons, S. E.; Tremblay, Y.; Costa, D. P.

    2006-12-01

    In recent years with technological advances, instruments deployed on diving marine animals have been used to sample the environment in addition to their behavior. Of all oceanographic variables one of the most valuable and easiest to record is temperature. Here we report on a series of lab calibration and field validation experiments that consider the accuracy of temperature measurements from animal borne ocean samplers. Additionally we consider whether sampling frequency or animal behavior affects the quality of the temperature data collected by marine animals. Rapid response, external temperature sensors on eight Wildlife Computers MK9 time-depth recorders (TDRs) were calibrated using water baths at the Naval Postgraduate School (Monterey, CA). These water baths are calibrated using a platinum thermistor to 0.001° C. Instruments from different production batches were calibrated before and after deployments on adult female northern elephant seals, to examine tag performance over time and under `normal' usage. Tag performance in the field was validated by comparisons with temperature data from a Seabird CTD. In April/May of 2004, casts to 200m were performed over the Monterey Canyon using a CTD array carrying MK9s. These casts were performed before and after the release of a juvenile elephant seal from the boat. The seal was also carrying an MK9 TDR, allowing the assessment of any animal effect on temperature profiles. Sampling frequency during these field validations was set at one second intervals and the data from TDRs on both the CTD and the seals was sub-sampled at four, eight, 30 and 300 (5 min) seconds. The sub-sampled data was used to determine thermocline depth, a thermocline depth zone and temperature gradients and assess whether sampling frequency or animal behavior affects the quality of temperature data. Preliminary analyses indicate that temperature sensors deployed on elephant seals can provide water column temperature data of high quality and

  18. A Low Temperature Limit for Life on Earth

    PubMed Central

    Clarke, Andrew; Morris, G. John; Fonseca, Fernanda; Murray, Benjamin J.; Price, Hannah C.

    2013-01-01

    There is no generally accepted value for the lower temperature limit for life on Earth. We present empirical evidence that free-living microbial cells cooling in the presence of external ice will undergo freeze-induced desiccation and a glass transition (vitrification) at a temperature between −10°C and −26°C. In contrast to intracellular freezing, vitrification does not result in death and cells may survive very low temperatures once vitrified. The high internal viscosity following vitrification means that diffusion of oxygen and metabolites is slowed to such an extent that cellular metabolism ceases. The temperature range for intracellular vitrification makes this a process of fundamental ecological significance for free-living microbes. It is only where extracellular ice is not present that cells can continue to metabolise below these temperatures, and water droplets in clouds provide an important example of such a habitat. In multicellular organisms the cells are isolated from ice in the environment, and the major factor dictating how they respond to low temperature is the physical state of the extracellular fluid. Where this fluid freezes, then the cells will dehydrate and vitrify in a manner analogous to free-living microbes. Where the extracellular fluid undercools then cells can continue to metabolise, albeit slowly, to temperatures below the vitrification temperature of free-living microbes. Evidence suggests that these cells do also eventually vitrify, but at lower temperatures that may be below −50°C. Since cells must return to a fluid state to resume metabolism and complete their life cycle, and ice is almost universally present in environments at sub-zero temperatures, we propose that the vitrification temperature represents a general lower thermal limit to life on Earth, though its precise value differs between unicellular (typically above −20°C) and multicellular organisms (typically below −20°C). Few multicellular organisms can

  19. Varying properties along lengths of temperature limited heaters

    DOEpatents

    Vinegar, Harold J.; Xie, Xueying; Miller, David Scott; Ginestra, Jean Charles

    2011-07-26

    A system for heating a subsurface formation is described. The system includes an elongated heater in an opening in the formation. The elongated heater includes two or more portions along the length of the heater that have different power outputs. At least one portion of the elongated heater includes at least one temperature limited portion with at least one selected temperature at which the portion provides a reduced heat output. The heater is configured to provide heat to the formation with the different power outputs. The heater is configured so that the heater heats one or more portions of the formation at one or more selected heating rates.

  20. Temperature Sensing Above 1000 C Using Cr-Doped GdAlO3 Spin-Allowed Broadband Luminescence

    NASA Technical Reports Server (NTRS)

    Eldridge, Jeffrey I.; Chambers, Matthew D.

    2012-01-01

    Cr-doped GdAlO3 (Cr:GdAlO3) is shown to produce remarkably high-intensity spin-allowed broadband luminescence with sufficiently long decay times to make effective luminescence-decay-time based temperature measurements above 1000 C. This phosphor is therefore an attractive alternative to the much lower luminescence intensity rare-earth-doped thermographic phosphors that are typically utilized at these elevated temperatures. In particular, Cr:GdAlO3 will be preferred over rare-earth-doped phosphors, such as Dy:YAG, at temperatures up to 1200 C for intensity-starved situations when the much lower emission intensity from rare-earth-doped phosphors is insufficient for accurate temperature measurements in the presence of significant radiation background. While transition-metal-doped phosphors such as Cr:Al2O3 (ruby) are known to exhibit high luminescence intensity at low dopant concentrations, quenching due to nonradiative decay pathways competing with the (sup 2)E to (sup 4)A(sub 2) radiative transition (R line) has typically restricted their use for temperature sensing to below 600 C. Thermal quenching of the broadband (sup 4)T(sub 2) to (sup 4)A(sub 2) radiative transition from Cr:GdAlO3, however, is delayed until much higher temperatures (above 1000 C). This spin-allowed broadband emission persists to high temperatures because the lower-lying (sup 2)E energy level acts as a reservoir to thermally populate the higher shorter-lived (sup 4)T(sub 2) energy level and because the activation energy for nonradiative crossover relaxation from the (sup 4)T(sub 2) level to the (sup 4)A(sub 2) ground state is high. The strong crystal field associated with the tight bonding of the AlO6 octahedra in the GdAlO3 perovskite structure is responsible for this behavior.

  1. Limitations of using a thermal imager for snow pit temperatures

    NASA Astrophysics Data System (ADS)

    Schirmer, M.; Jamieson, B.

    2014-03-01

    Driven by temperature gradients, kinetic snow metamorphism plays an import role in avalanche formation. When gradients based on temperatures measured 10 cm apart appear to be insufficient for kinetic metamorphism, faceting close to a crust can be observed. Recent studies that visualised small-scale (< 10 cm) thermal structures in a profile of snow layers with an infrared (IR) camera produced interesting results. The studies found melt-freeze crusts to be warmer or cooler than the surrounding snow depending on the large-scale gradient direction. However, an important assumption within these studies was that a thermal photo of a freshly exposed snow pit was similar enough to the internal temperature of the snow. In this study, we tested this assumption by recording thermal videos during the exposure of the snow pit wall. In the first minute, the results showed increasing gradients with time, both at melt-freeze crusts and artificial surface structures such as shovel scours. Cutting through a crust with a cutting blade or shovel produced small concavities (holes) even when the objective was to cut a planar surface. Our findings suggest there is a surface structure dependency of the thermal image, which was only observed at times during a strong cooling/warming of the exposed pit wall. We were able to reproduce the hot-crust/cold-crust phenomenon and relate it entirely to surface structure in a temperature-controlled cold laboratory. Concave areas cooled or warmed more slowly compared with convex areas (bumps) when applying temperature differences between snow and air. This can be explained by increased radiative and/or turbulent energy transfer at convex areas. Thermal videos suggest that such processes influence the snow temperature within seconds. Our findings show the limitations of using a thermal camera for measuring pit-wall temperatures, particularly during windy conditions, clear skies and large temperature differences between air and snow. At crusts or other

  2. 40 CFR Table 1 to Subpart Tttt of... - Leather Finishing HAP Emission Limits for Determining the Allowable HAP Loss

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Leather Finishing HAP Emission Limits... Leather Finishing Operations Pt. 63, Subpt. TTTT, Table 1 Table 1 to Subpart TTTT of Part 63—Leather...), you must meet the appropriate emission limits in the following table: Type of Leather Product...

  3. Short communication: calf body temperature following chemical disbudding with sedation: effects of milk allowance and supplemental heat.

    PubMed

    Vasseur, E; Rushen, J; de Passillé, A M

    2014-01-01

    The use of caustic paste combined with a sedative is one of the least painful methods for disbudding. It is recommended to disbud at as early as 5d of age. However, the sedative xylazine reportedly causes a decrease in core temperature. Furthermore, young calves do not thermoregulate efficiently. We investigated the effects of disbudding calves at 5d of age using caustic paste and xylazine sedation on body temperature, activity, and milk intake of 46 individually housed 5-d-old calves in a 2×2 factorial design, with milk fed at 4.5L/d (low-fed calves) versus 9L/d (high-fed calves), with or without a heat lamp. Body temperature, calf activity (standing time), and barn temperature were monitored continuously using automatic data loggers on the day of, before the day of, and the day after disbudding. All calves were injected intramuscularly with 0.25mL of 2mg/mL xylazine 20min before disbudding (dose: 0.12±0.003mL/kg of BW). We found that the body temperature of 5-d-old calves decreased immediately after the injection of the sedative xylazine. The body temperature of calves decreased 0.9±0.09°C and it took 3.8±0.32h to climb back to the preinjection body temperature. Calves that were fed the lower amount of milk, received a higher dose of xylazine (mL/kg BW), or were disbudded in a colder environment were more affected by body temperature variations (lower and longest decrease in body temperature and higher magnitude). Calf activity recovery followed the pattern of body temperature recovery. Milk allowance and supplemental heat did not help enhance recovery during the 6h following the procedure. The disbudding procedure did not affect milk intake but calves with less body temperature decrease or kept in a warmer environment drank more milk following disbudding. Low-fed calves were overall more affected by the procedure than high-fed calves during the disbudding day and the following day (greater decrease in body temperature and drank less in the colder

  4. The effect of maximum-allowable payload temperature on the mass of a multimegawatt space-based platform

    SciTech Connect

    Dobranich, D.

    1987-08-01

    Calculations were performed to determine the mass of a space-based platform as a function of the maximum-allowed operating temperature of the electrical equipment within the platform payload. Two computer programs were used in conjunction to perform these calculations. The first program was used to determine the mass of the platform reactor, shield, and power conversion system. The second program was used to determine the mass of the main and secondary radiators of the platform. The main radiator removes the waste heat associated with the power conversion system and the secondary radiator removes the waste heat associated with the platform payload. These calculations were performed for both Brayton and Rankine cycle platforms with two different types of payload cooling systems: a pumped-loop system (a heat exchanger with a liquid coolant) and a refrigerator system. The results indicate that increases in the maximum-allowed payload temperature offer significant platform mass savings for both the Brayton and Rankine cycle platforms with either the pumped-loop or refrigerator payload cooling systems. Therefore, with respect to platform mass, the development of high temperature electrical equipment would be advantageous. 3 refs., 24 figs., 7 tabs.

  5. Gradient Limitations in Room Temperature and Superconducting Acceleration Structures

    SciTech Connect

    Solyak, N. A.

    2009-01-22

    Accelerating gradient is a key parameter of the accelerating structure in large linac facilities, like future Linear Collider. In room temperature accelerating structures the gradient is limited mostly by breakdown phenomena, caused by high surface electric fields or pulse surface heating. High power processing is a necessary procedure to clean surface and improve the gradient. In the best tested X-band structures the achieved gradient is exceed 100 MV/m in of {approx}200 ns pulses for breakdown rate of {approx}10{sup -7}. Gradient limit depends on number of factors and no one theory which can explain all sets of experimental results and predict gradient in new accelerating structure. In paper we briefly overview the recent experimental results of breakdown studies, progress in understanding of gradient limitations and scaling laws. Although superconducting rf technology has been adopted throughout the world for ILC, it has frequently been difficult to reach the predicted performance in these structures due to a number of factors: multipactoring, field emission, Q-slope, thermal breakdown. In paper we are discussing all these phenomena and the ways to increase accelerating gradient in SC cavity, which are a part of worldwide R and D program.

  6. Gradient limitations in room temperature and superconducting acceleration structures

    SciTech Connect

    Solyak, N.A.; /Fermilab

    2008-10-01

    Accelerating gradient is a key parameter of the accelerating structure in large linac facilities, like future Linear Collider. In room temperature accelerating structures the gradient is limited mostly by breakdown phenomena, caused by high surface electric fields or pulse surface heating. High power processing is a necessary procedure to clean surface and improve the gradient. In the best tested X-band structures the achieved gradient is exceed 100 MV/m in of {approx}200 ns pulses for breakdown rate of {approx} 10{sup -7}. Gradient limit depends on number of factors and no one theory which can explain all sets of experimental results and predict gradient in new accelerating structure. In paper we briefly overview the recent experimental results of breakdown studies, progress in understanding of gradient limitations and scaling laws. Although superconducting rf technology has been adopted throughout the world for ILC, it has frequently been difficult to reach the predicted performance in these structures due to a number of factors: multipactoring, field emission, Q-slope, thermal breakdown. In paper we are discussing all these phenomena and the ways to increase accelerating gradient in SC cavity, which are a part of worldwide R&D program.

  7. 50 CFR Table 1 (north) to Part 660... - Limited Entry Trawl Rockfish Conservation Areas and Landing Allowances for non-IFQ Species and...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Limited Entry Trawl Rockfish Conservation Areas and Landing Allowances for non-IFQ Species and Pacific Whiting North of 40°10â² N. Lat. 1 Table 1... Conservation Areas and Landing Allowances for non-IFQ Species and Pacific Whiting North of 40°10′ N....

  8. 50 CFR Table 1 (south) to Part 660... - Limited Entry Trawl Rockfish Conservation Areas and Landing Allowances for non-IFQ Species and...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Limited Entry Trawl Rockfish Conservation Areas and Landing Allowances for non-IFQ Species and Pacific Whiting South of 40°10â² N. Lat. 1 Table 1... Conservation Areas and Landing Allowances for non-IFQ Species and Pacific Whiting South of 40°10′ N....

  9. Identification of lifetime limiting defects by temperature- and injection-dependent photoluminescence imaging

    NASA Astrophysics Data System (ADS)

    Schön, Jonas; Youssef, Amanda; Park, Sungeun; Mundt, Laura E.; Niewelt, Tim; Mack, Sebastian; Nakajima, Kazuo; Morishita, Kohei; Murai, Ryota; Jensen, Mallory A.; Buonassisi, Tonio; Schubert, Martin C.

    2016-09-01

    Identification of the lifetime limiting defects in silicon plays a key role in systematically optimizing the efficiency potential of material for solar cells. We present a technique based on temperature and injection dependent photoluminescence imaging to determine the energy levels and capture cross section ratios of Shockley-Read-Hall defects. This allows us to identify homogeneously and inhomogeneously distributed defects limiting the charge carrier lifetime in any silicon wafer. The technique is demonstrated on an n-type wafer grown with the non-contact crucible (NOC) method and an industrial Czochralski (Cz) wafer prone to defect formation during high temperature processing. We find that the energy levels for the circular distributed defects in the Cz wafer are in good agreement with literature data for homogeneously grown oxide precipitates. In contrast, the circular distributed defects found in NOC Si have significantly deeper trap levels, despite their similar appearance.

  10. 41 CFR 302-7.17 - Is the maximum weight allowance for HHG and temporary storage limited when quarters are furnished...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 41 Public Contracts and Property Management 4 2012-07-01 2012-07-01 false Is the maximum weight... Government OCONUS or upon return to CONUS? 302-7.17 Section 302-7.17 Public Contracts and Property Management...) General Rules § 302-7.17 Is the maximum weight allowance for HHG and temporary storage limited...

  11. 26 CFR 1.42-1T - Limitation on low-income housing credit allowed with respect to qualified low-income buildings...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 1 2012-04-01 2012-04-01 false Limitation on low-income housing credit allowed with respect to qualified low-income buildings receiving housing credit allocations from a State or local housing credit agency (temporary). 1.42-1T Section 1.42-1T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY INCOME...

  12. 26 CFR 1.42-1T - Limitation on low-income housing credit allowed with respect to qualified low-income buildings...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 1 2011-04-01 2009-04-01 true Limitation on low-income housing credit allowed... to $1.25 multiplied by the State's population. A State's population for any calendar year is... the Bureau of the Census publication, “Current Population Reports, Series P-25: Population...

  13. Temperature and Photoperiod Interactions with Phosphorus-Limited Growth and Competition of Two Diatoms

    PubMed Central

    Shatwell, Tom; Köhler, Jan; Nicklisch, Andreas

    2014-01-01

    In lakes, trophic change and climate change shift the relationship between nutrients and physical factors, like temperature and photoperiod, and interactions between these factors should affect the growth of phytoplankton species differently. We therefore determined the relationship between P-limited specific growth rates and P-quota (biovolume basis) of Stephanodiscus minutulus and Nitzschia acicularis (diatoms) at or near light saturation in axenic, semi-continuous culture at 10, 15 and 20 °C and at 6, 9 and 12 h d−1 photoperiod. Photoperiod treatments were performed at constant daily light exposure to allow comparison. Under these conditions, we also performed competition experiments and estimated relative P-uptake rates of the species. Temperature strongly affected P-limited growth rates and relative P uptake rates, whereas photoperiod only affected maximum growth rates. S. minutulus used internal P more efficiently than N. acicularis. N. acicularis was the superior competitor for P due to a higher relative uptake rate and its superiority increased with increasing temperature and photoperiod. S. minutulus conformed to the Droop relationship but N. acicularis did not. A model with a temperature-dependent normalised half-saturation coefficient adequately described the factor interactions of both species. The temperature dependence of the quota model reflected each species’ specific adaptation to its ecological niche. The results demonstrate that increases in temperature or photoperiod can partially compensate for a decrease in P-quota under moderately limiting conditions, like during spring in temperate lakes. Thus warming may counteract de-eutrophication to some degree and a relative shift in growth factors can influence the phytoplankton species composition. PMID:25010420

  14. Temperature and photoperiod interactions with phosphorus-limited growth and competition of two diatoms.

    PubMed

    Shatwell, Tom; Köhler, Jan; Nicklisch, Andreas

    2014-01-01

    In lakes, trophic change and climate change shift the relationship between nutrients and physical factors, like temperature and photoperiod, and interactions between these factors should affect the growth of phytoplankton species differently. We therefore determined the relationship between P-limited specific growth rates and P-quota (biovolume basis) of Stephanodiscus minutulus and Nitzschia acicularis (diatoms) at or near light saturation in axenic, semi-continuous culture at 10, 15 and 20 °C and at 6, 9 and 12 h d(-1) photoperiod. Photoperiod treatments were performed at constant daily light exposure to allow comparison. Under these conditions, we also performed competition experiments and estimated relative P-uptake rates of the species. Temperature strongly affected P-limited growth rates and relative P uptake rates, whereas photoperiod only affected maximum growth rates. S. minutulus used internal P more efficiently than N. acicularis. N. acicularis was the superior competitor for P due to a higher relative uptake rate and its superiority increased with increasing temperature and photoperiod. S. minutulus conformed to the Droop relationship but N. acicularis did not. A model with a temperature-dependent normalised half-saturation coefficient adequately described the factor interactions of both species. The temperature dependence of the quota model reflected each species' specific adaptation to its ecological niche. The results demonstrate that increases in temperature or photoperiod can partially compensate for a decrease in P-quota under moderately limiting conditions, like during spring in temperate lakes. Thus warming may counteract de-eutrophication to some degree and a relative shift in growth factors can influence the phytoplankton species composition.

  15. Low and High Temperature Limits to PSII 1

    PubMed Central

    Terzaghi, William B.; Fork, David C.; Berry, Joseph A.; Field, Christopher B.

    1989-01-01

    Many studies have shown that membrane lipids of chilling-sensitive plants begin lateral phase separation (i.e. a minor component begins freezing) at chilling temperatures and that chilling-sensitive plants are often of tropical origin. We tested the hypothesis that membranes of tropical plants begin lateral phase separation at chilling temperatures, and that plants lower the temperature of lateral phase separation as they invade cooler habitats. To do so we studied plant species in one family confined to the tropics (Piperaceae) and in three families with both tropical and temperate representatives (Fabaceae [Leguminosae], Malvaceae, and Solanaceae). We determined lateral phase separation temperatures by measuring the temperature dependence of fluorescence from trans-parinaric acid inserted into liposomes prepared from isolated membrane phospholipids. In all families we detected lateral phase separations at significantly higher temperatures, on average, in species of tropical origin. To test for associated physiological effects we measured the temperature dependence of delayed light emission (DLE) by discs cut from the same leaves used for lipid analysis. We found that the temperature of maximum DLE upon chilling was strongly correlated with lateral phase separation temperatures, but was on average approximately 4°C lower. We also tested the hypothesis that photosystem II (PSII) (the most thermolabile component of photosynthesis) of tropical plants tolerates higher temperatures than PSII of temperate plants, using DLE and Fo chlorophyll fluorescence upon heating to measure the temperature at which PSII thermally denatured. We found little difference between the two groups in PSII denaturation temperature. We also found that the temperature of maximum DLA upon heating was not significantly different from the critical temperature for Fo fluorescence. Our results indicate that plants lowered their membrane freezing temperatures as they radiated from their tropical

  16. Body core temperature of rats subjected to daily exercise limited to a fixed time

    NASA Astrophysics Data System (ADS)

    Shido, O.; Sugimoto, Naotoshi; Sakurada, Sotaro; Kaneko, Yoshiko; Nagasaka, Tetsuo

    Several timed daily environmental cues alter the pattern of nycthemeral variations in body core temperature in rodents. The present study investigated the effect of timed exercise on variations of daily body core temperature. Male rats were housed in cages with a running wheel at an ambient temperature of 24° C with a 12:12 h light/dark cycle. Timed daily exercise rats (TEX) were allowed access to the wheel for 6 h in the last half of the dark phase, freely exercising rats (FEX) could run at any time, and sedentary rats (NEX) were not allowed to run. After a 3-week exercise period, all animals were denied access to the wheel. The intraabdominal temperatures (Tab) and spontaneous activities of rats were measured for 6 days after the exercise period. The Tab values of the TEX rats were significantly higher than those of the other two groups only in the last half of the dark phase, while Tab in the FEX and NEX rats showed no significant difference. The specific Tab changes in the TEX rats lasted for 2 days after the exercise period. Spontaneous activity levels were higher in the TEX rats than the FEX and NEX rats in the last half of the dark phase for 1 day after the exercise period. The results suggest that daily exercise limited to a fixed time per day modifies nycthemeral variations of body core temperature in rats so that the temperature increases during the period when the animals had previously exercised. Such a rise in body core temperature is partly attributed to an increase in the spontaneous activity level.

  17. Adjusting alloy compositions for selected properties in temperature limited heaters

    DOEpatents

    Brady; Michael Patrick , Horton, Jr.; Joseph Arno , Vitek; John Michael

    2010-03-23

    Heaters for treating a subsurface formation are described herein. Such heaters can be obtained by using the systems and methods described herein. The heater includes a heater section including iron, cobalt, and carbon. The heater section has a Curie temperature less than a phase transformation temperature. The Curie temperature is at least 740.degree. C. The heater section provides, when time varying current is applied to the heater section, an electrical resistance.

  18. Temperature limits trail following behaviour through pheromone decay in ants

    NASA Astrophysics Data System (ADS)

    van Oudenhove, Louise; Billoir, Elise; Boulay, Raphaël; Bernstein, Carlos; Cerdá, Xim

    2011-12-01

    In Mediterranean habitats, temperature affects both ant foraging behaviour and community structure. Many studies have shown that dominant species often forage at lower temperature than subordinates. Yet, the factors that constrain dominant species foraging activity in hot environments are still elusive. We used the dominant ant Tapinoma nigerrimum as a model species to test the hypothesis that high temperatures hinder trail following behaviour by accelerating pheromone degradation. First, field observations showed that high temperatures (> 30°C) reduce the foraging activity of T. nigerrimum independently of the daily and seasonal rhythms of this species. Second, we isolated the effect of high temperatures on pheromone trail efficacy from its effect on worker physiology. A marked substrate was heated during 10 min (five temperature treatments from 25°C to 60°C), cooled down to 25°C, and offered in a test choice to workers. At hot temperature treatments (>40°C), workers did not discriminate the previously marked substrate. High temperatures appeared therefore to accelerate pheromone degradation. Third, we assessed the pheromone decay dynamics by a mechanistic model fitted with Bayesian inference. The model predicted ant choice through the evolution of pheromone concentration on trails as a function of both temperature and time since pheromone deposition. Overall, our results highlighted that the effect of high temperatures on recruitment intensity was partly due to pheromone evaporation. In the Mediterranean ant communities, this might affect dominant species relying on chemical recruitment, more than subordinate ant species, less dependent on chemical communication and less sensitive to high temperatures.

  19. Temperature limits trail following behaviour through pheromone decay in ants.

    PubMed

    van Oudenhove, Louise; Billoir, Elise; Boulay, Raphaël; Bernstein, Carlos; Cerdá, Xim

    2011-12-01

    In Mediterranean habitats, temperature affects both ant foraging behaviour and community structure. Many studies have shown that dominant species often forage at lower temperature than subordinates. Yet, the factors that constrain dominant species foraging activity in hot environments are still elusive. We used the dominant ant Tapinoma nigerrimum as a model species to test the hypothesis that high temperatures hinder trail following behaviour by accelerating pheromone degradation. First, field observations showed that high temperatures (> 30°C) reduce the foraging activity of T. nigerrimum independently of the daily and seasonal rhythms of this species. Second, we isolated the effect of high temperatures on pheromone trail efficacy from its effect on worker physiology. A marked substrate was heated during 10 min (five temperature treatments from 25°C to 60°C), cooled down to 25°C, and offered in a test choice to workers. At hot temperature treatments (>40°C), workers did not discriminate the previously marked substrate. High temperatures appeared therefore to accelerate pheromone degradation. Third, we assessed the pheromone decay dynamics by a mechanistic model fitted with Bayesian inference. The model predicted ant choice through the evolution of pheromone concentration on trails as a function of both temperature and time since pheromone deposition. Overall, our results highlighted that the effect of high temperatures on recruitment intensity was partly due to pheromone evaporation. In the Mediterranean ant communities, this might affect dominant species relying on chemical recruitment, more than subordinate ant species, less dependent on chemical communication and less sensitive to high temperatures. PMID:22038287

  20. Temperature limited heaters using phase transformation of ferromagnetic material

    DOEpatents

    Vitek, John Michael [Oak Ridge, TN; Brady, Michael Patrick [Oak Ridge, TN

    2009-10-06

    Systems, methods, and heaters for treating a subsurface formation are described herein. Systems and methods for making heaters are described herein. At least one heater includes a ferromagnetic conductor and an electrical conductor. The electrical conductor is electrically coupled to the ferromagnetic conductor. The heater provides a first amount of heat at a lower temperature. The heater may provide a second reduced amount of heat when the heater reaches a selected temperature, or enters a selected temperature range, at which the ferromagnetic conductor undergoes a phase transformation.

  1. Temperature limited heater utilizing non-ferromagnetic conductor

    DOEpatents

    Vinegar; Harold J. , Harris; Christopher Kelvin

    2012-07-17

    A heater is described. The heater includes a ferromagnetic conductor and an electrical conductor electrically coupled to the ferromagnetic conductor. The ferromagnetic conductor is positioned relative to the electrical conductor such that an electromagnetic field produced by time-varying current flow in the ferromagnetic conductor confines a majority of the flow of the electrical current to the electrical conductor at temperatures below or near a selected temperature.

  2. Measurement of the phonon mean free path spectra and the universality in the high temperature limit

    NASA Astrophysics Data System (ADS)

    Regner, Keith; Freedman, Justin; Sitar, Zlatko; Leach, Jacob; Davis, Robert; Malen, Jonathan

    2013-03-01

    Here, we use broadband frequency domain thermoreflectance (BB-FDTR) to measure thermal conductivity accumulation functions (kaccum) of Si, GaAs, GaN, AlN, and SiC at temperatures of 80 K, 150 K, 300 K, and 400 K and show that they collapse to a universal accumulation function (kuniv) in the high temperature limit. BB-FDTR is a novel technique developed to measure the spectral contributions of phonons to bulk thermal conductivity as a function of phonon MFP i.e., kaccum. BB-FDTR uses a heterodyne approach allowing for continuous resolution of the phonon MFP spectrum spanning two orders of magnitude (0.3 - 8 μm in Si at T = 300 K). Results in Si and GaAs compare favorably to numerical predictions (Esfarjani, et al., PRB, 2011) (Luo et al., arXiv, 2012) and show that phonons with long MFPs (>1 μm) contribute significantly to the bulk thermal conductivity at T = 300 K. Next, we present a method to predict kaccum as the temperature of the material approaches its Debye temperature. Using the measured spectra at T = 400 K and assuming Umklapp scattering as the dominant scattering mechanism, kuniv was found to exist in GaAs, GaN, and Si after normalizing the phonon MFP. The existence of kuniv suggests that the phonon MFP spectrum is a universal feature of matter in the high temperature limit, and can be used to predict kaccum for any crystalline semiconductor near its Debye temperature.

  3. Upper Limit to Black Smoker Temperatures Not Yet in Sight

    NASA Astrophysics Data System (ADS)

    Devey, C. W.; Garbe-Schoenberg, C.

    2011-12-01

    The world's hottest-known black smoker vent field (Turtle Pits Field, 4°50'S, Mid-Atlantic Ridge) has previously been reported as showing transient venting temperatures up to 464°C (Koschinsky et al., 2008). The calculated Mg-free endmember fluid has low salinity (ca. 280 mM Cl) suggesting it is a separated vapour phase. This end-member chlorinity has remained constant over the period of 26 months during which samples were repeatedly collected. We present new data showing that venting at Turtle Pits has in fact reached measured exit temperatures of at least 524°C, that the measured temperature is related to where on the smoker samples are collected (with higher temperatures found near the base) and that sampling temperature and salinity are not correlated. These observations can be explained by a simple two-stage model consisting of (1) a stable, high-temperature vapour production region at depth and (2) a region of cooling of the vapours within the smoker structure at the seafloor by heat exchange with ambient seawater. Sub-seafloor vapour transport between these two regions must occur with negligible heat loss to the surrounding rock - deposition of high-temperature minerals (e.g., Cu-sulphides, anhydrite) may, however, occur. Future attempts to sample the vapour before heat exchange will demonstrate its true maximum temperature - there seems to be no a priori reason why it could not approach magmatic temperatures, however. From chemical and phase equilibrium constraints, the vapour production region must lie at pressures of >550 bars (the pressure at which a vapour of the measured salinity will be formed on the two-phase boundary at 524°C), in conflict with the 350 bars given by silica geobarometry of the fluids (Koschinsky et al., 2008). This discrepancy may be related to the absence of quartz in the reaction zone, the very high fluid temperatures (outside the 390-430°C validity region of the Si barometry calibration) or a lack of fluid/rock equilibrium

  4. Temperature limitation of primary and secondary alkaline battery electrodes

    NASA Astrophysics Data System (ADS)

    McKubre, M. C. H.

    1983-05-01

    The results of studies of the mechanisms of dissolution and passivation of Fe and Zn electrodes in concentrated KOH, as these processes effect the charge/discharge characteristics of alkaline batteries are discussed. The experimental techniques principally employed were: potentiodynamic sweep voltammetry and coulometry, rotating disk and rotating ring disk electrode studies under constant velocity and constant acceleration rotation conditions, and AC impedance studies. The results obtained on Fe electrodes enabled a detailed mechanism for the formation and discharge of an oxide film on iron via a number of dissolved intermediate species. The mechanisms are different at high and low temperatures, but at all temperatures pathways via dissolved phase intermediates result in substantial dissolution of metal and oxide. At 750 C dissolution processes account for more than 7.5% of the total charge stored per cycle. AC impedance measurements were used to characterize the nature of the oxide film, and to determine an effective exchange current density for the Fe/Fe(2) Redox process.

  5. Fast Detection Allows Analysis of the Electronic Structure of Metalloprotein by X-ray Emission Spectroscopy at Room Temperature.

    PubMed

    Davis, Katherine M; Mattern, Brian A; Pacold, Joseph I; Zakharova, Taisiya; Brewe, Dale; Kosheleva, Irina; Henning, Robert W; Graber, Timothy J; Heald, Steve M; Seidler, Gerald T; Pushkar, Yulia

    2012-07-19

    The paradigm of "detection-before-destruction" was tested for a metalloprotein complex exposed at room temperature to the high x-ray flux typical of third generation synchrotron sources. Following the progression of the x-ray induced damage by Mn Kβ x-ray emission spectroscopy, we demonstrated the feasibility of collecting room temperature data on the electronic structure of native Photosystem II, a trans-membrane metalloprotein complex containing a Mn(4)Ca cluster. The determined non-damaging observation timeframe (about 100 milliseconds using continuous monochromatic beam, deposited dose 1*10(7) photons/µm(2) or 1.3*10(4) Gy, and 66 microseconds in pulsed mode using pink beam, deposited dose 4*10(7) photons/µm(2) or 4.2*10(4) Gy) is sufficient for the analysis of this protein's electron dynamics and catalytic mechanism at room temperature. Reported time frames are expected to be representative for other metalloproteins. The described instrumentation, based on the short working distance dispersive spectrometer, and experimental methodology is broadly applicable to time-resolved x-ray emission analysis at synchrotron and x-ray free-electron laser light sources.

  6. Preferred temperature and thermal breadth of birds wintering in peninsular Spain: the limited effect of temperature on species distribution

    PubMed Central

    Palomino, David

    2016-01-01

    Background. The availability of environmental energy, as measured by temperature, is expected to limit the abundance and distribution of endotherms wintering at temperate latitudes. A prediction of this hypothesis is that birds should attain their highest abundances in warmer areas. However, there may be a spatial mismatch between species preferred habitats and species preferred temperatures, so some species might end-up wintering in sub-optimal thermal environments. Methods. We model the influence of minimum winter temperature on the relative abundance of 106 terrestrial bird species wintering in peninsular Spain, at 10 ×10 km2 resolution, using 95%-quantile regressions. We analyze general trends across species on the shape of the response curves, the environmental preferred temperature (at which the species abundance is maximized), the mean temperature in the area of distribution and the thermal breadth (area under the abundance-temperature curve). Results. Temperature explains a low proportion of variation in abundance. The most significant effect is on limiting the maximum potential abundance of species. Considering this upper-limit response, there is a large interspecific variability on the thermal preferences and specialization of species. Overall, there is a preponderance of positive relationships between species abundance and temperature; on average, species attain their maximum abundances in areas 1.9 °C warmer than the average temperature available in peninsular Spain. The mean temperature in the area of distribution is lower than the thermal preferences of the species. Discussion. Many species prefer the warmest areas to overwinter, which suggests that temperature imposes important restrictions to birds wintering in the Iberian Peninsula. However, one third of species overwinter in locations colder than their thermal preferences, probably reflecting the interaction between habitat and thermal requirements. There is a high inter-specific variation in

  7. Preferred temperature and thermal breadth of birds wintering in peninsular Spain: the limited effect of temperature on species distribution.

    PubMed

    Carrascal, Luis M; Villén-Pérez, Sara; Palomino, David

    2016-01-01

    Background. The availability of environmental energy, as measured by temperature, is expected to limit the abundance and distribution of endotherms wintering at temperate latitudes. A prediction of this hypothesis is that birds should attain their highest abundances in warmer areas. However, there may be a spatial mismatch between species preferred habitats and species preferred temperatures, so some species might end-up wintering in sub-optimal thermal environments. Methods. We model the influence of minimum winter temperature on the relative abundance of 106 terrestrial bird species wintering in peninsular Spain, at 10 ×10 km(2) resolution, using 95%-quantile regressions. We analyze general trends across species on the shape of the response curves, the environmental preferred temperature (at which the species abundance is maximized), the mean temperature in the area of distribution and the thermal breadth (area under the abundance-temperature curve). Results. Temperature explains a low proportion of variation in abundance. The most significant effect is on limiting the maximum potential abundance of species. Considering this upper-limit response, there is a large interspecific variability on the thermal preferences and specialization of species. Overall, there is a preponderance of positive relationships between species abundance and temperature; on average, species attain their maximum abundances in areas 1.9 °C warmer than the average temperature available in peninsular Spain. The mean temperature in the area of distribution is lower than the thermal preferences of the species. Discussion. Many species prefer the warmest areas to overwinter, which suggests that temperature imposes important restrictions to birds wintering in the Iberian Peninsula. However, one third of species overwinter in locations colder than their thermal preferences, probably reflecting the interaction between habitat and thermal requirements. There is a high inter-specific variation in

  8. Climate change and temperature-dependent biogeography: oxygen limitation of thermal tolerance in animals

    NASA Astrophysics Data System (ADS)

    Pörtner, H. O.

    2001-03-01

    Recent years have shown a rise in mean global temperatures and a shift in the geographical distribution of ectothermic animals. For a cause and effect analysis the present paper discusses those physiological processes limiting thermal tolerance. The lower heat tolerance in metazoa compared with unicellular eukaryotes and bacteria suggests that a complex systemic rather than molecular process is limiting in metazoa. Whole-animal aerobic scope appears as the first process limited at low and high temperatures, linked to the progressively insufficient capacity of circulation and ventilation. Oxygen levels in body fluids may decrease, reflecting excessive oxygen demand at high temperatures or insufficient aerobic capacity of mitochondria at low temperatures. Aerobic scope falls at temperatures beyond the thermal optimum and vanishes at low or high critical temperatures when transition to an anaerobic mitochondrial metabolism occurs. The adjustment of mitochondrial densities on top of parallel molecular or membrane adjustments appears crucial for maintaining aerobic scope and for shifting thermal tolerance. In conclusion, the capacity of oxygen delivery matches full aerobic scope only within the thermal optimum. At temperatures outside this range, only time-limited survival is supported by residual aerobic scope, then anaerobic metabolism and finally molecular protection by heat shock proteins and antioxidative defence. In a cause and effect hierarchy, the progressive increase in oxygen limitation at extreme temperatures may even enhance oxidative and denaturation stress. As a corollary, capacity limitations at a complex level of organisation, the oxygen delivery system, define thermal tolerance limits before molecular functions become disturbed.

  9. Performance limits of low-temperature, continuous locomotion are exceeded when locomotion is intermittent in the ghost crab.

    PubMed

    Weinstein, R B; Full, R J

    1998-01-01

    Since a decline in temperature decreases aerobic capacity and slows the kinetics of exercise-to-rest transitions in ectotherms, we manipulated body temperature to better understand the performance limits of intermittent locomotion. Distance capacity (i.e., the total distance traveled before fatigue) of the ghost crab, Ocypode quadrata, was determined during acute exposure to 15 degrees C inside a treadmill-respirometer. Instead of exacerbating the near-paralyzing effects of low body temperature resulting from the frequent transitions, intermittent locomotion allowed animals to exceed the performance limits measured during steady-state locomotion. At low temperature, distance capacity for continuous locomotion at 0.04 m s(-1) (83% maximum aerobic speed) was 60 m. When 30 s of exercise at 0.08 m s(-1) (166% maximum aerobic speed) was alternated with 30 s of rest, distance capacity increased to 271 m, 4.5-fold greater than continuous locomotion at the same average speed (83% maximum aerobic speed). A 30-s pause following a 30-s exercise period was sufficient for maintaining low lactate concentrations in muscle and for partial resynthesis of arginine phosphate. A greater dependency on nonoxidative metabolism due to slowed oxygen uptake kinetics at low temperature resulted in a decreased duration of the critical exercise period, which increased performance relative to that measured at higher temperatures (30 s at 15 degrees C vs. 120 s at 24 degrees C). Despite the ghost crab's limited aerobic capacity at 15 degrees C, distance capacity during intermittent locomotion at low temperature can be comparable to that of a crab moving continuously at a body temperature 10 degrees C warmer. While endurance capacity is generally correlated with maximum aerobic speed, we have demonstrated that both locomotor behavior and body temperature must be considered when characterizing performance limits.

  10. Dynamic microscale temperature gradient in a gold nanorod solution measured by diffraction-limited nanothermometry

    SciTech Connect

    Li, Chengmingyue; Gan, Xiaosong; Li, Xiangping; Gu, Min

    2015-09-21

    We quantify the dynamic microscale temperature gradient in a gold nanorod solution using quantum-dot-based microscopic fluorescence nanothermometry. By incorporating CdSe quantum dots into the solution as a nanothermometer, precise temperature mapping with diffraction-limited spatial resolution and sub-degree temperature resolution is achieved. The acquired data on heat generation and dissipation show an excellent agreement with theoretical simulations. This work reveals an effective approach for noninvasive temperature regulation with localized nanoheaters in microfluidic environment.

  11. Plasticity of upper thermal limits to acute and chronic temperature variation in Manduca sexta larvae.

    PubMed

    Kingsolver, Joel G; MacLean, Heidi J; Goddin, Silvan B; Augustine, Kate E

    2016-05-01

    In many ectotherms, exposure to high temperatures can improve subsequent tolerance to higher temperatures. However, the differential effects of single, repeated or continuous exposure to high temperatures are less clear. We measured the effects of single heat shocks and of diurnally fluctuating or constant rearing temperatures on the critical thermal maximum (CTmax) for final instar larvae of Manduca sexta Brief (2 h) heat shocks at temperatures of 35°C and above significantly increased CTmax relative to control temperatures (25°C). Increasing mean temperatures (from 25 to 30°C) or greater diurnal fluctuations (from constant to ±10°C) during larval development also significantly increased CTmax Combining these data showed that repeated or continuous temperature exposure during development improved heat tolerance beyond the effects of a single exposure to the same maximum temperature. These results suggest that both acute and chronic temperature exposure can result in adaptive plasticity of upper thermal limits. PMID:26944498

  12. The flammability limits of hydrogen and methane in air at moderately elevated temperatures

    SciTech Connect

    Ale, B.B.; Wierzba, I.

    1997-12-31

    The flammability limits of hydrogen and methane in air were determined experimentally at elevated initial mixture temperatures up to 350 C at atmospheric pressure for upward flame propagation in a conventional steel test tube apparatus. Additionally, the extent to which a prolonged exposure (i.e., residence time) of the mixture to elevated temperatures before spark ignition and, consequently, the existence of pre-ignition reactions that may influence the value of the lean and rich flammability limits was also investigated. It was shown that the flammability limits for methane widened approximately linearly with an increase in the initial mixture temperature over the whole range of temperatures tested. These limits were not affected by the length of the residence time before spark ignition. Different behavior was observed for flammability limits of hydrogen. They were also widened with an increase in the initial temperature but only up to 200 C. In this initial temperature range the limits were not affected by the length of the residence time. However, at initial temperature exceeding 200 C the flammability limits, especially, the rich limits narrowed with an increase in the temperature and were significantly affected by the residence time before spark ignition. It was suggested that the substantial drop in the value of the rich limit with the increase in the residence time was caused by the relatively low temperature catalytic reactions on the stainless steel surface of the flame tube. Simple method for calculating the hydrogen conversion to water was proposed. The results of calculations are in fair agreement with the experimental evidence.

  13. Hazard report update. ECRI Institute revises its recommendation for temperature limits on blanket warmers.

    PubMed

    2009-07-01

    ECRI Institute now recommends that temperature settings on blanket warming cabinets be limited to 130 degrees F (54 degrees C). We had previously recommended a limit of 110 degrees F (43 degrees C) because solutions were often being warmed in the same cabinets as blankets, and the lower temperature eliminated the serious burn risk presented by excessively heated solutions. With increasing recognition in the healthcare community that solutions should be kept at lower temperatures than--and therefore heated separately from--blankets, we believe that our recommendation for blankets can be made less stringent. We continue to recommend that solution warming cabinets be limited to 110 degrees F. PMID:20848953

  14. Limitation of Grassland Productivity by Low Temperature and Seasonality of Growth.

    PubMed

    Wingler, Astrid; Hennessy, Deirdre

    2016-01-01

    The productivity of temperate grassland is limited by the response of plants to low temperature, affecting winter persistence and seasonal growth rates. During the winter, the growth of perennial grasses is restricted by a combination of low temperature and the lack of available light, but during early spring low ground temperature is the main limiting factor. Once temperature increases, growth is stimulated, resulting in a peak in growth in spring before growth rates decline later in the season. Growth is not primarily limited by the ability to photosynthesize, but controlled by active regulatory processes that, e.g., enable plants to restrict growth and conserve resources for cold acclimation and winter survival. An insufficient ability to cold acclimate can affect winter persistence, thereby also reducing grassland productivity. While some mechanistic knowledge is available that explains how low temperature limits plant growth, the seasonal mechanisms that promote growth in response to increasing spring temperatures but restrict growth later in the season are only partially understood. Here, we assess the available knowledge of the physiological and signaling processes that determine growth, including hormonal effects, on cellular growth and on carbohydrate metabolism. Using data for grass growth in Ireland, we identify environmental factors that limit growth at different times of the year. Ideas are proposed how developmental factors, e.g., epigenetic changes, can lead to seasonality of the growth response to temperature. We also discuss perspectives for modeling grass growth and breeding to improve grassland productivity in a changing climate. PMID:27512406

  15. Limitation of Grassland Productivity by Low Temperature and Seasonality of Growth.

    PubMed

    Wingler, Astrid; Hennessy, Deirdre

    2016-01-01

    The productivity of temperate grassland is limited by the response of plants to low temperature, affecting winter persistence and seasonal growth rates. During the winter, the growth of perennial grasses is restricted by a combination of low temperature and the lack of available light, but during early spring low ground temperature is the main limiting factor. Once temperature increases, growth is stimulated, resulting in a peak in growth in spring before growth rates decline later in the season. Growth is not primarily limited by the ability to photosynthesize, but controlled by active regulatory processes that, e.g., enable plants to restrict growth and conserve resources for cold acclimation and winter survival. An insufficient ability to cold acclimate can affect winter persistence, thereby also reducing grassland productivity. While some mechanistic knowledge is available that explains how low temperature limits plant growth, the seasonal mechanisms that promote growth in response to increasing spring temperatures but restrict growth later in the season are only partially understood. Here, we assess the available knowledge of the physiological and signaling processes that determine growth, including hormonal effects, on cellular growth and on carbohydrate metabolism. Using data for grass growth in Ireland, we identify environmental factors that limit growth at different times of the year. Ideas are proposed how developmental factors, e.g., epigenetic changes, can lead to seasonality of the growth response to temperature. We also discuss perspectives for modeling grass growth and breeding to improve grassland productivity in a changing climate.

  16. Limitation of Grassland Productivity by Low Temperature and Seasonality of Growth

    PubMed Central

    Wingler, Astrid; Hennessy, Deirdre

    2016-01-01

    The productivity of temperate grassland is limited by the response of plants to low temperature, affecting winter persistence and seasonal growth rates. During the winter, the growth of perennial grasses is restricted by a combination of low temperature and the lack of available light, but during early spring low ground temperature is the main limiting factor. Once temperature increases, growth is stimulated, resulting in a peak in growth in spring before growth rates decline later in the season. Growth is not primarily limited by the ability to photosynthesize, but controlled by active regulatory processes that, e.g., enable plants to restrict growth and conserve resources for cold acclimation and winter survival. An insufficient ability to cold acclimate can affect winter persistence, thereby also reducing grassland productivity. While some mechanistic knowledge is available that explains how low temperature limits plant growth, the seasonal mechanisms that promote growth in response to increasing spring temperatures but restrict growth later in the season are only partially understood. Here, we assess the available knowledge of the physiological and signaling processes that determine growth, including hormonal effects, on cellular growth and on carbohydrate metabolism. Using data for grass growth in Ireland, we identify environmental factors that limit growth at different times of the year. Ideas are proposed how developmental factors, e.g., epigenetic changes, can lead to seasonality of the growth response to temperature. We also discuss perspectives for modeling grass growth and breeding to improve grassland productivity in a changing climate. PMID:27512406

  17. Limiting temperature of sympathetically cooled ions in a radio-frequency trap

    SciTech Connect

    Hasegawa, Taro; Shimizu, Tadao

    2003-01-01

    The limiting temperature achieved by sympathetic cooling in an rf trap is calculated with a theoretical model in which no fitting parameters are used. The calculated result agrees well with observation. The dependence of the temperature on trapping parameters and ion mass is also analyzed. The results can be used for designing an rf trap system.

  18. Ion acoustic solitons in a plasma with finite temperature drifting ions: Limit on ion drift velocity

    SciTech Connect

    Malik, H.K.; Singh, S.; Dahiya, R.P. )

    1994-05-01

    Propagation of ion acoustic solitons in a plasma consisting of finite temperature drifting ions and nondrifting electrons has been studied. It is shown that in addition to the electron inertia and weak relativistic effects, the ion temperature also modifies the soliton behavior. By including the finite ion temperature, limit for the ion drift velocity [ital u][sub 0] for which the ion acoustic solitons are possible, is obtained. The solitons can exist for [ital v][sub [ital Te

  19. Overcoming the high-temperature two-dimensional gas chromatography limits to elute heavy compounds.

    PubMed

    Mahé, Laure; Courtiade, Marion; Dartiguelongue, Cyril; Ponthus, Jérémie; Souchon, Vincent; Thiébaut, Didier

    2012-03-16

    Overcoming high-temperature (HT) two-dimensional gas chromatography (GC × GC) limits is critical for the analysis of heavy hydrocarbons, particularly those contained in heavy petroleum fractions. To reach this goal, HT-GC × GC analysis was adapted from HT-GC Simulated Distillation (HT-GC SimDist) operating conditions as this analysis embraces compounds whose boiling point ranges from 35 °C to 700 °C and from a previous study that enabled the elution of linear alkane nC(60) and tetraaromatic compounds by HT-GC × GC. This paper shows that HT-GC × GC analysis using CO(2) cryogenic modulator and short wide bore columns with a thin film of stationary phase allows the elution of linear alkanes up to nC(68) (641 °C) as well as of highly aromatic hydrocarbons like coronene. Furthermore, compared to previous studies, an on-column injector was used to reduce discrimination of high boiling point compounds.

  20. Priming and temperature limits for germination of dispersal units of Urochloa brizantha (Stapf) Webster cv. basilisk.

    PubMed

    Nakao, E A; Cardoso, V J M

    2015-01-01

    The objective of this study was to evaluate the effect of priming treatments on the upper and lower thermal limits for germination of Urochloa brizantha cv. basilisk, and testing the hypothesis that pré-imbibition affect thermal parameters of the germination. Pre-imbibed seeds both in distilled water (0 MPa) and PEG 6000 solution (-0.5 MPa) were put to germinate in different temperatures. It is suggested that U. brizantha seeds have low response to priming when they were placed to germinate in medium where water is not limiting. The response of U. brizantha seeds to priming is dependent on the temperature and water potential conditions at which the seeds are pre-imbibed, as well as on the germination temperature. The optimum temperature for germination of U. brizantha shift toward warmer temperatures in primed seeds. Priming effect was more pronounced at temperatures closer to the upper and lower limit for germination, but probably that response cannot be accounted for changes in the thermal time constant (θT(g)) and ceiling temperature (Tc(g)). Otherwise, a decrease in the base temperature (Tb) was observed in primed seeds, suggesting that the Tb distribution in U. brizantha seeds is influenced by priming.

  1. Temperature limitation may explain the containment of the trophozoites in the cornea during Acanthamoeba castellanii keratitis.

    PubMed

    Nielsen, Mattias Kiel; Nielsen, Kim; Hjortdal, Jesper; Sørensen, Uffe B Skov

    2014-12-01

    Acanthamoeba keratitis is a serious sight-threatening disease. The relatively low temperature of the cornea may explain why amoebic infections usually are localized in this tissue and rarely spread to other parts of the eye. In this study, the growth rate of the amoeba Acanthamoeba castellanii was examined at different temperatures. The aim was to establish the optimal growth temperature for A. castellanii and to examine the growth within the vicinity of the core body temperature. The growth rates of four clinical and two environmental strains of A. castellanii were estimated at different temperatures, and temperature limitations for the trophozoite stage was established. Movements influenced by temperature gradients were monitored for two clinical strains of A. castellanii. The highest growth rate for each of the six amoebic strains tested was found to be close to 32 °C. The growth of the trophozoites of all examined strains was greatly reduced or completely halted at temperatures above 36 °C and encysted at the elevated temperature. Thus, the optimal growth temperature for the four strains of A. castellanii is close to the surface temperature of the human cornea, while the higher body core-temperature induced encysting of the amoebae. This may explain why most amoebic eye infections are confined to the cornea. PMID:25204727

  2. Limiter

    DOEpatents

    Cohen, S.A.; Hosea, J.C.; Timberlake, J.R.

    1984-10-19

    A limiter with a specially contoured front face is provided. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution. This limiter shape accommodates the various power scrape-off distances lambda p, which depend on the parallel velocity, V/sub parallel/, of the impacting particles.

  3. Glycerol allows low-temperature phase separation of membrane proteins solubilized in Triton X-114: application to the purification of plant cytochromes P-450 and b5.

    PubMed

    Werck-Reichhart, D; Benveniste, I; Teutsch, H; Durst, F; Gabriac, B

    1991-08-15

    The potentiality of the Triton X-114 phase separation technique for the purification of proteins from plant microsomal membranes has been investigated. It was shown that glycerol significantly lowers the cloud point of Triton X-114 solutions in water and of Triton X-114 solubilizates from microsomal membranes. It was also established that solubilized membrane components decrease the temperature of Triton X-114 micellar aggregation. Solubilization of microsomal membrane using detergent to protein ratios lower than 3.5, however, resulted in complete inhibition of detergent phase separation. Phase partitioning of Triton X-114 microsomal solubilizates, performed at low temperature (4 degrees C), in the presence of glycerol, provided a very fast and efficient step for the purification of cytochromes P-450 and b5. Conditions allowing optimal recoveries of these cytochromes have been defined.

  4. Effects of C/O Ratio and Temperature on Sooting Limits of Spherical Diffusion Flames

    NASA Technical Reports Server (NTRS)

    Lecoustre, V. R.; Sunderland, P. B.; Chao, B. H.; Urban, D. L.; Stocker, D. P.; Axelbaum, R. L.

    2008-01-01

    Limiting conditions for soot particle inception in spherical diffusion flames were investigated numerically. The flames were modeled using a one-dimensional, time accurate diffusion flame code with detailed chemistry and transport and an optically thick radiation model. Seventeen normal and inverse flames were considered, covering a wide range of stoichiometric mixture fraction, adiabatic flame temperature, residence time and scalar dissipation rate. These flames were previously observed to reach their sooting limits after 2 s of microgravity. Sooting-limit diffusion flames with scalar dissipation rate lower than 2/s were found to have temperatures near 1400 K where C/O = 0.51, whereas flames with greater scalar dissipation rate required increased temperatures. This finding was valid across a broad range of fuel and oxidizer compositions and convection directions.

  5. Closed-form analytical solutions of high-temperature heat pipe startup and frozen startup limitation

    NASA Technical Reports Server (NTRS)

    Cao, Y.; Faghri, A.

    1992-01-01

    Previous numerical and experimental studies indicate that the high-temperature heat pipe startup process is characterized by a moving hot zone with relatively sharp fronts. Based on the above observation, a flat-front model for an approximate analytical solution is proposed. A closed-form solution related to the temperature distribution in the hot zone and the hot zone length as a function of time are obtained. The analytical results agree well with the corresponding experimental data, and provide a quick prediction method for the heat pipe startup performance. Finally, a heat pipe limitation related to the frozen startup process is identified, and an explicit criterion for the high-temperature heat pipe startup is derived. The frozen startup limit identified in this paper provides a fundamental guidance for high-temperature heat pipe design.

  6. Asymptotic diffusion limit of cell temperature discretisation schemes for thermal radiation transport

    NASA Astrophysics Data System (ADS)

    Smedley-Stevenson, Richard P.; McClarren, Ryan G.

    2015-04-01

    This paper attempts to unify the asymptotic diffusion limit analysis of thermal radiation transport schemes, for a linear-discontinuous representation of the material temperature reconstructed from cell centred temperature unknowns, in a process known as 'source tilting'. The asymptotic limits of both Monte Carlo (continuous in space) and deterministic approaches (based on linear-discontinuous finite elements) for solving the transport equation are investigated in slab geometry. The resulting discrete diffusion equations are found to have nonphysical terms that are proportional to any cell-edge discontinuity in the temperature representation. Based on this analysis it is possible to design accurate schemes for representing the material temperature, for coupling thermal radiation transport codes to a cell centred representation of internal energy favoured by ALE (arbitrary Lagrange-Eulerian) hydrodynamics schemes.

  7. Asymptotic diffusion limit of cell temperature discretisation schemes for thermal radiation transport

    SciTech Connect

    Smedley-Stevenson, Richard P.; McClarren, Ryan G.

    2015-04-01

    This paper attempts to unify the asymptotic diffusion limit analysis of thermal radiation transport schemes, for a linear-discontinuous representation of the material temperature reconstructed from cell centred temperature unknowns, in a process known as ‘source tilting’. The asymptotic limits of both Monte Carlo (continuous in space) and deterministic approaches (based on linear-discontinuous finite elements) for solving the transport equation are investigated in slab geometry. The resulting discrete diffusion equations are found to have nonphysical terms that are proportional to any cell-edge discontinuity in the temperature representation. Based on this analysis it is possible to design accurate schemes for representing the material temperature, for coupling thermal radiation transport codes to a cell centred representation of internal energy favoured by ALE (arbitrary Lagrange–Eulerian) hydrodynamics schemes.

  8. Calculated flame temperature (CFT) modeling of fuel mixture lower flammability limits.

    PubMed

    Zhao, Fuman; Rogers, William J; Mannan, M Sam

    2010-02-15

    Heat loss can affect experimental flammability limits, and it becomes indispensable to quantify flammability limits when apparatus quenching effect becomes significant. In this research, the lower flammability limits of binary hydrocarbon mixtures are predicted using calculated flame temperature (CFT) modeling, which is based on the principle of energy conservation. Specifically, the hydrocarbon mixture lower flammability limit is quantitatively correlated to its final flame temperature at non-adiabatic conditions. The modeling predictions are compared with experimental observations to verify the validity of CFT modeling, and the minor deviations between them indicated that CFT modeling can represent experimental measurements very well. Moreover, the CFT modeling results and Le Chatelier's Law predictions are also compared, and the agreement between them indicates that CFT modeling provides a theoretical justification for the Le Chatelier's Law. PMID:19819067

  9. Limiter

    DOEpatents

    Cohen, Samuel A.; Hosea, Joel C.; Timberlake, John R.

    1986-01-01

    A limiter with a specially contoured front face accommodates the various power scrape-off distances .lambda..sub.p, which depend on the parallel velocity, V.sub..parallel., of the impacting particles. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution.

  10. Fast acclimation of freezing resistance suggests no influence of winter minimum temperature on the range limit of European beech.

    PubMed

    Lenz, Armando; Hoch, Günter; Vitasse, Yann

    2016-04-01

    Low temperature extremes drive species distribution at a global scale. Here, we assessed the acclimation potential of freezing resistance in European beech (Fagus sylvaticaL.) during winter. We specifically asked (i) how do beech populations growing in contrasting climates differ in their maximum freezing resistance, (ii) do differences result from genetic differentiation or phenotypic plasticity to preceding temperatures and (iii) is beech at risk of freezing damage in winter across its distribution range. We investigated the genetic and environmental components of freezing resistance in buds of adult beech trees from three different populations along a natural large temperature gradient in north-western Switzerland, including the site holding the cold temperature record in Switzerland. Freezing resistance of leaf primordia in buds varied significantly among populations, with LT50values (lethal temperature for 50% of samples) ranging from -25 to -40 °C, correlating with midwinter temperatures of the site of origin. Cambial meristems and the pith of shoots showed high freezing resistance in all three populations, with only a trend to lower freezing resistance at the warmer site. After hardening samples at -6 °C for 5 days, freezing resistance of leaf primordia increased in all provenances by up to 4.5 K. After additional hardening at -15 °C for 3 days, all leaf primordia were freezing resistant to -40 °C. We demonstrate that freezing resistance ofF. sylvaticahas a high ability to acclimate to temperature changes in winter, whereas the genetic differentiation of freezing resistance among populations seems negligible over this small geographic scale but large climatic gradient. In contrast to the assumption made in most of the species distribution models, we suggest that absolute minimum temperature in winter is unlikely to shape the cold range limit of beech. We conclude that the rapid acclimation of freezing resistance to winter temperatures allows

  11. The Effect of Piston-Head Temperature on Knock-Limited Power

    NASA Technical Reports Server (NTRS)

    Imming, Harry S.

    1944-01-01

    To determine the effect of piston-head temperature on knock-limited power. Tests were made in a supercharged CFR engine over a range of fuel-air ratios from 0.055 to 0.120, using S-3 reference fuel, AN-F-28, Amendment-2, aviation gasoline, and AN-F-28 plus 2 percent xylidines by weight. Tests were run at a compression ratio of 7.0 with inlet-air temperatures of 150 F and 250 F and at a compression ratio of 8.0 with an inlet-air temperature of 250 F. All other engine conditions were held constant. The piston-head temperature was varied by circulation of oil through passages in the crown of a liquid-cooled piston. This method of piston cooling decreased the piston-head temperature about 80 F. The data are not intended to constitute a recommendation as to the advisability of piston cooling in practice.

  12. Limiting temperatures for urediniospore germination are low in a systemic rust fungus of tallgrass prairie.

    PubMed

    Worapong, J; Dendy, S P; Tang, Z; Awl, D J; Garrett, K A

    2009-01-01

    Potential responses of plant disease phenology to climate change have been addressed primarily in agricultural systems. As a first step toward understanding the phenology of Uropyxis petalostemonis, a rust fungus commonly infecting the legume Dalea candida in U.S.A. tallgrass prairie, we evaluated the effects of temperature on urediniospore germination. While urediniospore germination for many rust fungi has been reported to decline only when temperatures are well above 25 degrees C, in vitro germination of U. petalostemonis dropped sharply at this temperature. Responses observed on water agar, potato dextrose agar and lima bean agar were similar, although lima bean agar supported a higher percentage germination overall. The low limiting temperatures suggest that most epidemically important new infections by U. petalostemonis occur in spring. High summer temperatures in tallgrass prairie might push infection by this rust fungus species to earlier in the year and select for stronger systemic growth characteristics.

  13. Equatorial range limits of an intertidal ectotherm are more linked to water than air temperature.

    PubMed

    Seabra, Rui; Wethey, David S; Santos, António M; Gomes, Filipa; Lima, Fernando P

    2016-10-01

    As climate change is expected to impose increasing thermal stress on intertidal organisms, understanding the mechanisms by which body temperatures translate into major biogeographic patterns is of paramount importance. We exposed individuals of the limpet Patella vulgata Linnaeus, 1758, to realistic experimental treatments aimed at disentangling the contribution of water and air temperature for the buildup of thermal stress. Treatments were designed based on temperature data collected at the microhabitat level, from 15 shores along the Atlantic European coast spanning nearly 20° of latitude. Cardiac activity data indicated that thermal stress levels in P. vulgata are directly linked to elevated water temperature, while high air temperature is only stressful if water temperature is also high. In addition, the analysis of the link between population densities and thermal regimes at the studied locations suggests that the occurrence of elevated water temperature may represent a threshold P. vulgata is unable to tolerate. By combining projected temperatures with the temperature threshold identified, we show that climate change will likely result in the westward expansion of the historical distribution gap in the Bay of Biscay (southwest France), and northward contraction of the southern range limit in south Portugal. These findings suggest that even a minor relaxing of the upwelling off northwest Iberia could lead to a dramatic increase in thermal stress, with major consequences for the structure and functioning of the intertidal communities along Iberian rocky shores.

  14. Equatorial range limits of an intertidal ectotherm are more linked to water than air temperature.

    PubMed

    Seabra, Rui; Wethey, David S; Santos, António M; Gomes, Filipa; Lima, Fernando P

    2016-10-01

    As climate change is expected to impose increasing thermal stress on intertidal organisms, understanding the mechanisms by which body temperatures translate into major biogeographic patterns is of paramount importance. We exposed individuals of the limpet Patella vulgata Linnaeus, 1758, to realistic experimental treatments aimed at disentangling the contribution of water and air temperature for the buildup of thermal stress. Treatments were designed based on temperature data collected at the microhabitat level, from 15 shores along the Atlantic European coast spanning nearly 20° of latitude. Cardiac activity data indicated that thermal stress levels in P. vulgata are directly linked to elevated water temperature, while high air temperature is only stressful if water temperature is also high. In addition, the analysis of the link between population densities and thermal regimes at the studied locations suggests that the occurrence of elevated water temperature may represent a threshold P. vulgata is unable to tolerate. By combining projected temperatures with the temperature threshold identified, we show that climate change will likely result in the westward expansion of the historical distribution gap in the Bay of Biscay (southwest France), and northward contraction of the southern range limit in south Portugal. These findings suggest that even a minor relaxing of the upwelling off northwest Iberia could lead to a dramatic increase in thermal stress, with major consequences for the structure and functioning of the intertidal communities along Iberian rocky shores. PMID:27109165

  15. Fatigue limit of polycrystalline zirconium oxide ceramics: Effect of grinding and low-temperature aging.

    PubMed

    Pereira, G K R; Silvestri, T; Amaral, M; Rippe, M P; Kleverlaan, C J; Valandro, L F

    2016-08-01

    The following study aimed to evaluate the effect of grinding and low-temperature aging on the fatigue limit of Y-TZP ceramics for frameworks and monolithic restorations. Disc specimens from each ceramic material, Lava Frame (3M ESPE) and Zirlux FC (Ivoclar Vivadent) were manufactured according to ISO:6872-2008 and assigned in accordance with two factors: (1) "surface treatment"-without treatment (as-sintered, Ctrl), grinding with coarse diamond bur (181µm; Grinding); and (2) "low-temperature aging (LTD)" - presence and absence. Grinding was performed using a contra-angle handpiece under constant water-cooling. LTD was simulated in an autoclave at 134°C under 2-bar pressure for 20h. Mean flexural fatigue limits (20,000 cycles) were determined under sinusoidal loading using stair case approach. For Lava ceramic, it was observed a statistical increase after grinding procedure and different behavior after LTD stimuli (Ctrltemperature aging promoted a statistical increase in the fatigue limit (Ctrltemperature aging did not damage the fatigue limit values significantly for both materials evaluated, even though those conditions promoted increase in m-phase.

  16. [Effect of light and temperature on growth kinetics of Anabaena flosaquae under phosphorus limitation].

    PubMed

    Yin, Zhi-Kun; Li, Zhe; Wang, Sheng; Guo, Jin-Song; Xiao, Yan; Liu, Jing; Zhang, Ping

    2015-03-01

    Phosphorus, light and temperature are the key environmental factors leading to algae growth. But the effects of interaction between light and temperature on the growth of Anabaena flosaquae under phosphorus limitation were not well documented in literature. Anabaena flosaquae was selected for the study and lab-scale experiment and simulation were carried out. The results showed that the optimal temperature of Anabaena flosaquae was 20 degrees C under phosphorus limitation when the light intensity was constant, and the optimal light intensity (illuminance) of Anabaena flosaquae was 3 000 lx under phosphorus limitation when the temperature was constant. Based on model fitting and parameter calibration, the optimal temperature and light intensity of Anabaena flosaquae were 21.03 degress C ± 1.55 degrees C and 2 675.12 lx ± 262.93 lx, respectively. These data were close to the actual water environmental condition at the end of spring. Results of this study will provide important foundation for prediction of Anabaena blooms. PMID:25929064

  17. [Effect of light and temperature on growth kinetics of Anabaena flosaquae under phosphorus limitation].

    PubMed

    Yin, Zhi-Kun; Li, Zhe; Wang, Sheng; Guo, Jin-Song; Xiao, Yan; Liu, Jing; Zhang, Ping

    2015-03-01

    Phosphorus, light and temperature are the key environmental factors leading to algae growth. But the effects of interaction between light and temperature on the growth of Anabaena flosaquae under phosphorus limitation were not well documented in literature. Anabaena flosaquae was selected for the study and lab-scale experiment and simulation were carried out. The results showed that the optimal temperature of Anabaena flosaquae was 20 degrees C under phosphorus limitation when the light intensity was constant, and the optimal light intensity (illuminance) of Anabaena flosaquae was 3 000 lx under phosphorus limitation when the temperature was constant. Based on model fitting and parameter calibration, the optimal temperature and light intensity of Anabaena flosaquae were 21.03 degress C ± 1.55 degrees C and 2 675.12 lx ± 262.93 lx, respectively. These data were close to the actual water environmental condition at the end of spring. Results of this study will provide important foundation for prediction of Anabaena blooms.

  18. Temperature-Dependent Kinetic Model for Nitrogen-Limited Wine Fermentations▿

    PubMed Central

    Coleman, Matthew C.; Fish, Russell; Block, David E.

    2007-01-01

    A physical and mathematical model for wine fermentation kinetics was adapted to include the influence of temperature, perhaps the most critical factor influencing fermentation kinetics. The model was based on flask-scale white wine fermentations at different temperatures (11 to 35°C) and different initial concentrations of sugar (265 to 300 g/liter) and nitrogen (70 to 350 mg N/liter). The results show that fermentation temperature and inadequate levels of nitrogen will cause stuck or sluggish fermentations. Model parameters representing cell growth rate, sugar utilization rate, and the inactivation rate of cells in the presence of ethanol are highly temperature dependent. All other variables (yield coefficient of cell mass to utilized nitrogen, yield coefficient of ethanol to utilized sugar, Monod constant for nitrogen-limited growth, and Michaelis-Menten-type constant for sugar transport) were determined to vary insignificantly with temperature. The resulting mathematical model accurately predicts the observed wine fermentation kinetics with respect to different temperatures and different initial conditions, including data from fermentations not used for model development. This is the first wine fermentation model that accurately predicts a transition from sluggish to normal to stuck fermentations as temperature increases from 11 to 35°C. Furthermore, this comprehensive model provides insight into combined effects of time, temperature, and ethanol concentration on yeast (Saccharomyces cerevisiae) activity and physiology. PMID:17616615

  19. Estimation of the lower flammability limit of organic compounds as a function of temperature.

    PubMed

    Rowley, J R; Rowley, R L; Wilding, W V

    2011-02-15

    A new method of estimating the lower flammability limit (LFL) of general organic compounds is presented. The LFL is predicted at 298 K for gases and the lower temperature limit for solids and liquids from structural contributions and the ideal gas heat of formation of the fuel. The average absolute deviation from more than 500 experimental data points is 10.7%. In a previous study, the widely used modified Burgess-Wheeler law was shown to underestimate the effect of temperature on the lower flammability limit when determined in a large-diameter vessel. An improved version of the modified Burgess-Wheeler law is presented that represents the temperature dependence of LFL data determined in large-diameter vessels more accurately. When the LFL is estimated at increased temperatures using a combination of this model and the proposed structural-contribution method, an average absolute deviation of 3.3% is returned when compared with 65 data points for 17 organic compounds determined in an ASHRAE-style apparatus. PMID:21144650

  20. Indigenous soil bacteria and low moisture may limit but allow faecal bacteria to multiply and become a minor population in tropical soils

    USGS Publications Warehouse

    Byappanahalli, M.; Fujioka, R.

    2004-01-01

    The soil environment in Hawaii is generally characterised as sub-optimal but permissive to support the in situ growth of E. coli and enterococci. However, soil desiccation and competition for nutrients by major indigenous soil microflora have been identified as potential factors that could limit a rapid and continual growth of faecal indicator bacteria in this soil environment. Despite these limitations, the genetic capacities of E. coli and enterococci are robust enough to enable these bacteria to become established as minor populations of Hawaii's soil microflora. Although the concentrations of E. coli and enterococci may have represented a fraction of the total soil microbiota, their presence in this habitat was very significant, for two important reasons: (a) soil was a major environmental source of E. coli and enterococci, and (b) the elevated counts of these bacteria in streams that routinely exceeded the EPA standards were due to run-off from soil. As a result, E. coli and enterococci were inadequate indicators to measure the degree of faecal contamination and potential presence of sewage-borne pathogens in Hawaiian streams. ?? IWA Publishing 2004.

  1. Low temperature limits photoperiod control of smolting in atlantic salmon through endocrine mechanisms

    USGS Publications Warehouse

    McCormick, S.D.; Moriyama, S.

    2000-01-01

    We have examined the interaction of photoperiod and temperature in regulating the parr-smolt transformation and its endocrine control. Atlantic salmon juveniles were reared at a constant temperature of 10??C or ambient temperature (2??C from January to April followed by seasonal increase) under simulated natural day length. At 10??C, an increase in day length [16 h of light and 8 h of darkness (LD 16:8)] in February accelerated increases in gill Na+K+-ATPase activity, whereas fish at ambient temperature did not respond to increased day length. Increases in gill Na+K+-ATPase activity under both photoperiods occurred later at ambient temperature than at 10??C. Plasma growth hormone (GH), insulin-like growth factor, and thyroxine increased within 7 days of increased day length at 10??C and remained elevated for 5-9 wk; the same photoperiod treatment at 2??C resulted in much smaller increases of shorter duration. Plasma cortisol increased transiently 3 and 5 wk after LD 16:8 at 10??C and ambient temperature, respectively. Plasma thyroxine was consistently higher at ambient temperature than at 10??C. Plasma triiodothyronine was initially higher at 10??C than at ambient temperature, and there was no response to LD 16:8 under either temperature regimen. There was a strong correlation between gill Na+K+-ATPase activity and plasma GH; correlations were weaker with other hormones. The results provide evidence that low temperature limits the physiological response to increased day length and that GH, insulin-like growth factor I, cortisol, and thyroid hormones mediate the environmental control of the parr-smolt transformation.

  2. Limitations of Photosynthesis in Pinus taeda L. (Loblolly Pine) at Low Soil Temperatures 1

    PubMed Central

    Day, Thomas A.; Heckathorn, Scott A.; DeLucia, Evan H.

    1991-01-01

    The relative importance of stomatal and nonstomatal limitations to net photosynthesis (A) and possible signals responsible for stomatal limitations were investigated in unhardened Pinus taeda seedlings at low soil temperatures. After 2 days at soil temperatures between 13 and 7°C, A was reduced by 20 to 50%, respectively. The reduction in A at these moderate root-chilling conditions appeared to be the result of stomatal limitations, based on the decrease in intercellular CO2 concentrations (ci). This conclusion was supported by A versus ci analysis and measurements of O2 evolution at saturating CO2, which suggested increases in stomatal but not biochemical limitations at these soil temperatures. Nonuniform stomatal apertures, which were demonstrated with abscisic acid, were not apparent 2 days after root chilling, and results of our A versus ci analysis appear valid. Bulk shoot water potential (ψ) declined as soil temperature dropped below 16°C. When half the root system of seedlings was chilled, shoot ψ and gas-exchange rates did not decline. Thus, nonhydraulic root-shoot signals were not implicated in stomatal limitations. The initial decrease in leaf conductance to water vapor after root chilling appeared to precede any detectable decrease in bulk fascicle ψ, but may be in response to a decrease in turgor of epidermal cells. These reductions in leaf conductance to water vapor, which occurred within 30 minutes of root chilling, could be delayed and temporarily reversed by reducing the leaf-to-air vapor-pressure deficit, suggesting that hydraulic signals may be involved in initiating stomatal closure. By independently manipulating the leaf-to-air vapor-pressure deficit of individual fascicles, we could induce uptake of water vapor through stomata, suggesting that nonsaturated conditions occur in the intercellular airspaces. There was an anomaly in our results on seedlings maintained for 2 days at soil temperatures below 7°C. Lower A appeared primarily the

  3. Limits on decaying dark energy density models from the CMB temperature-redshift relation

    NASA Astrophysics Data System (ADS)

    Jetzer, Philippe; Tortora, Crescenzo

    2012-03-01

    We discuss the thermodynamic and dynamical properties of a variable dark energy model with density scaling as ρx propto (1 + z)m, z being the redshift. These models lead to the creation/disruption of matter and radiation, which affect the cosmic evolution of both matter and radiation components in the Universe. In particular, we have studied the temperature-redshift relation of radiation, which has been constrained using a recent collection of cosmic microwave background (CMB) temperature measurements up to z ~ 3. We find that, within the uncertainties, the model is indistinguishable from a cosmological constant which does not exchange any particles with other components. Future observations, in particular measurements of CMB temperature at large redshift, will allow to give firmer bounds on the effective equation of state parameter weff for such types of dark energy models.

  4. Temperature limits in laser cooling of free atoms with three-level cascade transitions

    NASA Astrophysics Data System (ADS)

    Cruz, Flavio C.; Sundheimer, Michael L.; Magno, Wictor C.

    2013-06-01

    We employ semiclassical theoretical analysis to study laser cooling of free atoms using three-level cascade transitions, where the upper transition is much weaker than the lower one. This represents an alternate cooling scheme, particularly useful for group II atoms. We find that temperatures below the Doppler limits associated with each of these transitions are expected. The lowest temperatures arise from a remarkable increase in damping and reduced diffusion compared to two-level cooling. They are reached at the two-photon resonance, where there is a crossing between the narrow and the partially dark dressed states, and can be estimated simply by the usual Doppler limit considering the decay rate of the optical coherence between these states.

  5. Recognizing a limitation of the TBLC-activated peroxide system on low-temperature cotton bleaching.

    PubMed

    Chen, Wenhua; Wang, Lun; Wang, Dong; Zhang, Jingjing; Sun, Chang; Xu, Changhai

    2016-04-20

    In this study, cotton was bleached at low temperatures with an activated peroxide system which was established by incorporating a bleach activator, namely, N-[4-(triethylammoniomethyl)benzoyl]caprolactam chloride (TBCC) into an aqueous solution of hydrogen peroxide (H2O2). Experimental results showed that the bleaching performance was unexpectedly diminished as the TBCC concentration was increased over the range of 25-100g/L. Kinetic adsorption experiment indicated that this was most likely ascribed to the adsorptive interactions of TBCC and the in situ-generated compounds with cotton fibers. Such a limitation was especially fatal to cold pad-batch bleaching process of cotton in which a high TBCC concentration was often required. The results of this study may stimulate further research to avoid or overcome the limitation of the TBCC-activated peroxide system on low-temperature cotton bleaching.

  6. Evolution of the ABC model among the segregated configurations in the zero-temperature limit

    NASA Astrophysics Data System (ADS)

    Misturini, Ricardo

    2016-05-01

    We consider the ABC model on a ring in a strongly asymmetric regime. The main result asserts that the particles almost always form three pure domains (one of each species) and that this segregated shape evolves, in a proper time scale, as a Brownian motion on the circle, which may have a drift. This is, to our knowledge, the first proof of a zero-temperature limit for a non-reversible dynamics whose invariant measure is not explicitly known.

  7. Fatigue limit of polycrystalline zirconium oxide ceramics: Effect of grinding and low-temperature aging.

    PubMed

    Pereira, G K R; Silvestri, T; Amaral, M; Rippe, M P; Kleverlaan, C J; Valandro, L F

    2016-08-01

    The following study aimed to evaluate the effect of grinding and low-temperature aging on the fatigue limit of Y-TZP ceramics for frameworks and monolithic restorations. Disc specimens from each ceramic material, Lava Frame (3M ESPE) and Zirlux FC (Ivoclar Vivadent) were manufactured according to ISO:6872-2008 and assigned in accordance with two factors: (1) "surface treatment"-without treatment (as-sintered, Ctrl), grinding with coarse diamond bur (181µm; Grinding); and (2) "low-temperature aging (LTD)" - presence and absence. Grinding was performed using a contra-angle handpiece under constant water-cooling. LTD was simulated in an autoclave at 134°C under 2-bar pressure for 20h. Mean flexural fatigue limits (20,000 cycles) were determined under sinusoidal loading using stair case approach. For Lava ceramic, it was observed a statistical increase after grinding procedure and different behavior after LTD stimuli (Ctrltemperature aging promoted a statistical increase in the fatigue limit (Ctrltemperature aging did not damage the fatigue limit values significantly for both materials evaluated, even though those conditions promoted increase in m-phase. PMID:26828768

  8. Limits to sustained energy intake. XVI. Body temperature and physical activity of female mice during pregnancy.

    PubMed

    Gamo, Yuko; Bernard, Amelie; Mitchell, Sharon E; Hambly, Catherine; Al Jothery, Aqeel; Vaanholt, Lobke M; Król, Elzbieta; Speakman, John R

    2013-06-15

    Lactation is the most energy-demanding phase of mammalian reproduction, and lactation performance may be affected by events during pregnancy. For example, food intake may be limited in late pregnancy by competition for space in the abdomen between the alimentary tract and fetuses. Hence, females may need to compensate their energy budgets during pregnancy by reducing activity and lowering body temperature. We explored the relationships between energy intake, body mass, body temperature and physical activity throughout pregnancy in the MF1 mouse. Food intake and body mass of 26 females were recorded daily throughout pregnancy. Body temperature and physical activity were monitored every minute for 23 h a day by implanted transmitters. Body temperature and physical activity declined as pregnancy advanced, while energy intake and body mass increased. Compared with a pre-mating baseline period, mice increased energy intake by 56% in late pregnancy. Although body temperature declined as pregnancy progressed, this served mostly to reverse an increase between baseline and early pregnancy. Reduced physical activity may compensate the energy budget of pregnant mice but body temperature changes do not. Over the last 3 days of pregnancy, food intake declined. Individual variation in energy intake in the last phase of pregnancy was positively related to litter size at birth. As there was no association between the increase in body mass and the decline in intake, we suggest the decline was not caused by competition for abdominal space. These data suggest overall reproductive performance is probably not constrained by events during pregnancy. PMID:23720802

  9. Limits to sustained energy intake. XVI. Body temperature and physical activity of female mice during pregnancy.

    PubMed

    Gamo, Yuko; Bernard, Amelie; Mitchell, Sharon E; Hambly, Catherine; Al Jothery, Aqeel; Vaanholt, Lobke M; Król, Elzbieta; Speakman, John R

    2013-06-15

    Lactation is the most energy-demanding phase of mammalian reproduction, and lactation performance may be affected by events during pregnancy. For example, food intake may be limited in late pregnancy by competition for space in the abdomen between the alimentary tract and fetuses. Hence, females may need to compensate their energy budgets during pregnancy by reducing activity and lowering body temperature. We explored the relationships between energy intake, body mass, body temperature and physical activity throughout pregnancy in the MF1 mouse. Food intake and body mass of 26 females were recorded daily throughout pregnancy. Body temperature and physical activity were monitored every minute for 23 h a day by implanted transmitters. Body temperature and physical activity declined as pregnancy advanced, while energy intake and body mass increased. Compared with a pre-mating baseline period, mice increased energy intake by 56% in late pregnancy. Although body temperature declined as pregnancy progressed, this served mostly to reverse an increase between baseline and early pregnancy. Reduced physical activity may compensate the energy budget of pregnant mice but body temperature changes do not. Over the last 3 days of pregnancy, food intake declined. Individual variation in energy intake in the last phase of pregnancy was positively related to litter size at birth. As there was no association between the increase in body mass and the decline in intake, we suggest the decline was not caused by competition for abdominal space. These data suggest overall reproductive performance is probably not constrained by events during pregnancy.

  10. Temperature and pressure dependent Mott potentials and their influence on self-limiting oxide film growth

    NASA Astrophysics Data System (ADS)

    Cai, Na; Zhou, Guangwen; Müller, Kathrin; Starr, David E.

    2012-10-01

    Classic Cabrera-Mott theory stipulates that the limited oxide-film growth results from electron tunneling from the metal through the oxide film to adsorbed oxygen. This leads to an electric field across the oxide film that assists ion migration for low-temperature oxide-film growth. Here, we show that the field-driven oxide-film growth can be manipulated via the temperature and pressure of oxidation. The magnitude of the self-generated electric field depends on the oxygen surface coverage that exhibits a Langmuir isotherm behavior with changes in temperature and oxygen pressure. These observations demonstrate the ability to tune an interfacial reaction via self-adaptation to its environment.

  11. Low temperature phase barium borate: A new optical limiter in continuous wave and nano pulsed regime

    NASA Astrophysics Data System (ADS)

    Babeela, C.; Girisun, T. C. Sabari

    2015-11-01

    Low temperature phase barium borate was synthesized by hydrothermal method. XRD analysis confirms the formation of γ-BBO or hydrated barium polyborate (Ba3B6O9(OH)6) which crystallizes in monoclinic system in the P2/c space group. The molecular structure analysis shows the presence of dominant BO4 unit and the hydrated nature of material. γ-BBO exhibits sharp absorption edge at 202 nm and highly transparency in the UV-Visible-NIR region. The peak at 347 nm in the emission spectrum is due to the presence of self-trapped exciton. The third order nonlinear optical properties and limiting behavior of low temperature barium borate in both pulsed and continuous wave regime were studied. The effective 2PA absorption coefficient of γ-BBO under ns pulse excitation is estimated to be 0.38 × 10-10 m/W. The nonlinear absorption coefficient, refractive index and optical susceptibility of the material in cw regime were found to be in the order of 10-5 m W-1, 10-12 m2 W-1, 10-6 esu respectively. In both regimes, low temperature phase barium borate exhibits better optical limiting properties than high temperature phase β-BBO.

  12. Milk production of Friesian cows subjected to high daytime temperatures when allowed food either ad lib or at night-time only.

    PubMed

    Richards, J I

    1985-08-01

    Four lactating Friesian cows housed in climate chambers were exposed to the following sequential treatments: I, a four-week period when they were allowed constant access to an ad lib supply of a complete diet and water in a thermoneutral environment (ambient temperature (Ta) 14 to 20 degrees C and relative humidity (r.h.) 50 to 75%); II, a five-week period during which they were exposed to Ta 38.5 degrees C/r.h. 85% for 61/2 h during daytime and Ta 14 to 20 degrees C/r.h. 50 to 75% for the remainder of each day with constant access to ad lib complete diet and water; III, a four-week period under the same environment as treatment II but with access to food restricted to between 19.00 and 07.00; IV; a four-week period under the environment and feeding regime described for treatment II. The voluntary food intake (VFI) of cows subjected to II was not depressed as a result of high daytime temperature despite the fact that they exhibited daytime clinical features indicative of heat stress; this was because of a 27.8% compensatory increase in night-time feeding. Nevertheless there was an accompanying significant increase in the rate of lactation decline of 8.7% per month greater than that normally expected under the thermoneutral conditions (I). Subsequent restriction of food access to night-time (III) resulted in a significant reduction in mean VFI of 7.5%; however, the rate of lactation decline was drastically reduced to a value not dissimilar to the natural decline of 3.97% per month observed under thermoneutral conditions (I).

  13. Extending the low temperature operational limit of double-layer capacitors

    NASA Astrophysics Data System (ADS)

    Brandon, Erik J.; West, William C.; Smart, Marshall C.; Whitcanack, Larry D.; Plett, Gary A.

    This work describes the design and testing of organic electrolyte systems that extend the low temperature operational limit of double-layer capacitors (also known as supercapacitors) beyond that of typical commercially available components. Electrolytes were based on a tetraethylammonium tetrafluoroborate/acetonitrile system, modified with low melting co-solvents (such as formates, esters and cyclic ethers) to enable charging and discharging of test cells to as low as -75 °C. Cell capacitance exhibited little dependence on the electrolyte salt concentration or the nature of the co-solvent used, however, both variables strongly influenced the cell equivalent series resistance (ESR). Minimizing the increase in ESR posed the greatest design challenge, which limited realistic operation of these test cells to -55 °C (still improved relative to the typical rated limit of -40 °C for commercially available non-aqueous cells).

  14. Cell model and elastic moduli of disordered solids - Low temperature limit

    NASA Technical Reports Server (NTRS)

    Peng, S. T. J.; Landel, R. F.; Moacanin, J.; Simha, Robert; Papazoglou, Elisabeth

    1987-01-01

    The cell theory has been previously employed to compute the equation of state of a disordered condensed system. It is now generalized to include anisotropic stresses. The condition of affine deformation is adopted, transforming an orginally spherical into an ellipsoidal cell. With a Lennard-Jones n-m potential between nonbonded centers, the formal expression for the deformational free energy is derived. It is to be evaluated in the limit of the linear elastic range. Since the bulk modulus in this limit is already known, it is convenient to consider a uniaxial deformation. To begin with, restrictions are made to the low-temperature limit in the absence of entropy contributions. Young's modulus and Poisson's ratio then follow.

  15. Laboratory and Natural Constraints on the Temperature Limit for Preservation of the Dolomite Clumped Isotope Thermometer

    NASA Astrophysics Data System (ADS)

    Lloyd, M. K.; Eiler, J. M.

    2014-12-01

    Kinetic barriers generally inhibit intercrystalline equilibration of cations and isotopic compositions at temperatures below ~350˚C, greatly limiting the geothermometers available to study the upper 10-15 km of the crust. Calcite 'clumped' isotopes commonly appear to record homogeneous equilibrium during crystallization at surface temperatures, but kinetic models predict that reordering due to solid-state exchange among nearby carbonate groups modifies primary compositions at temperatures above ~115˚C on timescales of 10^6 - 10^8 years and fully re-equilibrates above 200˚C in most geological environments1. Slowly cooled dolomitic marbles commonly preserve apparent temperatures of ~300˚C, indicating that dolomite may have slower reordering kinetics and thus greater preservation of primary crystallization temperatures. If so, dolomite clumped isotope thermometry may be a useful geothermometer in much of the the shallow crust. We measured the kinetics of clumped isotope reordering in dolomite with heating experiments at 400-800˚C in a TZM cold seal apparatus pressurized with CO2. Results predict that no detectable reordering occurs in dolomite held at temperatures less than ~250˚C over timescales of up to 10^8 years, demonstrating the viability of the system as a shallow crustal geothermometer. The non-first order behavior observed in calcite1,2,3is exhibited by dolomite as well, albeit at higher temperatures. To test these predictions, we measured the clumped isotopic compositions of coexisting calcite and dolomite in marbles from the Notch Peak aureole, UT. Dolomite clumped isotope temperatures in the outer aureole match peak conditions predicted by thermal models up to ~275˚C, indicating that the system resisted reordering below this grade. Calcite clumped isotope temperatures are never greater than ~150˚C at all grades in the aureole; this is consistent with the ambient burial temperature in the section and indicates that all metamorphic calcite was fully

  16. Environmental temperatures, physiology and behavior limit the range expansion of invasive Burmese pythons in southeastern USA.

    PubMed

    Jacobson, Elliott R; Barker, David G; Barker, Tracy M; Mauldin, Richard; Avery, Michael L; Engeman, Richard; Secor, Stephen

    2012-09-01

    A well-established population of Burmese pythons resides in the Everglades of southern Florida. Prompted in part by a report that identified much of southern USA as suitable habitat for expansion or establishment of the Burmese python, we examined the plausibility of this snake to survive winters at sites north of the Everglades. We integrated daily low and high temperatures recorded from October to February from 2005-2011 at Homestead, Orlando and Gainesville, Florida; and Aiken, South Carolina, with minimum temperatures projected for python digestion (16 °C), activity (5 °C) and survival (0 °C). Mean low and high temperatures decreased northward from Homestead to Aiken and the number of days of freezing temperatures increased northward. Digestion was impaired or inhibited for 2 months in the Everglades and up to at least 5 months in Aiken, and activity was increasingly limited northward during these months. Reports of overwinter survivorship document that a single bout of low and freezing temperatures results in python death. The capacity for Burmese pythons to successfully overwinter in more temperate regions of the USA is seemingly prohibited because they lack the behaviors to seek refuge from, and the physiology to tolerate, cold temperatures. As tropical Southeast Asia is the source of the Everglades Burmese pythons, we predict it is unlikely that they will be able to successfully expand to or colonize more temperate areas of Florida and adjoining states due to their lack of behavioral and physiological traits to seek refuge from cold temperatures. PMID:22938524

  17. Cadmium-dependent oxygen limitation affects temperature tolerance in eastern oysters (Crassostrea virginica Gmelin).

    PubMed

    Lannig, Gisela; Cherkasov, Anton S; Pörtner, Hans-O; Bock, Christian; Sokolova, Inna M

    2008-04-01

    Marine ectotherms, including oysters are exposed to variable environmental conditions in coastal shallow waters and estuaries. In the light of global climate change, additional stressors like pollution might pose higher risk to populations. On the basis of the concept of oxygen- and capacity-limited thermal tolerance in aquatic ectotherms (40), we show that a persistent pollutant, cadmium, can have detrimental effects on oysters (Crassostrea virginica). During acute warming from 20 to 28 degrees C (4 degrees C/48 h) standard metabolic rate (SMR) rose in control and cadmium-exposed (50 microg Cd2+/l) animals, with a consistently higher SMR in Cd-exposed oysters. Additionally, Cd-exposed oysters showed a stronger temperature-dependent decrease in hemolymph oxygen partial pressures. This observation indicates that the effect of temperature on aerobic metabolism was exacerbated due to the additional Cd stress. The oxygen delivery systems could not provide enough oxygen to cover Cd-induced elevated metabolic demands at high temperatures. Interestingly, cardiac performance (measured as the heart rate and hemolymph supply to tissues) rose to a similar extent in control and Cd-exposed oysters with warming indicating that cardiac output was unable to compensate for elevated energy demand in Cd-exposed oysters. Together with the literature data on metal-induced reduction of ventilatory capacity, these findings suggest that synergistic effects of elevated temperatures and cadmium exposure led to oxygen limitation by impaired performance in oxygen supply through ventilation and circulation. Overall, cadmium exposure resulted in progressive hypoxemia in oysters at high temperatures, suggesting that the thermal tolerance window is narrowed in marine ectotherms inhabiting polluted areas compared with pristine environments. PMID:18272660

  18. Cadmium-dependent oxygen limitation affects temperature tolerance in eastern oysters (Crassostrea virginica Gmelin).

    PubMed

    Lannig, Gisela; Cherkasov, Anton S; Pörtner, Hans-O; Bock, Christian; Sokolova, Inna M

    2008-04-01

    Marine ectotherms, including oysters are exposed to variable environmental conditions in coastal shallow waters and estuaries. In the light of global climate change, additional stressors like pollution might pose higher risk to populations. On the basis of the concept of oxygen- and capacity-limited thermal tolerance in aquatic ectotherms (40), we show that a persistent pollutant, cadmium, can have detrimental effects on oysters (Crassostrea virginica). During acute warming from 20 to 28 degrees C (4 degrees C/48 h) standard metabolic rate (SMR) rose in control and cadmium-exposed (50 microg Cd2+/l) animals, with a consistently higher SMR in Cd-exposed oysters. Additionally, Cd-exposed oysters showed a stronger temperature-dependent decrease in hemolymph oxygen partial pressures. This observation indicates that the effect of temperature on aerobic metabolism was exacerbated due to the additional Cd stress. The oxygen delivery systems could not provide enough oxygen to cover Cd-induced elevated metabolic demands at high temperatures. Interestingly, cardiac performance (measured as the heart rate and hemolymph supply to tissues) rose to a similar extent in control and Cd-exposed oysters with warming indicating that cardiac output was unable to compensate for elevated energy demand in Cd-exposed oysters. Together with the literature data on metal-induced reduction of ventilatory capacity, these findings suggest that synergistic effects of elevated temperatures and cadmium exposure led to oxygen limitation by impaired performance in oxygen supply through ventilation and circulation. Overall, cadmium exposure resulted in progressive hypoxemia in oysters at high temperatures, suggesting that the thermal tolerance window is narrowed in marine ectotherms inhabiting polluted areas compared with pristine environments.

  19. Clark Lake microbursts - On a lower limit to type III burst brightness temperatures

    NASA Technical Reports Server (NTRS)

    White, S. M.; Kundu, M. R.; Szabo, A.

    1987-01-01

    Further observations of solar microbursts by the Clark Lake radioheliograph are reported. The microbursts have properties consistent with weak type III bursts, with the implication that type III's can have brightness temperatures as low as 1 million K. The importance of this result is explored. A single model to explain the stronger type III bursts and the weaker microbursts is sought. It is shown that none of the models for stabilizing the strongest type III electron streams can explain the observed microbursts: these models have threshold levels of Langmuir waves which imply emission (due to spontaneous scattering off ions) with brightness temperatures in excess of those observed. It appears that either some vital physics is still missing from models for type III bursts, or that microbursts should have properties significantly different from those of type III bursts. In the latter case further observations should allow important tests of type III models.

  20. Promotion of Flowering by Apple Latent Spherical Virus Vector and Virus Elimination at High Temperature Allow Accelerated Breeding of Apple and Pear.

    PubMed

    Yamagishi, Norioko; Li, Chunjiang; Yoshikawa, Nobuyuki

    2016-01-01

    Plant viral vectors are superior tools for genetic manipulation, allowing rapid induction or suppression of expression of a target gene in plants. This is a particularly effective technology for use in breeding fruit trees, which are difficult to manipulate using recombinant DNA technologies. We reported previously that if apple seed embryos (cotyledons) are infected with an Apple latent spherical virus (ALSV) vector (ALSV-AtFT/MdTFL1) concurrently expressing the Arabidopsis thaliana florigen (AtFT) gene and suppressing the expression of the apple MdTFL1-1 gene, the period prior to initial flowering (generally lasts 5-12 years) will be reduced to about 2 months. In this study, we examined whether or not ALSV vector technology can be used to promote flowering in pear, which undergoes a very long juvenile period (germination to flowering) similar to that of apple. The MdTFL1 sequence in ALSV-AtFT/MdTFL1 was replaced with a portion of the pear PcTFL1-1 gene. The resulting virus (ALSV-AtFT/PcTFL1) and ALSV-AtFT/MdTFL1 were used individually for inoculation to pear cotyledons immediately after germination in two inoculation groups. Those inoculated with ALSV-AtFT/MdTFL1 and ALSV-AtFT/PcTFL1 then initiated flower bud formation starting one to 3 months after inoculation, and subsequently exhibited continuous flowering and fruition by pollination. Conversely, Japanese pear exhibited extremely low systemic infection rates when inoculated with ALSV-AtFT/MdTFL1, and failed to exhibit any induction of flowering. We also developed a simple method for eliminating ALSV vectors from infected plants. An evaluation of the method for eliminating the ALSV vectors from infected apple and pear seedlings revealed that a 4-week high-temperature (37°C) incubation of ALSV-infected apples and pears disabled the movement of ALSV to new growing tissues. This demonstrates that only high-temperature treatment can easily eliminate ALSV from infected fruit trees. A method combining the promotion

  1. Promotion of Flowering by Apple Latent Spherical Virus Vector and Virus Elimination at High Temperature Allow Accelerated Breeding of Apple and Pear

    PubMed Central

    Yamagishi, Norioko; Li, Chunjiang; Yoshikawa, Nobuyuki

    2016-01-01

    Plant viral vectors are superior tools for genetic manipulation, allowing rapid induction or suppression of expression of a target gene in plants. This is a particularly effective technology for use in breeding fruit trees, which are difficult to manipulate using recombinant DNA technologies. We reported previously that if apple seed embryos (cotyledons) are infected with an Apple latent spherical virus (ALSV) vector (ALSV-AtFT/MdTFL1) concurrently expressing the Arabidopsis thaliana florigen (AtFT) gene and suppressing the expression of the apple MdTFL1-1 gene, the period prior to initial flowering (generally lasts 5–12 years) will be reduced to about 2 months. In this study, we examined whether or not ALSV vector technology can be used to promote flowering in pear, which undergoes a very long juvenile period (germination to flowering) similar to that of apple. The MdTFL1 sequence in ALSV-AtFT/MdTFL1 was replaced with a portion of the pear PcTFL1-1 gene. The resulting virus (ALSV-AtFT/PcTFL1) and ALSV-AtFT/MdTFL1 were used individually for inoculation to pear cotyledons immediately after germination in two inoculation groups. Those inoculated with ALSV-AtFT/MdTFL1 and ALSV-AtFT/PcTFL1 then initiated flower bud formation starting one to 3 months after inoculation, and subsequently exhibited continuous flowering and fruition by pollination. Conversely, Japanese pear exhibited extremely low systemic infection rates when inoculated with ALSV-AtFT/MdTFL1, and failed to exhibit any induction of flowering. We also developed a simple method for eliminating ALSV vectors from infected plants. An evaluation of the method for eliminating the ALSV vectors from infected apple and pear seedlings revealed that a 4-week high-temperature (37°C) incubation of ALSV-infected apples and pears disabled the movement of ALSV to new growing tissues. This demonstrates that only high-temperature treatment can easily eliminate ALSV from infected fruit trees. A method combining the

  2. Stability of cable thermocouples at the upper temperature limit of their working range

    NASA Astrophysics Data System (ADS)

    Ulanovskiy, A. A.; Zemba, E. S.; Belenkiy, A. M.; Chibizova, S. I.; Bursin, A. N.

    2013-09-01

    Experimental results of EMF stability research are presented for MIMS thermocouples of types K and N of external diameters 1.5; 3.0 and 5.0 mm. All thermocouples had heat resistant sheath and were not used before the tests. They were subjected to every-day cyclic heating and cooling. During each cycle there was 6 h annealing in air at the temperature 1200 °C Results shows, that stability of a cable thermocouple in air at the temperature 1200 °C depends, mainly, on its diameter, instead of on thermocouple type or metal sheath material. Acceptable time of operation in a thermal cycling mode for 1.5 mm cable thermocouples is limited by (15, 16) h, and for 3 mm thermocouples it is equal to (40, 45) h. Besides, the effect of signal shunting is shown in the work for a thermocouple under heating of its average part to the temperature 1200 °C Experiment has shown that use of long cable thermocouple of 1.5 mm diameter at the temperatures above 1000°C can lead to serious errors in temperature measurement. Heating of 400 mm thermocouple length to 1100 °C causes positive EMF in the 1.5 mm cable thermocouple equivalent to +3.4 °C and +18 °C at 1200°C. For 3 mm cable thermocouple EMF at 1200 °C reaches the value equivalent to +2.3 °C, but double increase in heating length makes the value greater to +13.5 °C. The given facts are necessary to consider while using of thin (1, 3) mm cable thermocouples at the temperatures (1100, 1200) °C.

  3. Shot-noise-limited magnetometer with sub-picotesla sensitivity at room temperature

    SciTech Connect

    Lucivero, Vito Giovanni; Anielski, Pawel; Gawlik, Wojciech; Mitchell, Morgan W.

    2014-11-15

    We report a photon shot-noise-limited (SNL) optical magnetometer based on amplitude modulated optical rotation using a room-temperature {sup 85}Rb vapor in a cell with anti-relaxation coating. The instrument achieves a room-temperature sensitivity of 70 fT/√(Hz) at 7.6 μT. Experimental scaling of noise with optical power, in agreement with theoretical predictions, confirms the SNL behaviour from 5 μT to 75 μT. The combination of best-in-class sensitivity and SNL operation makes the system a promising candidate for application of squeezed light to a state-of-the-art atomic sensor.

  4. Shot-noise-limited magnetometer with sub-picotesla sensitivity at room temperature.

    PubMed

    Lucivero, Vito Giovanni; Anielski, Pawel; Gawlik, Wojciech; Mitchell, Morgan W

    2014-11-01

    We report a photon shot-noise-limited (SNL) optical magnetometer based on amplitude modulated optical rotation using a room-temperature (85)Rb vapor in a cell with anti-relaxation coating. The instrument achieves a room-temperature sensitivity of 70 fT / √Hz at 7.6 μT. Experimental scaling of noise with optical power, in agreement with theoretical predictions, confirms the SNL behaviour from 5 μT to 75 μT. The combination of best-in-class sensitivity and SNL operation makes the system a promising candidate for application of squeezed light to a state-of-the-art atomic sensor.

  5. Transcriptome comparison reveals a genetic network regulating the lower temperature limit in fish.

    PubMed

    Hu, Peng; Liu, Mingli; Liu, Yimeng; Wang, Jinfeng; Zhang, Dong; Niu, Hongbo; Jiang, Shouwen; Wang, Jian; Zhang, Dongsheng; Han, Bingshe; Xu, Qianghua; Chen, Liangbiao

    2016-01-01

    Transcriptional plasticity is a major driver of phenotypic differences between species. The lower temperature limit (LTL), namely the lower end of survival temperature, is an important trait delimiting the geographical distribution of a species, however, the genetic mechanisms are poorly understood. We investigated the inter-species transcriptional diversification in cold responses between zebrafish Danio rerio and tilapia Oreochromis niloticus, which were reared at a common temperature (28 °C) but have distinct LTLs. We identified significant expressional divergence between the two species in the orthologous genes from gills when the temperature cooled to the LTL of tilapia (8 °C). Five KEGG pathways were found sequentially over-represented in the zebrafish/tilapia divergently expressed genes in the duration (12 hour) of 8 °C exposure, forming a signaling cascade from metabolic regulation to apoptosis via FoxO signaling. Consistently, we found differential progression of apoptosis in the gills of the two species in which zebrafish manifested a delayed and milder apoptotic phenotype than tilapia, corresponding with a lower LTL of zebrafish. We identified diverged expression in 25 apoptosis-related transcription factors between the two species which forms an interacting network with diverged factors involving the FoxO signaling and metabolic regulation. We propose a genetic network which regulates LTL in fishes. PMID:27356472

  6. The critical limiting temperature and selective brain cooling: neuroprotection during exercise?

    PubMed

    Marino, Frank E

    2011-01-01

    There is wide consensus that long duration exercise in the heat is impaired compared with cooler conditions. A common observation when examining exercise tolerance in the heat in laboratory studies is the critical limiting core temperature (CLT) and the apparent attenuation in central nervous system (CNS) drive leading to premature fatigue. Selective brain cooling (SBC) purportedly confers neuroprotection during exercise heat stress by attenuating the increase in brain temperature. As the CLT is dependent on heating to invoke a reduction in efferent drive, it is thus not compatible with SBC which supposedly attenuates the rise in brain temperature. Therefore, the CLT and SBC hypotheses cannot be complimentary if the goal is to confer neuroprotection from thermal insult as it is counter-intuitive to selectively cool the brain if the purpose of rising brain temperature is to down-regulate skeletal muscle recruitment. This presents a circular model for which there is no apparent end to the ultimate physiological outcome; a 'hot brain' selectively cooled in order to reduce the CNS drive to skeletal muscle. This review will examine the postulates of the CLT and SBC with their relationship to the avoidance of a 'hot brain' which together argue for a theoretical position against neuroprotection as the key physiological strategy in exercise-induced hyperthermia.

  7. Transcriptome comparison reveals a genetic network regulating the lower temperature limit in fish

    PubMed Central

    Hu, Peng; Liu, Mingli; Liu, Yimeng; Wang, Jinfeng; Zhang, Dong; Niu, Hongbo; Jiang, Shouwen; Wang, Jian; Zhang, Dongsheng; Han, Bingshe; Xu, Qianghua; Chen, Liangbiao

    2016-01-01

    Transcriptional plasticity is a major driver of phenotypic differences between species. The lower temperature limit (LTL), namely the lower end of survival temperature, is an important trait delimiting the geographical distribution of a species, however, the genetic mechanisms are poorly understood. We investigated the inter-species transcriptional diversification in cold responses between zebrafish Danio rerio and tilapia Oreochromis niloticus, which were reared at a common temperature (28 °C) but have distinct LTLs. We identified significant expressional divergence between the two species in the orthologous genes from gills when the temperature cooled to the LTL of tilapia (8 °C). Five KEGG pathways were found sequentially over-represented in the zebrafish/tilapia divergently expressed genes in the duration (12 hour) of 8 °C exposure, forming a signaling cascade from metabolic regulation to apoptosis via FoxO signaling. Consistently, we found differential progression of apoptosis in the gills of the two species in which zebrafish manifested a delayed and milder apoptotic phenotype than tilapia, corresponding with a lower LTL of zebrafish. We identified diverged expression in 25 apoptosis-related transcription factors between the two species which forms an interacting network with diverged factors involving the FoxO signaling and metabolic regulation. We propose a genetic network which regulates LTL in fishes. PMID:27356472

  8. Invariant tori for the Nosé thermostat near the high-temperature limit

    NASA Astrophysics Data System (ADS)

    Butler, Leo T.

    2016-11-01

    Let H(q,p)=\\frac{1}{2}{{p}2}+V(q) be a 1-degree of freedom mechanical Hamiltonian with a C r periodic potential V where r  >  4. The Nosé-thermostated system associated to H is shown to have invariant tori near the infinite temperature limit. This is shown to be true for all thermostats similar to Nosé’s. These results complement the result of Legoll, Luskin and Moeckel who proved the existence of such tori near the decoupling limit (Frederic et al 2007 Arch. Ration. Mech. Anal. 184 449-63, Frederic L et al 2009 Nonlinearity 22 1673-94).

  9. Freezing temperatures as a limit to forest recruitment above tropical Andean treelines.

    PubMed

    Rehm, Evan M; Feeley, Kenneth J

    2015-07-01

    The elevation of altitudinal treelines is generally believed to occur where low mean temperatures during the growing season limit growth and prevent trees from establishing at higher elevations. Accordingly, treelines should move upslope with increasing global temperatures. Contrary to this prediction, tropical treelines have remained stable over the past several decades despite increasing mean temperatures. The observed stability of tropical treelines, coupled with the drastically different temperature profiles between temperate and tropical treelines, suggests that using mean measures of temperature to predict tropical treeline movements during climate change may be overly simplistic. We hypothesize that frost events at tropical treelines may slow climate driven treeline movement by preventing tree recruitment beyond the established forest canopy. To assess this hypothesis, we measured freezing resistance of four canopy-forming treeline species (Weinmannia fagaroides, Polylepis pauta, Clethra cuneata, and Gynoxys nitida) at two life stages (juvenile and adult) and during two seasons (warm-wet and cold-dry). Freezing resistances were then compared to microclimatic data to determine if freezing events in the grassland matrix above treeline are too harsh for these forest species. Freezing resistance varied among species and life stages from -5.7 degrees C for juveniles of P. pauta to -11.1 degrees C for juveniles of W. fagaroides. Over a four-year period, the lowest temperatures recorded at 10 cm above ground level in the grasslands above treeline and at treeline itself were -8.9 degrees C and -6.8 degrees C, respectively. Juveniles maintained freezing resistances similar to adults during the coldest parts of the year and ontogenetic differences in freezing resistance were only present during the warm season when temperatures did not represent a significant threat to active plant tissue. These findings support the hypothesis that rare extreme freezing events at and

  10. Freezing temperatures as a limit to forest recruitment above tropical Andean treelines.

    PubMed

    Rehm, Evan M; Feeley, Kenneth J

    2015-07-01

    The elevation of altitudinal treelines is generally believed to occur where low mean temperatures during the growing season limit growth and prevent trees from establishing at higher elevations. Accordingly, treelines should move upslope with increasing global temperatures. Contrary to this prediction, tropical treelines have remained stable over the past several decades despite increasing mean temperatures. The observed stability of tropical treelines, coupled with the drastically different temperature profiles between temperate and tropical treelines, suggests that using mean measures of temperature to predict tropical treeline movements during climate change may be overly simplistic. We hypothesize that frost events at tropical treelines may slow climate driven treeline movement by preventing tree recruitment beyond the established forest canopy. To assess this hypothesis, we measured freezing resistance of four canopy-forming treeline species (Weinmannia fagaroides, Polylepis pauta, Clethra cuneata, and Gynoxys nitida) at two life stages (juvenile and adult) and during two seasons (warm-wet and cold-dry). Freezing resistances were then compared to microclimatic data to determine if freezing events in the grassland matrix above treeline are too harsh for these forest species. Freezing resistance varied among species and life stages from -5.7 degrees C for juveniles of P. pauta to -11.1 degrees C for juveniles of W. fagaroides. Over a four-year period, the lowest temperatures recorded at 10 cm above ground level in the grasslands above treeline and at treeline itself were -8.9 degrees C and -6.8 degrees C, respectively. Juveniles maintained freezing resistances similar to adults during the coldest parts of the year and ontogenetic differences in freezing resistance were only present during the warm season when temperatures did not represent a significant threat to active plant tissue. These findings support the hypothesis that rare extreme freezing events at and

  11. Limiting temperature of pion gas with the van der Waals equation of state

    NASA Astrophysics Data System (ADS)

    Poberezhnyuk, R. V.; Vovchenko, V.; Anchishkin, D. V.; Gorenstein, M. I.

    2016-09-01

    The grand canonical ensemble formulation of the van der Waals equation of state that includes the effects of Bose statistics is applied to the equilibrium system of interacting pions. If the attractive interaction between pions is large enough, a limiting temperature T 0 emerges, i.e., no thermodynamical equilibrium is possible at T\\gt {T}0. The system pressure p, particle number density n, and energy density ε remain finite at T={T}0, whereas for T near T 0 both the specific heat C={{d}}\\varepsilon /{{d}}T and the scaled variance of particle number fluctuations ω [N] are proportional to {({T}0-T)}-1/2 and, thus, go to infinity at T\\to {T}0. The limiting temperature also corresponds to the softest point of the equation of state, i.e., the speed of sound squared {c}s2={{d}}p/{{d}}\\varepsilon goes to zero as {({T}0-T)}1/2. Very similar thermodynamical behavior takes place in the Hagedorn model for the special choice of a power, namely {m}-4, in the pre-exponential factor of the mass spectrum ρ (m).

  12. Status of high temperature superconductor cable and fault current limiter projects at American Superconductor

    NASA Astrophysics Data System (ADS)

    Maguire, J. F.; Yuan, J.

    2009-10-01

    This paper will describe the status of three key programs currently underway at American Superconductor Corp. The first program is the LIPA project which is a transmission voltage high temperature superconducting cable program, with funding support from the US Department of Energy. The 600 m cable, capable of carrying 574 MVA, was successfully installed and commissioned in LIPA grid on April 22, 2008. An overview of the project, system level design details and operational data will be provided. In addition, the status of the newly awarded LIPA II project will be described. The second program is Project Hydra, with funding support from the US Department of Homeland Security, to design, develop and demonstrate an HTS cable with fault current limiting functionality. The cable is 300 m long and is being designed to carry 96 MVA at a distribution level voltage of 13.8 kV. The cable will be permanently installed and energized in Manhattan, New York in 2010. The initial status of Project Hydra will be presented. The final program to be discussed is a transmission voltage, high temperature superconducting fault current limiter funded by the US DOE. The project encompasses the design, construction and test of a 115 kV FCL for power transmission within a time frame of 4-5 years. Installation and testing are planned for a Southern California Edison substation. A project overview and progress under the first phase will be reported.

  13. Medicare program; limit on the valuation of a depreciable asset recognized as an allowance for depreciation and interest on capital indebtedness after a change of ownership--HCFA. Final rule with comment period.

    PubMed

    1998-01-01

    This final rule with comment period revises the Medicare provider reimbursement regulations relative to allowable costs and sets a limit on the valuation of a depreciable asset that may be recognized in establishing an appropriate allowance for depreciation and for interest on capital indebtedness after a change of ownership that occurs on or after December 1, 1997. These provisions apply to providers that are reimbursed on the basis of reasonable costs. This change implements the mandate in section 4404 of the Balanced Budget Act of 1997 (Pub. L. 105-33).

  14. Stream water temperature limits occupancy of salamanders in mid-Atlantic protected areas

    USGS Publications Warehouse

    Grant, Evan H. Campbell; Wiewel, Amber N. M.; Rice, Karen C.

    2014-01-01

    Stream ecosystems are particularly sensitive to urbanization, and tolerance of water-quality parameters is likely important to population persistence of stream salamanders. Forecasted climate and landscape changes may lead to significant changes in stream flow, chemical composition, and temperatures in coming decades. Protected areas where landscape alterations are minimized will therefore become increasingly important for salamander populations. We surveyed 29 streams at three national parks in the highly urbanized greater metropolitan area of Washington, DC. We investigated relationships among water-quality variables and occupancy of three species of stream salamanders (Desmognathus fuscus, Eurycea bislineata, and Pseudotriton ruber). With the use of a set of site-occupancy models, and accounting for imperfect detection, we found that stream-water temperature limits salamander occupancy. There was substantial uncertainty about the effects of the other water-quality variables, although both specific conductance (SC) and pH were included in competitive models. Our estimates of occupancy suggest that temperature, SC, and pH have some importance in structuring stream salamander distribution.

  15. The effect of time of exposure to elevated temperatures on the flammability limits of some common gaseous fuels in air

    SciTech Connect

    Wierzba, I.; Ale, B.B.

    1999-01-01

    The flammability limits of methane, ethylene, propane, and hydrogen were experimentally determined at elevated initial mixture temperatures up to 350 C at atmospheric pressure for upward flame propagation in a steel test tube apparatus. The existence of preignition reactions at these levels of temperatures that may influence the value of the flammability limits was also investigated. The fuel-air mixtures were exposed to elevated temperatures over different periods of time before spark ignition (up to 2 h). It was shown that the flammability limits for methane widened approximately linearly with an increase in the initial mixture temperature over the entire range of temperatures tested and were not affected by the length of the exposure time to these temperatures before spark ignition. However, different behavior was observed for the flammability limits of the other tested fuels--ethylene, propane, and hydrogen. At higher temperatures the flammability limits narrowed and were very significantly affected by the exposure time. The longer was the exposure time of fuel-air mixtures to the elevated temperatures, the narrower were their flammability limits.

  16. Upper Temperature Limit of Environmental Barrier Coatings for Enabling Propulsion Materials Established

    NASA Technical Reports Server (NTRS)

    Lee, Kang N.; Fox, Dennis S.; Robinson, R. Craig

    2001-01-01

    Silicon-based ceramics, such as SiC/SiC composites and Si3N4, are the prime candidates for hot section structural components of next-generation gas turbines. A key barrier to such an application is the rapid recession of silicon-based ceramics in combustion environments because of the volatilization of silica scale by water vapor (refs. 1 and 2). Environmental barrier coatings (EBC's) were developed to prevent recession in the High Speed Research--Enabling Propulsion Materials (HSR-EPM) Program (refs. 3 and 4). An investigation under the Ultra-Efficient Engine Technology Program was undertaken at the NASA Glenn Research Center to establish the upper temperature limit of the EPM EBC.

  17. Application limits of the interpretation of near-surface temperature time series to assess groundwater recharge

    NASA Astrophysics Data System (ADS)

    Gosselin, J. S.; Rivard, C.; Martel, R.; Lefebvre, R.

    2016-07-01

    The main objective of this study was to test the application limits of a groundwater recharge assessment technique based on the inversion of a vertical one-dimensional numerical model of advective-conductive heat transport, using temperature time series at three different depths (1, 3, 5 m) in the unsaturated zone. For this purpose, several synthetic hourly datasets of subsurface temperatures, representing various weather, ground cover, and soil texture conditions, thus covering a wide range of groundwater recharge values, were produced with the vertical one-dimensional coupled heat and moisture transport simulator SHAW (Simultaneous Heat and Water model). Estimates of the vertical flux of water in the soil were then retrieved from these realistic temperature profiles using a simple one-dimensional numerical simulator of advective and conductive heat transport in the unsaturated zone that was developed as part of this study. The water flux was assumed constant on a weekly, monthly, semiannual, and annual basis. From these vertical water flux estimates, annual (potential) groundwater recharge rates were then computed and results were compared to those calculated previously with SHAW to assess the accuracy of the method. Results showed that, under ideal conditions, it would be possible to estimate annual recharge rates that are above 200 mm/y, with an acceptable error of less than 20%. These "ideal" conditions include the resolution of the water flux on a weekly basis, error-free temperature measurements below the soil freezing zone, and model parameter values (thermal conductivity and heat capacity of the soil) known a priori with no uncertainty. However, this work demonstrates that the accuracy of the method is highly sensitive to the uncertainty of the input model parameters of the numerical model used to carry out the inversion and to measurement errors of temperature time series. For the conditions represented in this study, these findings suggest that, despite

  18. Lower temperature limits for activity of several Ixodid ticks (Acari: Ixodidae): effects of body size and rate of temperature change.

    PubMed

    Clark, D D

    1995-07-01

    Uncoordinated activity threshold temperature, the temperature below which ticks can no longer seek a host in a coordinated manner, and the activity threshold temperature, when all activity ceases, were examined for three species of ticks found in coastal sections of New York. The mean uncoordinated activity threshold and activity threshold temperatures were determined for nymphal, female and male Ixodes scapularis Say, nymphal, female, and male Amblyomma americanum (L.), and for female and male Dermacentor variabilis (Say). Only the uncoordinated activity threshold and activity threshold temperatures for adult I. scapularis were significantly correlated to the rate of temperature decrease. The mean uncoordinated activity threshold and activity threshold temperatures were significantly correlated to the mean size of each tick species.

  19. The effect of water temperature and flow on respiration in barnacles: patterns of mass transfer versus kinetic limitation.

    PubMed

    Nishizaki, Michael T; Carrington, Emily

    2014-06-15

    In aquatic systems, physiological processes such as respiration, photosynthesis and calcification are potentially limited by the exchange of dissolved materials between organisms and their environment. The nature and extent of physiological limitation is, therefore, likely to be dependent on environmental conditions. Here, we assessed the metabolic sensitivity of barnacles under a range of water temperatures and velocities, two factors that influence their distribution. Respiration rates increased in response to changes in temperature and flow, with an interaction where flow had less influence on respiration at low temperatures, and a much larger effect at high temperatures. Model analysis suggested that respiration is mass transfer limited under conditions of low velocity (<7.5 cm (-1)) and high temperature (20-25°C). In contrast, limitation by uptake reaction kinetics, when the biotic capacity of barnacles to absorb and process oxygen is slower than its physical delivery by mass transport, prevailed at high flows (40-150 cm s(-1)) and low temperatures (5-15°C). Moreover, there are intermediate flow-temperature conditions where both mass transfer and kinetic limitation are important. Behavioral monitoring revealed that barnacles fully extend their cirral appendages at low flows and display abbreviated 'testing' behaviors at high flows, suggesting some form of mechanical limitation. In low flow-high temperature treatments, however, barnacles displayed distinct 'pumping' behaviors that may serve to increase ventilation. Our results suggest that in slow-moving waters, respiration may become mass transfer limited as temperatures rise, whereas faster flows may serve to ameliorate the effects of elevated temperatures. Moreover, these results underscore the necessity for approaches that evaluate the combined effects of multiple environmental factors when examining physiological and behavioral performance.

  20. Upper Temperature Limit of Environmental Barrier Coatings Based on Mullite and BSAS

    NASA Technical Reports Server (NTRS)

    Lee, Kang N.; Fox, Dennis S.; Eldridge, Jeffrey I.; Zhu, Dongming; Bansal, Narottam P.; Miller, Robert A.; Robinson, Raymond C.

    2002-01-01

    Current state-of-the-art environmental barrier coatings (EBCs) for Si-based ceramics consist of three layers: a silicon bond coat, an intermediate mullite (3Al2O3-2SiO2) or mullite + BSAS (1-xBaO-xSrO-Al2O3-2SiO2) layer, and a BSAS top coat. Areas of concern for long-term durability are environmental durability, chemical compatibility, silica volatility, phase stability, and thermal conductivity. Variants of this family of EBCs were applied to monolithic SiC and melt infiltrated SiC/SiC composites. Reaction between BSAS and silica results in low melting (approx. 1300 C) glasses at T > 1400 C, which can cause the spallation of the EBC. At temperatures greater than 1400 C, the BSAS top coat also degrades by formation of a porous structure, and it suffers significant recession via silica volatilization in water vapor-containing atmospheres. All of these degradation mechanisms can be EBC life-limiting factors. BSAS undergoes a very sluggish phase transformation (hexagonal celsian to monoclinic celsian), the implications of which are not fully understood at this point. There was evidence of rapid sintering at temperatures as low as 1300 C, as inferred from the sharp increase in thermal conductivity.

  1. High temperature stability limit of phase egg, AlSiO3(OH)

    NASA Astrophysics Data System (ADS)

    Ono, Shigeaki

    The stability relations of phase egg, AlSiO3(OH), have been investigated at pressures from 7 to 20GPa, and temperatures from 900 to 1700°C in a multi-anvil apparatus. At the lower pressures phase egg breaks down according to the univariant reaction, phase egg=stishovite+topaz-OH, which extends from 1100°C at 11GPa to 1400°C at 13GPa where it terminates at an invariant point involving corundum. At pressures above the invariant point, the stability of phase egg is limited by the breakdown reaction, phase egg=stishovite+corundum+fluid, which extends from the invariant point to 1700°C at 20GPa. Stishovite crystallized in the Al2O3-SiO2-H2O system contains Al2O3, and the amount of Al2O3 increases with increasing temperature. It is inferred that the Al2O3 content is controlled by the charge-balanced substitution of Si4+ by Al3+ and H+. Aluminum-bearing stishovite coexisting with an H2O-rich fluid may contain a certain amount of water. Therefore, phase egg and stishovite in a subducting slab could transport some H2O into the deep Earth.

  2. Practical limitations on the use of diurnal temperature signals to quantify groundwater upwelling

    USGS Publications Warehouse

    Briggs, Martin; Lautz, Laura K.; Buckley, Sean F.; Lane, Jr., John W.

    2014-01-01

    Groundwater upwelling to streams creates unique habitat by influencing stream water quality and temperature; upwelling zones also serve as vectors for contamination when groundwater is degraded. Temperature time series data acquired along vertical profiles in the streambed have been applied to simple analytical models to determine rates of vertical fluid flux. These models are based on the downward propagation characteristics (amplitude attenuation and phase-lag) of the surface diurnal signal. Despite the popularity of these models, there are few published characterizations of moderate-to-strong upwelling. We attribute this limitation to the thermodynamics of upwelling, under which the downward conductive signal transport from the streambed interface occurs opposite the upward advective fluid flux. Governing equations describing the advection–diffusion of heat within the streambed predict that under upwelling conditions, signal amplitude attenuation will increase, but, counterintuitively, phase-lag will decrease. Therefore the extinction (measurable) depth of the diurnal signal is very shallow, but phase lag is also short, yielding low signal to noise ratio and poor model sensitivity. Conversely, amplitude attenuation over similar sensor spacing is strong, yielding greater potential model sensitivity. Here we present streambed thermal time series over a range of moderate to strong upwelling sites in the Quashnet River, Cape Cod, Massachusetts. The predicted inverse relationship between phase-lag and rate of upwelling was observed in the field data over a range of conditions, but the observed phase-lags were consistently shorter than predicted. Analytical solutions for fluid flux based on signal amplitude attenuation return results consistent with numerical models and physical seepage meters, but the phase-lag analytical model results are generally unreasonable. Through numerical modeling we explore reasons why phase-lag may have been over-predicted by the

  3. Application Study of a High Temperature Superconducting Fault Current Limiter for Electric Power System

    NASA Astrophysics Data System (ADS)

    Naito, Yuji; Shimizu, Iwao; Yamaguchi, Iwao; Kaiho, Katsuyuki; Yanabu, Satoru

    Using high temperature superconductor, a Superconducting Fault Current Limiter (SFCL) was made and tested. Superconductor and vacuum interrupter as commutation switch are connected in parallel with bypass coil. When a fault occurs and the excessive current flows, superconductor is first quenched and the current is transferred to bypass coil because on voltage drop of superconductor. At the same time, since magnetic field is generated by current which flows in bypass coil, commutation switch is immediately driven by electromagnetic repulsion plate connected to driving rod of vacuum interrupter, and superconductor is separated from this circuit. Using the testing model, we could separate the superconductor from a circuit due to movement of vacuum interrupter within half-cycle current and transfer all current to bypass coil. Since operation of a commutation switch is included in current limiting operation of this testing model, it is one of helpful circuit of development of SFCL in the future. Moreover, since it can make the consumed energy of superconductor small during fault state due to realization of high-speed switch with simple composition, the burden of superconductor is reduced compared with conventional resistive type SFCL and it is considered that the flexibility of a SFCL design increases. Cooperation with a circuit breaker was also considered, the trial calculation of a parameter and energy of operation is conducted and discussion in the case of installing the SFCL to electric power system is made.

  4. Design, Test and Demonstration of Saturable Reactor High-Temperature Superconductor Fault Current Limiters

    SciTech Connect

    Darmann, Frank; Lombaerde, Robert; Moriconi, Franco; Nelson, Albert

    2012-03-01

    Zenergy Power has successfully designed, built, tested, and installed in the US electrical grid a saturable reactor Fault Current Limiter. Beginning in 2007, first as SC Power Systems and from 2008 as Zenergy Power, Inc., ZP used DOE matching grant and ARRA funds to help refine the design of the saturated reactor fault current limiter. ZP ultimately perfected the design of the saturated reactor FCL to the point that ZP could reliably design a suitable FCL for most utility applications. Beginning with a very basic FCL design using 1G HTS for a coil housed in a LN2 cryostat for the DC bias magnet, the technology progressed to a commercial system that was offered for sale internationally. Substantial progress was made in two areas. First, the cryogenics cooling system progressed from a sub-cooled liquid nitrogen container housing the HTS coils to cryostats utilizing dry conduction cooling and reaching temperatures down to less than 20 degrees K. Large, round cryostats with warm bore diameters of 1.7 meters enabled the design of large tanks to hold the AC components. Second, the design of the AC part of the FCL was refined from a six legged spider design to a more compact and lighter design with better fault current limiting capability. Further refinement of the flux path and core shape led to an efficient saturated reactor design requiring less Ampere-turns to saturate the core. In conclusion, the development of the saturable reactor FCL led to a more efficient design not requiring HTS magnets and their associated peripheral equipment, which yielded a more economical product in line with the electric utility industry expectations. The original goal for the DOE funding of the ZP project Design, Test and Demonstration of Saturable Reactor High-Temperature Superconductor Fault Current Limiters was to stimulate the HTS wire industry with, first 1G, then 2G, HTS wire applications. Over the approximately 5 years of ZP's product development program, the amount of HTS wire

  5. Limits to global and Australian temperature change this century based on expert judgment of climate sensitivity

    NASA Astrophysics Data System (ADS)

    Grose, Michael R.; Colman, Robert; Bhend, Jonas; Moise, Aurel F.

    2016-07-01

    The projected warming of surface air temperature at the global and regional scale by the end of the century is directly related to emissions and Earth's climate sensitivity. Projections are typically produced using an ensemble of climate models such as CMIP5, however the range of climate sensitivity in models doesn't cover the entire range considered plausible by expert judgment. Of particular interest from a risk-management perspective is the lower impact outcome associated with low climate sensitivity and the low-probability, high-impact outcomes associated with the top of the range. Here we scale climate model output to the limits of expert judgment of climate sensitivity to explore these limits. This scaling indicates an expanded range of projected change for each emissions pathway, including a much higher upper bound for both the globe and Australia. We find the possibility of exceeding a warming of 2 °C since pre-industrial is projected under high emissions for every model even scaled to the lowest estimate of sensitivity, and is possible under low emissions under most estimates of sensitivity. Although these are not quantitative projections, the results may be useful to inform thinking about the limits to change until the sensitivity can be more reliably constrained, or this expanded range of possibilities can be explored in a more formal way. When viewing climate projections, accounting for these low-probability but high-impact outcomes in a risk management approach can complement the focus on the likely range of projections. They can also highlight the scale of the potential reduction in range of projections, should tight constraints on climate sensitivity be established by future research.

  6. INSTABILITY-DRIVEN LIMITS ON HELIUM TEMPERATURE ANISOTROPY IN THE SOLAR WIND: OBSERVATIONS AND LINEAR VLASOV ANALYSIS

    SciTech Connect

    Maruca, Bennett A.; Kasper, Justin C.; Gary, S. Peter

    2012-04-01

    Kinetic microinstabilities in the solar wind arise when the plasma deviates too far from thermal equilibrium. Previously published work has provided strong evidence that the cyclotron, mirror, and parallel and oblique firehose instabilities limit proton (i.e., ionized hydrogen) temperature anisotropy. However, few studies have thoroughly explored whether a less-abundant ion species can also trigger these instabilities. This study considered the possibility of similar instability-driven limits on {alpha}-particle (i.e., fully ionized helium) temperature anisotropy. Linear Vlasov analysis was used to derive the expected threshold conditions for instabilities driven by {alpha}-particle temperature anisotropy. Measurements in situ of {alpha}-particle temperature anisotropy from the Wind spacecraft's Faraday cups were found to be consistent with the limits imposed by these instability thresholds. This strongly suggests that {alpha}-particles, which only constitute {approx}5% of ions in the solar wind, can drive an instability if their temperature anisotropy becomes sufficiently extreme.

  7. Limiting the Temperatures in Naturally Ventilated Buildings in Warm Climates. Building Research Establishment Current Paper 7/74.

    ERIC Educational Resources Information Center

    Petherbridge, P.

    Formulas used in the calculation of cooling loads and indoor temperatures are employed to demonstrate the influence of various building parameters--such as thermal transmittance (U-value), solar absorptivity, and thermal storage--on the indoor thermal environment. The analysis leads to guidance on ways of limiting temperatures in naturally…

  8. Critical Analysis of Dry Storage Temperature Limits for Zircaloy-Clad Spent Nuclear Fuel Based on Diffusion Controlled Cavity Growth

    SciTech Connect

    Hayes, T.A.; Rosen, R.S.; Kassner, M.E.

    1999-12-01

    Interim dry storage of spent nuclear fuel (SNF) rods is of critical concern because a shortage of existing SNF wet storage capacity combined with delays in the availability of a permanent disposal repository has led to an increasing number of SNF rods being placed into interim dry storage. Safe interim dry storage must be maintained for a minimum of twenty years according to the Standard Review Plan for Dry Cask Storage Systems [1] and the Code of Federal Regulations, 10 CFR Part 72 [2]. Interim dry storage licensees must meet certain safety conditions when storing SNF rods to ensure that there is a ''very low probability (e.g. 0.5%) of cladding breach during long-term storage'' [1]. Commercial SNF typically consists of uranium oxide pellets surrounded by a thin cladding. The cladding is usually an {alpha}-zirconium based alloy know as ''Zircaloy''. In dry storage, the SNF rods are confined in one of several types of cask systems approved by the Nuclear Regulatory Commission (NRC). ''The cask system must be designed to prevent degradation of fuel cladding that results in a type of cladding breach, such as axial-splits or ductile fracture, where irradiated UO{sub 2} particles may be released. In addition, the fuel cladding should not degrade to the point where more than one percent of the fuel rods suffer pinhole or hairline crack type failure under normal storage conditions [1].'' The NRC has approved two models [3,4] for use by proposed dry storage licensees to determine the maximum initial temperature limit for nuclear fuel rods in dry storage that supposedly meet the above criteria and yield consistent temperature limits. Though these two models are based on the same fundamental failure theory, different assumptions have been made including the choice of values for material constants in the failure equation. This report will examine and compare the similarities and inconsistencies of these two models. It will illustrate some of the shortcomings of the current

  9. Moisture rivals temperature in limiting photosynthesis by trees establishing beyond their cold-edge range limit under ambient and warmed conditions.

    PubMed

    Moyes, Andrew B; Germino, Matthew J; Kueppers, Lara M

    2015-09-01

    Climate change is altering plant species distributions globally, and warming is expected to promote uphill shifts in mountain trees. However, at many cold-edge range limits, such as alpine treelines in the western United States, tree establishment may be colimited by low temperature and low moisture, making recruitment patterns with warming difficult to predict. We measured response functions linking carbon (C) assimilation and temperature- and moisture-related microclimatic factors for limber pine (Pinus flexilis) seedlings growing in a heating × watering experiment within and above the alpine treeline. We then extrapolated these response functions using observed microclimate conditions to estimate the net effects of warming and associated soil drying on C assimilation across an entire growing season. Moisture and temperature limitations were each estimated to reduce potential growing season C gain from a theoretical upper limit by 15-30% (c. 50% combined). Warming above current treeline conditions provided relatively little benefit to modeled net assimilation, whereas assimilation was sensitive to either wetter or drier conditions. Summer precipitation may be at least as important as temperature in constraining C gain by establishing subalpine trees at and above current alpine treelines as seasonally dry subalpine and alpine ecosystems continue to warm.

  10. A primer vector system that allows temperature dependent gene amplification and expression in mammalian cells: regulation of the influenza virus NS1 gene expression.

    PubMed

    Portela, A; Melero, J A; Martínez, C; Domingo, E; Ortín, J

    1985-11-25

    Influenza virus RNA segment 8 has been cloned into primer-vector pSLts1. This vector was designed to replicate in simian cells in a temperature dependent fashion by use of the SV40 tsA209 T-antigen gene. The oriented synthesis of cDNA on dT-tailed pSLts1 was performed on in vitro synthesized mRNA, and the second DNA strand was primed with an influenza-specific terminal oligodeoxynucleotide. Recombinant pSLVa232 contained the RNA segment 8 sequence directly fused to the SV40 late promoter contained in pSLts1, and followed by the SV40 polyadenylation signal. Expression of NS1 gene in transfected COS cells took place at a level comparable to that found in infected cells. When VERO cell cultures were transfected with recombinant pSLVa232, expression of the NS1 gene was temperature dependent. Close to one hundred fold increase in the amplification and expression of the cloned gene was observed after shift down of the transfected cells to permissive temperature. Vector pSLts1 and the cloning strategy described may be useful for the specific cloning and regulated expression of mRNAs of known 5'-terminal sequence.

  11. Exercise hyperthermia as a factor limiting physical performance - Temperature effect on muscle metabolism

    NASA Technical Reports Server (NTRS)

    Kozlowski, S.; Brzezinska, Z.; Kruk, B.; Kaciuba-Uscilko, H.; Greenleaf, J. E.

    1985-01-01

    The effect of trunk cooling on the muscle contents of ATP, ADP, AMP, creatine phosphate (CrP), and creatine, as well as of glycogen, some glycolytic intermediates, pyruvate, and lactate were assessed in 11 fasted dogs exercised at 20 C on treadmill to exhaustion. Without cooling, dogs were able to run 57 min, and their rectal (Tre) and muscle (Tm) temperatures increased to 41.8 and 43.0 C, respectively. Cooling with ice packs prolonged the ability to run by 45 percent, and resulted in lower Tre (by 1.1 C) and Tm (by 1.2 C). Depletion of muscle content of total high-energy phosphates (ATP + CrP) and glycogen, and increases in contents of AMP, pyruvate, and lactate were lower in cooled dogs than in non-cooled dogs. The muscle content of lactiate correlated positively with TM. These results indicate that hypothermia accelerates glycolysis, and shifts the equilibrium between high- and low-energy phosphates in favor of the latter. The adverse effect of hypothermia on muscle metabolism may be relevant to the limitation of endurance.

  12. Temperature-dependent innate defense against the common cold virus limits viral replication at warm temperature in mouse airway cells.

    PubMed

    Foxman, Ellen F; Storer, James A; Fitzgerald, Megan E; Wasik, Bethany R; Hou, Lin; Zhao, Hongyu; Turner, Paul E; Pyle, Anna Marie; Iwasaki, Akiko

    2015-01-20

    Most isolates of human rhinovirus, the common cold virus, replicate more robustly at the cool temperatures found in the nasal cavity (33-35 °C) than at core body temperature (37 °C). To gain insight into the mechanism of temperature-dependent growth, we compared the transcriptional response of primary mouse airway epithelial cells infected with rhinovirus at 33 °C vs. 37 °C. Mouse airway cells infected with mouse-adapted rhinovirus 1B exhibited a striking enrichment in expression of antiviral defense response genes at 37 °C relative to 33 °C, which correlated with significantly higher expression levels of type I and type III IFN genes and IFN-stimulated genes (ISGs) at 37 °C. Temperature-dependent IFN induction in response to rhinovirus was dependent on the MAVS protein, a key signaling adaptor of the RIG-I-like receptors (RLRs). Stimulation of primary airway cells with the synthetic RLR ligand poly I:C led to greater IFN induction at 37 °C relative to 33 °C at early time points poststimulation and to a sustained increase in the induction of ISGs at 37 °C relative to 33 °C. Recombinant type I IFN also stimulated more robust induction of ISGs at 37 °C than at 33 °C. Genetic deficiency of MAVS or the type I IFN receptor in infected airway cells permitted higher levels of viral replication, particularly at 37 °C, and partially rescued the temperature-dependent growth phenotype. These findings demonstrate that in mouse airway cells, rhinovirus replicates preferentially at nasal cavity temperature due, in part, to a less efficient antiviral defense response of infected cells at cool temperature.

  13. Dynamics of Kinetically Limited Strain and Threading Dislocations in Temperature- and Compositionally Graded ZnSSe/GaAs (001) Metamorphic Heterostructures

    NASA Astrophysics Data System (ADS)

    Kujofsa, Tedi; Ayers, J. E.

    2016-09-01

    We have investigated the evolution of the strain and threading dislocation density in metamorphic compositionally and temperature-graded ZnS y Se1- y buffer layers. Linear variation in composition in conjunction with temperature grading may allow control over the relaxation process. Previously, we reported the development of a general kinetic model based on dislocation flow, which accounted for the time evolution of the strain relaxation in semiconductor structures under kinetically limited conditions, including interactions of threading and misfit defects. In this work, we studied ZnS y Se1- y /GaAs (001) heterostructures with linear compositional grading and a convex-upward (type A), linear (type B) or convex-downward (type C) temperature grading profile. The thermal budget available for relaxation in these types of structures is controlled by the temperature grading profile, made up of combinations of linear ramps and constant-temperature sections. In all cases, the temperature was varied from T 0 (400°C to 600°C) at the substrate interface to T F = 300°C at the surface. We also investigated the effect of varying the compositional gradient in the range from 0.18%/ μm to 1.6%/ μm. Structures with higher average temperature (greater thermal budget) and/or higher grading coefficient exhibited greater extent of relaxation and therefore reduced residual strain. Furthermore, controlling the extent of strain relaxation enabled optimization of the dislocation densities in these heterostructures.

  14. Mixing it up in the Makassar Strait: Seasonal Reconstructions from Corals of Sea Surface Temperature and Salinity Allow for Records of Source Water Mixing in the Makassar Strait

    NASA Astrophysics Data System (ADS)

    Murty, S. A.; Goodkin, N.; Halide, H.; Natawidjaja, D. H.; Suwargadi, B. W.; Suprinhanto, I.; Prayudi, D.

    2015-12-01

    The Indonesian seas provide a maze of passages through which relatively warm and fresh water flows from the equatorial Pacific to the Indian Ocean forming the Indonesian Throughflow (ITF). As it flows, the ITF provides a transport pathway affecting heat and buoyancy fluxes throughout the region, interacting with both the Asian monsoon and the El Niño Southern Oscillation (ENSO). The present and past behavior of the ITF is therefore one of the keys to understanding regional and global climate variability. Past ITF behavior has been previously recorded in massive coral colonies, which serve as continuous, high-resolution climate archives because of their high linear extension rates and annual banding pattern. Here we present Sr/Ca-SST and δ18O-SSS calibrations from three Porites spp. coral colonies located in the southern Makassar Strait, through which roughly 75-80% of all ITF waters flow. At interannual timescales, we find that in all three corals Sr/Ca significantly (all p-values<0.05) correlates with sea surface temperature (SST) during the SE monsoon from July to September, while δ18O is correlated with sea surface salinity (SSS) during the NW monsoon from December to March (all p-values<0.05). HADI SST and SODA SSS instrumental temperature-salinity diagrams from our coral sites indicate that the southern Makassar Strait is a region of surface seawater mixing between end member water masses of the ITF during the SE monsoon. During the NW monsoon, however, end members of the South China Sea Throughflow (SCSTF) instead mix in the surface waters. The strength of our interannual calibrations suggests that it may be possible to reconstruct the ITF and SCSTF surface mixing patterns during their respective monsoon seasons. To preliminarily assess this, we present 150-year seasonally resolved records of Sr/Ca and δ18O to reconstruct surface water mixing in the southern Makassar Strait.

  15. Characterization of Tensile Properties, Limiting Strains, and Deep Drawing Behavior of AA5754-H22 Sheet at Elevated Temperature

    NASA Astrophysics Data System (ADS)

    Panicker, Sudhy S.; Singh, Har Govind; Panda, Sushanta Kumar; Dashwood, Richard

    2015-11-01

    Automotive industries are very much interested in characterization of formability improvement of aluminum alloys at elevated temperatures before designing tools, heating systems, and processing sequences for fabrication of auto-body panels by warm forming technology. In this study, tensile tests of AA5754-H22 aluminum alloy were carried out at five different temperatures and three different strain rates to investigate the deformation behavior correlating with Cowper-Symonds constitutive equation. Laboratory scale warm forming facilities were designed and fabricated to perform limiting dome height and deep drawing tests to evaluate forming limit strains and drawability of sheet metal at different tool temperatures. The forming limit strain and dome height improved significantly when both the die and punch were heated to 200 °C. Remarkable improvement in deep drawn cup depth was observed when die and punch temperatures were maintained at 200 and 30 °C, respectively, producing a non-isothermal temperature gradient of approximately 93 °C across the blank from flange to center. The forming behavior at different isothermal and non-isothermal conditions were predicted successfully using a thermo-mechanical FE model incorporating temperature-dependent properties in Barlat-89 yield criterion coupled with Cowper-Symonds hardening model, and the thinning/failure location in deformed cups were validated implementing the experimental limiting strains as damage model.

  16. A semi-classical approach of the relationship between simple cells' size and their living temperature limits based on number fluctuations of water coherence domains

    NASA Astrophysics Data System (ADS)

    Preoteasa, E. A.; Negoita, C.

    2011-12-01

    Starting from the concepts of the quantum electrodynamics (QED) theory of coherence domains (CD) in water we propose a model aimed to evaluate the relationship between the size and the living temperature limits for simple, small cells. Cells are described as spherical potential wells with impenetrable walls, with CDs moving inside. The radius of the spherical potential well was estimated for physiological temperatures and the results match to bacteria and yeasts cells' size. As a CD in the spherical cell exerts a force upon the membrane, a 'gas' formed by CDs bears a pressure on the walls. A classical statistical stability condition relates this pressure to cell volume and to the relative fluctuations of the CD number, allowing the evaluation of an upper temperature limit as a function of cellular volume. Assuming further that the CDs in the living cell form together a coherent state, the number-phase incertitude relationship (Heisenberg limit) applies. The maximum coherence between CDs is found in the ground state, a picture consistent also to Fröhlich's postulate. For a given phase dispersion, a lower temperature limit as a function of the cell volume is found. Although we neglected the rod-like shape of certain bacteria and the presence of nucleus in yeasts, the biological data of volume and optimal living temperature intervals fit well to our model's predictions. Moreover the larger the cell volume, the higher are the number of CDs and the coherence of their system. In addition we suggest a new classification criterion for small cells based on model's parameters, which show discontinuities between Gram negative and positive microorganisms as well as between prokaryotes and the smallest eukaryotes.

  17. Temperature of Mercury's plasma electron environment: limits from the first MESSENGER flyby

    NASA Astrophysics Data System (ADS)

    McNutt, Ralph L., Jr.; Zurbuchen, Thomas H.; Raines, Jim M.; Gloeckler, George; Krimigis, Stamatios M.; Anderson, Brian J.; Slavin, James A.; Koehn, Patrick L.; Killen, Rosemary M.; Solomon, Sean C.

    2008-09-01

    Introduction The Fast Imaging Plasma Spectrometer (FIPS) component of the Energetic Particle and Plasma Spectrometer (EPPS) [1] on the MESSENGER spacecraft has provided evidence of a multi-species magnetospheric plasma at Mercury [2]. In addition, relatively low values of mass-per-charge in the compositional spectrogram are indicative of multiple ionizations of some species, in turn, a feature diagnostic of relatively high electron temperatures. While there is no means of directly assessing how closely the conditions of local thermodynamic equilibrium (LTE) apply, testing this assumption for consistency with the measured data can potentially help advance our understanding of both the composition and temperature of this plasma. Poor particle statistics (low counting rates) necessitated the summing of data over the entire magnetospheric pass to provide a statistically significant mass-per-charge spectrum. Hence, we make the ab initio assumption that time-aliasing is not an issue, i.e., the ionic composition of the magnetosphere is approximately constant along the spacecraft trajectory. Such multicomponent plasmas, with multiply charged but kinetically cold ions, are well known in Jupiter's magnetosphere, with their compositional origins at Io and their (multiple) charge states resulting from the electrons in the hot, Io plasma torus [3,4,5]. Observations FIPS provides both energy-per-charge and velocity measurements, allowing for the mass per charge of detected components to be determined. Within Mercury's magnetosphere, ions in the mass/charge range 1-56 amu/e were detected with a time resolution of 8 s and within an energy range 0.1-13.5 keV/e. An overview of the data and compositional inferences from the signals corresponding to singly ionized species have already been discussed [2]. The multiply charged ions (mass-per-charge ~12 amu/e and less) are likely the result of impact ionization by hot electrons in the magnetosphere, most likely from the plasma sheet

  18. Large reptiles and cold temperatures: Do extreme cold spells set distributional limits for tropical reptiles in Florida?

    USGS Publications Warehouse

    Mazzotti, Frank J.; Cherkiss, Michael S.; Parry, Mark; Beauchamp, Jeff; Rochford, Mike; Smith, Brian J.; Hart, Kristen M.; Brandt, Laura A.

    2016-01-01

    Distributional limits of many tropical species in Florida are ultimately determined by tolerance to low temperature. An unprecedented cold spell during 2–11 January 2010, in South Florida provided an opportunity to compare the responses of tropical American crocodiles with warm-temperate American alligators and to compare the responses of nonnative Burmese pythons with native warm-temperate snakes exposed to prolonged cold temperatures. After the January 2010 cold spell, a record number of American crocodiles (n = 151) and Burmese pythons (n = 36) were found dead. In contrast, no American alligators and no native snakes were found dead. American alligators and American crocodiles behaved differently during the cold spell. American alligators stopped basking and retreated to warmer water. American crocodiles apparently continued to bask during extreme cold temperatures resulting in lethal body temperatures. The mortality of Burmese pythons compared to the absence of mortality for native snakes suggests that the current population of Burmese pythons in the Everglades is less tolerant of cold temperatures than native snakes. Burmese pythons introduced from other parts of their native range may be more tolerant of cold temperatures. We documented the direct effects of cold temperatures on crocodiles and pythons; however, evidence of long-term effects of cold temperature on their populations within their established ranges remains lacking. Mortality of crocodiles and pythons outside of their current established range may be more important in setting distributional limits.

  19. A laboratory validation study of comfort and limit temperatures of four sleeping bags defined according to EN 13537 (2002).

    PubMed

    Lin, Li-Yen; Wang, Faming; Kuklane, Kalev; Gao, Chuansi; Holmér, Ingvar; Zhao, Mengmeng

    2013-03-01

    In this study, we validated comfort and limit temperatures of four sleeping bags with different levels of insulation defined according to EN 13537. Six male subjects and four female subjects underwent totally 20 two-hour exposures in four sleeping bags at four intended testing temperatures: 11.2, 3.8, 2.1 and -9.0 °C. The subjective perceptions and physiological responses of these subjects were reported and analyzed. It was found that the EN 13537 defined comfort temperature and limit temperature were underestimated for sleeping bags MA3, HAG and MAM. The predictions are so conservative that further revision may be required to meet the requirements of both manufacturers and consumers. In contrast, for the sleeping bag MA0 with a low level of insulation, the limit temperature defined by EN 13537 was slightly overestimated. In addition, two individual case studies (-28.0 and -32.0 °C) demonstrated that low toe temperatures were widely observed among the male and female subjects, although the mean skin temperatures were almost within the thermoneutrality range (32.0-34.0 °C). It seems that the IREQ model (ISO 11079) overestimated both the comfort and limit temperatures of the sleeping bags. Finally, traditional sleeping bags may be required to be re-designed to provide consumers both whole body comfort as well as local thermal comfort at feet/toes or users need to be made aware of the higher need for their insulation.

  20. High-temperature tolerance in anhydrobiotic tardigrades is limited by glass transition.

    PubMed

    Hengherr, S; Worland, M R; Reuner, A; Brümmer, F; Schill, R O

    2009-01-01

    Survival in microhabitats that experience extreme fluctuations in water availability and temperature requires special adaptations. To withstand such environmental conditions, tardigrades, as well as some nematodes and rotifers, enter a completely desiccated state known as anhydrobiosis. We examined the effects of high temperatures on fully desiccated (anhydrobiotic) tardigrades. Nine species from the classes Heterotardigrada and Eutardigrada were exposed to temperatures of up to 110 degrees C for 1 h. Exposure to temperatures of up to 80 degrees C resulted in a moderate decrease in survival. Exposure to temperatures above this resulted in a sharp decrease in survival, with no animals of the families Macrobiotidae and Echiniscidae surviving 100 degrees C. However, Milnesium tardigradum (Milnesidae) showed survival of >90% after exposure to 100 degrees C; temperatures above this resulted in a steep decrease in survival. Vitrification is assumed to play a major role in the survival of anhydrobiotic organisms during exposure to extreme temperatures, and consequently, the glass-transition temperature (T(g)) is critical to high-temperature tolerance. In this study, we provide the first evidence of the presence of a glass transition during heating in an anhydrobiotic tardigrade through the use of differential scanning calorimetry.

  1. Fundamental limitations of noninvasive temperature imaging by means of ultrasound echo strain estimation.

    PubMed

    Miller, Naomi R; Bamber, Jeffrey C; Meaney, Paul M

    2002-10-01

    Ultrasonic estimation of temperature-induced echo strain has been suggested as a means of predicting the location of thermal lesions formed by focused ultrasound (US) surgery before treatment. Preliminary investigations of this technique have produced optimistic results because they were carried out with rubber phantoms and used room temperature, rather than body temperature, as the baseline. The objective of the present study was to determine, through modelling, the likely feasibility of using ultrasonic temperature imaging to detect and localise the focal region of the heating beam for a medium with a realistic temperature-dependence of sound speed subjected to a realistic temperature rise. We determined the minimum ultrasonic signal-to-noise ratio (SNR) required to visualise the heated region for liver of varying fat content. Due to the small (0.5%) change in sound speed at the focus, the threshold SNR for normal liver (low fat content) was found to be at least 20 dB. This implies that temperature imaging in this tissue type will only be feasible if the effects of electronic noise can be minimised and if other sources of noise, such as cardiac-induced motion, do not substantially reduce the visibility of the focal region. For liver of intermediate fat content, the heated region could not be visualised even when the echo data were noise-free. Tissues with a very high fat content are likely to represent the most favourable conditions for ultrasonic temperature imaging. PMID:12467859

  2. Fundamental limitations of noninvasive temperature imaging by means of ultrasound echo strain estimation.

    PubMed

    Miller, Naomi R; Bamber, Jeffrey C; Meaney, Paul M

    2002-10-01

    Ultrasonic estimation of temperature-induced echo strain has been suggested as a means of predicting the location of thermal lesions formed by focused ultrasound (US) surgery before treatment. Preliminary investigations of this technique have produced optimistic results because they were carried out with rubber phantoms and used room temperature, rather than body temperature, as the baseline. The objective of the present study was to determine, through modelling, the likely feasibility of using ultrasonic temperature imaging to detect and localise the focal region of the heating beam for a medium with a realistic temperature-dependence of sound speed subjected to a realistic temperature rise. We determined the minimum ultrasonic signal-to-noise ratio (SNR) required to visualise the heated region for liver of varying fat content. Due to the small (0.5%) change in sound speed at the focus, the threshold SNR for normal liver (low fat content) was found to be at least 20 dB. This implies that temperature imaging in this tissue type will only be feasible if the effects of electronic noise can be minimised and if other sources of noise, such as cardiac-induced motion, do not substantially reduce the visibility of the focal region. For liver of intermediate fat content, the heated region could not be visualised even when the echo data were noise-free. Tissues with a very high fat content are likely to represent the most favourable conditions for ultrasonic temperature imaging.

  3. A simple temperature-based model predicts the upper latitudinal limit of the temperate coral Astrangia poculata

    NASA Astrophysics Data System (ADS)

    Dimond, J. L.; Kerwin, A. H.; Rotjan, R.; Sharp, K.; Stewart, F. J.; Thornhill, D. J.

    2013-06-01

    A few hardy ahermatypic scleractinian corals occur in shallow waters well outside of the tropics, but little is known concerning their distribution limits at high latitudes. Using field data on the growth of Astrangia poculata over an annual period near its northern range limit in Rhode Island, USA, we tested the hypothesis that the distribution of this coral is limited by low temperature. A simple model based on satellite sea surface temperature and field growth data at monthly temporal resolution was used to estimate annual net coral growth north and south of the known range limit of A. poculata. Annual net coral growth was the result of new polyp budding above ~10 °C minus polyp loss below ~10 °C, which is caused by a state of torpor that leads to overgrowth by encroaching and settling organisms. The model accurately predicted A. poculata's range limit around Cape Cod, Massachusetts, predicting no net growth northward as a result of corals' inability to counteract polyp loss during winter with sufficient polyp budding during summer. The model also indicated that the range limit of A. poculata coincides with a decline in the benefit of associating with symbiotic dinoflagellates ( Symbiodinium B2/ S. psygmophilum), suggesting that symbiosis may become a liability under colder temperatures. While we cannot exclude the potential role of other coral life history traits or environmental factors in setting A. poculata's northern range limit, our analysis suggests that low temperature constrains the growth and persistence of adult corals and would preclude coral growth northward of Cape Cod.

  4. Simulated Seasonal Photoperiods and Fluctuating Temperatures Have Limited Effects on Blood Feeding and Life History in Aedes triseriatus (Diptera: Culicidae).

    PubMed

    Westby, K M; Juliano, S A

    2015-09-01

    Biotic and abiotic factors change seasonally and impact life history in temperate-zone ectotherms. Temperature and photoperiod are factors that change in predictable ways. Most studies testing for effects of temperature on vectors use constant temperatures and ignore potential correlated effects of photoperiod. In two experiments, we tested for effects of larval rearing environments creating ecologically relevant temperatures and photoperiods simulating early and late season conditions (June and August), or constant temperatures (cool and warm) with the June or August photoperiods, respectively. We determined effects on survivorship, development, size, and a composite performance index in a temperate-zone population of Aedes triseriatus (Say). We followed cohorts of resulting females, all held under the same environmental conditions, to assess carry-over effects of rearing conditions for larvae on longevity, blood feeding, and egg production. Larval survivorship was affected by treatment in one experiment. Development time was greater in the June and cool treatments, but the constant and fluctuating temperatures did not differ. Significantly larger mosquitoes were produced in fluctuating versus constant temperature treatments. There were no significant treatment effects on the composite performance index. Adult female longevity was lower after rearing at constant versus fluctuating temperature, but there was no difference between June and August, nor did size affect longevity. There was no effect of treatments on blood feeding and a limited effect on egg production. We conclude that seasonal temperatures and photoperiods during development have limited effects on this population of A. triseriatus and find little evidence of strong effects of fluctuating versus constant temperatures.

  5. Simulated Seasonal Photoperiods and Fluctuating Temperatures Have Limited Effects on Blood Feeding and Life History in Aedes triseriatus (Diptera: Culicidae).

    PubMed

    Westby, K M; Juliano, S A

    2015-09-01

    Biotic and abiotic factors change seasonally and impact life history in temperate-zone ectotherms. Temperature and photoperiod are factors that change in predictable ways. Most studies testing for effects of temperature on vectors use constant temperatures and ignore potential correlated effects of photoperiod. In two experiments, we tested for effects of larval rearing environments creating ecologically relevant temperatures and photoperiods simulating early and late season conditions (June and August), or constant temperatures (cool and warm) with the June or August photoperiods, respectively. We determined effects on survivorship, development, size, and a composite performance index in a temperate-zone population of Aedes triseriatus (Say). We followed cohorts of resulting females, all held under the same environmental conditions, to assess carry-over effects of rearing conditions for larvae on longevity, blood feeding, and egg production. Larval survivorship was affected by treatment in one experiment. Development time was greater in the June and cool treatments, but the constant and fluctuating temperatures did not differ. Significantly larger mosquitoes were produced in fluctuating versus constant temperature treatments. There were no significant treatment effects on the composite performance index. Adult female longevity was lower after rearing at constant versus fluctuating temperature, but there was no difference between June and August, nor did size affect longevity. There was no effect of treatments on blood feeding and a limited effect on egg production. We conclude that seasonal temperatures and photoperiods during development have limited effects on this population of A. triseriatus and find little evidence of strong effects of fluctuating versus constant temperatures. PMID:26336255

  6. Simulated Seasonal Photoperiods and Fluctuating Temperatures Have Limited Effects on Blood Feeding and Life History in Aedes triseriatus (Diptera: Culicidae)

    PubMed Central

    Westby, K. M.

    2015-01-01

    Biotic and abiotic factors change seasonally and impact life history in temperate-zone ectotherms. Temperature and photoperiod are factors that change in predictable ways. Most studies testing for effects of temperature on vectors use constant temperatures and ignore potential correlated effects of photoperiod. In two experiments, we tested for effects of larval rearing environments creating ecologically relevant temperatures and photoperiods simulating early and late season conditions (June and August), or constant temperatures (cool and warm) with the June or August photoperiods, respectively. We determined effects on survivorship, development, size, and a composite performance index in a temperate-zone population of Aedes triseriatus (Say). We followed cohorts of resulting females, all held under the same environmental conditions, to assess carry-over effects of rearing conditions for larvae on longevity, blood feeding, and egg production. Larval survivorship was affected by treatment in one experiment. Development time was greater in the June and cool treatments, but the constant and fluctuating temperatures did not differ. Significantly larger mosquitoes were produced in fluctuating versus constant temperature treatments. There were no significant treatment effects on the composite performance index. Adult female longevity was lower after rearing at constant versus fluctuating temperature, but there was no difference between June and August, nor did size affect longevity. There was no effect of treatments on blood feeding and a limited effect on egg production. We conclude that seasonal temperatures and photoperiods during development have limited effects on this population of A. triseriatus and find little evidence of strong effects of fluctuating versus constant temperatures. PMID:26336255

  7. Plasticity of protective mechanisms only partially explains interactive effects of temperature and UVR on upper thermal limits.

    PubMed

    Kern, Pippa; Cramp, Rebecca L; Seebacher, Frank; Ghanizadeh Kazerouni, Ensiyeh; Franklin, Craig E

    2015-12-01

    Temperature and ultraviolet radiation (UVR) are key environmental drivers that are linked in their effects on cellular damage. Exposure to both high temperatures and UVR can cause cellular damage that result in the up-regulation of common protective mechanisms, such as the induction of heat shock proteins (Hsps) and antioxidants. As such, the interactive effects of these stressors at the cellular level may determine physiological limits, such as thermal tolerance. Furthermore, antioxidant activity is often thermally sensitive, which may lead to temperature dependent effects of UVR exposure. Here we examined the interactive effects of temperature and UVR on upper thermal limits, Hsp70 abundance, oxidative damage and antioxidant (catalase) activity. We exposed Limnodynastes peronii tadpoles to one of three temperature treatments (constant 18°C, constant 28°C and daily fluctuations between 18 and 28°C) in the presence or absence of UVR. Tadpoles were tested for upper thermal limits (CTmax), induction of Hsp70, oxidative damage and catalase activity. Our results show that CTmax was influenced by an interactive effect between temperature and UVR treatment. For tadpoles kept in cold temperatures, exposure to UVR led to cross-tolerance to high temperatures, increasing CTmax. Plasticity in this trait was not fully explained by changes in the lower level mechanistic traits examined. These results highlight the difficulty in predicting the mechanistic basis for the interactive effects of multiple stressors on whole animal traits. Multifactorial studies may therefore be required to understand how complex mechanistic processes shape physiological tolerances, and determine responses to environmental variation. PMID:26408107

  8. In Situ Thermal Ion Temperature Measurements in the E Region Ionosphere: Techniques, Results, and Limitations

    NASA Astrophysics Data System (ADS)

    Burchill, J. K.; Archer, W. E.; Clemmons, J. H.; Knudsen, D. J.; Nicolls, M. J.

    2011-12-01

    In situ measurements of thermal ion temperature are rare at E region altitudes, which are too low for satellites. Here we present ion temperature measurements from a Thermal Ion Imager (TII) that flew on NASA sounding rocket 36.234 (the "Joule-2" mission) into the nightside E region ionosphere on 19 January 2007 from Poker Flat, AK. The TII is an electrostatic ion energy/angle imager that provides 2D ion distributions at 8 ms resolution. Ion temperatures are derived at altitudes between 100 km and 190 km by modelling the detector total count rate versus ion bulk flow angle with respect to the plane of the imager's field of view. Modelling this count rate spin profile shows that the analysis technique is robust against a number of error sources, including variability in payload floating potential, ion upflow, and aperture widening due to reflections from electrode surfaces. A significant uncertainty is associated with the average mass of the ions, which is not measured independently. Using the International Reference Ionosphere model to estimate ion mass, we obtain an ion temperature of 1300 K at 125 km, increasing to more than 3000 K at 180 km. These temperatures are much larger than neutral temperatures obtained from an ionization gauge on the same rocket (Tn˜500 K at 125 km, ˜600 K at 180 km), and do not agree with incoherent scatter radar observations in the vicinity of the rocket. These anomalous ion temperatures are, however, consistent with results from an independent analysis of the shape of the ion distribution images from a similar instrument on a separate payload flown 10 minutes earlier [Archer, MSc Thesis, University of Calgary, 2009]. We conclude that the high ion temperature readings are an artifact related to the environment in the vicinity of the probe, and investigate mechanisms for the cause. We discuss the implications of this effect for future in situ attempts to measure ion temperature in the E region ionosphere.

  9. Growth Rate of Escherichia coli at Elevated Temperatures: Limitation by Methionine

    PubMed Central

    Ron, Eliora Z.; Davis, Bernard D.

    1971-01-01

    When Escherichia coli growing in minimal medium is shifted from 37 C to any temperature in the range 40 to 45 C, the growth rate immediately assumes a new, lower value, characteristic of that temperature. The decrease is shown to be due, in several strains, to decreased activity of the first enzyme of the methionine pathway, homoserine trans-succinylase, which thus appears to be more heat-sensitive than any other essential enzyme in the cell. This sensitivity does not involve progressive denaturation of the enzyme; rather, the response to a shift of temperature, in either direction, is immediate and reversible. PMID:4939758

  10. Remarks on thermoelastic effects at low temperatures and quantum limits in displacement measurements

    SciTech Connect

    Somiya, Kentaro; Kokeyama, Keiko; Nawrodt, Ronny

    2010-12-15

    The noise level of thermoelastic fluctuations of a mirror at low temperature was derived and introduced by M. Cerdonio et al.[Phys. Rev. D 63, 082003 (2001)]. The importance of the paper has become remarkable according to the increasing attention to the low-temperature high-precision measurement device. Here we would like to introduce the analytical form of their equation of thermoelastic noise in the integral form in order to reduce the computational labor.

  11. Effects of Upper-Limit Water Temperatures on the Dispersal of the Asian Clam Corbicula fluminea

    PubMed Central

    Rosa, Inês Correia; Pereira, Joana Luísa; Costa, Raquel; Gonçalves, Fernando; Prezant, Robert

    2012-01-01

    Temperature is a determinant environmental variable in metabolic rates of organisms ultimately influencing important physiological and behavioural features. Stressful conditions such as increasing temperature, particularly within high ranges occurring in the summer, have been suggested to induce flotation behaviour in Corbicula fluminea which may be important in dispersal of this invasive species. However, there has been no experimental evidence supporting this hypothesis. It was already proven that C. fluminea drift is supported by a mucilaginous drogue line produced by mucocytes present in the ctenidia. Detailed microscopic examination of changes in these cells and quantification of clam flotation following one, two and three weeks of exposure to 22, 25 and 30°C was carried out so that the effects of increasing water temperatures in dispersal patterns could be discussed. Results show that changes in temperature triggered an acceleration of the mucocytes production and stimulated flotation behaviour, especially following one week of exposure. Dilution of these effects occurred following longer exposure periods. It is possible that these bivalves perceive changing temperature as a stress and respond accordingly in the short-term, and then acclimate to the new environmental conditions. The response patterns suggest that increasing water temperatures could stimulate C. fluminea population expansion. PMID:23056377

  12. Surface temperatures and glassy state investigations in tribology, part 3. [limiting shear stress rheological model

    NASA Technical Reports Server (NTRS)

    Bair, S.; Winer, W. O.

    1980-01-01

    Research related to the development of the limiting shear stress rheological model is reported. Techniques were developed for subjecting lubricants to isothermal compression in order to obtain relevant determinations of the limiting shear stress and elastic shear modulus. The isothermal compression limiting shear stress was found to predict very well the maximum traction for a given lubricant. Small amounts of side slip and twist incorporated in the model were shown to have great influence on the rising portion of the traction curve at low slide-roll ratio. The shear rheological model was also applied to a Grubin-like elastohydrodynamic inlet analysis for predicting film thicknesses when employing the limiting shear stress model material behavior.

  13. Limitations of predicting in vivo biostability of multiphase polyurethane elastomers using temperature-accelerated degradation testing.

    PubMed

    Padsalgikar, Ajay; Cosgriff-Hernandez, Elizabeth; Gallagher, Genevieve; Touchet, Tyler; Iacob, Ciprian; Mellin, Lisa; Norlin-Weissenrieder, Anna; Runt, James

    2015-01-01

    Polyurethane biostability has been the subject of intense research since the failure of polyether polyurethane pacemaker leads in the 1980s. Accelerated in vitro testing has been used to isolate degradation mechanisms and predict clinical performance of biomaterials. However, validation that in vitro methods reproduce in vivo degradation is critical to the selection of appropriate tests. High temperature has been proposed as a method to accelerate degradation. However, correlation of such data to in vivo performance is poor for polyurethanes due to the impact of temperature on microstructure. In this study, we characterize the lack of correlation between hydrolytic degradation predicted using a high temperature aging model of a polydimethylsiloxane-based polyurethane and its in vivo performance. Most notably, the predicted molecular weight and tensile property changes from the accelerated aging study did not correlate with clinical explants subjected to human biological stresses in real time through 5 years. Further, DMTA, ATR-FTIR, and SAXS experiments on samples aged for 2 weeks in PBS indicated greater phase separation in samples aged at 85°C compared to those aged at 37°C and unaged controls. These results confirm that microstructural changes occur at high temperatures that do not occur at in vivo temperatures. In addition, water absorption studies demonstrated that water saturation levels increased significantly with temperature. This study highlights that the multiphase morphology of polyurethane precludes the use of temperature accelerated biodegradation for the prediction of clinical performance and provides critical information in designing appropriate in vitro tests for this class of materials.

  14. Limits to the thermal tolerance of corals adapted to a highly fluctuating, naturally extreme temperature environment

    PubMed Central

    Schoepf, Verena; Stat, Michael; Falter, James L.; McCulloch, Malcolm T.

    2015-01-01

    Naturally extreme temperature environments can provide important insights into the processes underlying coral thermal tolerance. We determined the bleaching resistance of Acropora aspera and Dipsastraea sp. from both intertidal and subtidal environments of the naturally extreme Kimberley region in northwest Australia. Here tides of up to 10 m can cause aerial exposure of corals and temperatures as high as 37 °C that fluctuate daily by up to 7 °C. Control corals were maintained at ambient nearshore temperatures which varied diurnally by 4-5 °C, while treatment corals were exposed to similar diurnal variations and heat stress corresponding to ~20 degree heating days. All corals hosted Symbiodinium clade C independent of treatment or origin. Detailed physiological measurements showed that these corals were nevertheless highly sensitive to daily average temperatures exceeding their maximum monthly mean of ~31 °C by 1 °C for only a few days. Generally, Acropora was much more susceptible to bleaching than Dipsastraea and experienced up to 75% mortality, whereas all Dipsastraea survived. Furthermore, subtidal corals, which originated from a more thermally stable environment compared to intertidal corals, were more susceptible to bleaching. This demonstrates that while highly fluctuating temperatures enhance coral resilience to thermal stress, they do not provide immunity to extreme heat stress events. PMID:26627576

  15. Limits to the thermal tolerance of corals adapted to a highly fluctuating, naturally extreme temperature environment

    NASA Astrophysics Data System (ADS)

    Schoepf, Verena; Stat, Michael; Falter, James L.; McCulloch, Malcolm T.

    2015-12-01

    Naturally extreme temperature environments can provide important insights into the processes underlying coral thermal tolerance. We determined the bleaching resistance of Acropora aspera and Dipsastraea sp. from both intertidal and subtidal environments of the naturally extreme Kimberley region in northwest Australia. Here tides of up to 10 m can cause aerial exposure of corals and temperatures as high as 37 °C that fluctuate daily by up to 7 °C. Control corals were maintained at ambient nearshore temperatures which varied diurnally by 4-5 °C, while treatment corals were exposed to similar diurnal variations and heat stress corresponding to ~20 degree heating days. All corals hosted Symbiodinium clade C independent of treatment or origin. Detailed physiological measurements showed that these corals were nevertheless highly sensitive to daily average temperatures exceeding their maximum monthly mean of ~31 °C by 1 °C for only a few days. Generally, Acropora was much more susceptible to bleaching than Dipsastraea and experienced up to 75% mortality, whereas all Dipsastraea survived. Furthermore, subtidal corals, which originated from a more thermally stable environment compared to intertidal corals, were more susceptible to bleaching. This demonstrates that while highly fluctuating temperatures enhance coral resilience to thermal stress, they do not provide immunity to extreme heat stress events.

  16. Limits to the thermal tolerance of corals adapted to a highly fluctuating, naturally extreme temperature environment.

    PubMed

    Schoepf, Verena; Stat, Michael; Falter, James L; McCulloch, Malcolm T

    2015-01-01

    Naturally extreme temperature environments can provide important insights into the processes underlying coral thermal tolerance. We determined the bleaching resistance of Acropora aspera and Dipsastraea sp. from both intertidal and subtidal environments of the naturally extreme Kimberley region in northwest Australia. Here tides of up to 10 m can cause aerial exposure of corals and temperatures as high as 37 °C that fluctuate daily by up to 7 °C. Control corals were maintained at ambient nearshore temperatures which varied diurnally by 4-5 °C, while treatment corals were exposed to similar diurnal variations and heat stress corresponding to ~20 degree heating days. All corals hosted Symbiodinium clade C independent of treatment or origin. Detailed physiological measurements showed that these corals were nevertheless highly sensitive to daily average temperatures exceeding their maximum monthly mean of ~31 °C by 1 °C for only a few days. Generally, Acropora was much more susceptible to bleaching than Dipsastraea and experienced up to 75% mortality, whereas all Dipsastraea survived. Furthermore, subtidal corals, which originated from a more thermally stable environment compared to intertidal corals, were more susceptible to bleaching. This demonstrates that while highly fluctuating temperatures enhance coral resilience to thermal stress, they do not provide immunity to extreme heat stress events. PMID:26627576

  17. Further efforts to limit lunar internal temperatures from electrical conductivity determinations

    NASA Technical Reports Server (NTRS)

    Hood, L. L.; Herbert, F.; Sonett, C. P.

    1982-01-01

    A representative set of 18 electrical conductivity profiles consistent with lunar transfer function data in the 0.00001 to 0.001 Hz range is generated by means of a Monte Carlo procedure. Laboratory electrical conductivity vs temperature data extrapolated to lower and higher temperatures are used to convert the 18 profiles into temperature profiles for a series of radially homogeneous olivine-pyroxene mixtures ranging from 100% olivine to 100% aluminous orthopyroxene. The former yields selenotherms approaching the Ringwood-Essene solidus at depths near 500 km, while additions of the latter in concentrations greater than 15-30 vol% leads to cooler selenotherms which approach the solidus only at depths greater than about 1000 km. On the basis of independent geophysical constraints, the profile envelopes for compositions containing more than 15-30 vol% aluminous orthopyroxene are considered to be the most probable.

  18. Accuracy limitations on Brillouin lidar measurements of temperature and sound speed in the ocean.

    PubMed

    Fry, E S; Emery, Y; Quan, X; Katz, J W

    1997-09-20

    There are five mutually dependent variables relevant to Brillouin lidar measurements of temperature and sound speed in the ocean; they are (1) the Brillouin shift, (2) the sound speed, (3) the index of refraction, (4) the temperature, and (5) the salinity. We use three well-known relations to analyze rigorously the interdependence of these five variables. Clearly, a Brillouin shift measurement does not provide a stand-alone determination of temperature or sound speed; one more variable or one more relation must be known. The use of mean values of salinity that have been obtained by an analysis of a large set of historical in situ data is considered for this additional relation. PMID:18259560

  19. Complex terrain alters temperature and moisture limitations of forest soil respiration across a semiarid to subalpine gradient

    USGS Publications Warehouse

    Berryman, Erin Michele; Barnard, H.R.; Adams, H.R.; Burns, M.A.; Gallo, E.; Brooks, P.D.

    2015-01-01

    Forest soil respiration is a major carbon (C) flux that is characterized by significant variability in space and time. We quantified growing season soil respiration during both a drought year and a nondrought year across a complex landscape to identify how landscape and climate interact to control soil respiration. We asked the following questions: (1) How does soil respiration vary across the catchments due to terrain-induced variability in moisture availability and temperature? (2) Does the relative importance of moisture versus temperature limitation of respiration vary across space and time? And (3) what terrain elements are important for dictating the pattern of soil respiration and its controls? Moisture superseded temperature in explaining watershed respiration patterns, with wetter yet cooler areas higher up and on north facing slopes yielding greater soil respiration than lower and south facing areas. Wetter subalpine forests had reduced moisture limitation in favor of greater seasonal temperature limitation, and the reverse was true for low-elevation semiarid forests. Coincident climate poorly predicted soil respiration in the montane transition zone; however, antecedent precipitation from the prior 10 days provided additional explanatory power. A seasonal trend in respiration remained after accounting for microclimate effects, suggesting that local climate alone may not adequately predict seasonal variability in soil respiration in montane forests. Soil respiration climate controls were more strongly related to topography during the drought year highlighting the importance of landscape complexity in ecosystem response to drought.

  20. Effect of temperature on leg kinematics in sprinting tarantulas (Aphonopelma hentzi): high speed may limit hydraulic joint actuation

    PubMed Central

    Booster, N. A.; Su, F. Y.; Adolph, S. C.; Ahn, A. N.

    2015-01-01

    ABSTRACT Tarantulas extend the femur–patella (proximal) and tibia–metatarsal (distal) joints of their legs hydraulically. Because these two hydraulically actuated joints are positioned in series, hemolymph flow within each leg is expected to mechanically couple the movement of the joints. In the current study, we tested two hypotheses: (1) at lower temperatures, movement of the two in-series hydraulic joints within a leg will be less coupled because of increased hemolymph viscosity slowing hemolymph flow; and (2) at higher temperatures, movement of the two in-series hydraulic joints will be less coupled because the higher stride frequencies limit the time available for hemolymph flow. We elicited maximal running speeds at four ecologically relevant temperatures (15, 24, 31 and 40°C) in Texas Brown tarantulas (Aphonopelma hentzi). The spiders increased sprint speed 2.5-fold over the temperature range by changing their stride frequency but not stride length. The coefficient of determination for linear regression (R2) of the proximal and distal joint angles was used as the measure of the degree of coupling between the two joints. This coupling coefficient between the proximal and distal joint angles, for both forelegs and hind­legs, was significantly lowest at the highest temperature at which the animals ran the fastest with the highest stride frequencies. The coordination of multiple, in-series hydraulically actuated joints may be limited by operating speed. PMID:25833132

  1. Limited Capacity for Faster Digestion in Larval Coral Reef Fish at an Elevated Temperature

    PubMed Central

    Clark, Timothy D.

    2016-01-01

    The prevalence of extreme, short-term temperature spikes in coastal regions during summer months is predicted to increase with ongoing climate change. In tropical systems, these changes are predicted to increase the metabolic demand of coral reef fish larvae while also altering the plankton communities upon which the larvae feed during their pelagic phase. The consequences of these predictions remain speculative in the absence of empirical data on the interactive effects of warm temperatures on the metabolism, postprandial processes and growth responses of coral reef fish larvae. Here, we tested the effect of increased temperature on the metabolism, postprandial performance and fine-scale growth patterns of a coral reef fish (Amphiprion percula) in the latter half of its ~11-d larval phase. First, we measured the length and weight of fed versus fasted larvae (N = 340; mean body mass 4.1±0.05 mg) across fine temporal scales at a typical current summer temperature (28.5°C) and a temperature that is likely be encountered during warm summer periods later this century (31.5°C). Second, we measured routine metabolic rate (Mo2 routine) and the energetics of the postprandial processes (i.e., digestion, absorption and assimilation of a meal; termed specific dynamic action (SDA)) at both temperatures. Larvae fed voraciously when provided with food for a 12-hour period and displayed a temperature-independent increase in mass of 40.1% (28.5°C) and 42.6% (31.5°C), which was largely associated with the mass of prey in the gut. A subsequent 12-h fasting period revealed that the larvae had grown 21.2±4.8% (28.5°C) and 22.8±8.8% (31.5°C) in mass and 10.3±2.0% (28.5°C) and 7.8±2.6% (31.5°C) in length compared with pre-feeding values (no significant temperature effect). Mo2 routine was 55±16% higher at 31.5°C and peak Mo2 during the postprandial period was 28±11% higher at 31.5°C, yet elevated temperature had no significant effect on SDA (0.51±0.06 J at 28.5°C vs

  2. Limited Capacity for Faster Digestion in Larval Coral Reef Fish at an Elevated Temperature.

    PubMed

    McLeod, Ian M; Clark, Timothy D

    2016-01-01

    The prevalence of extreme, short-term temperature spikes in coastal regions during summer months is predicted to increase with ongoing climate change. In tropical systems, these changes are predicted to increase the metabolic demand of coral reef fish larvae while also altering the plankton communities upon which the larvae feed during their pelagic phase. The consequences of these predictions remain speculative in the absence of empirical data on the interactive effects of warm temperatures on the metabolism, postprandial processes and growth responses of coral reef fish larvae. Here, we tested the effect of increased temperature on the metabolism, postprandial performance and fine-scale growth patterns of a coral reef fish (Amphiprion percula) in the latter half of its ~11-d larval phase. First, we measured the length and weight of fed versus fasted larvae (N = 340; mean body mass 4.1±0.05 mg) across fine temporal scales at a typical current summer temperature (28.5°C) and a temperature that is likely be encountered during warm summer periods later this century (31.5°C). Second, we measured routine metabolic rate (Mo2 routine) and the energetics of the postprandial processes (i.e., digestion, absorption and assimilation of a meal; termed specific dynamic action (SDA)) at both temperatures. Larvae fed voraciously when provided with food for a 12-hour period and displayed a temperature-independent increase in mass of 40.1% (28.5°C) and 42.6% (31.5°C), which was largely associated with the mass of prey in the gut. A subsequent 12-h fasting period revealed that the larvae had grown 21.2±4.8% (28.5°C) and 22.8±8.8% (31.5°C) in mass and 10.3±2.0% (28.5°C) and 7.8±2.6% (31.5°C) in length compared with pre-feeding values (no significant temperature effect). Mo2 routine was 55±16% higher at 31.5°C and peak Mo2 during the postprandial period was 28±11% higher at 31.5°C, yet elevated temperature had no significant effect on SDA (0.51±0.06 J at 28.5°C vs

  3. High temperatures limit plant growth but hasten flowering in root chicory (Cichorium intybus) independently of vernalisation.

    PubMed

    Mathieu, Anne-Sophie; Lutts, Stanley; Vandoorne, Bertrand; Descamps, Christophe; Périlleux, Claire; Dielen, Vincent; Van Herck, Jean-Claude; Quinet, Muriel

    2014-01-15

    An increase in mean and extreme summer temperatures is expected as a consequence of climate changes and this might have an impact on plant development in numerous species. Root chicory (Cichorium intybus L.) is a major crop in northern Europe, and it is cultivated as a source of inulin. This polysaccharide is stored in the tap root during the first growing season when the plant grows as a leafy rosette, whereas bolting and flowering occur in the second year after winter vernalisation. The impact of heat stress on plant phenology, water status, photosynthesis-related parameters, and inulin content was studied in the field and under controlled phytotron conditions. In the field, plants of the Crescendo cultivar were cultivated under a closed plastic-panelled greenhouse to investigate heat-stress conditions, while the control plants were shielded with a similar, but open, structure. In the phytotrons, the Crescendo and Fredonia cultivars were exposed to high temperatures (35°C day/28°C night) and compared to control conditions (17°C) over 10 weeks. In the field, heat reduced the root weight, the inulin content of the root and its degree of polymerisation in non-bolting plants. Flowering was observed in 12% of the heat stressed plants during the first growing season in the field. In the phytotron, the heat stress increased the total number of leaves per plant, but reduced the mean leaf area. Photosynthesis efficiency was increased in these plants, whereas osmotic potential was decreased. High temperature was also found to induced flowering of up to 50% of these plants, especially for the Fredonia cultivar. In conclusion, high temperatures induced a reduction in the growth of root chicory, although photosynthesis is not affected. Flowering was also induced, which indicates that high temperatures can partly substitute for the vernalisation requirement for the flowering of root chicory.

  4. Experimental Limiting Oxygen Concentrations for Nine Organic Solvents at Temperatures and Pressures Relevant to Aerobic Oxidations in the Pharmaceutical Industry

    PubMed Central

    2015-01-01

    Applications of aerobic oxidation methods in pharmaceutical manufacturing are limited in part because mixtures of oxygen gas and organic solvents often create the potential for a flammable atmosphere. To address this issue, limiting oxygen concentration (LOC) values, which define the minimum partial pressure of oxygen that supports a combustible mixture, have been measured for nine commonly used organic solvents at elevated temperatures and pressures. The solvents include acetic acid, N-methylpyrrolidone, dimethyl sulfoxide, tert-amyl alcohol, ethyl acetate, 2-methyltetrahydrofuran, methanol, acetonitrile, and toluene. The data obtained from these studies help define safe operating conditions for the use of oxygen with organic solvents. PMID:26622165

  5. Influence of temperature upon elastic limit and dislocation mobility of single-crystal HgI/sub 2/

    SciTech Connect

    Milstein, F.; Farber, B.; Kim, K.; van den Berg, L.; Schnepple, W.

    1982-01-01

    There are three primary observations obtained from the present work. First, the initial CRSS, i.e., the stress at which plastic deformation first occurs on the c shear planes, seems to be as low as 0.8 kpa (0.1 psi) and may, in fact, be much lower. This very low yield behavior, if confirmed by other tests, can be an important consideration in crystal growth and detector fabrication. Second, workhardened single crystals of mercuric iodide soften and become more ductile with increased temperatures. Third, hard glide dislocations are generated more easily and become more mobile at higher temperatures. These last two are intimately linked. The mobility of the hard glide dislocations at the higher temperatures allow for easier slip, thus lowering the yield stresses and increasing the ductility.

  6. Coupling between Solid 3He on Aerogel and Superfluid 3He in the Low Temperature Limit

    SciTech Connect

    Bradley, D. I.; Fisher, S. N.; Guenault, A. M.; Haley, R. P.; Pickett, G. R.; Tsepelin, V.; Whitehead, R. C. V.; Skyba, P.

    2006-09-07

    We have cooled liquid 3He contained in a 98% open aerogel sample surrounded by bulk superfluid 3He-B at zero pressure to below 120 {mu}K. The aerogel sample is placed in a quasiparticle blackbody radiator cooled by a Lancaster-style nuclear cooling stage to {approx}200 {mu}K. We monitor the temperature of the 3He inside the blackbody radiator using a vibrating wire resonator. We find that reducing the magnetic field on the aerogel sample causes substantial cooling of all the superfluid inside the blackbody radiator. We believe this is due to the demagnetization of the solid 3He layers on the aerogel strands. This system has potential for achieving extremely low temperatures in the confined fluid.

  7. Exploring the limits: A low-pressure, low-temperature Haber-Bosch process

    NASA Astrophysics Data System (ADS)

    Vojvodic, Aleksandra; Medford, Andrew James; Studt, Felix; Abild-Pedersen, Frank; Khan, Tuhin Suvra; Bligaard, T.; Nørskov, J. K.

    2014-04-01

    The Haber-Bosch process for ammonia synthesis has been suggested to be the most important invention of the 20th century, and called the ‘Bellwether reaction in heterogeneous catalysis’. We examine the catalyst requirements for a new low-pressure, low-temperature synthesis process. We show that the absence of such a process for conventional transition metal catalysts can be understood as a consequence of a scaling relation between the activation energy for N2 dissociation and N adsorption energy found at the surface of these materials. A better catalyst cannot obey this scaling relation. We define the ideal scaling relation characterizing the most active catalyst possible, and show that it is theoretically possible to have a low pressure, low-temperature Haber-Bosch process. The challenge is to find new classes of catalyst materials with properties approaching the ideal, and we discuss the possibility that transition metal compounds have such properties.

  8. LIMITS ON ALPHA PARTICLE TEMPERATURE ANISOTROPY AND DIFFERENTIAL FLOW FROM KINETIC INSTABILITIES: SOLAR WIND OBSERVATIONS

    SciTech Connect

    Bourouaine, Sofiane; Verscharen, Daniel; Chandran, Benjamin D. G.; Maruca, Bennett A.; Kasper, Justin C.

    2013-11-01

    Previous studies have shown that the observed temperature anisotropies of protons and alpha particles in the solar wind are constrained by theoretical thresholds for pressure and anisotropy driven instabilities such as the Alfvén/ion-cyclotron (A/IC) and fast-magnetosonic/whistler (FM/W) instabilities. In this Letter, we use a long period of in situ measurements provided by the Wind spacecraft's Faraday cups to investigate the combined constraint on the alpha proton differential flow velocity and the alpha particle temperature anisotropy due to A/IC and FM/W instabilities. We show that the majority of the data are constrained to lie within the region of parameter space in which A/IC and FM/W waves are either stable or have extremely low growth rates. In the minority of observed cases in which the growth rate of the A/IC (FM/W) instability is comparatively large, we find relatively higher values of T {sub α}/T {sub p} (T {sub ∥α}/T {sub ∥p}) when the alpha proton differential flow velocity is small, where T {sub α} and T {sub p} (T {sub ∥α} and T {sub ∥p}) are the perpendicular (parallel) temperatures of alpha particles and protons. We conjecture that this observed feature might arise from preferential alpha particle heating which can drive the alpha particles beyond the instability thresholds.

  9. Vibration amplitude and induced temperature limitation of high power air-borne ultrasonic transducers.

    PubMed

    Saffar, Saber; Abdullah, Amir

    2014-01-01

    The acoustic impedances of matching layers, their internal loss and vibration amplitude are the most important and influential parameters in the performance of high power airborne ultrasonic transducers. In this paper, the optimum acoustic impedances of the transducer matching layers were determined by using a genetic algorithm, the powerful tool for optimizating domain. The analytical results showed that the vibration amplitude increases significantly for low acoustic impedance matching layers. This enhancement is maximum and approximately 200 times higher for the last matching layer where it has the same interface with the air than the vibration amplitude of the source, lead zirconate titanate-pizo electric while transferring the 1 kW is desirable. This large amplitude increases both mechanical failure and temperature of the matching layers due to the internal loss of the matching layers. It has analytically shown that the temperature in last matching layer with having the maximum vibration amplitude is high enough to melt or burn the matching layers. To verify suggested approach, the effect of the amplitude of vibration on the induced temperature has been investigated experimentally. The experimental results displayed good agreement with the theoretical predictions.

  10. Performance limitation and the role of core temperature when wearing light-weight workwear under moderate thermal conditions.

    PubMed

    Kofler, Philipp; Burtscher, Martin; Heinrich, Dieter; Bottoni, Giuliamarta; Caven, Barnaby; Bechtold, Thomas; Teresa Herten, Anne; Hasler, Michael; Faulhaber, Martin; Nachbauer, Werner

    2015-01-01

    The objective of this investigation was to achieve an understanding about the relationship between heat stress and performance limitation when wearing a two-layerfire-resistant light-weight workwear (full-clothed ensemble) compared to an one-layer short sports gear (semi-clothed ensemble) in an exhaustive, stressful situation under moderate thermal condition (25°C). Ten well trained male subjects performed a strenuous walking protocol with both clothing ensembles until exhaustion occurred in a climatic chamber. Wearing workwear reduced the endurance performance by 10% (p=0.007) and the evaporation by 21% (p=0.003), caused a more pronounced rise in core temperature during submaximal walking (0.7±0.3 vs. 1.2±0.4°C; p≤0.001) and from start till exhaustion (1.4±0.3 vs. 1.8±0.5°C; p=0.008), accelerated sweat loss (13±2 vs. 15±3gmin(-1); p=0.007), and led to a significant higher heart rate at the end of cool down (103±6 vs. 111±7bpm; p=0.004). Correlation analysis revealed that core temperature development during submaximal walking and evaporation may play important roles for endurance performance. However, a critical core temperature of 40°C, which is stated to be a crucial factor for central fatigue and performance limitation, was not reached either with the semi-clothed or the full-clothed ensemble (38.3±0.4 vs. 38.4±0.5°C). Additionally, perceived exertion did not increase to a higher extent parallel with the rising core temperature with workwear which would substantiate the critical core temperature theory. In conclusion, increased heat stress led to cardiovascular exercise limitation rather than central fatigue. PMID:25526658

  11. Increasing the Upper Temperature Oxidation Limit of Alumina Forming Austenitic Stainless Steels in Air with Water Vapor

    SciTech Connect

    Brady, Michael P; Unocic, Kinga A; Lance, Michael J; Santella, Michael L; Yamamoto, Yukinori; Walker, Larry R

    2011-01-01

    A family of alumina-forming austenitic (AFA) stainless steels is under development for use in aggressive oxidizing conditions from {approx}600-900 C. These alloys exhibit promising mechanical properties but oxidation resistance in air with water vapor environments is currently limited to {approx}800 C due to a transition from external protective alumina scale formation to internal oxidation of aluminum with increasing temperature. The oxidation behavior of a series of AFA alloys was systematically studied as a function of Cr, Si, Al, C, and B additions in an effort to provide a basis to increase the upper-temperature oxidation limit. Oxidation exposures were conducted in air with 10% water vapor environments from 800-1000 C, with post oxidation characterization of the 900 C exposed samples by electron probe microanalysis (EPMA), scanning and transmission electron microscopy, and photo-stimulated luminescence spectroscopy (PSLS). Increased levels of Al, C, and B additions were found to increase the upper-temperature oxidation limit in air with water vapor to between 950 and 1000 C. These findings are discussed in terms of alloy microstructure and possible gettering of hydrogen from water vapor at second phase carbide and boride precipitates.

  12. Investigation of Coupled Processes and Impact of High Temperature Limits in Argillite Rock

    SciTech Connect

    Zheng, Liange; Rutqvist, Jonny; Kim, Kunhwi; Houseworth, Jim

    2015-07-01

    The focus of research within the UFD Campaign is on repository-induced interactions that may affect the key safety characteristics of an argillaceous rock. These include thermal-hydrological-mechanical-chemical (THMC) process interactions that occur as a result of repository construction and waste emplacement. Some of the key questions addressed in this report include the development of fracturing in the excavation damaged zone (EDZ) and THMC effects on the near-field argillaceous rock and buffer minerals and petrophysical characteristics, particularly the impacts of induced temperature rise caused by waste heat.

  13. Compensation of noise in optical lattices via feedback: Low-temperature limit

    SciTech Connect

    Ivanova, T. Yu.; Ivanov, D. A.

    2008-02-15

    We consider the problem of suppression of noise acting on atomic ensembles trapped in optical lattices in the low-energy limit. Noise affecting external degrees of freedom of each atom independently and noise influencing only the center-of-mass (c.m.) mode of the ensemble are addressed. Taking into account the quantum character of the atomic motion, we show that negative feedback loop acting on the c.m. coordinate of the atomic ensemble is able to partially compensate both noise sources mentioned above.

  14. Transformation behavior of Ni-Mn-Ga in the low-temperature limit.

    PubMed

    Pérez-Landazábal, J I; Recarte, V; Sánchez-Alarcos, V; Chernenko, V A; Barandiarán, J M; Lázpita, P; Rodriguez Fernández, J; Righi, L

    2012-07-11

    The magnetic, magnetocaloric and thermal characteristics have been studied in a Ni(50.3)Mn(20.8)Ga(27.6)V(1.3) ferromagnetic shape memory alloy (FSMA) transforming martensitically at around 40 K. The alloy shows first a transformation from austenite to an intermediate phase and then a partial transformation to an orthorhombic martensite, all the phases being ferromagnetically ordered. The thermomagnetization dependences enabled observation of the magnetocaloric effect in the vicinity of the martensitic transformation (MT). The Debye temperature and the density of states at the Fermi level are equal to θ(D) = (276 ± 4) K and 1.3 states/atom eV , respectively, and scarcely dependent on the magnetic field. The MT exhibited by Ni-Mn-Ga FSMAs at very low temperatures is distinctive in the sense that it is accompanied by a hardly detectable entropy change as a sign of a small driving force. The enhanced stability of the cubic phase and the low driving force of the MT stem from the reduced density of states near the Fermi level.

  15. Linear viscoelastic limits of asphalt concrete at low and intermediate temperatures

    NASA Astrophysics Data System (ADS)

    Mehta, Yusuf A.

    The purpose of this dissertation is to demonstrate the hypothesis that a region at which the behavior of asphalt concrete can be represented as a linear viscoelastic material can be determined at low and intermediate temperatures considering the stresses and strains typically developed in the pavements under traffic loading. Six mixtures containing different aggregate gradations and nominal maximum aggregate sizes varying from 12.5 to 37.5 mm were used in this study. The asphalt binder grade was the same for all mixtures. The mixtures were compacted to 7 +/- 1% air voids, using the Superpave Gyratory Compactor. Tests were conducted at low temperatures (-20°C and -10°C), using the indirect tensile test machine, and at intermediate temperatures (4°C and 20°C), using the Superpave shear machine. To determine the linear viscoelastic range of asphalt concrete, a relaxation test for 150 s, followed by a creep test for another 150 s, was conducted at 150 and 200 microstrains (1 microstrain = 1 x 10-6), at -20°C, and at 150 and 300 microstrains, at -10°C. A creep test for 200 s, followed by a recovery test for another 200 s, was conducted at stress levels up to 800 kPa at 4°C and up to 500 kPa at 20°C. At -20°C and -10°C, the behavior of the mixtures was linear viscoelastic at 200 and 300 microstrains, respectively. At intermediate temperatures (4°C and 20°C), an envelope defining the linear and nonlinear region in terms of stress as a function of shear creep compliance was constructed for all the mixtures. For creep tests conducted at 20°C, it was discovered that the commonly used protocol to verify the proportionality condition of linear viscoelastic behavior was unable to detect the appearance of nonlinear behavior at certain imposed shear stress levels. Said nonlinear behavior was easily detected, however, when checking the satisfaction of the superposition condition. The envelope constructed for determining when the material becomes nonlinear should be

  16. The kinetic dose limit in room-temperature time-resolved macromolecular crystallography

    SciTech Connect

    Schmidt, M.; Srajer, V.; Purwar, N.; Tripathi, S.

    2012-05-24

    Protein X-ray structures are determined with ionizing radiation that damages the protein at high X-ray doses. As a result, diffraction patterns deteriorate with the increased absorbed dose. Several strategies such as sample freezing or scavenging of X-ray-generated free radicals are currently employed to minimize this damage. However, little is known about how the absorbed X-ray dose affects time-resolved Laue data collected at physiological temperatures where the protein is fully functional in the crystal, and how the kinetic analysis of such data depends on the absorbed dose. Here, direct evidence for the impact of radiation damage on the function of a protein is presented using time-resolved macromolecular crystallography. The effect of radiation damage on the kinetic analysis of time-resolved X-ray data is also explored.

  17. Thermal Transport by Ballistic Quasiparticles in Superfluid 3He-B in the Low Temperature Limit

    SciTech Connect

    Bradley, D. I.; Fisher, S. N.; Guenault, A. M.; Haley, R. P.; Martin, H.; Pickett, G. R.; Roberts, J. E.; Tsepelin, V.

    2006-09-07

    In the temperature range below 0.2Tc, the gas of thermal excitations from the superfluid 3He-B ground state is in the ultra-dilute ballistic regime. Here we discuss preliminary measurements of the transport properties of this quasiparticle gas in a cell of cylindrical geometry with dimensions much smaller than any mean free path. The vertical cylinder, constructed from epoxy-coated paper, has vibrating wire resonator (VWR) heaters and thermometers at the top and bottom, and a small aperture at the top which provides the only exit for quasiparticles. Using the thermometer VWRs, we measure the difference in quasiparticle density between the top and bottom of the tube when we excite the top or bottom VWR heater. This gives information about the transport of energy along the cylindrical 3He sample and hence about the scattering behaviour involved when a quasiparticle impinges on the cylinder wall.

  18. Summer declines in activity and body temperature offer polar bears limited energy savings

    USGS Publications Warehouse

    Whiteman, J.P.; Harlow, H.J.; Durner, George M.; Anderson-Sprecher, R.; Albeke, Shannon E.; Regehr, Eric V.; Amstrup, Steven C.; Ben-David, M.

    2015-01-01

    Polar bears (Ursus maritimus) summer on the sea ice or, where it melts, on shore. Although the physiology of “ice” bears in summer is unknown, “shore” bears purportedly minimize energy losses by entering a hibernation-like state when deprived of food. Such a strategy could partially compensate for the loss of on-ice foraging opportunities caused by climate change. However, here we report gradual, moderate declines in activity and body temperature of both shore and ice bears in summer, resembling energy expenditures typical of fasting, nonhibernating mammals. Also, we found that to avoid unsustainable heat loss while swimming, bears employed unusual heterothermy of the body core. Thus, although well adapted to seasonal ice melt, polar bears appear susceptible to deleterious declines in body condition during the lengthening period of summer food deprivation.

  19. Animal physiology. Summer declines in activity and body temperature offer polar bears limited energy savings.

    PubMed

    Whiteman, J P; Harlow, H J; Durner, G M; Anderson-Sprecher, R; Albeke, S E; Regehr, E V; Amstrup, S C; Ben-David, M

    2015-07-17

    Polar bears (Ursus maritimus) summer on the sea ice or, where it melts, on shore. Although the physiology of "ice" bears in summer is unknown, "shore" bears purportedly minimize energy losses by entering a hibernation-like state when deprived of food. Such a strategy could partially compensate for the loss of on-ice foraging opportunities caused by climate change. However, here we report gradual, moderate declines in activity and body temperature of both shore and ice bears in summer, resembling energy expenditures typical of fasting, nonhibernating mammals. Also, we found that to avoid unsustainable heat loss while swimming, bears employed unusual heterothermy of the body core. Thus, although well adapted to seasonal ice melt, polar bears appear susceptible to deleterious declines in body condition during the lengthening period of summer food deprivation.

  20. Animal physiology. Summer declines in activity and body temperature offer polar bears limited energy savings.

    PubMed

    Whiteman, J P; Harlow, H J; Durner, G M; Anderson-Sprecher, R; Albeke, S E; Regehr, E V; Amstrup, S C; Ben-David, M

    2015-07-17

    Polar bears (Ursus maritimus) summer on the sea ice or, where it melts, on shore. Although the physiology of "ice" bears in summer is unknown, "shore" bears purportedly minimize energy losses by entering a hibernation-like state when deprived of food. Such a strategy could partially compensate for the loss of on-ice foraging opportunities caused by climate change. However, here we report gradual, moderate declines in activity and body temperature of both shore and ice bears in summer, resembling energy expenditures typical of fasting, nonhibernating mammals. Also, we found that to avoid unsustainable heat loss while swimming, bears employed unusual heterothermy of the body core. Thus, although well adapted to seasonal ice melt, polar bears appear susceptible to deleterious declines in body condition during the lengthening period of summer food deprivation. PMID:26185248

  1. The kinetic dose limit in room-temperature time-resolved macromolecular crystallography

    PubMed Central

    Schmidt, M.; Šrajer, V.; Purwar, N.; Tripathi, S.

    2012-01-01

    Protein X-ray structures are determined with ionizing radiation that damages the protein at high X-ray doses. As a result, diffraction patterns deteriorate with the increased absorbed dose. Several strategies such as sample freezing or scavenging of X-ray-generated free radicals are currently employed to minimize this damage. However, little is known about how the absorbed X-ray dose affects time-resolved Laue data collected at physiological temperatures where the protein is fully functional in the crystal, and how the kinetic analysis of such data depends on the absorbed dose. Here, direct evidence for the impact of radiation damage on the function of a protein is presented using time-resolved macromolecular crystallography. The effect of radiation damage on the kinetic analysis of time-resolved X-ray data is also explored. PMID:22338689

  2. Increase in family allowances.

    PubMed

    1989-01-01

    In July 1989 the family allowance structure in Australia was changed from a 4-rate to a 2-rate structure. The new rates were increased to $A9 a week for the 1st 3 children and $A12 for each additional child. The Family Allowance Supplment rate for children 13-15 years old was raised from $A31 to $A34.10/week. PMID:12344544

  3. The metabolic, locomotor and sex-dependent effects of elevated temperature on Trinidadian guppies: limited capacity for acclimation.

    PubMed

    Muñoz, Nicolas J; Breckels, Ross D; Neff, Bryan D

    2012-10-01

    Global warming poses a threat to many ectothermic organisms because of the harmful effects that elevated temperatures can have on resting metabolic rate (RMR) and body size. This study evaluated the thermal sensitivity of Trinidadian guppies (Poecilia reticulata) by describing the effects of developmental temperature on mass, burst speed and RMR, and investigated whether these tropical fish can developmentally acclimate to their thermal conditions. These traits were measured following exposure to one of three treatments: 70 days at 23, 25, 28 or 30°C (acclimated groups); 6 h at 23, 28 or 30°C following 70 days at 25°C (unacclimated groups); or 6 h at 25°C following 70 days in another 25°C tank (control group). Body mass was lower in warmer temperatures, particularly amongst females and individuals reared at 30°C. The burst speed of fish acclimated to each temperature did not differ and was marginally higher than that of unacclimated fish, indicative of complete compensation. Conversely, acclimated and unacclimated fish did not differ in their RMR at each temperature. Amongst the acclimated groups, RMR was significantly higher at 30°C, indicating that guppies may become thermally limited at this temperature as a result of less energy being available for growth, reproduction and locomotion. Like other tropical ectotherms, guppies appear to be unable to adjust their RMR through physiological acclimation and may consequently be susceptible to rising temperatures. Also, because larger females have higher fecundity, our data suggest that fecundity will be reduced in a warmer climate, potentially decreasing the viability of guppy populations.

  4. Limits on the ion temperature anisotropy in the turbulent intracluster medium

    NASA Astrophysics Data System (ADS)

    Santos-Lima, R.; Yan, H.; de Gouveia Dal Pino, E. M.; Lazarian, A.

    2016-08-01

    Turbulence in the weakly collisional intracluster medium (ICM) of galaxies is able to generate strong thermal velocity anisotropies in the ions (with respect to the local magnetic field direction), if the magnetic moment of the particles is conserved in the absence of Coulomb collisions. In this scenario, the anisotropic pressure magnetohydrodynamic (AMHD) turbulence shows a very different statistical behaviour from the standard MHD one and is unable to amplify seed magnetic fields. This is in contrast to previous cosmological MHD simulations that are successful in explaining the observed magnetic fields in the ICM. On the other hand, temperature anisotropies can also drive plasma instabilities that can relax the anisotropy. This work aims to compare the relaxation rate with the growth rate of the anisotropies driven by the turbulence. We employ quasi-linear theory to estimate the ion scattering rate resulting from the parallel firehose, mirror and ion-cyclotron instabilities, for a set of plasma parameters resulting from AMHD simulations of the turbulent ICM. We show that the ICM turbulence can sustain only anisotropy levels very close to the instability thresholds. We argue that the AMHD model that bounds the anisotropies at the marginal stability levels can describe the Alfvénic turbulence cascade in the ICM.

  5. Relativistic entrainment matrix of a superfluid nucleon-hyperon mixture: The zero temperature limit

    SciTech Connect

    Gusakov, Mikhail E.; Kantor, Elena M.; Haensel, Pawel

    2009-05-15

    We calculate the relativistic entrainment matrix Y{sub ik} at zero temperature for a nucleon-hyperon mixture composed of neutrons, protons, and {lambda} and {sigma}{sup -} hyperons, as well as electrons and muons. This matrix is analogous to the entrainment matrix (also termed mass-density matrix or Andreev-Bashkin matrix) of nonrelativistic theory. It is an important ingredient for modeling the pulsations of massive neutron stars with superfluid nucleon-hyperon cores. The calculation is done in the frame of the relativistic Landau Fermi-liquid theory generalized to the case of superfluid mixtures; the matrix Y{sub ik} is expressed through the Landau parameters of nucleon-hyperon matter. The results are illustrated with a particular example of the {sigma}-{omega}-{rho} mean-field model with scalar self-interactions. Using this model, we calculate the matrix Y{sub ik} and the Landau parameters. We also analyze the stability of the ground state of nucleon-hyperon matter with respect to small perturbations.

  6. Cracking Prediction in Hot Stamping of High-Strength Steel by a Temperature-Dependent Forming Limit Surface Approach

    NASA Astrophysics Data System (ADS)

    Liu, Hongsheng; Cui, Junjia; Jiang, Kaiyong; Zhou, Guangtao

    2016-10-01

    Hot stamping of high-strength steel (HSS) can significantly improve ultimate tensile strength (UTS) of hot-stamped part and thus meet the increasing demands for weight reduction and safety standards in vehicles. However, the prediction of forming defect such as cracking in hot stamping using traditional forming limit curve (FLC) is still challenging. In this paper, to predict HSS BR1500HS cracking in hot stamping, a temperature-dependent forming limit surface (FLS) is developed by simulations combined with experiments of biaxial tension of the plate with a groove at different temperatures. Different from the FLC, the newly developed FLS in which temperature is included suits the hot stamping of HSS. Considering the interplay among phase transformation, stress and strain, a finite element (FE)-coupled thermo-mechanical model of the hot stamping is developed and implemented under ABAQUS/Explicit platform where the developed FLS is built-in to predict strain distributions and HSS BR1500HS cracking in the hot stamping. Finally, the developed FLS is used to evaluate hot formability of HSS BR1500HS by using a hot stamping experiment for forming a box-shaped part. Results confirm that the developed FLS can accurately predict HSS BR1500HS cracking occurrence in the hot stamping.

  7. Effects of platinum stagnation surface on the lean extinction limits of premixed methane/air flames at moderate surface temperatures

    SciTech Connect

    Wiswall, J.T.; Li, J.; Wooldridge, M.S.; Im, H.G.

    2011-01-15

    A stagnation flow reactor was used to study the effects of platinum on the lean flammability limits of atmospheric pressure premixed methane/air flames at moderate stagnation surface temperatures. Experimental and computational methods were used to quantify the equivalence ratio at the lean extinction limit ({phi}{sub ext}) and the corresponding stagnation surface temperature (T{sub s}). A range of flow rates (57-90 cm/s) and corresponding strain rates were considered. The results indicate that the gas-phase methane/air flames are sufficiently strong relative to the heterogeneous chemistry for T{sub s} conditions less than 750 K that the platinum does not affect {phi}{sub ext}. The computational results are in good agreement with the experimentally observed trends and further indicate that higher reactant flow rates (>139 cm/s) and levels of dilution (>{proportional_to}10% N{sub 2}) are required to weaken the gas-phase flame sufficiently for surface reaction to play a positive role on extending the lean flammability limits. (author)

  8. Ocean acidification limits temperature-induced poleward expansion of coral habitats around Japan

    NASA Astrophysics Data System (ADS)

    Yara, Y.; Vogt, M.; Fujii, M.; Yamano, H.; Hauri, C.; Steinacher, M.; Gruber, N.; Yamanaka, Y.

    2012-12-01

    Using results from four coupled global carbon cycle-climate models combined with in situ observations, we estimate the effects of future global warming and ocean acidification on potential habitats for tropical/subtropical and temperate coral communities in the seas around Japan. The suitability of coral habitats is classified on the basis of the currently observed regional ranges for temperature and saturation states with regard to aragonite (Ωarag). We find that, under the "business as usual" SRES A2 scenario, coral habitats are projected to expand northward by several hundred kilometers by the end of this century. At the same time, coral habitats are projected to become sandwiched between regions where the frequency of coral bleaching will increase, and regions where Ωarag will become too low to support sufficiently high calcification rates. As a result, the habitat suitable for tropical/subtropical corals around Japan may be reduced by half by the 2020s to 2030s, and is projected to disappear by the 2030s to 2040s. The habitat suitable for the temperate coral communities is also projected to decrease, although at a less pronounced rate, due to the higher tolerance of temperate corals for low Ωarag. Our study has two important caveats: first, it does not consider the potential adaptation of the coral communities, which would permit them to colonize habitats that are outside their current range. Second, it also does not consider whether or not coral communities can migrate quickly enough to actually occupy newly emerging habitats. As such, our results serve as a baseline for the assessment of the future evolution of coral habitats, but the consideration of important biological and ecological factors and feedbacks will be required to make more accurate projections.

  9. Winter temperatures decrease swimming performance and limit distributions of tropical damselfishes

    PubMed Central

    Johansen, Jacob L.; Steffensen, John F.; Jones, Geoffrey P.

    2015-01-01

    Coral reefs within 10° of the equator generally experience ≤3°C seasonal variation in water temperature. Ectotherms that have evolved in these conditions are therefore expected to exhibit narrow thermal optima and be very sensitive to the greater thermal variability (>6°C) experienced at higher latitudes (≥10°N/S). The impact of increased thermal variability on the fitness and distribution of thermally sensitive reef ectotherms is currently unknown. Here, we examine site-attached planktivorous coral reef damselfishes that rely on their physiological capacity to swim and forage in the water column year round. We focus on 10 species spanning four evolutionarily distinct genera from a region of the Great Barrier Reef that experiences ≥6°C difference between seasons. Four ecologically important indicators showed reduced performance during the winter low (23°C) compared with the summer peak (29°C), with effect sizes varying among species and genera, as follows: (i) the energy available for activity (aerobic scope) was reduced by 35–45% in five species and three genera; (ii) the energetically most efficient swimming speed was reduced by 17% across all species; and (iii) the maximal critical swimming speed and (iv) the gait transition speed (the swimming mode predominantly used for foraging) were reduced by 16–42% in six species spanning all four genera. Comparisons with field surveys within and across latitudes showed that species-specific distributions were strongly correlated with these performance indicators. Species occupy habitats where they can swim faster than prevailing habitat currents year round, and >95% of individuals were observed only in habitats where the gait transition speed can be maintained at or above habitat currents. Thermal fluctuation at higher latitudes appears to reduce performance as well as the possible distribution of species and genera within and among coral reef habitats. Ultimately, thermal variability across latitudes may

  10. Winter temperatures decrease swimming performance and limit distributions of tropical damselfishes.

    PubMed

    Johansen, Jacob L; Steffensen, John F; Jones, Geoffrey P

    2015-01-01

    Coral reefs within 10° of the equator generally experience ≤3°C seasonal variation in water temperature. Ectotherms that have evolved in these conditions are therefore expected to exhibit narrow thermal optima and be very sensitive to the greater thermal variability (>6°C) experienced at higher latitudes (≥10°N/S). The impact of increased thermal variability on the fitness and distribution of thermally sensitive reef ectotherms is currently unknown. Here, we examine site-attached planktivorous coral reef damselfishes that rely on their physiological capacity to swim and forage in the water column year round. We focus on 10 species spanning four evolutionarily distinct genera from a region of the Great Barrier Reef that experiences ≥6°C difference between seasons. Four ecologically important indicators showed reduced performance during the winter low (23°C) compared with the summer peak (29°C), with effect sizes varying among species and genera, as follows: (i) the energy available for activity (aerobic scope) was reduced by 35-45% in five species and three genera; (ii) the energetically most efficient swimming speed was reduced by 17% across all species; and (iii) the maximal critical swimming speed and (iv) the gait transition speed (the swimming mode predominantly used for foraging) were reduced by 16-42% in six species spanning all four genera. Comparisons with field surveys within and across latitudes showed that species-specific distributions were strongly correlated with these performance indicators. Species occupy habitats where they can swim faster than prevailing habitat currents year round, and >95% of individuals were observed only in habitats where the gait transition speed can be maintained at or above habitat currents. Thermal fluctuation at higher latitudes appears to reduce performance as well as the possible distribution of species and genera within and among coral reef habitats. Ultimately, thermal variability across latitudes may

  11. Photosynthetic and stomatal responses to high temperature and light in two oaks at the western limit of their range.

    PubMed

    Hamerlynck, E; Knapp, A K

    1996-06-01

    Bur oak (Quercus macrocarpa Michx.) and chinquapin oak (Q. muehlenbergii Engl.) leaves were exposed to high temperatures at various photosynthetic photon flux densities under laboratory conditions to determine if species-specific responses to these factors were consistent with the distribution of these oaks in gallery forests in the tallgrass prairies of northeastern Kansas, USA. Measurements of the ratio of chlorophyll fluorescence decrease, R(fd), indicated that chinquapin oak maintained greater photosynthetic capacity than bur oak across all tested combinations of irradiance (100, 400, 700 and 1000 micro mol m(-2) s(-1)) and temperature (40, 42, 44, 46 and 48 degrees C). In both oak species, manipulation of leaf temperature to about 47 degrees C for 45 min in the field led to a 45% decrease in carbon assimilation up to one week after the heat treatment, and to sharp reductions in stomatal conductance. Photosynthetic recovery patterns indicated that bur oak took longer to recover from heat stress than chinquapin oak, suggesting that heat stress may be important in determining distribution patterns of these oak species. Based on a comparison of the results with data from other forest species, we conclude that the photosynthetic temperature tolerances of bur oak and chinquapin oaks facilitate their dominance at the western limit of the eastern deciduous forest.

  12. Determination of the Lower Temperature Limit of Void Swelling of Stainless Steels at Relatively Low Displacement Rates

    SciTech Connect

    Porollo, S. I.; Konobeev, Yu V.; Dvoriashin, Alexander M.; Krigan, V. M.; Garner, Francis A.

    2002-03-31

    An issue of current interest to PWRs is the possibility that void swelling of austenitic near-core internal components may exert some deleterious effect on component functionality, particularly during extended operation to 60 years. A similar concern has also been raised for water-cooled fusion devices. One question of particular interest is the range of temperature over which void swelling can occur, since the internal components experience temperatures from ~290 to perhaps as high as 390 degrees C in some limited locations. This question was addressed using a flow restrictor component from the low-flux breeder zone of the BN-350 fast reactor in Kazakhstan. This component was constructed of annealed 12X18H10T, an alloy similar to AISI 321 which is used in Russian reactors for applications where AISI 304L would be used in comparable Western and Japanese reactors. Extensive sectioning to produce 114 separate specimens, followed by examination of the radiation-induced microstructure showed that void swelling in the range of temperatures and dpa rates of PWR interest occurs down to ~305 degrees C. At 330 degrees C the swelling reached ~1% at 20 dpa. Comparison of these data with other published results from Russian LWR reactors at <10 dpa confirms that the lowest temperature that stainless steels can begin swelling appears to be ~300 degrees C. Since fusion and PWR spectra generate similar levels of hydrogen and helium, it is expected that these conclusions are also application to fusion devices operating at comparable dpa rates.

  13. Pushing the upper limit of Rayleigh-scatter Temperatures Retrievals into the Lower Thermosphere Using an Inversion Approach

    NASA Astrophysics Data System (ADS)

    Bandoro, J.; Sica, R. J.; Argall, S.

    2012-12-01

    An important aspect of solar terrestrial relations is the coupling between the lower and upper atmosphere-ionosphere system. The coupling is evident in the general circulation of the atmosphere, where waves generate in the lower atmosphere play an important role in the dynamics of the upper atmosphere, which feeds back on the lower atmosphere's circulation. To address coupling problems requires measurements over the broadest range of heights possible. A recently developed retrieval method for temperature profiles from Rayleigh-scatter lidar measurements using an inversion approach allows the upward extension of the altitude range of temperature by 10 to 15 km over the conventional method, thus producing the equivalent of increasing the systems power-aperture product by 4 times [1]. The method requires no changes to the lidar's hardware and thus, can be applied to the body of existing measurements. In addition, since the uncertainties of the retrieved temperature profile are found by a Monte Carlo error analysis, it is possible to isolate systematic and random uncertainties to model the effect of each one on the final uncertainty product for the temperature profile. This unambiguous separation of uncertainties was not previously possible as only the propagation of the statistical uncertainties are typically reported. For the Purple Crow Lidar, corrections for saturation (e.g. non-linearity) in the photocount returns, ozone extinction and background removal all contribute to the overall systematic uncertainty. Results of individually varying each systematic correction and the effect on the final temperature uncertainty through Monte Carlo realizations are presented to determine the importance for each one. For example, it was found that treatment of the background correction as a systematic versus statistical uncertainty gave results in agreement with each other. This new method is then applied to measurements obtained by the Purple Crow lidar' Rayleigh

  14. Increases in the evolutionary potential of upper thermal limits under warmer temperatures in two rainforest Drosophila species.

    PubMed

    van Heerwaarden, Belinda; Malmberg, Michelle; Sgrò, Carla M

    2016-02-01

    Tropical and subtropical species represent the majority of biodiversity. These species are predicted to lack the capacity to evolve higher thermal limits in response to selection imposed by climatic change. However, these assessments have relied on indirect estimates of adaptive capacity, using conditions that do not reflect environmental changes projected under climate change. Using a paternal half-sib full-sib breeding design, we estimated the additive genetic variance and narrow-sense heritability for adult upper thermal limits in two rainforest-restricted species of Drosophila reared under two thermal regimes, reflecting increases in seasonal temperature projected for the Wet Tropics of Australia and under standard laboratory conditions (constant 25°C). Estimates of additive genetic variation and narrow-sense heritability for adult heat tolerance were significantly different from zero in both species under projected summer, but not winter or constant, thermal regimes. In contrast, significant broad-sense genetic variation was apparent in all thermal regimes for egg-to-adult viability. Environment-dependent changes in the expression of genetic variation for adult upper thermal limits suggest that predicting adaptive responses to climate change will be difficult. Estimating adaptive capacity under conditions that do not reflect future environmental conditions may provide limited insight into evolutionary responses to climate change.

  15. Determination of the Lower Temperature Limit of Void Swelling of Stainless Steels at PWR-Relevant Displacement Rates

    SciTech Connect

    Porollo, S. I.; Konobeev, Yury V.; Dvoriashin, Alexander M.; Krigan, V. M.; Garner, Francis A.

    2004-01-01

    Recent studies associated with light water reactors (LWR) in both the USA and Russia have raised the question of void swelling in austenitic components of core internals. One question of particular interest is the range of temperatures over which voids can develop, especially the lowest temperature. To address this question a flow restrictor component manufactured from annealed X18H9T was removed from the reflector region of the BN-350 fast reactor, located in Kazakhstan. During operation this component spanned temperatures and dpa rates of direct interest to pressurized water reactors (PWRs) in the West and VVERs in Russia. This steel is analogous to AISI 321 and is used in Russian reactors for applications where AISI 304 would be used in the West and in Japan. This component was sectioned on a very fine scale to determine in what range of conditions voids existed. Microstructural data were obtained for 157 separate locations, with 111 specimens showing voids over the relevant range of temperatures and displacement rates, allowing construction of a parametric map of swelling with temperature, dpa and dpa rate. These data show that swelling at doses as high as ~50 dpa persists down to ~306°C for dose rates in the range 0.11 x 10-7 to 1.6 x 10-7dpa/sec. Finally, since the helium generation rate is rather low in the spectral environment of the flow restrictor, the early onset of swelling is attributed primarily to the lower displacement rate, a conclusion supported by a number of other experimental studies.

  16. Temperature and food concentration have limited influence on the mixture toxicity of copper and Microcystis aeruginosa to Daphnia magna.

    PubMed

    Hochmuth, Jennifer D; Janssen, Colin R; De Schamphelaere, Karel A C

    2016-03-01

    Standard ecotoxicity tests are conducted under constant and favorable experimental conditions. In natural communities, however, the toxicity of chemicals may be influenced by abiotic and biotic environmental factors. Firstly, the authors examined the influence of temperature and total food concentration on the nature of the combined effects of copper (Cu) and the cyanobacterium Microcystis aeruginosa to Daphnia magna (i.e., whether the combined effects deviated from noninteraction). Secondly, the authors investigated the relative influence of the percentage of M. aeruginosa in the diet, temperature, and total food concentration on chronic Cu toxicity to D. magna. The nature of the combined effects between Cu and M. aeruginosa (i.e., synergism according to the independent action reference model and noninteraction according to concentration addition reference model) was not affected by temperature and total food concentration. In line with other studies, the concentration addition reference model gave rise to more protective predictions of mixture toxicity than the independent action reference model, thus confirming the former model's suitability as a conservative scenario for evaluating mixture toxicity of Cu and M. aeruginosa under the temperature and food concentrations tested. Further, the 21-d median effective concentration for Cu based on reproduction varied between 20 μg/L and 100 μg/L, and the results indicate that the percentage of M. aeruginosa explained 76% of the variance in the Cu median effective concentration for reproduction, whereas the effects of temperature and total food were limited (together explaining 11% of the variance). The present study suggests that environmental risk assessment of Cu should consider specific situations where harmful M. aeruginosa blooms can co-occur with elevated Cu exposure.

  17. Geographic and seasonal patterns and limits on the adaptive response to temperature of European Mytilus spp. and Macoma balthica populations

    PubMed Central

    Pronker, Annelies E.; Kube, Sandra; Sokolowski, Adam; Sola, J. Carlos; Marquiegui, Mikel A.; Schiedek, Doris; Wendelaar Bonga, Sjoerd; Wolowicz, Maciej; Hummel, Herman

    2007-01-01

    Seasonal variations in seawater temperature require extensive metabolic acclimatization in cold-blooded organisms inhabiting the coastal waters of Europe. Given the energetic costs of acclimatization, differences in adaptive capacity to climatic conditions are to be expected among distinct populations of species that are distributed over a wide geographic range. We studied seasonal variations in the metabolic adjustments of two very common bivalve taxa at European scale. To this end we sampled 16 populations of Mytilus spp. and 10 Macoma balthica populations distributed from 39° to 69°N. The results from this large-scale comprehensive comparison demonstrated seasonal cycles in metabolic rates which were maximized during winter and springtime, and often reduced in the summer and autumn. Studying the sensitivity of metabolic rates to thermal variations, we found that a broad range of Q10 values occurred under relatively cold conditions. As habitat temperatures increased the range of Q10 narrowed, reaching a bottleneck in southern marginal populations during summer. For Mytilus spp., genetic-group-specific clines and limits on Q10 values were observed at temperatures corresponding to the maximum climatic conditions these geographic populations presently experience. Such specific limitations indicate differential thermal adaptation among these divergent groups. They may explain currently observed migrations in mussel distributions and invasions. Our results provide a practical framework for the thermal ecophysiology of bivalves, the assessment of environmental changes due to climate change and its impact on (and consequences for) aquaculture. Electronic supplementary material The online version of this article (doi:10.1007/s00442-007-0808-x) contains supplementary material, which is available to authorized users. PMID:17846800

  18. Validation of satellite Land Surface Temperature products using ground-based measurements and heritage satellite data - Protocol, limitations and results

    NASA Astrophysics Data System (ADS)

    Guillevic, P. C.; Biard, J. C.; Hulley, G. C.; Goettsche, F. M.; Ghent, D.; Privette, J. L.

    2013-12-01

    Land Surface Temperature (LST) products derived from satellite thermal infrared observations provide key information for monitoring Earth surface energy and water fluxes. Because users of satellite products put a high priority on the provision of uncertainty estimates, validation of LST products is of crucial importance for estimating the accuracy of standard products and understanding the potential and limitations of satellite observations. This work presents different approaches to evaluate quantitative uncertainties in satellite-derived LST products using ground-based measurements made operationally at many field and weather stations, or using heritage satellite data. For most vegetated landscapes composed of various land cover types or soils, the LST measured by a station at one specific location does not represent the surrounding area that is part of the coarser satellite sensor pixel. Furthermore, depending on illumination and viewing direction configurations, satellites measure different surface radiometric temperatures, especially over sparsely vegetated regions with directionally varying radiometric contributions from soil and vegetation. In addition to comparisons with in situ data, inter-comparisons of satellite LST products provide important quality information regarding the overall consistency between remotely sensed products, as well as characterization of spatio-temporal patterns in the LST differences. Based on multi-sensor analysis, we present the complexity involved in each approach, identify the limitations associated with spatial variability or directional effects, and outline validation protocols. The satellite data used in this study are from the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument onboard the Suomi - National Polar-orbiting Partnership (Suomi-NPP), the MODerate resolution Imaging Spectrometer (MODIS) instrument onboard Terra and Aqua satellites and from the Spinning Enhanced Visible and Infrared Imager (SEVIRI

  19. Life Limiting Behavior in Interlaminar Shear of Continuous Fiber-Reinforced Ceramic Matrix Composites at Elevated Temperatures

    NASA Technical Reports Server (NTRS)

    Choi, Sung R.; Calomino, Anthony M.; Bansal, Narottam P.; Verrilli, Michael J.

    2006-01-01

    Interlaminar shear strength of four different fiber-reinforced ceramic matrix composites was determined with doublenotch shear test specimens as a function of test rate at elevated temperatures ranging from 1100 to 1316 C in air. Life limiting behavior, represented as interlaminar shear strength degradation with decreasing test rate, was significant for 2-D crossplied SiC/MAS-5 and 2-D plain-woven C/SiC composites, but insignificant for 2-D plain-woven SiC/SiC and 2-D woven Sylramic (Dow Corning, Midland, Michigan) SiC/SiC composites. A phenomenological, power-law delayed failure model was proposed to account for and to quantify the rate dependency of interlaminar shear strength of the composites. Additional stress rupture testing in interlaminar shear was conducted at elevated temperatures to validate the proposed model. The model was in good agreement with SiC/MAS-5 and C/SiC composites, but in poor to reasonable agreement with Sylramic SiC/SiC. Constant shear stress-rate testing was proposed as a possible means of life prediction testing methodology for ceramic matrix composites subjected to interlaminar shear at elevated temperatures when short lifetimes are expected.

  20. 50 CFR 85.41 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... applicable Federal cost principles in 43 CFR 12.60(b). Purchase of informational signs, program signs, and... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Allowable costs. 85.41 Section 85.41... Use/Acceptance of Funds § 85.41 Allowable costs. (a) Allowable grant costs are limited to those...

  1. 34 CFR 80.22 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CFR part 31. Contract Cost Principles and Procedures, or uniform cost accounting standards that comply... 34 Education 1 2010-07-01 2010-07-01 false Allowable costs. 80.22 Section 80.22 Education Office... Allowable costs. (a) Limitation on use of funds. Grant funds may be used only for: (1) The allowable...

  2. 34 CFR 80.22 - Allowable costs.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CFR part 31. Contract Cost Principles and Procedures, or uniform cost accounting standards that comply... 34 Education 1 2011-07-01 2011-07-01 false Allowable costs. 80.22 Section 80.22 Education Office... Allowable costs. (a) Limitation on use of funds. Grant funds may be used only for: (1) The allowable...

  3. 45 CFR 1157.22 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... named in OBM Circular A-122 as not subject to that circular 48 CFR part 31. Contract Cost Principles and... 45 Public Welfare 3 2010-10-01 2010-10-01 false Allowable costs. 1157.22 Section 1157.22 Public... Allowable costs. (a) Limitation on use of funds. Grant funds may be used only for: (1) The allowable...

  4. The Thermal Boundary Resistance of the Superfluid 3He A-B Phase Interface in the Low Temperature Limit

    SciTech Connect

    Bradley, D. I.; Fisher, S. N.; Guenault, A. M.; Haley, R. P.; Martin, H.; Pickett, G. R.; Roberts, J. E.; Tsepelin, V.

    2006-09-07

    We have constructed a vertical cylindrical cell in which we cool superfluid 3He to the low temperature limit. At the top and bottom of this cylinder are pairs of vibrating wire resonators (VWRs), one to act as a heater and the other as a thermometer. Quasiparticle excitations are created by driving the heater VWRs. These excitations can only leave the cylinder via a small hole at the top. Using a shaped magnetic field, we can produce a layer of A phase across the tube, while maintaining low field B phase in the vicinity of the VWRs for reliable thermometry. Preliminary results show that the two A-B interfaces lead to a measurable extra resistance for quasiparticles between the top and bottom of the cylinder.

  5. Room temperature diode-pumped Yb:CaYAlO4 laser with near quantum limit slope efficiency

    NASA Astrophysics Data System (ADS)

    Tan, W. D.; Tang, D. Y.; Xu, X. D.; Li, D. Z.; Zhang, J.; Xu, C. W.; Cong, Z. H.; Xu, J.

    2011-03-01

    The room temperature continuous wave (CW) laser performance of a compact Yb:CaYAlO4 (Yb:CYA) laser with near quantum limit slope efficiency is demonstrated. Pumped with a CW diode operating at 979 nm, the laser emitted a maximum CW output power of 2.3 W at 1050 nm. The corresponding slope efficiency was found to be 92% while the optical to optical conversion efficiency was 70%. The laser can also be continuously tuned from 1008 nm to 1063 nm using an intra-cavity SF 10 prism. The round trip cavity losses of Yb:CYA was 0.6% while the loss coefficient of the crystal was 0.01 cm-1.

  6. Apparent limitations in the ability of CMIP5 climate models to simulate recent multi-decadal change in surface temperature: implications for global temperature projections

    NASA Astrophysics Data System (ADS)

    Power, Scott; Delage, François; Wang, Guomin; Smith, Ian; Kociuba, Greg

    2016-09-01

    Observed surface temperature trends over the period 1998-2012/2014 have attracted a great deal of interest because of an apparent slowdown in the rate of global warming, and contrasts between climate model simulations and observations of such trends. Many studies have addressed the statistical significance of these relatively short-trends, whether they indicate a possible bias in the model values and the implications for global warming generally. Here we re-examine these issues, but as they relate to changes over much longer-term changes. We find that on multi-decadal time scales there is little evidence for any change in the observed global warming rate, but some evidence for a recent temporary slowdown in the warming rate in the Pacific. This multi-decadal slowdown can be partly explained by a cool phase of the Interdecadal Pacific Oscillation and a short-term excess of La Niña events. We also analyse historical and projected changes in 38 CMIP climate models. All of the model simulations examined simulate multi-decadal warming in the Pacific over the past half-century that exceeds observed values. This difference cannot be fully explained by observed internal multi-decadal climate variability, even if allowance is made for an apparent tendency for models to underestimate internal multi-decadal variability in the Pacific. Models which simulate the greatest global warming over the past half-century also project warming that is among the highest of all models by the end of the twenty-first century, under both low and high greenhouse gas emission scenarios. Given that the same models are poorest in representing observed multi-decadal temperature change, confidence in the highest projections is reduced.

  7. Is the Growth of Birch at the UPPER Timberline in the Himalayas Limited By Moisture or By Temperature?

    NASA Astrophysics Data System (ADS)

    Liang, E.; Dawadi, B.; Pederson, N.; Eckstein, D.

    2014-12-01

    Birch (Betula) trees and forests are found across much of the temperate and boreal zones of the Northern Hemisphere. Yet, despite being an ecologically-significant genus, it is much less-well studied compared to common genera like Pinus, Picea, Juniperus, Quercus, and Fagus. In the Himalayas, Himalayan birch (Betula utilis) is a widespread, important broadleaf timberline species that survives in mountain rain shadows via access to water from snowmelt. Because precipitation in the Nepalese Himalayas decreases with increasing elevation, we hypothesized that the growth of birch at the upper timberlines between 3,900 and 4,150 m a.s.l. is primarily limited by moisture availability rather than by low temperature. To verify this assumption, a total of 292 increment cores were extracted from 211 birch trees at nine timberline sites. The synchronous occurrence of narrow rings and high inter-series correlations within and among sites evidenced a reliable cross-dating and a common climatic signal in the tree-ring widths variations. From March-May, all nine tree-ring width site chronologies showed a strongly positive response to total precipitation and a less strongly negative response to temperature. During the instrumental meteorological record (after 1960), years with a high percentage of missing rings coincided with pre-monsoon drought events. Periods of below-average growth are in phase with well-known drought events all over monsoon Asia, showing additional evidence that Himalayan birch growth at the upper timberlines is persistently limited by moisture availability. Our study describes the rare case of a drought-induced altitudinal timberline that is composed by a broadleaf tree species.

  8. Extensive phenotypic plasticity of a Red Sea coral over a strong latitudinal temperature gradient suggests limited acclimatization potential to warming.

    PubMed

    Sawall, Yvonne; Al-Sofyani, Abdulmoshin; Hohn, Sönke; Banguera-Hinestroza, Eulalia; Voolstra, Christian R; Wahl, Martin

    2015-03-10

    Global warming was reported to cause growth reductions in tropical shallow water corals in both, cooler and warmer, regions of the coral species range. This suggests regional adaptation with less heat-tolerant populations in cooler and more thermo-tolerant populations in warmer regions. Here, we investigated seasonal changes in the in situ metabolic performance of the widely distributed hermatypic coral Pocillopora verrucosa along 12° latitudes featuring a steep temperature gradient between the northern (28.5°N, 21-27°C) and southern (16.5°N, 28-33°C) reaches of the Red Sea. Surprisingly, we found little indication for regional adaptation, but strong indications for high phenotypic plasticity: Calcification rates in two seasons (winter, summer) were found to be highest at 28-29°C throughout all populations independent of their geographic location. Mucus release increased with temperature and nutrient supply, both being highest in the south. Genetic characterization of the coral host revealed low inter-regional variation and differences in the Symbiodinium clade composition only at the most northern and most southern region. This suggests variable acclimatization potential to ocean warming of coral populations across the Red Sea: high acclimatization potential in northern populations, but limited ability to cope with ocean warming in southern populations already existing at the upper thermal margin for corals.

  9. Extensive phenotypic plasticity of a Red Sea coral over a strong latitudinal temperature gradient suggests limited acclimatization potential to warming.

    PubMed

    Sawall, Yvonne; Al-Sofyani, Abdulmoshin; Hohn, Sönke; Banguera-Hinestroza, Eulalia; Voolstra, Christian R; Wahl, Martin

    2015-01-01

    Global warming was reported to cause growth reductions in tropical shallow water corals in both, cooler and warmer, regions of the coral species range. This suggests regional adaptation with less heat-tolerant populations in cooler and more thermo-tolerant populations in warmer regions. Here, we investigated seasonal changes in the in situ metabolic performance of the widely distributed hermatypic coral Pocillopora verrucosa along 12° latitudes featuring a steep temperature gradient between the northern (28.5°N, 21-27°C) and southern (16.5°N, 28-33°C) reaches of the Red Sea. Surprisingly, we found little indication for regional adaptation, but strong indications for high phenotypic plasticity: Calcification rates in two seasons (winter, summer) were found to be highest at 28-29°C throughout all populations independent of their geographic location. Mucus release increased with temperature and nutrient supply, both being highest in the south. Genetic characterization of the coral host revealed low inter-regional variation and differences in the Symbiodinium clade composition only at the most northern and most southern region. This suggests variable acclimatization potential to ocean warming of coral populations across the Red Sea: high acclimatization potential in northern populations, but limited ability to cope with ocean warming in southern populations already existing at the upper thermal margin for corals. PMID:25754672

  10. Limited tolerance by insects to high temperatures across tropical elevational gradients and the implications of global warming for extinction.

    PubMed

    García-Robledo, Carlos; Kuprewicz, Erin K; Staines, Charles L; Erwin, Terry L; Kress, W John

    2016-01-19

    The critical thermal maximum (CTmax), the temperature at which motor control is lost in animals, has the potential to determine if species will tolerate global warming. For insects, tolerance to high temperatures decreases with latitude, suggesting that similar patterns may exist along elevational gradients as well. This study explored how CTmax varies among species and populations of a group of diverse tropical insect herbivores, the rolled-leaf beetles, across both broad and narrow elevational gradients. Data from 6,948 field observations and 8,700 museum specimens were used to map the elevational distributions of rolled-leaf beetles on two mountains in Costa Rica. CTmax was determined for 1,252 individual beetles representing all populations across the gradients. Initial morphological identifications suggested a total of 26 species with populations at different elevations displaying contrasting upper thermal limits. However, compared with morphological identifications, DNA barcodes (cytochrome oxidase I) revealed significant cryptic species diversity. DNA barcodes identified 42 species and haplotypes across 11 species complexes. These 42 species displayed much narrower elevational distributions and values of CTmax than the 26 morphologically defined species. In general, species found at middle elevations and on mountaintops are less tolerant to high temperatures than species restricted to lowland habitats. Species with broad elevational distributions display high CTmax throughout their ranges. We found no significant phylogenetic signal in CTmax, geography, or elevational range. The narrow variance in CTmax values for most rolled-leaf beetles, especially high-elevation species, suggests that the risk of extinction of insects may be substantial under some projected rates of global warming. PMID:26729867

  11. Limited tolerance by insects to high temperatures across tropical elevational gradients and the implications of global warming for extinction.

    PubMed

    García-Robledo, Carlos; Kuprewicz, Erin K; Staines, Charles L; Erwin, Terry L; Kress, W John

    2016-01-19

    The critical thermal maximum (CTmax), the temperature at which motor control is lost in animals, has the potential to determine if species will tolerate global warming. For insects, tolerance to high temperatures decreases with latitude, suggesting that similar patterns may exist along elevational gradients as well. This study explored how CTmax varies among species and populations of a group of diverse tropical insect herbivores, the rolled-leaf beetles, across both broad and narrow elevational gradients. Data from 6,948 field observations and 8,700 museum specimens were used to map the elevational distributions of rolled-leaf beetles on two mountains in Costa Rica. CTmax was determined for 1,252 individual beetles representing all populations across the gradients. Initial morphological identifications suggested a total of 26 species with populations at different elevations displaying contrasting upper thermal limits. However, compared with morphological identifications, DNA barcodes (cytochrome oxidase I) revealed significant cryptic species diversity. DNA barcodes identified 42 species and haplotypes across 11 species complexes. These 42 species displayed much narrower elevational distributions and values of CTmax than the 26 morphologically defined species. In general, species found at middle elevations and on mountaintops are less tolerant to high temperatures than species restricted to lowland habitats. Species with broad elevational distributions display high CTmax throughout their ranges. We found no significant phylogenetic signal in CTmax, geography, or elevational range. The narrow variance in CTmax values for most rolled-leaf beetles, especially high-elevation species, suggests that the risk of extinction of insects may be substantial under some projected rates of global warming.

  12. Limited tolerance by insects to high temperatures across tropical elevational gradients and the implications of global warming for extinction

    PubMed Central

    García-Robledo, Carlos; Kuprewicz, Erin K.; Staines, Charles L.; Erwin, Terry L.; Kress, W. John

    2016-01-01

    The critical thermal maximum (CTmax), the temperature at which motor control is lost in animals, has the potential to determine if species will tolerate global warming. For insects, tolerance to high temperatures decreases with latitude, suggesting that similar patterns may exist along elevational gradients as well. This study explored how CTmax varies among species and populations of a group of diverse tropical insect herbivores, the rolled-leaf beetles, across both broad and narrow elevational gradients. Data from 6,948 field observations and 8,700 museum specimens were used to map the elevational distributions of rolled-leaf beetles on two mountains in Costa Rica. CTmax was determined for 1,252 individual beetles representing all populations across the gradients. Initial morphological identifications suggested a total of 26 species with populations at different elevations displaying contrasting upper thermal limits. However, compared with morphological identifications, DNA barcodes (cytochrome oxidase I) revealed significant cryptic species diversity. DNA barcodes identified 42 species and haplotypes across 11 species complexes. These 42 species displayed much narrower elevational distributions and values of CTmax than the 26 morphologically defined species. In general, species found at middle elevations and on mountaintops are less tolerant to high temperatures than species restricted to lowland habitats. Species with broad elevational distributions display high CTmax throughout their ranges. We found no significant phylogenetic signal in CTmax, geography, or elevational range. The narrow variance in CTmax values for most rolled-leaf beetles, especially high-elevation species, suggests that the risk of extinction of insects may be substantial under some projected rates of global warming. PMID:26729867

  13. Limits to sustained energy intake XXIV: impact of suckling behaviour on the body temperatures of lactating female mice

    PubMed Central

    Gamo, Y.; Bernard, A.; Troup, C.; Munro, F.; Derrer, K.; Jeannesson, N.; Campbell, A.; Gray, H.; Miller, J.; Dixon, J.; Mitchell, S. E.; Hambly, C.; Vaanholt, L. M.; Speakman, J. R.

    2016-01-01

    The objective of this study was to investigate the potential causes of high body temperature (Tb) during lactation in mice as a putative limit on energy intake. In particular we explored whether or not offspring contributed to heat retention in mothers while suckling. Tb and physical activity were monitored in 26 female MF1 mice using intraperitoneally implanted transmitters. In addition, maternal behaviour was scored each minute for 8 h d−1 throughout lactation. Mothers that raised larger litters tended to have higher Tb while nursing inside nests (P < 0.05), suggesting that nursing offspring may have influenced heat retention. However, Tb during nursing was not higher than that recorded during other behaviours. In addition, the highest Tb during the observation period was not measured during nursing behaviour. Finally, there was no indication that mothers discontinued suckling because of a progressive rise in their Tb while suckling. Tb throughout lactation was correlated with daily increases in energy intake. Chronic hyperthermia during lactation was not caused by increased heat retention due to surrounding offspring. Other factors, like metabolic heat produced as a by-product of milk production or energy intake may be more important factors. Heat dissipation limits are probably not a phenomenon restricted to lactation. PMID:27157478

  14. 38 CFR 3.810 - Clothing allowance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... prosthetic or orthopedic appliance (including, but not limited to, a wheelchair) which tends to wear or tear... appliance (including, but not limited to, a wheelchair) which tends to wear or tear clothing; or (B) A... allowance for each prosthetic or orthopedic appliance (including, but not limited to, a wheelchair)...

  15. 38 CFR 3.810 - Clothing allowance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... prosthetic or orthopedic appliance (including, but not limited to, a wheelchair) which tends to wear or tear... appliance (including, but not limited to, a wheelchair) which tends to wear or tear clothing; or (B) A... allowance for each prosthetic or orthopedic appliance (including, but not limited to, a wheelchair)...

  16. Moisture rivals temperature in limiting photosynthesis by trees establishing beyond their cold-edge range limit under ambient and warmed conditions

    USGS Publications Warehouse

    Moyes, Andrew B.; Germino, Matthew J.; Kueppers, Lara M.

    2015-01-01

    Summer precipitation may be at least as important as temperature in constraining C gain by establishing subalpine trees at and above current alpine treelines as seasonally dry subalpine and alpine ecosystems continue to warm.

  17. Towards Determining the Upper Temperature Limits to Life on Earth: An In-situ Sulfide-Microbial Incubator

    NASA Astrophysics Data System (ADS)

    Kelley, D.; Baross, J.; Delaney, J.; Girguis, P.; Schrenk, M.

    2004-12-01

    Determining the maximum conditions under which life thrives, survives, and expires is critical to understanding how and where life might have evolved on our planet and for investigation of life in extraterrestrial environments. Submarine black smoker systems are optimal sites to study such questions because thermal gradients are extreme and accessible within the chimney walls under high-pressure conditions. Intact cells containing DNA and ribosomes have been observed even within the most extreme environments of sulfide structure walls bounded by 300\\deg C fluids. Membrane lipids from archaea have been detected in sulfide flanges and chimneys where temperatures are believed to be 200-300\\deg C. However, a balanced inquiry into the limits of life must focus on characterization of the actual conditions in a given system that favor reactions necessary to initiate and/or sustain life. At present, in-situ instrumentation of sulfide deposits is the only effective way to gain direct access to these natural high-temperature environments for documentation and experimentation. With this goal in mind, three prototype microbial incubators were developed with funding from the NSF, University of Washington, and the W.M. Keck Foundation. The incubators were deployed in 2003 in the walls of active black smoker chimneys in the Mothra Hydrothermal Field, Endeavour Segment of the Juan de Fuca Ridge. All instruments were successfully recovered in 2004, and one was redeployed for a short time-series experiment. Each 53-cm-long titanium assembly houses 27 temperature sensors that record temperatures from 0 to 500\\deg C within three discrete incubation chambers. Data are logged in a separate housing and inductively coupled links provide access to the data loggers without removal of the instruments. During the initial deployment, data were collected from 189 to 245 days, with up to ˜478° K temperature measurements completed for an individual instrument. Temperatures within the chimney

  18. 14 CFR 23.1521 - Powerplant limitations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., and liquid coolant temperatures. (d) Fuel grade or designation. The minimum fuel grade (for... reciprocating engines); (3) The maximum allowable gas temperature (for turbine engines); (4) The time limit for...) through (3) of this section; and (5) The maximum allowable cylinder head (as applicable), liquid...

  19. Modelling the impact of temperature-induced life history plasticity and mate limitation on the epidemic potential of a marine ectoparasite.

    PubMed

    Groner, Maya L; Gettinby, George; Stormoen, Marit; Revie, Crawford W; Cox, Ruth

    2014-01-01

    Temperature is hypothesized to contribute to increased pathogenicity and virulence of many marine diseases. The sea louse (Lepeophtheirus salmonis) is an ectoparasite of salmonids that exhibits strong life-history plasticity in response to temperature; however, the effect of temperature on the epidemiology of this parasite has not been rigorously examined. We used matrix population modelling to examine the influence of temperature on demographic parameters of sea lice parasitizing farmed salmon. Demographically-stochastic population projection matrices were created using parameters from the existing literature on vital rates of sea lice at different fixed temperatures and yearly temperature profiles. In addition, we quantified the effectiveness of a single stage-specific control applied at different times during a year with seasonal temperature changes. We found that the epidemic potential of sea lice increased with temperature due to a decrease in generation time and an increase in the net reproductive rate. In addition, mate limitation constrained population growth more at low temperatures than at high temperatures. Our model predicts that control measures targeting preadults and chalimus are most effective regardless of the temperature. The predictions from this model suggest that temperature can dramatically change vital rates of sea lice and can increase population growth. The results of this study suggest that sea surface temperatures should be considered when choosing salmon farm sites and designing management plans to control sea louse infestations. More broadly, this study demonstrates the utility of matrix population modelling for epidemiological studies. PMID:24505493

  20. Feedback damping of a microcantilever at room temperature to the minimum vibration amplitude limited by the noise level

    PubMed Central

    Kawamura, Y.; Kanegae, R.

    2016-01-01

    Cooling the vibration amplitude of a microcantilever as low as possible is important to improve the sensitivity and resolutions of various types of scanning type microscopes and sensors making use of it. When the vibration amplitude is controlled to be smaller using a feed back control system, it is known that the obtainable minimum amplitude of the vibration is limited by the floor noise level of the detection system. In this study, we demonstrated that the amplitude of the thermal vibration of a microcantilever was suppressed to be about 0.15 pmHz−1/2, which is the same value with the floor noise level, without the assistance of external cryogenic cooling. We think that one of the reason why we could reach the smaller amplitude at room temperature is due to stiffer spring constant of the lever, which leads to higher natural frequency and consequently lower floor noise level. The other reason is considered to be due to the increase in the laser power for the diagnostics, which lead to the decrease in the signal to noise ratio determined by the optical shot noise. PMID:27312284

  1. A Limited Number of Caenorhabditis Elegans Genes Are Readily Mutable to Dominant, Temperature-Sensitive Maternal-Effect Embryonic Lethality

    PubMed Central

    Mitenko, N. L.; Eisner, J. R.; Swiston, J. R.; Mains, P. E.

    1997-01-01

    Dominant gain-of-function mutations can give unique insights into the study of gene function. In addition, gain-of-function mutations, unlike loss-of-function alleles, are not biased against the identification of genetically redundant loci. To identify novel genetic functions active during Caenorhabditis elegans embryogenesis, we have collected a set of dominant temperature-sensitive maternal-effect embryonic lethal mutations. In a previous screen, we isolated eight such mutations, distributed among six genes. In the present study, we describe eight new dominant mutations that identify only three additional genes, yielding a total of 16 dominant mutations found in nine genes. Therefore, it appears that a limited number of C. elegans genes mutate to this phenotype at appreciable frequencies. Five of the genes that we identified by dominant mutations have loss-of-function alleles. Two of these genes may lack loss-of-function phenotypes, indicating that they are nonessential and so may represent redundant loci. Loss-of-function mutations of three other genes are associated with recessive lethality, indicating nonredundancy. PMID:9409829

  2. Feedback damping of a microcantilever at room temperature to the minimum vibration amplitude limited by the noise level

    NASA Astrophysics Data System (ADS)

    Kawamura, Y.; Kanegae, R.

    2016-06-01

    Cooling the vibration amplitude of a microcantilever as low as possible is important to improve the sensitivity and resolutions of various types of scanning type microscopes and sensors making use of it. When the vibration amplitude is controlled to be smaller using a feed back control system, it is known that the obtainable minimum amplitude of the vibration is limited by the floor noise level of the detection system. In this study, we demonstrated that the amplitude of the thermal vibration of a microcantilever was suppressed to be about 0.15 pmHz-1/2, which is the same value with the floor noise level, without the assistance of external cryogenic cooling. We think that one of the reason why we could reach the smaller amplitude at room temperature is due to stiffer spring constant of the lever, which leads to higher natural frequency and consequently lower floor noise level. The other reason is considered to be due to the increase in the laser power for the diagnostics, which lead to the decrease in the signal to noise ratio determined by the optical shot noise.

  3. Potential for reducing air-pollutants while achieving 2 °C global temperature change limit target.

    PubMed

    Hanaoka, Tatsuya; Akashi, Osamu; Fujiwara, Kazuya; Motoki, Yuko; Hibino, Go

    2014-12-01

    This study analyzes the potential to reduce air pollutants while achieving the 2 °C global temperature change limit target above pre-industrial levels, by using the bottom-up optimization model, AIM/Enduse[Global]. This study focuses on; 1) estimating mitigation potentials and costs for achieving 2 °C, 2.5 °C, and 3 °C target scenarios, 2) assessing co-benefits of reducing air pollutants such as NOx, SO2, BC, PM, and 3) analyzing features of sectoral attributions in Annex I and Non-Annex I groups of countries. The carbon tax scenario at 50 US$/tCO2-eq in 2050 can reduce GHG emissions more than the 3 °C target scenario, but a higher carbon price around 400 US$/tCO2-eq in 2050 is required to achieve the 2 °C target scenario. However, there is also a co-benefit of large reduction potential of air pollutants, in the range of 60-80% reductions in 2050 from the reference scenario while achieving the 2 °C target. PMID:25028265

  4. Feedback damping of a microcantilever at room temperature to the minimum vibration amplitude limited by the noise level

    NASA Astrophysics Data System (ADS)

    Kawamura, Y.; Kanegae, R.

    2016-06-01

    Cooling the vibration amplitude of a microcantilever as low as possible is important to improve the sensitivity and resolutions of various types of scanning type microscopes and sensors making use of it. When the vibration amplitude is controlled to be smaller using a feed back control system, it is known that the obtainable minimum amplitude of the vibration is limited by the floor noise level of the detection system. In this study, we demonstrated that the amplitude of the thermal vibration of a microcantilever was suppressed to be about 0.15 pmHz‑1/2, which is the same value with the floor noise level, without the assistance of external cryogenic cooling. We think that one of the reason why we could reach the smaller amplitude at room temperature is due to stiffer spring constant of the lever, which leads to higher natural frequency and consequently lower floor noise level. The other reason is considered to be due to the increase in the laser power for the diagnostics, which lead to the decrease in the signal to noise ratio determined by the optical shot noise.

  5. Feedback damping of a microcantilever at room temperature to the minimum vibration amplitude limited by the noise level.

    PubMed

    Kawamura, Y; Kanegae, R

    2016-01-01

    Cooling the vibration amplitude of a microcantilever as low as possible is important to improve the sensitivity and resolutions of various types of scanning type microscopes and sensors making use of it. When the vibration amplitude is controlled to be smaller using a feed back control system, it is known that the obtainable minimum amplitude of the vibration is limited by the floor noise level of the detection system. In this study, we demonstrated that the amplitude of the thermal vibration of a microcantilever was suppressed to be about 0.15 pmHz(-1/2), which is the same value with the floor noise level, without the assistance of external cryogenic cooling. We think that one of the reason why we could reach the smaller amplitude at room temperature is due to stiffer spring constant of the lever, which leads to higher natural frequency and consequently lower floor noise level. The other reason is considered to be due to the increase in the laser power for the diagnostics, which lead to the decrease in the signal to noise ratio determined by the optical shot noise. PMID:27312284

  6. Potential for reducing air-pollutants while achieving 2 °C global temperature change limit target.

    PubMed

    Hanaoka, Tatsuya; Akashi, Osamu; Fujiwara, Kazuya; Motoki, Yuko; Hibino, Go

    2014-12-01

    This study analyzes the potential to reduce air pollutants while achieving the 2 °C global temperature change limit target above pre-industrial levels, by using the bottom-up optimization model, AIM/Enduse[Global]. This study focuses on; 1) estimating mitigation potentials and costs for achieving 2 °C, 2.5 °C, and 3 °C target scenarios, 2) assessing co-benefits of reducing air pollutants such as NOx, SO2, BC, PM, and 3) analyzing features of sectoral attributions in Annex I and Non-Annex I groups of countries. The carbon tax scenario at 50 US$/tCO2-eq in 2050 can reduce GHG emissions more than the 3 °C target scenario, but a higher carbon price around 400 US$/tCO2-eq in 2050 is required to achieve the 2 °C target scenario. However, there is also a co-benefit of large reduction potential of air pollutants, in the range of 60-80% reductions in 2050 from the reference scenario while achieving the 2 °C target.

  7. 28 CFR 66.22 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... applicable to the organization incurring the costs. The following chart lists the kinds of organizations and... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Allowable costs. 66.22 Section 66.22... Administration § 66.22 Allowable costs. (a) Limitation on use of funds. Grant funds may be used only for: (1)...

  8. 21 CFR 1403.22 - Allowable costs.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... and an organization named in OMB Circular A-122 as not subject to that circular 48 CFR part 31... 21 Food and Drugs 9 2011-04-01 2011-04-01 false Allowable costs. 1403.22 Section 1403.22 Food and....22 Allowable costs. (a) Limitation on use of funds. Grant funds may be used only for: (1)...

  9. 36 CFR 1207.22 - Allowable costs.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Circular A-122 as not subject to that circular 48 CFR part 31. Contract Cost Principles and Procedures, or... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false Allowable costs. 1207.22... GOVERNMENTS Post-Award Requirements Financial Administration § 1207.22 Allowable costs. (a) Limitation on...

  10. 45 CFR 1183.22 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... than a hospital and an organization named in OBM Circular A-122 as not subject to that circular 48 CFR... 45 Public Welfare 3 2010-10-01 2010-10-01 false Allowable costs. 1183.22 Section 1183.22 Public....22 Allowable costs. (a) Limitation on use of funds. Grant funds may be used only for: (1)...

  11. 7 CFR 3016.22 - Allowable costs.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Circular A-122 as not subject to that circular 48 CFR part 31. Contract Cost Principles and Procedures, or... 7 Agriculture 15 2011-01-01 2011-01-01 false Allowable costs. 3016.22 Section 3016.22 Agriculture... GOVERNMENTS Post-Award Requirements Financial Administration § 3016.22 Allowable costs. (a) Limitation on...

  12. 38 CFR 43.22 - Allowable costs.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... not subject to that circular 48 CFR part 31. Contract Cost Principles and Procedures, or uniform cost... 38 Pensions, Bonuses, and Veterans' Relief 2 2011-07-01 2011-07-01 false Allowable costs. 43.22... Requirements Financial Administration § 43.22 Allowable costs. (a) Limitation on use of funds. Grant funds...

  13. 45 CFR 602.22 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CFR part 31. Contract Cost Principles and Procedures, or uniform cost accounting standards that comply... 45 Public Welfare 3 2010-10-01 2010-10-01 false Allowable costs. 602.22 Section 602.22 Public... Requirements § 602.22 Allowable costs. (a) Limitation on use of funds. Grant funds may be used only for:...

  14. 29 CFR 1470.22 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... to that circular 48 CFR part 31. Contract Cost Principles and Procedures, or uniform cost accounting... 29 Labor 4 2010-07-01 2010-07-01 false Allowable costs. 1470.22 Section 1470.22 Labor Regulations... Financial Administration § 1470.22 Allowable costs. (a) Limitation on use of funds. Grant funds may be...

  15. 45 CFR 1174.22 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... than a hospital and an organization named in OBM Circular A-122 as not subject to that circular 48 CFR... 45 Public Welfare 3 2010-10-01 2010-10-01 false Allowable costs. 1174.22 Section 1174.22 Public....22 Allowable costs. (a) Limitation on use of funds. Grant funds may be used only for: (1)...

  16. 45 CFR 2541.220 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... not subject to that circular 48 CFR Part 31. Contract Cost Principles and Procedures, or uniform cost... 45 Public Welfare 4 2010-10-01 2010-10-01 false Allowable costs. 2541.220 Section 2541.220 Public... Post-Award Requirements § 2541.220 Allowable costs. (a) Limitation on use of funds. Grant funds may...

  17. 45 CFR 92.22 - Allowable costs.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... to that circular 48 CFR Part 31. Contract Cost Principles and Procedures, or uniform cost accounting... 45 Public Welfare 1 2011-10-01 2011-10-01 false Allowable costs. 92.22 Section 92.22 Public... Financial Administration § 92.22 Allowable costs. (a) Limitation on use of funds. Grant funds may be...

  18. 34 CFR 656.30 - What are allowable costs and limitations on allowable costs?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) Library acquisitions; (3) Teaching and research materials; (4) Curriculum planning and development; (5) Bringing visiting scholars and faculty to the Center to teach, conduct research, or participate in...; and (8) Summer institutes in the United States or abroad designed to provide language and...

  19. 34 CFR 656.30 - What are allowable costs and limitations on allowable costs?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) Library acquisitions; (3) Teaching and research materials; (4) Curriculum planning and development; (5) Bringing visiting scholars and faculty to the Center to teach, conduct research, or participate in...; and (8) Summer institutes in the United States or abroad designed to provide language and...

  20. 34 CFR 656.30 - What are allowable costs and limitations on allowable costs?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) Library acquisitions; (3) Teaching and research materials; (4) Curriculum planning and development; (5) Bringing visiting scholars and faculty to the Center to teach, conduct research, or participate in...; and (8) Summer institutes in the United States or abroad designed to provide language and...

  1. 34 CFR 656.30 - What are allowable costs and limitations on allowable costs?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) Library acquisitions; (3) Teaching and research materials; (4) Curriculum planning and development; (5) Bringing visiting scholars and faculty to the Center to teach, conduct research, or participate in...; and (8) Summer institutes in the United States or abroad designed to provide language and...

  2. 34 CFR 656.30 - What are allowable costs and limitations on allowable costs?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... FOREIGN LANGUAGE AND AREA STUDIES OR FOREIGN LANGUAGE AND INTERNATIONAL STUDIES What Conditions Must Be...) Library acquisitions; (3) Teaching and research materials; (4) Curriculum planning and development; (5...; and (8) Summer institutes in the United States or abroad designed to provide language and...

  3. Allowable carbon emissions lowered by multiple climate targets.

    PubMed

    Steinacher, Marco; Joos, Fortunat; Stocker, Thomas F

    2013-07-11

    Climate targets are designed to inform policies that would limit the magnitude and impacts of climate change caused by anthropogenic emissions of greenhouse gases and other substances. The target that is currently recognized by most world governments places a limit of two degrees Celsius on the global mean warming since preindustrial times. This would require large sustained reductions in carbon dioxide emissions during the twenty-first century and beyond. Such a global temperature target, however, is not sufficient to control many other quantities, such as transient sea level rise, ocean acidification and net primary production on land. Here, using an Earth system model of intermediate complexity (EMIC) in an observation-informed Bayesian approach, we show that allowable carbon emissions are substantially reduced when multiple climate targets are set. We take into account uncertainties in physical and carbon cycle model parameters, radiative efficiencies, climate sensitivity and carbon cycle feedbacks along with a large set of observational constraints. Within this framework, we explore a broad range of economically feasible greenhouse gas scenarios from the integrated assessment community to determine the likelihood of meeting a combination of specific global and regional targets under various assumptions. For any given likelihood of meeting a set of such targets, the allowable cumulative emissions are greatly reduced from those inferred from the temperature target alone. Therefore, temperature targets alone are unable to comprehensively limit the risks from anthropogenic emissions.

  4. 40 CFR 35.2025 - Allowance and advance of allowance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... advance of allowance. (a) Allowance. Step 2+3 and Step 3 grant agreements will include an allowance for facilities planning and design of the project and Step 7 agreements will include an allowance for facility... would receive under paragraph (a) of this section. (5) In the event a Step 2+3, Step 3 or Step 7...

  5. Interaction Effects of Light, Temperature and Nutrient Limitations (N, P and Si) on Growth, Stoichiometry and Photosynthetic Parameters of the Cold-Water Diatom Chaetoceros wighamii.

    PubMed

    Spilling, Kristian; Ylöstalo, Pasi; Simis, Stefan; Seppälä, Jukka

    2015-01-01

    Light (20-450 μmol photons m(-2) s(-1)), temperature (3-11 °C) and inorganic nutrient composition (nutrient replete and N, P and Si limitation) were manipulated to study their combined influence on growth, stoichiometry (C:N:P:Chl a) and primary production of the cold water diatom Chaetoceros wighamii. During exponential growth, the maximum growth rate (~0.8 d(-1)) was observed at high temperature and light; at 3 °C the growth rate was ~30% lower under similar light conditions. The interaction effect of light and temperature were clearly visible from growth and cellular stoichiometry. The average C:N:P molar ratio was 80:13:1 during exponential growth, but the range, due to different light acclimation, was widest at the lowest temperature, reaching very low C:P (~50) and N:P ratios (~8) at low light and temperature. The C:Chl a ratio had also a wider range at the lowest temperature during exponential growth, ranging 16-48 (weight ratio) at 3 °C compared with 17-33 at 11 °C. During exponential growth, there was no clear trend in the Chl a normalized, initial slope (α*) of the photosynthesis-irradiance (PE) curve, but the maximum photosynthetic production (P(m)) was highest for cultures acclimated to the highest light and temperature. During the stationary growth phase, the stoichiometric relationship depended on the limiting nutrient, but with generally increasing C:N:P ratio. The average photosynthetic quotient (PQ) during exponential growth was 1.26 but decreased to <1 under nutrient and light limitation, probably due to photorespiration. The results clearly demonstrate that there are interaction effects between light, temperature and nutrient limitation, and the data suggests greater variability of key parameters at low temperature. Understanding these dynamics will be important for improving models of aquatic primary production and biogeochemical cycles in a warming climate.

  6. Variation in the daily rhythm of body temperature of free-living Arabian oryx (Oryx leucoryx): does water limitation drive heterothermy?

    PubMed

    Hetem, Robyn Sheila; Strauss, Willem Maartin; Fick, Linda Gayle; Maloney, Shane Kevin; Meyer, Leith Carl Rodney; Shobrak, Mohammed; Fuller, Andrea; Mitchell, Duncan

    2010-10-01

    Heterothermy, a variability in body temperature beyond the limits of homeothermy, has been advanced as a key adaptation of Arabian oryx (Oryx leucoryx) to their arid-zone life. We measured body temperature using implanted data loggers, for a 1-year period, in five oryx free-living in the deserts of Saudi Arabia. As predicted for adaptive heterothermy, during hot months compared to cooler months, not only were maximum daily body temperatures higher (41.1 ± 0.3 vs. 39.7 ± 0.1°C, P = 0.0002) but minimum daily body temperatures also were lower (36.1 ± 0.3 vs. 36.8 ± 0.2°C, P = 0.04), resulting in a larger daily amplitude of the body temperature rhythm (5.0 ± 0.5 vs. 2.9 ± 0.2°C, P = 0.0007), while mean daily body temperature rose by only 0.4°C. The maximum daily amplitude of the body temperature rhythm reached 7.7°C for two of our oryx during the hot-dry period, the largest amplitude ever recorded for a large mammal. Body temperature variability was influenced not only by ambient temperature but also water availability, with oryx displaying larger daily amplitudes of the body temperature rhythm during warm-dry months compared to warm-wet months (3.6 ± 0.6 vs. 2.3 ± 0.3°C, P = 0.005), even though ambient temperatures were the same. Free-living Arabian oryx therefore employ heterothermy greater than that recorded in any other large mammal, but water limitation, rather than high ambient temperature, seems to be the primary driver of this heterothermy. PMID:20502901

  7. 43 CFR 418.13 - Maximum allowable limits.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Truckee Canal to Rock Dam Ditch) must be charged to the MAD except as provided in §§ 418.23 and 418.35 of... 308,319 acre-feet for the 1995 Example. The sample MAD corresponds to a system efficiency for...

  8. 43 CFR 418.13 - Maximum allowable limits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Truckee Canal to Rock Dam Ditch) must be charged to the MAD except as provided in §§ 418.23 and 418.35 of... 308,319 acre-feet for the 1995 Example. The sample MAD corresponds to a system efficiency for...

  9. Conserved and narrow temperature limits in alpine insects: Thermal tolerance and supercooling points of the ice-crawlers, Grylloblatta (Insecta: Grylloblattodea: Grylloblattidae).

    PubMed

    Schoville, Sean D; Slatyer, Rachel A; Bergdahl, James C; Valdez, Glenda A

    2015-07-01

    For many terrestrial species, habitat associations and range size are dependent on physiological limits, which in turn may influence large-scale patterns of species diversity. The temperature range experienced by individuals is considered to shape the breadth of the thermal niche, with species occupying temporally and/or geographically stable climates tolerating a narrow temperature range. High-elevation environments experience large temperature fluctuations, with frequent periods below 0 °C, but Grylloblatta (Grylloblattodea: Grylloblattidae) occupy climatically stable microhabitats within this region. Here we test critical thermal limits and supercooling points for five Grylloblatta populations from across a large geographic area, to examine whether the stable microhabitats of this group are associated with a narrow thermal niche and assess their capacity to tolerate cold conditions. Thermal limits are highly conserved in Grylloblatta, despite substantial genetic divergence among populations spanning 1500 m elevation and being separated by over 500 km. Further, Grylloblatta show exceptionally narrow thermal limits compared to other insect taxa with little capacity to improve cold tolerance via plasticity. In contrast, upper thermal limits were significantly depressed by cold acclimation. Grylloblatta maintain coordinated movement until they freeze, and they die upon freezing. Convergence of the critical thermal minima, supercooling point and lower lethal limits point to adaptation to a cold but, importantly, constant thermal environment. These physiological data provide an explanation for the high endemism and patchy distribution of Grylloblatta, which relies on subterranean retreats to accommodate narrow thermal limits. These retreats are currently buffered from temperature fluctuations by snow cover, and a declining snowpack thus places Grylloblatta at risk of exposure to temperatures beyond its tolerance capacity.

  10. Increasing the upper-limit intensity and temperature range for thermal self-focusing of a laser beam by using plasma density ramp-up

    SciTech Connect

    Bokaei, B.; Niknam, A. R.

    2014-03-15

    This work is devoted to improving relativistic and ponderomotive thermal self-focusing of the intense laser beam in an underdense plasma. It is shown that the ponderomotive nonlinearity induces a saturation mechanism for thermal self-focusing. Therefore, in addition to the well-known lower-limit critical intensity, there is an upper-limit intensity for thermal self-focusing above which the laser beam starts to experience ponderomotive defocusing. It is indicated that the upper-limit intensity value is dependent on plasma and laser parameters such as the plasma electron temperature, plasma density, and laser spot size. Furthermore, the effect of the upward plasma density ramp profile on the thermal self-focusing is studied. Results show that by using the plasma density ramp-up, the upper-limit intensity increases and the self-focusing temperature range expands.

  11. Interaction Effects of Light, Temperature and Nutrient Limitations (N, P and Si) on Growth, Stoichiometry and Photosynthetic Parameters of the Cold-Water Diatom Chaetoceros wighamii

    PubMed Central

    Spilling, Kristian; Ylöstalo, Pasi; Simis, Stefan; Seppälä, Jukka

    2015-01-01

    Light (20-450 μmol photons m-2 s-1), temperature (3-11°C) and inorganic nutrient composition (nutrient replete and N, P and Si limitation) were manipulated to study their combined influence on growth, stoichiometry (C:N:P:Chl a) and primary production of the cold water diatom Chaetoceros wighamii. During exponential growth, the maximum growth rate (~0.8 d-1) was observed at high temperture and light; at 3°C the growth rate was ~30% lower under similar light conditions. The interaction effect of light and temperature were clearly visible from growth and cellular stoichiometry. The average C:N:P molar ratio was 80:13:1 during exponential growth, but the range, due to different light acclimation, was widest at the lowest temperature, reaching very low C:P (~50) and N:P ratios (~8) at low light and temperature. The C:Chl a ratio had also a wider range at the lowest temperature during exponential growth, ranging 16-48 (weight ratio) at 3°C compared with 17-33 at 11°C. During exponential growth, there was no clear trend in the Chl a normalized, initial slope (α*) of the photosynthesis-irradiance (PE) curve, but the maximum photosynthetic production (Pm) was highest for cultures acclimated to the highest light and temperature. During the stationary growth phase, the stoichiometric relationship depended on the limiting nutrient, but with generally increasing C:N:P ratio. The average photosynthetic quotient (PQ) during exponential growth was 1.26 but decreased to <1 under nutrient and light limitation, probably due to photorespiration. The results clearly demonstrate that there are interaction effects between light, temperature and nutrient limitation, and the data suggests greater variability of key parameters at low temperature. Understanding these dynamics will be important for improving models of aquatic primary production and biogeochemical cycles in a warming climate. PMID:25993327

  12. Temperature dependence of the liquid structure factor of dense monatomic fluids in the long wavelength limit in relation to thermal expansivity

    NASA Astrophysics Data System (ADS)

    March, N. H.; Alonso, J. A.

    2012-03-01

    The temperature dependence of the liquid structure factor S(k) of dense monatomic fluids, and especially a variety of liquid metals, is studied by combining thermodynamics and fluctuation theory in the long wavelength limit k → 0. Emphasis is placed on the connection of ? with thermal expansivity. Reference here is then made to recent semiempirical work of Lawson, who advocated an approximate relation, but at the melting temperature T m , between ? and the Gruneisen constant.

  13. Evaluation of the Maximum Allowable Cost Program

    PubMed Central

    Lee, A. James; Hefner, Dennis; Dobson, Allen; Hardy, Ralph

    1983-01-01

    This article summarizes an evaluation of the Maximum Allowable Cost (MAC)-Estimated Acquisition Cost (EAC) program, the Federal Government's cost-containment program for prescription drugs.1 The MAC-EAC regulations which became effective on August 26, 1976, have four major components: (1) Maximum Allowable Cost reimbursement limits for selected multisource or generically available drugs; (2) Estimated Acquisition Cost reimbursement limits for all drugs; (3) “usual and customary” reimbursement limits for all drugs; and (4) a directive that professional fee studies be performed by each State. The study examines the benefits and costs of the MAC reimbursement limits for 15 dosage forms of five multisource drugs and EAC reimbursement limits for all drugs for five selected States as of 1979. PMID:10309857

  14. Budget-limited thermal biology: Design, construction and performance of a large, walk-in style temperature-controlled chamber.

    PubMed

    Martinez, Eloy; Agosta, Salvatore J

    2016-05-01

    We describe a partial redesign of the conventional air-conditioning system and apply it to the construction of a relatively large (1.87m(3) air mass), walk-in style temperature-controlled chamber (TCC) using parts easily obtained in most countries. We conducted several tests to demonstrate the performance of the TCC. Across the physiologically relevant range of 5-37°C, the TCC took 26.5-50.0min to reach the desired set point temperature. Once at set point, temperature inside the chamber was controlled with an accuracy of ±1.0°C. User-entry effects on deviations from and return times to set point temperature were minimal. Overall, performance of the TCC was sufficient to make precise physiological measurements of insect metabolic rate while controlling assay temperature. Major advantages of the TCC include its simplicity, flexibility, and low cost. PMID:27157331

  15. Seeking the Limits of Low-Temperature Nuclear Fusion: Sticking in Muon-Catalyzed Fusion, and Piezonuclear Fusion in Deuterium/condensed Matter Systems

    NASA Astrophysics Data System (ADS)

    Taylor, Stuart F.

    Studies seeking an upper limit of two types of low temperature nuclear fusion is presented. The upper limit for muon catalyzed fusion is generally considered to be the number of fusions per muon obtainable. The limiting factor has been found to be how often the muon remains bound to the alpha produced by the fusion, known as the "sticking fraction." Experiments directly measuring the sticking and determining the sticking using high tritium fractions are presented. In deuterium/condensed matter systems the question is nearly whether nuclear fusion proceeds at all. Experiments where neutrons around deuterided titanium and palladium are measured are presented.

  16. Biochemical acclimation, stomatal limitation and precipitation patterns underlie decreases in photosynthetic stimulation of Soybean (Glycine max) at elevated [CO2] and temperatures under fully open air field conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The net effect of elevated [CO2] and temperature on photosynthetic acclimation and plant productivity is poorly resolved. We assessed the effects of canopy warming and fully open air [CO2] enrichment on 1) the acclimation of two biochemical parameters that frequently limit photosynthesis (A), the ma...

  17. Biochemical acclimation, stomatal limitation and precipitation patterns underlie decreases in photosynthetic stimulation of soybean (Glycine max) at elevated [CO₂] and temperatures under fully open air field conditions.

    PubMed

    Rosenthal, David M; Ruiz-Vera, Ursula M; Siebers, Matthew H; Gray, Sharon B; Bernacchi, Carl J; Ort, Donald R

    2014-09-01

    The net effect of elevated [CO2] and temperature on photosynthetic acclimation and plant productivity is poorly resolved. We assessed the effects of canopy warming and fully open air [CO2] enrichment on (1) the acclimation of two biochemical parameters that frequently limit photosynthesis (A), the maximum carboxylation capacity of Rubisco (Vc,max) and the maximum potential linear electron flux through photosystem II (Jmax), (2) the associated responses of leaf structural and chemical properties related to A, as well as (3) the stomatal limitation (l) imposed on A, for soybean over two growing seasons in a conventionally managed agricultural field in Illinois, USA. Acclimation to elevated [CO2] was consistent over two growing seasons with respect to Vc,max and Jmax. However, elevated temperature significantly decreased Jmax contributing to lower photosynthetic stimulation by elevated CO2. Large seasonal differences in precipitation altered soil moisture availability modulating the complex effects of elevated temperature and CO2 on biochemical and structural properties related to A. Elevated temperature also reduced the benefit of elevated [CO2] by eliminating decreases in stomatal limitation at elevated [CO2]. These results highlight the critical importance of considering multiple environmental factors (i.e. temperature, moisture, [CO2]) when trying to predict plant productivity in the context of climate change.

  18. The temperature response of CO2 assimilation, photochemical activities and Rubisco activation in Camelina sativa, a potential bioenergy crop with limited capacity for acclimation to heat stress.

    PubMed

    Carmo-Silva, A Elizabete; Salvucci, Michael E

    2012-11-01

    The temperature optimum of photosynthesis coincides with the average daytime temperature in a species' native environment. Moderate heat stress occurs when temperatures exceed the optimum, inhibiting photosynthesis and decreasing productivity. In the present study, the temperature response of photosynthesis and the potential for heat acclimation was evaluated for Camelina sativa, a bioenergy crop. The temperature optimum of net CO(2) assimilation rate (A) under atmospheric conditions was 30-32 °C and was only slightly higher under non-photorespiratory conditions. The activation state of Rubisco was closely correlated with A at supra-optimal temperatures, exhibiting a parallel decrease with increasing leaf temperature. At both control and elevated temperatures, the modeled response of A to intercellular CO(2) concentration was consistent with Rubisco limiting A at ambient CO(2). Rubisco activation and photochemical activities were affected by moderate heat stress at lower temperatures in camelina than in the warm-adapted species cotton and tobacco. Growth under conditions that imposed a daily interval of moderate heat stress caused a 63 % reduction in camelina seed yield. Levels of cpn60 protein were elevated under the higher growth temperature, but acclimation of photosynthesis was minimal. Inactivation of Rubisco in camelina at temperatures above 35 °C was consistent with the temperature response of Rubisco activase activity and indicated that Rubisco activase was a prime target of inhibition by moderate heat stress in camelina. That photosynthesis exhibited no acclimation to moderate heat stress will likely impact the development of camelina and other cool season Brassicaceae as sources of bioenergy in a warmer world.

  19. Estimation of upper flammability limits of C-H compounds in air at standard atmospheric pressure and evaluation of temperature dependence.

    PubMed

    Mendiburu, Andrés Z; de Carvalho, João A; Coronado, Christian R

    2016-03-01

    This study focuses on estimating the upper flammability limits of C-H compounds. A method was developed to determine the upper flammability limits in air at standard atmospheric pressure for the following cases: (a) estimation of the UFLs of pure C-H compounds at standard ambient temperature (25°C); (b) estimation of the UFLs of binary mixtures of C-H compounds at standard ambient temperature (25°C); (c) estimation of the UFLs of C-H compounds at different initial temperatures. The method was accurate in all cases. In case (a), for a total set of 115 compounds, the absolute average relative error was 7.27% and a squared correlation coefficient of 0.9248 was obtained. In case (b), the average absolute relative error was 5.55%; in case (c) it was 2.19%. PMID:26619050

  20. Estimation of upper flammability limits of C-H compounds in air at standard atmospheric pressure and evaluation of temperature dependence.

    PubMed

    Mendiburu, Andrés Z; de Carvalho, João A; Coronado, Christian R

    2016-03-01

    This study focuses on estimating the upper flammability limits of C-H compounds. A method was developed to determine the upper flammability limits in air at standard atmospheric pressure for the following cases: (a) estimation of the UFLs of pure C-H compounds at standard ambient temperature (25°C); (b) estimation of the UFLs of binary mixtures of C-H compounds at standard ambient temperature (25°C); (c) estimation of the UFLs of C-H compounds at different initial temperatures. The method was accurate in all cases. In case (a), for a total set of 115 compounds, the absolute average relative error was 7.27% and a squared correlation coefficient of 0.9248 was obtained. In case (b), the average absolute relative error was 5.55%; in case (c) it was 2.19%.

  1. Limitations to the room temperature mobility of two- and three-dimensional electron liquids in SrTiO{sub 3}

    SciTech Connect

    Mikheev, Evgeny; Himmetoglu, Burak; Kajdos, Adam P.; Moetakef, Pouya; Cain, Tyler A.; Van de Walle, Chris G.; Stemmer, Susanne

    2015-02-09

    We analyze and compare the temperature dependence of the electron mobility of two- and three-dimensional electron liquids in SrTiO{sub 3}. The contributions of electron-electron scattering must be taken into account to accurately describe the mobility in both cases. For uniformly doped, three-dimensional electron liquids, the room temperature mobility crosses over from longitudinal optical (LO) phonon-scattering-limited to electron-electron-scattering-limited as a function of carrier density. In high-density, two-dimensional electron liquids, LO phonon scattering is completely screened and the mobility is dominated by electron-electron scattering up to room temperature. The possible origins of the observed behavior and the consequences for approaches to improve the mobility are discussed.

  2. The Tangle of Student Allowances.

    ERIC Educational Resources Information Center

    Thomson, Norman J.

    1980-01-01

    A discussion of the distribution of student financial aid in Australia focuses on these issues: direct vs. indirect payment to students; inequality in living allowances given to secondary and postsecondary students; and distribution of expense allowances by state government and living allowances by the Commonwealth. (MSE)

  3. Transfer of nonclassical properties from a microscopic superposition to macroscopic thermal states in the high temperature limit.

    PubMed

    Jeong, Hyunseok; Ralph, Timothy C

    2006-09-01

    We present several examples where prominent quantum properties are transferred from a microscopic superposition to thermal states at high temperatures. Our work is motivated by an analogy of Schrödinger's cat paradox, where the state corresponding to the virtual cat is a mixed thermal state with a large average photon number. Remarkably, quantum entanglement can be produced between thermal states with nearly the maximum Bell-inequality violation even when the temperatures of both modes approach infinity.

  4. 15 CFR 24.22 - Allowable costs.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... than a hospital and an organization named in OBM Circular A-122 as not subject to that circular 48 CFR... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false Allowable costs. 24.22 Section 24.22... Administration § 24.22 Allowable costs. (a) Limitation on use of funds. Grant funds may be used only for: (1)...

  5. Regulatory treatment of allowances and compliance costs

    SciTech Connect

    Rose, K.

    1993-07-01

    The Clean Air Act Amendments of 1990 (CAAA) established a national emission allowance trading system, a market-based form of environmental regulation designed to reduce and limit sulfur dioxide emissions. However, the allowance trading system is being applied primarily to an economically regulated electric utility industry. The combining of the new form of environmental regulation and economic regulation of electric utilities has raised a number of questions including what the role should be of the federal and state utility regulating commissions and how those actions will affect the decision making process of the utilities and the allowance market. There are several dimensions to the regulatory problems that commissions face. Allowances and utility compliance expenditures have implications for least-cost/IPR (integrated resource planning), prudence review procedures, holding company and multistate utility regulation and ratemaking treatment. The focus of this paper is on the ratemaking treatment. The following topics are covered: ratemaking treatment of allowances and compliance costs; Traditional cost-recovery mechanisms; limitations to the traditional approach; traditional approach and the allowance trading market; market-based cost recovery mechanisms; methods of determining the benchmark; determining the split between ratepayers and the utility; other regulatory approaches; limitations of incentive mechanisms.

  6. Extreme high temperature redox kinetics in ceria: exploration of the transition from gas-phase to material-kinetic limitations.

    PubMed

    Ji, Ho-Il; Davenport, Timothy C; Gopal, Chirranjeevi Balaji; Haile, Sossina M

    2016-08-01

    The redox kinetics of undoped ceria (CeO2-δ) are investigated by the electrical conductivity relaxation method in the oxygen partial pressure range of -4.3 ≤ log(pO2/atm) ≤ -2.0 at 1400 °C. It is demonstrated that extremely large gas flow rates, relative to the mass of the oxide, are required in order to overcome gas phase limitations and access the material kinetic properties. Using these high flow rate conditions, the surface reaction rate constant kchem is found to obey the correlation log(kchem/cm s(-1)) = (0.84 ± 0.02) × log(pO2/atm) - (0.99 ± 0.05) and increases with oxygen partial pressure. This increase contrasts the known behavior of the dominant defect species, oxygen vacancies and free electrons, which decrease in concentration with increasing oxygen partial pressure. For the sample geometries employed, diffusion was too fast to be detected. At low gas flow rates, the relaxation process becomes limited by the capacity of the sweep gas to supply/remove oxygen to/from the oxide. An analytical expression is derived for the relaxation in the gas-phase limited regime, and the result reveals an exponential decay profile, identical in form to that known for a surface reaction limited process. Thus, measurements under varied gas flow rates are required to differentiate between surface reaction limited and gas flow limited behavior. PMID:27425414

  7. Ambient temperature shapes reproductive output during pregnancy and lactation in the common vole (Microtus arvalis): a test of the heat dissipation limit theory.

    PubMed

    Simons, Mirre J P; Reimert, Inonge; van der Vinne, Vincent; Hambly, Catherine; Vaanholt, Lobke M; Speakman, John R; Gerkema, Menno P

    2011-01-01

    The heat dissipation limit theory suggests that heat generated during metabolism limits energy intake and, thus, reproductive output. Experiments in laboratory strains of mice and rats, and also domestic livestock generally support this theory. Selection for many generations in the laboratory and in livestock has increased litter size or productivity in these animals. To test the wider validity of the heat dissipation limit theory, we studied common voles (Microtus arvalis), which have small litter sizes by comparison with mice and rats, and regular addition of wild-caught individuals of this species to our laboratory colony ensures a natural genetic background. A crossover design of ambient temperatures (21 and 30°C) during pregnancy and lactation was used. High ambient temperature during lactation decreased milk production, slowing pup growth. The effect on pup growth was amplified when ambient temperature was also high during pregnancy. Shaving fur off dams at 30°C resulted in faster growth of pups; however, no significant increase in food intake and or milk production was detected. With increasing litter size (natural and enlarged), asymptotic food intake during lactation levelled off in the largest litters at both 21 and 30°C. Interestingly, the effects of lactation temperature on pup growth where also observed at smaller litter sizes. This suggests that vole dams trade-off costs associated with hyperthermia during lactation with the yield from investment in pup growth. Moreover, pup survival was higher at 30°C, despite lower growth, probably owing to thermoregulatory benefits. It remains to be seen how the balance is established between the negative effect of high ambient temperature on maternal milk production and pup growth (and/or future reproduction of the dam) and the positive effect of high temperatures on pup survival. This balance ultimately determines the effect of different ambient temperatures on reproductive success. PMID:21147967

  8. Respiratory Response of the Deep-Sea Amphipod Stephonyx biscayensis Indicates Bathymetric Range Limitation by Temperature and Hydrostatic Pressure

    PubMed Central

    Brown, Alastair; Thatje, Sven

    2011-01-01

    Depth zonation of fauna on continental margins is well documented. Whilst increasing hydrostatic pressure with depth has long been considered a factor contributing significantly to this pattern, discussion of the relative significance of decreasing temperature with depth has continued. This study investigates the physiological tolerances of fed and starved specimens of the bathyal lysianassoid amphipod Stephonyx biscayensis at varying temperature to acute pressure exposure by measuring the rate of oxygen consumption. Acclimation to atmospheric pressure is shown to have no significant interaction with temperature and/or pressure effects. Similarly, starvation is shown to have no significant effect on the interaction of temperature and pressure. Subsequently, the effect of pressure on respiration rate is revealed to be dependent on temperature: pressure equivalent to 2000 m depth was tolerated at 1 and 3°C; pressure equivalent to 2500 m depth was tolerated at 5.5°C; at 10°C pressure equivalent to 3000 m depth was tolerated. The variation in tolerance is consistent with the natural distribution range reported for this species. There are clear implications for hypotheses relating to the observed phenomenon of a biodiversity bottleneck between 2000 and 3000 metres, and for the potential for bathymetric range shifts in response to global climate change. PMID:22174838

  9. Perchlorate Found by Phoenix Could Provide a Mobile Brine Sludge at the Bed of Mars Northern Ice Cap that Would Allow Flow with Very Low Basal Temperatures: Possible Mechanism for Water Table Re-Charge

    NASA Astrophysics Data System (ADS)

    Fisher, D. A.; Hecht, M.; Kounaves, S.; Catling, D.

    2009-03-01

    The north cap of Mars has basal temperature that precludes the flow of ice. Phoenix discovered polar soils contain perchlorate salts. These salts depress the melting point so it could form a sludge that provides a mobile bed that moves the ice outwards.

  10. Low temperature limits for mixing recycled oil, diesel fuel, and ammonium nitrate to make ANFO-type blasting agents

    SciTech Connect

    Ruhe, T.C.; Bajpayee, T.S.

    1996-12-31

    The Bureau of Mines conducted research to determine the safe operating conditions for using recycled (used) lubricating oil from mining equipment as a partial replacement for diesel fuel to make ANFO-type blasting agents. The use of recycled oil (RO) saves energy, reduces oil imports, and reduces mining costs. Low ambient temperatures may cause these recycled oils to become too viscous for proper absorption by ammonium nitrate (AN) prills and result in poor blast performance, safety hazards, and environmental problems. To help quantify and resolve these issues, viscosity, mixing, and performance tests were conducted at various temperatures. Diesel fuels No. 1 and No. 2 were studied separately and in blends with 25, 50, and 75% RO. Good quality ANFO mixes (94-6) were produced with dry absorbent prills and blended fuel (No. 1 diesel plus RO) at temperatures as low as {minus}40 F ({minus}40 C) with 75% No. 1/25% RO, and at {minus}20 F ({minus}29 C) with 50/50. Diesel fuel No. 2 also made good mixes as low as {minus}30 F ({minus}34 C) with 75% No. 2/25% RO, and at 0 F ({minus}18 C) with 50/50. Reference detonation velocity tests were conducted in 1.4 in. (3.6 cm) diameter steel pipe at 70 F (21 C) on No. 1 diesel ANFO (94-6), giving an average value of 9,722 ft/s (2,964 m/s). Comparison tests showed good ANFO performance at low temperatures. Based on these results, a practical field method has been developed to help evaluate whether a specific oil blend will mix properly with AN at a low ambient temperature. This method will help to promote the safe and reliable use of RO ANFO at low temperatures, with adequate performance.

  11. High-level expression of ice nuclei in a Pseudomonas syringae strain is induced by nutrient limitation and low temperature.

    PubMed

    Nemecek-Marshall, M; LaDuca, R; Fall, R

    1993-07-01

    Attempts were made to maximize the expression of ice nuclei in Pseudomonas syringae T1 isolated from a tomato leaf. Nutritional starvation for nitrogen, phosphorous, sulfur, or iron but not carbon at 32 degrees C, coupled to a shift to 14 to 18 degrees C, led to the rapid induction of type 1 ice nuclei (i.e., ice nuclei active at temperatures warmer than -5 degrees C). Induction was most pronounced in stationary-phase cells that were grown with sorbitol as the carbon source and cooled rapidly, and under optimal conditions, the expression of type 1 ice nuclei increased from < 1 per 10(7) cells (i.e., not detectable) to 1 in every cell in 2 to 3 h. The induction was blocked by protein and RNA synthesis inhibitors, indicative of new gene expression. Pulse-labeling of nongrowing cultures with [35S]methionine after a shift to a low temperature demonstrated that the synthesis of a new set of "low-temperature" proteins was induced. Induced ice nuclei were stable at a low temperature, with no loss in activity at 4 degrees C after 8 days, but after a shift back to 32 degrees C, type 1 ice nuclei completely disappeared, with a half-life of approximately 1 h. Repeated cycles of low-temperature induction and high-temperature turnover of these ice nuclei could be demonstrated with the same nongrowing cells. Not all P. syringae strains from tomato or other plants were fully induced under the same culture conditions as strain T1, but all showed increased expression of type 1 ice nuclei after the shift to the low temperature. In support of this view, analysis of the published DNA sequence preceding the translational start site of the inaZ gene (R. L. Green and G. Warren, Nature [London] 317:645-648, 1985) suggests the presence of a gearbox-type promoter (M. Vincente, S. R. Kushner, T. Garrido, and M. Aldea, Mol. Microbiol. 5:2085-2091, 1991).

  12. Mangrove expansion and contraction at a poleward range limit: Climate extremes and land-ocean temperature gradients

    USGS Publications Warehouse

    Osland, Michael J.; Day, Richard H.; Hall, Courtney T.; Brumfield, Marisa D; Dugas, Jason; Jones, William R.

    2016-01-01

    Within the context of climate change, there is a pressing need to better understand the ecological implications of changes in the frequency and intensity of climate extremes. Along subtropical coasts, less frequent and warmer freeze events are expected to permit freeze-sensitive mangrove forests to expand poleward and displace freeze-tolerant salt marshes. Here, our aim was to better understand the drivers of poleward mangrove migration by quantifying spatiotemporal patterns in mangrove range expansion and contraction across land-ocean temperature gradients. Our work was conducted in a freeze-sensitive mangrove-marsh transition zone that spans a land-ocean temperature gradient in one of the world's most wetland-rich regions (Mississippi River Deltaic Plain; Louisiana, USA). We used historical air temperature data (1893-2014), alternative future climate scenarios, and coastal wetland coverage data (1978-2011) to investigate spatiotemporal fluctuations and climate-wetland linkages. Our analyses indicate that changes in mangrove coverage have been controlled primarily by extreme freeze events (i.e., air temperatures below a threshold zone of -6.3 to -7.6 °C). We expect that in the past 121 years, mangrove range expansion and contraction has occurred across land-ocean temperature gradients. Mangrove resistance, resilience, and dominance were all highest in areas closer to the ocean where temperature extremes were buffered by large expanses of water and saturated soil. Under climate change, these areas will likely serve as local hotspots for mangrove dispersal, growth, range expansion, and displacement of salt marsh. Collectively, our results show that the frequency and intensity of freeze events across land-ocean temperature gradients greatly influences spatiotemporal patterns of range expansion and contraction of freeze-sensitive mangroves. We expect that, along subtropical coasts, similar processes govern the distribution and abundance of other freeze

  13. 40 CFR 35.2025 - Allowance and advance of allowance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... facilities planning and design of the project and Step 7 agreements will include an allowance for facility... grant applicants for facilities planning and project design. (2) The State may request that the right...

  14. 40 CFR 35.2025 - Allowance and advance of allowance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... facilities planning and design of the project and Step 7 agreements will include an allowance for facility... grant applicants for facilities planning and project design. (2) The State may request that the right...

  15. 40 CFR 35.2025 - Allowance and advance of allowance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... facilities planning and design of the project and Step 7 agreements will include an allowance for facility... grant applicants for facilities planning and project design. (2) The State may request that the right...

  16. 40 CFR 35.2025 - Allowance and advance of allowance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... facilities planning and design of the project and Step 7 agreements will include an allowance for facility... grant applicants for facilities planning and project design. (2) The State may request that the right...

  17. 76 FR 70883 - Clothing Allowance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-16

    ... published in the Federal Register on February 2, 2011 (76 FR 5733-5734), VA proposed to amend its... appliances affecting different articles of clothing. 76 FR 5733; Sursely, 551 F.3d at 1356. VA will make the... allowances. The amendment provides for an annual clothing allowance for each qualifying prosthetic...

  18. Explosion and combustion properties of alkylsilanes I : temperature-composition limits of explosion for methyl-,dimethyl-,trimethyl-,tetramethyl-,and vinylsilane at atmospheric pressure

    NASA Technical Reports Server (NTRS)

    Schalla, Rose L; Mcdonald, Glen E

    1954-01-01

    The explosion limits of five alkylsilanes were determined as a function of temperature and composition at a pressure of 1 atmosphere. Over a fuel concentration range of 2 to 10 percent, the lowest temperatures (zero C) below which explosion did not occur for the five fuels studied were: tetramethylsilane (CHsub3)sub4Si, 450 degrees; trimethlysilane (CHsub3)sub3SiH, 310 degrees;dimethylsilane (CHsub3)sub2SiHsub2, 220 degrees; methylsilane CHsub3SiHsub3, 130 degrees; and vinylsilane Hsub2C=CH-SiHsub3, 90 degrees. Explosion limits for hydrocarbons analogous to these silanes fall in a temperature range of 500 degrees to 600 degrees C. Since the explosion temperatures of the alkylsilanes are lower than those of the hydrocarbons and since they decrease as hydrogen atoms are substituted for methyl groups, it was concluded that the Si-H bond is more readily susceptible to oxidation than the C-H bond.

  19. The Effect of Temperature and Hydrogen Limited Growth on the Fractionation of Sulfur Isotopes by Thermodesulfatator indicus, a Deep-sea Hydrothermal Vent Sulfate-Reducing Bacterium

    NASA Astrophysics Data System (ADS)

    Hoek, J.; Reysenbach, A.; Habicht, K.; Canfield, D. E.

    2004-12-01

    Sulfate-reducing bacteria fractionate sulfur isotopes during dissimilatory sulfate reduction, producing sulfide depleted in 34S. Although isotope fractionation during sulfate reduction of pure cultures has been extensively studied, most of the research to date has focused on mesophilic sulfate reducers, particularly for the species Desulfovibrio desulfuricans. Results from these studies show that: 1) fractionations range from 3-46‰ with an average around 18‰ , 2) when organic electron donors are utilized, the extent of fractionation is dependent on the rate of sulfate reduction, with decreasing fractionations observed with higher specific rates, 3) fractionations are suppressed with low sulfate concentrations, and when hydrogen is used as the electron donor. High specific sulfate-reduction rates are encountered when sulfate-reducing bacteria metabolize at their optimal temperature and under non-limiting substrate conditions. Changes in both temperature and substrate availability could shift fractionations from those expressed under optimal growth conditions. Sulfate reducers may frequently experience substrate limitation and sub-optimal growth temperatures in the environment. Therefore it is important to understand how sulfate-reducing bacteria fractionate sulfur isotopes under conditions that more closely resemble the restrictions imposed by the environment. In this study the fractionation of sulfur isotopes by Thermodesulfatator indicus was explored during sulfate reduction under a wide range of temperatures and with both hydrogen-saturating and hydrogen-limited conditions. T. indicus is a thermophilic (temperature optimum = 70° C) chemolithotrophic sulfate-reducing bacterium, which was recently isolated from a deep-sea hydrothermal vent on the Central Indian Ridge. This bacterium represents the type species of a new genus and to date is the most deeply branching sulfate-reducing bacterium known. T. indicus was grown in carbonate-buffered salt-water medium

  20. Temperature-driven self-assembly of self-limiting uniform supraparticles from non-uniform unimolecular micelles.

    PubMed

    Picco, Agustín S; Yameen, Basit; Knoll, Wolfgang; Ceolín, Marcelo R; Azzaroni, Omar

    2016-06-01

    In this work, the self-assembly of non-uniform unimolecular micelles constituted of a hyperbranched polyester core decorated with a corona of thermoresponsive poly(N-isopropylacrylamide) (PNIPAm) chains has been studied. As revealed by dynamic light scattering (DLS), transmission electron microscopy (TEM) and small angle X-ray scattering (SAXS), these unimicelles form uniform supraparticles through a thermally-induced self-limited process, as well as exhibit molecular features commonly observed in PNIPAm-based gels. We believe that these results provide new insights into the application of stimuli-responsive polymeric materials as versatile building blocks to build up soft supraparticles displaying well-defined dimensional characteristics.

  1. Use and Limitations of a Climate-Quality Data Record to Study Temperature Trends on the Greenland Ice Sheet

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy K.; Comiso, Josefino C.; Shuman, Christopher A.; Koenig, Lora S.; DiGirolamo, Nicolo E.

    2011-01-01

    Enhanced melting of the Greenland Ice Sheet has been documented in recent literature along with surface-temperature increases measured using infrared satellite data since 1981. Using a recently-developed climate-quality data record, 11- and 12-year trends in the clear-sky ice-surface temperature (IST) of the Greenland Ice Sheet have been studied using the Moderate-Resolution Imaging Spectroradiometer (MODIS) IST product. Daily and monthly MODIS ISTs of the Greenland Ice Sheet beginning on 1 March 2000 and continuing through 31 December 2010 are now available at 6.25-km spatial resolution on a polar stereographic grid as described in Hall et al. (submitted). This record will be elevated in status to a climate-data record (CDR) when more years of data become available either from the MODIS on the Terra or Aqua satellites, or from the Visible Infrared Imager Radiometer Suite (VIIRS) to be launched in October 2011. Maps showing the maximum extent of melt for the entire ice sheet and for the six major drainage basins have been developed from the MODIS IST dataset. Twelve-year trends of the duration of the melt season on the ice sheet vary in different drainage basins with some basins melting progressively earlier over the course of the study period. Some (but not all) of the basins also show a progressively-longer duration of melt. IST 12-year trends are compared with in-situ data, and climate data from the Modern Era Retrospective-Analysis for Research and Applications (MERRA) Reanalysis.

  2. The effects of thermal acclimation on lethal temperatures and critical thermal limits in the green vegetable bug, Nezara viridula (L.) (Hemiptera: Pentatomidae).

    PubMed

    Chanthy, Pol; Martin, Robert J; Gunning, Robin V; Andrew, Nigel R

    2012-01-01

    According to geographical distribution, Nezara viridula (Heteroptera: Pentatomidae) can be found across tropical, subtropical, and temperate regions and this pattern is assumed to reflect differences in thermal adaptation, particularly in cold tolerance. Here the lethal temperature (LT) and critical thermal limits (CTL) (thermal tolerance) are examined for N. viridula. The upper LT for N. viridula at two contrasting climate locations (Breeza and Grafton, New South Wales, Australia) was 40.3°C with 20% survival under the stress of high temperature. The lower LT did not differ between these two populations and was -8.0°C with 20% survival under low temperature stress. Survival of N. viridula increased after acclimation at high temperature for 7 days. In contrast, when acclimated at lower temperatures (10 and 15°C), survival of Breeza and Grafton N. viridula was lower than 20% at -8.0°C. Control-reared N. viridula adults (25°C) had a mean CT(MinOnset) (cold stupor) of 1.3 ± 2.1°C and a mean CT(Max) (heat coma) of 45.9 ± 0.9°C. After 7 days of acclimation at 10, 20, 30, or 35°C, N. viridula adults exhibited a 1°C change in CT(Max) and a ~1.5°C change in CT(MinOnset). CT(Max) and CT(MinOnset) of Breeza and Grafton N. viridula populations did not differ across acclimation temperatures. These results suggest that short-term temperature acclimation is more important than provenance for determining LTs and CTL in N. viridula.

  3. Critical thermal limits, temperature tolerance and water balance of a sub-Antarctic caterpillar, Pringleophaga marioni (Lepidoptera: Tineidae).

    PubMed

    Chown, S L.; Jaco Klok, C

    1997-07-01

    Thermal tolerance, supercooling point, water balance and osmoregulatory ability of Pringleophaga marioni Viette (Lepidoptera: Tineidae) are investigated in this study. Field-fresh larvae had a mean CT(Min) (cold stupor) of -0.6 degrees C and a mean CT(Max) (heat coma) of 38.7 degrees C. The mean supercooling point of field-fresh individuals was -5.0 degrees C. Caterpillars showed 100% survival of freezing to -6.5 degrees C, but at -12 degrees C mortality rose to 100%. Survival of a 30h exposure to -6.0 degrees C was 80%, but declined to 30% in the 6-12h interval at -7.5 degrees C. No caterpillars survived for longer than 12h at -9.0 degrees C. Survival of high temperatures (35 degrees C and above) was poor. Tolerance of water loss (46% of fresh mass) and rates of water loss (1% fresh massh(-1)) were similar to those found in other mesic insects. P. marioni larvae were incapable of metabolizing lipids to replenish lost water and showed no haemolymph osmoregulatory ability. It is suggested that the preponderance of freeze tolerance in high-latitude southern hemisphere species may be associated with their occurrence in moist habitats, and that the "freeze tolerance" category be re-examined in the light of the range of strategies adopted by such arthropods.

  4. The effects of acclimation and rates of temperature change on critical thermal limits in Tenebrio molitor (Tenebrionidae) and Cyrtobagous salviniae (Curculionidae).

    PubMed

    Allen, Jessica L; Clusella-Trullas, Susana; Chown, Steven L

    2012-05-01

    Critical thermal limits provide an indication of the range of temperatures across which organisms may survive, and the extent of the lability of these limits offers insights into the likely impacts of changing thermal environments on such survival. However, investigations of these limits may be affected by the circumstances under which trials are undertaken. Only a few studies have examined these effects, and typically not for beetles. This group has also not been considered in the context of the time courses of acclimation and its reversal, both of which are important for estimating the responses of species to transient temperature changes. Here we therefore examine the effects of rate of temperature change on critical thermal maxima (CT(max)) and minima (CT(min)), as well as the time course of the acclimation response and its reversal in two beetle species, Tenebrio molitor and Cyrtobagous salviniae. Increasing rates of temperature change had opposite effects on T. molitor and C. salviniae. In T. molitor, faster rates of change reduced both CT(max) (c. 2°C) and CT(min) (c. 3°C), while in C. salviniae faster rates of change increased both CT(max) (c. 6°C) and CT(min) (c. 4°C). CT(max) in T. molitor showed little response to acclimation, while the response to acclimation of CT(min) was most pronounced following exposure to 35°C (from 25°C) and was complete within 24 h. The time course of acclimation of CT(max) in C. salviniae was 2 days when exposed to 36°C (from c. 26°C), while that of CT(min) was less than 3 days when exposed to 18°C. In T. molitor, the time course of reacclimation to 25°C after treatments at 15°C and 35°C at 75% RH was longer than the time course of acclimation, and varied from 3-6 days for CT(max) and 6 days for CT(min). In C. salviniae, little change in CT(max) and CT(min) (<0.5°C) took place in all treatments suggesting that reacclimation may only occur after the 7 day period used in this study. These results indicate that both T

  5. New Stands of Species of the Paramecium aurelia Complex; is the Occurrence of Particular Species Limited by Temperature Barriers?

    PubMed

    Przyboś, Ewa; Prajer, Małgorzata

    2015-01-01

    The occurrence of ciliates, especially the Paramecium aurelia complex, has not yet been studied in many parts of the world, or sampling was done only occasionally. Generally, the southern hemisphere still awaits investigation. In North America only the USA was studied in greater detail; the majority of species of the complex were there recorded. In Asia, more frequent sampling was performed only in Japan and Asiatic Russia. Europe was studied more carefully, however, a different number of habitats was studied in particular zones of Europe, the least in the southern zone. New stands of P. tetraurelia , P. sexaurelia, P. octaurelia, and P. novaurelia were revealed as a result of the present investigations carried out in Africa (Mozambique--P. tetraurelia, P. sexaurelia), Asia (Indonesia--P. sexaurelia), borderland of Asia and Europe (Georgia--P. octaurelia), and Europe (Macedonia--P. tetraurelia and Romania--P. novaurelia). Are climatic zones the main factor limiting the occurrence of species of the P. aurelia complex? Analysis of data on the distribution of the P. aurelia species complex in warm "tropical" zones on different continents may suggest such preferences for some species, including P. sexaurelia, P. octaurelia, P. tredecaurelia, P. quadecaurelia. The first two of these species were recorded herein in warm or "tropical" zone. PMID:26462333

  6. Antiphase light and temperature cycles affect PHYTOCHROME B-controlled ethylene sensitivity and biosynthesis, limiting leaf movement and growth of Arabidopsis.

    PubMed

    Bours, Ralph; van Zanten, Martijn; Pierik, Ronald; Bouwmeester, Harro; van der Krol, Alexander

    2013-10-01

    In the natural environment, days are generally warmer than the night, resulting in a positive day/night temperature difference (+DIF). Plants have adapted to these conditions, and when exposed to antiphase light and temperature cycles (cold photoperiod/warm night [-DIF]), most species exhibit reduced elongation growth. To study the physiological mechanism of how light and temperature cycles affect plant growth, we used infrared imaging to dissect growth dynamics under +DIF and -DIF in the model plant Arabidopsis (Arabidopsis thaliana). We found that -DIF altered leaf growth patterns, decreasing the amplitude and delaying the phase of leaf movement. Ethylene application restored leaf growth in -DIF conditions, and constitutive ethylene signaling mutants maintain robust leaf movement amplitudes under -DIF, indicating that ethylene signaling becomes limiting under these conditions. In response to -DIF, the phase of ethylene emission advanced 2 h, but total ethylene emission was not reduced. However, expression analysis on members of the 1-aminocyclopropane-1-carboxylic acid (ACC) synthase ethylene biosynthesis gene family showed that ACS2 activity is specifically suppressed in the petiole region under -DIF conditions. Indeed, petioles of plants under -DIF had reduced ACC content, and application of ACC to the petiole restored leaf growth patterns. Moreover, acs2 mutants displayed reduced leaf movement under +DIF, similar to wild-type plants under -DIF. In addition, we demonstrate that the photoreceptor PHYTOCHROME B restricts ethylene biosynthesis and constrains the -DIF-induced phase shift in rhythmic growth. Our findings provide a mechanistic insight into how fluctuating temperature cycles regulate plant growth.

  7. ITER Experts' meeting on density limits

    SciTech Connect

    Borrass, K.; Igitkhanov, Y.L.; Uckan, N.A.

    1989-12-01

    The necessity of achieving a prescribed wall load or fusion power essentially determines the plasma pressure in a device like ITER. The range of operation densities and temperatures compatible with this condition is constrained by the problems of power exhaust and the disruptive density limit. The maximum allowable heat loads on the divertor plates and the maximum allowable sheath edge temperature practically impose a lower limit on the operating densities, whereas the disruptive density limit imposes an upper limit. For most of the density limit scalings proposed in the past an overlap of the two constraints or at best a very narrow accessible density range is predicted for ITER. Improved understanding of the underlying mechanisms is therefore a crucial issue in order to provide a more reliable basis for extrapolation to ITER and to identify possible ways of alleviating the problem.

  8. Antiphase Light and Temperature Cycles Affect PHYTOCHROME B-Controlled Ethylene Sensitivity and Biosynthesis, Limiting Leaf Movement and Growth of Arabidopsis1[C][W

    PubMed Central

    Bours, Ralph; van Zanten, Martijn; Pierik, Ronald; Bouwmeester, Harro; van der Krol, Alexander

    2013-01-01

    In the natural environment, days are generally warmer than the night, resulting in a positive day/night temperature difference (+DIF). Plants have adapted to these conditions, and when exposed to antiphase light and temperature cycles (cold photoperiod/warm night [−DIF]), most species exhibit reduced elongation growth. To study the physiological mechanism of how light and temperature cycles affect plant growth, we used infrared imaging to dissect growth dynamics under +DIF and −DIF in the model plant Arabidopsis (Arabidopsis thaliana). We found that −DIF altered leaf growth patterns, decreasing the amplitude and delaying the phase of leaf movement. Ethylene application restored leaf growth in −DIF conditions, and constitutive ethylene signaling mutants maintain robust leaf movement amplitudes under −DIF, indicating that ethylene signaling becomes limiting under these conditions. In response to −DIF, the phase of ethylene emission advanced 2 h, but total ethylene emission was not reduced. However, expression analysis on members of the 1-aminocyclopropane-1-carboxylic acid (ACC) synthase ethylene biosynthesis gene family showed that ACS2 activity is specifically suppressed in the petiole region under −DIF conditions. Indeed, petioles of plants under −DIF had reduced ACC content, and application of ACC to the petiole restored leaf growth patterns. Moreover, acs2 mutants displayed reduced leaf movement under +DIF, similar to wild-type plants under −DIF. In addition, we demonstrate that the photoreceptor PHYTOCHROME B restricts ethylene biosynthesis and constrains the −DIF-induced phase shift in rhythmic growth. Our findings provide a mechanistic insight into how fluctuating temperature cycles regulate plant growth. PMID:23979970

  9. Effect of acclimation temperature on the upper thermal tolerance of Colorado River cutthroat trout Oncorhynchus clarkii pleuriticus: thermal limits of a North American salmonid.

    PubMed

    Underwood, Z E; Myrick, C A; Rogers, K B

    2012-06-01

    In an effort to explore the thermal limitations of Colorado River cutthroat trout Oncorhynchus clarkii pleuriticus, the critical thermal maxima (T(cmax) ) of 1+ year Lake Nanita strain O. c. pleuriticus were evaluated when acclimated to 10, 15 and 20° C. The mean ±s.d.T(cmax) for O. c. pleuriticus acclimated to 10° C was 24·6 ± 2·0°C (n = 30), for 15° C-acclimated fish was 26·9 ± 1·5° C (n = 23) and for 20° C-acclimated fish was 29·4 ± 1·1° C (n = 28); these results showed a marked thermal acclimation effect (Q₁₀ = 1·20). Interestingly, there was a size effect within treatments, wherein the T(cmax) of larger fish was significantly lower than that of smaller fish acclimated to the same temperature. The critical thermal tolerances of age 0 year O. c. pleuriticus were also evaluated from three separate populations: Lake Nanita, Trapper Creek and Carr Creek reared under 'common-garden' conditions prior to thermal acclimation. The Trapper Creek population had significantly warmer T(cmax) than the Lake Nanita population, but that of the Carr Creek fish had T(cmax) similar to both Trapper Creek and Lake Nanita fish. A comparison of these O. c. pleuriticus T(cmax) results with those of other stream-dwelling salmonids suggested that O. c. pleuriticus are less resistant to rapid thermal fluctuations when acclimated to cold temperatures, but can tolerate similar temperatures when acclimated to warmer temperatures. PMID:22650425

  10. Estimation of lower flammability limits of C-H compounds in air at atmospheric pressure, evaluation of temperature dependence and diluent effect.

    PubMed

    Mendiburu, Andrés Z; de Carvalho, João A; Coronado, Christian R

    2015-03-21

    Estimation of the lower flammability limits of C-H compounds at 25 °C and 1 atm; at moderate temperatures and in presence of diluent was the objective of this study. A set of 120 C-H compounds was divided into a correlation set and a prediction set of 60 compounds each. The absolute average relative error for the total set was 7.89%; for the correlation set, it was 6.09%; and for the prediction set it was 9.68%. However, it was shown that by considering different sources of experimental data the values were reduced to 6.5% for the prediction set and to 6.29% for the total set. The method showed consistency with Le Chatelier's law for binary mixtures of C-H compounds. When tested for a temperature range from 5 °C to 100 °C, the absolute average relative errors were 2.41% for methane; 4.78% for propane; 0.29% for iso-butane and 3.86% for propylene. When nitrogen was added, the absolute average relative errors were 2.48% for methane; 5.13% for propane; 0.11% for iso-butane and 0.15% for propylene. When carbon dioxide was added, the absolute relative errors were 1.80% for methane; 5.38% for propane; 0.86% for iso-butane and 1.06% for propylene. PMID:25528241

  11. Estimation of lower flammability limits of C-H compounds in air at atmospheric pressure, evaluation of temperature dependence and diluent effect.

    PubMed

    Mendiburu, Andrés Z; de Carvalho, João A; Coronado, Christian R

    2015-03-21

    Estimation of the lower flammability limits of C-H compounds at 25 °C and 1 atm; at moderate temperatures and in presence of diluent was the objective of this study. A set of 120 C-H compounds was divided into a correlation set and a prediction set of 60 compounds each. The absolute average relative error for the total set was 7.89%; for the correlation set, it was 6.09%; and for the prediction set it was 9.68%. However, it was shown that by considering different sources of experimental data the values were reduced to 6.5% for the prediction set and to 6.29% for the total set. The method showed consistency with Le Chatelier's law for binary mixtures of C-H compounds. When tested for a temperature range from 5 °C to 100 °C, the absolute average relative errors were 2.41% for methane; 4.78% for propane; 0.29% for iso-butane and 3.86% for propylene. When nitrogen was added, the absolute average relative errors were 2.48% for methane; 5.13% for propane; 0.11% for iso-butane and 0.15% for propylene. When carbon dioxide was added, the absolute relative errors were 1.80% for methane; 5.38% for propane; 0.86% for iso-butane and 1.06% for propylene.

  12. [Effects of plastic mulch on soil moisture and temperature and limiting factors to yield increase for dryland spring maize in the North China].

    PubMed

    Liu, Sheng-Yao; Zhang, Li-Feng; Li, Zhi-Hong; Jia, Jian-Ming; Fan, Feng-Cui; Shi, Yu-Fang

    2014-11-01

    Four treatments, including ridge tillage with plastic mulch (RP), ridge tillage without mulch (RB), flat tillage with plastic mulch (FP) and flat tillage without mulch (FB), were carried out to examine the tillage type and mulch on the effects of soil moisture and temperature, yield and water use efficiency (WUE) of dry land spring maize in the North China. Results showed that the average soil temperature was increased by 1-3 °C and the accumulated soil temperature was increased by 155.2-280.9 °C from sowing to tasseling by plastic mulch, and the growing duration was extended by 5.9-10.7 d. The water conservation effect of plastic mulch was significant from sowing to the seedling establishment, with WUE being increased by 81.6%-136.4% under mulch as compared with that without mulch. From the seedling to jointing stage, which coincided with the dry period in the region, soil water utilization by the maize under mulch could reach the depth of 80-100 cm, and its WUE was about 17.0%-21.6% lower than the maize without mulch, since the latter was affected by dry stress. With the coming of rainy season around the trumpeting stage, soil water in each treatment was replenished and maintained at relative high level up to harvest. Yield of maize was increased by 9.5% under RP as compared with RB. However, yield was reduced by 5.0% under FP, due to the plastic film under flat tillage prevented the infiltration of rainfall and waterlogging occurred. No significant difference in yield was found between RB and FB. Higher yield of spring maize was limited because of the mismatching in water supply and demand characterized by soil water shortage before the rainy season and abundant soil water storage after the rainy season.

  13. A TIR-NBS protein encoded by Arabidopsis Chilling Sensitive 1 (CHS1) limits chloroplast damage and cell death at low temperature.

    PubMed

    Zbierzak, Anna Maria; Porfirova, Svetlana; Griebel, Thomas; Melzer, Michael; Parker, Jane E; Dörmann, Peter

    2013-08-01

    Survival of plants at low temperature depends on mechanisms for limiting physiological damage and maintaining growth. We mapped the chs1-1 (chilling sensitive1-1) mutation in Arabidopsis accession Columbia to the TIR-NBS gene At1g17610. In chs1-1, a single amino acid exchange at the CHS1 N-terminus close to the conserved TIR domain creates a stable mutant protein that fails to protect leaves against chilling stress. The sequence of another TIR-NBS gene (At5g40090) named CHL1 (CHS1-like 1) is related to that of CHS1. Over-expression of CHS1 or CHL1 alleviates chilling damage and enhances plant growth at moderate (24°C) and chilling (13°C) temperatures, suggesting a role for both proteins in growth homeostasis. chs1-1 mutants show induced salicylic acid production and defense gene expression at 13°C, indicative of autoimmunity. Genetic analysis of chs1-1 in combination with defense pathway mutants shows that chs1-1 chilling sensitivity requires the TIR-NBS-LRR and basal resistance regulators encoded by EDS1 and PAD4 but not salicylic acid. By following the timing of metabolic, physiological and chloroplast ultrastructural changes in chs1-1 leaves during chilling, we have established that alterations in photosynthetic complexes and thylakoid membrane integrity precede leaf cell death measured by ion leakage. At 24°C, the chs1-1 mutant appears normal but produces a massive necrotic response to virulent Pseudomonas syringae pv. tomato infection, although this does not affect bacterial proliferation. Our results suggest that CHS1 acts at an intersection between temperature sensing and biotic stress pathway activation to maintain plant performance over a range of conditions.

  14. [Effects of plastic mulch on soil moisture and temperature and limiting factors to yield increase for dryland spring maize in the North China].

    PubMed

    Liu, Sheng-Yao; Zhang, Li-Feng; Li, Zhi-Hong; Jia, Jian-Ming; Fan, Feng-Cui; Shi, Yu-Fang

    2014-11-01

    Four treatments, including ridge tillage with plastic mulch (RP), ridge tillage without mulch (RB), flat tillage with plastic mulch (FP) and flat tillage without mulch (FB), were carried out to examine the tillage type and mulch on the effects of soil moisture and temperature, yield and water use efficiency (WUE) of dry land spring maize in the North China. Results showed that the average soil temperature was increased by 1-3 °C and the accumulated soil temperature was increased by 155.2-280.9 °C from sowing to tasseling by plastic mulch, and the growing duration was extended by 5.9-10.7 d. The water conservation effect of plastic mulch was significant from sowing to the seedling establishment, with WUE being increased by 81.6%-136.4% under mulch as compared with that without mulch. From the seedling to jointing stage, which coincided with the dry period in the region, soil water utilization by the maize under mulch could reach the depth of 80-100 cm, and its WUE was about 17.0%-21.6% lower than the maize without mulch, since the latter was affected by dry stress. With the coming of rainy season around the trumpeting stage, soil water in each treatment was replenished and maintained at relative high level up to harvest. Yield of maize was increased by 9.5% under RP as compared with RB. However, yield was reduced by 5.0% under FP, due to the plastic film under flat tillage prevented the infiltration of rainfall and waterlogging occurred. No significant difference in yield was found between RB and FB. Higher yield of spring maize was limited because of the mismatching in water supply and demand characterized by soil water shortage before the rainy season and abundant soil water storage after the rainy season. PMID:25898617

  15. Production of a two-years meteorological dataset with a coupling framework between a Limited Area Atmospheric Model and a sequential Land Surface Temperature Assimilation scheme

    NASA Astrophysics Data System (ADS)

    Campo, Lorenzo; Castelli, Fabio; Entekhabi, Dara; Caparrini, Francesca

    2010-05-01

    The representation of the surface phenomena like the turbulent exchange of heat between the land and the atmosphere is a traditional weakness in the atmospheric models. These phenomena have been often neglected or poorly represented in the past, especially in the Global Circulation Models. The modern generation models (in particular Limited Area Models) present, on the opposite, much more accurate modelizations that require very complex parametrization, difficult or impossible to retrieve with sufficient accuracy. In this work remote sensed maps of Land Surface Temperature retrieved by MSG-SEVIRI sensor have been used in a 1D variational assimilation scheme in order to produce optimal estimates of the surface energy budget in terms of sensible and latent heat fluxes patterns. This assimilation scheme, ACHAB, has then been coupled with the limited area atmospheric model RAMS replacing the surface module of the latter, LEAF-3, with the assimilation run products. A two years long meteorological dataset (March 1st, 2005 - December 31st, 2006) was produced on the Italian territory using this coupling framework. A control run was used in order to evaluate performances of the atmospheric model also in absence of the LST assimilation. Evaluations of the results of the coupling framework by comparison with both observations of the ground sensors network and the atmospheric soundings available in the study period are presented.

  16. 40 CFR 467.05 - Removal allowances for pretreatment standards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) EFFLUENT GUIDELINES AND STANDARDS ALUMINUM FORMING POINT SOURCE CATEGORY General Provisions § 467.05 Removal allowances for pretreatment standards. Removal allowances pursuant to 40 CFR 403.7(a) may be granted for the toxic metals limited in 40 CFR part 467 when used as indicator pollutants....

  17. 40 CFR 467.05 - Removal allowances for pretreatment standards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) EFFLUENT GUIDELINES AND STANDARDS ALUMINUM FORMING POINT SOURCE CATEGORY General Provisions § 467.05 Removal allowances for pretreatment standards. Removal allowances pursuant to 40 CFR 403.7(a) may be granted for the toxic metals limited in 40 CFR part 467 when used as indicator pollutants....

  18. 40 CFR 467.05 - Removal allowances for pretreatment standards.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) ALUMINUM FORMING POINT SOURCE CATEGORY General Provisions § 467.05 Removal allowances for pretreatment standards. Removal allowances pursuant to 40 CFR 403.7(a) may be granted for the toxic metals limited in 40 CFR part 467 when used as indicator pollutants....

  19. 42 CFR 489.31 - Allowable charges: Blood.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 5 2012-10-01 2012-10-01 false Allowable charges: Blood. 489.31 Section 489.31... Allowable charges: Blood. (a) Limitations on charges. (1) A provider may charge the beneficiary (or other person on his or her behalf) only for the first three pints of blood or units of packed red...

  20. 42 CFR 489.31 - Allowable charges: Blood.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 5 2013-10-01 2013-10-01 false Allowable charges: Blood. 489.31 Section 489.31... Allowable charges: Blood. (a) Limitations on charges. (1) A provider may charge the beneficiary (or other person on his or her behalf) only for the first three pints of blood or units of packed red...

  1. 42 CFR 489.31 - Allowable charges: Blood.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Allowable charges: Blood. 489.31 Section 489.31... Allowable charges: Blood. (a) Limitations on charges. (1) A provider may charge the beneficiary (or other person on his or her behalf) only for the first three pints of blood or units of packed red...

  2. 42 CFR 489.31 - Allowable charges: Blood.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 5 2011-10-01 2011-10-01 false Allowable charges: Blood. 489.31 Section 489.31... Allowable charges: Blood. (a) Limitations on charges. (1) A provider may charge the beneficiary (or other person on his or her behalf) only for the first three pints of blood or units of packed red...

  3. 42 CFR 489.31 - Allowable charges: Blood.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 5 2014-10-01 2014-10-01 false Allowable charges: Blood. 489.31 Section 489.31... Allowable charges: Blood. (a) Limitations on charges. (1) A provider may charge the beneficiary (or other person on his or her behalf) only for the first three pints of blood or units of packed red...

  4. Aluminium Sheet Metal Forming at Low Temperatures

    NASA Astrophysics Data System (ADS)

    Schneider, R.; Heine, B.; Grant, R. J.; Zouaoui, Z.

    2015-02-01

    Low-temperature forming technology offers a new potential for forming operations of aluminium wrought alloys which show a limited formability at ambient temperatures. This paper indicates the mechanical behaviour of the commercial aluminium alloys EN AW-5182 and EN AW-6016 at low temperatures. Stress-strain relationships at different temperatures were investigated through tensile testing experiments. Flow curves were extrapolated using an adapted mathematical constitutive relationship of flow stress and strain. A device which allows cupping tests at sub-zero temperatures was specially designed and a limiting dome height was determined.

  5. 49 CFR 266.11 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Allowable costs. 266.11 Section 266.11... TRANSPORTATION ACT § 266.11 Allowable costs. Allowable costs include only the following costs which are properly allocable to the work performed: Planning and program operation costs which are allowed under...

  6. 46 CFR 154.421 - Allowable stress.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Allowable stress. 154.421 Section 154.421 Shipping COAST... § 154.421 Allowable stress. The allowable stress for the integral tank structure must meet the American Bureau of Shipping's allowable stress for the vessel's hull published in “Rules for Building and...

  7. 46 CFR 154.421 - Allowable stress.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Allowable stress. 154.421 Section 154.421 Shipping COAST... § 154.421 Allowable stress. The allowable stress for the integral tank structure must meet the American Bureau of Shipping's allowable stress for the vessel's hull published in “Rules for Building and...

  8. 46 CFR 154.421 - Allowable stress.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Allowable stress. 154.421 Section 154.421 Shipping COAST... § 154.421 Allowable stress. The allowable stress for the integral tank structure must meet the American Bureau of Shipping's allowable stress for the vessel's hull published in “Rules for Building and...

  9. 46 CFR 154.440 - Allowable stress.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Allowable stress. 154.440 Section 154.440 Shipping COAST... Tank Type A § 154.440 Allowable stress. (a) The allowable stresses for an independent tank type A must... Commandant (CG-522). (b) A greater allowable stress than required in paragraph (a)(1) of this section may...

  10. 46 CFR 154.421 - Allowable stress.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Allowable stress. 154.421 Section 154.421 Shipping COAST... § 154.421 Allowable stress. The allowable stress for the integral tank structure must meet the American Bureau of Shipping's allowable stress for the vessel's hull published in “Rules for Building and...

  11. 46 CFR 154.421 - Allowable stress.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Allowable stress. 154.421 Section 154.421 Shipping COAST... § 154.421 Allowable stress. The allowable stress for the integral tank structure must meet the American Bureau of Shipping's allowable stress for the vessel's hull published in “Rules for Building and...

  12. 46 CFR 154.440 - Allowable stress.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Allowable stress. 154.440 Section 154.440 Shipping COAST... Tank Type A § 154.440 Allowable stress. (a) The allowable stresses for an independent tank type A must... Commandant (CG-ENG). (b) A greater allowable stress than required in paragraph (a)(1) of this section may...

  13. 46 CFR 154.440 - Allowable stress.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Allowable stress. 154.440 Section 154.440 Shipping COAST... Tank Type A § 154.440 Allowable stress. (a) The allowable stresses for an independent tank type A must... Commandant (CG-ENG). (b) A greater allowable stress than required in paragraph (a)(1) of this section may...

  14. 46 CFR 154.440 - Allowable stress.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Allowable stress. 154.440 Section 154.440 Shipping COAST... Tank Type A § 154.440 Allowable stress. (a) The allowable stresses for an independent tank type A must... Commandant (CG-ENG). (b) A greater allowable stress than required in paragraph (a)(1) of this section may...

  15. Temperature response of isoprene emission in vivo reflects a combined effect of substrate limitations and isoprene synthase activity: a kinetic analysis.

    PubMed

    Rasulov, Bahtijor; Hüve, Katja; Bichele, Irina; Laisk, Agu; Niinemets, Ulo

    2010-11-01

    The responses of isoprene emission rate to temperature are characterized by complex time-dependent behaviors that are currently not entirely understood. To gain insight into the temperature dependencies of isoprene emission, we studied steady-state and transient responses of isoprene emission from hybrid aspen (Populus tremula × Populus tremuloides) leaves using a fast-response gas-exchange system coupled to a proton-transfer reaction mass spectrometer. A method based on postillumination isoprene release after rapid temperature transients was developed to determine the rate constant of isoprene synthase (IspS), the pool size of its substrate dimethylallyldiphosphate (DMADP), and to separate the component processes of the temperature dependence of isoprene emission. Temperature transients indicated that over the temperature range 25°C to 45°C, IspS was thermally stable and operated in the linear range of its substrate DMADP concentration. The in vivo rate constant of IspS obeyed the Arrhenius law, with an activation energy of 42.8 kJ mol(-1). In contrast, steady-state isoprene emission had a significantly lower temperature optimum than IspS and higher activation energy. The reversible temperature-dependent decrease in the rate of isoprene emission between 35°C and 44°C was caused by decreases in DMADP concentration, possibly reflecting reduced pools of energetic metabolites generated in photosynthesis, particularly of ATP. Strong control of isoprene temperature responses by the DMADP pool implies that transient temperature responses under fluctuating conditions in the field are driven by initial DMADP pool size as well as temperature-dependent modifications in DMADP pool size during temperature transients. These results have important implications for the development of process-based models of isoprene emission.

  16. 14 CFR 25.1527 - Ambient air temperature and operating altitude.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Ambient air temperature and operating... Information Operating Limitations § 25.1527 Ambient air temperature and operating altitude. The extremes of the ambient air temperature and operating altitude for which operation is allowed, as limited...

  17. 14 CFR 25.1527 - Ambient air temperature and operating altitude.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Ambient air temperature and operating... Information Operating Limitations § 25.1527 Ambient air temperature and operating altitude. The extremes of the ambient air temperature and operating altitude for which operation is allowed, as limited...

  18. 14 CFR 25.1527 - Ambient air temperature and operating altitude.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Ambient air temperature and operating... Information Operating Limitations § 25.1527 Ambient air temperature and operating altitude. The extremes of the ambient air temperature and operating altitude for which operation is allowed, as limited...

  19. 14 CFR 25.1527 - Ambient air temperature and operating altitude.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Ambient air temperature and operating... Information Operating Limitations § 25.1527 Ambient air temperature and operating altitude. The extremes of the ambient air temperature and operating altitude for which operation is allowed, as limited...

  20. 14 CFR 25.1527 - Ambient air temperature and operating altitude.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ambient air temperature and operating... Information Operating Limitations § 25.1527 Ambient air temperature and operating altitude. The extremes of the ambient air temperature and operating altitude for which operation is allowed, as limited...

  1. Serial FBG sensor network allowing overlapping spectra

    NASA Astrophysics Data System (ADS)

    Abbenseth, S.; Lochmann, S.; Ahrens, A.; Rehm, B.

    2016-05-01

    For structure or material monitoring low impact serial fiber Bragg grating (FBG) networks have attracted increasing research interest. Common sensor networks using wavelength division multiplexing (WDM) for FBG interrogation are limited in their efficiency by the spectral width of their light source, the FBG tuning range and the spectral guard bands. Overlapping spectra are strictly forbidden in this case. Applying time division multiplexing (TDM) or active resonator schemes may overcome these restrictions. However, they introduce other substantial disadvantages like signal roundtrip dependency or sophisticated control of active resonating structures. Code division multiplexing (CDM) as a means of FBG interrogation by simple autocorrelation of appropriate codes has been shown to be superior in this respect. However, it came at the cost of a second spectrometer introducing additional equalization efforts. We demonstrate a new serial FBG sensor network utilizing CDM signal processing for efficient sensor interrogation without the need of a second spectrometer and additional state of polarization (SOP) controlling components. It allows overlapping spectra even when all sensing FBGs are positioned at the same centre wavelength and it shows a high degree of insensitivity to SOP. Sequence inversed keyed (SIK) serial signal processing utilizing quasi-orthogonal balanced codes ensures simple and quick sensor interrogation with high signal-to-interference/noise ratio.

  2. Effect of hydrogen limitation and temperature on the fractionation of sulfur isotopes by a deep-sea hydrothermal vent sulfate-reducing bacterium

    NASA Astrophysics Data System (ADS)

    Hoek, Joost; Reysenbach, Anna-Louise; Habicht, Kirsten S.; Canfield, Donald E.

    2006-12-01

    The fractionation of sulfur isotopes by the thermophilic chemolithoautotrophic Thermodesulfatator indicus was explored during sulfate reduction under excess and reduced hydrogen supply, and the full temperature range of growth (40-80 °C). Fractionation of sulfur isotopes measured under reduced H 2 conditions in a fed-batch culture revealed high fractionations (24-37‰) compared to fractionations produced under excess H 2 supply (1-6‰). Higher fractionations correlated with lower sulfate reduction rates. Such high fractionations have never been reported for growth on H 2. For temperature-dependant fractionation experiments cell-specific rates of sulfate reduction increased with increasing temperatures to 70 °C after which sulfate-reduction rates rapidly decreased. Fractionations were relatively high at 40 °C and decreased with increasing temperature from 40-60 °C. Above 60 °C, fractionation trends switched and increased again with increasing temperatures. These temperature-dependant fractionation trends have not previously been reported for growth on H 2 and are not predicted by a generally accepted fractionation model for sulfate reduction, where fractionations are controlled as a function of temperature, by the balance of the exchange of sulfate across the cell membrane, and enzymatic reduction rates of sulfate. Our results are reproduced with a model where fractionation is controlled by differences in the temperature response of enzyme reaction rates and the exchange of sulfate in and out of the cell.

  3. At the edge of the thermal window: effects of elevated temperature on the resting metabolism, hypoxia tolerance and upper critical thermal limit of a widespread African cichlid

    PubMed Central

    McDonnell, Laura H.; Chapman, Lauren J.

    2015-01-01

    Tropical inland fishes are predicted to be especially vulnerable to thermal stress because they experience small temperature fluctuations that may select for narrow thermal windows. In this study, we measured resting metabolic rate (RMR), critical oxygen tension (Pcrit) and critical thermal maximum (CTMax) of the widespread African cichlid (Pseudocrenilabrus multicolor victoriae) in response to short-term acclimation to temperatures within and above their natural thermal range. Pseudocrenilabrus multicolor collected in Lake Kayanja, Uganda, a population living near the upper thermal range of the species, were acclimated to 23, 26, 29 and 32°C for 3 days directly after capture, and RMR and Pcrit were then quantified. In a second group of P. multicolor from the same population, CTMax and the thermal onset of agitation were determined for fish acclimated to 26, 29 and 32°C for 7 days. Both RMR and Pcrit were significantly higher in fish acclimated to 32°C, indicating decreased tolerance to hypoxia and increased metabolic requirements at temperatures only slightly (∼1°C) above their natural thermal range. The CTMax increased with acclimation temperature, indicating some degree of thermal compensation induced by short-term exposure to higher temperatures. However, agitation temperature (likely to represent an avoidance response to increased temperature during CTMax trials) showed no increase with acclimation temperature. Overall, the results of this study demonstrate that P. multicolor is able to maintain its RMR and Pcrit across the range of temperatures characteristic of its natural habitat, but incurs a higher cost of resting metabolism and reduced hypoxia tolerance at temperatures slightly above its present range. PMID:27293734

  4. 10 CFR 600.317 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... OMB Circular A-122 is determined in accordance with the for-profit costs principles in 48 CFR part 31... Organizations.” (iii) Hospitals. Allowability is determined in accordance with the provisions of 45 CFR part 74... Allowable costs. (a) DOE determines allowability of costs in accordance with the cost principles...

  5. 7 CFR 550.25 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... at 2 CFR part 230. The allowability of costs incurred by institutions of higher education is... at 2 CFR part 225. The allowability of costs incurred by non-profit organizations is determined in... Institutions” codified at 2 CFR 220. The allowability of costs incurred by hospitals is determined...

  6. 20 CFR 211.8 - Displacement allowance.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false Displacement allowance. 211.8 Section 211.8 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT CREDITABLE RAILROAD COMPENSATION § 211.8 Displacement allowance. An allowance paid to an employee because he has...

  7. 20 CFR 211.8 - Displacement allowance.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 1 2014-04-01 2012-04-01 true Displacement allowance. 211.8 Section 211.8 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT CREDITABLE RAILROAD COMPENSATION § 211.8 Displacement allowance. An allowance paid to an employee because he has...

  8. 20 CFR 211.8 - Displacement allowance.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Displacement allowance. 211.8 Section 211.8 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT CREDITABLE RAILROAD COMPENSATION § 211.8 Displacement allowance. An allowance paid to an employee because he has...

  9. 20 CFR 211.8 - Displacement allowance.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Displacement allowance. 211.8 Section 211.8 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT CREDITABLE RAILROAD COMPENSATION § 211.8 Displacement allowance. An allowance paid to an employee because he has...

  10. 20 CFR 211.8 - Displacement allowance.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Displacement allowance. 211.8 Section 211.8 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT CREDITABLE RAILROAD COMPENSATION § 211.8 Displacement allowance. An allowance paid to an employee because he has...

  11. 44 CFR 206.228 - Allowable costs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Allowable costs. General policies for determining allowable costs are established in 44 CFR 13.22. Exceptions to those policies as allowed in 44 CFR 13.4 and 13.6 are explained below. (a) Eligible direct... accordance with 44 CFR part 207. (b)...

  12. 44 CFR 204.63 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ....63 Allowable costs. 44 CFR 13.22 establishes general policies for determining allowable costs. (a) We will reimburse direct costs for the administration of a fire management assistance grant under 44 CFR... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Allowable costs....

  13. 50 CFR 80.15 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., see 5 CFR 1310.3.). (b) What is required to determine the allowability of costs? Source documents or... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Allowable costs. 80.15 Section 80.15... WILDLIFE RESTORATION AND DINGELL-JOHNSON SPORT FISH RESTORATION ACTS § 80.15 Allowable costs. (a) What...

  14. 34 CFR 675.33 - Allowable costs.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 3 2011-07-01 2011-07-01 false Allowable costs. 675.33 Section 675.33 Education... costs. (a)(1) Allowable and unallowable costs. Except as provided in paragraph (a)(2) of this section, costs reasonably related to carrying out the programs described in § 675.32 are allowable. (2)...

  15. 42 CFR 417.534 - Allowable costs.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 3 2011-10-01 2011-10-01 false Allowable costs. 417.534 Section 417.534 Public... PLANS Medicare Payment: Cost Basis § 417.534 Allowable costs. (a) Definition—Allowable costs means the direct and indirect costs, including normal standby costs incurred by the HMO or CMP, that are proper...

  16. 42 CFR 417.802 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Allowable costs. 417.802 Section 417.802 Public... PLANS Health Care Prepayment Plans § 417.802 Allowable costs. (a) General rule. The costs that are considered allowable for HCPP reimbursement are the same as those for reasonable cost HMOs and CMPs...

  17. 45 CFR 1180.56 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Allowable costs. 1180.56 Section 1180.56 Public... by a Grantee General Administrative Responsibilities § 1180.56 Allowable costs. (a) Determination of costs allowable under a grant is made in accordance with government-wide cost principles in...

  18. 34 CFR 304.21 - Allowable costs.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Grantee § 304.21 Allowable costs. In addition to the allowable costs established in the Education Department General Administrative Regulations in 34 CFR 75.530 through 75.562, the following items are... 34 Education 2 2011-07-01 2010-07-01 true Allowable costs. 304.21 Section 304.21...

  19. 42 CFR 417.802 - Allowable costs.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 3 2011-10-01 2011-10-01 false Allowable costs. 417.802 Section 417.802 Public... PLANS Health Care Prepayment Plans § 417.802 Allowable costs. (a) General rule. The costs that are considered allowable for HCPP reimbursement are the same as those for reasonable cost HMOs and CMPs...

  20. 34 CFR 304.21 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Grantee § 304.21 Allowable costs. In addition to the allowable costs established in the Education Department General Administrative Regulations in 34 CFR 75.530 through 75.562, the following items are... 34 Education 2 2010-07-01 2010-07-01 false Allowable costs. 304.21 Section 304.21...

  1. 42 CFR 417.534 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Allowable costs. 417.534 Section 417.534 Public... PLANS Medicare Payment: Cost Basis § 417.534 Allowable costs. (a) Definition—Allowable costs means the direct and indirect costs, including normal standby costs incurred by the HMO or CMP, that are proper...

  2. 24 CFR 17.43 - Allowable claims.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Allowable claims. (a) A claim may be allowed only if: (1) The damage or loss was not caused wholly or partly...) of this section, and the other provisions of this subpart, any claim for damage to, or loss of... types of claims may be allowed, unless excluded by §§ 17.44 and 17.45: (1) Property loss or damage...

  3. 44 CFR 206.228 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Allowable costs. 206.228... Allowable costs. General policies for determining allowable costs are established in 44 CFR 13.22... costs for major disasters and emergencies will be paid in accordance with 44 CFR part 207. (b)...

  4. 44 CFR 206.439 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Allowable costs. 206.439... Allowable costs. (a) General requirements for determining allowable costs are established in 44 CFR 13.22... section. (b) Administrative and management costs for major disasters will be paid in accordance with...

  5. 46 CFR 154.447 - Allowable stress.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Allowable stress. 154.447 Section 154.447 Shipping COAST... Tank Type B § 154.447 Allowable stress. (a) An independent tank type B designed from bodies of revolution must have allowable stresses 3 determined by the following formulae: 3 See Appendix B for...

  6. 46 CFR 154.447 - Allowable stress.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Allowable stress. 154.447 Section 154.447 Shipping COAST... Tank Type B § 154.447 Allowable stress. (a) An independent tank type B designed from bodies of revolution must have allowable stresses 3 determined by the following formulae: 3 See Appendix B for...

  7. 46 CFR 154.447 - Allowable stress.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Allowable stress. 154.447 Section 154.447 Shipping COAST... Tank Type B § 154.447 Allowable stress. (a) An independent tank type B designed from bodies of revolution must have allowable stresses 3 determined by the following formulae: 3 See Appendix B for...

  8. 46 CFR 154.428 - Allowable stress.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Allowable stress. 154.428 Section 154.428 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS FOR... § 154.428 Allowable stress. The membrane tank and the supporting insulation must have allowable...

  9. 46 CFR 154.428 - Allowable stress.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Allowable stress. 154.428 Section 154.428 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS FOR... § 154.428 Allowable stress. The membrane tank and the supporting insulation must have allowable...

  10. 46 CFR 154.428 - Allowable stress.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Allowable stress. 154.428 Section 154.428 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS FOR... § 154.428 Allowable stress. The membrane tank and the supporting insulation must have allowable...

  11. 46 CFR 154.428 - Allowable stress.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Allowable stress. 154.428 Section 154.428 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS FOR... § 154.428 Allowable stress. The membrane tank and the supporting insulation must have allowable...

  12. 46 CFR 154.428 - Allowable stress.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Allowable stress. 154.428 Section 154.428 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS FOR... § 154.428 Allowable stress. The membrane tank and the supporting insulation must have allowable...

  13. 46 CFR 154.447 - Allowable stress.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Allowable stress. 154.447 Section 154.447 Shipping COAST... Tank Type B § 154.447 Allowable stress. (a) An independent tank type B designed from bodies of revolution must have allowable stresses 3 determined by the following formulae: 3 See Appendix B for...

  14. 46 CFR 154.447 - Allowable stress.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Allowable stress. 154.447 Section 154.447 Shipping COAST... Tank Type B § 154.447 Allowable stress. (a) An independent tank type B designed from bodies of revolution must have allowable stresses 3 determined by the following formulae: 3 See Appendix B for...

  15. 34 CFR 304.21 - Allowable costs.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 2 2012-07-01 2012-07-01 false Allowable costs. 304.21 Section 304.21 Education... Grantee § 304.21 Allowable costs. In addition to the allowable costs established in the Education Department General Administrative Regulations in 34 CFR 75.530 through 75.562, the following items...

  16. 34 CFR 304.21 - Allowable costs.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 2 2014-07-01 2013-07-01 true Allowable costs. 304.21 Section 304.21 Education... Grantee § 304.21 Allowable costs. In addition to the allowable costs established in the Education Department General Administrative Regulations in 34 CFR 75.530 through 75.562, the following items...

  17. 34 CFR 304.21 - Allowable costs.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 2 2013-07-01 2013-07-01 false Allowable costs. 304.21 Section 304.21 Education... Grantee § 304.21 Allowable costs. In addition to the allowable costs established in the Education Department General Administrative Regulations in 34 CFR 75.530 through 75.562, the following items...

  18. Influence of salinity and temperature on the physiology of Limia melanonotata (Cyprinodontiformes: Poeciliidae): A search for abiotic factors limiting insular distribution in Hispaniola

    USGS Publications Warehouse

    Haney, D.C.; Walsh, S.J.

    2003-01-01

    We investigated salinity and temperature effects on routine metabolic rate (RMR), temperature tolerance (CTMax, critical thermal maximum), and salinity tolerance of Limia melanonotata, a poecliid fish that occurs in west-central inland waters of Hispaniola. Routine metabolic rate and CTMax were measured in fish acclimated to three salinities (0, 30, and 60 ppt) and temperatures (25??, 30??, and 35??C) for nine temperature-salinity combinations. Salinity and temperature did not significantly interact in their effect on RMR. For combined salinity acclimations, adjusted RMR (ANCOVA) was significantly lower at 25??C than either 30?? or 35??C. For combined temperature acclimations, mean RMR was significantly lower at 60 ppt than either 0 or 30 ppt. Salinity and temperature had a significant interactive effect on temperature tolerance. Mean CTMax was significantly higher at 30?? than 25??C at all salinities, but at 35??C was significantly higher than at 25?? or 30??C only among fish acclimated in fresh water. Fish exposed to a chronic increase in salinity experienced most mortality in a salinity range of 70-107 ppt, with females exhibiting greater salinity tolerance than males. Limia melanonotata approaches the upper extreme in salinity and temperature tolerances known for poeciliids. Our results also suggest that L. melanonotata may reduce energy expenditures at environmental extremes to tolerate harsh conditions for extended periods. Despite its curythermal and euryhaline adaptations, L. melanonotata has a relatively restricted inland range in Hispaniola and is unknown from inshore brackish or marine habitats. The present distribution of this species and congeners may be the result of a combination of factors that include historical zoogeography and ecological requirements.

  19. Possibilities and limitations of the ART-Sample algorithm for reconstruction of 3D temperature fields and the influence of opaque obstacles

    PubMed Central

    Li, Yuanyang; Herman, Cila

    2013-01-01

    The need for the measurement of complex, unsteady, three-dimensional (3D) temperature distributions arises in a variety of engineering applications, and tomographic techniques are applied to accomplish this goal. Holographic interferometry (HI), one of the optical methods used for visualizing temperature fields, combined with tomographic reconstruction techniques requires multi-directional interferometric data to recover the 3D information. However, the presence of opaque obstacles (such as solid objects in the flow field and heaters) in the measurement volume, prevents the probing light beams from traversing the entire measurement volume. As a consequence, information on the average value of the field variable will be lost in regions located in the shade of the obstacle. The capability of the ART-Sample tomographic reconstruction method to recover 3D temperature distributions both in unobstructed temperature fields and in the presence of opaque obstacles is discussed in this paper. A computer code for tomographic reconstruction of 3D temperature fields from 2D projections was developed. In the paper, the reconstruction accuracy is discussed quantitatively both without and with obstacles in the measurement volume for a set of phantom functions mimicking realistic temperature distributions. The reconstruction performance is optimized while minimizing the number of irradiation directions (experimental hardware requirements) and computational effort. For the smooth temperature field both with and without obstacles, the reconstructions produced by this algorithm are good, both visually and using quantitative criteria. The results suggest that the location and the size of the obstacle and the number of viewing directions will affect the reconstruction of the temperature field. When the best performance parameters of the ART-Sample algorithm identified in this paper are used to reconstruct the 3D temperature field, the 3D reconstructions with and without obstacle are

  20. Study of the gluon propagator in the large-N {sub f} limit at finite temperature and chemical potential for weak and strong couplings

    SciTech Connect

    Blaizot, Jean-Paul . E-mail: blaizot@ect.it; Ipp, Andreas . E-mail: ipp@ect.it; Rebhan, Anton . E-mail: rebhana@hep.itp.tuwien.ac.at

    2006-09-15

    At finite temperature and chemical potential, the leading-order (hard-thermal-loop) contributions to the gauge-boson propagator lead to momentum-dependent thermal masses for propagating quasiparticles as well as dynamical screening and Landau damping effects. We compare the hard-thermal-loop propagator with the complete large-N {sub f} gluon propagator, for which the usually subleading contributions, such as a finite width of quasiparticles, can be studied at nonperturbatively large effective coupling. We also study quantitatively the effect of Friedel oscillations in low-temperature electrostatic screening.

  1. The effects of elevated summer temperature and sublethal pollutants (ammonia, low pH) on protein turnover in the gill and liver of rainbow trout (Oncorhynchus mykiss) on a limited food ration.

    PubMed

    Morgan, I J; D'Cruz, L M; Dockray, J J; Linton, T K; Wood, C M

    1999-05-01

    Protein synthesis, degradation and growth of the liver and gills were determined in juvenile rainbow trout (Oncorhynchus mykiss) fed a limited ration and exposed for 90 days to normal or elevated summer temperatures (+2 degrees above ambient) and either low pH (5.2) in softwater or 70 microM total ammonia in hardwater. The limited ration resulted in low rates of growth (< 0.80% per day) and protein synthesis in all fish. In softwater, whole-body growth was significantly inhibited by elevated temperature but stimulated by low pH, although tissue protein metabolism was generally unaffected by these treatments. There was no significant difference in final size between the groups of fish in hardwater, but liver protein synthesis and degradation were significantly lower at +2 degrees C, the reduction in synthesis being due to an inhibition of both the capacity for protein synthesis, Cs and the RNA translational efficiency, kRNA. Gill protein metabolism was unaffected by the experimental treatments in trout in hardwater. The authors conclude that a global warming scenario would be detrimental to protein synthesis and growth in freshwater fish under conditions of food limitation in summer, and when late summer temperatures approached the upper thermal limit of the species, regardless of food availability.

  2. 13 CFR 120.971 - Allowable fees paid by Borrower.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Development Company Loan Program (504) Fees § 120.971 Allowable fees paid by Borrower. (a) CDC fees. The fees a CDC may charge the Borrower in connection with a 504 loan and Debenture are limited to the following: (1) Processing fee. The CDC may charge up to 1.5 percent of the net Debenture proceeds to...

  3. 13 CFR 120.971 - Allowable fees paid by Borrower.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Development Company Loan Program (504) Fees § 120.971 Allowable fees paid by Borrower. (a) CDC fees. The fees a CDC may charge the Borrower in connection with a 504 loan and Debenture are limited to the following: (1) Processing fee. The CDC may charge up to 1.5 percent of the net Debenture proceeds to...

  4. 13 CFR 120.971 - Allowable fees paid by Borrower.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Development Company Loan Program (504) Fees § 120.971 Allowable fees paid by Borrower. (a) CDC fees. The fees a CDC may charge the Borrower in connection with a 504 loan and Debenture are limited to the following: (1) Processing fee. The CDC may charge up to 1.5 percent of the net Debenture proceeds to...

  5. 13 CFR 120.971 - Allowable fees paid by Borrower.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Development Company Loan Program (504) Fees § 120.971 Allowable fees paid by Borrower. (a) CDC fees. The fees a CDC may charge the Borrower in connection with a 504 loan and Debenture are limited to the following: (1) Processing fee. The CDC may charge up to 1.5 percent of the net Debenture proceeds to...

  6. 13 CFR 120.971 - Allowable fees paid by Borrower.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Development Company Loan Program (504) Fees § 120.971 Allowable fees paid by Borrower. (a) CDC fees. The fees a CDC may charge the Borrower in connection with a 504 loan and Debenture are limited to the following: (1) Processing fee. The CDC may charge up to 1.5 percent of the net Debenture proceeds to...

  7. 48 CFR 31.201-2 - Determining allowability.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... principles in this subpart are mandatory unless the contract is CAS-covered (see 48 CFR 9903). Business units... the following requirements: (1) Reasonableness. (2) Allocability. (3) Standards promulgated by the CAS... selected CAS and limit the allowability of costs to the amounts determined using the criteria in...

  8. 48 CFR 31.201-2 - Determining allowability.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... principles in this subpart are mandatory unless the contract is CAS-covered (see 48 CFR 9903). Business units... the following requirements: (1) Reasonableness. (2) Allocability. (3) Standards promulgated by the CAS... selected CAS and limit the allowability of costs to the amounts determined using the criteria in...

  9. 48 CFR 31.201-2 - Determining allowability.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... principles in this subpart are mandatory unless the contract is CAS-covered (see 48 CFR 9903). Business units... the following requirements: (1) Reasonableness. (2) Allocability. (3) Standards promulgated by the CAS... selected CAS and limit the allowability of costs to the amounts determined using the criteria in...

  10. 44 CFR 11.74 - Claims not allowed.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... not allowable if: (1) The damage or loss was caused wholly or partly by the negligent or wrongful act... damage or loss occurred in quarters occupied by the claimant within the 50 states and the District of..., or other directive. This does not apply to limitation imposed on the weight of shipments of...

  11. 34 CFR 645.40 - What are allowable costs?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) Courses in English language instruction for project participants with limited proficiency in English and for whom English language proficiency is necessary to succeed in postsecondary education. (l... What are allowable costs? The cost principles that apply to the Upward Bound Program are in 34 CFR...

  12. Trehalose limits BSA aggregation in spray-dried formulations at high temperatures: implications in preparing polymer implants for long-term protein delivery.

    PubMed

    Rajagopal, Karthikan; Wood, Joseph; Tran, Benjamin; Patapoff, Thomas W; Nivaggioli, Thierry

    2013-08-01

    Polymer implants are promising systems for sustained release applications but their utility for protein delivery has been hindered because of concerns over drug stability at elevated temperatures required for processing. Using bovine serum albumin (BSA) as a model, we have assessed whether proteins can be formulated for processing at elevated temperatures. Specifically, the effect of trehalose and histidine-HCl buffer on BSA stability in a spray-dried formulation has been investigated at temperatures ranging from 80°C to 110°C. When both the sugar and buffer are present, aggregation is suppressed even when exposed to 100°C, the extrusion temperature of poly(lactide-co-glycolide) (PLGA), a bioresorbable polymer. Estimation of aggregation rate constants (k) indicate that though both trehalose and histidine-HCl buffer contribute to BSA stability, the effect because of trehalose alone is more pronounced. BSA-loaded PLGA implants were prepared using hot-melt extrusion process and in vitro release was conducted in phosphate buffered saline at 37°C. Comparison of drug released from implants prepared using four different formulations confirmed that maximal release was achieved from the formulation in which BSA was least aggregated. These studies demonstrate that when trehalose and histidine-HCl buffer are included in spray-dried formulations, BSA stability is maintained both during processing at 100°C and long-term residence within implants.

  13. Limited efficacy of Fever Tag(®) temperature sensing ear tags in calves with naturally occurring bovine respiratory disease or induced bovine viral diarrhea virus infection.

    PubMed

    McCorkell, Robert; Wynne-Edwards, Katherine; Windeyer, Claire; Schaefer, Al

    2014-07-01

    Temperature sensing ear tags were tested in 1) auction-derived calves with 50% incidence of bovine respiratory disease, and 2) specific pathogen-free calves infected with bovine virus diarrhea virus. There were no false positives, but tag placement, probe displacement, and a high threshold for activation all contributed to failure to reliably detect sick calves.

  14. 20 CFR 631.84 - Allowable projects.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Allowable projects. 631.84 Section 631.84... THE JOB TRAINING PARTNERSHIP ACT Disaster Relief Employment Assistance § 631.84 Allowable projects...) Shall be used exclusively to provide employment on projects that provide food, clothing, shelter...

  15. 27 CFR 28.334 - Credit allowance.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Credit allowance. 28.334... OF THE TREASURY LIQUORS EXPORTATION OF ALCOHOL Action on Claims § 28.334 Credit allowance. Where the credit relates to internal revenue taxes on beer that have been determined but not yet paid by...

  16. 27 CFR 28.334 - Credit allowance.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Credit allowance. 28.334... OF THE TREASURY LIQUORS EXPORTATION OF ALCOHOL Action on Claims § 28.334 Credit allowance. Where the credit relates to internal revenue taxes on beer that have been determined but not yet paid by...

  17. 27 CFR 28.334 - Credit allowance.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Credit allowance. 28.334... OF THE TREASURY LIQUORS EXPORTATION OF ALCOHOL Action on Claims § 28.334 Credit allowance. Where the credit relates to internal revenue taxes on beer that have been determined but not yet paid by...

  18. 27 CFR 28.334 - Credit allowance.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Credit allowance. 28.334... OF THE TREASURY ALCOHOL EXPORTATION OF ALCOHOL Action on Claims § 28.334 Credit allowance. Where the credit relates to internal revenue taxes on beer that have been determined but not yet paid by...

  19. 27 CFR 28.334 - Credit allowance.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Credit allowance. 28.334... OF THE TREASURY ALCOHOL EXPORTATION OF ALCOHOL Action on Claims § 28.334 Credit allowance. Where the credit relates to internal revenue taxes on beer that have been determined but not yet paid by...

  20. 20 CFR 437.22 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... CFR Part 31. Contract Cost Principles and Procedures, or uniform cost accounting standards that comply... allowable costs of the grantees, subgrantees and cost-type contractors, including allowable costs in the form of payments to fixed-price contractors; and (2) Reasonable fees or profit to cost-type...

  1. 34 CFR 642.40 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Allowable costs. 642.40 Section 642.40 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION TRAINING PROGRAM FOR FEDERAL TRIO PROGRAMS What Conditions Must Be Met by a Grantee? § 642.40 Allowable costs....

  2. 10 CFR 600.222 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... than a hospital and an organization named in OBM Circular A-122 as not subject to that circular 48 CFR... organization named in OMB Circular A-122 as not subject to that circular. 48 CFR 931.2 Hospitals 45 CFR part 74... allowable costs of the grantees, subgrantees and cost-type contractors, including allowable costs in...

  3. 45 CFR 92.22 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... to that circular 48 CFR Part 31. Contract Cost Principles and Procedures, or uniform cost accounting... grantee or subgrantee. (b) Applicable cost principles. For each kind of organization, there is a set of Federal principles for determining allowable costs. Allowable costs will be determined in accordance...

  4. 15 CFR 24.22 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Part 31. Contract Cost Principles and Procedures, or uniform cost accounting standards that comply with...) Applicable cost principles. For each kind of organization, there is a set of Federal principles for determining allowable costs. Allowable costs will be determined in accordance with the cost...

  5. 20 CFR 617.46 - Travel allowance.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... mile at the prevailing mileage rate authorized under the Federal travel regulations (see 41 CFR part... the same trip in the same vehicle. (2) Lodging and meals. The cost allowable for lodging and meals for... prevailing per diem allowance rate authorized under the Federal travel regulations (see 41 CFR part...

  6. 20 CFR 617.46 - Travel allowance.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... mile at the prevailing mileage rate authorized under the Federal travel regulations (see 41 CFR part... the same trip in the same vehicle. (2) Lodging and meals. The cost allowable for lodging and meals for... prevailing per diem allowance rate authorized under the Federal travel regulations (see 41 CFR part...

  7. 30 CFR 206.160 - Operating allowances.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Operating allowances. 206.160 Section 206.160 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR MINERALS REVENUE MANAGEMENT PRODUCT VALUATION Federal Gas § 206.160 Operating allowances. Notwithstanding any other provisions...

  8. Moral Appraisals Affect Doing/Allowing Judgments

    ERIC Educational Resources Information Center

    Cushman, Fiery; Knobe, Joshua; Sinnott-Armstrong, Walter

    2008-01-01

    An extensive body of research suggests that the distinction between doing and allowing plays a critical role in shaping moral appraisals. Here, we report evidence from a pair of experiments suggesting that the converse is also true: moral appraisals affect doing/allowing judgments. Specifically, morally bad behavior is more likely to be construed…

  9. Allocation of Allowances and Associated Family Practices.

    ERIC Educational Resources Information Center

    Kerr, M. Kaye; Cheadle, Tannis

    This study gathered information on general family practices concerning allowances given to children, parental reasons for the provision of allowances, the bases for their administration, and the frequency of conflicts generated around them. The subjects were 81 parents of elementary school children in a midwest Canadian city. Subjects completed…

  10. 20 CFR 632.258 - Allowable activities.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR INDIAN AND NATIVE AMERICAN EMPLOYMENT AND TRAINING PROGRAMS Summer Youth Employment and Training Programs § 632.258 Allowable activities. Allowable activities are those listed in § 632.78-80 except that community service employment is...

  11. 20 CFR 632.258 - Allowable activities.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR INDIAN AND NATIVE AMERICAN EMPLOYMENT AND TRAINING PROGRAMS Summer Youth Employment and Training Programs § 632.258 Allowable activities. Allowable activities are those listed in § 632.78-80 except that community service employment is...

  12. 42 CFR 417.802 - Allowable costs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) MEDICARE PROGRAM (CONTINUED) HEALTH MAINTENANCE ORGANIZATIONS, COMPETITIVE MEDICAL PLANS, AND HEALTH CARE PREPAYMENT PLANS Health Care Prepayment Plans § 417.802 Allowable costs. (a) General rule. The costs that are... 42 Public Health 3 2014-10-01 2014-10-01 false Allowable costs. 417.802 Section 417.802...

  13. 4 CFR 5.6 - Allowances.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 4 Accounts 1 2010-01-01 2010-01-01 false Allowances. 5.6 Section 5.6 Accounts GOVERNMENT ACCOUNTABILITY OFFICE PERSONNEL SYSTEM COMPENSATION § 5.6 Allowances. The provisions of chapter 59 of title 5, U.S. Code and the implementing regulations for the Executive Branch apply to Government...

  14. 20 CFR 617.46 - Travel allowance.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... mile at the prevailing mileage rate authorized under the Federal travel regulations (see 41 CFR part... prevailing per diem allowance rate authorized under the Federal travel regulations (see 41 CFR part 101-7... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Travel allowance. 617.46 Section...

  15. 44 CFR 208.33 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Allowable costs. 208.33... HOMELAND SECURITY DISASTER ASSISTANCE NATIONAL URBAN SEARCH AND RESCUE RESPONSE SYSTEM Response Cooperative Agreements § 208.33 Allowable costs. (a) Cost neutrality. DHS policy is that an Alert or Activation should...

  16. 30 CFR 1206.160 - Operating allowances.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Operating allowances. 1206.160 Section 1206.160 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR Natural Resources Revenue PRODUCT VALUATION Federal Gas § 1206.160 Operating allowances. Notwithstanding any...

  17. 20 CFR 633.303 - Allowable costs.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... otherwise indicated below, direct and indirect costs shall be charged in accordance with 41 CFR part 29-70... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Allowable costs. 633.303 Section 633.303... FARMWORKER PROGRAMS Program Design and Administrative Procedures § 633.303 Allowable costs. (a) General....

  18. 24 CFR 85.22 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Circular A-122 as not subject to that circular 48 CFR part 31. Contract Cost Principles and Procedures, or... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Allowable costs. 85.22 Section 85... TRIBAL GOVERNMENTS Post-Award Requirements Financial Administration § 85.22 Allowable costs....

  19. 45 CFR 74.27 - Allowable costs.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... determined in accordance with the provisions of the Federal Acquisition Regulation (FAR) at 48 CFR part 31... 45 Public Welfare 1 2011-10-01 2011-10-01 false Allowable costs. 74.27 Section 74.27 Public... Allowable costs. (a) For each kind of recipient, there is a particular set of Federal principles...

  20. 2 CFR 215.27 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... CFR part 230, “Cost Principles for Non-Profit Organizations (OMB Circular A-122).” The allowability of... CFR part 220, “Cost Principles for Educational Institutions (OMB Circular A-21).” The allowability of costs incurred by hospitals is determined in accordance with the provisions of appendix E of 45 CFR...

  1. 24 CFR 85.22 - Allowable costs.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Circular A-122 as not subject to that circular 48 CFR part 31. Contract Cost Principles and Procedures, or... 24 Housing and Urban Development 1 2011-04-01 2011-04-01 false Allowable costs. 85.22 Section 85... TRIBAL GOVERNMENTS Post-Award Requirements Financial Administration § 85.22 Allowable costs....

  2. 10 CFR 600.317 - Allowable costs.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Organizations.” (iii) Hospitals. Allowability is determined in accordance with the provisions of 45 CFR part 74... OMB Circular A-122 is determined in accordance with the for-profit costs principles in 48 CFR part 31... Contracts with Hospitals.” (iv) Governmental organizations. Allowability for State, local, or...

  3. 33 CFR 136.211 - Compensation allowable.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; CLAIMS PROCEDURES; DESIGNATION OF SOURCE; AND ADVERTISEMENT Procedures for Particular Claims § 136.211 Compensation allowable. (a) The amount of compensation allowable is the reasonable cost of assessing damages, and...

  4. 21 CFR 1303.24 - Inventory allowance.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Inventory allowance. 1303.24 Section 1303.24 Food... Quotas § 1303.24 Inventory allowance. (a) For the purpose of determining individual manufacturing quotas... sufficient to maintain an inventory equal to, (1) For current manufacturers, 50 percent of his...

  5. 10 CFR 600.127 - Allowable costs.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... recipient, there is a set of Federal principles for determining allowable costs. Allowability of costs shall... incurred by hospitals is determined in accordance with the provisions of Appendix E of 45 CFR part 74... Federal Acquisition Regulation (FAR) at 48 CFR part 31. (b) Indirect costs. Unless restricted by...

  6. 10 CFR 600.127 - Allowable costs.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... recipient, there is a set of Federal principles for determining allowable costs. Allowability of costs shall... incurred by hospitals is determined in accordance with the provisions of Appendix E of 45 CFR part 74... Federal Acquisition Regulation (FAR) at 48 CFR part 31. (b) Indirect costs. Unless restricted by...

  7. 10 CFR 600.127 - Allowable costs.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... recipient, there is a set of Federal principles for determining allowable costs. Allowability of costs shall... incurred by hospitals is determined in accordance with the provisions of Appendix E of 45 CFR part 74... Federal Acquisition Regulation (FAR) at 48 CFR part 31. (b) Indirect costs. Unless restricted by...

  8. 10 CFR 600.127 - Allowable costs.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... recipient, there is a set of Federal principles for determining allowable costs. Allowability of costs shall... incurred by hospitals is determined in accordance with the provisions of Appendix E of 45 CFR part 74... Federal Acquisition Regulation (FAR) at 48 CFR part 31. (b) Indirect costs. Unless restricted by...

  9. 75 FR 4098 - Utility Allowance Adjustments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-26

    ... URBAN DEVELOPMENT Utility Allowance Adjustments AGENCY: Office of the Chief Information Officer, HUD... are required to advise the Secretary of the need for and request of a new utility allowance for... whether the information will have practical utility; (2) Evaluate the accuracy of the agency's estimate...

  10. 32 CFR 32.27 - Allowable costs.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... of allowable costs that are in accordance with uniform cost accounting standards and comply with cost... NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 32.27 Allowable... contractors is determined in accordance with the provisions of Appendix E to 45 CFR part 74, “Principles...

  11. 28 CFR 70.27 - Allowable costs.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 70.27 Allowable costs. (a... bids, proposals, and applications. Bid and proposal costs of the current accounting period are all allowable as indirect costs. Bid and proposal costs of past accounting periods are unallowable in...

  12. 32 CFR 32.27 - Allowable costs.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... of allowable costs that are in accordance with uniform cost accounting standards and comply with cost... NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 32.27 Allowable... contractors is determined in accordance with the provisions of Appendix E to 45 CFR part 74, “Principles...

  13. 28 CFR 70.27 - Allowable costs.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 70.27 Allowable costs. (a... bids, proposals, and applications. Bid and proposal costs of the current accounting period are all allowable as indirect costs. Bid and proposal costs of past accounting periods are unallowable in...

  14. 28 CFR 70.27 - Allowable costs.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 70.27 Allowable costs. (a... bids, proposals, and applications. Bid and proposal costs of the current accounting period are all allowable as indirect costs. Bid and proposal costs of past accounting periods are unallowable in...

  15. 32 CFR 32.27 - Allowable costs.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... of allowable costs that are in accordance with uniform cost accounting standards and comply with cost... NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 32.27 Allowable... contractors is determined in accordance with the provisions of Appendix E to 45 CFR part 74, “Principles...

  16. 30 CFR 1206.160 - Operating allowances.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Operating allowances. 1206.160 Section 1206.160 Mineral Resources OFFICE OF NATURAL RESOURCES REVENUE, DEPARTMENT OF THE INTERIOR NATURAL RESOURCES REVENUE PRODUCT VALUATION Federal Gas § 1206.160 Operating allowances. Notwithstanding any...

  17. 30 CFR 1206.160 - Operating allowances.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Operating allowances. 1206.160 Section 1206.160 Mineral Resources OFFICE OF NATURAL RESOURCES REVENUE, DEPARTMENT OF THE INTERIOR NATURAL RESOURCES REVENUE PRODUCT VALUATION Federal Gas § 1206.160 Operating allowances. Notwithstanding any...

  18. 30 CFR 1206.160 - Operating allowances.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Operating allowances. 1206.160 Section 1206.160 Mineral Resources OFFICE OF NATURAL RESOURCES REVENUE, DEPARTMENT OF THE INTERIOR NATURAL RESOURCES REVENUE PRODUCT VALUATION Federal Gas § 1206.160 Operating allowances. Notwithstanding any...

  19. The Role of Allowances in Adolescent Socialization.

    ERIC Educational Resources Information Center

    Miller, Joanne; Yung, Susan

    1990-01-01

    Examines high school student perceptions of allowances and the conditions under which they are received. Finds that, contrary to adult conceptions, students perceive allowances as an entitlement or earned income rather than as an educational opportunity promoting financial decision making and money management. (FMW)

  20. 45 CFR 602.22 - Allowable costs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION UNIFORM...) The allowable costs of the grantees, subgrantees and cost-type contractors, including allowable costs in the form of payments to fixed-price contractors; and (2) Reasonable fees or profit to...

  1. 45 CFR 602.22 - Allowable costs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION UNIFORM...) The allowable costs of the grantees, subgrantees and cost-type contractors, including allowable costs in the form of payments to fixed-price contractors; and (2) Reasonable fees or profit to...

  2. 45 CFR 602.22 - Allowable costs.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION UNIFORM...) The allowable costs of the grantees, subgrantees and cost-type contractors, including allowable costs in the form of payments to fixed-price contractors; and (2) Reasonable fees or profit to...

  3. 40 CFR 30.27 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 30.27 Allowable..., “Cost Principles for State and Local Governments.” The allowability of costs incurred by non-profit... organizations and those non-profit organizations listed in Attachment C to Circular A-122 is determined...

  4. 38 CFR 49.27 - Allowable costs.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 49.27 Allowable... for State, Local, and Indian Tribal Governments.” The allowability of costs incurred by non-profit... organizations and those non-profit organizations listed in Attachment C to Circular A-122 is determined...

  5. Family allowances and fertility: socioeconomic differences.

    PubMed

    Schellekens, Jona

    2009-08-01

    This article explores socioeconomic differences in the effect of family allowances on fertility. Although several studies have examined the relationship between cash benefits and fertility, few studies have addressed the possible differential effects of cash benefits on families of different income or education levels. I reconstructed the birth histories of women in the past two Israeli censuses of 1983 and 1995 to study socioeconomic differences in the effect of family allowances up to the seventh parity. The results indicate that family allowances have a significant effect at every parity. Using female education as an indicator of socioeconomic status, I find that socioeconomic status is a significant modifier of the effect of family allowances. Family allowances seem to have a relatively large impact on more-educated women.

  6. Allowance trading: Correcting the past and looking to the future

    SciTech Connect

    Shah, A.Y.; Canter, L.W.

    1995-09-01

    Allowance trading is basic to the Title IV acid rain provisions of the 1990 Clean Air Act Amendments (CAAA) in the United States; the provisions seek to achieve a 10-million-ton reduction in annual sulfur dioxide emissions from the electric power utility industry. Allowance trading, a market-based approach, is conceptually similar to the emissions trading policy of the US Environmental Protection Agency (EPA). An allowance is defined as the authorization to emit, during or after a specified calendar year, one ton of sulfur dioxide. This paper provides an overview of the allowance trading program by summarizing some important features, particularly as they are responsive to limitations and concern as related to the precursor emissions trading program in the early to mid-1980s. Such features include a simple definition of baseline emission levels, encouragements for nationwide trading, disincentives for accumulation of excess allowance,s opportunities for leasing other short-term allowance transfer arrangements, enforcement provisions, and benefits of bonus allowances and early emission reductions. Adherence to implementation protocols for the acid rain provisions of Title IV of the CAAA will provide a good opportunity to evaluate this market-based approach for environmental quality management.

  7. Advanced High Temperature Structural Seals

    NASA Astrophysics Data System (ADS)

    Newquist, Charles W.; Verzemnieks, Juris; Keller, Peter C.; Rorabaugh, Michael; Shorey, Mark

    2002-10-01

    This program addresses the development of high temperature structural seals for control surfaces for a new generation of small reusable launch vehicles. Successful development will contribute significantly to the mission goal of reducing launch cost for small, 200 to 300 pound payloads. Development of high temperature seals is mission enabling. For instance, ineffective control surface seals can result in high temperature (3100 F) flows in the elevon area exceeding structural material limits. Longer sealing life will allow use for many missions before replacement, contributing to the reduction of hardware, operation and launch costs.

  8. Advanced High Temperature Structural Seals

    NASA Technical Reports Server (NTRS)

    Newquist, Charles W.; Verzemnieks, Juris; Keller, Peter C.; Rorabaugh, Michael; Shorey, Mark

    2002-01-01

    This program addresses the development of high temperature structural seals for control surfaces for a new generation of small reusable launch vehicles. Successful development will contribute significantly to the mission goal of reducing launch cost for small, 200 to 300 pound payloads. Development of high temperature seals is mission enabling. For instance, ineffective control surface seals can result in high temperature (3100 F) flows in the elevon area exceeding structural material limits. Longer sealing life will allow use for many missions before replacement, contributing to the reduction of hardware, operation and launch costs.

  9. Probabilistic quantification of allowable carbon emissions for meeting multiple climate targets

    NASA Astrophysics Data System (ADS)

    Steinacher, M.; Joos, F.; Stocker, T. F.

    2013-12-01

    Climate targets are designed to inform policies that would limit the magnitude and impacts of climate change caused by anthropogenic emissions of greenhouse gases and other substances. The target that is currently recognized by most world governments places a limit of two degrees Celsius on the global mean warming since preindustrial times. This would require large sustained reductions in carbon dioxide emissions during the twenty-first century and beyond. Such a global temperature target, however, is not sufficient to control many other quantities, such as transient sea level rise, ocean acidification, and net primary production on land. Here, using an Earth system model of intermediate complexity (EMIC) in an observation-informed Bayesian approach, we show that allowable carbon emissions are substantially reduced when multiple climate targets are set. We take into account uncertainties in physical and carbon cycle model parameters, radiative efficiencies, climate sensitivity, and carbon cycle feedbacks by varying nineteen key model parameters. A broad set of site-specific and gridded observational data from atmosphere, ocean, and land is used to constrain the model ensemble to realizations that are compatible with observations. Within this framework, we explore a broad range of economically feasible greenhouse gas scenarios from the integrated assessment community to determine the likelihood of meeting a combination of specific global and regional targets under various assumptions. For any given likelihood of meeting a set of such targets, the allowable cumulative emissions are greatly reduced from those inferred from the temperature target alone. Therefore, temperature targets alone are unable to comprehensively limit the risks from anthropogenic emissions.

  10. The continuum emission spectrum of Hf 2-2 near the Balmer limit and the ORL versus CEL abundance and temperature discrepancy

    NASA Astrophysics Data System (ADS)

    Storey, P. J.; Sochi, Taha

    2014-05-01

    The continuum spectrum of the planetary nebula Hf 2-2 close to the Balmer discontinuity is modelled in the context of the long-standing problem of the abundance and temperature discrepancy found when analysing optical recombination lines and collisionally excited forbidden lines in nebulae. Models are constructed using single and double Maxwell-Boltzmann distributions as well as κ-distributions for the energies of the free electrons. New results for the necessary continuum and line emission coefficients are presented calculated with κ-distributed energies. The best fit to the observed continuum spectrum is found to be a model comprising two components with dramatically different temperatures and with a Maxwell-Boltzmann distribution of electron energies. On the basis of a χ2 analysis, this model is strongly favoured over a model with κ-distributed electron energies.

  11. cGMP-Dependent Protein Kinase Inhibition Extends the Upper Temperature Limit of Stimulus-Evoked Calcium Responses in Motoneuronal Boutons of Drosophila melanogaster Larvae

    PubMed Central

    Dawson-Scully, Ken

    2016-01-01

    While the mammalian brain functions within a very narrow range of oxygen concentrations and temperatures, the fruit fly, Drosophila melanogaster, has employed strategies to deal with a much wider range of acute environmental stressors. The foraging (for) gene encodes the cGMP-dependent protein kinase (PKG), has been shown to regulate thermotolerance in many stress-adapted species, including Drosophila, and could be a potential therapeutic target in the treatment of hyperthermia in mammals. Whereas previous thermotolerance studies have looked at the effects of PKG variation on Drosophila behavior or excitatory postsynaptic potentials at the neuromuscular junction (NMJ), little is known about PKG effects on presynaptic mechanisms. In this study, we characterize presynaptic calcium ([Ca2+]i) dynamics at the Drosophila larval NMJ to determine the effects of high temperature stress on synaptic transmission. We investigated the neuroprotective role of PKG modulation both genetically using RNA interference (RNAi), and pharmacologically, to determine if and how PKG affects presynaptic [Ca2+]i dynamics during hyperthermia. We found that PKG activity modulates presynaptic neuronal Ca2+ responses during acute hyperthermia, where PKG activation makes neurons more sensitive to temperature-induced failure of Ca2+ flux and PKG inhibition confers thermotolerance and maintains normal Ca2+ dynamics under the same conditions. Targeted motoneuronal knockdown of PKG using RNAi demonstrated that decreased PKG expression was sufficient to confer thermoprotection. These results demonstrate that the PKG pathway regulates presynaptic motoneuronal Ca2+ signaling to influence thermotolerance of presynaptic function during acute hyperthermia. PMID:27711243

  12. Limitations on Silicon in the Outer Core: Ultrasonic Measurements at High Temperatures and High dK/dP's of Fe-Ni-Si Liquids at High Pressures

    NASA Astrophysics Data System (ADS)

    Williams, Q. C.; Manghnani, M. H.; Secco, R.; Fu, S.

    2015-12-01

    The sound velocities of four iron-nickel-silicon liquids (Fe-5wt%Ni-6wt%Si, Fe-5wt%Ni-10wt%Si, Fe-5wt%Ni-14wt%Si and Fe-5wt%Ni-20wt%Si) are measured between 1460 and 1925 K at ambient pressures using ultrasonic interferometry. The results constrain both the dependence on Si content of the bulk modulus of these liquids, and the temperature-dependence of their elasticity. These elastic data are utilized to assess both relatively low-pressure (to 12 GPa) compressional data on Fe-Si liquids, and to extrapolate to higher pressure and temperature conditions. If a single equation of state for Fe-Ni-Si liquids of a given composition applies from low pressure to near core conditions, then our results imply that the isothermal pressure derivative of the bulk modulus of these liquids is high: likely 8 and above at high temperatures. This high value of the pressure derivative of the bulk modulus at low-pressures in Fe-Si liquids causes marked stiffening at higher pressures, leading to notable incompressibility and apparent low values of the pressure derivative of the bulk modulus at core conditions. These results reinforce the conclusion that silicon is not a major alloying component of Earth's core.

  13. 45 CFR 34.4 - Allowable claims.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... occurred. (7) Claims for automobiles, only when required to perform official business or parked on a... amount allowed is the value of the vehicle at the time of loss as determined by the National...

  14. 38 CFR 3.810 - Clothing allowance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... a wheelchair) because of such disability and such disability is the loss or loss of use of a hand or... wheelchair. (b) Effective August 1, 1972, the initial lump sum clothing allowance is due and payable...

  15. 38 CFR 3.810 - Clothing allowance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... a wheelchair) because of such disability and such disability is the loss or loss of use of a hand or... wheelchair. (b) Effective August 1, 1972, the initial lump sum clothing allowance is due and payable...

  16. Higher Education Tax Allowances: An Analysis

    ERIC Educational Resources Information Center

    Leslie, Larry L.

    1976-01-01

    Tax allowances are receiving renewed attention at the federal level. Various forms are evaluated that would aid middle-income students and private institutions, and specific bills and proposals are examined. (Editor/LBH)

  17. Progress Report on Alloy 617 Time Dependent Allowables

    SciTech Connect

    Wright, Julie Knibloe

    2015-06-01

    Time dependent allowable stresses are required in the ASME Boiler and Pressure Vessel Code for design of components in the temperature range where time dependent deformation (i.e., creep) is expected to become significant. There are time dependent allowable stresses in Section IID of the Code for use in the non-nuclear construction codes, however, there are additional criteria that must be considered in developing time dependent allowables for nuclear components. These criteria are specified in Section III NH. St is defined as the lesser of three quantities: 100% of the average stress required to obtain a total (elastic, plastic, primary and secondary creep) strain of 1%; 67% of the minimum stress to cause rupture; and 80% of the minimum stress to cause the initiation of tertiary creep. The values are reported for a range of temperatures and for time increments up to 100,000 hours. These values are determined from uniaxial creep tests, which involve the elevated temperature application of a constant load which is relatively small, resulting in deformation over a long time period prior to rupture. The stress which is the minimum resulting from these criteria is the time dependent allowable stress St. In this report data from a large number of creep and creep-rupture tests on Alloy 617 are analyzed using the ASME Section III NH criteria. Data which are used in the analysis are from the ongoing DOE sponsored high temperature materials program, form Korea Atomic Energy Institute through the Generation IV VHTR Materials Program and historical data from previous HTR research and vendor data generated in developing the alloy. It is found that the tertiary creep criterion determines St at highest temperatures, while the stress to cause 1% total strain controls at low temperatures. The ASME Section III Working Group on Allowable Stress Criteria has recommended that the uncertainties associated with determining the onset of tertiary creep and the lack of significant

  18. Limited Energy Engineering Analysis (EEAP) study of summer boiler at high temperature hot water plants, Fort Leonard Wood, Missouri. Final report

    SciTech Connect

    1993-09-02

    This report is a study of the existing High Temperature Hot Water Distribution Systems at Fort Leonard Wood, Missouri. There are two systems with central boilers located in Buildings 1021 and 2369. The study focuses on the operation of the boilers during the summer months which is required to provide domestic hot water and sanitizing steam to various buildings. Because the boilers are operating under a reduced load condition, it may be cost effective in terms of energy conservation to implement one of the following energy conservation opportunities (ECO`s).

  19. Use of vegetation index and surface temperature to estimate soil moisture in a semi-arid catchment in Brazil with limited monitoring

    NASA Astrophysics Data System (ADS)

    Rebello, V. P. A.; Cunha, T. M.; Rotunno Filho, O. C.; Barbosa, M. C.; Franklin, M. R.; Lakshmi, V.

    2014-12-01

    During the last two decades, there have been numerous studies using remote sensing to study catchment energy and water balance. A well-known example is the combination of surface temperature (Ts) and the normalized difference vegetation index (NDVI), which can provide information on vegetation and moisture conditions at the land surface. Since the soil moisture is a key variable in hydrological modeling, this information is potentially useful in large watersheds and remote areas in developing countries, where little infrastructure and few resources still make continuous in-situ monitoring of environmental variables a difficult task, as well as in semi arid areas, where the lack of water may represent an obstacle to the regional economic and sustainable development. The basic methodology is to calculate soil moisture indexes by the scatter plots of NDVI and Ts and to analyze the Ts/NDVI slope, in order to estimate temporal patterns of soil moisture. We will utilize the standard vegetation index and surface temperature products from MODIS and NOAA - AVHRR, and the results will be compared with soil moisture derived from a hydrological model (Soil Moisture Accounting Procedure). This work will focus on a 18200 km² semi-arid catchment in Northeastern Brazil.

  20. Intrinsic noise temperatures of YBa2Cu3O7 - delta Josephson devices on bicrystal substrates and the upper frequency limit for their operation

    NASA Astrophysics Data System (ADS)

    Chen, J.; Myoren, H.; Nakajima, K.; Yamashita, T.; Wu, P. H.

    1996-12-01

    Following a method proposed by Divin and Modovets [Sov. Tech. Phys. Lett. 9, 108 (1983)], we have measured at millimeter waveband the intrinsic noise temperatures TN of YBa2Cu3O7-δ Josephson junctions or dc superconducting quantum interference devices (SQUIDs) fabricated on SrTiO3, yttria-stabilized ZrO2, or Si bicrystal substrates. Over wide ranges of physical temperatures TP and the junction's normal resistance RN, it was found that TN follows TP pretty well. This indicates that the intrinsic noise in the devices is dominated by Johnson noise. TN was also measured in cases where there is external magnetic field applied, or where there is another microwave radiation like the local oscillator in a mixer. The magnetic field or microwave radiation does not seem to affect TN in any appreciable way. To estimate the high frequency performance of the junctions on Si bicrystal substrates, direct irradiation by a far infrared laser at 1.81 THz is carried out and the clear first Shapiro step is observed.